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  • Enhanced AMPA receptor-mediated excitatory transmission in the rodent rostromedial tegmental nucleus following lesion of the nigrostriatal pathway
    Neurochem. Int. (IF 3.603) Pub Date : 2018-11-15
    Yongli Chang, Chengxue Du, Lingna Han, Shuxuan Lv, Jin Zhang, Guanyun Bian, Guoyi Tang, Yiwei Liu, Tao Chen, Jian Liu

    The GABAergic rostromedial tegmental nucleus (RMTg) has reciprocal connections with the dopaminergic ventral tegmental area and substantia nigra pars compacta (SNc), and is involved in inhibitory control of monoaminergic nuclei. At present, it is not clear whether unilateral 6-hydroxydopamine lesions of the SNc in rats affect AMPA receptor-mediated excitatory transmission in the RMTg. Here we found that lesions of the SNc in rats increased the firing rate of GABAergic neurons and the level of glutamate in the RMTg compared to sham-operated rats. Intra-RMTg injection of AMPA receptor agonist (S)-AMPA increased the firing rate of the GABAergic neurons in both sham-operated and the lesioned rats, while AMPA receptor antagonist NBQX decreased the firing rate of the neurons. Further, intra-RMTg injection of (S)-AMPA decreased the levels of dopamine and serotonin in the medial prefrontal cortex (mPFC) in the two groups of rats; conversely, NBQX increased the levels of dopamine and serotonin. Compared to sham-operated rats, the duration of (S)-AMPA and NBQX action on the firing rate of GABAergic neurons in the RMTg and release of doapmine and serotonin in the mPFC was prolonged in the lesioned rats. In addition, lesions of the SNc in rats increased protein expression of t-GluR1 and p-GluR1-S831 subunits compared to sham-operated rats. Therefore, these changes in the lesioned rats are associated with increased release of glutamate and up-regulated expression of GluR1 subunit-containing AMPA receptors in the RMTg, which suggest that degeneration of the nigrostriatal pathway enhances AMPA receptor-mediated excitatory transmission in the RMTg.

    更新日期:2018-11-16
  • Impact of C57BL/6 substrain on sex-dependent differences in mouse stroke models
    Neurochem. Int. (IF 3.603) Pub Date : 2018-11-15
    Thaddeus S. Nowak, Megan K. Mulligan

    We have recently found significant variation in stroke vulnerability among substrains of C57BL/6 mice, observing that commonly used N-lineage substrains exhibit larger infarcts than C57BL/6J and related substrains. Parallel variation was also seen with respect to sex differences in stroke vulnerability, in that C57BL/6 mice of the N-lineage exhibited comparable infarct sizes in males and females, whereas infarcts tended to be smaller in females than in males of J-lineage substrains. This adds to the growing list of recognized phenotypic and genetic differences among C57BL/6 substrains. Although no previous studies have explicitly compared substrains with respect to sex differences in stroke vulnerability, unrecognized background mismatch has occurred in some studies involving control and genetically modified mice. The aims of this review are to: present the evidence for associated substrain- and sex-dependent differences in a mouse permanent occlusion stroke model; examine the extent to which the published literature in other models compares with these recent results; and consider the potential impact of unrecognized heterogeneity in substrain background on the interpretation of studies investigating the impact of genetic modifications on sex differences in stroke outcome. Substrain emerges as a critical variable to be documented in any experimental stroke study in mice.

    更新日期:2018-11-16
  • Intracellular emetic signaling cascades by which the selective neurokinin type 1 receptor (NK1R) agonist GR73632 evokes vomiting in the least shrew (Cryptotis parva)
    Neurochem. Int. (IF 3.603) Pub Date : 2018-11-16
    W. Zhong, S. Chebolu, N.A. Darmani

    To characterize mechanisms involved in neurokinin type 1 receptor (NK1R)-mediated emesis, we investigated the brainstem emetic signaling pathways following treating least shrews with the selective NK1R agonist GR73632. In addition to episodes of vomiting over a 30-min observation period, a significant increase in substance P-immunoreactivity in the emetic brainstem dorsal motor nucleus of the vagus (DMNX) occurred at 15 min post an intraperitoneal (i.p.) injection GR73632 (5 mg/kg). In addition, time-dependent upregulation of phosphorylation of several emesis -associated protein kinases occurred in the brainstem. In fact, Western blots demonstrated significant phosphorylations of Ca2+/calmodulin kinase IIα (CaMKIIα), extracellular signal-regulated protein kinase1/2 (ERK1/2), protein kinase B (Akt) as well as α and βII isoforms of protein kinase C (PKCα/βII). Moreover, enhanced phospho-ERK1/2 immunoreactivity was also observed in both brainstem slices containing the dorsal vagal complex emetic nuclei as well as in jejunal sections from the shrew small intestine. Furthermore, our behavioral findings demonstrated that the following agents suppressed vomiting evoked by GR73632 in a dose-dependent manner: i) the NK1R antagonist netupitant (i.p.); ii) the L-type Ca2+ channel (LTCC) antagonist nifedipine (subcutaneous, s.c.); iii) the inositol trisphosphate receptor (IP3R) antagonist 2-APB (i.p.); iv) store-operated Ca2+ entry inhibitors YM-58483 and MRS-1845, (i.p.); v) the ERK1/2 pathway inhibitor U0126 (i.p.); vi) the PKC inhibitor GF109203X (i.p.); and vii) the inhibitor of phosphatidylinositol 3-kinase (PI3K)-Akt pathway LY294002 (i.p.). Moreover, NK1R, LTCC, and IP3R are required for GR73632-evoked CaMKIIα, ERK1/2, Akt and PKCα/βII phosphorylation. In addition, evoked ERK1/2 phosphorylation was sensitive to inhibitors of PKC and PI3K. These findings indicate that the LTCC/IP3R-dependent PI3K/PKCα/βII-ERK1/2 signaling pathways are involved in NK1R-mediated vomiting.

    更新日期:2018-11-16
  • Autophagy activation alleviates nonylphenol-induced apoptosis in cultured cortical neurons
    Neurochem. Int. (IF 3.603) Pub Date : 2018-11-14
    Siyao Li, Zhixin Jiang, Wenjie Chai, Yuanyuan Xu, Yi Wang

    Emerging evidence indicates that nonylphenol (NP), a widely diffused and stable environmental contaminant, causes damage to the central nervous system (CNS). Although NP could cross the blood-brain barrier (BBB) and accumulate in key brain regions, little is known about the direct effects of NP on neurons. In this study, we aimed to investigate the direct effects of NP exposure on induction of apoptosis and autophagy in primary cortical neurons. Results showed that exposure to NP decreased the cell viability in a concentration-dependent manner. The exposure led to both the increase of TUNEL-positive neurons and the activation of caspase-3. Increased levels of endoplasmic reticulum (ER) stress-related proteins, GRP78, CHOP, ATF4, and casepase-12, were observed in neurons exposed to NP. At the same time, the exposure decreased Bcl-2/Bax ratio and mitochondrial transmembrane potential, and increased the release of Cytochrome-C. In addition, NP exposure enhanced LC3-II conversion, decreased levels of SQSTM1/p62, and increased levels of Beclin-1 and LAMP2. NP exposure also reduced the protein levels of p-mTOR, and did not change the levels of total mTOR. Furthermore, to investigate the role of autophagy in NP-induced apoptosis, both the autophagy inhibitor chloroquine (CQ) and the autophagy inducer rapamycin (RAP) were applied to modulate autophagy activation in primary cortical neurons. The inhibition of autophagy caused by CQ enhanced NP-induced apoptosis; conversely, RAP-induced autophagy remarkably suppressed it. In conclusion, our findings demonstrate that NP exposure induced apoptosis with a concomitant increase of autophagic flux in primary cortical neurons, which supports the idea that this potential neurotoxin has direct effects of on neurons. Both ER stress and mitochondrial pathways may be involved in NP-induced apoptosis in neurons. Furthermore, our results also suggest that autophagy activation might be a protective strategy to ameliorate NP-induced apoptosis in neurons.

    更新日期:2018-11-15
  • The prion protein in neuroimmune crosstalk
    Neurochem. Int. (IF 3.603) Pub Date : 2018-11-15
    Øyvind Salvesen, Jörg Tatzelt, Michael A. Tranulis

    The cellular prion protein (PrPC) is a medium-sized glycoprotein, attached to the cell surface by a glycosylphosphatidylinositol anchor. PrPC is encoded by a single-copy gene, PRNP, which is abundantly expressed in the central nervous system and at lower levels in non-neuronal cells, including those of the immune system. Evidence from experimental knockout of PRNP in rodents, goats, and cattle and the occurrence of a nonsense mutation in goat that prevents synthesis of PrPC, have shown that the molecule is non-essential for life. Indeed, no easily recognizable phenotypes are associate with a lack of PrPC, except the potentially advantageous trait that animals without PrPC cannot develop prion disease. This is because, in prion diseases, PrPC converts to a pathogenic “scrapie” conformer, PrPSc, which aggregates and eventually induces neurodegeneration. In addition, endogenous neuronal PrPC serves as a toxic receptor to mediate prion-induced neurotoxicity. Thus, PrPC is an interesting target for treatment of prion diseases. Although loss of PrPC has no discernable effect, alteration of its normal physiological function can have very harmful consequences. It is therefore important to understand cellular processes involving PrPC, and research of this topic has advanced considerably in the past decade. Here, we summarize data that indicate the role of PrPC in modulating immune signaling, with emphasis on neuroimmune crosstalk both under basal conditions and during inflammatory stress.

    更新日期:2018-11-15
  • An overview of the neuroprotective potential of rosmarinic acid and its association with nanotechnology-based delivery systems: A novel approach to treating neurodegenerative disorders
    Neurochem. Int. (IF 3.603) Pub Date : 2018-11-12
    Flávia Nathiely Silveira Fachel, Roselena Silvestri Schuh, Kleyton Santos Veras, Valquíria Linck Bassani, Letícia Scherer Koester, Amelia Teresinha Henriques, Elizandra Braganhol, Helder Ferreira Teixeira

    Neurodegenerative disorders (ND) are characterized by slow and progressive neuronal dysfunction induced by the degeneration of neuronal cells in the central nervous system (CNS). Recently, the neuroprotective effects of natural compounds with anti-inflammatory and antioxidant activities has been clearly demonstrated. This appears to be an attractive therapeutic approach for ND, particularly regarding the use of polyphenols. In this review, we present an overview of the neuroprotective potential of rosmarinic acid (RA) and discuss the use of nanotechnology as a novel approach to treating ND. RA presents a variety of biological important activities, i.e. the modulation of pro-inflammatory cytokine expression, prevention of neurodegeneration and damage reduction. However, its poor bioavailability represents a limitation in terms of pharmacodynamics. In this sense, nanotechnology-based carriers could allow for the administration of higher but still safe amounts of RA, aiming for CNS delivery. Nasal administration could be a pleasant route for delivery to the CNS, as this represents a direct route to the CNS. With these advantages, RA-loaded nanotechnology-based therapy through the nasal route could be promising approach for the treatment of ND.

