Rat cavernous nerve reconstruction with CD133+ cells derived from human bone marrow.

INTRODUCTION: Erectile dysfunction remains a major complication after surgery of pelvic organs, especially after radical prostatectomy.

AIM: The aim of this study was to assess the effect of endothelial progenitor cells on the regeneration of cavernous nerves in a rat injury model.

METHODS: A 2 mm length of the right and left cavernous nerves of 8-week-old male nude rats were excised. Alginate gel sponge sheets supplemented with 1 × 10(4) CD133+ cells derived from human bone marrow were then placed over the gaps on both sides (CD group). The same experiments were performed on sham-operated rats (SH group), rats with only the nerve excision (EX group), and rats with alginate gel sheets placed on the injured nerves (AL group).

MAIN OUTCOME MEASURES: Immunofluorescence staining and molecular evaluation were performed 4 days later. Functional and histological evaluations were performed 12 weeks later.

RESULTS: The intracavernous pressure elicited by electrical stimulation and the neuronal nitric oxide synthase-positive area in surrounding tissues of the prostate was significantly greater in the CD group. Immunofluorescence microscopy showed that CD133+ cells were assimilated as vascular endothelial cells, and the real-time polymerase chain reaction showed upregulation of nerve growth factor and vascular endothelial growth factor in the alginate gel sponge sheets of the CD group.

CONCLUSIONS: Transplantation of CD133+ cells accelerated the functional and histological recovery in this cavernous nerve injury model, and the recovery mechanism is thought to be angiogenesis and upregulation of growth factors. CD133+ cells could be an optional treatment for cavernous nerve injury after prostatectomy in clinical settings.