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Klapczyńska K, Aleksandrowicz M, Koźniewska E. Role of the endothelial reverse mode sodium-calcium exchanger in the dilation of the rat middle cerebral artery during hypoosmotic hyponatremia. Pflugers Arch 2023; 475:381-390. [PMID: 36394650 PMCID: PMC9908729 DOI: 10.1007/s00424-022-02770-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 10/22/2022] [Accepted: 11/04/2022] [Indexed: 11/18/2022]
Abstract
A decrease in serum sodium ion concentration below 135 mmol L-1 is usually accompanied by a decrease in plasma osmolality (hypoosmotic hyponatremia) and leads to the disorder of intracranial homeostasis mainly due to cellular swelling. Recently, using an in vitro model of hypoosmotic hyponatremia, we have found that a decrease in sodium ion concentration in the perfusate to 121 mmol L-1 relaxes the isolated rat middle cerebral artery (MCA). The aim of the present study was to explore the mechanism responsible for this relaxation. Isolated, pressurized, and perfused MCAs placed in a vessel chamber were subjected to a decrease in sodium ion concentration to 121 mmol L-1. Changes in the diameter of the vessels were monitored with a video camera. The removal of the endothelium and inhibition of nitric oxide-dependent signaling or the reverse mode sodium-calcium exchanger (NCX) were used to study the mechanism of the dilation of the vessel during hyponatremia. The dilation of the MCA (19 ± 5%, p < 0.005) in a low-sodium buffer was absent after removal of the endothelium or administration of the inhibitor of the reverse mode of sodium-calcium exchange and was reversed to constriction after the inhibition of nitric oxide (NO)/cGMP signaling. The dilation of the middle cerebral artery of the rat in a 121 mmol L-1 Na+ buffer depends on NO signaling and reverse mode of sodium-calcium exchange. These results suggest that constriction of large cerebral arteries with impaired NO-dependent signaling may be observed in response to hypoosmotic hyponatremia.
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Affiliation(s)
- Katarzyna Klapczyńska
- grid.79757.3b0000 0000 8780 7659Institute of Physical Culture Sciences, Faculty of Health and Physical Education, University of Szczecin, Szczecin, Poland
| | - Marta Aleksandrowicz
- grid.413454.30000 0001 1958 0162Laboratory of Experimental and Clinical Neurosurgery, Mossakowski Medical Research Institute Polish Academy of Sciences, Warsaw, Poland
| | - Ewa Koźniewska
- Laboratory of Experimental and Clinical Neurosurgery, Mossakowski Medical Research Institute Polish Academy of Sciences, Warsaw, Poland.
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2
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Correia MC, Santos ESA, Neves BJ, Rocha ML. Acetaminophen treatment evokes anticontractile effects in rat aorta by blocking L-type calcium channels. Pharmacol Rep 2022; 74:493-502. [PMID: 35438421 DOI: 10.1007/s43440-022-00367-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Revised: 03/30/2022] [Accepted: 03/31/2022] [Indexed: 10/18/2022]
Abstract
BACKGROUND Acetaminophen (APAP) is the most widely used analgesic and antipyretic in the world. However, in high or continuous doses, it can cause serious side effects including blood pressure variability and cardiovascular injuries, which are barely explored. This study aimed to evaluate the acute effect of APAP treatment on vascular tone focused on the blocking of Ca2+ channels. METHODS Rats were treated with APAP orally by gavage (500 mg/kg/single dose). After 12 h, the aorta was isolated for vascular reactivity studies in an isolated organ bath. Vascular contraction and relaxation were measured after different stimuli. Moreover, molecular docking studies were performed to evaluate the action of NAPQI (APAP metabolite) on L-type calcium channels. RESULTS Phenylephrine-induced maximal vascular contraction was reduced in the APAP group (138.4 ± 9.2%) compared to the control group (172.2 ± 11.1%). APAP treatment significantly reduced contraction induced by Ca2+ influx stimulated with phenylephrine or KCl and reduced contraction mediated by Ca2+ released from the sarcoplasmic reticulum induced by caffeine. There was no difference in vascular relaxation induced by acetylcholine or sodium nitroprusside. Computational molecular docking demonstrated that NAPQI is capable of blocking L-type Ca2+ channels (Cav1.2), which would limit the influx of Ca2+. CONCLUSION These results suggest that APAP treatment causes an anticontractile effect in rat aorta, possibly by blocking the influx of Ca2+ through L-type channels (Cav1.2).
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Affiliation(s)
- Mikaelle C Correia
- Laboratory of Pharmacology, UFG, Faculty of Pharmacy, Federal University of Goias, Setor Leste Universitário, CEP, Rua 240, esquina com 5ª Avenida, s/n, Goiânia, GO, 74605-170, Brazil
| | - Eder S A Santos
- LabMol-Laboratory for Molecular Modeling and Drug Design, Faculty of Pharmacy, Federal University of Goias, Rua 240, esquina com 5ª Avenida, s/n, Setor Leste Universitário, Goiânia, GO, 74605-170, Brazil
| | - Bruno J Neves
- LabMol-Laboratory for Molecular Modeling and Drug Design, Faculty of Pharmacy, Federal University of Goias, Rua 240, esquina com 5ª Avenida, s/n, Setor Leste Universitário, Goiânia, GO, 74605-170, Brazil
| | - Matheus L Rocha
- Laboratory of Pharmacology, UFG, Faculty of Pharmacy, Federal University of Goias, Setor Leste Universitário, CEP, Rua 240, esquina com 5ª Avenida, s/n, Goiânia, GO, 74605-170, Brazil.
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Berra-Romani R, Guzmán-Silva A, Vargaz-Guadarrama A, Flores-Alonso JC, Alonso-Romero J, Treviño S, Sánchez-Gómez J, Coyotl-Santiago N, García-Carrasco M, Moccia F. Type 2 Diabetes Alters Intracellular Ca 2+ Handling in Native Endothelium of Excised Rat Aorta. Int J Mol Sci 2019; 21:ijms21010250. [PMID: 31905880 PMCID: PMC6982087 DOI: 10.3390/ijms21010250] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 12/24/2019] [Accepted: 12/25/2019] [Indexed: 02/03/2023] Open
Abstract
An increase in intracellular Ca2+ concentration ([Ca2+]i) plays a key role in controlling endothelial functions; however, it is still unclear whether endothelial Ca2+ handling is altered by type 2 diabetes mellitus, which results in severe endothelial dysfunction. Herein, we analyzed for the first time the Ca2+ response to the physiological autacoid ATP in native aortic endothelium of obese Zucker diabetic fatty (OZDF) rats and their lean controls, which are termed LZDF rats. By loading the endothelial monolayer with the Ca2+-sensitive fluorophore, Fura-2/AM, we found that the endothelial Ca2+ response to 20 µM and 300 µM ATP exhibited a higher plateau, a larger area under the curve and prolonged duration in OZDF rats. The “Ca2+ add-back” protocol revealed no difference in the inositol-1,4,5-trisphosphate-releasable endoplasmic reticulum (ER) Ca2+ pool, while store-operated Ca2+ entry was surprisingly down-regulated in OZDF aortae. Pharmacological manipulation disclosed that sarco-endoplasmic reticulum Ca2+-ATPase (SERCA) activity was down-regulated by reactive oxygen species in native aortic endothelium of OZDF rats, thereby exaggerating the Ca2+ response to high agonist concentrations. These findings shed new light on the mechanisms by which type 2 diabetes mellitus may cause endothelial dysfunction by remodeling the intracellular Ca2+ toolkit.
