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Fan Q, Hadla M, Peterson Z, Nelson G, Ye H, Wang X, Mardirossian JM, Harris PC, Alper SL, Prakash YS, Beyder A, Torres VE, Chebib FT. Activation of Piezo1 Inhibits Kidney Cystogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.11.593717. [PMID: 38766249 PMCID: PMC11101129 DOI: 10.1101/2024.05.11.593717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
The disruption of calcium signaling associated with polycystin deficiency has been proposed as the primary event underlying the increased abnormally patterned epithelial cell growth characteristic of Polycystic Kidney Disease. Calcium can be regulated through mechanotransduction, and the mechanosensitive cation channel Piezo1 has been implicated in sensing of intrarenal pressure and in urinary osmoregulation. However, a possible role for PIEZO1 in kidney cystogenesis remains undefined. We hypothesized that cystogenesis in ADPKD reflects altered mechanotransduction, suggesting activation of mechanosensitive cation channels as a therapeutic strategy for ADPKD. Here, we show that Yoda-1 activation of PIEZO1 increases intracellular Ca 2+ and reduces forskolin-induced cAMP levels in mIMCD3 cells. Yoda-1 reduced forskolin-induced IMCD cyst surface area in vitro and in mouse metanephros ex vivo in a dose-dependent manner. Knockout of polycystin-2 dampened the efficacy of PIEZO1 activation in reducing both cAMP levels and cyst surface area in IMCD3 cells. However, collecting duct-specific Piezo1 knockout neither induced cystogenesis in wild-type mice nor affected cystogenesis in the Pkd1 RC/RC model of ADPKD. Our study suggests that polycystin-2 and PIEZO1 play a role in mechanotransduction during cystogenesis in vitro , and ex vivo , but that in vivo cyst expansion may require inactivation or repression of additional suppressors of cystogenesis and/or growth. Our study provides a preliminary proof of concept for PIEZO1 activation as a possible component of combination chemotherapy to retard or halt cystogenesis and/or cyst growth.
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Davis MJ, Earley S, Li YS, Chien S. Vascular mechanotransduction. Physiol Rev 2023; 103:1247-1421. [PMID: 36603156 PMCID: PMC9942936 DOI: 10.1152/physrev.00053.2021] [Citation(s) in RCA: 43] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 09/26/2022] [Accepted: 10/04/2022] [Indexed: 01/07/2023] Open
Abstract
This review aims to survey the current state of mechanotransduction in vascular smooth muscle cells (VSMCs) and endothelial cells (ECs), including their sensing of mechanical stimuli and transduction of mechanical signals that result in the acute functional modulation and longer-term transcriptomic and epigenetic regulation of blood vessels. The mechanosensors discussed include ion channels, plasma membrane-associated structures and receptors, and junction proteins. The mechanosignaling pathways presented include the cytoskeleton, integrins, extracellular matrix, and intracellular signaling molecules. These are followed by discussions on mechanical regulation of transcriptome and epigenetics, relevance of mechanotransduction to health and disease, and interactions between VSMCs and ECs. Throughout this review, we offer suggestions for specific topics that require further understanding. In the closing section on conclusions and perspectives, we summarize what is known and point out the need to treat the vasculature as a system, including not only VSMCs and ECs but also the extracellular matrix and other types of cells such as resident macrophages and pericytes, so that we can fully understand the physiology and pathophysiology of the blood vessel as a whole, thus enhancing the comprehension, diagnosis, treatment, and prevention of vascular diseases.
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Affiliation(s)
- Michael J Davis
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri
| | - Scott Earley
- Department of Pharmacology, University of Nevada, Reno, Nevada
| | - Yi-Shuan Li
- Department of Bioengineering, University of California, San Diego, California
- Institute of Engineering in Medicine, University of California, San Diego, California
| | - Shu Chien
- Department of Bioengineering, University of California, San Diego, California
- Institute of Engineering in Medicine, University of California, San Diego, California
- Department of Medicine, University of California, San Diego, California
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3
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Cui Y, Gollasch M, Kassmann M. Arterial myogenic response and aging. Ageing Res Rev 2023; 84:101813. [PMID: 36470339 DOI: 10.1016/j.arr.2022.101813] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 11/21/2022] [Accepted: 11/29/2022] [Indexed: 12/12/2022]
Abstract
The arterial myogenic response is an inherent property of resistance arteries. Myogenic tone is crucial for maintaining a relatively constant blood flow in response to changes in intraluminal pressure and protects delicate organs from excessive blood flow. Although this fundamental physiological phenomenon has been extensively studied, the underlying molecular mechanisms are largely unknown. Recent studies identified a crucial role of mechano-activated angiotensin II type 1 receptors (AT1R) in this process. The development of myogenic response is affected by aging. In this review, we summarize recent progress made to understand the role of AT1R and other mechanosensors in the control of arterial myogenic response. We discuss age-related alterations in myogenic response and possible underlying mechanisms and implications for healthy aging.
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Affiliation(s)
- Yingqiu Cui
- Charité - Universitätsmedizin Berlin, Experimental and Clinical Research Center (ECRC), a joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine (MDC), Lindenberger Weg 80, 13125 Berlin, Germany
| | - Maik Gollasch
- Department of Internal Medicine and Geriatrics, University Medicine Greifswald, Felix-Hausdorff-Straße 3, 17487 Greifswald, Germany
| | - Mario Kassmann
- Department of Internal Medicine and Geriatrics, University Medicine Greifswald, Felix-Hausdorff-Straße 3, 17487 Greifswald, Germany.
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4
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Yamaguchi Y, Nishiyama M, Kai H, Kaneko T, Kaihara K, Iribe G, Takai A, Naruse K, Morimatsu M. High hydrostatic pressure induces slow contraction in mouse cardiomyocytes. Biophys J 2022; 121:3286-3294. [PMID: 35841143 PMCID: PMC9463647 DOI: 10.1016/j.bpj.2022.07.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 05/26/2022] [Accepted: 07/11/2022] [Indexed: 11/28/2022] Open
Abstract
Cardiomyocytes are contractile cells that regulate heart contraction. Ca2+ flux via Ca2+ channels activates actomyosin interactions, leading to cardiomyocyte contraction, which is modulated by physical factors (e.g., stretch, shear stress, and hydrostatic pressure). We evaluated the mechanism triggering slow contractions using a high-pressure microscope to characterize changes in cell morphology and intracellular Ca2+ concentration ([Ca2+]i) in mouse cardiomyocytes exposed to high hydrostatic pressures. We found that cardiomyocytes contracted slowly without an acute transient increase in [Ca2+]i, while a myosin ATPase inhibitor interrupted pressure-induced slow contractions. Furthermore, transmission electron microscopy showed that, although the sarcomere length was shortened upon the application of 20 MPa, this pressure did not collapse cellular structures such as the sarcolemma and sarcomeres. Our results suggest that pressure-induced slow contractions in cardiomyocytes are driven by the activation of actomyosin interactions without an acute transient increase in [Ca2+]i.
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Affiliation(s)
- Yohei Yamaguchi
- Department of Cardiovascular Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan; Department of Physiology, Asahikawa Medical University, Asahikawa, Hokkaido, Japan.
| | - Masayoshi Nishiyama
- Department of Physics, Faculty of Science and Engineering, Kindai University, Higashiosaka, Osaka, Japan
| | - Hiroaki Kai
- Department of Cardiovascular Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Toshiyuki Kaneko
- Department of Physiology, Asahikawa Medical University, Asahikawa, Hokkaido, Japan
| | - Keiko Kaihara
- Department of Cardiovascular Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Gentaro Iribe
- Department of Cardiovascular Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan; Department of Physiology, Asahikawa Medical University, Asahikawa, Hokkaido, Japan
| | - Akira Takai
- Department of Physiology, Asahikawa Medical University, Asahikawa, Hokkaido, Japan
| | - Keiji Naruse
- Department of Cardiovascular Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Masatoshi Morimatsu
- Department of Cardiovascular Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan.
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Fallah HP, Ahuja E, Lin H, Qi J, He Q, Gao S, An H, Zhang J, Xie Y, Liang D. A Review on the Role of TRP Channels and Their Potential as Drug Targets_An Insight Into the TRP Channel Drug Discovery Methodologies. Front Pharmacol 2022; 13:914499. [PMID: 35685622 PMCID: PMC9170958 DOI: 10.3389/fphar.2022.914499] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 04/27/2022] [Indexed: 01/13/2023] Open
Abstract
Transient receptor potential (TRP) proteins are a large group of ion channels that control many physiological functions in our body. These channels are considered potential therapeutic drug targets for various diseases such as neurological disorders, cancers, cardiovascular disease, and many more. The Nobel Prize in Physiology/Medicine in the year 2021 was awarded to two scientists for the discovery of TRP and PIEZO ion channels. Improving our knowledge of technologies for their study is essential. In the present study, we reviewed the role of TRP channel types in the control of normal physiological functions as well as disease conditions. Also, we discussed the current and novel technologies that can be used to study these channels successfully. As such, Flux assays for detecting ionic flux through ion channels are among the core and widely used tools for screening drug compounds. Technologies based on these assays are available in fully automated high throughput set-ups and help detect changes in radiolabeled or non-radiolabeled ionic flux. Aurora’s Ion Channel Reader (ICR), which works based on label-free technology of flux assay, offers sensitive, accurate, and reproducible measurements to perform drug ranking matching with patch-clamp (gold standard) data. The non-radiolabeled trace-based flux assay coupled with the ICR detects changes in various ion types, including potassium, calcium, sodium, and chloride channels, by using appropriate tracer ions. This technology is now considered one of the very successful approaches for analyzing ion channel activity in modern drug discovery. It could be a successful approach for studying various ion channels and transporters, including the different members of the TRP family of ion channels.
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Affiliation(s)
- Hamideh P Fallah
- Aurora Biomed Inc., Vancouver, BC, Canada
- *Correspondence: Hamideh P Fallah,
| | - Ekta Ahuja
- Aurora Biomed Inc., Vancouver, BC, Canada
| | | | - Jinlong Qi
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China
| | - Qian He
- Aurora Discovery Inc., Foshan, China
| | - Shan Gao
- Aurora Discovery Inc., Foshan, China
| | | | | | | | - Dong Liang
- Aurora Biomed Inc., Vancouver, BC, Canada
- Aurora Discovery Inc., Foshan, China
- Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
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6
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Wagdi A, Malan D, Sathyanarayanan U, Beauchamp JS, Vogt M, Zipf D, Beiert T, Mansuroglu B, Dusend V, Meininghaus M, Schneider L, Kalthof B, Wiegert JS, König GM, Kostenis E, Patejdl R, Sasse P, Bruegmann T. Selective optogenetic control of G q signaling using human Neuropsin. Nat Commun 2022; 13:1765. [PMID: 35365606 PMCID: PMC8975936 DOI: 10.1038/s41467-022-29265-w] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 03/03/2022] [Indexed: 01/07/2023] Open
Abstract
Gq proteins are universally important for signal transduction in mammalian cells. The underlying kinetics and transformation from extracellular stimuli into intracellular signaling, however could not be investigated in detail so far. Here we present the human Neuropsin (hOPN5) for specific and repetitive manipulation of Gq signaling in vitro and in vivo with high spatio-temporal resolution. Properties and G protein specificity of hOPN5 are characterized by UV light induced IP3 generation, Ca2+ transients and inhibition of GIRK channel activity in HEK cells. In adult hearts from a transgenic animal model, light increases the spontaneous beating rate. In addition, we demonstrate light induced contractions in the small intestine, which are not detectable after pharmacological Gq protein block. All-optical high-throughput screening for TRPC6 inhibitors is more specific and sensitive than conventional pharmacological screening. Thus, we demonstrate specific Gq signaling of hOPN5 and unveil its potential for optogenetic applications.
