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  • Could glucagon-like peptide-1 be a potential biomarker of early-stage intestinal ischemia?
    Biochimie (IF 3.188) Pub Date : 2018-11-14
    Lorène J. Lebrun, Jacques Grober

    Intestinal ischemia, also called mesenteric ischemia, is a severe gastrointestinal and vascular medical emergency caused by a sudden decrease of blood flow through the mesenteric vessels. It generates hypoperfusion of intestinal tissues and can rapidly progress to intestinal wall infarction, systemic inflammation or even death if not treated in time. The mortality of this condition is still considerably high despite all the medical advances of the past few years. This is partially due to the difficulty of diagnosing early stage mesenteric ischemia. Indeed, a speedy and correct diagnosis is decisive for suitable medical care. However, early symptoms are unspecific and conventional clinical markers are neither specific nor sensitive enough. In the last few years, significant clinical and preclinical efforts have been made to find biomarkers which could predict gastrointestinal damage before it becomes irreversible. Here, the gut-derived hormone glucagon-like peptide-1 (GLP-1) is described as a potential early biomarker of this severe condition. Indeed, GLP-1 plasma levels rise rapidly in both mice and humans with intestinal ischemia. This discovery could counter the cruel lack of clinical biomarkers available to diagnose and therefore manage intestinal ischemia efficiently in the early stages. GLP-1 could thus become part of a panel of biomarkers for intestinal ischemia and could help to reduce the associated high mortality rates.

    更新日期:2018-11-14
  • Neotuberostemonine inhibits osteoclastogenesis via blockade of NF-κB pathway
    Biochimie (IF 3.188) Pub Date : 2018-11-13
    Jangmi Yun, Ki Yong Lee, Byoungduck Park

    Osteoporosis has been attributed to low bone mass arising from cellular communications between bone formation and bone resorption. Osteoclastogenesis is induced by M-CSF and RANKL in hematopoietic lineage cells. Once RANK/RANKL complex is formed, TRAF6 is recruited and triggers the activation of NF-κB pathway and the expression of osteoclast-related genes including NFATc1. Neotuberostemonine (NTS) is an active compound isolated from Stemona tuberosa Lour. Pharmacologically, NTS has been known to possess antitussive, anti-fibrotic and anti-inflammatory activities through regulation of macrophage. However, the influence of NTS to osteoclastogenesis has not been reported. The purpose of this study is to investigate whether NTS can modulate the osteoclastogenesis induced by RANKL or cancer cells. We found that NTS inhibits RANKL- or cancer cell-mediated osteoclastogenesis via blockade of TRAF6 and NF-κB activation. NTS also impairs the formation of F-actin ring structure, an important feature of osteoclast differentiation and function. These results indicate that NTS can be a preventive and therapeutic candidate for bone-related disease and that NTS provides insights underlying molecular mechanisms that influence osteoclastogenesis.

    更新日期:2018-11-13
  • Study of the metabolomic relationship between lung cancer and chronic obstructive pulmonary disease based on direct infusion mass spectrometry
    Biochimie (IF 3.188) Pub Date : 2018-11-13
    B. Callejón-Leblic, A. Pereira-Vega, E. Vazquez-Gandullo, J.L. Sánchez-Ramos, J.L. Gómez-Ariza, T. García-Barrera

    The high prevalence of lung cancer (LC) has triggered the search of biomarkers for early diagnosis of this disease. For this purpose the study of metabolic changes related to the development of lung cancer could provide interesting information about its early diagnosis. In this sense, chronic obstructive pulmonary disease (COPD), a disease associated with tumor development, is a comorbidity that increases the risk of onset and progression of lung neoplasia and has also to be considered in the study of pathology related to lung cancer. This work develop a metabolomic approach based on direct infusion mass spectrometry using a hybrid triple quadrupole-time of flight mass spectrometer (DI-ESI-QqQ-TOF-MS) in order to identify altered metabolites from serum of LC and COPD patients and evaluate its relationship and implication in the progression of LC. This methodology has been applied to 30 serum samples from LC, 30 healthy patients used as controls (HC) and 30 serum samples from COPD to found altered metabolites from both LC and COPD diseases. In addition, some metabolic differences and similarities were found in Pulmonary Emphysema and Chronic Bronchitis patients. On the other hand, altered metabolites were studied in different stages of LC (II, III and IV) to evaluate the perturbation of them throughout the progression of disease. The sample treatment consisted of the extraction of polar and non-polar metabolites from serum that was later infused into the mass spectrometer using an electrospray ionization source in positive and negative mode. Partial least squares discriminant analysis (PLS-DA) allowed a classification between LC, HC and COPD groups in all acquisition modes. A total of 35 altered and common metabolites between LC and COPD, including amino acids, fatty acids, lysophospholipids, phospholipids and triacylglycerides were identified, being alanine, aspartate and glutamate metabolism the most altered. Finally, ROC curves were applied to the dataset and metabolites with AUC value higher than 0.70 were considered as relevant in the progression of LC.

    更新日期:2018-11-13
  • Serotonin in retina
    Biochimie (IF 3.188) Pub Date : 2018-11-09
    Justine Masson

    The expression of serotonin (5-HT) in the retina was first reported in the sixties. The detection of vesicular monoamine transporter and serotonin receptors in several retinal cells confirm that 5-HT is playing a neuromodulatory role in this structure. Whereas signaling pathways activated by 5-HT receptor binding has been poorly investigated so far, numerous data demonstrated that 5-HT is involved in retinal physiology, retinal physiopathology and photoreceptor survival.

    更新日期:2018-11-09
  • A novel uORF-based regulatory mechanism controls translation of the human MDM2 and eIF2D mRNAs during stress
    Biochimie (IF 3.188) Pub Date : 2018-11-09
    Kseniya A. Akulich, Pavel G. Sinitcyn, Desislava S. Makeeva, Dmitry E. Andreev, Ilya M. Terenin, Aleksandra S. Anisimova, Ivan N. Shatsky, Sergey E. Dmitriev
    更新日期:2018-11-09
  • Role of Adenomatous Polyposis Coli (APC) gene mutations in the pathogenesis of colorectal cancer; current status and perspectives
    Biochimie (IF 3.188) Pub Date : 2018-11-08
    Amirsaeed Sabeti Aghabozorgi, Amirhossein Bahreyni, Atena Soleimani, Afsane Bahrami, Majid Khazaei, Gordon A. Ferns, Amir Avan, Seyed Mahdi Hassanian

    Colorectal cancer (CRC) is one of the most common forms of solid tumors in the world with high rates of mortality and morbidity. Most cases of CRCs are initiated by inactivating mutations in a tumor suppressor gene, adenomatous polyposis coli (APC), leading to constitutive activation of the Wnt signaling pathway. This review summarizes the roles of somatic and germline mutations of the APC gene in hereditary as well as sporadic forms of CRC. We also discuss the diagnostic and prognostic value of the APC gene in the pathogenesis of CRC for a better understanding of CRC disease.

    更新日期:2018-11-08
  • A secondary structure within a human piRNA modulates its functionality
    Biochimie (IF 3.188) Pub Date : 2018-11-08
    Sumirtha Balaratnam, Madara Hettiarachchilage, Nicole West, Helen Piontkivska, Soumitra Basu
    更新日期:2018-11-08
  • Virus-like nanoparticles as a novel delivery tool in gene therapy
    Biochimie (IF 3.188) Pub Date : 2018-11-05
    Jaison Jeevanandam, Kaushik Pal, Michael K. Danquah
    更新日期:2018-11-05
  • Mo-CBP3-PepI, Mo-CBP3-PepII, and Mo-CBP3-PepIII are synthetic antimicrobial peptides active against human pathogens by stimulating ROS generation and increasing plasma membrane permeability
    Biochimie (IF 3.188) Pub Date : 2018-10-31
    Jose T.A. Oliveira, Pedro F.N. Souza, Ilka M. Vasconcelos, Lucas P. Dias, Thiago F. Martins, Mauricio F. Van Tilburg, Maria I.F. Guedes, Daniele O.B. Sousa
    更新日期:2018-11-02
  • Cytotoxic action of acetate on tumor cells of thymic origin: Role of MCT-1, pH homeostasis and altered cell survival regulation
    Biochimie (IF 3.188) Pub Date : 2018-11-01
    Shrish Kumar Pandey, Saveg Yadav, Yugal Goel, Sukh Mahendra Singh

    Neoplastic cells display altered biosynthetic and bioenergetic machinery to support cell survival. Therefore, cancer cells optimally utilize all available fuel resources to pump their highly upregulated metabolic pathways. While glucose is the main carbon source, transformed cells also utilize other molecules, which can be utilized in metabolic pathways, designated as alternative fuels. Acetate is one of such alternative metabolic fuels, which is mainly consumed in carbohydrate and lipid metabolism. However, studies demonstrate the contradictory effects of acetate on tumor cell survival. Moreover, the mechanisms of its antitumor actions remain poorly understood. Further, the spectrum of acetate susceptible tumor targets needs to be characterized in order to optimize the use of acetate in maneuvering tumor progression as a therapeutic strategy. As the effect of acetate on survival properties of the tumor cells of thymic origin is not worked out, in the present study the effect of acetate was investigated against tumor cells derived from a murine thymoma designated as Dalton’s Lymphoma (DL). Acetate treatment of tumor cells inhibited tumor cell survival accompanied by induction of apoptotic cell death, associated with modulated expression of cell survival regulatory HIF1α, ROS, p53, Caspase 3, Bax and HSP70 along with the elevated level of cytosolic cytochrome c. Acetate treatment also modulated the expression of pH regulators MCT-1 and V-ATPase accompanied by altered pH homeostasis. Expression of MDR and lipid metabolism regulatory molecules was also inhibited in tumor cells upon acetate exposure. Further, pre-exposure of tumor cells to α-CHC (α-cyano-4-hydroxycinnamate), an inhibitor of MCT-1, partially abrogated the cytotoxic action of acetate. These findings shed a new light regarding the effect and mechanisms of the exogenous acetate on the biology of tumor cells of thymic origin.