    更新日期:2018-11-12
  • Behavioral tests predicting striatal dopamine level in a rat hemi-Parkinson's disease model
    Neurochem. Int. (IF 3.603) Pub Date : 2018-11-09
    Kazuya Miyanishi, Mohammed E. Choudhury, Minori Watanabe, Madoka Kubo, Masahiro Nomoto, Hajime Yano, Junya Tanaka
    更新日期:2018-11-10
  • Pentobarbital and other anesthetic agents induce opposite regulations of MAP kinases p-MEK and p-ERK, and upregulate p-FADD/FADD neuroplastic index in brain during hypnotic states in mice
    Neurochem. Int. (IF 3.603) Pub Date : 2018-11-10
    Glòria Salort, María Álvaro-Bartolomé, Jesús A. García-Sevilla

    Midazolam and ketamine-induced anesthesia were recently shown to induce a disruption of MEK/ERK sequential phosphorylation with parallel upregulation of p-FADD in the mouse brain. The present study was designed to assess whether other structurally diverse anesthetic agents (pentobarbital, ethanol, chloral hydrate, isoflurane) also impair brain p-MEK to p-ERK signal and increase p-FADD during the particular time course of ‘sleep’ in mice. Pentobarbital (50 mg/kg)-, ethanol (4000 mg/kg)-, chloral hydrate (400 mg/kg)-, and isoflurane (2% in O2)-induced anesthesia (range: 24–60 min) were associated with unaltered or increased p-MEK1/2 (up to +155%) and decreased p-ERK1/2 (up to −60%) contents, revealing disruption of MEK to ERK activation in mouse brain cortex. These anesthetic agents also upregulated cortical p-FADD (up to +110%), but not total FADD (moderately decreased), which resulted in increased neuroplastic/survival p-FADD/FADD ratios (up to +2.8 fold). The inhibition of pentobarbital metabolism with SKF525-A (a cytochrome P450 inhibitor) augmented barbiturate anesthesia (2.6 times) and induced a greater and sustained upregulation of p-MEK with p-ERK downregulation, as well as prolonged increases of p-FADD content and p-FADD/FADD ratio (effects lasting for more than 240 min). Pentobarbital also upregulated significantly the cortical contents of other markers of neuroplasticity such as the ERK inhibitor p-PEA-15 (up to +46%), the transcription factor NF-κB (up to +27%) and the synaptic density protein PSD-95 (up to +20%) during ‘sleep’. The results reveal a paradoxical stimulation of p-MEK without the concomitant (canonical) activation of p-ERK (e.g. with pentobarbital and isoflurane), for which various molecular mechanisms are discussed. The downregulation of brain p-ERK may participate in the manifestations of adverse effects displayed by most hypnotic/anesthetic agents in clinical use (e.g. amnesia).

    更新日期:2018-11-10
  • Long-term challenge of methylphenidate changes the neuronal population and membrane property of dopaminergic neuron in rats
    Neurochem. Int. (IF 3.603) Pub Date : 2018-11-10
    Sanford PC. Hsu, Dao-Yuan Wang, Ming-Yuan Min, Yu-Show Fu

    Attention deficit hyperactivity disorder (ADHD) has a prevalence of 7.5% in school-age children in Taiwan. A number of ADHD patients start taking medications in elementary school and continue their treatment until they are in college or adulthood. Methylphenidate is the most frequently used medication prescribed for ADHD treatment. The influence of long-term treatment of methylphenidate on neuro-development, especially dopaminergic neurons, in rats would be explored. This study investigated the impact of long-term treatment of methylphenidate on different neurons. Rats aged 1 month were divided into three groups: Normal group receiving only sucrose solution, Low-dose group receiving 2 mg/kg methylphenidate, and High-dose group receiving 10 mg/kg methylphenidate; for each group, the drug was administreted twice per day. After 7 months of the treatment period, then the alterations in number of norepinephrine, serotonergic, cholinergic and dopaminergic neurons were quantified. The number of dopaminergic neurons in the substantia nigra (SN), the serotonergic neurons in the dorsal raphe nucleus, and the cholinergic neurons in the tegmental nucleus significantly decreased as compared with Normal group, whereas the noradrenergic neurons in the locus coeruleus substantially increased. The whole-cell recording was made from dopaminergic neurons residing in the SN for examination of their firing activity. The recorded dopaminergic neurons in SN were categorized into slow and fast firing using 10 Hz as a classified index. The results displayed that the ratio of dopaminergic neurons with fast firing in the High-dose group was less as compared with those in the Normal and the Low-dose group. Furthermore, the amplitude of action potential of the dopaminergic neurons with slow firing was higher in the High-dose group than those in the Normal and Low-dose groups. The firing behavior of dopaminergic neurons and dopamine concentration in the brain is affected by the long-term challenge of methylphenidate.

    更新日期:2018-11-10
  • Microglia metabolism in health and disease
    Neurochem. Int. (IF 3.603) Pub Date : 2018-11-10
    Katharina Borst, Marius Schwabenland, Marco Prinz

    In the last decade tremendous progress has been made in understanding how the immune system reacts to insults. During this progress it became obvious that those immune responses are tightly regulated and cross-linked with distinct metabolic changes in immune cells. Extensive research has been conducted mainly on subtypes of T cells, which use different metabolic pathways during differentiation processes and activation states. In addition, it has also been established later, that the innate immune cell lineage of myeloid cells includes a variety of different subsets of bone marrow-derived as well as tissue-specific macrophages, which elicit much more functions than simply killing bacteria. To execute this high variety of functions, also macrophages use different metabolic pathways and are tightly regulated by key metabolic regulators, such as the mechanistic target of rapamycin (mTOR). Upon activation, metabolic changes within the cell occur to meet the requirements of the phenotypic switch. In addition, metabolic changes correlate with the ability of innate immune cells to show hallmarks of adaptive immune responses. Little is known about specific metabolic changes of myeloid cells and specifically microglia in vivo. Microglia are key players in neurodegenerative and neuroinflammatory diseases and have become a major target of medical research. Here, we review the existing data on microglia metabolism and the connection of microglia phenotypes with neuroinflammatory and neurodegenerative diseases. Lastly, we will discuss how our knowledge about the cellular metabolism might be used to develop new treatment options for neurological diseases.

    更新日期:2018-11-10
  • Sex differences in miRNA as therapies for ischemic stroke
    Neurochem. Int. (IF 3.603) Pub Date : 2018-11-02
    Farida Sohrabji, Amutha Selvamani

    MicroRNAs, a subset of non-coding RNAs, are present in virtually all tissues including body fluids and are global regulators of the transcriptome. In view of the expanding number of microRNAs and the large number of gene targets that each microRNA can potentially regulate, they have been compared to hormones in the scope of their effects. MicroRNA have been implicated as biomarkers for several diseases including stroke, as well as chronic conditions that are associated with stroke. Recent research has focused on manipulating miRNA to improve stroke outcomes. Although several miRNAs have been shown to have neuroprotective properties, the overwhelming majority of these studies have employed only male animals. This review will focus on two miRNAs, Let7f and mir363–3p, whose effectiveness as a stroke neuroprotectant is sex-specific.

    更新日期:2018-11-05
  • Protein disulfide-isomerase A3 significantly reduces ischemia-induced damage by reducing oxidative and endoplasmic reticulum stress
    Neurochem. Int. (IF 3.603) Pub Date : 2018-11-03
    Dae Young Yoo, Su Bin Cho, Hyo Young Jung, Woosuk Kim, Kwon Young Lee, Jong Whi Kim, Seung Myung Moon, Moo-Ho Won, Jung Hoon Choi, Yeo Sung Yoon, Dae Won Kim, Soo Young Choi, In Koo Hwang

    Ischemia causes oxidative stress in the endoplasmic reticulum (ER), accelerates the accumulation of unfolded and misfolded proteins, and may ultimately lead to neuronal cell apoptosis. In the present study, we investigated the effects of protein disulfide-isomerase A3 (PDIA3), an ER-resident chaperone that catalyzes disulfide-bond formation in a subset of glycoproteins, against oxidative damage in the hypoxic HT22 cell line and against ischemic damage in the gerbil hippocampus. We also confirmed the neuroprotective effects of PDIA3 by using PDIA3-knockout HAP1 cells. The HT22 and HAP1 cell lines showed effective (dose-dependent and time-dependent) penetration and stable expression of the Tat-PDIA3 fusion protein 24 h after Tat-PDIA3 treatment compared to that in the control-PDIA3-treated group. We observed that the fluorescence for both 2′,7′-dichlorofluorescein diacetate (DCF-DA) and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL), which are markers for the formation of hydrogen peroxide (H2O2)-induced reactive oxygen species and apoptosis, respectively, was higher in HAP1 cells than in HT22 cells. The administration of Tat-PDIA3 significantly reduced the (1) DCF-DA and TUNEL fluorescence in HT22 and HAP1 cells, (2) ischemia-induced hyperactivity that was observed 1 day after ischemia/reperfusion, (3) ischemia-induced neuronal damage and glial (astrocytes and microglia) activation that was observed in the hippocampal CA1 region 4 days after ischemia/reperfusion, and (4) lipid peroxidation and nitric oxide generation in the hippocampal homogenates 3–12 h after ischemia/reperfusion. Transient forebrain ischemia significantly elevated the immunoglobulin-binding protein (BiP) and C/EBP-homologous protein (CHOP) mRNA levels in the hippocampus at 12 h and 4 days after ischemia, relative to those in the time-matched sham-operated group. Administration of Tat-PDIA3 ameliorated the ischemia-induced upregulation of BiP mRNA levels versus the Tat peptide- or control-PDIA3-treated groups, and significantly reduced the induction of CHOP mRNA levels, at 12 h or 4 days after ischemia. Collectively, these results suggest that Tat-PDIA3 acts as a neuroprotective agent against ischemia by attenuating oxidative damage and blocking the apoptotic pathway that is related to the unfolded protein response in the ER.

    更新日期:2018-11-05
  • The GSK3β inhibitor, TDZD-8, rescues cognition in a zebrafish model of okadaic acid-induced Alzheimer's disease
    Neurochem. Int. (IF 3.603) Pub Date : 2018-10-28
    Daniel Koehler, Zahoor A. Shah, Frederick E. Williams

    Currently, no treatments exist that are able to directly treat against Alzheimer's disease (AD), and we are facing an inevitable increase in the near future of the amount of patients who will suffer from AD. Most animal models of AD are limited by not being able to recapitulate the entire pathology of AD. Recently an AD model in zebrafish was established by using the protein phosphatase 2A inhibitor, okadaic acid (OKA). Administering OKA to zebrafish was able to recapitulate most of the neuropathology associated with AD. Therefore, providing a drug discovery model for AD that is also time and cost efficient. This study was designed to investigate the effects of GSK3β inhibition by 4-benzyl-2-methyl-1, 2, 4-thiadiazolidine-3, 5-dione (TDZD-8) on this newly developed AD model. Fish were divided into 4 groups and each group received a different treatment. The fish were divided into a control group, a group treated with 1 μM TDZD-8 only, a group treated with 1 μM TDZD-8 + 100 nM OKA, and a group treated with 100 nM OKA only. Administering the GSK3β inhibitor to zebrafish concomitantly with OKA proved to be protective. TDZD-8 treatment reduced the mortality rate, the ratio of active: inactive GSK3β, pTau (Ser199), and restored PP2A activity. This further corroborates the use of GSKβ inhibitors in the treatment against AD and bolsters the use of the OKA-induced AD-like zebrafish model for drug discovery.

    更新日期:2018-10-30
  • Methoxetamine: A foe or friend?
    Neurochem. Int. (IF 3.603) Pub Date : 2018-10-24
    Chrislean Jun Botanas, June Bryan de la Peña, Hee Jin Kim, Yong Sup Lee, Jae Hoon Cheong

    Methoxetamine (MXE) is an N-methyl-D-aspartate (NMDA) receptor antagonist that is chemically and pharmacologically similar to other dissociative substances, such as ketamine and phencyclidine. There are reports on the misuse of MXE, which sometimes resulted in adverse consequences and death. Studies have also shown that MXE has abuse liability and stimulates dopamine neurotransmission in the mesolimbic reward pathway in the brain. These findings have contributed to the negative impression on MXE. However, recent preclinical studies have identified the antidepressant properties of MXE, which are attributed to its ability to affect the glutamatergic and serotonergic systems. MXE is also reported to have analgesic effects. These findings show some of the “redeeming qualities” of MXE and indicate its possible therapeutic uses. In this paper, we have reviewed the findings that provide insights into the adverse and potential therapeutic effects of MXE. We compiled studies on the toxicity, psychotomimetic effects, and abuse liability of MXE, as well as its promising antidepressant and analgesic properties. We also have discussed the mechanism of action that might mediate the somewhat paradoxical effects observed. Importantly, this review provides valuable information on MXE for future research and will enable a better understanding of its psychopharmacological properties and the mechanisms responsible for its unique effects.

