Sex-based Single-Cell Heterogeneity after Murine Contusional Traumatic Brain Injury in Genes Related to Sulfonylurea Receptor-1 (S4.009)

Abstract

<h3>Objective:</h3> To evaluate sexual dimorphism at a single-cell (SC) level in genes related to sulfonylurea-receptor-1 (SUR1). <h3>Background:</h3> SUR1-inhibition is being evaluated in a phase-II trial of contusional-traumatic brain injury (TBI). Sex-based differences in related gene/pathway expression may impact drug efficacy and downstream consequences. Differences may further vary between cell-types. <h3>Design/Methods:</h3> Pericontusional tissue 24h after controlled cortical impact (CCI) or naive from male and female mice was dissociated into single-cells (10X Genomics) (n=3–6/group). SC RNA sequencing (Novaseq6000) was performed and analyzed (Seurat) for differentially-expressed genes (DEGs), biological pathway, pseudotime, and cell-signaling based communication (R-packages) in the SUR1-related pathway of 200 a priori identified genes. Significance was determined using adjusted p-values (Benjamini-Hochberg). <h3>Results:</h3> 213,632 sequenced cells revealed 11 cell-types with multiple subtypes (14 myeloid, 5 neutrophil, 7 astrocyte, 10 ependymal, 9 endothelial, 8 mural, 7 T-cell, 3 B-cell, 5 neuron, 4 oligodendrocyte). SUR1-pathway expression activity varied with cell-subtype- e.g. monocyte-type-1 and microglia-type-8 had high SUR1-pathway gene-expression in both sexes; these subtypes were essentially absent in naive. SUR1-related pathway gene-expression activity varied by sex in endothelial-cells, ependymal-cells, myeloid-cells, T-cells, and neurons. Individual gene-expression was diffusely different between sexes. Some DEGs (Il1β, ApoE, Tnf) were highly expressed in male vs female CCI across several cell subtypes. Others (Nos2, Mmp9, Mif, mitochondrial genes) were more highly expressed after female CCI. Biological pathways and cell-signaling differed between sexes. Certain pathways were predominantly male (Insulin, TGFβ, SPP1, APP, TNF) vs female (EGF, OCLN, SELPLG, CXCL). Females had fewer inferred cell-cell interactions. <h3>Conclusions:</h3> Robust sex-based SC heterogeneity in SUR-1-related gene-expression, and biological and cell-communication pathways was observed after murine TBI. These may represent mechanistic underpinnings of reported sex differences in TBI outcomes in SUR1-deficient mice. Nonetheless, differences were marked/greater than anticipated. Affected genes/pathways varied across cell subtypes. This may guide development of cell-specific biomarkers, targets, and treatments. <b>Disclosure:</b> Dr. Jha has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Biogen. An immediate family member of Dr. Jha has received personal compensation in the range of $5,000-$9,999 for serving as an Expert Witness for Legal fees. The institution of Dr. Jha has received research support from NIH/NINDS, Chuck Noll Foundation, University of Pittsburgh, Barrow Neurological Foundation. Dr. Xiong has nothing to disclose. Mr. Sneiderman has nothing to disclose. Dr. Simon has nothing to disclose. Dr. Catapano has nothing to disclose. Mr. Rulney has nothing to disclose. Dr. Raikwar has nothing to disclose. Dr. Rani has nothing to disclose. Dr. Shahjouei has nothing to disclose. Mrs. Mihaljevic has nothing to disclose. Dr. Winkler has nothing to disclose. Ms. Miller has nothing to disclose. Mr. Lim has nothing to disclose. Ms. Feldman has nothing to disclose. Vincent Vagni has nothing to disclose. Patrick M. Kochanek, MD, MCCM has received personal compensation in the range of $10,000-$49,999 for serving as an Expert Witness for Johns Hopkins Health System. The institution of Patrick M. Kochanek, MD, MCCM has received research support from Chuck Noll Foundation. The institution of Patrick M. Kochanek, MD, MCCM has received research support from NIH. Patrick M. Kochanek, MD, MCCM has received publishing royalties from a publication relating to health care. The institution of Dr. Kohanbash has received research support from NIH. Dr. Rajasundaram has nothing to disclose.