    更新日期:2018-11-02
  • Silencing of LncRNA Steroid Receptor RNA Activator attenuates polycystic ovary syndrome in Mice
    Biochimie (IF 3.188) Pub Date : 2018-11-01
    Yan Li, Wanqiu Zhao, Haixu Wang, Chen Chen, Dongmei Zhou, Shengnan Li, Xiaohong Zhang, Haibo Zhao, Dangxia Zhou, Biliang Chen

    Background Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women of reproductive age and has a prevalence of 1 in 15 women worldwide. This study aims to investigate the role of lncRNA SRA in the pathological processes of polycystic ovary syndrome (PCOS). Methods Twenty five-day old female C57BL/6 mice received subcutaneous injection of 60 mg/kg dehydroepiandrosterone for 20 days to induce PCOS. Lentivirus containing lncRNA SRA-specific shRNA was subcapsularly injected into the ovaries of PCOS mice. Granulosa cell was primary cultured to explore the mechanism of DHEA-induced inflammatory responses. H&E staining was used to examine the histological changes of ovaries. ELISA was used to assess serum insulin level and proinflammatory cytokines and angiogenetic factors contents in ovary tissue. The expression levels of LncRNA SRA and proteins involved in the NF-κB signaling pathway were detected through Quantitative real-time PCR and Western blot. The nuclear translocation of NF-κB was observed by immunofluorescence and the activity of NF-κB-DNA binding was detected using EMSA. Results Silencing of lncRNA SRA changed insulin release, attenuated ovary injury and reduced the production of angiogenetic factors in the PCOS mice. In addition, shRNA targeting lncRNA SRA inhibited DHEA-induced pro-inflammatory cytokines production and NF-κB nuclear translocation in the ovary of PCOS mice and primary granulosa cells. Conclusion Silencing of lncRNA Steroid Receptor RNA Activator (SRA) attenuates polycystic ovary syndrome (PCOS) in mice. LncRNA SRA plays important roles in the development of PCOS.

    更新日期:2018-11-02
  • Autoantibody against arrestin-1 as a potential biomarker of renal cell carcinoma
    Biochimie (IF 3.188) Pub Date : 2018-10-30
    Alexey V. Baldin, Alena N. Grishina, Dmitry O. Korolev, Ekaterina B. Kuznetsova, Marina O. Golovastova, Alexey S. Kalpinskiy, Boris Y. Alekseev, Andrey D. Kaprin, Dmitry V. Zinchenko, Lyudmila V. Savvateeva, Vladimir A. Varshavsky, Evgeni Yu Zernii, Andrey Z. Vinarov, Alexandr V. Bazhin, Pavel P. Philippov, Andrey A. Zamyatnin

    Renal cell carcinoma (RCC) is the second-most common uronephrological cancer. In the absence of specific symptoms, early diagnosis of RCC is challenging. Monitoring of the aberrant expression of tumour-associated antigens (TAAs) and related autoantibody response is considered as a novel approach of RCC diagnostics. The aim of this study was to examine the aberrant expression of arrestin-1 in renal tumours, to investigate the possible epigenetic mechanism underlying arrestin-1 expression, and to assess the frequency of anti-arrestin-1 autoantibody response. Immunohistochemistry was used to assess the presence of arrestin-1 in primary tumours and metastases of 39 patients with RCC and renal oncocytoma. Bisulfite sequencing was employed to analyse the methylation status of the promoter of the SAG gene encoding arrestin-1. Western blot analysis was performed to detect autoantibodies against arrestin-1 in serum samples of 36 RCC and oncocytoma patients. Arrestin-1 was found to be expressed in RCC (58.7% of cases) and renal oncocytoma (90% of cases) cells, while being absent in healthy kidney. The expression of arrestin-1 in RCC metastases was more prominent than in primary tumours. Hypomethylation of the SAG gene promoter is unlikely to be the mechanism for the aberrant expression of arrestin-1. Autoantibodies against arrestin-1 were detected in sera of 75% of RCC patients. Taken together, our findings suggest employment of autoantibody against arrestin-1 as biomarker of RCC.

    更新日期:2018-10-31
  • Thermal Denaturation Profile: A Straightforward Signature to Characterize Parallel G-quadruplexes
    Biochimie (IF 3.188) Pub Date : 2018-10-31
    Yingying Zhang, Jielin Chen, Huangxian Ju, Jun Zhou
    更新日期:2018-10-31
  • Subatomic structure of hyper-sweet thaumatin D21N mutant reveals the importance of flexible conformations for enhanced sweetness
    Biochimie (IF 3.188) Pub Date : 2018-10-31
    Tetsuya Masuda, Kyohei Okubo, Kazuki Murata, Bunzo Mikami, Michihiro Sugahara, Mamoru Suzuki, Piero Andrea Temussi, Fumito Tani
    更新日期:2018-10-31
  • 3D structure of the natural tetrameric form of human butyrylcholinesterase as revealed by cryoEM, SAXS and MD
    Biochimie (IF 3.188) Pub Date : 2018-10-29
    Konstantin M. Boyko, Timur N. Baymukhametov, Yury M. Chesnokov, Michael Hons, Sofya V. Lushchekina, Petr V. Konarev, Alexey V. Lipkin, Alexandre L. Vasiliev, Patrick Masson, Vladimir O. Popov, Michail V. Kovalchuk
    更新日期:2018-10-30
  • The 5-HT1A receptor: signaling to behavior
    Biochimie (IF 3.188) Pub Date : 2018-10-25
    Paul R. Albert, Faranak Vahid-Ansari
    更新日期:2018-10-26
  • Secretome proteins regulate comparative osteogenic and adipogenic potential in bone marrow and dental stem cells
    Biochimie (IF 3.188) Pub Date : 2018-10-24
    Ajay Kumar, Vinod Kumar, Vidya Rattan, Vivekananda Jha, Shalmoli Bhattacharyya
    更新日期:2018-10-25
  • Bacterial ribosome heterogeneity: Changes in ribosomal protein composition during transition into stationary growth phase
    Biochimie (IF 3.188) Pub Date : 2018-10-23
    Silva Lilleorg, Kaspar Reier, Arto Pulk, Aivar Liiv, Triin Tammsalu, Lauri Peil, Jamie.H.D. Cate, Jaanus Remme
    更新日期:2018-10-23
  • Epigenetics in the early divergent eukaryotic Giardia duodenalis: an update
    Biochimie (IF 3.188) Pub Date : 2018-10-19
    Francisco Alejandro Lagunas-Rangel, Rosa María Bermúdez-Cruz

    Giardia duodenalis is a flagellated unicellular eukaryotic microorganism that usually parasitizes the small intestine of humans and many other vertebrates causing diarrheal disease throughout the world. Notably, Giardia despite minimization of most cellular systems shows different strategies to adapt to environmental conditions, evade the immune system and resist exposure to antimicrobial agents. Over the past years, epigenetic regulation of gene expression has been shown to have a relevant role in the parasite’s biology. Interestingly, analysis of the Giardia genome revealed the presence of enzymes responsible for post-translational modification in histones, therefore suggesting that epigenetic mechanisms may regulate gene expression in this parasite. Thus, the purpose of this review is to summarize how epigenetic mechanisms play relevant roles in the pathogenicity of Giardia, with a particular emphasis on the molecular mechanisms associated with parasite differentiation, antigenic variation and antimicrobial resistance.

    更新日期:2018-10-22
  • High altitude mediated skeletal muscle atrophy: Protective role of curcumin
    Biochimie (IF 3.188) Pub Date : 2018-10-19
    Pooja Chaudhary, Yogendra Kumar Sharma, Shivani Sharma, Som Nath Singh, Geetha Suryakumar

    Chronic hypobaric hypoxia induced muscle atrophy results in decreased physical performance at high altitude. Curcumin has been shown to have muscle sparing effects under cachectic conditions. However, the protective effects of curcumin under chronic hypobaric hypoxia have not been studied till now. Therefore, the present study aims at evaluating the effects of curcumin administration on muscle atrophy under chronic hypobaric hypoxia. Male Sprague Dawley rats were divided into four groups: Control (C)-normoxia exposed, Control Treated (CT)-normoxia exposed and administered with curcumin at a dose of 100 mg/kg body weight for 14 days, Hypoxia (H)-exposed to hypobaric hypoxia for 14 days and Hypoxia Treated (HT)-exposed to hypobaric hypoxia and administered with curcumin for 14 days. Oxidative stress, muscle protein degradation, proteolytic pathways, myosin heavy chain (MHC), CPK activity and muscle histology were performed in gastrocnemius muscle samples of the exposed rats. In addition, fatigue time on treadmill running was also evaluated to observe the effects of curcumin administration on physical performance of the rats. As previously shown, hypobaric hypoxia increased muscle protein degradation via upregulated calpain and ubiquitin-proteolytic pathways. An enhanced oxidative stress has been linked to upregulation of these pathways under hypoxic conditions. Curcumin administration resulted in reduced oxidative stress as well as reduced activity of the proteolytic pathways in HT group as compared to H group thereby resulting in reduced muscle protein degradation under hypobaric hypoxia. Histology of rat muscle revealed an increased number of muscle fibres in HT as compared to H group. Thus, increased number of muscle fibres and decreased muscle proteolysis following curcumin administration, lead to enhanced muscle mass under hypobaric hypoxia resulting in improved physical performance of the rats.

