1
|
Wu C, Li X, Li J, Huo R, Zhao H, Ying Y. Association between serum calcium and prognosis in patients with acute ischemic stroke in ICU: analysis of the MIMIC-IV database. BMC Anesthesiol 2024; 24:139. [PMID: 38609861 PMCID: PMC11010421 DOI: 10.1186/s12871-024-02528-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Accepted: 04/06/2024] [Indexed: 04/14/2024] Open
Abstract
BACKGROUND While serum Ca has proven to be a reliable predictor of mortality across various diseases, its connection with the clinical outcomes of ischemic stroke (IS) remains inconclusive. Our research aimed to explore the relationships between serum total Ca (tCa) and serum ionized Ca (iCa) and mortality among acute IS (AIS) patients. METHODS We gathered data from 1773 AIS patients in the Medical Information Mart for Intensive Care Database IV, including baseline demographic data, comorbidities, vital signs, laboratory-based data, and scoring systems. Endpoints for the study encompassed 30-d, 90-d, and 365-d all-cause mortalities. Employing restricted cubic spline Cox regression, we explored potential nonlinear relationships between admission serum iCa and tCa levels and mortality. Participants were categorized into four groups based on serum iCa and tCa quartiles. Multivariable Cox regression analysis was then conducted to evaluate the independent association of iCa and tCa quartiles with all-cause mortality. RESULTS The restricted cubic spline revealed a U-shaped association between iCa and 30-d and 90-d mortality (P<0.05), while the relationship between iCa and 365-d mortality was linear (P<0.05). After adjusting for confounders, multivariable Cox analysis demonstrated that the lowest serum iCa level quartile was independently associated with increased risks of 30-d, 90-d, and 365-d mortality. Similarly, the highest serum iCa level quartile was independently associated with increased risks of 30-d and 90-d mortality, but not 365-d mortality. Notably, serum tCa level showed no association with increased risks of 30-d, 90-d, and 365-d mortality. CONCLUSIONS Our findings suggest that serum iCa, rather than tCa, is linked to ischemic stroke prognosis. Both high and low serum iCa levels are associated with poor short-term prognosis, while only low serum iCa is associated with poor long-term prognosis in AIS patients.
Collapse
Affiliation(s)
- Caijiao Wu
- Department of Dermatology and Venereology, the First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, Guangxi, China
| | - Xiaorong Li
- Department of Critical Care Medicine, the First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Jiaxing Li
- Department of Neurology Intensive Care Unit, the First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Ruiling Huo
- Department of Dermatology and Venereology, the First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, Guangxi, China.
| | - Huihan Zhao
- Department of Nursing, the First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, Guangxi, China
| | - Yanping Ying
- Department of Nursing, the First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, Guangxi, China.
| |
Collapse
|
2
|
Li W, Sun W, Zhang G, Lu Y, Dai C. Thermosensitive hydrogel containing ethosuximide-loaded multivesicular liposomes attenuates age-related hearing loss in C57BL/6J mice. Neurosci Lett 2024; 826:137693. [PMID: 38428726 DOI: 10.1016/j.neulet.2024.137693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 01/20/2024] [Accepted: 02/13/2024] [Indexed: 03/03/2024]
Abstract
Ethosuximide is the first drug reported to protect against age-related hearing loss, but its benefits are hampered by the pronounced side effects generated through systemic administration. We prepared a thermosensitive hydrogel containing ethosuximide-encapsulated multivesicular liposomes (ethosuximide-loaded MVLs-Gel) and evaluated its functional and histological effects on age-related hearing loss in C57BL/6J mice. The MVLs-Gel showed slow sustained-release characteristics up to over 120 h. After 8 weeks of treatment, compared to the oral systemic administration of ethosuximide, intratympanic ethosuximide-loaded MVLs-Gel injection dramatically reduced the loss of age-related spiral ganglion neurons in the apical turns of the mice (low-frequency regions, p < 0.05). Correspondingly, compared to the oral systemic administration group, the intratympanic ethosuximide-loaded MVLs-Gel injection group showed significantly lower auditory brainstem response threshold shifts at stimulus frequencies of 4, 8, and 16 kHz (low-and middle-frequency regions, p < 0.05). In conclusion, intratympanic ethosuximide-loaded MVLs-Gel injection can reach the apical turn of the cochlea, which is extremely difficult with oral systemic administration of the drug. The ethosuximide-loaded MVLs-Gel, as a novel intratympanic sustained-release drug delivery system, attenuated age-related hearing loss in C57BL/6J mice.
