Activation of JAK-STAT pathway is required for platelet-derived growth factor-induced proliferation of pancreatic stellate cells

AIM: To clarify the role of Janus kinase-signal transducersand activators of transcription (JAK-STAT) pathway in platelet-derived growth factor (PDGF) induced proliferation in activated pancreatic stellate cells (PSCs).METHODS: PSCs were isolated from rat pancreas tissue, and used in their culture-activated, myofibroblast-like phenotype. STAT-specific binding activity was assessed by electrophoretic mobility shift assay. Activation of Src, JAK2,STAT1, STAT3, and ERK was determined by Western blotting using anti-phosphospecific antibodies. Cell proliferation was assessed by measuring the incorporation of 5-bromo-2′deoxyuridine.RESULTS: PDGF-BB induced STAT-specific binding activity, and activation of Src, JAK2, STAT1, STAT3, and ERK. Ethanol and acetaldehyde at clinically relevant concentrations decreased basal activation of JAK2 and STAT3. PDGFinduced activation of STAT1 and STAT3 was inhibited bya Src inhibitor PP1 and a JAK2 inhibitor AG490, whereasPDGF-induced activation of ERK was inhibited by PP1, and not by AG490. PDGF-induced proliferation was inhibited by PP1 and AG490 as well as by STAT3 antisense oligonucleotide.CONCLUSION: PDGF-BB activated JAK2-STAT pathwayvia Src-dependent mechanism. Activation of JAK2-STAT3pathway, in addition to ERK, may play a role in PDGF-induced proliferation of PSCs.

Green tea polyphenol epigallocatechin-3-gallate blocks PDGF-induced proliferation and migration of rat pancreatic stellate cells

AIM: To clarify the effects of epigallocatechin-3-gallate (EGCG) on the platelet-derived growth factor (PDGF)-BBinduced proliferation and migration of pancreatic stellate cells (PSCs).METHODS: PSCs were isolated from rat pancreas tissue and used in their culture-activated, myofibroblast-like phenotype. Cell proliferation was assessed by measuring the incorporation of 5-bromo-2'-deoxyuridine. Cell migration was assessed using modified Boyden chambers. CyclinD1, p21waf1, and p27kip1 expression and phosphorylation of PDGF β-receptor, extracellular signal-regulated kinase, and Akt were examined by Western blotting. Activation of phosphatidylinositol 3-kinase was examined by kinase assay using phosphatidylinositol as a substrate. Cell cycle was assessed by flow cytometry after staining with propidium iodide. RESULTS: EGCG at non-cytotoxic concentrations inhibited PDGF-induced proliferation and migration. This effect was associated with the inhibition of cell cycle progression beyondthe G1 phase, decreased cyclin D1 and increased p27Kip1 expression. EGCG inhibited tyrosine phosphorylation of PDGF β-receptor and downstream activation of extracellular signal-regulated kinase and phosphatidylinositol 3-kinase/ Akt pathways.CONCLUSION: EGCG inhibited PDGF-BB-induced proliferation and migration of PSCs through the inhibrdon of PDGF-mediated signaling pathways.

Endothelin-1 stimulates contraction and migration of rat pancreatic stellate cells

AIM: To examine the ability of ET-1 to affect the cell functions of PSCs and the underlying molecular mechanisms.METHODS: PSCs were isolated from the pancreas of male Wistar rats after perfusion with collagenase, and cells between passages two and five were used. Expression of ET-1 and ET receptors was assessed by reverse transcription-PCR and immunostaining. Phosphorylation of myosin regulatory light chain (MLC), extracellular-signal regulated kinase (ERK), and Akt was examined by Western blotting. Contraction of PSCs was assessed on hydrated collagen lattices. Cell migration was examined using modified Boyden chambers. Cell proliferation was assessed by measuring the incorporation of 5-bromo-2'-deoxyuridine.RESULTS: Culture-activated PSCs expressed ETA and ETB receptors, and ET-1. ET-1 induced phosphorylation of MLC and ERK, but not Akt. ET-1 induced contraction and migration,but did not alter proliferation of PSCs. ET-1-induced contraction was inhibited by an ETA receptor antagonist BQ-123 and an ETB receptor antagonist BQ-788, whereas migration was inhibited by BQ-788 but not by BQ-123. A Rho kinase inhibitor Y-27632 abolished both contraction and migration.CONCLUSION: ET-1 induced contraction and migration of PSCs through ET receptors and activation of Rho-Rho kinase. ETA and ETB receptors play different roles in the regulation of these cellular functions in response to ET-1.

