FOXO3a-dependent up-regulation of Mxi1-0 promotes hypoxia-induced apoptosis in endothelial cells Cell Signal. (IF 3.487) Pub Date : 2018-08-16 Zhenzhen Hu, Feng Wang, Zhen Wu, Hao Gu, Na Dong, Xiuqin Jiang, Jinjin Xu, Zhiwei Wu, Daniel S. Wechsler, Datong Zheng
The EZH2- H3K27me3-DNMT1 complex orchestrates epigenetic silencing of the wwc1 gene, a Hippo/YAP pathway upstream effector, in breast cancer epithelial cells Cell Signal. (IF 3.487) Pub Date : 2018-08-16 Xiong Liu, Chun Li, Rengdong Zhang, Wenjun Xiao, Xia Niu, Xiajun Ye, Zijia Li, Yuxian Guo, Junyu Tan, Yaochen Li
It is well known that epithelial-mesenchymal transition (EMT) can confer cancer cells with invasive and migratory capabilities associated with distant metastasis. As a key upstream factor in the Hippo pathway, Kibra (wwc1 gene) has been shown to suppress EMT in breast cancer cells, and we have found that its expression is reduced or lost completely in both human breast cancer cell lines and clinical tissue samples, particularly in triple negative breast cancer (TNBC). Unfortunately, the molecular mechanisms underlying this progression-associated event remain to be elucidated. Epigenetic gene silencing is one of the most common causes of suppressed expression of tumor suppressor genes. Furthermore, recent studies have demonstrated that EZH2 can recruit DNA methyltransferases, resulting in DNA methylation and subsequent gene silencing in certain circumstances. Thus, we hypothesized that there may exist a link between EZH2 and DNA methylation in association with wwc1 silencing in breast cancer. To test this hypothesis, we performed bisulfite sequencing, shRNA, co-IP, ChIP, MeDIP and ChIP-qPCR. As expected, RG108 or 5-Aza treatment improved the wwc1 gene transcription and Kibra protein expression. Both bisulfite sequencing and MeDIP demonstrated higher CpG methylation of the wwc1 promoter the TNBC cells (MDA-MB-231) than in luminal breast cancer cells (MCF7). It is noteworthy that ChIP and co-IP assays showed that EZH2, H3K27me3 and DNMT1 are enriched at the wwc1 promoter, and there exist physiologically relevant protein-protein interactions between them. We also found that EZH2 knockdown leads to a partial increase in Kibra expression and a considerable reduction in H3K27 and DNMT1 trimethylation. Moreover, ChIP-qPCR revealed more DNA fragments containing the wwc1 promoter in MDA-MB-231 than in MCF7 cells after immunoprecipitation with EZH2, DNMT1 and H3K27me3 antibodies. Collectively, our results reveal crosstalk between H3K27me3 inhibition catalyzed by EZH2 and CpG island methylation mediated by DNMT1 within the wwc1 promoter, which synergistically silence wwc1 gene expression in TNBC. Based on these results, we conclude that EZH2 shows promise as a potential anti-tumor target.
Auto-inhibition of adenylyl cyclase 9 (AC9) by an isoform-specific motif in the carboxyl-terminal region Cell Signal. (IF 3.487) Pub Date : 2018-08-16 Adrienn Pálvölgyi, James Simpson, Ibolya Bodnár, Judit Bíró, Miklós Palkovits, Tamás Radovits, Paul Skehel, Ferenc A. Antoni
Factor XII in coagulation, inflammation and beyond Cell Signal. (IF 3.487) Pub Date : 2018-08-15 Miroslava Didiasova, Lukasz Wujak, Liliana Schaefer, Malgorzata Wygrecka
Factor XII (FXII) is a protease that is mainly produced in the liver and circulates in plasma as a single chain zymogen. Following contact with negatively charged surfaces, FXII is converted into the two-chain active form, FXIIa. FXIIa initiates the intrinsic blood coagulation pathway via activation of factor XI. Furthermore, it converts plasma prekallikrein to kallikrein (PK), which reciprocally activates FXII and liberates bradykinin from high molecular weight kininogen. In addition, FXIIa initiates fibrinolysis via PK-mediated urokinase activation and activates the classical complement pathway. Even though the main function of FXII seems to relate to the activation of the intrinsic coagulation pathway and the kallikrein-kinin system, a growing body of evidence suggests that FXII may also directly regulate cellular responses. In this regard, it has been found that FXII/FXIIa induces the expression of inflammatory mediators, promotes cell proliferation, and enhances the migration of neutrophils and lung fibroblasts. In addition, it has been reported that genetic ablation of FXII protects against neuroinflammation, reduces the formation of atherosclerotic lesions in Apoe−/− mice, improves wound healing, and inhibits postnatal angiogenesis. Although the aforementioned effects can be partially explained by the downstream products of FXII activation, the ability of FXII/FXIIa to directly regulate cellular responses has recently emerged as an alternative hypothesis. These direct cellular reactions to FXII/FXIIa will be discussed in the review.
Pharmacological targeting of p38 MAP-Kinase 6 (MAP2K6) inhibits the growth of esophageal adenocarcinoma Cell Signal. (IF 3.487) Pub Date : 2018-08-11 Sijie Lin, Kuancan Liu, Yongchun Zhang, Ming Jiang, Rong Lu, Christopher J. Folts, Xia Gao, Mark D. Noble, Tingting Zhao, Zhongren Zhou, Xiaopeng Lan, Jianwen Que
Drug repurposing with a better understanding of the underlying mechanism has provided new avenues to find treatment for malignancies. Esophageal adenocarcinoma (EAC) is a rapidly increasing cancer with a dismal 5-year survival rate of <15%. Lack of efficient treatment options contributes to the high mortality rate of EAC. To find new therapy against EAC we performed unbiased drug screening of an FDA-approved drug library and identified that the cardiac glycosides including Ouabain, Digoxin and Digitoxin efficiently inhibit the proliferation of EAC cell lines (OE33 and OE19) both in vitro and in vivo. RNA-Sequencing analysis combined with RNAi screening revealed that Ouabain suppresses the proliferation of EAC cells through downregulation of p38 MAP-Kinase 6 (MAP2K6, also known as MKK6). Consistently, shRNA-mediated knockdown of MKK6 reduced the proliferation of EAC cells and tumor growth. Further analysis demonstrated that MKK6 inhibition leads to the reduced levels of the transcription factor SOX9. In line with this finding, deletion of SOX9 with CRISPR/Cas9 resulted in decreased proliferation of EACs in 3D organoid culture and reduced tumor growth. Together these findings establish a druggable axis that can be harnessed for therapeutic gain against EAC.
A new coumarin derivative plays a role in rhabdoviral clearance by interfering glycoprotein function during the early stage of viral infection Cell Signal. (IF 3.487) Pub Date : 2018-08-11 Wei-Chao Chen, Lei Liu, Yu-Feng Shen, Yang Hu, Fei Ling, Gao-Xue Wang, Bin Zhu
Upstream regulators of apoptosis mediates methionine-induced changes of lipid metabolism Cell Signal. (IF 3.487) Pub Date : 2018-08-09 Yu-Feng Song, Yan Gao, Christer Hogstrand, Dan-Dan Li, Ya-Xiong Pan, Zhi Luo
Although the role of methionine (Met), as precursor for l-carnitine synthesis, in the regulation of lipid metabolism has been explored. Met seems to have tissue- and species-specific regulatory effect on lipid metabolism, implying that the mechanisms in Met regulation of lipid metabolism is complex and may involve the upstream regulatory pathway of lipid metabolism. The present study was performed to determine the mechanism of apoptosis signaling pathways mediating Met-induced changes of hepatic lipid deposition and metabolism in fish, and compare the differences of the mechanisms between the fish and mammals. By iTRAQ-based quantitative proteome analyses, we found that both dietary Met deficiency and excess evoked apoptosis signaling pathways, increased hepatic lipid deposition and caused aberrant hepatic lipid metabolism of yellow catfish Pelteobagrus fulvidraco. Using primary hepatocytes from P. fulvidraco, inhibition of caspase by Z-VAD-FMK blocked the apoptotic signaling pathways with a concomitant reversal of Met deficiency- and excess-induced increase of lipid deposition, indicating that apoptosis involved the Met-mediated changes of hepatic lipid metabolism. Moreover, we explored the roles of three upstream apoptotic signaling pathways (PI3K/AKT-TOR pathway, cAMP/PKA/CREB pathway and LKB1/AMPK-FOXO pathway) influencing hepatic lipid metabolism of P. fulvidraco. The three upstream pathways participated in apoptosis mediating Met-induced changes of lipid metabolism in P. fulvidraco. At last, HepG2 cell line was used to compare the similarities of mechanisms in apoptosis mediating Met-induced changes of lipid metabolism between fish and mammals. Although several slight differences existed, apoptosis mediated the Met-induced changes of lipid metabolism between fish and mammals. The present study reveals novel apoptosis-relevant signal transduction axis which mediates the Met-induced changes of lipid metabolism, which will help understand the mechanistic link between apoptosis and lipid metabolism, and highlight the importance of the evolutionary conservative apoptosis signaling axis in regulating Met–induced changes of hepatic lipid metabolism.
Cellular phosphatase activity of C1-Ten/Tensin2 is controlled by Phosphatidylinositol-3,4,5-triphosphate binding through the C1-Ten/Tensin2 SH2 domain Cell Signal. (IF 3.487) Pub Date : 2018-08-07 Eui Kim, Do-Hyeon Kim, Indira Singaram, Heeyoon Jeong, Ara Koh, Jiyoun Lee, Wonhwa Cho, Sung Ho Ryu
Regulation of tyrosine phosphorylation on insulin receptor substrate-1 (IRS-1) is essential for insulin signaling. The protein tyrosine phosphatase (PTP) C1-Ten/Tensin2 has been implicated in the regulation of IRS-1, but the molecular basis of this dephosphorylation is not fully understood. Here, we demonstrate that the cellular phosphatase activity of C1-Ten/Tensin2 on IRS-1 is mediated by the binding of the C1-Ten/Tensin2 Src-homology 2 (SH2) domain to phosphatidylinositol-3,4,5-trisphosphate (PtdIns(3,4,5)P3). We show that the role of C1-Ten/Tensin2 is dependent on insulin-induced phosphoinositide 3-kinase activity. The C1-Ten/Tensin2 SH2 domain showed strong preference and high affinity for PtdIns(3,4,5)P3. Using site-directed mutagenesis, we identified three basic residues in the C1-Ten/Tensin2 SH2 domain that were critical for PtdIns(3,4,5)P3 binding but were not involved in phosphotyrosine binding and PTP activity. Using a PtdIns(3,4,5)P3 binding-deficient mutant, we showed that the specific binding of the C1-Ten/Tensin2 SH2 domain to PtdIns(3,4,5)P3 allowed C1-Ten/Tensin2 to function as a PTP in cells. Collectively, our findings suggest that the interaction between the C1-Ten/Tensin2 SH2 domain and PtdIns(3,4,5)P3 produces a negative feedback loop of insulin signaling through IRS-1.
