Role Of Insulin Receptor Substrate-2 In Insulin Resistance Of Viral Hepatitis B Patients

Aim To observe the expression of insulin receptor substrate-2 (IRS-2) protein and its tyrosine phosphorylation in hepatic tissue of chronic hepatitis B(CHB) patients,and to explore the role of IRS-2 on insulin resistance in CHB patients.Methods Eighteen patients with CHB were included , and six individuals with normal liver function were enrolled as control. Based on the insulin resistance index determined by Homeostasis Model Assessment (HOMA), CHB patients were further divided into CHB without insulin resistance group(<2.69, n=10) and CHB with insulin resistance group(>2.69, n=8) .Hepatic tissues were harvested from all patients during operation or with liver biopsy. The protein expression of IRS-2 was detected by Western blotting. Immunoprecipitation and enhanced chemiluminescent immunoblotting technique were used to measure the tyrosine phosphorylation of IRS-2.Results In CHB without insulin resistance group,the protein expression(0.94±0.18)and the tyrosine phosphorylation(0.78±0.09) of IRS-2 in hepatic tissue were decreased ,but without statistically significant difference (all P>0.05), as compared to those in control group(0.99±0.20,1.00±0.23,respectively).In CHB with insulin resistance group the protein expression(0.67±0.11) and the tyrosine phosphorylation(0.63±0.14)of IRS-2 in hepatic tissue were significantly decreased compared with those of the control group with statistically significant difference(P<0.05 or P<0.01).Conclusion Chronic hepatitis B virus infection may lead to insulin resistance. The decreased expression of protein expression and the reduced tyrosine phosphorylation of IRS-2 in CHB patients with insulin resistance inducing impairment of the insulin signal pathway, may be one of the mechanisms underlying insulin resistance.