Differences in adipose-derived stem cells from rats with various health statuses and their effects in diabetic rats with erectile dysfunction

It is essential to use high-quality adipose-derived stem cells (ADSCs) for clinical applications. The functional characteristics of ADSCs differ in the presence of various health conditions. Specifically, recent studies of the therapeutic effects of ADSCs from individuals with diabetes and no erectile dysfunction (NED-ADSCs), ADSCs from those with diabetes and erectile dysfunction (ED-ADSCs), and normal ADSCs have generated conflicting results. Therefore, we aimed to provide evidence for the clinical utility of ADSCs. Diabetes mellitus (DM) was induced in rats by the intraperitoneal injection of streptozotocin (STZ; 40 mg kg-1) following 4 weeks of high-fat diet feeding. After 12 weeks, erectile dysfunction was confirmed using the apomorphine (80 µg kg-1) test, and those with diabetes mellitus-related erectile dysfunction (DMED) were randomly assigned to treatment groups. Each group was administered 1 × 106 allogeneic ADSCs by injection into the corpus cavernosum; then, erectile function and penile histology were evaluated 28 days later. Of the three ADSCs types injected, normal ADSCs exhibited the strongest proliferation and differentiation capabilities. Following ADSCs treatment, there was an increase in smooth muscle cell number and a higher muscle-to-collagen fiber ratio. The expression of neuronal nitric oxide synthase (nNOS) in the dorsal nerve significantly increased. In addition, proteomic analysis revealed that heat shock protein expression was very low in the diabetic rats, but upregulated by stem cell therapy, which may represent a mechanism for the beneficial effects of ADSCs. Therefore, men with diabetes should consider the early preservation of ADSCs to help prevent the onset of erectile dysfunction (ED).