The functional pathway analysis and clinical significance of miR-20a and its related lncRNAs in breast cancer Cell Signal. (IF 3.487) Pub Date : 2018-08-06 Luqing Zhao, Yuelong Zhao, Yanong He, Qingling Li, Yitao Mao
BackgroundmiR-20a is a critical molecule in various biological processes and cancer progression procedures. However, its relationships with lncRNAs and their functional pathway analysis in breast tumorigenesis are less intensively studied.MethodsThe expression data from TCGA database and multiple bioinformatics resources were used to check the expression levels, survival curves, interactions and functional illustrations of miR-20a and its related lncRNAs (XIST, H19 and MALAT1) in breast cancer patients. The luciferase reporter assays and Pearson's correlation analyses were utilized to verify the direct regulatory relationship between miR-20a and three lncRNAs (XIST, H19 and MALAT1). In vitro cell proliferation, migration and invasion assays, were performed to check the biological effects of miR-20a and XIST in different breast cancer cell lines. The receiver operating characteristic curve (ROC) analyses were done for evaluating diagnostic values of serum miR-20a and XIST in breast cancer patients.ResultsThe miR-20a expression was significantly up-regulated in both breast cancer samples and serum samples, and correlated with poor survival rate in breast cancer patients. LncRNAs (XIST, H19 and MALAT1) directly bound to hsa-miR-20a and were negatively correlated with hsa-miR-20a expression in breast cancer patient samples. For functional illustrations and downstream signaling pathways analysis, XIST, H19 and MALAT1 mainly shared their regulatory functions in cell motility and interleukin signaling in breast cancer progression. Additionally, over-expression of miR-20a and inhibition of XIST promoted breast cancer cell growth, migration and invasion in vitro, and serum miR-20a and XIST served as potential diagnostic biomarkers for breast cancer with the area under ROC curve (AUC) of 0.87 (95% CI = 0.78 to 0.97), and 0.78 (95% CI = 0.67 to 0.89) respectively.ConclusionsTaken together, these findings provide us novel insights and avenues for utilizing miR-20a and its related lncRNAs as potential diagnostic biomarkers and promising therapeutic targets for breast cancer treatment.
Smooth muscle cell-specific FoxM1 controls hypoxia-induced pulmonary hypertension Cell Signal. (IF 3.487) Pub Date : 2018-08-06 Jingbo Dai, Qiyuan Zhou, Haiyang Tang, Tianji Chen, Jing Li, Pradip Raychaudhuri, Jason X.-J. Yuan, Guofei Zhou
RationaleForkhead box M1 (FoxM1) is a transcription factor that promotes cell proliferation by regulating a broad spectrum of genes that participate in cell cycle regulation, such as Cyclin B, CDC25B, and Aurora B Kinase. We have shown that hypoxia, a well-known stimulus for pulmonary hypertension (PH), induces FoxM1 in pulmonary artery smooth muscle cells (PASMC) in a HIF-dependent pathway, resulting in PASMC proliferation, while the suppression of FoxM1 prevents hypoxia-induced PASMC proliferation. However, the implications of FoxM1 in the development of PH remain less known.MethodsWe determined FoxM1 levels in the lung samples of idiopathic PAH (pulmonary arterial hypertension) (IPAH) patients and hypoxia-induced PH mice. We generated constitutive and inducible smooth muscle cell (SMC)-specific FoxM1 knockdown or knockout mice as well as FoxM1 transgenic mice which overexpress FoxM1, and exposed them to hypoxia (10% O2, 90% N2) or normoxia (Room air, 21% oxygen) for four weeks, and measured PH indices. We also isolated mouse PASMC (mPASMC) and mouse embryonic fibroblasts (MEF) from these mice to examine the cell proliferation and expression levels of SMC contractile proteins.ResultsWe showed that in hypertensive human lungs or mouse lungs, FoxM1 levels were elevated. Constitutive knockout of FoxM1 in mouse SMC caused early lethality, whereas constitutive knockdown of FoxM1 in mouse SMC prevented hypoxia-induced PH and PASMC proliferation. Inducible knockout of FoxM1 in SMC reversed hypoxia-induced pulmonary artery wall remodeling in existing PH. Overexpression of FoxM1 enhanced hypoxia-induced pulmonary artery wall remodeling and right ventricular hypertrophy in mice. Alteration of FoxM1 status did not affect hypoxia-induced hypoxia-inducible factor (HIF) activity in mice. Knockout of FoxM1 decreased PASMC proliferation and induced expression of SMC contractile proteins and TGF-β/Smad3 signaling.ConclusionsOur studies provide clear evidence that altered FoxM1 expression in PASMC contributes to PH and uncover a correlation between Smad3-dependent signaling in FoxM1-mediated proliferation and de-differentiation of PASMC.
The TGFβ-ERK pathway contributes to Notch3 upregulation in the renal tubular epithelial cells of patients with obstructive nephropathy Cell Signal. (IF 3.487) Pub Date : 2018-08-04 Mei Huang, Jin Zhang, Hui Xu, Ting Ding, Damu Tang, Qiongjing Yuan, Lijian Tao, Zunlong Ye
Renal interstitial fibrosis is a common renal injury resulted from a variety of chronic kidney conditions and an array of factors. We report here that Notch3 is a potential contributor. In comparison to 6 healthy individuals, a robust elevation of Notch3 expression was observed in the renal tubular epithelial cells of 18 patients with obstructive nephropathy. In a rat unilateral ureteral obstruction (UUO) model which mimics the human disease, Notch3 upregulation closely followed the course of renal injury, renal fibrosis, TGFβ expression, and alpha-smooth muscle actin (α-SMA) expression, suggesting a role of Notch3 in promoting tubulointerstitial fibrosis. This possibility was supported by the observation that TGFβ, the major renal fibrogenic cytokine, stimulated Notch3 expression in human proximal tubule epithelial HK-2 cells. TGFβ enhanced the activation of ERK, p38, but not JNK MAP kinases in HK-2 cells. While inhibition of p38 activation using SB203580 did not affect TGFβ-induced Notch3 expression, inhibition of ERK activation with a MEK1 inhibitor PD98059 dramatically reduced the event. Furthermore, enforced ERK activation through overexpression of the constitutively active MEK1 mutant MEK1Q56P upregulated Notch3 expression in HK-2 cells, and PD98059 reduced ERK activation and Notch3 expression in HK-2 cells expressing MEK1Q56P. Collectively, we provide the first clinical evidence for Notch3 upregulation in patients with obstructive nephropathy; the upregulation is likely mediated through the TGFβ-ERK pathway. This study suggests that Notch3 upregulation contributes to renal injury caused by obstructive nephropathy, which could be prevented or delayed through ERK inhibition.
Tie2 signalling through Erk1/2 regulates TLR4 driven inflammation Cell Signal. (IF 3.487) Pub Date : 2018-08-02 Tracy L. Smith, Paul Van Slyke, Nina Jones, Daniel J. Dumont, C. Jane McGlade
Inhibition of cytokine-mediated JNK signalling by purinergic P2Y11 receptors, a novel protective mechanism in endothelial cells Cell Signal. (IF 3.487) Pub Date : 2018-08-02 Pei Y. Ng, Kathryn A. McIntosh, Gillian Hargrave, Ka H. Ho, Andrew Paul, Robin Plevin
Lung mesenchymal stem cells-derived extracellular vesicles attenuate the inflammatory profile of Cystic Fibrosis epithelial cells Cell Signal. (IF 3.487) Pub Date : 2018-08-01 Aida Zulueta, Michela Colombo, Valeria Peli, Monica Falleni, Delfina Tosi, Mario Ricciardi, Alessandro Baisi, Gaetano Bulfamante, Raffaella Chiaramonte, Anna Caretti
Background Mesenchymal stromal/stem cells (MSCs) are multi-potent non-hematopoietic stem cells, residing in most tissues including the lung. MSCs have been used in therapy of chronic inflammatory lung diseases such as Cystic Fibrosis (CF), asthma, and chronic obstructive pulmonary disease (COPD) but the main beneficial effects reside in the anti-inflammatory potential of the released extracellular vesicles (EVs). Recent reports demonstrate that EVs are effective in animal model of asthma, E.coli pneumonia, lung ischemia-reperfusion, and virus airway infection among others. Despite this growing literature, the EV effects on CF are largely unexplored. Methods We treated IB3-1 cells, an in vitro human model of CF, with EVs derived from human lung MSCs under basal and inflammatory conditions (TNFα stimulation). Results We demonstrated here that treatment of IB3-1 CF cell line with EVs, down-regulates transcription and protein expression of pro-inflammatory cytokines such as IL-1β, IL-8, IL-6 under TNFα - stimulated conditions. EVs treatment upregulates the mRNA expression of PPARγ, a transcription factor controlling anti-inflammatory and antioxidant mechanisms via NF-kB and HO-1. Accordingly, NF-kB nuclear translocation is reduced resulting in impairment of the downstream inflammation cascade. In addition, the mRNA of HO-1 is enhanced together with the antioxidant defensive response of the cells. Conclusions We conclude that the anti-inflammatory and anti-oxidant efficacy of EVs derived from lung MSCs could be mediated by up-regulation of the PPARγ axis, whose down-stream effectors (NF-kB and HO-1) are well-known modulators of these pathways. General significance EVs could be a novel strategy to control the hyper-inflamed condition in Cystic Fibrosis.
Differential regulation of β2-adrenoceptor and adenosine A2B receptor signalling by GRK and arrestin proteins in arterial smooth muscle Cell Signal. (IF 3.487) Pub Date : 2018-07-31 Craig A. Nash, Carl P. Nelson, Rajendra Mistry, Christian Moeller-Olsen, Elena Christofidou, R.A. John Challiss, Jonathon M. Willets
Colony-stimulating factor-1 receptor provides a growth advantage in epithelial cancer cell line A431 in the presence of epidermal growth factor receptor inhibitor gefitinib Cell Signal. (IF 3.487) Pub Date : 2018-07-31 Svenja Ellen Niehus, Doan Duy Hai Tran, Michaela Mischak, Alexandra Koch
Although epidermal growth factor receptor (EGFR) has been identified as a potent “oncogenic driver” in various tumors of epithelial origin, EGFR-targeted therapies are often of limited success. One of the challenges of improving targeted therapies is to overcome bypassing signaling pathways.Analysis of RNA-seq data of 1006 cell lines from the Cancer Cell Line Encyclopedia (CCLE) revealed that >12% of carcinoma cell lines expressed markedly elevated mRNA levels of colony-stimulating factor (CSF)-1 receptor (CSF-1R). Since epithelial cells also express CSF-1, elevated levels of CSF-1R may participate in providing alternative growth and survival signals under targeted therapies. To address this question, we ectopically expressed CSF-1R in A431 cells that express EGFR at high levels, but no biologically relevant level of CSF-1R. In the presence of EGFR inhibitor gefitinib, CSF-1R provided a significant growth advantage in A431 cells. As expected, activation of both receptors, EGFR or CSF-1R, induced phosphorylation of extracellular signal-regulated kinase (Erk)1/2, Akt, protein kinase C (PKC) and signal transducer and activator of transcription (STAT)3. However, EGFR, but not CSF-1R, also induced STAT5 phosphorylation. Inhibitor of phosphatidylinositol 3–kinase (PI3K) (AZD8186), MAPK/ERK kinase (MEK)1/2 (U0126), PKCs (Bisindolylmaleimide I or Gö6976) or STAT3 (Stattic) partially reduced proliferation of CSF-1R expressing A431 cells in the presence of gefitinib. Moreover, multi-kinase inhibitor, cabozantinib, suppressed CSF-1R activation and drastically reduced cell growth when combined with gefitinib. These data suggest that CSF-1R has the potential to reduce sensitivity to gefitinib and may be involved in resistance development.
Long non-coding RNAs regulation in adipogenesis and lipid metabolism: Emerging insights in obesity Cell Signal. (IF 3.487) Pub Date : 2018-07-31 Chen Chen, Qingming Cui, Xing Zhang, Xuan Luo, Yingying Liu, Jianbo Zuo, Yinglin Peng
Obesity is a widespread health problem that brings about various adipose tissue dysfunctions. The balance of energy storage and energy expenditure is critical for normal fat accumulation and lipid metabolism. Therefore, understanding the molecular basis of adipogenesis and thermogenesis is essential to maintain adipose development and lipid homeostasis. Increasing evidence demonstrated that lncRNAs (long non-coding RNAs), a class of non-protein coding RNAs of >200 nucleotides in length, are identified as key regulators in obesity-related biological processes through diverse regulatory mechanisms. In this review, we concentrate on recent and relevant studies on the roles of lncRNAs in regulation of white adipogenesis, brown adipocyte differentiation and lipid metabolism. In addition, the diagnostic and therapeutic potential of lncRNAs is highlighted, and that will make recommendations for the future application of lncRNAs in the treatment of obesity.
