(274) BMP2 Restores Erectile Dysfunction Through Neurovascular Regeneration and Fibrosis Reduction in Diabetic Mice.

Introduction: The odds of erectile dysfunction (ED) are thrice more prevalent in diabetes. Severe peripheral vascular and neural damage in diabetic patients responds poorly to PDE5 inhibitors. However, bone morphogenetic protein 2 (BMP2) is known to be involved in angiogenesis. Objective: To assess the efficacy of BMP2 stimulating angiogenesis and augmenting nerve regeneration in a mouse model of diabetic-induced erectile dysfunction. Methods: The induction of diabetes mellitus was done by streptozotocin (STZ, 50 mg/kg daily) administered intraperitoneally for five successive days to male C57BL/6 mice that were 8 weeks old. Eight weeks post inductions, animals were allocated to one of five groups: a control group, an STZ-induced diabetic mouse group receiving two intra-cavernous 20 μL PBS injections, or one of three BMP2 groups administered two injections of BMP2 protein (1μg, 5 μg, or 10 μg) diluted in 20 μL of PBS with three days interval between the first and second injection. The erectile functions were assessed two weeks after PBS or BMP2 protein injections by recording the ICP (intracavernous pressure) through cavernous nerve electrical stimulation. Angiogenic activities also nerve regenerating effects of BMP2 were determined in penile tissues, aorta, vena cava, the main pelvic ganglions, the dorsal roots, and from the primary cultured MCECs (mouse cavernous endothelial cells). Moreover, fibrosis-related factors protein expressions were evaluated by western blot. Results: Erectile function recovery to 81% of the control value in diabetic mice was found with intra-cavernous BMP2 injection (5 μg/20 μL). Pericytes and also endothelial cells were extensively restored. It was confirmed that angiogenesis was promoted in the corpus cavernosum of diabetic mice treated with BMP2 through increased ex vivo sprouting of aortic rings, vena cava and penile tissues, and migration and tube formation of MCECs. BMP2 protein enhanced cell proliferation and reduced apoptosis in MCECs and penile tissues, and promoted neurite outgrowth in major pelvic ganglia and dorsal root ganglia under high-glucose conditions. Furthermore, BMP2 suppressed fibrosis by reducing MCEC fibronectin, collagen 1, and collagen 4 levels under high-glucose conditions. Conclusions: BMP2 modulates neurovascular regeneration and inhibits fibrosis to revive the mice's erection function in diabetic conditions. Our findings propose that the BMP2 protein represents a novel and promising approach to treating diabetes-related erectile dysfunction (ED). Disclosure: No. [ABSTRACT FROM AUTHOR]