Free fatty acid receptor 2 Free fatty acid receptor 2 Free fatty acid receptor 2 (FFAR2) is a G-protein coupled receptor encoded by the FFAR2 gene. FFAR2 mRNA is expressed in adipose tissue, pancreas, spleen, lymph nodes, bone marrow, and peripheral blood mononuclear cells. FFAR2 transcription is regulated by the XBP1 transcription factor which binds to the core promoter. Mouse studies utilizing Ffar2 gene deletions have implicated the receptor in the regulation of energy metabolism and immune responses. Short Chain Fatty Acids (SCFA's) generated in the processing of fiber by intestinal microbiota act as ligands for the receptor and can affect neutrophil chemotaxis. However, discrepancies
White adipose tissue Upon release of insulin from the pancreas, white adipose cells' insulin receptors cause a dephosphorylation cascade that lead to the inactivation of hormone-sensitive lipase. It was previously thought that upon release of glucagon from the pancreas, glucagon receptors cause a phosphorylation cascade that activates hormone-sensitive lipase, causing the breakdown of the stored fat to fatty acids, which are exported into the blood and bound to albumin, and glycerol, which is exported into the blood freely. There is actually no evidence at present that glucagon has any effect on lipolysis in white adipose tissue. Glucagon is now thought to act exclusively