Effect of IL-10 on the expression of HSC growth factors in hepatic fibrosis rat

AIM: To study the effect of IL-10 on the expression of growth factors - transforming growth factor-β1(TGF-β1), epidermal growth factor (EGF), hepatocyte growth factor (HGF)and platelet-derived growth factor (PDGF) of hepatic stellate cells (HSCs) of hepatic fibrosis rat and the anti-fibrogenic role of exogenous IL-10. METHODS: Hepatic fibrosis was induced by CCl4 administration intra-peritoneally. Sixty clean male Sprague-Dawley (SD) rats were randomly divided into three groups: normal control group (GN, 8 rats), hepatic fibrosis model group (GC, 28 rats) and IL-10 treated group (GI, 24 rats). At the beginning of the 7th and 11th wk, rats in each group were routinely perfused with pronase E and type IV collag-enase through a portal vein catheter and the suspension obtained from the liver was spun by centrifugation with 11% Nycodenz density gradient to isolate HSCs. Histological examination was used to determine the degree of hepatic fibrosis. RT-PCR was employed to analyze mRNA expression from freshly isolated cells. Immunocytochemistry was performed to detect protein expression in primary cultured HSCs. RESULTS: Rat hepatic fibrosis was developed with the increase of injection frequency of CCl4, and HSCs were successfully isolated. At the 7th and 11th wk, TGF-β1, EGF, and HGF mRNA in GC increased obviously compared with GN (P= 0.001/0.042, 0.001/0.001, 0.001/0.001) and GI (P=0.001/0.007, 0.002/0.001, 0.001/0.001). For TGF-β1, no difference was observed between GI and GN. For EGF, mRNA level in GI increased compared with GN during the 7th wk (P=0.005) and 11th wk (P=0.049). For HGF, mRNA level in GI decreased compared with GN at the 7th wk (P=0.001) and 11th wk (P=0.021). Between these two time points, TGF-β1 expression at the 7th wk was higher than that of the 11th wk (P=0.049), but for EGF, the former was lower than the latter (P=0.022). As for PDGF mRNA, there was no significant difference between these groups, but difference seemed to exist in protein levels. Results by immunocytochemistry of TGF-β1 and EGF were paralleled with the above findings. CONCLUSION: The expression of TGF-β1, EGF and HGF increased in HSC of hepatic fibrosis rat and decreased after treatment with IL-10. IL-10 plays an anti-fibrogenic role by suppressing growth factors expression.     

Expression of matrix metalloproteinase-2 and tissue inhibitor of metalloproteinase-1 in hepatic stellate cells during rat hepatic fibrosis and its intervention by IL-10

AIM: To investigate the expression of matrix metallopr-oteinase-2 and tissue inhibitor of metalloproteinase-1 in hepatic fibrosis and the antifibrogenic role of exogenous interleukin-10 (IL-10). METHODS: Hepatic fibrosis was induced by CCI4 administration and 60 male Sprague-Dawley rats were randomly divided into normal control group (group N, 8 rats), CCI4-induced group (group C, 28 rats) and IL-10-treated group (group I, 24 rats). At the beginning of the 7th and 11th wk, rats in each group were routinely perfused with pronase E and type IV collagenase through portal vein catheter and the suspension was centrifuged by 11% Nycodenz density gradient to isolate hepatic stellate cells (HSCs). RT-PCR was used to analyze mRNA of MMP-2 and TIMP-1 from freshly isolated cells. Densitometric data were standardized with β-actin signals. Immunocytochemistry was performed to detect MMP-2 and TIMP-1 expression in HSC cultured for 72 h. RESULTS: Compared to group N in the 7th wk, MMP-2 and TIMP-1 mRNA increased in group C (P= 0.001/0.001) and group I (P= 0.001/0.009). The level of MMP-2 and TIMP-1 mRNA in group I was significantly lower than that in group C (P= 0.001/0.001). In the 11th wk, MMP-2 mRNA in group I was still lower than that in group C (P = 0.005), but both dropped compared with that in the 7th week (P = 0.001/0.004). TIMP-1 mRNA in group I was still lower than that in group C (P= 0.001), and increased in group C (P= 0.001) while decreased in group I (P = 0.042) compared with that in the 7th wk. Same results were found by immunocytochemistry. CONCLUSION: Expression of MMP-2 and TIMP-1 is increased in hepatic fibrosis. IL-10 exhibits an antifibrogenic effect by suppressing MMP-2 and TIMP-1 expression.     