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Affiliation(s)
- Roberto Berra-Romani
- Laboratory of Cardiovascular Physiology, Biomedicine School, Faculty of Medicine, Benemérita Universidad Autónoma de Puebla, Puebla 72410, Mexico; (A.G.-S.); (J.A.-R.); (N.C.-S.)
- Correspondence: (R.B.-R.); (F.M.)
| | - Alejandro Guzmán-Silva
- Laboratory of Cardiovascular Physiology, Biomedicine School, Faculty of Medicine, Benemérita Universidad Autónoma de Puebla, Puebla 72410, Mexico; (A.G.-S.); (J.A.-R.); (N.C.-S.)
| | - Ajelet Vargaz-Guadarrama
- Faculty of Medicine, Benemérita Universidad Autónoma de Puebla, Puebla 72410, Mexico; (A.V.-G.); (J.S.-G.); (M.G.-C.)
| | - Juan Carlos Flores-Alonso
- Centro de Investigación Biomédica de Oriente, Instituto Mexicano del Seguro Social, Puebla 74360, Mexico;
| | - José Alonso-Romero
- Laboratory of Cardiovascular Physiology, Biomedicine School, Faculty of Medicine, Benemérita Universidad Autónoma de Puebla, Puebla 72410, Mexico; (A.G.-S.); (J.A.-R.); (N.C.-S.)
| | - Samuel Treviño
- Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, Puebla 72540, Mexico;
| | - Josué Sánchez-Gómez
- Faculty of Medicine, Benemérita Universidad Autónoma de Puebla, Puebla 72410, Mexico; (A.V.-G.); (J.S.-G.); (M.G.-C.)
| | - Nayeli Coyotl-Santiago
- Laboratory of Cardiovascular Physiology, Biomedicine School, Faculty of Medicine, Benemérita Universidad Autónoma de Puebla, Puebla 72410, Mexico; (A.G.-S.); (J.A.-R.); (N.C.-S.)
| | - Mario García-Carrasco
- Faculty of Medicine, Benemérita Universidad Autónoma de Puebla, Puebla 72410, Mexico; (A.V.-G.); (J.S.-G.); (M.G.-C.)
| | - Francesco Moccia
- Laboratory of General Physiology, Department of Biology and Biotechnology “Lazzaro Spallanzani”, University of Pavia, 27100 Pavia, Italy
- Correspondence: (R.B.-R.); (F.M.)
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4
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Automated Intracellular Calcium Profiles Extraction from Endothelial Cells Using Digital Fluorescence Images. Int J Mol Sci 2018; 19:ijms19113440. [PMID: 30400174 PMCID: PMC6274978 DOI: 10.3390/ijms19113440] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2018] [Revised: 10/22/2018] [Accepted: 10/24/2018] [Indexed: 01/13/2023] Open
Abstract
Endothelial cells perform a wide variety of fundamental functions for the cardiovascular system, their proliferation and migration being strongly regulated by their intracellular calcium concentration. Hence it is extremely important to carefully measure endothelial calcium signals under different stimuli. A proposal to automate the intracellular calcium profiles extraction from fluorescence image sequences is presented. Digital image processing techniques were combined with a multi-target tracking approach supported by Kalman estimation. The system was tested with image sequences from two different stimuli. The first one was a chemical stimulus, that is, ATP, which caused small movements in the cells trajectories, thereby suggesting that the bath application of the agonist does not generate significant artifacts. The second one was a mechanical stimulus delivered by a glass microelectrode, which caused major changes in cell trajectories. The importance of the tracking block is evidenced since more accurate profiles were extracted, mainly for cells closest to the stimulated area. Two important contributions of this work are the automatic relocation of the region of interest assigned to the cells and the possibility of data extraction from big image sets in efficient and expedite way. The system may adapt to different kind of cell images and may allow the extraction of other useful features.
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Ocal I, Yilmaz MB, Kocaturk-Sel S, Tufan T, Erkoc MA, Comertpay G, Oksuz H, Barc ED. ATP sensitive K + channel subunits (Kir6.1, Kir6.2) are the candidate mediators regulating ameliorating effects of pulsed magnetic field on aortic contractility in diabetic rats. Bioelectromagnetics 2018; 39:299-311. [PMID: 29446477 DOI: 10.1002/bem.22111] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 12/13/2017] [Indexed: 11/11/2022]
Abstract
Diabetes mellitus is a metabolic disease that causes increased morbidity and mortality in developed and developing countries. With recent advancements in technology, alternative treatment methods have begun to be investigated in the world. This study aims to evaluate the effect of pulsed magnetic field (PMF) on vascular complications and contractile activities of aortic rings along with Kir6.1 and Kir6.2 subunit expressions of ATP-sensitive potassium channels (KATP ) in aortas of controlled-diabetic and non-controlled diabetic rats. Controlled-diabetic and non-controlled diabetic adult male Wistar rats were exposed to PMF for a period of 6 weeks according to the PMF application protocol (1 h/day; intensity: 1.5 mT; consecutive frequency: 1, 10, 20, and 40 Hz). After PMF exposure, body weight and blood glucose levels were measured. Then, thoracic aorta tissue was extracted for relaxation-contraction and Kir6.1 and Kir6.2 expression experiments. Blood plasma glucose levels, body weight, and aortic ring contraction percentage decreased in controlled-diabetic rats but increased in non-controlled diabetic rats. PMF therapy repressed Kir6.1 mRNA expression in non-controlled diabetic rats but not in controlled diabetic rats. Conversely, Kir6.2 mRNA expressions were repressed both in controlled diabetic and non-controlled diabetic rats by PMF. Our findings suggest that the positive therapeutic effects of PMF may act through (KATP ) subunits and may frequently occur in insulin-free conditions. Bioelectromagnetics. 39:299-311, 2018. © 2018 Wiley Periodicals, Inc.
