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

AIM: To investigate the effect of interferon-a (IFN-α) on preventing or reversing hepatic fibrosis in rat experimental model induced by CCI4. 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 intramuscular injection of IFN-a in saline daily at the doses of 1× 105 U for 6 wk, group D (IFN-a treatment, n = 24) treated with intra-muscular injection of IFN-a in saline daily at the doses of 1×105 U for 6 wk after the first 6 wk, group E (0.9% sodium chloride treatment control, n = 24) treated with intra-muscular injection of 0.01 mL/kg daily for 6 wk after the first 6 wk. 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-pi (TGF- μ41) and α-smooth muscle actin (α-SMA). RESULTS: The expressions of TGF-pl, the number of activated hepatic stellate cells and a-SMA in hepatic tissue of group C were significantly less than those of group B (P<0.01). The degree of fibrosis score in group B was also significantly less than that of group C under light microscope (P<0.01). CONCLUSION: IFN-a can inhibit the production of TGF-pl, decrease HSC activation and stimulate its apoptosis.     

Effects of N-acetylcysteine on expression of transforming growth factor-β1 in diabetic nephropathy rats

Objective To investigate the effects of N-acetylcysteine (NAC) on the expression of transforming growth factor-β1 (TGF-β1) in renal cortex of diabetic nephropathy rats.Methods A rat model of DN was established.The rats were randomly divided into control group,DN group and NAC group.After 8 weeks treatment,urinary albumin excretion rate (UAER) was determined.The expression of TGF-β1 in renal cortex was detected by immunohistochemistry and RT-PCR analysis.Pathomorphological changes of renal cortex were observed.Results (1)The levels of UA ER were significantly higher in DN group and NAC group [(1268.3±297.5) μg/24 h and (315.9-±86.8) μg/24 h] than in control group [(31.2±8.9) μg/24 h,q-29.85,16.76,both P＜0.01].The groups of DN and NAC versus group of control showed the increased levels of activity of TGF-β1 in renal cortex [immune-histochemistry index of glomerular mesangial area:7.35±1.17 and 3.87 ± 0.71 vs.1.95±0.34,q= 10.75,5.82,both P＜0.01];immune-histochemistry index of renal tubulointerstitium [21.21± 3.78 and 10.67±1.86 vs.3.62±0.79,q=15.20,11.36,both P＜0.01];the expression of mRNA in renal cortex[0.72±0.06 and 0.45±0.05 vs.0.23±0.04,q=9.13,7.45,both P＜0.01].The pathomorphological changes were significant in DN group and NAC group.(2)The NAC group versus DN group showed a decreased levels of UAER (q=8.17,P＜0.01),activity of TGF-β1 in renal cortex [immune-histochemistry index of glomerular mesangial area:q= 4.97,P＜0.01]immune-histochemistry index of renal tubulointerstitium (q = 6.86,P ＜ 0.01 );the expression of mRNA in renal cortex (q= 3.69,P＜0.05) and showed improvement of pathomorphology in renal cortex.(3) There was a significantly positive correlation between expression quantity of TGF-β1 mRNA in renal cortex and UAER level in NAC group(r= 0.749,P＜0.05).Conclusions The protective effects of NAC on the kidney of DN rats may be partly related with inhibition on the expression of TGF-β1.     

Effects of N-acetylcysteine on expression of transforming growth factor-β1 in diabetic nephropathy rats

