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Bkaily G, Jacques D. Calcium Homeostasis, Transporters, and Blockers in Health and Diseases of the Cardiovascular System. Int J Mol Sci 2023; 24:ijms24108803. [PMID: 37240147 DOI: 10.3390/ijms24108803] [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: 02/21/2023] [Revised: 05/06/2023] [Accepted: 05/10/2023] [Indexed: 05/28/2023] Open
Abstract
Calcium is a highly positively charged ionic species. It regulates all cell types' functions and is an important second messenger that controls and triggers several mechanisms, including membrane stabilization, permeability, contraction, secretion, mitosis, intercellular communications, and in the activation of kinases and gene expression. Therefore, controlling calcium transport and its intracellular homeostasis in physiology leads to the healthy functioning of the biological system. However, abnormal extracellular and intracellular calcium homeostasis leads to cardiovascular, skeletal, immune, secretory diseases, and cancer. Therefore, the pharmacological control of calcium influx directly via calcium channels and exchangers and its outflow via calcium pumps and uptake by the ER/SR are crucial in treating calcium transport remodeling in pathology. Here, we mainly focused on selective calcium transporters and blockers in the cardiovascular system.
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Affiliation(s)
- Ghassan Bkaily
- Department of Immunology and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
| | - Danielle Jacques
- Department of Immunology and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
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2
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Aguiar F, Rhana P, Bloise E, Rodrigues ALP, Ferreira E. L-type voltage-dependent Ca2+ channels expression involved in pre-neoplastic transformation of breast cancer. SURGICAL AND EXPERIMENTAL PATHOLOGY 2022. [DOI: 10.1186/s42047-022-00117-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Intracellular Ca2+ levels can modulate several cellular functions, including proliferation and other processes found altered in neoplastic cells. Helping to maintain Ca2+ homeostasis, L-type voltage-dependent Ca2+ channels had its expression identified in neoplasias, including breast cancer. Invasive breast carcinoma of no special type, the most common classification of breast cancer, has ductal hyperplasia and ductal carcinoma in situ as its possible non-obligate precursors. This channel’s role in breast cancer development from these precursors has not been investigated. Evaluate protein expression and subcellular localization of CaV1.1, CaV1.2, and CaV1.3 in mammary epithelium without alteration and neoplastic and non-neoplastic ductal proliferative lesions through immunohistochemistry was the aim of this investigation.
Methods
In the present study, CaV1.1, CaV1.2, and CaV1.3 protein expression was evaluated by immunohistochemistry in breast without alteration and in proliferative non-neoplastic and neoplastic ductal epithelial lesions of the human breast.
Results
It was observed that CaV1.3 presented a reduction in nuclear expression at neoplastic lesions, in addition to an increase in cytoplasmic CaV1.1 expression. The analyses of membrane immunostaining showed that CaV1.2 and CaV1.3 had an increase of expression as the lesions progressed in the stages leading to invasive carcinomas.
Conclusions
Changes in protein expression and subcellular localization of these channels during the progression stages indicate that they may be involved in neoplastic transformation.
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3
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Hypotension in hereditary cardiomyopathy. Pflugers Arch 2022; 474:517-527. [PMID: 35141778 DOI: 10.1007/s00424-022-02669-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 01/14/2022] [Accepted: 01/22/2022] [Indexed: 12/25/2022]
Abstract
It is well accepted that hypertension may lead to the development of heart failure (HF). However, little is known about the development of hypotension that may contribute to the onset of hereditary cardiomyopathy (HCM), thus promoting heart failure and early death. The purpose of this study is to verify whether a decrease in blood pressure takes place during different phases of HCM (asymptomatic, necrosis, hypertrophy, and heart failure). Using the well-known animal model, the UM-X7.1 hamster strain of HCM (HCMH), our results showed the absence of a change in mean arterial pressure (MAP) during the asymptomatic phase preceding the development of necrosis in HCMHs when compared to age-matched normal hamster (NH). However, there was a progressive decrease in MAP that reached its lowest level during the heart failure phase. The MAP during the development of the necrosis phase of HCM was accompanied by a significant increase in the level of the sodium-hydrogen exchanger, NHE1. Treatments with the potent NHE1 inhibitor, EMD 87580 (rimeporide), did not affect MAP of NH. However, treatments with EMD 87580 during the three phases of the development of HCM significantly reversed the hypotension associated with HCM.Our results showed that the development of HCM is associated with hypotension. These results suggest that a decrease in blood pressure could be a biomarker signal for HCM leading to HF and early death. Since the blockade of NHE1 significantly but partially prevented the reduction in MAP, this suggests that other mechanisms can contribute to the development of hypotension in HCM.
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Klose E, Kuhrt H, Kohen L, Wiedemann P, Bringmann A, Hollborn M. Hypoxic and osmotic expression of Kir2.1 potassium channels in retinal pigment epithelial cells: Contribution to vascular endothelial growth factor expression. Exp Eye Res 2021; 211:108741. [PMID: 34425102 DOI: 10.1016/j.exer.2021.108741] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 07/22/2021] [Accepted: 08/19/2021] [Indexed: 12/31/2022]
Abstract
Retinal pigment epithelial (RPE) cells express different subtypes of inwardly rectifying potassium (Kir) channels. We investigated whether human and rat RPE cells express genes of strongly rectifying Kir2 channels. We also determined the hypoxic and hyperosmotic regulation of Kir2.1 gene expression in cultured human RPE cells and the effects of siRNA-mediated knockdown of Kir2.1 on VEGFA expression, VEGF secretion, proliferation, and viability of the cells. Extracellular hyperosmolarity was induced by addition of NaCl or sucrose. Hypoxia and chemical hypoxia were produced by cell culture in 0.25% O2 and addition of CoCl2, respectively. Gene expression levels were evaluated by real-time RT-PCR. Rat RPE cells contained Kir2.1, Kir2.2, Kir2.3, and Kir2.4 gene transcripts while human RPE cells contained Kir2.1, Kir2.2, and Kir2.4 transcripts. Immunocytochemical data may suggest that Kir2.1 protein in cultured human cells is expressed in both perinuclear and plasma membranes. Kir2.1 gene expression and Kir2.1 protein level in human cells increased under hypoxic and hyperosmotic conditions. The expression of the Kir2.1 gene was mediated in part by diverse intracellular signal transduction pathways and transcription factor activities under both conditions; the hyperosmotic, but not the CoCl2-induced Kir2.1 gene expression was dependent on intracellular calcium signaling. Autocrine/paracrine activation of purinergic receptors contributed to Kir2.1 gene expression under hyperosmotic (P2Y1, P2Y2, P2X7) and CoCl2-induced conditions (P2Y2, P2X7). Exogenous VEGF, TGF-β1, and blood serum decreased Kir2.1 gene expression. Inhibition of VEGF receptor-2 increased the Kir2.1 gene expression under control conditions and in CoCl2-simulated hypoxia, and decreased it under high NaCl conditions. Knockdown of Kir2.1 by siRNA inhibited the CoCl2-induced and hyperosmotic transcription of the VEGFA gene and caused a delayed decrease of the constitutive VEGFA gene expression while VEGF protein secretion was not altered. Kir2.1 knockdown stimulated RPE cell proliferation under control and hyperosmotic conditions without affecting cell viability. The data indicate that Kir2.1 channel activity is required for the expression of the VEGFA gene and inhibits the proliferation of RPE cells. Under control and hypoxic conditions, the extracellular VEGF level may regulate the production of VEGF via its inhibitory effect on the Kir2.1 gene transcription; this feedback loop may prevent overproduction of VEGF.