Alterations of mast cells and TGF-β1 on the silymarin treatment for CCl_4-induced hepatic fibrosis

AIM: Silymarin is a potent antioxidant, antiinflammatory and anti-fibrogenic agent in the liver, which is mediated by alteration of hepatic Kupffer cell function, lipid peroxidation, and collagen production. Especially, in hepatic fibrogenesis, mast cells are expressed in chronic inflammatory conditions, and promote fibroblast growth and stimulate production of the extracellular matrix by hepatic stellate cells. METHODS: We examined the inhibitory mechanism of silymarin on CCI4-induced hepatic cirrhosis in rats. At 4, 8, and 12 wk, liver tissues were examined histopathologically for fibrotic changes produced by silymarin treatment. RESULTS: In the silymarin with CCU-treated group, increase of hepatic stellate cells and TGF-β1 production were lower than in the CCI4-treated group at early stages. Additionally, at the late fibrogenic stage, expressions of TGF-β1 were weaker and especially not expressed in hepatocytes located in peripheral areas. Moreover, the number of mast cell in portal areas gradually increased and was dependent on the fibrogenic stage, but those of CCI4+silymarin-treated group decreased significantly. CONCLUSION: Anti-fibrotic and antiinflammatory effects of silymarin were associated with activation of hepatic stellate cells through the expression of TGF-β1 and stabilization of mast cells. These results suggest that silymarin prevent hepatic fibrosis through suppression of inflammation and hypoxia in the hepatic fibrogenesis.     

Therapeutic effect of interleukin-10 on CCI_4-induced hepatic fibrosis in rats

AIM: To study the therapeutic effect of exogenous inter-leukin-10 on CCI4-induced hepatic fibrosis in rats and its possible mechanisms. METHODS: Fourty-seven SD rats were randomly divided into control group (group N) and CCI4-induced hepatic fibrosis model group (group C). After CCI4 was given for 9 wk, the model group was divided into three groups. Rats in group M were put to death immediately, rats in group T were treated with IL-10 for another three wk and then put to death, rats in group R recovered after three weeks and were then killed. The degree of hepatic fibrosis was measured by HE staining and histological activity index (HAI). Histological activity index (HAI), change of collagen typesⅠandⅢwere measured by Picrosirius staining. The expression of TNF-α, MMP-2 and TIMP-1 in liver tissue was measured by S-P immunohis-tochemistry. RESULTS: CCI4- induced experimental rat hepatic fibrosis model was established successfully. The degree of hepatic fibrosis was markedly lower in group T than in groups M and R, and there was no difference between the two groups. The expression of collagen typesⅠandⅢwas significantly suppressed in group T and was slightly suppressed in groups M and R. The positive levels of TNF-α, MMP-2 and TIMP-1 in group M increased significantly compared to those in group N (P<0.01). The positive signals decreased significantly in groups T and R (P<0.01), but positive score was significantly lower in group T than in group R (P< 0.01). CONCLUSION: Exogenous IL-10 can reverse CCI4-in-duced hepatic fibrosis in rats. IL-10 may exert its reversible effects on hepatic fibrosis by blocking CCI4-induced inflammation, inhibiting expression of MMP-2 and TIMP-1 and promoting resolution of collagen typesⅠandⅢ.     

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.     

