An interleukin-1 receptor antagonist decreases fibrosis induced by dimethylnitrosamine in rat liver

The main pathological feature of liver fibrosis is the accumulation of extracellular matrix associated with hyperplasia and activation of perisinusoidal (Ito) cells (PSC) to myofibroblast-like cells. Interleukin-1 enhances collagen synthesis by increasing the proliferative activity of cultured PSC and has been implicated in the pathogenesis of hepatic fibrosis.Interleukin-1 receptor antagonist (IL-1ra) can block the binding of IL-1 to its receptors and act as a natural inhibitor of IL-1. We have examined whether the administration of IL-1ra can interfere with the development of experimental cirrhosis induced by dimethylnitrosamine (DMN). Rats were divided in three groups and received respectively DMN, DMN+IL-1ra and IL-1ra. For each group the collagen content of the hepatic tissue and the volume density of the inflammatory infiltrate were measured. Immunostaining for laminin and alpha-smooth muscle actin were also performed.In animals given DMN+IL-1ra we observed a decreased deposition of laminin and collagen, and a decreased number of laminin-positive PSC and of alpha-smooth muscle actin reactive cells, compared with animals receiving DMN alone. The present findings suggest that the early activation of PSC in vivo is at least in part mediated by IL-1 and confirm that the administration of IL-1ra may be of interest in modifying the biological effects of IL-1.     

Effect of cholinergic denervation on hepatic fibrosis induced by carbon tetrachloride in rats

Various factors involved in the development of liver fibrosis, including hepatic stellate cells (HSCs), cholinergic nervous activity and fibrogenetic cytokines. The present study aims to investigate the role of cholinergic regulation in the promoting of liver fibrogenesis relating to bone morphogenetic protein-6 (BMP-6) and/or transforming growth factor-beta1 (TGFbeta1). We treated carbon tetrachloride (CCl(4)) into rats for eight weeks to induce liver fibrosis and arranged these rats for cholinergic denervation, hepatic branch vagotomy or atropine administration. Acetylcholinesterase (AChE) staining showed the distribution of cholinergic nerve around fibrosis scaring septa. The immunohistochemical staining for alpha smooth muscle actin (alphaSMA) indicated the less HSCs in CCl(4) treated rat liver with cholinergic denervation as compared to the sham-operated CCl(4) treated rats. It seems that cholinergic nerve not only innervates around the fibrosis area but also promotes HSCs. We also detected TGFbeta1 and BMP-6 expressions using RT-PCR and immunohistochemistry. The obtained results show that cholinergic denerveration decreases BMP-6 and TGF-beta1 expressions in CCl(4) induced liver fibrosis of rats. In conclusion, cholinergic nerve may influence HSCs in addition to the lowering of BMP-6 and TGF-beta1 gene expressions to modify liver fibrosis.     

大鼠肝纤维化与microRNA-181a调控肝星状细胞自噬的关系

目的:观察四氯化碳(CCl4)诱导肝纤维化(HF)大鼠肝脏结构的改变、肝组织中转化生长因子β1(TGF-β1)、微小RNA-181a(microRNA-181a)、自噬标志性蛋白LC3-II/-I和beclin-1水平及胶原沉积的变化,以及mi?croRNA-181a对TGF-β1诱导大鼠肝星状细胞(HSCs)自噬的作...     

NK细胞与肝纤维化关系的研究进展

以活化的肝星状细胞为中心的局部免疫微环境在肝纤维化的发展中起着关键作用。而近年来一些研究表明NK细胞可通过产生具有抗纤维化作用的IFN-γ并且直接杀死活化HSCs,起到明显的抗肝纤维化作用。因此,刺激NK细胞活化极可能成为治疗肝纤维化的新途径。     

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。     

Regulation of SIRT1-TLR2/TLR4 pathway in cell communication from macrophages to hepatic stellate cells contribute to alleviates hepatic fibrosis by Luteoloside

