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Murray KO, Brant JO, Spradlin RA, Thome T, Laitano O, Ryan TE, Riva A, Kladde MP, Clanton TL. Exertional heat stroke causes long-term skeletal muscle epigenetic reprogramming, altered gene expression, and impaired satellite cell function in mice. Am J Physiol Regul Integr Comp Physiol 2024; 326:R160-R175. [PMID: 38047316 DOI: 10.1152/ajpregu.00226.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 11/26/2023] [Accepted: 11/26/2023] [Indexed: 12/05/2023]
Abstract
The effect of exertional heat stroke (EHS) exposure on skeletal muscles is incompletely understood. Muscle weakness is an early symptom of EHS but is not considered a major target of multiorgan injury. Previously, in a preclinical mouse model of EHS, we observed the vulnerability of limb muscles to a second EHS exposure, suggesting hidden processes contributing to declines in muscle resilience. Here, we evaluated the possible molecular origins of EHS-induced declines in muscle resilience. Female C57BL/6 mice [total n = 56; 28/condition, i.e., EHS and exercise control (EXC)] underwent forced wheel running at 37.5°C/40% relative humidity until symptom limitation (unconsciousness). EXC mice exercised identically at room temperature (22-23°C). After 1 mo of recovery, the following were assessed: 1) specific force and caffeine-induced contracture in soleus (SOL) and extensor digitorum longus (EDL) muscles; 2) transcriptome and DNA methylome responses in gastrocnemius (GAST); and 3) primary satellite cell function (proliferation and differentiation). There were no differences in specific force in either SOL or EDL from EXC. Only EHS solei exhibited lower caffeine sensitivity. EHS GAST exhibited higher RNA expression of genes encoding structural proteins of slow fibers, heat shock proteins, and myogenesis. A total of ∼2,500 differentially methylated regions of DNA that could potentially affect many cell functions were identified. Primary satellite cells exhibited suppressed proliferation rates but normal differentiation responses. Results demonstrate long-term changes in skeletal muscles 1 mo after EHS that could contribute to declines in muscle resilience. Skeletal muscle may join other, more recognized tissues considered vulnerable to long-term effects of EHS.NEW & NOTEWORTHY Exertional heat stroke (EHS) in mice induces long-term molecular and functional changes in limb muscle that could reflect a loss of "resilience" to further stress. The phenotype was characterized by altered caffeine sensitivity and suppressed satellite cell proliferative potential. This was accompanied by changes in gene expression and DNA methylation consistent with ongoing muscle remodeling and stress adaptation. We propose that EHS may induce a prolonged vulnerability of skeletal muscle to further stress or injury.
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Affiliation(s)
- Kevin O Murray
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, Florida, United States
| | - Jason O Brant
- Department of Biostatistics, University of Florida, Gainesville, Florida, United States
- University of Florida Health Cancer Center, University of Florida, Gainesville, Florida, United States
| | - Ray A Spradlin
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, Florida, United States
| | - Trace Thome
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, Florida, United States
| | - Orlando Laitano
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, Florida, United States
| | - Terence E Ryan
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, Florida, United States
| | - Alberto Riva
- University of Florida Health Cancer Center, University of Florida, Gainesville, Florida, United States
- Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida, United States
| | - Michael P Kladde
- Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, Florida, United States
- University of Florida Health Cancer Center, University of Florida, Gainesville, Florida, United States
| | - Thomas L Clanton
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, Florida, United States
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Diaz-Villegas V, Pichardo-Macías LA, Juárez-Méndez S, Ignacio-Mejía I, Cárdenas-Rodríguez N, Vargas-Hernández MA, Mendoza-Torreblanca JG, Zamudio SR. Changes in the Dentate Gyrus Gene Expression Profile Induced by Levetiracetam Treatment in Rats with Mesial Temporal Lobe Epilepsy. Int J Mol Sci 2024; 25:1690. [PMID: 38338984 PMCID: PMC10855401 DOI: 10.3390/ijms25031690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Revised: 01/24/2024] [Accepted: 01/25/2024] [Indexed: 02/12/2024] Open
Abstract
Temporal lobe epilepsy (TLE) is one of the most common forms of focal epilepsy. Levetiracetam (LEV) is an antiepileptic drug whose mechanism of action at the genetic level has not been fully described. Therefore, the aim of the present work was to evaluate the relevant gene expression changes in the dentate gyrus (DG) of LEV-treated rats with pilocarpine-induced TLE. Whole-transcriptome microarrays were used to obtain the differential genetic profiles of control (CTRL), epileptic (EPI), and EPI rats treated for one week with LEV (EPI + LEV). Quantitative RT-qPCR was used to evaluate the RNA levels of the genes of interest. According to the results of the EPI vs. CTRL analysis, 685 genes were differentially expressed, 355 of which were underexpressed and 330 of which were overexpressed. According to the analysis of the EPI + LEV vs. EPI groups, 675 genes were differentially expressed, 477 of which were downregulated and 198 of which were upregulated. A total of 94 genes whose expression was altered by epilepsy and modified by LEV were identified. The RT-qPCR confirmed that LEV treatment reversed the increased expression of Hgf mRNA and decreased the expression of the Efcab1, Adam8, Slc24a1, and Serpinb1a genes in the DG. These results indicate that LEV could be involved in nonclassical mechanisms involved in Ca2+ homeostasis and the regulation of the mTOR pathway through Efcab1, Hgf, SLC24a1, Adam8, and Serpinb1a, contributing to reduced hyperexcitability in TLE patients.
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Affiliation(s)
- Veronica Diaz-Villegas
- Departamento de Fisiología, Instituto Politécnico Nacional, Escuela Nacional de Ciencias Biológicas, Mexico City 07738, Mexico; (V.D.-V.); (L.A.P.-M.)
- Laboratorio de Neurociencias, Subdirección de Medicina Experimental, Instituto Nacional de Pediatría, Mexico City 04530, Mexico;
| | - Luz Adriana Pichardo-Macías
- Departamento de Fisiología, Instituto Politécnico Nacional, Escuela Nacional de Ciencias Biológicas, Mexico City 07738, Mexico; (V.D.-V.); (L.A.P.-M.)
| | - Sergio Juárez-Méndez
- Laboratorio de Oncología Experimental, Instituto Nacional de Pediatría, Secretaría de Salud, Mexico City 04530, Mexico;
| | - Iván Ignacio-Mejía
- Laboratorio de Medicina Traslacional, Escuela Militar de Graduados de Sanidad, Universidad del Ejército y Fuerza Aérea, Mexico City 11200, Mexico;
| | - Noemí Cárdenas-Rodríguez
- Laboratorio de Neurociencias, Subdirección de Medicina Experimental, Instituto Nacional de Pediatría, Mexico City 04530, Mexico;
| | - Marco Antonio Vargas-Hernández
- Subdirección de Investigación, Escuela Militar de Graduados de Sanidad, Universidad del Ejército y Fuerza Aérea, Mexico City 11200, Mexico;
| | | | - Sergio R. Zamudio
- Departamento de Fisiología, Instituto Politécnico Nacional, Escuela Nacional de Ciencias Biológicas, Mexico City 07738, Mexico; (V.D.-V.); (L.A.P.-M.)
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Kochurova AM, Beldiia EA, Nefedova VV, Ryabkova NS, Yampolskaya DS, Matyushenko AM, Bershitsky SY, Kopylova GV, Shchepkin DV. N-Terminal Fragment of Cardiac Myosin Binding Protein C Modulates Cooperative Mechanisms of Thin Filament Activation in Atria and Ventricles. Biochemistry (Mosc) 2024; 89:116-129. [PMID: 38467549 DOI: 10.1134/s0006297924010073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 12/09/2023] [Accepted: 12/11/2023] [Indexed: 03/13/2024]
Abstract
Cardiac myosin binding protein C (cMyBP-C) is one of the essential control components of the myosin cross-bridge cycle. The C-terminal part of cMyBP-C is located on the surface of the thick filament, and its N-terminal part interacts with actin, myosin, and tropomyosin, affecting both kinetics of the ATP hydrolysis cycle and lifetime of the cross-bridge, as well as calcium regulation of the actin-myosin interaction, thereby modulating contractile function of myocardium. The role of cMyBP-C in atrial contraction has not been practically studied. We examined effect of the N-terminal C0-C1-m-C2 (C0-C2) fragment of cMyBP-C on actin-myosin interaction using ventricular and atrial myosin in an in vitro motility assay. The C0-C2 fragment of cMyBP-C significantly reduced the maximum sliding velocity of thin filaments on both myosin isoforms and increased the calcium sensitivity of the actin-myosin interaction. The C0-C2 fragment had different effects on the kinetics of ATP and ADP exchange, increasing the affinity of ventricular myosin for ADP and decreasing the affinity of atrial myosin. The effect of the C0-C2 fragment on the activation of the thin filament depended on the myosin isoforms. Atrial myosin activates the thin filament less than ventricular myosin, and the C0-C2 fragment makes these differences in the myosin isoforms more pronounced.
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Affiliation(s)
- Anastasia M Kochurova
- Institute of Immunology and Physiology, Russian Academy of Sciences, Yekaterinburg, 620049, Russia
| | - Evgenia A Beldiia
- Institute of Immunology and Physiology, Russian Academy of Sciences, Yekaterinburg, 620049, Russia
- Ural Federal University, Ekaterinburg, 620002, Russia
| | - Victoria V Nefedova
- Bach Institute of Biochemistry, Research Center of Biotechnology, Russian Academy of Sciences, Moscow, 119071, Russia
| | - Natalia S Ryabkova
- Department of Biochemistry, Faculty of Biology, Lomonosov Moscow State University, Moscow, 119234, Russia
- HyTest Ltd., Turku, 20520, Finland
| | - Daria S Yampolskaya
- Bach Institute of Biochemistry, Research Center of Biotechnology, Russian Academy of Sciences, Moscow, 119071, Russia
| | - Alexander M Matyushenko
- Bach Institute of Biochemistry, Research Center of Biotechnology, Russian Academy of Sciences, Moscow, 119071, Russia
| | - Sergey Y Bershitsky
- Institute of Immunology and Physiology, Russian Academy of Sciences, Yekaterinburg, 620049, Russia
| | - Galina V Kopylova
- Institute of Immunology and Physiology, Russian Academy of Sciences, Yekaterinburg, 620049, Russia
| | - Daniil V Shchepkin
- Institute of Immunology and Physiology, Russian Academy of Sciences, Yekaterinburg, 620049, Russia.
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Paiva ÉAS, Figueredo CC, Martinez HEP. Vascular Tissues Distribution Affects Calcium and Calcium Oxalate Crystals in Fruits of Wild Tomato ( Lycopersicon pimpinellifolium (L.) Mill.). Plants (Basel) 2023; 12:3893. [PMID: 38005789 PMCID: PMC10675387 DOI: 10.3390/plants12223893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 11/06/2023] [Accepted: 11/16/2023] [Indexed: 11/26/2023]
Abstract
Tomato fruit is an excellent model for evaluating calcium regulation in plants since it expresses symptoms of either calcium deficiency or calcium excess. Aiming to evaluate the structure of the vascular system and its interactions with calcium and calcium oxalate crystals (CaOx), fruits of Lycopersicon pimpinellifolium were studied. Calcium levels were evaluated in basal, median, and distal pericarp portions, which were also analyzed under a light microscope to describe the structure. The L. pimpinellifolium pericarp shows idioblasts with calcium oxalate crystals. Vascular bundles of the basal pericarp show large transverse sections and abundant xylem vessels. The vascular bundles were smaller in the distal pericarp, and the xylem showed fewer and narrower vessels. The terminal bundles often consisted exclusively of phloem. Despite the differences observed in vascular bundle composition, the density of the vascular system was uniform in the pericarp as a consequence of bundle ramifications that occur at distal portions. The calcium concentration and crystal idioblasts decrease towards the apex of the fruit. The reduction in the xylem:phloem ratio seems to determine the low calcium concentration in the distal fruit portion.
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Affiliation(s)
- Élder Antônio Sousa Paiva
- Departamento de Botânica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, Minas Gerais, Brazil;
| | - Cleber Cunha Figueredo
- Departamento de Botânica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, Minas Gerais, Brazil;
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MacLeod K. Sex-related differences in biology - ignore them at your peril. J Physiol 2023; 601:3983-3984. [PMID: 37589557 DOI: 10.1113/jp285313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 08/07/2023] [Indexed: 08/18/2023] Open
Affiliation(s)
- Ken MacLeod
- National Heart & Lung Institute, Imperial Centre for Translational and Experimental Medicine, Imperial College, Hammersmith Hospital, London, UK
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Zhong W, Pathak JL, Liang Y, Zhytnik L, Pals G, Eekhoff EMW, Bravenboer N, Micha D. The intricate mechanism of PLS3 in bone homeostasis and disease. Front Endocrinol (Lausanne) 2023; 14:1168306. [PMID: 37484945 PMCID: PMC10361617 DOI: 10.3389/fendo.2023.1168306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 06/19/2023] [Indexed: 07/25/2023] Open
Abstract
Since our discovery in 2013 that genetic defects in PLS3 lead to bone fragility, the mechanistic details of this process have remained obscure. It has been established that PLS3 variants cause syndromic and nonsyndromic osteoporosis as well as osteoarthritis. PLS3 codes for an actin-bundling protein with a broad pattern of expression. As such, it is puzzling how PLS3 specifically leads to bone-related disease presentation. Our review aims to summarize the current state of knowledge regarding the function of PLS3 in the predominant cell types in the bone tissue, the osteocytes, osteoblasts and osteoclasts. This is related to the role of PLS3 in regulating mechanotransduction, calcium regulation, vesicle trafficking, cell differentiation and mineralization as part of the complex bone pathology presented by PLS3 defects. Considering the consequences of PLS3 defects on multiple aspects of bone tissue metabolism, our review motivates the study of its mechanism in bone diseases which can potentially help in the design of suitable therapy.
