The experimental study on mouse pristine hepatic fibrosis induced by different doses of alcohol
JIA Qing, ZHANG Wei-dong, WANG Zhao-xia, WANG Zhao-peng, ZHANG Yue-ying, ZHANG Jun-ping
Department of Experimental Pathology, Institute of Basic Medicine, Shandong Academy of Medical Science, Jinan 250062,China. E-mail:zhangweidongkui@163.com
Abstract：AIM: To explore the difference on formation mechanism and the pathology in the process of early liver fibration induced by two dose of ethanol. METHODS: 24 male KM mice were randomly divided into 3 groups which are control group, low dose of alcohol group and high dose of alcohol group, respectively. The mice treated with 8 g·kg-1·d-1 ethanol, 3 g·kg-1·d-1 ethanol by oral were killed 30 days later. The liver histomorphology,inflammation grade and fibration staging were observed and the areas of collagen per high power field were calculated by hematoxylin-feosin (HE) and Masson staining; the expression of Toll like receptor-4(TLR-4), α-smooth muscle actin (α-SMA) and content of transforming growth factor-β (TGF-β), nuclear factor-kappa B (NF-кB) protein, BMP and activin membrane-bound inhibitor (Bambi) mRNA were measured using immunohistochemistry, Western blotting, real-time quantitative polymerase chain reaction, respectively; apoptosis cell number was calculated by In Situ Nick-End Labeling (TUNEL). RESULTS: Different degree of fibration mice induced by ethanol appeared (P<0.01) and hepatic stellate cells (HSCs) in these mice liver were activated, meanwhile the apoptosis cell number increased too (P<0.01). The liver fibration at high dose group was more serious than that at low dose group mice, and the number of apoptosis cells showed the same trend as fibration, but the content of Bambi mRNA in high dose group down regulated compared to that in low dose group (P<0.05). On the other hand, the expression of TLR-4 enhanced in low dose group while decreased in high dose group compared to control group (P<0.01). CONCLUSION: The mechanism of early mouse liver fibration induced by two dose of alcohol is different. Apoptosis may be more responsible for the liver fibration induced by high dose alcohol than TLR-4 pass way, and there is a TLR-4 independent pathway to down-regulate the Bambi that probably is one of the reasons that the fibrosis is more serious in the high dose group.
Tanaka Y, Nouchi T, Yamane M, et al. Phenotypic modulation in lipocytes in experimental liver fibrosis[J]. J Pathol,1991,164(3):273-278.
[2]
Friedman SL. The cellular basis of hepatic fibrosis[J]. N Engl J Med,1993,328(25):1828-1835.
[3]
Rockey DC, Housset CN, Friedman SL. Activation-dependent contractility of rat hepatic lipocytes in culture and in vivo[J]. J Clin Invest,1993,92(4):1795-1804.
[4]
Carson EJ, Pruett SB. Development and characterization of a binge drinking model in mice for evaluation of the immunological effects of ethanol[J]. Alcohol Clin Exp Res,1996,20(1): 132-138.
Ramm GA, Li SCY, Britton RS,et al. Chronic iron overload causes activation of rat lipocytes in vivo[J]. Am J Physiol, 1995, 268(3):451-458.
[10]
Gressner AM,Weiskirchen R,Breitkopf K, et al. Roles of TGF beta in hepatic fibrosis[J]. Front Biosci, 2002,7: 793-807.
[11]
Bachem MG, Sell KM, Melchior R,et al.Tumor necrosis factor-alpha (TNF-alpha)and transforming growth factor-beta 1 (TGF-beta 1) stimulate fibronectin synthesis and the transdifferentiation of fat storing cells in the rat liver into myofibroblasts[J]. Virchows Arch B Cell Pathol,1993, 63(2): 123-130.
[12]
Iredale JP, Murphy G, Hembry RM,et al. Human hepatic lipocytes synthesize tissue inhibitor of metalloproteinases-1-implications for regulation of matrix degradation in liver[J]. J Clin Invest,1992, 90(1):282-287.
[13]
Iredale JP. Tissue inhibitors of metalloproteinases in liver fibrosis[J]. Int J Biochem Cell Biol,1997,29(1):43-54.
[14]
Schrum L, Bird MA, Salcher O,et al. Autocrine expression of activated transforming growth factor-beta1 induces apoptosis in normal rat liver[J]. Am J Physiol Gastrointest Liver Physiol,2001,280(1):139-148.
[15]
Nacu N, Luzina IG, Highsmith K, et al. Macrophages produce TGF-beta-induced (beta-ig-h3) following ingestion of apoptotic cells and regulate MMP14 levels and collagen turnover in fibroblasts[J]. J Immunol,2008,180 (7):5036-5044.
[16]
Seki E, De Minicis S, Osterreicher CH, et al. TLR4 enhances TGF-beta signaling and hepatic fibrosis[J]. Nat Med, 2007,13(11):1324-1332.
