Recovery of erectile dysfunction after administration of hydrogen sulfide donor sodium hydrogen sulfide and transplantation of adipose-derived stem cells in rats with bilateral cavernous nerve injury

Abstract

ABSTRACT Introduction Radical prostatectomy causes nerve injury-related erectile dysfunction (ED), which results in a poor response to phosphodiesterase 5 inhibitors. Hydrogen sulfide (H2S), an endogenous gasotransmitter, is produced by cystathionine-β-synthase (CBS), cystathionine-γ-lyase (CSE) and 3-mercaptopyruvate sulfurtransferase (3-MST) and participates in erectile physiology. Adipose-derived stem cells (ADSCs) represent a promising cell source for cell replacement therapy in several degenerative diseases because of its self-renewal properties and multi-differentiation potential with low immunogenicity. Objective The current study was to evaluate the effects of H2S donor, sodium hydrogen sulfide (NaHS), and transplantation of ADSCs per se and their combination treatment on bilateral cavernous nerve injury (BCNI)-induced erectile dysfunction (ED). Methods A total of 35 Sprague-Dawley rats were divided into 5 groups, including sham-operated (Sham), BCNI (4-wk), BCNI treated with NaHS (5.6 mg/kg/day, i.p.), BCNI treated with ADSCs (1x106 cells by intracavernosal injection) and BCNI treated with NaHS and ADSCs groups. Rats in the ADSCs treatment groups were subjected to intracavernosal injection after BCNI. Erectile function was evaluated by the ratio of intracavernous pressure (ICP)/mean arterial pressure (MAP) and total ICP. The relaxant and contractile responses of corpus cavernosum (CC) were measured from in vitro studies. Protein expression and localization of nitric oxide synthases (NOS) and H2S synthesis enzymes were analyzed by Western blotting and immunohistochemistry. The smooth muscle/collagen ratio was determined using Masson trichrome staining. Results Rats with BCNI displayed significantly reduced ICP/MAP and total ICP (p<0.001 vs controls) when were partially restored by NaHS and ADSCs treatments alone. Interestingly, combined treatment completely enhanced decreased in vivo erectile responses (p<0.001 vs the NC group). Relaxation responses to acetylcholine and electrical field stimulation (EFS) as well as contractile responses to phenylephrine and EFS in the CN group were less than in controls (p< 0.05), which was normalized after all treatments groups. The combined treatment modulated changes of protein expressions and reduced ratio of smooth muscle to collagen in rats with BCNI. Conclusions The current data indicated that the combination treatment with NaHS and ADSCs is more successful than monotherapies in reversing BCNI-induced ED. H2S and cell-based therapy most probably may have a synergistic effect on erectile function via controlling molecular regulation and morphological penile alterations, which supports combined treatment for expanding clinical outcomes radical prostatectomy-induced ED. Disclosure Work supported by industry: no.