Advances in targeting epidermal growth factor receptor signaling pathway in mammary cancer Cell Signal. (IF 3.487) Pub Date : 2018-07-31 Konstantina Kyriakopoulou, Elena Kefali, Zoi Piperigkou, Heba Bassiony, Nikos K. Karamanos
Balance and circumstance: The renin angiotensin system in wound healing and fibrosis Cell Signal. (IF 3.487) Pub Date : 2018-07-30 Rocco Bernasconi, Alexander Nyström
The tissue renin angiotensin system (tRAS) is a locally-acting master-modulator of tissue homeostasis and regeneration. Through these abilities, it is emerging as an attractive target for therapies aiming to restore tissue homeostasis in conditions associated with disturbed wound healing. The tRAS can be divided into two axes – one being pro-inflammatory and pro-fibrotic and one being anti-inflammatory and anti-fibrotic. However, the division of the axes is fuzzy and imperfect as the axes are codependent and the outcome of tRAS activation is determined by the context. Although the tRAS is a local system it shares its key enzymes, ligands and receptors with the systemic RAS and is consequently also targeted by repurposing of drugs developed against the systemic RAS to manage hypertension. With a focus on the skin we will here discuss the tRAS, its involvement in physiological and pathological wound healing, and the therapeutic aptitude of its targeting to treat chronic wounds and fibrosis.
The LPA2 receptor agonist Radioprotectin-1 spares Lgr5-positive intestinal stem cells from radiation injury in murine enteroids Cell Signal. (IF 3.487) Pub Date : 2018-07-29 Bryan Kuo, Erzsébet Szabó, Sue Chin Lee, Andrea Balogh, Derek Norman, Asuka Inoue, Yuki Ono, Junken Aoki, Gábor Tigyi
CaMKIIδ interacts directly with IKKβ and modulates NF-κB signalling in adult cardiac fibroblasts Cell Signal. (IF 3.487) Pub Date : 2018-07-27 Tamara P. Martin, Claire McCluskey, Margaret R. Cunningham, James Beattie, Andrew Paul, Susan Currie
Calcium/calmodulin dependent protein kinase IIδ (CaMKIIδ) acts as a molecular switch regulating cardiovascular Ca2+ handling and contractility in health and disease. Activation of CaMKIIδ is also known to regulate cardiovascular inflammation and is reported to be required for pro-inflammatory NF-κB signalling. In this study the aim was to characterise how CaMKIIδ interacts with and modulates NF-κB signalling and whether this interaction exists in non-contractile cells of the heart. Recombinant or purified CaMKIIδ and the individual inhibitory -κB kinase (IKK) proteins of the NF-κB signalling pathway were used in autoradiography and Surface Plasmon Resonance (SPR) to explore potential interactions between both components. Primary adult rat cardiac fibroblasts were then used to study the effects of selective CaMKII inhibition on pharmacologically-induced NF-κB activation as well as interaction between CaMKII and specific IKK isoforms in a cardiac cellular setting. Autoradiography analysis suggested that CaMKIIδ phosphorylated IKKβ but not IKKα. SPR analysis further supported a direct interaction between CaMKIIδ and IKKβ but not between CaMKIIδ and IKKα or IKKγ. CaMKIIδ regulation of IκΒα degradation was explored in adult cardiac fibroblasts exposed to pharmacological stimulation. Cells were stimulated with agonist in the presence or absence of a CaMKII inhibitor, autocamtide inhibitory peptide (AIP). Selective inhibition of CaMKII resulted in reduced NF-κB activation, as measured by agonist-stimulated IκBα degradation. Importantly, and in agreement with the recombinant protein work, an interaction between CaMKII and IKKβ was evident following Proximity Ligation Assays in adult cardiac fibroblasts. This study provides new evidence supporting direct interaction between CaMKIIδ and IKKβ in pro-inflammatory signalling in cardiac fibroblasts and could represent a feature that may be exploited for therapeutic benefit.
An incretin-based tri-agonist promotes superior insulin secretion from murine pancreatic islets via PLC activation Cell Signal. (IF 3.487) Pub Date : 2018-07-25 Noushafarin Khajavi, Brian Finan, Oliver Kluth, Timo D. Müller, Stefan Mergler, Angela Schulz, Gunnar Kleinau, Patrick Scheerer, Annette Schürmann, Thomas Gudermann, Matthias H. Tschöp, Heiko Krude, Richard D. DiMarchi, Heike Biebermann
Recently, a unimolecular tri-agonist with activity at glucagon-like peptide 1 receptor (GLP-1R), glucose dependent insulinotropic receptor, and the glucagon receptor was reported to improve glycemic control in mice. Here, we defined the underlying molecular mechanisms of enhanced insulin secretion in murine pancreatic islets for a specific tri-agonist. The tri-agonist induced an increase in insulin secretion from murine islets compared to the respective mono-agonists. GLP-1R mainly signals via activation of the Gαs pathway, but inhibition of protein kinase A (H89) and exchange protein activation by cAMP (EPAC) (ESI-09) could not completely block insulin release induced by tri-agonist. Electrophysiological observations identified a strong increase of intracellular Ca2+ concentration and whole-cell currents induced by tri-agonist via transient receptor potential channels (TRPs). Although, EPAC activation mobilizes intracellular Ca2+ via TRPs, the TRPs blockers (La3+ and Ruthenium Red) had a larger inhibitory impact than ESI-09 on tri-agonist stimulatory effects. To test for other potential mechanisms, we blocked PLC activity (U73122) which reduced the superior effect of tri-agonist to induce insulin secretion, and partially inhibited the induced Ca2+ influx. This result suggests that the relative effect of tri-agonist on insulin secretion caused by GLP-1R agonism is mediated mainly via Gαs signaling and partially by activation of PLC. Therefore, the large portion of the increased intracellular Ca2+ concentration and the enhanced whole-cell currents induced by tri-agonist might be attributable to TRP channel activation resulting from signaling through multiple G-proteins. Here, we suggest that broadened intracellular signaling may account for the superior in vivo effects observed with tri-agonism.
Portal myofibroblasts are sensitive to CCN-mediated endoplasmic reticulum stress-related apoptosis with potential to attenuate biliary fibrogenesis Cell Signal. (IF 3.487) Pub Date : 2018-07-22 Erawan Borkham-Kamphorst, Bettina Therese Steffen, Eddy van de Leur, Ute Haas, Ralf Weiskirchen
Portal fibroblasts are mesenchyme-derived fibroblasts surrounding the bile ducts, and activated into portal myofibroblasts (pMF) during cholestatic liver injury. pMF express α-smooth muscle actin (α-SMA) and produce the fibrogenic extracellular matrix (ECM) collagen type I and fibronectin, playing important roles in portal fibrosis. A cholestatic bile duct-ligated (BDL) model is characterized by impaired hepatobiliary excretion of bile, leading to increased bile acid accumulation. Accumulation of bile acids is known to induce endoplasmic reticulum (ER) stress leading to liver damage and cell death. Additionally, a BDL fibrotic model is also associated with upregulation of CCN (CYR61, CTGF and NOV) matricellular proteins and reported to induce ER stress both in vitro and in vivo. To explore the effects of CCN proteins, we used adenovirus-mediated CCN1-4 (Ad-CCN1-4) gene transfers into cultured pMF. Overexpression of CCN proteins leads to protein accumulation in the ER lumen, causing ER stress and unfolded protein response (UPR). We further found ER stress and UPR to mitigate fibrogenesis in pMF by decreased cellular production of fibronectin, collagen type 1 and α-SMA. In this scenario, Tauroursodeoxycholic acid, a pharmaceutical chaperone and ER stress inhibitor, attenuated Ad-CCN1-4 induced pMF apoptosis and restored collagen and fibronectin levels. Since hepatic fibrogenesis is accompanied by ER stress and upregulation of CCN proteins in a BDL, we further evaluated ER stress responses after Ad-CCN1 gene transfer in such a model and found overexpressed CCN1 to enhance the ER stress-associated proteins BiP and CHOP with positive cleaved caspase 3 and 9 staining in periportal nonparenchymal cells. This indicates that these nonparenchymal cells, most likely pMF, have the tendency to undergo apoptosis during later stages of BDL. Ad-CCN1 transduction furthermore sensitized pMF for ER stress and apoptosis. We suggest that CCN proteins are key factors in the fibrotic microenvironment impacting pMF survival during fibrogenesis and pMF apoptosis during fibrosis resolution.
Agmatine modulates calcium handling in cardiomyocytes of hibernating ground squirrels through calcium-sensing receptor signaling Cell Signal. (IF 3.487) Pub Date : 2018-07-17 Alexander V. Maltsev
True hibernators are remarkable group of mammals whose hearts are resistant to such stressors as deep hypothermia, ischemia, arrhythmia. Capability of cardiac cells from hibernating species to effectively rule Ca2+ homeostasis during torpor is poorly studied. Better understanding of these mechanisms could allow to introduce new strategies for improvement the cardiac performance and may be useful for cardiovascular medicine. Here for the first time we have shown that the regulation of Ca2+ handling and thereby cardiomyocyte contractility by endogenous neurotransmitter agmatine occurs through the modulation of calcium-sensing receptor (CaSR). In isolated cardiocytes of hibernating ground squirrels generating stationary Ca2+ transients in the absence of actual myocellular excitation, low doses of this polyamine (up to 500 μM) induce the Gβγ-dependent activation of PI3-kinase with subsequent stimulation of Akt-kinase and nitric oxide (NO) production by endothelial NO-synthase (eNOS). NO production abolishes Ca2+ oscillations in virtue of the enhancement of Ca2+ reuptake by sarco(endo)plasmic Ca2+ ATPase (SERCA). Simultaneously, the activation of phospholipase A2 (PLA2) and arachidonic-acid dependent Ca2+ entry occur providing replenishment of Ca2+ store. High concentrations of agmatine (> 2 mM) induce other CaSR-mediated pathways involving phospholipase C (PLC) pathway, the formation of inositoltriphosphate (IP3) and diacylglicerol (DAG) followed by induction of their targets: IP3 receptors and protein kinase C isoforms (PKC), respectively. Furthermore, it is also responsible for the stimulation of PLA2 and elevation of intracellular calcium caused by arachidonic acid-regulated Ca2+-permeable (ARC) channels. Additionally, there is a potent store-operated Ca2+ entry (SOC) in cardiomyocyte. Negative (NPS 2143) and positive (R 568) allosteric modulators of CaSR recapitulate effects of low and high agmatine doses on Ca2+ handling and NO synthesis. These facts and the alteration of agmatine influence in response to an increase of extracellular Ca2+, which is the direct agonist of CaSR, may confirm the participation of CaSR in regulation of Ca2+ handling and excitability of cardiomyocytes by agmatine.