Objective To investigate the effects of N-acetylcysteine (NAC) on the expression of transforming growth factor-β1 (TGF-β1) in renal cortex of diabetic nephropathy rats.Methods A rat model of DN was established.The rats were randomly divided into control group,DN group and NAC group.After 8 weeks treatment,urinary albumin excretion rate (UAER) was determined.The expression of TGF-β1 in renal cortex was detected by immunohistochemistry and RT-PCR analysis.Pathomorphological changes of renal cortex were observed.Results (1)The levels of UA ER were significantly higher in DN group and NAC group [(1268.3±297.5) μg/24 h and (315.9-±86.8) μg/24 h] than in control group [(31.2±8.9) μg/24 h,q-29.85,16.76,both P＜0.01].The groups of DN and NAC versus group of control showed the increased levels of activity of TGF-β1 in renal cortex [immune-histochemistry index of glomerular mesangial area:7.35±1.17 and 3.87 ± 0.71 vs.1.95±0.34,q= 10.75,5.82,both P＜0.01];immune-histochemistry index of renal tubulointerstitium [21.21± 3.78 and 10.67±1.86 vs.3.62±0.79,q=15.20,11.36,both P＜0.01];the expression of mRNA in renal cortex[0.72±0.06 and 0.45±0.05 vs.0.23±0.04,q=9.13,7.45,both P＜0.01].The pathomorphological changes were significant in DN group and NAC group.(2)The NAC group versus DN group showed a decreased levels of UAER (q=8.17,P＜0.01),activity of TGF-β1 in renal cortex [immune-histochemistry index of glomerular mesangial area:q= 4.97,P＜0.01]immune-histochemistry index of renal tubulointerstitium (q = 6.86,P ＜ 0.01 );the expression of mRNA in renal cortex (q= 3.69,P＜0.05) and showed improvement of pathomorphology in renal cortex.(3) There was a significantly positive correlation between expression quantity of TGF-β1 mRNA in renal cortex and UAER level in NAC group(r= 0.749,P＜0.05).Conclusions The protective effects of NAC on the kidney of DN rats may be partly related with inhibition on the expression of TGF-β1.     

Effects of N-acetylcysteine on expression of transforming growth factor-β1 in diabetic nephropathy rats

Objective To investigate the effects of N-acetylcysteine (NAC) on the expression of transforming growth factor-β1 (TGF-β1) in renal cortex of diabetic nephropathy rats.Methods A rat model of DN was established.The rats were randomly divided into control group,DN group and NAC group.After 8 weeks treatment,urinary albumin excretion rate (UAER) was determined.The expression of TGF-β1 in renal cortex was detected by immunohistochemistry and RT-PCR analysis.Pathomorphological changes of renal cortex were observed.Results (1)The levels of UA ER were significantly higher in DN group and NAC group [(1268.3±297.5) μg/24 h and (315.9-±86.8) μg/24 h] than in control group [(31.2±8.9) μg/24 h,q-29.85,16.76,both P＜0.01].The groups of DN and NAC versus group of control showed the increased levels of activity of TGF-β1 in renal cortex [immune-histochemistry index of glomerular mesangial area:7.35±1.17 and 3.87 ± 0.71 vs.1.95±0.34,q= 10.75,5.82,both P＜0.01];immune-histochemistry index of renal tubulointerstitium [21.21± 3.78 and 10.67±1.86 vs.3.62±0.79,q=15.20,11.36,both P＜0.01];the expression of mRNA in renal cortex[0.72±0.06 and 0.45±0.05 vs.0.23±0.04,q=9.13,7.45,both P＜0.01].The pathomorphological changes were significant in DN group and NAC group.(2)The NAC group versus DN group showed a decreased levels of UAER (q=8.17,P＜0.01),activity of TGF-β1 in renal cortex [immune-histochemistry index of glomerular mesangial area:q= 4.97,P＜0.01]immune-histochemistry index of renal tubulointerstitium (q = 6.86,P ＜ 0.01 );the expression of mRNA in renal cortex (q= 3.69,P＜0.05) and showed improvement of pathomorphology in renal cortex.(3) There was a significantly positive correlation between expression quantity of TGF-β1 mRNA in renal cortex and UAER level in NAC group(r= 0.749,P＜0.05).Conclusions The protective effects of NAC on the kidney of DN rats may be partly related with inhibition on the expression of TGF-β1.     

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.     

