Human epicardial adipose tissue inflammation correlates with coronary artery disease

Abstract

Background and aims: This study investigates the expression of novel adipocytokines and inflammatory cells infiltration in epicardial adipose tissue (EAT) and subcutaneous adipose tissue (SAT) between 27 coronary artery disease (CAD) and 21 non-CAD (NCAD) patients enrolled from September 2020 to September 2021.

Methods and results: Serum, gene, and protein expression levels of the novel adipocytokines were determined using ELISA, RT-qPCR, and western blot analyses. The number of blood vessels and adipocytes morphology were measured via hematoxylin-eosin staining, and inflammatory cells infiltration was examined via immunohistochemistry. Serum ANGPTL8, CTRP5, and Wnt5a levels were higher in the CAD than in the NCAD group, while serum CTRP3, Sfrp5, and ZAG levels were lower in the CAD than in the NCAD group. Compared to the EAT of NCAD and SAT of CAD patients, the EAT of CAD patients had higher mRNA levels of ANGPTL8, CTRP5, and Wnt5a while lower levels of CTRP3, Sfrp5, and ZAG; higher protein expression levels of ANGPTL8 and CTRP5 but lower levels of CTRP3; more blood vessels; and higher infiltration rates of macrophages (CD68 + ), pro-inflammatory M1 macrophages (CD11c + ), mast cells (Tryptase + ), T lymphocytes (CD3 + ), and B lymphocytes (CD20 + ) but lower infiltration rates of anti-inflammatory M2 macrophages (CD206 + ).

Conclusion: Novel adipocytokines and inflammatory cells infiltration are dysregulated in human EAT, and could be important pathophysiological mechanisms and novelly promising medicating targets of CAD.

Keywords: Adipocytokine; Coronary artery disease; Epicardial adipose tissue; Inflammatory cell.