The Effect And Mechanism Of BMP9 On Alcoholic Liver Disease In Mice

Background/ Objective In recent years,the morbidity and mortality of Alcoholic liver disease?ALD?has been increasing,which has caused a great economic burden to China and countries around the world.However,even after years of experimental research by researchers,the pathogenesis of ALD remains unclear.Bone Morphogenetic Protein 9?BMP9?is a member of the TGF? superfamily.It is mainly produced by hepatic stellate cells and is closely related to various liver diseases.For example,BMP9 can inhibit liver regeneration and promote liver fibrosis,and liver cancer.However,the role of BMP9 in the development of ALD is still unclear.Therefore,the subject systematically knocked out the BMP9 gene of mice through gene knockout technology to explore the role of BMP9 in the occurrence and development of ALD.Methods 1.Using C57BL/6J wild type?WT?mice to construct systemic BMP9 gene knockout(BMP9^-/-) mice.2.WT and BMP9^-/-mice were fed 10 days of control or alcohol liquid feed feeding and one maltose or alcohol gavage to establish a chronic plus binge alcohol feeding model in mice?ALD model,Gao-Binge model?.3.To explore the effects and mechanisms of BMP9 on alcoholic liver disease in mice,the liver injury indicators content of two groups of different mice(serum alanine aminotransferase?ALT?and aspartate aminotransferase?AST?,HE staining;liver fat deposition?oil red staining,intrahepatic glycerol triglyceride,Fat synthesis gene and oxidation gene?,liver inflammation?neutrophils,macrophages immunohistochemistry;proinflammatory cytokines and chemokine related gene expression?and oxidative stress indicators?4-HNE immune group Genes related to oxidative stress genes?were detected.Results 1.The results of Quantitative real-time PCR?q PCR?experimental showed that the expression level of BMP9 was the highest,and after chronic-plus-binge feeding,the expression level of BMP9 in WT mice increased.2.After chronic-plus-binge feeding,firstly,this study found that the ALT and AST levels of ALD model groups(WT and BMP9^-/-)is higher than the corresponding ALD control groups(WT And BMP9^-/-);Secondly,it was also found that the ALT and AST levels of the BMP9^-/-model group were lower than those of the WT model group.Similarly,the detection of liver pathological damage by HE staining found that the degree of liver damage induced by alcohol in the ALD model groups was greater than that in the corresponding ALD control groups,and the degree of damage in the BMP9^-/-model groups was lower than that in the WT model groups.3.The oil red staining,the detection of triglyceride content and the fat synthesis and oxidation genes in the liver were used to explore the deposition of liver fat in the ALD mice.The content of triglycerides in ALD model groups was lower than that of the WT model groups.It was also found that the expression level of fat synthesis genes in the BMP9^-/-model group was higher than that of the WT model group,while the degree of fat oxidation gene was lower than that of the WT model group.4.MPO,F4/80,4-HNE immunohistochemical staining and detection of inflammatory cytokines were used to detect liver inflammation in mice.Compared with ALD control groups,it was found that the degree of liver inflammation in ALD model groups were increased.In addition,it was also found that in the two groups of ALD model mice,the infiltration degree of liver inflammatory cells in BMP9^-/-group mice were lower than that in WT group.5.This study found that the expression level of TLR4 was increased in the WT model group,and also found that BMP9 increased the expression of TLR4 in vitro experiments.Conclusion 1.Alcohol stimulation on the ALD induced the expression of BMP9 increasing in mouse liver.2.In alcoholic liver disease,BMP9 increased the degree of alcohol-induced liver damage in mice.3.BMP9 aggravated liver fat deposition in liver alcoholic liver disease.4.BMP9 promoted the degree of inflammation and infiltration in liver alcoholic liver disease.5.BMP9 increased the degree of liver injury and inflammation infiltration of alcoholic liver disease by up-regulating the expression of TLR4.