肝纤维化发生机制的研究进展

肝纤维化(hepatic fibrosis,HF)是继发于各种形式慢性肝损伤之后组织修复过程中的代偿反应,它也是慢性肝病发展为肝硬化必经的病理过程.目前研究显示,HF发生的中心环节是肝星状细胞(HSC)增生和激活,激活后的HSC进一步转化为成肌纤维细胞,后者可大量合成细胞外基质(ECM)蛋白,而ECM的大量沉积最终导致了HF形成.HF的发生机制一直是慢性肝病的研究热点之一,本文就近年有关研究进展作一介绍.     

肝纤维化进程中细胞外基质对肝星状细胞的作用及机制研究进展*

肝纤维化是一种肝内弥漫性细胞外基质（ECM）过度沉积的病理过程,且肝星状细胞（HSC）的激活是肝纤维化发生发展的中心环节。本文主要介绍了在肝纤维化进程中ECM各种成分比例、分子结构的改变及其ECM分子空间结构改变对HSC的激活、增殖和凋亡的作用和机制。     

肝纤维化基因治疗的现状及展望

肝纤维化是各种致病原因引起肝内以肝星状细胞(hepatic stellate cell,HSC)激活和细胞外基质(extracellular matrix,ECM)过多产生为病理特征[1,2].HSC激活是从静止状态向肌成纤维样细胞的表型转变,激活的HSC具有表达α-平滑肌动蛋白(α-SMA),失去维生素A脂滴空泡,加速增殖及加快合成ECM的特性[1,2].致病因子引起肝脏氧化应激反应和以枯否细胞为主要细胞产生细胞因子是肝纤维化发生的始动环节.     

中药干预肝纤维化中转化生长因子-β1的作用研究

肝纤维化(hepatic fibros,HF)是指肝细胞发生坏死及炎症刺激时,肝脏内纤维结缔组织异常增生的病理过程。从现有的肝纤维化的发生发展研究机制中我们可以知道,在肝纤维化形成的过程中,肝星状细胞(hepatic satellite cell,HSC)的活化是肝纤维化的中心环节[1]。其中激活的HSC被认为是促进细胞外基质(extracelluar matrix,ECM)过度沉积的主要细胞,而多种细胞因子参与了肝星状细胞的激活,其     

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.     

肝纤维化进程中细胞外基质对肝星状细胞的作用及机制研究进展

肝纤维化是一种肝内弥漫性细胞外基质(ECM)过度沉积的病理过程,且肝星状细胞(HSC)的激活是肝纤维化发生发展的中心环节。本文主要介绍了在肝纤维化进程中ECM各种成分比例、分子结构的改变及其ECM分子空间结构改变对HSC的激活、增殖和凋亡的作用和机制。     

TNF-alpha与肝星状细胞.

0 引言肝纤维化是各种慢性肝病共有的病理改变,其病理生理基础为以胶原为主的细胞外基质(extracellular matrix,ECM)合成增多,降解相对不足,过多沉积而导致肝脏内纤维结缔组织异常增生.肝纤维化时,合成 ECM 的细胞主要是被激活的肝星状细胞(hepatic stellate cell,HSC).HSC 位于 Disse 间隙,又称 Ito 细胞、贮脂细胞,其胞质内富含类维生素 A 脂滴,是肝间质细胞中兼有肌细胞、成纤维细胞及脂肪细胞性质的一种细胞.在肝纤维化形成过程中,HSC 的激活是关键性的病理事     

肝纤维化中医药治疗进展

肝纤维化（hepatic fibrosis，HF）是许多慢性肝病晚期共有的、渐进性的病理改变，是发展到肝硬化的必经阶段，其主要病理特征为以胶原为主的细胞外间质（extra cellular matrix，ECM）在肝脏的过量沉积。发病机制在于各种损肝因子引起肝细胞损伤，激活肝星状细胞（hepatic stellate cell，HSC）使其转变成为肌纤维母细胞。损伤及再生的肝细胞、Kupffer细胞、窦内皮细胞、     

内质网应激与肝纤维化关系研究进展*

肝纤维化（HF）的防治是一项重大的医学难题。目前普遍认为肝星状细胞（HSC）的激活和细胞外基质（ECM）的过度沉积是HF发生发展的重要因素,而越来越多的研究发现内质网应激（ERS）参与HF的发生发展和逆转过程。本文讨论了ERS与 HF发生的关系,以为防治HF拓展新的视野。     

Leukocytes as Modulators of Stellate Cell Activation

Activation of stellate cells is central to the process of hepatic fibrogenesis. Stellate cell activation can be influenced by many factors, including cytokines, oxidants, and alterations in the perisinusoidal extracellular matrix. These factors can be produced by resident liver cells (hepatocytes, Kupffer cells, or stellate cells themselves); however, infiltrating leukocytes may also play an important role. Because liver fibrosis often follows a prolonged period of hepatic inflammation, investigators have begun to study leukocytes as modulators of stellate cell activation. The following data summarize recent investigations in this area that focus on neutrophils as well as mononuclear cells.     