Effects of dietary supplementation with vitamin E and selenium on rat hepatic stellate cell apoptosis

AIM: To evaluate the effects of dietary supplementation with vitamin E and selenium on proliferation and apoptosis of hepatic stellate cells (HSCs), in acute liver injury induced by CCl4, and to explore their role in the recovery from hepatic fibrosis phase. METHODS: An acute liver damage model of rats was established by intraperitoneal injection of carbon tetrachloride (0.3 mL/100 g body weight) twice a week, then the rats were killed at 6, 24, 48, and 72 h after the first and third injection, respectively. A liver fibrosis model was established by the same injection for 8 wk. Then three rats were killed at 3, 7,14, and 28 d after the last injection, respectively. The rats from the intervention group were fed with chow supplemented with vitamin E (250 mg/kg) and selenium (0.2 mg/kg), and the rats in the normal control group and pathological group were given standard chow. Livers were harvested and stained with hematoxylin and eosin, Sirius red. Activated HSCs were determined by α-smooth muscle actin immunohistochemistry staining. Apoptotic HSCs were determined by dual staining with the terminal deoxynucleotidyl transferase UTP nick end labeling (TUNEL) and α-smooth muscle actin immunohistochemistry. Serum alanine aminotransferase and aspartate aminotransferase were also analyzed. RESULTS: In the acute liver damage model, the degree of liver injury was more serious in the pathological group than in the intervention group. At each time point, the number of activated HSCs was less in the intervention group than in the pathological group, while the number of apoptotic HSCs was more in the intervention group than in the pathological group. In the liver fibrosis model, the degree of liver fibrosis was more serious in the pathological group than in the intervention group. At each time point, the number of activated HSCs was less in the intervention group than in the pathological group, and the number of apoptotic HSCs was more in the intervention group than in the pathological group. CONCLUSION: Vitamin E and selenium supplementation at the given level can inhibit CCl4-induced activation and proliferation of HSCs and promote the apoptosis of activated HSCs in acute damage phase. Vitamin E and selenium can also effectively decrease the degree of hepatic fibrosis and promote the recovery process.     

Effects of AT1 receptor antagonist, Iosartan, on rat hepatic fibrosis induced by CCl4

AIM To investigate effect of Iosartan, an AT1 receptor antagonist, on hepatic fibrosis induced by CCI4; and to determine whether or not AT1 receptors are expressed on hepatic stellate cells. M~THODS AND RESULTS Fifty male SpragueDawley rats, weighing (180 ± 20) g, were randomized into five groups (control group, model group, and three Iosartan treated groups ), in which all rats were given the subcutaneous injection of 40% CCl4 (every 3 days for 6 weeks) except for rats of control group. Rats of Iosartantreated groups were treated with Iosartan (20 mg/ kg, 10 mg/kg, 5 mg/kg, daily gavage). After 6 weeks liver tissue and serum samples of all rats were examined. Serum hyaluronic acid (HA), procollagen type Ⅲ (PC Ⅲ ) were detected by radioimmunoassays. van Giesion collagen staining was used to evaluate the extracellular matrix of rats with liver fibrosis. The expression of AT1 receptors, transforming growth factor-beta (TGFβ), and alpha-smooth muscle actin (α-SMA) in liver tissue were determined by immunohistochemical techniques. Compared with model group, serum ALT and AST of Iosartantreated groups were significantly reduced (t = 4.20, P < 0.01 and t = 4.57, P < 0.01 ). Serum HA and PC Ⅲ also had significant differences (t = 3.53, P<0.01 and t=2.20, P<0.05). The degree of fibrosis was improved by Iosartan and correlated with the expressions of AT1 receptors, TGF-β, and α-SMA in liver tissue. CONCLUSION AT1 receptor antagonist, Iosartan, could limit the progression of the hepatic fibrosis induced by CCl4. The mechanism may be related to the decrease in the expression of AT1 receptors and TGF-β, ameliorating the injury of hepatocytes; activation of local renin-angiotensin system might relate to hepatic fibrosis; and during progression of fibrosis, activated hepatic stellate cells might express AT1 receptors.     