RhoA regulates Drp1 mediated mitochondrial fission through ROCK to protect cardiomyocytes Cell Signal. (IF 3.487) Pub Date : 2018-06-25 Cameron S. Brand, Valerie P. Tan, Joan Heller Brown, Shigeki Miyamoto
Relevance of N-terminal residues for amyloid-β binding to platelet integrin αIIbβ3, integrin outside-in signaling and amyloid-β fibril formation Cell Signal. (IF 3.487) Pub Date : 2018-06-30 Lili Donner, Lothar Gremer, Tamar Ziehm, Christoph G.W. Gertzen, Holger Gohlke, Dieter Willbold, Margitta Elvers
A pathological hallmark of Alzheimer's disease (AD) is the aggregation of amyloid-β peptides (Aβ) into fibrils, leading to deposits in cerebral parenchyma and vessels known as cerebral amyloid angiopathy (CAA). Platelets are major players of hemostasis but are also implicated in AD. Recently we provided strong evidence for a direct contribution of platelets to AD pathology. We found that monomeric Aβ40 binds through its RHDS sequence to integrin αIIbβ3, and promotes the formation of fibrillar Aβ aggregates by the secretion of adenosine diphosphate (ADP) and the chaperone protein clusterin (CLU) from platelets. Here we investigated the molecular mechanisms of Aβ binding to integrin αIIbβ3 by using Aβ11 and Aβ16 peptides. These peptides include the RHDS binding motif important for integrin binding but lack the central hydrophobic core and the C-terminal sequence of Aβ. We observed platelet adhesion to truncated N-terminal Aβ11 and Aβ16 peptides that was not mediated by integrin αIIbβ3. Thus, no integrin outside-in signaling and reduced CLU release was detected. Accordingly, platelet mediated Aβ fibril formation was not observed. Taken together, the RHDS motif of Aβ is not sufficient for Aβ binding to platelet integrin αIIbβ3 and platelet mediated Aβ fibril formation but requires other recognition or binding motifs important for platelet mediated processes in CAA. Thus, increased understanding of the molecular mechanisms of Aβ binding to platelet integrin αIIbβ3 is important to understand the role of platelets in amyloid pathology.
HRD1-mediated PTEN degradation promotes cell proliferation and hepatocellular carcinoma progression Cell Signal. (IF 3.487) Pub Date : 2018-06-27 Liu Liu, Hua Long, Yan Wu, Hui Li, Ling Dong, Julia Li Zhong, Zhaojian Liu, Xiaolong Yang, Xiaotian Dai, Lei Shi, Maozhi Ren, Zhenghong Lin
The tyrosine phosphatases family member PTEN is a tumor suppressor which is widely expressed throughout the body and is involved in a variety of biological functions. PTEN is known to be frequently mutated or downregulated in human cancers. However, the underlying molecular mechanism remains largely unknown. Here, using a proteomic approach, we identified the E3 ubiquitin ligase HRD1, which was previously reported to be involved in endoplasmic reticulum associated degradation (ERAD), as one of the PTEN-interacting proteins. We also found that HRD1 promoted PTEN degradation by positively regulating its ubiquitination. In addition, suppression of HRD1 expression resulted in the inhibition of the growth, migration and invasion of hepatocellular carcinoma in vitro and in vivo. Finally, we detected a negative correlation between HRD1 and PTEN expression in human hepatocellular carcinoma. From these results we propose a novel molecular mechanism of HRD1 to promote hepatocellular tumorigenesis via PTEN inactivation. We conclude that targeting HRD1 may represent a new therapeutic strategy for PTEN-loss hepatocellular carcinoma.
MiR-429 regulates rat liver regeneration and hepatocyte proliferation by targeting JUN/MYC/BCL2/CCND1 signaling pathway Cell Signal. (IF 3.487) Pub Date : 2018-06-26 Chunyan Zhang, Cuifang Chang, Hang Gao, Qiwen Wang, Fuchun Zhang, Cunshuan Xu
Increasing evidence indicates that miR-429 is involved in tumor suppression in various human cancers. However, its role in liver regeneration remains unexplored. Liver regeneration is a highly orchestrated process that can be regulated by microRNAs (miRNAs), although the mechanisms are largely unclear. In this study, we aimed to identify the role of miR-429 in hepatocyte proliferation during liver regeneration. First, we performed microarray analysis and qRT-PCR. Results indicated that miR-429 level in rat liver markedly decreased 30 h after partial hepatectomy, and miR-429 overexpression disrupted BRL-3A proliferation and the transition of G1 to S phase in rat hepatocyte and promoted hepatocyte apoptosis. By contrast, miR-429 down-regulation had inverse effects. MiR-429 negatively regulated JUN expression in vitro and in vivo. After using JUN siRNA, we found that JUN inhibition mediates the effect of miR-429 in hepatocyte proliferation and growth and miR-429 negatively regulates JUN/MYC/BCL2/CCND1 signaling pathways. Our results also indicated that miR-429 inhibits hepatocyte proliferation and liver regeneration by targeting JUN/MYC/BCL2/CCND1.
PTEN is indispensable for cells to respond to MAPK inhibitors in myeloid leukemia Cell Signal. (IF 3.487) Pub Date : 2018-06-28 Jingliao Zhang, Zhifu Xiang, Priyangi A. Malaviarachchi, Yan Yan, Nicholas J. Baltz, Peter D. Emanuel, Y. Lucy Liu
Constitutively activated MAPK and AKT signaling pathways are often found in solid tumors and leukemias. PTEN is one of the tumor suppressors that are frequently found deficient in patients with late-stage cancers or leukemias. In this study we demonstrate that a MAPK inhibitor, PD98059, inhibits both AKT and ERK phosphorylation in a human myeloid leukemia cell line (TF-1), but not in PTEN-deficient leukemia cells (TF-1a). Ectopic expression of wild-type PTEN in myeloid leukemia cells restored cytokine responsiveness at physiological concentrations of GM-CSF (<0.02 ng/mL) and significantly improved cell sensitivity to MAPK inhibitor. We also found that Early Growth Response 1 (EGR1) was constitutively over-expressed in cytokine-independent TF-1a cells, and ectopic expression of PTEN down-regulated EGR1 expression and restored dynamics of EGR1 expression in response to GM-CSF stimulation. Data from primary bone marrow cells from mice with Pten deletion further supports that PTEN is indispensible for myeloid leukemia cells in response to MAPK inhibitors. Finally, We demonstrate that the absence of EGR1 expression dynamics in response to GM-CSF stimulation is one of the mechanisms underlying drug resistance to MAPK inhibitors in leukemia cells with PTEN deficiency. Our data suggest a novel mechanism of PTEN in regulating expression of EGR1 in hematopoietic cells in response to cytokine stimulation. In conclusion, this study demonstrates that PTEN is dispensable for myeloid leukemia cells in response to MAPK inhibitors, and PTEN regulates EGR1 expression and contributes to the cytokine sensitivity in leukemia cells.
Different mode of arrestin-3 binding at the human Y1 and Y2 receptor Cell Signal. (IF 3.487) Pub Date : 2018-06-23 Lizzy Wanka, Stefanie Babilon, Anette Kaiser, Karin Mörl, Annette G. Beck-Sickinger
Spatial regulation of signaling by the coordinated action of the protein tyrosine kinases MET and FER Cell Signal. (IF 3.487) Pub Date : 2018-06-18 Jiali Zhang, Zuo Wang, Siwei Zhang, Yanxun Chen, Xuexue Xiong, Xiaojuan Li, Nicholas K. Tonks, Gaofeng Fan
A critical aspect of understanding the regulation of signal transduction is not only to identify the protein-protein interactions that govern assembly of signaling pathways, but also to understand how those pathways are regulated in time and space. In this report, we have applied both gain-of-function and loss-of-function analyses to assess the role of the non-receptor protein tyrosine kinase FER in activation of the HGF Receptor protein tyrosine kinase MET. Overexpression of FER led to direct phosphorylation of several signaling sites in MET, including Tyr1349, but not the activation loop residues Tyr1234/5; in contrast, suppression of FER by RNAi revealed that phosphorylation of both a C-terminal signaling site (Tyr1349) and the activation loop (Tyr1234/5) were influenced by the function of this kinase. Adaptin β, a component of the adaptor protein complex 2 (AP-2) that links clathrin to receptors in coated vesicles, was recruited to MET following FER-mediated phosphorylation. Furthermore, we provide evidence to support a role of FER in maintaining plasma membrane distribution of MET and thereby delaying protein-tyrosine phosphatase PTP1B-mediated inactivation of the receptor. Simultaneous up-regulation of FER and down-regulation of PTP1B observed in ovarian carcinoma-derived cell lines would be expected to contribute to persistent activation of HGF-MET signaling, suggesting that targeting of both FER and MET may be an effective strategy for therapeutic intervention in ovarian cancer.
Signaling pathways activated by PACAP in MCF-7 breast cancer cells Cell Signal. (IF 3.487) Pub Date : 2018-06-20 Kazem Zibara, Asad Zeidan, Khalil Mallah, Nouhad Kassem, Ali Awad, Frédéric Mazurier, Bassam Badran, Nabil El-Zein
PACAP has opposing roles ranging from activation to inhibition of tumor growth and PACAP agonists/antagonists could be used in tumor therapy. In this study, the effect of PACAP stimulation on signaling pathways was investigated in MCF-7 human adenocarcinoma breast cancer cells. Results showed that MCF-7 cells express VPAC1 and VPAC2, but not PAC1, receptors. In addition, PACAP increased the phosphorylation levels of STAT1, Src and Raf within seconds, confirming their involvement in early stages of PACAP signaling whereas maximal phosphorylation of AKT, ERK and p38 was reached 10 to 20 min later. Moreover, selective inhibition of Src or PI3K resulted in a significant decrease in the phosphorylation of ERK and AKT, but not p38, demonstrating that PACAP signaling follows Src/Raf/ERK and PI3K/AKT pathways. On the other hand, selective inhibition of PLC or PKA resulted in a significant decrease in the phosphorylation of p38, but not AKT or ERK, indicating that PACAP signaling also follows the PLC and PKA/cAMP pathways. Furthermore, PACAP induced ROS through H₂O₂ production whereas pretreatment with NAC inhibitor decreased AKT and ERK phosphorylation, but not p38. Selective NOX2 inhibition affected Src/Raf/Erk and PI3K/Akt pathways, without affecting the p38/PLC/PKA pathway whereas other inhibitors (ML171, VAS2870) had no effect on PACAP induced ROS generation. On the other hand, PACAP induced calcium release, which was decreased by pretreatment with PLC inhibitor. Finally, PACAP stimulation promoted apoptosis by increasing Bax and decreasing Bcl2 expression. In conclusion, we demonstrated that PACAP signaling in MCF-7 cells follows the Src/Raf/ERK and PI3K/AKT pathways and is VPAC1 dependent in a ROS dependent manner, whereas it follows PLC and PKA/cAMP pathways and is VPAC2 dependent through p38 MAP kinase activation involving calcium.
MicroRNA-206 suppresses TGF-β signalling to limit tumor growth and metastasis in lung adenocarcinoma Cell Signal. (IF 3.487) Pub Date : 2018-06-20 Kathleen Watt, Daniel Newsted, Elena Voorand, Robert J. Gooding, Adrianna Majewski, Peter Truesdell, Binchen Yao, Thomas Tuschl, Neil Renwick, Andrew W. Craig
MicroRNA-206 (miR-206) has demonstrated tumor suppressive effects in a variety of cancers. Numerous studies have identified aberrantly expressed targets of miR-206 that contribute to tumor progression and metastasis, however, the broader gene-networks and pathways regulated by miR-206 remain poorly defined. Here, we have ectopically expressed miR-206 in lung adenocarcinoma cell lines and tumors to identify differentially expressed genes, and study the effects on tumor growth and metastasis. In H1299 tumor xenograft assays, stable expression of miR-206 suppressed both tumor growth and metastasis in mice. Profiling of xenograft tumors using small RNA sequencing and a targeted panel of tumor progression and metastasis-related genes revealed a network of genes involved in TGF-β signalling that were regulated by miR-206. Among these were the TGFB1 ligand, as well as direct transcriptional targets of Smad3. Other differentially expressed genes included components of the extracellular matrix involved in TGF-β activation and signalling, including Thrombospondin-1, which is responsible for the activation of latent TGF-β in the stroma. In cultured lung adenocarcinoma cells treated with recombinant TGF-β, ectopic expression of miR-206 impaired canonical signalling, and expression of TGF-β target genes linked to epithelial-mesenchymal transition. This was due at least in part to the suppression of Smad3 protein levels in lung adenocarcinoma cells with ectopic miR-206 expression. Together, these findings indicate that miR-206 can suppress tumor progression and metastasis by limiting autocrine production of TGF-β, and highlight the potential utility of TGF-β inhibitors for the treatment of lung adenocarcinomas.