Hepatic fibrogenesis in response to chronic liver injury: novel insights on the role of cell‐to‐cell interaction and transition

Hepatic fibrosis represents the wound‐healing response process of the liver to chronic injury, independently from aetiology. Advanced liver fibrosis results in cirrhosis that can lead to liver failure, portal hypertension and hepatocellular carcinoma. Currently, no effective therapies are available for hepatic fibrosis. After the definition of hepatic stellate cells (HSCs) as the main liver extracellular matrix‐producing cells in the 1980s, the subsequent decade was dedicated to determine the role of specific cytokines and growth factors. Fibrotic progression of chronic liver diseases can be nowadays considered as a dynamic and highly integrated process of cellular response to chronic liver injury. The present review is dedicated to the novel mechanisms of cellular response to chronic liver injury leading to hepatic myofibroblasts' activation. The understanding of the cellular and molecular pathways regulating their function is crucial to counteract therapeutically the organ dysfunction caused by myofibroblasts' activation.     

The physiopathological mechanism of hepatic fibrosis

Liver fibrosis is the end result of an imbalance between synthesis and degradation of extracellular matrix proteins of the liver. The extracellular matrix of the liver is complex. It comprises multiple components of three major types of macromolecules: proteins, glycoproteins and proteoglycans. The normal liver contains limited amounts of extracellular matrix composed of elastin, fibronectin, collagen, proteoglycans and other macromolecules. These molecules have specific structure-function properties. In the liver they provide a structural framework and modulate tissue repair. The fibrogenesis is a reaction to liver injury, it leads to marked impairment of hepatic sinusoidal blood flow and ultimately to cirrhosis associated with portal hypertension and hepatocyte dysfunction. The process of fibrosis is the result from complex interactions between extracellular matrix macromolecules, hepatic cells, cytokines and growth factors, that activate the stellate cells of the liver to induce the synthesis of extracellular matrix components that deposit into the local extracellular matrix and to produce the inhibitor of metalloproteinase. The end result of these activities is an imbalance in the synthesis/degradation homeostasis of the liver, that is, liver fibrosis.     

Osteopontin – A potential biomarker of advanced liver disease

Cirrhosis is a primary cause of liver-related mortality and morbidity. The basic process driving chronic liver disease to cirrhosis is accelerated fibrogenesis. Although the pathogenesis of liver cirrhosis is a multifactorial process, the essential step in the evolution of liver fibrosis is the activation of hepatic stellate cells, which are the main source of collagen produced in the extracellular matrix. This activation process is mediated by multiple growth factors, cytokines, and chemokines. One of the hepatic stellate cell-activating signaling molecules (and also one associated with cell injury and fibrosis) is osteopontin (OPN). OPN concentration in the plasma has been found to be predictive of liver fibrosis in various liver diseases. OPN concentrations correlate significantly with the stage of fibrosis, liver insufficiency, portal hypertension, and the presence of hepatocellular cancer. However, due to its versatile signaling functions, OPN not only contributes to the development of liver cirrhosis, but is also implicated in the pathogenesis of other chronic hepatic diseases such as viral hepatitis, both alcoholic and non-alcoholic steatohepatitis, drug-induced liver injury, and hepatocellular cancer. Thus, the targeting of OPN pathways seems to be a promising approach in the treatment of chronic liver diseases.     

Intracellular Signaling Pathways in Stellate Cell Activation

Pathological fibrogenesis in the liver is mediated by activated stellate cells. These cells have a myofibroblastic phenotype with the ability to proliferate and synthesize large quantities of extracellular matrix components. A number of factors have been proposed to initiate and perpetuate the fibrogenic process in stellate cells, including inflammatory cytokines, alterations in the extracellular matrix, growth factors, and oxidative stress. Some recent research has focused on the intracellular signaling pathways that are stimulated by these factors in stellate cells, including mitogen-activated protein kinases, phosphatidylinositol 3-kinase, focal adhesion kinase, and protein kinase C. This paper will summarize the experimental evidence that implicates these pathways in stellate cell activation, focusing on the effects of exposure to platelet-derived growth factor, tumor necrosis factor-alpha, and fibronectin. Implications for alcohol-induced hepatic fibrosis and future directions for research will also be discussed.     

