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Alganga H, Almabrouk TAM, Katwan OJ, Daly CJ, Pyne S, Pyne NJ, Kennedy S. Short Periods of Hypoxia Upregulate Sphingosine Kinase 1 and Increase Vasodilation of Arteries to Sphingosine 1-Phosphate (S1P) via S1P 3. J Pharmacol Exp Ther 2019; 371:63-74. [PMID: 31371480 DOI: 10.1124/jpet.119.257931] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Accepted: 07/30/2019] [Indexed: 02/06/2023] Open
Abstract
Sphingosine kinase [(SK), isoforms SK1 and SK2] catalyzes the formation of the bioactive lipid, sphingosine 1-phosphate (S1P). This can be exported from cells and bind to S1P receptors to modulate vascular function. We investigated the effect of short-term hypoxia on SK1 expression and the response of arteries to S1P. SK1 expression in rat aortic and coronary artery endothelial cells was studied using immunofluorescence and confocal microscopy. Responses of rat aortic rings were studied using wire myography and reversible hypoxia induced by bubbling myography chambers with 95% N2:5% CO2 Inhibitors were added 30 minutes before induction of hypoxia. S1P induced endothelium-dependent vasodilation via activation of S1P3 receptors and generation of nitric oxide. Hypoxia significantly increased relaxation to S1P and this was attenuated by (2R)-1-[[(4-[[3-methyl-5-[(phenylsulfonyl)methyl] phenoxy]methyl]phenyl]methyl]-2-pyrrolidinemethanol [(PF-543), SK1 inhibitor] but not (R)-FTY720 methyl ether [(ROMe), SK2 inhibitor]. Hypoxia also increased vessel contractility to the thromboxane mimetic, 9,11-dideoxy-11α,9α-epoxymethanoprostaglandin F2α, which was further increased by PF-543 and ROMe. Hypoxia upregulated SK1 expression in aortic and coronary artery endothelial cells and this was blocked by PF-543 and 2-(p-hydroxyanilino)-4-(p-chlorophenyl)thiazole [(SKi), SK1/2 inhibitor]. The effects of PF-543 and SKi were associated with increased proteasomal/lysosomal degradation of SK1. A short period of hypoxia increases the expression of SK1, which may generate S1P to oppose vessel contraction. Under hypoxic conditions, upregulation of SK1 is likely to lead to increased export of S1P from the cell and vasodilation via activation of endothelial S1P3 receptors. These data have significance for perfusion of tissue during episodes of ischemia.
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Affiliation(s)
- H Alganga
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, United Kingdom (H.A., T.A.M.A., O.J.K., C.J.D., S.K.); Strathclyde Institute of Pharmacy and Biomedical Science, University of Strathclyde, Glasgow, United Kingdom (S.P., N.J.P.); Department of Pharmacology, School of Medicine, University of Zawia, Zawia, Libya (H.A., T.A.M.A.); and Department of Biochemistry, College of Medicine, University of Diyala, Baqubah, Iraq (O.J.K.)
| | - T A M Almabrouk
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, United Kingdom (H.A., T.A.M.A., O.J.K., C.J.D., S.K.); Strathclyde Institute of Pharmacy and Biomedical Science, University of Strathclyde, Glasgow, United Kingdom (S.P., N.J.P.); Department of Pharmacology, School of Medicine, University of Zawia, Zawia, Libya (H.A., T.A.M.A.); and Department of Biochemistry, College of Medicine, University of Diyala, Baqubah, Iraq (O.J.K.)
| | - O J Katwan
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, United Kingdom (H.A., T.A.M.A., O.J.K., C.J.D., S.K.); Strathclyde Institute of Pharmacy and Biomedical Science, University of Strathclyde, Glasgow, United Kingdom (S.P., N.J.P.); Department of Pharmacology, School of Medicine, University of Zawia, Zawia, Libya (H.A., T.A.M.A.); and Department of Biochemistry, College of Medicine, University of Diyala, Baqubah, Iraq (O.J.K.)
| | - C J Daly
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, United Kingdom (H.A., T.A.M.A., O.J.K., C.J.D., S.K.); Strathclyde Institute of Pharmacy and Biomedical Science, University of Strathclyde, Glasgow, United Kingdom (S.P., N.J.P.); Department of Pharmacology, School of Medicine, University of Zawia, Zawia, Libya (H.A., T.A.M.A.); and Department of Biochemistry, College of Medicine, University of Diyala, Baqubah, Iraq (O.J.K.)
