RESUMO
BACKGROUND: Hepatic stellate cell hyperactivation is a central link in liver fibrosis development, transforming growth factor ß1 (TGF-ß1) is a key activator of HSCs. AIMS: This study investigated whether anlotinib attenuates CCl4 induced liver fibrosis in mice and explored its antifibrotic mechanism. METHODS: We used the human hepatic stellate cell line LX-2 for in vitro assays and used TGF-ß1 to induce hepatic fibrosis in LX-2 cells. We analyzed cytotoxicity using a cell-counting kit-8 and transwell chambers to detect the migratory ability of LX-2 cells. Western blotting was used to detect the protein levels of collagen type I, α-smooth muscle actin, and p-Smad3. In addition, mice with CCl4-induced hepatic fibrosis were used as in vivo models. Histopathological examination was performed using H&E staining, Masson's trichrome staining, and immunohistochemistry. RESULTS: Anlotinib significantly reversed TGF-ß1-induced protein levels of Col I, α-SMA and p-Smad3 and inhibits migratory and proliferative abilities in vitro using LX-2 cells. CCl4 cause F4 grade (Ishak) hepatic fibrosis, liver inflammatory scores ranged from 12 to 14 (Ishak), a mean ALT measurement of 130 U/L and a mean measurement AST value of 119 U/L in mice. However, the CCl4-induced changes were markedly attenuated by anlotinib treatment, which returned to F2 grade (Ishak) hepatic fibrosis, liver inflammatory scores ranged from 4 to 6 (Ishak), a mean ALT measurement of 40 U/L and a mean measurement AST value of 56 U/L in mice. CONCLUSIONS: Our results suggest that anlotinib-mediated suppression of liver fibrosis is related to the inhibition of TGF-ß1 signaling pathway. Hepatic stellate cell hyper activation is a central link in liver fibrosis development, transforming growth factor ß1 is a key activator of HSCs. Anlotinib is a multi-targeted tyrosine kinase inhibitor that has similar targets to nintedanib, a clinically used anti-pulmonary fibrosis drug. Our study demonstrates an FDA-approved drug-anlotinib-that could prevent liver fibrosis and inflammation. Experiments in cell cultures and mice show that anlotinib can inhibit the activation of hepatic stellate cells by down-regulating the TGFß1/smad3 pathway, thereby reversing liver fibrosis. In animal experiments, anlotinib showed protective effects on the CCl4-induced liver damage, including ameliorating liver inflammation, reversing liver fibrosis and reducing liver enzymes. This is a very good signal, anlotinib may be useful for halting or reversing the progression of liver fibrosis and could be employed in the development of novel therapeutic drugs for the management of chronic liver diseases.
RESUMO
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.