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Affiliation(s)
- Eva Klose
- Department of Ophthalmology and Eye Hospital, University of Leipzig, Leipzig, Germany
| | - Heidrun Kuhrt
- Institute of Anatomy, University of Leipzig, Germany
| | - Leon Kohen
- Department of Ophthalmology and Eye Hospital, University of Leipzig, Leipzig, Germany; Helios Klinikum Aue, Aue, Germany
| | - Peter Wiedemann
- Department of Ophthalmology and Eye Hospital, University of Leipzig, Leipzig, Germany
| | - Andreas Bringmann
- Department of Ophthalmology and Eye Hospital, University of Leipzig, Leipzig, Germany
| | - Margrit Hollborn
- Department of Ophthalmology and Eye Hospital, University of Leipzig, Leipzig, Germany.
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5
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High Na + Salt Diet and Remodeling of Vascular Smooth Muscle and Endothelial Cells. Biomedicines 2021; 9:biomedicines9080883. [PMID: 34440087 PMCID: PMC8389691 DOI: 10.3390/biomedicines9080883] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/19/2021] [Accepted: 07/21/2021] [Indexed: 12/12/2022] Open
Abstract
Our knowledge on essential hypertension is vast, and its treatment is well known. Not all hypertensives are salt-sensitive. The available evidence suggests that even normotensive individuals are at high cardiovascular risk and lower survival rate, as blood pressure eventually rises later in life with a high salt diet. In addition, little is known about high sodium (Na+) salt diet-sensitive hypertension. There is no doubt that direct and indirect Na+ transporters, such as the Na/Ca exchanger and the Na/H exchanger, and the Na/K pump could be implicated in the development of high salt-induced hypertension in humans. These mechanisms could be involved following the destruction of the cell membrane glycocalyx and changes in vascular endothelial and smooth muscle cells membranes’ permeability and osmolarity. Thus, it is vital to determine the membrane and intracellular mechanisms implicated in this type of hypertension and its treatment.
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6
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Chamoun M, Jacques D, Bkaily G. Extracellular and intracellular tumor necrosis factor alpha modulates cytosolic and nuclear calcium in human cardiovascular cells 1. Can J Physiol Pharmacol 2019; 97:820-828. [PMID: 30897335 DOI: 10.1139/cjpp-2019-0070] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Tumor necrosis factor alpha (TNFα) and its type 1 receptor (TNFR1) are implicated in several autoimmune diseases, including rheumatoid arthritis, and are associated with complications at the cardiovascular level. Using human cardiomyocytes, vascular smooth muscle, vascular endothelial, and endocardial endothelial cells coupled to indirect immunofluorescence, our results showed the presence of TNFR1 at the levels of the plasma membrane (including the cytosol) and mostly at the level of the nuclear membranes (including the nucleoplasm). The distribution of the receptor is different between cell types; however, the density is significantly higher at the nuclear level in all 4 cell types. The density of the receptor was the highest in contractile cells including the cardiomyocytes and vascular smooth muscle cells, compared with endothelial cells including endocardial endothelial and vascular endothelial cells. Using the Ca2+ probe Fluo-3 coupled to quantitative confocal microscopy, our results showed that the cytokine induced a sustained Ca2+ increase in both the cytosol and nucleoplasm of all 4 cell types. This increase was more significant at the nuclear level, mainly in endothelial cells. Our results demonstrated the presence of TNFR1 at both the cell and nuclear membranes of cardiovascular cells, and that its activation modulated both cytosolic and nuclear Ca2+.
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Affiliation(s)
- Marc Chamoun
- Department of Anatomy and Cell Biology, Faculty of Medicine, University of Sherbrooke, Sherbrooke, QC J1H 5N4, Canada.,Department of Anatomy and Cell Biology, Faculty of Medicine, University of Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
| | - Danielle Jacques
- Department of Anatomy and Cell Biology, Faculty of Medicine, University of Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
| | - Ghassan Bkaily
- Department of Anatomy and Cell Biology, Faculty of Medicine, University of Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
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7
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NR1 and NR3B Composed Intranuclear N-methyl-d-aspartate Receptor Complexes in Human Melanoma Cells. Int J Mol Sci 2018; 19:ijms19071929. [PMID: 29966365 PMCID: PMC6073738 DOI: 10.3390/ijms19071929] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 06/27/2018] [Indexed: 01/05/2023] Open
Abstract
Heterotetrameric N-methyl-d-aspartate type glutamate receptors (NMDAR) are cationic channels primarily permeable for Ca2+. NR1 and NR3 subunits bind glycine, while NR2 subunits bind glutamate for full activation. As NR1 may contain a nuclear localization signal (NLS) that is recognized by importin-α, our aim was to investigate if NMDARs are expressed in the nuclei of melanocytes and melanoma cells. A detailed NMDAR subunit expression pattern was examined by RT-PCRs (reverse transcription followed by polymerase chain reaction), fractionated western blots and immunocytochemistry in human epidermal melanocytes and in human melanoma cell lines A2058, HT199, HT168M1, MEL35/0 and WM35. All kind of NMDAR subunits are expressed as mRNAs in melanocytes, as well as in melanoma cells, while NR2B protein remained undetectable in any cell type. Western blots proved the exclusive presence of NR1 and NR3B in nuclear fractions and immunocytochemistry confirmed NR1-NR3B colocalization inside the nuclei of all melanoma cells. The same phenomenon was not observed in melanocytes. Moreover, protein database analysis revealed a putative NLS in NR3B subunit. Our results support that unusual, NR1-NR3B composed NMDAR complexes are present in the nuclei of melanoma cells. This may indicate a new malignancy-related histopathological feature of melanoma cells and raises the possibility of a glycine-driven, NMDA-related nuclear Ca2+-signalling in these cells.
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8
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Nikolova-Krstevski V, Wagner S, Yu ZY, Cox CD, Cvetkovska J, Hill AP, Huttner IG, Benson V, Werdich AA, MacRae C, Feneley MP, Friedrich O, Martinac B, Fatkin D. Endocardial TRPC-6 Channels Act as Atrial Mechanosensors and Load-Dependent Modulators of Endocardial/Myocardial Cross-Talk. ACTA ACUST UNITED AC 2017; 2:575-590. [PMID: 30062171 PMCID: PMC6058914 DOI: 10.1016/j.jacbts.2017.05.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 03/05/2017] [Accepted: 05/22/2017] [Indexed: 12/01/2022]
Abstract
Mechanoelectrical feedback may increase arrhythmia susceptibility, but the molecular mechanisms are incompletely understood. This study showed that mechanical stretch altered the localization, protein levels, and function of the cation-selective transient receptor potential channel (TRPC)-6 in atrial endocardial cells in humans, pigs, and mice. In endocardial/myocardial cross-talk studies, addition of media from porcine atrial endocardium (AE) cells altered the calcium (Ca2+) transient characteristics of human-induced pluripotent stem cell-derived cardiomyocytes. These changes did not occur with media from stretched AE cells. Our data suggested that endocardial TRPC-6-dependent paracrine signaling may modulate myocardial Ca2+ homeostasis under basal conditions and protect against stretch-induced atrial arrhythmias.