Regulating macrophage-hepatic stellate cells (HSCs) crosstalk through SIRT1-TLR2/TLR4 has contributed to the essence of new pharmacologic strategies to improve hepatic fibrosis. We investigated how Luteoloside (LUT), one of the flavonoid monomers isolated from Eclipta prostrata (L.) L., modulates macrophage-HSCs crosstalk during hepatic fibrosis. HSC-T6 or rat peritoneal macrophages were activated by TGF-β or LPS/ATP, and then treated with LUT or Sirtinol (SIRT1 inhibitor) for 6 h. Further, HSCs were cultured with the conditioned medium from the LPS/ATP activated peritoneal macrophages. In HSC-T6 or peritoneal macrophages, LUT could decrease the expressions of α-SMA, Collagen-I, the ratio of TIMP-1/MMP-13. LUT also significantly increased the expressions of SIRT1 and ERRα. And LUT significantly suppressed the releases of pro-inflammatory cytokines, including NLRP3, ASC, caspase-1, IL-1β, and regulated signaling TLR2/TLR4-MyD88 activation. The expressions of TLR2, TLR4, NLRP3, caspase-1, IL-1β, α-SMA were increased and the expression of ERRα was decreased by Sirtinol, indicated that LUT might mediate SIRT1 to regulate TLR4 expression and further alleviate inflammation and fibrosis. LUT could regulate SIRT1-mediated TLR4 and ECM in HSCs was reduced, when HSCs were cultured with conditioned medium. Hence, LUT could decrease the expressions of fibrosis markers, reduce the releases of inflammatory cytokines in activated HSCs or macrophages. In conclusion, LUT might be a promising candidate that regulating SIRT1-TLR2/TLR4 signaling in macrophages interacting with HSCs during hepatic fibrosis.     

Monocyte-derived immature dendritic cells negatively regulate hepatic stellate cells in vitro by secreting IL-10

The development of liver fibrosis is associated with inflammatory responses resulting from chronic liver disease. Immature dendritic cells (imDCs) play an important role in modulating the inflammatory environment of the liver. This study investigated the effects of imDCs on the regulation of hepatic stellate cells (HSCs) during liver fibrosis. We isolated and induced imDCs from monocytes of healthy volunteers, activated LX-2 cells with TGF-β to establish in vivo liver fibrosis HSCs model, and then set up a cell co-culture system with transwell membranes. imDC surface markers and apoptosis rates of LX-2 cells were detected by flow cytometry. The concentration of IL-10 secreted by imDC was measured through ELISA. The expression of α-SMA in LX-2 after co-culture was examined by qRT?PCR. Proliferation of LX-2 cells were detected by CCK-8. The western blot was used to illustrate the LX-2 activation-related proteins such as Smad3/7 and TGF-β1. The imDCs co-culture group and the interleukin-10 (IL-10) treatment group had similar results, as they were both able to increase apoptosis, inhibit proliferation, downregulate α-SMA mRNA, and reduce TGF-β1 and Smad3 protein expression in LX-2 cells. Additionally, the Smad7 protein level was increased after treatment with imDC and IL-10. However, the results in the IL-10 antagonist group showed the opposite trend to that of imDCs and IL-10 groups. Thus, these results suggest that imDC secretion of IL-10 negatively regulates activated LX-2 cells, probably via inhibition of the TGF-β1/Smad3 pathway and increased expression of Smad7 protein. This may be a potential therapeutic target for liver fibrosis.     

