Mesenchymal stem cell derived microvesicles: trophic shuttles for enhancement of sperm quality parameters.

Diminishing sperm quality during cryopreservation process ends up in a complete or partial loss of sperm's fertilizing potential. Rehabilitation of such affected sperm is crucial to improve their fertilizing potential. A variety of evidence has indicated that secreted microvesicles (MVs) from mesenchymal stem cells (MSCs) are involved in regeneration of injured endogenous cells via shuttling MSC trophic molecules. Sperm obtained from cauda epididymides of adult male Wistar rats were equally assigned to four separate groups. Following suspension in cryoprotectant extender, sperm were untreated or treated with increasing concentrations of MSC-derived MVs (25, 50 and 100μg). After incubation in successive steps, sperm were cryopreserved. The frozen-thawed sperm were assessed for viability, motility and antioxidant capacity parameters. Consequently, expression levels of surface adhesion molecules (CD29, CD44, ICAM-I and VCAM-I) involved in sperm fusogenic and signaling properties, were assessed by flow cytometry. Results showed an enhanced quality parameters and adhesive properties of cryopreserved sperm following treatment with MSC-derived MVs.