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HIF prolyl hydroxylase 2/3 deletion disrupts astrocytic integrity and exacerbates neuroinflammation

Authors

  • K.S. Rosiewicz
  • B. Muinjonov
  • S. Kunz
  • H. Radbruch
  • J. Chen
  • R. Jüttner
  • J. Kerkering
  • J. Ucar
  • T. Crowley
  • B. Wielockx
  • F. Paul
  • M. Alisch
  • V. Siffrin

Journal

  • Glia

Citation

  • Glia 71 (8): 2024-2044

Abstract

  • Astrocytes constitute the parenchymal border of the blood-brain barrier (BBB), modulate the exchange of soluble and cellular elements, and are essential for neuronal metabolic support. Thus, astrocytes critically influence neuronal network integrity. In hypoxia, astrocytes upregulate a transcriptional program that has been shown to boost neuroprotection in several models of neurological diseases. We investigated transgenic mice with astrocyte-specific activation of the hypoxia-response program by deleting the oxygen sensors, HIF prolyl-hydroxylase domains 2 and 3 (Phd2/3). We induced astrocytic Phd2/3 deletion after onset of clinical signs in experimental autoimmune encephalomyelitis (EAE) that led to an exacerbation of the disease mediated by massive immune cell infiltration. We found that Phd2/3-ko astrocytes, though expressing a neuroprotective signature, exhibited a gradual loss of gap-junctional Connexin-43 (Cx43), which was induced by vascular endothelial growth factor-alpha (Vegf-a) expression. These results provide mechanistic insights into astrocyte biology, their critical role in hypoxic states, and in chronic inflammatory CNS diseases.


DOI

doi:10.1002/glia.24380