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Affiliation(s)
- Ahmed Wagdi
- grid.411984.10000 0001 0482 5331Institute for Cardiovascular Physiology, University Medical Center Göttingen, Göttingen, Germany ,grid.452396.f0000 0004 5937 5237German Center for Cardiovascular Research (DZHK), Partner site Göttingen, Göttingen, Germany ,grid.7450.60000 0001 2364 4210Present Address: Department of Cardiology and Pulmonology, University Medical Center Göttingen, Georg August University of Göttingen, Göttingen, Germany
| | - Daniela Malan
- grid.10388.320000 0001 2240 3300Institute of Physiology I, Medical Faculty, University of Bonn, Bonn, Germany
| | - Udhayabhaskar Sathyanarayanan
- grid.411984.10000 0001 0482 5331Institute for Cardiovascular Physiology, University Medical Center Göttingen, Göttingen, Germany
| | - Janosch S. Beauchamp
- grid.411984.10000 0001 0482 5331Institute for Cardiovascular Physiology, University Medical Center Göttingen, Göttingen, Germany
| | - Markus Vogt
- grid.411984.10000 0001 0482 5331Institute for Cardiovascular Physiology, University Medical Center Göttingen, Göttingen, Germany
| | - David Zipf
- grid.411984.10000 0001 0482 5331Institute for Cardiovascular Physiology, University Medical Center Göttingen, Göttingen, Germany
| | - Thomas Beiert
- grid.15090.3d0000 0000 8786 803XDepartment of Internal Medicine II, University Hospital Bonn, University of Bonn, Bonn, Germany
| | - Berivan Mansuroglu
- grid.10388.320000 0001 2240 3300Institute of Physiology I, Medical Faculty, University of Bonn, Bonn, Germany ,grid.10388.320000 0001 2240 3300Research Training Group 1873, University of Bonn, Bonn, Germany
| | - Vanessa Dusend
- grid.10388.320000 0001 2240 3300Institute of Physiology I, Medical Faculty, University of Bonn, Bonn, Germany ,grid.10388.320000 0001 2240 3300Research Training Group 1873, University of Bonn, Bonn, Germany
| | - Mark Meininghaus
- grid.420044.60000 0004 0374 4101Bayer AG, Research & Development, Pharmaceuticals, 42096 Wuppertal, Germany
| | - Linn Schneider
- grid.420044.60000 0004 0374 4101Bayer AG, Research & Development, Pharmaceuticals, 42096 Wuppertal, Germany
| | - Bernd Kalthof
- grid.420044.60000 0004 0374 4101Bayer AG, Research & Development, Pharmaceuticals, 42096 Wuppertal, Germany
| | - J. Simon Wiegert
- grid.13648.380000 0001 2180 3484Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Gabriele M. König
- grid.10388.320000 0001 2240 3300Molecular, Cellular and Pharmacobiology Section, Institute of Pharmaceutical Biology, University of Bonn, Bonn, Germany
| | - Evi Kostenis
- grid.10388.320000 0001 2240 3300Molecular, Cellular and Pharmacobiology Section, Institute of Pharmaceutical Biology, University of Bonn, Bonn, Germany
| | - Robert Patejdl
- grid.413108.f0000 0000 9737 0454Oscar-Langendorff Institute of Physiology, Rostock University Medical Center, Rostock, Germany
| | - Philipp Sasse
- grid.10388.320000 0001 2240 3300Institute of Physiology I, Medical Faculty, University of Bonn, Bonn, Germany
| | - Tobias Bruegmann
- grid.411984.10000 0001 0482 5331Institute for Cardiovascular Physiology, University Medical Center Göttingen, Göttingen, Germany ,grid.452396.f0000 0004 5937 5237German Center for Cardiovascular Research (DZHK), Partner site Göttingen, Göttingen, Germany ,grid.10388.320000 0001 2240 3300Institute of Physiology I, Medical Faculty, University of Bonn, Bonn, Germany ,grid.10388.320000 0001 2240 3300Research Training Group 1873, University of Bonn, Bonn, Germany ,grid.7450.60000 0001 2364 4210Cluster of Excellence “Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells” (MBExC), University of Göttingen, Göttingen, Germany
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7
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Sancho M, Fletcher J, Welsh DG. Inward Rectifier Potassium Channels: Membrane Lipid-Dependent Mechanosensitive Gates in Brain Vascular Cells. Front Cardiovasc Med 2022; 9:869481. [PMID: 35419431 PMCID: PMC8995785 DOI: 10.3389/fcvm.2022.869481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 02/28/2022] [Indexed: 11/13/2022] Open
Abstract
Cerebral arteries contain two primary and interacting cell types, smooth muscle (SMCs) and endothelial cells (ECs), which are each capable of sensing particular hemodynamic forces to set basal tone and brain perfusion. These biomechanical stimuli help confer tone within arterial networks upon which local neurovascular stimuli function. Tone development is intimately tied to arterial membrane potential (VM) and changes in intracellular [Ca2+] driven by voltage-gated Ca2+ channels (VGCCs). Arterial VM is in turn set by the dynamic interplay among ion channel species, the strongly inward rectifying K+ (Kir) channel being of special interest. Kir2 channels possess a unique biophysical signature in that they strongly rectify, display negative slope conductance, respond to elevated extracellular K+ and are blocked by micromolar Ba2+. While functional Kir2 channels are expressed in both smooth muscle and endothelium, they lack classic regulatory control, thus are often viewed as a simple background conductance. Recent literature has provided new insight, with two membrane lipids, phosphatidylinositol 4,5-bisphosphate (PIP2) and cholesterol, noted to (1) stabilize Kir2 channels in a preferred open or closed state, respectively, and (2) confer, in association with the cytoskeleton, caveolin-1 (Cav1) and syntrophin, hemodynamic sensitivity. It is these aspects of vascular Kir2 channels that will be the primary focus of this review.
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Affiliation(s)
- Maria Sancho
- Department of Pharmacology, University of Vermont, Burlington, VT, United States
- Department of Physiology, Faculty of Medicine, Universidad Complutense de Madrid, Madrid, Spain
- *Correspondence: Maria Sancho,
| | - Jacob Fletcher
- Department of Physiology and Pharmacology, Robarts Research Institute, University of Western Ontario, London, ON, Canada
| | - Donald G. Welsh
- Department of Physiology and Pharmacology, Robarts Research Institute, University of Western Ontario, London, ON, Canada
- Donald G. Welsh,
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Sroubek J, Matos J, Locke A, Kaplinskiy V, Levine YC, Shen C, Buxton AE. N-terminal pro-B-type natriuretic peptide is a specific predictor of appropriate device therapies in patients with primary prevention implantable cardioverter-defibrillators. Heart Rhythm 2020; 18:71-78. [PMID: 32866691 DOI: 10.1016/j.hrthm.2020.08.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 08/21/2020] [Accepted: 08/23/2020] [Indexed: 11/24/2022]
Abstract
BACKGROUND Sudden death risk stratification of patients with left ventricular systolic dysfunction remains challenging. Retrospective studies have suggested N-terminal pro-B-type natriuretic peptide (NT-proBNP) may be a useful risk stratification tool. OBJECTIVE The purpose of this study was to ascertain the utility of NT-proBNP as a predictor of appropriate implantable cardioverter-defibrillator (ICD) therapies in primary prevention ICD recipients. METHODS This was a prospective study of 342 stable patients with left ventricular ejection fraction ≤40% who received a primary prevention ICD. NT-proBNP assay was performed at the time of device implant and used as a dichotomized variable (1st-3rd NT-proBNP quartiles vs 4th NT-proBNP quartile) to predict primary (appropriate ICD therapies) and secondary (death, ICD-deactivation, chronic inotropic support, transplant) outcomes. RESULTS Median follow-up was 35.0 months (interquartile range 15.2-55.3). In unadjusted analyses, NT-proBNP predicted both primary (hazard ratio [HR] 1.89; 95% confidence interval [CI] 1.00-3.56); P = .049) and secondary outcomes (HR 2.13; 95% CI 1.18-3.85; P =.012). Multivariable analysis reaffirmed NT-proBNP as a primary outcome predictor (HR 4.31; 95% CI 1.92-9.70; P <.001) but not as a secondary outcome predictor (HR 1.23; 95% CI 0.61-2.50; P = .564). Instead, secondary outcome was predicted by patient age and renal function. In an unadjusted subanalysis limited to patients with blood urea nitrogen <30 mg/dL, NT-proBNP remained a primary endpoint predictor (HR 2.51; 95% CI 1.25-5.05; P = .010) but not a secondary endpoint predictor (HR 1.34; 95% CI 0.52-3.44; P = .541). Receiver operating analyses at 2- and 3-year follow-up timepoints confirmed that NT-proBNP significantly improved the performance of multivariable models designed to predict future appropriate ICD therapies. CONCLUSION In multivariable analysis, NT-proBNP is a reasonable and specific predictor of future appropriate device therapies in primary prevention ICD recipients. In contrast, adjusted NT-proBNP does not predict all-cause mortality.
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Affiliation(s)
- Jakub Sroubek
- Harvard-Thorndike Electrophysiology Institute, Cardiovascular Division, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Jason Matos
- Cardiovascular Division, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Andrew Locke
- Harvard-Thorndike Electrophysiology Institute, Cardiovascular Division, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Vladimir Kaplinskiy
- Cardiovascular Division, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Yehoshua C Levine
- University of Tennessee Health Sciences Center, Memphis, Tennessee; Methodist le Bonheur Healthcare, Memphis, Tennessee
| | - Changyu Shen
- Smith Center for Outcomes Research in Cardiology, Cardiovascular Division, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Alfred E Buxton
- Harvard-Thorndike Electrophysiology Institute, Cardiovascular Division, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts.
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9
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Yin MZ, Kim HJ, Suh EY, Zhang YH, Yoo HY, Kim SJ. Endurance exercise training restores atrophy-induced decreases of myogenic response and ionic currents in rat skeletal muscle artery. J Appl Physiol (1985) 2019; 126:1713-1724. [DOI: 10.1152/japplphysiol.00962.2018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Atrophic limbs exhibit decreased blood flow and histological changes in the arteries perfusing muscles. However, the effect of atrophy on vascular smooth muscle function is poorly understood. Here, we investigated the effect of unilateral sciatic denervation on the myogenic response (MR) and the ionic currents in deep femoral artery (DFA) smooth muscles from Sprague-Dawley rats. Because denervated rats were capable of treadmill exercise (20 m/min, 30 min, 3 times/wk), the impact of exercise training on these effects was also assessed. Skeletal arteries were harvested 3 or 5 wk after surgery. Then skeletal arteries or myocytes were subjected to video analysis of pressurized artery, myography, whole-cell patch clamp, and real-time quantitative PCR to determine the effect of hindlimb paralysis in the presence/absence of exercise training on MR, contractility, ionic currents, and channel transcription, respectively. In sedentary rats, atrophy was associated with loss of MR in the DFA at 5 wk. The contralateral DFA had a normal MR. At 5 wk after surgery, DFA myocytes from the atrophic limbs exhibited depressed L-type Ca2+currents, GTPγS-induced transient receptor potential cation channel (TRPC)-like currents, 80 mM KCl-induced vasoconstriction, TRPC6 mRNA, and voltage-gated K+and inwardly rectifying K+currents. Exercise training abrogated the differences in all of these functions between atrophic side and contralateral side DFA myocytes. These results suggest that a probable increase in hemodynamic stimuli in skeletal artery smooth muscle plays an important role in maintaining MR and ionic currents in skeletal artery smooth muscle. This may also explain the observed benefits of exercise in patients with limb paralysis.NEW & NOTEWORTHY Myogenic responses (MRs) in rat skeletal arteries feeding the unilateral atrophic hindlimb were impaired. In addition, the L-type Ca2+channel current, the TRPC6-like current, and TRPC6 mRNA levels in the corresponding myocytes decreased. Voltage-gated K+channel currents and inwardly rectifying K+channel currents were also attenuated in atrophic side myocytes. Exercise training effectively abrogated electrophysiological dysfunction of atrophic side myocytes and prevented loss of the MR.
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Affiliation(s)
- Ming Zhe Yin
- Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Hae Jin Kim
- Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Eun Yeong Suh
- Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Yin Hua Zhang
- Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, Republic of Korea
- Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Hae Young Yoo
- Chung-Ang University Red Cross College of Nursing, Seoul, Republic of Korea
| | - Sung Joon Kim
- Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, Republic of Korea
- Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul, Republic of Korea
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10
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Izumisawa Y, Tanaka-Yamamoto K, Ciriello J, Kitamura N, Shibuya I. Persistent cytosolic Ca 2+ increase induced by angiotensin II at nanomolar concentrations in acutely dissociated subfornical organ (SFO) neurons of rats. Brain Res 2019; 1718:137-147. [PMID: 31085158 DOI: 10.1016/j.brainres.2019.05.014] [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] [Received: 01/10/2019] [Revised: 04/23/2019] [Accepted: 05/11/2019] [Indexed: 10/26/2022]
Abstract
It is known that angiotensin II (AII) is sensed by subfornical organ (SFO) to induce drinking behaviors and autonomic changes. AII at picomolar concentrations have been shown to induce Ca2+ oscillations and increase in the amplitude and frequency of spontaneous Ca2+ oscillations in SFO neurons. The present study was conducted to examine effects of nanomolar concentrations of AII using the Fura-2 Ca2+-imaging technique in acutely dissociated SFO neurons. AII at nanomolar concentrations induced an initial [Ca2+]i peak followed by a persistent [Ca2+]i increase lasting for longer than 1 hour. By contrast, [Ca2+]i responses to 50 mM K+, maximally effective concentrations of glutamate, carbachol, and vasopressin, and AII given at picomolar concentrations returned to the basal level within 20 min. The AII-induced [Ca2+]i increase was blocked by the AT1 antagonist losartan. However, losartan had no effect when added during the persistent phase. The persistent phase was suppressed by extracellular Ca2+ removal, significantly inhibited by blockers of L and P/Q type Ca2+ channels , but unaffected by inhibition of Ca2+ store Ca2+ ATPase. The persistent phase was reversibly suppressed by GABA and inhibited by CaMK and PKC inhibitors. These results suggest that the persistent [Ca2+]i increase evoked by nanomolar concentrations of AII is initiated by AT1 receptor activation and maintained by Ca2+ entry mechanisms in part through L and P/Q type Ca2+ channels, and that CaMK and PKC are involved in this process. The persistent [Ca2+]i increase induced by AII at high pathophysiological levels may have a significant role in altering SFO neuronal functions.
