Bone morphogenetic protein-7 represses hepatic stellate cell activation and liver fibrosis via regulation of TGF-ß/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-ß) 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-ß during 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-ß1, 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-ß1 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-ß1 protein expression. In vitro experiment results showed that TGF-ß1 inhibited BMP7 expression in a time- and dose-dependent manner. In contrast, high doses of exogenous BMP7 inhibited TGF-ß1-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-ß1 in a time- and dose-dependent manner. Exogenous BMP7 could selectively regulate TGF-ß/Smad pathway-associated factors to inhibit activation, migration, and proliferation of HSCs and exert anti-liver fibrosis functions. Exogenous BMP7 has the potential to be used as an anti-liver fibrosis drug.

Ferulic acid attenuates liver fibrosis and hepatic stellate cell activation via inhibition of TGF-ß/Smad signaling pathway.

PURPOSE: Liver fibrosis is a worldwide health issue. Development of effective new drugs for treatment of this disease is of great importance. This study investigated the therapeutic effects of ferulic acid on liver fibrosis in vitro and in vivo. MATERIALS AND METHODS: Human hepatic stellate cell line (HSC) LX-2 was used for in vitro assays. Transforming growth factor ß1 (TGF-ß1) was used to induce hepatic fibrosis in LX-2 cells. Western blot was used to detect protein levels of collagen I, fibronectin, α-smooth muscle actin (SMA), p-Smad2, p-Smad3, p-p38, and p-JNK. Gene expression was measured by RT-qPCR. Fluorescence staining was used to determine localization of Smad4. CCl4-induced hepatic fibrosis in SD rats was used as an in vivo model. Histological features were detected by hematoxylin and eosin staining. Levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), hexadecenoic acid (HA), and hydroxyproline (Hyp) were measured by ELISA. RESULTS: TGF-ß1 treatment significantly increased levels of collagen I, fibronectin, α-SMA, p-Smad2, p-Smad3, and Smad4 in LX-2 cells. Ferulic acid improved TGF-ß1-induced hepatic fibrosis via regulation of the TGF-ß1/Smad pathway. Consistent with in vitro data, CCl4 caused severe hepatic fibrosis in SD rats, as determined by ALT, AST, HA, and Hyp upregulation. Protein levels of p-Smad2 and p-Smad3 in liver tissues were significantly increased following treatment with CCl4. All CCL4-induced changes were markedly attenuated by ferulic acid treatment. CONCLUSION: Ferulic acid potently improved hepatic fibrosis via inhibition of the TGF-ß1/Smad pathway in vitro and in vivo. These findings provided evidence for potential use of ferulic acid to treat or prevent liver fibrosis.

[Eighty three cases of post transfusion HCV infection: a 10-year follow up].

OBJECTIVE: To find out clinical characteristics and natural history of post transfusion HCV infection. METHODS: 83 subjects who have received the blood from a same blood donor from January 1998 to July 2002 were investigated by the method combining cross-sectional study with retrospective study. HCV-antibody, HCV RNA, liver function, abdomen B-ultrasound and Fibroscan were detected. RESULTS: The HCV-antibody were all positive. The HCV RNA of 56 out of the 83 cases were positive. The chronicity rates of hepatis C were 76.3% (29/38) in male patients and 60.00% (27/45) in female patients respectively, without significant difference (X² = 2.99, P = 0.11). The average age of the HCV RNA positive patients was (36.54 ± 14.37) years old. The average age of the HCV RNA negative patients was (27.43 ± 12.51) years old. A significant difference (T = -2.41, P = 0.018) existed between. The HCV genotype was type1b. Among the HCV RNA positive patients,10 cases were with mild asthenia, anorexia and abdominal distention, 9 cases with increased serum ALT, 12 cases.with chronic hepatitis and 1 case was diagnosed with decompensated liver cirrhosis. CONCLUSION: The clinical manifestations of HCV infection are occult and chronic. The chronicity rate is related to gender and the age when infection was caught.