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Affiliation(s)
- Wenchao Zhong
- Department of Human Genetics, Amsterdam UMC Location Vrije Universiteit Amsterdam, Amsterdam, Netherlands
- Department of Clinical Chemistry, Amsterdam UMC Location Vrije Universiteit Amsterdam, Amsterdam, Netherlands
- Amsterdam Movement Sciences, Tissue Function And Regeneration, Amsterdam, Netherlands
- Department of Temporomandibular Joint, Guangdong Engineering Research Center of Oral Restoration and Reconstruction, Guangzhou Key Laboratory of Basic and Applied Research of Oral Regenerative Medicine, Affiliated Stomatology Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Janak L. Pathak
- Department of Temporomandibular Joint, Guangdong Engineering Research Center of Oral Restoration and Reconstruction, Guangzhou Key Laboratory of Basic and Applied Research of Oral Regenerative Medicine, Affiliated Stomatology Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Yueting Liang
- Department of Radiation Oncology, Peking University Cancer Hospital & Institute, Beijing, China
- The Second Clinical College, Guangzhou Medical University, Guangzhou, China
| | - Lidiia Zhytnik
- Department of Human Genetics, Amsterdam UMC Location Vrije Universiteit Amsterdam, Amsterdam, Netherlands
- Amsterdam Movement Sciences, Tissue Function And Regeneration, Amsterdam, Netherlands
- Department of Traumatology and Orthopaedics, Institute of Clinical Medicine, The University of Tartu, Tartu, Estonia
| | - Gerard Pals
- Department of Human Genetics, Amsterdam UMC Location Vrije Universiteit Amsterdam, Amsterdam, Netherlands
- Amsterdam Movement Sciences, Tissue Function And Regeneration, Amsterdam, Netherlands
| | - Elisabeth M. W. Eekhoff
- Department Internal Medicine Section Endocrinology and Metabolism, Amsterdam UMC Location Vrije Universiteit Amsterdam, Rare Bone Disease Center, AMS, Amsterdam, Netherlands
- Amsterdam Reproduction and Development Research Institute, Amsterdam, Netherlands
| | - Nathalie Bravenboer
- Department of Clinical Chemistry, Amsterdam UMC Location Vrije Universiteit Amsterdam, Amsterdam, Netherlands
- Amsterdam Movement Sciences, Tissue Function And Regeneration, Amsterdam, Netherlands
| | - Dimitra Micha
- Department of Human Genetics, Amsterdam UMC Location Vrije Universiteit Amsterdam, Amsterdam, Netherlands
- Amsterdam Movement Sciences, Tissue Function And Regeneration, Amsterdam, Netherlands
- Amsterdam Reproduction and Development Research Institute, Amsterdam, Netherlands
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Kamisah Y, Jalil J, Yunos NM, Zainalabidin S. Cardioprotective Properties of Kaempferol: A Review. Plants (Basel) 2023; 12:plants12112096. [PMID: 37299076 DOI: 10.3390/plants12112096] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 05/14/2023] [Accepted: 05/23/2023] [Indexed: 06/12/2023]
Abstract
Cardiac diseases, such as myocardial infarction and heart failure, have become a major clinical problem globally. The accumulating data demonstrate that bioactive compounds with antioxidant and anti-inflammatory properties have favorable effects on clinical problems. Kaempferol is a flavonoid found in various plants; it has demonstrated cardioprotective properties in numerous cardiac injury models. This review aims to collate updated information regarding the effects of kaempferol on cardiac injury. Kaempferol improves cardiac function by alleviating myocardial apoptosis, fibrosis, oxidative stress, and inflammation while preserving mitochondrial function and calcium homeostasis. However, the mechanisms of action of its cardioprotective properties remain unclear; therefore, elucidating its action could provide insight into directions for future studies.
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Affiliation(s)
- Yusof Kamisah
- Department of Pharmacology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur 56000, Malaysia
| | - Juriyati Jalil
- Centre for Drug and Herbal Development, Faculty of Pharmacy, Universiti Kebangsaan Malaysia, Kuala Lumpur 50300, Malaysia
| | - Nurhanan Murni Yunos
- Natural Products Division, Forest Research Institute of Malaysia, Selangor 52109, Malaysia
| | - Satirah Zainalabidin
- Program of Biomedical Science, Centre of Applied and Health Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur 50300, Malaysia
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Cheng X, Huang L. The Mechanism of the Anti-Cardiac Hypertrophy Effect of Glycyrrhizic Acid Is Related to Reducing STIM1-Dependent Store-Operated Calcium Entry. Bull Exp Biol Med 2023; 174:701-706. [PMID: 37162628 DOI: 10.1007/s10517-023-05774-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Indexed: 05/11/2023]
Abstract
We explored the anti-cardiac hypertrophy mechanism of glycyrrhizic acid from the perspective of calcium regulation under pathological conditions. For this purpose, we used a rat model of myocardial hypertrophy induced by pressure overload. The effect of glycyrrhizic acid on BP was measured non-invasively with a sphygmomanometer and recorded in PC. In rats with modeled cardiac hypertrophy, the effect of GA on expression of type 1 matrix interaction molecules was determined in horizontal tissues and cultured cardiomyocytes of the left ventricle. The laser confocal microscopy and calcium ion probe Fluo-4 AM were used to assess the effect of glycyrrhizic acid on stromal interaction molecule 1 (STIM1)-dependent store-operated calcium entry in cultured cardiomyocytes derived from the hypertrophic myocardium. Glycyrrhizic acid exerted the anti-hypertrophic effect in rats with hypertrophic myocardium by down-regulating STIM1 protein expression and reducing the intensity of STIM1-dependent store-operated calcium entry.
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Affiliation(s)
- X Cheng
- Department of Cardiology, Nanping First Hospital Affiliated to Fujian Medical University, Nanping City, Fujian Province, China.
| | - L Huang
- Department of Cardiology, Nanping First Hospital Affiliated to Fujian Medical University, Nanping City, Fujian Province, China
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Moise N, Weinberg SH. Emergent Activity, Heterogeneity, and Robustness in a Calcium Feedback Model of the Sinoatrial Node. Biophys J 2023; 122:1613-1632. [PMID: 36945778 PMCID: PMC10183324 DOI: 10.1016/j.bpj.2023.03.024] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 02/16/2023] [Accepted: 03/15/2023] [Indexed: 03/23/2023] Open
Abstract
The sinoatrial node (SAN) is the primary pacemaker of the heart. SAN activity emerges at an early point in life and maintains a steady rhythm for the lifetime of the organism. The ion channel composition and currents of SAN cells can be influenced by a variety of factors. Therefore, the emergent activity and long-term stability imply some form of dynamical feedback control of SAN activity. We adapt a recent feedback model - previously utilized to describe control of ion conductances in neurons - to a model of SAN cells and tissue. The model describes a minimal regulatory mechanism of ion channel conductances via feedback between intracellular calcium and an intrinsic target calcium level. By coupling a SAN cell to the calcium feedback model, we show that spontaneous electrical activity emerges from quiescence and is maintained at steady-state. In a 2D SAN tissue model, spatial variability in intracellular calcium targets lead to significant, self-organized heterogeneous ion channel expression and calcium transients throughout the tissue. Further, multiple pacemaking regions appear, which interact and lead to time-varying cycle length, demonstrating that variability in heart rate is an emergent property of the feedback model. Finally, we demonstrate that the SAN tissue is robust to the silencing of leading cells or ion channel knockouts. Thus, the calcium feedback model can reproduce and explain many fundamental emergent properties of activity in the SAN that have been observed experimentally based on a minimal description of intracellular calcium and ion channel regulatory networks.
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Affiliation(s)
- Nicolae Moise
- Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio; Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Seth H Weinberg
- Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio; Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio.
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O’Day DH. Calmodulin and Amyloid Beta as Coregulators of Critical Events during the Onset and Progression of Alzheimer's Disease. Int J Mol Sci 2023; 24:ijms24021393. [PMID: 36674908 PMCID: PMC9863087 DOI: 10.3390/ijms24021393] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 01/03/2023] [Accepted: 01/05/2023] [Indexed: 01/12/2023] Open
Abstract
Calmodulin (CaM) and a diversity of CaM-binding proteins (CaMBPs) are involved in the onset and progression of Alzheimer's disease (AD). In the amyloidogenic pathway, AβPP1, BACE1 and PSEN-1 are all calcium-dependent CaMBPs as are the risk factor proteins BIN1 and TREM2. Ca2+/CaM-dependent protein kinase II (CaMKII) and calcineurin (CaN) are classic CaMBPs involved in memory and plasticity, two events impacted by AD. Coupled with these events is the production of amyloid beta monomers (Aβ) and oligomers (Aβo). The recent revelations that Aβ and Aβo each bind to both CaM and to a host of Aβ receptors that are also CaMBPs adds a new level of complexity to our understanding of the onset and progression of AD. Multiple Aβ receptors that are proven CaMBPs (e.g., NMDAR, PMCA) are involved in calcium homeostasis an early event in AD and other neurodegenerative diseases. Other CaMBPs that are Aβ receptors are AD risk factors while still others are involved in the amyloidogenic pathway. Aβ binding to receptors not only serves to control CaM's ability to regulate critical proteins, but it is also implicated in Aβ turnover. The complexity of the Aβ/CaM/CaMBP interactions is analyzed using two events: Aβ generation and NMDAR function. The interactions between Aβ, CaM and CaMBPs reveals a new level of complexity to critical events associated with the onset and progression of AD and may help to explain the failure to develop successful therapeutic treatments for the disease.
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Affiliation(s)
- Danton H. O’Day
- Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada;
- Department of Biology, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada
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Tavoulari S, Lacabanne D, Thangaratnarajah C, Kunji ERS. Pathogenic variants of the mitochondrial aspartate/glutamate carrier causing citrin deficiency. Trends Endocrinol Metab 2022; 33:539-553. [PMID: 35725541 PMCID: PMC7614230 DOI: 10.1016/j.tem.2022.05.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 04/26/2022] [Accepted: 05/19/2022] [Indexed: 12/22/2022]
Abstract
Citrin deficiency is a pan-ethnic and highly prevalent mitochondrial disease with three different stages: neonatal intrahepatic cholestasis (NICCD), a relatively mild adaptation stage, and type II citrullinemia in adulthood (CTLN2). The cause is the absence or dysfunction of the calcium-regulated mitochondrial aspartate/glutamate carrier 2 (AGC2/SLC25A13), also called citrin, which imports glutamate into the mitochondrial matrix and exports aspartate to the cytosol. In citrin deficiency, these missing transport steps lead to impairment of the malate-aspartate shuttle, gluconeogenesis, amino acid homeostasis, and the urea cycle. In this review, we describe the geological spread and occurrence of citrin deficiency, the metabolic consequences and use our current knowledge of the structure to predict the impact of the known pathogenic mutations on the calcium-regulatory and transport mechanism of citrin.
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Affiliation(s)
- Sotiria Tavoulari
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
| | - Denis Lacabanne
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
| | - Chancievan Thangaratnarajah
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
| | - Edmund R S Kunji
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK.
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Zhang L, Qi J, Zhang X, Zhao X, An P, Luo Y, Luo J. The Regulatory Roles of Mitochondrial Calcium and the Mitochondrial Calcium Uniporter in Tumor Cells. Int J Mol Sci 2022; 23:ijms23126667. [PMID: 35743109 PMCID: PMC9223557 DOI: 10.3390/ijms23126667] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 06/10/2022] [Accepted: 06/10/2022] [Indexed: 02/06/2023] Open
Abstract
Mitochondria, as the main site of cellular energy metabolism and the generation of oxygen free radicals, are the key switch for mitochondria-mediated endogenous apoptosis. Ca2+ is not only an important messenger for cell proliferation, but it is also an indispensable signal for cell death. Ca2+ participates in and plays a crucial role in the energy metabolism, physiology, and pathology of mitochondria. Mitochondria control the uptake and release of Ca2+ through channels/transporters, such as the mitochondrial calcium uniporter (MCU), and influence the concentration of Ca2+ in both mitochondria and cytoplasm, thereby regulating cellular Ca2+ homeostasis. Mitochondrial Ca2+ transport-related processes are involved in important biological processes of tumor cells including proliferation, metabolism, and apoptosis. In particular, MCU and its regulatory proteins represent a new era in the study of MCU-mediated mitochondrial Ca2+ homeostasis in tumors. Through an in-depth analysis of the close correlation between mitochondrial Ca2+ and energy metabolism, autophagy, and apoptosis of tumor cells, we can provide a valuable reference for further understanding of how mitochondrial Ca2+ regulation helps diagnosis and therapy.
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Affiliation(s)
- Linlin Zhang
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China;
- Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing 100193, China; (J.Q.); (X.Z.); (X.Z.)
| | - Jingyi Qi
- Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing 100193, China; (J.Q.); (X.Z.); (X.Z.)
| | - Xu Zhang
- Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing 100193, China; (J.Q.); (X.Z.); (X.Z.)
| | - Xiya Zhao
- Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing 100193, China; (J.Q.); (X.Z.); (X.Z.)
| | - Peng An
- Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing 100193, China; (J.Q.); (X.Z.); (X.Z.)
- Correspondence: (P.A.); (Y.L.); (J.L.)
| | - Yongting Luo
- Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing 100193, China; (J.Q.); (X.Z.); (X.Z.)
- Correspondence: (P.A.); (Y.L.); (J.L.)
| | - Junjie Luo
- Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing 100193, China; (J.Q.); (X.Z.); (X.Z.)
- Correspondence: (P.A.); (Y.L.); (J.L.)
