吲哚-3-原醇对乙醇损伤性大鼠肝切片的保护作用

目的　采用精密肝切片技术 ,研究十字花科类蔬菜提取物吲哚 3 原醇 (I3C)对乙醇肝损伤的作用及机制。方法　制作大鼠乙醇损伤肝切片模型 ,观察不同剂量I3C对培养液中肝损伤标志酶及肝细胞浆苯胺羟化酶 (ANH)、乙醇脱氢酶 (ADH)活性的影响 ,并进行组织学检查。结果　乙醇5 0mmol·L-1作用肝切片 4h时 ,培养液谷丙转氨酶、谷草转氨酶、乳酸脱氢酶和谷胱甘肽S 转移酶活性明显升高 ,同时肝细胞浆ANH活性升高、ADH活性降低 ;加入 10 0～ 4 0 0μmol·L-1的I3C后 ,培养液中各酶活性降低的同时 ,肝细胞ANH和ADH活性恢复正常。肝切片病理学检查也证实I3C的保护作用。结论　I3C能有效拮抗乙醇所致的肝损伤 ,其机制与改变乙醇代谢途径有关。     

吲哚-3-原醇对肝星状细胞凋亡及细胞周期的影响

目的：研究吲哚-3-原醇（13C）对肝星状细胞（HSC）凋亡及细胞周期的影响及其机制。方法：培养永生化肝星状细胞株HSC-T6，不同浓度13C（25、50、100μmol／L）处理细胞48h后，四甲基偶氮唑盐（MTT）法检测细胞存活率；碘化丙啶（PI）染色测细胞周期；FITC-AnnexinV／PI荧光染色，流式细胞术观测细胞凋亡；荧光实时定量PCR法检测细胞凋亡相关蛋白FasL、bax、bcl-2、caspase-3及细胞周期调节蛋白CyclinD1、CDK4的mRNA表达；Western blot方法检测细胞磷酸化及非磷酸化p38信号分子的表达。结果：①MTT法显示，100mol／L及以下浓度的13C处理HSC-T6后，细胞的存活率在90％以上；②凋亡分析显示，对照组细胞没有发生凋亡，25～100mol／L13C组细胞的凋亡率分别为37．6％、64．2％和79．4％；③细胞周期结果显示，对照组细胞的S期为（58．7±4．7）％，25～100mol／L　13C使细胞的S期分别降低到（34．0±3．0）％、（26．3±3．3）％及（24．9±5．3）％，而G0／G1期细胞从（31．8±3．4）％（OM）升高到（54．6±3．0）％（100M），差异有显著性（P〈0．01）；④13C能剂量依赖性升高细胞Bax／Bcl-2及caspase-3的mRNA水平（P〈0．05），对Fas的mRNA表达无影响。同时能降低Cyclin D1和CDK4的mRNA水平（P〈0．05）；⑤13C能减少细胞内p38的磷酸化水平，呈剂量依赖性，对非磷酸化p38无影响。结论：13C可诱导体外活化的HSC凋亡，其机制与阻滞细胞周期进展、抑制p38信号途径及增加凋亡相关诱导因子的表达有关。     

精密肝切片中乙醛活化肝星状细胞模型的建立

目的:在精密肝切片中利用乙醛激活肝星状细胞,建立一种星状细胞激活的体外模型,为研究和筛选阻抑肝纤维化发生的药物奠定基础。方法:利用振荡切片机制备精密肝切片,建立培养系统。以700μmol·L-1乙醛孵育切片,培养0、2、4、6h,测定培养基和组织匀浆中谷胱甘肽S-转移酶(GST)、乳酸脱氢酶(LDH)和羟脯氨酸(Hyp)含量,观察病理切片中α-平滑肌肌动蛋白(α-SMA)表达。结果:与0h相比,乙醛培养2、4、6h培养基的GST、LDH漏出量均显著升高(P<0.05)。切片组织Hyp含量6h较0h相比明显升高(P<0.05)。免疫组化片镜下可见4、6h有α-SMA阳性细胞表达,图像分析显示面积和阳性率较0h明显增加(P<0.05)。结论:精密肝切片与终浓度为700μmol·L-1乙醛共孵育6h可活化切片中星状细胞,该技术可作为良好的体外肝星状细胞激活模型。α-SMA免疫组化是一鉴定体外星状细胞激活的可靠指标。     

