Antifibrotic effects of interleukin-10 on experimental hepatic fibrosis

BACKGROUND/AIMS: To study the effects of interleukin-10 on hepatic stellate cells and liver tissue in experimental rats hepatic fibrosis. METHODOLOGY: Rat hepatic fibrosis model induced by carbon tetrachloride was established. Liver tissues were harvested from the rats administered CCl4 with or without IL-10 treatment and the animals of the control group. The expression of TGF-beta1, MMP-2 and TIMP-1 in the liver tissues was measured by S-P immunohistochemistry. In addition, another model was established; HSCs in rats in each group were isolated. RT-PCR was employed to analyze TGF-beta1, MMP-2 and TIMP-1 mRNA expression in cells and immunocytochemistry was performed to detect protein expression of alpha-SMA, NF-kappaB, TGF-beta1, MMP-2 and TIMP-1 in HSCs. RESULTS: Rat hepatic fibrosis was developed successfully. The fibrosis changes were partially reversed by simultaneous administration of IL-10. The positive signals of TGF-beta1, MMP-2 and TIMP-1 were observed more frequently (P<0.05) in the CCl4-treated group compared to those in the IL-10-treated group and the control group. HSCs were successfully isolated. TGF-beta1, MMP-2 and TIMP-1 mRNA in HSCs increased obviously during the course of hepatic fibrosis, and their levels were decreased after the treatment with IL-10 (P<0.05). The immunocytochemistry positive levels for TGF-beta1, MMP-2, TIMP-1, alpha-SMA and NF-kappaB in the fibrogenesis group were increased significantly compared to the normal group (P<0.01). The positive signals decreased significantly (P<0.05) after the treatment with IL-10. CONCLUSIONS: The expression of TGF-beta1, MMP-2 and TIMP-1 increased in liver or in HSC of hepatic fibrosis rats and decreased after treatment with IL-10. The IL-10 could inhibit the activation of HSCs and make an antifibrogenic process come into effect in this way.     

An herbal formula, CGX, exerts hepatotherapeutic effects on dimethylnitrosamine-induced chronic liver injury model in rats

INTRODUCTION Several pathologic conditions, including chronic alcohol consumption, viral B or C hepatitis, and constant cholestasis, induce chronic injury to liver tissue. Moreover, these chronic liver disorders lead progressively to fibrosis or liver cir…     

Antifibrotic effects of a tissue inhibitor of metalloproteinase-1 antibody on established liver fibrosis in rats

Liver fibrosis is characterized by increased synthesis, and decreased degradation, of extracellular matrix (ECM) within the injured tissue. Decreased ECM degradation results, in part, from increased expression of tissue inhibitor of metalloproteinase-1 (TIMP-1), which blocks matrix metalloproteinase (MMP) activity. TIMP-1 is also involved in promoting survival of activated hepatic stellate cells (HSCs), a major source of ECM. This study examined the effects of blocking TIMP-1 activity in a clinically relevant model of established liver fibrosis. Rats were treated with carbon tetrachloride (CCl(4)), or olive oil control, for 6 weeks; 24 days into the treatment, the rats were administered a neutralizing anti-TIMP-1 antibody derived from a fully human combinatorial antibody library (HuCAL), PBS, or an isotype control antibody. Livers from CCl(4)-treated rats exhibited substantial damage, including bridging fibrosis, inflammation, and extensive expression of smooth muscle alpha-actin (alpha-SMA). Compared to controls, rats administered anti-TIMP-1 showed a reduction in collagen accumulation by histological examination and hydroxyproline content. Administration of anti-TIMP-1 resulted in a marked decrease in alpha-SMA staining. Zymography analysis showed antibody treatment decreased the activity of MMP-2. In conclusion, administration of a TIMP-1 antibody attenuated CCl(4)-induced liver fibrosis and decreased HSC activation and MMP-2 activity.     

