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  • Signal interaction between the tumour and inflammatory cells in patients with gastrointestinal cancer: Implications for treatment
    Cell Signal. (IF 3.487) Pub Date : 2018-11-17
    Kathryn A.F. Pennel, James H. Park, Donald C. McMillan, Antonia K. Roseweir, Joanne Edwards

    Over the last 15 years there has been a change in how we understand the impact of the interaction between the tumour and the host on cancer outcomes. From the simplistic view that the make-up of tumours cells largely determines their aggressiveness to a more complex view that the interaction between the products of tumour and host cell signal transduction pathways is crucial in determining whether the tumour cell is eliminated or survives in the host. Of the host cells, those with an immune/inflammatory function are most well documented to inhibit or promote tumour cell proliferation and dissemination. It is only in the last few years that there has been greater recognition of the impact of intracellular, cellular and systemic immune/inflammatory phenotypes on patient outcomes independent of current tumour staging and that these phenotypes are useful in informing oncological research and practice. In the present review we will examine the importance of inflammatory phenotypes at the intra-cellular, cellular and systemic levels on outcomes in patients with gastrointestinal cancer with focus on colorectal cancer. Based on these phenotypes we will examine and discuss the prospects for therapeutic intervention.

    更新日期:2018-11-17
  • miR-382-5p modulates the ATRA-induced differentiation of acute promyelocytic leukemia by targeting tumor suppressor PTEN
    Cell Signal. (IF 3.487) Pub Date : 2018-11-17
    Dongdong Liu, Liang Zhong, Zhen Yuan, Juanjuan Yao, Pengqiang Zhong, Junmei Liu, Shifei Yao, Yi Zhao, Lu Liu, Min Chen, Lianwen Li, Beizhong Liu

    In acute promyelocytic leukemia (APL), all-trans retinoic acid (ATRA) treatment induces granulocytic differentiation and maturation. MicroRNAs play pivotal roles in formation of the leukemic phenotype. Previously, microRNA-382-5p (miR-382-5p) was upregulated in acute myeloid leukemia (AML) with t(15;17). In the present study, we found that miR-382-5p expression was elevated with ATRA-induced differentiation of APL. To investigate the potential functional role of miR-382-5p in APL differentiation, an APL cell line was transfected with miR-382-5p mimics, inhibitors, or negative control (NC). The results showed in APL cell line NB4 that miR-382-5p downregulation upon ATRA treatment was a key event in the drug response. Mechanistic investigations revealed that miR-382-5p targeted the ATRA-regulated tumor suppressor gene PTEN through direct binding to its 3′ UTR. Enforced expression of miR-382-5p or specific PTEN inhibitors inhibited ATRA-induced granulocytic differentiation via regulation of the cell cycle regulator cyclinD1. Conversely, PTEN overexpression promoted differentiation and enhanced sensitivity of NB4 cell line to physiological levels of ATRA. Finally, we found that PTEN overexpression restored PML nuclear bodies (NBs). Taken together, these results demonstrated that up-regulated miR-382-5p in NB4 cell line inhibited granulocytic differentiation through the miR-382-5p/PTEN axis, uncovering PTEN as a critical element in the granulocytic differentiation program induced by ATRA in APL.

    更新日期:2018-11-17
  • Phosphorylation and inhibition of ceramide kinase by protein kinase C-β: Their changes by serine residue mutations
    Cell Signal. (IF 3.487) Pub Date : 2018-11-15
    Hiromasa Takahashi, Hitomi Ashikawa, Hiroyuki Nakamura, Toshihiko Murayama

    Ceramide kinase (CerK) phosphorylates ceramide to ceramide-1-phosphate (C1P), and various roles for the CerK/C1P pathway in the regulation of cellular/biological functions have been demonstrated. CerK is constitutively phosphorylated at several serine (Ser, S) residues, however, the roles of Ser residues, including their phosphorylation, in CerK activity, have not yet been elucidated in detail. Therefore, we conducted the present study to investigate this issue. In A549 cells expressing wild-type CerK, a treatment with phorbol 12-myristate 13-acetate (PMA) decreased the formation of C1P in a protein kinase C (PKC)-βI/II-mediated manner. In the Phos-tag SDS-PAGE analysis, CerK existed in its phosphorylated form and was further phosphorylated by the PMA treatment in a PKC-βI/II-mediated manner. We examined the effects of the displacement of Ser residues (72/300/340/403/408/427) in CerK by alanine (Ala, A) on its activity and phosphorylation. Triple mutations (S340/408/427A), but not a single or double mutations (S340/408A), in CerK significantly decreased the formation of C1P. PMA-induced phosphorylation levels in S340/408A- and S340/408/427A-CerK were significantly and maximally reduced, respectively, but were similar in CerK with a single mutation and wild-type CerK. Ser residue mutations tested, including six mutations, did not affect PMA-induced decreases in C1P formation more than expected. Treatments with the protein phosphatase inhibitors, okadaic acid and cyclosporine A, decreased the formation of C1P. These results demonstrated that the activity of CerK was regulated in a phosphorylation-dependent manner in cells.

    更新日期:2018-11-16
  • ACTL6A interacts with p53 in acute promyelocytic leukemia cell lines to affect differentiation via the Sox2/Notch1 signaling pathway
    Cell Signal. (IF 3.487) Pub Date : 2018-11-15
    Peng-Qiang Zhong, Liang Zhong, Juan-Juan Yao, Dong-Dong Liu, Zhen Yuan, Jun-Mei Liu, Min Chen, Shi-Fei Yao, Yi Zhao, Lu Liu, Lian-Wen Li, Bei-Zhong Liu

    Actin-like 6A (ACTL6A), a component of BAF chromatin remodeling complexes, is important for cell differentiation. Nevertheless, its role and mechanism in acute promyelocytic leukemia (APL) has not been reported. To identify the genes that may participate in the development of APL, we analyzed data from an APL cDNA microarray (GSE12662) in the NCBI database, and found that ACTL6A was up-regulated in APL patients. Subsequently, we investigated the function and mechanisms of ACTL6A in myeloid cell development. The expression of ACTL6A was gradually decreased during granulocytic differentiation in all-trans retinoic acid-treated NB4 and HL-60 cells, and phorbol myristate acetate-treated HL-60 cells. We also found that knockdown of ACTL6A promoted differentiation in NB4 and HL-60 cells, and decreased the levels of Sox2 and Notch1. Mechanistically, ACTL6A interacted with and was co-localized with Sox2 and p53. Meanwhile, CBL0137, an activator of p53, decreased the expression of ACTL6A and promoted differentiation in NB4 and HL-60 cells. These findings suggest that the inhibition of ACTL6A promotes differentiation via the Sox2 and Notch1 signaling pathways. Furthermore, the differentiation promoted by inhibiting ACTL6A could be regulated by p53 via its physical interaction with ACTL6A.

    更新日期:2018-11-16
  • Bevacizumab induces inflammation in MDA-MB-231 breast cancer cell line and in a mouse model
    Cell Signal. (IF 3.487) Pub Date : 2018-11-14
    Layal EL-Hajjar, Nour Jalaleddine, Abdullah Shaito, Kazem Zibara, Jalal Kazan, Jamal El-Saghir, Marwan El-Sabban

    BackgroundBevacizumab or Avastin® (Av) is an anti-vascular endothelial growth factor agent. It does not improve survival of breast cancer patients due to development of refractoriness. Av treatment was shown to increase inflammation in a diabetic mouse model, and also to induce epithelial-to-mesenchymal transition of non-transformed breast epithelia. This study aimed to understand if the Av-induced inflammatory microenvironment could be a mechanism of Av refractoriness. Expression profiles of inflammatory mediators, in vitro in MDA-MB-231 cells, in vivo in a mouse model xenografted with MDA-MB-231 cells and from archived cases of human breast carcinoma tissues were evaluated. Gap junctions are also crucial for angiogenesis and tumor cell extravasation. The effect of connexin 43 (Cx43) overexpression on the expression of inflammatory markers in MDA-MB-231 cells treated with Av was assessed.MethodsMDA-MB-231 cells, control or overexpressing Cx43, were used in this study. Proliferation and invasion assays were performed. Quantitative PCR, ELISA and western blotting were performed to assess the regulation of inflammatory mediators and other factors upon Av treatment. Immunofluorescence was performed to document the translocation of Nuclear Factor-kappa B p65.ResultsBreast cancer tissues had elevated transcriptional levels of inflammatory mediators. Av treatment increased expression levels of inflammatory mediators and metastatic factors in vitro and in vivo. Interestingly, overexpressing Cx43 in MDA-MB-231 cells alleviated the inflammatory effects induced by Av treatment.ConclusionThis study attributes Av refractoriness to the Av therapy-induced inflammatory microenvironment.

    更新日期:2018-11-14
  • Neuroprotective effects of overexpressed microRNA-200a on activation of glaucoma-related retinal glial cells and apoptosis of ganglion cells via downregulating FGF7-mediated MAPK signaling pathway
    Cell Signal. (IF 3.487) Pub Date : 2018-11-12
    Hui Peng, Ya-Bin Sun, Ji-Long Hao, Cheng-Wei Lu, Ming-Chao Bi, E. Song

    Glaucoma is a progressive optic neuropathy and is one of the leading causes of blindness in the industrialized countries. The involvement of microRNAs (miRs) has been implicated in regulating the complex biological responses to changes in intraocular pressure. However, the therapeutic role of miR-200a on glaucoma has not been well studied yet. In this study, we confirmed the role of miR-200a in glaucoma progression and identified the related mechanism. Microarray expression profiles were used to screen the glaucoma-related genes. The relationship between miR-200a and FGF7 was validated by bioinformatics analysis and dual-luciferase reporter gene assay. Glaucoma-related parameters including the expression of CD11b and iNOS, activation of Muller cells, and apoptosis of retinal ganglion cells (RGCs) in the mouse model were measured by immunohistochemistry, MTT assay and TUNEL assay, respectively. miR-200a was reduced in glaucoma, whereas FGF7 was robustly induced. Thereby, we speculated that FGF7 was negatively regulated by miR-200a. Downregulated miR-200a could activate the MAPK signaling pathway following elevations in ERK, JNK, p38 and Bax expression and reduction in Bcl-2 expression. In the mouse model, downregulated miR-200a increased the expression of CD11b and iNOS and the apoptosis of RGCs, but stimulated the inactivation of Muller cells. However, the above-mentioned alternations induced by downregulated miR-200a were reversed after FGF7 repression. miR-200a can inhibit the FGF7-mediated MAPK signaling pathway and play a protective role on improving the glaucoma-induced optical nerve injury.

