DOCK2 deficiency mitigates HFD-induced obesity by reducing adipose tissue inflammation and increasing energy expenditure.

ABSTRACT

Obesity is the major risk factor for type 2 diabetes, cardiovascular disorders, and many other diseases. Adipose tissue inflammation is frequently associated with obesity and contributes to the morbidity and mortality. Dedicator of cytokinesis 2 (DOCK2) is involved in several inflammatory diseases, but its role in obesity remains unknown. To explore the function of DOCK2 in obesity and insulin resistance, WT and DOCK2-deficient (DOCK2-/-) mice were given chow or high-fat diet (HFD) for 12 weeks followed by metabolic, biochemical, and histologic analyses. DOCK2 was robustly induced in adipose tissues of WT mice given HFD. DOCK2-/- mice with HFD showed decreased body weight gain and improved metabolic homeostasis and insulin resistance compared with WT mice. DOCK2 deficiency also attenuated adipose tissue and systemic inflammation accompanied by reduced macrophage infiltration. Moreover, DOCK2-/- mice exhibited increased expression of metabolic genes in adipose tissues with greater energy expenditure. Mechanistically, DOCK2 appeared to regulate brown adipocyte differentiation because increased preadipocyte differentiation to brown adipocytes in interscapular and inguinal fat was observed in DOCK2-/- mice, as compared with WT. These data indicated that DOCK2 deficiency protects mice from HFD-induced obesity, at least in part, by stimulating brown adipocyte differentiation. Therefore, targeting DOCK2 may be a potential therapeutic strategy for treating obesity-associated diseases.