Bioinformatic approach for understanding the heterogeneity of cholangiocytes

微数组技术将近到达了一个尖顶，是显著的。进一步的分析的建立和从微数组技术导出的庞大的数据的管理当前是最高的优先级。cholangiocytes 的异构的功能在与的关系调整胆汁的上皮的病理生理学能分泌，增生的和 apoptotic 活动。二根鼠科的 cholangiocyte 线的不同表达式侧面，称为小、大被微数组分析揭示了。二根 cholangiocyte 房间线的特征，根据基因本体论部分分类，显示每根房间线的特定的生理的角色。大 cholangiocytes 作为“运输”被描绘并且“ immune/ 煽动性的回答”。相反，小 cholangiocytes 与象 Eph 受体一样的特定的分子与有限生理的功能的能力和增殖 / 移居的潜力的性质被联系，比得上间质细胞。“ Omic 学习将具有在理解 cholangiocytes 的 heterogeniety 的大帮助。

Sustained viral response of a case of acute hepatitis C virus infection via needle-stick injury

有感染由针棍子损害引起了的一个丙肝病毒(HCV ) 的一个 29 岁的护士与在尖锐肝炎的发作以后开始大约一年的干扰素贝它被对待。有一般疲劳，黄疸，和腹水的症状的耐心的发达尖锐丙肝在针棍子损害以后的 4 wk。当这些症状被介绍时，病人由人工授精是怀孕的。她希望了继续她的怀孕。在交货以后，生物化学的肝酶回到了正常层次。不过， HCV RNA 是积极的，病理学的发现显示了前进到慢性。遗传型是有低病毒的负担的 1b。在 600 万个单位的剂量的干扰素贝它的每日的静脉注射被开始并且继续八个星期。没有严重不利效果， HCV 被根除。在尖锐丙肝，推迟治疗被认为减少功效，但是干扰素贝它治疗是为在长期的阶段的丙肝感染的有用治疗之一。

Stellate cells regulate Nrf2 signaling to orchestrate metabolic changes and ROS detoxification in pancreatic cancer cells

OBJECTIVE We previously showed that human pancreatic stellate cells(HPSCs)promote pancreatic ductal adenocarcinoma(PDAC)cell growth by activating nuclear factor erythroid2-related factor 2(Nrf2),a key transcriptional regulator of cytoprotective genes.We aim to investigate whether Nrf2-mediated metabolic reprogramming and reactive oxygen species(ROS)detoxification are involved in HPSCs-mediated cell growth.METHODS Nrf2-mediated metabolic genes expression of pentose phosphate pathway(PPP)for purine nucleotide synthesis;glutamine metabolism for nicotinamide adenine dinucleotide phosphate(NADPH)-equivalent producers and also glutathione biosynthesis both for intracellular ROS inactivation were examined using quantitative real-time PCR(qRT-PCR)after treated with conditioned media derived from HPSCs(HPSC-CM)in human PDAC cells(BxPC-3and AsPC-1)with or without Nrf2 gene silencing using siRNA-mediated technique.Metabolites involved in PPP for purine nucleotide and NADPH generation were selected and their concentration was measured using UHPLC-MS/MS.Antioxidants,tiron and N-acetylcysteine(NAC)were used to attenuate the intracellular ROS rendered by Nrf2 before measuring PDAC cell growth and also phosphorylation of extracellular signal-regulated kinase(ERK)1/2and protein kinase B(AKT)using MTT and Western blotting,respectively.RESULTS Metabolically,HPSC-CMupregulated Nrf2-mediated genes involved in three metabolic pathways(G6PD,PGD,TKT,PPAT,MTHFD2,ME1,IDH1,GCLC and GCLM)in BxPC-3and AsPC-1cells.HPSC-CM was able to upregulate all the metabolic genes after Nrf2 gene silencing,and also significantly increased the metabolite concentration of ribose 5-phosphate and inosine 5′-monophosphate,which are involved in nucleotide synthesis for cell growth.Decreasing the intracellular ROS rendered by Nrf2 suppressed PDAC cell growth and also phosphorylation of ERK 1/2and AKT protein.CONCLUSION Our findings reveal that HPSC-CM activates Nrf2-mediated metabolic reprogramming,which leads to purine nucleotide synthesis and ROS detoxification to promote PDAC cell growth.