    更新日期:2018-11-12
  • Individual Smad2 linker region phosphorylation sites determine the expression of proteoglycan and glycosaminoglycan synthesizing genes
    Cell Signal. (IF 3.487) Pub Date : 2018-11-10
    Danielle Kamato, Micah Burch, Zhou Yang, Raafat Mohamed, Jennifer L. Stow, Narin Osman, Peter J. Little

    Growth factors such as thrombin and transforming Growth Factor (TGF)-β facilitate glycosaminoglycan (GAG) chain hyperelongation on proteoglycans, a phenomenon that increases lipoprotein binding in the vessel wall and the development of atherosclerosis. TGF -β signals via canonical carboxy terminal phosphorylation of R-Smads and also non-canonical linker region phosphorylation of R-Smads. The G protein coupled receptor agonist, thrombin, can transactivate the TGF-β receptor leading to both canonical and non-canonical Smad signalling. Linker region phosphorylation drives the expression of genes for the synthesis of the proteoglycan, biglycan. Proteoglycan synthesis involves core protein synthesis, the initiation of GAG chains and the subsequent elongation of GAG chains. We have explored the relationship between the thrombin stimulated phosphorylation of individual serine and threonine sites in the linker region of Smad2 and the expression of GAG initiation xylosyltransferase-1 (XT-1) and GAG elongation chondroitin 4-sulfotransferase-1(C4ST-1) and chondroitin synthase-1 (CHSY-1) genes. Thrombin stimulated the phosphorylation of all four target residues (Thr220, Ser245, Ser250 and Ser255 residues) with a similar temporal pattern – phosphorylation was maximal at 15 min (the earliest time point studied) and the level of the phospho-proteins declined thereafter over the following 4 h. Jnk, p38 and PI3K, selectively mediated the phosphorylation of the Thr220 residue whereas the serine residues were variously phosphorylated by multiple kinases. Thrombin stimulated the expression of all three genes – XT-1, C4ST-1 and CHSY-1. The three pathways mediating Thr220 phosphorylation were also involved in the expression of XT-1. The target pathways (excluding Jnk) were involved in the expression of the GAG elongation genes (C4ST-1 and CHSY-1). These findings support the contention that individual Smad linker region phosphorylation sites are linked to the expression of genes for the initiation and elongation of GAG chains on proteoglycans. The context of this work is that a specific inhibitor of GAG elongation represents a potential therapeutic agent for preventing GAG elongation and lipid binding and the results indicate that the specificity of the pathways is such that it might be therapeutically feasible to specifically target GAG elongation without interfering with other physiological processes with which proteoglycans are involved.

    更新日期:2018-11-12
  • Distinct phosphorylation sites/clusters in the carboxyl terminus regulate α1D-adrenergic receptor subcellular localization and signaling
    Cell Signal. (IF 3.487) Pub Date : 2018-11-09
    Gabriel Carmona-Rosas, David A. Hernández-Espinosa, Rocío Alcántara-Hernández, Marco A. Alfonzo-Méndez, J. Adolfo García-Sainz

    The human α1D-adrenergic receptor is a seven transmembrane-domain protein that mediates many of the physiological actions of adrenaline and noradrenaline and participates in the development of hypertension and benign prostatic hyperplasia. We recently reported that different phosphorylation patterns control α1D-adrenergic receptor desensitization. However, to our knowledge, there is no data regarding the role(s) of this receptor's specific phosphorylation residues in its subcellular localization and signaling. In order to address this issue, we mutated the identified phosphorylated residues located on the third intracellular loop and carboxyl tail. In this way, we experimentally confirmed α1D-AR phosphorylation sites and identified, in the carboxyl tail, two groups of residues in close proximity to each other, as well as two individual residues in the proximal (T442) and distal (S543) regions. Our results indicate that phosphorylation of the distal cluster (T507, S515, S516 and S518) favors α1D-AR localization at the plasma membrane, i. e., substitution of these residues for non-phosphorylatable amino acids results in the intracellular localization of the receptors, whereas phospho-mimetic substitution allows plasma membrane localization. Moreover, we found that T442 phosphorylation is necessary for agonist- and phorbol ester-induced receptor colocalization with β-arrestins. Additionally, we observed that substitution of intracellular loop 3 phosphorylation sites for non-phosphorylatable amino acids resulted in sustained ERK1/2 activation; additional mutations in the phosphorylated residues in the carboxyl tail did not alter this pattern. In contrast, mobilization of intracellular calcium and receptor internalization appear to be controlled by the phosphorylation of both third-intracellular-loop and carboxyl terminus-domain residues. In summary, our data indicate that a) both the phosphorylation sites present in the third intracellular loop and in the carboxyl terminus participate in triggering calcium signaling and in turning-off α1D-AR-induced ERK activation; b) phosphorylation of the distal cluster appears to play a role in receptor's plasma membrane localization; and c) T442 appears to play a critical role in receptor phosphorylation and receptor-β-arrestin colocalization.

    更新日期:2018-11-09
  • Nitric oxide mediated redox regulation of protein homeostasis
    Cell Signal. (IF 3.487) Pub Date : 2018-11-05
    Irmgard Tegeder

    Nitric oxide is a versatile diffusible signaling molecule, whose biosynthesis by three NO synthases (NOS) is tightly regulated at transcriptional and posttranslational levels, availability of co-factors, and calcium binding. Above normal levels of NO have beneficial protective effects for example in the cardiovascular system, but also contribute to the pathophysiology in the context of inflammatory diseases, and to aging and neurodegeneration in the nervous system. The effect specificity relies on the functional and spatial specificity of the NOS isoenzymes, and on the duality of two major signaling mechanisms (i) activation of soluble guanylycylase (sGC)-dependent cGMP production and (ii) direct S-nitrosylation of redox sensitive cysteines of susceptible proteins. The present review summarizes the functional implications of S-nitrosylation in the context of proteostasis, and focuses on two NO target proteins, heat shock cognate of 70 kDa (Hsc70/HSPA8) and the ubiquitin 2 ligase (UBE2D), because both are modified on functionally critical cysteines and are key regulators of chaperone mediated and assisted autophagy and proteasomal protein degradation. SNO modifications of these candidates are associated with protein accumulations and adoption of a senescent phenotype of neuronal cells suggesting that S-nitrosylations of protein homeostatic machineries contribute to aging phenomena.

    更新日期:2018-11-06
  • Co-activation of WT1 and AP-1 proteins on WT1 gene promoter to induce WT1 gene expression in K562 cells
    Cell Signal. (IF 3.487) Pub Date : 2018-11-03
    Songyot Anuchapreeda, Methee Rungrojsakul, Singkome Tima, Sawitree Chiampanichayakul, Sheryl R. Krig
    更新日期:2018-11-05
  • Role of SMURF1 ubiquitin ligase in BMP receptor trafficking and signaling
    Cell Signal. (IF 3.487) Pub Date : 2018-11-03
    Koko Murakami, Joseph D. Etlinger

    Heterozygous germline mutations in the bone morphogenetic protein type II receptor gene (BMPRII) are associated with hereditary pulmonary arterial hypertension (HPAH). Missense mutations, both in the extracellular ligand-binding and cytoplasmic kinase domains, mostly involve substitution of conserved Cys residues. Singular substitution at any of those Cys residues causes cytoplasmic, perinuclear localization of BMPR with reduced cell surface expression and BMP signaling. The present study examined the effect of Cys residue substitution on BMPR endocytic trafficking and lysosome degradation. We demonstrate that endocytosis/lysosomal degradation of BMPR occurs by two distinct pathways: SMURF1 and Ser/Thr kinase-associated. SMURF1 ubiquitin ligase induces lysosomal degradation of BMPR, while ligase-inactive SMURF1 maintains BMPR protein level and cell surface expression. Substitution of BMPR Cys residues increases lysosomal degradation which is blocked by ligase-inactive SMURF1, elevating protein levels of Cys-substituted BMPRs. Expression of Cys-substituted BMPR suppresses basal BMP signaling activity which is also up-regulated by ligase-inactive SMURF1. Cys-residue substitution thus appears to cause BMPR endocytosis to lysosomes in a SMURF1 ubiquitin ligase-associated pathway. In contrast, kinase-activated BMPR undergoes endocytic/lysosomal degradation by a pathway which is independent of SMURF1 and characterized with unique properties. Therefore, our results may describe a novel mechanism that SMURF1 ubiquitin ligase regulates constitutive endocytosis of BMPR which may be mediated by its conserved Cys residues.

    更新日期:2018-11-05
  • 更新日期:2018-10-31
  • The role of STAT3/mTOR-regulated autophagy in angiotensin II-induced senescence of human glomerular mesangial cells
    Cell Signal. (IF 3.487) Pub Date : 2018-10-30
    Shuang Yang, Dan Sun, Lining Wang, Xiuying Wang, Mai Shi, Xue Jiang, Xinran Gao

    The kidney is one of the fastest-aging organs, and renal senescence has become a major disease affecting human health. Renal cellular senescence is regulated by the joint action of multiple signal transduction pathways. The previous study by our research group found that the Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) pathway was involved in angiotensin II (Ang II)-induced senescence of human glomerular mesangial cells. However, the unique role of STAT3 activation in Ang II-induced senescence of human glomerular mesangial cells and the underlying mechanisms remain unclear. The present study revealed that Ang II induced premature senescence, promoted autophagy and activated oxidative stress responses in human glomerular mesangial cells. Autophagy mediates the senescence-inducing effect of Ang II on human glomerular mesangial cells. Inhibition of oxidative stress with N-acetylcysteine (NAC) or interference with STAT3/mechanistic target of rapamycin (mTOR) activity with S3I-201 or STAT3-siRNA suppressed autophagy to a certain extent, which was conducive to delaying the senescence of glomerular mesangial cells. The antioxidant probucol reduced autophagy in human glomerular mesangial cells and alleviated the aging process of these cells by regulating STAT3/mTOR. These findings identify a role of STAT3/mTOR-regulated autophagy in Ang II-induced senescence of human glomerular mesangial cells and may provide a theoretical basis for anti-senescence treatment in clinical practice.

