Cell cycle regulation of pulmonary fibroblasts proliferation in neonate rats induced by transforming growth factor- β1 / 中华实用儿科临床杂志

ABSTRACT

Objective@#To investigate the effect of transforming growth factor(TGF)-β1 stimulation on the proliferation of lung fibroblasts and the pathogenesis of bronchopulmonary dysplasia(BPD).@*Methods@#The lung fibroblasts of newborn rats were isolated, purified and identified on the 1st day after birth.The primary lung fibroblasts were stimulated by TGF-β1, and the protein expression of cyclin-dependent kinase-2(CDK2) and p27 were detected by immunohistochemistry and Western blotting.Real-time fluorescence quantitative polymerase chain reaction(PCR) was used to detect the mRNA expression of CDK2 and p27.CCK8 kit was used to detect cell proliferation, and cell cycle was detected by flow cytometry.@*Results@#The expression of CDK2 protein and mRNA in primary fibroblasts was increased after TGF-β1 stimulation in lung fibroblasts of newborn rats, accompanied by the decrease of p27 protein and mRNA.CCK8 showed that the value of A increased significantly, proliferation significantly increased the proportion of S phase cells at the same time, G0/G1 phase decreased.The percentage of S phase cells after stimulation with 0 μg/L, 10 μg/L TGF-β1 was 4.63%, 67.09%, respectively.The percentage of G0/G1 phase was 83.67% and 67.09%, respectively.The percentage of S phase cells was 7.64% and 9.11% respectively after stimulated with 10 μg/L TGF-β1 for 12 h and 48 h, respectively.The percentage of G0/G1 phase was 73.99% and 59.81% respectively.With the increase of TGF-β1 levels (0 μg/L, 5 μg/L and 10 μg/L), CDK2 protein and mRNA expression further increased; and the same level of TGF-β1 stimulation, stimulated for 12, 24 and 48 h, the expression of CDK2 protein and mRNA increased further, and increased significantly at 48 h (P<0.05 and <0.01 respectively). The levels of p27 protein and mRNA decreased further(all P<0.01).@*Conclusions@#TGF-β1 can up-regulate the expression of CDK2/p27 in primary lung fibroblasts of neonatal rats, accelerating cell cycle progression and over-proliferation of fibroblasts.