Methyl protodioscin reduces c-Myc to ameliorate diabetes mellitus erectile dysfunction via downregulation of AKAP12

Background Diabetes mellitus erectile dysfunction (DMED) is one of common complications of diabetes. We aimed to investigate the potential efficacy of methyl protodioscin (MPD) in DMED and explored the underlying mechanism. Methods Diabetic mice were induced by streptozotocin, while vascular endothelial cells (VECs) and vascular smooth muscle cells (VSMCs) were stimulated with high glucose. MPD was administrated in vitro and in vivo to verify its efficacy on DMED. The interaction of c-Myc and AKAP12 was determined by luciferase reporter assay and chromatin immunoprecipitation assay. Results c-Myc and AKAP12 were upregulated in penile tissues in DMED mice. In high glucose-stimulated VSMCs or VECs, MPD intervention enhanced cell viability, inhibited apoptosis, decreased c-Myc and AKAP12, as well as elevated p-eNOS Ser1177. MPD-induced apoptosis inhibition, AKAP12 reduction and p-eNOSSer1177 elevation were reversed by AKAP12 overexpression. c-Myc functioned as a positive regulator of AKAP12. Overexpression of c-Myc reversed the effects induced by MPD in vitro, which was neutralized by AKAP12 silencing. MPD ameliorated erectile function in diabetic mice via inhibiting AKAP12. Conclusions MPD improved erectile dysfunction in streptozotocin-caused diabetic mice by regulating c-Myc/AKAP12 pathway, indicating that MPD could be developed as a promising natural agent for the treatment of DMED.