FRI015 Single Nuclei Transcriptomics Of Epicardial Adipose Tissue From Female Pigs Reveals Differential Effects Of Endurance Exercise On Resident Innate And Adaptive Immune Cells
Authors: Ahmad Irshad , Faulkner Patricia , Gupta Shreyan , Mullens Destiny , Thomas Micah , Sytha Sharanee P , Ivan Ivanov , Cai James J , Heaps Cristine L , Newell-Fugate Anne Elizabeth 
Published: October 2023

Abstract
Disclosure: I. Ahmad: None. P. Faulkner: None. S. Gupta: None. D. Mullens: None. M. Thomas: None. S.P. Sytha: None. I. Ivan: None. J.J. Cai: None. C.L. Heaps: None. A.E. Newell-Fugate: None.
Coronary artery disease (CAD) is the leading cause of global mortality. Although exercise training mitigates CAD progression, the mechanisms by which exercise training impacts epicardial adipose tissue (EAT) are unknown. We hypothesized that exercise training modulates EAT to promote an anti-inflammatory microenvironment in the coronary arteries of female pigs. Female Yucatan pigs (n=7) had an occluder placed around the proximal left circumflex artery. Eight-weeks postoperatively, pigs were assigned to sedentary or exercise groups with exercised pigs undergoing a 14-week treadmill running program. Upon termination, EAT was snap frozen. Bulk transcriptome sequencing was performed, and log fold change expression data was analyzed with Ingenuity Pathway Analysis. Microdroplet-based single nuclei transcriptome was analyzed using Seurat pipeline. Cell-cell interactome (CCI) analysis was performed using CellChat. Bulk RNA-sequencing revealed G-protein coupled receptor signaling, S100 family signaling, FAK signaling, and glutathione-mediated detoxification pathways were upregulated with exercise. Cellular movement, cell to cell communication, inflammatory response, and immune cell trafficking were predicted to be upregulated in exercised EAT. In adipocyte, B cell, and endothelial cell clusters, exercise induced upregulation of genes related to fatty acid synthesis and cellular metabolism. Exercise also caused upregulation of cell adhesion associated oncogene regulated and downregulation of S100 calcium binding protein A9 in B cells. By contrast, exercise caused downregulation of genes related to cell-cell adhesion and cellular metabolism in T cells. Although exercise increased macrophage numbers in EAT, macrophages displayed downregulation of genes related to protein folding and trafficking. Smooth muscle cells from exercised EAT showed upregulation of genes related to lipoprotein and glycogen turnover. CCI revealed increased interactions among all cell types in the insulin-like growth factor pathway of exercised EAT. By contrast, EAT from sedentary pigs had increased CCI for platelet derived growth factor (all cell types), galectin and WNT signaling (immune and mesenchymal cells), TGF (adipocytes, immune and mesenchymal cells), and VEGF (adipocytes, immune and endothelial cells). These findings suggest that exercise training downregulates genes related to cellular function in immune cells from both the innate (macrophages) and adaptive immune systems (T cells), but stimulates genes related to cellular metabolism and migration in B cells from EAT. CCI results suggest that sedentary EAT may secrete increased factors to stimulate inflammation, cell movement, and cell growth. These results provide a foundation for future functional studies of the effects of exercise on EAT and coronary artery regulation.
Presentation: Friday, June 16, 2023