Collapse
Affiliation(s)
- Wei Li
- Department of Otology and Skull Base Surgery, Eye Ear Nose and Throat Hospital, Fudan University, Shanghai, China; Key Laboratory of Hearing Medicine, Ministry of Health, Shanghai, China
| | - Wenfang Sun
- Department of Otology and Skull Base Surgery, Eye Ear Nose and Throat Hospital, Fudan University, Shanghai, China; Key Laboratory of Hearing Medicine, Ministry of Health, Shanghai, China
| | - Guoming Zhang
- Department of Otolaryngology, Yuecheng District People's Hospital, Shaoxing, China
| | - Yi Lu
- School of Pharmacy, Fudan University, Shanghai, China.
| | - Chunfu Dai
- Department of Otology and Skull Base Surgery, Eye Ear Nose and Throat Hospital, Fudan University, Shanghai, China; Key Laboratory of Hearing Medicine, Ministry of Health, Shanghai, China.
| |
Collapse
|
3
|
de la Cruz L, Bui D, Moreno CM, Vivas O. Sympathetic Motor Neuron Dysfunction is a Missing Link in Age-Associated Sympathetic Overactivity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.09.27.559800. [PMID: 37808870 PMCID: PMC10557755 DOI: 10.1101/2023.09.27.559800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
Overactivity of the sympathetic nervous system is a hallmark of aging. The cellular mechanisms behind this overactivity remain poorly understood, with most attention paid to likely central nervous system components. In this work, we hypothesized that aging also affects the function of motor neurons in the peripheral sympathetic ganglia. To test this hypothesis, we compared the electrophysiological responses and ion-channel activity of neurons isolated from the superior cervical ganglia of young (12 weeks), middle-aged (64 weeks), and old (115 weeks) mice. These approaches showed that aging does impact the intrinsic properties of sympathetic motor neurons, increasing spontaneous and evoked firing responses. A reduction of KCNQ channel currents emerged as a major contributor to age-related hyperexcitability. Thus, it is essential to consider the effect of aging on motor components of the sympathetic reflex as a crucial part of the mechanism involved in sympathetic overactivity.
Collapse
Affiliation(s)
- Lizbeth de la Cruz
- Department of Physiology and Biophysics, University of Washington, Seattle, WA
| | - Derek Bui
- Department of Physiology and Biophysics, University of Washington, Seattle, WA
| | - Claudia M. Moreno
- Department of Physiology and Biophysics, University of Washington, Seattle, WA
- Howard Hughes Medical Institute
| | - Oscar Vivas
- Department of Physiology and Biophysics, University of Washington, Seattle, WA
- Department of Pharmacology, University of Washington, Seattle, WA
| |
Collapse
|
4
|
Butova X, Myachina T, Simonova R, Kochurova A, Mukhlynina E, Kopylova G, Shchepkin D, Khokhlova A. The inter-chamber differences in the contractile function between left and right atrial cardiomyocytes in atrial fibrillation in rats. Front Cardiovasc Med 2023; 10:1203093. [PMID: 37608813 PMCID: PMC10440706 DOI: 10.3389/fcvm.2023.1203093] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 07/24/2023] [Indexed: 08/24/2023] Open
Abstract
Introduction The left and right atria (LA, RA) work under different mechanical and metabolic environments that may cause an intrinsic inter-chamber diversity in structure and functional properties between atrial cardiomyocytes (CM) in norm and provoke their different responsiveness to pathological conditions. In this study, we assessed a LA vs. RA difference in CM contractility in paroxysmal atrial fibrillation (AF) and underlying mechanisms. Methods We investigated the contractile function of single isolated CM from LA and RA using a 7-day acetylcholine (ACh)-CaCl2 AF model in rats. We compared auxotonic force, sarcomere length dynamics, cytosolic calcium ([Ca2+]i) transients, intracellular ROS and NO production in LA and RA CM, and analyzed the phosphorylation levels of contractile proteins and actin-myosin interaction using an in vitro motility assay. Results AF resulted in more prominent structural and functional changes in LA myocardium, reducing sarcomere shortening amplitude, and velocity of sarcomere relengthening in mechanically non-loaded LA CM, which was associated with the increased ROS production, decreased NO production, reduced myofibrillar content, and decreased phosphorylation of cardiac myosin binding protein C and troponin I. However, in mechanically loaded CM, AF depressed the auxotonic force amplitude and kinetics in RA CM, while force characteristics were preserved in LA CM. Discussion Thus, inter-atrial differences are increased in paroxysmal AF and affected by the mechanical load that may contribute to the maintenance and progression of AF.