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Affiliation(s)
- Isil Ocal
- Faculty of Medicine, Department of Biophysics, Cukurova University, Adana, Turkey
| | - Mehmet B Yilmaz
- Faculty of Medicine, Department of Medical Biology, Cukurova University, Adana, Turkey
| | - Sabriye Kocaturk-Sel
- Faculty of Medicine, Department of Medical Biology, Cukurova University, Adana, Turkey
| | - Turan Tufan
- Faculty of Medicine, Department of Medical Biology, Cukurova University, Adana, Turkey
| | - Mehmet A Erkoc
- Faculty of Medicine, Department of Medical Biology, Cukurova University, Adana, Turkey
| | - Gamze Comertpay
- Faculty of Medicine, Department of Medical Biology, Cukurova University, Adana, Turkey
| | - Hale Oksuz
- Faculty of Medicine, Department of Medical Biology, Cukurova University, Adana, Turkey
| | - Esma D Barc
- Faculty of Medicine, Department of Medical Biology, Cukurova University, Adana, Turkey
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6
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Bondarenko AI, Panasiuk O, Okhai I, Montecucco F, Brandt KJ, Mach F. Ca 2+-dependent potassium channels and cannabinoid signaling in the endothelium of apolipoprotein E knockout mice before plaque formation. J Mol Cell Cardiol 2018; 115:54-63. [PMID: 29305938 DOI: 10.1016/j.yjmcc.2018.01.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Revised: 12/30/2017] [Accepted: 01/02/2018] [Indexed: 01/06/2023]
Abstract
Endothelial Ca2+-dependent K+ channels (KCa) regulate endothelial function. We also know that stimulation of type 2 cannabinoid (CB2) receptors ameliorates atherosclerosis. However, whether atherosclerosis is accompanied by altered endothelial KCa- and CB2 receptor-dependent signaling is unknown. By utilizing an in situ patch-clamp approach, we directly evaluated the KCa channel function and the CB2 receptor-dependent electrical responses in the endothelium of aortic strips from young ApoE-/- and C57Bl/6 mice. In the ApoE-/- group, the resting membrane potential (-30.1±1.1mV) was less negative (p<0.05) compared to WT (-38.9±1.4mV) and voltage ramps generated an overall KCa current of reduced amplitude. The peak hyperpolarization to 2μM Ach was not different between the groups. However, the sustained component was significantly reduced in ApoE-/- strips. In contrast, the peak hyperpolarization to 0.2μM Ach was increased in the ApoE-/- group, and SKA-31, a direct IKCa/SKCa channel opener, produced a hyperpolarization and whole-cell current of greater amplitude. The BKCa opener NS1619 produced hyperpolarization that was enhanced in ApoE-/- group. N-arachidonoyl glycine, a BKCa opener, produced a hyperpolarization of enhanced amplitude in ApoE-/- arteries. Selective CB2 receptor agonist AM1241 (5μM) had no effect on endothelial membrane potential in WT group; however, in ApoE-/- group, it elicited hyperpolarization that was inhibited by a selective CB2 receptor antagonist AM630. Conclusively, our data point to functional down-regulation of basal IKCa activity in unstimulated endothelium of ApoE-/- mice. Direct and indirect IKCa stimulation resulted in increased recruitment of the channels. In addition, our data point to up-regulation of endothelial BKCa channels and CB2 receptors in ApoE-/- arteries.
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Affiliation(s)
- Alexander I Bondarenko
- Circulatory Physiology Department, Bogomoletz Institute of Physiology, NAS of Ukraine, Bogomoletz Str.4, 01024 Kiev, Ukraine.
| | - Olga Panasiuk
- Circulatory Physiology Department, Bogomoletz Institute of Physiology, NAS of Ukraine, Bogomoletz Str.4, 01024 Kiev, Ukraine
| | - Iryna Okhai
- Circulatory Physiology Department, Bogomoletz Institute of Physiology, NAS of Ukraine, Bogomoletz Str.4, 01024 Kiev, Ukraine
| | - Fabrizio Montecucco
- First Clinic of Internal Medicine, Department of Internal Medicine, University of Genoa, 6 viale Benedetto XV, 16132 Genoa, Italy; Ospedale Policlinico San Martino, largo Benzi 10, 16132 Genoa, Italy; Centre of Excellence for Biomedical Research (CEBR), University of Genoa, 9 viale Benedetto XV, 16132 Genoa, Italy
| | - Karim J Brandt
- Division of Cardiology, Foundation for Medical Researches, Department of Internal Medicine, University of Geneva, Av. de la Roseraie 64, CH -1211 Geneva, 4, Switzerland
| | - François Mach
- Division of Cardiology, Foundation for Medical Researches, Department of Internal Medicine, University of Geneva, Av. de la Roseraie 64, CH -1211 Geneva, 4, Switzerland
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7
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Lillo MA, Gaete PS, Puebla M, Ardiles NM, Poblete I, Becerra A, Simon F, Figueroa XF. Critical contribution of Na +-Ca 2+ exchanger to the Ca 2+-mediated vasodilation activated in endothelial cells of resistance arteries. FASEB J 2018; 32:2137-2147. [PMID: 29217667 DOI: 10.1096/fj.201700365rr] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Na+-Ca2+ exchanger (NCX) contributes to control the intracellular free Ca2+ concentration ([Ca2+]i), but the functional activation of NCX reverse mode (NCXrm) in endothelial cells is controversial. We evaluated the participation of NCXrm-mediated Ca2+ uptake in the endothelium-dependent vasodilation of rat isolated mesenteric arterial beds. In phenylephrine-contracted mesenteries, the acetylcholine (ACh)-induced vasodilation was abolished by treatment with the NCXrm blockers SEA0400, KB-R7943, or SN-6. Consistent with that, the ACh-induced hyperpolarization observed in primary cultures of mesenteric endothelial cells and in smooth muscle of isolated mesenteric resistance arteries was attenuated by KB-R7943 and SEA0400, respectively. In addition, both blockers abolished the NO production activated by ACh in intact mesenteric arteries. In contrast, the inhibition of NCXrm did not affect the vasodilator responses induced by the Ca2+ ionophore, ionomycin, and the NO donor, S-nitroso- N-acetylpenicillamine. Furthermore, SEA0400, KB-R7943, and a small interference RNA directed against NCX1 blunted the increase in [Ca2+]i induced by ACh or ATP in cultured endothelial cells. The analysis by proximity ligation assay showed that the NO-synthesizing enzyme, eNOS, and NCX1 were associated in endothelial cell caveolae of intact mesenteric resistance arteries. These results indicate that the activation of NCXrm has a central role in Ca2+-mediated vasodilation initiated by ACh in endothelial cells of resistance arteries.-Lillo, M. A., Gaete, P. S., Puebla, M., Ardiles, N. M., Poblete, I., Becerra, A., Simon, F., Figueroa, X. F. Critical contribution of Na+-Ca2+ exchanger to the Ca2+-mediated vasodilation activated in endothelial cells of resistance arteries.
