239-LB: Single-Cell Analysis Identified Inhibitory Neurons Associated with High-Fat Diet in the Bed Nucleus of the Stria Terminalis

Abstract

Obesity occurs due to inadequate homeostatic function controlled by the central nervous system (CNS) . Outside of a few brain areas, little information is available on structures, such as the bed nucleus of the stria terminalis (BST) and preoptic area (POA) , that are essential for body weight regulation. To better understand BST and POA mechanisms involved in obesity, we overlayed deep sequencing results collected from obese (by Echo MRI) and diabetic (by glucose tolerance test) mice on high fat diet (HFD) with a previously published single cell RNA-seq data set. We identified neural subtypes using Seurat (Fig. 1A) and deconvoluted the RNA-seq with CIBERSORT. The Inhibitory 1 subtype had a lower proportion in HFD BST than control BST (Fig. 1B, p=0.035) but no difference was found between BST and POA (Fig. 1C, p=0.505) . We performed differential gene expression analysis to identify Inhibitory 1 markers and associated pathways. Aminobutyric acid (GABA) -ergic synapse pathway was enriched (Fig. 1D,E, p< 0.0001) , which is essential to the CNS control of body weight. HFD induced strong transcriptional changes in BST Inhibitory 1 markers between HFD and control diet (Fig. 1F) . One gene of particular interest was Glutathione Peroxidase 3 (GPX3, p<0.0001) . GPX3, localized to the BST and POA (Fig. 1G) , is down-regulated in both prostate and adipose tissues during HFD and implicated in neurodegenerative disease, but not yet been studied in the brain and obesity. Future studies will investigate BST GPX3 in obesity. Disclosure X. Yang: None. J. Flak: Research Support; Eli Lilly and Company. T. S. Johnson: Research Support; Eli Lilly and Company.