Dysregulation of Inflammation, Oxidative Stress, and Glucose Metabolism-Related Genes and miRNAs in Visceral Adipose Tissue of Women with Type 2 Diabetes Mellitus.

ABSTRACT

BACKGROUND Human visceral adipose tissue (VAT), now identified as an endocrine organ, plays a significant role in impaired fasting glucose and diabetes through the deregulated metabolism and adipogenesis of visceral adipocytes in obesity. Our study focuses on exploring the link between inflammation, oxidative stress, and glucose metabolism-associated genes with corresponding miRNAs in human visceral adipocytes and VAT from individuals with glucose metabolism disorders. MATERIAL AND METHODS We examined the expression of ATM, NFKB1, SOD2, INSR, and TIGAR, along with their related miRNAs using PCR, in two contexts1 - During the three-stage visceral adipogenesis under normal glucose levels (5.5 millimoles), intermittent, and chronic hyperglycemia (30 millimoles).2 - In visceral adipose tissue from subjects (34 F, 18 M) with normal glucose metabolism, impaired fasting glucose, and type 2 diabetes mellitus. RESULTS Both chronic and intermittent hyperglycemia similarly influenced ATM, NFKB1, TIGAR, SOD2, INSR gene expression in visceral adipocytes, with corresponding changes in a few tested miRNAs (eg, let-7g-5p, miR-145-5p, miR-21-5p). Anthropometric and biochemical parameters led us to focus on female subjects. Our results showed transactivation of NFKB1, TIGAR, miR-10b-5p, miR-132-3p, miR-20a-5p, miR-21-5p, and miR-26a-5p exclusively in type 2 diabetes mellitus. Upregulated molecules (excluding miR-10b-5p and miR-20a-5p) positively correlated with glucose metabolism markers. CONCLUSIONS The genes studied may undergo miRNA interferences and hyperglycemic memory in visceral adipocytes under hyperglycemic conditions. VAT from women with type 2 diabetes mellitus, but not with impaired fasting glucose, showed transactivated miRNAs and a molecular dysregulation of TIGAR and NFKB1, possibly enhancing inflammation, oxidative stress, and disrupted glucose metabolism. These findings highlight the epigenetic and molecular disturbances in VAT related to glucose metabolism abnormalities. However, additional research is necessary to further understand their biological significance.