| | - S Pyne
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, United Kingdom (H.A., T.A.M.A., O.J.K., C.J.D., S.K.); Strathclyde Institute of Pharmacy and Biomedical Science, University of Strathclyde, Glasgow, United Kingdom (S.P., N.J.P.); Department of Pharmacology, School of Medicine, University of Zawia, Zawia, Libya (H.A., T.A.M.A.); and Department of Biochemistry, College of Medicine, University of Diyala, Baqubah, Iraq (O.J.K.)
| | - N J Pyne
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, United Kingdom (H.A., T.A.M.A., O.J.K., C.J.D., S.K.); Strathclyde Institute of Pharmacy and Biomedical Science, University of Strathclyde, Glasgow, United Kingdom (S.P., N.J.P.); Department of Pharmacology, School of Medicine, University of Zawia, Zawia, Libya (H.A., T.A.M.A.); and Department of Biochemistry, College of Medicine, University of Diyala, Baqubah, Iraq (O.J.K.)
| | - S Kennedy
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, United Kingdom (H.A., T.A.M.A., O.J.K., C.J.D., S.K.); Strathclyde Institute of Pharmacy and Biomedical Science, University of Strathclyde, Glasgow, United Kingdom (S.P., N.J.P.); Department of Pharmacology, School of Medicine, University of Zawia, Zawia, Libya (H.A., T.A.M.A.); and Department of Biochemistry, College of Medicine, University of Diyala, Baqubah, Iraq (O.J.K.)
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Le Brocq M, Leslie SJ, Milliken P, Megson IL. Endothelial dysfunction: from molecular mechanisms to measurement, clinical implications, and therapeutic opportunities. Antioxid Redox Signal 2008; 10:1631-74. [PMID: 18598143 DOI: 10.1089/ars.2007.2013] [Citation(s) in RCA: 130] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Endothelial dysfunction has been implicated as a key factor in the development of a wide range of cardiovascular diseases, but its definition and mechanisms vary greatly between different disease processes. This review combines evidence from cell-culture experiments, in vitro and in vivo animal models, and clinical studies to identify the variety of mechanisms involved in endothelial dysfunction in its broadest sense. Several prominent disease states, including hypertension, heart failure, and atherosclerosis, are used to illustrate the different manifestations of endothelial dysfunction and to establish its clinical implications in the context of the range of mechanisms involved in its development. The size of the literature relating to this subject precludes a comprehensive survey; this review aims to cover the key elements of endothelial dysfunction in cardiovascular disease and to highlight the importance of the process across many different conditions.
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Affiliation(s)
- Michelle Le Brocq
- Health Faculty, UHI Millennium Institute, Inverness, University of Edinburgh, Edinburgh, Scotland
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Jansen-Olesen I, Mortensen CH, El-Bariaki N, Ploug KB. Characterization of K(ATP)-channels in rat basilar and middle cerebral arteries: studies of vasomotor responses and mRNA expression. Eur J Pharmacol 2005; 523:109-18. [PMID: 16226739 DOI: 10.1016/j.ejphar.2005.08.028] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2005] [Accepted: 08/15/2005] [Indexed: 11/23/2022]
Abstract
Changes in the activity of K+ channels represent a major mechanism that regulates vascular tone. Cerebrovascular adenosine 5'-triphosphate-sensitive K+(K(ATP)) channels were characterized in studies of the molecular expression and vasomotor reactivity to different K(ATP) channel openers in rat basilar and middle cerebral arteries. Both arteries showed strong mRNA expression of the subunits of the pore-forming inward-rectifying K+ channel type 6.1 (Kir6.1), Kir6.2 and the connected sulfonylurea receptor (SUR) subunits, SUR1 and SUR2B, while only weak bands for SUR2A were seen. The K(ATP) channel openers induced relaxation of prostaglalndin F2alpha-precontracted isolated basilar and middle cerebral arteries with the order of potency N-Cyano-N-(1,1-dimethylpropyl)-N''-3pyridylguanidine (P-1075)>levcromakalim>N-(4-Phenylsulfonylphenyl)-3,3,3-trifluoro-2-hydroxy-2-methylpropanamide (ZM226600)>pinacidil>diazoxide. The