FRI395 Ovary-derived Hydrogels Elucidate The Matrisome Properties That May Influence Folliculogenesis

Abstract

Abstract Disclosure: H.B. McDowell: None. N. Henning: None. M.M. Laronda: None. Chemotherapy treatments can be gonadotoxic and lead to loss of fertility and hormone function. Currently, the only pre-treatment strategy available to preserve fertility for prepubescent individuals is ovarian tissue cryopreservation (OTC) and the only option to restore fertility or hormone function is through ovarian tissue transplantation (OTT). Although in most cases OTT restores endocrine function, the tissue functions for an average of 2-5 years. To extend tissue function, the development of a bioengineered ovary that supports long-term follicle growth and endocrine function is critical. Tissue longevity depends on the number of primordial follicles (PMF) and their activation rate. While most PMFs survive the cryopreservation process, 80% are lost shortly after OTT. In bovine ovaries, the cortex, housing PMFs, is 8.5 times more rigid than deep medulla and is comprised of differential matrisome proteins. As mono-ovulatory animals, their ovaries closely mimic humans, making them a suitable model. Here, we developed decellularized extracellular matrix (dECM) hydrogels from bovine cortical tissue (c-dECM) and medullary tissue (m-dECM). Using atomic force microscopy, we determined that c-dECM and m-dECM did not display significantly different rigidities (537Pa, 468Pa). We found that the concentration of COL1, COL4, DCN, and VTN in the dECM hydrogels recapitulated what is seen in native bovine ovarian compartments. Therefore, we hypothesized that differences observed in downstream applications of these gels are due to differences in biochemical cues - or protein composition and relative abundance - in the ovarian ECM. The chemical and structural properties of ECM proteins play an integral role in cellular behavior. Therefore, we performed second harmonic generation scanning microscopy and determined that c-dECM hydrogels have significantly different fiber architecture when compared to m-dECM hydrogels. m-dECM hydrogels had significantly wider and longer fibers than c-dECM (6.22,6.419 and 38.22, 38.84 pixel/ppm microns) and displayed a lower fiber angle alignment (91.01°,87.95°). We assessed whether compartmental c-dECM and m-dECM hydrogels could drive differential expression patterns of downstream candidate genes. We then depleted our gels of proteins of interest using magnetic-activated protein filtration (MAPF). We found that our depleted gels modulate expression of genes associated with regulating follicle growth. Our work employed a novel method for examining the contribution of matrisome proteins in folliculogenesis. We anticipate our work to be influential in studying matrisome-dependent biochemical cues within other organ systems. IMPACT: Determining how the matrisome of the ovary can influence follicle activation will contribute critical data on how we can extend tissue function in OTT. Presentation: Friday, June 16, 2023