    更新日期:2018-10-31
  • Effects of long non-coding RNA LINC00667 on renal tubular epithelial cell proliferation, apoptosis and renal fibrosis via the miR-19b-3p/LINC00667/CTGF signaling pathway in chronic renal failure
    Cell Signal. (IF 3.487) Pub Date : 2018-10-26
    Wen Chen, Zhong-Qi Zhou, Yue-Qin Ren, Lei Zhang, Li-Na Sun, Yu-Lin Man, Zhi-Kui Wang

    The global prevalence of chronic renal failure (CRF) has significantly elevated with various reports indicating there to be a 10% worldwide rate. The functions of long non-coding RNAs (lncRNAs) and their deeper association with CRF at present remain poorly understood. Hence, the aim of the present study was to investigate the altered expressions of lncRNA LINC00667 in CRF and its associated effects on renal tubular epithelial cell proliferation, apoptosis and renal fibrosis through the microRNA-19b-3p (miR-19b-3p)/LINC00667/connective tissue growth factor (CTGF) signaling pathway. Initially, verification of the targeting relationship between LINC00667, CTGF and miR-19b-3p was performed, after which evidence was obtained indicating that miR-19b-3p could negatively regulate LINC00667 and CTGF. The expressions of CTGF in both the CRF and normal renal tissues were determined by immunohistochemistry means, with LINC00667 and CTGF determined to be highly expressed, while poor expression levels of miR-19b-3p were detected among the CRF tissues. The expressions of LINC00667, miR-19b-3p, fibrosis- and epithelial-mesenchymal transition (EMT)-related genes were also examined. The successfully established CRF rat models were treated with varying mimics, inhibitors, and siRNA. ELISA was applied to determine the renal function-related factors. Besides, the renal cell proliferation, migration and apoptosis were detected. In response to LINC00667 silencing, the renal tubular epithelial cells displayed increased proliferation and migration accompanied by reduced apoptosis based on upregulated miR-19b-3p, along with inhibited renal fibrosis and EMT detected. Taken together, the key findings of our study demonstrated that decreased lncRNA LINC00667 could promote renal tubular epithelial cell proliferation and ameliorate renal fibrosis in CRF via the miR-19b-3p/LINC00667/CTGF signaling pathway.

    更新日期:2018-10-27
  • 更新日期:2018-10-27
  • Autophagy induction impairs Wnt/β-catenin signalling through β-catenin relocalisation in glioblastoma cells
    Cell Signal. (IF 3.487) Pub Date : 2018-10-26
    Barbara Colella, Fiorella Faienza, Marianna Carinci, Giuseppina D'Alessandro, Myriam Catalano, Antonio Santoro, Francesco Cecconi, Cristina Limatola, Sabrina Di Bartolomeo
    更新日期:2018-10-26
  • Ergothioneine-induced neuronal differentiation is mediated through activation of S6K1 and neurotrophin 4/5-TrkB signaling in murine neural stem cells
    Cell Signal. (IF 3.487) Pub Date : 2018-10-22
    Takahiro Ishimoto, Yusuke Masuo, Yukio Kato, Noritaka Nakamichi

    The promotion of neurogenesis is considered to be an effective therapeutic strategy for neuropsychiatric disorders because impairment of neurogenesis is associated with the onset and progression of these disorders. We have previously demonstrated that orally ingested ergothioneine (ERGO), a naturally occurring antioxidant and hydrophilic amino acid, promotes neurogenesis in the hippocampal dentate gyrus (DG) with its abundant neural stem cells (NSCs) and exerts antidepressant-like effects in mice. Independent of its antioxidant activities, ERGO induces in cultured NSCs this differentiation through induction of the basic helix-loop-helix transcription factor Math1. However, the upstream signaling of Math1 in the mechanisms underlying ERGO-induced neuronal differentiation remains unclear. The purpose of the present study was to elucidate the upstream signaling with the aim of discovering novel targets for the treatment of neuropsychiatric disorders. We focused on neurotrophic factor signaling, as it is important for the promotion of neurogenesis and the induction of antidepressant effects. We also focused on the signaling of the mammalian target of rapamycin (mTOR) complex 1 (mTORC1), a known amino acid sensor, and the members of this signaling pathway, mTOR and p70 ribosomal protein S6 kinase 1 (S6K1). Exposure of cultured NSCs to ERGO significantly increased the expression of phosphorylated S6K1 (p-S6K1) at Thr389 in only 1 h, of phosphorylated mTOR (p-mTOR) in 6 h, and of the gene product of neurotrophin 4/5 (NT5) which activates tropomyosin receptor kinase B (TrkB) in 24 h. ERGO increased the population of βIII-tubulin-positive neurons, and this effect was suppressed by the inhibitors of S6K1 (PF4708671), mTORC1 (rapamycin), and TrkB (GNF5837). Oral administration of ERGO to mice significantly increased in the DG the expression of p-S6K1 at Thr389, the gene product of NT5, and phosphorylated TrkB but not that of p-mTOR. Thus, neuronal differentiation of NSCs induced by ERGO is mediated, at least in part, through phosphorylation of S6K1 at Thr389 and subsequent activation of TrkB signaling through the induction of NT5. Thus, S6K1 and NT5 might be promising target molecules for the treatment of neuropsychiatric disorders.

    更新日期:2018-10-23
  • Chemical denervation using botulinum toxin increases Akt expression and reduces submaximal insulin-stimulated glucose transport in mouse muscle
    Cell Signal. (IF 3.487) Pub Date : 2018-10-21
    Zhencheng Li, Lui Näslund-Koch, Carlos Henriquez-Olguin, Jonas R. Knudsen, Jingwen Li, Agnete B. Madsen, Satoru Ato, Jacob Wienecke, Riki Ogasawara, Jens B. Nielsen, Thomas E. Jensen

    Botulinum toxin A (botox) is a toxin used for spasticity treatment and cosmetic purposes. Botox blocks the excitation of skeletal muscle fibers by preventing the release of acetylcholine from motor nerves, a process termed chemical denervation. Surgical denervation is associated with increased expression of the canonical insulin-activated kinase Akt, lower expression of glucose handling proteins GLUT4 and hexokinase II (HKII) and insulin resistant glucose uptake, but it is not known if botox has a similar effect. To test this, we performed a time-course study using supra-maximal insulin-stimulation in mouse soleus ex vivo. No effect was observed in the glucose transport responsiveness at day 1, 7 and 21 after intramuscular botox injection, despite lower expression of GLUT4, HKII and expression and phosphorylation of TBC1D4. Akt protein expression and phosphorylation of the upstream kinase Akt were increased by botox treatment at day 21. In a follow-up study, botox decreased submaximal insulin-stimulated glucose transport. The marked alterations of insulin signaling, GLUT4 and HKII and submaximal insulin-stimulated glucose transport are a potential concern with botox treatment which merit further investigation in human muscle. Furthermore, the botox-induced chemical denervation model may be a less invasive alternative to surgical denervation.

    更新日期:2018-10-22
  • Isomers of conjugated linoleic acid induce insulin resistance through a mechanism involving activation of protein kinase cε in liver cells
    Cell Signal. (IF 3.487) Pub Date : 2018-10-21
    Adriana Roura-Guiberna, Judith Hernandez-Aranda, Carlos Jorge Ramirez-Flores, Ricardo Mondragon-Flores, Nayely Garibay-Nieto, Gloria Queipo-Garcia, Estibalitz Laresgoiti-Servitje, Jae-Won Soh, Jesus Alberto Olivares-Reyes
    更新日期:2018-10-22
  • Dual-specificity phosphatases regulate mitogen-activated protein kinase signaling in adipocytes in response to inflammatory stress
    Cell Signal. (IF 3.487) Pub Date : 2018-10-19
    Bradley S. Ferguson, Heesun Nam, Ron F. Morrison

    Obesity is a strong predictor of heart disease, insulin resistance, and type II diabetes. Chronic, low-grade inflammation links obesity and insulin resistance through mitogen-activated protein kinase (MAPK) signaling pathways. Upstream kinases activate MAPK signaling, while MAPK-specific dual-specificity phosphatases (DUSPs) act as key modulators and controllers of MAPK deactivation (i.e. dephosphorylation). Using tumor necrosis factor α (TNFα) in 3 T3-L1 adipocytes as a model of inflammation, we report that TNFα-mediated induction of Dusp1, Dusp8 and Dusp16 modulated the transient regulation of MAPK (i.e., ERK, JNK, and p38) phosphorylation and subsequent inflammatory gene expression. All three MAPKs examined were phosphorylated in preadipocytes and adipocytes in response to TNFα, where signaling magnitude and duration were phenotype-specific. Moreover, TNFα increased mRNA abundance of DUSPs in preadipocytes and adipocytes in a phenotype-specific manner, concomitant with dephosphorylation of MAPKs. RNA interference (RNAi)-mediated knockdown of Dusp1, Dusp8 and Dusp16 increased signaling magnitude and duration of ERK, JNK, and p38 that subsequently resulted in significant increases in MAPK-dependent inflammatory gene expression of MCP-1, IL-6, and Cox-2 in response to TNFα. This study highlights important roles for DUSPs as integral components of MAPK signaling and adipocyte inflammatory gene expression.

    更新日期:2018-10-22
  • Microtubule destabilization caused by particulate matter contributes to lung endothelial barrier dysfunction and inflammation
    Cell Signal. (IF 3.487) Pub Date : 2018-10-16
    Pratap Karki, Angelo Meliton, Albert Sitikov, Yufeng Tian, Tomomi Ohmura, Anna A. Birukova

    Exposure to particulate matter (PM) associated with air pollution remains a major public health concern, as it has been linked to significant increase in cardiopulmonary morbidity and mortality. Lung endothelial cell (EC) dysfunction is one of the hallmarks of cardiovascular events of lung exposure to PM. However, the role of PM in acute lung injury (ALI) exacerbation and delayed recovery remains incompletely understood. This study tested a hypothesis that PM augments lung injury and EC barrier dysfunction via microtubule-dependent mechanisms. Our data demonstrate that in pulmonary EC PM caused time- and dose-dependent remodeling of actin cytoskeleton and considerable destabilization of the microtubule (MT) network. These events led to the weakening of cell junctions and formation of actin stress fibers, resulting in disruption of lung EC monolayer and increased permeability. PM also caused ROS-dependent activation of MT-specific deacetylase, HDAC6. Suppression of HDAC6 activity by pharmacological inhibitors or siRNA-based depletion of HDAC6 abolished PM-induced EC permeability increase, which was accompanied by reduced activation of stress kinase signaling, inhibition of Rho cascade, decreased IL-6 production and suppressed activation of its downstream target STAT3. Pretreatment of pulmonary EC with IL-6 inhibitor led to inhibition of STAT3 activity and decreased PM-induced hyper-permeability. Because one of the major activators of Rho-GTPase, GEFH1, is localized on the MT, we examined its involvement in PM-caused EC barrier compromise. Inhibition of GEF-H1 activation significantly attenuated PM-induced permeability increase. Moreover, combined inhibition of IL-6 and GEF-H1 signaling exhibited additive protective effect. Taken together, these results demonstrate a critical involvement of MT-associated signaling in the PM-induced exacerbation of lung EC barrier compromise and inflammatory response.