Angiotensin (1–7) does not interact directly with MAS1, but can potently antagonize signaling from the AT1 receptor Cell Signal. (IF 3.487) Pub Date : 2018-06-19 Ibragim Gaidarov, John Adams, John Frazer, Todd Anthony, Xiaohua Chen, Joel Gatlin, Graeme Semple, David J. Unett
Angiotensin (1–7) has been reported to be a ligand for the GPCR MAS1. Small molecule MAS1 modulators have also been recently characterized. Aside from convincing evidence for MAS1 activation of Gq signaling, little is known about MAS1 mediated signaling pathways initiated by these ligands, especially Ang (1–7). We performed a comprehensive characterization of recombinant MAS1 signaling induced by Ang (1–7) and small molecule ligands through numerous G protein-dependent and independent pathways, and in a signaling pathway agnostic approach. We find that small molecule ligands modulate numerous G protein-dependent and independent pathways through MAS1, including Gq and Gi pathways, GTPγS binding, β-arrestin recruitment, Erk1/2 and Akt phosphorylation, arachidonic acid release, and receptor internalization. Moreover, in dynamic mass redistribution (DMR) assays that provide a pathway-agnostic readout of cellular responses, small molecule agonists produced robust responses. In contrast, Ang (1–7) failed to induce or block signaling in any of these assay platforms. We detected specific binding of radiolabeled Ang (1–7) to rat aortic endothelial cell (RAEC) membranes, but not to recombinant MAS1. Biphasic, concentration-dependent biased signaling responses to Ang II were detected in RAEC. These phases were associated with vastly different DMR characteristics and this likely provides a molecular basis for previously observed concentration-dependent divergent physiological actions of Ang II. Both phases of Ang II signaling in RAECs were potently inhibited by Ang (1–7), providing a plausible molecular mechanism for Ang (1–7) as counter regulator of the Ang II- AT1 axis, responsible at least in part for Ang (1–7) physiological activities.
Pharmacological inhibition of MALT1 protease activity suppresses endothelial activation via enhancing MCPIP1 expression Cell Signal. (IF 3.487) Pub Date : 2018-06-18 Yong Li, Shengping Huang, Xuan Huang, Xiuzhen Li, Adrian Falcon, Adele Soutar, Frederic Bornancin, Zhisheng Jiang, Hong-Bo Xin, Mingui Fu
Mucosa associated lymphoid tissue lymphoma translocation protein 1 (MALT1) is not only an intracellular signaling scaffold protein but also a paracaspase that plays a key role in the signal transduction and cellular activation of lymphocytes and macrophages. However, its role in endothelial cells remains unknown. Here we report that pharmacological inhibition of MALT1 protease activity strongly suppresses endothelial activation via enhancing MCPIP1 expression. Treatment with MALT1 protease inhibitors selectively inhibited TNFα-induced VCAM-1 expression in HUVECs and LPS-induced VCAM-1 expression in mice. In addition, Inhibition of MALT1 protease activity also significantly inhibited TNFα-induced adhesion of THP-1 monocytic cells to HUVECs. To explore the mechanisms, MALT1 inhibitors does not affect the activation of NF-κB signaling pathway in HUVEC. However, they can stabilize MCPIP1 protein and significantly enhance MCPIP1 protein level in endothelial cells. These results suggest that MALT1 paracaspase also targets MCPIP1 and degrade MCPIP1 protein in endothelial cells similar as it does in immune cells. Taken together, the study suggest inhibition of MALT1 protease activity may represent a new strategy for prevention/therapy of vascular inflammatory diseases such as atherosclerosis.
Phosphoinositide 3-kinase p110α negatively regulates thrombopoietin-mediated platelet activation and thrombus formation Cell Signal. (IF 3.487) Pub Date : 2018-05-21 T.A. Blair, S.F. Moore, T.G. Walsh, J.L. Hutchinson, T.N. Durrant, K.E. Anderson, A.W. Poole, I. Hers
Phosphoinositide 3-kinase (PI3K) plays an important role in platelet function and contributes to platelet hyperreactivity induced by elevated levels of circulating peptide hormones, including thrombopoietin (TPO). Previous work established an important role for the PI3K isoform; p110β in platelet function, however the role of p110α is still largely unexplored. Here we sought to investigate the role of p110α in TPO-mediated hyperactivity by using a conditional p110α knockout (KO) murine model in conjunction with platelet functional assays. We found that TPO-mediated enhancement of collagen-related peptide (CRP-XL)-induced platelet aggregation and adenosine triphosphate (ATP) secretion were significantly increased in p110α KO platelets. Furthermore, TPO-mediated enhancement of thrombus formation by p110α KO platelets was elevated over wild-type (WT) platelets, suggesting that p110α negatively regulates TPO-mediated priming of platelet function. The enhancements were not due to increased flow through the PI3K pathway as phosphatidylinositol 3,4,5-trisphosphate (PI(3,4,5)P3) formation and phosphorylation of Akt and glycogen synthase kinase 3 (GSK3) were comparable between WT and p110α KO platelets. In contrast, extracellular responsive kinase (ERK) phosphorylation and thromboxane (TxA2) formation were significantly enhanced in p110α KO platelets, both of which were blocked by the MEK inhibitor PD184352, whereas the p38 MAPK inhibitor VX-702 and p110α inhibitor PIK-75 had no effect. Acetylsalicylic acid (ASA) blocked the enhancement of thrombus formation by TPO in both WT and p110α KO mice. Together, these results demonstrate that p110α negatively regulates TPO-mediated enhancement of platelet function by restricting ERK phosphorylation and TxA2 synthesis in a manner independent of its kinase activity.
Role of cAMP and phosphodiesterase signaling in liver health and disease Cell Signal. (IF 3.487) Pub Date : 2018-06-11 Banrida Wahlang, Craig McClain, Shirish Barve, Leila Gobejishvili
Liver disease is a significant health problem worldwide with mortality reaching around 2 million deaths a year. Non-alcoholic fatty liver disease (NAFLD) and alcoholic liver disease (ALD) are the major causes of chronic liver disease. Pathologically, NAFLD and ALD share similar patterns of hepatic disorders ranging from simple steatosis to steatohepatitis, fibrosis and cirrhosis. It is becoming increasingly important to identify new pharmacological targets, given that there is no FDA-approved therapy yet for either NAFLD or ALD. Since the evolution of liver diseases is a multifactorial process, several mechanisms involving parenchymal and non-parenchymal hepatic cells contribute to the initiation and progression of liver pathologies. Moreover, certain protective molecular pathways become repressed during liver injury including signaling pathways such as the cyclic adenosine monophosphate (cAMP) pathway. cAMP, a key second messenger molecule, regulates various cellular functions including lipid metabolism, inflammation, cell differentiation and injury by affecting gene/protein expression and function. This review addresses the current understanding of the role of cAMP metabolism and consequent cAMP signaling pathway(s) in the context of liver health and disease. The cAMP pathway is extremely sophisticated and complex with specific cellular functions dictated by numerous factors such abundance, localization and degradation by phosphodiesterases (PDEs). Furthermore, because of the distinct yet divergent roles of both of its effector molecules, the cAMP pathway is extensively targeted in liver injury to modify its role from physiological to therapeutic, depending on the hepatic condition. This review also examines the behavior of the cAMP-dependent pathway in NAFLD, ALD and in other liver diseases and focuses on PDE inhibition as an excellent therapeutic target in these conditions.
MiR-20a-3p regulates TGF-β1/Survivin pathway to affect keratinocytes proliferation and apoptosis by targeting SFMBT1 in vitro Cell Signal. (IF 3.487) Pub Date : 2018-06-07 Ronghua Li, Meng Qiao, Xintong Zhao, Jianjun Yan, Xiaoyan Wang, Qing Sun
Psoriasis is a common immune-mediated chronic inflammatory skin disease characterized by abnormal keratinocyte proliferation, differentiation and apoptosis. However, the exact etiology and pathogenesis are still unclear. Evidence is rapidly accumulating for the role of microRNAs in psoriasis. It has been demonstrated that Interleukin-22 (IL-22) plays vital role in T cell-mediated immune response by interacting with keratinocytes in the pathogenesis of psoriasis. The aim of our study was to explore the possible functional role of miR-20a-3p in psoriasis and in IL-22 induced keratinocyte proliferation. Here, we found that miR-20a-3p was down-regulated in psoriatic lesions and in HaCaT cells (human keratinocyte cell line) treated by IL-22 stimulation. Functional experiments showed that overexpression of miR-20a-3p in HaCaT cells suppressed proliferation and induced apoptosis while its knockdown promoted cell proliferation and reduces cell apoptosis. Mechanistically, SFMBT1 was identified as the direct target of miR-20a-3p by dual luciferase reporter assay. SFMBT1 knockdown was demonstrated to inhibit cell growth and induced apoptosis, which was consistent with the function of miR-20a-3p upregulation in HaCaT cells. In addition, results of western blot analysis showed that miR-20a-3p upregulation or SFMBT1 knockdown changed the protein expression levels of TGF-β1 and survivin. Our findings suggest that miR-20a-3p play roles through targeting SFMBT1 and TGF-β1/Survivin pathway in HaCaT cells, and loss of miR-20a-3p in psoriasis may contribute to hyperproliferation and aberrant apoptosis of keratinocytes.
Nuclear accumulation of SHIP1 mutants derived from AML patients leads to increased proliferation of leukemic cells Cell Signal. (IF 3.487) Pub Date : 2018-05-28 Marcus M. Nalaskowski, Patrick Ehm, Christoph Rehbach, Nina Nelson, Maike Täger, Kathrin Modest, Manfred Jücker
Bioinformatical identification of key pathways and genes in human hepatocellular carcinoma after CSN5 depletion Cell Signal. (IF 3.487) Pub Date : 2018-06-07 Qiang Fu, Fan Yang, Ji Zhao, Xingxing Yang, Tengxiao Xiang, Guoli Huai, Jiashu Zhang, Liang Wei, Shaoping Deng, Hongji Yang
Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer. It has been previously reported that CSN5 depletion is an effective method in human HCC. In the current study, we aimed to uncover gene signatures and key pathways during HCC. Gene expression profiles of GSE26485 were downloaded from GEO database. Totally, 101 differentially expressed genes (DEGs) were up-regulated and 146 ones were down-regulated. Biological processes (BP) and Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) analysis showed that the DEGs were mainly enriched in regulation of cell growth, oxidation-reduction process, mitotic cytokinesis, negative regulation of macroautophagy, endosome organization, lysosome, biosynthesis of antibiotics, small cell lung cancer and glutathione metabolism and so on (P < 0.05). Protein–protein interaction (PPI) network, Kaplan–Meier, log-rank method, western blot, immunohistochemistry and encyclopedia of DNA elements (ENCODE) analysis showed that CSN5 depletion took effects through down-regulation of SMAD5-related pathways which include EXO1, CENPA and NCAPG, resulting in the inactivation of H3K4me3 and H3K36me3. Those genes represent the promising targets for therapeutic intervention in HCC patients.
Trapidil induces osteogenesis by upregulating the signaling of bone morphogenetic proteins Cell Signal. (IF 3.487) Pub Date : 2018-06-05 Bongjun Kim, Jong-Ho Lee, Won Jong Jin, Hong-Hee Kim, Hyunil Ha, Zang Hee Lee
Platelet-derived growth factor receptor (PDGFR) signaling has been shown to inhibit osteogenesis. However, therapeutic efficacy of inhibiting PDGF signaling to bone regeneration in vivo and the specific mechanisms by which PDGFR signaling inhibits osteogenic differentiation remain unclear. In the present study, we examined the osteogenic effect of inhibiting PDGFR using trapidil, a PDGFR antagonist, in vivo and in vitro, and evaluated its mechanisms. A rat calvarial defect model was analyzed by micro-computed tomography and histology to determine the pro-osteogenic effect of trapidil in vivo. In addition, primary mouse calvarial osteoblast precursors were cultured in osteogenic differentiation medium with trapidil to study the mechanisms. Trapidil greatly promoted bone regeneration in a rat calvarial defect model and osteogenic differentiation of calvarial osteoblast precursors. For the mechanisms, trapidil induced phosphorylation of Smad1/5/9 and mitogen-activated protein kinase (MAPK) leading to enhance expression of Runx2, crucial transcription factor for osteogenesis. The pro-osteogenic effects of trapidil were inhibited by LDN193189, specific inhibitor of bone morphogenetic protein (BMP) receptor, ALK2 and ALK3, and by depletion of ALK3, and treatment with noggin, an antagonist of BMPs. Moreover, trapidil showed a synergistic effect with BMP2 on osteogenic differentiation. In conclusion, trapidil induced BMPR activity through upregulation of BMP signaling, leading to promoted osteogenesis in vitro and in vivo. Attenuated BMPR activity may be involved in the inhibition of osteogenesis by PDGFR signaling.