辣椒素抑制大鼠肝纤维化的实验研究

 目的：探讨辣椒素（capsaicin）对大鼠肝星状细胞（hepatic stellate cells, HSCs）活性的影响及其对实验性肝纤维化的治疗作用。方法：DCFH-DA法检测辣椒素对HSCs中活性氧的影响;CCK-8法检测辣椒素对HSCs增殖的影响;Western blotting检测HSCs α-平滑肌肌动蛋白的表达;RT-PCR检测辣椒素对HSCs纤维化相关基因表达的影响;流式细胞术检测辣椒素对HSCs凋亡的影响;通过腹腔注射四氯化碳建立鼠肝纤维化模型,经腹腔输注辣椒素,检测肝组织病理切片,观察肝纤维化指标的变化。结果：与对照组比较,辣椒素抑制了HSCs中活性氧的产生,明显抑制了HSCs的活化与增殖(P<0.05),促进了HSCs的凋亡(P<0.05),降低了金属蛋白酶组织抑制物1及转化生长因子β 1的表达(P<0.05),降低了肝羟脯氨酸含量及血清Ⅲ型胶原和透明质酸水平(P<005)。结论：辣椒素抑制HSCs增殖、活化并诱导其凋亡。辣椒素对实验性肝纤维化具有一定的抑制作用。     

柔肝方通过抑制纤维化蛋白抗肝纤维化的机制研究

目的:柔肝方是上海市名中医王灵台教授治疗肝纤维化的临床有效验方,本研究旨在探讨柔肝方通过抑制纤维化蛋白(FBRS)抗肝纤维化的分子机制.方法:质谱法鉴定柔肝方的化学成分及其入血成分.BALB/c小鼠随机分对照组、模型组、柔肝方高剂量组、柔肝方中剂量组和柔肝方低剂量组.通过尾静脉注射ConA(12.5 mg/kg),每周...     

大鼠腹腔注射人血清白蛋白免疫性肝纤维化模型的实验研究

目的 通过腹腔注射人血清白蛋白建立免疫损伤性大鼠肝纤维化模型。方法 雄性Wistar大鼠，体重110—120g，皮下多点注射人血清白蛋白（共4次。分别间隔14、10、10d）。10d后，腹腔注射人血清白蛋白（每周2次，共8周，剂量从5mg逐渐增至20mg）。在攻击前、攻击后15、30、60d和停止攻击后30、60、90、120d，分别留取肝组织和血清标本，进行肝病理检查和肝羟脯氨酸生化测定，采用放射免疫法测定肝纤维化血清指标透明质酸（HA）和层粘连蛋白（LN）含量。结果 攻击后。肝纤维化分级、肝羟脯氨酸含量、血清HA、LN均升高（P〈0．05）。随造模时间延长，肝纤维化分级逐渐加重（P〈0．05）、肝羟脯氨酸含量、血清HA逐渐升高（P〈0．01）。停止造模后，肝羟脯氨酸含量、血清HA明显降低（P〈0．01），但仍显著高于正常对照组（P〈0．01）。纤维化形成率为100％，纤维化持续时间120d以上。结论 此造模方法简单，肝纤维化成功率高，维持时间长，可用于抗纤维化药物的研究。     

Increased immunoreactivities against endothelin-converting enzyme-1 and monocyte chemotactic protein-1 in hepatic stellate cells of rat fibrous liver induced by thioacetamide

The progression of rat liver fibrosis induced by intraperitoneal administration of thioacetamide (TAA) was evaluated by immunocytochemistry using anti-α-smooth muscle actin (α-SMA), antiendothelin-converting enzyme (ECE)-1, and anti-monocyte chemotactic protein (MCP)-1 antibodies. The fibrous septal spaces gradually increased after administration of TAA, and pseudolobules were established in the 7-week TAA-treated groups. Immunoreactivities against α-SMA were not detected in hepatic stellate cells (HSCs) of the control group without TAA treatment, although they were observed in the HSCs around the fibrous septal spaces in all TAA-treated groups, indicating that activation of HSCs occurs during the establishment of pseudolobules. Immunoreactivities against ECE-1 and MCP-1 were seen in such HSCs of the TAA-treated groups, but few or no immunoreactivities were detected in the HSCs of the control group. The most significant increase in the ECE-1 immunoreactivities was detected in the 1-week TAA-treated group, whereas that in MCP-1 was observed in the 7-week TAA-treated group. The present immunocytochemistry indicated a difference in the accelerated expression period between immunoreactivities against ECE-1 and MCP-1 in the HSCs during the progression of TAA-induced liver fibrosis, suggesting that ECE-1 is involved in the early phase of liver fibrosis and that MCP-1 plays a role during the later phase.     