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13
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Tripp TR, Frankish BP, Lun V, Wiley JP, Shearer J, Murphy RM, MacInnis MJ. Time course and fibre type-dependent nature of calcium-handling protein responses to sprint interval exercise in human skeletal muscle. J Physiol 2022; 600:2897-2917. [PMID: 35556249 DOI: 10.1113/jp282739] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 04/22/2022] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Sprint interval training (SIT) has been shown to cause fragmentation of the sarcoplasmic reticulum calcium-release channel, ryanodine receptor 1 (RyR1) 24 hours post-exercise, which may act as a signal for mitochondrial biogenesis. In this study, we examined the time course of RyR1 fragmentation in human whole muscle and pooled type I and type II skeletal muscle fibres following a single session of SIT. Full-length RyR1 protein content was significantly lower than pre-exercise by 6 h post-SIT in whole muscle, and fragmentation was detectable in type II but not type I fibres, though to a lesser extent than in whole muscle. The peak in PGC1A mRNA expression occurred earlier than RyR1 fragmentation. The increased temporal resolution and fibre type-specific responses for RyR1 fragmentation provide insights into its importance to mitochondrial biogenesis in humans. ABSTRACT Sprint interval training (SIT) causes fragmentation of the skeletal muscle sarcoplasmic reticulum Ca2+ release channel, ryanodine receptor 1 (RyR1), 24h post-exercise, potentially signaling mitochondrial biogenesis by increasing cytosolic [Ca2+ ]. Yet, the time course and skeletal muscle fibre type-specific patterns of RyR1 fragmentation following a session of SIT remain unknown. Ten participants (n = 4 females; n = 6 males) performed a session of SIT (6 × 30 s "all-out" with 4.5 min rest after each sprint) with vastus lateralis muscle biopsy samples collected before and 3, 6, and 24h after exercise. In whole muscle, full-length RyR1 protein content was significantly reduced 6 h (mean [SD]; -38 [38]%; p<0.05) and 24 h post-SIT (-30 [48]%; p<0.05) compared to pre-exercise. Examining each participant's largest response in pooled samples, full-length RyR1 protein content was reduced in type II (-26 [30]%; p<0.05) but not type I fibres (-11 [40]%; p>0.05). 3h post-SIT, there was also a decrease in SERCA1 in type II fibres (-23 [17]%; p<0.05) and SERCA2a in type I fibres (-19 [21]%; p<0.05), despite no time effect for either protein in whole muscle samples (p>0.05). PGC1A mRNA content was elevated 3h and 6h post-SIT (5.3- and 3.7-fold change from pre, respectively; p<0.05 for both), but peak PGC1A mRNA expression was not significantly correlated with peak RyR1 fragmentation (r2 = 0.10; p>0.05). In summary, altered Ca2+ -handling protein expression, which occurs primarily in type II muscle fibres, may influence signals for mitochondrial biogenesis as early as 3-6 h post-SIT in humans. Abstract figure legend Western blotting was performed on whole muscle and pooled type I and II muscle fibre preparations derived from human vastus lateralis muscle biopsy samples collected before and after a single session of sprint interval training (SIT). Full-length ryanodine receptor 1 (RyR1) protein content was reduced 6 and 24 h post-exercise in whole muscle samples compared to baseline, despite a heterogeneous time course among individuals. This RyR1 fragmentation proceeded and outlasted the increase in peroxisome proliferator-activated γ receptor coactivator 1α (PGC1A) mRNA expression. When examining the time point of each individual's peak response, RyR1 fragmentation was evident in type II, but not type I, muscle fibres. These findings suggest that, in humans, mitochondrial biogenesis could be influenced by RyR1 fragmentation 3-6 h post-SIT in a fibre type-dependent manner. Created with BioRender.com. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Thomas R Tripp
- Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
| | - Barnaby P Frankish
- Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada.,Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, Melbourne, Australia
| | - Victor Lun
- University of Calgary Sport Medicine Centre, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
| | - J Preston Wiley
- Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada.,University of Calgary Sport Medicine Centre, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
| | - Jane Shearer
- Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada.,Department of Biochemistry & Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Robyn M Murphy
- Department of Physiology, Anatomy and Microbiology, School of Life Sciences, La Trobe University, Melbourne, Australia
| | - Martin J MacInnis
- Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
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14
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Pérez-Liébana I, Juaristi I, González-Sánchez P, González-Moreno L, Rial E, Podunavac M, Zakarian A, Molgó J, Vallejo-Illarramendi A, Mosqueira-Martín L, Lopez de Munain A, Pardo B, Satrústegui J, Del Arco A. A Ca 2+-Dependent Mechanism Boosting Glycolysis and OXPHOS by Activating Aralar-Malate-Aspartate Shuttle, upon Neuronal Stimulation. J Neurosci 2022; 42:3879-3895. [PMID: 35387872 PMCID: PMC9097769 DOI: 10.1523/jneurosci.1463-21.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 12/20/2021] [Accepted: 01/27/2022] [Indexed: 01/18/2023] Open
Abstract
Calcium is an important second messenger regulating a bioenergetic response to the workloads triggered by neuronal activation. In embryonic mouse cortical neurons using glucose as only fuel, activation by NMDA elicits a strong workload (ATP demand)-dependent on Na+ and Ca2+ entry, and stimulates glucose uptake, glycolysis, pyruvate and lactate production, and oxidative phosphorylation (OXPHOS) in a Ca2+-dependent way. We find that Ca2+ upregulation of glycolysis, pyruvate levels, and respiration, but not glucose uptake, all depend on Aralar/AGC1/Slc25a12, the mitochondrial aspartate-glutamate carrier, component of the malate-aspartate shuttle (MAS). MAS activation increases glycolysis, pyruvate production, and respiration, a process inhibited in the presence of BAPTA-AM, suggesting that the Ca2+ binding motifs in Aralar may be involved in the activation. Mitochondrial calcium uniporter (MCU) silencing had no effect, indicating that none of these processes required MCU-dependent mitochondrial Ca2+ uptake. The neuronal respiratory response to carbachol was also dependent on Aralar, but not on MCU. We find that mouse cortical neurons are endowed with a constitutive ER-to-mitochondria Ca2+ flow maintaining basal cell bioenergetics in which ryanodine receptors, RyR2, rather than InsP3R, are responsible for Ca2+ release, and in which MCU does not participate. The results reveal that, in neurons using glucose, MCU does not participate in OXPHOS regulation under basal or stimulated conditions, while Aralar-MAS appears as the major Ca2+-dependent pathway tuning simultaneously glycolysis and OXPHOS to neuronal activation.SIGNIFICANCE STATEMENT Neuronal activation increases cell workload to restore ion gradients altered by activation. Ca2+ is involved in matching increased workload with ATP production, but the mechanisms are still unknown. We find that glycolysis, pyruvate production, and neuronal respiration are stimulated on neuronal activation in a Ca2+-dependent way, independently of effects of Ca2+ as workload inducer. Mitochondrial calcium uniporter (MCU) does not play a relevant role in Ca2+ stimulated pyruvate production and oxygen consumption as both are unchanged in MCU silenced neurons. However, Ca2+ stimulation is blunt in the absence of Aralar, a Ca2+-binding mitochondrial carrier component of Malate-Aspartate Shuttle (MAS). The results suggest that Ca2+-regulated Aralar-MAS activation upregulates glycolysis and pyruvate production, which fuels mitochondrial respiration, through regulation of cytosolic NAD+/NADH ratio.
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Affiliation(s)
- Irene Pérez-Liébana
- Departamento de Biología Molecular, Instituto Universitario de Biología Molecular -IUBM, Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, Madrid, Spain; and Instituto de Investigación Sanitaria Fundación Jiménez Díaz, Madrid, 28049, Spain
| | - Inés Juaristi
- Departamento de Biología Molecular, Instituto Universitario de Biología Molecular -IUBM, Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, Madrid, Spain; and Instituto de Investigación Sanitaria Fundación Jiménez Díaz, Madrid, 28049, Spain
| | - Paloma González-Sánchez
- Departamento de Biología Molecular, Instituto Universitario de Biología Molecular -IUBM, Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, Madrid, Spain; and Instituto de Investigación Sanitaria Fundación Jiménez Díaz, Madrid, 28049, Spain
| | - Luis González-Moreno
- Departamento de Biología Molecular, Instituto Universitario de Biología Molecular -IUBM, Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, Madrid, Spain; and Instituto de Investigación Sanitaria Fundación Jiménez Díaz, Madrid, 28049, Spain
| | - Eduardo Rial
- Department of Structural and Chemical Biology, Centro de Investigaciones Biológicas Margarita Salas, Madrid, 28040, Spain
| | - Maša Podunavac
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106
| | - Armen Zakarian
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106
| | - Jordi Molgó
- Université Paris-Saclay, CEA, Institut des Sciences du Vivant Frédéric Joliot, ERL Centre National de la Recherche Scientifique no. 9004, Département Médicaments et Technologies pour la Santé, Service d'Ingénierie Moléculaire pour la Santé, Gif sur Yvette, F-91191, France
| | - Ainara Vallejo-Illarramendi
- IIS Biodonostia-University of the Basque Country, Donostia, Spain; CIBERNED (institute Carlos III), Madrid, Spain; and Department of Neurology, Hospital Universitario Donostia-OSAKIDETZA, San Sebastián, 20014, Spain
| | - Laura Mosqueira-Martín
- IIS Biodonostia-University of the Basque Country, Donostia, Spain; CIBERNED (institute Carlos III), Madrid, Spain; and Department of Neurology, Hospital Universitario Donostia-OSAKIDETZA, San Sebastián, 20014, Spain
| | - Adolfo Lopez de Munain
- IIS Biodonostia-University of the Basque Country, Donostia, Spain; CIBERNED (institute Carlos III), Madrid, Spain; and Department of Neurology, Hospital Universitario Donostia-OSAKIDETZA, San Sebastián, 20014, Spain
| | - Beatriz Pardo
- Departamento de Biología Molecular, Instituto Universitario de Biología Molecular -IUBM, Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, Madrid, Spain; and Instituto de Investigación Sanitaria Fundación Jiménez Díaz, Madrid, 28049, Spain
| | - Jorgina Satrústegui
- Departamento de Biología Molecular, Instituto Universitario de Biología Molecular -IUBM, Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, Madrid, Spain; and Instituto de Investigación Sanitaria Fundación Jiménez Díaz, Madrid, 28049, Spain
| | - Araceli Del Arco
- Departamento de Biología Molecular, Instituto Universitario de Biología Molecular -IUBM, Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, Madrid, Spain; and Instituto de Investigación Sanitaria Fundación Jiménez Díaz, Madrid, 28049, Spain
- Facultad de Ciencias Ambientales y Bioquímica, Universidad de Castilla la Mancha, Toledo, 45071 Spain; and Centro Regional de Investigaciones Biomédicas, Unidad Asociada de Biomedicina, Toledo, 45071, Spain
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15
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Bera M, Ramakrishnan S, Coleman J, Krishnakumar SS, Rothman JE. Molecular determinants of complexin clamping and activation function. eLife 2022; 11:e71938. [PMID: 35442188 PMCID: PMC9020821 DOI: 10.7554/elife.71938] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 03/15/2022] [Indexed: 11/13/2022] Open
Abstract
Previously we reported that Synaptotagmin-1 and Complexin synergistically clamp the SNARE assembly process to generate and maintain a pool of docked vesicles that fuse rapidly and synchronously upon Ca2+ influx (Ramakrishnan et al., 2020). Here, using the same in vitro single-vesicle fusion assay, we determine the molecular details of the Complexin-mediated fusion clamp and its role in Ca2+-activation. We find that a delay in fusion kinetics, likely imparted by Synaptotagmin-1, is needed for Complexin to block fusion. Systematic truncation/mutational analyses reveal that continuous alpha-helical accessory-central domains of Complexin are essential for its inhibitory function and specific interaction of the accessory helix with the SNAREpins enhances this functionality. The C-terminal domain promotes clamping by locally elevating Complexin concentration through interactions with the membrane. Independent of their clamping functions, the accessory-central helical domains of Complexin also contribute to rapid Ca2+-synchronized vesicle release by increasing the probability of fusion from the clamped state.
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Affiliation(s)
- Manindra Bera
- Yale Nanobiology InstituteNew HavenUnited States
- Department of Cell Biology, Yale University School of MedicineNew HavenUnited States
| | - Sathish Ramakrishnan
- Yale Nanobiology InstituteNew HavenUnited States
- Department of Pathology, Yale University School of MedicineNew HavenUnited States
| | - Jeff Coleman
- Yale Nanobiology InstituteNew HavenUnited States
- Department of Cell Biology, Yale University School of MedicineNew HavenUnited States
| | - Shyam S Krishnakumar
- Yale Nanobiology InstituteNew HavenUnited States
- Departments of Neurology, Yale University School of MedicineNew HavenUnited States
| | - James E Rothman
- Yale Nanobiology InstituteNew HavenUnited States
- Department of Cell Biology, Yale University School of MedicineNew HavenUnited States
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16
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Chen J, Gao Y, Su XN, Yu L. [Effects of 6-week aerobic exercise on calcium regulation in skeletal muscle of ApoE knockout mice fed by high-fat diet]. Zhongguo Ying Yong Sheng Li Xue Za Zhi 2022; 38:137-142. [PMID: 36031571 DOI: 10.12047/j.cjap.6221.2022.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Objective: To investigate the effects of 6 weeks of aerobic exercise on the sarcoplasmic reticulum calcium regulatory proteins in skeletal muscle of apolipoprotein E (ApoE) knockout mice fed by high-fat diet. Methods: There were a total of twenty five 9-week-old ApoE knockout mice (ApoE knockout mice, ApoE KO), five of which were selected randomly for the maximum running speed test. The running speed would be increased by 1.2 m/min every 3 min after a 5-min duration of initial speed of 4.8 m/min without slope until exhaustion, then the final speed was set as maximal speed, and the test result of the maximum running speed was (27.0±2.4)m/min. The remaining 20 ApoE KO mice were randomly divided into ApoE KO mouse high-fat diet group (KO) and ApoE KO mouse high-fat diet + aerobic exercise group (KE), 10 mice per group. Ten 9-week-old wild-type C57BL/6J mice were used as a blank control group (wild-type, WT). High fat diet composition: fat content was 21% (w/w) and cholesterol content was 1.5% (w/w). Exercise intervention was initiated 1 week after adaptive training in the KE group with an exercise protocol consisting of 40% maximal running speed (10.8 m/min), 40 min/d and a frequency of 3 d/w for a total of 6 weeks. All mice were anesthetized and sacrificed by cardiac puncture then bilateral gastrocnemius muscles were isolated immediately 48 h after the final exercise. Skeletal muscle Ca2+ concentration was detected by visible light colorimetry; the expression levels of RyR, CaM, CaMK Ⅱ, SERCA1 and SERCA2, which are calcium regulated proteins of sarcoplasmic reticulum, in mouse skeletal muscle, was detected by Western blotting. Results: Compared with WT mice, the Ca2+ concentration, the expression levels of the sarcoplasmic reticulum calcium releasing proteins RyR, CaMKⅡ, and the calcium recycling proteins SERCA1 and SERCA2 were decreased significantly in skeletal muscle of the KO mice (P<0.05, P<0.01), while the expression of CaM protein did not change. Skeletal muscle Ca2+ concentration and the levels of sarcoplasmic reticulum calcium recycling proteins SERCA1 and SERCA2 were increased significantly (P<0.05) in KE mice compared with KO mice, but there were no significant differences in the expressions of the sarcoplasmic reticulum calcium release proteins RyR, CaM and CaMK II. Conclusion: High fat diet can reduce the concentration of Ca2+ in skeletal muscle and weaken the release and recovery of sarcoplasmic reticulum calcium in ApoE knockout mice. 6-week aerobic exercise training can significantly increase its Ca2+concentration and promote the recovery of sarcoplasmic reticulum calcium.
