Skeletal Muscle Mitochondrial Bioenergetics and Morphology in High Fat Diet Induced Obesity and Insulin Resistance: Focus on Dietary Fat Source

Abstract

It has been suggested that skeletal muscle mitochondria play a key role in high fat (HF) diet induced insulin resistance (IR). Two opposite views are debated on mechanisms by which mitochondrial function could be involved in skeletal muscle IR. In one theory, mitochondrial dysfunction is suggested to cause intramyocellular lipid accumulation leading to IR. In the second theory, excess fuel within mitochondria in the absence of increased energy demand stimulates mitochondrial oxidant production and emission, ultimately leading to the development of IR. Noteworthy, mitochondrial bioenergetics is strictly associated with the maintenance of normal mitochondrial morphology by maintaining the balance between the fusion and fission processes. A shift toward mitochondrial fission with reduction of fusion protein, mainly mitofusin 2, has been associated with reduced insulin sensitivity and inflammation in obesity and IR development. However, dietary fat source during chronic overfeeding differently affects mitochondrial morphology. Saturated fatty acids induce skeletal muscle IR and inflammation associated with fission phenotype, whereas ω-3 polyunsaturated fatty acids improve skeletal muscle insulin sensitivity and inflammation, associated with a shift toward mitochondrial fusion phenotype. The present minireview focuses on mitochondrial bioenergetics and morphology in skeletal muscle IR, with particular attention to the effect of different dietary fat sources on skeletal muscle mitochondria morphology and fusion/fission balance.

Identifying suitable reference genes for gene expression analysis in developing skeletal muscle in pigs

“…Studies of muscle development are important to improve meat production, to understand human diseases like diabetes (Li et al, 2016a; Nixon et al, 2016; Obata et al, 2016; Zabielski et al, 2016) and obesity (Costa Junior et al, 2016; Fonvig et al, 2015; Putti et al, 2015; Thivel et al, 2016) due to the important role of skeletal muscle in lipid and energy metabolism. Many studies investigated the mechanism of skeletal muscle development by performing gene expression analysis (Krist et al, 2015; Wang, Xiao & Wang, 2016; Zhang et al, 2016a; Zhang et al, 2015).…”

Mitochondria and Reactive Oxygen Species in Aging and Age-Related Diseases

“…Increased mitochondrial network fragmentation and Fis1 expression is observed in venous endothelial cells of type 2 diabetes mellitus patients compared to control (Shenouda et al, 2011). A shift toward mitochondrial fission with reduction of fusion protein, mainly Mfn2, has been associated with reduced insulin sensitivity and inflammation in obesity and insulin resistance development (Putti et al, 2015), which can be associated with altered ROS production.…”

Mitochondrial behaviour, morphology, and animal performance

“…Salin et al ., , ; Zhang & Hood, ; Mowry et al ., ; Hill et al ., ). Genetic and environmental factors can have direct impacts on animal performance such as lifespan and reproductive output (Navarro et al ., ; Liau et al ., ), but they also affect mitochondrial morphology (Sogo & Yaffe, ; Visser et al ., ; Zick et al ., ; Putti et al ., ). In particular, energy production can increase significantly from changes in the morphology of the inner mitochondrial membrane (IMM; Mannella, Lederer, & Jafri, ; Nielsen et al ., ; Afzal et al ., ).…”