Thalidomide is used in clinical practice to treat gastrointestinal vascular malformation (GIVM), but the pathogenesis of GIVM is not clear. Hypoxia inducible factor 1 alpha (HIF-1α) and 2 alpha (HIF-2α/EPAS1) are in the same family and act as master regulators of the adaptive response to hypoxia. HIF-1α and HIF-2α are up-regulated in vascular malformations in intestinal tissues from GIVM patien...

We have previously reported on the inhibition of HIF-1α (hypoxia-inducible factor α)-regulated pathways by HEXIM1 [HMBA (hexamethylene-bis-acetamide)-inducible protein 1]. Disruption of HEXIM1 activity in a knock-in mouse model expressing a mutant HEXIM1 protein resulted in increased susceptibility to the development of mammary tumours, partly by up-regulation of VEGF (vascular endothelial grow...

Hypoxia-inducible factor (HIF) controls an extensive range of adaptive responses to hypoxia. To better understand this transcriptional cascade we performed genome-wide chromatin immunoprecipitation using antibodies to two major HIF-alpha subunits, and correlated the results with genome-wide transcript profiling. Within a tiled promoter array we identified 546 and 143 sequences that bound, respe...

Hypoxia-inducible transcription factor (HIF) is regulated by two oxygen-dependent events that are catalyzed by the HIF prolyl 4-hydroxylases (HIF-P4Hs) and HIF asparaginyl hydroxylase (FIH). We have purified the three recombinant human HIF-P4Hs to near homogeneity and characterized their catalytic properties and inhibition and those of FIH. The specific activities of the HIF-P4Hs were at least ...

In Hashimoto’s thyroiditis (HT), oxidative stress (OS) is driven by Th1 cytokines’ response interfering with the normal function of thyrocytes. OS results from an imbalance between excessive production reactive oxygen species (ROS) and a lowering antioxidant production. Moreover, has been shown to inhibit Sirtuin 1 (SIRT1), which able prevent hypoxia-inducible factor (HIF)-1α stabilization. The...

Hypoxia-inducible factor (HIF), an important mediator of hypoxia response, is implicated in tumorigenesis the setting pseudohypoxia, such as inactivation von Hippel–Lindau tumor suppressor protein (pVHL), leading to development and progression clear cell renal carcinoma (ccRCC). Targeting downstream molecules HIF pathway, vascular endothelial growth (VEGF), has led improvement clinical outcome ...

PURPOSE To characterize ocular disease in HIF-2alpha-null mice. METHODS Histologic, electroretinographic (ERG), and molecular studies were performed on samples obtained from age- and gender-matched HIF-2alpha-null (HIF-2alpha-KO), HIF-2alpha-heterozygous (HIF-2alpha-HET), and wild-type (WT) littermate mice. RESULTS HIF-2alpha-KO mice exhibited marked thinning of the retina and abnormal reti...

PURPOSE Androgen deprivation is implicated in reducing neoangiogenesis in prostate cancer (PCA). Androgens regulate the expression of the vascular endothelial growth factor (VEGF); hypoxia stimulates VEGF expression through the activation of the transcriptional factor, hypoxia-inducible factor 1 (HIF-1). We tested the hypothesis that an effect of androgens on VEGF expression is regulated direct...

HIF-1 is the master regulator of cellular hypoxia response; the oxygen sensitive HIF-1α subunit transactivates its own expression in hypoxia via a hypoxia response element (HRE) in the promoter of the HIF-1α gene. This transactivation loop significantly contributes to the build up of HIF-1α at the onset of hypoxia, with the binding of HIF-1 to the HIF-1α promoter being dependent on the epigenet...