ABSTRACT
Objective: To explore the role and mechanism of aging pathway in patent ductus arteriosus closure of rats. Methods: Thirty outbreeding Sprague Dawley rats(20 females, 10-15 weeks old, 270-330 g) underwent random mating and conception. The primary Ductus Arteriosus smooth muscle cells (DASMCs) of pregnant 19 days(E19 group), 21 days(E21 group) and newborn(Day0 group) fetus were extracted and cultured. mRNA expression of cell senescence related markers p16, 21 and 53 genes in each group were detected by real-time fluorescent quantitative PCR(RT-PCR) after 48 hours culture. After hypoxic culture on DASMCs for 3 days, the DASMCs were divided into 3 groups: hypoxic control group(G0 group), 3 hours normal oxygen concentration treatment group(G3 group) and 6 hours normal oxygen concentration treatment group(G6 group). After intervention, mRNA expression of p16, 21 and 53 RT-PCR was detected. The DASMCs of newborn rats(Day0 group) were extracted and divided into 3 groups:low-oxygen culture control group, low-oxygen+siRNA culture group and normal oxygen concentration culture group. The DASMCs migration ability was tested experimentally by Transwell method. Result: The mRNA levels of p16, 21 and 53 in DASMCs were higher in E19 group than in Day0 group(all P<0.01), and the mRNA levels of p16, 21 and 53 in DASMCs were also higher in E21 group than those in Day0 group (all P<0.01). The mRNA levels of p16, 21 and 53 in DASMC were all higher in G0 group than those in G3 group (P<0.05 or 0.01), and the mRNA levels of p16, 21 and 53 in DASMCs were all higher in G0 group than those in G6 group (all P<0.01), and the mRNA levels of p16, 21 and 53 in DASMCs were all higher in G3 group than those in G6 group (all P<0.05). DASMCs migration ability of newborn rats was higher in normal oxygen concentration culture group than that in low-oxygen culture group (P<0.01), and DASMCs migration ability of newborn rats was also higher in low-oxygen+siRNA culture group than that in low-oxygen culture group (P<0.01). Conclusion: The expression of senescence marker of DASMCs decreases with the birth in rats during the process of ductal closure, and the aging pathway may affect ductal closure by inhibiting DASMCs migration in rats.