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Felício D, du Mérac TR, Amorim A, Martins S. Functional implications of paralog genes in polyglutamine spinocerebellar ataxias. Hum Genet 2023; 142:1651-1676. [PMID: 37845370 PMCID: PMC10676324 DOI: 10.1007/s00439-023-02607-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 09/22/2023] [Indexed: 10/18/2023]
Abstract
Polyglutamine (polyQ) spinocerebellar ataxias (SCAs) comprise a group of autosomal dominant neurodegenerative disorders caused by (CAG/CAA)n expansions. The elongated stretches of adjacent glutamines alter the conformation of the native proteins inducing neurotoxicity, and subsequent motor and neurological symptoms. Although the etiology and neuropathology of most polyQ SCAs have been extensively studied, only a limited selection of therapies is available. Previous studies on SCA1 demonstrated that ATXN1L, a human duplicated gene of the disease-associated ATXN1, alleviated neuropathology in mice models. Other SCA-associated genes have paralogs (i.e., copies at different chromosomal locations derived from duplication of the parental gene), but their functional relevance and potential role in disease pathogenesis remain unexplored. Here, we review the protein homology, expression pattern, and molecular functions of paralogs in seven polyQ dominant ataxias-SCA1, SCA2, MJD/SCA3, SCA6, SCA7, SCA17, and DRPLA. Besides ATXN1L, we highlight ATXN2L, ATXN3L, CACNA1B, ATXN7L1, ATXN7L2, TBPL2, and RERE as promising functional candidates to play a role in the neuropathology of the respective SCA, along with the parental gene. Although most of these duplicates lack the (CAG/CAA)n region, if functionally redundant, they may compensate for a partial loss-of-function or dysfunction of the wild-type genes in SCAs. We aim to draw attention to the hypothesis that paralogs of disease-associated genes may underlie the complex neuropathology of dominant ataxias and potentiate new therapeutic strategies.
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Affiliation(s)
- Daniela Felício
- Instituto de Investigação e Inovação em Saúde (i3S), 4200-135, Porto, Portugal
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), 4200-135, Porto, Portugal
- Instituto Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, 4050-313, Porto, Portugal
| | - Tanguy Rubat du Mérac
- Instituto de Investigação e Inovação em Saúde (i3S), 4200-135, Porto, Portugal
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), 4200-135, Porto, Portugal
- Faculty of Science, University of Amsterdam, 1098 XH, Amsterdam, The Netherlands
| | - António Amorim
- Instituto de Investigação e Inovação em Saúde (i3S), 4200-135, Porto, Portugal
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), 4200-135, Porto, Portugal
- Department of Biology, Faculty of Sciences, University of Porto, 4169-007, Porto, Portugal
| | - Sandra Martins
- Instituto de Investigação e Inovação em Saúde (i3S), 4200-135, Porto, Portugal.
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), 4200-135, Porto, Portugal.
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Li YL. Stellate Ganglia and Cardiac Sympathetic Overactivation in Heart Failure. Int J Mol Sci 2022; 23:ijms232113311. [PMID: 36362099 PMCID: PMC9653702 DOI: 10.3390/ijms232113311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Revised: 10/28/2022] [Accepted: 10/29/2022] [Indexed: 11/06/2022] Open
Abstract
Heart failure (HF) is a major public health problem worldwide, especially coronary heart disease (myocardial infarction)-induced HF with reduced ejection fraction (HFrEF), which accounts for over 50% of all HF cases. An estimated 6 million American adults have HF. As a major feature of HF, cardiac sympathetic overactivation triggers arrhythmias and sudden cardiac death, which accounts for nearly 50–60% of mortality in HF patients. Regulation of cardiac sympathetic activation is highly integrated by the regulatory circuitry at multiple levels, including afferent, central, and efferent components of the sympathetic nervous system. Much evidence, from other investigators and us, has confirmed the afferent and central neural mechanisms causing sympathoexcitation in HF. The stellate ganglion is a peripheral sympathetic ganglion formed by the fusion of the 7th cervical and 1st thoracic sympathetic ganglion. As the efferent component of the sympathetic nervous system, cardiac postganglionic sympathetic neurons located in stellate ganglia provide local neural coordination independent of higher brain centers. Structural and functional impairments of cardiac postganglionic sympathetic neurons can be involved in cardiac sympathetic overactivation in HF because normally, many effects of the cardiac sympathetic nervous system on cardiac function are mediated via neurotransmitters (e.g., norepinephrine) released from cardiac postganglionic sympathetic neurons innervating the heart. This review provides an overview of cardiac sympathetic remodeling in stellate ganglia and potential mechanisms and the role of cardiac sympathetic remodeling in cardiac sympathetic overactivation and arrhythmias in HF. Targeting cardiac sympathetic remodeling in stellate ganglia could be a therapeutic strategy against malignant cardiac arrhythmias in HF.
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Affiliation(s)
- Yu-Long Li
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA; ; Tel.: +1-402-559-3016; Fax: +1-402-559-9659
- Department of Cellular & Integrative Physiology, University of Nebraska Medical Center, Omaha, NE 68198, USA
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3
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Zhang D, Tu H, Hu W, Duan B, Zimmerman MC, Li YL. Hydrogen Peroxide Scavenging Restores N-Type Calcium Channels in Cardiac Vagal Postganglionic Neurons and Mitigates Myocardial Infarction-Evoked Ventricular Arrhythmias in Type 2 Diabetes Mellitus. Front Cardiovasc Med 2022; 9:871852. [PMID: 35548411 PMCID: PMC9082497 DOI: 10.3389/fcvm.2022.871852] [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: 02/09/2022] [Accepted: 03/31/2022] [Indexed: 11/13/2022] Open
Abstract
ObjectiveWithdrawal of cardiac vagal activity is associated with ventricular arrhythmia-related high mortality in patients with type 2 diabetes mellitus (T2DM). Our recent study found that reduced cell excitability of cardiac vagal postganglionic (CVP) neurons is involved in cardiac vagal dysfunction and further exacerbates myocardial infarction (MI)-evoked ventricular arrhythmias and mortality in T2DM. However, the mechanisms responsible for T2DM-impaired cell excitability of CVP neurons remain unclear. This study tested if and how elevation of hydrogen peroxide (H2O2) inactivates CVP neurons and contributes to cardiac vagal dysfunction and ventricular arrhythmogenesis in T2DM.Methods and ResultsRat T2DM was induced by a high-fat diet plus streptozotocin injection. Local in vivo transfection of adenoviral catalase gene (Ad.CAT) successfully induced overexpression of catalase and subsequently reduced cytosolic H2O2 levels in CVP neurons in T2DM rats. Ad.CAT restored protein expression and ion currents of N-type Ca2+ channels and increased cell excitability of CVP neurons in T2DM. Ad.CAT normalized T2DM-impaired cardiac vagal activation, vagal control of ventricular function, and heterogeneity of ventricular electrical activity. Additionally, Ad.CAT not only reduced the susceptibility to ventricular arrhythmias, but also suppressed MI-evoked lethal ventricular arrhythmias such as VT/VF in T2DM.ConclusionsWe concluded that endogenous H2O2 elevation inhibited protein expression and activation of N-type Ca2+ channels and reduced cell excitability of CVP neurons, which further contributed to the withdrawal of cardiac vagal activity and ventricular arrhythmogenesis in T2DM. Our current study suggests that the H2O2-N-type Ca2+ channel signaling axis might be an effective therapeutic target to suppress ventricular arrhythmias in T2DM patients with MI.
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Affiliation(s)
- Dongze Zhang
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE, United States
| | - Huiyin Tu
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE, United States
| | - Wenfeng Hu
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE, United States
| | - Bin Duan
- Mary and Dick Holland Regenerative Medicine Program, Division of Cardiology, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, United States
| | - Matthew C. Zimmerman
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, NE, United States
| | - Yu-Long Li
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE, United States
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, NE, United States
- *Correspondence: Yu-Long Li
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4
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Murakami M, Murakami AM, Nemoto T, Ohba T, Yonekura M, Toyama Y, Tomita H, Matsuzaki Y, Sawamura D, Hirota K, Itagaki S, Asada Y, Miyoshi I. Enhanced β-adrenergic response in mice with dominant-negative expression of the PKD2L1 channel. PLoS One 2022; 17:e0261668. [PMID: 35051185 PMCID: PMC8775249 DOI: 10.1371/journal.pone.0261668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 12/08/2021] [Indexed: 11/19/2022] Open
Abstract
Polycystic kidney disease (PKD) is the most common genetic cause of kidney failure in humans. Among the various PKD-related molecules, PKD2L1 forms cation channels, but its physiological importance is obscure. In the present study, we established a transgenic mouse line by overexpressing the dominant-negative form of the mouse PKD2L1 gene (i.e., lacking the pore-forming domain). The resulting PKD2L1del-Tg mice exhibited supraventricular premature contraction, as well as enhanced sensitivity to β-adrenergic stimulation and unstable R-R intervals in electrocardiography. During spontaneous atrial contraction, PKD2L1del-Tg atria showed enhanced sensitivity to isoproterenol, norepinephrine, and epinephrine. Action potential recording revealed a shortened action potential duration in PKD2L1del-Tg atria in response to isoproterenol. These findings indicated increased adrenergic sensitivity in PKD2L1del-Tg mice, suggesting that PKD2L1 is involved in sympathetic regulation.
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Affiliation(s)
- Manabu Murakami
- Department of Pharmacology, Faculty of Medicine, University of Miyazaki, Miyazaki, Miyazaki, Japan
- * E-mail:
| | - Agnieszka M. Murakami
- Department of Pharmacology, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, Japan
| | - Takayuki Nemoto
- Department of Pharmacology, Faculty of Medicine, University of Miyazaki, Miyazaki, Miyazaki, Japan
| | - Takayoshi Ohba
- Department of Cell Physiology, Akita University School of Medicine, Akita, Akita, Japan
| | - Manabu Yonekura
- Department of Cardiology and Nephrology, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, Japan
| | - Yuichi Toyama
- Department of Cardiology and Nephrology, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, Japan
| | - Hirofumi Tomita
- Department of Cardiology and Nephrology, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, Japan
| | - Yasushi Matsuzaki
- Department of Dermatology, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, Japan
| | - Daisuke Sawamura
- Department of Dermatology, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, Japan
| | - Kazuyoshi Hirota
- Department of Anesthesiology, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, Japan
| | - Shirou Itagaki
- Collaboration Center for Community and Industry, Sapporo Medical University, Sapporo, Hokkaido, Japan
| | - Yujiro Asada
- Division of Pathophysiology, Department of Pathology, Faculty of Medicine, University of Miyazaki, Miyazaki, Miyazaki, Japan
| | - Ichiro Miyoshi
- Department of Laboratory Animal Medicine, Tohoku University School of Medicine, Sendai, Miyagi, Japan
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5
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Calcium channel blocker in patients with chronic kidney disease. Clin Exp Nephrol 2021; 26:207-215. [PMID: 34748113 PMCID: PMC8847284 DOI: 10.1007/s10157-021-02153-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Accepted: 10/24/2021] [Indexed: 10/26/2022]
Abstract
BACKGROUND Chronic kidney disease (CKD) is involved in a progressive deterioration in renal function over the years and is now a global public health problem. Currently, reducing the number of patients progressing to end-stage renal failure is urgently necessary. Hypertension and CKD interact with each other, and good control of blood pressure (BP) can improve CKD patients' prognosis. With the current global trend for more strict BP control, the importance of BP management and the need for medication to achieve this strict goal are increasing. Calcium channel blockers (CCBs), which target voltage-dependent calcium channels, are frequently used in combination with renin-angiotensin-aldosterone system inhibitors for CKD patients because of their strong BP-lowering properties and relatively few adverse side effects. Calcium channels have several subtypes, including L, N, T, P/Q, and R, and three types of CCBs, L-type CCBs, L-/T-type CCBs, and L-/N-type CCBs, that are available. Nowadays, the new functions and effects of the CCBs are being elucidated. CONCLUSION We should use different types of CCBs properly depending on their pharmacological effects, such as the strength of antihypertensive effects and the organ protection effects, taking into account the pathophysiology of the patients. In this article, the role and the use of CCBs in CKD patients are reviewed.