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Affiliation(s)
- Jun Chen
- School of Sport Science, Beijing Sport University, Beijing 100084
| | - Yang Gao
- School of Sport Science, Beijing Sport University, Beijing 100084
| | - Xiang-Nan Su
- School of Sport Science, Beijing Sport University, Beijing 100084
| | - Liang Yu
- School of Sport Science, Beijing Sport University, Beijing 100084
- School of Strength and Conditioning Training Beijing Sport University, Beijing 100084, China
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Montaño LM, Sommer B, Solís-Chagoyán H, Romero-Martínez BS, Aquino-Gálvez A, Gomez-Verjan JC, Calixto E, González-Avila G, Flores-Soto E. Could Lower Testosterone in Older Men Explain Higher COVID-19 Morbidity and Mortalities? Int J Mol Sci 2022; 23:935. [PMID: 35055119 DOI: 10.3390/ijms23020935] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 01/06/2022] [Accepted: 01/07/2022] [Indexed: 01/08/2023] Open
Abstract
The health scourge imposed on humanity by the COVID-19 pandemic seems not to recede. This fact warrants refined and novel ideas analyzing different aspects of the illness. One such aspect is related to the observation that most COVID-19 casualties were older males, a tendency also noticed in the epidemics of SARS-CoV in 2003 and the Middle East respiratory syndrome in 2012. This gender-related difference in the COVID-19 death toll might be directly involved with testosterone (TEST) and its plasmatic concentration in men. TEST has been demonstrated to provide men with anti-inflammatory and immunological advantages. As the plasmatic concentration of this androgen decreases with age, the health benefit it confers also diminishes. Low plasmatic levels of TEST can be determinant in the infection’s outcome and might be related to a dysfunctional cell Ca2+ homeostasis. Not only does TEST modulate the activity of diverse proteins that regulate cellular calcium concentrations, but these proteins have also been proven to be necessary for the replication of many viruses. Therefore, we discuss herein how TEST regulates different Ca2+-handling proteins in healthy tissues and propose how low TEST concentrations might facilitate the replication of the SARS-CoV-2 virus through the lack of modulation of the mechanisms that regulate intracellular Ca2+ concentrations.
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Yan C, Sack JS. X-ray structure of a human cardiac muscle troponin C/troponin I chimera in two crystal forms. Acta Crystallogr F Struct Biol Commun 2022; 78:17-24. [PMID: 34981771 PMCID: PMC8725003 DOI: 10.1107/s2053230x21012395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 11/22/2021] [Indexed: 01/03/2023] Open
Abstract
The X-ray crystal structure of a human cardiac muscle troponin C/troponin I chimera has been determined in two different crystal forms and shows a conformation of the complex that differs from that previously observed by NMR. The chimera consists of the N-terminal domain of troponin C (cTnC; residues 1-80) fused to the switch region of troponin I (cTnI; residues 138-162). In both crystal forms, the cTnI residues form a six-turn α-helix that lays across the hydrophobic groove of an adjacent cTnC molecule in the crystal structure. In contrast to previous models, the cTnI helix runs in a parallel direction relative to the cTnC groove and completely blocks the calcium desensitizer binding site of the cTnC-cTnI interface.
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Affiliation(s)
- Chunhong Yan
- Small Molecule Drug Discovery, Bristol Myers Squibb Research and Development, PO Box 4000, Princeton, NJ 08543-4000, USA
| | - John S. Sack
- Small Molecule Drug Discovery, Bristol Myers Squibb Research and Development, PO Box 4000, Princeton, NJ 08543-4000, USA,Correspondence e-mail:
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Zhang X, Tomar N, Kandel SM, Audi SH, Cowley AW, Dash RK. Substrate- and Calcium-Dependent Differential Regulation of Mitochondrial Oxidative Phosphorylation and Energy Production in the Heart and Kidney. Cells 2021; 11:131. [PMID: 35011693 PMCID: PMC8750792 DOI: 10.3390/cells11010131] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 12/26/2021] [Accepted: 12/28/2021] [Indexed: 11/16/2022] Open
Abstract
Mitochondrial dehydrogenases are differentially stimulated by Ca2+. Ca2+ has also diverse regulatory effects on mitochondrial transporters and other enzymes. However, the consequences of these regulatory effects on mitochondrial oxidative phosphorylation (OxPhos) and ATP production, and the dependencies of these consequences on respiratory substrates, have not been investigated between the kidney and heart despite the fact that kidney energy requirements are second only to those of the heart. Our objective was, therefore, to elucidate these relationships in isolated mitochondria from the kidney outer medulla (OM) and heart. ADP-induced mitochondrial respiration was measured at different CaCl2 concentrations in the presence of various respiratory substrates, including pyruvate + malate (PM), glutamate + malate (GM), alpha-ketoglutarate + malate (AM), palmitoyl-carnitine + malate (PCM), and succinate + rotenone (SUC + ROT). The results showed that, in both heart and OM mitochondria, and for most complex I substrates, Ca2+ effects are biphasic: small increases in Ca2+ concentration stimulated, while large increases inhibited mitochondrial respiration. Furthermore, significant differences in substrate- and Ca2+-dependent O2 utilization towards ATP production between heart and OM mitochondria were observed. With PM and PCM substrates, Ca2+ showed more prominent stimulatory effects in OM than in heart mitochondria, while with GM and AM substrates, Ca2+ had similar biphasic regulatory effects in both OM and heart mitochondria. In contrast, with complex II substrate SUC + ROT, only inhibitory effects on mitochondrial respiration was observed in both the heart and the OM. We conclude that the regulatory effects of Ca2+ on mitochondrial OxPhos and ATP synthesis are biphasic, substrate-dependent, and tissue-specific.
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Affiliation(s)
- Xiao Zhang
- Department of Biomedical Engineering, Medical College of Wisconsin, Milwaukee, WI 53226, USA; (X.Z.); (N.T.); (S.M.K.)
| | - Namrata Tomar
- Department of Biomedical Engineering, Medical College of Wisconsin, Milwaukee, WI 53226, USA; (X.Z.); (N.T.); (S.M.K.)
| | - Sunil M. Kandel
- Department of Biomedical Engineering, Medical College of Wisconsin, Milwaukee, WI 53226, USA; (X.Z.); (N.T.); (S.M.K.)
| | - Said H. Audi
- Department of Biomedical Engineering, Marquette University, Milwaukee, WI 53223, USA;
| | - Allen W. Cowley
- Center of Systems Molecular Medicine, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Ranjan K. Dash
- Department of Biomedical Engineering, Medical College of Wisconsin, Milwaukee, WI 53226, USA; (X.Z.); (N.T.); (S.M.K.)
- Center of Systems Molecular Medicine, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
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20
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Autry JM, Svensson B, Carlson SF, Chen Z, Cornea RL, Thomas DD, Valberg SJ. Sarcoplasmic Reticulum from Horse Gluteal Muscle Is Poised for Enhanced Calcium Transport. Vet Sci 2021; 8:289. [PMID: 34941816 DOI: 10.3390/vetsci8120289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 11/02/2021] [Accepted: 11/17/2021] [Indexed: 11/16/2022] Open
Abstract
We have analyzed the enzymatic activity of the sarcoplasmic reticulum (SR) Ca2+-transporting ATPase (SERCA) from the horse gluteal muscle. Horses are bred for peak athletic performance yet exhibit a high incidence of exertional rhabdomyolysis, with elevated levels of cytosolic Ca2+ proposed as a correlative linkage. We recently reported an improved protocol for isolating SR vesicles from horse muscle; these horse SR vesicles contain an abundant level of SERCA and only trace-levels of sarcolipin (SLN), the inhibitory peptide subunit of SERCA in mammalian fast-twitch skeletal muscle. Here, we report that the in vitro Ca2+ transport rate of horse SR vesicles is 2.3 ± 0.7-fold greater than rabbit SR vesicles, which express close to equimolar levels of SERCA and SLN. This suggests that horse myofibers exhibit an enhanced SR Ca2+ transport rate and increased luminal Ca2+ stores in vivo. Using the densitometry of Coomassie-stained SDS-PAGE gels, we determined that horse SR vesicles express an abundant level of the luminal SR Ca2+ storage protein calsequestrin (CASQ), with a CASQ-to-SERCA ratio about double that in rabbit SR vesicles. Thus, we propose that SR Ca2+ cycling in horse myofibers is enhanced by a reduced SLN inhibition of SERCA and by an abundant expression of CASQ. Together, these results suggest that horse muscle contractility and susceptibility to exertional rhabdomyolysis are promoted by enhanced SR Ca2+ uptake and luminal Ca2+ storage.
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21
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Markakis I, Charitakis I, Beeton C, Galani M, Repousi E, Aggeloglou S, Sfikakis PP, Pennington MW, Chandy KG, Poulopoulou C. Kv1.3 Channel Up-Regulation in Peripheral Blood T Lymphocytes of Patients With Multiple Sclerosis. Front Pharmacol 2021; 12:714841. [PMID: 34630091 PMCID: PMC8495199 DOI: 10.3389/fphar.2021.714841] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 09/09/2021] [Indexed: 11/02/2022] Open
Abstract
Voltage-gated Kv1.3 potassium channels are key regulators of T lymphocyte activation, proliferation and cytokine production, by providing the necessary membrane hyper-polarization for calcium influx following immune stimulation. It is noteworthy that an accumulating body of in vivo and in vitro evidence links these channels to multiple sclerosis pathophysiology. Here we studied the electrophysiological properties and the transcriptional and translational expression of T lymphocyte Kv1.3 channels in multiple sclerosis, by combining patch clamp recordings, reverse transcription polymerase chain reaction and flow cytometry on freshly isolated peripheral blood T lymphocytes from two patient cohorts with multiple sclerosis, as well as from healthy and disease controls. Our data demonstrate that T lymphocytes in MS, manifest a significant up-regulation of Kv1.3 mRNA, Kv1.3 membrane protein and Kv1.3 current density and therefore of functional membrane channel protein, compared to control groups (p < 0.001). Interestingly, patient sub-grouping shows that Kv1.3 channel density is significantly higher in secondary progressive, compared to relapsing-remitting multiple sclerosis (p < 0.001). Taking into account the tight connection between Kv1.3 channel activity and calcium-dependent processes, our data predict and could partly explain the reported alterations of T lymphocyte function in multiple sclerosis, while they highlight Kv1.3 channels as potential therapeutic targets and peripheral biomarkers for the disease.
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Affiliation(s)
- Ioannis Markakis
- National and Kapodistrian University of Athens, Medical School, Athens, Greece.,Department of Neurology, "St. Panteleimon" General State Hospital, Nikaia, Greece
| | - Ioannis Charitakis
- National and Kapodistrian University of Athens, Medical School, Athens, Greece
| | - Christine Beeton
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA, United States.,Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, United States
| | - Melpomeni Galani
- National and Kapodistrian University of Athens, Medical School, Athens, Greece
| | - Elpida Repousi
- National and Kapodistrian University of Athens, Medical School, Athens, Greece.,Department of Neurology, "St. Panteleimon" General State Hospital, Nikaia, Greece
| | - Stella Aggeloglou
- Department of Neurology, "St. Panteleimon" General State Hospital, Nikaia, Greece
| | - Petros P Sfikakis
- National and Kapodistrian University of Athens, Medical School, Athens, Greece
| | | | - K George Chandy
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA, United States.,Lee Kong Chian School of Medicine, Nanyang Technological University, Nanyang Ave, Singapore
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22
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Kim J, You GE, Woo M, Chang NH, Lee J. Discovery of Lactoferrin as a Stimulant for hADSC-Derived EV Secretion and Proof of Enhancement of Resulting EVs through Skin Model. Int J Mol Sci 2021; 22:10993. [PMID: 34681650 DOI: 10.3390/ijms222010993] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 10/02/2021] [Accepted: 10/10/2021] [Indexed: 11/17/2022] Open
Abstract
Extracellular vesicles (EVs) are secreted from hADSCs in low concentrations, which makes it difficult to utilize them for the development of therapeutic products. To overcome the problem associated with low concentration, we proposed human lactoferrin (hLF) as a stimulant for the secretion of hADSC-derived EVs. hLF has been reported to upregulate intracellular Ca2+, which is known to be capable of increasing EV secretion. We cultured hADSCs in hLF-supplemented media and analyzed the changes in intracellular Ca2+ concentration. The characteristics of hADSC-derived EVs secreted by hLF stimulation were analyzed through their number, membrane protein markers, and the presence of hLFs to EVs. The function of hADSC-derived EVs was investigated through their effects on dermal fibroblasts. We found that hLF helped hADSCs effectively uptake Ca2+, resulting in an increase of EVs secretion by more than a factor of 4. The resulting EVs had enhanced proliferation and collagen synthesis effect on dermal fibroblasts when compared to the same number of hADSC-derived EVs secreted without hLF stimulation. The enhanced secretion of hADSC-derived EVs increased collagen synthesis through enhanced epidermal penetration, which resulted from increased EV numbers. In summary, we propose hLF to be a useful stimulant in increasing the secretion rate of hADSC-derived EVs.