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Affiliation(s)
- Yu Izumisawa
- Department of Veterinary Physiology, Faculty of Agriculture, Tottori University, Tottori 680-0945, Japan
| | - Keiko Tanaka-Yamamoto
- Center for Functional Connectomics, Korea Institute of Science and Technology, Seoul 136-791, Republic of Korea
| | - John Ciriello
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario N6A 5C1, Canada
| | - Naoki Kitamura
- Department of Veterinary Physiology, Faculty of Agriculture, Tottori University, Tottori 680-0945, Japan
| | - Izumi Shibuya
- Department of Veterinary Physiology, Faculty of Agriculture, Tottori University, Tottori 680-0945, Japan.
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11
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Abstract
The human cerebral vasculature originates in the fourth week of gestation and continues to expand and diversify well into the first few years of postnatal life. A key feature of this growth is smooth muscle differentiation, whereby smooth muscle cells within cerebral arteries transform from migratory to proliferative to synthetic and finally to contractile phenotypes. These phenotypic transformations can be reversed by pathophysiological perturbations such as hypoxia, which causes loss of contractile capacity in immature cerebral arteries. In turn, loss of contractility affects all whole-brain cerebrovascular responses, including those involved in flow-metabolism coupling, vasodilatory responses to acute hypoxia and hypercapnia, cerebral autoregulation, and reactivity to activation of perivascular nerves. Future strategies to minimize cerebral injury following hypoxia-ischemic insults in the immature brain might benefit by targeting treatments to preserve and promote contractile differentiation in the fetal cerebrovasculature. This could potentially be achieved through inhibition of receptor tyrosine kinase-mediated growth factors, such as vascular endothelial growth factor and platelet-derived growth factor, which are mobilized by hypoxic and ischemic injury and which facilitate contractile dedifferentiation. Interruption of the effects of other vascular mitogens, such as endothelin and angiotensin-II, and even some miRNA species, also could be beneficial. Future experimental work that addresses these possibilities offers promise to improve current clinical management of neonates who have suffered and survived hypoxic, ischemic, asphyxic, or inflammatory cerebrovascular insults.
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Affiliation(s)
- William J Pearce
- From the Center for Perinatal Biology, Loma Linda University School of Medicine, Loma Linda, CA.
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12
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Dryer SE, Kim EY. Permeation and Rectification in Canonical Transient Receptor Potential-6 (TRPC6) Channels. Front Physiol 2018; 9:1055. [PMID: 30123138 PMCID: PMC6085515 DOI: 10.3389/fphys.2018.01055] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 07/16/2018] [Indexed: 01/25/2023] Open
Abstract
Transient receptor potential-6 channels are widely expressed cation channels that play a role in regulating Ca2+ dynamics, especially during G protein-coupled receptor signaling. The permeation of cations through TRPC6 is complex and the relative permeability to Ca2+ relative to monovalent cations appears to be highly voltage-dependent and is reduced upon membrane depolarization. Many investigators have observed complex current-voltage (I-V) relationships in recordings of TRPC6 channels, which often manifest as flattening of I-V curves between 0 and +40 mV and negative to -60 mV. These features are especially common in recordings from TRPC6 channels expressed in heterologous expression systems. Indeed, it is sometimes argued that marked rectification at both negative and positive membrane potentials is a defining feature of TRPC6, and that recordings in which these features are reduced or absent cannot reflect activity of TRPC6. Here we present a review of the literature to show that complex rectification is not seen in every cell type expressing TRPC6, even when comparing recordings made from the same groups of investigators, or in recordings from what is nominally the same heterologous expression system. Therefore other criteria, such as gene knockout or knockdown, or the use of newly emerging selective blockers, must be used to ascertain that a given current reflects activity of endogenously expressed TRPC6 channels. We also discuss the possibility that complex rectification may not be an intrinsic property of TRPC6 in cells where it is observed, and may instead reflect presence of endogenous substances that cause voltage-dependent inhibition of the channels.
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Affiliation(s)
- Stuart E Dryer
- Department of Biology and Biochemistry, University of Houston, Houston, TX, United States.,Department of Medicine, Division of Nephrology, Baylor College of Medicine, Houston, TX, United States
| | - Eun Young Kim
- Department of Biology and Biochemistry, University of Houston, Houston, TX, United States
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13
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Abstract
Mechanoreceptors mediate a wide variety of physiological processes, such as hearing, touch, proprioception, and blood flow regulation. It is generally believed that mechanoreceptors are force-gated ion channels. Now, Xu et al. uncover a GPCR that is activated by shear force in endothelial cells of blood vessels.
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14
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Sachs F. Mechanical Transduction and the Dark Energy of Biology. Biophys J 2018; 114:3-9. [PMID: 29320693 PMCID: PMC5984904 DOI: 10.1016/j.bpj.2017.10.035] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 09/26/2017] [Accepted: 10/11/2017] [Indexed: 12/27/2022] Open
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15
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Liang M, Zhong W, Miao F, Wu H, Liu Y. Effects of losartan on vasomotor function and canonical transient receptor potential channels in the aortas of sinoaortic denervation rats. Clin Exp Hypertens 2017; 40:39-48. [PMID: 29072489 DOI: 10.1080/10641963.2017.1299746] [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] [Indexed: 01/19/2023]
Abstract
Increased short-term blood pressure variability (BPV) is strongly correlated with target organ damage. However, the molecular mechanisms underlying abnormal BPV-induced organ damage and effective therapeutic targets are poorly understood. The purpose of this study was to investigate the effects of losartan on vasomotor function and canonical transient receptor potential (TRPC) channels in the aortas of rats with arterial pressure lability induced by sinoaortic denervation (SAD). SAD was performed in male Sprague-Dawley rats at the age of 10 weeks. The experiment included sham-operated (Sham), SAD, and losartan-treated SAD (SAD+Los) groups. After 8 weeks of treatment, hemodynamic parameters were measured via catheterization, thoracic aortic vasomotor functions were evaluated using a physiological vascular ring tension recording system, and TRPC1 and 6 mRNA and protein expression levels in the endothelial cells (ECs) and smooth muscle cells (SMCs) of the thoracic aorta were determined via reverse transcription polymerase chain reaction (RT-PCR) and Western-blotting, respectively. Compared with Sham rats, SAD rats exhibited significantly increased BPV, enhanced norepinephrine-induced aortic contraction, and attenuated acetylcholine-induced aortic relaxation. Both the mRNA and the protein expression levels of TRPC1 and 6 were significantly downregulated in the ECs and upregulated in the SMCs of the thoracic aortas of SAD rats. Losartan treatment prevented these SAD-induced changes. In conclusion, losartan efficiently prevented vasomotor function impairment in SAD rats by reducing BPV and regulating TRPC1 and 6 expression levels.
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Affiliation(s)
- Minlie Liang
- a Department of Cardiology , Zhujiang Hospital Affiliated to Southern Medical University , Guangzhou , Guangdong Province , P.R. China.,b Department of Cardiology , The First Hospital of Nanping , Nanping , Fujian Province , P.R. China
| | - Wenliang Zhong
- b Department of Cardiology , The First Hospital of Nanping , Nanping , Fujian Province , P.R. China
| | - Fei Miao
- a Department of Cardiology , Zhujiang Hospital Affiliated to Southern Medical University , Guangzhou , Guangdong Province , P.R. China
| | - Hongchao Wu
- a Department of Cardiology , Zhujiang Hospital Affiliated to Southern Medical University , Guangzhou , Guangdong Province , P.R. China
| | - Yingfeng Liu
- a Department of Cardiology , Zhujiang Hospital Affiliated to Southern Medical University , Guangzhou , Guangdong Province , P.R. China
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16
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Lindström JB, Pierce NT, Latz MI. Role of TRP Channels in Dinoflagellate Mechanotransduction. THE BIOLOGICAL BULLETIN 2017; 233:151-167. [PMID: 29373067 DOI: 10.1086/695421] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Transient receptor potential (TRP) ion channels are common components of mechanosensing pathways, mainly described in mammals and other multicellular organisms. To gain insight into the evolutionary origins of eukaryotic mechanosensory proteins, we investigated the involvement of TRP channels in mechanosensing in a unicellular eukaryotic protist, the dinoflagellate Lingulodinium polyedra. BLASTP analysis of the protein sequences predicted from the L. polyedra transcriptome revealed six sequences with high similarity to human TRPM2, TRPM8, TRPML2, TRPP1, and TRPP2; and characteristic TRP domains were identified in all sequences. In a phylogenetic tree including all mammalian TRP subfamilies and TRP channel sequences from unicellular and multicellular organisms, the L. polyedra sequences grouped with the TRPM, TPPML, and TRPP clades. In pharmacological experiments, we used the intrinsic bioluminescence of L. polyedra as a reporter of mechanoresponsivity. Capsaicin and RN1734, agonists of mammalian TRPV, and arachidonic acid, an agonist of mammalian TRPV, TRPA, TRPM, and Drosophila TRP, all stimulated bioluminescence in L. polyedra. Mechanical stimulation of bioluminescence, but not capsaicin-stimulated bioluminescence, was inhibited by gadolinium (Gd3+), a general inhibitor of mechanosensitive ion channels, and the phospholipase C (PLC) inhibitor U73122. These pharmacological results are consistent with the involvement of TRP-like channels in mechanosensing by L. polyedra. The TRP channels do not appear to be mechanoreceptors but rather are components of the mechanotransduction signaling pathway and may be activated via a PLC-dependent mechanism. The presence and function of TRP channels in a dinoflagellate emphasize the evolutionary conservation of both the channel structures and their functions.
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Key Words
- AA, amino acids
- AMTB hydrochloride, N-(3-Aminopropyl)-2-[(3-methylphenyl)methoxy]-N-(2-thienylmethyl)benzamide hydrochloride
- Ce, Caenorhabditis elegans
- Cr, Chlamydomonas reinhardtii
- DMSO, dimethyl sulfoxide
- Dm, Drosophila melanogaster
- Dr, Danio rerio
- FSW, filtered seawater
- Gd3+, gadolinium
- GsMTx4, Grammostola spatulata mechanotoxin 4
- HC067047, 2-Methyl-1-[3-(4-morpholinyl)propyl]-5-phenyl-N-[3-(trifluoromethyl)phenyl]-1H-pyrrole-3-carboxamide
- HMM, Hidden Markov Model
- Hs, Homo sapiens
- Lp, Lingulodinium polyedra
- ML204, 4-Methyl-2-(1-piperidinyl)-quinoline
- Mb, Monosiga brevicollis
- ORF, open reading frame
- PIP2, Phosphatidylinositol 4,5-bisphosphate
- PLC, phospholipase C
- Pt, Paramecium tetraurelia
- RHC80267, O,O′-[1,6-Hexanediylbis(iminocarbonyl)]dioxime cyclohexanone
- RN1734, 2,4-Dichloro-N-isopropyl-N-(2-isopropylaminoethyl)benzenesulfonamide
- RN1747, 1-(4-Chloro-2-nitrophenyl)sulfonyl-4-benzylpiperazine
- TMHMM, transmembrane helix prediction
- TRP, transient receptor potential channel
- U73122, 1-[6-[((17β)-3-Methoxyestra-1,3,5[10]-trien-17-yl)amino]hexyl]-1H-pyrrole-2,5-dione
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18
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Ferreira RR, Vermot J. The balancing roles of mechanical forces during left-right patterning and asymmetric morphogenesis. Mech Dev 2017; 144:71-80. [DOI: 10.1016/j.mod.2016.11.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 11/03/2016] [Indexed: 11/17/2022]
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19
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Riva G, Serino S, Di Lernia D, Pavone EF, Dakanalis A. Embodied Medicine: Mens Sana in Corpore Virtuale Sano. Front Hum Neurosci 2017; 11:120. [PMID: 28360849 PMCID: PMC5352908 DOI: 10.3389/fnhum.2017.00120] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 02/28/2017] [Indexed: 01/31/2023] Open
Abstract
Progress in medical science and technology drastically improved physicians’ ability to interact with patient’s physical body. Nevertheless, medicine still addresses the human body from a Hippocratic point of view, considering the organism and its processes just as a matter of mechanics and fluids. However, the interaction between the cognitive neuroscience of bodily self-consciousness (BSC), fundamentally rooted in the integration of multisensory bodily inputs, with virtual reality (VR), haptic technologies and robotics is giving a new meaning to the classic Juvenal’s latin dictum “Mens sana in corpore sano” (a healthy mind in a healthy body). This vision provides the basis for a new research field, “Embodied Medicine”: the use of advanced technologies for altering the experience of being in a body with the goal of improving health and well-being. Up to now, most of the research efforts in the field have been focused upon how external bodily information is processed and integrated. Despite the important results, we believe that existing bodily illusions still need to be improved to enhance their capability to effectively correct pathological dysfunctions. First, they do not follow the suggestions provided by the free-energy and predictive coding approaches. More, they lacked to consider a peculiar feature of the human body, the multisensory integration of internal inputs (interoceptive, proprioceptive and vestibular) that constitute our inner body dimension. So, a future challenge is the integration of simulation/stimulation technologies also able to measure and modulate this internal/inner experience of the body. Finally, we also proposed the concept of “Sonoception” as an extension of this approach. The core idea is to exploit recent technological advances in the acoustic field to use sound and vibrations to modify the internal/inner body experience.