吲哚-3-原醇对猪血清诱导大鼠肝纤维化的治疗作用

研究吲哚-3-原醇(I3C)对猪血清诱导大鼠肝纤维化的治疗作用及其机制。腹腔注射猪血清制备大鼠肝纤维化模型,造模成功后用I3C治疗17天。采用HE和Masson三色染色法分别观察肝脏病理学和胶原含量改变;生化比色法测定肝组织羟脯氨酸(Hyp)含量;免疫组织化学法观察肝脏中α-平滑肌肌动蛋白(α-SMA)的表达。进一步培养大鼠肝星状细胞株HSC-T6,用13C处理24 h后,FITC-Annexin V/PI双重染色法检测细胞凋亡;实时荧光定量PCR法检测细胞凋亡相关蛋白Bax和Bcl-2的mRNA表达。结果显示,与模型对照组比较,各I3C治疗组的肝组织Hyp含量不同程度降低,肝细胞损伤减轻,胶原纤维沉积减少(P<0.01),α-SMA表达降低(P<0.01)。细胞实验显示,I3C可明显增加HSC-T6细胞凋亡率,升高Bax/Bcl-2的mRNA表达(P<0.05)。以上结果说明,I3C对猪血清诱导大鼠肝纤维化有一定治疗作用,可能与其诱导活化HSC凋亡继而促进基质胶原降解有关。     

吲哚-3-原醇对复合因素所致肝纤维化大鼠的治疗作用及部分机制研究

目的观察吲哚-3-原醇(I3C)对复合因素诱导肝纤维化大鼠的治疗作用并探讨其可能机制。方法采用复合因素(CCl4、酒精、高脂低蛋白饲料)制备大鼠肝纤维化模型,用I3C治疗10 d后,检测大鼠肝组织的羟脯氨酸(Hyp)、超氧化物歧化酶(SOD)、丙二醛(MDA)的含量;通过HE及Mas-son三色染色,观察肝脏病理学改变及胶原含量改变;免疫组化法观察肝脏中α-平滑肌肌动蛋白(α-SMA)的表达;West-ern blot检测肝组织中基质金属蛋白-2(MMP-2)的表达。结果与模型对照组比较,I3C治疗组肝组织Hyp含量降低,SOD活性升高,以大剂量(12 mg.kg-1)组明显(P<0.01),MMP-2蛋白表达升高;病理学改变尤其是胶原纤维的沉积明显减轻(P<0.05),α-SMA表达也降低。结论 I3C可促进复合因素所致大鼠肝纤维化模型的恢复,其机制与降低肝组织氧化应激、减少活化HSC数量以及促进基质胶原降解有关。     

吲哚-3-原醇对博莱霉素所致小鼠肺纤维化的干预作用及其机制

目的观察吲哚-3-原醇(indole-3-carbinol,I3C)对博莱霉素致小鼠肺纤维化的干预作用并初步探讨其机制。方法Imprinting Control Region(ICR)小鼠随机分为6组:正常组、模型组、醋酸泼尼松组(6.67 mg.kg-1)、吲哚-3-原醇小、中、大剂量组(25、50、100 mg.kg-1)。小鼠气管内注射博莱霉素制备肺纤维化模型后,第2天给予相应药物,每天1次。连续给药28 d后处死小鼠检测其肺系数、血清和肺组织羟脯氨酸(Hydroxyproline,HYP)、血清总抗氧化能力(To-tal antioxidative capacity,T-AOC);取固定部位肺组织切片HE染色,进行病理学观察;RT-PCR法检测肺组织中α-SMA、CollagenⅠ、TGF-β、Smad2 mRNA的表达;Western blot法检测肺组织中α-SMA、TGF-β、Smad2蛋白的表达。结果吲哚-3-原醇能够提高小鼠血清的总抗氧化能力(P<0.05或P<0.01),同时可以降低肺系数和肺组织中的HYP含量(P<0.05或P<0.01);光镜观察表明吲哚-3-原醇能明显减轻肺纤维化小鼠肺泡炎和肺纤维化程度(P<0.05或P<0.01);RT-PCR检测发现吲哚-3-原醇能明显降低肺组织α-SMA、CollagenⅠ、TGF-β、Smad2基因表达水平(P<0.05或P<0.01);Western blot分析结果说明吲哚-3-原醇能明显降低肺组织α-SMA、TGF-β、Smad2蛋白表达(P<0.05或P<0.01)。结论吲哚-3-原醇可能通过抑制TGF-β/Smad信号通路来减轻博莱霉素致小鼠肺纤维化。     

