Smooth Muscle Progenitor Cells Preserve the Erectile Function by Reducing Corporal Smooth Muscle Cell Apoptosis after Bilateral Cavernous Nerve Crush Injury in Rats

Abstract

Radical prostatectomy causes erectile dysfunction (ED) and irreversible morphologic changes, including induction of endothelial and smooth muscle cell (SMC) apoptosis in the corpus cavernosum (CC). The injection of smooth muscle progenitor cells (SPCs) thickens the vascular intima and has demonstrated therapeutic benefit in cardiovascular disease animal. Herein, we investigated the effect of SPCs on the recovery of erectile function (EF) in rat models with bilateral cavernous nerve (CN) injury. Twenty-four male Sprague-Dawley rats were randomized into sham, vehicle only, or SPC treatment groups. Rats in the SPC treatment and vehicle groups were subjected to bilateral CN injury before intracavernosal injection. Intracavernosal injections of SPCs increased all EF parameters at day 28 after injury and simultaneously reduced apoptosis of the SMCs. Ultrastructural analysis revealed that SPCs maintained the integrity of the CC by preserving the structure of the adherens junctions. Tracking transplanted SPCs labeled with EdU showed that transplanted SPCs remained in the CC 28 days after treatment. Intracavernosal SPC injection restored EF after bilateral CN injury by reducing SMC apoptosis, which favored the maintenance of the structure of adherens junctions and regulated the stability of corporal vessels. These findings demonstrate the therapeutic potential of SPCs for treating ED in humans.