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Affiliation(s)
- Giuseppe Riva
- Department of Psychology, Università Cattolica del Sacro CuoreMilan, Italy; Applied Technology for Neuro-Psychology Laboratory, Istituto Auxologico ItalianoMilan, Italy
| | - Silvia Serino
- Department of Psychology, Università Cattolica del Sacro CuoreMilan, Italy; Applied Technology for Neuro-Psychology Laboratory, Istituto Auxologico ItalianoMilan, Italy
| | - Daniele Di Lernia
- Department of Psychology, Università Cattolica del Sacro Cuore Milan, Italy
| | - Enea Francesco Pavone
- Fondazione Santa Lucia, Istituto Di Ricovero e Cura a Carattere ScientificoRome, Italy; Braintrends Ltd, Applied NeuroscienceRome, Italy
| | - Antonios Dakanalis
- Department of Brain and Behavioral Sciences, University of PaviaPavia, Italy; Department of Medicine and Surgery, University of Milano-BicoccaMilan, Italy
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20
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Abstract
Prostaglandins are ubiquitous signaling molecules in the body that produce autocrine/paracrine effects on target cells in response to mechanical or chemical signals. In the heart, long-term exposure to prostaglandin (PG) F2α has been linked to the development of hypertrophy; however, there is no consensus on the acute effect of PGF2α. Our aim was to determine the response to exogenous PGF2α in isolated trabeculae from rat hearts. PGF2α (1 μM) increased both the Ca transients and the isometric stress in trabeculae, reaching steady state after 10-15 minutes, without altering the time course of Ca transient decay. The precursor of PGF2α, arachidonic acid, also stimulated a similar response. The positive inotropic effect of PGF2α was mediated through a protein kinase C signaling pathway that involved activation of the sarcolemmal Na/H exchanger. We also found that the slow force response to stretch was attenuated in the presence of PGF2α and by addition of indomethacin, a blocker of prostaglandin synthesis. In conclusion, PGF2α was positively inotropic when acutely applied to trabeculae and contributed to the increased Ca transients during the slow force response to stretch. Together, these data suggest that PGF2α is important in maintaining homeostasis during volume loading in healthy hearts.
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21
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Left ventricular sphericity independently predicts appropriate implantable cardioverter-defibrillator therapy. Heart Rhythm 2015; 13:490-7. [PMID: 26409099 DOI: 10.1016/j.hrthm.2015.09.022] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Indexed: 11/21/2022]
Abstract
BACKGROUND Whether echocardiographic markers of remodeling are associated with ventricular tachyarrhythmias is unknown. OBJECTIVE The purpose of this study was to determine whether a transthoracic echocardiographic (TTE) marker of spherical left ventricular (LV) remodeling is associated with appropriate implantable cardioverter-defibrillator (ICD) therapy in patients with primary prevention ICDs. METHODS From TTE images, we calculated sphericity index (SI), the ratio of biplane LV end-diastolic volume to the volume of a hypothetical sphere with a diameter of the LV end-diastolic length, and examined the relation between SI and therapy for ventricular tachyarrhythmias in 278 patients with primary prevention ICDs and in 50 controls without structural heart disease or ventricular arrhythmias. RESULTS SI in normal healthy adult subjects and in subjects receiving ICDs was 0.44 ± 0.02 and 0.65 ± 0.04, respectively (P <.001). Median time to first appropriate ICD therapy was significantly shorter in ICD patients with SI in the upper vs lower 50% of SI values (1.40 vs 2.38 years, P = .02 for conventional ICD patients; 1.54 vs 2.65 years, P = .02 for cardiac resynchronization therapy-defibrillator [CRT-D] patients). In multivariable Cox regression analysis, SI in the upper 50% was independently associated with appropriate ICD therapy after multivariable adjustment (hazard ratio 2.2, P = .03 for ICD cohort; hazard ratio 4.4, P = .01 for CRT-D cohort). SI was not associated with total mortality in either cohort. CONCLUSION SI is associated with appropriate ICD therapy, but not total mortality, in patients receiving primary prevention ICDs. These observations suggest spherical LV remodeling may predispose to ventricular arrhythmias. Furthermore, SI appears to add predictive accuracy for appropriate ICD therapy in patients with reduced ejection fraction.
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22
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Forst AL, Olteanu VS, Mollet G, Wlodkowski T, Schaefer F, Dietrich A, Reiser J, Gudermann T, Mederos y Schnitzler M, Storch U. Podocyte Purinergic P2X4 Channels Are Mechanotransducers That Mediate Cytoskeletal Disorganization. J Am Soc Nephrol 2015; 27:848-62. [PMID: 26160898 DOI: 10.1681/asn.2014111144] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Accepted: 06/10/2015] [Indexed: 11/03/2022] Open
Abstract
Podocytes are specialized, highly differentiated epithelial cells in the kidney glomerulus that are exposed to glomerular capillary pressure and possible increases in mechanical load. The proteins sensing mechanical forces in podocytes are unconfirmed, but the classic transient receptor potential channel 6 (TRPC6) interacting with the MEC-2 homolog podocin may form a mechanosensitive ion channel complex in podocytes. Here, we observed that podocytes respond to mechanical stimulation with increased intracellular calcium concentrations and increased inward cation currents. However, TRPC6-deficient podocytes responded in a manner similar to that of control podocytes, and mechanically induced currents were unaffected by genetic inactivation of TRPC1/3/6 or administration of the broad-range TRPC blocker SKF-96365. Instead, mechanically induced currents were significantly decreased by the specific P2X purinoceptor 4 (P2X4) blocker 5-BDBD. Moreover, mechanical P2X4 channel activation depended on cholesterol and podocin and was inhibited by stabilization of the actin cytoskeleton. Because P2X4 channels are not intrinsically mechanosensitive, we investigated whether podocytes release ATP upon mechanical stimulation using a fluorometric approach. Indeed, mechanically induced ATP release from podocytes was observed. Furthermore, 5-BDBD attenuated mechanically induced reorganization of the actin cytoskeleton. Altogether, our findings reveal a TRPC channel-independent role of P2X4 channels as mechanotransducers in podocytes.
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Affiliation(s)
- Anna-Lena Forst
- Walther-Straub-Institute of Pharmacology and Toxicology, University of Munich, Munich, Germany
| | - Vlad Sorin Olteanu
- Walther-Straub-Institute of Pharmacology and Toxicology, University of Munich, Munich, Germany
| | - Géraldine Mollet
- INSERM U1163, Laboratory of Hereditary Kidney Diseases, Imagine Institute, Paris, France
| | - Tanja Wlodkowski
- Division of Pediatric Nephrology, Heidelberg University Center for Pediatrics and Adolescent Medicine, Heidelberg, Germany
| | - Franz Schaefer
- Division of Pediatric Nephrology, Heidelberg University Center for Pediatrics and Adolescent Medicine, Heidelberg, Germany
| | - Alexander Dietrich
- Walther-Straub-Institute of Pharmacology and Toxicology, University of Munich, Munich, Germany
| | - Jochen Reiser
- Department of Medicine, Rush University Medical Center, Chicago, Illinois; and
| | - Thomas Gudermann
- Walther-Straub-Institute of Pharmacology and Toxicology, University of Munich, Munich, Germany; DZHK (German Centre for Cardiovascular Research), Munich Heart Alliance, Munich, Germany
| | - Michael Mederos y Schnitzler
- Walther-Straub-Institute of Pharmacology and Toxicology, University of Munich, Munich, Germany; DZHK (German Centre for Cardiovascular Research), Munich Heart Alliance, Munich, Germany
| | - Ursula Storch
- Walther-Straub-Institute of Pharmacology and Toxicology, University of Munich, Munich, Germany
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Abstract
Skeletal loading is an important physiological regulator of bone mass. Theoretically, mechanical forces or administration of drugs that activate bone mechanosensors would be a novel treatment for osteoporotic disorders, particularly age-related osteoporosis and other bone loss caused by skeletal unloading. Uncertainty regarding the identity of the molecular targets that sense and transduce mechanical forces in bone, however, has limited the therapeutic exploitation of mechanosesning pathways to control bone mass. Recently, two evolutionally conserved mechanosensing pathways have been shown to function as "physical environment" sensors in cells of the osteoblasts lineage. Indeed, polycystin-1 (Pkd1, or PC1) and polycystin-2 (Pkd2, or PC2' or TRPP2), which form a flow sensing receptor channel complex, and TAZ (transcriptional coactivator with PDZ-binding motif, or WWTR1), which responds to the extracellular matrix microenvironment act in concert to reciprocally regulate osteoblastogenesis and adipogenesis through co-activating Runx2 and a co-repressing PPARγ activities. Interactions of polycystins and TAZ with other putative mechanosensing mechanism, such as primary cilia, integrins and hemichannels, may create multifaceted mechanosensing networks in bone. Moreover, modulation of polycystins and TAZ interactions identify novel molecular targets to develop small molecules that mimic the effects of mechanical loading on bone.
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Affiliation(s)
- Zhousheng Xiao
- Department of Medicine, University of Tennessee Health Science Center, Memphis, TN 38165, USA
| | - Leigh Darryl Quarles
- Department of Medicine, University of Tennessee Health Science Center, Memphis, TN 38165, USA
- Coleman College of Medicine Building, Suite B216, University of Tennessee Health Science Center, 956 Court Avenue, Memphis, TN 38163, USA
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24
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Humphrey JD, Schwartz MA, Tellides G, Milewicz DM. Role of mechanotransduction in vascular biology: focus on thoracic aortic aneurysms and dissections. Circ Res 2015; 116:1448-61. [PMID: 25858068 PMCID: PMC4420625 DOI: 10.1161/circresaha.114.304936] [Citation(s) in RCA: 259] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Thoracic aortic diseases that involve progressive enlargement, acute dissection, or rupture are influenced by the hemodynamic loads and mechanical properties of the wall. We have only limited understanding, however, of the mechanobiological processes that lead to these potentially lethal conditions. Homeostasis requires that intramural cells sense their local chemomechanical environment and establish, maintain, remodel, or repair the extracellular matrix to provide suitable compliance and yet sufficient strength. Proper sensing, in turn, necessitates both receptors that connect the extracellular matrix to intracellular actomyosin filaments and signaling molecules that transmit the related information to the nucleus. Thoracic aortic aneurysms and dissections are associated with poorly controlled hypertension and mutations in genes for extracellular matrix constituents, membrane receptors, contractile proteins, and associated signaling molecules. This grouping of factors suggests that these thoracic diseases result, in part, from dysfunctional mechanosensing and mechanoregulation of the extracellular matrix by the intramural cells, which leads to a compromised structural integrity of the wall. Thus, improved understanding of the mechanobiology of aortic cells could lead to new therapeutic strategies for thoracic aortic aneurysms and dissections.
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MESH Headings
- Aortic Dissection/genetics
- Aortic Dissection/metabolism
- Aortic Dissection/pathology
- Aortic Dissection/physiopathology
- Aortic Dissection/therapy
- Animals
- Aorta, Thoracic/metabolism
- Aorta, Thoracic/pathology
- Aorta, Thoracic/physiopathology
- Aortic Aneurysm, Thoracic/genetics
- Aortic Aneurysm, Thoracic/metabolism
- Aortic Aneurysm, Thoracic/pathology
- Aortic Aneurysm, Thoracic/physiopathology
- Aortic Aneurysm, Thoracic/therapy
- Aortic Rupture/genetics
- Aortic Rupture/metabolism
- Aortic Rupture/pathology
- Aortic Rupture/physiopathology
- Aortic Rupture/therapy
- Biomechanical Phenomena
- Disease Progression
- Extracellular Matrix Proteins/genetics
- Extracellular Matrix Proteins/metabolism
- Genetic Predisposition to Disease
- Hemodynamics
- Humans
- Mechanotransduction, Cellular
- Phenotype
- Stress, Mechanical
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Affiliation(s)
- Jay D Humphrey
- From the Departments of Biomedical Engineering (J.D.H., M.A.S.), Medicine (Cardiology) (M.A.S.), Cell Biology (M.A.S.), and Surgery (G.T.), Yale University, New Haven, CT; and Department of Internal Medicine, University of Texas Health Science Center, Houston (D.M.M.)
| | - Martin A Schwartz
- From the Departments of Biomedical Engineering (J.D.H., M.A.S.), Medicine (Cardiology) (M.A.S.), Cell Biology (M.A.S.), and Surgery (G.T.), Yale University, New Haven, CT; and Department of Internal Medicine, University of Texas Health Science Center, Houston (D.M.M.)
| | - George Tellides
- From the Departments of Biomedical Engineering (J.D.H., M.A.S.), Medicine (Cardiology) (M.A.S.), Cell Biology (M.A.S.), and Surgery (G.T.), Yale University, New Haven, CT; and Department of Internal Medicine, University of Texas Health Science Center, Houston (D.M.M.)
| | - Dianna M Milewicz
- From the Departments of Biomedical Engineering (J.D.H., M.A.S.), Medicine (Cardiology) (M.A.S.), Cell Biology (M.A.S.), and Surgery (G.T.), Yale University, New Haven, CT; and Department of Internal Medicine, University of Texas Health Science Center, Houston (D.M.M.).