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Zhang D, Hu W, Tu H, Hackfort BT, Duan B, Xiong W, Wadman MC, Li YL. Macrophage depletion in stellate ganglia alleviates cardiac sympathetic overactivation and ventricular arrhythmogenesis by attenuating neuroinflammation in heart failure. Basic Res Cardiol 2021; 116:28. [PMID: 33884509 PMCID: PMC8060235 DOI: 10.1007/s00395-021-00871-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Accepted: 04/13/2021] [Indexed: 12/21/2022]
Abstract
Cardiac sympathetic overactivation is involved in arrhythmogenesis in patients with chronic heart failure (CHF). Inflammatory infiltration in the stellate ganglion (SG) is a critical factor for cardiac sympathoexcitation in patients with ventricular arrhythmias. This study aims to investigate if macrophage depletion in SGs decreases cardiac sympathetic overactivation and ventricular arrhythmogenesis in CHF. Surgical ligation of the coronary artery was used for induction of CHF. Clodronate liposomes were microinjected into bilateral SGs of CHF rats for macrophage depletion. Using cytokine array, immunofluorescence staining, and Western blot analysis, we found that macrophage expansion and expression of TNFα and IL-1β in SGs were markedly increased in CHF rats. Flow cytometry data confirmed that the percentage of macrophages in SGs was higher in CHF rats than that in sham rats. Clodronate liposomes significantly reduced CHF-elevated proinflammatory cytokine levels and macrophage expansion in SGs. Clodronate liposomes also reduced CHF-increased N-type Ca2+ currents and excitability of cardiac sympathetic postganglionic neurons and inhibited CHF-enhanced cardiac sympathetic nerve activity. ECG data from 24-h, continuous telemetry recording in conscious rats demonstrated that clodronate liposomes not only restored CHF-induced heterogeneity of ventricular electrical activities, but also decreased the incidence and duration of ventricular tachycardia/fibrillation in CHF. Macrophage depletion with clodronate liposomes attenuated CHF-induced cardiac sympathetic overactivation and ventricular arrhythmias through reduction of macrophage expansion and neuroinflammation in SGs.
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Affiliation(s)
- Dongze Zhang
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE, 68198, USA.
| | - Wenfeng Hu
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Huiyin Tu
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Bryan T Hackfort
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Bin Duan
- Mary & Dick Holland Regenerative Medicine Program, Division of Cardiology, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Wanfen Xiong
- Department of Surgery, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Michael C Wadman
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Yu-Long Li
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE, 68198, USA.
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, NE, 68198, USA.
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Blazon M, LaCarubba B, Bunda A, Czepiel N, Mallat S, Londrigan L, Andrade A. N-type calcium channels control GABAergic transmission in brain areas related to fear and anxiety. OBM NEUROBIOLOGY 2021; 5:10.21926/obm.neurobiol.2101083. [PMID: 33521586 PMCID: PMC7845927 DOI: 10.21926/obm.neurobiol.2101083] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
N-type (CaV2.2) calcium channels are key for action potential-evoked transmitter release in the peripheral and central nervous system. Previous studies have highlighted the functional relevance of N-type calcium channels at both the peripheral and central level. In the periphery, the N-type calcium channels regulate nociceptive and sympathetic responses. At the central level, N-type calcium channels have been linked to aggression, hyperlocomotion, and anxiety. Among the areas of the brain that are involved in anxiety are the basolateral amygdala, medial prefrontal cortex, and ventral hippocampus. These three areas share similar characteristics in their neuronal circuitry, where pyramidal projection neurons are under the inhibitory control of a wide array of interneurons including those that express the peptide cholecystokinin. This type of interneuron is well-known to rely on N-type calcium channels to release GABA in the hippocampus, however, whether these channels control GABA release from cholecystokinin-expressing interneurons in the basolateral amygdala and medial prefrontal cortex is not known. Here, using mouse models to genetically label cholecystokinin-expressing interneurons and electrophysiology, we found that in the basolateral amygdala, N-type calcium channels control ~50% of GABA release from these neurons onto pyramidal cells. By contrast, in the medial prefrontal cortex N-type calcium channels are functionally absent in synapses of cholecystokinin-expressing interneurons, but control ~40% of GABA release from other types of interneurons. Our findings provide insights into the precise localization of N-type calcium channels in interneurons of brain areas related to anxiety.
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Affiliation(s)
- Maxwell Blazon
- Department of Biological Sciences, University of New Hampshire. 46 College Road, 245 Rudman Hall. Durham, NH, USA
| | - Brianna LaCarubba
- Department of Biological Sciences, University of New Hampshire. 46 College Road, 245 Rudman Hall. Durham, NH, USA
| | - Alexandra Bunda
- Department of Biological Sciences, University of New Hampshire. 46 College Road, 245 Rudman Hall. Durham, NH, USA
| | - Natalie Czepiel
- Department of Biological Sciences, University of New Hampshire. 46 College Road, 245 Rudman Hall. Durham, NH, USA
| | - Shayna Mallat
- Department of Biological Sciences, University of New Hampshire. 46 College Road, 245 Rudman Hall. Durham, NH, USA
| | - Laura Londrigan
- Department of Biological Sciences, University of New Hampshire. 46 College Road, 245 Rudman Hall. Durham, NH, USA
| | - Arturo Andrade
- Department of Biological Sciences, University of New Hampshire. 46 College Road, 245 Rudman Hall. Durham, NH, USA
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8
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Zhang D, Tu H, Wang C, Cao L, Hu W, Hackfort BT, Muelleman RL, Wadman MC, Li YL. Inhibition of N-type calcium channels in cardiac sympathetic neurons attenuates ventricular arrhythmogenesis in heart failure. Cardiovasc Res 2021; 117:137-148. [PMID: 31995173 PMCID: PMC7797209 DOI: 10.1093/cvr/cvaa018] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 11/13/2019] [Accepted: 01/21/2020] [Indexed: 02/07/2023] Open
Abstract
AIMS Cardiac sympathetic overactivation is an important trigger of ventricular arrhythmias in patients with chronic heart failure (CHF). Our previous study demonstrated that N-type calcium (Cav2.2) currents in cardiac sympathetic post-ganglionic (CSP) neurons were increased in CHF. This study investigated the contribution of Cav2.2 channels in cardiac sympathetic overactivation and ventricular arrhythmogenesis in CHF. METHODS AND RESULTS Rat CHF was induced by surgical ligation of the left coronary artery. Lentiviral Cav2.2-α shRNA or scrambled shRNA was transfected in vivo into stellate ganglia (SG) in CHF rats. Final experiments were performed at 14 weeks after coronary artery ligation. Real-time polymerase chain reaction and western blot data showed that in vivo transfection of Cav2.2-α shRNA reduced the expression of Cav2.2-α mRNA and protein in the SG in CHF rats. Cav2.2-α shRNA also reduced Cav2.2 currents and cell excitability of CSP neurons and attenuated cardiac sympathetic nerve activities (CSNA) in CHF rats. The power spectral analysis of heart rate variability (HRV) further revealed that transfection of Cav2.2-α shRNA in the SG normalized CHF-caused cardiac sympathetic overactivation in conscious rats. Twenty-four-hour continuous telemetry electrocardiogram recording revealed that this Cav2.2-α shRNA not only decreased incidence and duration of ventricular tachycardia/ventricular fibrillation but also improved CHF-induced heterogeneity of ventricular electrical activity in conscious CHF rats. Cav2.2-α shRNA also decreased susceptibility to ventricular arrhythmias in anaesthetized CHF rats. However, Cav2.2-α shRNA failed to improve CHF-induced cardiac contractile dysfunction. Scrambled shRNA did not affect Cav2.2 currents and cell excitability of CSP neurons, CSNA, HRV, and ventricular arrhythmogenesis in CHF rats. CONCLUSIONS Overactivation of Cav2.2 channels in CSP neurons contributes to cardiac sympathetic hyperactivation and ventricular arrhythmogenesis in CHF. This suggests that discovering purely selective and potent small-molecule Cav2.2 channel blockers could be a potential therapeutic strategy to decrease fatal ventricular arrhythmias in CHF.
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MESH Headings
- Action Potentials
- Animals
- Calcium/metabolism
- Calcium Channels, N-Type/genetics
- Calcium Channels, N-Type/metabolism
- Calcium Signaling
- Cells, Cultured
- Disease Models, Animal
- Heart/innervation
- Heart Failure/genetics
- Heart Failure/metabolism
- Heart Failure/physiopathology
- Heart Rate
- Male
- RNA Interference
- RNA, Small Interfering/genetics
- RNA, Small Interfering/metabolism
- Rats, Sprague-Dawley
- Stellate Ganglion/metabolism
- Stellate Ganglion/physiopathology
- Sympathetic Fibers, Postganglionic/metabolism
- Sympathetic Fibers, Postganglionic/physiopathology
- Tachycardia, Ventricular/genetics
- Tachycardia, Ventricular/metabolism
- Tachycardia, Ventricular/physiopathology
- Tachycardia, Ventricular/prevention & control
- Ventricular Fibrillation/genetics
- Ventricular Fibrillation/metabolism
- Ventricular Fibrillation/physiopathology
- Ventricular Fibrillation/prevention & control
- Rats
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Affiliation(s)
- Dongze Zhang
- Department of Emergency Medicine, University of Nebraska Medical Center, 985850 Nebraska Medical Center, Omaha, NE 68198-5850, USA
| | - Huiyin Tu
- Department of Emergency Medicine, University of Nebraska Medical Center, 985850 Nebraska Medical Center, Omaha, NE 68198-5850, USA
| | - Chaojun Wang
- Department of Emergency Medicine, University of Nebraska Medical Center, 985850 Nebraska Medical Center, Omaha, NE 68198-5850, USA
- Department of Cardiovascular Disease, the First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, 710061, China
| | - Liang Cao
- Department of Emergency Medicine, University of Nebraska Medical Center, 985850 Nebraska Medical Center, Omaha, NE 68198-5850, USA
- Department of Cardiac Surgery, Second Xiangya Hospital, Central South University, Changsha 410011, China
| | - Wenfeng Hu
- Department of Emergency Medicine, University of Nebraska Medical Center, 985850 Nebraska Medical Center, Omaha, NE 68198-5850, USA
| | - Bryan T Hackfort
- Department of Cellular & Integrative Physiology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Robert L Muelleman
- Department of Emergency Medicine, University of Nebraska Medical Center, 985850 Nebraska Medical Center, Omaha, NE 68198-5850, USA
| | - Michael C Wadman
- Department of Emergency Medicine, University of Nebraska Medical Center, 985850 Nebraska Medical Center, Omaha, NE 68198-5850, USA
| | - Yu-Long Li
- Department of Emergency Medicine, University of Nebraska Medical Center, 985850 Nebraska Medical Center, Omaha, NE 68198-5850, USA
- Department of Cellular & Integrative Physiology, University of Nebraska Medical Center, Omaha, NE 68198, USA
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9
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Tajiri K, Guichard JB, Qi X, Xiong F, Naud P, Tardif JC, Costa AD, Aonuma K, Nattel S. An N-/L-type calcium channel blocker, cilnidipine, suppresses autonomic, electrical, and structural remodelling associated with atrial fibrillation. Cardiovasc Res 2020; 115:1975-1985. [PMID: 31119260 DOI: 10.1093/cvr/cvz136] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 03/18/2019] [Accepted: 05/16/2019] [Indexed: 12/15/2022] Open
Abstract
AIMS Autonomic dysfunction can promote atrial fibrillation (AF) and results from AF-related remodelling. N-type Ca2+-channels (NTCCs) at sympathetic nerve terminals mediate Ca2+-entry that triggers neurotransmitter release. AF-associated remodelling plays an important role in AF pathophysiology but the effects of NTCC inhibition on such remodelling is unknown. Here, we investigated the ability of a clinically available Ca2+-channel blocker (CCB) with NTCC-blocking activity to suppress the arrhythmogenic effects of AF-promoting remodelling in dogs. METHODS AND RESULTS Mongrel dogs were kept in AF by right atrial tachypacing at 600 bpm. Four groups were studied under short-term AF (7 days): (i) Shams, instrumented but without tachypacing (n = 5); (ii) a placebo group, tachypaced while receiving placebo (n = 6); (iii) a control tachypacing group receiving nifedipine (10 mg orally twice-daily; n = 5), an L-type CCB; and (iv) a cilnidipine group, subjected to tachypacing and treatment with cilnidipine (10 mg orally twice-daily; n = 7), an N-/L-type CCB. With cilnidipine therapy, dogs with 1-week AF showed significantly reduced autonomic changes reflected by heart rate variability (decreases in RMSSD and pNN50) and plasma norepinephrine concentrations. In addition, cilnidipine-treated dogs had decreased extracellular matrix gene expression vs. nifedipine-dogs. As in previous work, atrial fibrosis had not yet developed after 1-week AF, so three additional groups were studied under longer-term AF (21 days): (i) Shams, instrumented without tachypacing or drug therapy (n = 8); (ii) a placebo group, tachypaced while receiving placebo (n = 8); (iii) a cilnidipine group, subjected to tachypacing during treatment with cilnidipine (10 mg twice-daily; n = 8). Cilnidipine attenuated 3-week AF effects on AF duration and atrial conduction, and suppressed AF-induced increases in fibrous-tissue content, decreases in connexin-43 expression and reductions in sodium-channel expression. CONCLUSIONS Cilnidipine, a commercially available NTCC-blocking drug, prevents AF-induced autonomic, electrical and structural remodelling, along with associated AF promotion.
