TRIM59 deficiency aggravates HFD-induced obesity in mice associated with increased adipose tissue inflammation, lipid accumulation, and apoptosis

Abstract

TRIM59 (tripartite motif-containing 59) is involved in many pathological processes including inflammation and tumorigenesis. However, the effect of TRIM59 on obesity remains unknown. In this study, we aimed to investigate the role of TRIM59 in obesity and clarify the involved mechanisms. Our results showed that TRIM59 expression was significantly decreased in fat from high-fat diet (HFD)-induced obese mice. The TRIM59^+/- mice with HFD showed increased body weight and white adipose tissue (WAT) weight, larger adipocyte sizes, and increased adipose tissue inflammation with the elevated expression of pro-inflammatory cytokines including TNF-α, IL-1β and IL-6 accompanied by an increased macrophage infiltration. Moreover, TRIM59 knockdown increased the serum levels of triglyceride (TG), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C). Mechanistically, TRIM59 knockdown is associated with heightened activation of TLR4/JNK-p38/NF-κB signaling pathways to promote inflammation, increase adipogenesis and lipogenesis related genes while decreased lipolysis and β-oxidation related genes expression to increase lipid accumulation, simultaneously increased Bax and caspase 3 while decreased Bcl-2 expression to induce apoptosis, thereby leading to obesity. Taken together, our findings define a new critical biological role of TRIM59 in the regulation of diet-induced obesity through attenuating inflammation, improving lipid metabolism and apoptosis, and we conclude that TRIM59 may provide a novel insight in therapeutic target research for treatment of obesity-associated metabolic diseases.

Keywords: Apoptosis; Inflammation; Lipid metabolism; Obesity; TRIM59.