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25
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Zhang XJ, Jiang DS, Li H. The interferon regulatory factors as novel potential targets in the treatment of cardiovascular diseases. Br J Pharmacol 2015; 172:5457-76. [PMID: 25131895 DOI: 10.1111/bph.12881] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 07/26/2014] [Accepted: 08/12/2014] [Indexed: 02/06/2023] Open
Abstract
The family of interferon regulatory factors (IRFs) consists of nine members (IRF1-IRF9) in mammals. They act as transcription factors for the interferons and thus exert essential regulatory functions in the immune system and in oncogenesis. Recent clinical and experimental studies have identified critically important roles of the IRFs in cardiovascular diseases, arising from their participation in divergent and overlapping molecular programmes beyond the immune response. Here we review the current knowledge of the regulatory effects and mechanisms of IRFs on the immune system. The role of IRFs and their potential molecular mechanisms as novel stress sensors and mediators of cardiovascular diseases are highlighted.
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Affiliation(s)
- Xiao-Jing Zhang
- Department of Cardiology, Renmin Hospital, Wuhan University, Wuhan, China.,Cardiovascular Research Institute, Wuhan University, Wuhan, China.,State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China
| | - Ding-Sheng Jiang
- Department of Cardiology, Renmin Hospital, Wuhan University, Wuhan, China.,Cardiovascular Research Institute, Wuhan University, Wuhan, China
| | - Hongliang Li
- Department of Cardiology, Renmin Hospital, Wuhan University, Wuhan, China.,Cardiovascular Research Institute, Wuhan University, Wuhan, China
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26
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Doleschal B, Primessnig U, Wölkart G, Wolf S, Schernthaner M, Lichtenegger M, Glasnov TN, Kappe CO, Mayer B, Antoons G, Heinzel F, Poteser M, Groschner K. TRPC3 contributes to regulation of cardiac contractility and arrhythmogenesis by dynamic interaction with NCX1. Cardiovasc Res 2015; 106:163-73. [PMID: 25631581 PMCID: PMC4362401 DOI: 10.1093/cvr/cvv022] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Aim TRPC3 is a non-selective cation channel, which forms a Ca2+ entry pathway involved in cardiac remodelling. Our aim was to analyse acute electrophysiological and contractile consequences of TRPC3 activation in the heart. Methods and results We used a murine model of cardiac TRPC3 overexpression and a novel TRPC3 agonist, GSK1702934A, to uncover (patho)physiological functions of TRPC3. GSK1702934A induced a transient, non-selective conductance and prolonged action potentials in TRPC3-overexpressing myocytes but lacked significant electrophysiological effects in wild-type myocytes. GSK1702934A transiently enhanced contractility and evoked arrhythmias in isolated Langendorff hearts from TRPC3-overexpressing but not wild-type mice. Interestingly, pro-arrhythmic effects outlasted TRPC3 current activation, were prevented by enhanced intracellular Ca2+ buffering, and suppressed by the NCX inhibitor 3′,4′-dichlorobenzamil hydrochloride. GSK1702934A substantially promoted NCX currents in TRPC3-overexpressing myocytes. The TRPC3-dependent electrophysiologic, pro-arrhythmic, and inotropic actions of GSK1702934A were mimicked by angiotensin II (AngII). Immunocytochemistry demonstrated colocalization of TRPC3 with NCX1 and disruption of local interaction upon channel activation by either GSK1702934A or AngII. Conclusion Cardiac TRPC3 mediates Ca2+ and Na+ entry in proximity of NCX1, thereby elevating cellular Ca2+ levels and contractility. Excessive activation of TRPC3 is associated with transient cellular Ca2+ overload, spatial uncoupling between TRPC3 and NCX1, and arrhythmogenesis. We propose TRPC3-NCX micro/nanodomain communication as determinant of cardiac contractility and susceptibility to arrhythmogenic stimuli.
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Affiliation(s)
| | - Uwe Primessnig
- Department of Cardiology, Medical University of Graz, Graz, Austria Ludwig Boltzmann Institute of Translational Heart Failure Research, Graz, Austria
| | - Gerald Wölkart
- Institute of Pharmaceutical Sciences, University of Graz, Graz, Austria
| | - Stefan Wolf
- Institute of Pharmaceutical Sciences, University of Graz, Graz, Austria
| | - Michaela Schernthaner
- Institute of Biophysics, Medical University of Graz, Harrachgasse 21, Graz 8010, Austria
| | | | - Toma N Glasnov
- Institute of Chemistry, University of Graz, Graz, Austria Christian Doppler Laboratory for Continuous Flow Chemistry, Institute of Chemistry, University of Graz, Graz, Austria
| | - C Oliver Kappe
- Institute of Chemistry, University of Graz, Graz, Austria
| | - Bernd Mayer
- Institute of Pharmaceutical Sciences, University of Graz, Graz, Austria
| | - Gudrun Antoons
- Department of Cardiology, Medical University of Graz, Graz, Austria Ludwig Boltzmann Institute of Translational Heart Failure Research, Graz, Austria
| | - Frank Heinzel
- Department of Cardiology, Medical University of Graz, Graz, Austria Ludwig Boltzmann Institute of Translational Heart Failure Research, Graz, Austria
| | - Michael Poteser
- Institute of Biophysics, Medical University of Graz, Harrachgasse 21, Graz 8010, Austria
| | - Klaus Groschner
- Ludwig Boltzmann Institute of Translational Heart Failure Research, Graz, Austria Institute of Biophysics, Medical University of Graz, Harrachgasse 21, Graz 8010, Austria
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Cardiac mechano-electric coupling research: Fifty years of progress and scientific innovation. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2014; 115:71-5. [DOI: 10.1016/j.pbiomolbio.2014.06.007] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 06/19/2014] [Indexed: 12/22/2022]
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B-type natriuretic peptide is a major predictor of ventricular tachyarrhythmias. Heart Rhythm 2014; 11:1109-16. [DOI: 10.1016/j.hrthm.2014.04.024] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Indexed: 12/28/2022]
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Bewick GS, Banks RW. Mechanotransduction in the muscle spindle. Pflugers Arch 2014; 467:175-90. [PMID: 24888691 PMCID: PMC4281366 DOI: 10.1007/s00424-014-1536-9] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2014] [Revised: 04/09/2014] [Accepted: 05/12/2014] [Indexed: 12/26/2022]
Abstract
The focus of this review is on the principal sensory ending of the mammalian muscle spindle, known as the primary ending. The process of mechanosensory transduction in the primary ending is examined under five headings: (i) action potential responses to defined mechanical stimuli—representing the ending's input–output properties; (ii) the receptor potential—including the currents giving rise to it; (iii) sensory-terminal deformation—measurable changes in the shape of the primary-ending terminals correlated with intrafusal sarcomere length, and what may cause them; (iv) putative stretch-sensitive channels—pharmacological and immunocytochemical clues to their identity; and (v) synaptic-like vesicles—the physiology and pharmacology of an intrinsic glutamatergic system in the primary and other mechanosensory endings, with some thoughts on the possible role of the system. Thus, the review highlights spindle stretch-evoked output is the product of multi-ionic receptor currents plus complex and sophisticated regulatory gain controls, both positive and negative in nature, as befits its status as the most complex sensory organ after the special senses.
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Affiliation(s)
- Guy S Bewick
- School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Aberdeen, AB25 2ZD, UK,
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Retailleau K, Duprat F. Polycystins and partners: proposed role in mechanosensitivity. J Physiol 2014; 592:2453-71. [PMID: 24687583 DOI: 10.1113/jphysiol.2014.271346] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Mutations of the two polycystins, PC1 and PC2, lead to polycystic kidney disease. Polycystins are able to form complexes with numerous families of proteins that have been suggested to participate in mechanical sensing. The proposed role of polycystins and their partners in the kidney primary cilium is to sense urine flow. A role for polycystins in mechanosensing has also been shown in other cell types such as vascular smooth muscle cells and cardiac myocytes. At the plasma membrane, polycystins interact with diverse ion channels of the TRP family and with stretch-activated channels (Piezos, TREKs). The actin cytoskeleton and its interacting proteins, such as filamin A, have been shown to be essential for these interactions. Numerous proteins involved in cell-cell and cell-extracellular matrix junctions interact with PC1 and/or PC2. These multimeric protein complexes are important for cell structure integrity, the transmission of force, as well as for mechanosensing and mechanotransduction. A group of polycystin partners are also involved in subcellular trafficking mechanisms. Finally, PC1 and especially PC2 interact with elements of the endoplasmic reticulum and are essential components of calcium homeostasis. In conclusion, we propose that both PC1 and PC2 act as conductors to tune the overall cellular mechanosensitivity.
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Affiliation(s)
- Kevin Retailleau
- CNRS Institute of Molecular and Cellular Pharmacology (IPMC), Valbonne, France
| | - Fabrice Duprat
- CNRS Institute of Molecular and Cellular Pharmacology (IPMC), Valbonne, France
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G protein-coupled receptor signalling potentiates the osmo-mechanical activation of TRPC5 channels. Pflugers Arch 2013; 466:1635-46. [DOI: 10.1007/s00424-013-1392-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Revised: 10/04/2013] [Accepted: 10/19/2013] [Indexed: 10/26/2022]
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Eijkelkamp N, Quick K, Wood JN. Transient Receptor Potential Channels and Mechanosensation. Annu Rev Neurosci 2013; 36:519-46. [DOI: 10.1146/annurev-neuro-062012-170412] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Niels Eijkelkamp
- Laboratory of Neuroimmunology and Developmental Origins of Disease, University Medical Center Utrecht, 3584 EA Utrecht, The Netherlands;
| | - Kathryn Quick
- Wolfson Institute for Biomedical Research, University College London, London WC1 6BT, United Kingdom; ,
| | - John N. Wood
- Wolfson Institute for Biomedical Research, University College London, London WC1 6BT, United Kingdom; ,
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Quick K, Zhao J, Eijkelkamp N, Linley JE, Rugiero F, Cox JJ, Raouf R, Gringhuis M, Sexton JE, Abramowitz J, Taylor R, Forge A, Ashmore J, Kirkwood N, Kros CJ, Richardson GP, Freichel M, Flockerzi V, Birnbaumer L, Wood JN. TRPC3 and TRPC6 are essential for normal mechanotransduction in subsets of sensory neurons and cochlear hair cells. Open Biol 2013; 2:120068. [PMID: 22724068 PMCID: PMC3376737 DOI: 10.1098/rsob.120068] [Citation(s) in RCA: 122] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Accepted: 04/16/2012] [Indexed: 12/21/2022] Open
Abstract
Transient receptor potential (TRP) channels TRPC3 and TRPC6 are expressed in both sensory neurons and cochlear hair cells. Deletion of TRPC3 or TRPC6 in mice caused no behavioural phenotype, although loss of TRPC3 caused a shift of rapidly adapting (RA) mechanosensitive currents to intermediate-adapting currents in dorsal root ganglion sensory neurons. Deletion of both TRPC3 and TRPC6 caused deficits in light touch and silenced half of small-diameter sensory neurons expressing mechanically activated RA currents. Double TRPC3/TRPC6 knock-out mice also showed hearing impairment, vestibular deficits and defective auditory brain stem responses to high-frequency sounds. Basal, but not apical, cochlear outer hair cells lost more than 75 per cent of their responses to mechanical stimulation. FM1-43-sensitive mechanically gated currents were induced when TRPC3 and TRPC6 were co-expressed in sensory neuron cell lines. TRPC3 and TRPC6 are thus required for the normal function of cells involved in touch and hearing, and are potential components of mechanotransducing complexes.
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Affiliation(s)
- Kathryn Quick
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, London WC1E 6BT, UK
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Retailleau K, Toutain B, Galmiche G, Fassot C, Sharif-Naeini R, Kauffenstein G, Mericskay M, Duprat F, Grimaud L, Merot J, Lardeux A, Pizard A, Baudrie V, Jeunemaitre X, Feil R, Göthert JR, Lacolley P, Henrion D, Li Z, Loufrani L. Selective Involvement of Serum Response Factor in Pressure-Induced Myogenic Tone in Resistance Arteries. Arterioscler Thromb Vasc Biol 2013; 33:339-46. [DOI: 10.1161/atvbaha.112.300708] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Objective—
In resistance arteries, diameter adjustment in response to pressure changes depends on the vascular cytoskeleton integrity. Serum response factor (SRF) is a dispensable transcription factor for cellular growth, but its role remains unknown in resistance arteries. We hypothesized that SRF is required for appropriate microvascular contraction.
Methods and Results—
We used mice in which SRF was specifically deleted in smooth muscle or endothelial cells, and their control. Myogenic tone and pharmacological contraction was determined in resistance arteries. mRNA and protein expression were assessed by quantitative real-time PCR (qRT-PCR) and Western blot. Actin polymerization was determined by confocal microscopy. Stress-activated channel activity was measured by patch clamp. Myogenic tone developing in response to pressure was dramatically decreased by SRF deletion (5.9±2.3%) compared with control (16.3±3.2%). This defect was accompanied by decreases in actin polymerization, filamin A, myosin light chain kinase and myosin light chain expression level, and stress-activated channel activity and sensitivity in response to pressure. Contractions induced by phenylephrine or U46619 were not modified, despite a higher sensitivity to p38 blockade; this highlights a compensatory pathway, allowing normal receptor-dependent contraction.