    更新日期:2018-10-17
  • Bone morphogenetic protein 2 increases lysyl oxidase activity via up-regulation of snail in human granulosa-lutein cells
    Cell Signal. (IF 3.487) Pub Date : 2018-10-12
    Long Bai, Hsun-Ming Chang, Yi-Min Zhu, Peter C.K. Leung

    Lysyl oxidase (LOX) is a copper-dependent enzyme that maintains and stabilizes the extracellular matrix (ECM) by catalyzing the cross-linking of elastin and collagen. ECM within the ovarian follicle plays a crucial role in regulating follicular development and oocyte maturation. Bone morphogenetic protein 2 (BMP2) belongs to the BMP subfamily that has been shown to be involved in the process of ovarian folliculogenesis and luteal formation. To date, whether BMP2 regulates the activity of LOX during human follicular development remains to be elucidated. The aim of this study was to investigate the effect of BMP2 on the regulation of LOX expression and activity in human granulosa-lutein cells (hGL) and the underlying mechanisms. Using both primary and immortalized (SVOG cells) hGL cells, we demonstrated that BMP2 up-regulated the expression and activity of LOX and hence decreased the soluble collagens in cultured medium in hGL cells. Additionally, the mRNA and protein levels of two transcriptional factors, SNAIL and SLUG, were increased following cell exposure to BMP2. Knockdown of SNAIL, but not SLUG partially reversed BMP2-induced increases in LOX expression and activity. The BMP2-induced up-regulation of SNAIL expression was abolished by the pre-treatment with two BMP type I receptor inhibitors, dorsomorphin and DMH-1, but not SB431542. Moreover, knockdown of SMAD4 completely abolished BMP2-induced up-regulation of SNAIL expression and the subsequent increases in LOX expression and activity. Our results suggest that BMP2 increases LOX expression and activity via the up-regulation of SNAIL in hGL cells. These findings may provide insights into the functional role of BMP2 in the regulation of ECM formation during folliculogenesis.

    更新日期:2018-10-14
  • Arginine 313 of the putative 8th helix mediates Gαq/14 coupling of human CC chemokine receptors CCR2a and CCR2b
    Cell Signal. (IF 3.487) Pub Date : 2018-10-12
    Daniel Markx, Julia Schuhholz, Michael Abadier, Sandra Beier, Mariana Lang, Barbara Moepps

    In man, two CC chemokine receptor isoforms, CCR2a and CCR2b, are present that belong to the rhodopsin-like G protein-coupled receptor family, and couple to Gi and Gq family members. The CCR2 receptors are known to regulate canonical functions of chemokines such as directed migration of leukocytes, and to potentially control non-canonical functions such as differentiation, proliferation, and gene transcription of immune and non-immune cells. We recently reported on the activation of phospholipase C isoenzymes and RhoA GTPases by coupling of the two CCR2 receptors to members of the Gq family, in particular Gαq and Gα14. So far little is known about the structural requirements for the CCR2/Gq/14 interaction. Interestingly, the CCR2 receptor isoforms are identical up to arginine 313 (R313) that is part of the putative 8th helix in CCR2 receptors, and the 8th helix has been implicated in the interaction of rhodopsin-like G protein-coupled receptors with Gαq. In the present work we describe that the 8th helix of both CCR2a and CCR2b is critically involved in selectively activating Gαq/14-regulated signaling. Refined analysis using various CCR2a and CCR2b mutants and analyzing their cellular signaling, e.g. ligand-dependent (i) activation of phospholipase C isoenzymes, (ii) stimulation of serum response factor-mediated gene transcription, (iii) activation of mitogen-activated protein kinases, (iv) internalization, and (v) changes in intracellular calcium concentrations, identified arginine 313 within the amino terminal portion of helix 8 to play a role for the agonist-mediated conformational changes and the formation of a Gαq/14 binding surface. We show that R313 determines Gαq/14 protein-dependent but not Gi protein-dependent cellular signaling but plays no role in Gq/Gi-independent receptor internalization, indicating a role of R313 in biased signaling of CCR2 receptors.

    更新日期:2018-10-12
  • A positive role of Sin3A in regulating Notch signaling during Drosophila wing development
    Cell Signal. (IF 3.487) Pub Date : 2018-10-12
    Xiao Zhang, Chen Miao, Zi Nan, Jialan Lyu, Yongmei Xi, Xiaohang Yang, Wanzhong Ge

    Notch is a transmembrane receptor that mediates intercellular signaling through a conserved signaling cascade in all animal species. Transcriptional and posttranscriptional regulation of Notch receptor are important for maintaining Notch signaling activity. Here, we show that depletion of Drosophila Sin3A leads to loss of the adult wing margin and downregulation of Notch target gene expression in the developing wing disc. Sin3A regulates the Notch pathway downstream of Delta and upstream of Notch activation. The role of Sin3A in the Notch pathway is partly mediated by its ability to modulate Notch receptor transcription. Furthermore, the transcriptional activation of Notch receptor is autoregulated by Notch itself. We also provide evidence that Sin3A is required for Notch activation mediated Notch transcription. Together, our data demonstrate that Sin3A activates Notch signaling by promoting Notch transcription and reveal a previously unknown autoregulatory mechanism for Notch signaling activation during Drosophila wing development.

    更新日期:2018-10-12
  • Loss of hypermethylated in cancer 1 (HIC1) promotes lung cancer progression
    Cell Signal. (IF 3.487) Pub Date : 2018-10-10
    Yue Li, Mengfei Yao, Tianqi Wu, Liyan Zhang, Yingying Wang, Liang Chen, Guohui Fu, Xiaoling Weng, Jianhua Wang
    更新日期:2018-10-10
  • Interleukin-1β signaling in osteoarthritis – chondrocytes in focus
    Cell Signal. (IF 3.487) Pub Date : 2018-10-09
    Zsuzsa Jenei-Lanzl, Andrea Meurer, Frank Zaucke
    更新日期:2018-10-10
  • Protective effect of lodoxamide on hepatic steatosis through GPR35
    Cell Signal. (IF 3.487) Pub Date : 2018-10-07
    So-Yeon Nam, Soo-Jin Park, Dong-Soon Im

    Although GPR35 is an orphan G protein-coupled receptor, synthetic agonists and antagonists have been developed. Recently, cromolyn, a mast cell stabilizer, was reported as an agonist of GPR35 and was shown to exhibit antifibrotic effects through its actions on hepatocytes and stellate cells. In this study, the role of GPR35 in hepatic steatosis was investigated using an in vitro model of liver X receptor (LXR)-mediated hepatocellular steatosis and an in vivo model of high fat diet-induced liver steatosis. GPR35 was expressed in Hep3B human hepatoma cells and mouse primary hepatocytes. A specific LXR activator, T0901317, induced lipid accumulation in Hep3B cells. Lodoxamide, the most potent agonist of GPR35, inhibited lipid accumulation in a concentration-dependent manner. The protective effect of lodoxamide was inhibited by a specific GPR35 antagonist, CID2745687, and by siRNA-mediated knockdown of GPR35. The expression of SREBP-1c, a key transcription factor for lipid synthesis, was induced by T0901317 and the induction was inhibited by lodoxamide. Through the use of specific inhibitors of cellular signaling components, the lodoxamide-induced inhibition of lipid accumulation was found to be mediated through p38 MAPKs and JNK, but not through Gi/o proteins and ERKs. Furthermore, the protective effect of lodoxamide was confirmed in mouse primary hepatocytes. Lodoxamide suppressed high fat diet-induced fatty liver development, which suggested the protective function of GPR35 in liver steatosis. Therefore, the present data suggest that GPR35 may function to protect against fatty liver development.

    更新日期:2018-10-08
  • Hepatic signalling disruption by pollutant Polychlorinated biphenyls in steatohepatitis
    Cell Signal. (IF 3.487) Pub Date : 2018-10-06
    Josiah E. Hardesty, Banrida Wahlang, K. Cameron Falkner, Hongxue Shi, Jian Jin, Daniel Wilkey, Michael Merchant, Corey Watson, Russell A. Prough, Matthew C. Cave
    更新日期:2018-10-08
  • Role of calcium in adult onset polycystic kidney disease
    Cell Signal. (IF 3.487) Pub Date : 2018-10-05
    Murali K. Yanda, Qiangni Liu, Valeriu Cebotaru, William B. Guggino, Liudmila Cebotaru
    更新日期:2018-10-06
  • Amphiregulin potentiates airway inflammation and mucus hypersecretion induced by urban particulate matter via the EGFR-PI3Kα-AKT/ERK pathway
    Cell Signal. (IF 3.487) Pub Date : 2018-10-03
    Jian Wang, Mengchan Zhu, Linlin Wang, Cuicui Chen, Yuanlin Song

    Ambient particulate matter (PM) promotes the development and exacerbation of chronic respiratory diseases, including chronic obstructive pulmonary disease (COPD) and asthma, by increasing inflammation and mucus hypersecretion. However, the biological mechanisms underlying PM-induced airway inflammation and mucus hypersecretion remain unclear. Amphiregulin (AREG) is an important ligand for epidermal growth factor receptor (EGFR) and participates in the regulation of several biological functions. Here, the PM-exposed human bronchial epithelial cell (HBEC) model was used to define the role of AREG in PM-induced inflammation and mucus hypersecretion and its related signaling pathways. The expression of AREG was significantly increased in a dose-dependent manner in HBECs subjected to PM exposure. Moreover, PM could induce inflammation and mucus hypersecretion by upregulating the expression of IL-1α, IL-1β, and Muc-5ac in HBECs. The EGFR, AKT, and ERK signaling pathways were also activated in a time- and dose-dependent manner. The AREG siRNA markedly attenuated PM-induced inflammation and mucus hypersecretion, and activation of the EGFR-AKT/ERK pathway. Exogenous AREG significantly increased the expression of IL-1α, IL-1β, and Muc-5ac, and induced activation of the EGFR-AKT/ERK pathway in HBECs. Further, under PM exposure, exogenous AREG significantly potentiated PM-induced inflammation and mucus hypersecretion, and activation of the EGFR-AKT/ERK pathway. Tumor-necrosis factor-alpha converting enzyme (TACE) and EGFR specific inhibitor pretreatment showed that AREG was secreted by TACE-mediated cleavage to regulate PM-induced inflammation and mucus hypersecretion by binding to the EGFR. Moreover, according to the inhibitory effect of specific inhibitors of the class I PI3K isoforms, AKT and ERK, PM-induced inflammation and mucus hypersecretion was regulated by PI3Kα activation and its downstream AKT and ERK pathways. This study strongly suggests the adverse effect of AREG in PM-induced inflammation and mucus hypersecretion via the EGFR-PI3Kα-AKT/ERK pathway. These findings contribute to a better understanding of the biological mechanisms underlying exacerbation of chronic respiratory diseases induced by PM exposure.