肝纤维化过程中胶原、基质金属蛋白酶及其抑制因子表达的动态变化及相互关系

目的研究在整个肝纤维化形成过程中肝组织Ⅰ、Ⅲ型胶原,间质性胶原酶(MMP 1 3)及其抑制因子(TIMP-1)表达水平的动态变化规律及相互间的关系.方法将大鼠随机分成正常对照组与模型组.模型组以二甲基亚硝胺腹腔内注射,第1周注射3次,随后每周2次,共注射6周,停用后再观察2周;正常对照组以等渗盐水代替腹腔内注射.分别于第1、4、10、17、28、42、56天分批处死大鼠.留取的肝脏组织做HE与Masson染色,按0～4期标准判定肝纤维化程度,测定羟脯氨酸含量,应用半定量RTPCR检测Ⅰ、Ⅲ型胶原、MMp-13和TIMP-1 mRNA.结果在肝纤维化形成过程中,胶原持续增高,其中Ⅰ型胶原mRNA在肝组织受损后10 d开始较正常对照明显增高(正常组0.468±0.015,模型组0.603±0.031,t=2.8 5,P＜0.05),并保持不断增高的表达水平直至实验结束;Ⅲ型胶原mRNA从28d左右开始显著增高(正常组0.774±0.043,模型组0.922±0.079,t=4.16,P＜0.01),直至实验结束;TIMP-1 mRNA从第4天即开始明显增高(正常组0.618±0.030,模型组0.728±0.013,t=2.60,P＜0.05),并保持不断增高的趋势直至实验结束;MMP-13 mRNA从10 d后到28 d有显著增高(17d左右达到高峰,正常组0.987±0.048,模型组1.141±0.033,t=4.08,P＜0.01),此后便逐渐下降至实验结束.结论在肝纤维化形成过程中MMP-13的表达虽有增高,但由于TIMP-1的表达在肝受损后早期即开始持续不断增高,从而MMP-13降解胶原的能力受到抑制,致使过度产生与沉积的胶原得不到有效降解,促进了肝纤维化的发展.     

MMP/TIMP expression in spontaneously hypertensive heart failure rats: the effect of ACE- and MMP-inhibition

OBJECTIVE: Determine the effect of a matrix metalloproteinase inhibitor (MMPi) and angiotensin converting enzyme inhibitor (ACEi) on collagen, MMP, tissue inhibitors of MMPs (TIMPs) expression in the spontaneously hypertensive heart failure (SHHF) rat. METHODS: Six groups were tested: normotensive 9- and 13-month-old Wistar-Furth (WF) rats, 9-month-old SHHFs (compensatory hypertrophy), 13-month-old SHHFs with HF, and 13-month-old SHHFs orally administered with either an MMPi (PD166793, 5 mgkg(-1)day(-1)) or ACEi (quinapril, 10 mgkg(-1)day(-1)) for 4 months. Collagen volume fraction was assessed histomorphometrically. Left ventricular (LV) mRNA [MMP-1,-2,-3,-7,-9,-11,-13,-14; TIMP-1,-2,-3,-4; and collagen alpha1(I) and alpha1(III)] and protein (MMP-2 and MMP-9 zymographic activity; Western blot analysis of MMP-13, and TIMP-1,-2,-4) levels could be quantified. RESULTS: Collagen mRNA levels were elevated in SHHFs compared to age-matched controls, but collagen volume fraction was elevated only in 13-month-old SHHFs (approximately 2x). Only MMP-2 mRNA levels increased significantly with HF. However, MMP-2 and MMP-9 zymographic activity, and MMP-13 protein levels increased. TIMP-1 and TIMP-2 mRNA and protein levels increased, and TIMP-4 protein levels decreased in SHHFs vs. controls. Both drug treatments reduced LV dilation; preserved systolic function; and normalized MMP/TIMP expression. Both drug treatments also reduced collagen volume fraction, but only quinapril reduced collagen mRNA levels and LV hypertrophy. CONCLUSIONS: The divergent effect of MMPi and ACEi on collagen mRNA levels and hypertrophy indicate that drug efficacy is mediated by different pathways in the SHHF rat.     

慢性乙型肝炎肝组织中MMP-2、TIMP-1与肝纤维化关系的研究

为了研究慢性乙型肝炎患者肝纤维化与肝组织中基质金属蛋白酶-2(MMP-2)及其天然抑制物金属蛋白酶组织抑制剂-1(TIMP-1)的关系,对60例慢性乙型肝炎患者进行肝组织病理活检,其中S_110例,S_224例,S_312例,S_414例。采用苦叶酸天狼猩红染色检测胶原面积百分比,单克隆抗体(McAb)免疫组织化学染色检测MMP-2、TIMP-1阳性细胞的方法进行病理分析。结果显示：慢性乙型肝炎肝组织中胶原面积百分比与肝组织纤维化分期正相关(r=0．885,P=0．000);慢性乙型肝炎肝组织中MMP-2与肝纤维化的分期无关(r=0．034,P= 0．896);慢性乙型肝炎肝组织中TIMP-1和肝纤维化的分期正相关(r=0．760,P=0．000);慢性乙型肝炎肝组织中MMP-2/TIMP-1和肝纤维化分期负相关(r=-0．674,P=0．000)。总之,TIMP-1参与了慢性乙型肝炎肝纤维化纤维化的过程,而MMP-2/TIMP-1是诊断肝纤维化的比较合适的指标。     