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Affiliation(s)
- Kazuko Tajiri
- Department of Medicine and Research Center, Montreal Heart Institute and Université de Montréal, Belanger St E, Montreal, Quebec, Canada.,Department of Cardiology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, Japan
| | - Jean-Baptiste Guichard
- Department of Medicine and Research Center, Montreal Heart Institute and Université de Montréal, Belanger St E, Montreal, Quebec, Canada.,Department of Cardiology, University Hospital of Saint-Étienne, University Jean Monnet, Saint-Étienne, France
| | - Xiaoyan Qi
- Department of Medicine and Research Center, Montreal Heart Institute and Université de Montréal, Belanger St E, Montreal, Quebec, Canada
| | - Feng Xiong
- Department of Medicine and Research Center, Montreal Heart Institute and Université de Montréal, Belanger St E, Montreal, Quebec, Canada
| | - Patrice Naud
- Department of Medicine and Research Center, Montreal Heart Institute and Université de Montréal, Belanger St E, Montreal, Quebec, Canada
| | - Jean-Claude Tardif
- Department of Medicine and Research Center, Montreal Heart Institute and Université de Montréal, Belanger St E, Montreal, Quebec, Canada
| | - Antoine Da Costa
- Department of Cardiology, University Hospital of Saint-Étienne, University Jean Monnet, Saint-Étienne, France
| | - Kazutaka Aonuma
- Department of Cardiology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, Japan
| | - Stanley Nattel
- Department of Medicine and Research Center, Montreal Heart Institute and Université de Montréal, Belanger St E, Montreal, Quebec, Canada.,Department of Pharmacology and Therapeutics, McGill University, Promenade Sir-William-Osler, Montreal, Quebec, Canada.,Institute of Pharmacology, West German Heart and Vascular Center, Faculty of Medicine, University Duisburg-Essen, Hufelandstr. 55, Essen, Germany.,IHU LIRYC and Fondation Bordeaux Université, Avenue du Haut Lévêque, Pessac, Bordeaux, France
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10
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Bardsley EN, Paterson DJ. Neurocardiac regulation: from cardiac mechanisms to novel therapeutic approaches. J Physiol 2020; 598:2957-2976. [PMID: 30307615 PMCID: PMC7496613 DOI: 10.1113/jp276962] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 10/02/2018] [Indexed: 12/15/2022] Open
Abstract
Cardiac sympathetic overactivity is a well-established contributor to the progression of neurogenic hypertension and heart failure, yet the underlying pathophysiology remains unclear. Recent studies have highlighted the importance of acutely regulated cyclic nucleotides and their effectors in the control of intracellular calcium and exocytosis. Emerging evidence now suggests that a significant component of sympathetic overactivity and enhanced transmission may arise from impaired cyclic nucleotide signalling, resulting from compromised phosphodiesterase activity, as well as alterations in receptor-coupled G-protein activation. In this review, we address some of the key cellular and molecular pathways that contribute to sympathetic overactivity in hypertension and discuss their potential for therapeutic targeting.
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Affiliation(s)
- E. N. Bardsley
- Wellcome Trust OXION Initiative in Ion Channels and DiseaseOxfordUK
- Burdon Sanderson Cardiac Science Centre, Department of PhysiologyAnatomy and Genetics, University of OxfordOxfordOX1 3PTUK
| | - D. J. Paterson
- Wellcome Trust OXION Initiative in Ion Channels and DiseaseOxfordUK
- Burdon Sanderson Cardiac Science Centre, Department of PhysiologyAnatomy and Genetics, University of OxfordOxfordOX1 3PTUK
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11
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Mishima K, Nakasatomi M, Takahashi S, Ikeuchi H, Sakairi T, Kaneko Y, Hiromura K, Nojima Y, Maeshima A. Attenuation of renal fibrosis after unilateral ureteral obstruction in mice lacking the N-type calcium channel. PLoS One 2019; 14:e0223496. [PMID: 31596895 PMCID: PMC6785082 DOI: 10.1371/journal.pone.0223496] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Accepted: 09/22/2019] [Indexed: 11/18/2022] Open
Abstract
The N-type Ca2+ channel (Cav2.2) is distributed in sympathetic nerves that innervate the tubules, the vessels, and the juxtaglomerular granular cells of the kidney. However, the role of N-type Ca2+ channels in renal disease remains unknown. To address this issue, Cav2.2 knockout mice were utilized. Immunoreactive Cav2.2 was undetectable in normal kidneys of C57BL/6N mice, but it became positive in the interstitial S100-positive nerve fibers after unilateral ureteral obstruction (UUO). There were no significant differences in mean blood pressure, heart rate, and renal function between wild-type littermates and Cav2.2-knockout mice at baseline, as well as after UUO. Cav2.2 deficiency significantly reduced the EVG-positive fibrotic area, alpha-SMA expression, the production of type I collagen, and the hypoxic area in the obstructed kidneys. The expression of tyrosine hydroxylase, a marker for sympathetic neurons, was significantly increased in the obstructed kidneys of wild-type mice, but not in Cav2.2-knockout mice. These data suggest that increased Cav2.2 is implicated in renal nerve activation leading to the progression of renal fibrosis. Blockade of Cav2.2 might be a novel therapeutic approach for preventing renal fibrosis.
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Affiliation(s)
- Keiichiro Mishima
- Department of Nephrology and Rheumatology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Masao Nakasatomi
- Department of Nephrology and Rheumatology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Shunsuke Takahashi
- Department of Nephrology and Rheumatology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Hidekazu Ikeuchi
- Department of Nephrology and Rheumatology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Toru Sakairi
- Department of Nephrology and Rheumatology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Yoriaki Kaneko
- Department of Nephrology and Rheumatology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Keiju Hiromura
- Department of Nephrology and Rheumatology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Yoshihisa Nojima
- Department of Nephrology and Rheumatology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Akito Maeshima
- Department of Nephrology and Rheumatology, Gunma University Graduate School of Medicine, Maebashi, Japan
- * E-mail:
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12
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Arostegui MC, Quinn TP, Seeb LW, Seeb JE, McKinney GJ. Retention of a chromosomal inversion from an anadromous ancestor provides the genetic basis for alternative freshwater ecotypes in rainbow trout. Mol Ecol 2019; 28:1412-1427. [DOI: 10.1111/mec.15037] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 01/18/2019] [Accepted: 01/28/2019] [Indexed: 12/20/2022]
Affiliation(s)
- Martin C. Arostegui
- School of Aquatic and Fishery Sciences University of Washington Seattle Washington
| | - Thomas P. Quinn
- School of Aquatic and Fishery Sciences University of Washington Seattle Washington
| | - Lisa W. Seeb
- School of Aquatic and Fishery Sciences University of Washington Seattle Washington
| | - James E. Seeb
- School of Aquatic and Fishery Sciences University of Washington Seattle Washington
| | - Garrett J. McKinney
- School of Aquatic and Fishery Sciences University of Washington Seattle Washington
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13
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Nishimura A, Shimauchi T, Tanaka T, Shimoda K, Toyama T, Kitajima N, Ishikawa T, Shindo N, Numaga-Tomita T, Yasuda S, Sato Y, Kuwahara K, Kumagai Y, Akaike T, Ide T, Ojida A, Mori Y, Nishida M. Hypoxia-induced interaction of filamin with Drp1 causes mitochondrial hyperfission-associated myocardial senescence. Sci Signal 2018; 11:11/556/eaat5185. [PMID: 30425165 DOI: 10.1126/scisignal.aat5185] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Defective mitochondrial dynamics through aberrant interactions between mitochondria and actin cytoskeleton is increasingly recognized as a key determinant of cardiac fragility after myocardial infarction (MI). Dynamin-related protein 1 (Drp1), a mitochondrial fission-accelerating factor, is activated locally at the fission site through interactions with actin. Here, we report that the actin-binding protein filamin A acted as a guanine nucleotide exchange factor for Drp1 and mediated mitochondrial fission-associated myocardial senescence in mice after MI. In peri-infarct regions characterized by mitochondrial hyperfission and associated with myocardial senescence, filamin A colocalized with Drp1 around mitochondria. Hypoxic stress induced the interaction of filamin A with the GTPase domain of Drp1 and increased Drp1 activity in an actin-binding-dependent manner in rat cardiomyocytes. Expression of the A1545T filamin mutant, which potentiates actin aggregation, promoted mitochondrial hyperfission under normoxia. Furthermore, pharmacological perturbation of the Drp1-filamin A interaction by cilnidipine suppressed mitochondrial hyperfission-associated myocardial senescence and heart failure after MI. Together, these data demonstrate that Drp1 association with filamin and the actin cytoskeleton contributes to cardiac fragility after MI and suggests a potential repurposing of cilnidipine, as well as provides a starting point for innovative Drp1 inhibitor development.