血管新生与肝纤维化

近年研究发现,血管新生和星状细胞活化、细胞外基质积聚一样,既是肝组织损伤后组织修复的表现,同时它又在损伤因素、细胞因子等共同作用下影响肝纤维化的进展和结局。     

干扰素治疗肝纤维化机制的研究进展

肝纤维化是多种病因导致慢性肝病共有的病理改变,肝纤维化为一动态过程,属可逆性病变,但若进一步发展至肝硬化阶段,则不可逆,因此阻断抑制或逆转肝纤维化是治疗慢性肝病的一个十分重要的目标.干扰素(interferon,IFN)具有广泛的抗病毒、抗肿瘤和免疫调节作用.目前有许多研究认为干扰素(IFN)具有抗肝纤维化作用,并已在临床应用中取得一定效果,但其抗肝纤维化的确切机制尚不明了,有学者认为可能与其抗病毒,抑制肝星状细胞的活化增殖,促进肝星状细胞的凋亡,抑制细胞外基质(ECM)合成,促进细胞外基质降解等作用有关.     

What's new in liver fibrosis? The origin of myofibroblasts in liver fibrosis

Chronic liver injury of many etiologies produces liver fibrosis and may eventually lead to the formation of cirrhosis. Fibrosis is part of a dynamic process associated with the continuous deposition and resorption of extracellular matrix, mainly fibrillar collagen. Studies of fibrogenesis conducted in many organs including the liver demonstrate that the primary source of the extracellular matrix in fibrosis is the myofibroblast. Hepatic myofibroblasts are not present in the normal liver but transdifferentiate from heterogeneous cell populations in response to a variety of fibrogenic stimuli. Debate still exists regarding the origin of hepatic myofibroblasts. It is considered that hepatic stellate cells and portal fibroblasts have fibrogenic potential and are the major origin of hepatic myofibroblasts. Depending on the primary site of injury the fibrosis may be present in the hepatic parenchyma as seen in chronic hepatitis or may be restricted to the portal areas as in most biliary diseases. It is suggested that hepatic injury of different etiology triggers the transdifferentiation to myofibroblasts from distinct cell populations. Here we discuss the origin and fate of myofibroblast in liver fibrosis.     

Hepatic stellate cells and alcoholic liver disease.

Liver fibrosis represents a significant health problem worldwide for which no effective therapy exists. A great deal of research has been carried out to understand the molecular mechanisms responsible for the development of liver fibrosis. Activated stellate cells are the primary cell type responsible for the production of collagen I, the key protein involved in the development of liver fibrosis. Excessive deposition of collagen I occurs along with impaired extracellular matrix remodeling. Following a fibrogenic stimulus stellate cells transform into an activated collagen type I-producing cell. Numerous changes in gene expression are associated with stellate cell activation, including the induction of several intracellular signaling cascades, which help maintain the activated phenotype and control the fibrogenic and proliferative state of the cell. Activation of stellate cells is mediated by factors released from hepatocytes and Kupffer cells as they produce reactive oxygen species, nitric oxide, cytokines, growth factors, and cyclooxygenase and lipoxygenase metabolites, which provide pivotal paracrine effects in the liver milieu. Inhibition of stellate cell activation, proliferation, and the increased production of extracellular matrix (i.e. collagen type I) are therefore crucial steps for intervention in hepatic fibrogenesis.     

促纤维化因子在肝纤维化发生中的作用研究进展

肝纤维化是多种病因所致的慢性肝损伤的一种创伤愈合反应,持续的炎症与纤维形成最终导致肝硬化。肝星状细胞（HSC）是肝纤维化的主要生成细胞,肝脏内细胞外基质（ECM）的过度沉积是其主要功能。各种促纤维化因子如血管紧张素-II（AngII）、血小板衍生生长因子（PDGF）、血管内皮生长因子（VEGF）、转化生长因子-β（TGF-β）、瘦素、结缔组织因子等可与HSC表面上相应的受体结合,并激活相应的信号通路,进而导致HSC的激活、增殖,ECM过度沉积,引起肝纤维化形成。因此,了解各种促纤维化因子与肝纤维化的关系,可为抗纤维化的科学研究及临床治疗提供理论依据。