Adipose tissue macrophages
Adipose tissue macrophages are macrophages residing in the adipose tissue. They are one of the mononuclear phagocyte systems of the body. Others are monocytes in bone marrow, Kupffer cells in liver, histiocytes in connective tissues, microglia in central nervous system, etc.
Apart from adipocytes, the cellular components of the adipose tissues are fibroblasts, vascular endothelial cells, and immune cells (e.g. mast cells, eosinophils, lymphocytes, and macrophages).1 One of the factors that led to the recruitment of macrophages in adipose tissue is the expanding adipose tissue and wherein dead cells or cellular debris had to be removed. This occurs in obese conditions. Sudden weight loss also leads to increased macrophage recruitment. Macrophages regulate lipolysis, i.e. the process of breaking down of lipids into fatty acids and glycerol. The release of free fatty acids results in the recruitment of macrophages into the adipose tissue.2
Abbreviation / Acronym: ATMs
1 Schipper, H. S., Prakken, B., Kalkhoven, E., & Boes, M. Adipose tissue-resident immune cells: key players in immunometabolism. Trends Endocrinol Metab 2012; 23:407-15.
2 Eagle, A. R. & Chawla, A. In obesity and weight loss, all roads lead to the mighty macrophage. Journal of Clinical Investigation 2010; 120:3437-40.