Phospholipase C delta 4 (PLCδ4) is a nuclear protein involved in cell proliferation and senescence in mesenchymal stromal stem cells Cell Signal. (IF 3.487) Pub Date : 2018-06-01 Marianna Kunrath-Lima, Marcelo Coutinho de Miranda, Andrea da Fonseca Ferreira, Camila Cristina Fraga Faraco, Mariane Izabella Abreu de Melo, Alfredo Miranda Goes, Michele Angela Rodrigues, Jerusa Araújo Quintão Arantes Faria, Dawidson Assis Gomes
Ca2+ is an important second messenger, and it is involved in many cellular processes such as cell death and proliferation. The rise in intracellular Ca2+ levels can be due to the generation of inositol 1,4,5-trisphosphate (InsP3), which is a product of phosphatidylinositol 4,5-bisphosphate (PIP2) hydrolysis by phospholipases C (PLCs), that leads to Ca2+ release from endoplasmic reticulum by InsP3 receptors (InsP3R). Ca2+ signaling patterns can vary in different regions of the cell and increases in nuclear Ca2+ levels have specific biological effects that differ from those of Ca2+ increase in the cytoplasm. There are PLCs in the cytoplasm and nucleus, but little is known about the functions of nuclear PLCs. This work aimed to characterize phenotypically the human PLCδ4 (hPLCδ4) in mesenchymal stem cells. This nuclear isoform of PLC is present in different cell types and has a possible role in proliferative processes. In this work, hPLCδ4 was found to be mainly nuclear in human adipose-derived mesenchymal stem cells (hASC). PLCδ4 knockdown demonstrated that it is essential for hASC proliferation, without inducing cell death. An increase of cells in G1, and a reduction of cells on interphase and G2/M in knockdown cells were seen. Furthermore, PLCδ4 knockdown increased the percentage of senescent cells, p16INK4A+ and p21Cip1 mRNAs expression, which could explain the impaired cell proliferation. The results show that hPLCδ4 is in involved in cellular proliferation and senescence in hASC.
Interleukin-32 induced thymic stromal lymphopoietin plays a critical role in the inflammatory response in human corneal epithelium Cell Signal. (IF 3.487) Pub Date : 2018-05-24 Jing Lin, Rui Xu, LiTing Hu, Jia You, Nan Jiang, Cui Li, Chengye Che, Qian Wang, Qiang Xu, Jinghui Li, Guiqiu Zhao
Interleukin (IL)-32, a novel cytokine, participates in a variety of inflammatory disorders. Thymic stromal lymphopoietin (TSLP) plays important roles in mucosal epithelial cells, especially in allergy-induced inflammation, through the TSLP-TSLPR (thymic stromal lymphopoietin receptor) signalling pathway. However, the association of IL-32 with TSLP on the ocular surface remains unclear. The present work aimed to assess the functional association of IL-32 with TSLP in the control of pro-inflammatory cytokine levels in the corneal epithelium. Human corneal tissue specimens and human corneal epithelial cells (HCECs) were administered different concentrations of IL-32 in the presence or absence of various inhibitors to assess TSLP levels and localization, as well as the molecular pathways that control pro-inflammatory cytokine production. TSLP mRNA levels were determined by real time RT- PCR, while protein levels were quantitated by ELISA and immunohistochemical staining. TSLP protein expression was examined in donor corneal epithelium samples. IL-32 significantly upregulated TSLP and pro-inflammatory cytokines (TNFα and IL-6) in HCECs at the gene and protein levels. The production of pro-inflammatory molecules by IL-32 was increased by recombinant TSLP. Interestingly, both NF-κB (quinazoline) and caspase-1 (VX-765) inhibitors suppressed the IL-32-related upregulation of pro-inflammatory cytokines (TNFα and IL-6). These findings demonstrate that IL-32 and IL-32-induced-TSLP are critical cytokines that participate in inflammatory responses through the caspase-1 and NF-κB signalling pathways in the corneal epithelium, suggesting new molecular targets for inflammatory diseases of the ocular surface. The effects of IL-32 on cell proliferation and apoptosis were investigated by MTT assays and RT-PCR,respectively. The results demonstrated that IL-32 inhibits cells apoptosis in HCECs.
EphA2 stimulates VCAM-1 expression through calcium-dependent NFAT1 activity Cell Signal. (IF 3.487) Pub Date : 2018-05-21 Steven Daniel Funk, Alexandra C. Finney, Arif Yurdagul, Christopher B. Pattillo, A. Wayne Orr
Endothelial cell activation by proinflammatory stimuli drives leukocyte recruitment through enhanced expression of counter-receptors such as vascular cell adhesion molecule-1 (VCAM-1). We previously demonstrated that activation of the receptor tyrosine kinase EphA2 with its ligand ephrin-A1 induces VCAM-1 expression. Here, we sought to characterize the proinflammatory signaling pathways involved. Analysis of over-represented transcription factors in ephrin-A1-induced genes identified multiple potential transcriptional regulators, including the Rel family members nuclear factor-κB (NF-κB/p65) and nuclear factor of activated T-cells (NFAT). While ephrin-A1 failed to induce endothelial NF-κB activation, NF-κB inhibitors prevented ephrin-A1-induced VCAM-1 expression, suggesting basal NF-κB activity is required. In contrast, ephrin-A1 induced a robust EphA2-dependent increase in NFAT activation, and mutation of the NF-κB/NFAT-binding sites in the VCAM-1 promoter blunted ephrin-A1-induced promoter activity. NFAT activation classically occurs through calcium-dependent calcineurin activation, and inhibiting NFAT signaling with calcineurin inhibitors (cyclosporine A, FK506) or direct NFAT inhibitors (A-285222) was sufficient to block ephrin-A1-induced VCAM-1 expression. Consistent with robust NFAT activation, ephrin-A1-induced an EphA2-dependent calcium influx in endothelial cells that was required for ephrin—A1-induced NFAT activation and VCAM-1 expression. This work provides the first data showing EphA2-dependent calcium influx and NFAT activation and identifies NFAT as a novel EphA2-dependent proinflammatory pathway in endothelial activation.
Deltex interacts with Eiger and consequently influences the cell death in Drosophila melanogaster Cell Signal. (IF 3.487) Pub Date : 2018-05-15 Debdeep Dutta, Ankita Singh, Maimuna Sali Paul, Vartika Sharma, Mousumi Mutsuddi, Ashim Mukherjee
TNF-JNK signaling is one of the highly conserved signaling pathways that regulate a broad spectrum of cellular processes including proliferation and apoptosis. Eiger, the sole homologue of TNF in Drosophila, initiates the TNF-JNK pathway to induce cell death. Previously, Deltex (Dx) has been identified as a Notch signaling component that regulates vesicular trafficking of Notch. In the present study, we have investigated the interaction between these two proteins in order to identify how Dx influences the activity of Eiger. Dx is found to act as a novel modulator of JNK-mediated cell death inducing activity of Eiger. Additionally, we observe that dx genetically interacts with eiger during wing development, and these two proteins, Dx and Eiger, colocalize in the cytoplasm. Our analysis reveals that Dx is involved in the cytoplasmic relocalization of Eiger from the cell membrane, thereby influencing Eiger-mediated JNK-activation process. Moreover, we demonstrate that Dx potentiates the activity of Eiger to downregulate Notch signaling pathway by retaining the Notch protein in the cytoplasm. Together, our findings reveal a novel role of Dx to modulate the signaling activity of Eiger and subsequent JNK-mediated cell death.
Sec6 enhances cell migration and suppresses apoptosis by elevating the phosphorylation of p38 MAPK, MK2, and HSP27 Cell Signal. (IF 3.487) Pub Date : 2018-05-02 Toshiaki Tanaka, Mitsuyoshi Iino, Kaoru Goto
The signaling axis of p38 mitogen-activated protein kinase (p38 MAPK) and MAPK-activated protein kinase 2 (MK2) is the dominant pathway that leads to heat shock protein 27 (HSP27) phosphorylation. After activation of MK2 by p38 MAPK, HSP27 is phosphorylated and depolymerized by MK2, thereby increasing the cell migration and directly interfering with the apoptotic signaling cascades. Sec6 is one of the components of the exocyst complex that is an evolutionarily conserved 8-protein complex. Even though several studies have demonstrated that Sec6 is involved in various cellular physiological functions, the relationship between Sec6 and HSP27 or p38 MAPK during cell migration and apoptosis remains unclear. In the present study, we observed that Sec6 increased the phosphorylation of p38 MAPK through the activation of MAPK kinase 3/6 (MKK3/6). Moreover, Sec6 knockdown suppressed the phosphorylation of HSP27 at Ser78 and Ser82 sites via suppression of activated MK2. Furthermore, the reduction of phosphorylated HSP27 or p38 MAPK by Sec6 knockdown suppressed cell migration and promoted apoptosis after treatment with tumor necrosis factor-α and cycloheximide. The present study suggested that Sec6 is involved in the enhancement of cell migration and suppression of apoptosis through the activation of HSP27 or p38 MAPK phosphorylation.
Mechanisms for localising calcineurin and CaMKII in dendritic spines Cell Signal. (IF 3.487) Pub Date : 2018-05-27 Christopher J. Penny, Matthew G. Gold
Calcineurin and calmodulin-dependent protein kinase II (CaMKII) are both highly abundant in neurons, and both are activated by calmodulin at similar Ca2+ concentrations in the test tube. However, they fulfill opposite functions in dendritic spines, with CaMKII activity driving long-term synaptic potentiation following large influxes of Ca2+ through NMDA-type glutamate receptors (NMDARs), and calcineurin responding to smaller influxes of Ca2+ through the same receptors to induce long-term depression. In this review, we explore the notion that precise dynamic localisation of the two enzymes at different sites within dendritic spines is fundamental to this behaviour. We describe the structural basis of calcineurin and CaMKII localisation by their interaction with proteins including AKAP79, densin-180, α-actinin, and NMDARs. We then consider how interactions with these proteins likely position calcineurin and CaMKII at different distances from Ca2+ microdomains emanating from the mouths of NMDARs in order to drive the divergent responses. We also highlight shortcomings in our current understanding of synaptic localisation of these two important signalling enzymes.
