Regenerative Potential of Stem and Progenitor Cells from Ischemic Testes of C57Bl/6 Mice in Culture and in the Model of Spermatogenesis Suppression Caused by Busulfan.

The regenerative potential of stem and progenitor cells from ischemic testes of C57Bl/6 mice was studied in vitro (cell culture) and in vivo (mouse model of busulfan-induced suppression of spermatogenesis). Spermatogonial stem cells with phenotypes CD117 ^- CD90 ⁺ and CD51 ^- CD24 ⁺ CD52 ⁺ from ischemic testes demonstrated 33-fold and 7-fold increments of cell mass and generated colonies in vitro. Epithelial (CD45 ^- CD31 ^- Sca-1 ⁺ CD49f ⁺ ) and endothelial (CD45 ^- CD31 ⁺ ) precursors exhibited lower self-renewal capacity. On day 30 after injection of stem and progenitor cells from ischemic testes to the rete testis zone of the testes of busulfantreated animals, an increase in the count of CD117 ^- CD90 ⁺ spermatogonial stem cells, total count, and mobile sperm count in the testes of recipient mice was observed. In addition, we observed an increase in Sca-1 ⁺ cell count, recovery of the spermatogenic epithelium in the seminiferous tubules, and appearance of immature Leydig cells in "busulfan" testes; the level of tissue testosterone and fertility index also increased.