Metaflammation is responsible for several metabolic syndromes,such as type 2 diabetes.However,the mechanisms by which metabolic disorders trigger metaflammation remain unclear.We identified a cell type-specific downre...Metaflammation is responsible for several metabolic syndromes,such as type 2 diabetes.However,the mechanisms by which metabolic disorders trigger metaflammation remain unclear.We identified a cell type-specific downregulation of CD1d expression in M2 macrophages during the progression of obesity prior to the onset of inflammation in visceral adipose tissues.A reduction in CD1d expression influenced the ability of M2 macrophages to present antigens and caused a change in antigen-presenting cells from M2 macrophages to M1 macrophages.With CD1d conditional knockout(KO)mice,we further demonstrated that natural killer T(NKT)cell activation by M2 macrophages inhibited metaflammation and insulin resistance by promoting Th2 responses and M2 polarization in visceral adipose tissues of obese mice,whereas NKT cell activation by M1 macrophages exacerbated metaflammation and insulin resistance by promoting Th1 responses and inhibiting M2 polarization.Our results suggest that an M2-specific reduction of CD1d is an initiating event that switches NKT cell-mediated immune responses and disrupts the immune balance in visceral adipose tissues in obese mice.展开更多
基金supported by the Major State Basic Research Development Program of China(973 Program)2013CB944902the National Natural Science Foundation of China 91542203 and 31470859+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences XDA12030201the Fundamental Research Funds for the Central Universities and Users with Potential 2015HSC-UP018.
文摘Metaflammation is responsible for several metabolic syndromes,such as type 2 diabetes.However,the mechanisms by which metabolic disorders trigger metaflammation remain unclear.We identified a cell type-specific downregulation of CD1d expression in M2 macrophages during the progression of obesity prior to the onset of inflammation in visceral adipose tissues.A reduction in CD1d expression influenced the ability of M2 macrophages to present antigens and caused a change in antigen-presenting cells from M2 macrophages to M1 macrophages.With CD1d conditional knockout(KO)mice,we further demonstrated that natural killer T(NKT)cell activation by M2 macrophages inhibited metaflammation and insulin resistance by promoting Th2 responses and M2 polarization in visceral adipose tissues of obese mice,whereas NKT cell activation by M1 macrophages exacerbated metaflammation and insulin resistance by promoting Th1 responses and inhibiting M2 polarization.Our results suggest that an M2-specific reduction of CD1d is an initiating event that switches NKT cell-mediated immune responses and disrupts the immune balance in visceral adipose tissues in obese mice.