    更新日期:2018-10-04
  • S1PR2 antagonist alleviates oxidative stress-enhanced brain endothelial permeability by attenuating p38 and Erk1/2-dependent cPLA2 phosphorylation
    Cell Signal. (IF 3.487) Pub Date : 2018-10-02
    Changchun Cao, Li Dai, Junyu Mu, Xiaofei Wang, Yali Hong, Chao Zhu, Lai Jin, Shengnan Li
    更新日期:2018-10-03
  • Epidermal growth factor can signal via β-catenin to control proliferation of mesenchymal stem cells independently of canonical Wnt signalling
    Cell Signal. (IF 3.487) Pub Date : 2018-10-01
    Charlotte Knight, Sally James, David Kuntin, James Fox, Katherine Newling, Sam Hollings, Rebecca Pennock, Paul Genever

    Bone marrow mesenchymal stem/stromal cells (MSCs) maintain bone homeostasis and repair through the ability to expand in response to mitotic stimuli and differentiate into skeletal lineages. Signalling mechanisms that enable precise control of MSC function remain unclear. Here we report that by initially examining differences in signalling pathway expression profiles of individual MSC clones, we identified a previously unrecognised signalling mechanism regulated by epidermal growth factor (EGF) in primary human MSCs. We demonstrate that EGF is able to activate β-catenin, a key component of the canonical Wnt signalling pathway. EGF is able to induce nuclear translocation of β-catenin in human MSCs but does not drive expression of Wnt target genes or T cell factor (TCF) activity in MSC reporter cell lines. Using an efficient Design of Experiments (DoE) statistical analysis, with different combinations and concentrations of EGF and Wnt ligands, we were able to confirm that EGF does not influence the Wnt/β-catenin pathway in MSCs. We show that the effects of EGF on MSCs are temporally regulated to initiate early “classical” EGF signalling mechanisms (e.g via mitogen activated protein kinase) with delayed activation of β-catenin. By RNA-sequencing, we identified gene sets that were exclusively regulated by the EGF/β-catenin pathway, which were distinct from classical EGF-regulated genes. However, subsets of classical EGF gene targets were significantly influenced by EGF/β-catenin activation. These signalling pathways cooperate to enable EGF-mediated proliferation of MSCs by alleviating the suppression of cell cycle pathways induced by classical EGF signalling.

    更新日期:2018-10-02
  • Ribosomal RACK1 promotes proliferation of neuroblastoma cells independently of global translation upregulation
    Cell Signal. (IF 3.487) Pub Date : 2018-10-01
    Nicla Romano, Matteo Veronese, Nicola Manfrini, Lello Zolla, Marcello Ceci

    Neuroblastoma is the most frequent solid tumor among those diagnosed during infancy and like most tumors, it is characterized by elevated rates of cell proliferation, migration and invasion. RACK1 is among the top 10 genes identified for unfavorable prognosis at 5 years in neuroblastoma cases and its depletion negatively affects proliferation, invasion and migration. Here, we show that the ribosomal localization of RACK1 modulates the proliferation of SH-SY5Y neuroblastoma cells by regulating the expression of cell cycle genes, such as Cyclin D1, D3 and B1 independently of global translation increase. Ribosomal RACK1 is not involved in general protein synthesis, which is instead dependent on total RACK1 and PKC but independent from mTOR. Thus, ribosomal RACK1 may represent a new target to develop more efficient therapies for neuroblastoma treatment.

    更新日期:2018-10-02
  • The effect of lentivirus-mediated SIRT1 gene knockdown in the ATDC5 cell line via inhibition of the Wnt signaling pathway
    Cell Signal. (IF 3.487) Pub Date : 2018-09-25
    Yu Fei, Yuan Yusong, Li Dongdong, Kou Yuhui, Jiang Baoguo, Zhang Peixun

    SIRT1 is a highly conserved type III acetyltransferase gene located on chromosome 10 in mammals that belong to the Sirtuins family. In order to explore the effects of the SIRT1 gene in the ATDC5 cell line, an RNAi SIRT1 target sequence was designed and synthesized, aimed to knockdown the expression of SIRT1 in ATDC5 by a lentivirus. Gene chip, qrt-PCR, and WES analyses were used to detect the expression of SIRT1 and changes to the Wnt signaling pathway, while detecting any changes in proliferation and differentiation factors. The results showed that the expressions of the SIRT1 gene, mRNA, and protein were lower after transfection of the RNAi SIRT1sequence into ATDC5 cells. The Wnt signaling pathway, especially the classical pathway, was inhibited by the knockdown of SIRT1. The cartilaginous proliferation and differentiation of ATDC5 cells were simultaneously inhibited, and apoptosis was accelerated. In summary, knocking down SIRT1 gene increased the degeneration of ATDC5 cells via inhibiting the Wnt signaling pathway. We also found some novel factors related to the Wnt signaling pathway after SIRT1 gene knockdown (BIRC3, IL1RAP, PPP3CA, PPP2R2A, PPP2R5E, GSN, PPP2R1B, etc), which might provide new clues in disease research related to chondrocyte degeneration.

    更新日期:2018-09-26
  • PKCδ stimulates macropinocytosis via activation of SSH1-cofilin pathway
    Cell Signal. (IF 3.487) Pub Date : 2018-09-24
    Bhupesh Singla, Hui-Ping Lin, Pushpankur Ghoshal, Mary Cherian-Shaw, Gábor Csányi

    Macropinocytosis is an actin-dependent endocytic mechanism mediating internalization of extracellular fluid and associated solutes into cells. The present study was designed to identify the specific protein kinase C (PKC) isoform(s) and downstream effectors regulating actin dynamics during macropinocytosis. We utilized various cellular and molecular biology techniques, pharmacological inhibitors and genetically modified mice to study the signaling mechanisms mediating macropinocytosis in macrophages. The qRT-PCR experiments identified PKCδ as the predominant PKC isoform in macrophages. Scanning electron microscopy and flow cytometry analysis of FITC-dextran internalization demonstrated the functional role of PKCδ in phorbol ester- and hepatocyte growth factor (HGF)-induced macropinocytosis. Western blot analysis demonstrated that phorbol ester and HGF stimulate activation of slingshot phosphatase homolog 1 (SSH1) and induce cofilin Ser-3 dephosphorylation via PKCδ in macrophages. Silencing of SSH1 inhibited cofilin dephosphorylation and macropinocytosis stimulation. Interestingly, we also found that incubation of macrophages with BMS-5, a potent inhibitor of LIM kinase, does not stimulate macropinocytosis. In conclusion, the findings of the present study demonstrate a previously unidentified mechanism by which PKCδ via activation of SSH1 and cofilin dephosphorylation stimulates membrane ruffle formation and macropinocytosis. The results of the present study may contribute to a better understanding of the regulatory mechanisms during macrophage macropinocytosis.

    更新日期:2018-09-25
  • The amino acid transporter PAT1 regulates mTORC1 in a nutrient-sensitive manner that requires its transport activity
    Cell Signal. (IF 3.487) Pub Date : 2018-09-22
    Lingling Zhao, Xiangxiang Zhang, Xin Ji, Yaping Jin, Wei Liu

    The proton-coupled amino acid transporter PAT1 has been postulated to regulate the amino acid-stimulated mTORC1 through two different mechanisms, either it activates mTORC1 by sensing and transducing the lysosomal amino acid signal to mTORC1, or it inhibits mTORC1 by decreasing the signal level, as increased PAT1 has been shown to either activate or inactivate mTORC1 in the human embryonic kidney HEK293 cells. The current study aims to clarify the cause of these controversial observations, which is promoted by the recent discovery that the lysosomal PAT1 can be induced by starvation. Here, we show that under the normal culture condition, overexpression of PAT1 did not apparently change the mTORC1 activity in the fast proliferating cells. However when these cells were synchronized by starvation, followed by nutrient replenishment for a short period of time, the mTORC1 activity was decreased by PAT1 overexpression; if the nutrient stimulation lasted for longer time, the mTORC1 activities could be recovered in the PAT1-overexpressing cells. In addition, we showed the starvation-induced lysosomal PAT1 was gradually decreased during the nutrient replenishment. These results reveal that the influence of PAT1 on mTORC1 seems to be affected by the nutrient condition and the level of lysosomal PAT1. We further demonstrate that suppressing the transport activity of PAT1 abolished its inhibitory effect on mTORC1. Our data support a mechanism that PAT1 can negatively regulate mTORC1 by controlling the cellular nutrient signal level.