Effects of c-myb antisense RNA on TGF-β1 and α1-Ⅰ collagen expression in cultured hepatic stellate cells

AIM: To investigate the effects of c-myb antisense RNA on cell proliferation and the expression of c-myb, TGF-β1 and α1-Ⅰ collagen in cultured hepatic stellate cells (HSC) from rats.METHODS: Recombinant retroviral vector of c-myb antisense gene (pDOR-myb) was constructed, and then transfected into retroviral package cell line PA317 by means of DOTAP.The pseudoviruses produced from the resistant PA317 cells were selected with G418 to infect HSCs isolated from rat livers. The cell proliferation was measured by 3-[4,5-Dimethylthiazolzyl]-2, 5-diphenyl tetrazo-dium bromide (MTT) method.The expression of c-myb, α1-Ⅰ collagen and TGF-β1 rnRNA, and c-myb protein in HSCs was detected with semi-quantitive reverse transeription-polymerase chain reaction (RT-PCR) and Western-blot respectively.RESULTS: HSCs from rats were isolated successfully with the viability &gt;98%. In the pDOR-myb infected HSCs, the cmyb protein expression, cell proliferation,and α1-Ⅰ collagen and TGF-β1 mRNA expression were repressed significantly compared with their corresponding control groups (P&lt;0.01).CONCLUSION: c-myb plays a key role in activation and proliferation of HSC. c-myb antisense RNA can inhibit cell proliferation, α1-Ⅰ collagen and TGF-β1 mRNA expression,suggesting that inhibition of c-myb gene expression might be a potential way for the treatment of liver fibrosis.     

Transforming growth factor-β1 gene polymorphisms are associated with progression of liver fibrosis in Caucasians with chronic hepatitis C infection

AIM: Considerable attention is focused on polymorphisms in the gene encoding transforming growth factor-β1 (TGF-β1), a multifunctional cytokine that is in turn a potent growth inhibitor involved in wound healing and differentiation. In humans, it promotes the pathogenesis of organ fibrosis, atherosclerosis, cancer, autoimmune and inflammatory diseases, keloid disease, and hypertrophic scarring. Forth is reason, much emphasis has been placed on studies elucidating the impact of TGF-131 and its gene variationsf or the susceptibility and pathogenesis of these diseases. Unfortunately, some studies have serious limitations. METHODS: We have recently described a high-throughput method for investigation the Arg25Pro polymorphism of human TGF-β1 gene and showed that the frequency of the Pro25 allele is significantly associated with hepatic fibrogenesis. In this report, we describe two novel Light Cycler (LC) techniques that facilitate the examination of the two other known alterations in the coding region of TGF-β1. We investigated whether these polymorphisms contribute to hepatitis-induced progression of fibrogenesis in Chinese and Caucasians. RESULTS: In the Chinese ancestry, the gene polymorphisms at codons 25 and 263 were not found and the genetic variant at codon 10 is unlikely to confer susceptibility to hepatic fibrosis. Contrarily, in Caucasians TGF-β1 allelic variations are more frequent and the presence of prolines     

Diagnostic value of platelet derived growth factor-BB, transforming growth factor-β1,matrix metalloproteinase-1, and tissue inhibitor of matrix metaUoproteinase-1 in serum and peripheral blood mononuclear cells for hepatic fibrosis

