肝纤维化大鼠肝脏中组蛋白修饰水平的变化

目的:观察肝纤维化大鼠肝脏中组蛋白修饰的变化,并探讨其在肝纤维化发生发展过程中可能的作用。方法:雄性Wistar大鼠20只,随机分为正常对照组和肝纤维化组,其中肝纤维化组采用CCl_4皮下注射以制备大鼠肝纤维化模型,正常组注射等量植物油溶液。实验第8周末,股动脉放血处死大鼠,取2组血清,采用生化和放射免疫法测定血清肝功能指标丙氨酸氨基转移酶(ALT)和天门冬氨酸氨基转移酶(AST),以及肝纤维化标志物血清透明质酸(HA)、层粘连蛋白(LN)、Ⅳ型胶原(Col Ⅳ)和Ⅲ型前胶原(PCⅢ)的水平;取2组大鼠肝脏,测定肝脏指数;取肝组织常规固定,HE染色和Masson染色观察组织病理改变及胶原纤维沉积情况;Western blot检测2组大鼠肝脏组织中α-平滑肌肌动蛋白(α-SMA)和I型胶原(ColⅠ)表达情况,以及acH4K12、acH3K9、H3K4me2和H3K9me2修饰水平的变化。结果:与对照组相比,模型组大鼠肝脏指数及ALT、AST、HA、LN、ColⅣ和PCⅢ水平明显增高(P0.05);Western blot检测发现,与对照组比较,肝纤维化组大鼠肝组织的acH4K12修饰水平减少(P0.05),acH3K9和H3K9me2修饰水平及α-SMA和ColⅠ表达明显增加(P0.05),H3K4me2修饰水平的差异无统计学显著性。结论:肝纤维化大鼠肝脏中acH4K12、acH3K9和H3K9me2修饰水平改变可能与某些细胞外基质代谢相关基因转录调控有关,从而参与了大鼠肝纤维化发生。     

大鼠原代肝星状细胞活化后组蛋白修饰水平的观察

<正>目的:观察体外培养大鼠肝星状细胞(HSCs)活化过程中组蛋白修饰的改变以及与HSCs活化指标α-平滑肌肌动蛋白(α-SMA)的关系,探讨组蛋白修饰在HSCs活化过程中可能的作用。方法:体外分离、鉴定、培养大鼠HSCs,光镜观察HSCs活化过程中的形态变化,细胞免疫荧光染色和Western bloting检测desmin和α-SMA的表达,比较静止型HSCs和激活型HSCs中     

罗格列酮抑制体外大鼠肝星状细胞活化

目的探讨罗格列酮（PPARγ配体）对肝星状细胞（HSCs）作用的机制。方法将原代HSCs随机分为3组：对照组;TGF-β1（5μg/L）组;TGF-β1加10μmol/L罗格列酮组。加药后48h用RT-PCR法检测细胞Ⅰ型前胶原的表达。用Western blot方法检测细胞SMAD3、SMAD4、SMAD7、α-平滑肌肌动蛋白（α-SMA）和Ⅰ型胶原的表达。免疫荧光化学标记,共聚焦显微镜下观察α-SMA的表达。用四甲基偶氮唑盐（MTT）法检测细胞的增殖。结果TGF-β1明显促进HSCs的增殖,促进HSCs表达Ⅰ型胶原和α-SMA（P〈0.01）;罗格列酮显著降低TGF-β1的作用（P〈0.01）。各组细胞SMAD3、SMAD4、SMAD7的表达无明显差异。结论PPARγ配体可以抑制TGF-β1对HSCs的活化作用。     

改良法分离大鼠肝星状细胞

目的　探讨一种高效、经济、稳定的肝星状细胞的分离方法 ,为探索肝纤维化的发生机制提供细胞模型。方法　采用链霉蛋白酶、胶原酶原位灌流 ,以Nycodenz为分离介质 ,单层一步密度梯度离心法 ,分离大鼠的肝星状细胞。结果　肝星状细胞的获得率为 3 .95× 10 7 只、纯度为 97% ,存活率为 98%。结论　本法是一种较理想的分离肝星状细胞的方法。     

