RESUMO
OBJECTIVE: Natural killer (NK) cells are understudied in the context of metabolic disease and obesity. The goal of this study was to define the effect of NK cell ablation on systemic inflammation and glucose homeostasis in murine obesity. METHODS: A transgenic murine model was used to study the effect of NK cell ablation on systemic inflammation and glucose homeostasis in the context of diet-induced obesity using flow cytometry, QRTPCR, and glucose tolerance and insulin sensitivity testing. RESULTS: NK cell ablation achieved a three to fourfold decrease in NK cells but had no effect on T-cell levels in adipose tissues and spleen. NK cell ablation was associated with decreased total macrophage infiltration in intra-abdominal adipose tissue, but macrophage infiltration in subcutaneous adipose tissue and spleen was unaffected. NK cell ablation was associated with modest improvement in insulin sensitivity but had no effect on tissue transcript levels of inflammatory cytokines. CONCLUSIONS: NK cells play a role in promoting intra-abdominal adipose tissue macrophage infiltration and systemic insulin resistance in obesity.
Assuntos
Células Matadoras Naturais/metabolismo , Macrófagos/metabolismo , Obesidade/metabolismo , Gordura Subcutânea/metabolismo , Animais , Citocinas/metabolismo , Inflamação/metabolismo , Insulina/metabolismo , Resistência à Insulina , Gordura Intra-Abdominal/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Camundongos Transgênicos , Linfócitos T/metabolismoRESUMO
OBJECTIVE: Adipose tissue inflammation is a cause of obesity-related metabolic disease. Natural killer (NK) cells are an understudied cell type in the context of obesity. The goal of this study was to determine the phenotype of human adipose tissue NK cells. METHODS: We used flow cytometry phenotyping to study adipose tissue and peripheral blood NK cells from obese and lean humans. RESULTS: Human adipose tissue NK cells, relative to peripheral blood NK cells, express increased levels of activation markers. Adipose tissue NK cells also demonstrate an activated phenotype in obese relative to lean subjects, with increased expression of the activating receptor NKG2D. CONCLUSIONS: These data are the first detailed phenotypic characterization of human adipose tissue NK cells, and suggest a role for NK cells in adipose tissue inflammation in obesity.