(229) Effect of Filtrated Bone Marrow-Derived Stem Cell Lysate on Erectile Function and Nerve Regeneration in Rats With Neurogenic Erectile Dysfunction
Authors: Mori T , Hotta Y , Kataoka T , Matsumoto S , Yamamoto T , Kimura K 
Published: May 2023

Abstract

Introduction
The transplantation of bone marrow-derived mesenchymal stem cell (BMSC) is believed to be a novel therapy for erectile dysfunction (ED) following radical prostatectomy (RP). However, the difficulty in preparation and higher costs challenge clinical application of this therapy. To overcome these challenges, we investigated the feasibility of filtrated BMSC lysate (BSCL) to alleviate ED in rats. We have reported BSCL improved erectile function in a rat model of bilateral cavernous nerve injury (BCNI). However, the mechanism remains unclear.

Objective
The study aimed to investigate the mechanism of BSCL for improving neurogenic ED focusing on nerve regeneration.

Methods
BSCL was obtained by freeze fracturing and filtrating BMSCs which were obtained from Wistar/ST rats. Three experiments were performed in this study. The first experiment included an eight-week-old male Wistar/ST rats, further divided into three groups: Sham + PBS, BCNI + PBS, and BCNI + BSCL (n=8). Rats in the Sham + PBS group underwent sham surgery, while those in the BCNI + PBS group underwent BCNI surgery. Immediately after the surgery, phosphate-buffered saline (PBS) was injected into the corpus cavernosum. Rats in the BCNI+BSCL group also underwent BCNI surgery. Immediately after the surgery, BSCL was injected into the corpus cavernosum. Four weeks after the surgery, erectile function was evaluated by measuring intracavernosal pressure (ICP)/mean arterial pressure (MAP) under stimulation of cavernous nerve. The second experiment was conducted on eight-week-old male Wistar/ST rats, further divided into three groups, same as in the first experiment. Three weeks after the surgery, fluorogold (FG) was injected into the corpus cavernosum from both sides. One week after the injection, bilateral major pelvic ganglions (MPGs) were dissected. FG reaching to MPG was observed using fluorescence microscope. The MPGs were also proved with anti PGP9.5, a neuron cell marker. In the third experiment, MPG were dissected from ten-week-old male Wistar/ST rats, placed on Matrigel and incubated with normal medium or medium including BSCL (50, 125, 250, and 500 ng/mL, respectively). After 48 hours, neurite outgrowth was measured using a Z-stack microscope.

Results
ICP/MAP in the BCNI+PBS group was significantly lower than that in the Sham+PBS group (P &lt; 0.05), and ICP/MAP in the BCNI+BSCL group was significantly higher than that in the BCNI+PBS group (P &lt; 0.05). The ratios of FG positive cells to PGP9.5 positive cells in the BCNI+PBS group were significantly lower than those in the Sham+PBS group. Those in the BCNI+BSCL group were higher than those in the BCNI+PBS group. MPG treated with the medium including BSCL had longer neurite outgrowth than MPG treated with normal medium. This neurite outgrowth effect of BSCL increased in a dose-dependent manner.

Conclusions
In conclusion, BSCL treatment improved erectile function in rats with neurogenic ED. In addition, BSCL has the potential to improve neurotransmission of cavernous nerves and BSCL exhibited neurite outgrowth effects on rat MPG. The study demonstrates that BSCL can regenerate a crushed cavernous nerve, improving erectile function. Further study should be conducted to identify active factors in BSCL contributing to nerve regeneration.

Disclosure
No