肝纤维化大鼠部分肝切除后肝星状细胞活化和肝细胞生长因子的表达

目的：研究肝星状细胞在肝纤维化大鼠部分肝切除后的活化情况及其对肝细胞生长因子表达和肝再生的影响。方法：成年雄性SD大鼠，随机分成3组：正常组、肝纤维化组和肝纤维化大鼠部分肝切除组。其中肝纤维化大鼠部分肝切除组根据术后取材时间又分为6小组，分别于术后12h、1、3、5、7和14d取材。计算肝指数评价肝再生情况；用免疫组化、免疫荧光和免疫印迹方法检测各组大鼠肝组织中α平滑肌肌动蛋白和肝细胞生长因子的表达情况。结果：肝纤维化大鼠部分肝切除后肝指数逐渐增加，但递增速度缓慢；肝组织中α平滑肌肌动蛋白的表达呈现出先降低后升高的规律；肝细胞生长因子表达早期下降，而后升到一最高值后开始降低。结论：（1）肝纤维化大鼠部分肝切除后残肝可以再生；（2）活化肝星状细胞术后呈现出先减少后增多的规律性变化；（3）肝星状细胞可能是术后肝细胞生长因子表达和残肝再生的重要影响因素。     

活化的肝星状细胞凋亡及其影响因素研究进展

肝星状细胞(HSCs)的凋亡在肝纤维化中的作用日益受到人们的重视,其凋亡途径是近年学术界研究的热点.激活的HSCs可自发发生凋亡,可通过Fas/FasL途径或其他途径实现.通过诱导激活的HSCs凋亡可能为肝纤维化的防治提供一条新途径.     

肝纤维化形成过程中肝星状细胞的活化机制

肝纤维化的形成是一个多因素、多细胞参与的复杂过程,肝星状细胞(HSC)的活化可能是其中的核心环节;活化后的HSC在形态和功能上都发生了显著变化.枯否细胞、pit细胞、炎症细胞和炎症反应的旁分泌作用,HSC活化后的自分泌作用,以及基因改变、活化HSC凋亡等均参与了HSC活化过程的调节.     

辛二酰苯胺异羟肟酸诱导大鼠原代肝星状细胞凋亡

目的:通过研究辛二酰苯胺异羟肟酸(SAHA)对大鼠原代肝星状细胞(HSCs)凋亡及相关蛋白表达的影响,探讨SAHA诱导HSCs凋亡的作用机制。方法:采用Opti Prep梯度离心法分离大鼠原代HSCs;通过实时细胞分析技术检测SAHA对HSCs增殖的影响;倒置显微镜观察不同浓度SAHA处理HSCs后的形态变化;荧光显微镜及流式细胞术Annexin V-FITC/PI法检测细胞凋亡率;Western blotting法检测α-平滑肌肌动蛋白(α-SMA)、Ⅰ型胶原、金属蛋白酶组织抑制物1(TIMP1)、葡萄糖调节蛋白78(GRP78)和组蛋白去乙酰化酶6(HDAC6)的蛋白表达;免疫共沉淀法检测GRP78蛋白与HDAC6蛋白是否形成复合物。结果:成功分离的HSCs连续培养14 d,HSCs逐渐由静止状态变为激活状态。SAHA可显著抑制HSCs增殖,且呈剂量时间依赖性(P0.05);SAHA对HSCs的促凋亡作用具有时间依赖性(P0.05)。SAHA处理HSCs后,α-SMA、Ⅰ型胶原、HDAC6和TIMP1的蛋白表达水平明显降低(P0.05),GRP78的蛋白表达水平明显升高(P0.05)。与激活型的HSCs相比,SAHA处理后的HSCs中免疫共沉淀下的蛋白复合物中GRP78与总的乙酰化赖氨酸蛋白显著增多,而HDAC6蛋白显著降低,同时证明GRP78与HDAC6形成复合物。结论:SAHA抗肝纤维化的机制可能是,SAHA下调HDAC6蛋白表达水平,上调乙酰化GRP78蛋白表达水平,诱导HSCs内质网应激,促进肝星状细胞凋亡,从而起到抗肝纤维化的作用。     