吲哚-3-原醇对人肺癌细胞株A549的促凋亡和增殖抑制作用

目的探讨吲哚-3-原醇(Indol-3-carbinol,I3C)对肺腺癌细胞株A549细胞增殖和凋亡的影响及其作用机制。方法将对数生长期的A549细胞分别用不同浓度的I3C处理(0、25、50、100μg/m L)。细胞培养72 h后,采用M TT观察I3C对A549细胞的增殖抑制作用;Annexin V-PI/FITC检测细胞凋亡;Western blotting检测细胞中PI3K、p-AKT、Bax、Bcl-2、Cleavage-PARP、Clevage-Caspase3蛋白的变化。结果 I3C可以呈浓度依赖性地诱导A549细胞的增殖抑制和凋亡,上调Bax和Cleavage-PARP、Cleavage-Caspase3表达,下调PI3K、p-AKT和Bcl-2,对AKT表达无明显影响。结论 I3C可通过抑制PI3K/AKT信号通路而诱导A549细胞增殖抑制和凋亡。     

3-吲哚甲醇的抗肿瘤作用

目的 探讨硫代葡萄糖苷的降解产物3-吲哚甲醇(IC)在体内、外的抗癌活性,为十字花科蔬菜的防癌作用以及从蔬菜中筛选药用成分提供理论依据.方法 体内试验以荷瘤小鼠实体瘤重、抑瘤率及对脾脏、胸腺指数的影响为指标,评价IC对S180移植性肉瘤的抑制作用;长期实验在饮水中加入化学致癌剂甲硝基亚硝基胍(MNNG),诱发小鼠前胃鳞癌及癌前病变,同时给予不同剂量IC进行预防,观察癌前病变和癌变发生率;体外采用MTT法,观察IC对HeLa细胞增殖的抑制作用.结果 IC在体内能明显抑制实体瘤重,使荷瘤小鼠的脾脏和胸腺指数下降,表现出一定的免疫抑制作用;长期试验能明显降低MNNG诱发的癌前病变和癌变发生率;在体外对HeLa细胞有明显的生长抑制作用,且作用随药物浓度增加而加大.结论 IC具有一定的抗肿瘤活性.     

Effect of indole-3-carbinol on ethanol-induced liver injury and acetaldehyde-stimulated hepatic stellate cells activation using precision-cut rat liver slices

1. Indole-3-carbinol (I3C), a major indole compound found in high levels in cruciferous vegetables, shows a broad spectrum of biological activities. However, few studies have reported the effect of I3C on alcoholic liver injury. In the present study, we investigated the protective effect of I3C on acute ethanol-induced hepatotoxicity and acetaldehyde-stimulated hepatic stellate cells (HSC) activation using precision-cut liver slices (PCLS). 2. Rat PCLS were incubated with 50 mmol/L ethanol or 350 μmol/L acetaldehyde, and different concentrations (100-400 μmol/L) of I3C were added into the culture system of these two liver injury models, respectively. Hepatotoxicity was assessed by measuring enzyme leakage and malondialdehyde (MDA) content in tissue. Activities of alcoholic enzymes were also determined. α-Smooth muscle actin (α-SMA), transforming growth factor (TGF-β(1) ) and hydroxyproline (HYP) were used as indices to evaluate the activation of HSC. In addition, matrix metalloproteinase-1 (MMP-1) and the tissue inhibitor of metalloproteinase (TIMP-1) were observed to estimate collagen degradation. 3. I3C significantly reduced the enzyme leakage in ethanol-treated slices. In I3C groups, cytochrome P450 (CYP) 2E1 activities were inhibited by 40.9-51.8%, whereas alcohol dehydrogenase (ADH) activity was enhanced 1.6-fold compared with the ethanol-treated group. I3C also showed an inhibitory effect against HSC activation and collagen production stimulated by acetaldehyde. After being incubated with I3C (400 μmol/L), the expression of MMP-1 was markedly enhanced, whereas TIMP-1 was decreased. 4. These results showed that I3C protected PCLS against alcoholic liver injury, which might be associated with the regulation of ethanol metabolic enzymes, attenuation of oxidative injury and acceleration of collagen degradation.     

Precision-cut liver slices as a new model to study toxicity-induced hepatic stellate cell activation in a physiologic milieu.

Hepatic stellate cell (HSC) activation is a key event in the natural process of wound healing as well as in fibrosis development in liver. Current in vitro models for HSC activation contribute significantly to the understanding of HSC biology and fibrogenesis but still fall far short of recapitulating in vivo intercellular functional and anatomic relationships. In addition, when cultured on uncoated plastic, HSC spontaneously activate, which makes HSC activation difficult to regulate or analyze. We have examined whether the use of precision-cut liver slices might overcome these limitations. Liver slices (8 mm diameter, 250 microm thickness) were generated from normal rat liver and incubated for 3 or 16 h with increasing doses of carbon tetrachloride (CCl4). Rat liver slices remained viable during incubation, as shown by minimal enzyme leakage. Expression of markers for HSC activation and the onset of fibrogenesis in the liver slices was studied using real-time PCR and Western blotting. In unstimulated liver slices, mRNA and protein levels of desmin, heat shock protein 47, and alpha B-crystallin remained constant, indicating quiescence of HSC, whereas Krüppel-like factor 6 expression was increased. In contrast, incubation with CCl4 led to a time- and dose-dependent increase in mRNA expression of all markers and an increased alpha B-crystallin protein expression. In conclusion, we have developed a technique to induce activation of quiescent HSC in rat liver slices. This model permits the study of toxicity-induced HSC activation within a physiological milieu, not only in animal but ultimately also in human tissue, and could contribute to the reduction of animal experiments.     