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Affiliation(s)
- Mauricio A Lillo
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Pablo S Gaete
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Mariela Puebla
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Nicolás M Ardiles
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Inés Poblete
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Alvaro Becerra
- Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas and Facultad de Medicina, Universidad Andres Bello, Santiago, Chile.,Millennium Institute on Immunology and Immunotherapy, Santiago, Chile.,Departamento de Ciencias Químicas y Biológicas, Facultad de Salud, Deporte y Recreación, Universidad Bernardo O'Higgins, Santiago, Chile
| | - Felipe Simon
- Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas and Facultad de Medicina, Universidad Andres Bello, Santiago, Chile.,Millennium Institute on Immunology and Immunotherapy, Santiago, Chile
| | - Xavier F Figueroa
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
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Bai XJ, Hao JT, Wang J, Zhang WF, Yan CP, Zhao JH, Zhao ZQ. Curcumin inhibits cardiac hypertrophy and improves cardiovascular function via enhanced Na +/Ca 2+ exchanger expression after transverse abdominal aortic constriction in rats. Pharmacol Rep 2017; 70:60-68. [PMID: 29331788 DOI: 10.1016/j.pharep.2017.07.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Revised: 07/08/2017] [Accepted: 07/13/2017] [Indexed: 11/28/2022]
Abstract
BACKGROUND This study tested the hypothesis that inhibition of cardiac hypertrophy and preservation of cardiac/endothelial function by the natural yellow pigment curcumin are associated with upregulated expression of Na+/Ca2+ exchanger (NCX) after transverse aortic constriction (TAC). METHODS Male Wistar rats were subjected to TAC for 10 weeks and curcumin (50 mg/kg/day) was fed by gastric gavage during TAC. Expression of NCX and endothelial nitric oxide synthase (eNOS) was analyzed by Western blot and immunohistochemistry. RESULTS Compared with the animals in the TAC group, curcumin significantly increased the survival rate and reduced the ratio of heart or left ventricle (LV) to body weight and the cross sectional area of cardiomyocytes. In coincidence with improved LV systolic pressure and reduced LV end-diastolic pressure, curcumin significantly reduced LV end-systolic and diastolic diameter/dimension, and enhanced LV ejection fraction and LV fractional shortening as measured by echocardiography. Furthermore, endothelium-dependent relaxation of aortic rings in response to acetylcholine was significantly improved by curcumin. Along with these modifications, the expression and localization of NCX and eNOS in the myocardium and vascular endothelium were significantly upregulated by curcumin. The protective effect of curcumin on endothelium-dependent relaxation was partly blocked by pretreatment with the NCX inhibitor, KB-R7943. CONCLUSIONS These results demonstrate that inhibition of cardiac hypertrophy, improvement of cardiac systolic/diastolic function and preservation of vascular endothelium by curcumin might be associated with upregulated NCX expression level in response to increased afterload.
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Affiliation(s)
- Xiao-Jie Bai
- Department of Physiology, Shanxi Medical University, Taiyuan, Shanxi, People's Republic of China.
| | - Jun-Tao Hao
- Department of Thoracic Surgery, Shanxi Provincial People's Hospital, Taiyuan, Shanxi, People's Republic of China
| | - Jin Wang
- Department of Physiology, Shanxi Medical University, Taiyuan, Shanxi, People's Republic of China
| | - Wei-Fang Zhang
- Department of Physiology, Shanxi Medical University, Taiyuan, Shanxi, People's Republic of China
| | - Cai-Ping Yan
- Department of Physiology, Shanxi Medical University, Taiyuan, Shanxi, People's Republic of China
| | - Jia-Hui Zhao
- Department of Physiology, Shanxi Medical University, Taiyuan, Shanxi, People's Republic of China
| | - Zhi-Qing Zhao
- Cardiovascular Research Laboratory, Mercer University School of Medicine, Savannah, GA, USA
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9
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Direct activation of Ca 2+ and voltage-gated potassium channels of large conductance by anandamide in endothelial cells does not support the presence of endothelial atypical cannabinoid receptor. Eur J Pharmacol 2017; 805:14-24. [PMID: 28327344 DOI: 10.1016/j.ejphar.2017.03.038] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 03/15/2017] [Accepted: 03/17/2017] [Indexed: 11/23/2022]
Abstract
Endocannabinoid anandamide induces endothelium-dependent relaxation commonly attributed to stimulation of the G-protein coupled endothelial anandamide receptor. The study addressed the receptor-independent effect of anandamide on large conductance Ca2+-dependent K+ channels expressed in endothelial cell line EA.hy926. Under resting conditions, 10µM anandamide did not significantly influence the resting membrane potential. In a Ca2+-free solution the cells were depolarized by ~10mV. Further administration of 10µM anandamide hyperpolarized the cells by ~8mV. In voltage-clamp mode, anandamide elicited the outwardly rectifying whole-cell current sensitive to paxilline but insensitive to GDPβS, a G-protein inhibitor. Administration of 70µM Mn2+, an agent used to promote integrin clustering, reversibly stimulated whole-cell current, but failed to further facilitate the anandamide-stimulated current. In an inside-out configuration, anandamide (0.1-30µM) facilitated single BKCa channel activity in a concentration-dependent manner within a physiological Ca2+ range and a wide range of voltages, mainly by reducing mean closed time. The effect is essentially eliminated following chelation of Ca2+ from the cytosolic face and pre-exposure to cholesterol-reducing agent methyl-β-cyclodextrin. O-1918 (3µM), a cannabidiol analog used as a selective antagonist of endothelial anandamide receptor, reduced BKCa channel activity in inside-out patches. These results do not support the existence of endothelial cannabinoid receptor and indicate that anandamide acts as a direct BKCa opener. The action does not require cell integrity or integrins and is caused by direct modification of BKCa channel activity.
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10
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Bondarenko AI, Montecucco F, Panasiuk O, Sagach V, Sidoryak N, Brandt KJ, Mach F. GPR55 agonist lysophosphatidylinositol and lysophosphatidylcholine inhibit endothelial cell hyperpolarization via GPR-independent suppression of Na +-Ca 2+ exchanger and endoplasmic reticulum Ca 2+ refilling. Vascul Pharmacol 2017; 89:39-48. [PMID: 28064014 DOI: 10.1016/j.vph.2017.01.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 12/21/2016] [Accepted: 01/03/2017] [Indexed: 11/18/2022]
Abstract
Lysophosphatidylinositol (LPI) and lysophosphatidylcholine (LPC) are lipid signaling molecules that induce endothelium-dependent vasodilation. In addition, LPC suppresses acetylcholine (Ach)-induced responses. We aimed to determine the influence of LPC and LPI on hyperpolarizing responses in vitro and in situ endothelial cells (EC) and identify the underlying mechanisms. Using patch-clamp method, we show that LPI and LPC inhibit EC hyperpolarization to histamine and suppress Na+/Ca2+ exchanged (NCX) currents in a concentration-dependent manner. The inhibition is non-mode-specific and unaffected by intracellular GDPβS infusion and tempol, a superoxide dismutase mimetic. In excised mouse aorta, LPI strongly inhibits the sustained and the peak endothelial hyperpolarization induced by Ach, but not by SKA-31, an opener of Ca2+-dependent K+ channels of intermediate and small conductance. The hyperpolarizing responses to consecutive histamine applications are strongly reduced by NCX inhibition. In a Ca2+-re-addition protocol, bepridil, a NCX inhibitor, and KB-R7943, a blocker of reversed NCX, inhibit the hyperpolarizing responses to Ca2+-re-addition following Ca2+ stores depletion. These finding indicate that LPC and LPI inhibit endothelial hyperpolarization to Ach and histamine independently of G-protein coupled receptors and superoxide anions. Reversed NCX is critical for ER Ca2+ refilling in EC. The inhibition of NCX by LPI and LPC underlies diminished endothelium-dependent responses and endothelial dysfunction accompanied by increased levels of these lipids in the blood.
