Description
Irisin is a hormone that is involved in converting white adipose tissue into brown adipose tissue after physical exercise. It is formed after the membrane bound protein fibronectin type III domain containing protein 5 (FNDC5) is cleaved resulting in a secreted protein. FNDC5 is found in muscle tissue and is activated during physical exertion via the protein PGC1a. Soluble Irisin has also been shown to up regulate UCP-1 gene expression in mice. UCP-1 is a mitochondrial transporter protein and a marker of brown adipose tissue conversion. This suggests that Irisin plays an important role in energy regulation and furthermore may lead to improvements in glucose regulation, insulin sensitivity, hypertension, and obesity