Mitochondrial myopathy induces a starvation-like response

• Mitochondrial respiratory chain (RC) deficiency is among the most common causes of inherited metabolic disease, but its physiological consequences are poorly characterized. We studied the skeletal muscle gene expression profiles of mice with late-onset mitochondrial myopathy. These animals express a dominant patient mutation in the mitochondrial replicative helicase Twinkle, leading to accumulation of multiple mtDNA deletions and progressive subtle RC deficiency in the skeletal muscle. The global gene expression pattern of the mouse skeletal muscle showed induction of pathways involved in amino acid starvation response and activation of Akt signaling. Furthermore, the muscle showed induction of a fasting-related hormone, fibroblast growth factor 21 (Fgf21). This secreted regulator of lipid metabolism was also elevated in the mouse serum, and the animals showed widespread changes in their lipid metabolism: small adipocyte size, low fat content in the liver and resistance to high-fat diet. We propose that RC deficiency induces a mitochondrial stress response, with local and global changes mimicking starvation, in a normal nutritional state. These results may have important implications for understanding the metabolic consequences of mitochondrial myopathies.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Andra medicinska och farmaceutiska grundvetenskaper (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Other Basic Medicine (hsv//eng)

Nyckelord

Mitochondrial myopathies

signal transduction

mutation

mitochondria

amino acids

stress response

diet

hormones

adipocytes

dna

mitochondrial

fasting

gene expression profiling

skeletal muscles

liver

mice

proto-oncogene proteins c-akt

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)