瘦素及其信号通路促肝纤维化机制研究进展

多种慢性肝病能导致肝纤维化,肝纤维化是发展为肝硬化的中间阶段。肝星状细胞的激活在肝纤维化的发生发展中起关键作用。在各种炎症刺激下,体内促肝纤维化因子激活其信号转导通路,使肝星状细胞的形态和功能发生变化,引起胶原沉积。瘦素作为一种促肝纤维化因子,通过其信号转导机制在肝纤维化发生发展中发挥重要作用。     

特异性靶向肝星状细胞治疗肝纤维化研究进展

肝纤维化是慢性肝病进展过程必经的一种病理组织学改变,而肝星状细胞的激活和增生是肝纤维化发生进展的中心环节.目前研究通过基因调控治疗及受体介导药物靶向肝星状细胞,可提高肝纤维化治疗的特异性,为临床应用开辟了新方向.     

肝纤维化中肝星状细胞内主要信号转导通路

肝纤维化是肝脏对各种慢性刺激进行损伤修复反应时,以胶原为主的细胞外基质(ECM)在肝内大量沉积的病理过程.活化的肝星状细胞(HSC)是肝纤维化时产生ECM的主要细胞.细胞因子、氧化应激以及ECM的改变等外部因素通过一定的细胞内信号转导通路激活HSC.了解HSC活化的信号转导通路能从根本上为治疗肝纤维化提供更多更有效的思路和方法.目前研究较多的信号途径有TGF-β/Smad通路、MAPK通路、PI3K通路、JAK/STAT通路、NF-κB通路、过氧化物酶体增殖物激活受体通路等.本文简要综述了肝纤维化时HSC中主要的细胞内信号转导通路.     

bFGF在肝纤维化中的研究进展

肝纤维化是慢性肝病共有的病理改变,肝星状细胞(HSC)激活分泌大量的细胞外基质(ECM)沉积在肝内引起肝纤维化.碱性成纤维细胞生长因子(bFGF)是从牛脑垂体中分离纯化而来,能促进多种细胞产生ECM,导致肝纤维化形成.     

基于Rho-ROCK信号转导通路调控肝纤维化研究进展

肝纤维化是各种慢性肝功能损伤保护性的代偿反应,是以细胞外基质生成增多和降解减少为主要表现、大量细胞外基质在肝内沉积为主要特征的病理过程。肝纤维化是慢性肝病向肝硬化和肝癌转变的必经过程。Rho-ROCK信号转导通路参与多种细胞生理活动,主要通过调节肝星状细胞的收缩和迁移参与肝纤维化的形成。肝星状细胞的活化在肝纤维化形成中具有重要作用,其活化后分泌的细胞外基质(extracellular matrixc,ECM)是肝纤维化形成的物质基础。本文通过对Rho-ROCK信号转导通路和肝星状细胞的生物学特性以及Rho-ROCK信号转导通路对肝星状细胞的调控进行综述,以期为肝纤维化的防治提供新方向。     

蛋白酶活化受体(PARs)在肝纤维化中的调节作用

肝星状细胞(hepatic stellate cell,HSC)激活并转化为肌纤维母细胞并分泌细胞外基质 (ECM)成分是肝纤维化发生、发展的核心环节,肝损伤是引发肝纤维化的始动环节．蛋白酶激活受体(protease activated receptors, PARS)属于G蛋白偶联受体家族成员,他可通过介导细胞外信号调节激酶(extracellar signal- regulated kinase,ERK1／2)信号转导通路,引起细胞核反应,激活多种细胞转录因子,参与调节肝纤维化过程中HSC细胞增殖、分化和分泌大量细胞外基质,促使肝纤维化的发生和发展的方法,寻找通过抑制蛋白酶激活受体以期发现能阻断肝纤维化的形成和发展,逆转已形成的肝纤维化,将为肝纤维化的治疗提供新的理论基础．     

肝星状细胞与肝纤维化

肝纤维化是各种慢性肝病共有的病理改变,逆转肝纤维化可阻止大多数慢性肝病进展。肝星状细胞(HSC)是肝内一种具有多功能、变化不定的非实质细胞,HSC活化是肝纤维化发生的中心环节。阐明其关系,有助于以HSC为靶点的肝纤维化方面的研究。     

水飞蓟素在抗肝纤维化中的应用

肝纤维化是各种病因引起慢性肝损伤,激活肝星状细胞(HSC),导致细胞外基质(ECM)合成大于降解进而在肝脏异常沉积的结果,进一步发展,则引起肝小叶结构改建,假小叶形成,称为肝硬化.肝纤维化是慢性肝病重要的病理特征,也是肝硬化发生的前奏和必经中间环节.近年来有关肝纤维化的研究取得了长足进展,水飞蓟素(silymarin)在世界各国治疗肝病已有数千年的历史,其在抗肝纤维化中的作用值得人们关注.     

