Development and maintenance of an ovarian follicle, and thus a functional ovary is a remarkable tissue
remodeling processes that requires involvements of various proteases. However, our knowledge concerning
the enzymes that are responsible for, and underlying mechanisms are incomplete. Our long-term objective
is to identify molecules and pathways that affect female fertility, and therefore to advance knowledge on the
regulators for reproductive processes and fertility in female animals. The specific aims of this grant
application are to elucidate functions, processes, interacting molecules and pathways, and targets of an
overlooked metalloprotease, i.e., Adamts9 (a disintegrin and metalloproteinase with thrombospondin type 1
motifs, member 9) in the development and maintenance of an ovarian follicle. Our published or preliminary
results strongly indicate Adamts9 has a critical role in survival and programmed death of an ovarian follicle.
We hypothesize that oocyte originated Adamts9 enzyme is vital for normal follicle development and
survival by varying turnover of extracellular matrix (ECM) proteins therefore increase or decrease of
intra-follicular signaling. We will test this hypothesis via a comprehensive examination of status of ovarian
follicles, i.e., healthy vs. dying follicles in wildtype or various knockouts, targeted molecules and pathways
using tradition approaches including but not limited to confocal microscope imaging, assays of apoptosis,
proliferation & Western blots, staining of RNA or proteins. We will also apply advanced tools using in vivo
fluorescence reporters or molecular biosensors as well as utilizing unbiased approaches, e.g., single cell
RNA sequencing (scRNAseq) and mass spectrometry. To elucidate cell- or molecule-specific events, we
have established or obtained various knockouts, reporter or biosensor lines for targeted cells or signaling
molecules, which allow us to characterize detailed changes of germ cells, gonad somatic cells, or targeted
molecules at a high resolution. Using the advantages of these in vivo systems and fluorescence reporters,
we will characterize and elucidate Adamts9 dependent ECM turnover, gene expression, signaling molecule
changes, pathways, and processes in development and maintenance of an ovarian follicle. For the first
time, functions, and mechanisms of Adamts9, particularly in folliculogenesis, will be comprehensively
characterized in a vertebrate model, which will fill a knowledge gap, i.e., how a germ cell originated enzyme
such as Adatmts9, regulates its ECM environments, thus determines survival or programmed death of an
ovarian follicle. New knowledge gained will be appreciated for understanding or designing new treatments
for reproductive disorders such as infertility, gonadal dysgenesis, early menopause, primary ovarian
insufficiency (POI) and polycystic ovarian syndrome (PCOS). This AREA grant will also provide critical
research opportunities and training for diverse undergraduates at a university mainly serving rural areas and
disadvantage populations, and also address NIH mission for biomedical workforce enhancement.