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23
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Garcia-Elias A, Tajes M, Yañez-Bisbe L, Enjuanes C, Comín-Colet J, Serra SA, Fernández-Fernández JM, Aguilar-Agon KW, Reilly S, Martí-Almor J, Benito B. Atrial Fibrillation in Heart Failure Is Associated with High Levels of Circulating microRNA-199a-5p and 22-5p and a Defective Regulation of Intracellular Calcium and Cell-to-Cell Communication. Int J Mol Sci 2021; 22:10377. [PMID: 34638717 DOI: 10.3390/ijms221910377] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/20/2021] [Accepted: 09/21/2021] [Indexed: 11/16/2022] Open
Abstract
MicroRNAs (miRNAs) participate in atrial remodeling and atrial fibrillation (AF) promotion. We determined the circulating miRNA profile in patients with AF and heart failure with reduced ejection fraction (HFrEF), and its potential role in promoting the arrhythmia. In plasma of 98 patients with HFrEF (49 with AF and 49 in sinus rhythm, SR), differential miRNA expression was determined by high-throughput microarray analysis followed by replication of selected candidates. Validated miRNAs were determined in human atrial samples, and potential arrhythmogenic mechanisms studied in HL-1 cells. Circulating miR-199a-5p and miR-22-5p were significantly increased in HFrEF patients with AF versus those with HFrEF in SR. Both miRNAs, but particularly miR-199a-5p, were increased in atrial samples of patients with AF. Overexpression of both miRNAs in HL-1 cells resulted in decreased protein levels of L-type Ca2+ channel, NCX and connexin-40, leading to lower basal intracellular Ca2+ levels, fewer inward currents, a moderate reduction in Ca2+ buffering post-caffeine exposure, and a deficient cell-to-cell communication. In conclusion, circulating miR-199a-5p and miR-22-5p are higher in HFrEF patients with AF, with similar findings in human atrial samples of AF patients. Cells exposed to both miRNAs exhibited altered Ca2+ handling and defective cell-to-cell communication, both findings being potential arrhythmogenic mechanisms.
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24
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Jung H, Kim SY, Canbakis Cecen FS, Cho Y, Kwon SK. Dysfunction of Mitochondrial Ca 2+ Regulatory Machineries in Brain Aging and Neurodegenerative Diseases. Front Cell Dev Biol 2020; 8:599792. [PMID: 33392190 PMCID: PMC7775422 DOI: 10.3389/fcell.2020.599792] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 11/06/2020] [Indexed: 12/20/2022] Open
Abstract
Calcium ions (Ca2+) play critical roles in neuronal processes, such as signaling pathway activation, transcriptional regulation, and synaptic transmission initiation. Therefore, the regulation of Ca2+ homeostasis is one of the most important processes underlying the basic cellular viability and function of the neuron. Multiple components, including intracellular organelles and plasma membrane Ca2+-ATPase, are involved in neuronal Ca2+ control, and recent studies have focused on investigating the roles of mitochondria in synaptic function. Numerous mitochondrial Ca2+ regulatory proteins have been identified in the past decade, with studies demonstrating the tissue- or cell-type-specific function of each component. The mitochondrial calcium uniporter and its binding subunits are major inner mitochondrial membrane proteins contributing to mitochondrial Ca2+ uptake, whereas the mitochondrial Na+/Ca2+ exchanger (NCLX) and mitochondrial permeability transition pore (mPTP) are well-studied proteins involved in Ca2+ extrusion. The level of cytosolic Ca2+ and the resulting characteristics of synaptic vesicle release properties are controlled via mitochondrial Ca2+ uptake and release at presynaptic sites, while in dendrites, mitochondrial Ca2+ regulation affects synaptic plasticity. During brain aging and the progress of neurodegenerative disease, mitochondrial Ca2+ mishandling has been observed using various techniques, including live imaging of Ca2+ dynamics. Furthermore, Ca2+ dysregulation not only disrupts synaptic transmission but also causes neuronal cell death. Therefore, understanding the detailed pathophysiological mechanisms affecting the recently discovered mitochondrial Ca2+ regulatory machineries will help to identify novel therapeutic targets. Here, we discuss current research into mitochondrial Ca2+ regulatory machineries and how mitochondrial Ca2+ dysregulation contributes to brain aging and neurodegenerative disease.
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Affiliation(s)
- Hyunsu Jung
- Center for Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology, Seoul, South Korea.,Division of Life Sciences, Korea University, Seoul, South Korea
| | - Su Yeon Kim
- Center for Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology, Seoul, South Korea.,Department of Biomedical Sciences, College of Medicine, Korea University, Seoul, South Korea
| | - Fatma Sema Canbakis Cecen
- Center for Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology, Seoul, South Korea.,Division of Bio-Medical Science & Technology, KIST School, Korea University of Science and Technology (UST), Seoul, South Korea
| | - Yongcheol Cho
- Division of Life Sciences, Korea University, Seoul, South Korea
| | - Seok-Kyu Kwon
- Center for Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology, Seoul, South Korea.,Division of Bio-Medical Science & Technology, KIST School, Korea University of Science and Technology (UST), Seoul, South Korea
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25
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Louch WE. A horse of a different colour: distinct mechanisms of HFpEF and HFrEF. J Physiol 2020; 598:5005-5006. [PMID: 32985684 PMCID: PMC7756253 DOI: 10.1113/jp280691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- William E Louch
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway.,KG Jebsen Center for Cardiac Research, University of Oslo, Norway
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26
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Firth JM, Yang HY, Francis AJ, Islam N, MacLeod KT. The Effect of Estrogen on Intracellular Ca 2+ and Na + Regulation in Heart Failure. ACTA ACUST UNITED AC 2020; 5:901-912. [PMID: 33015413 PMCID: PMC7524784 DOI: 10.1016/j.jacbts.2020.06.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 06/22/2020] [Accepted: 06/23/2020] [Indexed: 12/31/2022]
Abstract
During the progression toward heart failure, indicators of in vivo whole-heart function suggest greater impairment in the absence of estrogen. At the single cardiac myocyte level, the absence of estrogen results in further reduction of Ca2+ transient amplitudes, further slowing of transient decay kinetics, less SR Ca2+ content, and a further increase in Ca2+ spark frequencies and spark-mediated SR leak compared with animals with normal estrus cycles. Cardiac myocyte Na+ regulation is also more disrupted in the absence of estrogen.
Contradictory findings of estrogen supplementation in cardiac disease highlight the need to investigate the involvement of estrogen in the progression of heart failure in an animal model that lacks traditional comorbidities. Heart failure was induced by aortic constriction (AC) in female guinea pigs. Selected AC animals were ovariectomized (ACOV), and a group of these received 17β-estradiol supplementation (ACOV+E). One hundred-fifty days post-AC surgery, left-ventricular myocytes were isolated, and their electrophysiology and Ca2+ and Na+ regulation were examined. Long-term absence of ovarian hormones exacerbates the decline in cardiac function during the progression to heart failure. Estrogen supplementation reverses these aggravating effects.
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Key Words
- AC, aortic constriction
- ACOV+E, aortic constriction with ovariectomy, supplemented with 17β-estradiol
- ACOV, aortic constriction with ovariectomy
- FS, fractional shortening
- ICa, l-type Ca2+ channel current (cadmium-sensitive)
- INa,L, late Na+ current (ranolazine-sensitive)
- NCX, Na+/Ca2+ exchange
- OV, ovariectomy
- SERCA, Sarco/endoplasmic reticulum Ca2+-ATPase
- SR, sarcoplasmic reticulum
- calcium regulation
- cardiomyocytes
- estrogen
- excitation-contraction coupling
- female
- heart failure
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Affiliation(s)
- Jahn M Firth
- National Heart and Lung Institute, Imperial College, Hammersmith Hospital, London, United Kingdom
| | - Hsiang-Yu Yang
- Cardiovascular Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan (R.O.C.)
| | - Alice J Francis
- National Heart and Lung Institute, Imperial College, Hammersmith Hospital, London, United Kingdom
| | - Najah Islam
- National Heart and Lung Institute, Imperial College, Hammersmith Hospital, London, United Kingdom
| | - Kenneth T MacLeod
- National Heart and Lung Institute, Imperial College, Hammersmith Hospital, London, United Kingdom
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27
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Pinotsis N, Zielinska K, Babuta M, Arolas JL, Kostan J, Khan MB, Schreiner C, Salmazo A, Ciccarelli L, Puchinger M, Gkougkoulia EA, Ribeiro EA Jr, Marlovits TC, Bhattacharya A, Djinovic-Carugo K. Calcium modulates the domain flexibility and function of an α-actinin similar to the ancestral α-actinin. Proc Natl Acad Sci U S A 2020; 117:22101-12. [PMID: 32848067 DOI: 10.1073/pnas.1917269117] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The actin cytoskeleton, a dynamic network of actin filaments and associated F-actin-binding proteins, is fundamentally important in eukaryotes. α-Actinins are major F-actin bundlers that are inhibited by Ca2+ in nonmuscle cells. Here we report the mechanism of Ca2+-mediated regulation of Entamoeba histolytica α-actinin-2 (EhActn2) with features expected for the common ancestor of Entamoeba and higher eukaryotic α-actinins. Crystal structures of Ca2+-free and Ca2+-bound EhActn2 reveal a calmodulin-like domain (CaMD) uniquely inserted within the rod domain. Integrative studies reveal an exceptionally high affinity of the EhActn2 CaMD for Ca2+, binding of which can only be regulated in the presence of physiological concentrations of Mg2+ Ca2+ binding triggers an increase in protein multidomain rigidity, reducing conformational flexibility of F-actin-binding domains via interdomain cross-talk and consequently inhibiting F-actin bundling. In vivo studies uncover that EhActn2 plays an important role in phagocytic cup formation and might constitute a new drug target for amoebic dysentery.
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28
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Finch MS, Bagit A, Marko DM. Amyloid beta 42 oligomers induce neuronal and synaptic receptor dysfunctions. J Physiol 2020; 598:3545-3546. [PMID: 32495946 DOI: 10.1113/jp280038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 06/01/2020] [Indexed: 11/08/2022] Open
Affiliation(s)
- Michael S Finch
- Department of Health Sciences, Brock University, St. Catharines, ON, L2S 3A1, Canada
| | - Ahmed Bagit
- Department of Health Sciences, Brock University, St. Catharines, ON, L2S 3A1, Canada
| | - Daniel M Marko
- Department of Health Sciences, Brock University, St. Catharines, ON, L2S 3A1, Canada
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29
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Abstract
Stanniocalcin, a glycosylated peptide hormone, first discovered in a bony fish has originally been shown to play critical role in calcium and phosphate homeostasis. Two paralogs of stanniocalcin (STC1 and STC2) identified in mammals are widely expressed in variety of tissues. This review provides historical perspective on the discovery of fish and mammalian stanniocalcin, describes molecular regulation of STC2 gene, catalogs distribution as well as expression of STC2 in tissues, and provides key structural information known till date regarding mammalian STC2. Additionally, this mini review summarizes pivotal functions of STC2 in calcium and phosphate regulation, cytoprotection, cell development, and angiogenesis. Finally, STC2's role as a novel marker for human cancers has also been outlined. Reviewing these studies will provide an opportunity to understand STC2's structure, biological functions as well as key molecular pathways involving STC2, which will help us design innovative therapeutic interventions using this novel hormone.
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Affiliation(s)
- Aditya D. Joshi
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX, United States
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30
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Porter JJ, Jang HS, Haque MM, Stuehr DJ, Mehl RA. Tyrosine nitration on calmodulin enhances calcium-dependent association and activation of nitric-oxide synthase. J Biol Chem 2019; 295:2203-2211. [PMID: 31914408 DOI: 10.1074/jbc.ra119.010999] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Revised: 12/19/2019] [Indexed: 12/14/2022] Open
Abstract
Production of reactive oxygen species caused by dysregulated endothelial nitric-oxide synthase (eNOS) activity is linked to vascular dysfunction. eNOS is a major target protein of the primary calcium-sensing protein calmodulin. Calmodulin is often modified by the main biomarker of nitroxidative stress, 3-nitrotyrosine (nitroTyr). Despite nitroTyr being an abundant post-translational modification on calmodulin, the mechanistic role of this modification in altering calmodulin function and eNOS activation has not been investigated. Here, using genetic code expansion to site-specifically nitrate calmodulin at its two tyrosine residues, we assessed the effects of these alterations on calcium binding by calmodulin and on binding and activation of eNOS. We found that nitroTyr-calmodulin retains affinity for eNOS under resting physiological calcium concentrations. Results from in vitro eNOS assays with calmodulin nitrated at Tyr-99 revealed that this nitration reduces nitric-oxide production and increases eNOS decoupling compared with WT calmodulin. In contrast, calmodulin nitrated at Tyr-138 produced more nitric oxide and did so more efficiently than WT calmodulin. These results indicate that the nitroTyr post-translational modification, like tyrosine phosphorylation, can impact calmodulin sensitivity for calcium and reveal Tyr site-specific gain or loss of functions for calmodulin-induced eNOS activation.
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Affiliation(s)
- Joseph J Porter
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331
| | - Hyo Sang Jang
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331
| | - Mohammad Mahfuzul Haque
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195
| | - Dennis J Stuehr
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195
| | - Ryan A Mehl
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331.
