Purpose of review: Tubulointerstitial hypoxia in the kidney has been considered a hallmark of injury and mediator of disease progression. This review focuses on hypoxia-inducible factor (HIF)-1, a master transcription factor in cellular adaptation to hypoxia.
Recent findings: HIF-1alpha is expressed in the hypoxic tubular epithelium as well in as the papillary interstitium and glomerular epithelial cells. Although HIF-1 plays a protective role in a number of acute kidney injury models when overexpressed, its activation in chronic kidney disease results in multiple phenotypic changes, depending on the pathological context.
Summary: Hypoxia, especially HIF-1, is a critical mediator in the pathogenesis of chronic kidney disease. Underlying molecular mechanisms, together with responsible HIF target genes, are currently under investigation.