Scoparone attenuates hepatic stellate cell activation through inhibiting TGF-β/Smad signaling pathway.

Activation of hepatic stellate cells (HSCs) plays a critical role in liver fibrosis. Scoparone, a major constituent isolated from Artemisia capillaris, was reported to possess hepatoprotective effect. However, the role of scoparone in liver fibrosis remains unknown. In the present study, we investigated the effects of scoparone on liver fibrosis in HSCs. Our results demonstrated that scoparoene inhibited the proliferation of HSCs exposed to transforming growth factor (TGF)-β1. In addition, scoparoene significantly suppressed TGF-β1-induced the expression of α-smooth muscle actin (α-SMA) and collagen I in HSC-T6 cells, as well as attenuated the expression of NADPH oxidase (NOX) isoforms expression and ROS production in TGF-β1-stimialted HSC-T6 cells. Mechanistically, scoparoene suppressed the phosphorylation level of Smad3 in TGF-β1-stimialted HSC-T6 cells. In conclusion, these findings showed that scoparone significantly inhibited the proliferation and activation of HSCs through the inactivation of TGF-β/Smad signaling pathway. These data provide that scoparone may have potential to treat liver fibrosis.

Liu X ，Zhao X 《-》

Decursin attenuates hepatic fibrogenesis through interrupting TGF-beta-mediated NAD(P)H oxidase activation and Smad signaling in vivo and in vitro.

We studied that a potent antifibrotic effect of decursin on in vivo liver damage model and the mechanism in inhibiting which transforming growth factor (TGF)-β1-induced human hepatic stellate cells (HSCs) activation. Liver injury was induced in vivo by intraperitoneal injection of carbon tetrachloride (CCl4) with or without decursin for 4weeks in mice. Human hepatic stellate cell line, an immortalized human HSC line, was used in in vitro assay system. The effects of decursin on HSC activation were measured by analyzing the expression of α-smooth muscle actin (α-SMA) and collagen I in liver tissue and human HSCs. Decursin treatment significantly reduced the ratio of liver/body weight, α-SMA activation, and type I collagen overexpression in CCl4 treated mice liver. The elevated serum levels, including ALT, AST, and ALP, were also decreased by decursin treatment. Treatment of decursin markedly proved the generation of reactive oxygen species, NAD(P)H oxidase (NOX) protein (1, 2, and 4) upregulation, NOX activity, and superoxide anion production in HSCs by TGF-β1. It also significantly reduced TGF-β1-induced Smad 2/3 phosphorylation, nuclear translocation of Smad 4, and association of Smad 2/3-Smad 4 complex. Consistent with in vitro results, decursin treatment effectively blocked the levels of NOX protein, and Smad 2/3 phosphorylation in injured mice liver. Decursin blocked CCl4-induced liver fibrosis and inhibited TGF-β1-mediated HSC activation in vitro. These data demonstrated that decursin exhibited hepatoprotective effects on experimental fibrosis, potentially by inhibiting the TGF-β1 induced NOX activation and Smad signaling.

Choi YJ ，Kim DH ，Kim SJ ，Kim J ，Jeong SI ，Chung CH ，Yu KY ，Kim SY ... -  《-》

Caffeic acid phenethyl ester attenuates liver fibrosis via inhibition of TGF-β1/Smad3 pathway and induction of autophagy pathway.

Caffeic acid phenethyl ester (CAPE) has been reported to possess the hepatoprotective effect. This study was to investigate the mechanism underlying CAPE against liver fibrosis in a liver fibrosis model induced by toxic carbon tetrachloride (CCl4) in male Sprague-Dawley rats and in vitro in CAPE (5 μM, 10 μM, 15 μM) treated hepatic stellate cells (HSC-T6). We found that CAPE treatment remarkably attenuated CCl4-induced liver fibrosis by blocking the activation of HSCs as determined by the expression alternation of transforming growth factor (TGF)-β1, phosphorylated Smad3 (p-Smad3), collage I, α-smooth muscle actin (α-SMA), matrix metalloproteinases (MMPs) 2, tissue inhibitor of matrix metalloproteinases (TIMPs) 1. The hepatoprotective effects of CAPE were also associated with upregulation of autophasomes in HSCs as determined by transmission electron microscopy (TEM) detection. The in vitro study further confrimed that CAPE attenuated liver fibrogenesis via inducing authophagic markers including LC3, ATG5, Beclin 1 expressions, while inhibiting AKT/mTOR signaling in HSC-T6 cells. Thus, the protective effects of CAPE against liver fibrosis might due to the inhibition of TGF-β1/Smad3 signaling and induction of authophagy in HSCs.