    更新日期:2018-10-22
  • LncRNA ANRIL promotes NLRP3 inflammasome activation in uric acid nephropathy through miR-122-5p/BRCC3 axis
    Biochimie (IF 3.188) Pub Date : 2018-10-19
    Jiacai Hu, Hao Wu, Daochun Wang, Zhijie Yang, Junjun Dong

    This study is designed to explore the mechanism by which long non-coding RNA (lncRNA) antisense non-coding RNA in the INK4 locus (ANRIL) plays a pathogenic role in uric acid nephropathy (UAN). The expressions of ANRIL, miR-122-5p, BRCA1-BRCA2-containing complex subunit 3 (BRCC3) and NOD-like receptor protein 3 (NLRP3) were determined in UAN patients and uric acid-treated HK-2 cells by qRT-PCR. Protein levels of BRCC3 and NLRP3 were examined by western blot. The levels of inflammatory cytokines were quantified by ELISA. CCK-8 assay was used to assess cell viability. Apoptosis was detected by Annexin V-FITC/PI double-labeled flow cytometry and TUNEL assay. The interaction between ANRIL, miR-122-5p and BRCC3 were studied using luciferase reporter assay. The role of ANRIL in renal injury was evaluated in experimental rats. ANRIL and BRCC3 were highly expressed while miR-122-5p was down-regulated in serum of UAN patients and uric acid-treated tubular epithelial cells. Luciferase reporter assay and in vitro rescue experiment confirmed that ANRIL promoted NLRP3 inflammasome activation by up-regulating BRCC3 expression via sponging miR-122-5p. Furthermore, in vivo experiment validated that knockdown of ANRIL alleviated renal injury of UAN rats. ANRIL exerted pathogenic effect in UAN to promote NLRP3 inflammasome activation via miR-122-5p/BRCC3 axis.

    更新日期:2018-10-22
  • Neuroprotective effects of Tat-ATOX1 protein against MPP+-induced SH-SY5Y cell deaths and in MPTP-induced mouse model of Parkinson’s disease
    Biochimie (IF 3.188) Pub Date : 2018-10-21
    Won Sik Eum, Min Jea Shin, Chi Hern Lee, Hyeon Ji Yeo, Eun Ji Yeo, Yeon Joo Choi, Hyun Jung Kwon, Duk-Soo Kim, Oh Shin Kwon, Keun Wook Lee, Kyu Hyung Han, Jinseu Park, Dae Won Kim, Soo Young Choi

    Parkinson’s disease (PD), a neurodegenerative disorder, is characterized by a loss of dopaminergic neurons in the substantia nigra (SN) of the brain and it is well known that the pathogenesis of PD is related to a number of risk factors including oxidative stress. Antioxidant 1 (ATOX1) protein plays a crucial role in various diseases as an antioxidant and chaperone. In this study, we determined whether Tat-ATOX1 could protect against 1-methyl-4-phenylpyridinium ion (MPP+)-induced SH-SY5Y cell death and in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced animal model of PD. In the MPP+ exposed SH-SY5Y cells, Tat-ATOX1 markedly inhibited cell death and toxicities. In addition, Tat-ATOX1 markedly suppressed the activation of Akt and mitogen activated protein kinases (MAPKs) as well as cleavage of caspase-3 and Bax expression levels. In a MPTP-induced animal model, Tat-ATOX1 transduced into brain and protected dopaminergic neuronal cell loss. Taken together, Tat-ATOX1 inhibits dopaminergic neuronal death through the suppression of MAPKs and apoptotic signal pathways. Thus, Tat-ATOX1 represents a potential therapeutic protein drug candidate for PD.

    更新日期:2018-10-22
  • Ferrochelatase activity of plant frataxin
    Biochimie (IF 3.188) Pub Date : 2018-10-18
    Alejandro M. Armas, Manuel Balparda, Agustina Terenzi, Maria V. Busi, Maria A. Pagani, Diego F. Gomez-Casati

    Frataxin plays a key role in cellular iron homeostasis of different organisms. It is engaged in several activities at the Fe-S cluster assembly machinery and it is also involved in heme biosynthesis. In plants, two genes encoding ferrochelatases (FC1 and FC2) catalyze the incorporation of iron into protoporphyrin IX in the last stage of heme synthesis in chloroplasts. Despite ferrochelatases are absent from other cell compartments, a remaining ferrochelatase activity has been observed in plant mitochondria. Here we analyze the possibility that frataxin acts as the iron donor to protoporphyrin IX for the synthesis of heme groups in plant mitochondria. Our findings show that frataxin catalyzes the formation of heme in vitro when it is incubated with iron and protoporphyrin IX. When frataxin is combined with AtNFS1 and AtISD11 the ferrochelatse activity is increased. These results suggest that frataxin could be the iron donor in the final step of heme synthesis in plant mitochondria, and constitutes an important advance in the elucidation of the mechanisms of heme synthesis in plants.

    更新日期:2018-10-19
  • Influence of Passage Number on the Impact of the Secretome of Adipose Tissue Stem Cells on Neural Survival, Neurodifferentiation and Axonal Growth
    Biochimie (IF 3.188) Pub Date : 2018-10-17
    Sofia C. Serra, João C. Costa, Rita C. Assunção-Silva, Fábio G. Teixeira, Nuno A. Silva, Sandro I. Anjo, Bruno Manadas, Jeffrey Gimble, Leo A. Behie, António J. Salgado

    Mesenchymal stem cells (MSCs), and within them adipose tissue derived stem cells (ASCs), have been shown to have therapeutic effects on central nervous system (CNS) cell populations. Such effects have been mostly attributed to soluble factors, as well as vesicles, present in their secretome. Yet, little is known about the impact that MSC passaging might have in the secretion therapeutic profile. Our aim was to show how human ASCs (hASCs) passage number influences the effect of their secretome in neuronal survival, differentiation and axonal growth. For this purpose, post-natal rat hippocampal primary cultures, human neural progenitor cell (hNPCs) cultures and dorsal root ganglia (DRGs) explants were incubated with secretome, collected as conditioned media (CMs), obtained from hASCs in P3, P6, P9 and P12. Results showed no differences when comparing percentages of MAP-2 positive cells (a mature neuronal marker) in neuronal cultures or of hNPCs that differentiated, after incubation with hASCs secretome from different passages. The same was observed regarding DRG neurite outgrowth. In order to characterize the secretomes obtained from different passages, a proteomic analysis was performed, revealing that its composition did not vary significantly with passage number P3 to P12. Results allowed us to identify several key proteins, such as pigment epithelium derived factor (PEDF), DJ-1, interleucin-6 (IL-6) and galectin, all of which have already proven to play neuroprotective and neurodifferentiating roles. Proteins that promote neurite outgrowth were also found present, such as semaphorin 7A and glypican-1. We conclude that cellular passaging does not influence significantly hASC’s secretome properties especially their ability to support post-natal neuronal survival, induce neurodifferentiation and promote axonal growth.

    更新日期:2018-10-18
  • Self-association and folding in membrane determine the mode of action of peptides from the lytic segment of sticholysins
    Biochimie (IF 3.188) Pub Date : 2018-10-13
    Uris Ros, Gustavo P.B. Carretero, Joana Paulino, Edson Crusca, Fabiola Pazos, Eduardo M. Cilli, Maria E. Lanio, Shirley Schreier, Carlos Alvarez
    更新日期:2018-10-14
  • Stabilization of miRNAs in esophageal cancer contributes to radioresistance and limits efficacy of therapy
    Biochimie (IF 3.188) Pub Date : 2018-10-13
    Akshay Malhotra, Uttam Sharma, Shyamly Puhan, Naga Chandra Bandari, Anjali Kharab, P.P Arifa, Lovlesh Thakur, Hridayesh Prakash, Karen M. Vasquez, Aklank Jain

    The five-year survival rate of esophageal cancer patients is less than 20%. This may be due to increased resistance (acquired or intrinsic) of tumor cells to chemo/radiotherapies, often caused by aberrant cell cycle, deregulated apoptosis, increases in growth factor signaling pathways, and/or changes in the proteome network. In addition, deregulation in non-coding RNA-mediated signaling pathways may contribute to resistance to therapies. At the molecular level, these resistance factors have now been linked to various microRNA (miRNAs), which have recently been shown to control cell development, differentiation and neoplasia. The increased stability and dysregulated expression of miRNAs have been associated with increased resistance to various therapies in several cancers, including esophageal cancer. Therefore, miRNAs represent the next generation of molecules with tremendous potential as biomarkers and therapeutic targets. Yet, a detailed studies on miRNA-based therapeutic intervention is still in its infancy. Hence, in this review, we have summarized the current status of microRNAs in dictating the resistance/sensitivity of tumor cells against chemotherapy and radiotherapy. In addition, we have discussed various strategies to increase radiosensitivity, including targeted therapy, and the use of miRNAs as radiosensitive/radioresistance biomarkers for esophageal cancer in the clinical setting.

