Astragaloside Alleviates Hepatic Fibrosis Function via PAR2 Signaling Pathway in Diabetic Rats.

BACKGROUND/AIMS: Astragaloside (AGS) extracted from radix astragalin (Huangqi) has been considered to be beneficial to liver diseases. In this study, we examined the role played by AGS in alleviating hepatic fibrosis function via protease-activated receptor-2 (PAR2) mechanisms. We hypothesized that AGS affects PAR2 signaling pathway thereby improving hepatic function in rats with hepatic fibrosis induced by carbon tetrachloride (CCl4). We further hypothesized that AGS attenuates impaired hepatic function evoked by CCl4 to a greater degree in diabetic animals. METHODS: ELISA and Western Blot analysis were used to examine PAR2 signaling pathway in diabetic CCl4-rats and non-diabetic CCl4-rats. RESULTS: AGS inhibited the protein expression of PAR2 and its downstream pathway PKA and PKCɛ in CCl4-rats. Notably, the effects of AGS were greater in CCl4-rats with diabetes. AGS also significantly attenuated the CCl4-induced upregulations of pro-inflammatory cytokines, namely interleukin-1ß, interleukin-6 and tumor necrosis factor-α accompanied with decreases of collagenic parameters such as hexadecenoic acid, laminin and hydroxyproline. Additionally, AGS improved the CCl4-induced exaggerations of liver index and functions including alanine aminotransferase, aspartate aminotransferase. Moreover, TGF-ß1, a marker of hepatic fibrosis, was increased in CCl4-rats and AGS inhibited increases in TGF-ß1 induced by CCl4. CONCLUSIONS: AGS alleviates hepatic fibrosis by inhibiting PAR2 signaling expression and its effects are largely enhanced in diabetic animals. Targeting one or more of these signaling molecules may present new opportunities for treatment and management of hepatic fibrosis; and results of our study are likely to shed light on strategies for application of AGS because it has potentially greater therapeutic effectiveness for hepatic fibrosis in diabetes.

Activation of corticotropin releasing factor receptors up regulates collagen production by hepatic stellate cells via promoting p300 expression.

Liver fibrosis is characterized with the over expression and excessive accumulation of extracellular matrix proteins, including collagens. The causative factors in the over production of collagens are not fully understood. This study aims to test a hypothesis that activation of corticotropin releasing factor receptors up regulates the expression of collagen in hepatic stellate cells. In this study, human hepatic stellate cell line, LX-2 cells were cultured. Expression of collagens by LX-2 cells was assessed by real time RT-PCR, Western blotting. The results showed that, upon exposure to urocortin in the culture, LX-2 cells (a human hepatic stellate cell line) increased the expression of collagen IV (Col4) markedly. The exposure to urocortin also enhanced the levels of pTip60, H3K9, RNA polymerase II and forkhead box protein 3 at the collagen promoter locus as well as increase in the expression of Col4 mRNA and protein in the cells. Blocking p300 efficiently suppressed the urocortin-induced Col4 expression in LX-2 cells and unveiled an apoptosis-inducing effect of urocortin. In conclusion, activation of CRF receptors is capable of enforcing the production of Col4 by LX-2 cells via up regulating the p300 pathway, which may contribute to the development of liver fibrosis.

Corilagin Counteracts IL-13Rα1 Signaling Pathway in Macrophages to Mitigate Schistosome Egg-Induced Hepatic Fibrosis.

The IL-13Rα1 signaling pathway and M2 macrophages play crucial roles in schistosome egg-induced hepatic fibrosis via the expression of pro-fibrotic molecules. This study aims to investigate the inhibitory effect and mechanism of action of corilagin on schistosome egg-induced hepatic fibrosis via the IL-13Rα1 signaling pathway in M2 macrophages in vitro and in vivo. The mRNA and protein expression of IL-13Rα1, PPARγ, KLF4, SOCS1, STAT6, p-STAT6, and TGF-ß was measured in vitro with corilagin treatment after IL-13 stimulation and in vivo corilagin treatment after effectively killing the adult schistosomes in schistosome-infected mice. Histological analysis of liver tissue was assessed for the degree of hepatic fibrosis. The results revealed that corilagin significantly reduced the expression of PPARγ, KLF4, SOCS1, p-STAT6, and TGF-ß compared with model group and praziquantel administration (p < 0.01 or p < 0.05) in vivo and in vitro, which indicated a strong inhibitory effect of corilagin on IL-13Rα1 signaling pathway. As well, the inhibitory effect of corilagin showed a significant dose-dependence (p < 0.05). The area of fibrosis and distribution of M2 macrophages in mouse liver tissue were reduced significantly and dose-dependently with corilagin treatment compared to model group or praziquantel administration (p < 0.01 or p < 0.05), indicating that corilagin suppressed IL-13Rα1 signaling pathway and M2 macrophage polarization effectively in vivo. Furthermore, the anti-fibrogenic effect persisted even when IL-13Rα1 was up- or down-regulated in vitro. In conclusion, corilagin can suppress schistosome egg-induced hepatic fibrosis via inhibition of M2 macrophage polarization in the IL-13Rα1 signaling pathway.