Yang N ，Dang S ，Shi J ，Wu F ，Li M ，Zhang X ，Li Y ，Jia X ，Zhai S ... -  《-》

Methyl ferulic acid attenuates liver fibrosis and hepatic stellate cell activation through the TGF-β1/Smad and NOX4/ROS pathways.

Liver fibrosis is a pathological wound-healing response caused by chronic liver damage due to a virus, autoimmune disorder, or drugs. Hepatic stellate cells (HSCs) play an essential role in the pathogenesis of liver fibrosis. Methyl ferulic acid (MFA), a biologically active monomer, has a protective effect on liver injury. However, the effects and roles of MFA in liver fibrosis remain unknown. The purpose of the current study was to investigate the effect of MFA on hepatic fibrosis and the underlying mechanisms. Human hepatic stellate LX-2 cells were exposed to 5 μg/L TGF-β1 for 48 h to stimulate liver fibrosis in vitro. Using MTT, RT-PCR and Western blot analysis, we revealed that MFA significantly inhibited the proliferation of LX-2 cells as well as decreased the expressions of α-SMA and type I collagen in LX-2 cells. SD rats were fed with ethanol, and this combined with the intraperitoneal injection of CCl4 induced liver fibrosis in vivo. We found that the administration of MFA markedly decreased the levels of hyaluronic acid (HA), procollagen type III (PC-III), type IV collagen (CIV) and laminin (LN) in the serum, inhibited the expression of α-smooth muscle actin (α-SMA) as well as type I and type III collagen, and up-regulated the ratio of MMP-2/TIMP-1 in rats. The antifibrotic effects of MFA were also evaluated by H&E staining and Masson's trichrome staining. In addition, further studies suggested that this protection by MFA from liver fibrosis was possibly related to the inhibition of TGF-β1/Smad and NOX4/ROS signalling. In conclusion, our results demonstrate that MFA attenuated liver fibrosis and hepatic stellate cell activation by inhibiting the TGF-β1/Smad and NOX4/ROS signalling pathways.

Cheng Q ，Li C ，Yang CF ，Zhong YJ ，Wu D ，Shi L ，Chen L ，Li YW ，Li L ... -  《-》

CTRP3 attenuates hepatic stellate cell activation through transforming growth factor-β/Smad signaling pathway.

Activation of hepatic stellate cells (HSCs) plays a pivotal role in the development of liver fibrosis. C1q/tumor necrosis factor-related protein 3 (CTRP3), a member of CTRPs, was involved in fibrosis. However, little is known about the role of CTRP3 in liver fibrosis. This study aimed to determine its role in liver fibrosis and explore the possible mechanism. Our results demonstrated that CTRP3 was lowly expressed in liver fibrosis tissues and activated HSCs. Overexpression of CTRP3 inhibited the proliferation and migration of HSCs, as well as suppressed the expression of extracellular matrix (ECM) in transforming growth factor-β1 (TGF-β1)-stimulated HSC-T6 cells. Furthermore, CTRP3 overexpression greatly inhibited the expression level of phosphorylation of Smad3 in TGF-β1-stimulated HSC-T6 cells. In conclusion, the present study demonstrated that CTRP3 inhibited the proliferation and migration of TGF-β1-induced HSC-T6 cells and attenuated liver fibrosis, at least in part, through inhibiting the Smad signaling pathway. These findings suggest that CTRP3 may be a promising therapeutic target for the treatment of liver fibrosis.

Cheng C ，Yu S ，Kong R ，Yuan Q ，Ma Y ，Yang W ，Cao G ，Xie L ... -  《-》