    更新日期:2018-10-24
  • Clinical spectrum of inflammatory central nervous system demyelinating disorders associated with antibodies against myelin oligodendrocyte glycoprotein
    Neurochem. Int. (IF 3.603) Pub Date : 2018-10-23
    Tetsuya Akaishi, Douglas Kazutoshi Sato, Toshiyuki Takahashi, Ichiro Nakashima

    Immunoglobulin G (IgG) antibodies against myelin oligodendrocyte glycoprotein (MOG) are detected in the serum of some patients with demyelinating diseases. These patients are known to show repeated clinical episodes of inflammatory demyelinating attacks in the central nervous system. Although the associated pathogenicity and mechanism of inflammatory demyelination remains inconclusive, it is known that patients with MOG-IgG antibodies have a different clinical spectrum from those with other demyelinating diseases, such as multiple sclerosis. Based on our database of 85 MOG-IgG antibody positive (+) cases, the most frequently associated clinical episodes were isolated optic neuritis (67.5%), encephalitis (26.5%), and myelitis (19.3%). Optic neuritis in MOG-IgG (+) disease usually involves the long segment of optic nerves and sometimes happens bilaterally, but visual acuity usually recovers with proper treatment in the acute phase. Brain and brainstem lesions usually present vague and focal appearances with irregular margins, typically in subcortical or brainstem regions, but occasionally in the cortex or corpus callosum. Due to these characteristics, MOG-IgG (+) cases with brain or brainstem lesions are sometimes diagnosed with acute disseminated encephalomyelitis, meningitis, or symptomatic epilepsy. The myelitis in MOG-IgG (+) typically shows longitudinally extensive lesions as seen in neuromyelitis optica spectrum disorders. Acute treatment to reduce attack-related disability is recommended in MOG-IgG (+) disease, and long-term immunosuppression may be considered in patients with a high frequency of relapses and/or high risk of neurological disability.

    更新日期:2018-10-23
  • MiR-34a and stroke: Assessment of non-modifiable biological risk factors in cerebral ischemia
    Neurochem. Int. (IF 3.603) Pub Date : 2018-10-23
    Xuefang Ren, Elizabeth B. Engler-Chiurazzi, Ashley E. Russell, Saumyendra N. Sarkar, Stephanie L. Rellick, Sara Lewis, Deborah Corbin, Jared Clapper, James W. Simpkins

    Aging of the nervous system, and the occurrence of age-related brain diseases such as stroke, are associated with changes to a variety of cellular processes controlled by many distinct genes. MicroRNAs (miRNAs), short non-coding functional RNAs that can induce translational repression or site-specific cleavage of numerous target mRNAs, have recently emerged as important regulators of cellular senescence, aging, and the response to neurological insult. Here, we focused on the assessment of the role of miR-34a in stroke. We noted increases in miR-34a expression in the blood of stroke patients as well as in blood and brain of mice subjected to experimental stroke. Our methodical genetic manipulation of miR-34a expression substantially impacted stroke-associated preclinical outcomes and we have in vitro evidence that these changes may be driven at least in part by disruptions to blood brain barrier integrity and mitochondrial oxidative phosphorylation in endothelial cells. Finally, aging, independent of brain injury, appears to be associated with shifts in circulating miRNA profiles. Taken together, these data support a role for miRNAs, and specifically miR-34a, in brain aging and the physiological response to age-related neurological insult, and lay the groundwork for future investigation of this novel therapeutic target.

    更新日期:2018-10-23
  • Docosahexaenoic acid protection in a rotenone induced Parkinson's model: Prevention of tubulin and synaptophysin loss, but no association with mitochondrial function
    Neurochem. Int. (IF 3.603) Pub Date : 2018-10-19
    Norma Serrano-García, Francisca Fernández-Valverde, Erika Rubi Luis-Garcia, Leticia Granados-Rojas, Tarsila Elizabeth Juárez-Zepeda, Sandra Adela Orozco-Suárez, José Pedraza-Chaverri, Marisol Orozco-Ibarra, Anabel Jiménez-Anguiano

    Rotenone, a classic mitochondrial complex I inhibitor, leads to dopaminergic neuronal death resulting in a Parkinson's-like-disease. Docosahexaenoic acid (DHA) has shown neuroprotective effects in other experimental models of Parkinson's disease, but its effect on the rotenone-induced parkinsonism is still unknown. We tested whether DHA in vivo exerts a neuroprotective effect on rotenone-induced parkinsonism and explored the mechanisms involved, including mitochondrial function and ultrastructure as well as the expression of tubulin and synaptophysin. We pretreated eighty male Wistar rats with DHA (35 mg/kg/day) for 7 days and then administered rotenone for either 8 or 14 days. We then measured rearing behavior, number of dopaminergic neurons, tyrosine hydroxylase content, tubulin and synaptophysin expression, mitochondrial complex I, respiratory control ratio, mitochondrial transmembrane potential, ATP production activity and mitochondrial ultrastructure. We found that in vivo DHA supply exerted a neuroprotective effect, evidenced by decreased dopaminergic neuron cell death. Although we detected rotenone induced mitochondrial ultrastructure alterations, these were not associated with mitochondrial dysfunction. Rotenone had no effect on mitochondrial complex I, respiratory control ratio, mitochondrial transmembrane potential or ATP production activity. DHA also prevented a rotenone-induced decrease in tubulin and synaptophysin expression. Our results support the neuroprotective effect of DHA on rotenone-induced parkinsonism, and a possible effect on early stage Parkinson's disease. This protective effect is not associated with mitochondrial function improvement, but rather with preventing loss of tubulin and synaptophysin, proteins relevant to synaptic transmission.

    更新日期:2018-10-22
  • Adrenergic control of lymphocyte trafficking and adaptive immune responses
    Neurochem. Int. (IF 3.603) Pub Date : 2018-10-19
    Akiko Nakai, Kazuhiro Suzuki

    Since the beginning of the last century, substantial evidence has suggested that various aspects of the immune system are influenced by the activity of the nervous system. However, the cellular and molecular basis for the neural control of immune responses has emerged only in the past decade. Recent studies have shown that adrenergic nerves control trafficking of immune cells through cell-type-specific mechanisms. Activation of the β2-adrenergic receptor expressed on lymphocytes enhances signals mediated by a particular set of chemokine receptors, and consequently inhibits their exit from lymph nodes. This mechanism is involved in the diurnal variation of adaptive immune responses and the progression of inflammatory diseases. In the present review, we focus on the role of adrenergic nerves in the control of lymphocyte trafficking and adaptive immune responses in physiological and pathological conditions.

    更新日期:2018-10-22
  • Inflammation and neural repair after ischemic brain injury
    Neurochem. Int. (IF 3.603) Pub Date : 2018-10-19
    Seiichiro Sakai, Takashi Shichita

    Stroke causes neuronal cell death and destruction of neuronal circuits in the brain and spinal cord. Injury to the brain tissue induces sterile inflammation triggered by the extracellular release of endogenous molecules, but cerebral inflammation after stroke is gradually resolved within several days. In this pro-resolving process, inflammatory cells adopt a pro-resolving or repairing phenotype in the injured brain, activating endogenous repairing programs. Although the mechanisms involved in the transition from inflammation to neural repair after stroke remain largely unknown to date, some of the mechanisms for inflammation and neural repair have been clarified in detail. This review focuses on the molecular or cellular mechanisms involved in sterile inflammation and neural repair after stroke. This accumulation of evidence may be helpful for speculating about the endogenous repairing mechanisms in the brain and identifying therapeutic targets for improving the functional prognoses of stroke patients.

    更新日期:2018-10-22
  • Knockdown of RTN1-C attenuates traumatic neuronal injury through regulating intracellular Ca2+ homeostasis
    Neurochem. Int. (IF 3.603) Pub Date : 2018-10-21
    Xiao-xuan Fan, Yu-ying Hao, Shi-wen Guo, Xiao-ping Zhao, Yi Xiang, Fei-xue Feng, Ge-ting Liang, Yu-wei Dong

    Reticulons (RTNs) are a family of membrane-bound proteins that are dominantly localized to the endoplasmic reticulum (ER) membrane. RTN1-C is one member of RTNs abundantly expressed in the brain and has been shown to mediate neuronal injury in cerebral ischemia models. In the present study, we investigated the role of RTN1-C in an in vitro brain trauma model mimicked by traumatic neuronal injury (TNI) in primary cultured cortical neurons. TNI increased the expression of RTN1-C in cortical neurons but had no effect on RTN1-A and RTN1-B. Knockdown of RTN1-C with specific siRNA (Si-RTN1-C) significantly decreased cytotoxicity and apoptosis after TNI. The results of Ca2+ imaging showed that intracellular Ca2+ overload induced by TNI was attenuated by RTN1-C knockdown. Furthermore, the activation of metabotropic glutamate receptor 1 (mGluR1)-induced Ca2+ response was partially prevented by Si-RTN1-C transfection. We also evaluated the role of RTN1-C in store-operated Ca2+ entry (SOCE) in cortical neurons using the ER Ca2+ inducer thapsigargin (Tg). The results showed that knockdown of RTN1-C alleviated the SOCE-mediated Ca2+ influx and decreased the expression of stromal interactive molecule 1 (STIM1). In summary, the present study found that knockdown of RTN1-C protected neurons against TNI via preservation of intracellular Ca2+ homeostasis, which was associated with the inhibition of mGluR1-mediated ER Ca2+ release and suppression of STIM1-related SOCE. Thus, RTN1-C might represent a therapeutic target for traumatic brain injury (TBI) research.

    更新日期:2018-10-22
  • Expression and secretion of synaptic proteins during stem cell differentiation to cortical neurons
    Neurochem. Int. (IF 3.603) Pub Date : 2018-10-18
    Faisal Hayat Nazir, Bruno Becker, Ann Brinkmalm, Kina Höglund, Åsa Sandelius, Petra Bergström, Tugce Munise Satir, Annika Öhrfelt, Kaj Blennow, Lotta Agholme, Henrik Zetterberg
    更新日期:2018-10-19
  • Blockade of IL-6 signaling in neuromyelitis optica
    Neurochem. Int. (IF 3.603) Pub Date : 2018-10-17
    Manabu Araki

    Neuromyelitis optica (NMO) and neuromyelitis optica spectrum disorder (NMOSD) are autoimmune diseases associated with a disease-specific autoantibody directed against the water channel protein aquaporin-4. Standard immunotherapy, immunosuppressive agents, and corticosteroids can prevent acute attacks and maintain remission in most patients with NMOSD. However, there is a strong need for additional options for patients who are refractory to standard treatments. Emerging therapies targeting specific molecules related to the pathogenicity of NMOSD are currently being developed. The review focuses on improving preventive treatments for NMOSD, including ongoing randomized clinical trials using biological drugs targeting CD19 and CD20 on B cells, interleukin-6, and complement protein C5. The anti-IL-6 receptor monoclonal antibody tocilizumab (TCZ), which can block IL-6 signaling, was shown to be highly effective for refractory patients with NMOSD. Notably, TCZ has marked effects on chronic neuropathic pain and general fatigue in patients refractory to standard medications. TCZ is a promising drug for preventing acute attacks in patients with NMOSD.

    更新日期:2018-10-18
  • Assessment of neuroprotective effects of Gallic acid against glutamate-induced neurotoxicity in primary rat cortex neuronal culture
    Neurochem. Int. (IF 3.603) Pub Date : 2018-10-17
    S. Maya, T. Prakash, Krishna Das

    Glutamate excitotoxicity plays a crucial role in the pathogenesis behind the development and progression of several neurodegenerative diseases. The study aimed to investigate the neuroprotective activity of Gallic acid (GA) against glutamate-induced neurotoxicity in primary rat cortex neurons (RCN). Treated the RCNs with GA 25 & 50 μg/ml for 2 h and later treated the cells with 100 μM glutamate (GLU) and incubated for 24 h at 37 °C. The results demonstrated that, the GA improved the antioxidant profile in the cortex neurons and inhibited the production of the proinflammatory cytokine. GA also maintained the Ca2+ homeostasis, IGF-1 expression, and protected the neurons from glutamate-induced neuronal toxicity. The neuroprotective activity of GA has further confirmed from the results of N-acetylaspartate and expression of microtubule-associated protein-2 expression. The reports suggest that, GA is significantly attenuated the glutamate-induced neurotoxicity and protected neurons from various chemical events that are involved in the pathogenesis of neurotoxicity.

