Elucidating the mechanisms of GLIS3-regulated development in the pancreas and kidney

The National Institute of Diabetes and Digestive and Kidney Diseases awarded Murray State University $232,752 on September 15, 2025, for a Project Grant (CFDA 93.847, Diabetes, Digestive, and Kidney Diseases Extramural Research) investigating the mechanisms of GLIS3-regulated development in pancreatic and renal tissues.

The research characterizes pancreatic and renal development in a GLIS3EX4DEL/EX4DEL mutant zebrafish line lacking functional GLIS3 expression. Specific Aim 1 examines GLIS3's role in directing development of pancreatic ducts and specification of secondary islets emerging from the ductal epithelium. Specific Aim 2 investigates mechanisms by which loss of GLIS3 expression results in cystic kidneys, with particular emphasis on characterizing the association between GLIS3 and the primary cilium. Specific Aim 3 employs single-cell RNA sequencing (scRNA-seq) analysis to identify specific cell types expressing GLIS3 during development and characterize how loss of GLIS3 expression alters gene expression in developing zebrafish. Mutations within the GLIS3 locus have been implicated in diabetes, Alzheimer's disease, and cancer.

Performance occurs at Murray State University in Murray, Kentucky, with a period of performance from September 15, 2025, through March 31, 2029. The award is classified as a Project Grant.

Abstract

Embryonic development is orchestrated through complex networks of genes that specify cell fates and choreograph the migration and reorganization of cells into tissues. Mutations within developmental genes can both give rise to birth defects and increase susceptibility to diseases later in life. The transcription factor, GLI-similar 3 (GLIS3) has been found to be important during embryological development and mutations within the GLIS3 locus have been implicated in the development of several diseases including diabetes, alzheimer's disease, and cancer. Currently, little is known about the specific roles GLIS3 plays during development or how divergence from its normal function promotes disease at the molecular level. In this proposal, experiments are described intended to characterize pancreatic and renal development in the GLIS3EX4DEL/EX4DEL mutant zebrafish line that lacks functional GLIS3 expression. In specific aim 1, we will characterize pancreatic development in GLIS3 knockout fish to determine what role GLIS3 plays in directing development of the pancreatic ducts and the specification of secondary islets that emerge from the ductal epithelium. The experiments described in specific aim 2 are designed to examine the mechanisms by which loss of GLIS3 expression results in cystic kidneys. Particular emphasis will be placed on characterizing the association between GLIS3 and the mechano-sensory organelle known as the primary cilium. Finally, in specific aim 3, plans are described to gain a better understanding of the specific cell types that express GLIS3 during development and how loss of GLIS3 expression alters gene expression in the developing zebrafish by conducting scrna- SEQ analysis. The research described in this proposal will be conducted at a regional comprehensive university that serves a predominately rural, economically underdeveloped community for whom access to scientific research is traditionally restricted. The research will be completed with extensive support from undergraduate researchers who will gain the opportunity to CO-author manuscripts and present findings at local, state, and national meetings. Broadly, the completion of the studies outlined in this proposal will increase our understanding of how GLIS3 specifies cell fates during development and may help shed light on how GLIS3 mutations lead to diseases in humans such as diabetes mellitus and polycystic kidney disease. Furthermore, a greater understanding of the mechanisms that regulate pancreatic and renal development is likely to be achieved including a more thorough knowledge of the transcription factor networks that direct cell fates and tissue organization. Ultimately, completion of the research described may lead to the establishment of a complementary zebrafish model for the study of human disease.