Bone marrow c-kit⁺ cells injected intravenously improved the sperm parameters and stereological changes in the testes...

Here, the regenerative properties of c-kit⁺ cells were evaluated on testes in terms of histological and stereological changes as well as sperm parameters in type 2 diabetic rats. In this investigation, 48 male Wistar rats (180-220 g) were randomly divided into four groups (each n = 12); including control (C), diabetic rats (D), diabetic rats treated by c-kit^- (D+c-Kit^-) and c-kit⁺ (D+c-Kit⁺) cells. To induce type 2 diabetes mellitus, animals received a low dose of streptozotocin (35 mg/kg, i.p.) followed by feeding with a high-fat diet for 4 weeks. After diabetes confirmation, 50 μl PBS containing 3 × 10⁵ bone marrow c-kit^- and c-kit⁺ cells were administered in rats of D+c-Kit^- and D+c-Kit⁺ groups, respectively. Eight weeks later, sperm parameters, morphological features, and changes in testicular tissue and stereological changes were evaluated in diabetic rate after cell transplantation. Immunofluorescence imaging showed the successful homing of fluorochrome-labeled cells into the testicular tissues of both D+c-Kit^- and D+c-Kit⁺ groups. Diabetes induction led to structural abnormalities in the testes with prominent stereological changes. Sperm parameters including total count, motility, viability, normal appearance, and large halo malformation were significantly reduced in the D group compared to the C group (p < 0.001). Other features such as sperm abnormality index, teratozoospermia index (TZI), sperm malformations, percent of immotile sperm (grade E), and DNA fragmentation like small halo and non-halo malformations increased in non-treated diabetic rats compared to controls (p < 0.001). Injection of c-kit⁺ cells in the D group^, but not c-kit^- cells, blunted detrimental effects of hyperglycemic conditions. The results showed that administration of c-kit⁺ cells in type 2 diabetic rats had beneficial effects on reproductive competence including sperm parameters, sperm malformation, and DNA fragmentation as well as testicular structure and stereology.