Autologous Bone Marrow-Derived Mesenchymal Stem Cells in the Reversal of Unobstructed Azoospermia in Rats

Non-obstructive azoospermia (NOA) is an important cause of male infertility. This study is being proposed to assess the efficacy of autologous bone marrow-derived mesenchymal stem cells (MSCs) in the reversal of busulfan-induced NOA in rats.

Twenty adult 3-month-old male rats were divided into two groups: a control group and a study group. In the study group, bone marrow was aspirated to culture MSCs. NOA was created by stopping endogenous spermatogenesis in all the animals by injecting two doses of busulfan 10 mg/kg body weight with a 3 week interval. Four weeks after the last dose of busulfan, two animals were euthanized and the testes were studied histologically to confirm complete azoospermia. In the study group, five million MSCs in 1 mL normal saline were injected into seminiferous tubules; and in the control group, 1 mL of normal saline was injected. After 4 weeks of MSC injection, all the rats were euthanized and epididymis tails and testes were harvested and sent for measurement of serological indices, including luminal, cellular, and total diameters, luminal, cellular, and cross-sectional areas, number of tubules per unit area of testis, numerical density of the tubules, and spermatogenesis index, pre- and post-MSC transplantation.

The effect of busulfan on the testicular tissue was universally devastating. In the control group, there was variable length and width of markedly necrotic seminiferous tubules, whereas in the group treated with autologous bone marrow-derived MSCs there was variable height of germinal epithelium in seminiferous tubules, with active spermatogenesis, showing spermatogonia, spermatocytes, and sperm.

MSC injection in the testis has the potential to reverse the testicular function of spermatogenesis after cytotoxic therapy. Human trials should be undertaken to confirm our findings and bring the results into clinical practice.