Spermatogenesis after allotransplanting of adipose tissue-derived and bone marrow-derived mesenchymal stem cells in seminiferous tubules of azoospermic mice

Background: Adipose tissue-derived mesenchymal stem cells (AT-MSCs) and bone marrow-derived mesenchymal stem cells (BM-MSCs) could be used for cell therapy of azoospermia due to their differentiation and therapeutic potential. AT-MSCs and BM-MSCs have proliferative induction potential and immunomodulatory effects, and can secret growth factors and cytokines. In this experimental study the ability of allotransplantation of AT-MSCs and BM-MSCs in recovery of fertility in busulfan-induced azoospermic testes of mice were evaluated using histomorphometric indices and flowcytometry. The aims of the present study were also to evaluate the potential of differentiation of AT-MSCs and/or BM-MSCs into germinal layer cells of seminiferous tubules.Materials and Methods: Adult male mice were randomly divided into four groups including the intact control, azoospermia-induced, AT-MSCs therapy, and BM-MSCs therapy groups. Except intact control, the other groups were intraperitoneally received two doses of 10 mg/kg of busulfan with 21 days’ interval in order to induce azoospermia. AT-MSCs and BM-MSCs were isolated from subcutaneous fat and bone marrow tissues of two donor eGFP+/+ mice. The MSCs were injected into the efferent ducts of testes of cell therapy mice 35 days after the last busulfan injection. The cell therapy groups were sampled 60 days after cell therapy and the other groups were sampled in the same time. The histomorphometric indices of testes were evaluated. Flow cytometry were used to compare expression of eGFP in the produced sperm in epididymis of all groups.Results: Histomorphometric evaluation of seminiferous tubules of cell therapy groups showed that most of the tubules had degrees of spermatogenesis. Histopathologic evaluation of testes showed that most of the seminiferous tubules of cell therapy group had normal cell morphology. Spermatogenesis was not seen in the azoospermia group. Production of some eGFP sperm showed evidences of probable differentiation of MSCs into germinal cell layers.Conclusion: Allotransplanted AT-MSCs and BM-MSCs could successfully induce spermatogenesis in azoospermic seminiferous tubules of mice. AT-MSCs are easier and safer to obtain for stem cell therapy of azoospermia in comparison with BM-MSCs. Therefore, AT-MSCs and BM-MSCs can be injected in cell transplantation of azoospermia in human.