Conclusion—
This study shows for the first time that SRF has a major part to play in the control of local blood flow via its central role in pressure-induced myogenic tone in resistance arteries.
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Affiliation(s)
- Kevin Retailleau
- From the CNRS UMR-6214, INSERM U1083, Université d’Angers, PRES LUNAM, Angers, France (K.R., B.T., C.F., G.K., L.G., D.H., L.L.); CHU Angers, France (D.H., L.L.); Université Pierre & Marie Curie, Paris, France (G.G., M.M., Z.L.); IPMC-CNRS, Valbonne, France (R.S.-N., F.D.); INSERM 915, Nantes, France (J.M., A.L.); INSERM 961, Vandoeuvre les Nancy, France (A.P., P.L.); INSERM 970, Paris–Centre de Recherche Cardiovasculaire (PARCC), Faculty of Medicine, Université Paris Descartes, PRES Sorbonne
| | - Bertrand Toutain
- From the CNRS UMR-6214, INSERM U1083, Université d’Angers, PRES LUNAM, Angers, France (K.R., B.T., C.F., G.K., L.G., D.H., L.L.); CHU Angers, France (D.H., L.L.); Université Pierre & Marie Curie, Paris, France (G.G., M.M., Z.L.); IPMC-CNRS, Valbonne, France (R.S.-N., F.D.); INSERM 915, Nantes, France (J.M., A.L.); INSERM 961, Vandoeuvre les Nancy, France (A.P., P.L.); INSERM 970, Paris–Centre de Recherche Cardiovasculaire (PARCC), Faculty of Medicine, Université Paris Descartes, PRES Sorbonne
| | - Guillaume Galmiche
- From the CNRS UMR-6214, INSERM U1083, Université d’Angers, PRES LUNAM, Angers, France (K.R., B.T., C.F., G.K., L.G., D.H., L.L.); CHU Angers, France (D.H., L.L.); Université Pierre & Marie Curie, Paris, France (G.G., M.M., Z.L.); IPMC-CNRS, Valbonne, France (R.S.-N., F.D.); INSERM 915, Nantes, France (J.M., A.L.); INSERM 961, Vandoeuvre les Nancy, France (A.P., P.L.); INSERM 970, Paris–Centre de Recherche Cardiovasculaire (PARCC), Faculty of Medicine, Université Paris Descartes, PRES Sorbonne
| | - Céline Fassot
- From the CNRS UMR-6214, INSERM U1083, Université d’Angers, PRES LUNAM, Angers, France (K.R., B.T., C.F., G.K., L.G., D.H., L.L.); CHU Angers, France (D.H., L.L.); Université Pierre & Marie Curie, Paris, France (G.G., M.M., Z.L.); IPMC-CNRS, Valbonne, France (R.S.-N., F.D.); INSERM 915, Nantes, France (J.M., A.L.); INSERM 961, Vandoeuvre les Nancy, France (A.P., P.L.); INSERM 970, Paris–Centre de Recherche Cardiovasculaire (PARCC), Faculty of Medicine, Université Paris Descartes, PRES Sorbonne
| | - Reza Sharif-Naeini
- From the CNRS UMR-6214, INSERM U1083, Université d’Angers, PRES LUNAM, Angers, France (K.R., B.T., C.F., G.K., L.G., D.H., L.L.); CHU Angers, France (D.H., L.L.); Université Pierre & Marie Curie, Paris, France (G.G., M.M., Z.L.); IPMC-CNRS, Valbonne, France (R.S.-N., F.D.); INSERM 915, Nantes, France (J.M., A.L.); INSERM 961, Vandoeuvre les Nancy, France (A.P., P.L.); INSERM 970, Paris–Centre de Recherche Cardiovasculaire (PARCC), Faculty of Medicine, Université Paris Descartes, PRES Sorbonne
| | - Gilles Kauffenstein
- From the CNRS UMR-6214, INSERM U1083, Université d’Angers, PRES LUNAM, Angers, France (K.R., B.T., C.F., G.K., L.G., D.H., L.L.); CHU Angers, France (D.H., L.L.); Université Pierre & Marie Curie, Paris, France (G.G., M.M., Z.L.); IPMC-CNRS, Valbonne, France (R.S.-N., F.D.); INSERM 915, Nantes, France (J.M., A.L.); INSERM 961, Vandoeuvre les Nancy, France (A.P., P.L.); INSERM 970, Paris–Centre de Recherche Cardiovasculaire (PARCC), Faculty of Medicine, Université Paris Descartes, PRES Sorbonne
| | - Mathias Mericskay
- From the CNRS UMR-6214, INSERM U1083, Université d’Angers, PRES LUNAM, Angers, France (K.R., B.T., C.F., G.K., L.G., D.H., L.L.); CHU Angers, France (D.H., L.L.); Université Pierre & Marie Curie, Paris, France (G.G., M.M., Z.L.); IPMC-CNRS, Valbonne, France (R.S.-N., F.D.); INSERM 915, Nantes, France (J.M., A.L.); INSERM 961, Vandoeuvre les Nancy, France (A.P., P.L.); INSERM 970, Paris–Centre de Recherche Cardiovasculaire (PARCC), Faculty of Medicine, Université Paris Descartes, PRES Sorbonne
| | - Fabrice Duprat
- From the CNRS UMR-6214, INSERM U1083, Université d’Angers, PRES LUNAM, Angers, France (K.R., B.T., C.F., G.K., L.G., D.H., L.L.); CHU Angers, France (D.H., L.L.); Université Pierre & Marie Curie, Paris, France (G.G., M.M., Z.L.); IPMC-CNRS, Valbonne, France (R.S.-N., F.D.); INSERM 915, Nantes, France (J.M., A.L.); INSERM 961, Vandoeuvre les Nancy, France (A.P., P.L.); INSERM 970, Paris–Centre de Recherche Cardiovasculaire (PARCC), Faculty of Medicine, Université Paris Descartes, PRES Sorbonne
| | - Linda Grimaud
- From the CNRS UMR-6214, INSERM U1083, Université d’Angers, PRES LUNAM, Angers, France (K.R., B.T., C.F., G.K., L.G., D.H., L.L.); CHU Angers, France (D.H., L.L.); Université Pierre & Marie Curie, Paris, France (G.G., M.M., Z.L.); IPMC-CNRS, Valbonne, France (R.S.-N., F.D.); INSERM 915, Nantes, France (J.M., A.L.); INSERM 961, Vandoeuvre les Nancy, France (A.P., P.L.); INSERM 970, Paris–Centre de Recherche Cardiovasculaire (PARCC), Faculty of Medicine, Université Paris Descartes, PRES Sorbonne
| | - Jean Merot
- From the CNRS UMR-6214, INSERM U1083, Université d’Angers, PRES LUNAM, Angers, France (K.R., B.T., C.F., G.K., L.G., D.H., L.L.); CHU Angers, France (D.H., L.L.); Université Pierre & Marie Curie, Paris, France (G.G., M.M., Z.L.); IPMC-CNRS, Valbonne, France (R.S.-N., F.D.); INSERM 915, Nantes, France (J.M., A.L.); INSERM 961, Vandoeuvre les Nancy, France (A.P., P.L.); INSERM 970, Paris–Centre de Recherche Cardiovasculaire (PARCC), Faculty of Medicine, Université Paris Descartes, PRES Sorbonne
| | - Aurelie Lardeux
- From the CNRS UMR-6214, INSERM U1083, Université d’Angers, PRES LUNAM, Angers, France (K.R., B.T., C.F., G.K., L.G., D.H., L.L.); CHU Angers, France (D.H., L.L.); Université Pierre & Marie Curie, Paris, France (G.G., M.M., Z.L.); IPMC-CNRS, Valbonne, France (R.S.-N., F.D.); INSERM 915, Nantes, France (J.M., A.L.); INSERM 961, Vandoeuvre les Nancy, France (A.P., P.L.); INSERM 970, Paris–Centre de Recherche Cardiovasculaire (PARCC), Faculty of Medicine, Université Paris Descartes, PRES Sorbonne
| | - Anne Pizard
- From the CNRS UMR-6214, INSERM U1083, Université d’Angers, PRES LUNAM, Angers, France (K.R., B.T., C.F., G.K., L.G., D.H., L.L.); CHU Angers, France (D.H., L.L.); Université Pierre & Marie Curie, Paris, France (G.G., M.M., Z.L.); IPMC-CNRS, Valbonne, France (R.S.-N., F.D.); INSERM 915, Nantes, France (J.M., A.L.); INSERM 961, Vandoeuvre les Nancy, France (A.P., P.L.); INSERM 970, Paris–Centre de Recherche Cardiovasculaire (PARCC), Faculty of Medicine, Université Paris Descartes, PRES Sorbonne
| | - Véronique Baudrie
- From the CNRS UMR-6214, INSERM U1083, Université d’Angers, PRES LUNAM, Angers, France (K.R., B.T., C.F., G.K., L.G., D.H., L.L.); CHU Angers, France (D.H., L.L.); Université Pierre & Marie Curie, Paris, France (G.G., M.M., Z.L.); IPMC-CNRS, Valbonne, France (R.S.-N., F.D.); INSERM 915, Nantes, France (J.M., A.L.); INSERM 961, Vandoeuvre les Nancy, France (A.P., P.L.); INSERM 970, Paris–Centre de Recherche Cardiovasculaire (PARCC), Faculty of Medicine, Université Paris Descartes, PRES Sorbonne
| | - Xavier Jeunemaitre
- From the CNRS UMR-6214, INSERM U1083, Université d’Angers, PRES LUNAM, Angers, France (K.R., B.T., C.F., G.K., L.G., D.H., L.L.); CHU Angers, France (D.H., L.L.); Université Pierre & Marie Curie, Paris, France (G.G., M.M., Z.L.); IPMC-CNRS, Valbonne, France (R.S.-N., F.D.); INSERM 915, Nantes, France (J.M., A.L.); INSERM 961, Vandoeuvre les Nancy, France (A.P., P.L.); INSERM 970, Paris–Centre de Recherche Cardiovasculaire (PARCC), Faculty of Medicine, Université Paris Descartes, PRES Sorbonne
| | - Robert Feil
- From the CNRS UMR-6214, INSERM U1083, Université d’Angers, PRES LUNAM, Angers, France (K.R., B.T., C.F., G.K., L.G., D.H., L.L.); CHU Angers, France (D.H., L.L.); Université Pierre & Marie Curie, Paris, France (G.G., M.M., Z.L.); IPMC-CNRS, Valbonne, France (R.S.-N., F.D.); INSERM 915, Nantes, France (J.M., A.L.); INSERM 961, Vandoeuvre les Nancy, France (A.P., P.L.); INSERM 970, Paris–Centre de Recherche Cardiovasculaire (PARCC), Faculty of Medicine, Université Paris Descartes, PRES Sorbonne
| | - Joachim R. Göthert
- From the CNRS UMR-6214, INSERM U1083, Université d’Angers, PRES LUNAM, Angers, France (K.R., B.T., C.F., G.K., L.G., D.H., L.L.); CHU Angers, France (D.H., L.L.); Université Pierre & Marie Curie, Paris, France (G.G., M.M., Z.L.); IPMC-CNRS, Valbonne, France (R.S.-N., F.D.); INSERM 915, Nantes, France (J.M., A.L.); INSERM 961, Vandoeuvre les Nancy, France (A.P., P.L.); INSERM 970, Paris–Centre de Recherche Cardiovasculaire (PARCC), Faculty of Medicine, Université Paris Descartes, PRES Sorbonne
| | - Patrick Lacolley
- From the CNRS UMR-6214, INSERM U1083, Université d’Angers, PRES LUNAM, Angers, France (K.R., B.T., C.F., G.K., L.G., D.H., L.L.); CHU Angers, France (D.H., L.L.); Université Pierre & Marie Curie, Paris, France (G.G., M.M., Z.L.); IPMC-CNRS, Valbonne, France (R.S.-N., F.D.); INSERM 915, Nantes, France (J.M., A.L.); INSERM 961, Vandoeuvre les Nancy, France (A.P., P.L.); INSERM 970, Paris–Centre de Recherche Cardiovasculaire (PARCC), Faculty of Medicine, Université Paris Descartes, PRES Sorbonne
| | - Daniel Henrion
- From the CNRS UMR-6214, INSERM U1083, Université d’Angers, PRES LUNAM, Angers, France (K.R., B.T., C.F., G.K., L.G., D.H., L.L.); CHU Angers, France (D.H., L.L.); Université Pierre & Marie Curie, Paris, France (G.G., M.M., Z.L.); IPMC-CNRS, Valbonne, France (R.S.-N., F.D.); INSERM 915, Nantes, France (J.M., A.L.); INSERM 961, Vandoeuvre les Nancy, France (A.P., P.L.); INSERM 970, Paris–Centre de Recherche Cardiovasculaire (PARCC), Faculty of Medicine, Université Paris Descartes, PRES Sorbonne
| | - Zhenlin Li
- From the CNRS UMR-6214, INSERM U1083, Université d’Angers, PRES LUNAM, Angers, France (K.R., B.T., C.F., G.K., L.G., D.H., L.L.); CHU Angers, France (D.H., L.L.); Université Pierre & Marie Curie, Paris, France (G.G., M.M., Z.L.); IPMC-CNRS, Valbonne, France (R.S.-N., F.D.); INSERM 915, Nantes, France (J.M., A.L.); INSERM 961, Vandoeuvre les Nancy, France (A.P., P.L.); INSERM 970, Paris–Centre de Recherche Cardiovasculaire (PARCC), Faculty of Medicine, Université Paris Descartes, PRES Sorbonne
| | - Laurent Loufrani
- From the CNRS UMR-6214, INSERM U1083, Université d’Angers, PRES LUNAM, Angers, France (K.R., B.T., C.F., G.K., L.G., D.H., L.L.); CHU Angers, France (D.H., L.L.); Université Pierre & Marie Curie, Paris, France (G.G., M.M., Z.L.); IPMC-CNRS, Valbonne, France (R.S.-N., F.D.); INSERM 915, Nantes, France (J.M., A.L.); INSERM 961, Vandoeuvre les Nancy, France (A.P., P.L.); INSERM 970, Paris–Centre de Recherche Cardiovasculaire (PARCC), Faculty of Medicine, Université Paris Descartes, PRES Sorbonne
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Chen SJ, Zhang W, Tong Q, Conrad K, Hirschler-Laszkiewicz I, Bayerl M, Kim JK, Cheung JY, Miller BA. Role of TRPM2 in cell proliferation and susceptibility to oxidative stress. Am J Physiol Cell Physiol 2013; 304:C548-60. [PMID: 23302782 DOI: 10.1152/ajpcell.00069.2012] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The transient receptor potential (TRP) channel TRPM2 is an ion channel that modulates cell survival. We report here that full-length (TRPM2-L) and short (TRPM2-S) isoform expression was significantly increased in human neuroblastoma compared with adrenal gland. To differentiate the roles of TRPM2-L and TRPM2-S in cell proliferation and survival, we established neuroblastoma SH-SY5Y cell lines stably expressing either TRPM2 isoform or empty vector. Cells expressing TRPM2-S showed significantly enhanced proliferation, downregulation of phosphatase and tensin homolog (PTEN), and increased protein kinase B (Akt) phosphorylation and cell surface glucose transporter 1 (Glut1) compared with cells expressing TRPM2-L or empty vector. ERK phosphorylation was increased, and forkhead box O 3a (FOXO3a) levels were decreased. Inhibitor studies demonstrated that enhanced proliferation was dependent on phosphatidylinositol 3-kinase/Akt, ERK, and NADPH oxidase activation. On the other hand, TRPM2-S-expressing cells were significantly more susceptible to cell death induced by low H2O2 concentrations (50-100 μM), whereas TRPM2-L-expressing cells were protected. This was associated with a significant increase in FOXO3a, MnSOD (SOD2), and membrane Glut1 in TRPM2-L-expressing cells compared with TRPM2-S expressing cells. We conclude that TRPM2 channels occupy a key role in cell proliferation and survival following oxidative stress in neuroblastoma. Our results suggest that overexpression of TRPM2-S results in increased proliferation through phosphatidylinositol 3-kinase/Akt and ERK pathways, while overexpression of TRPM2-L confers protection against oxidative stress-induced cell death through FOXO3a and SOD. TRPM2 channels may represent a novel future therapeutic target in diseases involving oxidative stress.