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31
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Li A, Nelson SR, Rahmanseresht S, Braet F, Cornachione AS, Previs SB, O'Leary TS, McNamara JW, Rassier DE, Sadayappan S, Previs MJ, Warshaw DM. Skeletal MyBP-C isoforms tune the molecular contractility of divergent skeletal muscle systems. Proc Natl Acad Sci U S A 2019; 116:21882-92. [PMID: 31591218 DOI: 10.1073/pnas.1910549116] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Skeletal muscle myosin-binding protein C (MyBP-C) is a myosin thick filament-associated protein, localized through its C terminus to distinct regions (C-zones) of the sarcomere. MyBP-C modulates muscle contractility, presumably through its N terminus extending from the thick filament and interacting with either the myosin head region and/or the actin thin filament. Two isoforms of MyBP-C (fast- and slow-type) are expressed in a muscle type-specific manner. Are the expression, localization, and Ca2+-dependent modulatory capacities of these isoforms different in fast-twitch extensor digitorum longus (EDL) and slow-twitch soleus (SOL) muscles derived from Sprague-Dawley rats? By mass spectrometry, 4 MyBP-C isoforms (1 fast-type MyBP-C and 3 N-terminally spliced slow-type MyBP-C) were expressed in EDL, but only the 3 slow-type MyBP-C isoforms in SOL. Using EDL and SOL native thick filaments in which the MyBP-C stoichiometry and localization are preserved, native thin filament sliding over these thick filaments showed that, only in the C-zone, MyBP-C Ca2+ sensitizes the thin filament and slows thin filament velocity. These modulatory properties depended on MyBP-C's N terminus as N-terminal proteolysis attenuated MyBP-C's functional capacities. To determine each MyBP-C isoform's contribution to thin filament Ca2+ sensitization and slowing in the C-zone, we used a combination of in vitro motility assays using expressed recombinant N-terminal fragments and in silico mechanistic modeling. Our results suggest that each skeletal MyBP-C isoform's N terminus is functionally distinct and has modulatory capacities that depend on the muscle type in which they are expressed, providing the potential for molecular tuning of skeletal muscle performance through differential MyBP-C expression.
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32
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Xiang B, Liu Y, Zhao W, Zhao H, Yu H. Extracellular calcium regulates the adhesion and migration of osteoclasts via integrin α v β 3 /Rho A/Cytoskeleton signaling. Cell Biol Int 2019; 43:1125-1136. [PMID: 30022569 DOI: 10.1002/cbin.11033] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Integrin αv β3 is a transmembrane integrin, which can initiate osteoclasts' attachment on bones, leading to downward signaling pathways and subsequent bone resorption. Different calcium concentrations have been reported to have an influence on the activation of integrin αv β3 . To elucidate the regulatory mechanism of extracellular calcium concentrations on osteoclasts, a controlled micro flow plate (M04S) was utilized in the ONIX flow control system to observe the osteoclasts' adhesion and migration in different calcium concentration media. Fluorescent staining is conducted to show the distribution of integrin αv β3 and cytoskeleton reorganization. In addition, western blots were performed to detect the expression of integrin αv β3 and its downstream signaling pathways related to bone resorption. Also, real-time reverse-transcription polymerase chain reaction data of transcription co-activator (YAP/TAZ) and hydrolytic enzymes (the matrix metalloproteinase 9 and cathepsin K) are evaluated. Our findings suggest that osteoclasts' migration and adhesion is better promoted at 0.5 mM than 1.2 mM, which can be partly explained by the induced cytoskeleton organization via integrin αv β3 /Rho GTPase. But the activation and nuclear localization of YAP/TAZ, and the secretion of hydrolytic enzymes were upregulated when the calcium concentration is at a higher level (1.2 mM). According to our study, there is a high possibility that the migration and attachment of osteoclasts and subsequent osteoclastic bone resorption are regulated over a specific range of extracellular calcium concentration.
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Affiliation(s)
- Bilu Xiang
- The State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, 14S Renmin Road, 3rd sec, 610041, Chengdu, China
| | - Yang Liu
- The State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, 14S Renmin Road, 3rd sec, 610041, Chengdu, China
| | - Wei Zhao
- The State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, 14S Renmin Road, 3rd sec, 610041, Chengdu, China
| | - Hanchi Zhao
- The State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, 14S Renmin Road, 3rd sec, 610041, Chengdu, China
| | - Haiyang Yu
- The State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, 14S Renmin Road, 3rd sec, 610041, Chengdu, China
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33
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Affiliation(s)
- Jil C Tardiff
- From Departments of Internal Medicine and Cellular and Molecular Medicine, University of Arizona, Tucson.
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34
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McCulloch KM, Yamakawa I, Shifrin DA, McConnell RE, Foegeding NJ, Singh PK, Mao S, Tyska MJ, Iverson TM. An alternative N-terminal fold of the intestine-specific annexin A13a induces dimerization and regulates membrane-binding. J Biol Chem 2019; 294:3454-3463. [PMID: 30610115 DOI: 10.1074/jbc.ra118.004571] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 12/20/2018] [Indexed: 12/11/2022] Open
Abstract
Annexin proteins function as Ca2+-dependent regulators of membrane trafficking and repair that may also modulate membrane curvature. Here, using high-resolution confocal imaging, we report that the intestine-specific annexin A13 (ANX A13) localizes to the tips of intestinal microvilli and determined the crystal structure of the ANX A13a isoform to 2.6 Å resolution. The structure revealed that the N terminus exhibits an alternative fold that converts the first two helices and the associated helix-loop-helix motif into a continuous α-helix, as stabilized by a domain-swapped dimer. We also found that the dimer is present in solution and partially occludes the membrane-binding surfaces of annexin, suggesting that dimerization may function as a means for regulating membrane binding. Accordingly, as revealed by in vitro binding and cellular localization assays, ANX A13a variants that favor a monomeric state exhibited increased membrane association relative to variants that favor the dimeric form. Together, our findings support a mechanism for how the association of the ANX A13a isoform with the membrane is regulated.
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Affiliation(s)
| | | | | | | | | | | | - Suli Mao
- Cell and Developmental Biology, and
| | | | - T M Iverson
- From the Departments of Pharmacology, .,Biochemistry.,the Center for Structural Biology, and.,the Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee 37232
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35
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Pearman CM, Madders GW, Radcliffe EJ, Kirkwood GJ, Lawless M, Watkins A, Smith CE, Trafford AW, Eisner DA, Dibb KM. Increased Vulnerability to Atrial Fibrillation Is Associated With Increased Susceptibility to Alternans in Old Sheep. J Am Heart Assoc 2018; 7:e009972. [PMID: 30520673 PMCID: PMC6405564 DOI: 10.1161/jaha.118.009972] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 09/17/2018] [Indexed: 12/17/2022]
Abstract
Background Atrial fibrillation ( AF ) is common in the elderly, but rare in the young; however, the changes that occur with age that promote AF are not fully understood. Action potential ( AP ) alternans may be involved in the initiation of AF . Using a translationally relevant model, we investigated whether age-associated atrial vulnerability to AF was associated with susceptibility to AP alternans. Methods and Results AF was induced in conscious young and old sheep using 50 Hz burst pacing. Old sheep were more vulnerable to AF . Monophasic and cellular AP s were recorded from the right atrium in vivo and from myocytes isolated from the left and right atrial appendages. AP alternans occurred at lower stimulation frequencies in old sheep than young in vivo (old, 3.0±0.1 Hz; young, 3.3±0.1 Hz; P<0.05) and in isolated myocytes (old, 1.6±0.1 Hz; young, 2.0±0.1 Hz; P<0.05). Simultaneous recordings of [Ca2+]i and membrane potential in myocytes showed that alternans of AP s and [Ca2+]i often occurred together. However, at low stimulation rates [Ca2+]i alternans could occur without AP alternans, whereas at high stimulation rates AP alternans could still be observed despite disabling Ca2+ cycling using thapsigargin. Conclusions We have shown, for the first time in a large mammalian model, that aging is associated with increased duration of AF and susceptibility to AP alternans. We suggest that instabilities in Ca2+ handling initiate alternans at low stimulation rates, but that AP restitution alone can sustain alternans at higher rates.
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Palee S, Minta W, Mantor D, Sutham W, Kerdphoo S, Pratchayasakul W, Chattipakorn SC, Chattipakorn N. Estrogen deprivation aggravates intracellular calcium dyshomeostasis in the heart of obese-insulin resistant rats. J Cell Physiol 2018; 234:6983-6991. [PMID: 30417357 DOI: 10.1002/jcp.27444] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 08/28/2018] [Indexed: 12/19/2022]
Abstract
The incidence of cardiovascular disease and metabolic syndrome increases after the onset of menopause, giving evidence for the vital role of estrogen. Intracellular calcium [Ca2+ ]i regulation plays an important role in the maintenance of left ventricular (LV) contractile function. Although either estrogen deprivation or obesity has been shown to strongly affect the metabolic status and LV function, the effects of estrogen deprivation on the cardiometabolic status and cardiac [Ca 2+ ]i regulation in the obese-insulin resistant condition have never been investigated. Our hypothesis was that estrogen deprivation aggravates LV dysfunction through the increased impairment of [Ca 2+ ]i homeostasis in obese-insulin resistant rats. Female rats were fed on either a high-fat (HFD, 59.28% fat) or normal (ND, 19.77% fat) diet for 13 weeks. Then, rats were divided into sham (HFS and NDS) operated or ovariectomized (HFO and NDO) groups. Six weeks after surgery, metabolic status, LV function and incidence of [Ca 2+ ]i transients were determined. NDO, HFS, and HFO rats had evidence of obese-insulin resistance indicated by increased body weight with hyperinsulinemia and euglycemia. Although NDO, HFS, and HFO rats had markedly reduced %LV fractional shortening, E/A ratio and decreased [Ca 2+ ]i transient amplitude and decay rate, HFO rats had the most severe impairments. These findings indicate that estrogen deprivation had a strong impact on abnormal LV function through [Ca 2+ ]i regulation. In addition, evidence was found that in obese-insulin resistant rats, estrogen deprivation severely aggravates LV dysfunction via increased impairment of [Ca 2+ ]i homeostasis.
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Affiliation(s)
- Siripong Palee
- Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.,Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai, Thailand
| | - Wanitchaya Minta
- Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.,Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai, Thailand.,Cardiac Electrophysiology Unit, Department of Physiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Duangkamol Mantor
- Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.,Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai, Thailand.,Cardiac Electrophysiology Unit, Department of Physiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Wissuta Sutham
- Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.,Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai, Thailand.,Cardiac Electrophysiology Unit, Department of Physiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Sasiwan Kerdphoo
- Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.,Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai, Thailand
| | - Wasana Pratchayasakul
- Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.,Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai, Thailand.,Cardiac Electrophysiology Unit, Department of Physiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Siriporn C Chattipakorn
- Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.,Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai, Thailand.,Department of Oral Biology and Diagnostic Science, Faculty of Dentistry, Chiang Mai University, Chiang Mai, Thailand
| | - Nipon Chattipakorn
- Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.,Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai, Thailand.,Cardiac Electrophysiology Unit, Department of Physiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
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Nawaratna SSK, You H, Jones MK, McManus DP, Gobert GN. Calcium and Ca 2+/Calmodulin-dependent kinase II as targets for helminth parasite control. Biochem Soc Trans 2018; 46:1743-51. [PMID: 30420417 DOI: 10.1042/BST20180480] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 09/07/2018] [Accepted: 10/01/2018] [Indexed: 11/17/2022]
Abstract
In eukaryotes, effective calcium homeostasis is critical for many key biological processes. There is an added level of complexity in parasites, particularly multicellular helminth worms, which modulate calcium levels while inhabiting the host microenvironment. Parasites ensure efficient calcium homeostasis through gene products, such as the calmodulin-dependent kinases (CaMK), the main focus of this review. The importance of CaMK is becoming increasingly apparent from recent functional studies of helminth and protozoan parasites. Investigations on the molecular regulation of calcium and the role of CaMK are important for both supplementing current drug regimens and finding new antiparasitic compounds. Whereas calcium regulators, including CaMK, are well characterised in mammalian systems, knowledge of their functional properties in parasites is increasing but is still in its infancy.
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Niu J, Dick IE, Yang W, Bamgboye MA, Yue DT, Tomaselli G, Inoue T, Ben-Johny M. Allosteric regulators selectively prevent Ca 2+-feedback of Ca V and Na V channels. eLife 2018; 7:35222. [PMID: 30198845 PMCID: PMC6156082 DOI: 10.7554/elife.35222] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 09/09/2018] [Indexed: 12/31/2022] Open
Abstract
Calmodulin (CaM) serves as a pervasive regulatory subunit of CaV1, CaV2, and NaV1 channels, exploiting a functionally conserved carboxy-tail element to afford dynamic Ca2+-feedback of cellular excitability in neurons and cardiomyocytes. Yet this modularity counters functional adaptability, as global changes in ambient CaM indiscriminately alter its targets. Here, we demonstrate that two structurally unrelated proteins, SH3 and cysteine-rich domain (stac) and fibroblast growth factor homologous factors (fhf) selectively diminish Ca2+/CaM-regulation of CaV1 and NaV1 families, respectively. The two proteins operate on allosteric sites within upstream portions of respective channel carboxy-tails, distinct from the CaM-binding interface. Generalizing this mechanism, insertion of a short RxxK binding motif into CaV1.3 carboxy-tail confers synthetic switching of CaM regulation by Mona SH3 domain. Overall, our findings identify a general class of auxiliary proteins that modify Ca2+/CaM signaling to individual targets allowing spatial and temporal orchestration of feedback, and outline strategies for engineering Ca2+/CaM signaling to individual targets.
