The good, the bad, and the cell type-specific roles of hypoxia inducible factor-1 alpha in neurons and astrocytes.
Hypoxia inducible factor-1alpha (HIF-1alpha) is a key regulator of oxygen homeostasis, because it is responsible for the regulation of genes involved in glycolysis, erythropoiesis, angiogenesis, and apoptosis. In the CNS, HIF-1alpha is stabilized by insults associated with hypoxia and ischemia. Because its many target genes mediate both adaptive and pathological processes, the role of HIF-1alpha in neuronal survival is debated. Although neuronal HIF-1alpha function has been the topic of several studies, the role of HIF-1alpha function in astrocytes has received much less attention. To characterize the role of HIF-1alpha in neurons and astrocytes, we induced loss of HIF-1alpha function specifically in neurons, astrocytes, or both cell types in neuron/astrocyte cocultures exposed to hypoxia. Although loss of HIF-1alpha function in neurons reduced neuronal viability during hypoxia, selective loss of HIF-1 function in astrocytes markedly protected neurons from hypoxic-induced neuronal death. Although the pathological processes induced by HIF-1alpha in astrocytes remain to be defined, induction of inducible nitric oxide synthase likely contributes to the pathological process. This study delineates, for the first time, a cell type-specific action for HIF-1alpha within astrocytes and neurons.
Vangeison
Grace
G
Department of Neurology, Center for Neural Development and Disease, and Interdepartmental Graduate Program in Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642, USA.
Carr
Dan
D
Federoff
Howard J
HJ
Rempe
David A
DA
D000818:Animals; D000831:Animals, Newborn; D001253:Astrocytes / Q000166:cytology* / Q000201:enzymology / Q000502:physiology*; D018920:Coculture Techniques; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D051379:Mice; D008822:Mice, Transgenic; D009474:Neurons / Q000166:cytology* / Q000201:enzymology / Q000502:physiology*; D052247:Nitric Oxide Synthase Type II / Q000096:biosynthesis / Q000502:physiology
D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D052247:Nitric Oxide Synthase Type II