Matrix metalloproteinases and their inhibitors in acute viral hepatitis

Matrix metalloproteases (MMPs) and their inhibitors are effector molecules involved in extracellular matrix remodelling. The serum profile for these proteolytic enzymes and their inhibitors during acute self-limiting viral hepatitis has not been studied. We therefore determined serum concentrations of MMP-1, MMP-3, MMP-2, MMP-9 and their inhibitors (tissue inhibitors of metalloproteinase) TIMP-1, TIMP-2 and alpha2 macroglobulin (AMG) in the serum of patients during the icteric stage of self-limiting acute viral hepatitis. Transforming growth factor-beta (TGF-beta) and interleukin (IL)-10, two cytokines involved in the regulation of MMPs and TIMPs were also assessed. Nineteen patients (12 men, seven women) with a mean age of 29.9 years (range 16-65 years) participated in the study. Fifteen had hepatitis B virus (HBV, two HCV and two HAV infection. The values of patients were compared with those obtained from 15 blood donor controls (eight men, seven women), mean age 36.2 years (range 18-55 years). Serum levels of TGF-beta, IL-10, MMP-1, MMP-3, MMP-2, MMP-9, TIMP-1 and TIMP-2 were assessed by ELISA. MMP-2 and MMP-9 were also measured by a zymogram protease assay. alpha2 macroglobulin (AMG) was measured by nephelometry. Compared with the healthy controls the mean serum concentrations of all MMPs were significantly decreased in the acute hepatitis patients. There was no difference in the serum concentration of TIMP-1 between patients and the controls. Serum levels of TIMP-2 (P < 0001), TGF-beta (P < 0.05), IL-10 (P < 0.001) and AMG (P < 0001) were increased in patients compared to healthy controls. A statistically significant negative correlation by linear regression analysis was found between AMG and MMP-1 (P=0003). The decreased levels of MMPs observed, together with normal and increased levels of TIMP-1 and TIMP-2, may indicate an attempt to limit matrix degradation at this stage of disease resolution. The increased levels of the anti-inflammatory cytokines IL-10 and TGF-beta might be the underlying mechanism responsible for the above effect. AMG inhibition especially for MMP-1 may play an additional important role.     

Disruption of tissue-type plasminogen activator gene in mice aggravated liver fibrosis

Background and Aim:  Tissue-type plasminogen activator (tPA) is one of the major components in the matrix proteolytic network whose role in the pathogenesis of liver fibrosis remains unknown. The aim of this study is to investigate the role of tPA in carbon tetrachloride (CCl₄)-induced liver fibrosis.
Methods:  Wild-type and tPA knockout mice (8 mice per group) were injected interperitoneumly with 25% CCl₄ 2 ml/kg twice per week as CCl₄ administration groups and olive oil 2 ml/kg as controls. After 4 weeks, the livers of mice were removed under deep anesthesia and prepared for further studies such as histology, immunostaining, hydroxyproline assay, zymography and western blot analysis.
Results:  Mice lacking tPA developed more severe morphological injury and displayed an increased deposition of collagen in the liver after CCl₄ administration compared with wild-type counterparts. Deficiency of tPA increased α-smooth muscle actin expression in the mice livers. On the other hand, the decrease of matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-9 (MMP-9) activities, metalloproteinase-13 (MMP-13) expression and a marked increase of tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) expression were found in the liver of CCl₄ administrated tPA^−/− mice compared with wild-type counterparts.
Conclusions:  Deficiency of tPA aggravated liver fibrosis through promoting hepatic stellate cells (HSCs) activation and inhibiting ECM degradation by decreasing MMP-2, MMP-9 activities and disrupting the balance between MMP-13 and TIMP-1.     

