Expression of insulin－like growth factor 1 and insulin－like growth factor 1 receptor and its intervention by interleukin－lO in experimental hepatic fibrosis

AIM: To study the expression of IGF-1 and IGF-1R and its intervention by interleukin-10 in the course of experimental hepatic fibrosis. METHODS: Hepatic fibrosis was induced in rats by carbon tetrachloride intoxication and liver specimens were taken from the rats administered CCl4 with or without IL-10 treatment and the animals of the control group. Immunoreactivities for insulin-like growth factor-1 (IGF-1) and IGF-1 receptor(IGF-1R) were demonstrated by immunohistochemistry, and their intensities were evaluated in different animal groups. RESULTS: The positive levels for IGF-1 and IGF-1R were increased with the development of hepatic fibrosis, with the positive signals localized in cytoplasm and/or at the plasmic membrane of hepatocytes. The positive signals of IGF-1 and IGF-1R were observed more frequently (P<0.01) in the CCl4-treated group (92.0 % and 90.0 %) compared to those in the control group. The positive signals decreased significantly (P<0.05) in IL-10-treated group. The responses in IGF-1 and IGF-1R expression correlated with the time of IL-10 treatment. CONCLUSION: The expression of IGF-1 and IGF-1R immunoreactivities in liver tissue seems to be up-regulated during development of hepatic fibrosis induced by CCl(4), and exogenic IL-10 inhibits the responses.     

IL-10对实验性肝纤维化大鼠转化生长因子β1表达的影响

目的探讨TGFβ1在实验性肝纤维化过程中的表达状况及IL-10对肝纤维化大鼠转化生长因子β1(TGFβ1)表达的影响.方法建立大鼠肝纤维化模型并行IL-10干预实验.从正常对照组(C组)和CCl4诱导肝纤维化模型组(M组)及IL-10干预肝纤维化组(T组)中取肝脏组织,采用S-P免疫组织化学方法检测分析不同组大鼠在肝纤维化进程的不同阶段肝组织中TGFβ1表达的情况.结果成功建立大鼠肝纤维化模型;随着肝纤维化程度的加重,TGFβ1在肝组织中阳性表达明显增强;经Ridit分析,C组与M组间TGFβ1阳性表达水平有显著性差异(P＜0.01);T组TGFβ1阳性表达较M组明显减弱,经Ridit分析,组间差异有显著性(P＜0.01).结论TGFβ1的阳性表达随着肝纤维化程度的进展升高,外源性IL-10对CCl4诱导的肝纤维化中TGFβ1的表达具有明显拮抗作用.     

白介素—10血小板衍生生化因子对肝星状细胞表达转化生长因子—β1的影响

目的：探讨IL－10，PDGF对体外培养HSC表达TGF－β1的影响。方法：原位灌流分离HSC，体外培养激活，分别用IL－10，PDGF以及两者共干预，采用半定量RT－PCR方法和免疫细胞化学方法检测各组TGF－β1的mRNA及蛋白表达情况。结果：IL－10干预组TGF－β1表达较对照组减弱，PDGF干预组较对照组明显增强，IL－10干预组较IL－10，DGA共干预组明显减弱（P＜0．01）。结论：PDGF可促进HSC表达TGF－β1，而抑制HSC表达TGF－β1可能是外源性IL－10的抗肝纤维化作用机制之一。     

Effects of interferon-alpha on expression of hepatic stellate cell and transforming growth factor-β1 and α-smooth muscle actin in rats with hepatic fibrosis

AIM: To investigate the effect of interferon-α(IFN-α) on preventing or reversing hepatic fibrosis in rat experimental model induced by CCl4.METHODS: One hundred and ten Sprague-Dawley rats were divided into five groups: group A (normal controls,n=18), group B (fibrotic model controls, n=22), group C (IFN-α prevention, n=22) initially treated with intra-muscular injection of IFN-α in saline daily at the doses of 1&#215;105U for 6wk, group D (IFN-α treatment, n=24) treated with intra-muscular injection of IFN-α in saline daily at the doses of 1&#215;105U for 6wk after the first 6wk, group E (0.9% sodium chloride treatment control, n=24) treated with intra-muscular injection of 0.01mL/kg daily for 6wk after the first 6wk. At the end of the experiment, all rats of each group were killed. Samples of the liver obtained by biopsy were subjected to histological, immunohistochemical and electron microscopic studies for the expressions of transforming growth factor-β1(TGF-β1) and α-smooth muscle actin (α-SMA).RESULTS: The expressions of TGF-β1, the number of activated hepatic stellate cells and α-SMA in hepatic tissue of group C were significantly less than those of group B(P&lt;0.01). The degree of fibrosis score in group B was also significantly less than that of group C under light microscope (P&lt;0.01).CONCLUSION: IFN-α can inhibit the production of TGF-β1, decrease HSC activation and stimulate its apoptosis.     

