HIF-1α (Hypoxia-Inducible Factor 1α)

HIF-1α is the part of a master switch your cells use to respond to low oxygen. It is the oxygen-sensitive half of a transcription factor called HIF-1 (one half, HIF-1α, plus a partner, HIF-1β, also called ARNT). When oxygen is normal, your cells keep HIF-1α low: enzymes called PHDs tag it, a protein called VHL marks it for the trash, and it is quickly destroyed. When oxygen drops, the PHDs stall, so HIF-1α builds up, pairs with HIF-1β, and switches on survival genes. Those genes cover sugar-burning without oxygen (GLUT1, LDHA), new blood-vessel growth (VEGF), and red-blood-cell production (EPO). In aging, HIF-1α cuts both ways. In the worm C. elegans, both turning it down and cranking it up can extend lifespan, depending on conditions like temperature and oxygen. In mammals, you need the right amount: it is vital for adapting to low oxygen and for protecting tissue against loss of blood flow, but when it is dysregulated it can feed tumors, lung-vessel disease (pulmonary hypertension), and possibly age-related metabolic decline.

Last reviewed: June 22, 2026

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