辛二酰苯胺异羟肟酸对人肝星状细胞增殖和凋亡的影响

目的研究组蛋白去乙酰化酶抑制剂辛二酰苯胺异羟肟酸(SAHA)对人肝星状细胞系LX-2增殖及凋亡的影响及其可能机制。方法体外应用SAHA作用于LX-2细胞,倒置显微镜观察LX-2细胞形态,MTT法检测细胞增殖;荧光显微镜及流式细胞仪Annexin V-FITC/PI法检测细胞凋亡率;Western blot检测α-SMA、Ⅰ型胶原、ac H3K9、ac H3K14和ac H3K18蛋白表达。结果 SAHA呈剂量依赖性显著抑制LX-2细胞增殖(P0.05);SAHA对LX-2细胞凋亡具有呈时间依赖性的促进作用(P0.05);SAHA处理LX-2细胞后,α-SMA和Ⅰ型胶原蛋白表达水平明显降低(P0.05),而ac H3K9、ac H3K14和ac H3K18乙酰化修饰水平明显升高(P0.01)。结论 SAHA抗肝纤维化的机制可能与下调α-SMA及Ⅰ型胶原蛋白表达,上调组蛋白ac H3K9、ac H3K14和ac H3K18乙酰化修饰水平有关。     

库普弗细胞对肝星状细胞活化和增殖的影响

肝纤维化是各种慢性肝病向肝硬化发展的必经阶段,其形成过程可简单归纳为：致肝病因子损伤肝细胞→库普弗细胞（KC）激活→分泌多种细胞因子（CK）→星状细胞（HSC）激活、增殖、转化为肌样成纤维细胞→产生大量细胞外基质（ECM）→合成大于降解并沉积→肝纤维化形成。已知HSC的激活是肝纤维化发生的中心环节,HSC的激活受多种CK的调控。目前就KC和HSC之间的相互作用还缺乏更深入的认识,尤其关于KC对HSC活化和增殖的影响尚无定论。本文仅就这方面相关文献综述如下。     

基于HSC的肝纤维化发病及治疗研究进展

肝纤维化主要是由肝星状细胞（HSC）的活化、细胞外基质（ECM）的合成与降解失衡导致ECM的过度增生和沉积所致。HSC的激活和增生是肝纤维化发生、发展的中心环节,抑制HSC的活化是防治肝纤维化形成的关键。抗肝纤维化的治疗措施包括抑制HSC增殖或诱导HSC凋亡,抑制胶原蛋白的产生或促进胶原蛋白的降解、细胞因子的调控以及间质干细胞的灌注等,因而早期肝纤维化的防治研究具有重要意义。     

Wortmannin对离体肝星状细胞增殖的影响

目的观察Wortmannin对肝星状细胞增殖的影响,并探讨其作用的可能机制。方法用链酶蛋白酶和胶原酶原位灌流消化正常大鼠肝脏,Nycodenz密度梯度离心分离肝星状细胞,以流式细胞仪检测细胞周期,MTT比色法观察Wortman-nin对肝星状细胞增殖的影响。结果在20～60nmol/L浓度范围内,Wortmannin能剂量依赖性地抑制肝星状细胞增殖;可使G0/G1期细胞增多,S期细胞减少。结论Wortmannin可显著抑制肝星状细胞增殖,使肝星状细胞阻滞于G0/G1期,该作用可能是Wortmannin抗肝纤维化的机制之一。     

Relationship between plasma cells and hepatic stellate cells in autoimmune hepatitis

Autoimmune hepatitis is an inflammatory chronic disease of the liver, which frequently results in cirrhosis. The present study aimed to verify the relationship between plasma cells and stellate cells in autoimmune hepatitis. Thirty-three pre-treatment, 11 post-treatment, and 10 normal liver biopsies were reviewed. Sirius Red staining (for semi-quantitative analysis of hepatic fibrosis) and immunohistochemistry were carried out: double staining for smooth muscle α-actin and plasma cell marker (for detection and localization of activated hepatic stellate cells and plasma cells, respectively); and single staining for glial fibrillary acid protein (for detection of hepatic stellate cells). We found an increase in the stellate cell population, mainly with an activated phenotype in autoimmune hepatitis, compared to the control group (liver specimens with no histological evidence of liver disease, obtained from patients undergoing hepatic resection for benign liver mass). A positive significant correlation was observed between stellate cells and scores of fibrosis (measured by Sirius Red) and the number of plasma cells. Additionally, there was a co-localization of plasma cells and activated stellate cells. We also observed a reduction in the number of plasma cells, hepatic stellate cells, and fibrosis in patients who had successfully been treated and had a second liver biopsy post-treatment. Our findings support that the number of plasma cells can be a surrogate marker for the severity of liver disease, reflecting the number of hepatic stellate cells and the amount of fibrosis. It remains to be seen if this is a result of a direct interaction between the plasma cells and hepatic stellate cells or the response to the same stimulus that affects both cellular types.     

