An involvement of the mitochondrial fatty acid transporters in the development of myocellular insulin resistance

摘要

Long-chain fatty acids (LCFAs) are an important source of energy for working skeletal muscles. The predominant mechanism of LCFA influx into skeletal muscle involves sarcolemmal proteins, namely fatty-acid transporters. Recent studies imply strong correlations between increased plasmalemmal expression of FA transporters and the development of insulin resistance in skeletal muscles. However, it seems that a major feature of myocyte insulin resistance is the imbalance in lipid transport into the cells and the capacity of mitochondria for LCFA oxidation. Excess deposition of myocelluar fatty acids leads to the accumulation of triacylglycerols, diacyloglycerols, and ceramides. Most likely, the accumulation of intramuscular lipid fractions is responsible for disturbances in the insulin signaling pathway and the subsequent development of skeletal muscle insulin resistance.