Expression of apolipoprotein D in autosomal dominant polycystic kidney disease and its influence on proliferation of cyst-lining epithelial cells / 第二军医大学学报

ABSTRACT

Objective To investigate the role of apolipoprotein D (ApoD) in the pathogenesis of autosomal dominant polycystic kidney disease (ADPKD). Methods The expression of ApoD protein in renal cystic tissues of ADPKD patients was examined by immunofluorescence and Western blotting analysis. Western blotting analysis and real-time PCR were used to detect the expression of ApoD protein and mRNA in the renal tissues of Han SPRD rats. The cystic lining immortalized epithelial cells (WT9-12 cells) of ADPKD were stimulated with human recombinant ApoD protein and their proliferation was examined by MTT assay; flow cytometry was used to determine the cell apoptosis and cell cycle distribution. Results Immunohistochemisty and Western blotting analysis showed that ApoD expression was significantly lower in the renal tissues of ADPKD patients than that in healthy controls, and that in the Han SPRD cy/+ rats was significantly lower than that in the Han SPRD +/+ rats (P<0. 05, P<0. 01). ApoD mRNA expression in the kidneys of Han SPRD cy/+ rats of 8, 12, 16, and 24 weeks old was significantly lower than that of Han SPRD +/+ rats of same ages (P<0. 05). Recombinant ApoD protein at 100, 200, and 400 ng/ml inhibited the proliferation of WT9-12 cells by 8. 21%, 7. 59% and 8. 07% after 48 h stimulation (P<0. 05), and by 8. 62%, 6. 43% and 9. 42% after 72 h stimulation, respectively (P<0. 05). Treatment with 400 ng/ml human recombinant ApoD protein for 72 h increased Gi phase WT9-12 cells by 8. 26% and decreased S phase cells by 8. 09% (P<0. 05), but it had no significant effect on cell apoptosis. Conclusion ApoD may inhibit WT9-12 cell proliferation by regulating cell cycle, and decreased ApoD expression may participate in the pathogenesis of ADPKD.