    更新日期:2018-10-17
  • Susceptibility of the cerebral cortex to spreading depolarization in neurological disease states: The impact of aging
    Neurochem. Int. (IF 3.603) Pub Date : 2018-10-15
    Péter Hertelendy, Dániel P. Varga, Ákos Menyhárt, Ferenc Bari, Eszter Farkas

    Secondary injury following acute brain insults significantly contributes to poorer neurological outcome. The spontaneous, recurrent occurrence of spreading depolarization events (SD) has been recognized as a potent secondary injury mechanism in subarachnoid hemorrhage, malignant ischemic stroke and traumatic brain injury. In addition, SD is the underlying mechanism of the aura symptoms of migraineurs. The susceptibility of the nervous tissue to SD is subject to the metabolic status of the tissue, the ionic composition of the extracellular space, and the functional status of ion pumps, voltage-gated and other cation channels, glutamate receptors and excitatory amino acid transporters. All these mechanisms tune the excitability of the nervous tissue. Aging has also been found to alter SD susceptibility, which appears to be highest at young adulthood, and decline over the aging process. The lower susceptibility of the cerebral gray matter to SD in the old brain may be caused by the age-related impairment of mechanisms implicated in ion translocations between the intra- and extracellular compartments, glutamate signaling and surplus potassium and glutamate clearance. Even though the aging nervous tissue is thus less able to sustain SD, the consequences of SD recurrence in the old brain have proven to be graver, possibly leading to accelerated lesion maturation. Taken that recurrent SDs may pose an increased burden in the aging injured brain, the benefit of therapeutic approaches to restrict SD generation and propagation may be particularly relevant for elderly patients.

    更新日期:2018-10-16
  • Balance between dopamine and adenosine signals regulates the PKA/Rap1 pathway in striatal medium spiny neurons
    Neurochem. Int. (IF 3.603) Pub Date : 2018-10-15
    Xinjian Zhang, Taku Nagai, Rijwan Uddin Ahammad, Keisuke Kuroda, Shinichi Nakamuta, Takashi Nakano, Naoto Yukinawa, Yasuhiro Funahashi, Yukie Yamahashi, Mutsuki Amano, Junichiro Yoshimoto, Kiyofumi Yamada, Kozo Kaibuchi
    更新日期:2018-10-15
  • Systemic L-buthionine-S-R-sulfoximine administration modulates glutathione homeostasis via NGF/TrkA and mTOR signaling in the cerebellum
    Neurochem. Int. (IF 3.603) Pub Date : 2018-10-06
    Carla Garza-Lombó, Pavel Petrosyan, Miguel Tapia-Rodriguez, Cesar Valdovinos-Flores, María E. Gonsebatt
    更新日期:2018-10-06
  • Bacopa monnieri alleviates paraquat induced toxicity in Drosophila by inhibiting jnk mediated apoptosis through improved mitochondrial function and redox stabilization
    Neurochem. Int. (IF 3.603) Pub Date : 2018-10-05
    Saurabh Srivastav, Mahino Fatima, Amal Chandra Mondal

    Paraquat (PQ) is an organic chemical compound and a member of redox active family of heterocycles. In spite of its high toxicities, it is used as one of the potent herbicide throughout the world. Though its toxic manifestations are observed in different organs, its principal toxic effect is manifested in the brain leading to the development of Parkinsonian symptoms. PQ exposure adversely affects dopaminergic (DA-ergic) neuron-rich region in the substantia nigra pars compacta (SNPC) of brain in the animal models of Parkinson's disease (PD), thereby mimicking PD like symptoms. Currently, lack of a potential drug to counter the toxic effect of PQ makes the management difficult. Bacopa monnieri extract (BME) has been shown to have promising effect against neurodegenerative disorders. Therefore, the present study evaluated the role of BME against PQ induced toxicity in Drosophila model of PD, the results of which are reproducible in higher animal models including human subjects. Here, we showed that BME treatment attenuates acute PQ induced toxicity in Drosophila by decreasing mortality and improving climbing ability. BME functions by optimizing redox equilibrium, mitochondrial function and depreciating apoptosis level. The underlying mechanisms were attributed to optimization of active JNK and cleaved Caspase-3 activity along with transcriptional stabilization of the genes regulating oxidative stress and apoptosis (jnk, caspase-3, damb and nrf-2). These results showed therapeutic efficacy of BME against PQ toxicity in the brain. Our results pave the way for further detailed analysis of BME to combat the development of Parkinson's like symptoms following exposure to PQ toxicity in the brain of higher animal models.

    更新日期:2018-10-05
  • TRPV1 modulates morphine self-administration via activation of the CaMKII-CREB pathway in the nucleus accumbens
    Neurochem. Int. (IF 3.603) Pub Date : 2018-10-04
    Shi-Xun Ma, Hyoung-Chun Kim, Seok-Yong Lee, Choon-Gon Jang

    Opioid addiction is a growing problem for public health, and opioids have correspondingly become more heavily regulated over time. We have previously shown that TRPV1 plays a critical role in morphine addiction using a self-administration paradigm in rats, and the current study evaluates the effects of the TRPV1 signaling pathway on morphine self-administration (SA). We found that treatment with a selective TRPV1 antagonist, SB366791, significantly decreased the morphine SA-induced activation of Ca2+/calmodulin-dependent protein kinase II (CaMKII), Akt and the cAMP response element binding protein (CREB) in the nucleus accumbens (NAc). In addition, phospho-PKA and phospho-PKC expression levels were significantly increased in the NAc of the morphine-SA groups, regardless of SB366791 treatment. Finally, local microinjection of SB366791 into the NAc significantly suppressed the maintenance of morphine SA. Taken together, our findings highlight that TRPV1 plays an important role in morphine addiction, likely via activation of the CaMKII-CREB pathway in the NAc.

    更新日期:2018-10-04
  • The effect of age, sex and strains on the performance and outcome in animal models of stroke
    Neurochem. Int. (IF 3.603) Pub Date : 2018-10-03
    Hongxia Zhang, Siyang Lin, Xudong Chen, Lei Gu, Xiaohong Zhu, Yinuo Zhang, Kassandra Reyes, Brain Wang, Kunlin Jin

    Stroke is one of the leading causes of death worldwide, and the majority of cerebral stroke is caused by occlusion of cerebral circulation, which eventually leads to brain infarction. Although stroke occurs mainly in the aged population, most animal models for experimental stroke in vivo almost universally rely on young-adult rodents for the evaluation of neuropathological, neurological, or behavioral outcomes after stroke due to their greater availability, lower cost, and fewer health problems. However, it is well established that aged animals differ from young animals in physiology, neurochemistry, and behavior. Stroke-induced changes are more pronounced with advancing age. Therefore, the overlooked role of age in animal models of stroke could impact on data quality and hinder the translation of rodent models to humans. In addition to aging, other factors also influence the performance after ischemic stroke. In this article, we summarize the differences between young and aged animals, the impact of age, sex and animal strains on performance and outcome in the animal models of stroke and emphasize age as a key factor in preclinical stroke studies in animal models of stroke.

    更新日期:2018-10-04
  • Tyrosol attenuates pro-inflammatory cytokines from cultured astrocytes and NF-κB activation in in vitro oxygen glucose deprivation
    Neurochem. Int. (IF 3.603) Pub Date : 2018-10-04
    Gang Luo, Yinuo Huang, Dapeng Mo, Ning Ma, Feng Gao, Ligang Song, Xuan Sun, Xiaotong Xu, Lian Liu, Xiaochuan Huo, Bo Wang, Xiaoqing Li, Baixue Jia, Yiming Deng, Xuelei Zhang, Alejandro Fernandez-Escobar, Guangge Peng, Zhongrong Miao

    Subsequent inflammation in stroke plays an important role in the damage of neurons in the perilesional area. Therapeutic intervention targeting inflammation may be a promising complementary strategy to current treatments of stroke. Here, we explored the possible beneficial effects of tyrosol, a derivative of phenethyl alcohol and natural antioxidant, playing an anti-inflammatory role in astrocyte culture and in vitro oxygen glucose deprivation (OGD) model. MTT, western blot, ELISA and EMSA assays were carried out to investigate cell viability, protein expression level, cytokine expression and NF-κB activity. We found tyrosol protected cultured astrocytes against OGD-induced cell viability loss in MTT test. Meanwhile, tyrosol attenuated the released TNF-α and IL-6 level from astrocyte via regulating Janus N-terminal kinase (JNK). The reduction of cytokines from astrocyte might be due to its inhibition of astrocyte activation and regulation of STAT3 signaling pathway since tyrosol attenuated the expression level of GFAP (glial fibrillary acidic protein) and the phosphorylation of STAT3. Additionally, we demonstrated that tyrosol prevented the degradation of IκBα and the increase of IκBα phosphorylation in astrocytes exposed to OGD, which led to the suppression of NF-κB function during ischemia. Collectively, our results showed that tyrosol may be a promising complementary treatment compound for stroke via modulating the inflammatory response in astrocytes during ischemia.

    更新日期:2018-10-04
  • Interactions of the tricyclic antidepressant drug amitriptyline with L-DOPA in the striatum and substantia nigra of unilaterally 6-OHDA-lesioned rats. Relevance to motor dysfunction in Parkinson's disease
    Neurochem. Int. (IF 3.603) Pub Date : 2018-10-02
    Kinga Kamińska, Tomasz Lenda, Jolanta Konieczny, Jadwiga Wardas, Elżbieta Lorenc-Koci

    Antidepressant drugs are recommended for the treatment of Parkinson's disease (PD)-associated depression but their role in the modulation of L-DOPA-induced behavioral and neurochemical markers is poorly explored. The aim of the present study was to examine the impact of the tricyclic antidepressant amitriptyline and L-DOPA, administered chronically alone or in combination, on rotational behavior, monoamine levels and binding of radioligands to their transporters in the dopaminergic brain structures of unilaterally 6-OHDA-lesioned rats. Binding of [3H]nisoxetine to noradrenaline transporter (NET), [3H]GBR 12,935 to dopamine transporter (DAT) and [3H]citalopram to serotonin transporter (SERT) were analyzed by autoradiography. Amitriptyline administered alone did not induce rotational behavior but in combination with L-DOPA increased the number of contralateral rotations much more strongly than L-DOPA alone. The combined treatment also significantly increased the tissue dopamine (DA) content in the ipsilateral striatum and substantia nigra (SN) vs. L-DOPA alone. 6-OHDA-mediated lesion of nigrostriatal DA neurons drastically reduced DAT and NET bindings in the ipsilateral striatum. In the ipsilateral SN, DAT binding decreased while NET binding rose. SERT binding increased significantly mainly in the SN. Amitriptyline administered alone or jointly with L-DOPA had no effect on DAT binding on the lesioned side, significantly decreased SERT binding in the striatum and SN while NET binding only in the SN. Since in the DA-denervated striatum, SERT is mainly responsible for reuptake of L-DOPA-derived DA while in the SN, SERT and NET are involved, the inhibition of these transporters by antidepressant drugs may improve dopaminergic transmission and consequently motor behavior.

    更新日期:2018-10-03
  • Behavioral response to imipramine under chronic mild stress corresponds with increase of mRNA encoding somatostatin receptors sst2 and sst4 expression in medial habenular nucleus
    Neurochem. Int. (IF 3.603) Pub Date : 2018-10-03
    Faron-Górecka Agata, Kuśmider Maciej, Solich Joanna, Kolasa Magdalena, Gruca P, Pabian Paulina, Szlachta Marta, Dziedzicka-Wasylewska Marta
    更新日期:2018-10-03
  • Uncaria rhynchophylla ameliorates amyloid beta deposition and amyloid beta-mediated pathology in 5XFAD mice
    Neurochem. Int. (IF 3.603) Pub Date : 2018-10-03
    Soo Jung Shin, Yuon Jeong, Seong Gak Jeon, Sujin Kim, Seong-kyung Lee, Hong Seok Choi, Cheong Su Im, Seong Hee Kim, Soo Hwan Kim, Jae Ho Park, Jin-il Kim, Jwa-Jin Kim, Minho Moon

    One of the pathological hallmarks of Alzheimer's disease (AD) is the abnormal aggregation of amyloid beta (Aβ) peptides. Uncaria rhynchophylla (UR), one of the Uncaria species, has long been used to treat neurodegenerative disease. In particular, it has been reported that UR inhibits aggregation of Aβ in vitro. However, little is known about the histological effects of UR treatment on Aβ pathology in AD animal models. In the present study, we investigated the effect of UR on Aβ aggregation, Aβ-mediated pathologies and adult hippocampal neurogenesis in the brain of 5XFAD mice. First, using the thioflavin T assay and amyloid staining, we demonstrated that UR treatment effectively inhibited Aβ aggregation and accumulation in the cortex and subiculum. Second, immunofluorescence staining showed that administration of UR attenuated gliosis and neurodegeneration in the subiculum and cortex. Third, UR treatment ameliorated impaired adult hippocampal neurogenesis. The present results indicate that UR significantly alleviates Aβ deposition and Aβ-mediated neuropathology in the brain in 5XFAD mice, suggesting the potency of UR as a preventive and therapeutic agent for AD.