Selective disruption of cadherin/catenin complexes by oxidative stress in precision-cut mouse liver slices.

Previous work has shown that chemically induced oxidative stress disrupts the protein interactions of the E-cadherin/beta-catenin/alpha-catenin complex in precision-cut mouse liver slices (Parrish et al., 1999, Toxicol. Sci. 51, 80-86). Although these data suggest a role for oxidative stress in disruption of hepatic cadherin/catenin complexes, multiple complexes are co-expressed in the liver. Both E- and N- cadherin are co-expressed in hepatocytes, as well as beta-catenin and gamma-catenin; thus four distinct complexes mediate cell-cell adhesion in the liver: E-cadherin/beta-catenin/alpha-catenin, E-cadherin/gamma-catenin/alpha-catenin, N-cadherin/beta-catenin/alpha-catenin, and N-cadherin/gamma-catenin/alpha-catenin. Taking advantage of the retention of normal organ architecture and cellular heterogeneity offered by precision-cut mouse liver slices, the current study was designed to examine the impact of chemically induced oxidative stress on cadherin/catenin complexes. Precision-cut mouse liver slices were challenged with diamide (25-250 microM; 6 h) or tert-butylhydroperoxide (5-50 microM; 6 h). A polyclonal antibody against beta- or gamma-catenin was used to immunoprecipitate proteins prior to Western-blot analysis with monoclonal antibodies to E- or N-cadherin. Although a decrease in E-cadherin:beta-catenin co-immunoprecipitation was seen, interactions between beta-catenin and N-cadherin were not disrupted by chemical challenge. In addition, no effect on protein interactions of gamma-catenin with either cadherin was observed. Indirect immunofluorescence was used to co-localize catenins and cadherins following chemical challenge. Consistent with the biochemical observations, a heterogeneous reduction in co-localization of E-cadherin and beta-catenin was seen in precision-cut liver slices, but not other cadherin/catenin complexes. Taken together, these data suggest that oxidative stress selectively disrupts E-cadherin/beta-catenin complexes in the liver. This response is dictated, in part, by the protein composition of the cell-adhesion complex.     

以肝星状细胞为靶标的抗肝纤维化治疗进展

任何病因导致的慢性肝损伤,均可发展为肝纤维化。损伤肝脏的纤维化形成过程中,活化肝星状细胞(HSC)是主要细胞类型,并有重要细胞因子参与。目前治疗都以阻止活化HSC在损伤部位聚集和细胞外基质沉积为目标。该文就以HSC为靶标的抗肝纤维化最新治疗方案作一综述。     

肝星状细胞核糖体蛋白S5(RPS5)特异性敲减对肝纤维化的影响

目的 观察特异性敲减肝星状细胞（HSC）内核糖体蛋白S5(RPS5)对大鼠肝纤维化的影响。方法 构建胶质纤维酸性蛋白（GFAP）启动子驱动的RPS5 shRNA腺病毒,分别用AdGFa2-shRPS5及其对照AdGFa2 shNC转染大鼠原代HSC和肝细胞,通过蛋白印迹法和实时PCR测定RPS5、α-SMA和Ⅰ型胶原表达情况;采用二甲基亚硝胺（DMN）和胆管结扎术（BDL）的方法建立大鼠肝纤维化模型,尾静脉注射腺病毒特异性敲减肝内HSC的RPS5水平。肝组织切片HE染色分析病理改变情况;羟脯氨酸含量测定、切片天狼星红和Masson染色评价胶原沉积情况;免疫组织化学染色检测α-SMA和RPS5的表达情况。结果 AdGFa2-shRPS5能够特异性敲减HSC中的RPS5表达水平,增加α-SMA和Ⅰ型胶原在体外表达。体内研究结果表明,在两种慢性肝损伤动物模型中,特异性敲减HSC中RPS5表达水平能够促进HSC活化,增加细胞外基质的沉积,促进肝纤维化。结论 RPS5对HSC激活和肝纤维化发生至关重要,可能是治疗肝纤维化的潜在靶点。