Mechanism of Corilagin interference with IL-13/STAT6 signaling pathways in hepatic alternative activation macrophages in schistosomiasis-induced liver fibrosis in mouse model.

This study tried to find the mechanism of Corilagin interference with interleukin (IL)-13/signal transducer and activator of transcription (STAT) 6 signaling pathways in IL-13-activated liver alternative activation macrophages in schistosomiasis-induced liver fibrosis in Balb/c mice. As a result, IL-13 in serum and the mRNA expression of IL-13 Receptor α1, IL-4 Receptor α and downstream mediators supressor of cytokine signaling (SOCS) 1, Kruppel-like factor (KLF) 4, peroxisome proliferator-activated receptor (PPAR) δ in the liver tissue were significantly inhibited by Corilagin (P<0.05 or 0.01). The protein expression of IL-13 Receptor α1, IL-4 Receptor α, SOCS1, KLF4, PPARγ, PPARδ and Phospho-STAT6 (P-STAT6) in Corilagin group were also markedly suppressed when compared with the model group (P<0.05 or 0.01). Furthermore, the inhibitory effect was enhanced when the concentration of Corilagin increased (P<0.05). By hematoxylin and eosin (HE) staining, when compared with the model group, the Corilagin group showed smaller granulomas (P<0.05 or 0.01). The area of positive cells and integrated optical density (IOD) of CD68, CD206 and KLF4 was significantly decreased by Corilagin stained by IHC (P<0.05 or 0.01). In conclusion, Corilagin had potential to relieve hepatic fibrosis caused by egg granuloma in Schistosoma japonicum infection by decreasing the expression of molecules associated with IL-13/STAT6 signaling pathway in liver alternative activation macrophages.

Effect of Corilagin on the miR-21/smad7/ERK signaling pathway in a schistosomiasis-induced hepatic fibrosis mouse model.

This study sought to investigate the anti-fibrotic effect of Corilagin via interference with the miR-21/smad7/ERK signaling pathway in a schistosomiasis-induced hepatic fibrosis mouse model. Mice were infected with Schistosoma japonicum cercaria to establish the mouse model of schistosomiasis-induced hepatic fibrosis. At four weeks after infection, the groups were given different medications. The living conditions were observed. Real-time PCR was employed to detect the mRNA levels of miR-21, smad7 and connective tissue growth factor (CTGF), and western blotting was used to examine the protein levels of smad7, CTGF, smad1, p-smad1, smad2, p-smad2, ERK1/2, p-ERK1/2 and TGF-ß receptor I. Immunohistochemistry was used to examine the expression of CTGF. Compared with the model group, increasing concentrations of Corilagin improved the quality of life, inhibited the mRNA expression of miR-21, promoted smad7 protein expression, and inhibited CTGF protein expression (p<0.05 or 0.01). Moreover, Corilagin significantly reduced the protein levels of p-smad1, p-smad2, p-ERK1/2, and TGF-ß receptor I (p<0.05 or 0.01). CTGF staining in the cytoplasm was markedly decreased by Corilagin (p<0.05 or 0.01). In conclusion, Corilagin inhibited schistosomiasis-induced hepatic fibrosis via the miR21/smad7/ERK pathway in this animal model.

Effect of Rougan Huaqian granules combined with human mesenchymal stem cell transplantation on liver fibrosis in cirrhosis rats.

OBJECTIVE: To observe the effect of Rougan Huaqian granules combined with human mesenchymal stem cell (hMSC) transplantation on the liver fibrosis in carbon tetrachloride-induced cirrhosis rats. METHODS: Sixty SD rats were randomly divided into five groups. The rats in control group received intraperitoneal injection of saline, while those in model control group, treatment group A, group B and group C received intraperitoneal injection of carbon tetrachloride oily solution to induce liver cirrhosis within 8 weeks. Then, the rats in the model control group, treatment group A, treatment group B, treatment group C received vein tail injection of saline, Rougan Huaqian granules, hMSC suspension and Rougan Huaqian granules combined with hMSC suspension. RESULTS: The treatment groups had significantly different liver function (AST levels), liver fibrosis index (laminin and HA), hepatic sinusoidal wallsα-smooth muscle actin, IV collagen and laminin protein expression and I, III collagen from the model group (P<0.05). The transplanted cells showed human hepatocyte-like cells differentiation trend in the liver. CONCLUSIONS: The Rougan Huaqian granules combined with hMSC transplantation can alleviate liver fibrosis in cirrhosis rats.

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-ß1 and Smad expression were detected. RESULTS: Type III procollagen, IV collagen, hyaluronic acid, laminin levels of observation group were significantly lower than those of model group (P<0.05). The content and expression of TGF-ß1 in serum and liver tissue of observation group were significantly lower than those of model group(P<0.05). 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 (P<0.05). Compared with model group, Smad3, Smad4 mRNA and protein expression of observation group were significantly reduced, and Smad7 mRNA expression were significantly increased (P<0.05). CONCLUSIONS: BMSCs can regulate Smad expression to some extent, and reduce the degree of liver fibrosis.