    更新日期:2018-10-03
  • DNMT1 and Sp1 competitively regulate the expression of BACE1 in A2E-mediated photo-oxidative damage in RPE cells
    Neurochem. Int. (IF 3.603) Pub Date : 2018-09-28
    Peirong Huang, Junran Sun, Fenghua Wang, Xueting Luo, Hong Zhu, Qing Gu, Xiangjun Sun, Te Liu, Xiaodong Sun

    Numerous studies have focused on the deteriorate role of amyloid-β (Aβ) on retina, implying the potential pathogenic mechanism underlying age-related macular degeneration (AMD). However, the mechanism underlying the Aβ deposition in AMD patients remains unknown. Beta-site amyloid precursor protein-cleaving enzyme 1 (BACE1), rate-limiting enzyme for Aβ production, plays an important role in Aβ deposition in the brain. In the current study, we aimed to clarify the regulation mechanism of BACE1 and explore potential drug targets using a lipofuscinfluorophore A2E-mediated photo-oxidation model. In this model, Aβ1-40 and Aβ1-42 levels increased simultaneously with the enhanced BACE1 expression. These changes were associated with the hypomethylation of specific loci within the BACE1 gene promoter and the decreased levels of DNA methyltransferase 1 (DNMT1). Furthermore, we noticed overlapping regions of differentially methylated CpG islands and specificity protein (Sp1) binding sites within the BACE1 promoter. We employed chromatin immunoprecipitation (ChIP) assay to verify that the decreased BACE1 promoter methylation by DNMT1 enabled increased binding between Sp1 and the BACE1 promoter, which further enhanced BACE1 transcription. The inhibition of Sp1 with mithramycin A (MTM) could down-regulate the expression of BACE1 as well as alleviate the RPE barrier morphology and function impairment. Our results for the first time show the competitive regulation of BACE1 by transcription factor Sp1 and DNMT1 after photo-oxidation and confirm the potential novel protective role of MTM on RPE cells.

    更新日期:2018-09-29
  • Gateway reflex: Local neuroimmune interactions that regulate blood vessels
    Neurochem. Int. (IF 3.603) Pub Date : 2018-09-29
    Daisuke Kamimura, Takuto Ohki, Yasunobu Arima, Mitsutoshi Ota, Masaaki Murakami

    Neuroimmunology is a research field that intersects neuroscience and immunology, with the larger aim of gaining significant insights into the pathophysiology of chronic inflammatory diseases such as multiple sclerosis. Conventional studies in this field have so far mainly dealt with immune responses in the nervous system (i.e. neuroinflammation) or systemic immune regulation by the release of glucocorticoids. On the other hand, recently accumulating evidence has indicated bidirectional interactions between specific neural activations and local immune responses. Here we discuss one such local neuroimmune interaction, the gateway reflex. The gateway reflex represents a mechanism that translates specific neural stimulations into local inflammatory outcomes by changing the state of specific blood vessels to allow immune cells to extravasate, thus forming the gateway. Several types of gateway reflex have been identified, and each regulates distinct blood vessels to create gateways for immune cells that induce local inflammation. The gateway reflex represents a novel therapeutic strategy for neuroinflammation and is potentially applicable to other inflammatory diseases in peripheral organs.

    更新日期:2018-09-29
  • Nicotinamide Mononucleotide Adenylyltransferase 2 maintains neuronal structural integrity through the maintenance of golgi structure
    Neurochem. Int. (IF 3.603) Pub Date : 2018-09-29
    Tana Pottorf, Alexis Mann, Shaneann Fross, Clayton Mansel, Bhupinder P.S. Vohra

    Golgi fragmentation and loss of Nicotinamide Mononucleotide Adenylyltransferase 2 (NMNAT2) are the early key features of many neurodegenerative disorders. We investigated the link between NMNAT2 loss, Golgi fragmentation and axon degeneration. Golgi fragmentation in the cultured dorsal root ganglion (DRG) neurons resulted in caspase dependent axon degeneration and neuronal cell death. NMNAT2 depletion in the DRG neurons caused Golgi fragmentation and caspase dependent axon degeneration. NMNAT2 depletion did not cause ATP loss in the axons. These results indicate that NMNAT2 is required for maintenance of Golgi structure. Loss of Golgi structure or Nmnat2 depletion causes caspase dependent neurodegeneration. cytNmnat1 overexpression inhibited the axon degeneration induced by Golgi fragmentation or NMNAT2 depletion. These results also suggest that these degeneration signals converge on a common cytNmnat1 mediated axon protective program and are distinct from the SARM1 mediated caspase independent axon degeneration.

    更新日期:2018-09-29
  • Chronic high-fat diet-induced obesity in gerbils increases pro-inflammatory cytokines and mTOR activation, and elicits neuronal death in the striatum following brief transient ischemia
    Neurochem. Int. (IF 3.603) Pub Date : 2018-09-26
    Minah Song, Ji Hyeon Ahn, Hyunjung Kim, Dae Won Kim, Tae-Kyeong Lee, Jae-Chul Lee, Young-Myeong Kim, Choong-Hyun Lee, In Koo Hwang, Bing Chun Yan, Moo-Ho Won, Joon Ha Park

    Recent studies have shown that obesity and its related metabolic dysfunction exacerbate outcomes of ischemic brain injuries in some brain areas, such as the hippocampus and cerebral cortex when they are subjected to transient ischemia. However, the impact of obesity in the striatum after brief transient ischemia has not yet been addressed. The objective of this study was to investigate effects of obesity on neuronal damage and inflammation in the striatum after transient ischemia and to examine the role of mTOR which is involved in the pathogenesis of metabolic and neurological diseases. Gerbils were fed with normal diet (ND) or high-fat diet (HFD) for 12 weeks and subjected to 5 min of transient ischemia. HFD-fed gerbils showed significant increase in body weight, blood glucose level, serum triglycerides, total cholesterol and low-density lipoprotein cholesterol without affecting food intake. Neuronal death/loss in the HFD-fed gerbils occurred in the dorsolateral striatum 2 days after transient ischemia, and neuronal loss was increased 5 days after transient ischemia, although no neuronal loss was observed in ND-fed gerbils at any time after transient ischemia. The HFD-fed gerbils showed hypertrophied microglia and further increased expressions of tumor necrosis factor-alpha, interukin-1beta, mammalian target of rapamycin (mTOR) and phosphorylated-mTOR during pre- and post-ischemic phases compared with the ND-fed gerbils. Additionally, we found that treatment with mTOR inhibitor rapamycin in the HFD-fed gerbils significantly attenuated transient ischemia-induced neuronal death in the dorsolateral striatum. These findings reveal that chronic HFD-induced obesity results in severe neuroinflammation and significant increase of mTOR activation, which could contribute to neuronal death in the stratum following 5 min of transient ischemia. Especially, abnormal mTOR activation would play a key role in mediating obesity-induced severe ischemic brain injury.

    更新日期:2018-09-27
  • 1,8-cineole decreases neuropathic pain probably via a mechanism mediating P2X3 receptor in the dorsal root ganglion
    Neurochem. Int. (IF 3.603) Pub Date : 2018-09-22
    Ya-ling Zhang, Yi-guo Liu, Qing Li, Xiang-dong Wang, Xiao-bo Zheng, Bao-lin Yang, Bin Wan, Jian-min Ma, Zeng-xu Liu

    1,8-cineole is a natural monoterpene cyclic ether present in eucalyptus and has been reported to exhibit anti-inflammatory and antioxidant effects. The therapeutic effects of 1,8-cineole on neuropathic pain and the molecular mechanisms of its pharmacological actions remain largely unknown. In the present study, we investigated the analgesic mechanisms of orally administered 1,8-cineole in a rat model of chronic constriction injury (CCI) and examined the drug-induced modulation of P2X3 receptor expression in dorsal root ganglia. The mechanical withdrawal threshold and thermal withdrawal latency were measured in rats to assess behavioural changes 7 and 14 days after CCI surgery. Changes in P2X3 receptor mRNA expression of L4–5 dorsal root ganglia were analysed using quantitative real-time polymerase chain reaction at the 7th and 14th postoperative day. Additionally, we examined the expression of P2X3 receptor protein in L4–5 dorsal root ganglia 7 and 14 days after surgery using immunohistochemistry and western blots. We found that 1,8-cineole can alleviate pathological pain caused by P2X3 receptor stimulation and explored new methods for the prevention and treatment of neuropathic pain.

    更新日期:2018-09-25
  • “Polytox” synthetic cathinone abuse: A potential role for organic cation transporter 3 in combined cathinone-induced efflux
    Neurochem. Int. (IF 3.603) Pub Date : 2018-09-21
    Felix P. Mayer, Diethart Schmid, Marion Holy, Lynette C. Daws, Harald H. Sitte

    Synthetic cathinone derivatives are a new class of psychoactive substances (NPS), also known as “bath salts”, designed to exert psychostimulant effects resembling those of well-known psychostimulants, such as cocaine and 3,4-methylenedionxymethylamphetamine (MDMA, “ecstasy”). As major constituents of bath salts, the cathinone derivatives 3,4-methylenedioxypyrovalerone (MDPV) and 4-methylmethcathinone (mephedrone), have received considerable media attention. MDPV and mephedrone interfere with the function of the high affinity transporters for dopamine (DAT), norepinephrine (NET) and serotonin (SERT), resulting in increased extracellular levels of these monoamines, though their mechanism of action differs. MDPV acts as a powerful inhibitor of DAT, NET and SERT, whereas mephedrone promotes transporter-mediated release in an amphetamine-like fashion. MDPV and mephedrone are often taken together, creating a conundrum in as much as non-transported inhibitors, like MDPV, prevent mephedrone-induced reverse transport via DAT, NET and SERT. Here we provide evidence supporting a role for organic cation transporter 3 (OCT3) in the actions of mephedrone, which may account for its ability to enhance effects of MDPV, rather than block them. We show that mephedrone can induce substrate efflux via OCT3 in the presence of MDPV. Real-time recordings of the fluorescent OCT3 substrate (4-(4-dimethylamino)styryl)-N-methylpyridinium (ASP+) and radiotracer-flux studies using [3H]1-methyl-4-phenyl-pyridinium (MPP+), demonstrated that OCT3 is MDPV-insensitive when expressed in human embryonic kidney (HEK293) cells. Ex vivo experiments performed in cultured superior cervical ganglia (SCG) cells, rich in NET and OCT3, revealed that mephedrone induces [3H]MPP+ release in an OCT3-dependent manner when NET is fully occupied with MDPV. These results extend our recent findings that OCT3 is key in the mechanism of action of amphetamine-induced substrate release. OCT3 likewise appears to be a mechanism through which mephedrone can induce release of monoamines, thereby accounting for the paradoxically more potent psychostimulant effects of MDPV taken together with mephedrone, and greater risk for deleterious side effects.

