SUN-LB045 Microfluidic and Static Culture of Human Testicular Tissue

Testicular tissue culture has been used as a method to study testicular physiology for over 100 years. However, most of these investigations rely upon rodent tissues, and the translation of these techniques to the human model has proven comparably challenging. This is a critical gap in our fundamental knowledge of human testis biology and limits the value of testicular tissues currently being cryopreserved for men and boys requiring fertility preservation. To meet these twin objectives, maintaining or maturing human testicular tissues ex vivo must be accomplished using new technologies. Microfluidics is an emerging technology that has been developed to support cells ex vivo and has resulted in longer lived tissue function, including the murine ovary and human female reproductive tract. Recent work in the microfluidic culture of murine testes has also demonstrated superior germ cell maintenance comparatively with static culture. For these reasons, we hypothesized that the microfluidic culture will similarly improve and extend the viability of cultured human testicular tissue, while also enabling investigations into endocrine function through a non-invasive manner. To test our hypothesis, we cultured human testicular tissue in both microfluidic and static conditions. Our microfluidic culture system is composed of inert materials (optimal for the recovery of steroid and peptide hormones), and was run at a 40 μL/hour flow rate. Adult human tissues were donated through an IRB-approved autopsy protocol. Tissues were cultured at an air-liquid interface in both culture conditions for upwards of 2 weeks and in the presence of gonadotropins (hCG and FSH). At the completion of culture, tissues were fixed and processed for histological analysis, and major cell types and structures were identified. Secreted testosterone and Inhibin B within culture media was quantified via enzyme-linked immunosorbent assay. Cultured tissues demonstrated a dramatic reduction in germ cell number in both static and microfluidic conditions. However, tissues cultured in microfluidics demonstrated reduced tubule basement membrane breakdown and structural degeneration. Tissues cultured in both conditions were productive of secreted testosterone and inhibin B. In conclusion, the present study has explored the utility of microfluidics for human testicular culture. Similar to other tissues, microfluidic culture supported higher viability and better tissue integrity compared to static. Furthermore, microfluidic culture was a convenient way to study secreted hormones over time. Dissimilar to murine microfluidic reports, germ cell populations were not maintained in our studies, yet work is continuing to improve this outcome. Funding: This work was funded by a UH3 grant under the NIEHS and a F31 grant under the NICHD at the National Institutes of Health. Unless otherwise noted, all abstracts presented at ENDO are embargoed until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. Abstracts presented at a news conference are embargoed until the date and time of the news conference. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.