Abstract:

Objective To investigate the expression of transforming growth factor-β （TGF-β） and hypoxia inducible factor-1α (HIF-1α) in mice with paraquat poisoning. Methods Thirty male C57BL/6J mice were randomly divided into control group (n=10) and paraquat group (n=20). Paraquat (20 mg/kg) was intraperitoneally administered to mice in paraquat group, while the same volume of normal saline was intraperitoneally administered to those in control group. Ten mice in paraquat group were sacrificed on the 7th day after treatment with paraquat, and the rest of mice were killed on the 28th day. The pathological examinations of lung tissues were performed with HE staining and Masson staining, and the expression of TGF-β and HIF-1α protein in lung tissues was detected by immunohistochemistry. The correlation of expression of TGF-β protein with expression of HIF-1α protein was explored by Pearson correlation analysis. Results HE staining and Masson staining indicated that there were presentations of lung fibrosis in paraquat group on the 7th day, and the severity of lung fibrosis increased on the 28th day. The expression of TGF-β protein in lung tissues in paraquat group was significantly higher than that in control group on the 7th day (P<0.05), and the expression of TGF-β protein in lung tissues on the 28th day was significantly higher than that on the 7th day in paraquat group (P<0.05). The expression of HIF-1α protein in lung tissues in paraquat group was significantly higher than that in control group on the 7th day and 28th day (P<0.05). The expression of HIF-1α protein in lung tissues on the 28th day was higher than that on the 7th day in paraquat group, while there was no significant difference between them (P>0.05). There was no correlation of expression of TGF-β protein with expression of HIF-1α protein on the 7th day and 28th day in paraquat group (r=0.295, P=0.630; r=0.218, P=0.725). Conclusion Paraquat poisoning can up-regulate TGF-β and HIF-1α protein in lung tissues of mice, and TGF-β and HIF-1α may be involved in the formation of lung fibrosis through different pathways.

Key words: paraquat, poisoning, transforming growth factor-β, hypoxia inducible factor-1α, pulmonary fibrosis