    更新日期:2018-09-22
  • The PPARδ agonist GW0742 restores neuroimmune function by regulating Tim-3 and Th17/Treg-related signaling in the BTBR autistic mouse model
    Neurochem. Int. (IF 3.603) Pub Date : 2018-09-15
    Sheikh F. Ahmad, Ahmed Nadeem, Mushtaq A. Ansari, Saleh A. Bakheet, Musaad A. Alshammari, Sabry M. Attia

    Autism spectrum disorders (ASD) are neurodevelopmental disorders that are characterized by repetitive behaviors, and impairments in communication and social interaction. Studies have shown that activation of peroxisome proliferator-activated receptor-delta (PPARδ) causes anti-inflammatory effects in animal models of neuroinflammatory diseases. We investigated the possible anti-inflammatory effect of a PPARδ agonist, GW0742 in the BTBR T+ Itpr3tf/J (BTBR) mouse model of autism. BTBR and C57BL/6 (B6) mice were treated orally with GW0742 (30 mg/kg, p.o., once daily) for 7 days. Effect of GW0742 treatment on repetitive behavior, marble burying, and thermal sensitivity response was assessed on day 8. We further examined the effect of GW0742 treatment on immunological parameters in splenocytes using flow cytometry (CD4+TIM-3+, IL-17A+TIM-3+, IL-17A+CD4+, RORγT+TIM-3+, RORγT+CD4+, Stat3+TIM-3+, Foxp3+TIM-3+, Foxp3+CD4+, and IFN-γ+CD4+). We also explored the effects of GW0742 on mRNA and protein expression of TIM-3, IL-17A, RORγT, Stat3, IFN-γ, Foxp3, and IL-10 in the brain tissue using RT-PCR and western blot analyses. GW0742 treatment substantially decreased repetitive behaviors, and lowered thermal sensitivity response in BTBR mice. GW0742 attenuated the expression of inflammatory markers such as IL-17A, RORγT, Stat3, TIM-3, and IFN-γ, while upregulating anti-inflammatory markers such as IL-10/Foxp3 both in the brain and periphery of BTBR mice. In conclusion, this study suggests that GW0742 corrects neurobehavioral dysfunction in BTBR mice which is concurrent with modulation of multiple signaling pathways.

    更新日期:2018-09-17
  • Activation of α7 nicotinic acetylcholine receptor alleviates Aβ1-42-induced neurotoxicity via downregulation of p38 and JNK MAPK signaling pathways
    Neurochem. Int. (IF 3.603) Pub Date : 2018-09-11
    Ke-Wei Chang, Hang-Fan Zong, Kai-Ge Ma, Wan-Ying Zhai, Wei-Na Yang, Xiao-Dan Hu, Jie-Hua Xu, Xin-Lin Chen, Sheng-Feng Ji, Yi-Hua Qian

    Amyloid β peptide 1–42 (Aβ1-42) could induce cognitive deficits through oxidative stress, inflammation, and neuron death in Alzheimer's disease (AD). MAPK pathways have been thought to mediate Aβ1-42-induced neuroinflammation responses, neuron death and cognitive decline in AD. The α7 nicotinic acetylcholine receptor (α7nAChR) exerts a neuroprotective effect. However, whether α7nAChR alleviates Aβ1-42-induced neurotoxicity through MAPKs (p38, ERK, JNK) in vivo remains unclear. In our study, memory was assessed in C57BL/6 mice using a Y-maze test. Cell death was assessed by Nissl and Hoechst staining and Bax, Bcl-2, Caspase 3, and Cytochrome C levels using Western blotting. Oxidative stress was assayed by superoxide dismutase (SOD), catalase (CAT), and malondialdehyde (MDA) levels. Inflammation was examined with GFAP and Iba1 using immunohistochemistry. The Aβ degrading enzymes insulin degrading enzyme (IDE) and neprilysin (NEP) were tested using Western blotting. We found that activating α7nAChR or inhibiting p38 or JNK pathway alleviated Aβ1-42-induced cognitive deficits and neuron loss and death by reducing oxidative stress. In addition, activating α7nAChR or inhibiting p38 or JNK pathway also reduced inflammation, which was observed as reduced GFAP and Iba1 levels with different effects on Aβ degrading enzymes. Finally, we found that the activation of α7nAChR led to the downregulation of pp38 and pJNK levels. Conversely, the inhibition of p38 or JNK resulted in the upregulation of α7nAChR levels in the hippocampus and cortex. Our data indicate that the activation of α7nAChR alleviates Aβ1-42-induced neurotoxicity, and this protective effect might act through the downregulation of p38 and JNK MAPKs.

    更新日期:2018-09-11
  • Neuroprotective effects of levetiracetam, both alone and combined with propylparaben, in the long-term consequences induced by lithium-pilocarpine status epilepticus
    Neurochem. Int. (IF 3.603) Pub Date : 2018-09-10
    César Emmanuel Santana-Gómez, María Guadalupe Valle-Dorado, Ana Esmeralda Domínguez-Valentín, Arely Hernández-Moreno, Sandra Orozco-Suárez, Luisa Rocha

    Status epilepticus (SE) is a neurological condition that frequently induces severe neuronal injury in the hippocampus, subsequent epileptogenesis and pharmacoresistant spontaneous recurrent seizures (SRS). The repeated administration of LEV (a broad-spectrum antiepileptic drug) during the post-SE period does not prevent the subsequent development of SRS. However, this treatment reduces SE-induced neurodegeneration in the hippocampus. Conversely, propylparaben (PPB) is a widely used antimicrobial that blocks voltage-dependent Na+ channels, induces neuroprotection and reduces epileptiform activity in vitro. The present study attempted to determine if the neuroprotective effects induced by LEV are augmented when combined with a sub-effective dose of PPB. Long-term SE-induced consequences (hyperexcitability, high glutamate release, neuronal injury and volume loss) were evaluated in the hippocampus of rats. LEV alone, as well as combined with PPB, did not prevent the occurrence of SRS. However, animals treated with LEV plus PPB showed high prevalence of low frequency oscillations (0.1–4 Hz and 8–90 bands, p < 0.001) and low prevalence of high frequency activity (90–250 bands, p < 0.001) during the interictal period. In addition, these animals presented lower extracellular levels of glutamate, decreased rate of neurodegeneration and a similar hippocampal volume compared to the control conditions. This study's results suggest that LEV associated with PPB could represent a new therapeutic strategy to reduce long-term consequences induced by SE that facilitate pharmacoresistant SRS.

    更新日期:2018-09-11
  • Knockdown the P2X3 receptor in the stellate ganglia of rats relieved the diabetic cardiac autonomic neuropathy
    Neurochem. Int. (IF 3.603) Pub Date : 2018-09-06
    Xuan Sheng, Yu Dan, Bo Dai, Jingjing Guo, Huihong Ji, Xinge Zhang, Zhi Xie, Siqi Song, Qiwen Pan, Jiayue Wang, Shangdong Liang, Guilin Li

    Diabetic cardiac autonomic neuropathy (DCAN) is a common and serious complication of diabetes mellitus (DM), is manifested by nerve fiber injury in the sympathetic and parasympathetic nerve of the autonomic nervous system, and causes hypertension, cardiac arrhythmias, silent myocardial infarction, and sudden death. Our previous study observed that P2X3 receptor in superior cervical ganglia in rat was associated with sympathetic neuropathy caused by myocardial ischemia. However, whether the P2X3 receptor is involved in the diabetic cardiac autonomic neuropathy and the underlying mechanisms remain unclear. The aim of this research was explored the effect of P2X3 short hairpin RNA (shRNA) on information transmission of sympathetic nerve induced by DCAN. Sprague-Dawley (SD) male rats were randomly divided into four groups: Control, DM, DM treated with P2X3 shRNA and DM treated with scramble shRNA. Blood pressure, heart rate and heart rate variability were measured in each group. The expression of P2X3 in stellate ganglion (SG) was detected by immunohistochemistry, western blotting and QPCR. Results showed that P2X3 shRNA alleviated blood pressure and heart rate, improved heart rate variability, decreased the up-regulated expression levels of P2X3, interleukin-1beta and tumor necrosis factor alpha in stellate ganglion (SG) of diabetic rats. P2X3 shRNA also reduced the incremental concentration of serum epinephrine and the phosphorylation level of extracellular regulated protein kinases1/2 in diabetic rats. These results indicated that P2X3 shRNA could decrease sympathetic activity via inhibiting P2X3 receptor in the SG to alleviate DCAN.

    更新日期:2018-09-07
  • Neuronal Growth Factor regulates brain specific kinase 1 expression by inhibiting promoter methylation and promoting Sp1 recruitment
    Neurochem. Int. (IF 3.603) Pub Date : 2018-09-06
    Leticia Ramírez Martínez, Miguel Vargas Mejía, Josep Espadamala, Néstor Gomez, José Miguel Lizcano, Esther López-Bayghen

    Brain specific kinases (BRSKs) are serine/threonine kinases, preferentially expressed in the brain after Embryonic Day 12. Although BRSKs are crucial neuronal development factors and regulation of their enzymatic activity has been widely explored, little is known of their transcriptional regulation. In this work, we show that Neuronal Growth Factor (NGF) increased the expression of Brsk1 in PC12 cells. Furthermore, during neuronal differentiation, Brsk1 mRNA increased through a MAPK-dependent Sp1 activation. To gain further insight into this regulation, we analyzed the transcriptional activity of the Brsk1 promoter in PC12 cells treated with NGF. Initially, we defined the minimal promoter region (−342 to +125 bp) responsive to NGF treatment. This region had multiple Sp1 binding sites, one of which was within a CpG island. In vitro binding assays showed that NGF-induced differentiation increased Sp1 binding to this site and that DNA methylation inhibited Sp1 binding. In vitro methylation of the Brsk1 promoter reduced its transcriptional activity and impaired the NGF effect. To evaluate the participation of DNA methyltransferases in Brsk1 gene regulation, the 5′Aza-dC inhibitor was used. 5′Aza-dC acted synergistically with NGF to promote Brsk1 promoter activity. Accordingly, DNMT3B overexpression abolished the response of the Brsk1 promoter to NGF. Surprisingly, we found Dnmt3b to be a direct target of NGF regulation, via the MAPK pathway. In conclusion, our results provide evidence of a novel mechanism of Brsk1 transcriptional regulation changing the promoter's methylation status, which was incited by the NGF-induced neuronal differentiation process.

    更新日期:2018-09-07
  • Effect of Angelica polysaccharide on brain senescence of Nestin-GFP mice induced by D-galactose
    Neurochem. Int. (IF 3.603) Pub Date : 2018-09-07
    Xiao Cheng, Hui Yao, Yue Xiang, Linbo Chen, Minghe Xiao, Ziling Wang, Hanxianzhi Xiao, Lu Wang, Shunhe Wang, Yaping Wang

    The incidence of neurodegenerative diseases is severely increasing with the aging. It has been proposed that NSCs (neural stem cells) help to control aging, but the mechanisms responsible remain unclear. Angelica polysaccharide is an active ingredient of Angelica sinensis in traditional Chinese medicine, which possesses versatile pharmacological activities including anti-oxidative and anti-aging effects. In this study, D-gal (D-galactose) was used to construct an aging model of Nestin-GFP transgenic mice brain tissues and NSCs. Mouse model was subcutaneously injected with D-gal, as we observed that mice consistently displayed acceleration of aging-like behavior change, energy metabolism decreased, the expression of aging-related genes was up-regulated. Conversely, aging retardation was achieved in Nestin-GFP mice Induced by D-gal that was locally injected with ASP (Angelica polysaccharide). Mechanistically, we isolated and cultured NSCs in vitro. ASP protected NSCs by increasing the cell proliferation; decreasing the number of SA-β-gal stained neurons; increasing the activity of SOD(superoxide dismutase) and T-AOC(total antioxidant capacity), decreasing the content of MDA(malondialdehyde); decreasing the levels of IL-1b,IL-6,TNF-a and ROS; and down-regulated the expression of cellular senescence associated genes p53, p21 in the aging NSCs. In conclusion, ASP can delay aging speed by protecting NSCs and promote neurogenesis by enhancing the antioxidant and anti-inflammatory capacity, up-regulation of p53/p21 signaling pathway. As to provide theoretical basis for treatment for brain aging related diseases, add new scientific connotation for “qi and blood theory” and “supplement blood and delay aging” of Traditional Chinese Medicine.