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Key Words
- AE, atrial endocardium
- AF, atrial fibrillation
- APB, aminoethoxydiphenyl borate
- Ab, antibody
- CM, cardiomyocyte
- Ca2+, calcium
- Dil-Ac-LDL, dil acetylated−low-density lipoprotein
- ET, endothelin
- HUVEC, human umbilical vein endothelial cell
- OAG, 1-oleoyl-2-acetyl-sn-glycerol
- TAC, thoracic aortic constriction
- TRPC, transient receptor potential channel
- Tet, tetanus toxin
- [Ca2+]i, intracellular global Ca2+
- atrial endocardium
- endothelium
- iPS, induced pluripotent stem
- mechanical stretch
- transient receptor potential channels
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Affiliation(s)
- Vesna Nikolova-Krstevski
- Molecular Cardiology and Biophysics Division, Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia.,St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Kensington, New South Wales, Australia
| | - Soeren Wagner
- Department of Anesthesiology, University Clinic Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Ze Yan Yu
- St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Kensington, New South Wales, Australia.,Cardiac Physiology and Transplantation Division, Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia
| | - Charles D Cox
- Molecular Cardiology and Biophysics Division, Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia
| | - Jasmina Cvetkovska
- Molecular Cardiology and Biophysics Division, Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia
| | - Adam P Hill
- Molecular Cardiology and Biophysics Division, Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia.,St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Kensington, New South Wales, Australia
| | - Inken G Huttner
- Molecular Cardiology and Biophysics Division, Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia.,St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Kensington, New South Wales, Australia
| | - Victoria Benson
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Andreas A Werdich
- Cardiovascular Division, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts
| | - Calum MacRae
- Cardiovascular Division, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts
| | - Michael P Feneley
- St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Kensington, New South Wales, Australia.,Cardiac Physiology and Transplantation Division, Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia.,Cardiology Department, St. Vincent's Hospital, Darlinghurst, New South Wales, Australia
| | - Oliver Friedrich
- Molecular Cardiology and Biophysics Division, Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia.,Institute of Medical Biotechnology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Boris Martinac
- Molecular Cardiology and Biophysics Division, Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia.,St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Kensington, New South Wales, Australia
| | - Diane Fatkin
- Molecular Cardiology and Biophysics Division, Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia.,St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Kensington, New South Wales, Australia.,Cardiology Department, St. Vincent's Hospital, Darlinghurst, New South Wales, Australia
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9
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Zhu L, Lu Y, Zhang J, Hu Q. Subcellular Redox Signaling. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 967:385-398. [DOI: 10.1007/978-3-319-63245-2_25] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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10
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Kamal M, Jacques D, Bkaily G. Angiotensin II receptors’ modulation of calcium homeostasis in human vascular endothelial cells. Can J Physiol Pharmacol 2017; 95:1289-1297. [DOI: 10.1139/cjpp-2017-0416] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Angiotensin II (AngII) plays an important role in the regulation of vascular smooth muscle function. However, little is known about AngII and its receptors AT1 (AT1R) and AT2 (AT2R) and their modulation of intracellular calcium in vascular endothelial cells (VECs) in general and more particularly of human origin. Using western blots, our results showed that AT1Rs and AT2Rs are present in human VECs (hVECs). Using quantitative 3D confocal imaging, our results showed that AngII is present at the cytoplasmic and nucleoplasmic levels and its relative density is lower in the nucleoplasm. However, both AngII receptors AT1 and AT2 are present at both the plasma and the nuclear envelope membranes (NEMs). AngII (10−10 mol/L) induces a transient decrease of the relative density of cytosolic and nuclear AT1Rs. Blockade of AT1Rs with losartan or blocking protein synthesis with cycloheximide does not prevent internalization and nuclear translocation of AT1Rs but prevents de novo AT1R synthesis. In addition, AngII induces cytosolic and nuclear increases (EC50 near 5 × 10−14 mol/L) of calcium via the activation of AT1Rs. These results demonstrate that both AT1 and AT2 receptors are present in hVECs, and that only AT1Rs seem to undergo transcellular trafficking and modulate cytosolic and nuclear calcium homeostasis.
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Affiliation(s)
- Maud Kamal
- Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
- Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
| | - Danielle Jacques
- Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
- Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
| | - Ghassan Bkaily
- Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
- Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
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11
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Bkaily G, Al-Khoury J, Simon Y, Jacques D. Intracellular Free Calcium Measurement Using Confocal Imaging. Methods Mol Biol 2017; 1527:177-187. [DOI: 10.1007/978-1-4939-6625-7_14] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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12
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Abstract
Although convention dictates that G protein-coupled receptors localize to and signal at the plasma membrane, accumulating evidence suggests that G protein-coupled receptors localize to and signal at intracellular membranes, most notably the nucleus. In fact, there is now significant evidence indicating that endogenous alpha-1 adrenergic receptors (α1-ARs) localize to and signal at the nuclei in adult cardiac myocytes. Cumulatively, the data suggest that α1-ARs localize to the inner nuclear membrane, activate intranuclear signaling, and regulate physiologic function in adult cardiac myocytes. Although α1-ARs signal through Gαq, unlike other Gq-coupled receptors, α1-ARs mediate important cardioprotective functions including adaptive/physiologic hypertrophy, protection from cell death (survival signaling), positive inotropy, and preconditioning. Also unlike other Gq-coupled receptors, most, if not all, functional α1-ARs localize to the nuclei in adult cardiac myocytes, as opposed to the sarcolemma. Together, α1-AR nuclear localization and cardioprotection might suggest a novel model for compartmentalization of Gq-coupled receptor signaling in which nuclear Gq-coupled receptor signaling is cardioprotective.
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13
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Nuclear Membranes ETB Receptors Mediate ET-1–induced Increase of Nuclear Calcium in Human Left Ventricular Endocardial Endothelial Cells. J Cardiovasc Pharmacol 2015; 66:50-7. [DOI: 10.1097/fjc.0000000000000242] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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14
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Jang SH, Byun JK, Jeon WI, Choi SY, Park J, Lee BH, Yang JE, Park JB, O'Grady SM, Kim DY, Ryu PD, Joo SW, Lee SY. Nuclear localization and functional characteristics of voltage-gated potassium channel Kv1.3. J Biol Chem 2015; 290:12547-57. [PMID: 25829491 PMCID: PMC4432276 DOI: 10.1074/jbc.m114.561324] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 03/26/2015] [Indexed: 12/29/2022] Open
Abstract
It is widely known that ion channels are expressed in the plasma membrane. However, a few studies have suggested that several ion channels including voltage-gated K(+) (Kv) channels also exist in intracellular organelles where they are involved in the biochemical events associated with cell signaling. In the present study, Western blot analysis using fractionated protein clearly indicates that Kv1.3 channels are expressed in the nuclei of MCF7, A549, and SNU-484 cancer cells and human brain tissues. In addition, Kv1.3 is located in the plasma membrane and the nucleus of Jurkat T cells. Nuclear membrane hyperpolarization after treatment with margatoxin (MgTX), a specific blocker of Kv1.3 channels, provides evidence for functional channels at the nuclear membrane of A549 cells. MgTX-induced hyperpolarization is abolished in the nuclei of Kv1.3 silenced cells, and the effects of MgTX are dependent on the magnitude of the K(+) gradient across the nuclear membrane. Selective Kv1.3 blockers induce the phosphorylation of cAMP response element-binding protein (CREB) and c-Fos activation. Moreover, Kv1.3 is shown to form a complex with the upstream binding factor 1 in the nucleus. Chromatin immunoprecipitation assay reveals that Sp1 transcription factor is directly bound to the promoter region of the Kv1.3 gene, and the Sp1 regulates Kv1.3 expression in the nucleus of A549 cells. These results demonstrate that Kv1.3 channels are primarily localized in the nucleus of several types of cancer cells and human brain tissues where they are capable of regulating nuclear membrane potential and activation of transcription factors, such as phosphorylated CREB and c-Fos.