Taurine、EGCG和genistein联合对体外活化肝星状细胞自噬的影响

目的:探讨牛磺酸(taurine)、表没食子儿茶素没食子酸酯(EGCG)和三羟基异黄酮(genistein) 3种抗肝纤维化药物联合使用对体外活化大鼠肝星状细胞(HSCs)自噬的影响及可能机制。方法:体外培养大鼠肝星状细胞株HSC-T6,设立对照组、联合药物(taurine+EGCG+genistein,TEG)组、自噬抑制剂巴弗洛霉素A1(Baf-A1)组和联合药物+抑制剂(TEG+Baf-A1)组。采用CCK-8法分别检测各组HSCs的存活率,应用透射电镜观察HSCs内部自噬体超微结构变化,通过吖啶橙(AO)染色和荧光显微镜观察各组细胞内自噬溶酶体变化,Western blot分析自噬标志性蛋白LC3-Ⅱ和beclin-1的表达。结果:与对照组相比,TEG组、Baf-A1组和TEG+Baf-A1组细胞的存活率明显降低(P 0. 05);透射电镜观察到细胞内部出现双层或多层膜结构的自噬体,以及单层膜结构的自噬溶酶体。与对照组相比,AO染色结果显示TEG组和Baf-A1组红色荧光区域显著缩小,TEG组中LC3-Ⅱ和beclin-1的表达量显著降低(P 0. 05)。结论:活化的HSCs发生自噬现象,联合药物TEG可阻断HSCs的自噬过程,其作用机制可能与抑制HSCs中自噬体的生成有关。     

索拉非尼抑制人肝星状细胞胶原合成

目的: 研究索拉非尼(sorafenib)对人肝星状细胞胶原合成的影响。方法: 应用人肝星状细胞株LX-2进行体外研究,采用 -脯氨酸掺入法测定胶原的合成,采用免疫细胞化学法检测I型胶原蛋白表达,采用real-time PCR法测定I型胶原α1 mRNA表达。结果: 免疫细胞化学研究显示血小板源性生长因子(PDGF)刺激可引起LX-2细胞胶原合成增加,10.0 μmol·L^-1索拉非尼作用于LX-2细胞 24 h能明显抑制I型胶原蛋白的合成。无论有无PDGF的刺激,索拉非尼均呈剂量与时间依赖性地抑制LX-2细胞胶原合成(P<0.01);在10.0 μmol·L^-1浓度下,索拉非尼作用于LX-2细胞 12 h、24 h和48 h对胶原合成的抑制率为22.69%、37.52%和71.74%。索拉非尼剂量依赖性地抑制PDGF诱导的I型胶原α1 mRNA表达上调;在2.5 μmol·L^-1、5.0 μmol·L^-1和10.0 μmol·L^-1 索拉非尼作用下,I型胶原α1 mRNA表达较PDGF刺激组分别下调58.66%、 67.06%和81.64%。结论: 索拉非尼在体外能抑制人肝星状细胞胶原的合成,抑制I型胶原的表达,有可能成为一种新型的治疗肝纤维化药物。     

The predictive value of CD38 positive hepatic stellate cell count for assessing disease activity and fibrosis in patients with chronic hepatitis