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Affiliation(s)
- Jacqueline Niu
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, United States
| | - Ivy E Dick
- Department of Physiology, University of Maryland, Baltimore, United States
| | - Wanjun Yang
- Department of Cardiology, Johns Hopkins University, Baltimore, United States
| | | | - David T Yue
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, United States
| | - Gordon Tomaselli
- Department of Cardiology, Johns Hopkins University, Baltimore, United States
| | - Takanari Inoue
- Department of Cell Biology, Johns Hopkins University, Baltimore, United States.,Center for Cell Dynamics, Institute for Basic Biomedical Sciences, Johns Hopkins University, Baltimore, United States
| | - Manu Ben-Johny
- Department of Physiology and Cellular Biophysics, College of Physicians and Surgeons, Columbia University, New York, United States
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Bovo E, Mazurek SR, Zima AV. Oxidation of ryanodine receptor after ischemia-reperfusion increases propensity of Ca 2+ waves during β-adrenergic receptor stimulation. Am J Physiol Heart Circ Physiol 2018; 315:H1032-H1040. [PMID: 30028204 DOI: 10.1152/ajpheart.00334.2018] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
β-Adrenergic receptor (β-AR) activation produces the main positive inotropic response of the heart. During ischemia-reperfusion (I/R), however, β-AR activation can trigger life-threatening arrhythmias. Because I/R is frequently associated with oxidative stress, we investigated whether ryanodine receptor (RyR) oxidation contributes to proarrythmogenic Ca2+ waves during β-AR activation. Measurements of contractile and electrical activity from Langendorff-perfused rabbit hearts revealed that I/R produces tachyarrhythmias. Ventricular myocytes isolated from I/R hearts had an increased level of oxidized glutathione (i.e., oxidative stress) and a decreased level of free thiols in RyRs (i.e., RyR oxidation). Furthermore, myocytes from I/R hearts were characterized by increased sarcoplasmic reticulum (SR) Ca2+ leak and enhanced fractional SR Ca2+ release. In myocytes from nonischemic hearts, β-AR activation with isoproterenol (10 nM) produced only a positive inotropic effect, whereas in myocytes from ischemic hearts, isoproterenol at the same concentration triggered spontaneous Ca2+ waves. β-AR activation produced a similar effect on RyR phosphorylation in control and I/R myocytes. Treatment of myocytes from I/R hearts with the reducing agent mercaptopropionylglycine (100 μM) attenuated RyR oxidization and decreased Ca2+ wave frequency during β-AR activation. On the other hand, treatment of myocytes from nonischemic hearts with H2O2 (50 μM) increased SR Ca2+ leak and triggered Ca2+ waves during β-AR activation. Collectively, these results suggest that RyR oxidation after I/R plays a critical role in the transition from positive inotropic to arrhythmogenic effects during β-AR stimulation. Prevention of RyR oxidation can be a promising strategy to inhibit arrhythmias and preserve positive inotropic effect of β-AR activation during myocardial infarction. NEW & NOTEWORTHY Oxidative stress induced by ischemia plays a critical role in triggering arrhythmias during adrenergic stimulation. The combined increase in sarcoplasmic reticulum Ca2+ leak (because of ryanodine receptor oxidation) and sarcoplasmic reticulum Ca2+ load (because of adrenergic stimulation) can trigger proarrythmogenic Ca2+ waves. Restoring normal ryanodine receptor redox status can be a promising strategy to prevent arrhythmias and preserve positive inotropic effect of adrenergic stimulation during myocardial infarction.
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Affiliation(s)
- Elisa Bovo
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago , Maywood, Illinois
| | - Stefan R Mazurek
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago , Maywood, Illinois
| | - Aleksey V Zima
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago , Maywood, Illinois
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Abstract
Background Ryanodine receptors (RyR) mediate sarcoplasmic reticulum calcium (Ca2+) release and influence myocyte Ca2+ homeostasis and arrhythmias. In cardiac myocytes, RyRs are found in clusters of various sizes and shapes, and RyR cluster size may critically influence normal and arrhythmogenic Ca2+ spark and wave formation. However, the actual RyR cluster sizes at specific Ca2+ spark sites have never been measured in the physiological setting. Methods and Results Here we measured RyR cluster size and Ca2+ sparks simultaneously to assess how RyR cluster size influences Ca2+ sparks and sarcoplasmic reticulum Ca2+ leak. For small RyR cluster sizes (<50), Ca2+ spark frequency is very low but then increases dramatically at larger cluster sizes. In contrast, Ca2+ spark amplitude is nearly maximal even at relatively small RyR cluster size (≈10) and changes little at larger cluster size. These properties agreed with computational simulations of RyR gating within clusters. Conclusions Our study explains how this combination of properties may limit arrhythmogenic Ca2+ sparks and wave propagation (at many junctions) while preserving the efficacy and spatial synchronization of Ca2+‐induced Ca2+‐release during normal excitation‐contraction coupling. However, variations in RyR cluster size among individual junctions and RyR sensitivity could exacerbate heterogeneity of local sarcoplasmic reticulum Ca2+ release and arrhythmogenesis under pathological conditions.
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Affiliation(s)
- Samuel Galice
- Department of Pharmacology, University of California Davis, Davis, CA
| | - Yuanfang Xie
- Department of Pharmacology, University of California Davis, Davis, CA
| | - Yi Yang
- Department of Pharmacology, University of California Davis, Davis, CA
| | - Daisuke Sato
- Department of Pharmacology, University of California Davis, Davis, CA
| | - Donald M Bers
- Department of Pharmacology, University of California Davis, Davis, CA
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41
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Schelke MW, Attia P, Palenchar DJ, Kaplan B, Mureb M, Ganzer CA, Scheyer O, Rahman A, Kachko R, Krikorian R, Mosconi L, Isaacson RS. Mechanisms of Risk Reduction in the Clinical Practice of Alzheimer's Disease Prevention. Front Aging Neurosci 2018; 10:96. [PMID: 29706884 PMCID: PMC5907312 DOI: 10.3389/fnagi.2018.00096] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 03/21/2018] [Indexed: 12/18/2022] Open
Abstract
Alzheimer’s disease (AD) is a neurodegenerative dementia that affects nearly 50 million people worldwide and is a major source of morbidity, mortality, and healthcare expenditure. While there have been many attempts to develop disease-modifying therapies for late-onset AD, none have so far shown efficacy in humans. However, the long latency between the initial neuronal changes and onset of symptoms, the ability to identify patients at risk based on family history and genetic markers, and the emergence of AD biomarkers for preclinical disease suggests that early risk-reducing interventions may be able to decrease the incidence of, delay or prevent AD. In this review, we discuss six mechanisms—dysregulation of glucose metabolism, inflammation, oxidative stress, trophic factor release, amyloid burden, and calcium toxicity—involved in AD pathogenesis that offer promising targets for risk-reducing interventions. In addition, we offer a blueprint for a multi-modality AD risk reduction program that can be clinically implemented with the current state of knowledge. Focused risk reduction aimed at particular pathological factors may transform AD to a preventable disorder in select cases.
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Affiliation(s)
- Matthew W Schelke
- Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, United States
| | - Peter Attia
- Attia Medical, PC, San Diego, CA, United States
| | | | - Bob Kaplan
- Attia Medical, PC, San Diego, CA, United States
| | - Monica Mureb
- Weill Cornell Medicine, Cornell University, New York, NY, United States
| | - Christine A Ganzer
- Hunter College, City University of New York, New York, NY, United States
| | - Olivia Scheyer
- Weill Cornell Medicine, Cornell University, New York, NY, United States
| | - Aneela Rahman
- Weill Cornell Medicine, Cornell University, New York, NY, United States
| | | | - Robert Krikorian
- College of Medicine, University of Cincinnati, Cincinnati, OH, United States
| | - Lisa Mosconi
- Weill Cornell Medicine, Cornell University, New York, NY, United States
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Johnson CN, Potet F, Thompson MK, Kroncke BM, Glazer AM, Voehler MW, Knollmann BC, George AL, Chazin WJ. A Mechanism of Calmodulin Modulation of the Human Cardiac Sodium Channel. Structure 2018; 26:683-694.e3. [PMID: 29606593 DOI: 10.1016/j.str.2018.03.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 01/26/2018] [Accepted: 03/08/2018] [Indexed: 12/26/2022]
Abstract
The function of the human cardiac sodium channel (NaV1.5) is modulated by the Ca2+ sensor calmodulin (CaM), but the underlying mechanism(s) are controversial and poorly defined. CaM has been reported to bind in a Ca2+-dependent manner to two sites in the intracellular loop that is critical for inactivation of NaV1.5 (inactivation gate [IG]). The affinity of CaM for the complete IG was significantly stronger than that of fragments that lacked both complete binding sites. Structural analysis by nuclear magnetic resonance, crystallographic, and scattering approaches revealed that CaM simultaneously engages both IG sites using an extended configuration. Patch-clamp recordings for wild-type and mutant channels with an impaired CaM-IG interaction revealed CaM binding to the IG promotes recovery from inactivation while impeding the kinetics of inactivation. Models of full-length NaV1.5 suggest that CaM binding to the IG directly modulates channel function by destabilizing the inactivated state, which would promote resetting of the IG after channels close.
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Affiliation(s)
- Christopher N Johnson
- Division of Clinical Pharmacology, Vanderbilt University, Nashville, TN 37240, USA; Department of Biochemistry, Vanderbilt University, Nashville, TN 37205, USA; Center for Structural Biology, Vanderbilt University, Nashville, TN 37232, USA; Center for Arrhythmia Research and Therapeutics, Vanderbilt University, Nashville, TN 37240, USA.
| | - Franck Potet
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago IL 60611, USA
| | - Matthew K Thompson
- Department of Biochemistry, Vanderbilt University, Nashville, TN 37205, USA; Center for Structural Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Brett M Kroncke
- Division of Clinical Pharmacology, Vanderbilt University, Nashville, TN 37240, USA; Center for Arrhythmia Research and Therapeutics, Vanderbilt University, Nashville, TN 37240, USA
| | - Andrew M Glazer
- Division of Clinical Pharmacology, Vanderbilt University, Nashville, TN 37240, USA; Center for Arrhythmia Research and Therapeutics, Vanderbilt University, Nashville, TN 37240, USA
| | - Markus W Voehler
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA; Center for Structural Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Bjorn C Knollmann
- Division of Clinical Pharmacology, Vanderbilt University, Nashville, TN 37240, USA; Center for Arrhythmia Research and Therapeutics, Vanderbilt University, Nashville, TN 37240, USA
| | - Alfred L George
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago IL 60611, USA
| | - Walter J Chazin
- Department of Biochemistry, Vanderbilt University, Nashville, TN 37205, USA; Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA; Center for Structural Biology, Vanderbilt University, Nashville, TN 37232, USA.
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Banerjee R, Yoder JB, Yue DT, Amzel LM, Tomaselli GF, Gabelli SB, Ben-Johny M. Bilobal architecture is a requirement for calmodulin signaling to Ca V1.3 channels. Proc Natl Acad Sci U S A 2018; 115:E3026-35. [PMID: 29531055 DOI: 10.1073/pnas.1716381115] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Calmodulin (CaM) regulation of voltage-gated calcium (CaV) channels is a powerful Ca2+ feedback mechanism that adjusts Ca2+ influx, affording rich mechanistic insights into Ca2+ decoding. CaM possesses a dual-lobed architecture, a salient feature of the myriad Ca2+-sensing proteins, where two homologous lobes that recognize similar targets hint at redundant signaling mechanisms. Here, by tethering CaM lobes, we demonstrate that bilobal architecture is obligatory for signaling to CaV channels. With one lobe bound, CaV carboxy tail rearranges itself, resulting in a preinhibited configuration precluded from Ca2+ feedback. Reconstitution of two lobes, even as separate molecules, relieves preinhibition and restores Ca2+ feedback. CaV channels thus detect the coincident binding of two Ca2+-free lobes to promote channel opening, a molecular implementation of a logical NOR operation that processes spatiotemporal Ca2+ signals bifurcated by CaM lobes. Overall, a unified scheme of CaV channel regulation by CaM now emerges, and our findings highlight the versatility of CaM to perform exquisite Ca2+ computations.
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Huang SY, Chen YC, Kao YH, Hsieh MH, Lin YK, Chung CC, Lee TI, Tsai WC, Chen SA, Chen YJ. Fibroblast growth factor 23 dysregulates late sodium current and calcium homeostasis with enhanced arrhythmogenesis in pulmonary vein cardiomyocytes. Oncotarget 2018; 7:69231-69242. [PMID: 27713141 PMCID: PMC5342473 DOI: 10.18632/oncotarget.12470] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 09/29/2016] [Indexed: 12/19/2022] Open
Abstract
Fibroblast growth factor 23 (FGF23), elevated in chronic renal failure, increases atrial arrhythmogenesis and dysregulates calcium homeostasis. Late sodium currents (INa-Late) critically induces ectopic activity of pulmoanry vein (the most important atrial fibrillation trigger). This study was to investigate whether FGF23 activates the INa-Late leading to calcium dysregulation and increases PV arrhythmogenesis. Patch clamp, western blot, and confocal microscopy were used to evaluate the electrical activities, calcium homeostasis, and mitochondrial reactive oxygen species (ROS) in PV cardiomyocytes with or without FGF23 (0.1 or 1 ng/mL) incubation for 4~6 h. Compared to the control, FGF23 (1 ng/mL, but not 0.1 ng/mL)-treated PV cardiomyocytes had a faster beating rate. FGF23 (1 ng/mL)-treated PV cardiomyocytes had larger INa-Late, calcium transients, and mitochondrial ROS than controls. However, ranolazine (an inhibitor of INa-Late) attenuated FGF23 (1 ng/mL)-increased beating rates, calcium transients and mitochondrial ROS. FGF23 (1 ng/mL)-treated PV cardiomyocytes exhibited larger phosphorylation of calcium/calmodulin-dependent protein kinase II (CaMKII). Chelerythrine chloride (an inhibitor of protein kinase C) decreased INa-Late in FGF23 (1 ng/mL)-treated PV cardiomyocytes. However, KN93 (a selective CaMKII blocker) decreased INa-Late in control and FGF23 (1 ng/mL)-treated PV cardiomyocytes to a similar extent. In conclusion, FGF23 increased PV arrhythmogenesis through sodium and calcium dysregulation by acting protein kinase C signaling.