白藜芦醇对动脉粥样硬化兔心肌纤维化和基质金属蛋白酶2、组织型基质金属蛋白酶抑制剂2表达的影响

目的 观察白藜芦醇对动脉粥样硬化兔心肌间质胶原纤维变化和基质金属蛋白酶2及组织型基质金属蛋白酶抑制剂2表达水平的影响.方法 33只新西兰白兔随机分为对照组、模型组和白藜芦醇干预组.观察心肌间质胶原纤维的变化,测量心肌间质胶原容积分数.逆转录聚合酶链反应检测心肌组织基质金属蛋白酶2及组织型基质金属蛋白酶抑制剂2 mRNA水平.结果 与对照组相比,模型组胶原纤维明显增多、增粗、排列紊乱,呈不规则网状或粗块状沉积于心肌间质,胶原容积分数和基质金属蛋白酶2表达增多,组织型基质金属蛋白酶抑制剂2表达减少(P<0.01).白藜芦醇干预能显著减少上述指标的改变.结论 动脉粥样硬化进程中,存在着心肌纤维化、基质金属蛋白酶2表达增多和组织型基质金属蛋白酶抑制剂2表达减少等现象,白藜芦醇能减轻基质金属蛋白酶2/组织型基质金属蛋白酶抑制剂2表达的失衡,改善心肌纤维化.     

Relaxin inhibits effective collagen deposition by cultured hepatic stellate cells and decreases rat liver fibrosis in vivo

BACKGROUND: Following liver injury, hepatic stellate cells (HSC) transform into myofibroblast-like cells (activation) and are the major source of type I collagen and the potent collagenase inhibitors tissue inhibitors of metalloproteinases 1 and 2 (TIMP-1 and TIMP-2) in the fibrotic liver. The reproductive hormone relaxin has been reported to reduce collagen and TIMP-1 expression by dermal and lung fibroblasts and thus has potential antifibrotic activity in liver fibrosis. AIMS: To determine the effects of relaxin on activated HSC. METHODS: Following isolation, HSC were activated by culture on plastic and exposed to relaxin (1-100 ng/ml). Collagen deposition was determined by Sirius red dye binding and radiolabelled proline incorporation. Matrix metalloproteinase (MMP) and TIMP expression were assessed by zymography and northern analysis. Transforming growth factor beta1 (TGF-beta1) mRNA and protein levels were quantified by northern analysis and ELISA, respectively. RESULTS: Exposure of activated HSC to relaxin resulted in a concentration dependent decrease in both collagen synthesis and deposition. There was a parallel decrease in TIMP-1 and TIMP-2 secretion into the HSC conditioned media but no change in gelatinase expression was observed. Northern analysis demonstrated that primary HSC, continuously exposed to relaxin, had decreased TIMP-1 mRNA expression but unaltered type I collagen, collagenase (MMP-13), alpha smooth muscle actin, and TGF-beta1 mRNA expression. CONCLUSION: These data demonstrate that relaxin modulates effective collagen deposition by HSC, at least in part, due to changes in the pattern of matrix degradation.     

Effect of lamivudine treatment on plasma levels of transforming growth factor β1, tissue inhibitor of metalloproteinases-1 and metalloproteinase-1 in patients with chronic hepatitis B

AIM: Transforming growth factor (TGF)-β1, metalloproteinase (MMP)-1 and its tissue inhibitor (TIMP)-I are considered predictive biomarkers of chronic hepatitis activity and fibrosis.The aim of this study was to evaluate the effect of lamivudine treatment on the plasma levels of these peptides in patients with chronic hepatitis B.METHODS: TGF-β1, MMP-1 and TIMP-1 plasma concentrations were measured with an enzyme immunoassay in 40 patients treated with lamivudine for 48 wk. Elimination of HBV-DNA and HBV antigens was evaluated 24 wk after treatment completion.RESULTS: Baseline TGF-β1(29.6&#177;2.2 ng/mL) and TIMP-1(1 578&#177;93 ng/mL) significantly exceeded normal values(18.3&#177;1.6 ng/mL and 1 102&#177;67 ng/mL respectively). Lamivudine treatment resulted in a significant decrease of TGF-β1 and TIMP-1 during treatment with an increase after 24 wk of treatment. Pretreatment MMP-1 levels (6.7&#177;0.7 ng/mL) were significantly lower than normal values (11.9&#177;0.9 ng/mL) and increased during treatment and follow-up. A significant correlation was noted between TGF-β1 or TIMP-1 and aminotransferases as well as fibrosis scored in liver biopsy specimens. There were no statistically significant differences of TGF-β1, TIMP-1 and MMP-1 between four groups at baseline, 24 and 48 wk of treatment. TGF-β1 and TIMP-1 levels increased significantly in non-responders and normalized in responders at wk 72. MMP-1 also normalized in responders and decreased to values significantly lower than normal in non-responders.CONCLUSION: These findings support the role of TGF-β1,TIMP-1 and MMP-1 in the pathogenesis of chronic hepatitis B.Because of their association with hepatic injury and antiviral treatment efficacy, determination of these peptides may be useful in disease management.     