responses induced by levcromakalim, ZM226600 and diazoxide were significantly more potent in basilar arteries than in middle cerebral arteries, while pinacidil and P-1075 were equipotent. Endothelium removal decreased (P<0.05) the sensitivity (pIC50) of basilar arteries, but not of middle cerebral arteries, to pinacidil, levcromakalim, P-1075 and ZM226600. The maximum relaxant response to P-1075 was stronger (P<0.005) in basilar arteries with endothelium than without endothelium. Correlation of the relaxant potency of K(ATP) channel openers in rat basilar and middle cerebral arteries with historical measurements of affinity obtained in COS-7 cell lines expressing either SUR1, SUR2A or SUR2B showed that vasodilatation by K(ATP) channel openers correlated with binding to either the SUR2A or the SUR2B subunit. Glibenclamide was a blocker of relaxation induced by pinacidil, levcromakalim, P-1075 and ZM226600 in basilar arteries. Only a weak antagonistic effect of glibenclamide on pinacidil-, levcromakalim- and ZM226600-induced relaxations was found in middle cerebral arteries. The subunit profile and the observed pharmacological properties suggest that the K(ATP) channels expressed in rat basilar and middle cerebral artery are likely to be composed of SUR2B co-associated with Kir6.1 or Kir6.2. In basilar arteries, but not in middle cerebral arteries, endothelial K(ATP) channels may be involved.
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Affiliation(s)
- Inger Jansen-Olesen
- Department of Neurology, Glostrup Hospital, University of Copenhagen, Nordre Ringvej 57, 2600 Glostrup, Copenhagen, Denmark.
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Ren Z, Yang Q, Floten HS, Furnary AP, Yim AP, He GW. ATP-sensitive potassium channel openers may mimic the effects of hypoxic preconditioning on the coronary artery. Ann Thorac Surg 2001; 71:642-7. [PMID: 11235721 DOI: 10.1016/s0003-4975(00)02392-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
BACKGROUND This study was designed to investigate the effects of the potassium channel opener KRN4884 in mimicking hypoxic preconditioning on coronary arteries and to explore the possible mechanisms. METHODS In the organ chamber, porcine coronary artery rings (n = 96) were studied in 6 groups (n = 16 in each group): I. CONTROL normoxia (pO2 > 200 mmHg); II. Hypoxia-reoxygenation: 60-minute hypoxia (pO2 < 15 mmHg) followed by 30-minute reoxygenation; III. Preconditioning: 5-minute hypoxia followed by 10-minute reoxygenation prior to hypoxia-reoxygenation; IV. KRN4884-pretreatment: KRN4884 (30 microM) was added into the chamber 20 minutes before hypoxia-reoxygenation; V. 5-HD-pretreatment: sodium 5-hydroxydecanoate (5-HD, 10 microM) was given 20 minutes prior to KRN4884-pretreatment; and VI. GBC-pretreatment: glibenclamide (GBC, 3 microM) was added 20 minutes prior to KRN4884-pretreatment. Concentration-contraction curves for U46619 (n = 8 in each group) were constructed. Concentration-relaxation curves for bradykinin (n = 8 in each group) related to endothelium-derived hyperpolarizing factor (EDHF) were established in the rings precontracted with U46619 (30 microM) in the presence of Nomega-nitro-L-arginine (L-NNA, 300 microM) and indomethacin (7 microM). RESULTS The maximal relaxation induced by bradykinin was reduced in hypoxia-reoxygenation (54.6 +/- 4.3% versus 85.2 +/- 5.7% in control, p = 0.001). This reduced relaxation was recovered in KRN4884-pretreatment (78.9 +/- 3.7%, p = 0.014) or preconditioning (79.9 +/- 3.7%, p = 0.009). 5-HD- but not GBC-pretreatment abolished the effect of KRN4884-pretreatment (78.9 +/- 3.7% versus 53.5 +/- 4.7%, p = 0.009). CONCLUSIONS Hypoxia-reoxygenation reduces the relaxation mediated by EDHF in the coronary artery. This function can be restored by either hypoxic preconditioning or the potassium channel opener KRN4884. The mechanism of such effect is mainly related to the mitochondrial ATP-sensitive K+ channels.
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Affiliation(s)
- Z Ren
- Cardiovascular Research, Starr Academic Center, Providence Heart Institute, St Vincent Hospital, Portland, Oregon, USA
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