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Affiliation(s)
- Soo Hwa Jang
- From the Laboratories of Veterinary Pharmacology and the Biomedical Research Center, School of Biological Sciences, University of Ulsan, Ulsan 680-749, Korea
| | - Jun Kyu Byun
- From the Laboratories of Veterinary Pharmacology and
| | - Won-Il Jeon
- From the Laboratories of Veterinary Pharmacology and
| | | | - Jin Park
- the Department of Chemistry, Soongsil University, Seoul 156-743, Korea
| | - Bo Hyung Lee
- From the Laboratories of Veterinary Pharmacology and
| | - Ji Eun Yang
- From the Laboratories of Veterinary Pharmacology and
| | - Jin Bong Park
- the Department of Physiology, School of Medicine, Chungnam National University, Daejeon 305-764, Korea, and
| | - Scott M O'Grady
- the Department of Animal Science and Integrative Biology and Physiology, University of Minnesota, St. Paul, Minnesota 55455
| | - Dae-Yong Kim
- Veterinary Pathology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul 151-742, Korea
| | - Pan Dong Ryu
- From the Laboratories of Veterinary Pharmacology and
| | - Sang-Woo Joo
- the Department of Chemistry, Soongsil University, Seoul 156-743, Korea
| | - So Yeong Lee
- From the Laboratories of Veterinary Pharmacology and
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15
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Bkaily G, Avedanian L, Al-Khoury J, Chamoun M, Semaan R, Jubinville-Leblanc C, D’Orléans-Juste P, Jacques D. Nuclear membrane R-type calcium channels mediate cytosolic ET-1-induced increase of nuclear calcium in human vascular smooth muscle cells. Can J Physiol Pharmacol 2015; 93:291-7. [DOI: 10.1139/cjpp-2014-0519] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The objective of this work was to verify whether, as in the case of the plasma membrane of human vascular smooth muscle cells (hVSMCs), cytosolic ET-1-induced increase of nuclear calcium is mediated via the activation of calcium influx through the steady-state R-type calcium channel. Pharmacological tools to identify the R-type calcium channels, as well as real 3-D confocal microscopy imaging techniques coupled to calcium fluorescent probes, were used to study the effect of cytosolic ET-1 on nuclear calcium in isolated nuclei of human hepatocytes and plasma membrane perforated hVSMCs. Our results showed that pre-treatment with pertussis toxin (PTX) or cholera toxin (CTX) prevented cytosolic ET-1 (10−9 mol/L) from inducing a sustained increase in nuclear calcium. Furthermore, the L-type calcium channel blocker nifedipine did not prevent cytosolic ET-1 from inducing an increase in nuclear calcium, as opposed to the dual L- and R-type calcium channel blocker isradipine (PN200-110) (in the presence of nifedipine). In conclusion, the preventative effect with PTX and CTX, and the absence of an effect with nifedipine, as well as the blockade by isradipine on cytosolic ET-1-induced increase in nuclear calcium, suggest that this nuclear calcium influx in hVSMCs is due to activation of the steady-state R-type calcium channel. The sarcolemmal and nuclear membrane R-type calcium channels in hVSMCs are involved in ET-1 modulation of vascular tone in physiology and pathology.
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Affiliation(s)
- Ghassan Bkaily
- Department of Anatomy and Cell Biology, Faculty of Medicine – University of Sherbrooke, 3001, 12th Avenue North, Sherbrooke, QC J1H 5N4, Canada
- Department of Anatomy and Cell Biology, Faculty of Medicine – University of Sherbrooke, 3001, 12th Avenue North, Sherbrooke, QC J1H 5N4, Canada
| | - Levon Avedanian
- Department of Anatomy and Cell Biology, Faculty of Medicine – University of Sherbrooke, 3001, 12th Avenue North, Sherbrooke, QC J1H 5N4, Canada
- Department of Anatomy and Cell Biology, Faculty of Medicine – University of Sherbrooke, 3001, 12th Avenue North, Sherbrooke, QC J1H 5N4, Canada
| | - Johny Al-Khoury
- Department of Anatomy and Cell Biology, Faculty of Medicine – University of Sherbrooke, 3001, 12th Avenue North, Sherbrooke, QC J1H 5N4, Canada
- Department of Anatomy and Cell Biology, Faculty of Medicine – University of Sherbrooke, 3001, 12th Avenue North, Sherbrooke, QC J1H 5N4, Canada
| | - Marc Chamoun
- Department of Anatomy and Cell Biology, Faculty of Medicine – University of Sherbrooke, 3001, 12th Avenue North, Sherbrooke, QC J1H 5N4, Canada
- Department of Anatomy and Cell Biology, Faculty of Medicine – University of Sherbrooke, 3001, 12th Avenue North, Sherbrooke, QC J1H 5N4, Canada
| | - Rana Semaan
- Department of Anatomy and Cell Biology, Faculty of Medicine – University of Sherbrooke, 3001, 12th Avenue North, Sherbrooke, QC J1H 5N4, Canada
- Department of Anatomy and Cell Biology, Faculty of Medicine – University of Sherbrooke, 3001, 12th Avenue North, Sherbrooke, QC J1H 5N4, Canada
| | - Cynthia Jubinville-Leblanc
- Department of Anatomy and Cell Biology, Faculty of Medicine – University of Sherbrooke, 3001, 12th Avenue North, Sherbrooke, QC J1H 5N4, Canada
- Department of Anatomy and Cell Biology, Faculty of Medicine – University of Sherbrooke, 3001, 12th Avenue North, Sherbrooke, QC J1H 5N4, Canada
| | - Pedro D’Orléans-Juste
- Department of Anatomy and Cell Biology, Faculty of Medicine – University of Sherbrooke, 3001, 12th Avenue North, Sherbrooke, QC J1H 5N4, Canada
- Department of Anatomy and Cell Biology, Faculty of Medicine – University of Sherbrooke, 3001, 12th Avenue North, Sherbrooke, QC J1H 5N4, Canada
| | - Danielle Jacques
- Department of Anatomy and Cell Biology, Faculty of Medicine – University of Sherbrooke, 3001, 12th Avenue North, Sherbrooke, QC J1H 5N4, Canada
- Department of Anatomy and Cell Biology, Faculty of Medicine – University of Sherbrooke, 3001, 12th Avenue North, Sherbrooke, QC J1H 5N4, Canada
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Expression and distribution of the adrenomedullin system in newborn human thymus. PLoS One 2014; 9:e97592. [PMID: 24831942 PMCID: PMC4022580 DOI: 10.1371/journal.pone.0097592] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Accepted: 04/21/2014] [Indexed: 12/25/2022] Open
Abstract
