The Role of Irisin in Various Organs of the Human Body with Emphasis on the Beneficial Effects on Glucose Homeostasis

Maintaining a normal blood glucose level depends on the proper and coordinated functioning of several systems in the body. Understanding the various molecular mechanisms that regulate blood glucose levels has significant implications for maintaining human health. Insulin resistance can alter the secretion of cytokines or peptides called myokines, which are secreted from skeletal muscle tissue after glucose uptake. Irisin is a recently identified myokine secreted by skeletal muscle. Irisin is a secreted form of fibronectin type 111 domain containing-protein5 (FNDC5) with 112 amino acids and 12 kDa molecular weight. Increasing circulating irisin improves insulin resistance, weight control, cardiovascular and brain health. The secretion of this myokine is regulated by skeletal muscle and to a lesser extent by adipose tissue by various factors. The aim of this review study was to investigate the different pathways of irisin signal transduction pathways that lead to the regulation of carbohydrate and lipid metabolism in different tissues of the body in insulin resistance and type 2 diabetes through in vivo and in vitro experiments. The findings of this review study indicate the important role of irisin in regulating metabolic pathways in the human body. Irisin could be considered as a new therapeutic target in the treatment of metabolic diseases such as insulin resistance and type 2 diabetes.