Title:Irisin and Energy Metabolism and the Role of Irisin on Metabolic
Syndrome
Volume: 23
Issue: 20
Author(s): Tugce Aladag, Rasim Mogulkoc*Abdulkerim Kasim Baltaci
Affiliation:
- Department of Physiology, Medical Faculty, Selcuk University, Konya, Turkey
Keywords:
Irisin, energy metabolism, metabolic syndrome, glucose, FNDC5, adipose tissue.
Abstract:
Irisin is a thermogenic hormone that leads to causes energy expenditure by increasing
brown adipose tissue (BAT). This protein hormone that enables the conversion of white adipose tissue
(WAT) to BAT is the irisin protein. This causes energy expenditure during conversion. WAT stores
triglycerides and fatty acids and contains very few mitochondria. They also involve in the development
of insulin resistance (IR). WAT, which contains a very small amount of mitochondria, contributes
to the formation of IR by storing triglycerides and fatty acids.
WAT functions as endocrine tissue in the body, synthesizing various molecules such as leptin, ghrelin,
NUCB2/nesfatin-1, and irisin along with fat storage. BAT is quite effective in energy expenditure,
unlike WAT. The number of mitochondria and lipid droplets composed of multicellular cells in BAT
is much higher when compared to WAT. BAT contains a protein called uncoupling protein-1 (UCP1)
in the mitochondrial membranes. This protein pumps protons from the intermembrane space toward
the mitochondrial matrix. When UCP1 is activated, heat dissipation occurs while ATP synthesis does
not occur, because UCP1 is a division protein. At the same time, BAT regulates body temperature in
infants. Its effectiveness in adults became clear after the discovery of irisin. The molecular mechanism
of exercise, which increases calorie expenditure, became clear with the discovery of irisin. Thus, the
isolation of irisin led to the clarification of metabolic events and fat metabolism. In this review, literature
information will be given on the effect of irisin hormone on energy metabolism and metabolic
syndrome (MetS).