Adrenomedullin (AM) is a multifunctional peptide endowed with various biological actions mediated by the interaction with the calcitonin receptor-like receptor (CLR), which couples to the receptor activity-modifying proteins 2 or 3 (RAMP2 or RAMP3) to form the functional plasma membrane receptors AM1 and AM2, respectively. In this study, we investigated for the first time the expression and localization of AM, CLR, RAMP2 and RAMP3 in human thymic tissue from newborns and in primary cultures of thymic epithelial cells (TECs) and thymocytes. Immunohistochemical analysis of thymic tissue showed that both AM and RAMP2 are abundantly expressed in the epithelial cells of medulla and cortex, blood vessels and mastocytes. In contrast, RAMP3 could not be detected. In cultured TECs, double immunofluorescence coupled to confocal microscopy revealed that AM is present in the cytoplasmic compartment, whereas RAMP2 could be detected in the cytoplasm and nucleus, but not in the cell membrane. At variance with RAMP2, CLR was not only present in the nucleus and cytoplasm of TECs, but could also be detected in the cell membrane. The nuclear and cytoplasmic localizations of RAMP2 and CLR and the absence of RAMP2 in the cell membrane were confirmed by western-blot analysis performed on cell fractions. AM, RAMP2 and CLR could also be detected in thymocytes by means of double immunofluorescence coupled to confocal microscopy, although these proteins were not present in the whole thymocyte population. In these cells, AM and RAMP2 were detected in the cytoplasm, whereas CLR could be observed in the cytoplasm and the plasma membrane. In conclusion, our results show that the AM system is widely expressed in human thymus from newborns and suggest that both AM1 receptor components CLR and RAMP2 are not associated with the plasma membrane of TECs and thymocytes but are located intracellularly, notably in the nucleus.
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O'Connell TD, Jensen BC, Baker AJ, Simpson PC. Cardiac alpha1-adrenergic receptors: novel aspects of expression, signaling mechanisms, physiologic function, and clinical importance. Pharmacol Rev 2013; 66:308-33. [PMID: 24368739 DOI: 10.1124/pr.112.007203] [Citation(s) in RCA: 133] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Adrenergic receptors (AR) are G-protein-coupled receptors (GPCRs) that have a crucial role in cardiac physiology in health and disease. Alpha1-ARs signal through Gαq, and signaling through Gq, for example, by endothelin and angiotensin receptors, is thought to be detrimental to the heart. In contrast, cardiac alpha1-ARs mediate important protective and adaptive functions in the heart, although alpha1-ARs are only a minor fraction of total cardiac ARs. Cardiac alpha1-ARs activate pleiotropic downstream signaling to prevent pathologic remodeling in heart failure. Mechanisms defined in animal and cell models include activation of adaptive hypertrophy, prevention of cardiac myocyte death, augmentation of contractility, and induction of ischemic preconditioning. Surprisingly, at the molecular level, alpha1-ARs localize to and signal at the nucleus in cardiac myocytes, and, unlike most GPCRs, activate "inside-out" signaling to cause cardioprotection. Contrary to past opinion, human cardiac alpha1-AR expression is similar to that in the mouse, where alpha1-AR effects are seen most convincingly in knockout models. Human clinical studies show that alpha1-blockade worsens heart failure in hypertension and does not improve outcomes in heart failure, implying a cardioprotective role for human alpha1-ARs. In summary, these findings identify novel functional and mechanistic aspects of cardiac alpha1-AR function and suggest that activation of cardiac alpha1-AR might be a viable therapeutic strategy in heart failure.
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Affiliation(s)
- Timothy D O'Connell
- VA Medical Center (111-C-8), 4150 Clement St., San Francisco, CA 94121. ; or Dr. Timothy D. O'Connell, E-mail:
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You Z, Al Kindi H, Abdul-Karim A, Barrette PO, Schwertani A. Blocking the urotensin II receptor pathway ameliorates the metabolic syndrome and improves cardiac function in obese mice. FASEB J 2013; 28:1210-20. [PMID: 24297699 DOI: 10.1096/fj.13-236471] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The metabolic syndrome is defined by the presence of hyperlipidemia, obesity, hypertension, and diabetes. The syndrome is associated with significant cardiovascular morbidity and mortality. The aim of the present study was to determine the role of the vasoactive peptide urotensin II (UII) in the pathogenesis of the metabolic syndrome. We used obese mice (ob/ob) to determine the effect of UII receptor (UT) blockage on the different facets of the metabolic syndrome with special emphasis on cardiac function. Our data demonstrate a significant increase in UII and UT expression in the myocardium of obese mice accompanied by a significant decrease in sarco/endoplasmic reticulum Ca(2+)-ATPase 2a (SERCA2a) expression, as well as intracellular Na(+) and Ca(2+) compared with wild-type mice (P<0.05). Treatment of ob/ob mice with the UII receptor antagonist SB657510 significantly improved glucose levels, blood pressure, hyperlipidemia, expression of myocardial SERCA2a, intracellular Na(+) and Ca(2+) and cardiac function in association with a decrease in weight gain, and mammalian target of rapamycin (mTOR) and sodium/hydrogen exchanger 1 (NHE-1) protein expression compared with vehicle (P<0.05). These findings demonstrate an important role for UII in the pathogenesis of the metabolic syndrome and suggest that the use of UT receptor antagonists may provide a new therapeutic tool for the treatment of this syndrome.
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Affiliation(s)
- Zhipeng You
- 1McGill University Health Center, Ste. C9-166, Montreal General Hospital, 1650 Cedar Ave., Montreal, Quebec H3G 1A4, Canada.
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Distribution of voltage-dependent and intracellular Ca2+ channels in submucosal neurons from rat distal colon. Cell Tissue Res 2013; 353:355-66. [DOI: 10.1007/s00441-013-1643-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Accepted: 04/18/2013] [Indexed: 10/26/2022]
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Ahmarani L, Avedanian L, Al-Khoury J, Perreault C, Jacques D, Bkaily G. Whole-cell and nuclear NADPH oxidases levels and distribution in human endocardial endothelial, vascular smooth muscle, and vascular endothelial cells. Can J Physiol Pharmacol 2013; 91:71-9. [DOI: 10.1139/cjpp-2012-0265] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The results of our study show that whole-cell and nuclear levels of NADPH oxidase-1 (NOX1) are similar in human vascular endothelial cells (hVECs) and smooth muscle cells (hVSMCs), but lower in human endocardial endothelial cells (hEECs). NOX2 levels were higher in hVECs and lower in hVSMCs. NOX3 levels were the same in hVECs and hVSMCs, but lower in hEECs. NOX4 levels were similar in all of the cell types. NOX4 levels were higher in hVECs than in hVSMCs. NOX5 was also present throughout the 3 cell types, including their nuclei, in the following order: hEECs > hVSMCs > hVECs. The level of basal reactive oxygen species (ROS) was highest in hVECs and lowest in hVSMCs. However, the Ca2+ level was highest in hVSMCs and lowest in hVECs. These findings suggest that all types of NOXs exist in hEECs, hVECs, and hVSMCs, although their density and distribution are cell-type dependent. The density of the different NOXs correlated with the ROS level, but not with the Ca2+ level. In conclusion, NOXs, including NOX3, exist in cardiovascular cells and their nuclei. The nucleus is a major source of ROS generation. The nuclear NOXs may contribute to ROS and Ca2+ homeostasis, which may affect cell remodeling, including the formation of nuclear T-tubules in vascular diseases and aging.