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Affiliation(s)
- Alexander I Bondarenko
- Circulatory Physiology Department, Bogomoletz Institute of Physiology NAS of Ukraine, Bogomoletz Str.4, 01024 Kiev, Ukraine; Medical University of Graz, Institute of Molecular Biology and Biochemistry, Graz 8010, Austria.
| | - Fabrizio Montecucco
- First Clinic of Internal Medicine, Department of Internal Medicine, University of Genoa, 6 viale Benedetto XV, 16132 Genoa, Italy; IRCCS AOU San Martino - IST Istituto Nazionale per la Ricerca sul Cancro, Largo Benzi 10, 16132 Genoa, Italy
| | - Olga Panasiuk
- Circulatory Physiology Department, Bogomoletz Institute of Physiology NAS of Ukraine, Bogomoletz Str.4, 01024 Kiev, Ukraine
| | - Vadim Sagach
- Circulatory Physiology Department, Bogomoletz Institute of Physiology NAS of Ukraine, Bogomoletz Str.4, 01024 Kiev, Ukraine
| | - Nataliya Sidoryak
- Department of Physiology of Human and Animals, Melitopol State Pedagogical University, Ukraine
| | - Karim J Brandt
- Division of Cardiology, Foundation for Medical Researches, Department of Internal Medicine, University of Geneva, Av. de la Roseraie 64, CH-1211 Geneva 4, Switzerland
| | - François Mach
- Division of Cardiology, Foundation for Medical Researches, Department of Internal Medicine, University of Geneva, Av. de la Roseraie 64, CH-1211 Geneva 4, Switzerland
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Al Suleimani YM, Al Mahruqi AS. The endogenous lipid N-arachidonoyl glycine is hypotensive and nitric oxide-cGMP-dependent vasorelaxant. Eur J Pharmacol 2016; 794:209-215. [PMID: 27890711 DOI: 10.1016/j.ejphar.2016.11.040] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 11/13/2016] [Accepted: 11/23/2016] [Indexed: 10/20/2022]
Abstract
N-arachidonoyl glycine (NAGLY), is the endogenous lipid that activates the G protein-couple receptor 18 (GPR18) with vasodilatory activity in resistance arteries. This study investigates its hemodynamic effects and mechanisms of vasorelaxation. Hemodynamic effects of NAGLY in rats were assessed using a Biopac system and its vascular responses were assessed using a wire myograph. NAGLY (1mg/kg) decreased blood pressure by 69.4±5.5% and reduced renal blood flow by 88±12% and the effects were not sensitive to inhibition by O-1918 (3mg/kg). In resistant vessels, NAGLY (1-30µM) induced concentration- and endothelium-dependent vasorelaxation and the effect was inhibited by the nitric oxide synthase inhibitor, L-NAME (300µM), a cGMP synthase inhibitor, ODQ (10µM), the antagonists of "endothelial anandamide" receptor, rimonabant (3µM) and O-1918 (10µM) and the inhibitor of Na+/Ca2+ exchanger (NCX), KB-R7943 (10µM). On the other hand, NAGLY-induced vasorelaxation was not affected by CID 16020046 (GPR55 antagonist), AM 251 (cannabinoid CB1 receptor antagonist), AM 630 (cannabinoid CB2 receptor antagonist), capsazepine (TRPV1 antagonist), indomethacin (cyclooxygenase inhibitor), TRAM34 (IKCa channel blocker), iberiotoxin (BKCa channel blocker) and GW9662 (PPARɤ antagonist). At low concentrations of carbachol, NAGLY potentiated carbachol-induced vasorelaxation. NAGLY is an endothelium-dependent vasodilator and hypotensive lipid. The vasorelaxation is predominantly via activation of nitric oxide-cGMP pathway and NCX and probably mediated by the "endothelial anandamide" receptor, while the hypotensive effect of NAGLY appears not to involve the anandamide receptor. NAGLY also potentiates carbachol-induced vasorelaxation, the mechanism of which might involve stimulation of NO release.
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Affiliation(s)
- Yousuf M Al Suleimani
- Department of Pharmacology and Clinical Pharmacy, College of Medicine and Health Sciences, Sultan Qaboos University, 35, Alkoudh 123, Sultanate of Oman.
| | - Ahmed S Al Mahruqi
- Department of Pharmacology and Clinical Pharmacy, College of Medicine and Health Sciences, Sultan Qaboos University, 35, Alkoudh 123, Sultanate of Oman
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Bondarenko AI. Endothelial atypical cannabinoid receptor: do we have enough evidence? Br J Pharmacol 2014; 171:5573-88. [PMID: 25073723 PMCID: PMC4290703 DOI: 10.1111/bph.12866] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2014] [Revised: 07/14/2014] [Accepted: 07/24/2014] [Indexed: 12/16/2022] Open
Abstract
Cannabinoids and their synthetic analogues affect a broad range of physiological functions, including cardiovascular variables. Although direct evidence is still missing, the relaxation of a vast range of vascular beds induced by cannabinoids is believed to involve a still unidentified non-CB1 , non-CB2 Gi/o protein-coupled receptor located on endothelial cells, the so called endothelial cannabinoid receptor (eCB receptor). Evidence for the presence of an eCB receptor comes mainly from vascular relaxation studies, which commonly employ pertussis toxin as an indicator for GPCR-mediated signalling. In addition, a pharmacological approach is widely used to attribute the relaxation to eCB receptors. Recent findings have indicated a number of GPCR-independent targets for both agonists and antagonists of the presumed eCB receptor, warranting further investigations and cautious interpretation of the vascular relaxation studies. This review will provide a brief historical overview on the proposed novel eCB receptor, drawing attention to the discrepancies between the studies on the pharmacological profile of the eCB receptor and highlighting the Gi/o protein-independent actions of the eCB receptor inhibitors widely used as selective compounds. As the eCB receptor represents an attractive pharmacological target for a number of cardiovascular abnormalities, defining its molecular identity and the extent of its regulation of vascular function will have important implications for drug discovery. This review highlights the need to re-evaluate this subject in a thoughtful and rigorous fashion. More studies are needed to differentiate Gi/o protein-dependent endothelial cannabinoid signalling from that involving the classical CB1 and CB2 receptors as well as its relevance for pathophysiological conditions.
