DYNAMIC CHANGES OF ITO CELLS IN EXPERIMENTAL LIVER CIRRHOSIS OF RAT

That Ho cells in rat liver express desmin was confirmed by immunohistochemical technique. Consequently, changes of desmin-positive cells, lysozyme-positive cells and fibronectin were further studied in experimental cirrhosis of rat. It was found that desmln- positive cells, with the transitional feature between Ito cells and myofibroblasts or fibrobiasts under electron microscope, increased in number and expression of desmin in the necrotic areas as well as in the cellular fibrous septa, but decreased in number in the fibrous septa except those areas closed to the edges of the septa. These results suggested that Ito cells, myofibroblasts and fibroblasts might belong to the same cellular system and play an important role in the pathogenesis of cirrhosis. Meanwhile, it was also noted that changes of both fibronectin and lysozymepositive cells were correlated with those of desmin-positive cells. These provide evidence in vivo that flbronectin and Kupffer cells might exert certain effects on the migration and proliferation of Ito cells in liver cirrhosis.

Shugan Huoxue Huayu Fang(疏肝活血化瘀方)attenuates carbon tetrachloride-induced hepatic fibrosis in rats by inhibiting transforming growth factor-β1/Smad signaling

OBJECTIVE:To investigate the potential mechanism by which Shugan Huoxue Huayu Fang(疏肝活血化瘀方,SGHXHYF)ameliorates liver fibrosis.METHODS:Liver fibrosis was induced in rats by intraperitoneal injection of carbon tetrachloride(CCl_(4))in peanut oil solution(40%,3 m L/kg body weight)twice a week for 8 weeks.A normal control group received the same volume of peanut oil alone.During weeks 5-8,the CCl_(4)-injected rat groups were administered saline(vehicle control),colchicine(0.1 mg/mL,1 mg/kg,positive control),or SGHXHYF(0.1 mg/mL;0.3,0.6 and 1.2 mg/kg)once daily by oral gavage.Rats were sacrificed 24 h after the last treatment.Blood samples were collected for measurement of serum alanine aminotransferase(ALT),aspartate aminotransferase(AST),alkaline phosphatase(ALP),albumin(ALB),collagenⅠ,and collagenⅢlevels.Liver samples were analyzed by histopathological staining,Masson's staining of extracellular matrix proteins,and immune-ohistochemical staining ofα-smooth muscle actin(α-SMA).TGF-β1/Smad protein and mRNA levels were analyzed by Western blot and quantitative reverse transcription-polymerase chain reaction analysis,respectively.In vitro experiments were also performed using rat hepatic stellate cells(HSCs).RESULTS:Compared with the control animals,CCl_(4)-exposed rats exhibited elevated serum levels of ALT,AST,ALP,collagenⅠ,and collagenⅢ;reduced serum levels of ALB;and increased collagen deposition andα-SMA expression in liver sections,reflecting liver fibrosis.CCl_(4) also increased expression of TGF-β1 and the activated(phosphorylated)forms of Smad2 and Smad3 but reduced expression of the negative regulator Smad7 in the liver.Notably,concomitant administration of SGHXHYF to CCl_(4)-exposed rats was found to significantly reverse or abolish the pro-fibrotic effects of CCl_(4) in the liver and reduced serum transferase levels.Analysis of HSCs in vitro confirmed that,mechanistically,SGHXHYF inhibited activation of the TGF-β1/Smad signaling pathway by downregulating phosphorylated Smad2 and Smad3 and upregulating Smad7 levels.CONCLUSION:SGHXHYF ameliorated CCl_(4)-induced liver fibrosis by inhibiting the TGF-β1/Smad signaling pathway.These findings suggest that SGHXHYF may have clinical utility for the treatment or prevention of liver fibrosis.

Serum Pharmacological Effects of Fuzheng Huayu Decoction(扶正化瘀方) on lto Cell Proliferation and Collagen Synthesis in Rats

Objective: To explore mechanism of the effect of Fuzheng Huayu Decoction on Ito cell proliferation and collagen synthesis. Methods: Biological effects of the drug serum taken from rats fed with Fuzheng Huayu decoction （FZHYD） on cell proliferation and collagen synthesis of Ito cell line were observed. Serum collected from rats at various times （1, 2 or 3 hours） after animals were fed with FZHYD once （It） or twice （2t,2nd time repeated with the same dose）, was incubated with Ito cell. Results: The 1t-2h serum in O.46 g/kg FZHYD group, it seems to prevent cell proliferation, but had no significant difference. While all 2t drug serum could inhibit cell proliferation. The 2t-1h drug serum had no obvious effects on Ito cell morphology, but could improve cell viability, its effect on cell proliferation was dose and serum concentration dependent. Also the 2t-1h drug serum in all doses could inhibit Ito cells both intracellular and extracellular collagen production, the drug serum of 0.46 g/kg group had inhibitory effect in serum concentration dependent manner and similar effect as colchicine. Conclusion: Inhibition of Ito cells proliferation and collagen synthesis is perhaps One of main mechanism of FZHYD in antifibrotic action.