Further density gradient fractionation of HepG2 membranes revealed that hypoxia caused an increase in total membrane IRP1, with a shift in the membrane-bound fraction from Golgi to an endoplasmic reticulum (ER)-enriched fraction.
Here we describe the consequences of IRP regulation and show that iron homeostasis is regulated in 2 phases during hypoxia: an early phase where IRP1 RNA-binding activity decreases and iron uptake and Ft synthesis increase, and a late phase where IRP2 RNA-binding activity increases and iron uptake and Ft synthesis decrease.
Our results suggest that ADA2 may be active in sites of inflammation during hypoxia and in areas of tumour growth where the adenosine concentration is significantly elevated and the extracellular pH is acidic.
In preeclampsia, regional increases in ADM mRNA may be induced by hypoxia and mediate local fetal/placental adaptive responses to reduced placental perfusion.
Analysis of the cloned human A2BR promoter identified a functional hypoxia-responsive region, including a functional binding site for hypoxia-inducible factor (HIF) within the A2BR promoter.
Hypoxia suppresses the production of MMP-9 by human monocyte-derived dendritic cells and requires activation of adenosine receptor A2b via cAMP/PKA signaling pathway.
Furthermore, insight gained through microarray analysis revealed that the adenosine A2B receptor (AdoRA2B) is selectively up-regulated by hypoxia (>5-fold increase in mRNA), and that AdoRA2B antagonists effectively neutralize ATP-mediated changes in posthypoxic endothelial permeability.
Repression of alpha-fetoprotein gene expression under hypoxic conditions in human hepatoma cells: characterization of a negative hypoxia response element that mediates opposite effects of hypoxia inducible factor-1 and c-Myc.
A significant increase in the secretion (P <.01) and mRNA expression (P <.01) of angiogenin and a significant decrease in the secretion (P <.04) and mRNA expression (P <.03) of VCAM-1 from both term placental explants and trophoblast cultures subjected to hypoxia in vitro were observed.