The Asparaginyl Hydroxylase Factor Inhibiting HIF-1α Is an Essential Regulator of Metabolism

SummaryFactor inhibiting HIF-1α (FIH) is an asparaginyl hydroxylase. Hydroxylation of HIF-α proteins by FIH blocks association of HIFs with the transcriptional coactivators CBP/p300, thus inhibiting transcriptional activation. We have created mice with a null mutation in the FIH gene and found that it has little or no discernable role in mice in altering classical aspects of HIF function, e.g., angiogenesis, erythropoiesis, or development. Rather, it is an essential regulator of metabolism: mice lacking FIH exhibit reduced body weight, elevated metabolic rate, hyperventilation, and improved glucose and lipid homeostasis and are resistant to high-fat-diet-induced weight gain and hepatic steatosis. Neuron-specific loss of FIH phenocopied some of the major metabolic phenotypes of the global null animals: those mice have reduced body weight, increased metabolic rate, and enhanced insulin sensitivity and are also protected against high-fat-diet-induced weight gain. These results demonstrate that FIH acts to a significant degree through the nervous system to regulate metabolism.

► FIH is a nonredundant asparaginyl hydroxylase of HIF-1α
► FIH is an essential regulator of metabolism
► FIH null mice exhibit increased insulin sensitivity and decreased adiposity
► Neuronal loss of FIH phenocopies major metabolic phenotypes of global null animals