The Role Of Hmgb1in Chronic Hepatic Inflammation And Fibrosis Reaction

Background:Hepatic fibrosis is the common pathological process of a variety of chronic liver disease to cirrhosis, and is an important part of influencing the prognosis of chronic liver disease. The rate of liver fibrosis to cirrhosis and liver cancer is very high(25%～40%), and these diseases are becoming serious threats to people’s health worldwide. Hepatic fibrosis is a reversible pathological process, so holding back the progress of hepatic fibrosis is an important strategy to improve the liver disease prognosis. Recognized chronic inflammatory response is an important factor in hepatic fibrosis. Recent studies show that the High mobility group protein box1(HMGB1), as a typical endogenous Danger-associated molecular patterns(DAMPs), plays an important role in the inflammatory response of the liver damage. The study of the role of HMGB1in liver fibrosis, led to great interest of scholars. Therefore, we aim to observe the role of HMGB1in chronic hepatic inflammatory response and fibrosis reaction.Objective:To investigate the role of High Mobility Group Box Protein1in the chronic hepatic inflammation and fibrosis reaction through observe the expression of inflammatory cytokines and fibrosis factor.Methods:The first part of the experiment:Forty male Kunming mice, the ccl4gavage preparation of liver fibrosis were randomly divided into three groups:the normal control group,1ul/g saline was administered every five days;2weeks model group,4weeks model group,6weeks model group, ccl4(1ul/g,diluted with corn oil) was administered every five days. Each mice was sacrificed by removal of the eye method. The parameters of plasma’HA, Col-â… , Pâ…¢P and IL-6, TNF-α were measured by ELISA. The morphological changes of the liver tissue were observed with HE staining and Sirius red staining. The level of HMGB1in liver tissue were measured by western blot.The second part of the experiment:Twenty male Kunming mice,the ccl4gavage preparation of liver fibrosis were randomly divided into two groups:the model group, ccl4(1ul/g,diluted with corn oil) was administered every five days; the intervention group, ccl4(1ul/g, diluted with corn oil),50ug/mouse HMGB1-Ab,5ug/g ethyl pyruvate were administered by gavage or intraperitoneal injection every five days. Each mice was sacrificed by removal of the eye method. The parameters of plasma’HA, Col-â… , Pâ…¢P and IL-6, TNF-α were measured by ELISA. The morphological changes of the liver tissue were observed with HE staining and Sirius red staining. The level of HMGB1in liver tissue were measured by western blot. The level of TGF-β,α-SMAå'ŒMMP-9mRNA were detected by RT-PCR.Results:1. Successfully established liver fibrosis model. In6weeks model group, liver cells degenerate and necrosis, inflammatory cells infiltrate and liver fibrous tissue proliferate. The levels of HA, Col-â… , Pâ…¢P in the normal control group was very low in serum measured by ELISA. Compared with the normal control group, the levels of them in2weeks model group,4weeks model group and6weeks model group were remarkably increased (P<0.05), meanwhile, they in6weeks group were significantly higher than4weeks group(P<0.05).2. The changes of IL-6, TNF-α and HMGB1in ccl4induced liver fibrosis model. The levels of IL-6, TNF-α in the normal control group was very low in serum measured by ELISA. Compared with the normal control group, the levels of them in4weeks model group and6weeks model group were remarkably increased (P<0.05), meanwhile, they in6weeks group were significantly higher than4weeks group(P<0.05). Wester-blot results show that no HMGB1expression in the liver tissue of normal control group, and in the process of liver fibrosis, the higher HMGB1is expressed in liver tissue,the longer ccl4is administered. Compared with the normal control group, the levels of HMGB1in4weeks model group and6weeks model group were significantly increased (P<0.05), meanwhile, they in6weeks group were much higher than4weeks group(P<0.05).3. Antagonistic HMGB1can reduce the degree of liver fibrosis. In model group, liver cells steatosis and necrosis, inflammation cells infiltrate, liver fibrous tissue proliferate. Liver cells of intervention group have a small amount of steatosis,inflammatory cells infiltration,but no liver fibrosis formation in tissue. Antagonistic HMGB1can cause the marked decrease of liver fibrosis tissue by Sirius red staining (0.57%±0.21%vs1.02%±0.33%; P<0.05) and significantly reversed liver fibrosis. Compared with model group, the levels of HA, Col-â… , Pâ…¢P in intervention group were remarkably decreased (P<0.05). Compared with model group, The mRNA expression of TGF-β, α-SMA in intervention group were significantly downregulated (P<0.05), however, the mRNA expression of MMP-9was upregulated(P<0.05).4. Antagonistic HMGB1can reduce the content of IL-6, TNF-α. Compared with model group, the levels of IL-6, TNF-α in intervention group were remarkably decreased (P<0.05). Conclusion:1. In the CC14induced liver fibrosis model, the levels of HMGB1and inflammatory factors IL-6,TNF-a are significantly increased.2. There are relationship between fibrogenic role and proinflammatory role in HMGB1. HMGB1antibody can reduce the lever of the inflammatory factors and fibro-genic cytokines in mice with liver fibrosis.