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Affiliation(s)
- Akiyuki Nishimura
- National Institute for Physiological Sciences (NIPS), National Institutes of Natural Sciences, Aichi 444-8787, Japan.,Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Aichi 444-8787, Japan.,SOKENDAI (School of Life Science, The Graduate University for Advanced Studies), Aichi 444-8787, Japan.,Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Tsukasa Shimauchi
- National Institute for Physiological Sciences (NIPS), National Institutes of Natural Sciences, Aichi 444-8787, Japan.,Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Aichi 444-8787, Japan.,Kyushu University Graduate School of Medical Sciences, Fukuoka 812-8582, Japan
| | - Tomohiro Tanaka
- National Institute for Physiological Sciences (NIPS), National Institutes of Natural Sciences, Aichi 444-8787, Japan.,Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Aichi 444-8787, Japan
| | - Kakeru Shimoda
- National Institute for Physiological Sciences (NIPS), National Institutes of Natural Sciences, Aichi 444-8787, Japan.,Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Aichi 444-8787, Japan.,SOKENDAI (School of Life Science, The Graduate University for Advanced Studies), Aichi 444-8787, Japan
| | - Takashi Toyama
- National Institute for Physiological Sciences (NIPS), National Institutes of Natural Sciences, Aichi 444-8787, Japan.,Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan.,Faculty of Medicine, University of Tsukuba, Tsukuba 305-8575, Japan
| | - Naoyuki Kitajima
- National Institute for Physiological Sciences (NIPS), National Institutes of Natural Sciences, Aichi 444-8787, Japan.,Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Tatsuya Ishikawa
- Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan.,EA Pharma Co. Inc., Tokyo 104-0042, Japan
| | - Naoya Shindo
- Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Takuro Numaga-Tomita
- National Institute for Physiological Sciences (NIPS), National Institutes of Natural Sciences, Aichi 444-8787, Japan.,Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Aichi 444-8787, Japan.,SOKENDAI (School of Life Science, The Graduate University for Advanced Studies), Aichi 444-8787, Japan
| | - Satoshi Yasuda
- National Institute of Health Sciences, Kanagawa 210-9501, Japan
| | - Yoji Sato
- Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan.,National Institute of Health Sciences, Kanagawa 210-9501, Japan
| | | | - Yoshito Kumagai
- Faculty of Medicine, University of Tsukuba, Tsukuba 305-8575, Japan
| | - Takaaki Akaike
- Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Tomomi Ide
- Kyushu University Graduate School of Medical Sciences, Fukuoka 812-8582, Japan
| | - Akio Ojida
- Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Yasuo Mori
- Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Motohiro Nishida
- National Institute for Physiological Sciences (NIPS), National Institutes of Natural Sciences, Aichi 444-8787, Japan. .,Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Aichi 444-8787, Japan.,SOKENDAI (School of Life Science, The Graduate University for Advanced Studies), Aichi 444-8787, Japan.,Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan
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14
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Ritagliati C, Baro Graf C, Stival C, Krapf D. Regulation mechanisms and implications of sperm membrane hyperpolarization. Mech Dev 2018; 154:33-43. [PMID: 29694849 DOI: 10.1016/j.mod.2018.04.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 04/16/2018] [Accepted: 04/18/2018] [Indexed: 12/21/2022]
Abstract
Mammalian sperm are unable to fertilize the egg immediately after ejaculation. In order to gain fertilization competence, they need to undergo a series of biochemical and physiological modifications inside the female reproductive tract, known as capacitation. Capacitation correlates with two essential events for fertilization: hyperactivation, an asymmetric and vigorous flagellar motility, and the ability to undergo the acrosome reaction. At a molecular level, capacitation is associated to: phosphorylation cascades, modification of membrane lipids, alkalinization of the intracellular pH, increase in the intracellular Ca2+ concentration and hyperpolarization of the sperm plasma membrane potential. Hyperpolarization is a crucial event in capacitation since it primes the sperm to undergo the exocytosis of the acrosome content, essential to achieve fertilization of the oocyte.
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Affiliation(s)
- Carla Ritagliati
- Laboratory of Cell Signal Transduction Networks, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET-UNR), Rosario 2000, Argentina.
| | - Carolina Baro Graf
- Laboratory of Cell Signal Transduction Networks, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET-UNR), Rosario 2000, Argentina
| | - Cintia Stival
- Laboratory of Cell Signal Transduction Networks, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET-UNR), Rosario 2000, Argentina
| | - Dario Krapf
- Laboratory of Cell Signal Transduction Networks, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET-UNR), Rosario 2000, Argentina; Laboratorio de Especialidades Reproductivas, Facultad de Ciencias Bioquimicas y Farmacéuticas, UNR, Rosario 2000, Argentina.
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15
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González-Ramírez R, Felix R. Transcriptional regulation of voltage-gated Ca 2+ channels. Acta Physiol (Oxf) 2018; 222. [PMID: 28371478 DOI: 10.1111/apha.12883] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 02/14/2017] [Accepted: 03/21/2017] [Indexed: 12/30/2022]
Abstract
The transcriptional regulation of voltage-gated Ca2+ (CaV ) channels is an emerging research area that promises to improve our understanding of how many relevant physiological events are shaped in the central nervous system, the skeletal muscle and other tissues. Interestingly, a picture of how transcription of CaV channel subunit genes is controlled is evolving with the identification of the promoter regions required for tissue-specific expression and the identification of transcription factors that control their expression. These promoters share several characteristics that include multiple transcriptional start sites, lack of a TATA box and the presence of elements conferring tissue-selective expression. Likewise, changes in CaV channel expression occur throughout development, following ischaemia, seizures or chronic drug administration. This review focuses on insights achieved regarding the control of CaV channel gene expression. To further understand the complexities of expression and to increase the possibilities of detecting CaV channel alterations causing human disease, a deeper knowledge on the structure of the 5' upstream regions of the genes encoding these remarkable proteins will be necessary.
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Affiliation(s)
- R. González-Ramírez
- Departamento de Biología Molecular e Histocompatibilidad; Hospital General ‘Dr. Manuel Gea González’; Secretaría de Salud; Ciudad de México México
| | - R. Felix
- Departmento de Biología Celular; Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (Cinvestav-IPN); Ciudad de México México
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16
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Dysregulation of Neuronal Ca2+ Channel Linked to Heightened Sympathetic Phenotype in Prohypertensive States. J Neurosci 2017; 36:8562-73. [PMID: 27535905 DOI: 10.1523/jneurosci.1059-16.2016] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 05/27/2016] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED Hypertension is associated with impaired nitric oxide (NO)-cyclic nucleotide (CN)-coupled intracellular calcium (Ca(2+)) homeostasis that enhances cardiac sympathetic neurotransmission. Because neuronal membrane Ca(2+) currents are reduced by NO-activated S-nitrosylation, we tested whether CNs affect membrane channel conductance directly in neurons isolated from the stellate ganglia of spontaneously hypertensive rats (SHRs) and their normotensive controls. Using voltage-clamp and cAMP-protein kinase A (PKA) FRET sensors, we hypothesized that impaired CN regulation provides a direct link to abnormal signaling of neuronal calcium channels in the SHR and that targeting cGMP can restore the channel phenotype. We found significantly larger whole-cell Ca(2+) currents from diseased neurons that were largely mediated by the N-type Ca(2+) channel (Cav2.2). Elevating cGMP restored the SHR Ca(2+) current to levels seen in normal neurons that were not affected by cGMP. cGMP also decreased cAMP levels and PKA activity in diseased neurons. In contrast, cAMP-PKA activity was increased in normal neurons, suggesting differential switching in phosphodiesterase (PDE) activity. PDE2A inhibition enhanced the Ca(2+) current in normal neurons to a conductance similar to that seen in SHR neurons, whereas the inhibitor slightly decreased the current in diseased neurons. Pharmacological evidence supported a switching from cGMP acting via PDE3 in control neurons to PDE2A in SHR neurons in the modulation of the Ca(2+) current. Our data suggest that a disturbance in the regulation of PDE-coupled CNs linked to N-type Ca(2+) channels is an early hallmark of the prohypertensive phenotype associated with intracellular Ca(2+) impairment underpinning sympathetic dysautonomia. SIGNIFICANCE STATEMENT Here, we identify dysregulation of cyclic-nucleotide (CN)-linked neuronal Ca(2+) channel activity that could provide the trigger for the enhanced sympathetic neurotransmission observed in the prohypertensive state. Furthermore, we provide evidence that increasing cGMP rescues the channel phenotype and restores ion channel activity to levels seen in normal neurons. We also observed CN cross-talk in sympathetic neurons that may be related to a differential switching in phosphodiesterase activity. The presence of these early molecular changes in asymptomatic, prohypertensive animals could facilitate the identification of novel therapeutic targets with which to modulate intracellular Ca(2+) Turning down the gain of sympathetic hyperresponsiveness in cardiovascular disease associated with sympathetic dysautonomia would have significant therapeutic utility.
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17
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Tay A, Di Carlo D. Magnetic Nanoparticle-Based Mechanical Stimulation for Restoration of Mechano-Sensitive Ion Channel Equilibrium in Neural Networks. NANO LETTERS 2017; 17:886-892. [PMID: 28094958 DOI: 10.1021/acs.nanolett.6b04200] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Techniques offering remote control of neural activity with high spatiotemporal resolution and specificity are invaluable for deciphering the physiological roles of different classes of neurons in brain development and disease. Here, we first confirm that microfabricated substrates with enhanced magnetic field gradients allow for wireless stimulation of neural circuits dosed with magnetic nanoparticles using calcium indicator dyes. We also investigate the mechanism of mechano-transduction in this system and identify that N-type mechano-sensitive calcium ion channels play a key role in signal generation in response to magnetic force. We next applied this method for chronic stimulation of a fragile X syndrome (FXS) neural network model and found that magnetic force-based stimulation modulated the expression of mechano-sensitive ion channels which are out of equilibrium in a number of neurological diseases including FXS. This technique can serve as a tool for acute and chronic modulation of endogenous ion channel expression in neural circuits in a spatially localized manner to investigate a number of disease processes in the future.
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Affiliation(s)
- Andy Tay
- Department of Bioengineering, University of California , Los Angeles, California 90025, United States
- Department of Biomedical Engineering, National University of Singapore , Singapore 117583
| | - Dino Di Carlo
- Department of Bioengineering, University of California , Los Angeles, California 90025, United States
- California Nanosystems Institute, University of California , Los Angeles, California 90025, United States
- Jonsson Comprehensive Cancer Center, University of California , Los Angeles, California 90025, United States
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18
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Abstract
Cardiac arrhythmias can follow disruption of the normal cellular electrophysiological processes underlying excitable activity and their tissue propagation as coherent wavefronts from the primary sinoatrial node pacemaker, through the atria, conducting structures and ventricular myocardium. These physiological events are driven by interacting, voltage-dependent, processes of activation, inactivation, and recovery in the ion channels present in cardiomyocyte membranes. Generation and conduction of these events are further modulated by intracellular Ca2+ homeostasis, and metabolic and structural change. This review describes experimental studies on murine models for known clinical arrhythmic conditions in which these mechanisms were modified by genetic, physiological, or pharmacological manipulation. These exemplars yielded molecular, physiological, and structural phenotypes often directly translatable to their corresponding clinical conditions, which could be investigated at the molecular, cellular, tissue, organ, and whole animal levels. Arrhythmogenesis could be explored during normal pacing activity, regular stimulation, following imposed extra-stimuli, or during progressively incremented steady pacing frequencies. Arrhythmic substrate was identified with temporal and spatial functional heterogeneities predisposing to reentrant excitation phenomena. These could arise from abnormalities in cardiac pacing function, tissue electrical connectivity, and cellular excitation and recovery. Triggering events during or following recovery from action potential excitation could thereby lead to sustained arrhythmia. These surface membrane processes were modified by alterations in cellular Ca2+ homeostasis and energetics, as well as cellular and tissue structural change. Study of murine systems thus offers major insights into both our understanding of normal cardiac activity and its propagation, and their relationship to mechanisms generating clinical arrhythmias.