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Affiliation(s)
- Alexander I Bondarenko
- Circulatory Physiology Department, O.O.Bogomoletz Institute of PhysiologyKiev, Ukraine
- Institute of Molecular Biology and Biochemistry, Medical University of GrazGraz, Austria
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Bondarenko AI, Drachuk K, Panasiuk O, Sagach V, Deak AT, Malli R, Graier WF. N-Arachidonoyl glycine suppresses Na⁺/Ca²⁺ exchanger-mediated Ca²⁺ entry into endothelial cells and activates BK(Ca) channels independently of GPCRs. Br J Pharmacol 2014; 169:933-48. [PMID: 23517055 PMCID: PMC3687672 DOI: 10.1111/bph.12180] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2012] [Revised: 01/14/2013] [Accepted: 02/20/2013] [Indexed: 02/03/2023] Open
Abstract
Background and Purpose N-arachidonoyl glycine (NAGly) is a lipoamino acid with vasorelaxant properties. We aimed to explore the mechanisms of NAGly's action on unstimulated and agonist-stimulated endothelial cells. Experimental Approach The effects of NAGly on endothelial electrical signalling were studied in combination with vascular reactivity. Key Results In EA.hy926 cells, the sustained hyperpolarization to histamine was inhibited by the non-selective Na+/Ca2+ exchanger (NCX) inhibitor bepridil and by an inhibitor of reversed mode NCX, KB-R7943. In cells dialysed with Cs+-based Na+-containing solution, the outwardly rectifying current with typical characteristics of NCX was augmented following histamine exposure, further increased upon external Na+ withdrawal and inhibited by bepridil. NAGly (0.3–30 μM) suppressed NCX currents in a URB597- and guanosine 5′-O-(2-thiodiphosphate) (GDPβS)-insensitive manner, [Ca2+]i elevation evoked by Na+ removal and the hyperpolarization to histamine. In rat aorta, NAGly opposed the endothelial hyperpolarization and relaxation response to ACh. In unstimulated EA.hy926 cells, NAGly potentiated the whole-cell current attributable to large-conductance Ca2+-activated K+ (BKCa) channels in a GDPβS-insensitive, paxilline-sensitive manner and produced a sustained hyperpolarization. In cell-free inside-out patches, NAGly stimulated single BKCa channel activity. Conclusion and Implications Our data showed that NCX is a Ca2+ entry pathway in endothelial cells and that NAGly is a potent G-protein-independent modulator of endothelial electrical signalling and has a dual effect on endothelial electrical responses. In agonist pre-stimulated cells, NAGly opposes hyperpolarization and relaxation via inhibition of NCX-mediated Ca2+ entry, while in unstimulated cells, it promotes hyperpolarization via receptor-independent activation of BKCa channels.
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Affiliation(s)
- Alexander I Bondarenko
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, Graz, Austria.
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Bondarenko A, Panasiuk O, Stepanenko L, Goswami N, Sagach V. Reduced hyperpolarization of endothelial cells following high dietary Na+: effects of enalapril and tempol. Clin Exp Pharmacol Physiol 2012; 39:608-13. [PMID: 22540516 DOI: 10.1111/j.1440-1681.2012.05718.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
1. High dietary Na(+) is associated with impaired vascular endothelial function. However, the underlying mechanisms are not completely understood. In the present study, we investigated whether the endothelial hyperpolarization response to acetylcholine (ACh) exhibited any abnormalities in Wistar rats fed a high-salt diet (HSD) for 1 month and, if so, whether chronic treatment with the angiotensin-converting enzyme inhibitor enalapril or the anti-oxidant tempol could normalize the response. Membrane potential was recorded using the perforated patch-clamp technique on the endothelium of rat aorta. 2. Acetylcholine (2 μmol/L) produced a hyperpolarization sensitive to TRAM-34, a blocker of intermediate-conductance Ca(2+) -sensitive K(+) channels (IK(Ca)), but not to apamin, a blocker of small-conductance Ca(2+)-sensitive K(+) channels (SK(Ca)). NS309 (3 μmol/L), an activator of SK(Ca) and IK(Ca) channels, produced a hyperpolarization of similar magnitude as ACh. 3. In the HSD group, the ACh-evoked hyperpolarization was significantly attenuated compared with that in the control group, which was fed normal chow rather than an HSD. Similarly, the hyperpolarization produced by NS309 was weaker in tissues from HSD-fed rats. 4. Combination of HSD with chronic enalapril treatment (20 mg/kg per day for 1 month) normalized endothelial hyperpolarizing responses to ACh. Chronic tempol treatment (1 mmol/L in tap water for 1 month) prevented the reduced hyperpolarization to ACh. 5. The results of the present study indicate that excess in dietary Na(+) results in a failure of endothelial cells to generate normal IK(Ca) channel-mediated hyperpolarizing responses. Our observations implicate oxidative stress mediated by increased angiotensin II signalling as a mechanism underlying altered endothelial hyperpolarization during dietary salt loading.
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Affiliation(s)
- Alexander Bondarenko
- Circulatory Physiology Department, AA Bogomoletz Institute of Physiology, Kiev, Ukraine.
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Moccia F, Berra-Romani R, Tanzi F. Update on vascular endothelial Ca 2+ signalling: A tale of ion channels, pumps and transporters. World J Biol Chem 2012; 3:127-58. [PMID: 22905291 PMCID: PMC3421132 DOI: 10.4331/wjbc.v3.i7.127] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Revised: 07/04/2012] [Accepted: 07/11/2012] [Indexed: 02/05/2023] Open
Abstract
A monolayer of endothelial cells (ECs) lines the lumen of blood vessels and forms a multifunctional transducing organ that mediates a plethora of cardiovascular processes. The activation of ECs from as state of quiescence is, therefore, regarded among the early events leading to the onset and progression of potentially lethal diseases, such as hypertension, myocardial infarction, brain stroke, and tumor. Intracellular Ca2+ signals have long been know to play a central role in the complex network of signaling pathways regulating the endothelial functions. Notably, recent work has outlined how any change in the pattern of expression of endothelial channels, transporters and pumps involved in the modulation of intracellular Ca2+ levels may dramatically affect whole body homeostasis. Vascular ECs may react to both mechanical and chemical stimuli by generating a variety of intracellular Ca2+ signals, ranging from brief, localized Ca2+ pulses to prolonged Ca2+ oscillations engulfing the whole cytoplasm. The well-defined spatiotemporal profile of the subcellular Ca2+ signals elicited in ECs by specific extracellular inputs depends on the interaction between Ca2+ releasing channels, which are located both on the plasma membrane and in a number of intracellular organelles, and Ca2+ removing systems. The present article aims to summarize both the past and recent literature in the field to provide a clear-cut picture of our current knowledge on the molecular nature and the role played by the components of the Ca2+ machinery in vascular ECs under both physiological and pathological conditions.
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Affiliation(s)
- Francesco Moccia
- Francesco Moccia, Franco Tanzi, Department of Biology and Biotechnologies "Lazzaro Spallanzani", Laboratory of Physiology, University of Pavia, Via Forlanini 6, 27100 Pavia, Italy
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Berra-Romani R, Raqeeb A, Torres-Jácome J, Guzman-Silva A, Guerra G, Tanzi F, Moccia F. The mechanism of injury-induced intracellular calcium concentration oscillations in the endothelium of excised rat aorta. J Vasc Res 2011; 49:65-76. [PMID: 21997119 DOI: 10.1159/000329618] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Accepted: 05/20/2011] [Indexed: 01/13/2023] Open
Abstract
Endothelial injury is the primary event that leads to a variety of severe vascular disorders. Mechanical injury elicits a Ca(2+) response in the endothelium of excised rat aorta, which comprises an initial Ca(2+) release from inositol-1,4,5-trisphosphate (InsP(3))-sensitive stores followed by a long-lasting decay phase due to Ca(2+) entry through uncoupled connexons. The Ca(2+) signal may also adopt an oscillatory pattern, the molecular underpinnings of which are unclear. In the light of the role played by Ca(2+) spiking in tissue regeneration, this study aimed to unveil the mechanisms underlying injury-induced Ca(2+) oscillations. The latter reversibly ceased upon removal of extracellular Ca(2+) or addition of the gap junction blockers heptanol, 18 α,β-glycyrrhetinic acid, La(3+) and Ni(2+), but were insensitive to BTP-2 and SKF 96365. The spiking response was abolished by inhibiting the Ca(2+) entry mode of the Na(+)/Ca(2+) exchanger (NCX). The InsP(3)-producing agonist ATP resumed Ca(2+) oscillations in silent cells, while the phospholipase C inhibitor U73122 suppressed them. Injury-induced Ca(2+) transients were prevented by the sarcoplasmic-endoplasmic reticulum calcium ATPase (SERCA) blockers thapsigargin and cyclopiazonic acid, while they were unaffected by suramin and genistein. These data show for the first time that the coordinated interplay between NCX-mediated Ca(2+) entry and InsP(3)-dependent Ca(2+) release contributes to injury-induced intracellular Ca(2+) concentration oscillations.
