Abstract | BACKGROUND: METHODS AND RESULTS: To determine whether hypoxia regulates eNOS expression through Rho-kinase, we exposed human saphenous and pulmonary artery endothelial cells to hypoxia (3% O2) with and without a Rho-kinase inhibitor, hydroxyfasudil (0.1 to 100 micromol/L), for various durations (0 to 48 hours). Hypoxia increased Rho-kinase expression and activity by 50% and 74%, decreased eNOS mRNA and protein expression by 66+/-3% and 57+/-5%, and inhibited eNOS activity by 48+/-9%. All of these effects of hypoxia on eNOS were reversed by cotreatment with hydroxyfasudil. Furthermore, inhibition of Rho by Clostridium botulinum C3 transferase or Rho-kinase by overexpression of dominant-negative Rho-kinase reversed hypoxia-induced decrease in eNOS expression. Indeed, disruption of the actin cytoskeleton, the downstream target of Rho-kinase, by cytochalasin D also upregulated eNOS expression. Hypoxia reduced eNOS mRNA half-life from 22+/-2 to 13+/-2 hours, which was reversed by cotreatment with hydroxyfasudil. However, neither hypoxia nor hydroxyfasudil had any effects on eNOS gene transcription. CONCLUSIONS:
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Authors | Masao Takemoto, Jianxin Sun, Junko Hiroki, Hiroaki Shimokawa, James K Liao |
Journal | Circulation
(Circulation)
Vol. 106
Issue 1
Pg. 57-62
(Jul 02 2002)
ISSN: 1524-4539 [Electronic] United States |
PMID | 12093770
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)
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Chemical References |
- Enzyme Inhibitors
- Intracellular Signaling Peptides and Proteins
- RNA, Messenger
- hydroxyfasudil
- 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine
- NOS3 protein, human
- Nitric Oxide Synthase
- Nitric Oxide Synthase Type III
- Protein Serine-Threonine Kinases
- rho-Associated Kinases
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Topics |
- 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine
(analogs & derivatives, pharmacology)
- Cell Hypoxia
- Cells, Cultured
- Down-Regulation
- Endothelium, Vascular
(drug effects, enzymology)
- Enzyme Inhibitors
(pharmacology)
- Gene Expression Regulation
- Humans
- Intracellular Signaling Peptides and Proteins
- Nitric Oxide Synthase
(genetics, metabolism)
- Nitric Oxide Synthase Type III
- Protein Serine-Threonine Kinases
(antagonists & inhibitors, metabolism)
- Pulmonary Artery
(cytology, enzymology)
- RNA Stability
(drug effects)
- RNA, Messenger
(biosynthesis)
- Transcription, Genetic
(drug effects)
- rho-Associated Kinases
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