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Affiliation(s)
- Lena Ahmarani
- Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, 3001, 12th avenue Nord, Sherbrooke, QC J1H 5N4, Canada
| | - Levon Avedanian
- Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, 3001, 12th avenue Nord, Sherbrooke, QC J1H 5N4, Canada
| | - Johny Al-Khoury
- Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, 3001, 12th avenue Nord, Sherbrooke, QC J1H 5N4, Canada
| | - Claudine Perreault
- Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, 3001, 12th avenue Nord, Sherbrooke, QC J1H 5N4, Canada
| | - Danielle Jacques
- Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, 3001, 12th avenue Nord, Sherbrooke, QC J1H 5N4, Canada
| | - Ghassan Bkaily
- Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, 3001, 12th avenue Nord, Sherbrooke, QC J1H 5N4, Canada
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Abstract
The large conductance calcium- and voltage-activated potassium channel (BK(Ca)) is widely expressed at the plasma membrane. This channel is involved in a variety of fundamental cellular functions including excitability, smooth muscle contractility, and Ca(2+) homeostasis, as well as in pathological situations like proinflammatory responses in rheumatoid arthritis, and cancer cell proliferation. Immunochemical, biochemical and pharmacological studies from over a decade have intermittently shown the presence of BK(Ca) in intracellular organelles. To date, intracellular BK(Ca) (iBK(Ca)) has been localized in the mitochondria, endoplasmic reticulum, nucleus and Golgi apparatus but its functional role remains largely unknown except for the mitochondrial BK(Ca) whose opening is thought to play a role in protecting the heart from ischaemic injury. In the nucleus, pharmacology suggests a role in regulating nuclear Ca(2+), membrane potential and eNOS expression. Establishing the molecular correlates of iBK(Ca), the mechanisms defining iBK(Ca) organelle-specific targeting, and their modulation are challenging questions. This review summarizes iBK(Ca) channels, their possible functions, and efforts to identify their molecular correlates.
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Affiliation(s)
- Harpreet Singh
- Department of Anesthesiology, University of California, Los Angeles, CA 90095, USA
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Bkaily G, Avedanian L, Al-Khoury J, Ahmarani L, Perreault C, Jacques D. Receptors and ionic transporters in nuclear membranes: new targets for therapeutical pharmacological interventions. Can J Physiol Pharmacol 2012; 90:953-65. [DOI: 10.1139/y2012-077] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Work from our group and other laboratories showed that the nucleus could be considered as a cell within a cell. This is based on growing evidence of the presence and role of nuclear membrane G-protein coupled receptors and ionic transporters in the nuclear membranes of many cell types, including vascular endothelial cells, endocardial endothelial cells, vascular smooth muscle cells, cardiomyocytes, and hepatocytes. The nuclear membrane receptors were found to modulate the functioning of ionic transporters at the nuclear level, and thus contribute to regulation of nuclear ionic homeostasis. Nuclear membranes of the mentioned types of cells possess the same ionic transporters; however, the type of receptors is cell-type dependent. Regulation of cytosolic and nuclear ionic homeostasis was found to be dependent upon a tight crosstalk between receptors and ionic transporters of the plasma membranes and those of the nuclear membrane. This crosstalk seems to be the basis for excitation–contraction coupling, excitation–secretion coupling, and excitation – gene expression coupling. Further advancement in this field will certainly shed light on the role of nuclear membrane receptors and transporters in health and disease. This will in turn enable the successful design of a new class of drugs that specifically target such highly vital nuclear receptors and ionic transporters.
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Affiliation(s)
- Ghassan Bkaily
- Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, 3001 12th Avenue North, Sherbrooke, QC J1H 5N4, Canada
| | - Levon Avedanian
- Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, 3001 12th Avenue North, Sherbrooke, QC J1H 5N4, Canada
| | - Johny Al-Khoury
- Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, 3001 12th Avenue North, Sherbrooke, QC J1H 5N4, Canada
| | - Lena Ahmarani
- Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, 3001 12th Avenue North, Sherbrooke, QC J1H 5N4, Canada
| | - Claudine Perreault
- Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, 3001 12th Avenue North, Sherbrooke, QC J1H 5N4, Canada
| | - Danielle Jacques
- Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, 3001 12th Avenue North, Sherbrooke, QC J1H 5N4, Canada
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Role of NF-κB and p38 MAPK activation in mediating angiotensin II and endothelin-1-induced stimulation in leptin production and cardiomyocyte hypertrophy. Mol Cell Biochem 2012; 366:287-97. [DOI: 10.1007/s11010-012-1307-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2011] [Accepted: 04/03/2012] [Indexed: 10/28/2022]
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24
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Wright CD, Wu SC, Dahl EF, Sazama AJ, O'Connell TD. Nuclear localization drives α1-adrenergic receptor oligomerization and signaling in cardiac myocytes. Cell Signal 2012; 24:794-802. [PMID: 22120526 PMCID: PMC3393107 DOI: 10.1016/j.cellsig.2011.11.014] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2011] [Accepted: 11/08/2011] [Indexed: 11/17/2022]
Abstract
Conventional models of G-protein coupled receptor (GPCR) signaling describe cell surface receptors binding to external ligands, such as hormones or circulating peptides, to induce intracellular signaling and a physiologic response. However, recent studies identify new paradigms indicating that GPCRs localize to and signal at the nucleus and that GPCR oligomers can influence receptor function. Previously, we reported that endogenous α1-adrenergic receptors (α1-ARs) localize to and signal at the nuclei in adult cardiac myocytes. In this study, we examined the mechanisms behind α1-AR nuclear localization and how nuclear localization impacted receptor function. We verified that endogenous α1-ARs localized to the nuclear membrane of intact nuclei isolated from wild-type adult cardiac myocytes. Next, we identified and disrupted putative nuclear localization sequences in both the α1A- and α1B-adrenergic receptors, which led to mis-localization of α1-ARs in cultured adult cardiac myocytes. Using these mutants, we demonstrated that nuclear localization was required for α1-signaling in adult cardiac myocytes. We also found that the nuclear export inhibitor leptomycin B inhibited α1-AR signaling, indicating α1-AR signaling must arise in the nucleus in adult cardiac myocytes. Finally, we found that co-localization of the α1-subtypes at the nuclei in adult cardiac myocytes facilitated the formation of receptor oligomers that could affect receptor signaling. In summary, our data indicate that α1-AR nuclear localization can drive the formation of receptor oligomers and regulate signaling in adult cardiac myocytes.
