Mol. Hum. Reprod. Advance Access published online on September 21, 2009
Molecular Human Reproduction, doi:10.1093/molehr/gap081
Immature rat seminiferous tubules reconstructed in vitro express markers of Sertoli cell maturation after xenografting into nude mouse hosts
1Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh School of Medicine, Pittsburgh PA 15213, USA 2Department of Cell Biology and Physiology, University of Pittsburgh School of Medicine, Center for Research in Reproductive Physiology, Pittsburgh PA 15213, USA 3Centre of Reproductive Medicine and Andrology, Institute of Reproductive and Regenerative Biology, University of Münster, 48149 Münster, Germany
* Corresponding Author: jens.ehmcke{at}ukmuenster.de
Sertoli cells undergo a maturation process during postnatal testicular development that leads to the adult - type Sertoli cell, which is required for spermatogenesis. Understanding Sertoli cell maturation is therefore necessary to gain insight into the underlying causes of impaired spermatogenesis and male infertility. The present study characterized the cellular and molecular differentiation of Sertoli cells in a xenograft model of mammalian testicular development. Immature rat Sertoli cells were cultured in a three - dimensional culture system to allow the formation of cord - like structures. The in vitro Sertoli cell cultures were then grafted into nude mice. Sertoli cell proliferation, morphological differentiation and mRNA expression of Sertoli cell maturation markers were evaluated in xenografts. Sertoli cell proliferation significantly decreased between one week and four weeks (6.7 %±0.9 vs. 1.2 %±0.1, p<0.001), and was maintained at low levels thereafter. Sertoli cell cord - like structures significantly decreased between one week and four weeks (59.6 % vs. 21 %, p<0.05), whereas Sertoli cell tubules were more frequently observed after four weeks (13.3 % vs. 73.1 %, p<0.05). Furthermore, expression of androgen binding protein, transferrin, and follicle stimulating hormone receptor, markers for mature Sertoli cells, was detected after one week of grafting and increased significantly thereafter. We conclude from these results that rat Sertoli cells continue maturation after xenografting to the physiological environment of a host. This model of in vitro tubule formation will be helpful in future investigations addressing testicular maturation in the mammalian testis.
Key Words: 3-Dimensional Cell Culture/Sertoli Cell/Testicular Development/Xenografting
Submitted on June 5, 2009; resubmitted on September 10, 2009; accepted on September 16, 2009.