| Popis: |
White adipose tissue (WAT) is a complex endocrine organ composed of mature adipocytes and a variety of cells that compose the stromal vascular fraction (SVF). The SVF includes preadipocytes, fibroblasts, endothelial cells, and immune cells such as macrophages, T cells, natural killer cells, dendritic cells, and B cells. The cellular composition of the SVF and specific function of WAT depots depends on anatomical location. Growing evidence suggests that the immune cell populations present in WAT are intimately linked with the inflammatory, endocrine, and metabolic function and dysfunction of the individual WAT depots. Growth hormone (GH) impacts adiposity and immune function in a depot-dependent manner and is well known for its ability to decrease WAT mass by promoting lipolysis and inhibiting lipogenesis. To date, no one has reported the influence of a reduction of GH action on the immune cell profile in different WAT depot. Therefore, the purpose of the current study was to examine the WAT immune cell populations in dwarf growth hormone receptor knockout (GHR-/-) mice, which have no GH induced signaling. To this end, immune cell populations of three distinct WAT depots were characterized using flow cytometry. Although marked genotype differences in WAT immune cell populations were found in epididymal and mesenteric WAT, the immune cell profile of the subcutaneous depot was not different between genotypes. Interestingly, only subcutaneous fat was preferentially increased in GHR-/- mice, suggesting that immune cells do not contribute to the expansion of this depot. Our results also indicate that a lack of GH alters WAT immune cell populations ina depot-specific manner. |
