Hypoxia-inducible factor-1 signaling system

Abstract

Oxygen (O2) homeostasis is regulated by balancing the supply of O2 from the vasculature and O2 consumed by mitochondrial oxidative phosphorylation. If the balance of O2 is disturbed, cells are exposed to a state of either oxidative stress or oxidative depression. Hypoxia is a state of oxidative depression and occurs when there is a reduction in blood flow or O2 content of the blood. In the liver, as within other tissues, hypoxic cells initiate adaptive responses to help ensure their survival. These adaptive responses are aimed at increasing O2 supply and compensate for loss of energy via physiological, metabolic, and molecular mechanisms. Studies are continuing to define the molecular pathways of these mechanisms and reveal that they occur at every regulatory level, including gene transcription, protein translation, and posttranslational modifications. © 2010 Springer-Verlag Berlin Heidelberg.