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Affiliation(s)
- Roberto Berra-Romani
- Department of Biomedicine, School of Medicine, Benemérita Universidad Autónoma de Puebla, Puebla, México.
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Waldeck-Weiermair M, Jean-Quartier C, Rost R, Khan MJ, Vishnu N, Bondarenko AI, Imamura H, Malli R, Graier WF. Leucine zipper EF hand-containing transmembrane protein 1 (Letm1) and uncoupling proteins 2 and 3 (UCP2/3) contribute to two distinct mitochondrial Ca2+ uptake pathways. J Biol Chem 2011; 286:28444-55. [PMID: 21613221 PMCID: PMC3151087 DOI: 10.1074/jbc.m111.244517] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Cytosolic Ca2+ signals are transferred into mitochondria over a huge concentration range. In our recent work we described uncoupling proteins 2 and 3 (UCP2/3) to be fundamental for mitochondrial uptake of high Ca2+ domains in mitochondria-ER junctions. On the other hand, the leucine zipper EF hand-containing transmembrane protein 1 (Letm1) was identified as a mitochondrial Ca2+/H+ antiporter that achieved mitochondrial Ca2+ sequestration at small Ca2+ increases. Thus, the contributions of Letm1 and UCP2/3 to mitochondrial Ca2+ uptake were compared in endothelial cells. Knock-down of Letm1 did not affect the UCP2/3-dependent mitochondrial uptake of intracellularly released Ca2+ but strongly diminished the transfer of entering Ca2+ into mitochondria, subsequently, resulting in a reduction of store-operated Ca2+ entry (SOCE). Knock-down of Letm1 and UCP2/3 did neither impact on cellular ATP levels nor the membrane potential. The enhanced mitochondrial Ca2+ signals in cells overexpressing UCP2/3 rescued SOCE upon Letm1 knock-down. In digitonin-permeabilized cells, Letm1 exclusively contributed to mitochondrial Ca2+ uptake at low Ca2+ conditions. Neither the Letm1- nor the UCP2/3-dependent mitochondrial Ca2+ uptake was affected by a knock-down of mRNA levels of mitochondrial calcium uptake 1 (MICU1), a protein that triggers mitochondrial Ca2+ uptake in HeLa cells. Our data indicate that Letm1 and UCP2/3 independently contribute to two distinct, mitochondrial Ca2+ uptake pathways in intact endothelial cells.
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Affiliation(s)
- Markus Waldeck-Weiermair
- Institute of Molecular Biology and Biochemistry, Molecular and Cellular Physiology Research Unit, Center of Molecular Medicine, Medical University Graz, Harrachgasse 21/III, 8010 Graz, Austria
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Bondarenko A, Waldeck-Weiermair M, Naghdi S, Poteser M, Malli R, Graier WF. GPR55-dependent and -independent ion signalling in response to lysophosphatidylinositol in endothelial cells. Br J Pharmacol 2010; 161:308-20. [PMID: 20735417 PMCID: PMC2931756 DOI: 10.1111/j.1476-5381.2010.00744.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2010] [Revised: 01/31/2010] [Accepted: 02/06/2010] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND AND PURPOSE The glycerol-based lysophospholipid lysophosphatidylinositol (LPI) is an endogenous agonist of the G-protein-coupled receptor 55 (GPR55) exhibiting cannabinoid receptor-like properties in endothelial cells. To estimate the contribution of GPR55 to the physiological effects of LPI, the GPR55-dependent and -independent electrical responses in this cell type were investigated. EXPERIMENTAL APPROACH Applying small interference RNA-mediated knock-down and transient overexpression, GPR55-dependent and -independent effects of LPI on cytosolic free Ca(2+) concentration, membrane potential and transmembrane ion currents were studied in EA.hy296 cells. KEY RESULTS In a GPR55-dependent, GDPbetaS and U73122-sensitive manner, LPI induced rapid and transient intracellular Ca(2+) release that was associated with activation of charybdotoxin-sensitive, large conductance, Ca(2+)-activated, K(+) channels (BK(Ca)) and temporary membrane hyperpolarization. Following these initial electrical reactions, LPI elicited GPR55-independent long-lasting Na(+) loading and a non-selective inward current causing sustained membrane depolarization that depended on extracellular Ca(2+) and Na(+) and was partially inhibited by Ni(2+) and La(3+). This inward current was due to the activation of a voltage-independent non-selective cation current. The Ni(2+) and La(3+)-insensitive depolarization with LPI was prevented by inhibition of the Na/K-ATPase by ouabain. CONCLUSIONS AND IMPLICATIONS LPI elicited a biphasic response in endothelial cells of which the immediate Ca(2+) signalling depends on GPR55 while the subsequent depolarization is due to Na(+) loading via non-selective cation channels and an inhibition of the Na/K-ATPase. Thus, LPI is a potent signalling molecule that affects endothelial functions by modulating several cellular electrical responses that are only partially linked to GPR55.
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Affiliation(s)
- Alexander Bondarenko
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, Graz, Austria
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Na+-Ca2+ exchanger contributes to Ca2+ extrusion in ATP-stimulated endothelium of intact rat aorta. Biochem Biophys Res Commun 2010; 395:126-30. [PMID: 20353753 DOI: 10.1016/j.bbrc.2010.03.153] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2010] [Accepted: 03/25/2010] [Indexed: 11/20/2022]
Abstract
The role of Na(+)-Ca(2+) exchanger (NCX) in vascular endothelium is still matter of debate. Depending on both the endothelial cell (EC) type and the extracellular ligand, NCX has been shown to operate in either the forward (Ca(2+) out)- or the reverse (Ca(2+) in)-mode. In particular, acetylcholine (Ach) has been shown to promote Ca(2+) inflow in the intact endothelium of excised rat aorta. Herein, we assessed the involvement of NCX into the Ca(2+) signals elicited by ATP in such preparation. Removal of extracellular Na(+) (0Na(+)) causes the NCX to switch into the reverse-mode and induced an increase in intracellular Ca(2+) concentration ([Ca(2+)](i)), which disappeared in the absence of extracellular Ca(2+), and in the presence of benzamil, which blocks both modes of NCX, and KB-R 7943, a selective inhibitor of the reverse-mode. ATP induced a transient Ca(2+) signal, whose decay was significantly prolonged by 0Na(+), benzamil, DCB, and monensin while it was unaffected by KB-R 7943. Notably, lowering extracellular Na(+) concentration increased the sensibility to lower doses of ATP. These date suggest that, unlike Ach-stimulated ECs, NCX promotes Ca(2+) extrusion when the stimulus is provided by ATP in intact endothelium of rat aorta. These data show that, within the same preparation, NCX operates in both modes, depending on the chemical nature of the extracellular stimulus.
