Functions of Lipid Homeostasis During Neural Tube Closure

Neural tube closure (NTC) is the embryonic process that forms the precursor to our brain and spinal cord. Neural progenitor cells (NPCs) are the predominant cell type in the neural tube and are exquisitely regulated to balance cell specification, proliferation, and differentiation—all processes critical for NTC. When NPCs and NTC are disrupted by genetic and environmental insults, the neural tube does not close and results in a neural tube defect (NTD) such as Spina Bifida and Anencephaly. Metabolic disorders that dysregulate lipid homeostasis (maternal diabetes and obesity) are risk factors for NTDs in humans. In mouse, several metabolic and genetic NTDs models with dysregulated lipid homeostasis can be prevented by vitamin E supplementation. The correlation of disrupted lipid homeostasis to vitamin E rescue points to a critical question, can we predict if a genetic model is likely vitamin E responsive and therefore help prevent NTDs? In order to predict if vitamin E is a suitable strategy, we must figure out the key targets of vitamin E, and to narrow the scope of targets, we must understand what happens in NPCs when lipid homeostasis is dysregulated. Lipids are required for signaling pathways used in NPC specification, membrane composition which enable cell shape changes during proliferation and differentiation, and energetically fueling and maintaining cell health enabling the aforementioned processes. Although we know that lipid homeostasis is in principle important for NTC and NPC function, our understanding of how lipids are regulated in NPCs and their discrete functions in these cells is severely understudied. This proposal takes an integrated approach to address the relationship between lipids, NPC fate, and NTC and to evaluate vitamin E responsive processes using the FAF2 knockout mouse model as a test piece. FAF2 is an ER membrane protein that regulates lipid synthesis and lipid droplet maintenance, thus enabling investigation of lipid homeostasis from two distinct angles. The primary goal of my mentored phase is to use cutting-edge imaging, - omics, and genetic manipulation to identify the consequences of disrupted lipid synthesis and lipid droplet maintenance on NTC and NPC regulation downstream of FAF2 knockout in embryos and NPCs. These results will prepare me to independently adapt this experimental framework to assess the interplay between lipid homeostasis and vitamin E. Overall this work is of high significance to our understanding of structural birth defects and will provide insight into what makes lipid dysregulation so dangerous to neural tube closure. While in my K99 phase, I will take advantage of the rich academic environment of CU Boulder and its relationship with nearby CU Anschutz to adapt novel techniques to study lipid biology in embryos and develop robust analyses. My long-term career goal is to establish an independent research program that uses cell and developmental biology techniques to investigate gene-environment interactions in lipid-related NTDs. The techniques and methodologies developed in this proposal will create a scaffold of strategies by which any other lipid-associated gene or pathway can be interrogated for its role in NTC and NPC regulation in my independent lab. Project Number: 1K99HD116973-01A1 | Fiscal Year: 2025 | NIH Institute/Center: Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) | Principal Investigator: Anneke Kakebeen | Institution: UNIVERSITY OF COLORADO, Boulder, CO | Award Amount: $140,400 | Activity Code: K99 | Study Section: Developmental Biology Study Section[CHHD-C] View on NIH RePORTER: https://reporter.nih.gov/project-details/1K99HD11697301A1