Physiological oxygen-dependent cellular processes

Physiological oxygen-dependent cellular processes refer to the complex biochemical pathways, primarily the Hypoxia-Inducible Factor (HIF) signaling system, that allow cells to sense and adapt to varying oxygen levels [1]. Under normoxic conditions, oxygen-sensing prolyl hydroxylase domain (PHD) enzymes hydroxylate HIF-alpha subunits, targeting them for rapid proteasomal degradation [2]. When oxygen is limited (hypoxia), these enzymes become inactive, allowing HIF to stabilize and translocate to the nucleus where it activates genes responsible for erythropoiesis, angiogenesis, and anaerobic metabolism [3]. While this term describes a broad biological category rather than a single molecule, it is the functional focus of several therapeutic classes [4]. For example, PHD inhibitors like Roxadustat are used to treat anemia in chronic kidney disease by boosting endogenous erythropoietin production [5]. Conversely, in oncology, inhibitors such as Belzutifan target HIF-2alpha to treat cancers where these oxygen-dependent processes are pathologically hijacked, such as in von Hippel-Lindau (VHL) disease [6]. Clinical management of these processes requires careful oversight due to the potential for cardiovascular complications and unintended tissue proliferation [7]. [1] Semenza GL. Cell. 2012;148(3):399-408. [2] Kaelin WG Jr, Ratcliffe PJ. Mol Cell. 2008;30(4):393-402. [3] Maxwell PH, Eckardt KU. Nat Rev Nephrol. 2023;19(3):147-162. [4] Sanghani NS, Haase VH. Adv Chronic Kidney Dis. 2019;26(4):253-266. [5] Chen N, et al. N Engl J Med. 2019;381(11):1001-1010. [6] Jonasch E, et al. N Engl J Med. 2021;385(22):2036-2046. [7] Gupta N, Wish JB. Am J Kidney Dis. 2017;69(6):815-826.

Other names

Oxygen sensingHypoxia-inducible factor (HIF) pathwayCellular oxygen homeostasisAerobic metabolic signaling

Stabilization of Hypoxia-Inducible Factors (HIF) through the inhibition of Prolyl Hydroxylase Domain (PHD) enzymes, or direct antagonism of HIF-2alpha transcription factors.