Effect of bone marrow mesenchymal stem cells on the Smad expression of hepatic fibrosis rats

Objective:To investigate the impact of bone marrow mesenchymal stem cells on Smad expression of hepatic fibrosis rats.Methods:A total of 48 adult female SD rats were randomly divided into three groups,normal control group(n=10),observation group(n=19)with liver fibrosis model rats injected with BMSCs cells:model group(n=19),with liver fibrosis model rats injected with physiological saline.Serum index,TGF-β1 and Smad expression were detected.Results:TypeⅢprocollagen,Ⅳcollagen,hyaluronic acid,laminin levels of observation group were significantly lower than those of model group(P0.05).The content and expression of TGF-β1in serum and liver tissue of observation group were significantly lower than those of model group(P0.05).Compared with normal control group,the Smad3,Smad4 mRNA and protein expression of model group were significantly increased,the Smad7 mRNA and protein expression were significantly reduced(P0.05).Compared with model group.Smad3,Smad4 mRNA and protein expression of observation group were significantly reduced,and Smad7 mRNA expression were significantly increased(P0.05).Conclusions:BMSCs can regulate Smad expression to some extent,and reduce the degree of liver fibrosis.     

白细胞介素-17肝内表达与慢性乙型肝炎病毒感染所致肝纤维化的相关性

Objective To explore the relationship between intrahepatic expression of interleukin-17 (IL-17) and liver fibrosis in patients with chronic hepatitis B virus infection. Methods IL-17 expressions in livers with different inflammation activity grades and hepatic fibrosis stages from patients with chronic hepatitis B virus carriers (n= 30), chronic hepatitis B (CHB, n = 55), liver cirrhosis (LC, n=20) were measured by immunohistochemistry. Serum IL-17 and liver fibrosis indices of haluronic acid (HA), laminin (LN), type Ⅲ procollagen (PC Ⅲ ) and type Ⅳ collagen ( Ⅳ C) were determined by enzyme linked immunosorbent assay (ELISA). The differences between groups were compared by Kruskal-Wallis test, and the Mann-Whitney test, and the correlation analysis was done by Spearman test. Results Intrahepatic IL-17 expression in LC group was significantly higher than CHB group (x2 =25. 3982, P=0. 004), and that in CHB group was higher than chronic hepatitis B virus carriers group (x2 = 11. 5056, P= 0. 001). The inflammation activity grade and hepatic fibrosis stage were both positively correlated with IL-17 expression (r= 0.718, 0. 693, respectively; both P＜0.01). IL-17 mainly located in portal area and the expression was positively correlated with serum levels of HA, LN, PCⅢ and ⅣC (r=0. 793, 0. 834, 0. 722, 0. 883, respectively; all P＜0.01).Conclusion Intrahepatic IL-17 expression is closely correlated with liver inflammation activity grade and hepatic fibrosis stage.     

Effects of interleukin-10 on activation and apoptosis of hepatic stellate cells in fibrotic rat liver