    更新日期:2018-10-14
  • Activation of catalase via co-administration of aspirin and pioglitazone: Experimental and MLSD simulation approaches
    Biochimie (IF 3.188) Pub Date : 2018-10-14
    Yunes Panahi, Reza Yekta, Gholamreza Dehghan, Samaneh Rashtbari, Nematollah Jonaidi Jafari, Ali A. Moosavi-Movahedi

    Aspirin (ASP) and pioglitazone (PGL) are the most common drugs that are widely used by diabetic patients to control the blood sugar and hinder cardiovascular diseases. The interaction between PGL and ASP is one of the important medical issues to clarify the safety of co-administration of these drugs. In the present study, the effect of co-administered ASP with PGL was investigated on the structure and catalytic function of catalase as a potential target in the liver. Based on our data, co-administration of ASP-PGL significantly enhanced the catalase activity in comparison with PGL alone. However, ASP does not have any effects on the catalytic function of catalase. Moreover, the dialysis measurement and CD spectroscopy study revealed that binding of ASP to catalase could increase the stability of catalase-PGL complex. Based on the obtained data, it is shown that the binding of ASP to catalase led to increase the affinity of catalase to PGL. Binding analysis showed that the association constant of catalase-PGL was reduced considerably in the presence of ASP from 12.19 ±0. 1×106 M-1 to 6.4 ±0. 2×106 M-1 at 298K. Multiple ligands simultaneous docking (MLSD) also confirmed an increase in the binding affinity of PGL to catalase.

    更新日期:2018-10-14
  • Fragmentation of Escherichia coli mRNA by MazF and MqsR
    Biochimie (IF 3.188) Pub Date : 2018-10-10
    Toomas Mets, Sergo Kasvandik, Merilin Saarma, Ülo Maiväli, Tanel Tenson, Niilo Kaldalu

    MazEF and MqsRA are toxin-antitoxin systems, where the toxins MazF and MqsR sequence-specifically cleave single-stranded RNA, thereby shutting down protein synthesis and cell growth. However, it has been proposed that MazF functions in a highly specific pathway, where it truncates the 5’ ends of a set of E. coli transcripts (the MazF regulon), which are then translated under stress conditions by specialized ribosomes. We mapped the cleavage sites of MazF and MqsR throughout the E. coli transcriptome. Our results show that both toxins cleave mRNA independently of the recognition site position and MazF freely cleaves transcripts of the proposed MazF regulon within coding sequences. Proteome analysis indicated that MazF expression leads to overall inhibition of protein synthesis and the putative MazF regulon proteins are not selectively synthesized in response to the toxin. Our results support a simpler role for endoribonuclease TA systems as indifferent destroyers of unstructured RNA.

    更新日期:2018-10-11
  • Lysines residing in putative small ubiquitin-like modifier (SUMO) motifs regulate fate and function of 37 KDa Laminin Receptor
    Biochimie (IF 3.188) Pub Date : 2018-10-10
    Charles Samuel Umbaugh, Marxa L. Figueiredo

    There is a putative precursor to a mature receptor relationship between 37 Laminin Receptor (LR) and 67 LR. As such, the pair are frequently referred to as a single entity, the 37/67 kDa Laminin Receptor (37/67 LR) and 67 LR was identified as a laminin binding entity. 37/67 LR has been of clinical interest for many years, as 37/67 LR is a prognostic indicator for many cancers including breast, lung, colon, and prostate. However, the genesis of 67LR is controversial, and confounded by its stability under SDS-PAGE conditions, a lack of splice variants, and the existence of post-translational modifications that cannot account for the mass discrepancy between 37 and 67 LR. In the present work, we mutated potential SUMO motif sites (Lysine residues) in 37 LR and generated a series of 37 LR-expressing plasmids with a C-terminal histidine tag. We report an inability to detect 67 LR formation, suggesting that SUMOylation does not appear to directly occur at the lysine residues proposed. However, the work revealed that these lysine mutations still appear to be important and can impact the fate and function for 37 LR, for example impairing half-life and steady state pre-mRNA levels. These results suggest that the Lys residues within putative SUMO motifs in 37 LR may indirectly coordinate with SUMO pathways.

    更新日期:2018-10-10
  • α-Lipoic acid and Amlodipine/Perindopril combination potentiate the therapeutic effect of mesenchymal stem cells on Isoproterenol induced cardiac injury in rats
    Biochimie (IF 3.188) Pub Date : 2018-10-08
    Abeer I. Abd El-Fattah, M.S. Zaghloul, N.A. Eltablawy, L.A. Rashed

    Cardiac injury is a dangerous disease and become a greater issue in the forthcoming decades. The ultimate goal is to prevent the progression of heart failure and apoptotic processes. Cardiac tissue may regenerate itself but to certain extent depending on the number of resident stem cells that is limited. Thus, research had been focused on bone marrow derived stem cells (BM-MSCs) as a promising therapy in different types of tissues, including the heart. This study is designed not only to assess the therapeutic effect of BM-MSCs but also to improve their therapeutic effect in combination with antioxidant α-lipoic acid (ALA) and antihypertensive therapeutic drug form (AP) against isoproterenol-induced cardiac injury and compared with that of BM-MSCs alone. Cardiac injury was induced in 70 male rats by Isoproterenol (ISO was injected s.c. for four consecutive days). Experimental animals were divided into six ISO-treated groups beside a control non treated one. The six ISO-treated groups were divided into: ISO group, ISO+BM-MSCs group, ISO+ALA group, ISO+AP group, ISO+ALA+AP group and ISO+ALA+AP+BM-MSCs group, the last five groups were treated with the examined materials after one week of ISO injection. Isoproterenol significantly increased serum CK-MB, LDH activities, Troponin1 and TNF-α. Oxidative stress is evidenced by the increased MDA, NO and Caspase-3 activity associated with significant reduction of GSH content and SOD activity in cardiac tissue. Furthermore, mRNA expression of NFκB and iNOS were significantly up regulated and eNOS mRNA expression was down regulated. Administration of BM-MSCs, ALA and AP alone significantly mitigated the induced cardiac injury. Concomitant administration of ALA and AP after BM-MSCs induced a more pronounced improving effect on cardiac functions. In conclusion, the concomitant administration of ALA and AP after BM-MSCs infusion increases the cellular antioxidant levels of cardiac tissue that improves the repairing function of BM-MSCs.

    更新日期:2018-10-08
  • MiR-650 regulates the proliferation, migration and invasion of human oral cancer by targeting Growth factor independent 1 (Gfi1)
    Biochimie (IF 3.188) Pub Date : 2018-10-06
    Sun Ningning, Sun Libo, Wu Chuanbin, Sun Haijiang, Zhou Qing

    Oral cancer being one of the lethal cancers is generally detected at advanced stages and causes significant mortality world over. The unavailability of the reliable biomarkers and therapeutic targets/agents forms a bottleneck in the treatment of oral cancer. MicroRNAs are considered of immense therapeutic potential for the treatment of cancer. Consistently, in this study the role and therapeutic potential of miR-650 was explored in oral cancer. The analysis of miR-650 expression by qRT-PCR revealed significant (p < 0.05) upregulation of miR-650 in oral cancer cell lines. Cell cycle analysis by flow cytometery revealed that suppression of miR-650 significantly (p < 0.05) inhibits the proliferation of the SCC-25 cells by prompting Sub-G1 cell cycle arrest. Further, miR-650 suppression also inhibited the migration and invasion of the SCC-25 oral cancer cells as revealed by transwell assays. TargetScan analysis showed that miR-650 targets Growth factor independent 1 (Gfi1). Moreover, the results of western blot analysis showed that miR-650 suppression inhibits the expression of Gfi1. Interestingly, suppression of Gfi1 exhibited similar effects on cell proliferation, migration and invasion of the oral cancer cells as that of miR-650 suppression. Nonetheless, miR-650 promoted the proliferation, migration and invasion of the SCC-25 cells by upregulating the expression of Gfi1. Moreover, overexpression of miR-650 could not rescue the effects of Gfi1 silencing on SCC-25 oral cancer cells. Conversely, overexpression of Gfi1 could rescue the effects of miR-650 inhibition on SCC-25 cell proliferation, migration and invasion. Additionally, miR-650 suppression could also inhibit the xenografted tumor growth in vivo by inhibiting the expression of Gfi1. Taken together, miR-650 may prove to be an important therapeutic target for the management of oral cancers.