    更新日期:2018-09-07
  • The role of decreased cardiolipin and impaired electron transport chain in brain damage due to cardiac arrest
    Neurochem. Int. (IF 3.603) Pub Date : 2018-09-01
    Jonathan Tam, Angela Hong, Peter M. Naranjo, Tai Yin, Koichiro Shinozaki, Joshua W. Lampe, Lance B. Becker, Junhwan Kim

    Ischemic brain damage is the major cause of mortality in cardiac arrest (CA). However, the molecular mechanism responsible for brain damage is not well understood. We previously found that mitochondrial state-3 respiration, which had been decreased following CA, was recovered in the kidney and liver, but not in the brain following cardiopulmonary bypass (CPB) resuscitation. Examination of mitochondria from these tissues may shed light on why the brain is the most vulnerable. In this study, adult male Sprague-Dawley rats were subjected to asphyxia-induced CA for 30 min or 30 min followed by 60 min CPB resuscitation. Mitochondria were then isolated from brain, heart, kidney, and liver tissues for examination using spectrophotometry and mass spectrometry to measure the activities of mitochondrial electron transport complexes and the cardiolipin content. We found significantly decreased complex I activity in mitochondria isolated from all four organs following CA, while complex III and IV activities remained intact. Following CPB resuscitation, complex I activity was normalized in kidney and liver, but unrecovered in brain and heart mitochondria. In addition, complex III activity in brain mitochondria was decreased by 22% with a concomitant decrease in cardiolipin following CPB resuscitation. These results suggest that of the tissues tested only brain mitochondria suffer reperfusion injury in addition to ischemic alterations, resulting in diminished overall mitochondrial respiration following resuscitation.

    更新日期:2018-09-03
  • Model systems for analysis of dopamine transporter function and regulation
    Neurochem. Int. (IF 3.603) Pub Date : 2018-09-01
    Moriah J. Hovde, Garret H. Larson, Roxanne A. Vaughan, James D. Foster

    The dopamine transporter (DAT) plays a critical role in dopamine (DA) homeostasis by clearing transmitter from the extraneuronal space after vesicular release. DAT serves as a site of action for a variety of addictive and therapeutic reuptake inhibitors, and transport dysfunction is associated with transmitter imbalances in disorders such as schizophrenia, attention deficit hyperactive disorder, bipolar disorder, and Parkinson disease. In this review, we describe some of the model systems that have been used for in vitro analyses of DAT structure, function and regulation, and discuss a potential relationship between transporter kinetic values and membrane cholesterol.

    更新日期:2018-09-03
  • 3D human brain cell models: New frontiers in disease understanding and drug discovery for neurodegenerative diseases
    Neurochem. Int. (IF 3.603) Pub Date : 2018-09-01
    Paula Korhonen, Tarja Malm, Anthony R. White

    Neurodegenerative disorders have an enormous impact on society and healthcare budgets. There has been a high degree of failure in many recent clinical trials for disease-modifying therapeutics. A major factor in this failure is the difficulty of translating findings from animal-based cell models to human patients. The majority of non-animal neurodegenerative disease research has been conducted in 2 dimensional models of rodent neonatal neurons and glia. While these systems have provided valuable insights into neural cell function and dysfunction, they have largely reached the end of their useful life, as human stem cell technologies combined with major advances in microfluidic technologies have opened the door to development of patient-derived 3D brain cell models. These have major advantages in providing a micro-physiological system more closely reflecting the in vivo brain environment, and promote the interaction between different patient-derived brain cell-types. However, major challenges remain before these model systems will replace the 2D rodent models as the workhorse for neurodegenerative disease studies. Despite these challenges, we are likely to experience a rapid transition of research from old models to new patient derived 3D brain cell systems, which will likely improve translational outcomes for disease therapeutics.

    更新日期:2018-09-01
  • Beta-adrenergic receptor activation increases GABA uptake in adolescent mice frontal cortex: Modulation by cannabinoid receptor agonist WIN55,212-2
    Neurochem. Int. (IF 3.603) Pub Date : 2018-08-29
    Robertta Silva Martins, Isis Grigorio de Freitas, Matheus Figueiredo Sathler, Vladimir Pedro Peralva Borges Martins, Clarissa de Sampaio Schitine, Luzia da Silva Sampaio, Hércules Rezende Freitas, Alex Christian Manhães, Maurício dos Santos Pereira, Ricardo Augusto de Melo Reis, Regina Célia Cussa Kubrusly

    GABA transporters regulate synaptic GABA levels and dysfunctions in this system might result in psychiatric disorders. The endocannabinoid system (ECS) is the main circuit breaker in the nervous system and may alter noradrenaline (NA) communication, which in turn modulates the release of GABA. However, a close relationship between these systems has not been recognized. We asked whether NA and ECS might control extracellular GABA levels in slices of frontal cortex (FC) of adolescent Swiss mice with 40 days after birth (PN40). Here we show that NA and isoproterenol (ISO), a beta-adrenergic agonist, increased [3H]-GABA uptake in mice FC, while alpha1-adrenergic agonist phenylephrine had no effect. As GAT-1 is expressed and fully functional at the FC, addition of NO-711, a GAT-1 inhibitor, dose dependently blocked [3H]-GABA uptake. The increase of [3H]-GABA uptake induced by ISO was also blocked by NO-711. [3H]-GABA release induced by 80 mM KCl was reduced by NO-711, but not by removal of Ca2+. ISO also increased cyclic AMP (cAMP) levels and addition of WIN 55,212-2, a mixed CB1/CB2 receptor agonist, inhibited the effect of ISO in GABA uptake increase, GAT-1 expression and cAMP levels compared to control. Our data show that GABA transport increased by NA and ISO is negatively regulated by cannabinoid receptor agonist WIN55,212-2.

    更新日期:2018-08-29
  • Serum 25-hydroxyvitamin D deficiency predicts poor outcome among acute ischemic stroke patients without hypertension
    Neurochem. Int. (IF 3.603) Pub Date : 2018-05-03
    Bingjun Zhang, Yuge Wang, Yi Zhong, Siyuan Liao, Zhengqi Lu

    25-Hydroxyvitamin D (25(OH)D) deficiency is a frequent condition in patients who suffer acute ischemic stroke (AIS), and several studies suggested that it may be associated with a poorer prognosis. Whether this association is affected by hypertension is unclear. Our aim was to investigate the association between 25(OH)D levels and both clinical severity and outcome after 3 months in AIS patients stratified by the history of hypertension. Consecutive first-ever AIS patients admitted to the Third Affiliated Hospital of Sun Yat-sen University, China were identified. Clinical information was collected. Serum 25(OH)D levels were measured at baseline. Stroke severity was assessed at admission using the National Institutes of Health Stroke Scale (NIHSS) score. Functional outcome was evaluated after 3 months of onset using the modified Rankin Scale (mRS). Multivariate analyses were performed using logistic regression models. During the study period, 377 patients were diagnosed as AIS and were included in the analysis. 25(OH)D deficiency was not associated with the risk of NIHSS at admission and 3 months mRS both in total patients and the hypertension subgroup. Among AIS without hypertension, 25(OH)D deficiency subjects had a significantly higher of NIHSS at admission and 3 months mRS compared with those with 25(OH)D ≥ 50 nmol/L. The odds ratios (95% confidence interval) were 5.51(1.83–16.60) and 4.63(1.53–14.05) in the multivariable adjusted model (P for linear trend < 0.05). Serum lower 25(OH)D levels can be seen as an independent prognostic factor of functional outcome in AIS without hypertension. Additional studies about improving prognosis of AIS by vitamin D supplementation could be first applied to these patients.

    更新日期:2018-05-04
  • Huntington's disease pattern of transcriptional dysregulation in the absence of mutant huntingtin is produced by knockout of neuronal GLT-1
    Neurochem. Int. (IF 3.603) Pub Date : 2018-04-27
    Robert B. Laprairie, Geraldine T. Petr, Yan Sun, Kathryn D. Fischer, Eileen M. Denovan-Wright, Paul A. Rosenberg

    GLT-1 is the major glutamate transporter in the brain, and is expressed in astrocytes and in axon terminals in the hippocampus, cortex, and striatum. Neuronal GLT-1 accounts for only 5–10% of total brain GLT-1 protein, and its function is uncertain. In HD, synaptic dysfunction of the corticostriate synapse is well-established. Transcriptional dysregulation is a key feature of HD. We hypothesized that deletion of neuronal GLT-1, because it is expressed in axon terminals in the striatum, might produce a synaptopathy similar to that present in HD. If true, then some of the gene expression changes observed in HD might also be observed in the neuronal GLT-1 knockout. In situ hybridization using 33P labeled oligonucleotide probes was carried out to assess localization and expression of a panel of genes known to be altered in expression in HD. We found changes in the expression of cannabinoid receptors 1 and 2, preproenkaphalin, and PDE10A in the striatum of mice in which the GLT-1 gene was inactivated in neurons by expression of synapsin-Cre, compared to wild-type littermates. These changes in expression were observed at 12 weeks of age but not at 6 weeks of age. No changes in DARPP-32, PDE1B, NGFIA, or β-actin expression were observed. In addition, we found widespread alteration in expression of the dynamin 1 gene. The changes in expression in the neuronal GLT-1 knockout of genes thought to exemplify HD transcriptional dysregulation suggest an overlap in the synaptopathy caused by neuronal GLT-1 deletion and HD. These data further suggest that specific changes in expression of cannabinoid receptors, preproenkephalin, and PDE10A, considered to be the hallmark of HD transcriptional dysregulation, may be produced by an abnormality of glutamate homeostasis under the regulation of neuronal GLT-1, or a synaptic disturbance caused by that abnormality, independently of mutation in huntingtin.

    更新日期:2018-04-27
  • Endogenous acetylcholine regulates neuronal and astrocytic vascular endothelial growth factor expression levels via different acetylcholine receptor mechanisms
    Neurochem. Int. (IF 3.603) Pub Date : 2018-04-26
    Kyoko Kimura, Kinzo Matsumoto, Hironori Ohtake, Jun-Ichiro Oka, Hironori Fujiwara

    Vascular endothelial growth factor (VEGF), a signaling molecule involved in angiogenesis, plays an important role in neuroprotection and neurogenesis. In the present study, we aimed to elucidate the mechanisms underlying endogenous acetylcholine (ACh)-induced VEGF expression in neurons and astrocytes, and identify the neuronal cells contributing to its expression in the medial septal area, a nuclear origin of cholinergic neurons mainly projecting to the hippocampus. The mRNA expression and secretion of VEGF were measured by RT-PCR and ELISA using mouse primary cultured cortical neurons and astrocytes. VEGF expression in the medial septal area was assessed by RT-PCR and immunostaining using mice treated with tacrine [9-amino-1,2,3,4-tetrahydro-acridine HCl (THA); 2.5 mg/kg, i.p.] once daily for 7 days. The THA treatment increased VEGF mRNA expression in neurons in a manner that was reversed by mecamylamine, a nicotinic ACh receptor (AChR) antagonist, whereas in mouse primary cultured astrocytes, carbachol, but not THA dose-dependently increased VEGF mRNA expression and secretion in a manner that was inhibited by scopolamine, a muscarinic AChR inhibitor. In in vivo studies, the administration of THA significantly increased the expression of VEGF in medial septal cholinergic neurons and the effects of THA were significantly blocked by mecamylamine. THA also significantly increased the expression levels of a phosphorylated form of VEGF receptor 2 (p-VEGFR2), an activated form of VEGFR2. The present results suggest that endogenous ACh plays an up-regulatory role for VEGF expression in neurons and astrocytes via different mechanisms. Moreover, endogenous ACh-induced increases in VEGF levels appear to activate VEGFR2 on medial septal cholinergic neurons via an autocrine mechanism.

