Hindawi Publishing Corporation BioMed Research International Volume 2013, Article ID 529589, 18 pages http://dx.doi.org/10.1155/2013/529589 Research Article Recovery of Fertility in Azoospermia Rats after Injection of Adipose-Tissue-Derived Mesenchymal Stem Cells: The Sperm Generation Cihangir Cakici, 1 Bugra Buyrukcu, 1 Gokhan Duruksu, 2 Ahmet Hakan Haliloglu, 3 Ayca Aksoy, 2 Ayca IsJk, 1 Orhan Uludag, 4 Huseyin Ustun, 5 Cansu SubasJ, 2 and Erdal Karaoz 2 1 Ankalife IVF and Women Health Centre, Ankara, Turkey 2 Stem Cell Department, Institute of Health Sciences, Kocaeli University Center for Stem Cell and Gene herapies Research and Practice, Izmit, 41380 Kocaeli, Turkey 3 Urology Department, Faculty of Medicine, Ufuk University, Ankara, Turkey 4 Department of Pharmacology, Faculty of Pharmacy, Gazi University, Ankara, Turkey 5 Pathology Department, Ankara Hospital, Ankara, Turkey Correspondence should be addressed to Erdal Karaoz; ekaraoz@hotmail.com Received 10 October 2012; Revised 6 December 2012; Accepted 9 December 2012 Academic Editor: homas Skutella Copyright © 2013 Cihangir Cakici et al. his is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. he recent reports on the treatment of azoospermia patients, in which spermatozoa could not be traced in their testes, are focused more on the potential use of adult stem cells, like mesenchymal stem cells (MSCs). he aim of this study was to demonstrate the potential use of MSCs derived from adipose tissue in the treatment of azoospermia using rat disease models. Ater busulfan application, the rats ( = 20) were injected with the GFP + MSCs into let rete testes. Ater 12 weeks, the testes with cell injection (right testes) were compared to control (let testes) ater dimensional and immunohistochemical analyses. Testes treated with MSCs appeared morphologically normal, but they were atrophic in rats without stem cell treatment, in which the seminiferous tubules were empty. Spermatogenesis was detected, not in every but in some tubules of cell-treated testes. GFP + /VASA + and GFP + /SCP1 + cells in testes indicated the transdiferentiation of MSCs into spermatogenetic cells in the appropriate microenvironment. Rats with cell treatment were mated to show the full recovery of spermatogenesis, and continuous generations were obtained. he expression of GFP was detected in the mesenchymal stem cells derived from adipose tissue and bone marrow and also in the sperms of ofspring. In conclusion, MSCs might be studied for the same purpose in humans in future. 1. Introduction he self-renewal and the multilineage diferentiation capac- ities of adult stem cells (ASCs) show great promises for regenerative medicine. Despite of the greater diferentia- tion potential of embryonic stem cells (ESCs) compared to ASCs, ethical concerns and governmental restrictions are the main obstacles of the ESCs standing in the way of their clinical applications [1]. On the other hand, bone-marrow- derived MSCs (BM-MSCs) are among the mostly studied ASCs, and their potential to treat a wide variety of dis- eases, including erectile dysfunction and male infertility, was demonstrated. Alternatively, adipose-tissue-derived MSCs (AT-MSCs) could be used in future clinical applications instead of bone marrow stem cells due to their comparable diferentiation and therapeutic potential, but AT-MSCs are easier and safer to obtain [1–18]. he stem cells were relatively lately adapted in andrology researches on erectile dysfunction and infertility as potential therapeutic agents. he studies related in this area showed that ESC could participate in spermatogenesis by forming functional male germ cells in vitro or by supporting the mat- uration of primordial germ cells into haploid male gametes [19–21]. Nayernia et al. reported germ cell line formation