AIM:To study the effects of interleukin-10(IL-10)on the expression of α-smooth muscle actin(α-SMA),nuclear factor-κB(NF-κB)and Fas/Fas ligand(FasL)inhepatic stellate cells of experimental rats with hepaticfibrosis.METHODS:Sixty clean SD rats were randomly dividedinto control group(group N),liver fibrotic group(groupC)and IL-10 treatment group(group I).Control groupreceived intraperitoneal injection of saline(2ml·kg~(-1)),twicea week.Fibrotic group was injected intraperitoneallywith 50% carbon tetrachloride(CCl_4)(2 ml·kg~(-1)),twicea week.IL-10 treatment group was given IL-10 at adose of 4 μg·kg~(-1)20 minutes before CCl_4 administrationfrom the third week.Hepatic stellate cells(HSCs)wereisolated from these rats at the seventh and eleventhweeks during the course of liver fibrosis,respectively.The expression of α-SMA and NF-κB in HSCs wasmeasured by S-P immunohistochemistry.The expressionof Fas and FasL mRNA was measured by RT-PCR.Furthermore,liver tissues were harvested from threegroups at the same time.RESULTS:The CCl_4- induced experimental rat hepaticfibrosis model was established successfully.The purityof extracted hepatic stellate cells was about 95% andthe yield of hepatic stellate cells was 1.2-2.3×10~6/g livertissue averagely.The positive expression of α-SMA andNF-κB was 36.5% and 28.5% respectively in group N.The positive levels of α-SMA and NF-κB were increasedsignificantly in group C compared to group N(P<0.01).The positive signals decreased significantly(P<0.05)ingroup I.In the 11~(th)week,the HSCs of group I becameround with visible pyknotic nuclei.The expression ofNF-μB in group C was significantly increased in a time-dependentmanner(P<0.01),but there was no difference in the α-SMA expression(P>0.05).The mRNA of Fasand FasL in group C was significantly increased in a time-dependent manner compared to that in control group.After treated with IL-10,the expression level of Fas andFasL was higher in group I than in group C.CONCLUSION:The positive expression of α-SMA andNF-κB in hepatic stellate cells is decreased by ectogenicIL-10 in liver fibrosis induced by CCl_4.The expression ofFas and FasL is increased in the course of liver fibrosis,and is further increased by IL-10.IL-10 could inhibitthe activation of HSCs and cause apoptosis of activatedHSCs.     

白细胞介素-17肝内表达与慢性乙型肝炎病毒感染所致肝纤维化的相关性

Objective To explore the relationship between intrahepatic expression of interleukin-17 (IL-17) and liver fibrosis in patients with chronic hepatitis B virus infection. Methods IL-17 expressions in livers with different inflammation activity grades and hepatic fibrosis stages from patients with chronic hepatitis B virus carriers (n= 30), chronic hepatitis B (CHB, n = 55), liver cirrhosis (LC, n=20) were measured by immunohistochemistry. Serum IL-17 and liver fibrosis indices of haluronic acid (HA), laminin (LN), type Ⅲ procollagen (PC Ⅲ ) and type Ⅳ collagen ( Ⅳ C) were determined by enzyme linked immunosorbent assay (ELISA). The differences between groups were compared by Kruskal-Wallis test, and the Mann-Whitney test, and the correlation analysis was done by Spearman test. Results Intrahepatic IL-17 expression in LC group was significantly higher than CHB group (x2 =25. 3982, P=0. 004), and that in CHB group was higher than chronic hepatitis B virus carriers group (x2 = 11. 5056, P= 0. 001). The inflammation activity grade and hepatic fibrosis stage were both positively correlated with IL-17 expression (r= 0.718, 0. 693, respectively; both P＜0.01). IL-17 mainly located in portal area and the expression was positively correlated with serum levels of HA, LN, PCⅢ and ⅣC (r=0. 793, 0. 834, 0. 722, 0. 883, respectively; all P＜0.01).Conclusion Intrahepatic IL-17 expression is closely correlated with liver inflammation activity grade and hepatic fibrosis stage.     

Alterations of mast cells and TGF-β1 on the silymarin treatment for CCl4-induced hepatic fibrosis

