Ursodeoxycholyl lysophosphatidylethanolamide attenuates hepatofibrogenesis by impairment of TGF-β1/Smad2/3 signalling.

Chronic hepatic inflammation results in liver fibrosis. As effective anti-fibrogenic agents are lacking, we investigated ursodeoxycholyl lysophosphatidylethanolamide (UDCA-LPE), a synthetic bile acid-phospholipid conjugate with anti-inflammatory and anti-apoptotic properties for tis effects on hepatic fibrogenesis. To stimulate fibrogenesis, LX2 hepatic stellate cells were cultured with conditioned medium from CL48 liver cells after exposure to stress-inducing conditions - methionine-choline-deficient (MCD) medium or TNFα/cycloheximide (CHX) - with or without UDCA-LPE preincubation. Anti-fibrogenic effects of UDCA-LPE were further studied in CL48 and LX2 cells and in primary human hepatic stellate cells (HHStec) directly exposed to TGF-β1. To test UDCA-LPE in vivo, C57BL/6 mice were fed a MCD diet for 11 weeks followed by 30 mg·kg(-1) UDCA-LPE 3× per week for 2.5 weeks. Expression of α-smooth muscle actin (α-SMA), α1-collagen, vimentin and TGF-β1 was down-regulated by up to 93% by UDCA-LPE in LX-2 cells cultured with conditioned medium. Also, UDCA-LPE inhibited Smad3 phosphorylation in CL48 cells incubated with MCD medium or TNFα/CHX and in LX2 cells exposed to conditioned medium. UDCA-LPE also decreased phosphorylated Smad3 and Smad2 directly induced by TGF-β1. Inhibition of TGF-β1/Smad2/3 signalling with down-regulation of target genes was confirmed in HHStec. In vivo, UDCA-LPE decreased hepatic α-SMA, α1-collagen and TGF-β1 expression and markedly lowered α-SMA protein and collagen deposition in MCD mice. By blocking TGF-β1/Smad2/3 signalling, UDCA-LPE suppressed key mediators of hepatic fibrogenesis. Thus, UDCA-LPE could be suitable for prevention of fibrotic progression of chronic liver disease.

Pathil A ，Mueller J ，Ludwig JM ，Wang J ，Warth A ，Chamulitrat W ，Stremmel W ... -  《-》

Anti-inflammatory properties of ursodeoxycholyl lysophosphatidylethanolamide in endotoxin-mediated inflammatory liver injury.

Ludwig JM ，Zhang Y ，Chamulitrat W ，Stremmel W ，Pathil A ... -  《PLoS One》

Bivalent Ligand UDCA-LPE Inhibits Pro-Fibrogenic Integrin Signalling by Inducing Lipid Raft-Mediated Internalization.

Su J ，Gan-Schreier H ，Goeppert B ，Chamulitrat W ，Stremmel W ，Pathil A ... -  《INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES》

NLRC5 regulates TGF-β1-induced proliferation and activation of hepatic stellate cells during hepatic fibrosis.

Therapeutic management of liver fibrosis remains an unsolved clinical problem. Hepatic accumulation of extracellular matrix, mainly collagen, is mediated by the production of transforming growth factor-β1 (TGF-β1) in hepatic stellate cells (HSCs). NLRC5, the largest member of the NLR protein family, has recently been identified as a critical regulator of immune responses. Novel evidence shows that NLRC5 is an important negative modulator of inflammatory pathways. Herein, we determined the regulation of NLRC5 in liver fibrogenesis and its underlying mechanisms. We have shown that NLRC5 was upregulated in human liver fibrotic tissues. Overexpression of NLRC5 resulted in an upregulation of collagen 1 and α-smooth muscle actin expression in HSC LX-2 cells, which was inhibited by NLRC5 knockdown with its siRNA. Furthermore, NLRC5 deficiency significantly suppressed TGF-β1-induced proliferation but increased apoptosis (i.e., increased caspases-3, DR4 and DR5) in LX-2 cells. In addition, knockdown of NLRC5 promoted the activation of NF-κB signaling pathways but abrogated phosphorylation of Smad2 and Smad3 proteins in response to TGF-β1. These results indicate that NLRC5 is a potent pro-fibrogenic molecule for HSC activation through TGF-β1/Smad and NF-κB signaling pathways. NLRC5 inhibition would be a promising therapeutic avenue for treating hepatic fibrosis.

Xu T ，Ni MM ，Xing-Li ，Li XF ，Meng XM ，Huang C ，Li J ... -  《-》

Synergistic anti-liver fibrosis actions of total astragalus saponins and glycyrrhizic acid via TGF-β1/Smads signaling pathway modulation.

Huangqi decoction (HQD) is a well-known traditional Chinese herbal formulation, It is an effective treatment for consumptive disease and chronic liver diseases. It consists of Radix Astragali (Astragalus membranceus(Fisch.) Bge. Root, Huangqi) and Radix Glycyrrhizae (Glycyrrhiza uralensis Fisch., root and rhizome, Gancao). Total astragalus saponins (AST) is a main component of Radix Astragali and glycyrrhizic acid(GA) is a main component of Radix Glycyrrhizae. Our primary results showed that the combination of AST and GA had an obvious synergistic effect in reducing liver collagen deposition and decreasing serum alanine aminotransferase (ALT) activity in dimethylnitrosamine (DMN)-induced liver fibrosis. Through in vivo and in vitro experiments, we aimed at investigating the key anti-fibrosis signal pathway TGF-β1/Smads to further explore the synergistic mechanism of AST and GA. Two hepatic fibrosis animal models, bile duct ligation-induced (BDL) and DMN-induced, were utilized. Rats were treated orally with AST, GA or AST/GA, with the effects evaluated via liver histopathology, hydroxyproline (Hyp) levels, and α-SMA expression. In the hepatic stellate cell line JS-1, cells were treated with AST/GA for 24h, followed by a cell viability assessment using Cell Counting Kit-8(CCK-8) and Real-time PCR and Western blot analysis of α-SMA, ColⅠ and TGF-β1/Smads signaling pathway related components. The AST/GA combination attenuated liver tissue inflammation, collagen deposition, Hyp levels, and α-SMA expression in both BDL-and DMN-stimulated hepatic fibrosis rats. In vitro results showed that the AST/GA combination significantly inhibited JS-1 cell viability, significantly suppressed α-SMA, ColⅠ, TGF-β1, Smad2 and Smad3 mRNA and protein expression, as well reduced p-Smad2/3. Compared with AST or GA treatment alone, the AST/GA combination significantly reduced Smad3 mRNA expression levels and TGF-β1, Smad3, and p-Smad2/3 protein levels. AST and GA synergistically alleviated both BDL-and DMN-induced hepatic fibrosis via TGF-β1/Smads signaling pathway inhibition in hepatic stellate cells.

Zhou Y ，Tong X ，Ren S ，Wang X ，Chen J ，Mu Y ，Sun M ，Chen G ，Zhang H ，Liu P ... -  《-》