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Affiliation(s)
- Christopher L-H Huang
- Physiological Laboratory and the Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
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19
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Ablation of the N-type calcium channel ameliorates diabetic nephropathy with improved glycemic control and reduced blood pressure. Sci Rep 2016; 6:27192. [PMID: 27273361 PMCID: PMC4895143 DOI: 10.1038/srep27192] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 05/16/2016] [Indexed: 12/14/2022] Open
Abstract
Pharmacological blockade of the N- and L-type calcium channel lessens renal injury in kidney disease patients. The significance of specific blockade of α1 subunit of N-type calcium channel, Cav2.2, in diabetic nephropathy, however, remains to be clarified. To examine functional roles, we mated Cav2.2−/− mice with db/db (diabetic) mice on the C57BLKS background. Cav2.2 was localized in glomeruli including podocytes and in distal tubular cells. Diabetic Cav2.2−/− mice significantly reduced urinary albumin excretion, glomerular hyperfiltration, blood glucose levels, histological deterioration and systolic blood pressure (SBP) with decreased urinary catecholamine compared to diabetic Cav2.2+/+ mice. Interestingly, diabetic heterozygous Cav2.2+/− mice also decreased albuminuria, although they exhibited comparable systolic blood pressure, sympathetic nerve activity and creatinine clearance to diabetic Cav2.2+/+ mice. Consistently, diabetic mice with cilnidipine, an N-/L-type calcium channel blocker, showed a reduction in albuminuria and improvement of glomerular changes compared to diabetic mice with nitrendipine. In cultured podocytes, depolarization-dependent calcium responses were decreased by ω-conotoxin, a Cav2.2-specific inhibitor. Furthermore, reduction of nephrin by transforming growth factor-β (TGF-β) in podocytes was abolished with ω-conotoxin, cilnidipine or mitogen-activated protein kinase kinase inhibitor. In conclusion, Cav2.2 inhibition exerts renoprotective effects against the progression of diabetic nephropathy, partly by protecting podocytes.
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20
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Miller MR, Mansell SA, Meyers SA, Lishko PV. Flagellar ion channels of sperm: similarities and differences between species. Cell Calcium 2015; 58:105-13. [DOI: 10.1016/j.ceca.2014.10.009] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 10/16/2014] [Accepted: 10/20/2014] [Indexed: 10/24/2022]
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21
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Lenkey N, Kirizs T, Holderith N, Máté Z, Szabó G, Vizi ES, Hájos N, Nusser Z. Tonic endocannabinoid-mediated modulation of GABA release is independent of the CB1 content of axon terminals. Nat Commun 2015; 6:6557. [PMID: 25891347 PMCID: PMC4413030 DOI: 10.1038/ncomms7557] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 02/06/2015] [Indexed: 12/28/2022] Open
Abstract
The release of GABA from cholecystokinin-containing interneurons is modulated by type-1 cannabinoid receptors (CB1). Here we tested the hypothesis that the strength of CB1-mediated modulation of GABA release is related to the CB1 content of axon terminals. Basket cell boutons have on average 78% higher CB1 content than those of dendritic-layer-innervating (DLI) cells, a consequence of larger bouton surface and higher CB1 density. The CB1 antagonist AM251 caused a 54% increase in action potential-evoked [Ca(2+)] in boutons of basket cells, but not in DLI cells. However, the effect of AM251 did not correlate with CB1 immunoreactivity of individual boutons. Moreover, a CB1 agonist decreased [Ca(2+)] in a cell type- and CB1-content-independent manner. Replica immunogold labelling demonstrated the colocalization of CB1 with the Cav2.2 Ca(2+) channel subunit. Our data suggest that only a subpopulation of CB1s, within nanometre distances from their target Cav2.2 channels, are responsible for endocannabinoid-mediated modulation of GABA release.
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Affiliation(s)
- Nora Lenkey
- Lendület Laboratory of Cellular Neurophysiology,
Institute of Experimental Medicine, Hungarian Academy of Sciences,
Budapest
H1083, Hungary
| | - Tekla Kirizs
- Lendület Laboratory of Cellular Neurophysiology,
Institute of Experimental Medicine, Hungarian Academy of Sciences,
Budapest
H1083, Hungary
- János Szentágothai School of
Neurosciences, Semmelweis University, Budapest H1085,
Hungary
| | - Noemi Holderith
- Lendület Laboratory of Cellular Neurophysiology,
Institute of Experimental Medicine, Hungarian Academy of Sciences,
Budapest
H1083, Hungary
| | - Zoltán Máté
- Division of Medical Gene Technology, Institute of
Experimental Medicine, Hungarian Academy of Sciences, Budapest
H1083, Hungary
| | - Gábor Szabó
- Division of Medical Gene Technology, Institute of
Experimental Medicine, Hungarian Academy of Sciences, Budapest
H1083, Hungary
| | - E. Sylvester Vizi
- Laboratory of Drug Research, Institute of Experimental
Medicine, Hungarian Academy of Sciences, Budapest H1083,
Hungary
| | - Norbert Hájos
- Lendület Laboratory of Network Neurophysiology,
Institute of Experimental Medicine, Hungarian Academy of Sciences,
Szigony street 43, Budapest
H1083, Hungary
| | - Zoltan Nusser
- Lendület Laboratory of Cellular Neurophysiology,
Institute of Experimental Medicine, Hungarian Academy of Sciences,
Budapest
H1083, Hungary
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22
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Kuwahara K, Kimura T. The organ-protective effect of N-type Ca(2+) channel blockade. Pharmacol Ther 2015; 151:1-7. [PMID: 25659931 DOI: 10.1016/j.pharmthera.2015.02.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 01/20/2015] [Indexed: 01/13/2023]
Abstract
The six subtypes of voltage-dependent Ca(2+) channels (VDCCs) mediate a wide range of physiological responses. N-type VDCCs (NCCs) were originally identified as a high voltage-activated Ca(2+) channel selectively blocked by omega-conotoxin (ω-CTX)-GVIA. Predominantly localized in the nervous system, NCCs are key regulators of neurotransmitter release. Both pharmacological blockade with ω-CTX-GVIA and, more recently, mice lacking CNCNA1B, encoding the α1B subunit of NCC, have been used to assess the physiological and pathophysiological functions of NCCs, revealing in part their significant roles in sympathetic nerve activation and nociceptive transmission. The evidence now available indicates that NCCs are a potentially useful therapeutic target for the treatment of several pathological conditions. Efforts are therefore being made to develop effective NCC blockers, including both synthetic ω-CTX-GVIA derivatives and small-molecule inhibitors. Cilnidipine, for example, is a dihydropyridine L-type VDCC blocking agent that also possesses significant NCC blocking ability. As over-activation of the sympathetic nervous system appears to contribute to the pathological processes underlying cardiovascular, renal and metabolic diseases, NCC blockade could be a useful approach to treating these ailments. In this review article, we provide an overview of what is currently known about the physiological and pathophysiological activities of NCCs and the potentially beneficial effects of NCC blockade in several disease conditions, in particular cardiovascular diseases.
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Affiliation(s)
- Koichiro Kuwahara
- Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan.
| | - Takeshi Kimura
- Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan
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Sorota S. The sympathetic nervous system as a target for the treatment of hypertension and cardiometabolic diseases. J Cardiovasc Pharmacol 2014; 63:466-76. [PMID: 24805148 DOI: 10.1097/fjc.0000000000000064] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The regulation of blood pressure by the sympathetic nervous system is reviewed with an emphasis on the role of the sympathetic nervous system in the development and maintenance of hypertension. Evidence from patients and animal models is summarized. Because it is clear that there is a neural contribution to many types of human hypertension and other cardiometabolic diseases, the case is presented for a renewed emphasis on the development of sympatholytic approaches for the treatment of hypertension and other conditions associated with hyperactivity of the sympathetic nervous system.
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Affiliation(s)
- Steve Sorota
- Cardiorenal Department, Merck Research Laboratories, Kenilworth, NJ
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Weiss J, Pyrski M, Weissgerber P, Zufall F. Altered synaptic transmission at olfactory and vomeronasal nerve terminals in mice lacking N-type calcium channel Cav2.2. Eur J Neurosci 2014; 40:3422-35. [PMID: 25195871 DOI: 10.1111/ejn.12713] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 07/31/2014] [Accepted: 08/04/2014] [Indexed: 12/19/2022]
Abstract
We investigated the role of voltage-activated calcium (Cav) channels for synaptic transmission at mouse olfactory and vomeronasal nerve terminals at the first synapse of the main and accessory olfactory pathways, respectively. We provided evidence for a central role of the N-type Cav channel subunit Cav2.2 in presynaptic transmitter release at these synapses. Striking Cav2.2 immunoreactivity was localised to the glomerular neuropil of the main olfactory bulb (MOB) and accessory olfactory bulb (AOB), and co-localised with presynaptic molecules such as bassoon. Voltage-clamp recordings of sensory nerve-evoked, excitatory postsynaptic currents (EPSCs) in mitral/tufted (M/T) and superficial tufted cells of the MOB and mitral cells of the AOB, in combination with established subtype-specific Cav channel toxins, indicated a predominant role of N-type channels in transmitter release at these synapses, whereas L-type, P/Q-type, and R-type channels had either no or only relatively minor contributions. In Cacna1b mutant mice lacking the Cav2.2 (α1B) subunit of N-type channels, olfactory nerve-evoked M/T cell EPSCs were not reduced but became blocker-resistant, thus indicating a major reorganisation and compensation of Cav channel subunits as a result of the Cav2.2 deletion at this synapse. Cav2.2-deficient mice also revealed that Cav2.2 was critically required for paired-pulse depression of olfactory nerve-evoked EPSCs in M/T cells of the MOB, and they demonstrated an essential requirement for Cav2.2 in vomeronasal nerve-evoked EPSCs of AOB mitral cells. Thus, Cacna1b loss-of-function mutations are unlikely to cause general anosmia but Cacna1b emerges as a strong candidate in the search for mutations causing altered olfactory perception, such as changes in general olfactory sensitivity and altered social responses to chemostimuli.
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Affiliation(s)
- Jan Weiss
- Department of Physiology, University of Saarland School of Medicine, Kirrbergerstrasse, Building 58, D-66421, Homburg, Germany
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25
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Yamada Y, Kinoshita H, Kuwahara K, Nakagawa Y, Kuwabara Y, Minami T, Yamada C, Shibata J, Nakao K, Cho K, Arai Y, Yasuno S, Nishikimi T, Ueshima K, Kamakura S, Nishida M, Kiyonaka S, Mori Y, Kimura T, Kangawa K, Nakao K. Inhibition of N-type Ca2+ channels ameliorates an imbalance in cardiac autonomic nerve activity and prevents lethal arrhythmias in mice with heart failure. Cardiovasc Res 2014; 104:183-93. [DOI: 10.1093/cvr/cvu185] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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26
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Lee MS. Recent Progress in the Discovery and Development of N-Type Calcium Channel Modulators for the Treatment of Pain. PROGRESS IN MEDICINAL CHEMISTRY 2014; 53:147-86. [DOI: 10.1016/b978-0-444-63380-4.00004-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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27
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Mesirca P, Marger L, Toyoda F, Rizzetto R, Audoubert M, Dubel S, Torrente AG, Difrancesco ML, Muller JC, Leoni AL, Couette B, Nargeot J, Clapham DE, Wickman K, Mangoni ME. The G-protein-gated K+ channel, IKACh, is required for regulation of pacemaker activity and recovery of resting heart rate after sympathetic stimulation. ACTA ACUST UNITED AC 2013; 142:113-26. [PMID: 23858001 PMCID: PMC3727310 DOI: 10.1085/jgp.201310996] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Parasympathetic regulation of sinoatrial node (SAN) pacemaker activity modulates multiple ion channels to temper heart rate. The functional role of the G-protein–activated K+ current (IKACh) in the control of SAN pacemaking and heart rate is not completely understood. We have investigated the functional consequences of loss of IKACh in cholinergic regulation of pacemaker activity of SAN cells and in heart rate control under physiological situations mimicking the fight or flight response. We used knockout mice with loss of function of the Girk4 (Kir3.4) gene (Girk4−/− mice), which codes for an integral subunit of the cardiac IKACh channel. SAN pacemaker cells from Girk4−/− mice completely lacked IKACh. Loss of IKACh strongly reduced cholinergic regulation of pacemaker activity of SAN cells and isolated intact hearts. Telemetric recordings of electrocardiograms of freely moving mice showed that heart rate measured over a 24-h recording period was moderately increased (10%) in Girk4−/− animals. Although the relative extent of heart rate regulation of Girk4−/− mice was similar to that of wild-type animals, recovery of resting heart rate after stress, physical exercise, or pharmacological β-adrenergic stimulation of SAN pacemaking was significantly delayed in Girk4−/− animals. We conclude that IKACh plays a critical role in the kinetics of heart rate recovery to resting levels after sympathetic stimulation or after direct β-adrenergic stimulation of pacemaker activity. Our study thus uncovers a novel role for IKACh in SAN physiology and heart rate regulation.
