Expression and Effect of Cyclin Dependent Kinase-4 and p21 in Premature Rats with Hyperoxia-Induced Chronic Lung Disease / 实用儿科临床杂志

ABSTRACT

Objective To investigate the dynamic change of expression of cyclin dependent kinase-4(CDK4)and cyclin dependent kinase inhibitor(p21)in premature rats with hyperoxia-induced chronic lung disease(CLD)and its role.Methods Eighty premature rats were randomly and equally divided into model group(hyperoxia group)and control group(room air group).CLD was induced by hypemxia exposure.The expression of CDK4 and p21 were observed with immunohistochemical method,and the levels of type I collagen were detected by enzyme-linked immunosorbent assay on days 1,3,7,14 and 21.Results Compared with control group,in model group,the expression of CDK4 protein and level of type I collagen statistically increased,but expression of p21 protein decreased significantly on days 14 and 21.The expression of CDK4 was positive correlated with the degree of fibrosis,and expression of p21 was negative correlated with the degree of fibrosis in model group.Conclusion The expression of CDK4 increases and expression of p21 decreases in premature rats exposed to hyperoxia,which may play an important role in the lung fibrosis.