    更新日期:2018-04-27
  • Mitochondrial alterations in Parkinson's disease human samples and cellular models
    Neurochem. Int. (IF 3.603) Pub Date : 2018-04-26
    Mara Zilocchi, Giovanna Finzi, Marta Lualdi, Fausto Sessa, Mauro Fasano, Tiziana Alberio

    Mitochondrial impairment is one of the most important hallmarks of Parkinson's disease (PD) pathogenesis. In this work, we wanted to verify the molecular basis of altered mitochondrial dynamics and disposal in Substantia nigra specimens of sporadic PD patients, by the comparison with two cellular models of PD. Indeed, SH-SY5Y cells were treated with either dopamine or 1-methyl-4-phenylpyridinium (MPP+) in order to highlight the effect of altered dopamine homeostasis and of complex I inhibition, respectively. As a result, we found that fusion impairment of the inner mitochondrial membrane is a common feature of both PD human samples and cellular models. However, the effects of dopamine and MPP+ treatments resulted to be different in terms of the mitochondrial damage induced. Opposite changes in the levels of two mitochondrial protein markers (voltage-dependent anion channels (VDACs) and cytochrome c oxidase subunit 5β (COX5β)) were observed. In this case, dopamine treatment better recapitulated the molecular picture of patients' samples. Moreover, the accumulation of PTEN-induced putative kinase 1 (PINK1), a mitophagy marker, was not observed in both PD patients samples and cellular models. Eventually, in transmission electron microscopy images, small electron dense deposits were observed in mitochondria of PD subjects, which are uniquely reproduced in dopamine-treated cells. In conclusion, our study suggests that the mitochondrial molecular landscape of Substantia nigra specimens of PD patients can be mirrored by the impaired dopamine homeostasis cellular model, thus supporting the hypothesis that alterations in this process could be a crucial pathogenetic event in PD.

    更新日期:2018-04-26
  • Protective influences of N-acetylcysteine against alcohol abstinence-induced depression by regulating biochemical and GRIN2A, GRIN2B gene expression of NMDA receptor signaling pathway in rats
    Neurochem. Int. (IF 3.603) Pub Date : 2018-04-25
    Rutuja Yawalkar, Harish Changotra, Girdhari Lal Gupta

    Evidences have indicated a high degree of comorbidity of alcoholism and depression. N-acetylcysteine (NAC) has shown its clinical efficiency in the treatment of several psychiatric disorders and is identified as a multi-target acting drug. The ability of NAC to prevent alcohol abstinence-induced depression-like effects and underlying mechanism(s) have not been adequately addressed. This study was aimed to investigate the beneficial effects of NAC in the alcohol abstinence-induced depression developed following long-term voluntary alcohol intake. For evaluation of the effects of NAC, Sprague–Dawley rats were enabled to voluntary drinking of 4.5%, 7.5% and 9% v/v alcohol for fifteen days. NAC (25, 50, and 100 mg/kg) and fluoxetine (5 mg/kg) were injected intraperitoneally for three consecutive days during the alcohol abstinence period on the days 16, 17, 18. The behavioral studies were conducted employing forced swim test (FST), and tail suspension test (TST) on day 18 to determine the effects of N-acetylcysteine and fluoxetine in the ethanol withdrawal induced-depression. Blood alcohol concentration, alcohol biomarkers like SGPT, SGOT, ALP, GGT, and MCV were estimated by using commercially available kits. Serotonin concentrations were measured in the plasma, hippocampus and pre-frontal cortex using the rat ELISA kit. The expression of GRIN1, GRIN2A, GRIN2B genes for the N-methyl d-aspartate receptors (NMDAR) subunits in the hippocampus and the prefrontal cortex were also examined by reverse-transcription quantitative polymerase chain reaction. The results revealed that alcohol abstinence group depicted increased immobility time in FST and TST. Further, NAC exerted significant protective effect at the doses 50 mg/kg and 100 mg/kg, but 25 mg/kg showed insignificant protection against alcohol abstinence-induced depression. The increased level of biochemical parameters following ethanol abstinence were also reversed by NAC at the dose of 100 mg/kg. The significant reversal effect of NAC on the serotonin level following alcohol abstinence was greater in the hippocampus as compared to the third-day alcohol withdrawal group. The increased expression levels of GRIN2A and GRIN2B following ethanol abstinence were reversed with a higher dose of NAC (100 mg/kg) treatment. In conclusion, the results of the study reveal that NAC has remarkable protective effects in the alcohol abstinence-induced depression by modulating alcohol markers, serotonin levels and GRIN2A, GRIN2B gene expression of NMDAR signaling pathway in rats.

    更新日期:2018-04-26
  • Regulation of the ARE-binding proteins, TTP (tristetraprolin) and HuR (human antigen R), in inflammatory response in astrocytes
    Neurochem. Int. (IF 3.603) Pub Date : 2018-04-24
    Alina A. Astakhova, Dmitry V. Chistyakov, Marina G. Sergeeva, Georg Reiser

    Control of decay of mRNA containing the adenine-uridine rich elements (AREs) is an important post-transcriptional mechanism involved in the regulation of inflammatory gene expression. Two widely recognized proteins in this machinery are HuR (human antigen R) – a protein that stabilizes ARE-containing mRNA and TTP (tristetraprolin) – a protein that shortens half-lives of ARE-containing mRNA. Although HuR and TTP regulation mechanisms have been well studied in cells of hematopoietic origin, there are no respective data in astrocytes, cells of ectodermal origin which play an important role in neuroinflammation. Therefore we evaluated the existence of TTP and HuR in primary astrocytes and characterized the features of their regulation after stimulation by the proinflammatory stimuli thrombin, ATP, and agonists of TLR4, TLR2. All proinflammatory stimuli increased levels of TTP mRNA, but not HuR mRNA. Transcripts of both HuR and TTP underwent stabilization upon lipopolysaccharide (LPS) treatment, measured with the actinomycin D protocol. This effect was abolished by treatment with SB203580, an inhibitor of р38 МАРК. Both TTP and HuR transcripts were sensitive to modulation by anisomycin and cycloheximide. LPS induced translocation of HuR protein from nucleus to cytoplasm. TTP is localized in the cytosolic fraction and localization is not sensitive to LPS treatment. Our data for the first time reveal specificity of regulation of ARE-binding proteins in astrocytes. We propose possibilities to manipulate brain inflammatory processes via post-transcription regulatory steps in astrocytes.

    更新日期:2018-04-25
  • Activation of M2 muscarinic acetylcholine receptors by a hybrid agonist enhances cytotoxic effects in GB7 glioblastoma cancer stem cells
    Neurochem. Int. (IF 3.603) Pub Date : 2018-04-24
    Ilaria Cristofaro, Zaira Spinello, Carlo Matera, Mario Fiore, Luciano Conti, Marco De Amici, Clelia Dallanoce, Ada Maria Tata

    In previous studies, we found that the orthosteric muscarinic agonist arecaidine propargyl ester (APE) (100 μM) induced a decreased cell proliferation and severe apoptosis in glioblastoma cancer stem cells (GSCs). In this report, we have investigated the effects mediated by hybrid (orthosteric/allosteric) muscarinic agonists P-6-Iper and N-8-Iper on GSCs survival. At variance with APE, the agonist N-8-Iper inhibited cell growth in a dose dependent manner and also impaired cell survival at low doses. The inhibitory effects of the N-8-Iper action appear to be mediated by M2 receptor activation, since they were strongly reduced by co-administration of the selective M2 receptor antagonist methoctramine as well as upon M2 receptor silencing. Moreover, analysis of the expression of phosphorylated histone H2AX (γ-H2AX) indicated that the treatment with N-8-Iper produced a decreased cell survival by induction of DNA damage. The ability of N-8-Iper to produce a cytotoxic effect and apoptosis at low doses indicates that this muscarinic agonist is a suitable probe in a putative therapeutic intervention on glioblastoma through M2 receptor activation.

    更新日期:2018-04-25
  • Mitochondria in the nervous system: From Health to disease, part II
    Neurochem. Int. (IF 3.603) Pub Date : 2018-04-10
    Maria Teresa Carrì, Brian M. Polster, Philip M. Beart

    In Part II of this Special Issue on "Mitochondria in the Nervous System: From Health to Disease", the editors bring together more reviews and original articles from researchers in the field of mitochondrial metabolism in the healthy and diseased nervous system. Subjects span from basic mitochondrial physiology to papers on mitochondrial dynamics and to those altered states of the nervous system that can be considered “mitopathologies”. Finally, a few papers approach aspects of mitochondrial biology linked to the feasibility and validity of a mitochondrial therapy.

    更新日期:2018-04-10
  • Restorative effect of l-Dopa treatment against Ochratoxin A induced neurotoxicity
    Neurochem. Int. (IF 3.603) Pub Date : 2018-04-05
    Pratiksha V. Bhat, T. Anand, Manu T. Mohan, Farhath Khanum

    The toxic effects of Ochratoxin A (OTA), a fungal secondary metabolite of the genera Aspergillus and Penicillium with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) a Parkinson inducing drug were investigated to evaluate the neurotoxic effects exerted by OTA. OTA is known to contaminate food and feedstuff leading to a wide range of toxicity like nephrotoxicity, hepatotoxicity, and immunotoxicity. However, due to the dearth of available information on the possible mechanisms of OTA neurotoxicity and neurodegeneration the current study was undertaken. Hence, in this study, we examined the neurotoxic effects and the possible mechanism of action of neurodegeneration by OTA toxicity on mice brain by conducting a battery of behavioural studies and reviewing neurotransmitter levels and neuronal apoptotic pathways. Further, they were treated with l-Dopa, a precursor of dopamine (DA) to explore its ameliorative effects against OTA. The results of behavioural studies like gait analysis, spontaneous activity, cylinder test and pole test showed that OTA exhibits Parkinsonian physiognomies which were stabilized with l-Dopa treatment. Also, OTA toxicity showed insults on neurotransmitter levels and general brain function parameters that were normalized with l-Dopa treatment. The results of the present study suggest that OTA promotes neurodegeneration by targeting neuronal pathway leading to the development of Parkinson's diseases.

    更新日期:2018-04-06
  • The antipsychotic drug quetiapine stimulates oligodendrocyte differentiation by modulating the cell cycle
    Neurochem. Int. (IF 3.603) Pub Date : 2018-04-05
    Guiyun Mi, Yituo Wang, Enmao Ye, Yunyun Gao, Qiaowei Liu, Pinhong Chen, Yuyang Zhu, Hongju Yang, Zheng Yang

    Recent studies have revealed that oligodendrocyte differentiation deficits and de-myelination occur in the brains of schizophrenic patients. Cell cycle proteins play a critical role in modulating oligodendrocyte proliferation and differentiation. In our previous studies, we found that cuprizone, a copper chelant, induces oligodendrocyte loss and demyelination, and this effect can be alleviated by using the atypical antipsychotic drug quetiapine. To explore the mechanisms of quetiapine in oligodendrocyte development, we examined the effects of quetiapine on cell cycle progression. Quetiapine promoted cell cycle exit and blocked the mitogenic effect of PDGF in cultured rat cortical oligodendrocyte progenitor cells (OPCs). Quetiapine accelerated OPC differentiation in vitro. Moreover, the systemic administration of quetiapine up-regulated p21 mRNA expression, a cyclin-dependent kinase inhibitor, in mice. Knocking down p21 expression by RNA interference enhanced proliferation and delayed differentiation. Our results suggest that cell cycle regulation may contribute to the differentiation-promoting effect of quetiapine.

    更新日期:2018-04-06
  • 12/15 lipoxygenase: A crucial enzyme in diverse types of cell death
    Neurochem. Int. (IF 3.603) Pub Date : 2018-04-05
    Qiu-Qi Li, Qin-Li, Ji-Ning Jia, Zhao-Qian Liu, Hong-Hao Zhou, Xiao-Yuan Mao

    The 12/15-lipoxygenase (12/15-LOX) enzymes react with polyunsaturated fatty acids producing active lipid metabolites that are involved in plethora of human diseases including neurological disorders. A great many of elegant studies over the last decades have contributed to unraveling the mechanism how 12/15-lipoxygenase play a role in these diseases. And the way it works is mainly through apoptosis. However, recent years have found that the way 12/15-lipoxygenase works is also related to autophagy and ferroptosis, a newly defined type of cell death by Stockwell's lab in 2012. Figuring out how 12/15-lipoxygenase participate in these modes of cell death is of vital importance to understand its role in disease. The review aims to give a sight on our current knowledge on the role of this enzyme in apoptosis, autophagy and ferroptosis. And the relevant diseases that 12/15-lipoxygenase may be involved.

    更新日期:2018-04-06
Some contents have been Reproduced with permission of the American Chemical Society.
Some contents have been Reproduced by permission of The Royal Society of Chemistry.
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