Determining mechanisms of ovotoxicity from per- and polyfluoroalkyl substances

Candidate - The following application is intended to provide Dr. Kendra L. Clark with the technical and professional skills necessary to transition into an independent VA research career. Dr. Clark received her PhD in Genetics and Genomics with a focus on reproductive toxicology in December 2019 and is currently completing

her postdoctoral training focused exclusively on reproductive health research, specifically in regulation of follicle development, cell signaling, and impacts of per- and polyfluoroalkyl substances (PFAS) on folliculogenesis. This award will enable Dr. Clark to expand her research training and further investigate the molecular mechanisms

responsible for environmentally induced reproductive failure in both in vitro and in vivo models, impacts of in utero exposures on offspring health, and provide the means to prevent environmentally induced reproductive failure and preserve fertility. Environment - These goals will be accomplished under the primary mentorship of

Dr. John S. Davis, a prominent investigator in the field of ovarian biology and reproductive endocrinology, and who serves as VA Senior Research Career Scientist. The University of Nebraska Medical Center (UNMC) is a leading academic health and research center that is adjacent to the Omaha VA Medical Center, where strong

scientific relationships have been established to complete the proposed studies. Research - The ovary produces the female egg, the oocyte, and hormones which are critical for reproduction and quality-of-life. The effect of a chemical exposure on female reproductive function depends on the developmental/life stage of the exposure as

well as the level and duration of exposure. Ovotoxicants can selectively target a follicle population in the ovary, resulting in either temporary or permanent infertility, alter ovarian function maternally, and can also impact offspring through pregestational or in utero exposures. PFAS are a group of synthetic chemicals that are

resistant to biodegradation and are environmentally persistent. Although virtually 100% of the U.S. population has measurable exposure to several types of PFAS, little research has been done to understand the effects of PFAS on reproductive health. The use of aqueous film-forming foam (AFFF) and other PFAS containing

materials at military installations has significantly contributed to the contamination of surface and ground water, leaving military bases and the communities that surround them at higher risks for PFAS exposure. The most frequent female reproductive health diagnoses in the VA includes menstrual disorders, endometriosis,

menopausal disorders, and osteoporosis, all of which can be attributed to abnormal functioning of the ovary. Preliminary data for this proposal demonstrate a role for the Hippo pathway and its effector YAP1 in PFAS- induced cell proliferation in granulosa cells and follicle growth in cultured neonatal mouse ovaries. In the

research training component of this proposal, Dr. Clark will elucidate the effects of an environmentally relevant PFAS mixture on human and murine ovarian samples. The central hypothesis of this proposal is that (1) PFAS adversely impact folliculogenesis through the disruption of pathways that regulate proper and timely follicle

development leading to premature ovarian failure and infertility and (2) PFAS exposure prior to and throughout pregnancy results in multi/transgenerational effects in offspring that affect reproduction. Specific Aim 1 will determine PFAS-induced alterations in granulosa cell function in vitro. Specific Aim 2 will determine whether

an environmentally relevant exposure to a PFAS mixture alters follicular dynamics and disrupts Hippo Signaling in the ovary in vivo. Specific Aim 3 will determine if PFAS-induced alterations in follicular dynamics leads to premature ovarian failure and infertility in vivo and if pregestational/in utero PFAS

exposure impacts offspring health. The proposed studies are expected to provide a better understanding of the mechanistic underpinnings in which PFAS exposure may be detrimental for fertility and equip Dr. Clark with the necessary research and professional skills for her VA research career.