Effects of fibril- or fixed-collagen on matrix metalloproteinase-1 and tissue inhibitor of matrix metalloproteinase-1 production in the human hepatocyte cell line HLE

AIM: Matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) are central to the spontaneous resolution of liver fibrosis. The mechanisms involved have been investigated in hepatic stellate cells (HSC), but not in hepatocytes. We investigated the effects of fibril- and fixed-collagen on MMP-1 and TIMP-1 production in hepatocytes, using the HLE cell line. METHODS: Fibril type I and IV collagen were prepared by HCI digestion of type I and IV collagen, respectively. For fixed-collagen, culture dishes were coated with fibril type I or IV collagen and fixed by ultraviolet. Type I collagenase activity was measured using fluorescein isothiocyanate-labeled type I collagen. MMP-1 and TIMP-1 in HLE cells were measured by a one-step sandwich enzyme immunoassay. RESULTS: Both fibril type I and IV collagen significantly increased type I collagenase activity about two-fold compared with no fibril collagen. The effects of the fibril collagen were not affected by the coating condition. There was no significant difference in the effects on collagenase activity between cells cultured in medium containing fibril type I collagen and those cultured in the presence of type IV collagen. Both types of fibril collagen significantly increased MMP-1 production, and showed more than 10-fold higher levels of MMP-1 than the control. The enhanced MMP-1 production by fibril collagens was unaffected by the coating condition. By contrast, TIMP-1 production was not changed by the addition of fibril type I or IV collagen, and neither was it affected by the coating conditions. Coating with type I collagen significantly suppressed MMP-1 production by almost one-tenth compared with no coating. By contrast, TIMP-1 production was not affected by either the absence of a collagen coat or by increasing the concentration of the coating collagen. CONCLUSION: These results indicated that, in HLE cells, fibril- and fixed-collagen have opposite effects on MMP-1 production without affecting TIMP production. Fibril collagen induced collagenase activity by up-regulation of MMP-1 production without affecting TIMP-1 production. By contrast, fixed collagen reduced MMP-1 production. Our results suggest that hepatocytes might also play an important role in the regulation of the hepatic fibrosis alongside HSC.     

Adeno-associated virus mediated interferon-gamma inhibits the progression of hepatic fibrosis in vitro and in vivo

AIM: To investigate the effects of adeno-associated virus (AAV) mediated expression of human interferon-γ for gene therapy in experimental hepatic fibrosis in vitro and in vivo. METHODS: We constructed the recombinant AAV encoding human INF-γ (rAAV- INF-γ) and took the primary rat hepatic stellate cells and carbon tetrachloride induced rats as the experimental hepatic fibrosis model in vitro and in vivo. Immunocytochemistry analysis was used to reveal the expression of α-SMA, the marker protein expressed in hepatic stellate cells. The mRNA expression of TGF-β, TIMP-1, and MMP-13 were analyzed by RT-PCR method. In vivo study, the hydroxyproline content in liver and serum AST, ALT were also detected. RESULTS: In vitro study, AAV vector could mediated efficient expression of human INF-γ, which inhibit the activation of hepatic stellate cells, decrease the expression of α-SMA and mRNA of TIMP-1, TGF-β, with the MMP-13 unchanged. In vivo study, the histological examination revealed that rAAV- INF-γ could inhibit the progression of the hepatic fibrosis. In the rAAV-INF-γ induced group, the hydroxyproline content and serum AST, ALT level were decreased to 177±28 μg/g wet liver, 668.5±140.0, 458.4±123.5 U/L, compare with the fibrosis control group 236±31 μg/g wet liver, 1 019.1±276.3, 770.5±154.3 U/L, respectively (P<0.01). mRNA expression of TIMP-1 in the rAAV-INF-γ induced rat liver was decreased while no significant change was observed in TGF-β and MMP-13. CONCLUSION: All these results indicated that rAAV-INF-γ has potential effects for gene therapy of hepatic fibrosis, which could inhibit the progression of hepatic fibrosis.