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Affiliation(s)
- Shih-Yu Huang
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.,Division of Cardiology, Department of Internal Medicine, Cathay General Hospital, Taipei, Taiwan
| | - Yao-Chang Chen
- Department of Biomedical Engineering, National Defense Medical Center, Taipei, Taiwan
| | - Yu-Hsun Kao
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.,Department of Medical Education and Research, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
| | - Ming-Hsiung Hsieh
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan.,Division of Cardiology, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Yung-Kuo Lin
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan.,Division of Cardiology, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Cheng-Chih Chung
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.,Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
| | - Ting-I Lee
- Department of General Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.,Division of Endocrinology and Metabolism, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
| | - Wen-Chin Tsai
- Division of Cardiology, Tzu-Chi General Hospital, Institute of Medical Sciences, Tzu-Chi University, Hualien, Taiwan
| | - Shih-Ann Chen
- Division of Cardiology and Cardiovascular Research Center, Veterans General Hospital-Taipei, Taipei, Taiwan
| | - Yi-Jen Chen
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.,Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
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Bernardo-Seisdedos G, Nuñez E, Gomis-Perez C, Malo C, Villarroel Á, Millet O. Structural basis and energy landscape for the Ca 2+ gating and calmodulation of the Kv7.2 K + channel. Proc Natl Acad Sci U S A 2018; 115:2395-400. [PMID: 29463698 DOI: 10.1073/pnas.1800235115] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Ion channels are sophisticated proteins that exert control over a plethora of body functions. Specifically, the members of the Kv7 family are prominent components of the nervous systems, responsible for the ion fluxes that regulate the electrical signaling in neurons and cardiac myocytes. Albeit its relevance, there are still several questions, including the Ca2+/calmodulin (CaM)-mediated gating mechanism. We found that Ca2+ binding to CaM triggers a segmental rotation that allosterically transmits the signal from the cytosol up to the transmembrane region. NMR-derived analysis of the dynamics demonstrates that it occurs through a conformational selection mechanism. Energetically, CaM association with the channel tunes the affinities of the CaM lobes (calmodulation) so that the channel can sense the specific changes in [Ca2+] resulting after an action potential. The Kv7.2 (KCNQ2) channel is the principal molecular component of the slow voltage-gated, noninactivating K+ M-current, a key controller of neuronal excitability. To investigate the calmodulin (CaM)-mediated Ca2+ gating of the channel, we used NMR spectroscopy to structurally and dynamically describe the association of helices hA and hB of Kv7.2 with CaM, as a function of Ca2+ concentration. The structures of the CaM/Kv7.2-hAB complex at two different calcification states are reported here. In the presence of a basal cytosolic Ca2+ concentration (10–100 nM), only the N-lobe of CaM is Ca2+-loaded and the complex (representative of the open channel) exhibits collective dynamics on the millisecond time scale toward a low-populated excited state (1.5%) that corresponds to the inactive state of the channel. In response to a chemical or electrical signal, intracellular Ca2+ levels rise up to 1–10 μM, triggering Ca2+ association with the C-lobe. The associated conformational rearrangement is the key biological signal that shifts populations to the closed/inactive channel. This reorientation affects the C-lobe of CaM and both helices in Kv7.2, allosterically transducing the information from the Ca2+-binding site to the transmembrane region of the channel.
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Kabbani N, Nichols RA. Beyond the Channel: Metabotropic Signaling by Nicotinic Receptors. Trends Pharmacol Sci 2018; 39:354-366. [PMID: 29428175 DOI: 10.1016/j.tips.2018.01.002] [Citation(s) in RCA: 112] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2017] [Revised: 01/05/2018] [Accepted: 01/08/2018] [Indexed: 01/01/2023]
Abstract
The α7 nicotinic acetylcholine receptor (nAChR) is a ligand-gated ion channel (LGIC) that plays an important role in cellular calcium signaling and contributes to several neurological diseases. Agonist binding to the α7 nAChR induces fast channel activation followed by inactivation and prolonged desensitization while triggering long-lasting calcium signaling. These activities foster neurotransmitter release, synaptic plasticity, and somatodendritic regulation in the brain. We discuss here the ability of α7 nAChRs to operate in ionotropic (α7i) and metabotropic (α7m) modes, leading to calcium-induced calcium release (CICR) and G protein-associated inositol trisphosphate (IP3)-induced calcium release (IICR), respectively. Metabotropic activity extends the spatial and temporal aspects of calcium signaling by the α7 channel beyond its ionotropic limits, persisting into the desensitized state. Delineation of the ionotropic and metabotropic properties of the α7 nAChR will provide definitive indicators of moment-to-moment receptor functional status that will, in turn, spearhead new drug development.
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Affiliation(s)
- Nadine Kabbani
- School of Systems Biology, George Mason University, Manassas, VA 20110, USA.
| | - Robert A Nichols
- Department of Cell and Molecular Biology, University of Hawai'i at Manoa, Honolulu, HI 96813, USA
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Chiamvimonvat N, Song LS. LRRC10 (Leucine-Rich Repeat Containing Protein 10) and REEP5 (Receptor Accessory Protein 5) as Novel Regulators of Cardiac Excitation-Contraction Coupling Structure and Function. J Am Heart Assoc 2018; 7:JAHA.117.008260. [PMID: 29431105 PMCID: PMC5850266 DOI: 10.1161/jaha.117.008260] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Nipavan Chiamvimonvat
- Division of Cardiovascular Medicine, Department of Internal Medicine, School of Medicine, University of California, Davis Davis, CA .,Department of Veterans Affairs, Northern California Health Care System, Mather, CA
| | - Long-Sheng Song
- Division of Cardiovascular Medicine, Department of Internal Medicine, Abboud Cardiovascular Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA .,Department of Veterans Affairs, Iowa City Medical Center, Iowa City, IA
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Yang HY, Firth JM, Francis AJ, Alvarez-Laviada A, MacLeod KT. Effect of ovariectomy on intracellular Ca 2+ regulation in guinea pig cardiomyocytes. Am J Physiol Heart Circ Physiol 2017; 313:H1031-H1043. [PMID: 28778911 DOI: 10.1152/ajpheart.00249.2017] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 07/17/2017] [Accepted: 08/02/2017] [Indexed: 01/30/2023]
Abstract
This study addressed the hypothesis that long-term deficiency of ovarian hormones after ovariectomy (OVx) alters cellular Ca2+-handling mechanisms in the heart, resulting in the formation of a proarrhythmic substrate. It also tested whether estrogen supplementation to OVx animals reverses any alterations to cardiac Ca2+ handling and rescues proarrhythmic behavior. OVx or sham operations were performed on female guinea pigs using appropriate anesthetic and analgesic regimes. Pellets containing 17β-estradiol (1 mg, 60-day release) were placed subcutaneously in selected OVx animals (OVx + E). Cardiac myocytes were enzymatically isolated, and electrophysiological measurements were conducted with a switch-clamp system. In fluo-4-loaded cells, Ca2+ transients were 20% larger, and fractional sarcoplasmic reticulum (SR) Ca2+ release was 7% greater in the OVx group compared with the sham group. Peak L-type Ca2+ current was 16% larger in OVx myocytes with channel inactivation shifting to more positive membrane potentials, creating a larger "window" current. SR Ca2+ stores were 22% greater in the OVx group, and these cells showed a higher frequency of Ca2+ sparks and waves and shorter wave-free intervals. OVx myocytes showed higher frequencies of early afterdepolarizations, and a greater percentage of these cells showed delayed afterdepolarizations after exposure to isoprenaline compared with sham myocytes. The altered Ca2+ regulation occurring in the OVx group was not observed in the OVx + E group. These findings suggest that long-term deprivation of ovarian hormones in guinea pigs lead to changes in myocyte Ca2+-handling mechanisms that are considered proarrhythmogenic. 17β-Estradiol replacement prevented these adverse effects.NEW & NOTEWORTHY Ovariectomized guinea pig cardiomyocytes have higher frequencies of Ca2+ waves, and isoprenaline-challenged cells display more early afterdepolarizations, delayed afterdepolarizations, and extra beats compared with sham myocytes. These alterations to Ca2+ regulation were not observed in myocytes from ovariectomized guinea pigs supplemented with 17β-estradiol, suggesting that ovarian hormone deficiency modifies cardiac Ca2+ regulation, potentially creating proarrhythmic substrates.
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Affiliation(s)
- Hsiang-Yu Yang
- National Heart and Lung Institute, Imperial College London, London, United Kingdom; and.,Division of Cardiovascular Surgery, Department of Surgery, Tri-Service General Hospital, National Defence Medical Center, Taipei, Taiwan
| | - Jahn M Firth
- National Heart and Lung Institute, Imperial College London, London, United Kingdom; and
| | - Alice J Francis
- National Heart and Lung Institute, Imperial College London, London, United Kingdom; and
| | - Anita Alvarez-Laviada
- National Heart and Lung Institute, Imperial College London, London, United Kingdom; and
| | - Kenneth T MacLeod
- National Heart and Lung Institute, Imperial College London, London, United Kingdom; and
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Ferguson CH, Zhao H. Simultaneous Loss of NCKX4 and CNG Channel Desensitization Impairs Olfactory Sensitivity. J Neurosci 2017; 37:110-9. [PMID: 28053034 DOI: 10.1523/JNEUROSCI.2527-16.2016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 10/24/2016] [Accepted: 11/04/2016] [Indexed: 11/21/2022] Open
Abstract
In vertebrate olfactory sensory neurons (OSNs), Ca2+ plays key roles in both mediating and regulating the olfactory response. Ca2+ enters OSN cilia during the response through the olfactory cyclic nucleotide-gated (CNG) channel and stimulates a depolarizing chloride current by opening the olfactory Ca2+-activated chloride channel to amplify the response. Ca2+ also exerts negative regulation on the olfactory transduction cascade, through mechanisms that include reducing the CNG current by desensitizing the CNG channel via Ca2+/calmodulin (CaM), to reduce the response. Ca2+ is removed from the cilia primarily by the K+-dependent Na+/Ca2+ exchanger 4 (NCKX4), and the removal of Ca2+ leads to closure of the chloride channel and response termination. In this study, we investigate how two mechanisms conventionally considered negative regulatory mechanisms of olfactory transduction, Ca2+ removal by NCKX4, and desensitization of the CNG channel by Ca2+/CaM, interact to regulate the olfactory response. We performed electro-olfactogram (EOG) recordings on the double-mutant mice, NCKX4-/-;CNGB1ΔCaM, which are simultaneously lacking NCKX4 (NCKX4-/-) and Ca2+/CaM-mediated CNG channel desensitization (CNGB1ΔCaM). Despite exhibiting alterations in various response attributes, including termination kinetics and adaption properties, OSNs in either NCKX4-/- mice or CNGB1ΔCaM mice show normal resting sensitivity, as determined by their unchanged EOG response amplitude. We found that OSNs in NCKX4-/-;CNGB1ΔCaM mice displayed markedly reduced EOG amplitude accompanied by alterations in other response attributes. This study suggests that what are conventionally considered negative regulatory mechanisms of olfactory transduction also play a role in setting the resting sensitivity in OSNs. SIGNIFICANCE STATEMENT Sensory receptor cells maintain high sensitivity at rest. Although the mechanisms responsible for setting the resting sensitivity of sensory receptor cells are not well understood, it has generally been assumed that the sensitivity is set primarily by how effectively the components in the activation cascade of sensory transduction can be stimulated. Our findings in mouse olfactory sensory neurons suggest that mechanisms that are primarily responsible for terminating the olfactory response are also critical for proper resting sensitivity.
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Huang SY, Chen YC, Kao YH, Hsieh MH, Lin YK, Chen SA, Chen YJ. Redox and Activation of Protein Kinase A Dysregulates Calcium Homeostasis in Pulmonary Vein Cardiomyocytes of Chronic Kidney Disease. J Am Heart Assoc 2017; 6:JAHA.117.005701. [PMID: 28701305 PMCID: PMC5586294 DOI: 10.1161/jaha.117.005701] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Background Chronic kidney disease (CKD) increases the occurrence of atrial fibrillation and pulmonary vein (PV) arrhythmogenesis. Calcium dysregulation and reactive oxygen species (ROS) enhance PV arrhythmogenic activity. The purposes of this study were to investigate whether CKD modulates PV electrical activity through dysregulation of calcium homeostasis and ROS. Methods and Results Biochemical and electrocardiographic studies were conducted in rabbits with and without CKD (induced by 150 mg/kg per day neomycin sulfate and 500 mg/kg per day cefazolin). Confocal microscopy with fluorescence and a whole‐cell patch clamp were applied to study calcium homeostasis and electrical activities in control and CKD isolated single PV cardiomyocytes with or without treatment with H89 (1 μmol/L, a protein kinase A inhibitor) and MPG (N‐[2‐mercaptopropionyl]glycine; 100 μmol/L, a ROS scavenger). The ROS in mitochondria and cytosol were evaluated via intracellular dye fluorescence and lipid peroxidation. CKD rabbits had excessive atrial premature captures over those of control rabbits. Compared with the control, CKD PV cardiomyocytes had a faster beating rate and larger calcium transient amplitudes, sarcoplasmic reticulum calcium contents, sodium/calcium exchanger currents, and late sodium currents but smaller L‐type calcium current densities. CKD PV cardiomyocytes had a higher frequency and longer duration of calcium sparks and more ROS in the mitochondria and cytosol than did controls. Moreover, H89 suppressed all calcium sparks in CKD PV cardiomyocytes, and H89‐ and MPG‐treated CKD PV cardiomyocytes had similar calcium transients compared with control PV cardiomyocytes. Conclusions CKD increases PV arrhythmogenesis with enhanced calcium‐handling abnormalities through activation of protein kinase A and ROS.
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Affiliation(s)
- Shih-Yu Huang
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.,Division of Cardiology, Department of Internal Medicine, Cathay General Hospital, Taipei, Taiwan
| | - Yao-Chang Chen
- Department of Biomedical Engineering, National Defense Medical Center, Taipei, Taiwan
| | - Yu-Hsun Kao
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.,Department of Medical Education and Research, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
| | - Ming-Hsiung Hsieh
- Division of Cardiology, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.,Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
| | - Yung-Kuo Lin
- Division of Cardiology, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.,Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
| | - Shih-Ann Chen
- School of Medicine, National Yang-Ming University, Taipei, Taiwan.,Division of Cardiology and Cardiovascular Research Center, Veterans General Hospital-Taipei, Taipei, Taiwan
| | - Yi-Jen Chen
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan .,Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
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