IL-10 cytokine family secretion is associated with the activity of mitophagy components in visceral adipose tissue in obese with and without type 2 diabetes mellitus

Abstract

Autophagy is required to maintain cellular homeostasis and organ function by selectively ridding cells of potentially toxic proteins, lipids, and organelles. Impaired homeostasis of autophagic processes is associated with metabolic disorders such as obesity and type 2 diabetes mellitus. In obesity, a violation of autophagy in adipose tissue and its inflammation contributes to the formation of type 2 diabetes mellitus.
 The aim of the study was to analyze the expression of autophagy genes in the adipose tissue of the greater omentum and to search for their relationship with the levels of cytokines of the IL-10 family in blood plasma in obese patients, depending on the presence or absence of type 2 diabetes mellitus.
 Blood plasma and visceral adipose tissue samples were studied from 347 obese patients with and without type 2 diabetes. A biochemical analysis of the patients' blood was carried out. The level of cytokines was detected by flow fluorometry. Gene expression was determined by real-time PCR, and tissue-specific protein production was determined by immunoblotting. Statistical processing of the results was carried out using GraphPad Prism 9.0.0 software.
 Plasma levels of IL-10, IL-20, IL-22, IL-28A, and IL-29 are increased in obese patients without type 2 diabetes compared with patients with type 2 diabetes. In patients with type 2 diabetes mellitus, the expression of the SQSTM1_p62 and MAP1LC3B genes in the greater omentum increased compared to patients without it.
 High plasma levels of IL-22 and IL-26 are associated with the presence of type 2 diabetes mellitus. In patients without type 2 diabetes mellitus, an increase in the level of IL-28A in blood plasma is associated with a decrease in the expression of autophagy genes SQSTM1_p62 and MAP1LC3B in the adipose tissue of the greater omentum.