Collapse
Affiliation(s)
- Xenia Butova
- Institute of Immunology and Physiology, Ural Branch of Russian Academy of Sciences, Yekaterinburg, Russian Federation
| | - Tatiana Myachina
- Institute of Immunology and Physiology, Ural Branch of Russian Academy of Sciences, Yekaterinburg, Russian Federation
| | - Raisa Simonova
- Institute of Immunology and Physiology, Ural Branch of Russian Academy of Sciences, Yekaterinburg, Russian Federation
| | - Anastasia Kochurova
- Institute of Immunology and Physiology, Ural Branch of Russian Academy of Sciences, Yekaterinburg, Russian Federation
| | - Elena Mukhlynina
- Institute of Immunology and Physiology, Ural Branch of Russian Academy of Sciences, Yekaterinburg, Russian Federation
- Institute of Natural Sciences and Mathematics, Ural Federal University, Yekaterinburg, Russian Federation
| | - Galina Kopylova
- Institute of Immunology and Physiology, Ural Branch of Russian Academy of Sciences, Yekaterinburg, Russian Federation
| | - Daniil Shchepkin
- Institute of Immunology and Physiology, Ural Branch of Russian Academy of Sciences, Yekaterinburg, Russian Federation
- Institute of Natural Sciences and Mathematics, Ural Federal University, Yekaterinburg, Russian Federation
| | - Anastasia Khokhlova
- Institute of Immunology and Physiology, Ural Branch of Russian Academy of Sciences, Yekaterinburg, Russian Federation
- Institute of Physics and Technology, Ural Federal University, Yekaterinburg, Russian Federation
| |
Collapse
|
5
|
Salvia miltiorrhiza Protects Endothelial Dysfunction against Mitochondrial Oxidative Stress. Life (Basel) 2021; 11:life11111257. [PMID: 34833133 PMCID: PMC8622679 DOI: 10.3390/life11111257] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 11/05/2021] [Accepted: 11/16/2021] [Indexed: 11/23/2022] Open
Abstract
Salvia miltiorrhiza (SM) is a common traditional Chinese medicine used in the treatment of cardiovascular and cerebrovascular diseases. Endothelial dysfunction plays an important role in the pathology of cardiovascular diseases. Endothelial dysfunction may induce inflammation and change vascular tone and permeability. The main pathological mechanism of endothelial dysfunction is the formation of reactive oxygen species (ROS). Mitochondria are the main source of energy and can also produce large amounts of ROS. Recent studies have shown that extracts of SM have antioxidative, anti-inflammatory, and antithrombus properties. In this review, we discuss the mechanism of oxidative stress in the mitochondria, endothelial dysfunction, and the role of SM in these oxidative events.
Collapse
|
6
|
Di Benedetto G, Iannucci LF, Surdo NC, Zanin S, Conca F, Grisan F, Gerbino A, Lefkimmiatis K. Compartmentalized Signaling in Aging and Neurodegeneration. Cells 2021; 10:cells10020464. [PMID: 33671541 PMCID: PMC7926881 DOI: 10.3390/cells10020464] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 02/16/2021] [Accepted: 02/17/2021] [Indexed: 12/12/2022] Open
Abstract
The cyclic AMP (cAMP) signalling cascade is necessary for cell homeostasis and plays important roles in many processes. This is particularly relevant during ageing and age-related diseases, where drastic changes, generally decreases, in cAMP levels have been associated with the progressive decline in overall cell function and, eventually, the loss of cellular integrity. The functional relevance of reduced cAMP is clearly supported by the finding that increases in cAMP levels can reverse some of the effects of ageing. Nevertheless, despite these observations, the molecular mechanisms underlying the dysregulation of cAMP signalling in ageing are not well understood. Compartmentalization is widely accepted as the modality through which cAMP achieves its functional specificity; therefore, it is important to understand whether and how this mechanism is affected during ageing and to define which is its contribution to this process. Several animal models demonstrate the importance of specific cAMP signalling components in ageing, however, how age-related changes in each of these elements affect the compartmentalization of the cAMP pathway is largely unknown. In this review, we explore the connection of single components of the cAMP signalling cascade to ageing and age-related diseases whilst elaborating the literature in the context of cAMP signalling compartmentalization.
