title: Acclimatization to long-term hypoxia: gene expression in ovine carotid arteries.
abstract: Exposure to acute high-altitude hypoxia is associated with an increase in cerebral blood flow (CBF) as a consequence of low arterial O2 tension. However, in response to high altitude acclimatization, CBF returns to levels similar to those at sea level, and tissue blood flow is maintained by an increase in angiogenesis. Of consequence, dysregulation of the acclimatization responses and CBF can result in acute mountain sickness, acute cerebral and/or pulmonary edema. To elucidate the signal transduction pathways involved in successful acclimatization to high altitude, in ovine carotid arteries, we tested the hypothesis that high altitude-associated long-term hypoxia results in changes in gene expression of critical signaling pathways. We acclimatized nonpregnant adult sheep to 3,801 m altitude for ∼110 days and conducted oligonucleotide microarray experiments on carotid arteries. Of a total of 116 regulated genes, 58 genes were significantly upregulated and 58 genes were significantly downregulated (each >2-fold, P < 0.05). Major upregulated genes included suprabasin and myelin basic protein, whereas downregulated genes included BAG2. Several of these genes are known to activate the ERK canonical signal transduction pathway and the process of angiogenesis. We conclude that among other changes, the altered signal transduction molecules involved in high-altitude acclimatization are associated ERK activation and angiogenesis.
authors: Center for Perinatal Biology, School of Medicine, Loma Linda University, Loma Linda, California; and Epigenuity LLC, Loma Linda, California.
authors: Ravi
authors: R
authors: Goyal
authors: Center for Perinatal Biology, School of Medicine, Loma Linda University, Loma Linda, California; and Epigenuity LLC, Loma Linda, California llongo@llu.edu.
authors: Lawrence D
authors: LD
authors: Longo
mesh_terms: D000064:Acclimatization / Q000502:physiology*; D000532:Altitude Sickness / Q000378:metabolism / Q000503:physiopathology*; D000704:Analysis of Variance; D000818:Animals; D002196:Capillaries / Q000502:physiology; D002339:Carotid Arteries / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000235:genetics / Q000502:physiology*; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism; D015151:Immunoblotting; D008856:Microscopy, Fluorescence; D020411:Oligonucleotide Array Sequence Analysis; D060888:Real-Time Polymerase Chain Reaction; D012756:Sheep; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology*
chemical_list: D051795:Hypoxia-Inducible Factor 1, alpha Subunit
keywords: acute mountain sickness; chronic hypoxia; oligonucleotide microarray; prolonged hypoxia