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Affiliation(s)
- Shu-jen Chen
- Department of Pediatrics, Pennsylvania State University College of Medicine, Milton S. Hershey Medical Center, PO Box 850, Hershey, PA 17033, USA
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van Berlo JH, Maillet M, Molkentin JD. Signaling effectors underlying pathologic growth and remodeling of the heart. J Clin Invest 2013; 123:37-45. [PMID: 23281408 DOI: 10.1172/jci62839] [Citation(s) in RCA: 334] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Cardiovascular disease is the number one cause of mortality in the Western world. The heart responds to many cardiopathological conditions with hypertrophic growth by enlarging individual myocytes to augment cardiac pump function and decrease ventricular wall tension. Initially, such cardiac hypertrophic growth is often compensatory, but as time progresses these changes become maladaptive. Cardiac hypertrophy is the strongest predictor for the development of heart failure, arrhythmia, and sudden death. Here we discuss therapeutic avenues emerging from molecular and genetic studies of cardiovascular disease in animal models. The majority of these are based on intracellular signaling pathways considered central to pathologic cardiac remodeling and hypertrophy, which then leads to heart failure. We focus our discussion on selected therapeutic targets that have more recently emerged and have a tangible translational potential given the available pharmacologic agents that could be readily evaluated in human clinical trials.
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Affiliation(s)
- Jop H van Berlo
- Department of Pediatrics, University of Cincinnati, Cincinnati Children’s Hospital Medical Center, Howard Hughes Medical Institute, Cincinnati, Ohio 45229-3039, USA
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Biophysical Forces Modulate the Costamere and Z-Disc for Sarcomere Remodeling in Heart Failure. BIOPHYSICS OF THE FAILING HEART 2013. [DOI: 10.1007/978-1-4614-7678-8_7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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The zebrafish as a novel animal model to study the molecular mechanisms of mechano-electrical feedback in the heart. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2012; 110:154-65. [PMID: 22835662 DOI: 10.1016/j.pbiomolbio.2012.07.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Accepted: 07/16/2012] [Indexed: 02/07/2023]
Abstract
Altered mechanical loading of the heart leads to hypertrophy, decompensated heart failure and fatal arrhythmias. However, the molecular mechanisms that link mechanical and electrical dysfunction remain poorly understood. Growing evidence suggest that ventricular electrical remodeling (VER) is a process that can be induced by altered mechanical stress, creating persistent electrophysiological changes that predispose the heart to life-threatening arrhythmias. While VER is clearly a physiological property of the human heart, as evidenced by "T wave memory", it is also thought to occur in a variety of pathological states associated with altered ventricular activation such as bundle branch block, myocardial infarction, and cardiac pacing. Animal models that are currently being used for investigating stretch-induced VER have significant limitations. The zebrafish has recently emerged as an attractive animal model for studying cardiovascular disease and could overcome some of these limitations. Owing to its extensively sequenced genome, high conservation of gene function, and the comprehensive genetic resources that are available in this model, the zebrafish may provide new insights into the molecular mechanisms that drive detrimental electrical remodeling in response to stretch. Here, we have established a zebrafish model to study mechano-electrical feedback in the heart, which combines efficient genetic manipulation with high-precision stretch and high-resolution electrophysiology. In this model, only 90 min of ventricular stretch caused VER and recapitulated key features of VER found previously in the mammalian heart. Our data suggest that the zebrafish model is a powerful platform for investigating the molecular mechanisms underlying mechano-electrical feedback and VER in the heart.
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Abstract
The vascular myogenic response is an inherent property of VSM in the walls of small arteries and arterioles, allowing these principal resistance segments of the microcirculation to respond to changes in transmural pressure. Elevated intraluminal pressure leads to myogenic constriction, whereas reduced pressure leads to myogenic dilation. This review focuses on the physiological significance of the myogenic response in microvascular networks. First, historical concepts related to the detection of stretch by the vessel wall are reviewed, including the wall tension hypothesis, and the implications of the proposal that the arteriolar network responds to Pp changes as a system of series-coupled myogenic effectors. Next, the role of the myogenic response in the local regulation of blood flow and/or Pc is examined. Finally, the interaction of myogenic constriction and dilation with other local control mechanisms, including metabolic, neural and shear-dependent mechanisms, is discussed. Throughout the review, an attempt is made to integrate historical and current literature with an emphasis on the physiological role, rather than the underlying signaling mechanisms, of this important component of vascular control.
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Affiliation(s)
- Michael J Davis
- Department of Medical Pharmacology & Physiology, University of Missouri School of Medicine, Columbia, MO 65212, USA.
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Kauffenstein G, Laher I, Matrougui K, Guérineau NC, Henrion D. Emerging role of G protein-coupled receptors in microvascular myogenic tone. Cardiovasc Res 2012; 95:223-32. [PMID: 22637750 DOI: 10.1093/cvr/cvs152] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Blood flow autoregulation results from the ability of resistance arteries to reduce or increase their diameters in response to changes in intravascular pressure. The mechanism by which arteries maintain a constant blood flow to organs over a range of pressures relies on this myogenic response, which defines the intrinsic property of the smooth muscle to contract in response to stretch. The resistance to flow created by myogenic tone (MT) prevents tissue damage and allows the maintenance of a constant perfusion, despite fluctuations in arterial pressure. Interventions targeting MT may provide a more rational therapeutic approach in vascular disorders, such as hypertension, vasospasm, chronic heart failure, or diabetes. Despite its early description by Bayliss in 1902, the cellular and molecular mechanisms underlying MT remain poorly understood. We now appreciate that MT requires a complex mechanotransduction converting a physical stimulus (pressure) into a biological response (change in vessel diameter). Although smooth muscle cell depolarization and a rise in intracellular calcium concentration are recognized as cornerstones of the myogenic response, the role of wall strain-induced formation of vasoactive mediators is less well established. The vascular system expresses a large variety of Class 1 G protein-coupled receptors (GPCR) activated by an eclectic range of chemical entities, including peptides, lipids, nucleotides, and amines. These messengers can function in blood vessels as vasoconstrictors. This review focuses on locally generated GPCR agonists and their proposed contributions to MT. Their interplay with pivotal G(q-11) and G(12-13) protein signalling is also discussed.
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Affiliation(s)
- Gilles Kauffenstein
- Biologie Neurovasculaire et Mitochondriale Intégrée, UMR CNRS 6214 INSERM 1083, Université d'Angers, France
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Lindén M, Sens P, Phillips R. Entropic tension in crowded membranes. PLoS Comput Biol 2012; 8:e1002431. [PMID: 22438801 PMCID: PMC3305330 DOI: 10.1371/journal.pcbi.1002431] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Accepted: 02/01/2012] [Indexed: 11/18/2022] Open
Abstract
Unlike their model membrane counterparts, biological membranes are richly decorated with a heterogeneous assembly of membrane proteins. These proteins are so tightly packed that their excluded area interactions can alter the free energy landscape controlling the conformational transitions suffered by such proteins. For membrane channels, this effect can alter the critical membrane tension at which they undergo a transition from a closed to an open state, and therefore influence protein function in vivo. Despite their obvious importance, crowding phenomena in membranes are much less well studied than in the cytoplasm. Using statistical mechanics results for hard disk liquids, we show that crowding induces an entropic tension in the membrane, which influences transitions that alter the projected area and circumference of a membrane protein. As a specific case study in this effect, we consider the impact of crowding on the gating properties of bacterial mechanosensitive membrane channels, which are thought to confer osmoprotection when these cells are subjected to osmotic shock. We find that crowding can alter the gating energies by more than in physiological conditions, a substantial fraction of the total gating energies in some cases. Given the ubiquity of membrane crowding, the nonspecific nature of excluded volume interactions, and the fact that the function of many membrane proteins involve significant conformational changes, this specific case study highlights a general aspect in the function of membrane proteins. Biological membranes are a complex array of lipids and proteins. The typical bacterial membrane is made up of hundreds of copies of different species of membrane proteins embedded in a sea of different types of lipids. One of the distinguishing features of biological matter is the high degree of “crowding” to which the different macromolecules are subjected. In this work, we explore the consequences of such crowding in the membrane setting, building upon earlier work which has primarily focused on how crowding affects properties in the cytoplasm. The particular case study considered here centers on a class of membrane channels which respond to tension in the cell membrane serving to provide osmoprotection to cells subjected to osmotic shock. We explore how the critical tension at which these channels open depends upon the concentration of other membrane proteins, and conclude that it can be significantly higher at physiological protein densities compared to the intrinsic value measured in protein free membranes.
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Affiliation(s)
- Martin Lindén
- Department of Applied Physics, California Institute of Technology, Pasadena, California, United States of America
| | - Pierre Sens
- Laboratoire de Physico-Chimie Théorique, CNRS/UMR 7083, ESPCI, Paris, France
| | - Rob Phillips
- Department of Applied Physics, California Institute of Technology, Pasadena, California, United States of America
- Laboratoire de Physico-Chimie Théorique, CNRS/UMR 7083, ESPCI, Paris, France
- Division of Biology, California Institute of Technology, Pasadena, California, United States of America
- * E-mail:
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Abstract
Mechanosensation and -transduction are important for physiological processes like the senses of touch, hearing, and balance. The mechanisms underlying the translation of mechanical stimuli into biochemical information by activating various signaling pathways play a fundamental role in physiology and pathophysiology but are only poorly understood. Recently, G protein-coupled receptors (GPCRs), which are essential for the conversion of light, olfactory and gustatory stimuli, as well as of primary messengers like hormones and neurotransmitters into cellular signals and which play distinct roles in inflammation, cell growth, and differentiation, have emerged as potential mechanosensors. The first candidate for a mechanosensitive GPCR was the angiotensin-II type-1 (AT(1)) receptor. Agonist-independent mechanical receptor activation of AT(1) receptors induces an active receptor conformation that appears to differ from agonist-induced receptor conformations and entails the activation of G proteins. Mechanically induced AT(1) receptor activation plays an important role for myogenic vasoconstriction and for the initiation of cardiac hypertrophy. A growing body of evidence suggests that other GPCRs are involved in mechanosensation as well. These findings highlight physiologically relevant, ligand-independent functions of GPCRs and add yet another facet to the polymodal activation spectrum of this ubiquitous protein family.