    更新日期:2018-10-06
  • Chronic whole-body heat treatment relieves atherosclerotic lesions, cardiovascular and metabolic abnormalities, and enhances survival time restoring the anti-inflammatory and anti-senescent heat shock response in mice
    Biochimie (IF 3.188) Pub Date : 2018-09-28
    Maciel Alencar Bruxel, Angela Maria Vicente Tavares, Luiz Domingues Zavarize Neto, Victor de Souza Borges, Helena Trevisan Schroeder, Patricia Martins Bock, Maria Inês Lavina Rodrigues, Adriane Belló-Klein, Paulo Ivo Homem de Bittencourt
    更新日期:2018-09-29
  • Pro-inflammatory effects of extracellular Hsp70 and cigarette smoke in primary airway epithelial cells from COPD patients
    Biochimie (IF 3.188) Pub Date : 2018-09-27
    Andrea Hulina-Tomašković, Irene H. Heijink, Marnix R. Jonker, Anita Somborac-Bačura, Marija Grdić Rajković, Lada Rumora

    Extracellular Hsp70 (eHsp70) can activate immune cells via Toll-like receptors (TLR) 2 and 4, and induce cytokine synthesis. The aim of this study was to explore inflammation-associated effects of eHsp70 alone and in combination with cigarette smoke extract (CSE) in primary bronchial epithelial cells. We assessed IL-6 and IL-8 concentrations, TLR2, TLR4 and Hsp70 mRNA expressions, and mitogen-activated protein kinases (MAPKs) activation induced by recombinant human (rh) Hsp70, CSE or their combinations in normal human bronchial epithelial cells (NHBE) obtained commercially, and primary bronchial epithelial cells isolated from non-COPD lung donors (PBEC) or COPD patients (PBEC COPD). Baseline levels of IL-6 and IL-8 were significantly higher in PBEC COPD than in non-COPD PBECs. Upon rhHsp70 stimulation, IL-6 and IL-8 were significantly increased, with the strongest response in COPD-derived PBECs. CSE alone elevated cytokine secretion in all examined cells. rhHsp70 and CSE had antagonistic interactions on IL-8 release in PBECs from COPD patients, while the addition of rhHsp70 further increased CSE-induced IL-6 secretion in NHBE cells. rhHsp70 and CSE alone decreased TLR2 and TLR4 mRNA expression in COPD-derived PBECs. In non-COPD PBECs, combined treatments decreased only TLR2 mRNA expression. Hsp70 mRNA expression, as indicator of intracellular Hsp70, which may have anti-inflammatory effects, was reduced in COPD-derived cells upon exposure to CSE and rhHsp70 alone, but not with their combinations. Contrary to this, in PBECs from lung donors only combined treatments supressed Hsp70 gene expression. CSE activated JNK and p38 MAPKs, while rhHsp70 increased activation of c-Jun kinase in NHBE cells. Collectively, both eHsp70 and CSE induce pro-inflammatory responses in PBECs from non-COPD as well as COPD donors, but in combination antagonistic effects were observed in COPD-derived cells. These effects may be related to the regulation of TLR2/4 and might lead to modulation of inflammation with possible deleterious consequences for COPD patients.

    更新日期:2018-09-27
  • Nucleic acid aptamers in diagnosis of colorectal cancer
    Biochimie (IF 3.188) Pub Date : 2018-09-19
    Yaghoub Ahmadyousefi, Sara Malih, Younes Mirzaee, Massoud Saidijam
    更新日期:2018-09-20
  • Thermodynamics of the fourU RNA thermal switch derived from molecular dynamics simulations and spectroscopic techniques
    Biochimie (IF 3.188) Pub Date : 2018-09-19
    Filip Leonarski, Maciej Jasiński, Joanna Trylska
    更新日期:2018-09-20
  • Insulinotropic activity of the host-defense peptide frenatin 2D: conformational, structure-function and mechanistic studies
    Biochimie (IF 3.188) Pub Date : 2018-09-19
    Vishal Musale, Laure Guilhaudis, Yasser H.A. Abdel-Wahab, Peter R. Flatt, J. Michael Conlon

    Of four naturally occurring frenatin peptides tested, frenatin 2D (DLLGTLGNLPLPFI.NH2) from Discoglossus sardus was the most potent and effective in producing concentration-dependent stimulation of insulin release from BRIN-BD11 rat clonal β-cells without displaying cytotoxicity. The peptide also stimulated insulin release from 1.1B4 human-derived clonal β-cells and isolated mouse islets and improved glucose tolerance concomitant with increased circulating insulin concentrations in mice following intraperitoneal administration. The insulinotropic activity of frenatin 2D was not associated with membrane depolarization or an increase in intracellular [Ca2+] but incubation of the peptide (1μM) with BRIN-BD11 cells produced a modest, but significant (P < 0.05), increase in cAMP production. Stimulation of insulin release was abolished in protein kinase A-downregulated cells but maintained in protein kinase C-downregulated cells. Circular dichroism studies showed that, in the presence of dodecylphosphocholine micelles, frenatin 2D exhibited a helical content of 35% and a turn content of 28%. Substitution of the Thr5, Asn8, Pro10, and Ile14 residues in frenatin-2D by Trp and interchange of Pro12 and Phe13 led to loss of insulinotropic activity but the [D1W] and [G7W] analogues were as potent and effective as the native peptide. Frenatin 2D (1μM) also stimulated proliferation of BRIN-BD11 cells and provided significant protection of the cells against cytokine-induced apoptosis. It is concluded that the insulinotropic activity of frenatin 2D is mediated predominantly, if not exclusively, by the KATP channel-independent pathway.

    更新日期:2018-09-20
  • ARL3 subcellular localization and its suspected role in autophagy
    Biochimie (IF 3.188) Pub Date : 2018-09-15
    Guanghong Luo, Yangyang Sun, Ruili Feng, Qinping Zhao TieqiaoWen

    ADP-ribosylation factor-like3 (ARL3) is a member of the ADP-ribosylation factor family of GTP-binding proteins that plays important role in regulating Ciliary trafficking. It ubiquitously expressed in normal tissues and tumor cell lines. However, the location and function of ARL3 in organelles are rarely known. In this study, we explored ARL3 subcellular localization in an all-round way in HEK293T, Neuro-2A and U251 cells by density gradient centrifugation and immunofluorescence. The results showed that ARL3 is expressed in most of organelles, and an iodixonal step gradient was further confirmed that ARL3 is mainly localized to the mitochondria, endosomes, lysosomes, and proteasome. By molecular functional analysis, we observed that ARL3 promotes the aggregation of GFP-LC3, up-regulation of LC3-II/LC3-I and down-regulation of SQSMT1/BECN1, and knocking down of ARL3 inbibits autophagy, which suggested that ARL3 is necessary for autophagy. this study presents a comprehensive evaluation of the subcellular localization for ARL3 and provides important on understanding the functions of ARL3.

    更新日期:2018-09-17
  • Elucidating paramylon and other carbohydrate metabolism in Euglena gracilis: Kinetic characterization, structure and cellular localization of UDP-glucose pyrophosphorylase
    Biochimie (IF 3.188) Pub Date : 2018-09-15
    Robertino J. Muchut, Rodrigo D. Calloni, Fernando E. Herrera, Sergio A. Garay, Diego G. Arias, Alberto A. Iglesias, Sergio A. Guerrero

    Many oligo and polysaccharides (including paramylon) are critical in the Euglena gracilis life-cycle and they are synthesized by glycosyl transferases using UDP-glucose as a substrate. Herein, we report the molecular cloning of a gene putatively coding for a UDP-glucose pyrophosphorylase (EgrUDP-GlcPPase) in E. gracilis. After heterologous expression of the gene in Escherichia coli, the recombinant enzyme was characterized structural and functionally. Highly purified EgrUDP-GlcPPase exhibited a monomeric structure, able to catalyze synthesis of UDP-glucose with a Vmax of 3,350 U.mg-1. Glucose-1P and UTP were the preferred substrates, although the enzyme also used (with lower catalytic efficiency) TTP, galactose-1P and mannose-1P. Oxidation by hydrogen peroxide inactivated the enzyme, an effect reversed by reduction with dithiothreitol or thioredoxin. The redox process would involve sulfenic acid formation, since no pair of the 7 cysteine residues is close enough in the 3D structure of the protein to form a disulfide bridge. Electrophoresis studies suggest that, after oxidation, the enzyme arranges in many enzymatically inactive structural conformations; which were also detected in vivo. Finally, confocal fluorescence microscopy provided evidence for a cytosolic (mainly in the flagellum) localization of the enzyme.

    更新日期:2018-09-15
  • Paeonol attenuates ligation-induced periodontitis in rats by inhibiting osteoclastogenesis via regulating Nrf2/NF-κB/NFATc1 signaling pathway
    Biochimie (IF 3.188) Pub Date : 2018-09-10
    Ji Li, Yanping Li, Shuang Pan, Lin Zhang, Lina He, Yumei Niu

    Paeonol is a natural phenolic compound in Moutan Cortex with multiple biological functions, such as anti-inflammatory and anti-oxidant activity. Recent evidence has proven that persistent inflammation, oxidative stress, along with nuclear factor E2-related factor 2 (Nrf2) signaling dysfunction in periodontium are the possible causes of alveolar bone resorption, and ultimately lead to periodontitis. The present study was designed to explore the protective effects of paeonol on ligation-induced periodontitis in rats, and investigate the possible mechanism. We found that treatment with paeonol (40, 80 mg/kg, intraperitoneal injection) for 7 days remarkably decreased the expression of receptor activator of nuclear factor kappa-B ligand increased the expression of osteoprotegrin and inhibited the formation of osteoclasts. This function of paeonol might be correlated with its ability to reduce inflammatory factors (IL-1β, IL-6 and TNF-α) and alleviate oxidative stress (SOD, MDA, GSH and ROS) in gingival tissues. Besides, paeonol increased Nrf2 activity. Silence of Nrf2 using specific siRNA diminished the inhibitory effect of paeonol on NF-κB p65 activation and aftedexpression, suggesting that Nrf2 was essential for protective effect of paeonol. These results showed that paeonol protected against periodontitis-aggravated osteoclastogenesis and alveolar bone lesion via regulating Nrf2/NF-κB/NFATc1 signaling pathway.

