Correction of diabetes mellitus-induced erectile dysfunction with adipose tissue-derived stem cells modified with the DDAH 2 gene in a rat model

Objective: This study was designed to investigate the effect of DDAH2 transfected with adipose tissuederived stem cells (ADSCs) on improving erectile function in diabetic rats. Methods: Forty-eight male SpragueDawley rats were injected with streptozotocin to establish diabetes mellitus-induced erectile dysfunction (DMED). DMED rats were randomly divided into four groups: DMED+PBS group, rats received intracavernous injection of phosphate buffer solution; DMED+ADSCs group, rats received intracavernous injection of nontransfected ADSCs; DMED+null-ADSCs group, rats received intracavernous injection of empty vector transfected ADSCs; DMED+DDAH2ADSCs group, rats received intracavernous injection of Ad-DDAH2-transfected ADSCs. Before injection, high levels of DDAH2 expression were confirmed in rats in the DDAH2-ADSCs group by PCR and western blot. Four weeks after the injection, erectile function was ascertained by measuring intracavernous pressure (ICP). The pathological structure of penile tissues was evaluated by immunohistochemical analysis. Results: Compared with the other groups, ICP significantly increased after papaverine injection in rats in the DMED+DDAH2-ADSCs group. Diffused fibrosis and impairment of endothelial cells were observed in the corpus cavernosum of rats in the DMED+DDAH2-ADSCs group. Conclusion: Rats in the DMED+DDAH2-ADSCs group displayed a significant improvement of erectile function. DDAH2 was able to enhance the effect of ADSCs in the treatment of diabetes-associated erectile dysfunction.