    更新日期:2018-09-25
  • USF2 inhibits the transcriptional activity of Smurf1 and Smurf2 to promote breast cancer tumorigenesis
    Cell Signal. (IF 3.487) Pub Date : 2018-09-21
    Yawen Tan, Yujiao Chen, Mengge Du, Zhiqiang Peng, Ping Xie

    Smurf1 (Smad ubiquitylation regulatory factor 1) and Smurf2 are negative regulators of the TGF-β (transforming growth factor-β) pathway. The protein stability and ubiquitin E3 activity regulation of Smurfs have been well studied. However, the mechanism of Smurfs expression at the transcriptional level remains uncharacterized. Here, we reported that USF2 (upstream stimulatory factor 2), a basic helix-loop-helix-leucine-zip transcription factor, is necessary for the transcriptional activity of Smurf1 and Smurf2. The 5′-flanking sequences of the Smurfs gene have more than one E-box motifs, and USF2 bounds the Smurfs promoter in vitro and in vivo. Over-expression USF2 inhibited the transcriptional activity of the Smurfs, and Smurfs mRNA was markedly decreased. Therefore, the activity of TGF-β was distinctly enhanced. Furthermore, in human breast cancers, USF2 was abnormally high expressed and correlated with cancer progression. USF2 was specifically inversely correlated with Smurfs in Luminal A subtype breast cancer patients. These findings suggest the mechanism regulation of Smurfs transcriptional activity, and shed new light on the cancer-promoting role of USF2.

    更新日期:2018-09-25
  • Protectin DX prevents H2O2-mediated oxidative stress in vascular endothelial cells via an AMPK-dependent mechanism
    Cell Signal. (IF 3.487) Pub Date : 2018-09-20
    Hwan-Jin Hwang, Tae Woo Jung, Joo Won Kim, Jung A. Kim, You Bin Lee, So Hyeon Hong, Eun Roh, Kyung Mook Choi, Sei Hyun Baik, Hye Jin Yoo
    更新日期:2018-09-21
  • Jab1/Cops5 contributes to chemoresistance in breast cancer by regulating Rad51
    Cell Signal. (IF 3.487) Pub Date : 2018-09-20
    Guohong Liu, Mingxia Yu, Balu Wu, Shuang Guo, Xin Huang, Fuling Zhou, Francois X. Claret, Yunbao Pan
    更新日期:2018-09-21
  • BAFF inhibits autophagy promoting cell proliferation and survival by activating Ca2+-CaMKII-dependent Akt/mTOR signaling pathway in normal and neoplastic B-lymphoi d cells
    Cell Signal. (IF 3.487) Pub Date : 2018-09-20
    Xiaoqing Dong, Jiamin Qin, Jing Ma, Qingyu Zeng, Hai Zhang, Ruijie Zhang, Chunxiao Liu, Chong Xu, Shuangquan Zhang, Shile Huang, Long Chen
    更新日期:2018-09-21
  • Elucidating the microRNA-203 specific biological processes in glioblastoma cells from comprehensive RNA-sequencing transcriptome profiling
    Cell Signal. (IF 3.487) Pub Date : 2018-09-20
    Bhavesh K. Ahir, Sajani S. Lakka

    Glioblastoma (GBM) is the most common primary malignant intracranial adult brain tumor. Allelic deletion on chromosome 14q plays an essential role in GBM pathogenesis, and this chromosome 14q site was thought to harbor multiple tumor suppressor genes associated with GBM, a region that also encodes microRNA-203 (miR-203). This study was conducted to identify whole transcriptome profile changes associated with miR-203 expression by high-throughput RNA sequencing. Enrichment analyses for gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that miR-203 expression had a strong, negative effect on a number of fundamental and interconnected biological processes involved in cell growth and proliferation. The biological processes mostly influenced were p53 signaling pathway, FoxO signaling pathway, DNA replication, cell cycle, MAPK signaling pathway and apoptosis. In total, 847 upregulated and 345 downregulated differentially expressed genes were identified in control versus miR-203 expressing glioma cells. After GO enrichment, the downregulated differentially expressed genes such as BCL2, SPARC were found to be mainly enriched in cell cycle regulation and apoptosis processes, whereas the upregulated differentially expressed genes such as CCND1, E2F1 were involved in the DNA replication and cell cycle regulation. We also performed miR-203 target analysis and found BCL2, AKT, SPARC, ROBO1, c-JUN, PDGFA and CREB were predicted target of miR-203 and miR-203 expression suppressed the protein and mRNA levels of these target genes by western blotting and qRT-PCR analysis. Moreover, co-transfection experiments using a luciferase-based reporter assay demonstrated that miR-203 directly regulated BCL-2 expression and BCL-2 overexpression suppressed miR-203 mediated glioma cell apoptosis. These results indicate that overexpression of miR-203 coordinately regulate several oncogenic pathways in GBM.

    更新日期:2018-09-21
  • Cyclin-dependent kinase 1-mediated phosphorylation of YES links mitotic arrest and apoptosis during antitubulin chemotherapy
    Cell Signal. (IF 3.487) Pub Date : 2018-09-15
    Zhan Wang, Xingcheng Chen, Mei-Zuo Zhong, Shuping Yang, Jiuli Zhou, David L. Klinkebiel, Adam R. Karpf, Yuanhong Chen, Jixin Dong

    YES is a member of the SRC family kinase (SFK) group of non-receptor tyrosine kinases, which are implicated in multiple key cellular processes involved in oncogenesis. Antitubulin agents have been widely used as chemotherapeutics for cancer patients and these drugs arrest cells in mitosis, leading to subsequent cell death. In the present study, we define a mechanism for phospho-regulation of YES that is critical for its role in response to antitubulin agents. Specifically, we found that YES is phosphorylated at multiple sites on its N-terminal unique domain by the cell cycle kinase CDK1 during antitubulin drug-induced mitotic arrest. Phosphorylation of YES occurs during normal mitosis. Deletion of YES causes arrest in prometaphase and polyploidy in a p53-independent manner. We further show that YES regulates antitubulin chemosensitivity. Importantly, mitotic phosphorylation is essential for these effects. In support of our findings, we found that YES expression is high in recurrent ovarian cancer patients. Finally, through expression profiling, we documented that YES phosphorylation affects expression of multiple cell cycle regulators. Collectively, our results reveal a previously unrecognized mechanism for controlling the activity of YES during antitubulin chemotherapeutic treatment and suggest YES as a potential target for the treatment of antitubulin-resistant cancer.

    更新日期:2018-09-17
  • TGFβ, smooth muscle cells and coronary artery disease: a review
    Cell Signal. (IF 3.487) Pub Date : 2018-09-15
    Emma L. Low, Andrew H. Baker, Angela C. Bradshaw

    Excessive vascular smooth muscle cell (SMC) proliferation, migration and extracellular matrix (ECM) synthesis are key events in the development of intimal hyperplasia, a pathophysiological response to acute or chronic sources of vascular damage that can lead to occlusive narrowing of the vessel lumen. Atherosclerosis, the primary cause of coronary artery disease, is characterised by chronic vascular inflammation and dyslipidemia, while revascularisation surgeries such as coronary stenting and bypass grafting represent acute forms of vascular injury. Gene knockouts of transforming growth factor-beta (TGFβ), its receptors and downstream signalling proteins have demonstrated the importance of this pleiotropic cytokine during vasculogenesis and in the maintenance of vascular homeostasis. Dysregulated TGFβ signalling is a hallmark of many vascular diseases, and has been associated with the induction of pathological vascular cell phenotypes, fibrosis and ECM remodelling. Here we present an overview of TGFβ signalling in SMCs, highlighting the ways in which this multifaceted cytokine regulates SMC behaviour and phenotype in cardiovascular diseases driven by intimal hyperplasia.

    更新日期:2018-09-17
  • RNF186 impairs insulin sensitivity by inducing ER stress in mouse primary hepatocytes
    Cell Signal. (IF 3.487) Pub Date : 2018-09-14
    Xin Tong, Qifan Zhang, Lu Wang, Yizhong Ji, Lei Zhang, Liwei Xie, Wei Chen, Huabing Zhang

    RING finger 186 (RNF186) is involved in the process of endoplasmic reticulum (ER)-stress-mediated apoptosis and inflammation of different cell types, such as HeLa cells and colon epithelial cells. However, the physiological and functional roles of RNF186 in peripheral tissues remain largely unknown. In the current study, we investigate the physiological function of RNF186 in the regulation of ER stress with respect to its biological roles in regulating insulin sensitivity in mouse primary hepatocytes. RNF186 expression is induced in the livers of diabetic, obese and diet-induced obese (DIO) mice. Mouse primary hepatocytes were isolated and treated with Ad-RNF186 or Ad-GFP. The results suggest that overexpression of RNF186 increases the protein levels of the ER stress sensors inositol requiring kinase 1 (IRE1) and C/EBP homologous protein (CHOP) protein, as well as the phosphorylation level of eukaryotic initiation factor 2α (eIF2α), in mouse primary hepatocytes. This effect impedes the action of insulin through c-Jun N-terminal kinase (JNK)-mediated phosphorylation of insulin receptor substrate 1 (IRS1). Furthermore, overexpression of RNF186 also significantly increases the levels of proinflammatory cytokines, including TNFα, IL-6 and MCP1. In addition, tauroursodeoxycholic acid (TUDCA), an ER stress inhibitor, alleviates the expression of ER stress markers induced by RNF186 overexpression. Taken together, the results of the present study show that overexpression of RNF186 induces ER stress and impairs insulin signalling in mouse primary hepatocytes, suggesting that RNF186 merits further investigation as a potential therapeutic target for treatment of insulin-resistance-associated metabolic diseases.

    更新日期:2018-09-17
  • Sirt3 attenuates post-infarction cardiac injury via inhibiting mitochondrial fission and normalization of AMPK-Drp1 pathways
    Cell Signal. (IF 3.487) Pub Date : 2018-09-13
    Jixuan Liu, Wei Yan, Xiaojing Zhao, Qian Jia, Jinda Wang, Huawei Zhang, Chunlei Liu, Kunlun He, Zhijun Sun

    Mitochondrial damage is involved in the pathogenesis of post-infarction cardiac injury. However, the upstream regulators of mitochondrial damage have not yet been identified. The aim of our study is to explore the role of Sirt3 in post-infarction cardiac injury with a particular focus on mitochondrial fission and AMPK-Drp1 pathways. Our results indicated that Sirt3 was downregulated in the progression of post-infarction cardiac injury. Overexpression of Sirt3 attenuated cardiac fibrosis, sustained myocardial function, inhibited the inflammatory response, and reduced cardiomyocyte death. Functional studies illustrated that chronic post-infarction cardiac injury was characterized by increased mitochondrial fission, which triggered mitochondrial oxidative stress, metabolic disorders, mitochondrial potential reduction and caspase-9 apoptosis in cardiomyocytes. However, Sirt3 overexpression attenuated mitochondrial fission and thus preserved mitochondrial homeostasis and cardiomyocyte viability. Furthermore, our results confirmed that Sirt3 repressed mitochondrial fission via normalizing AMPK-Drp1 pathways. Inhibition of AMPK activity re-activated Drp1 and thus abrogated the inhibitory effect of Sirt3 on mitochondrial fission. Altogether, our results indicate that Sirt3 enhancement could be an effective approach to retard the development of post-infarction cardiac injury via disrupting mitochondrial fission and normalizing the AMPK-Drp1 axis.