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.     

大鼠原代肝星状细胞活化后组蛋白修饰水平的观察

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 blotting检测desmin和α-SMA的表达,比较静止型HSCs和激活型HSCs中H4K12乙酰化、H3K9乙酰化、H3K4二甲基化和H3K9二甲基化的变化。结果:(1)细胞形态学观察结果表明HSCs在培养过程中形态由静息状态向高度分化的肌成纤维细胞转化。细胞免疫荧光染色及Western blotting检测结果显示,分离培养24 h的HSCs有desmin表达,但几乎不表达α-SMA;随着培养时间延长,HSCs内α-SMA和desmin表达逐步增加,至15 d时达到最大。(2)根据HSCs细胞形态变化及HSCs活化标志蛋白检测结果,确定培养24 h的HSCs为静止型HSCs,培养15 d的HSCs为激活型HSCs,分别检测其组蛋白修饰变化。结果显示,与静止型HSCs比较,激活型HSCs中H4K12乙酰化、H3K9乙酰化和H3K9二甲基化修饰水平明显降低(P0.01),而H3K4二甲基化修饰水平明显增加(P0.01),且H3K4二甲基化修饰水平变化与α-SMA表达变化一致。结论:在体外培养HSCs活化过程中,组蛋白修饰发生明显异常,提示组蛋白修饰改变有可能参与了HSCs活化以及肝纤维化的发生。     

Antifibrotic effect of edaravone in rat liver cirrhosis induced by dimethylnitrosamine

Edaravone (EDA), a newly synthesized free radical scavenger, has shown excellent results in the treatment of stroke. An overproduction of reactive oxygen species (ROS) causing oxidative DNA damage has been accounted as a major factor causing liver injury and fibrosis. Therefore, we examined its effect of EDA in rat model of liver cirrhosis induced by dimethylnitrosamine (DMN). Ten rats (DMN-group) were injected intraperitoneally with DMN (10 μg/g body weight) alone and another ten rats (EDA-group) were injected intraperitoneally with EDA (10 mg/kg body weight) 2 h after being injected with DMN. Both groups underwent their injection regimen three times a week for 4 weeks, after which the rats were sacrificed and their liver tissue sections were stained with Azan–Mallory for quantitative analyses of fibrosis development, using soft imaging and a previously published scoring system. Additionally, these sections were immunohistochemically stained using an antibody against α-smooth muscle actin (α-SMA). The total-bililubin in the EDA-group was found to be lower than that in the DMN-group. Quantitive analysis of liver fibrosis showed that the fibrotic area of the EDA-group was significantly smaller than that of the DMN-group. Additionally, the number of α-SMA positive cells in the EDA-group were significantly lower than that in the DMN-group. This study showed that EDA reduces liver fibrosis in a rat of cirrhosis induced by DMN. These data suggest that the reduction of liver fibrosis by EDA may be induced by the suppression of activated hepatic stellate cells.     

PI3K/PKB信号通路在TGF-β_1诱导人肝星状细胞表达骨桥蛋白中的作用

目的:研究磷脂酰肌醇3-激酶/蛋白激酶B(PI3K/PKB)信号通路在转化生长因子β1(TGF-β1)诱导人肝星状细胞表达骨桥蛋白(OPN)的调控作用。方法:体外培养LX-2人肝星状细胞株,予TGF-β1(终浓度2.5、5、10、20μg/L)刺激24 h或予TGF-β1(终浓度10μg/L)刺激12 h、24 h、48 h;先经PI3K/PKB信号通路特异性抑制剂wortmannin(0.1μmol/L)预处理1 h,再予10μg/L TGF-β1刺激24 h,收集细胞,采用real-time PCR及Western blotting法检测OPN表达情况。结果:TGF-β1能够促进LX-2细胞表达OPN,在一定浓度和时间范围内,其表达量随着TGF-β1浓度和时间的增加而增加,呈剂量和时间依赖性关系;经wortmannin预处理再予TGF-β1刺激的LX-2细胞,与对照组相比,OPN表达受到明显抑制(P0.01)。结论:TGF-β1对LX-2人肝星状细胞OPN表达具有诱导作用,此作用可能受PI3K/PKB信号通路的调控。     

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.     