    更新日期:2018-09-11
  • 1-Naphthyl acetate: a chromogenic substrate for the detection of erythrocyte acetylcholinesterase activity
    Biochimie (IF 3.188) Pub Date : 2018-09-07
    Sheemona Chowdhary, Rajasri Bhattacharyya, Dibyajyoti Banerjee

    Erythrocyte acetylcholinesterase (AChE) is a preferred biomarker for the detection of organophosphorus poisoning. Acetylthiocholine (ATCh) is the most popular substrate for the detection of AChE activity. However, oximolysis is a prominent feature with ATCh. In this context, we have searched alternative substrates for AChE using in silico tools for screening of a better substrate. The in silico approach was performed to understand the fitness and the Total Interaction Energy (TIE) of substrates for AChE. The alternative substrates for AChE were screened in terms of high Goldscore and favorable TIE in comparison to acetylcholine (ACh)-AChE complex and other relevant esterases. Among the screened substrates, 1-Naphthyl acetate (1-NA) exhibited the most favorable interaction with AChE in terms of highest TIE and corresponding high Goldscore. The Molecular Dynamic (MD) simulation of the 1-NA-AChE complex showed a stable complex formation over a period of 5 ns. The results obtained in the in silico studies were validated in vitro using pure erythrocyte AChE and hemolysate. We observed 1-NA to be a better alternative substrate for AChE than ATCh in terms of lower Km value. Its specificity appeared at least similar to ATCh. Therefore, we propose that 1-NA can be an attractive chromogenic substrate for the measurement of AChE activity, and it possess the potential to detect organophosphorus pesticide (OP) poisoning.

    更新日期:2018-09-09
  • Structure basis of the improved sweetness and thermostability of a unique double-sites single-chain sweet-tasting protein monellin (MNEI) mutant
    Biochimie (IF 3.188) Pub Date : 2018-09-06
    Meng Zhao, Xiangqun Xu, Bo Liu

    The sweet protein monellin has an intensely sweet potency but limited stability. We have identified a double-sites mutant (E2N/E23A) of the single-chain monellin (MNEI) with both improved sweetness (about 3-fold) and thermostability (10 °C). However, the structural basis of its superior properties remains elusive until now. Herein we report its crystal structure at a resolution 1.90 Å. Similar to the wild-type, E2N/E23A adopts a wedge-shaped structure consisting of a five-strand β-sheet partially “wrapped” around an α-helix. However, distinguishing parts were present in the loops region, including a remarkable conformation shift from β-strand to loop around residue R39. Molecular docking revealed the persistence of conserved protein-receptor interface and formation of new intermolecular ionic bonds in the E2N/E23A-receptor complex involving the taste-active residue R39 of the sweet protein, which could account for its significant improvement of sweetness. On the other hand, a rearrangement of intramolecular interaction network including the C-H … π bond between A23 and F89 that led to enhanced hydrophobicity in the protein core, could be correlated with its improved thermostability. Furthermore, two new sweeter mutants of MNEI were created. These findings highlight the critical roles of key sweetness determinant residue R39 and hydrophobicity at the protein core for the sweetness and thermostability of the protein, respectively, which thus provide a deeper insight for understanding the structure-function relationship of the sweet protein as well as guidance for rational design of this unique biomacromolecule.

    更新日期:2018-09-06
  • Identification of a novel member of 2H phosphoesterases, 2ʹ,5ʹ-oligoadenylate degrading ribonuclease from the oyster Crassostrea gigas
    Biochimie (IF 3.188) Pub Date : 2018-09-05
    Annika Lopp, Tõnu Reintamm, Anne Kuusksalu, Allan Olspert, Merike Kelve

    Several genes of IFN-mediated pathways in vertebrates, among them the genes that participate in the 2ʹ,5ʹ-oligoadenylate synthetase (OAS)/RNase L pathway, have been identified in C. gigas. In the present study, we identified genes, which encode proteins having 2ʹ,5ʹ-oligoadenylate degrading activity in C. gigas. These proteins belong to the 2H phosphoesterase superfamily and have sequence similarity to the mammalian A kinase anchoring protein 7 (AKAP7) central domain, which is responsible for the 2ʹ,5ʹ-phosphodiesterase (2ʹ,5ʹ-PDE) activity. Comparison of the genomic structures of C. gigas proteins with that of AKAP7 suggests that these enzymes originate from a direct common ancestor. However, the identified nucleases are not typical 2ʹ,5ʹ-PDEs. The found enzymes catalyse the degradation of 2ʹ,5ʹ-linked oligoadenylates in a metal-ion-independent way, yielding products with 2ʹ,3ʹ -cyclic phosphate and 5ʹ-OH termini similarly to the 3ʹ−5ʹ bond cleavage in RNA, catalyzed by metal-independent ribonucleases. 3ʹ,5ʹ-linked oligoadenylates are not substrates for them. The preferred substrates for the C. gigas enzymes are 5ʹ-triphosphorylated 2ʹ,5ʹ-oligoadenylates, whose major cleavage reaction results in the removal of the 5ʹ-triphosphorylated 2ʹ,3ʹ-cyclic phosphate derivative, leaving behind the respective unphosphorylated 2ʹ,5ʹ-oligoadenylate. Such a cleavage reaction results in the direct inactivation of the biologically active 2-5A molecule. The 2ʹ,5ʹ-ribonucleases (2ʹ,5ʹ-RNases) from C. gigas could be members of the ancient group of ribonucleases, specific to 2ʹ−5ʹ phosphodiester bond, together with the enzyme that was characterized previously from the marine sponge Tethya aurantium. The novel 2ʹ,5ʹ-RNases may play a role in the control of cellular 2-5A levels, thereby limiting damage to host cells after viral infection.

    更新日期:2018-09-05
  • SELEX methods on the road to protein targeting with nucleic acid aptamers
    Biochimie (IF 3.188) Pub Date : 2018-09-05
    Payam Bayat, Rahim Nosrati, Mona Alibolandi, Houshang Rafatpanah, Khalil Abnous, Mostafa Khedri, Mohammad Ramezani
    更新日期:2018-09-05
  • Biological relevance of double lipoxygenase products of polyunsaturated fatty acids, especially within blood vessels and brain
    Biochimie (IF 3.188) Pub Date : 2018-09-01
    M. Guichardant, E. Véricel, M. Lagarde

    The double lipoxygenation of polyunsaturated fatty acids (PUFA) is possible with PUFA having at least three methylene-interrupted double bonds. Several PUFA of the omega-3/n-3 and -6 families may be converted through this route, and the products show interesting inhibitory effects on blood platelet function and cyclooxygenase activities. This review focuses on two main omega-3 PUFA of nutritional interest, namely docosahexaenoic acid (DHA/22:6n-3) and alpha linolenic acid (ALA/18:3n-3). The chemical configuration of the double lipoxygenase end-product from DHA (protectin DX) is compared with that of protectin D1 which is produced through a mono-lipoxygenation step followed by an epoxidation and epoxide hydrolysis process. The different metabolic pathways are discussed as well as the different biological activities of both protectins.

    更新日期:2018-09-03
  • ZNF224 is a transcriptional repressor of AXL in chronic myeloid leukemia cells
    Biochimie (IF 3.188) Pub Date : 2018-08-31
    Gaetano Sodaro, Giancarlo Blasio, Federica Fiorentino, Patrick Auberger, Paola Costanzo, Elena Cesaro

    ZNF224 is a KRAB-zinc finger transcription factor that exerts a key tumor suppressive role in chronic myelogenous leukemia. In this study, we identify the receptor tyrosine kinase Axl as a novel target of ZNF224 transcriptional repression activity. Axl overexpression is found in many types of cancer and is frequently associated with drug resistance. Interestingly, we also found that sensitivity to imatinib can be partly restored in imatinib-resistant chronic myelogenous leukemia cells by ZNF224 overexpression and the resulting suppression of Axl expression. These results, in accordance with our previous findings, support the role of ZNF224 in imatinib responsiveness and shed new insights into potential therapeutic use of ZNF224 in imatinib-resistant chronic myelogenous leukemia.

    更新日期:2018-09-01
  • Photoactivable DNA probes to trap single-stranded DNA binding proteins: updating the potential of 4-thiothymidine from a comparative study
    Biochimie (IF 3.188) Pub Date : 2018-08-29
    Tom Gérard-Hirne, Frédéric Thiebaut, Emmanuelle Sachon, Alexandre Désert, Thierry Drujon, Vincent Guérineau, Benoît Michel, Rachid Benhida, Stéphane Coulon, Carole Saintomé, Dominique Guianvarc'h
    更新日期:2018-08-30
  • CHROMATOGRAPHY OF OXYSTEROLS
    Biochimie (IF 3.188) Pub Date : 2018-05-09
    Irundika H.K. Dias, Steven R. Wilson, Hanne Roberg-Larsen
    更新日期:2018-05-09
  • The amyloidogenicity of a C-terminal region of TDP-43 implicated in Amyotrophic Lateral Sclerosis can be affected by anions, acetylation and homodimerization
    Biochimie (IF 3.188) Pub Date : 2018-05-08
    Archana Prasad, Vishwanath Sivalingam, Vidhya Bharathi, Amandeep Girdhar, Basant K. Patel
    更新日期:2018-05-09
  • Importance of genetic background of oxysterol signaling in cancer
    Biochimie (IF 3.188) Pub Date : 2018-05-07
    P. Holy, A. Kloudova, P. Soucek
    更新日期:2018-05-08
  • Bioinformatics analyses and in vitro evidence for five and six stacked G-quadruplex forming sequences
    Biochimie (IF 3.188) Pub Date : 2018-05-04
    Martin Bartas, Václav Brázda, Václav Karlický, Jiří Červeň, Petr Pečinka

    Quadruplexes are noncanonical DNA structures that arise in guanine rich loci and have important biological functions. Classically, quadruplexes contain four stacked intramolecular G-tetrads. Surprisingly, although some algorithms allow searching for longer than 4G tracts for quadruplex formation, these have not yet been systematically studied. Therefore, we analyzed the human genome for sequences that are predicted to adopt stacked intramolecular G-tetrads with greater than four stacks. The data provide evidence for numerous G-quadruplexes that contain five or six stacked intramolecular G-tetrads. These sequences are predominantly found in known gene regulatory regions. Electrophoretic mobility assays and circular dichroism spectroscopy indicate that these sequences form quadruplex structures in vitro under physiological conditions. The localization and in vitro stability of these G-quadruplexes indicate their potentially important roles in gene regulation and their potential for therapeutic applications.