Promoter polymorphism of transforming growth factor-β1 gene and ulcerative colitis

AIM： To elucidate the possible difference in two promoter polymorphisms of the transforming growth factor-β1 （TGF-β1） gene （-800G 〉 A, -509C 〉 T） between ulcerative colitis （UC） patients and normal subjects.
METHODS： A total of 155 patients with established ulcerative colitis and 139 normal subjects were selected as controls. Two single nucleotide polymorphisms within the promoter region of TGF-β1 gene （-509C 〉 T and -800G 〉 A） were genotyped using PCR-RFLP. RESULTS： There was a statistically significant difference in genotype and allele frequency distributions between UC patients and controls for the -800G 〉 A polymorphism of the TGF-β1 gene （P 〈 0.05）. The frequency of the TGF-β1 gene polymorphism at position -800 showed that the AA genotype and the allele A frequencies significantly differed between the patients and healthy controls （P 〈 0.05）. At position -509, there was no statically significant difference in genotype and allele frequency between the patients and control subjects.
CONCLUSION： The results of our study indicate that there is a significant difference in both allele and genotype frequency at position -800G 〉 A of TGF-β1 gene promoter between Iranian patients with UC and normal subjects.     

Down-regulation of transforming growth factor β1/activin receptor-like kinase 1 pathway gene expression by herbal compound 861 is related to deactivation of LX-2 cells

AIM： To investigate the effect of herbal compound 861 （Cpd861） on the transforming growth factor-β1 （TGFβ1）/ activin receptor-like kinase 1 （ALK1, type Ⅰ receptor） signaling-pathway-related gene expression in the LX-2 cell line, and the inhibitory mechanism of Cpd861 on the activation of LX-2 cells.
METHODS： LX-2 cells were treated with TGFβ1 （5 ng/mL） Cpd861 （0.1 mg/mL）, TGFβ1 （5 ng/mL） plus Cpd861 （5 ng/mL） for 24 h to investigate the effect of Cpd861 on the TGFβ1/ALK1 pathway. Real-time PCR was performed to examine the expression of α-SMA （α-smooth muscle actin）, ALK1, Id1 （inhibitor of differentiation 1）. Western blotting was carried out to measure the levels of α-SMA and phosphorylated Smad1, and immunocytochemical analysis for the expression of α-SMA.
RESULTS： In LX-2 cells, TGFβ1/ALK1-pathway-related gene expression could be stimulated by TGFβ1, which led to excessive activation of the cells. Cpd861 decreased the activation of LX-2 cells by reducing the expression of α-SMA mRNA and protein expression. This effect was related to inhibition of the above TGFβ1/ALK1-pathway- related expression of genes such as Id1 and ALK1, and phosphorylation of Smad1 in LX-2 cells, even with TGFβ1 co-treatment for 24 h.
CONCLUSION： Cpd861 can restrain the activation of LX-2 cells by inhibiting the TGFβ1/ALK1/Smad1 pathway.     

白介素-10血小板衍生生长因子对肝星状细胞表达转化生长因子-β1的影响

目的:探讨IL-10、PDGF对体外培养HSC表达TGF-β1的影响.方法:原位灌流分离HSC,体外培养激活,分别用IL-10、PDGF以及两者共干预,采用半定量RT-PCR方法和免疫细胞化学方法检测各组TGF-β1的mR-NA及蛋白表达情况.结果:IL-10干预组TGF-β1表达较对照组减弱,PDGF干预组较对照组明显增强,IL-10干预组较IL-10、PDGF共干预组明显减弱(P＜0.01).结论:PDGF可促进HSC表达TGF-β1,而抑制HSC表达TGF-β1可能是外源性IL-10的抗肝纤维化作用机制之一.     

Tetrandrine inhibits activation of rat hepatic stellate cells in vitro via transforming growth factor-β signaling

AIM: To investigate the effect of various concentrations of tetrandrine on activation of quiescent rat hepatic stellate cells (HSCs) and transforming growth factor-β (TGF-β) signaling in vitro. METHODS: HSCs were isolated from rats by in situ perfusion of liver and 18% Nycodenz gradient centrifugugation, and primarily cultured on uncoated plastic plates for 24 h with DMEM containing 20% fetal bovine serum (FBS/DMEM) before the culture medium was substituted with 2% FBS/DMEM for another 24 h. Then, the HSCs were cultured in 2% FBS/DMEM with tetrandrine (0.25, 0.5, 1,2 mg/L, respectively). Cell morphological features were observed under an inverted microscope, smooth muscle-α-actin (α-SMA) was detected by immunocytochemistry and image analysis system, laminin (LN) and type Ⅲ procollagen (PCⅢ) in supernatants were determined by radioimmunoassay. TGF-β1 mRNA, Smad 7 mRNA and Smad 7 protein were analyzed with RT-PCR and Western blotting, respectively. RESULTS: Tetrandrine at the concentrations of 0.25-2 mg/L prevented morphological transformation of HSC from the quiescent state to the activated one, while α-SMA, LN and PCⅢ expressions were inhibited. As estimated by gray values, the expression of α-SMA in tetrandrine groups (0.25, 0.5, 1, 2 mg/L) was reduced from 21.3% to 42.2% (control: 0.67, tetrandrine groups: 0.82, 0.85, 0.96, or 0.96, respectively, which were statistically different from the control, P&lt;0.01), and the difference was more significant in tetrandrine at 1 and 2 mg/L. The content of LN in supernatants was significantly decreased in tetrandrine groups to 58.5%, 69.1%, 65.8% or 60.0% that of the control respectively, and that of PCII] to 84.6%, 81.5%, 75.7% or 80.7% respectively (P&lt;0.05 vs control), with no significant difference among tetrandrine groups. RTPCR showed that TGF-β1 mRNA expression was reduced by tetrandrine treatments from 56.56% to 87.90% in comparison with the control, while Smad 7 mRNA was increased 1.4-4.8 times. The TGF-β1 mRNA and Smad 7 mRNA expression was in a significant negative correlation (r = -0.755, P&lt;0.01), and both were significantly correlated with α-SMA protein expression (r = -0.938, P&lt;0.01; r = 0.938, P&lt;0.01, respectively). The up-regulation of Smad 7 protein by tetrandrine (1 mg/L) was confirmed by Western blotting as well. CONCLUSION: Tetrandrine has a direct inhibiting effect on the activation of rat HSCs in culture. It up-regulates the expression of Smad 7 which in turn blocks TGF-β1 expression and signaling.     