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Affiliation(s)
- Pietro Mesirca
- Centre National de la Recherche Scientifique UMR 5203, Institut de Génomique Fonctionnelle, Département de Physiologie, Laboratoire d'Excellence Canaux Ioniques d'Intérêt Thérapeutique, 34094 Montpellier, France
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28
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Ferrero JJ, Bartolomé-Martín D, Torres M, Sánchez-Prieto J. Potentiation of mGlu7 receptor-mediated glutamate release at nerve terminals containing N and P/Q type Ca2+ channels. Neuropharmacology 2013; 67:213-22. [DOI: 10.1016/j.neuropharm.2012.10.032] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Revised: 09/18/2012] [Accepted: 10/06/2012] [Indexed: 12/27/2022]
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29
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Nishida M, Ishikawa T, Saiki S, Sunggip C, Aritomi S, Harada E, Kuwahara K, Hirano K, Mori Y, Kim-Mitsuyama S. Voltage-dependent N-type Ca2+ channels in endothelial cells contribute to oxidative stress-related endothelial dysfunction induced by angiotensin II in mice. Biochem Biophys Res Commun 2013; 434:210-6. [PMID: 23537646 DOI: 10.1016/j.bbrc.2013.03.040] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2013] [Accepted: 03/15/2013] [Indexed: 10/27/2022]
Abstract
N-type voltage-dependent Ca(2+)channels (VDCCs), expressed predominantly in the nervous system, play pivotal roles in sympathetic regulation of the circulatory system. Although N-type VDCCs are also reportedly expressed in the vasculature, their pathophysiological role is obscure. We demonstrated that oxidative stress-related endothelial dysfunction induced by angiotensin (Ang) II is suppressed in mice lacking the N-type VDCC α1B subunit (Cav 2.2). Impairment of endothelium-dependent relaxation of the thoracic aorta observed following Ang II treatment in wild-type (WT) mice was significantly attenuated in the Ang II-treated Cav 2.2-deficient mice, despite the comparable increase of the blood pressure in the two groups of mice. The thoracic aorta of the Cav 2.2-deficient mice showed a smaller positive area of oxidative stress markers as compared to the WT mice. The Ang II-induced endothelial dysfunction was also suppressed by cilnidipine, an L/N-type VDCC blocker, but not by amlodipine, an L-type VDCC blocker; however, this unique effect of cilnidipine was completely abolished in the Cav 2.2-deficient mice. Furthermore, selective inhibition of N-type VDCCs by ω-conotoxin GVIA dramatically suppressed the production of reactive oxygen species (ROS) as well as agonist-induced Ca(2+) influx in the vascular endothelial cells. These results suggest that N-type VDCCs expressed in the vascular endothelial cells contribute to ROS production and endothelial dysfunction observed in Ang II-treated hypertensive mice.
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Affiliation(s)
- Motohiro Nishida
- Department of Drug Discovery and Evolution, Graduate School of Pharmaceutical Sciences, Kyushu University, Maidashi 3-1-1, Fukuoka 812-8582, Japan.
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Cataldi M, Bruno F. 1,4-dihydropyridines: the multiple personalities of a blockbuster drug family. Transl Med UniSa 2012; 4:12-26. [PMID: 23905059 PMCID: PMC3728803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
More than 40 years after their introduction in therapy, 1,4-dihydropyridines (DHPs) are still amongst the most prescribed drugs in the world. Though they all share a similar mechanism of action blocking L-type voltage-gated Ca(2+) channels, DHPs differ in crucial pharmacological properties like tissue selectivity and cardiodepressant activity. This review examines how changes in the DHP structure can modify the pharmacological properties of these drugs and how some of these chemical manipulations have been exploited to obtain clinically more effective molecules. Special emphasis is given to the evidence that L-type Ca(2+) channels are an heterogeneous family and that DHPs with different pharmacological properties differ in their affinity for the different isoforms of this class of channels. Data showing that DHP pharmacological heterogeneity could be in part dependent on the interaction of some of these molecules with ion channels different from the L-type Ca(2+) channels is reviewed as well.
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Affiliation(s)
- Mauro Cataldi
- Division of Pharmacology, Department of Neuroscience, Federico II University of Naples, Naples, ITALY
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31
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Lee HK, Lee KH, Cho ES. Bile Acid Inhibition of N-type Calcium Channel Currents from Sympathetic Ganglion Neurons. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2012; 16:25-30. [PMID: 22416216 PMCID: PMC3298822 DOI: 10.4196/kjpp.2012.16.1.25] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Revised: 12/30/2011] [Accepted: 01/08/2012] [Indexed: 12/17/2022]
Abstract
Under some pathological conditions as bile flow obstruction or liver diseases with the enterohepatic circulation being disrupted, regurgitation of bile acids into the systemic circulation occurs and the plasma level of bile acids increases. Bile acids in circulation may affect the nervous system. We examined this possibility by studying the effects of bile acids on gating of neuronal (N)-type Ca2+ channel that is essential for neurotransmitter release at synapses of the peripheral and central nervous system. N-type Ca2+ channel currents were recorded from bullfrog sympathetic neuron under a cell-attached mode using 100 mM Ba2+ as a charge carrier. Cholic acid (CA, 10-6 M) that is relatively hydrophilic thus less cytotoxic was included in the pipette solution. CA suppressed the open probability of N-type Ca2+ channel, which appeared to be due to an increase in null (no activity) sweeps. For example, the proportion of null sweep in the presence of CA was ~40% at +40 mV as compared with ~8% in the control recorded without CA. Other single channel properties including slope conductance, single channel current amplitude, open and shut times were not significantly affected by CA being present. The results suggest that CA could modulate N-type Ca2+ channel gating at a concentration as low as 10-6 M. Bile acids have been shown to activate nonselective cation conductance and depolarize the cell membrane. Under pathological conditions with increased circulating bile acids, CA suppression of N-type Ca2+ channel function may be beneficial against overexcitation of the synapses.
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Affiliation(s)
- Hye Kyung Lee
- Department of Pharmacology, University of Ulsan College of Medicine, Seoul 138-736, Korea
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Ziatdinova NI, Zefirov AL, Zefirov TL. Opposite Changes in Cardiac Chronotropy Induced by Selective Blockade of α1A-Adrenoceptors in Rats of Different Age. Bull Exp Biol Med 2011; 152:19-21. [DOI: 10.1007/s10517-011-1442-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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33
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Darszon A, Nishigaki T, Beltran C, Treviño CL. Calcium Channels in the Development, Maturation, and Function of Spermatozoa. Physiol Rev 2011; 91:1305-55. [DOI: 10.1152/physrev.00028.2010] [Citation(s) in RCA: 243] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
A proper dialogue between spermatozoa and the egg is essential for conception of a new individual in sexually reproducing animals. Ca2+ is crucial in orchestrating this unique event leading to a new life. No wonder that nature has devised different Ca2+-permeable channels and located them at distinct sites in spermatozoa so that they can help fertilize the egg. New tools to study sperm ionic currents, and image intracellular Ca2+ with better spatial and temporal resolution even in swimming spermatozoa, are revealing how sperm ion channels participate in fertilization. This review critically examines the involvement of Ca2+ channels in multiple signaling processes needed for spermatozoa to mature, travel towards the egg, and fertilize it. Remarkably, these tiny specialized cells can express exclusive channels like CatSper for Ca2+ and SLO3 for K+, which are attractive targets for contraception and for the discovery of novel signaling complexes. Learning more about fertilization is a matter of capital importance; societies face growing pressure to counteract rising male infertility rates, provide safe male gamete-based contraceptives, and preserve biodiversity through improved captive breeding and assisted conception initiatives.
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Affiliation(s)
- Alberto Darszon
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Takuya Nishigaki
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Carmen Beltran
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Claudia L. Treviño
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
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Yamaguchi M, Nakayama T, Fu Z, Sato N, Soma M, Morita A, Hinohara S, Doba N, Mizutani T. The haplotype of the CACNA1B gene associated with cerebral infarction in a Japanese population. Hereditas 2011; 147:313-9. [PMID: 21166801 DOI: 10.1111/j.1601-5223.2009.02115.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Cerebral infarction (CI) is thought to be a multifactorial disease that is affected by several environmental factors and genetic variants. N-type voltage-gated calcium channels (VGCCs), which are expressed primarily in the neurons, have various roles in neuronal functions and are especially involved with neurotransmitter release at the sympathetic nerve terminals. We considered the α1B subunit of the N-type voltage-gated calcium channel (CACNA1B) to be representative of the general characteristics of this channel type. The aim of the present study was to assess the association of the human CACNA1B gene with the occurrence of CI via a haplotype-based case-control study that used single nucleotide polymorphisms (SNPs) from the Japanese population. A total of 165 CI patients and 314 controls were enrolled in the case-controlled studies that examined three SNPs of the human CACNA1B gene (rs7042521, rs11137351, rs10780199). There were significant differences between the CI and control groups for the overall distribution of the genotypes and the presence of the recessive rs10780199. Multiple logistic regression analyses revealed that even after adjusting for confounding factors (odds ratio: 1.716), the frequencies of the A/G and G/G genotypes of rs10780199 in the CI group were significantly higher than those observed in the control group (p = 0.021). Furthermore, the C-C-G and G-G-G haplotypes of rs7042521-rs11137351-rs10780199 were significantly more frequent in the CI group than in the control group (p = 0.024 and p < 0.000). In conclusion, significant differences were noted between the CI and control patients for the specific SNPs and haplotypes in the CACNA1B gene. The results indicate that these polymorphisms and haplotypes might be genetic markers for CI.
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Affiliation(s)
- Mai Yamaguchi
- Division of Neurology, Dept of Medicine, Nihon University School of Medicine, Tokyo, Japan
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Calcium channels link the muscle-derived synapse organizer laminin β2 to Bassoon and CAST/Erc2 to organize presynaptic active zones. J Neurosci 2011; 31:512-25. [PMID: 21228161 DOI: 10.1523/jneurosci.3771-10.2011] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Synapse formation requires the organization of presynaptic active zones, the synaptic vesicle release sites, in precise apposition to postsynaptic neurotransmitter receptor clusters; however, the molecular mechanisms responsible for these processes remain unclear. Here, we show that P/Q-type and N-type voltage-dependent calcium channels (VDCCs) play essential roles as scaffolding proteins in the organization of presynaptic active zones. The neuromuscular junction of double knock-out mice for P/Q- and N-type VDCCs displayed a normal size but had significantly reduced numbers of active zones and docked vesicles and featured an attenuation of the active-zone proteins Bassoon, Piccolo, and CAST/Erc2. Consistent with this phenotype, direct interactions of the VDCC β1b or β4 subunits and the active zone-specific proteins Bassoon or CAST/Erc2 were confirmed by immunoprecipitation. A decrease in the number of active zones caused by a loss of presynaptic VDCCs resembled the pathological conditions observed in the autoimmune neuromuscular disorder Lambert-Eaton myasthenic syndrome. At the synaptic cleft of double knock-out mice, we also observed a decrease of the synaptic organizer laminin β2 protein, an extracellular ligand of P/Q- and N-type VDCCs. However, the transcription level of laminin β2 did not decrease in double knock-out mice, suggesting that the synaptic accumulation of laminin β2 protein required its interaction with presynaptic VDCCs. These results suggest that presynaptic VDCCs link the target-derived synapse organizer laminin β2 to active-zone proteins and function as scaffolding proteins to anchor active-zone proteins to the presynaptic membrane.