    更新日期:2018-05-04
  • Unusual interaction of human apurinic/apyrimidinic endonuclease 1 (APE1) with abasic sites via the Schiff-base-dependent mechanism
    Biochimie (IF 3.188) Pub Date : 2018-05-03
    Ekaterina S. Ilina, Svetlana N. Khodyreva, Olga I. Lavrik

    Clustered apurinic/apyrimidinic (AP) sites are more cytotoxic than isolated AP lesions because double strand breaks (DSB) can be formed during repair of closely positioned bistranded AP sites. Formation of DSB due to simultaneous cleavage of bistranded AP sites may be regulated by proteins specifically interacting with this complex lesion. A set of AP DNA duplexes containing AP sites in both strands in different mutual orientation (BS-AP DNAs) was used for search in the extracts of human cells proteins specifically recognizing clustered AP sites. A protein, which formed the Schiff-base-dependent covalent products having an apparent molecular mass of 50 kDa with the subset of BS-AP DNAs, was identified by mass spectrometry as apurinic/apyrimidinic endonuclease 1 (APE1). The identity of trapped protein was confirmed by Western blot analysis with anti-APE1 antibodies. Purified recombinant human APE1 is also capable of forming the 50 kDa-adducts with efficiency of BS-AP DNAs cross-linking to APE1 being dependent on the mutual orientation of AP sites.In spite of formation of the Schiff-base-dependent intermediate, which is prerequisite for the β-elimination mechanism, APE1 is unable to cleave AP sites. APE1 lacking the first 34 amino acids at the N-terminus, unlike wild type enzyme, is unable to form cross-links with BS-AP DNAs that testifies to the involvement of disordered N-terminal extension, which is enriched in lysine residues, in the interaction with AP sites. The yield of APE1-AP DNA cross-links was found to correlate with the enzyme amount in the extracts estimated by the immunochemical approach; therefore the BS-AP DNA-probes can be useful for comparative analysis of APE1 content in cell extracts.

    更新日期:2018-05-04
  • Sabellastarte magnifica Carboxypetidase Inhibitor: the first Kunitz inhibitor simultaneously interacting with carboxypeptidases and serine proteases
    Biochimie (IF 3.188) Pub Date : 2018-05-03
    Mey Ling Reytor González, Maday Alonso-del-Rivero Antigua, Lizbeth Hedstrom, Petr Kuzmič, José Ricardo Pires

    Multi-domain inhibitors capable to block the activity of different classes of proteases are not very common in nature. However, these kinds of molecules are attractive systems for biomedical or biotechnological applications, where two or more different targets need to be neutralized. SmCI, the Sabellastarte magnifica Carboxypeptidase Inhibitor, is a tri-domain BPTI-Kunitz inhibitor capable to inhibit serine proteases and A-like metallocarboxypeptidases. The BPTI-Kunitz family of proteins includes voltage gated channel blockers and inhibitors of serine proteases. SmCI is therefore, the only BPTI-Kunitz protein capable of inhibiting metallocarboxypeptidases. The X-ray structure of the SmCI-carboxypeptidase A complex previously obtained by us, revealed that this enzyme interacts with SmCI N-tail. In the complex, the reactive loops for serine protease inhibition remain fully exposed to the solvent in each domain, suggesting SmCI can simultaneously interact with multiple serine proteases. The twofold goals of this study were: i) to establish serine proteases-SmCI binding stoichiometry, given that the inhibitor is comprised of three potential binding domains; and ii) to determine whether or not SmCI can simultaneously bind both classes of enzymes, to which it binds individually. Our experimental approach included a variety of techniques for the study of protein-protein interactions, using as model enzymes pancreatic trypsin, elastase and carboxypeptidase A. In particular, we combined information obtained from gel filtration chromatography, denaturing electrophoresis, nuclear magnetic resonance spectroscopy and enzyme inhibition assays. Our results show that SmCI is able to bind three trypsin molecules under saturating conditions, but only one elastase interacts with the inhibitor. Additionally, we demonstrated that SmCI can bind serine proteases and carboxypeptidases at the same time (at least in the ratio 1:1:1), becoming the first protease inhibitor that simultaneously block these two mechanistic classes of enzymes.

    更新日期:2018-05-04
  • Biological and regulatory roles of acid-induced small RNA RyeC in Salmonella Typhimurium
    Biochimie (IF 3.188) Pub Date : 2018-05-03
    Daniel Ryan, Mohana Mukherjee, Ritu Nayak, Ria Dutta, Mrutyunjay Suar

    Salmonella Typhimurium is an enteric pathogen that has evolved masterful strategies to enable survival under stress conditions both within and outside a host. The acid tolerance response (ATR) is one such mechanism that enhances the viability of acid adapted bacteria to lethal pH levels. While numerous studies exist on the protein coding components of this response, there is very little data on the roles of small RNAs (sRNAs). These non-coding RNA molecules have recently been shown to play roles as regulators of bacterial stress response and virulence pathways. They function through complementary base pairing interactions with target mRNAs and affect their translation and/or stability. There are also a few that directly bind to proteins by mimicking their respective targets. Here, we identify several sRNAs expressed during the ATR of S. Typhimurium and characterize one highly induced candidate, RyeC. Further, we identify ptsI as a trans-encoded target that is directly regulated by this sRNA. From a functional perspective, over-expression of RyeC in Salmonella produced a general attenuation of several in vitro phenotypes including acid survival, motility, adhesion and invasion of epithelial cell lines as well as replication within macrophages. Together, this study highlights the diverse roles played by sRNAs in acid tolerance and virulence of S. Typhimurium.

    更新日期:2018-05-04
  • Exploring the biophysical properties of phytosterols in the plasma membrane for novel cancer prevention strategies
    Biochimie (IF 3.188) Pub Date : 2018-05-03
    Omar Fakih, Didem Sanver, David Kane, James L. Thorne

    Cancer is a global problem with no sign that incidences are reducing. The great costs associated with curing cancer, through developing novel treatments and applying patented therapies, is an increasing burden to developed and developing nations alike. These financial and societal problems will be alleviated by research efforts into prevention, or treatments that utilise off-patent or repurposed agents.Phytosterols are natural components of the diet found in an array of seeds, nuts and vegetables and have been added to several consumer food products for the management of cardio-vascular disease through their ability to lower LDL-cholesterol levels. In this review, we provide a connected view between the fields of structural biophysics and cellular and molecular biology to evaluate the growing evidence that phytosterols impair oncogenic pathways in a range of cancer types. The current state of understanding of how phytosterols alter the biophysical properties of plasma membrane is described, and the potential for phytosterols to be repurposed from cardio-vascular to oncology therapeutics. Through an overview of the types of biophysical and molecular biology experiments that have been performed to date, this review informs the reader of the molecular and biophysical mechanisms through which phytosterols could have anti-cancer properties via their interactions with the plasma cell membrane. We also outline emerging and under-explored areas such as computational modelling, improved biomimetic membranes and ex vivo tissue evaluation. Focus of future research in these areas should improve understanding, not just of phytosterols in cancer cell biology but also to give insights into the interaction between the plasma membrane and the genome. These fields are increasingly providing meaningful biological and clinical data but iterative experiments between molecular biology assays, biosynthetic membrane studies and computational membrane modelling improve and refine our understanding of the role of different sterol components of the plasma membrane.

    更新日期:2018-05-04
  • Phosphorylation-Induced Conformational Changes of Photoactivated Rhodopsin Probed by Fluorescent Labeling at Cys140 and Cys316
    Biochimie (IF 3.188) Pub Date : 2018-05-04
    Sheerly Rodríguez, May-Li Silva, Gustavo Benaím, José Bubis

    In order to monitor conformational changes following photoactivation and phosphorylation of bovine rhodopsin, the two reactive sulfhydryl groups at Cys140 and Cys316 were specifically labeled with the monobromobimane (mBBr) fluorophore. Although alterations in conformation after light exposure of rhodopsin were not detected by fluorescence excitation scans (300-450 nm) of the mBBr-labeled protein, the fluorescence signal was reduced ∼ 90% in samples containing photoactivated phosphorhodopsin. Predominant labeling at either Cys140 or Cys316 in light-activated and phosphorylated rhodopsin merely generated a decrease of ∼ 38% and 28%, respectively, in the fluorescence excitation intensity. Thus, neither mBBr-modified Cys140 nor mBBr-modified Cys316 were involved single-handedly in the remarkable fall seen on the signal following phosphorylation of the protein; rather, the incorporation of phosphate groups on the mBBr-labeled light-activated rhodopsin appeared to affect its fluorescence signal in a cooperative or synergistic manner. These findings demonstrated that the phosphorylation of specific hydroxyl groups at the carboxyl terminal tail of rhodopsin causes definite conformational changes in the three-dimensional fold of the protein. Apparently, amino acid residues that are buried in the interior of the inactive protein become accessible following bleaching and phosphorylation of rhodopsin, quenching in turn the fluorescence excitation signal of mBBr-modified rhodopsin.