Collapse
Affiliation(s)
- Giulietta Di Benedetto
- Neuroscience Institute, National Research Council of Italy (CNR), 35121 Padova, Italy;
- Veneto Institute of Molecular Medicine, Foundation for Advanced Biomedical Research, 35129 Padova, Italy; (L.F.I.); (S.Z.); (F.C.); (F.G.)
- Correspondence: (G.D.B.); (K.L.)
| | - Liliana F. Iannucci
- Veneto Institute of Molecular Medicine, Foundation for Advanced Biomedical Research, 35129 Padova, Italy; (L.F.I.); (S.Z.); (F.C.); (F.G.)
- Department of Molecular Medicine, University of Pavia, 27100 Pavia, Italy
| | - Nicoletta C. Surdo
- Neuroscience Institute, National Research Council of Italy (CNR), 35121 Padova, Italy;
- Veneto Institute of Molecular Medicine, Foundation for Advanced Biomedical Research, 35129 Padova, Italy; (L.F.I.); (S.Z.); (F.C.); (F.G.)
| | - Sofia Zanin
- Veneto Institute of Molecular Medicine, Foundation for Advanced Biomedical Research, 35129 Padova, Italy; (L.F.I.); (S.Z.); (F.C.); (F.G.)
- Department of Molecular Medicine, University of Pavia, 27100 Pavia, Italy
| | - Filippo Conca
- Veneto Institute of Molecular Medicine, Foundation for Advanced Biomedical Research, 35129 Padova, Italy; (L.F.I.); (S.Z.); (F.C.); (F.G.)
- Department of Biology, University of Padova, 35122 Padova, Italy
| | - Francesca Grisan
- Veneto Institute of Molecular Medicine, Foundation for Advanced Biomedical Research, 35129 Padova, Italy; (L.F.I.); (S.Z.); (F.C.); (F.G.)
- Department of Biology, University of Padova, 35122 Padova, Italy
| | - Andrea Gerbino
- Department of Biosciences, Biotechnology and Biopharmaceutics, University of Bari, 70121 Bari, Italy;
| | - Konstantinos Lefkimmiatis
- Veneto Institute of Molecular Medicine, Foundation for Advanced Biomedical Research, 35129 Padova, Italy; (L.F.I.); (S.Z.); (F.C.); (F.G.)
- Department of Molecular Medicine, University of Pavia, 27100 Pavia, Italy
- Correspondence: (G.D.B.); (K.L.)
