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
Fatty acid metabolism All cells with mitochondria can take ketones up from the blood and reconvert them into acetyl-CoA, which can then be used as fuel in their citric acid cycles, as no other tissue can divert its oxaloacetate into the gluconeogenic pathway in the way that this can occur in the liver. Unlike free fatty acids, ketones can cross the blood-brain barrier and are therefore available as fuel for the cells of the central nervous system, acting as a substitute for glucose, on which these cells normally survive. The occurrence of high levels of ketones in the blood during starvation, a low