The effect of RDP on cell proliferation and apoptosis of porcine Leydig cells with hypoxia

Abstract

Abstract Rhodiola polysaccharides (RDP) has antioxidant effect on cells, but the underlying role of RDP in Leydig cells remains unknown. The study aimed to investigate the contribution of RDP to proliferation and apoptosis of porcine Leydig cells in hypoxia (1% O2, 4% CO2, 94% N2) and explore the mechanism.The porcine Leydig cells were divided into three groups: normal group, hypoxia group, and hypoxia+RDP group. Cell viability was measured by Cell Counting Kit-8 (CCK-8, Biosharp, China). The activities of Superoxide Dismutase(SOD), Malondialdehyde(MDA) and Glutathione Peroxidase(GSH-PX) was tested by enzyme-linked immunosorbent assay. Detection of cell cycle progression and cell apoptosis was using Flow Cytometry. The gene and protein expression levels were determined by quantitative real-time PCR and western blot assay, respectively. CCK-8 assay results showed that RDP can relieve the decrease in cell viability caused by hypoxia. The optimal treatment of porcine Leydig cells was as follows: porcine Leydig cells were cultured with 0.0125 mg/mL RDP polysaccharide in normoxia for 18 h, and then cultured in hypoxia for 18 h. Flow cytometry results showed that RDP can relieve that hypoxia induced cell cycle arrest in G1/S phase and decrease apoptosis in porcine Leydig cells. RDP exerted anti-inflammatory effects via inhibiting TNF-α and IL-6 expression and conferred anti-apoptotic effects by upregulating the Bax, CCND1, CDK4 and downregulating Bcl-2, Caspase-3,p21, p53 and pJNK expression.RDP may regulate p53 and JNK pathways to promote cell proliferation and inhibit cell apoptosis, thus effectively alleviating the adverse effects of hypoxia induction on porcine Leydig cells.