    更新日期:2018-05-04
  • Notch3 is involved in adipogenesis of human adipose-derived stromal/stem cells
    Biochimie (IF 3.188) Pub Date : 2018-04-27
    Demi A. Sandel, Mengcheng Liu, Ngozi Ogbonnaya, Jamie J. Newman

    Human adipose-derived stromal/stem cells (hASCs) have tremendous therapeutic potential and the ability to offer insight into human development and disease. Here we subject human ASCs to siRNA-mediated knockdown of Notch3 cultured under both self-renewing and adipogenic differentiation conditions. Self-renewal was monitored by assessing viability and proliferation rates through staining and alamarBlue assays, respectively. Adipogenesis was measured through Oil-Red O staining, western blot and quantitative real-time RT-PCR that determined expression levels of multipotency and adipogenic markers over time. Notch3 was expressed in self-renewing hASCs but knockdown, as validated by qRT-PCR and western blot, showed no impact on cell viability, as measured through live-dead staining, or cell proliferation rates, as measured through alamarBlue assays. However, as Notch3 expression was observed to increase during adipogenesis, in the absence of Notch3 there was a significant increase in hASC adipogenesis as demonstrated through an increased number of lipid vesicles, and increased expression of adipogenic markers ppar-γ, adiponectin, fabp4, and plin2. Although Notch3 is only one of four Notch receptors expressed on the surface of hASCs, this receptor appears important for proper regulation of adipogenic differentiation, possibly serving as a negative regulator to prevent inappropriate adipogenesis or promote other lineage commitments of ASCs.

    更新日期:2018-04-28
  • Increase in liver cytosolic lipases activities and VLDL-TAG secretion rate do not prevent the non-alcoholic fatty liver disease in cafeteria diet-fed rats
    Biochimie (IF 3.188) Pub Date : 2018-04-26
    Anderson Fernandes de Melo, Carolina Campos Lima Moreira, Camila Ferreira Sales, Thiago Rentz, Helena Fonseca Raposo, Maria Antonieta Rissato Garófalo, Leida Maria Botion, Isis do Carmo Kettelhut, Helena Coutinho Franco de Oliveira, Valéria Ernestânia Chaves

    We have previously shown that the cafeteria diet increases body fat mass, triacylglycerol (TAG) and insulin plasma levels, glucose uptake by white and brown adipose tissues, as well as the sympathetic activity to both adipose tissues in Wistar rats. The metabolic pathways responsible for the development of non-alcoholic fatty liver disease (NAFLD) were examined in cafeteria diet-fed rats. After 3 weeks offering cafeteria diet, we evaluated: (i) activity of the sympathetic nervous system by norepinephrine turnover rates; (ii) de novo fatty acid synthesis in vivo using 3H2O; (iii) secretion of very low density lipoprotein (VLDL)-TAG secretion measuring serum TAG levels after administration of lipase lipoprotein inhibitor, (iv) liver cytosolic lipases activity and (v) liver mRNA expression of enzymes involved in lipids secretion and oxidation by RT-PCR. The cafeteria diet induced an increase in TAG (120%) and cholesterol (30%) liver contents. Cafeteria diet did not change the sympathetic nervous system activity to liver, but induced a marked increase in the lipogenesis (approximately four-fold) and significant increase in cytosolic lipases activities (46%) and VLDL-TAG secretion (22%) compared to control diet-fed rats. The cafeteria diet also increased the microsomal triglyceride transfer protein (30%) and carnitine palmitoyltransferase I (130%) mRNA expression but decreased the apolipoprotein B100 (26%) mRNA expression. Our findings demonstrate that the increase in the cytosolic lipases activities and VLDL-TAG secretion rates were not able to compensate for the increased lipogenesis rates induced by the cafeteria diet, resulting in NAFLD.

    更新日期:2018-04-27
  • Ophiopogonin D improves osteointegration of titanium alloy implants under diabetic conditions by inhibition of ROS overproduction via Wnt/β-catenin signaling pathway
    Biochimie (IF 3.188) Pub Date : 2018-04-26
    Xiang-Yu Ma, Xin-Xin Wen, Xiao-Jiang Yang, Da-Peng Zhou, Qiong Wu, Ya-Fei Feng, Hai-Jiao Ding, Wei Lei, Hai-Long Yu, Bing Liu, Liang-Bi Xiang, Tian-Sheng Wang

    A high failure rate of titanium implants in diabetic patients has been indicated in clinical evidences. Excessive oxidative stress at the bone-implant interface plays an important role in the impaired osteointegration under diabetic conditions. While the underlying mechanisms remain unknown and the targeted treatments are urgently needed. Ophiopogonin D (OP-D), isolated from Chinese herbal Radix Ophiopogon japonicus, is generally reported to be a potent antioxidant agent. In the present study, we hypothesized that OP-D exerted promotive effects on osteointegration against oxidative stress, and investigated the underlying mechanisms associated with alteration of Wnt/β-catenin signaling pathway. Rabbit osteoblasts incubated on titanium alloy implant were co-cultured with normal serum (NS), diabetic serum (DS), DS + OP-D, DS + NAC (a potent ROS inhibitor) and DS + OP-D + Dkk1 (a Wnt inhibitor) for examinations of osteoblast behaviors. For in vivo study, titanium alloy implants were implanted into the femoral condyle defects on diabetic rabbits. Results demonstrated that diabetes-induced oxidative stress resulted in osteoblast dysfunctions and apoptotic injury at the bone-implant interface, concomitant with the inactivation of Wnt/β-catenin signaling. Importantly, OP-D administration attenuated oxidative stress, directly reactivating Wnt/β-catenin signaling. Osteoblast dysfunctions were thus reversed as evidenced by improved osteoblast adhesion, proliferation and differentiation, and ameliorated apoptotic injury, exerting similar effects to NAC treatment. In addition, the positive effects afforded by OP-D were confirmed by improved osteointegration and oetogenesis within the titanium alloy implants in vivo by Micro-CT and histological analyses. Furthermore, the pro-osteogenic effects of OP-D were almost completely abolished by the Wnt inhibitor Dkk1. These results demonstrated, for the first time, OP-D administration alleviated the damaged osteointegration of titanium alloy implants under diabetic conditions by means of inhibiting oxidative stress via a Wnt/β-catenin-dependent mechanism. The OP-D administration would become a reliable treatment strategy for implant failure therapy in diabetics due to the optimal anti-oxidative and pro-osteogenic properties.

    更新日期:2018-04-27
  • In vitro oxidized HDL and HDL from type 2 diabetes patients have reduced ability to efflux oxysterols from THP-1 macrophages
    Biochimie (IF 3.188) Pub Date : 2018-04-26
    Yinan Chena, Maud Arnal-Levron, Françoise Hullin-Matsuda, Carole Knibbe, Philippe Moulin, Céline Luquain-Costaz, Isabelle Delton

    Oxidized LDL (OxLDL) that are enriched in products of lipid peroxidation including oxysterols have been shown to induce cellular oxidative stress and cytotoxicity therefore accelerating atheroma plaque formation. Upon oxLDL exposure of THP-1 macrophages, intracellular oxidation of LDL derived-cholesterol as well as endogenous cholesterol was increased. The oxysterols intracellularly produced were efficiently exported to HDL whereas apolipoprotein A1 was inefficient. These findings prompted us to investigate the consequences of modification of HDL by oxidation and glycation as observed in type 2 diabetes with respect to oxysterol and cholesterol efflux. We show that efflux of oxysterols was significantly impaired after in vitro oxidation and glycoxidation of HDL whereas glycation alone had no impact. Cholesterol efflux was only slightly decreased by oxHDL or glycoxidized HDL and not changed with glycated HDL. The defect of HDL towards oxysterol efflux was also observed with HDL isolated from diabetic subjects as compared to healthy controls. These findings support a deleterious cellular retention of oxysterols due to dysfunctional HDL in type 2 diabetes.

    更新日期:2018-04-26
  • Determination of the binding properties of p-cresyl glucuronide to human serum albumin
    Biochimie (IF 3.188) Pub Date : 2018-04-26
    Dan Yi, Elisa Bernardes Monteiro, Stéphane Chambert, Hédi A. Soula, Julio B. Daleprane, Christophe O. Soulage

    p-Cresyl glucuronide (p-CG) is a by-product of tyrosine metabolism that accumulates in patients with end-stage renal disease. p-CG binding to human serum albumin in physiological conditions (37°C, pH 7.40) was studied by ultrafiltration (MWCO 10 kDa) and data were analyzed assuming one binding site. The estimated value of the association constant was 2.77×103 M-1 and a maximal stoichiometry of 3.80 mol per mole. At a concentration relevant for end-stage renal patients, p-CG was 23% bound to albumin. Competition experiments, using fluorescent probes, demonstrated that p-CG did not bind to Sudlow's site I or site II. The p-CG did not interfere with the binding of p-cresyl-sulfate or indoxyl sulfate to serum albumin.

    更新日期:2018-04-26
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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