Measurement of Fibroblast growth factor 21 (FGF21) concentrations are raised in serum of mice and humans with mitochondrial respiratory chain deficiencies and has been proposed by Suomalainen et al. (http://www.ncbi.nlm.nih.gov/pubmed/21820356) as a first-line diagnostic test for mitochondrial disorders to reduce the need for muscle biopsy.
FGF21 is a hormone secreted by the liver during fasting that elicits diverse aspects of the adaptive starvation response. Among its effects, FGF21 induces hepatic fatty acid oxidation and ketogenesis, increases insulin sensitivity, blocks somatic growth and causes bone loss. Zhang et al. have shown that transgenic overexpression of FGF21 markedly extends lifespan in mice without reducing food intake or affecting markers of NAD+ metabolism or AMP kinase and mTOR signaling. Transcriptomic analysis suggests that FGF21 acts primarily by blunting the growth hormone/insulin-like growth factor-1 signaling pathway in liver.
OMMBID, Part 10
Posted by Nicola Brunetti-Pierri, MD