Transforming growth factor β1 suppresses proinflammatory gene program independent of its regulation on vascular smooth muscle differentiation and autophagy Cell Signal. (IF 3.487) Pub Date : 2018-07-11 Ping Gao, Wen Wu, Jiemei Ye, Yao Wei Lu, Alejandro Pablo Adam, Harold A. Singer, Xiaochun Long
Transforming growth factor β (TGFβ) signaling plays crucial roles in maintaining vascular integrity and homeostasis, and is established as a strong activator of vascular smooth muscle cell (VSMC) differentiation. Chronic inflammation is a hallmark of various vascular diseases. Although TGFβ signaling has been suggested to be protective against inflammatory aortic aneurysm progression, its exact effects on VSMC inflammatory process and the underlying mechanisms are not fully unraveled. Here we revealed that TGFβ1 suppressed the expression of a broad array of proinflammatory genes while potently induced the expression of contractile genes in cultured primary human coronary artery SMCs (HCASMCs). The regulation of TGFβ1 on VSMC contractile and proinflammatory gene programs appeared to occur in parallel and both processes were through a SMAD4-dependent canonical pathway. We also showed evidence that the suppression of TGFβ1 on VSMC proinflammatory genes was mediated, at least partially through the blockade of signal transducer and activator of transcription 3 (STAT3) and NF-κB pathways. Interestingly, our RNA-seq data also revealed that TGFβ1 suppressed gene expression of a battery of autophagy mediators, which was validated by western blot for the conversion of microtubule-associated protein light chain 3 (LC3) and by immunofluo-rescence staining for LC3 puncta. However, impairment of VSMC autophagy by ATG5 deletion failed to rescue TGFβ1 influence on both VSMC contractile and proinflammatory gene programs, suggesting that TGFβ1-regulated VSMC differentiation and inflammation are not attributed to TGFβ1 suppression on autophagy. In summary, our results demonstrated an important role of TGFβ signaling in suppressing proinflammatory gene program in cultured primary human VSMCs via the blockade on STAT3 and NF-κB pathway, therefore providing novel insights into the mechanisms underlying the protective role of TGFβ signaling in vascular diseases.
Diversity matters: combinatorial information coding by GABAA receptor subunits during spatial learning and its allosteric modulation Cell Signal. (IF 3.487) Pub Date : 2018-07-11 Edit Szodorai, Konstantina Bampali, Roman A. Romanov, Siegfried Kasper, Tomas Hökfelt, Margot Ernst, Gert Lubec, Tibor Harkany
In the hippocampus, GABA inhibition tunes network oscillations and shapes synchronous activity during spatial learning and memory coding. Once released from the presynapse, GABA primarily binds to ionotropic GABAA receptors (GABAARs), which are heteropentamers combinatorially assembled from nineteen known subunits to induce Cl- currents postsynaptically. Dissecting GABAAR subtype specificities in neurobiology is daunting because of differences in their developmental dynamics, regional distribution and subcellular compartmentalization. Here, we review recent data to show that the combination of single-cell mRNA-seq and neuroanatomy can reveal unprecedented cell-type and network-specificity of GABAAR subunits and limit the permutation in subunit configurations, thus rationalizing GABAAR physiology and pharmacology. By comparing RNA-seq data on principal cells and interneurons we discuss a tight match between GABAAR subunit allocation, diversity in the origins of GABA inputs and operational rules at synaptic and extrasynaptic sites. We propose that coincident analysis of all GABAAR subunits, particularly in relation to specific behaviors, could overcome existing pitfalls of the genetic and pharmacological manipulation of single subunits. By using α1 and α5 GABAAR subunits, we single out hippocampal spatial learning as a process in which, despite the many studies available to date, neither consensus nor causality exists with regards to GABAAR subtype requirements, curtailing a unifying concept on postsynaptic coding of GABA signals. Finally, we address the modulation of GABAAR subunits by dopamine and endocannabinoids through receptor heteromerization, cross-modulation of signal transduction and allostery. In sum, data in this review infer that multiparametric computation gains momentum to improve knowledge on GABAARs function in cognition and neuropsychiatric illnesses.
Deguelin attenuates non-small cell lung cancer cell metastasis through inhibiting the CtsZ/FAK signaling pathway Cell Signal. (IF 3.487) Pub Date : 2018-07-07 Wei Li, Xinfang Yu, Xiaolong Ma, Li Xie, Zhenkun Xia, Lijun Liu, Xinyou Yu, Jian Wang, Huiling Zhou, Xinmin Zhou, Yifeng Yang, Haidan Liu
Lung cancer is the leading cause of cancer-related death among both men and women every year, mainly due to metastasis. Although natural compound deguelin has been reported to inhibited cell migration and invasion in various cancer cells, the details of this regulation progress remain to be fully elucidated. In this study, we investigated the underlying mechanism of deguelin-suppressed metastasis of non-small cell lung cancer (NSCLC) cells. Our results demonstrate that deguelin inhibits NSCLC cell migration, invasion, and metastasis both in vitro and in vivo. These inhibitory effects of deguelin were mediated by suppressing of Cathepsin Z (CtsZ) expression and interrupting the interaction of CtsZ with integrin β3. Moreover, deguelin inhibits the activation of CtsZ downstream FAK/Src/Paxillin signaling. Knockdown of CtsZ mimicked the effect of deguelin on NSCLC cells migration and invasion. Our study reveals that deguelin exerts its anti-metastatic effect both in vitro and in vivo is partly dependent on the suppression of CtsZ signaling. Deguelin would be a potential anti-metastasis agent against NSCLC.
Role of mitogen-activated protein kinase signaling in the pathogenesis of dengue virus infection Cell Signal. (IF 3.487) Pub Date : 2018-05-10 Gopinathan Pillai Sreekanth, Pa-thai Yenchitsomanus, Thawornchai Limjindaporn
Dengue virus (DENV) infection is a disease that is endemic to many parts of the world, and its increasing prevalence ranks it among the diseases considered to be a significant threat to public health. The clinical manifestations of DENV infection range from mild dengue fever (DF) to more severe dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). Increased proinflammatory cytokines and vascular permeability, both of which cause organ injury, are the hallmarks of severe dengue disease. Signs of liver injury were observed in studies using hepatic cell lines, mouse models, and autopsy specimens from DENV-infected patients, and these signs substantiated the effects of inflammatory responses and hepatic cell apoptosis. Mitogen-activated protein kinases (MAPK) are involved in inflammatory responses and cellular stress during viral infections. The roles of MAPK signaling in DENV infection were reviewed, and published data indicate MAPK signaling to be involved in inflammatory responses and hepatic cell apoptosis in both in vitro cultures and in vivo models. Modulation of MAPK signaling ameliorates the inflammatory responses and hepatic cell apoptosis in DENV infection. This accumulation of published data relative to the role of MAPK signaling in inflammatory responses and cell apoptosis in DENV infection is elucidatory, and may help to accelerate the development of novel or repositioned therapies to treat this unpredictable and often debilitating disease.
TRIM8 regulated autophagy modulates the level of cleaved Caspase-3 subunit to inhibit genotoxic stress induced cell death Cell Signal. (IF 3.487) Pub Date : 2018-04-17 Milton Roy, Dhanendra Tomar, Kritarth Singh, Sripada Lakshmi, Paresh Prajapati, Khyati Bhatelia, Dhruv Gohel, Rajesh Singh
In cancer patients, treatment modalities like chemotherapy and radiation exert their anticancer effects by inducing DNA damage. The cancer cells can survive under genotoxic stress by inducing DNA damage response (DDR) or can undergo cell death. The process of autophagy is emerging as crucial regulator of cell survival during different stress conditions. Post translational modification through ubiquitin plays an essential role in DDR during genotoxic stress conditions. Ubiquitin ligases regulate autophagy and cell death pathways however their role during genotoxic stress conditions is not understood. In the current study we identified TRIM8, RING E3 Ligase, as a novel regulator of autophagy during DDR. TRIM8 regulates lysosomal biogenesis and autophagy flux. The turnover of TRIM8 is high and is stabilized during genotoxic stress conditions. TRIM8 regulated autophagy is essential for its cytoprotective role during genotoxic stress induced cell death. TRIM8 stabilizes the turnover of XIAP during genotoxic stress and forms complex with XIAP and caspase-3 to inhibit its activation in presence of etoposide. TRIM8 mediated autophagy promotes degradation of cleaved caspase-3 subunits. This study described TRIM8, as a novel regulator of DDR-autophagy crosstalk, which may play role in survival of cancer cells in presence of genotoxic agents.
S6 kinase 1 plays a key role in mitochondrial morphology and cellular energy flow Cell Signal. (IF 3.487) Pub Date : 2018-04-17 Quangdon Tran, Jae-Hun Jung, Jisoo Park, Hyunji Lee, Youngeun Hong, Hyeonjeong Cho, Minhee Kim, Sungjin Park, So-Hee Kwon, Seon-Hwan Kim, George Thomas, Kwang Pyo Kim, Myung-Haing Cho, Jongsun Park
Mitochondrial morphology, which is associated with changes in metabolism, cell cycle, cell development and cell death, is tightly regulated by the balance between fusion and fission. In this study, we found that S6 kinase 1 (S6K1) contributes to mitochondrial dynamics, homeostasis and function. Mouse embryo fibroblasts lacking S6K1 (S6K1-KO MEFs) exhibited more fragmented mitochondria and a higher level of Dynamin related protein 1 (Drp1) and active Drp1 (pS616) in both whole cell extracts and mitochondrial fraction. In addition, there was no evidence for autophagy and mitophagy induction in S6K1 depleted cells. Glycolysis and mitochondrial respiratory activity was higher in S6K1-KO MEFs, whereas OxPhos ATP production was not altered. However, inhibition of Drp1 by Mdivi1 (Drp1 inhibitor) resulted in higher OxPhos ATP production and lower mitochondrial membrane potential. Taken together the depletion of S6K1 increased Drp1-mediated fission, leading to the enhancement of glycolysis. The fission form of mitochondria resulted in lower yield for OxPhos ATP production as well as in higher mitochondrial membrane potential. Thus, these results have suggested a potential role of S6K1 in energy metabolism by modulating mitochondrial respiratory capacity and mitochondrial morphology.
The cAMP-induced G protein subunits dissociation monitored in live Dictyostelium cells by BRET reveals two activation rates, a positive effect of caffeine and potential role of microtubules Cell Signal. (IF 3.487) Pub Date : 2018-04-24 A.F.M. Tariqul Islam, Haicen Yue, Margarethakay Scavello, Pearce Haldeman, Wouter-Jan Rappel, Pascale G. Charest
RASAL2 inhibits tumor angiogenesis via p-AKT/ETS1 signaling in bladder cancer Cell Signal. (IF 3.487) Pub Date : 2018-04-24 Ke Hui, Shiqi Wu, Yangyang Yue, Yanan Gu, Bing Guan, Xinyang Wang, Jer-Tsong Hsieh, Luke S. Chang, Dalin He, Kaijie Wu
Molecular mechanisms of platelet activation and aggregation induced by breast cancer cells Cell Signal. (IF 3.487) Pub Date : 2018-04-26 Marta Zarà, Ilaria Canobbio, Caterina Visconte, Jessica Canino, Mauro Torti, Gianni Francesco Guidetti
Tumor cell-induced platelet aggregation represents a critical process both for successful metastatic spread of the tumor and for the development of thrombotic complications in cancer patients. To get further insights into this process, we investigated and compared the molecular mechanisms of platelet aggregation induced by two different breast cancer cell lines (MDA-MB-231 and MCF7) and a colorectal cancer cell line (Caco-2). All the three types of cancer cells were able to induce comparable platelet aggregation, which, however, was observed exclusively in the presence of CaCl2 and autologous plasma. Aggregation was supported both by fibrinogen binding to integrin αIIbβ3 as well as by fibrin formation, and was completely prevented by the serine protease inhibitor PPACK. Platelet aggregation was preceded by generation of low amounts of thrombin, possibly through tumor cells-expressed tissue factor, and was supported by platelet activation, as revealed by stimulation of phospholipase C, intracellular Ca2+ increase and activation of Rap1b GTPase. Pharmacological inhibition of phospholipase C, but not of phosphatidylinositol 3-kinase or Src family kinases prevented tumor cell-induced platelet aggregation. Tumor cells also induced dense granule secretion, and the stimulation of the P2Y12 receptor by released ADP was found to be necessary for complete platelet aggregation. By contrast, prevention of thromboxane A2 synthesis by aspirin did not alter the ability of all the cancer cell lines analyzed to induce platelet aggregation. These results indicate that tumor cell-induced platelet aggregation is not related to the type of the cancer cells or to their metastatic potential, and is triggered by platelet activation and secretion driven by the generation of small amount of thrombin from plasma and supported by the positive feedback signaling through secreted ADP.
