Temporal Epigenetic Regulation in Human Hypothalamic Neurons and Body Weight

University Of Texas Hlth Science Center, San Antonio TX

Investigators

Abstract

ABSTRACT The hypothalamus is the brain hub that regulates energy homeostasis. The genetic and molecular basis of this regulation in humans is not well understood as access to this tissue is a major barrier and available only postmortem. To overcome the barrier of limited tissue access, we are generating induced pluripotent stem cell (iPSC)-derived neuronal cultures that recapitulate many of the features of hypothalamic neurons from the arcuate nucleus, including by benchmarking this in vitro model to in vivo events that are pivotal in hypothalamic development. We will use this human model and state of the art high throughput assays to test our hypothesis that non-coding genetic variants associated with obesity measures and body weight regulation impact on these traits secondarily through epigenetic regulation which is dynamic across hypothalamic development. We will employ genome editing techniques such as CRISPR in our human cells to experimentally assess physiologic effects of variants identified to influence chromatin status of obesity associated loci. The public health impact of all functional variants will then be assessed using data from large, multi-ethnic epidemiologic cohorts. These studies will represent the first attempt at establishing the epigenetic architecture of human hypothalamic neuronal cells and serve as a bioresource for understanding diseases linked to alterations in energy homeostasis. A unique component is the evaluation at multiple time points during development, thus providing a critical catalogue of the human epigenome at stages representing fetal development. We anticipate that the epigenetic map will differ from that in adult brain and will vary temporally. We also anticipate that genes associated with body weight regulation will cluster into distinct chromatin accessibility patterns that differ over time. Discovery of epigenetic mechanisms connected to genetic liability will identify potential underlying factors behind both heritable and diet-induced obesity and potential therapeutic means by which the epigenetic mechanisms that influence disease susceptibility can be reversed.