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MESH Headings
- Animals
- Cell Nucleus/metabolism
- Cells, Cultured
- Fluorescence Resonance Energy Transfer
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Mutation
- Myocytes, Cardiac/cytology
- Myocytes, Cardiac/metabolism
- Protein Multimerization
- Receptors, Adrenergic, alpha-1/analysis
- Receptors, Adrenergic, alpha-1/genetics
- Receptors, Adrenergic, alpha-1/metabolism
- Signal Transduction
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Affiliation(s)
- Casey D Wright
- Cardiovascular Health Research Center, Sanford Research/USD, Sioux Falls, SD 57104, United States
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25
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Goulbourne CN, Malhas AN, Vaux DJ. The induction of a nucleoplasmic reticulum by prelamin A accumulation requires CTP:phosphocholine cytidylyltransferase-α. J Cell Sci 2011; 124:4253-66. [PMID: 22223883 PMCID: PMC3258109 DOI: 10.1242/jcs.091009] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/22/2011] [Indexed: 12/24/2022] Open
Abstract
Farnesylated prelamin A accumulates when the final endoproteolytic maturation of the protein fails to occur and causes a dysmorphic nuclear phenotype; however, the morphology and mechanisms of biogenesis of these changes remain unclear. We show here that acute prelamin A accumulation after reduction in the activity of the ZMPSTE24 endoprotease by short interfering RNA knockdown, results in the generation of a complex nucleoplasmic reticulum that depends for its formation on the enzyme CTP:phosphocholine-cytidylyltransferase-α (CCT-α, also known as choline-phosphate cytidylyltransferase A). This structure can form during interphase, confirming that it is independent of mitosis and therefore not a consequence of disordered nuclear envelope assembly. Serial-section dual-axis electron tomography reveals that these invaginations can take two forms: one in which the inner nuclear membrane infolds alone with an inter membrane space interior, and the other in which an invagination of both nuclear membranes occurs, enclosing a cytoplasmic core. Both types of invagination can co-exist in one nucleus and both are frequently studded with nuclear pore complexes (NPC), which reduces NPC abundance on the nuclear surface.
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Affiliation(s)
- Chris N. Goulbourne
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, OX1 3RE, UK
| | - Ashraf N. Malhas
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, OX1 3RE, UK
| | - David J. Vaux
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, OX1 3RE, UK
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26
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Cook JL, Re RN. Lessons from in vitro studies and a related intracellular angiotensin II transgenic mouse model. Am J Physiol Regul Integr Comp Physiol 2011; 302:R482-93. [PMID: 22170617 DOI: 10.1152/ajpregu.00493.2011] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In the classical renin-angiotensin system, circulating ANG II mediates growth stimulatory and hemodynamic effects through the plasma membrane ANG II type I receptor, AT1. ANG II also exists in the intracellular space in some native cells, and tissues and can be upregulated in diseases, including hypertension and diabetes. Moreover, intracellular AT1 receptors can be found associated with endosomes, nuclei, and mitochondria. Intracellular ANG II can function in a canonical fashion through the native receptor and also in a noncanonical fashion through interaction with alternative proteins. Likewise, the receptor and proteolytic fragments of the receptor can function independently of ANG II. Participation of the receptor and ligand in alternative intracellular pathways may serve to amplify events that are initiated at the plasma membrane. We review historical and current literature relevant to ANG II, compared with other intracrines, in tissue culture and transgenic models. In particular, we describe a new transgenic mouse model, which demonstrates that intracellular ANG II is linked to high blood pressure. Appreciation of the diverse, pleiotropic intracellular effects of components of the renin-angiotensin system should lead to alternative disease treatment targets and new therapies.
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Affiliation(s)
- Julia L Cook
- Laboratory of Molecular Genetics, Department of Research, New Orleans, LA 70121, USA.
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Hagenston AM, Bading H. Calcium signaling in synapse-to-nucleus communication. Cold Spring Harb Perspect Biol 2011; 3:a004564. [PMID: 21791697 DOI: 10.1101/cshperspect.a004564] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Changes in the intracellular concentration of calcium ions in neurons are involved in neurite growth, development, and remodeling, regulation of neuronal excitability, increases and decreases in the strength of synaptic connections, and the activation of survival and programmed cell death pathways. An important aspect of the signals that trigger these processes is that they are frequently initiated in the form of glutamatergic neurotransmission within dendritic trees, while their completion involves specific changes in the patterns of genes expressed within neuronal nuclei. Accordingly, two prominent aims of research concerned with calcium signaling in neurons are determination of the mechanisms governing information conveyance between synapse and nucleus, and discovery of the rules dictating translation of specific patterns of inputs into appropriate and specific transcriptional responses. In this article, we present an overview of the avenues by which glutamatergic excitation of dendrites may be communicated to the neuronal nucleus and the primary calcium-dependent signaling pathways by which synaptic activity can invoke changes in neuronal gene expression programs.
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Affiliation(s)
- Anna M Hagenston
- CellNetworks-Cluster of Excellence, Department of Neurobiology, Interdisciplinary Center for Neurosciences, University of Heidelberg, 69120 Heidelberg, Germany
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28
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Malhas A, Goulbourne C, Vaux DJ. The nucleoplasmic reticulum: form and function. Trends Cell Biol 2011; 21:362-73. [DOI: 10.1016/j.tcb.2011.03.008] [Citation(s) in RCA: 179] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2011] [Revised: 03/17/2011] [Accepted: 03/23/2011] [Indexed: 11/29/2022]
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Bkaily G, Avedanian L, Al-Khoury J, Provost C, Nader M, D'Orléans-Juste P, Jacques D. Nuclear membrane receptors for ET-1 in cardiovascular function. Am J Physiol Regul Integr Comp Physiol 2011; 300:R251-63. [DOI: 10.1152/ajpregu.00736.2009] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Plasma membrane endothelin type A (ETA) receptors are internalized and recycled to the plasma membrane, whereas endothelin type B (ETB) receptors undergo degradation and subsequent nuclear translocation. Recent studies show that G protein-coupled receptors (GPCRs) and ion transporters are also present and functional at the nuclear membranes of many cell types. Similarly to other GPCRs, ETA and ETB are present at both the plasma and nuclear membranes of several cardiovascular cell types, including human cardiac, vascular smooth muscle, endocardial endothelial, and vascular endothelial cells. The distribution and density of ETARs in the cytosol (including the cell membrane) and the nucleus (including the nuclear membranes) differ between these cell types. However, the localization and density of ET-1 and ETB receptors are similar in these cell types. The extracellular ET-1-induced increase in cytosolic ([Ca]c) and nuclear ([Ca]n) free Ca2+ is associated with an increase of cytosolic and nuclear reactive oxygen species. The extracellular ET-1-induced increase of [Ca]c and [Ca]n as well as intracellular ET-1-induced increase of [Ca]n are cell-type dependent. The type of ET-1 receptor mediating the extracellular ET-1-induced increase of [Ca]c and [Ca]n depends on the cell type. However, the cytosolic ET-1-induced increase of [Ca]n does not depend on cell type. In conclusion, nuclear membranes' ET-1 receptors may play an important role in overall ET-1 action. These nuclear membrane ET-1 receptors could be targets for a new generation of antagonists.