AIM: Silymarin is a potent antioxidant, antiinflammatory and anti-fibrogenic agent in the liver, which is mediated by alteration of hepatic Kupffer cell function, lipid peroxidation, and collagen production, Especially, in hepatic fibrogenesis, mast cells are expressed in chronic inflammatory conditions, and promote fibroblast growth and stimulate production of the extracellular matrix by hepatic stellate cells. METHODS: We examined the inhibitory mechanism of silymarin on CCl4-induced hepatic cirrhosis in rats. At 4, 8, and 12 wk, liver tissues were examined histopathologically for fibrotic changes produced by silymarin treatment. RESULTS: In the silymarin with CCl4-treated group, increase of hepatic stellate cells and TGF-β1 production were lower than in the CCl4-treated group at early stages. Additionally, at the late fibrogenic stage, expressions of TGF-β1 were weaker and especially not expressed in hepatocytes located in peripheral areas. Moreover, the number of mast cell in portal areas gradually increased and was dependent on the fibrogenic stage, but those of CCl4+silymarin-treated group decreased significantly. CONCLUSION: Anti-fibrotic and antiinflammatory effects of silymarin were associated with activation of hepatic stellate cells through the expression of TGF-β1 and stabilization of mast cells, These results suggest that silymarin prevent hepatic fibrosis through suppression of inflammation and hypoxia in the hepatic fibrogenesis.     

Therapeutic effects and molecular mechanisms of anti-fibrosis herbs and selenium on rats with hepatic fibrosis

AIM:To study the therapeutic effects of anti-fibrosis herbsand selenium on hepatic fibrosis induced by carbontetrachloride (CCl_4) in rats and the underlining molecularmechanisms.METHODS:Fifty-three Wistar rats were randomly dividedinto:normal control group,model control group,colchicinegroup,anti-fibrosis herbs group (AF group) and anti-fibrosisherbs plus selenium group (AS group).The last four groupswere administered with CCl_4 at the beginning of experimentto induce hepatic fibrosis.Then colchicine,anti-fibrosis herbsand selenium were used to treat them.The normal controlgroup and the model control group were given normal salineat the same time.At the end of the 6~(th) week,rats in eachgroup were sacrificed.Blood and tissue specimens weretaken.Serum indicators (ALT,AST,HA,LN) were determinedand histopathological changes were graded.Lymphocyte CD_4and CD_8 were examined by flow cytometry.Expression ofTGF-β_1 and NF-κB was detected by immunohistochemistryand expression of TGF-β_1 mRNA was detected by semi-quantified RT-PCR.RESULTS:Histological grading showed much a smallerdegree of hepatic fibrogenesis in AS group and AF groupthan that in colchicine group and model control group.Theserum content of ALT,AST,HA and LN in AF group and ASgroup were significantly lower than that in colchicine group(ALT:65.8±26.5,67.3±18.4 and 96.2±20.9 in AF,AS andcolchicine groups respectively;AST:150.8±34.0,154.6±27.3and 215.8±24.6 respectively;HA:228±83,216±58 and416±135 respectively;LN:85.9±15.0,80.6±18.6 and106.3±14.2 respectively) (P<0.05).The level of CD_4 andCD_4/CD_8 ratio in AF group and AS group was significantly higherthat those in cochicine group (CD_4:50.8±3.8,52.6±3.4 and40.2±2.1 in AF,AS and colchicine groups respectively;CD_4/CD_8 ratio:1.45,1.46 and 1.26,respectively (P<0.05).The expression level of NF-κB and TGF-β_1 in the liver tissuesof AF and AS treatment groups was markedly decreasedcompared with that in cochicine group,and TGF-β_1 mRNAwas also markedly decreased (1.07±0.31 and 0.98±0.14 vs2.34±0.43,P<0.05).CONCLUSION:Anti-fibrosis herbs and selenium havebeneficial effects on hepatic fibrosis in rats by enhancingimmunity and inhibiting NF-κB and TGF-β_1 expressions.     