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Li J, Jin HB, Sun YM, Su Y, Wang LF. KB-R7943 inhibits high glucose-induced endothelial ICAM-1 expression and monocyte-endothelial adhesion. Biochem Biophys Res Commun 2010; 392:516-9. [PMID: 20096662 DOI: 10.1016/j.bbrc.2009.12.183] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Accepted: 12/13/2009] [Indexed: 10/19/2022]
Abstract
Hyperglycemia is the major cause of diabetic angiopathy. The aim of our study was to evaluate the impact of KB-R7943, an inhibitor of Na+/Ca2+ exchanger (NCX) on cell growth and function of human "diabetic" endothelial cells (EC). Intercellular adhesion molecule-1 (ICAM-1) expression and NCX activity were determined after EC were exposed to high glucose in the absence and presence of KB-R7943. Coincubation of EC with high glucose for 24 h resulted in a significant increase of monocyte-endothelial cell adhesion and the expression of ICAM-1. These effects were abolished by KB-R7943 and KB-R7943 significantly decreased the activation of NCX induced by high glucose. These findings suggested that KB-R7943 may play a role in inhibiting expression of adhesion molecules by inhibiting the reverse activation of NCX.
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Affiliation(s)
- Jia Li
- Department of Cardiac Care Unit, The First Affiliated Hospital of Harbin Medical University, and Department of Physiology, Harbin Medical University, Harbin 150001, China
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Brahma MK, Dohare P, Varma S, Rath SK, Garg P, Biswal PK, Chowdhury PD, Ray M. The neuronal apoptotic death in global cerebral ischemia in gerbil: Important role for sodium channel modulator. J Neurosci Res 2009; 87:1400-11. [DOI: 10.1002/jnr.21960] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Su Y, Liu XM, Sun YM, Jin HB, Luan Y, Wu Y. Na+/Ca2+EXCHANGER INHIBITOR AMELIORATES IMPAIRED ENDOTHELIUM-DEPENDENT Na+RELAXATION INDUCED BY HIGH GLUCOSE IN RAT AORTA. Clin Exp Pharmacol Physiol 2008; 35:1265-70. [DOI: 10.1111/j.1440-1681.2008.05002.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Silva HS, Kapela A, Tsoukias NM. A mathematical model of plasma membrane electrophysiology and calcium dynamics in vascular endothelial cells. Am J Physiol Cell Physiol 2007; 293:C277-93. [PMID: 17459942 DOI: 10.1152/ajpcell.00542.2006] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Vascular endothelial cells (ECs) modulate smooth muscle cell (SMC) contractility, assisting in vascular tone regulation. Cytosolic Ca2+ concentration ([Ca2+]i) and membrane potential ( Vm) play important roles in this process by controlling EC-dependent vasoactive signals and intercellular communication. The present mathematical model integrates plasmalemma electrophysiology and Ca2+ dynamics to investigate EC responses to different stimuli and the controversial relationship between [Ca2+]i and Vm. The model contains descriptions for the intracellular balance of major ionic species and the release of Ca2+ from intracellular stores. It also expands previous formulations by including more detailed transmembrane current descriptions. The model reproduces Vm responses to volume-regulated anion channel (VRAC) blockers and extracellular K+ concentration ([K+]o) challenges, predicting 1) that Vm changes upon VRAC blockade are [K+]o dependent and 2) a biphasic response of Vm to increasing [K+]o. Simulations of agonist-induced Ca2+ mobilization replicate experiments under control and Vm hyperpolarization blockade conditions. They show that peak [Ca2+]i is governed by store Ca2+ release while Ca2+ influx (and consequently Vm) impacts more the resting and plateau [Ca2+]i. The Vm sensitivity of rest and plateau [Ca2+]i is dictated by a [Ca2+]i “buffering” system capable of masking the Vm-dependent transmembrane Ca2+ influx. The model predicts plasma membrane Ca2+-ATPase and Ca2+ permeability as main players in this process. The heterogeneous Vm impact on [Ca2+]i may elucidate conflicting reports on how Vm influences EC Ca2+. The present study forms the basis for the development of multicellular EC-SMC models that can assist in understanding vascular autoregulation in health and disease.
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Affiliation(s)
- Haroldo S Silva
- Dept. of Biomedical Engineering, Florida International University, 10555 W. Flagler St., TEC 2674, Miami, FL 33174, USA
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Bondarenko A, Sagach V. Na+-K+-ATPase is involved in the sustained ACh-induced hyperpolarization of endothelial cells from rat aorta. Br J Pharmacol 2006; 149:958-65. [PMID: 17001300 PMCID: PMC2014692 DOI: 10.1038/sj.bjp.0706913] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND AND PURPOSE Inhibition of Na(+)-K(+)-ATPase is known to attenuate endothelium-dependent relaxation in many arteries. The purpose of this study was to evaluate the role of Na(+)-K(+)-ATPase in the regulation of endothelial membrane potential at rest and during stimulation by ACh. EXPERIMENTAL APPROACH Membrane potential was recorded from the endothelium of rat aorta using the perforated patch-clamp technique. KEY RESULTS Superfusion with K(+)-free solution produced a depolarization of about 11 mV from the resting value of -42.9+/-0.9 mV. Reintroduction of 4.7 mM K(+) transiently hyperpolarized endothelial cells to -52.4+/-1.8 mV and the membrane potential recovered within 10 min. Ouabain 500 microM depolarized endothelium by about 11 mV and inhibited the hyperpolarization induced by K(+) reintroduction into the K(+)-free solution. However, 500 nM ouabain did not affect the resting membrane potential or the hyperpolarization induced by K(+) reintroduction. Pre-exposure to ouabain 500 microM, but not 500 nM, attenuated the sustained component of hyperpolarization to ACh without affecting the amplitude of the transient peak hyperpolarization. In K(+)-free solution, the amplitude of peak hyperpolarization to ACh was increased, while the sustained component of hyperpolarization was attenuated. CONCLUSIONS AND IMPLICATIONS These results indicate that electrogenic Na(+)-K(+)-ATPase partially contributes to the sustained hyperpolarization of endothelial cells from rat aorta in response to ACh. They also suggest that the alpha1, but not alpha2 or alpha3 isoforms, is involved in ACh-mediated hyperpolarization.
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Affiliation(s)
- A Bondarenko
- Department of Blood Circulation, AA Bogomoletz Institute of Physiology, NAS of Ukraine, Kiev, Ukraine.
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