| |
Collapse
|
7
|
Genovese I, Giamogante F, Barazzuol L, Battista T, Fiorillo A, Vicario M, D'Alessandro G, Cipriani R, Limatola C, Rossi D, Sorrentino V, Poser E, Mosca L, Squitieri F, Perluigi M, Arena A, van Petegem F, Tito C, Fazi F, Giorgi C, Calì T, Ilari A, Colotti G. Sorcin is an early marker of neurodegeneration, Ca 2+ dysregulation and endoplasmic reticulum stress associated to neurodegenerative diseases. Cell Death Dis 2020; 11:861. [PMID: 33060591 PMCID: PMC7566454 DOI: 10.1038/s41419-020-03063-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 09/16/2020] [Accepted: 09/18/2020] [Indexed: 12/12/2022]
Abstract
Dysregulation of calcium signaling is emerging as a key feature in the pathogenesis of neurodegenerative diseases such as Alzheimer’s disease (AD), Parkinson’s disease (PD), and Huntington’s disease (HD), and targeting this process may be therapeutically beneficial. Under this perspective, it is important to study proteins that regulate calcium homeostasis in the cell. Sorcin is one of the most expressed calcium-binding proteins in the human brain; its overexpression increases endoplasmic reticulum (ER) calcium concentration and decreases ER stress in the heart and in other cellular types. Sorcin has been hypothesized to be involved in neurodegenerative diseases, since it may counteract the increased cytosolic calcium levels associated with neurodegeneration. In the present work, we show that Sorcin expression levels are strongly increased in cellular, animal, and human models of AD, PD, and HD, vs. normal cells. Sorcin partially colocalizes with RyRs in neurons and microglia cells; functional experiments with microsomes containing high amounts of RyR2 and RyR3, respectively, show that Sorcin is able to regulate these ER calcium channels. The molecular basis of the interaction of Sorcin with RyR2 and RyR3 is demonstrated by SPR. Sorcin also interacts with other ER proteins as SERCA2 and Sigma-1 receptor in a calcium-dependent fashion. We also show that Sorcin regulates ER calcium transients: Sorcin increases the velocity of ER calcium uptake (increasing SERCA activity). The data presented here demonstrate that Sorcin may represent both a novel early marker of neurodegenerative diseases and a response to cellular stress dependent on neurodegeneration.
Collapse
Affiliation(s)
- Ilaria Genovese
- Department of Medical Sciences, Laboratory for Technology of Advanced Therapies (LTTA) University of Ferrara, Ferrara, Italy
| | - Flavia Giamogante
- Department of Biomedical Sciences, University of Padova, Padova, Italy.,Padova Neuroscience Center (PNC), University of Padova, Padova, Italy
| | - Lucia Barazzuol
- Department of Biomedical Sciences, University of Padova, Padova, Italy.,Padova Neuroscience Center (PNC), University of Padova, Padova, Italy
| | - Theo Battista
- Department of Biochemical Sciences "A. Rossi Fanelli", University Sapienza of Rome, Rome, Italy
| | - Annarita Fiorillo
- Department of Biochemical Sciences "A. Rossi Fanelli", University Sapienza of Rome, Rome, Italy
| | - Mattia Vicario
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Giuseppina D'Alessandro
- Department of Physiology and Pharmacology, University of Rome "Sapienza", Rome, Italy.,IRCCS Neuromed, Pozzilli, Isernia, Italy
| | - Raffaela Cipriani
- Department of Physiology and Pharmacology, University of Rome "Sapienza", Rome, Italy
| | - Cristina Limatola
- IRCCS Neuromed, Pozzilli, Isernia, Italy.,Department of Physiology and Pharmacology, Sapienza University, Laboratory Affiliated to Istituto Pasteur Italia - Rome, Rome, Italy
| | - Daniela Rossi
- Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - Vincenzo Sorrentino
- Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - Elena Poser
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Luciana Mosca
- Department of Biochemical Sciences "A. Rossi Fanelli", University Sapienza of Rome, Rome, Italy
| | - Ferdinando Squitieri
- Huntington's and Rare Diseases Unit, IRCCS Ospedale Casa Sollievo della Sofferenza, Rome, Italy
| | - Marzia Perluigi
- Department of Biochemical Sciences "A. Rossi Fanelli", University Sapienza of Rome, Rome, Italy
| | - Andrea Arena
- Department of Biochemical Sciences "A. Rossi Fanelli", University Sapienza of Rome, Rome, Italy
| | - Filip van Petegem
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of British Columbia, Vancouver, Canada
| | - Claudia Tito
- Department of Anatomical, Histological, Forensic & Orthopedic Sciences, Section of Histology & Medical Embryology, Sapienza University of Rome, Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Rome, Italy
| | - Francesco Fazi
- Department of Anatomical, Histological, Forensic & Orthopedic Sciences, Section of Histology & Medical Embryology, Sapienza University of Rome, Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Rome, Italy
| | - Carlotta Giorgi
- Department of Medical Sciences, Laboratory for Technology of Advanced Therapies (LTTA) University of Ferrara, Ferrara, Italy
| | - Tito Calì
- Department of Biomedical Sciences, University of Padova, Padova, Italy.,Padova Neuroscience Center (PNC), University of Padova, Padova, Italy
| | - Andrea Ilari
- Institute of Molecular Biology and Pathology, Italian National Research Council, IBPM-CNR, Rome, Italy.