AIM: Noninvasive diagnosis of hepatic fibrosis has become the focus because of the limited biopsy, especially in the surveillance of treatment and in screening hepatic fibrosis. Recently, regulatory elements involved in liver fibrosis, such as platelet derived growth factor-BB (PDGF-BB), transforming growth factor-β1(TGF-β1), matrix metalloproteinase-1 (MMP-1), and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1), have been studied extensively. To determine whether these factors or enzymes could be used as the indices for the diagnosis of hepatic fibrosis, we investigated them by means of receiver operating characteristic (ROC) curve. METHODS: Serum samples from sixty patients with chronic viral hepatitis B and twenty healthy blood donors were assayed to determine the level of PDGF-BB, TGF-β1, MMP-1, and TIMP-1 with ELISA, and HA, PCIII, C-IV, and LNlevel with RIA. The message RNA (mRNA) expression of TIMP-1 and MMP-1 in peripheral blood mononuclear cells (PBMCs) was detected by RT-PCR and Northern blot hybridization. Liver biopsy was performed in all patients. The biopsy samples were histopatholocjically examined. The trial was double-blind controlled. RESULTS: The serum level of PDGF-BB, TIMP-1, the ratio of TIMP-1 and MMP-1 (TIMP-1/MMP-1), mRNA expression of TIMP-1 (TIMP-lmRNA), and the ratio of TIMP-lmRNA and MMP-lmRNA (TIMP-lmRNA/MMP-lmRNA) in patients was significantly higher than those in the healthy blood donors (t=2.514-11.435, P=0.000-0.016). The serum level of PDGF-BB, TIMP-1, TIMP-1/MMP-1, and TIMP-lmRNA was positively correlated with fibrosis stage and inflammation grade (r=0.239-0.565, P=0.000-0.033), while the serum level of MMP-1 was negatively correlated with fibrosis stage and inflammation grade, and TIMP-lmRNA/MMP-lmRNA was positively correlated with inflammation grade. Through the analysis by ROC curve, serum PDGF-BB was the most valuable marker, and its sensitivity was the highest among the nine indices. The markers with the highest specificity were TIMP-lmRNA and TIMP-lmRNA/MMP-lmRNA in PBMCs. The area under the curve (AUC) of PDGF-BB, TIMP-lmRNA, TIMP-lmRNA/MMP-lmRNA, TIMP-1/MMP-1, HA, PCIII, TIMP-1, C-IV, and LN was 0.985, 0.876, 0.792, 0.748, 0.728, 0.727, 0.726, 0.583, and 0.463, respectively. The sensitivity and the specificity in the parallel test was 99.0% and 95.0 % when serum PDGF-BB, TIMP-lmRNA and TIMP-lmRNA/MMP-lmRNA was detected simultaneously. CONCLUSION: Serum level of PDGF-BB, TIIVIP-lmRNA, TIMP-lmRNA/MMP-lmRNA in PBMCs, and serum level of TIMP-1 and TIMP-1/MMP-1 can be used as the indices for the diagnosis of hepatic fibrosis, but the former three are more useful. The combination of serum PDGF-BB, TIMP-lmRNA and TIMP-lmRNA/MMP-lmRNA in PBMCs is even more efficient in screening liver fibrosis.     

Effects of pentoxifylline on the hepatic content of TGF-β1 and collagen in Schistosomiasis japonica mice with liver fibrosis

To study the effects of pentoxif-ylline (PTX) on the content of hepatic TGF-β, type Ⅰand type Ⅲ collagen in schistosomiasis japonica mice with liver fibrosis and its mechanism of anti-fibrosis.     

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) onpreventing 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 intramuscular injection of IFN-α in saline daily at the doses of 1×105 U for 6 wk, group D (IFN-α treatment, n = 24) treated with intra-muscular injection of IFN-α in saline daily atthe doses of 1×105 U for 6 wk after the first 6 wk, group E (0.9% sodium chloride treatment control, n = 24) treated with intra-muscular injection of 0.01 mL/kg daily for 6 wk after the first 6 wk. At the end of the experiment, all rats of each group were killed. Samples of the liver obtained by biopsy were subjected to histological, immunohistochemicaland electron microscopic studies for the expressions of transforming growth factor-β1 (TGF- β1) and α-smoothmuscle 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＜0.01). The degree of fibrosis score in group B was also significantly less than that of group C under light microscope (P＜0.01).CONCLUSION: IFN-α can inhibit the production of TGF-β1,decrease HSC activation and stimulate its apoptosis.     

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。     

转化生长因子β信号传导阻断对鼠肝星状细胞培养激活的影响

目的 研究转化生长因子β(TGF-β)信号传导通路的阻断,对鼠肝星状细胞(HSC)培养激活的影响。 方法 利用腺病毒AdT β-ExR的表达产物阻断HSCs中TGF-β信号传导。用酶联免疫吸附试验,Western blot及免疫组织化学等方法检测HSCs中Ⅰ型胶原蛋白、α-平滑肌肌动蛋白(α-SMA)的表达及细胞增殖。 结果 感染AdT β—ExR与感染AdLacZ的HSCs相比,Ⅰ型胶原蛋白的表达量为对照组的42.99％(q=9.100,,P<0.001),α-SMA的表达明显被抑制,而细胞增殖指标5-溴脱氧尿苷的参入量,后者为前者的49.24％(q=7.835,.P<0.001)。 结论 阻断TGF-β信号传导能显著地抑制HSCs的培养激活,但促进HSCs的分裂。通过腺病毒AdT β-ExR的表达产物阻断TGF-β信号传导作为抑制肝纤维化的方法,还需深入一步的研究。     

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.     

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.