The activation of hepatic stellate cells (HSCs) is a critical event in hepatic fibrosis. The objectives of this study were to find out if cluster of differentiation 38 (CD38) can be demonstrated immunohistochemically on HSCs in liver biopsies from patients with chronic liver disease and if CD38 immunopositive HSC count is correlated with METAVIR inflammatory and fibrosis scores. Immunohistochemical labelling for CD38 was performed on 100 liver biopsies from patients with chronic liver disease. The CD38 immunopositive HSCs were identified and counted. The CD38 immunopositive HSC count was found to be associated with both the METAVIR score and the fibrosis scores. The CD38 immunopositive HSC count was able to discriminate between no fibrosis and stages 2, 3 or 4 fibrosis, but could not discriminate between no fibrosis and stage 1 fibrosis. Using receiver operating characteristic (ROC) curves, a cut-off point of 10 HSCs per 10 high power field (hpf), or 25 per 100 hepatocytes, is 80% sensitive and 70% specific for predicting fibrosis. The specificity rose to 100% in patients with hepatitis C viral (HCV) infection. We conclude that CD38 positive HSCs can be demonstrated immunohistochemically and that the count is highly predictive of moderate to severe hepatic fibrosis.     

Expression of mRNAs related to connective tissue metabolism in rat hepatic stellate cells and myofibroblasts

Hepatic stellate cells (HSC) and liver myofibroblasts (MFB) are two cell populations most likely responsible for the synthesis of most connective tissue components in fibrotic liver. They differ in their origin and location, and possibly in patterns of gene expression. Normal and carbon tetrachloride-cirrhotic livers from rats were used to isolate HSC. Liver was perfused with pronase and collagenase solutions, followed by centrifugation of the cell suspension on a density gradient. HSC were quiescent 2 days after plating on plastic but they became activated after another 5 days in culture. When the culture was passaged 5 times, its character changed profoundly as HSC were replaced by MFB. Microarray analysis was used to determine gene expression in quiescent HSC, activated HSC and MFB. The expression of 49 genes coding for connective tissue proteins, proteoglycans, metalloproteinases and their inhibitors, growth factors and cellular markers was determined. The pattern of gene expression changed during HSC activation and there were distinct differences between HSC and MFB. Little difference between normal cells and cells isolated from cirrhotic liver was found.     

逆转录病毒介导的反义c-myb对肝星状细胞增殖及Ⅰ型胶原基因表达的影响

目的:探讨反义c-mybRNA对体外培养的肝星状细胞(HSC)增殖及Ⅰ型胶原mRNA表达的影响。方法:构建含有反向c-myb基因片段的重组逆转录病毒载体pDOR-myb, 将其导入包装细胞PA317中, 收获含病毒的培养上清, 进一步感染体外培养的大鼠HSC, 采用四甲基偶氮唑盐(MTT)法测定细胞增殖反应, 采用半定量RT-PCR检测c-myb、α₁-Ⅰ型胶原mRNA表达。结果:成功分离培养大鼠HSC, 感染pDOR-myb病毒的HSC自身c-myb表达、细胞增殖及α-Ⅰ型胶原mRNA表达显著受抑。结论:c-myb在HSC激活增殖过程中起重要作用, 反义c-myb基因能抑制HSC增殖及Ⅰ型胶原基因表达, 这提示抑制c-myb表达可能是防治肝纤维化的有效途径。     

Transmembrane protein 88 attenuates liver fibrosis by promoting apoptosis and reversion of activated hepatic stellate cells

Transmembrane protein 88 (Tmem88) is a crucial inhibitor for Wnt/β-catenin pathway in the development of myocardial cells. Due to the important role of β-catenin in the activation and proliferation of hepatic stellate cells (HSCs), it is necessary to investigate the function of Tmem88 in HSCs. In this study, we found that Tmem88 expression was decreased in the human liver fibrotic tissues, primary HSCs from fibrotic mice and activated HSC-T6 cells. Functionally, Tmem88 could inhibit HSCs activation and proliferation by blocking Wnt/β-catenin pathway, and promoted the apoptosis of activated HSCs by initiating Bcl-2/Bax/Caspase3 pathway. Moreover, the level of DNA metyltransferase 3a (Dnmt3a) was upregulated in activated HSCs, and siRNA-mediated Dnmt3a silencing led to Tmem88 restoration. These results indicated that Tmem88 played an important role in HSCs activation, proliferation and apoptosis, and Tmem88 expression might be modulated by Dnmt3a.