    更新日期:2018-09-14
  • S3I-201, a selective Stat3 inhibitor, restores neuroimmune function through upregulation of Treg signaling in autistic BTBR T+ Itpr3tf/J mice
    Cell Signal. (IF 3.487) Pub Date : 2018-09-10
    Sheikh F. Ahmad, Mushtaq A. Ansari, Ahmed Nadeem, Saleh A. Bakheet, Musaad A. Alshammari, Mohammad R. Khan, Abdulaziz M.S. Alsaad, Sabry M. Attia

    Autism spectrum disorder (ASD) is a neurodevelopmental disorder whose symptoms include communication deficits, a lack of social skills, and stereotyped repetitive behaviors. We used BTBR T+ Itpr3tf/J (BTBR) mice, a model that demonstrates most of the core behavioral features of ASD, such as decreased sociability and high levels of repetitive behaviors. Currently, there is no treatment available that is able to improve most of the ASD disorder symptoms; thus, finding novel therapies is immediately required. Stat3 inhibitors are potential targets in the treatment of several immune disorders. The aim of the present study was to investigate the effects of S3I-201, a selective Stat3 inhibitor, to determine its potential mechanism in BTBR mice. In this study, we first examined the effects of S3I-201 on repetitive behavior and marble burying. We also examined the treatment of S3I-201 on Th1 (IFN-γ and T-bet), Th17 (IL-17A, RORγt, Stat3, IL-21, and IL-22), and T regulatory (Treg, Foxp3 and Helios) production in spleen CD4+ T cells. We further assessed Th1, Th17, and Treg mRNA and protein expression levels in brain tissues. S3I-201 treatment in BTBR mice significantly prevents marble burying and repetitive behavior. Furthermore, S3I-201 administration causes a considerable decrease in IFN-γ, T-bet, IL-17A, RORγt, Stat3, IL-21, and IL-22 levels, and increases in Foxp3 and Helios production CD4+ T cells in BTBR mice. Additionally, S3I-201 treatment also significantly decreases Th1 and Th17 levels, and increases Treg mRNA and protein expression levels. Therefore, these results suggest that S3I-201 could be considered as a therapeutic option for ASD.

    更新日期:2018-09-11
  • Ligand-mediated dephosphorylation signaling for MAP kinase
    Cell Signal. (IF 3.487) Pub Date : 2018-09-10
    Nataliia V. Shults, Faisal S. Almansour, Vladyslava Rybka, Dante I. Suzuki, Yuichiro J. Suzuki

    Extracellular signal-regulated kinase (ERK), also known as classical mitogen-activated protein kinase, plays critical roles in cell regulation. ERK is activated through phosphorylation by a cascade of protein kinases including MEK. Various ligands activate the MEK/ERK pathway through receptor-dependent cell signaling. In cultured cells, many ligands such as growth factors, hormones, cytokines and vasoactive peptides elicit transient activation of MEK/ERK, often peaking at ~10 min after the cell treatment. Here, we describe a novel biological event, in which ligand-mediated cell signaling results in the dephosphorylation of MEK/ERK. Neuromedin N and neurotensin, peptides derived from the same precursor polypeptide, elicit cell signaling through the neurotensin receptors. In cultured human pulmonary artery smooth muscle cells (PASMCs), but not in human pulmonary artery endothelial cells (PAECs), we found that both neuromedin N and neurotensin promoted the dephosphorylation of ERK and MEK. Human PASMCs were found to express neurotensin receptor (NTR)-1, −2 and −3, while human PAECs only express NTR3. Neuromedin N-mediated dephosphorylation was suppressed by small chemical inhibitors of protein phosphatase 1/2A and peptidyl-prolyl isomerase. Transmission electron microscopy showed the formation of endocytic vesicles in response to neuromedin N treatment, and dephosphorylation did not occur when sorting nexin 9, a critical regulator of the endocytic vesicle formation, was knocked down. We conclude that neuromedin N and neurotensin elicit a unique dephosphorylation signaling in the MEK/ERK pathway that is regulated by endocytosis. Considering the pathophysiological importance of the MEK/ERK pathway, this discovery of the dephosphorylation mechanism should advance the field of cell signaling.

    更新日期:2018-09-10
  • TGF-β receptors: In and beyond TGF-β signaling
    Cell Signal. (IF 3.487) Pub Date : 2018-09-07
    Alexandra Vander Ark, Jingchen Cao, Xiaohong Li

    Transforming growth factor β (TGF-β) plays an important role in normal development and homeostasis. Dysregulation of TGF-β responsiveness and its downstream signaling pathways contribute to many diseases, including cancer initiation, progression, and metastasis. TGF-β ligands bind to three isoforms of the TGF-β receptor (TGFBR) with different affinities. TGFBR1 and 2 are both serine/threonine and tyrosine kinases, but TGFBR3 does not have any kinase activity. They are necessary for activating canonical or noncanonical signaling pathways, as well as for regulating the activation of other signaling pathways. Another prominent feature of TGF-β signaling is its context-dependent effects, temporally and spatially. The diverse effects and context dependency are either achieved by fine-tuning the downstream components or by regulating the expressions and activities of the ligands or receptors. Focusing on the receptors in events in and beyond TGF-β signaling, we review the membrane trafficking of TGFBRs, the kinase activity of TGFBR1 and 2, the direct interactions between TGFBR2 and other receptors, and the novel roles of TGFBR3.

    更新日期:2018-09-09
  • Syndecan transmembrane domain modulates intracellular signaling by regulating the oligomeric status of the cytoplasmic domain
    Cell Signal. (IF 3.487) Pub Date : 2018-09-06
    Bohee Jang, Hyejung Jung, Heejeong Hong, Eok-Soo Oh

    Cell surface receptors must specifically recognize an extracellular ligand and then trigger an appropriate response within the cell. Their general structure enables this, as it comprises an extracellular domain that can bind an extracellular ligand, a cytoplasmic domain that can transduce a signal inside the cell to produce an appropriate response, and a transmembrane domain that links the two and is responsible for accurately delivering specific information on a binding event from the extracellular domain to the cytoplasmic domain, to trigger the proper response. A vast body of research has focused on elucidating the specific mechanisms responsible for regulating extracellular binding events and the subsequent interactions of the cytoplasmic domain with intracellular signaling. In contrast, far less work has focused on examining how the transmembrane domain links these domains and delivers the necessary information. In this review, we propose the importance of the transmembrane domain as a signal regulator. We highlight the cell adhesion receptor, syndecan, as a special case, and propose that the transmembrane domain-mediated oligomerization of the syndecan cytoplasmic domain is a unique regulatory mechanism in syndecan signaling.

    更新日期:2018-09-06
  • Tetraspanin CD82 represses Sp1-mediated Snail expression and the resultant E-cadherin expression interrupts nuclear signaling of β-catenin by increasing its membrane localization
    Cell Signal. (IF 3.487) Pub Date : 2018-09-04
    Moon-Sung Lee, Hee-Jung Byun, Jaeseob Lee, Doo-Il Jeoung, Young-Myeong Kim, Hansoo Lee

    Tetraspanin membrane proteins form physical complexes with signaling molecules and have been suggested to influence the signaling events of associated molecules. Of the tetraspanin proteins, CD82 has been shown to promote homotypic cell-cell adhesion, which partially accounts for its role in suppressing cancer invasion and metastasis. We found here that CD82-induced cell-cell adhesion is attributed to increased E-cadherin expression through CD82-mediated downregulation of the E-cadherin repressor Snail. The Snail repression by CD82 resulted from the reduced binding of the Sp1 transcription factor to the Snail gene promoter. Notably, high CD82 expression did not allow the fibronectin matrix to induce Sp1 phosphorylation, implicating CD82 inhibition of the fibronectin-integrin signaling-dependent Sp1 activation. Meanwhile, E-cadherin upregulated by CD82 pulled β-catenin up to the membrane region, and consequently reduced the amount of cytoplasmic β-catenin that was able to move into to the nucleus. The Wnt signal-induced nuclear translocation of β-catenin was also inhibited by the CD82 function of upregulating E-cadherin. Overall, high CD82 expression was likely to suppress fibronectin adhesion-induced Sp1 activation signaling for Snail expression, resulting in continuous E-cadherin expression, which contributed not only to the maintenance of strong cell-cell adhesion but also to the blockage of nuclear β-catenin signaling.