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Petrashevskaya NN, Ishii M, D'Souza K, Koch SE, Fuller-Bicer GA, Schwartz A. Presynaptic stimulus-release and postsynaptic compensatory changes in mice lacking the N-type calcium channel α1B-subunit. Auton Neurosci 2011; 160:9-15. [DOI: 10.1016/j.autneu.2010.09.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2010] [Revised: 09/09/2010] [Accepted: 09/20/2010] [Indexed: 01/08/2023]
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37
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Martín R, Bartolomé-Martín D, Torres M, Sánchez-Prieto J. Non-additive potentiation of glutamate release by phorbol esters and metabotropic mGlu7 receptor in cerebrocortical nerve terminals. J Neurochem 2011; 116:476-85. [DOI: 10.1111/j.1471-4159.2010.07134.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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38
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Tokuhara N, Namiki K, Uesugi M, Miyamoto C, Ohgoh M, Ido K, Yoshinaga T, Yamauchi T, Kuromitsu J, Kimura S, Miyamoto N, Kasuya Y. N-type calcium channel in the pathogenesis of experimental autoimmune encephalomyelitis. J Biol Chem 2010; 285:33294-33306. [PMID: 20720005 DOI: 10.1074/jbc.m109.089805] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
One of the family of voltage-gated calcium channels (VGCC), the N-type Ca(2+) channel, is located predominantly in neurons and is associated with a variety of neuronal responses, including neurodegeneration. A precise mechanism for how the N-type Ca(2+) channel plays a role in neurodegenerative disease, however, is unknown. In this study, we immunized N-type Ca(2+) channel α(1B)-deficient (α(1B)(-/-)) mice and their wild type (WT) littermates with myelin oligodendrocyte glycoprotein 35-55 and analyzed the progression of experimental autoimmune encephalomyelitis (EAE). The neurological symptoms of EAE in the α(1B)(-/-) mice were less severe than in the WT mice. In conjunction with these results, sections of the spinal cord (SC) from α(1B)(-/-) mice revealed a reduction in both leukocytic infiltration and demyelination compared with WT mice. No differences were observed in the delayed-type hypersensitivity response, spleen cell proliferation, or cytokine production from splenocytes between the two genotypes. On the other hand, Western blot array analysis and RT-PCR revealed that a typical increase in the expression of MCP-1 in the SC showed a good correlation with the infiltration of leukocytes into the SC. Likewise, immunohistochemical analysis showed that the predominant source of MCP-1 was activated microglia. The cytokine-induced production of MCP-1 in primary cultured microglia from WT mice was significantly higher than that from α(1B)(-/-) mice and was significantly inhibited by a selective N-type Ca(2+) channel antagonist, ω-conotoxin GVIA or a withdrawal of extracellular Ca(2+). These results suggest that the N-type Ca(2+) channel is involved in the pathogenesis of EAE at least in part by regulating MCP-1 production by microglia.
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Affiliation(s)
- Naoki Tokuhara
- From the Department of Biochemistry and Molecular Pharmacology, Graduate School of Medicine, Chiba University, Chiba 260-8670; Department of Biology/Pharmacology, Discovery Research, Neuroscience Product Creation Unit, Tsukuba, Ibaraki 300-2635, Japan
| | - Kana Namiki
- From the Department of Biochemistry and Molecular Pharmacology, Graduate School of Medicine, Chiba University, Chiba 260-8670
| | - Mai Uesugi
- Department of Genomics, Biomarkers and Personalized Medicine Core Function Unit, Tsukuba, Ibaraki 300-2635, Japan
| | - Chihiro Miyamoto
- Department of Tsukuba Discovery Research, KAN Product Creation Unit, Tsukuba, Ibaraki 300-2635, Japan
| | - Makoto Ohgoh
- Department of Biology/Pharmacology, Discovery Research, Neuroscience Product Creation Unit, Tsukuba, Ibaraki 300-2635, Japan
| | - Katsutoshi Ido
- Department of Biology/Pharmacology, Discovery Research, Neuroscience Product Creation Unit, Tsukuba, Ibaraki 300-2635, Japan
| | - Takashi Yoshinaga
- Department of Global Drug Safety, Biopharmaceutical Assessment Core Function Unit, Eisai Company, Limited, Tsukuba, Ibaraki 300-2635, Japan
| | - Toshihiko Yamauchi
- Department of Biology/Pharmacology, Discovery Research, Neuroscience Product Creation Unit, Tsukuba, Ibaraki 300-2635, Japan
| | - Junro Kuromitsu
- Department of Tsukuba Discovery Research, KAN Product Creation Unit, Tsukuba, Ibaraki 300-2635, Japan
| | - Sadao Kimura
- From the Department of Biochemistry and Molecular Pharmacology, Graduate School of Medicine, Chiba University, Chiba 260-8670
| | - Norimasa Miyamoto
- Department of Tsukuba Discovery Research, KAN Product Creation Unit, Tsukuba, Ibaraki 300-2635, Japan
| | - Yoshitoshi Kasuya
- From the Department of Biochemistry and Molecular Pharmacology, Graduate School of Medicine, Chiba University, Chiba 260-8670.
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Quantitative proteomics of the Cav2 channel nano-environments in the mammalian brain. Proc Natl Acad Sci U S A 2010; 107:14950-7. [PMID: 20668236 DOI: 10.1073/pnas.1005940107] [Citation(s) in RCA: 225] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Local Ca(2+) signaling occurring within nanometers of voltage-gated Ca(2+) (Cav) channels is crucial for CNS function, yet the molecular composition of Cav channel nano-environments is largely unresolved. Here, we used a proteomic strategy combining knockout-controlled multiepitope affinity purifications with high-resolution quantitative MS for comprehensive analysis of the molecular nano-environments of the Cav2 channel family in the whole rodent brain. The analysis shows that Cav2 channels, composed of pore-forming alpha1 and auxiliary beta subunits, are embedded into protein networks that may be assembled from a pool of approximately 200 proteins with distinct abundance, stability of assembly, and preference for the three Cav2 subtypes. The majority of these proteins have not previously been linked to Cav channels; about two-thirds are dedicated to the control of intracellular Ca(2+) concentration, including G protein-coupled receptor-mediated signaling, to activity-dependent cytoskeleton remodeling or Ca(2+)-dependent effector systems that comprise a high portion of the priming and release machinery of synaptic vesicles. The identified protein networks reflect the cellular processes that can be initiated by Cav2 channel activity and define the molecular framework for organization and operation of local Ca(2+) signaling by Cav2 channels in the brain.
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Abbadie C, McManus OB, Sun SY, Bugianesi RM, Dai G, Haedo RJ, Herrington JB, Kaczorowski GJ, Smith MM, Swensen AM, Warren VA, Williams B, Arneric SP, Eduljee C, Snutch TP, Tringham EW, Jochnowitz N, Liang A, Euan MacIntyre D, McGowan E, Mistry S, White VV, Hoyt SB, London C, Lyons KA, Bunting PB, Volksdorf S, Duffy JL. Analgesic effects of a substituted N-triazole oxindole (TROX-1), a state-dependent, voltage-gated calcium channel 2 blocker. J Pharmacol Exp Ther 2010; 334:545-55. [PMID: 20439438 DOI: 10.1124/jpet.110.166363] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Voltage-gated calcium channel (Ca(v))2.2 (N-type calcium channels) are key components in nociceptive transmission pathways. Ziconotide, a state-independent peptide inhibitor of Ca(v)2.2 channels, is efficacious in treating refractory pain but exhibits a narrow therapeutic window and must be administered intrathecally. We have discovered an N-triazole oxindole, (3R)-5-(3-chloro-4-fluorophenyl)-3-methyl-3-(pyrimidin-5-ylmethyl)-1-(1H-1,2,4-triazol-3-yl)-1,3-dihydro-2H-indol-2-one (TROX-1), as a small-molecule, state-dependent blocker of Ca(v)2 channels, and we investigated the therapeutic advantages of this compound for analgesia. TROX-1 preferentially inhibited potassium-triggered calcium influx through recombinant Ca(v)2.2 channels under depolarized conditions (IC(50) = 0.27 microM) compared with hyperpolarized conditions (IC(50) > 20 microM). In rat dorsal root ganglion (DRG) neurons, TROX-1 inhibited omega-conotoxin GVIA-sensitive calcium currents (Ca(v)2.2 channel currents), with greater potency under depolarized conditions (IC(50) = 0.4 microM) than under hyperpolarized conditions (IC(50) = 2.6 microM), indicating state-dependent Ca(v)2.2 channel block of native as well as recombinant channels. TROX-1 fully blocked calcium influx mediated by a mixture of Ca(v)2 channels in calcium imaging experiments in rat DRG neurons, indicating additional block of all Ca(v)2 family channels. TROX-1 reversed inflammatory-induced hyperalgesia with maximal effects equivalent to nonsteroidal anti-inflammatory drugs, and it reversed nerve injury-induced allodynia to the same extent as pregabalin and duloxetine. In contrast, no significant reversal of hyperalgesia was observed in Ca(v)2.2 gene-deleted mice. Mild impairment of motor function in the Rotarod test and cardiovascular functions were observed at 20- to 40-fold higher plasma concentrations than required for analgesic activities. TROX-1 demonstrates that an orally available state-dependent Ca(v)2 channel blocker may achieve a therapeutic window suitable for the treatment of chronic pain.
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Affiliation(s)
- Catherine Abbadie
- Department of Pharmacology,Merck Research Laboratories, Rahway, New Jersey 07065, USA
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41
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Decreased calcium channel currents and facilitated epinephrine release in the Ca2+ channel β3 subunit-null mice. Biochem Biophys Res Commun 2010; 394:464-9. [DOI: 10.1016/j.bbrc.2010.01.036] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2010] [Accepted: 01/10/2010] [Indexed: 11/30/2022]
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A region of N-type Ca2+ channel critical for blockade by the dihydropyridine amlodipine. Eur J Pharmacol 2010; 632:14-22. [DOI: 10.1016/j.ejphar.2010.01.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2009] [Revised: 12/08/2009] [Accepted: 01/12/2010] [Indexed: 11/20/2022]
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43
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Schlick B, Flucher BE, Obermair GJ. Voltage-activated calcium channel expression profiles in mouse brain and cultured hippocampal neurons. Neuroscience 2010; 167:786-98. [PMID: 20188150 DOI: 10.1016/j.neuroscience.2010.02.037] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2009] [Revised: 01/29/2010] [Accepted: 02/15/2010] [Indexed: 12/29/2022]
Abstract
The importance and diversity of calcium signaling in the brain is mirrored by the expression of a multitude of voltage-activated calcium channel (Ca(V)) isoforms. Whereas the overall distributions of alpha(1) subunits are well established, the expression patterns of distinct channel isoforms in specific brain regions and neurons, as well as those of the auxiliary beta and alpha(2)delta subunits are still incompletely characterized. Further it is unknown whether neuronal differentiation and activity induce changes of Ca(V) subunit composition. Here we combined absolute and relative quantitative TaqMan reverse transcription PCR (RT-PCR) to analyze mRNA expression of all high voltage-activated Ca(V) alpha(1) subunits and all beta and alpha(2)delta subunits. This allowed for the first time the direct comparison of complete Ca(V) expression profiles of mouse cortex, hippocampus, cerebellum, and cultured hippocampal neurons. All brain regions expressed characteristic profiles of the full set of isoforms, except Ca(V)1.1 and Ca(V)1.4. In cortex development was accompanied by a general down regulation of alpha(1) and alpha(2)delta subunits and a shift from beta(1)/beta(3) to beta(2)/beta(4). The most abundant Ca(V) isoforms in cerebellum were Ca(V)2.1, beta(4), and alpha(2)delta-2, and in hippocampus Ca(V)2.3, beta(2), and alpha(2)delta-1. Interestingly, cultured hippocampal neurons also expressed the same Ca(V) complement as adult hippocampus. During differentiation specific Ca(V) isoforms experienced up- or down-regulation; however blocking electrical activity did not affect Ca(V) expression patterns. Correlation analysis of alpha(1), beta and alpha(2)delta subunit expression throughout all examined preparations revealed a strong preference of Ca(V)2.1 for beta(4) and alpha(2)delta-2 and vice versa, whereas the other alpha(1) isoforms were non-selectively expressed together with each of the other beta and alpha(2)delta isoforms. Together our results revealed a remarkably stable overall Ca(2+) channel complement as well as tissue specific differences in expression levels. Developmental changes are likely determined by an intrinsic program and not regulated by changes in neuronal activity.
