Increased HIF-2α Activity in the Nucleus Pulposus Causes Mild Degenerative Changes in the Intervertebral Disc in the Aging Mouse Spine

Transcriptomic analysis of nucleus pulposus (NP) tissues from intervertebral discs of 14- and 24-month-old mice with the conditional postnatal overexpression of HIF-2α. Hypoxia-inducible factors (HIFs) are essential for the homeostasis of the hypoxic tissues, and therefore, increased activity of the transcription factor HIF-2α is shown to contribute to the pathogenesis of mild disc degeneration in the spine. We examined the transcriptomic profiles of nucleus pulposus cells in control and K19-HIF-2α-dPA overexpression mice using microarrays. Tissues from the nucleus pulposus (NP) were harvested from the intervertebral discs of four K19-HIF-2αdPA control (HIF-2αdPA/dPA) (WT) and four K19-HIF-2αdPA overexpression mice (K19-HIF-2αdPA/dPA) (MUT) at both 14 and 24 months of age. NP tissues were pooled from caudal discs in each animal for RNA extraction and hybridization using Affymetrix microarrays.