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Affiliation(s)
- Ghassan Bkaily
- Faculty of Medicine, Departments of 1Anatomy and Cell Biology and
| | - Levon Avedanian
- Faculty of Medicine, Departments of 1Anatomy and Cell Biology and
| | - Johny Al-Khoury
- Faculty of Medicine, Departments of 1Anatomy and Cell Biology and
| | - Chantale Provost
- Faculty of Medicine, Departments of 1Anatomy and Cell Biology and
| | - Moni Nader
- Faculty of Medicine, Departments of 1Anatomy and Cell Biology and
| | | | - Danielle Jacques
- Faculty of Medicine, Departments of 1Anatomy and Cell Biology and
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Avedanian L, Jacques D, Bkaily G. Presence of tubular and reticular structures in the nucleus of human vascular smooth muscle cells. J Mol Cell Cardiol 2010; 50:175-86. [PMID: 20937284 DOI: 10.1016/j.yjmcc.2010.10.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Revised: 10/01/2010] [Accepted: 10/01/2010] [Indexed: 11/30/2022]
Abstract
In recent decades, studies addressing nuclear calcium (Ca(2+)) homeostasis and signaling contributed to redefining the role of the nucleus. Yet many aspects of nuclear Ca(2+) signaling and homeostasis are only modestly understood. The present study aimed at investigating the presence of nuclear structures which could contribute to the regulation of nuclear Ca(2+) homeostasis. Using real 3D confocal microscopy, coupled to utilization of appropriate organelle probes and specific antibodies, we identified two entities in the nuclei of intact human vascular smooth muscle cells (hVSMCs) as well as in isolated hVSMCs nuclei. Our results demonstrate the presence of an ER-like nuclear reticular structure in nuclei of intact hVSMCs and in isolated nuclei. Similar to the ER/SR, this structure possesses thapsigargin binding sites, IP(3)Rs and RyRs, thus it was named nucleoplasmic reticulum (NR). Furthermore, nuclear tubular structures were also detected. The latter, similar to the nuclear envelope membranes, possess nuclear pores, thapsigargin binding sites, Angiotensin II receptor AT(2), and are associated with Lamin A/C. However, unlike the NR and the nuclear envelope membranes, these tubular structures disappeared when the nuclei were isolated from the cells. The nuclear tubular structures were called Nuclear T-Tubules (NTTs). Our calcium studies in isolated nuclei utilizing IP(3) and Ryanodine suggest that the NR may participate in nuclear Ca(2+) signaling. On the other hand, presence of nuclear pores on the NTTs suggests that these structures can play a role in cytosol-nucleus exchange. In conclusion, two distinct structures are present in the nucleus of hVSMCs and might play an important role in nuclear Ca(2+) homeostasis.
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Affiliation(s)
- Levon Avedanian
- Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, Quebec, Canada J1H 5N4
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31
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Fedorenko O, Yarotskyy V, Duzhyy D, Marchenko S. The large-conductance ion channels in the nuclear envelope of central neurons. Pflugers Arch 2010; 460:1045-50. [DOI: 10.1007/s00424-010-0882-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Revised: 08/03/2010] [Accepted: 09/14/2010] [Indexed: 11/30/2022]
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Abstract
The 21-amino-acid peptide ET-1 (endothelin-1) regulates a diverse array of physiological processes, including vasoconstriction, angiogenesis, nociception and cell proliferation. Most of the effects of ET-1 are associated with an increase in intracellular calcium concentration. The calcium influx and mobilization pathways activated by ET-1, however, vary immensely. The present review begins with the basics of calcium signalling and investigates the different ways intracellular calcium concentration can increase in response to a stimulus. The focus then shifts to ET-1, and discusses how ET receptors mobilize calcium. We also examine how disease alters calcium-dependent responses to ET-1 by discussing changes to ET-1-mediated calcium signalling in hypertension, as there is significant interest in the role of ET-1 in this important disease. A list of unanswered questions regarding ET-mediated calcium signals are also presented, as well as perspectives for future research of calcium mobilization by ET-1.
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Affiliation(s)
- Nathan R Tykocki
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824, USA.
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33
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Matzke AJM, Weiger TM, Matzke M. Ion channels at the nucleus: electrophysiology meets the genome. MOLECULAR PLANT 2010; 3:642-52. [PMID: 20410254 PMCID: PMC2910552 DOI: 10.1093/mp/ssq013] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2010] [Accepted: 03/12/2010] [Indexed: 05/21/2023]
Abstract
The nuclear envelope is increasingly viewed from an electrophysiological perspective by researchers interested in signal transduction pathways that influence gene transcription and other processes in the nucleus. Here, we describe evidence for ion channels and transporters in the nuclear membranes and for possible ion gating by the nuclear pores. We argue that a systems-level understanding of cellular regulation is likely to require the assimilation of nuclear electrophysiology into molecular and biochemical signaling pathways.
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Affiliation(s)
- Antonius J M Matzke
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, Dr. Bohr-Gasse 3, A-1030 Vienna, Austria.
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Provost C, Choufani F, Avedanian L, Bkaily G, Gobeil F, Jacques D. Nitric oxide and reactive oxygen species in the nucleus revisitedThis review is one of a selection of papers published in a Special Issue on Oxidative Stress in Health and Disease. Can J Physiol Pharmacol 2010; 88:296-304. [DOI: 10.1139/y10-011] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Recent work from our group showed that the nuclear envelope membranes contain several G protein-coupled receptors, including prostaglandin E2 (EP3R) and endothelin-1 (ET-1) receptors. Activation of EP3R increased endothelial nitric oxide synthase (eNOS) RNA expression in nuclei. eNOS and inducible NOS (iNOS) are reported to also be present at the nuclear level. Furthermore, reactive oxygen species (ROS) were also localized at the nuclear level. In this review, we show that stimulation with NO donor sodium nitroprusside results in an increase of intranuclear calcium that was dependent on guanylate cyclase activation, but independent of MAPK. This increase in nuclear calcium correlated with an increase in nuclear transcription of iNOS. H2O2 and ET-1 increase both cytosolic and nuclear ROS in human endocardial endothelial cells and in human aortic vascular smooth muscle cells. This increase in ROS levels by H2O2 and ET-1 was reversed by the antioxidant glutathione. In addition, our results strongly suggest that cytosolic signalization is not only transmitted to the nucleus but is also generated by the nucleus. Furthermore, we demonstrate that oxidative stress can be sensed by the nucleus. These results highly suggest that ROS formation is also generated directly by the nucleus and that free radicals may contribute to ET-1 regulation of nuclear Ca2+ homeostasis.
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Affiliation(s)
- Chantale Provost
- Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
- Department of Pharmacology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
| | - Faten Choufani
- Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
- Department of Pharmacology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
| | - Levon Avedanian
- Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
- Department of Pharmacology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
| | - Ghassan Bkaily
- Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
- Department of Pharmacology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
| | - Fernand Gobeil
- Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
- Department of Pharmacology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
| | - Danielle Jacques
- Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
- Department of Pharmacology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
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35
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Bkaily G, Jacques D. L-type calcium channel antagonists and suppression of expression of plasminogen receptors: is the missing link the L-type calcium channel? Circ Res 2009; 105:112-3. [PMID: 19608988 DOI: 10.1161/circresaha.109.202028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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