Stem Cells for Erectile Dysfunction

Seoul, Korea -

Despite introduction of phosphodiesterase V inhibitors such as Viagra for the treatment of erectile dysfunction, many patients remain unresponsive due to underlying endothelial and/or smooth muscle abnormalities in the corpus cavernosum and vessels supplying it.

Mesenchymal stem cells offer the possibility of treatment for erecticle dysfunction due to their ability to secrete angiogenic growth factors, stimulate smooth muscle proliferation, and increase responsiveness of endothelium to vasoactive factors.

In a recent paper (Song et al. Potential differentiation of human mesenchymal stem cell transplanted in rat corpus cavernosum toward endothelial or smooth muscle cells. Int J Impot Res. 2007 Apr 26) the possibility of mesenchymal stem cells to differentiate into tissues that are abnormal in erectile dysfunction patients was assessed.

Human mesenchymal stem cells were immortalized by introduction of the v-myc oncogene and introduced intracavernosally into rats. Two weeks later the rats were euthanized and penile tissue was examined.

Human CD31 and vWF was detected in the rat penile tissue, indicating differentiation along the endothelial lineage. Differentiation into the smooth muscle lineage was suggested by expression of smooth muscle cell actin, calponin and desmin.

The transplanted cells also differentiated into cells of the adipogenic, osteogenic and chondrogenic lineage.

While these experiments demonstrate feasibility of stem cell injections into the penile body, and possibility of differentiation into tissues useful for proper erectile function, the study did not examine functional benefit.

Additionally, it may be important in future studies to combine stem cells with agents such as testosterone which increase the smooth muscle to adipose ratio in the penile body.