How does high-fat diet induce adipose Tissue fibrosis?

Obesity is one of the most serious pandemic health problems in modern society and the predisposing factor for the type 2 diabetes mellitus. Chronic low-grade inflammation mediates the pathogenesis of insulin resistance in obese humans and rodents, and white adipose tissue is one of major tissues to modulate inflammation. Obese humans and rodents show dynamic changes of immunocellular compositions in white adipose tissue to induce inflammatory responses. Innate and adaptive immune responses mainly mediated by macrophages and T cells contribute insulin resistance. Recently, it has been shown that adipose tissue fibrosis is also enhanced in obese humans and rodents along with inflammatory responses, and suppression of adipose tissue fibrosis shows improved insulin sensitivity in rodent models, suggesting that adipose tissue fibrosis is involved in insulin resistance.