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
Packed red blood cells are kept with a minimal amount of fluid. Generally, an additive solution of citrate, dextrose, and adenine is mixed with the cells to keep them alive during storage. This process is sometimes done as automated apheresis, where the centrifuging and mixing take place at the donation site. Red blood cells are sometimes modified to address specific patient needs. The most common modification is leukoreduction, where the donor blood is filtered to remove white cells, although this is becoming increasingly universal throughout the blood supply (over 80% in the US, 100% in Europe). The blood may also be irradiated, which destroys