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Affiliation(s)
- B Schlick
- Department of Physiology and Medical Physics, Innsbruck Medical University, Innsbruck, Austria
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44
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Nakagawasai O, Onogi H, Mitazaki S, Sato A, Watanabe K, Saito H, Murai S, Nakaya K, Murakami M, Takahashi E, Tan-No K, Tadano T. Behavioral and neurochemical characterization of mice deficient in the N-type Ca2+ channel alpha1B subunit. Behav Brain Res 2009; 208:224-30. [PMID: 19963013 DOI: 10.1016/j.bbr.2009.11.042] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2009] [Revised: 11/24/2009] [Accepted: 11/30/2009] [Indexed: 12/11/2022]
Abstract
N-type voltage-dependent calcium channels (VDCCs) play an important role in neurotransmission, synaptic plasticity, and brain development. They are composed of several subunits named alpha(1), alpha(2), delta, beta and gamma. The alpha(1) subunit is essential for channel functions and determines fundamental channel properties. Since N-type VDCC are critically involved in the release of neurotransmitters and clinical relevance, we predicted that alpha(1) subunit KO mice would show several alterations in behavior. In the present study, we investigated neuronal functions in mice lacking the alpha(1B) (Ca(V)2.2) subunit of the N-type calcium channels. Ca(V)2.2(-/-) mice exhibited a significant increase in locomotion on an activity wheel during the dark phase. Furthermore, when challenged with apomorphine, mutant mice showed enhanced locomotor activity. Cognitive functions were examined using a Y-maze task for short-term memory and a passive avoidance task for long-term memory. The Y-maze revealed no differences in spontaneous alternation behavior between mutant and wild-type mice. The passive avoidance test revealed that the latency time in mutant mice was significantly decreased. The mutant mice showed prepulse inhibition deficits reminiscent of the sensorimotor gating deficits observed in a large majority of schizophrenic patients. Decreases in baseline levels of dopamine and serotonin within the striata and frontal cortices of mutant mice were also observed. These results suggest that Ca(2+) in the central nervous system modulates various neurophysiological functions, such as locomotor activity, long-term memory, and sensorimotor gating through the alpha(1B) subunit of the N-type calcium channels.
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Affiliation(s)
- Osamu Nakagawasai
- Department of Pharmacology, Tohoku Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai 981-8558, Japan.
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45
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Kimpinski K, Iodice V, Vernino S, Sandroni P, Low PA. Association of N-type calcium channel autoimmunity in patients with autoimmune autonomic ganglionopathy. Auton Neurosci 2009; 150:136-9. [PMID: 19541551 DOI: 10.1016/j.autneu.2009.06.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2008] [Revised: 05/11/2009] [Accepted: 06/01/2009] [Indexed: 11/27/2022]
Abstract
The nicotinic acetylcholine receptor (nAChR) antibody directly contributes to the autonomic dysfunction in Autoimmune Autonomic Ganglionopathy (AAG). The pathological mechanism leading to autonomic dysfunction in seronegative AAG is unclear. We evaluated patients with presumed antibody negative AAG (n=49) to determine whether there was an association with other autoantibodies. Three patients met the clinical criteria and were positive for N-type calcium channel antibodies. All patients had severe autonomic dysfunction characterized by orthostatic hypotension and gastrointestinal involvement. Autonomic testing revealed severe impairment of sudomotor, cardiovagal, and adrenergic domains. These findings raise the possibility that other autoantibodies may contribute to the pathogenesis of AAG.
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Affiliation(s)
- Kurt Kimpinski
- Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA
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46
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Ladera C, Martín R, Bartolomé-Martín D, Torres M, Sánchez-Prieto J. Partial compensation for N-type Ca(2+) channel loss by P/Q-type Ca(2+) channels underlines the differential release properties supported by these channels at cerebrocortical nerve terminals. Eur J Neurosci 2009; 29:1131-40. [PMID: 19302149 DOI: 10.1111/j.1460-9568.2009.06675.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
N-type and P/Q-type Ca(2+) channels support glutamate release at central synapses. To determine whether the glutamate release mediated by these channels exhibits distinct properties, we have isolated each release component in cerebrocortical nerve terminals from wild-type mice by specifically blocking N-type Ca(2+) channels with omega-conotoxin-GVIA and P/Q-type Ca(2+) channels with omega-agatoxin-IVA. In addition, we have determined the release properties at terminals from mice lacking the alpha(1B) subunit of N-type channels (Ca(v) 2.2) to test the possibility that P/Q-type channels can compensate for the loss of N-type Ca(2+) channels. We recently demonstrated that, while evoked glutamate release depends on P/Q- and N-type channels in wild-type nerve terminals, only P/Q-type channels participate in these knockout mice. Moreover, in nerve terminals expressing solely P/Q-type channels, metabotropic glutamate receptor 7 (mGluR7) fails to inhibit the evoked Ca(2+) influx and glutamate release. Here, we show that the failure of mGluR7 to modulate evoked glutamate release is not due to a lack of receptors, as nerve terminals from mice lacking N-type Ca(2+) channels express mGluR7. Indeed, we show that other receptor responses, such as the inhibition of forskolin-induced release, are preserved in these knockout mice. N-type channels are more loosely coupled to release than P/Q-type channels in nerve terminals from wild-type mice, as reflected by the tighter coupling of release in knockout nerve terminals. We conclude that the glutamate release supported by N- and P/Q-type channels exhibits distinct properties, and that P/Q-type channels cannot fully compensate for the loss of N-type channels.
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Affiliation(s)
- Carolina Ladera
- Departamento de Bioquímica, Facultad de Veterinaria, Universidad Complutense, Madrid, Spain
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47
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Modified autonomic regulation in mice with a P/Q-type calcium channel mutation. Biochem Biophys Res Commun 2009; 381:27-32. [PMID: 19351589 DOI: 10.1016/j.bbrc.2009.01.184] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2009] [Accepted: 01/25/2009] [Indexed: 11/23/2022]
Abstract
Recent genetic analyses revealed an important association between P/Q-type channels and hereditary neurological disorders. The alpha1 subunit of P/Q-type channels is coded by a single CaV2.1 gene. Since calcium entry via neuronal calcium channels is essential for neurotransmission, P/Q-type channels may play an important role in cardiac autonomic neurotransmission. To elucidate the physiological importance of P/Q-type channels in autonomic nerve control, we used rolling Nagoya (tg(rol)) mice, which have a mutation in the CaV2.1 gene and decreased P/Q-type channel currents with reduced voltage sensitivity. The tg(rol) mice demonstrated unmodified expression of other calcium channel subunits. Electrocardiogram and echocardiographic analyses revealed decreased heart rate. Furthermore, omega-agatoxin IVA, a P/Q-type channel inhibitor, decreased heart rate and ejection fraction only in wild-type mice, thus suggesting a significant involvement of P/Q-type channels in chronotropic regulation. Atrium contraction analyses revealed a minor but significant role for P/Q-type channels in sympathetic and parasympathetic nerve regulation.
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48
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Koganei H, Shoji M, Iwata S. Suppression of Formalin-Induced Nociception by Cilnidipine, a Voltage-Dependent Calcium Channel Blocker. Biol Pharm Bull 2009; 32:1695-700. [DOI: 10.1248/bpb.32.1695] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Hajime Koganei
- Pharmaceutical Research Laboratories, Ajinomoto Co., Inc
| | - Masataka Shoji
- Pharmaceutical Research Laboratories, Ajinomoto Co., Inc
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49
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Navarro B, Kirichok Y, Chung JJ, Clapham DE. Ion channels that control fertility in mammalian spermatozoa. THE INTERNATIONAL JOURNAL OF DEVELOPMENTAL BIOLOGY 2008; 52:607-13. [PMID: 18649274 DOI: 10.1387/ijdb.072554bn] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Whole-cell voltage clamp of mammalian spermatozoa was first achieved in 2006. This technical advance, combined with genetic deletion strategies, makes unambiguous identification of sperm ion channel currents possible. This review summarizes the ion channel currents that have been directly measured in mammalian sperm, and their physiological roles in fertilization. The predominant currents are a Ca2+-selective current requiring expression of the 4 mCatSper genes, and a rectifying K+ current with properties most similar to mSlo3. Intracellular alkalinization activates both channels and induces hyperactivated motility.
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Affiliation(s)
- Betsy Navarro
- Howard Hughes Medical Institute, Department of Cardiology, Children's Hospital, Department of Neurobiology, Harvard Medical School, Enders 1309, Children's Hospital Boston, 320 Longwood Avenue, Boston, MA 02115, USA
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50
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Gu H, Jiang SA, Campusano JM, Iniguez J, Su H, Hoang AA, Lavian M, Sun X, O'Dowd DK. Cav2-type calcium channels encoded by cac regulate AP-independent neurotransmitter release at cholinergic synapses in adult Drosophila brain. J Neurophysiol 2008; 101:42-53. [PMID: 19004991 DOI: 10.1152/jn.91103.2008] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Voltage-gated calcium channels containing alpha1 subunits encoded by Ca(v)2 family genes are critical in regulating release of neurotransmitter at chemical synapses. In Drosophila, cac is the only Ca(v)2-type gene. Cacophony (CAC) channels are localized in motor neuron terminals where they have been shown to mediate evoked, but not AP-independent, release of glutamate at the larval neuromuscular junction (NMJ). Cultured embryonic neurons also express CAC channels, but there is no information about the properties of CAC-mediated currents in adult brain nor how these channels regulate transmission in central neural circuits where fast excitatory synaptic transmission is predominantly cholinergic. Here we report that wild-type neurons cultured from late stage pupal brains and antennal lobe projection neurons (PNs) examined in adult brains, express calcium currents with two components: a slow-inactivating current sensitive to the spider toxin Plectreurys toxin II (PLTXII) and a fast-inactivating PLTXII-resistant component. CAC channels are the major contributors to the slow-inactivating PLTXII-sensitive current based on selective reduction of this component in hypomorphic cac mutants (NT27 and TS3). Another characteristic of cac mutant neurons both in culture and in whole brain recordings is a reduced cholinergic miniature excitatory postsynaptic current frequency that is mimicked in wild-type neurons by acute application of PLTXII. These data demonstrate that cac encoded Ca(v)2-type calcium channels regulate action potential (AP)-independent release of neurotransmitter at excitatory cholinergic synapses in the adult brain, a function not predicted from studies at the larval NMJ.
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Affiliation(s)
- Huaiyu Gu
- Department of Anatomy and Neurobiology, University of California, Irvine, CA, USA
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