转化生长因子β1对大鼠肝星状细胞表达β-连环蛋白的影响

目的研究转化生长因子β1（TGF—β1）对大鼠肝星状细胞（HSC）表达β-连环蛋白（β-catenin）的影响。方法采用逆转录聚合酶链反应（RT—PCR）比较经不同浓度的TGF-β1刺激不同时间后HSC表达β-catenin、smad3和α-SMA mRNA的变化,并比较三者之间的关系。结果1ng／ml TGF—β1刺激2h后,HSC表达β—catenin mRNA、smad3 mRNA和α—SMA mRNA量最大,β—catenin mRNA表达与两者均具有明显的相关关系（r=0．947,P〈0．01;r=0．950,P〈0．01）。结论β—catenin在TGF—β1活化HSC的过程中发挥重要作用。     

筛选转化生长因子β1刺激肝星状细胞差异表达基因的研究

目的 筛选转化生长因子β 1(TGF β 1)刺激大鼠肝星状细胞(Hsc)的差异表达基因,以揭示TGF β1介导肝纤维化的分子发病机制. 方法分别用Trizol法抽提TGF β1刺激的HSC及磷酸盐缓冲液刺激为对照的HSC总RNA,逆转录合成双链cDNA,制备掺入生物素标记的cDNA探针,与人基因表达谱芯片杂交,用Agilent扫描仪对芯片结果进行扫描,利用软件对差异表达基因进行生物信息学分析. 结果 从13824条目的 基因中筛选出177条差异表达基因,其中123条基因表达上调,其中包括:结缔组织生长因子,微管蛋白ε 1,V型胶原α2,连环蛋白6 2,钙粘蛋白6,2型,Smad3,丝裂源活化蛋白激酶4,生长因子受体结合蛋白7,丝裂原活化蛋白激酶相互作用/丝氨酸/苏氨酸激酶1等;54条基因表达下调,包括:肿瘤坏死因子受体相关因子4,干扰素调节因子7,干扰素诱生蛋白p78,骨形态发生蛋白7,基质gLa蛋白,人类丝氨酸蛋白酶抑制剂进化支B成员8,干扰素刺激基因2.0×104,死亡相关蛋白6,金属硫蛋白1H,超氧化物歧化酶2等;同时筛选到8个未知功能蛋白. 结论 应用基因表达谱芯片技术成功筛选了TGF β 1刺激HSC的差异表达基因,初步揭示了TGF β1致肝纤维化的分子机制是诸多因素共同作用的结果,为进一步寻找新的基因治疗靶点奠定了基础.     

大鼠肝星状细胞转化生长因子β3/β1 mRNA比值与Ⅰ型胶原合成的关系

转化生长因子β1(TGF β 1)是激活肝星状细胞(HSC)并促进其胶原合成的最重要因子.TGF β 3被认为具有抗组织纤维化的功能.Carrington等[1]研究提示:TGF β 1与TGF β 3的比值是纤维化发生程度的关键因素.本实验研究大鼠HSC中TGF β 3/TGF β 1 mRNA比值的变化及与Ⅰ型胶原合成的关系,阐明TGF β 3是拮抗TGF β 1的重要因子,为TGF β 3对肝纤维化的防治作用提供实验依据.     

转化生长因子β1刺激肝星状细胞中纤溶酶原激活物抑制剂1表达

肝星状细胞(HSC)的激活是肝纤维化发生的中心环节.活化的HSC大量增殖,并合成以胶原为主的细胞外基质(ECM)沉积在肝内.转化生长因子(TGF)β是激活HSC并促进其增殖的最重要细胞因子之一,可促进ECM产生,导致并加速肝纤维化的发生和发展.本实验拟通过免疫细胞化学法检测纤溶酶原激活物抑制剂(PAI)1在HSC中的定位,逆转录聚合酶链反应(RT-PCR)及免疫细胞化学法等研究TGF β1促进PAI 1 mRNA和蛋白质的表达,探讨PAI 1在肝纤维化发生和发展中的作用.