植物神经递质与肝纤维化

各种致病因素所致的慢性肝损伤均可引起肝纤维化.实验证明,肝星状细胞的激活是肝纤维化发生发展的中心环节,而诱导活化的肝星状细胞凋亡可使肝纤维化发生逆转.国内外的一些研究显示,植物神经系统参与对肝脏功能的调控,可影响肝纤维化的形成.其中,肝星状细胞可能是植物神经递质的作用靶点.作用于植物神经系统的药物可能为临床治疗肝纤维化提供新的方法和策略.     

肝纤维化与TGF-β和以其为靶位点的治疗策略

肝纤维化是细胞外基质(ECM)在肝脏中过量堆积的结果,是几乎各种慢性肝病的共同病理基础.转化生长因子β(TGF-β)是一类能够调节细胞生长和分化的多肽,在肝纤维化的发生、发展过程中起着重要作用,是最重要的促肝纤维化细胞因子之一.在细胞及分子水平上,肝纤维化主要以肝星状细胞(HSC)的活化和TGF-β的异常活性为特征.TGF-β-Smads信号转导通路与肝纤维化的发病机制具有密切关系,为肝纤维化的防治与治疗提供了新的有效途径.我们综述了肝纤维化与TGF-β-Smads信号转导通路的关系和以TGF-β为靶位点进行肝纤维化的治疗策略.     

Succinate is a paracrine signal for liver damage

BACKGROUND/AIMS: A G-protein-coupled succinate receptor has recently been identified in several tissues, including the liver. The objectives of this work were to determine the hepatic cell types that express this receptor and to determine its physiological role. METHODS: Expression and distribution of the succinate receptor was determined by RT-PCR and confocal immunofluorescence. Biochemical assays were used to measure succinate and cAMP. Cytosolic Ca2+ was monitored in single cells by time-lapse imaging. Western blot was used to study the effect of succinate on activation of hepatic stellate cells. RESULTS: The succinate receptor was expressed in quiescent hepatic stellate cells, and expression decreased with activation. Ischemia induced release of succinate in isolated perfused livers. In contrast to what is observed in cell expression systems, succinate did not inhibit cAMP production or increase cytosolic Ca2+ in primary hepatic stellate cells. However, succinate accelerated stellate cell activation. CONCLUSIONS: Hepatic stellate cells express the succinate receptor. Succinate may behave as a paracrine signal by which ischemic hepatocytes trigger stellate cell activation.     

PPARγ对肝纤维化中肝星状细胞相关信号通路的影响

肝星状细胞（HSC）是肝纤维化发展的核心,其激活和增殖受到多种细胞因子网络调控。过氧化物酶体增殖物激活受体（PPAR）是配体激活的核转录因子超家族成员。PPARγ是其一亚型,通过干扰调节HSC增殖与凋亡的信号途径参与肝纤维化的发生发展,可能为肝纤维化的治疗提供新方向。     

IL-13及其受体在血吸虫病肝纤维化中的作用

血吸虫病肝纤维化是以胶原蛋白为主的细胞外基质(extracellular matrix,ECM)的合成与降解失衡导致胶原过度沉积的结果,其纤维化过程主要是由多条信号转导途径和一系列的细胞因子网络共同调控的.近几年国内外研究发现白细胞介素-13(interleukin-13,IL-13)在血吸虫病肝纤维化形成和发展过程中起着重要作用.白细胞介素-13受体α1(interleukin-13 receptorα1,IL-13Rα1)作为IL-13功能受体,在肝星状细胞(hapatic stellate cells,HSC)膜表面起促纤维化作用,而IL-13Rα2作为IL-13诱饵受体(decoy receptor),起抑制纤维化的作用.此外,IL-13还可通过替代激活途径激活巨噬细胞发挥促纤维化作用.总之,IL-13及其受体与血吸虫病肝纤维化关系的研究目前已成为热点之一.该文就IL-13及其受体在血吸虫病肝纤维化中作用的最新研究进展做一综述.     