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Affiliation(s)
- Ursula Storch
- Walther-Straub-Institute of Pharmacology and Toxicology, University of Munich, Germany
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Hirschler-Laszkiewicz I, Zhang W, Keefer K, Conrad K, Tong Q, Chen SJ, Bronson S, Cheung JY, Miller BA. Trpc2 depletion protects red blood cells from oxidative stress-induced hemolysis. Exp Hematol 2011; 40:71-83. [PMID: 21924222 DOI: 10.1016/j.exphem.2011.09.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2011] [Revised: 08/22/2011] [Accepted: 09/09/2011] [Indexed: 11/29/2022]
Abstract
Transient receptor potential (TRP) channels Trpc2 and Trpc3 are expressed on normal murine erythroid precursors, and erythropoietin stimulates an increase in intracellular calcium ([Ca(2+)](i)) through TRPC2 and TRPC3. Because modulation of [Ca(2+)](i) is an important signaling pathway in erythroid proliferation and differentiation, Trpc2, Trpc3, and Trpc2/Trpc3 double knockout mice were utilized to explore the roles of these channels in erythropoiesis. Trpc2, Trpc3, and Trpc2/Trpc3 double knockout mice were not anemic, and had similar red blood cell counts, hemoglobins, and reticulocyte counts as wild-type littermate controls. Although the erythropoietin-induced increase in [Ca(2+)](i) was reduced, these knockout mice showed no defects in red cell production. The major phenotypic difference at steady state was that the mean corpuscular volume, mean corpuscular hemoglobin, and hematocrit of red cells were significantly greater in Trpc2 and Trpc2/Trpc3 double knockout mice, and mean corpuscular hemoglobin concentration was significantly reduced. All hematological parameters in Trpc3 knockout mice were similar to controls. When exposed to phenylhydrazine, unlike the Trpc3 knockouts, Trpc2 and Trpc2/Trpc3 double knockout mice showed significant resistance to hemolysis. This was associated with a significant reduction in hydrogen peroxide-induced calcium influx in erythroblasts. Although erythropoietin-induced calcium influx through TRPC2 or TRPC3 is not critical for erythroid production, these data demonstrate that TRPC2 plays an important role in oxidative stress-induced hemolysis, which may be related to reduced calcium entry in red cells in the presence of Trpc2 depletion.
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Pedersen SF, Kapus A, Hoffmann EK. Osmosensory mechanisms in cellular and systemic volume regulation. J Am Soc Nephrol 2011; 22:1587-97. [PMID: 21852585 DOI: 10.1681/asn.2010121284] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Perturbations of cellular and systemic osmolarity severely challenge the function of all organisms and are consequently regulated very tightly. Here we outline current evidence on how cells sense volume perturbations, with particular focus on mechanisms relevant to the kidneys and to extracellular osmolarity and whole body volume homeostasis. There are a variety of molecular signals that respond to perturbations in cell volume and osmosensors or volume sensors responding to these signals. The early signals of volume perturbation include integrins, the cytoskeleton, receptor tyrosine kinases, and transient receptor potential channels. We also present current evidence on the localization and function of central and peripheral systemic osmosensors and conclude with a brief look at the still limited evidence on pathophysiological conditions associated with deranged sensing of cell volume.
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Affiliation(s)
- Stine Falsig Pedersen
- Department of Biology, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen, Denmark.
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45
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Harvey RD, Calaghan SC. Caveolae create local signalling domains through their distinct protein content, lipid profile and morphology. J Mol Cell Cardiol 2011; 52:366-75. [PMID: 21782827 DOI: 10.1016/j.yjmcc.2011.07.007] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Revised: 06/21/2011] [Accepted: 07/07/2011] [Indexed: 01/02/2023]
Abstract
Compartmentation of signalling allows multiple stimuli to achieve diverse cellular responses with only a limited pool of second messengers. This spatial control of signalling is achieved, in part, by cellular structures which bring together elements of a particular cascade. One such structure is the caveola, a flask-shaped lipid raft. Caveolae are well-recognised as signalosomes, platforms for assembly of signalling complexes of receptors, effectors and their targets, which can facilitate efficient and specific cellular responses. Here we extend this simple model and present evidence to show how the protein and lipid profiles of caveolae, as well as their characteristic morphology, define their roles in creating local signalling domains in the cardiac myocyte. This article is part of a Special Issue entitled "Local Signaling in Myocytes."
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Affiliation(s)
- Robert D Harvey
- Department of Pharmacology, University of Nevada School of Medicine, Reno, NV 89557, USA
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46
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Hirschler-Laszkiewicz I, Tong Q, Waybill K, Conrad K, Keefer K, Zhang W, Chen SJ, Cheung JY, Miller BA. The transient receptor potential (TRP) channel TRPC3 TRP domain and AMP-activated protein kinase binding site are required for TRPC3 activation by erythropoietin. J Biol Chem 2011; 286:30636-30646. [PMID: 21757714 DOI: 10.1074/jbc.m111.238360] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Modulation of intracellular calcium ([Ca(2+)](i)) by erythropoietin (Epo) is an important signaling pathway controlling erythroid proliferation and differentiation. Transient receptor potential (TRP) channels TRPC3 and homologous TRPC6 are expressed on normal human erythroid precursors, but Epo stimulates an increase in [Ca(2+)](i) through TRPC3 but not TRPC6. Here, the role of specific domains in the different responsiveness of TRPC3 and TRPC6 to erythropoietin was explored. TRPC3 and TRPC6 TRP domains differ in seven amino acids. Substitution of five amino acids (DDKPS) in the TRPC3 TRP domain with those of TRPC6 (EERVN) abolished the Epo-stimulated increase in [Ca(2+)](i). Substitution of EERVN in TRPC6 TRP domain with DDKPS in TRPC3 did not confer Epo responsiveness. However, substitution of TRPC6 TRP with DDKPS from TRPC3 TRP, as well as swapping the TRPC6 distal C terminus (C2) with that of TRPC3, resulted in a chimeric TRPC6 channel with Epo responsiveness similar to TRPC3. Substitution of TRPC6 with TRPC3 TRP and the putative TRPC3 C-terminal AMP-activated protein kinase (AMPK) binding site straddling TRPC3 C1/C2 also resulted in TRPC6 activation. In contrast, substitution of the TRPC3 C-terminal leucine zipper motif or TRPC3 phosphorylation sites Ser-681, Ser-708, or Ser-764 with TRPC6 sequence did not affect TRPC3 Epo responsiveness. TRPC3, but not TRPC6, and TRPC6 chimeras expressing TRPC3 C2 showed significantly increased plasma membrane insertion following Epo stimulation and substantial cytoskeletal association. The TRPC3 TRP domain, distal C terminus (C2), and AMPK binding site are critical elements that confer Epo responsiveness. In particular, the TRPC3 C2 and AMPK site are essential for association of TRPC3 with the cytoskeleton and increased channel translocation to the cell surface in response to Epo stimulation.
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Affiliation(s)
| | - Qin Tong
- Departments of Pediatrics, Hershey, Pennsylvania 17033
| | | | | | - Kerry Keefer
- Departments of Pediatrics, Hershey, Pennsylvania 17033
| | - Wenyi Zhang
- Departments of Pediatrics, Hershey, Pennsylvania 17033
| | - Shu-Jen Chen
- Departments of Pediatrics, Hershey, Pennsylvania 17033
| | - Joseph Y Cheung
- Department of Medicine, Jefferson Medical College, Philadelphia, Pennsylvania 19107
| | - Barbara A Miller
- Departments of Pediatrics, Hershey, Pennsylvania 17033; Biochemistry and Molecular Biology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033.
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Adjobo-Hermans MJW, Goedhart J, van Weeren L, Nijmeijer S, Manders EMM, Offermanns S, Gadella TWJ. Real-time visualization of heterotrimeric G protein Gq activation in living cells. BMC Biol 2011; 9:32. [PMID: 21619590 PMCID: PMC3129320 DOI: 10.1186/1741-7007-9-32] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2011] [Accepted: 05/27/2011] [Indexed: 12/28/2022] Open
Abstract
Background Gq is a heterotrimeric G protein that plays an important role in numerous physiological processes. To delineate the molecular mechanisms and kinetics of signalling through this protein, its activation should be measurable in single living cells. Recently, fluorescence resonance energy transfer (FRET) sensors have been developed for this purpose. Results In this paper, we describe the development of an improved FRET-based Gq activity sensor that consists of a yellow fluorescent protein (YFP)-tagged Gγ2 subunit and a Gαq subunit with an inserted monomeric Turquoise (mTurquoise), the best cyan fluorescent protein variant currently available. This sensor enabled us to determine, for the first time, the kon (2/s) of Gq activation. In addition, we found that the guanine nucleotide exchange factor p63RhoGEF has a profound effect on the number of Gq proteins that become active upon stimulation of endogenous histamine H1 receptors. The sensor was also used to measure ligand-independent activation of the histamine H1 receptor (H1R) upon addition of a hypotonic stimulus. Conclusions Our observations reveal that the application of a truncated mTurquoise as donor and a YFP-tagged Gγ2 as acceptor in FRET-based Gq activity sensors substantially improves their dynamic range. This optimization enables the real-time single cell quantification of Gq signalling dynamics, the influence of accessory proteins and allows future drug screening applications by virtue of its sensitivity.
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Affiliation(s)
- Merel J W Adjobo-Hermans
- Swammerdam Institute for Life Sciences, Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
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Three 4-letter words of hypertension-related cardiac hypertrophy: TRPC, mTOR, and HDAC. J Mol Cell Cardiol 2011; 50:964-71. [PMID: 21320507 DOI: 10.1016/j.yjmcc.2011.02.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Revised: 01/26/2011] [Accepted: 02/02/2011] [Indexed: 12/12/2022]
Abstract
Left ventricular hypertrophy due to hypertension represents a major risk factor for adverse cardiovascular events and death. In recent years, the prevalence of cardiac hypertrophy has increased due to obesity and an aging population. Notably, a significant number of individuals have persistent cardiac hypertrophy in the face of blood pressure that is normalized by drug treatment. Thus, a better understanding of the processes underlying the cardiac remodeling events that are set into play by hypertension is needed. At the level of the cardiac myocytes, hypertrophic growth is often described as physiological, as occurs with exercise, or pathological, as seen with hypertension. Here we discuss recent developments in three areas that are fundamental to pathological hypertrophic growth of cardiac myocytes. These areas are the transient receptor potential canonical (TRPC) channels, mammalian target of rapamycin (mTOR) complexes, and histone deacetylase (HDAC) enzymes. In the last several years, studies in each of these areas have yielded new and exciting discoveries into the genesis of pathological growth of cardiac myocytes. The phosphoinositide 3-kinase-Akt signaling network may be the common denominator that links these areas together. Defining the interrelationship among TRPC channels, mTOR signaling, and HDAC enzymes is a promising, but challenging area of research. Such knowledge will undoubtedly lead to new drugs that better prevent or reverse left ventricular hypertension.
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Guinamard R, Demion M, Launay P. Physiological roles of the TRPM4 channel extracted from background currents. Physiology (Bethesda) 2010; 25:155-64. [PMID: 20551229 DOI: 10.1152/physiol.00004.2010] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Calcium-activated nonselective cationic currents have been known for 30 years, but their physiological implications have remained unresolved until the recent cloning of the TRPM4 ion channel. Since then, TRPM4 has been identified as a key modulator of numerous calcium-dependent mechanisms such as the immune response, insulin secretion, cerebral artery constriction, respiratory rhythm, and cardiac conduction.
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50
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Rowell J, Koitabashi N, Kass DA. TRP-ing up heart and vessels: canonical transient receptor potential channels and cardiovascular disease. J Cardiovasc Transl Res 2010; 3:516-24. [PMID: 20652467 DOI: 10.1007/s12265-010-9208-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2010] [Accepted: 06/28/2010] [Indexed: 12/24/2022]
Abstract
Transient receptor potential channels are a large superfamily of non-selective and non-voltage-gated ion channels that convey signaling information linked to a broad range of sensory inputs. In the cardiovascular system, the canonical transient receptor potential (TRPC) family has been particularly found to play a role in vascular and cardiac disease, responding to neurohormonal and mechanical load stimulation. TRPC1, TRPC3, and TRPC6 are often upregulated in models of cardiovascular disease, and their inhibition ameliorates the associated pathophysiology. Studies in gene deletion models and overexpression models of wild-type and dominant-negative proteins supports a direct role of these channels, which likely act together as heterotetramers to influence signaling. Recent evidence has further revealed the importance of protein kinase G phosphorylation as a mechanism to suppress TRPC6 channel current and dependent signaling in vascular and cardiac myocytes. This suggests a novel mechanism underlying benefits of drugs such as sildenafil, a phosphodiesterase type 5 inhibitor, nitrates, and atrial natriuretic peptides. This review describes new evidence supporting a pathophysiologic role of these three TRPC channels, and the potential utility of inhibition strategies to treat cardiovascular disease.
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Affiliation(s)
- Janelle Rowell
- The Division of Cardiology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
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