[HTML][HTML] Mitochondrial involvement in skeletal muscle insulin resistance: A case of imbalanced bioenergetics

C Affourtit - Biochimica et Biophysica Acta (BBA)-Bioenergetics, 2016 - Elsevier
C Affourtit
Biochimica et Biophysica Acta (BBA)-Bioenergetics, 2016Elsevier
Skeletal muscle insulin resistance in obesity associates with mitochondrial dysfunction, but
the causality of this association is controversial. This review evaluates mitochondrial models
of nutrient-induced muscle insulin resistance. It transpires that all models predict that insulin
resistance arises as a result of imbalanced cellular bioenergetics. The nature and precise
origin of the proposed insulin-numbing molecules differ between models but all species only
accumulate when metabolic fuel supply outweighs energy demand. This observation …
Abstract
Skeletal muscle insulin resistance in obesity associates with mitochondrial dysfunction, but the causality of this association is controversial. This review evaluates mitochondrial models of nutrient-induced muscle insulin resistance. It transpires that all models predict that insulin resistance arises as a result of imbalanced cellular bioenergetics. The nature and precise origin of the proposed insulin-numbing molecules differ between models but all species only accumulate when metabolic fuel supply outweighs energy demand. This observation suggests that mitochondrial deficiency in muscle insulin resistance is not merely owing to intrinsic functional defects, but could instead be an adaptation to nutrient-induced changes in energy expenditure. Such adaptive effects are likely because muscle ATP supply is fully driven by energy demand. This market-economic control of myocellular bioenergetics offers a mechanism by which insulin-signalling deficiency can cause apparent mitochondrial dysfunction, as insulin resistance lowers skeletal muscle anabolism and thus dampens ATP demand and, consequently, oxidative ATP synthesis.
Elsevier