四氯化碳诱导肝纤维化早期大鼠肝窦内皮细胞及基底膜形态改变的动态研究

 目的：探讨四氯化碳诱导肝纤维化早期大鼠肝窦毛细血管化的形成过程。方法：清洁级雄性SD大鼠采用随机数字表法随机分为2组：正常对照组（N组,6只）和肝纤维化模型组（M组,32只）。M组大鼠腹腔注射50%四氯化碳蓖麻油混合液, N组大鼠腹腔注射生理盐水,剂量为2 mL/kg,每周2次,共4周。分别于造模第3天、1周、2周和4周处死大鼠,HE染色和Masson染色观察肝脏组织炎症及纤维化的改变,透射电镜观察肝窦内皮细胞（LSECs）窗孔与基底膜（BM）的改变,免疫组织化学检测LSECs表面标志物CD31及基底膜成分IV型胶原（Col IV）和层黏连蛋白（LN）的改变。结果：HE及Masson染色显示四氯化碳造模4周早期肝纤维化已形成。肝组织透射电镜显示四氯化碳造模第3天后开始出现LSECs窗孔直径变小及数目减少,随着造模时间的延长,LSECs失窗孔现象逐步严重,至第4周时局部内皮下可见连续的基底膜。免疫组化染色显示LSECs表面标志物CD31表达随着LSECs窗孔数目的减少而逐渐增强;基底膜成分Col IV于造模第2周时表达开始显著增强并随着造模时间延长表达逐渐增强,LN于造模第4周时表达开始显著增强。结论：肝纤维化早期大鼠局部肝组织可见典型的肝窦毛细血管化形成;肝窦壁内LN沉积是肝窦毛细血管化时形成连续基底膜的关键因素。     

环黄芪醇对异丙肾上腺素诱导小鼠心肌纤维化的影响

目的:探讨环黄芪醇(cycloastragenol,CAG)对小鼠心肌纤维化的影响及其机制。方法:用异丙肾上腺素(isoproterenol,ISO)建立小鼠心肌纤维化模型,用低、高浓度CAG分别处理小鼠。超声心动法检测小鼠心功能;Masson三色染色法观察心脏纤维化情况;RT-qPCR、Western blot和免疫组织化学法检测与纤维化相关的信号分子表达。此外,分离培养乳大鼠心脏成纤维细胞,检测上述信号分子的表达。结果:CAG显著缓解了ISO刺激所致的心脏功能紊乱和心肌纤维化;抑制了氧化应激相关因子NADPH氧化酶4和诱导型一氧化氮合酶的转录;抑制了核因子κB信号通路中关键蛋白的磷酸化以及转化生长因子β(transforming growth factor-β,TGF-β)的表达;并且在原代成纤维细胞中验证了CAG可以缓解ISO刺激引起的上述因子表达。结论:CAG通过抑制氧化应激、炎症反应和TGF-β的表达缓解心肌纤维化。     

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。     

肝星状细胞SCAP特异性敲除对小鼠肝纤维化的影响

目的:探讨固醇调节元件结合蛋白裂解活化蛋白(SCAP)在肝星状细胞中缺失能否延缓小鼠肝纤维化进程.方法:将SCAPloxP/loxP小鼠与Lrat-Cre工具鼠繁殖得到Lrat-Cre+/+SCAPfl/fl、Lrat-Cre+/?SCAPfl/fl和Lrat-Cre?/?SCAPfl/fl小鼠,并用PCR法对小鼠基因...