Role of adipose tissue macrophages in the cross-talk between visceral adipose tissue and heart during high fat diet

Introduction Obesity is associated with remodeled and dysfunctional visceral white adipose tissue (vWAT). Recent studies suggest a cross-talk between vWAT and heart contributing to cardiac abnormalities. We hypothesized that adipose tissue macrophages (ATM) play a key role in the vWAT remodeling through a mechanism of premature senescence in high fat diet (HFD)-induced obesity. Objective Establish the chronological order of events leading to vWAT premature senescence in the context of obesity and figure out the role of senescent ATM in the cross-talk between vWAT and heart. Method Two-month-old C57BL/6 male mice (n = 5/group) fed with HFD (60% fat, 7% sucrose) or chow diet (CD) for 2, 5, or 10 weeks underwent in vivo cardiac evaluation (echocardiography) and metabolic tests (glucose and insulin tolerance tests). Myocardial fibrosis, vWAT remodeling, ATM infiltration (CD68), senescence (p16 and p21) and inflammation were assessed. Results Body weight gain induced by HFD diverged from CD (CD: 29.6 ± 0.5 vs HFD: 35.0 ± 1.3, P  Conclusion HFD disturbed glucose homeostasis, induced ATM senescence and myocardial dysfunction prior to body weight gain. These alterations preceded major inflammation and fibrotic remodeling both in vWAT and heart.