Modulation of TGFβ/Smad signaling by the small GTPase RhoB Cell Signal. (IF 3.487) Pub Date : 2018-04-26 Melina Livitsanou, Eleftheria Vasilaki, Christos Stournaras, Dimitris Kardassis
IRAK2 counterbalances oncogenic Smurf1 in colon cancer cells by dictating ER stress Cell Signal. (IF 3.487) Pub Date : 2018-05-09 Jingwen Liu, Yuhan Chen, Qingyang Huang, Wen Liu, Xiqing Ji, Fan Hu, Ying Zhu, Lingqiang Zhang, Guanglong Dong
IL-7-induced phosphorylation of the adaptor Crk-like and other targets Cell Signal. (IF 3.487) Pub Date : 2018-03-24 Francesca B. Aiello, Tad Guszczynski, Wenqing Li, Julie A. Hixon, Qiong Jiang, Deborah L. Hodge, Tania Massignan, Chiara Di Lisio, Anand Merchant, Antonio D. Procopio, Valentina Bonetto, Scott K. Durum
IL-7 is required for T cell differentiation and mature T cell homeostasis and promotes pro-B cell proliferation and survival. Tyrosine phosphorylation plays a central role in IL-7 signaling. We identified by two-dimensional electrophoresis followed by anti-phosphotyrosine immunoblotting and mass spectrometry sixteen tyrosine phosphorylated proteins from the IL-7-dependent cell line D1. IL-7 stimulation induced the phosphorylation of the proteins STI1, ATIC and hnRNPH, involved in pathways related to survival, proliferation and gene expression, respectively, and increased the phosphorylation of CrkL, a member of a family of adaptors including the highly homologous Crk isoforms CrkII and CrkI, important in multiple signaling pathways. We observed an increased phosphorylation of CrkL in murine pro-B cells and in murine and human T cells. In addition, IL-7 increased the association of CrkL with the transcription factor Stat5, essential for IL-7 pro-survival activity. The selective tyrosine kinase inhibitor Imatinib. counteracted the IL-7 pro-survival effect in D1 cells and decreased CrkL phosphorylation. These data suggested that CrkL could play a pro-survival role in IL-7-mediated signaling. We observed that pro-B cells also expressed, in addition to CrkL, the Crk isoforms CrkII and CrkI and therefore utilized pro-B cells conditionally deficient in all three to evaluate the role of these proteins. The observation that the IL-7 pro-survival effect was reduced in Crk/CrkL conditionally-deficient pro-B cells further pointed to a pro-survival role of these adaptors. To further evaluate the role of these proteins, gene expression studies were performed in Crk/CrkL conditionally-deficient pro-B cells. IL-7 decreased the transcription of the receptor LAIR1, which inhibits B cell proliferation, in a Crk/CrkL-dependent manner, suggesting that the Crk family of proteins may promote pro-B cell proliferation. Our data contribute to the understanding of IL-7 signaling and suggest the involvement of Crk family proteins in pathways promoting survival and proliferation.
Activation of the non-canonical NF-κB/p52 pathway in vascular endothelial cells by RANKL elicits pro-calcific signalling in co-cultured smooth muscle cells Cell Signal. (IF 3.487) Pub Date : 2018-04-17 Emma Harper, Keith D. Rochfort, Hannah Forde, Colin Davenport, Diarmuid Smith, Philip M. Cummins
Some contents have been Reproduced by permission of The Royal Society of Chemistry.
- Acc. Chem. Res.
- ACS Appl. Mater. Interfaces
- ACS Biomater. Sci. Eng.
- ACS Catal.
- ACS Cent. Sci.
- ACS Chem. Biol.
- ACS Chem. Neurosci.
- ACS Comb. Sci.
- ACS Earth Space Chem.
- ACS Energy Lett.
- ACS Infect. Dis.
- ACS Macro Lett.
- ACS Med. Chem. Lett.
- ACS Nano
- ACS Omega
- ACS Photonics
- ACS Sens.
- ACS Sustainable Chem. Eng.
- ACS Synth. Biol.
- Acta Biomater.
- Acta Crystallogr. A Found. Adv.
- Acta Mater.
- Adv. Colloid Interface Sci.
- Adv. Electron. Mater.
- Adv. Energy Mater.
- Adv. Funct. Mater.
- Adv. Healthcare Mater.
- Adv. Mater.
- Adv. Mater. Interfaces
- Adv. Opt. Mater.
- Adv. Sci.
- Adv. Synth. Catal.
- AlChE J.
- Anal. Bioanal. Chem.
- Anal. Chem.
- Anal. Chim. Acta
- Anal. Methods
- Angew. Chem. Int. Ed.
- Annu. Rev. Anal. Chem.
- Annu. Rev. Biochem.
- Annu. Rev. Environ. Resour.
- Annu. Rev. Food Sci. Technol.
- Annu. Rev. Mater. Res.
- Annu. Rev. Phys. Chem.
- Appl. Catal. A Gen.
- Appl. Catal. B Environ.
- Appl. Clay. Sci.
- Appl. Energy
- Aquat. Toxicol.
- Arab. J. Chem.
- Asian J. Org. Chem.
- Atmos. Environ.
- Carbohydr. Polym.
- Catal. Commun.
- Catal. Rev. Sci. Eng.
- Catal. Sci. Technol.
- Catal. Today
- Cell Chem. Bio.
- Cem. Concr. Res.
- Ceram. Int.
- Chem. Asian J.
- Chem. Bio. Drug Des.
- Chem. Biol. Interact.
- Chem. Commun.
- Chem. Educ. Res. Pract.
- Chem. Eng. J.
- Chem. Eng. Sci.
- Chem. Eur. J.
- Chem. Mater.
- Chem. Phys.
- Chem. Phys. Lett.
- Chem. Phys. Lipids
- Chem. Rev.
- Chem. Sci.
- Chem. Soc. Rev.
- Chin. J. Chem.
- Combust. Flame
- Compos. Part A Appl. Sci. Manuf.
- Compos. Sci. Technol.
- Compr. Rev. Food Sci. Food Saf.
- Comput. Chem. Eng.
- Constr. Build. Mater.
- Coordin. Chem. Rev.
- Corros. Sci.
- Crit. Rev. Food Sci. Nutr.
- Crit. Rev. Solid State Mater. Sci.
- Cryst. Growth Des.
- Curr. Opin. Chem. Eng.
- Curr. Opin. Colloid Interface Sci.
- Curr. Opin. Environ. Sustain
- Curr. Opin. Solid State Mater. Sci.
- Ecotox. Environ. Safe.
- Electrochem. Commun.
- Electrochim. Acta
- Energy Environ. Sci.
- Energy Fuels
- Energy Storage Mater.
- Environ. Impact Assess. Rev.
- Environ. Int.
- Environ. Model. Softw.
- Environ. Pollut.
- Environ. Res.
- Environ. Sci. Policy
- Environ. Sci. Technol.
- Environ. Sci. Technol. Lett.
- Environ. Sci.: Nano
- Environ. Sci.: Processes Impacts
- Environ. Sci.: Water Res. Technol.
- Eur. J. Inorg. Chem.
- Eur. J. Med. Chem.
- Eur. J. Org. Chem.
- Eur. Polym. J.
- J. Acad. Nutr. Diet.
- J. Agric. Food Chem.
- J. Alloys Compd.
- J. Am. Ceram. Soc.
- J. Am. Chem. Soc.
- J. Am. Soc. Mass Spectrom.
- J. Anal. Appl. Pyrol.
- J. Anal. At. Spectrom.
- J. Antibiot.
- J. Catal.
- J. Chem. Educ.
- J. Chem. Eng. Data
- J. Chem. Inf. Model.
- J. Chem. Phys.
- J. Chem. Theory Comput.
- J. Chromatogr. A
- J. Chromatogr. B
- J. Clean. Prod.
- J. CO2 UTIL.
- J. Colloid Interface Sci.
- J. Comput. Chem.
- J. Cryst. Growth
- J. Dairy Sci.
- J. Electroanal. Chem.
- J. Electrochem. Soc.
- J. Environ. Manage.
- J. Eur. Ceram. Soc.
- J. Fluorine Chem.
- J. Food Drug Anal.
- J. Food Eng.
- J. Food Sci.
- J. Funct. Foods
- J. Hazard. Mater.
- J. Heterocycl. Chem.
- J. Hydrol.
- J. Ind. Eng. Chem.
- J. Inorg. Biochem.
- J. Magn. Magn. Mater.
- J. Mater. Chem. A
- J. Mater. Chem. B
- J. Mater. Chem. C
- J. Mater. Process. Tech.
- J. Mech. Behav. Biomed. Mater.
- J. Med. Chem.
- J. Membr. Sci.
- J. Mol. Catal. A Chem.
- J. Mol. Liq.
- J. Nat. Gas Sci. Eng.
- J. Nat. Prod.
- J. Nucl. Mater.
- J. Org. Chem.
- J. Photochem. Photobiol. C Photochem. Rev.
- J. Phys. Chem. A
- J. Phys. Chem. B
- J. Phys. Chem. C
- J. Phys. Chem. Lett.
- J. Polym. Sci. A Polym. Chem.
- J. Porphyr. Phthalocyanines
- J. Power Sources
- J. Solid State Chem.
- J. Taiwan Inst. Chem. E.
- Macromol. Rapid Commun.
- Mass Spectrom. Rev.
- Mater. Chem. Front.
- Mater. Des.
- Mater. Horiz.
- Mater. Lett.
- Mater. Sci. Eng. A
- Mater. Sci. Eng. R Rep.
- Mater. Today
- Meat Sci.
- Med. Chem. Commun.
- Microchem. J.
- Microchim. Acta
- Micropor. Mesopor. Mater.
- Mol. Biosyst.
- Mol. Cancer Ther.
- Mol. Catal.
- Mol. Nutr. Food Res.
- Mol. Pharmaceutics
- Mol. Syst. Des. Eng.
- Nano Energy
- Nano Lett.
- Nano Res.
- Nano Today
- Nano-Micro Lett.
- Nanomed. Nanotech. Biol. Med.
- Nanoscale Horiz.
- Nat. Catal.
- Nat. Chem.
- Nat. Chem. Biol.
- Nat. Commun.
- Nat. Energy
- Nat. Mater.
- Nat. Med.
- Nat. Methods
- Nat. Nanotech.
- Nat. Photon.
- Nat. Prod. Rep.
- Nat. Protoc.
- Nat. Rev. Chem.
- Nat. Rev. Drug. Disc.
- Nat. Rev. Mater.
- Natl. Sci. Rev.
- Neurochem. Int.
- New J. Chem.
- NPG Asia Mater.
- npj 2D Mater. Appl.
- npj Comput. Mater.
- npj Flex. Electron.
- npj Mater. Degrad.
- npj Sci. Food
- Pharmacol. Rev.
- Pharmacol. Therapeut.
- Photochem. Photobiol. Sci.
- Phys. Chem. Chem. Phys.
- Phys. Life Rev.
- PLOS ONE
- Polym. Chem.
- Polym. Degrad. Stabil.
- Polym. J.
- Polym. Rev.
- Powder Technol.
- Proc. Combust. Inst.
- Prog. Cryst. Growth Ch. Mater.
- Prog. Energy Combust. Sci.
- Prog. Mater. Sci.
- Prog. Photovoltaics
- Prog. Polym. Sci.
- Prog. Solid State Chem.
- Sci. Adv.
- Sci. Bull.
- Sci. Rep.
- Sci. Total Environ.
- Sci. Transl. Med.
- Scr. Mater.
- Sens Actuators B Chem.
- Sep. Purif. Technol.
- Small Methods
- Soft Matter
- Sol. Energy
- Sol. Energy Mater. Sol. Cells
- Solar RRL
- Spectrochim. Acta. A Mol. Biomol. Spectrosc.
- Surf. Sci. Rep.
- Sustainable Energy Fuels