Induction of hypoxia-inducible factor 1 activity by muscarinic acetylcholine receptor signaling.
Hypoxia-inducible factor-1 (HIF-1) is a master regulator of cellular adaptive responses to hypoxia. Levels of the HIF-1alpha subunit increase under hypoxic conditions. Exposure of cells to growth factors, prostaglandin, and certain nitric oxide donors also induces HIF-1alpha expression under non-hypoxic conditions. We demonstrate that muscarinic acetylcholine signals induce HIF-1alpha expression and transcriptional activity in a receptor subtype-specific manner using HEK293 cells transiently overexpressing each of M1-M4 muscarinic acetylcholine receptors. The muscarinic signaling pathways inhibited HIF-1alpha hydroxylation and degradation and induced HIF-1alpha protein synthesis that was confirmed by pulse labeling studies. Muscarinic signal-induced HIF-1alpha protein and HIF-1-dependent gene expression were blocked by treating cells with inhibitors of phosphatidylinositol 3-kinase, MAP kinase kinase, or tyrosine kinase signaling pathways. Dominant-negative forms of Ras and/or Rac-1 significantly suppressed HIF-1 activation by muscarinic signaling. Signaling via M1- and M3- but not M2- or M4-AchRs promote accumulation and transcriptional activation of HIF-1alpha. We conclude that muscarinic acetylcholine signals activate HIF-1 by both stabilization and synthesis of HIF-1alpha and by inducing the transcriptional activity of HIF-1alpha.
Department of Anesthesia, The Tazuke Kofukai Medical Research Institute Kitano Hospital, 2-4-20, Ohgimachi, Kita-ku, Osaka 530-8480, Japan. hif1@mac.com
Kiichi
K
Hirota
Ryo
R
Fukuda
Satoshi
S
Takabuchi
Shinae
S
Kizaka-Kondoh
Takehiko
T
Adachi
Kazuhiko
K
Fukuda
Gregg L
GL
Semenza
D002460:Cell Line; D005786:Gene Expression Regulation; D006801:Humans; D006900:Hydroxylation; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism; D043643:Receptor, Muscarinic M1 / Q000235:genetics / Q000502:physiology; D043587:Receptor, Muscarinic M3 / Q000235:genetics / Q000502:physiology; D011976:Receptors, Muscarinic / Q000235:genetics / Q000502:physiology*; D015398:Signal Transduction; D014157:Transcription Factors / Q000096:biosynthesis / Q000378:metabolism*; D014158:Transcription, Genetic; D014162:Transfection
C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D043643:Receptor, Muscarinic M1; D043587:Receptor, Muscarinic M3; D011976:Receptors, Muscarinic; D014157:Transcription Factors; D019869:Phosphatidylinositol 3-Kinases; D020794:Receptor Protein-Tyrosine Kinases; D020928:Mitogen-Activated Protein Kinases