    更新日期:2018-09-05
  • Phosphorylation state of Ser165 in α-tubulin is a toggle switch that controls proliferating human breast tumors
    Cell Signal. (IF 3.487) Pub Date : 2018-09-01
    Ela Markovsky, Elisa de Stanchina, Aryeh Itzkowitz, Adriana Haimovitz-Friedman, Susan A. Rotenberg
    更新日期:2018-09-03
  • Wnt5a contributes to dectin-1 and LOX-1 induced host inflammatory response signature in Aspergillus fumigatus keratitis
    Cell Signal. (IF 3.487) Pub Date : 2018-08-31
    Chengye Che, Cui Li, Jing Lin, Jie Zhang, Nan Jiang, Kelan Yuan, Guiqiu Zhao

    Fungal keratitis causes devastating corneal ulcers which can result in significant visual impairment and even blindness. As a ligand that activates the non-canonical Wnt signaling pathways, Wnt5a triggers the production of important inflammatory chemokines and the chemotactic migration of neutrophils. In this study we aimed to characterize the role of Wnt5a production, in situ, in vivo and in vitro in response to fungal keratitis. Wnt5a expression in corneas of Aspergillus fumigatus (A. fumigatus) keratitis patients was determined by quantitative polymerase chain reaction (qRT-PCR) and immunofluorescence. In vivo and in vitro experiments were then performed in mouse models and THP-1 macrophages cell cultures infected with A. fumigatus, respectively. C57BL/6 mice were pretreated with siRNAs or neutralizing antibodies for dectin-1, LOX-1 and Wnt5a, or inhibitors of erk1/2 and JNK. Changes in Wnt5a expression were assessed by clinical evaluation, qRT-PCR, immunofluorescence, western blot and bioluminescence imaging system image acquisition. We confirmed that corneal Wnt5a expression increased with A. fumigatus keratitis in patients and a murine model. Wnt5a production was dependent on dectin-1 and LOX-1 expression with contributions by Erk1/2 and JNK pathways. Additionally, Wnt5a knockdown revealed decreased levels of MPO, lower neutrophil recruitment, and a higher fungal load in mouse models. Compared with controls, Wnt5a knockdown impaired pro-inflammatory cytokine IL-1β production in response to A. fumigatus exposure. Wnt5a also produces dectin-1 and LOX-1 induced inflammatory signature via effective neutrophil recruitment and inflammatory cytokine production in response to A. fumigatus keratitis. These findings demonstrate that Wnt5a is a critical component of the antifungal immune response.

    更新日期:2018-08-31
  • Amyloid precursor protein is required for in vitro platelet adhesion to amyloid peptides and potentiation of thrombus formation
    Cell Signal. (IF 3.487) Pub Date : 2018-08-30
    Caterina Visconte, Jessica Canino, Gianni Guidetti, Marta Zarà, Claudio Seppi, Abubaker Aisha Alsheikh, Giordano Pula, Mauro Torti, Ilaria Canobbio

    Amyloid precursor protein (APP) is the precursor of amyloid β (Aβ) peptides, whose accumulation in the brain is associated with Alzheimer's disease. APP is also expressed on the platelet surface and Aβ peptides are platelet agonists. The physiological role of APP is largely unknown. In neurons, APP acts as an adhesive receptor, facilitating integrin-mediated cell adhesion, while in platelets it regulates coagulation and venous thrombosis. In this work, we analyzed platelets from APP KO mice to investigate whether membrane APP supports platelet adhesion to physiological and pathological substrates. We found that APP-null platelets adhered and spread normally on collagen, von Willebrand Factor or fibrinogen. However, adhesion on immobilized Aβ peptides Aβ1–40, Aβ1–42 and Aβ25–35 was completely abolished in platelets lacking APP. By contrast, platelet activation and aggregation induced by Aβ peptides occurred normally in the absence of APP. Adhesion of APP-transfected HEK293 to Aβ peptides was significantly higher than that of control cells expressing low levels of APP. Co-coating of Aβ1–42 and Aβ25–35 with collagen strongly potentiated platelet adhesion when whole blood from wild type mice was perfused at arterial shear rate, but had no effects with blood from APP KO mice. These results demonstrate that APP selectively mediates platelet adhesion to Aβ under static condition but not platelet aggregation, and is responsible for Aβ-promoted potentiation of thrombus formation under flow. Therefore, APP may facilitate an early step in thrombus formation when Aβ peptides accumulate in cerebral vessel walls or atherosclerotic plaques.

    更新日期:2018-08-31
  • 更新日期:2018-08-30
  • Smooth muscle cell-driven vascular diseases and molecular mechanisms of VSMC plasticity
    Cell Signal. (IF 3.487) Pub Date : 2018-08-30
    Agne Frismantiene, Maria Philippova, Paul Erne, Therese J. Resink

    Vascular smooth muscle cells (VSMCs) are the major cell type in blood vessels. Unlike many other mature cell types in the adult body, VSMC do not terminally differentiate but retain a remarkable plasticity. Fully differentiated medial VSMCs of mature vessels maintain quiescence and express a range of genes and proteins important for contraction/dilation, which allows them to control systemic and local pressure through the regulation of vascular tone. In response to vascular injury or alterations in local environmental cues, differentiated/contractile VSMCs are capable of switching to a dedifferentiated phenotype characterized by increased proliferation, migration and extracellular matrix synthesis in concert with decreased expression of contractile markers. Imbalanced VSMC plasticity results in maladaptive phenotype alterations that ultimately lead to progression of a variety of VSMC-driven vascular diseases. The nature, extent and consequences of dysregulated VSMC phenotype alterations are diverse, reflecting the numerous environmental cues (e.g. biochemical factors, extracellular matrix components, physical) that prompt VSMC phenotype switching. In spite of decades of efforts to understand cues and processes that normally control VSMC differentiation and their disruption in VSMC-driven disease states, the crucial molecular mechanisms and signalling pathways that shape the VSMC phenotype programme have still not yet been precisely elucidated. In this article we introduce the physiological functions of vascular smooth muscle/VSMCs, outline VSMC-driven cardiovascular diseases and the concept of VSMC phenotype switching, and review molecular mechanisms that play crucial roles in the regulation of VSMC phenotypic plasticity.

    更新日期:2018-08-30
  • Long non-coding RNA H19/SAHH axis epigenetically regulates odontogenic differentiation of human dental pulp stem cells
    Cell Signal. (IF 3.487) Pub Date : 2018-08-27
    Li Zeng, Shichen Sun, Dong Han, Yang Liu, Haochen Liu, Hailan Feng, Yixiang Wang

    Long noncoding RNAs (lncRNAs) are emerging as important regulators in molecular processes and may play vital roles in odontogenic differentiation of human dental pulp stem cells (hDPSCs). However, their functions remain to be elucidated. As lncRNA H19 is one of the most classical lncRNA, which plays essential roles in cellular differentiation, thus we explored the effects and mechanisms of H19 in odontogenic differentiation of hDPSCs. Stable overexpression and knockdown of H19 in hDPSCs were constructed using recombinant lentiviruses containing H19 and short hairpin-H19 expression cassettes, respectively. Alkaline phosphatase (ALP) assay, Alizarin red staining assay, von kossa staining, quantitative polymerase chain reaction (qPCR), Western blot analysis, and immunofluorescent staining results indicated that overexpression of H19 in hDPSCs positively regulates the odontogenic differentiation of hDPSCs, while knockdown of H19 in hDPSCs inhibits odontogenic differentiation of hDPSCs. Further, we found that H19 promotes the odontogenic differentiation of hDPSCs through S-adenosylhomocysteine hydrolase (SAHH) epigenetically regulates the methylation and expression of distal-less homeobox (DLX3) gene. Herein, for the first time, we determined that H19/SAHH axis epigentically regulates odontogenic differentiaiton of hDPSCs by inhibiting the DNA methyltransferase 3B (DNMT3B)-mediated methylation of DLX3. Our findings provide a new insight into how H19/SAHH axis play its role in odontogenic differentiation of hDPSCs, and would be helpful in developing therapeutic approaches for dentin regeneration based on stem cells.

    更新日期:2018-08-29
  • β-Heregulin impairs EGF induced PLC-γ1 signalling in human breast cancer cells
    Cell Signal. (IF 3.487) Pub Date : 2018-08-27
    Nadine Rommerswinkel, Silvia Keil, Alshaimaa Adawy, Jan G. Hengstler, Bernd Niggemann, Kurt S. Zänker, Thomas Dittmar

    The interplay of ErbB receptor homo- and heterodimers plays a crucial role in the pathology of breast cancer since activated signal transduction cascades coordinate proliferation, survival and migration of cells. EGF and β-Heregulin are well characterised ligands known to induce ErbB homo- and heterodimerisation, which have been associated with disease progression. In the present study, we investigated the impact of both factors on the migration of MDA-NEO and MDA-HER2 human breast cancer cells. MDA-NEO cells are positive for EGFR and HER3, while MDA-HER2 cells express EGFR, HER2 and HER3. Cell migration analysis revealed that β-Heregulin potently impaired EGF induced migration in both cell lines. Western blot studies showed that both ErbB receptor and PLC-γ1 tyrosine phosphorylation levels were diminished in EGF and β-Heregulin co-treated MDA-NEO and MDA-HER2 cells, which was further correlated to a significantly impaired calcium influx. Our data indicate that EGF and HRG may interfere with each other for receptor binding and dimerisation, which ultimately has an impact on signalling outcome.

    更新日期:2018-08-29
  • EphA3 maintains radioresistance in head and neck cancers through epithelial mesenchymal transition
    Cell Signal. (IF 3.487) Pub Date : 2018-04-10
    Song Hee Kim, Won Hyeok Lee, Seong Who Kim, Je Hyoung Uk, Jong Cheol Lee, Hyo Won Chang, Young Min Kim, Kyungbin Kim, Sang Yoon Kim, Myung Woul Han

    Radiotherapy is a well-established therapeutic modality used in the treatment of many cancers. However, radioresistance remains a serious obstacle to successful treatment. Radioresistance can cause local recurrence and distant metastases in some patients after radiation treatment. Thus, many studies have attempted to identify effective radiosensitizers. Eph receptor functions contribute to tumor development, modulating cell-cell adhesion, invasion, neo-angiogenesis, tumor growth and metastasis. However, the role of EphA3 in radioresistance remains unclear. In the current study, we established a stable radioresistant head and neck cancer cell line (AMC HN3R cell line) and found that EphA3 was expressed predominantly in the radioresistant head and neck cancer cell line through DNA microarray, real time PCR and Western blotting. Additionally, we found that EphA3 was overexpressed in recurrent laryngeal cancer specimens after radiation therapy. EphA3 mediated the tumor invasiveness and migration in radioresistant head and neck cancer cell lines and epithelial mesenchymal transition- related protein expression. Inhibition of EphA3 enhanced radiosensitivity in the AMC HN 3R cell line in vitro and in vivo study. In conclusion, our results suggest that EphA3 is overexpressed in radioresistant head and neck cancer and plays a crucial role in the development of radioresistance in head and neck cancers by regulating the epithelial mesenchymal transition pathway.

    更新日期:2018-04-11
  • α-cyano-4-hydroxycinnamate impairs pancreatic cancer cells by stimulating the p38 signaling pathway
    Cell Signal. (IF 3.487) Pub Date : 2018-03-30
    Maria Schönrogge, Hagen Kerndl, Xianbin Zhang, Simone Kumstel, Brigitte Vollmar, Dietmar Zechner
    更新日期:2018-04-07
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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