Bone morphogenetic protein-7 represses hepatic stellate cell activation and liver fibrosis via regulation of TGF-β/Smad signaling pathway

BACKGROUND Liver fibrosis is a refractory disease whose persistence can eventually induce cirrhosis or even liver cancer.Early liver fibrosis is reversible by intervention.As a member of the transforming growth factor-beta(TGF-β)superfamily,bone morphogenetic protein 7(BMP7)has anti-liver fibrosis functions.However,little is known about BMP7 expression changes and its potential regulatory mechanism as well as the relationship between BMP7 and TGF-βduring liver fibrosis.In addition,the mechanism underlying the anti-liver fibrosis function of BMP7 needs to be further explored.AIM To investigate changes in the dynamic expression of BMP7 during liver fibrosis,interactions between BMP7 and TGF-β1,and possible mechanisms underlying the anti-liver fibrosis function of BMP7.METHODS Changes in BMP7 expression during liver fibrosis and the interaction between BMP7 and TGF-β1 in mice were observed.Exogenous BMP7 was used to treat mouse primary hepatic stellate cells(HSCs)to observe its effect on activation,migration,and proliferation of HSCs and explore the possible mechanism underlying the anti-liver fibrosis function of BMP7.Mice with liver fibrosis received exogenous BMP7 intervention to observe improvement of liver fibrosis by using Masson’s trichrome staining and detecting the expression of the HSC activation indicator alpha-smooth muscle actin(α-SMA)and the collagen formation associated protein type I collagen(Col I).Changes in the dynamic expression of BMP7 during liver fibrosis in the human body were further observed.RESULTS In the process of liver fibrosis induced by carbon tetrachloride(CCl4)in mice,BMP7 protein expression first increased,followed by a decrease;there was a similar trend in the human body.This process was accompanied by a sustained increase in TGF-β1 protein expression.In vitro experiment results showed that TGF-β1 inhibited BMP7 expression in a time-and dose-dependent manner.In contrast,high doses of exogenous BMP7 inhibited TGF-β1-induced activation,migration,and proliferation of HSCs;this inhibitory effect was associated with upregulation of pSmad1/5/8 and downregulation of phosphorylation of Smad3 and p38 by BMP7.In vivo experiment results showed that exogenous BMP7 improved liver fibrosis in mice.CONCLUSION During liver fibrosis,BMP7 protein expression first increases and then decreases.This changing trend is associated with inhibition of BMP7 expression by sustained upregulation of TGF-β1 in a time-and dose-dependent manner.Exogenous BMP7 could selectively regulate TGF-β/Smad pathway-associated factors to inhibit activation,migration,and proliferation of HSCs and exert antiliver fibrosis functions.Exogenous BMP7 has the potential to be used as an antiliver fibrosis drug.     

Expression of TIMP-1 and TIMP-2 in rats with hepatic fibrosis

AIM: To investigate the location and expression of TIMP-1 and TIMP-2 in the liver of normal and experimental hepatic fibrosis in rats. METHODS: The rat models of experimental immunity hepatic fibrosis (n=20) were prepared by the means of immunologic attacking with human serum albumin (HSA),and normal rats (n=10) served as control group. Both immunohistochemistry and in situ hybridization methods were respectively used to detect the TIMP-1 and TIMP-2 mRNA and related antigens in liver. The liver tissue was detected to find out the gene expression of TIMP-1 and TIMP-2 with RT-PCR. RESULTS: The TIMP-1 and TIMP-2 related antigens in livers of experimental group were expressed in myofibroblasts and fibroblasts (TIMP-1: 482&#177;65 vs 60&#177;20; TIMP-2:336&#177;48 vs 50&#177;19, P&lt;0.001). This was the most obvious in portal area and fibrous septum. The positive signals were located in cytoplasm, not in nucleus. Such distribution and location were confirmed bysitu hybridization (TIMP-1/β-actin: 1.86&#177;0.47 vs 0.36&#177;0.08; TIMP-2/β-actin: 1.06&#177;0.22 vs 0.36&#177;0.08,P&lt;0.001). The expression of TIMP-1 and TIMP-2 was seen in the liver of normal rats, but the expression level was very low. However, the expression of TIMP-1 and TIMP-2 in the liver of experimental group was obviously high. CONCLUSION: In the process of hepatic fibrosis, fibroblasts and myofibroblasts are the major cells that express TIMPs.The more serious the hepatic fibrosis is in the injured liver,the higher the level of TIMP-1 and TIMP-2 gene expression.