Exosomes derived from HEK293T cells interact in an efficient and noninvasive manner with mammalian sperm in vitro.

Aim: To investigate exosomes as a noninvasive delivery tool for mammalian sperm. Materials & Methods: Exosomes were isolated from HEK293T cells and co-incubated with boar sperm in vitro. Results: Internalized exosomes were detected within 10 min of co-incubation. Computer-assisted sperm analysis and flow cytometry demonstrated that even after 5-h of exposure to exosomes, there were no significant deleterious effects with regard to sperm motility, viability, membrane integrity and mitochondrial membrane potential (p > 0.05), thus indicating that exosomes did not interfere with basic sperm function. Conclusion: HEK293T-derived exosomes interacted with boar sperm without affecting sperm function. Exosomes represent a versatile and promising research tool for studying sperm biology and provide new options for the diagnosis and treatment of male infertility.

Influence of temperature, serum, and gonadotropin supplementation in short- and long-term organotypic culture of human immature testicular tissue.

OBJECTIVE: To study how temperature, serum, and gonadotropin supplementation affect the organotypic culture of human immature testicular tissue (ITT) in vitro. DESIGN: Experimental basic science study. SETTING: Reproductive biology laboratory. PATIENT(S): ITT from 4 boys with cancer that had testicular tissue cryopreserved as part of their fertility preservation treatment. INTERVENTION(S): In vitro organotypic culture of ITT, exposed to different temperatures (37°C vs. 34°C), serum (fetal bovine serum [FBS] vs. Knockout Serum Replacement [KOS]), and gonadotropin supplementation (with and without FSH and LH). MAIN OUTCOME MEASURE(S): Characterization of the tissue was performed at days 0, 14, and 70 with the use of reverse-transcription quantitative polymerase chain reaction, terminal deoxynucleotide transferase-mediated dUTP nick-end labeling, histologic analysis by means of hematoxylin-eosin staining, and immunohistochemical staining. Hormonal secretion was determined at days 3, 14, 28, and 70 by means of immunofluorescent assay. RESULT(S): The 37°C conditions showed an accelerated loss of tubular morphology and higher intratubular apoptosis. KOS supplementation triggered the up-regulation of STAR, SOX9, DAZL, DDX4, PLZF, and UTF1, the percentage of SOX9+/androgen receptor (AR)-positive mature Sertoli cells at day 14, and testosterone secretion. Gonadotropin supplementation increased the numbers of both undifferentiated UTF1+ spermatogonia and premeiotic VASA+/SYCP3+ spermatogonia at day 14, and the number of SOX9+ Sertoli cells at day 70. The low SOX9+/AR+ colocalization, the disorganized pattern of ZO-1, and the progressive decrease of antimüllerian hormone secretion indicated inefficient Sertoli cell maturation in vitro. CONCLUSION(S): The 34°C condition in KOS showed the best results for the survival of both spermatogonia and Sertoli cells. FSH/LH supplementation also improved long-term survival of Sertoli cells and the maturation of spermatogonia up to meiotic initiation in short-term culture.

Basic and Clinical Approaches for Fertility Preservation and Restoration in Cancer Patients.

As gonadotoxic adverse effects of antineoplastic treatments can result in infertility, gamete cryopreservation is routinely offered to patients as the strategy to preserve their fertility. However, there are many cases where gold standards cannot be applied, as is the case for prepubertal cancer patients and others unable to produce gametes or their precursors at the moment of diagnosis. With an increasing number of cancer survivors in our society, strategies using either cryopreserved gonadal tissue or stem cells have been developed to allow cancer survivors to achieve fatherhood, and recent advances in the field have increased public interest. In this review, we discuss the latest updates in fertility preservation from a basic and a clinical point of view.