Role of hepatic stellate cells on graft injury after small-for-size liver transplantation

Background and Aim: Small‐for‐size grafts are prone to mechanical injury and a series of chemical injuries that are related to hemodynamic force. Hepatic stellate cells activate and trans‐differentiate into contractile myofibroblast‐like cells during liver injury. However, the role of hepatic stellate cells on sinusoidal microcirculation is unknown with small‐for‐size grafts. Methods: Thirty‐five percent of small‐for‐size liver transplantation was performed with rats as donors and recipients. Endothelin‐1 levels as well as hepatic stellate cells activation‐related protein expression, endothelin‐1 receptors, and ultrastructural changes were examined. The cellular localizations of two types of endothelin‐1 receptors were detected. Furthermore, liver function and sinusoidal microcirculation were analyzed using two different selective antagonists of endothelin‐1 receptor. Results: Intragraft expression of hepatic stellate cells activation‐related protein such as desmin, crystallin‐B and smooth muscle α‐actin was upregulated as well as serum endothelin‐1 levels and intragraft expression of the two endothelin receptors. The antagonist to endothelin‐1 A receptor not to the endothelin‐1 B receptor could attenuate microcirculatory disturbance and improve liver function. Conclusions: Small‐for‐size liver transplantation displayed increased hepatic stellate cells activation and high level of endothelin‐1 binding to upregulation of endothelin‐1 A receptor on hepatic stellate cells, which contracted hepatic sinusoid inducing graft injury manifested as reduction of sinusoidal perfusion rate and elevation of sinusoidal blood flow.     

Wnt信号转导通路与肝纤维化

Wnt信号通路包括经典通路和非经典通路,其参与调控细胞的分化、癌变、凋亡及机体免疫、应激等生理病理过程。最近有研究表明Wnt信号通路与肝星状细胞的活化及肝纤维化的发生相关,深入研究Wnt信号通路在肝纤维化发生中的作用,将有助于进一步揭示肝纤维化的发生机制,为肝纤维化的防治提供新的可能途径及干预靶点。     

原发性胆汁性肝硬化的治疗进展

原发性胆汁性肝硬化(PBC)是一种慢性胆汁淤积性疾病。临床上主要表现为乏力、黄疸、皮肤瘙痒、门脉高压、骨质疏松和脂溶性维生素缺乏。多见于中年女性。由于PBC的病因尚未探明,所以还没有统一确切的治疗方案。此文对PBC的治疗进展做一总结。     

Involvement of integrin-linked kinase in carbon tetrachloride-induced hepatic fibrosis in rats

Integrin-linked kinase (ILK) is a multidomain focal adhesion protein implicated in signal transduction between integrins and growth factor receptors. Although its expression is upregulated in pulmonary and renal fibrosis, its role in the development of hepatic fibrosis remains to be determined. Therefore, we considered it important to investigate whether ILK is involved in activation of hepatic stellate cells and thus plays a role in the development of hepatic fibrosis. Immunohistochemical analysis of liver sections obtained from rats with CCl4-induced cirrhosis revealed increased expression and colocalization of ILK and alpha-smooth muscle actin in hepatic stellate cells in perisinusoidal areas. In addition, hepatic stellate cells isolated from fibrotic livers expressed high levels of ILK and alpha-smooth muscle actin, and their expression was sustained in culture. In contrast, hepatic stellate cells (HSCs) isolated from normal rat liver did not express ILK, but its expression was increased when the cells were activated in culture. Our studies also showed that ILK is involved in the phosphorylation of ERK 1/2, p38 MAPK, JNK, and PKB and that selective inhibition of ILK expression by siRNA results in a significant decrease in their phosphorylation. These changes were accompanied by significant inhibition of cell spreading and migration without affecting cell proliferation. In conclusion, ILK plays a key role in HSC activation and could be a possible target for antifibrogenic therapy.     

肝星状细胞在逆转肝纤维化中的作用

肝纤维化是一种能够导致门静脉高压、肝硬化、肝衰竭的严重疾病。已经发现肝星状细胞的活化是引起肝纤维化的中心环节,因此抑制肝星状细胞的活化、加速肝星状细胞的清除有望逆转肝纤维化。本文将对活化的肝星状细胞的凋亡、衰老以及清除的研究进展作综述,阐明肝星状细胞在肝纤维化过程中所起的作用及相关机制。