| | - Gianni Colotti
- Institute of Molecular Biology and Pathology, Italian National Research Council, IBPM-CNR, Rome, Italy.
| |
Collapse
|
8
|
Boczek T, Radzik T, Ferenc B, Zylinska L. The Puzzling Role of Neuron-Specific PMCA Isoforms in the Aging Process. Int J Mol Sci 2019; 20:ijms20246338. [PMID: 31888192 PMCID: PMC6941135 DOI: 10.3390/ijms20246338] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 12/10/2019] [Accepted: 12/13/2019] [Indexed: 01/02/2023] Open
Abstract
The aging process is a physiological phenomenon associated with progressive changes in metabolism, genes expression, and cellular resistance to stress. In neurons, one of the hallmarks of senescence is a disturbance of calcium homeostasis that may have far-reaching detrimental consequences on neuronal physiology and function. Among several proteins involved in calcium handling, plasma membrane Ca2+-ATPase (PMCA) is the most sensitive calcium detector controlling calcium homeostasis. PMCA exists in four main isoforms and PMCA2 and PMCA3 are highly expressed in the brain. The overall effects of impaired calcium extrusion due to age-dependent decline of PMCA function seem to accumulate with age, increasing the susceptibility to neurotoxic insults. To analyze the PMCA role in neuronal cells, we have developed stable transfected differentiated PC12 lines with down-regulated PMCA2 or PMCA3 isoforms to mimic age-related changes. The resting Ca2+ increased in both PMCA-deficient lines affecting the expression of several Ca2+-associated proteins, i.e., sarco/endoplasmic Ca2+-ATPase (SERCA), calmodulin, calcineurin, GAP43, CCR5, IP3Rs, and certain types of voltage-gated Ca2+ channels (VGCCs). Functional studies also demonstrated profound changes in intracellular pH regulation and mitochondrial metabolism. Moreover, modification of PMCAs membrane composition triggered some adaptive processes to counterbalance calcium overload, but the reduction of PMCA2 appeared to be more detrimental to the cells than PMCA3.
Collapse
Affiliation(s)
- Tomasz Boczek
- Department of Molecular Neurochemistry, Medical University, 92-215 Lodz, Poland; (T.B.); (T.R.); (B.F.)
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Tomasz Radzik
- Department of Molecular Neurochemistry, Medical University, 92-215 Lodz, Poland; (T.B.); (T.R.); (B.F.)
| | - Bozena Ferenc
- Department of Molecular Neurochemistry, Medical University, 92-215 Lodz, Poland; (T.B.); (T.R.); (B.F.)
| | - Ludmila Zylinska
- Department of Molecular Neurochemistry, Medical University, 92-215 Lodz, Poland; (T.B.); (T.R.); (B.F.)
- Correspondence: ; Tel.: +48-42-272-5680
| |
Collapse
|
9
|
Stofkova A, Murakami M. Neural activity regulates autoimmune diseases through the gateway reflex. Bioelectron Med 2019; 5:14. [PMID: 32232103 PMCID: PMC7098223 DOI: 10.1186/s42234-019-0030-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 07/18/2019] [Indexed: 12/15/2022] Open
Abstract
The brain, spinal cord and retina are protected from blood-borne compounds by the blood-brain barrier (BBB), blood-spinal cord barrier (BSCB) and blood-retina barrier (BRB) respectively, which create a physical interface that tightly controls molecular and cellular transport. The mechanical and functional integrity of these unique structures between blood vessels and nervous tissues is critical for maintaining organ homeostasis. To preserve the stability of these barriers, interplay between constituent barrier cells, such as vascular endothelial cells, pericytes, glial cells and neurons, is required. When any of these cells are defective, the barrier can fail, allowing blood-borne compounds to encroach neural tissues and cause neuropathologies. Autoimmune diseases of the central nervous system (CNS) and retina are characterized by barrier disruption and the infiltration of activated immune cells. Here we review our recent findings on the role of neural activity in the regulation of these barriers at the vascular endothelial cell level in the promotion of or protection against the development of autoimmune diseases. We suggest nervous system reflexes, which we named gateway reflexes, are fundamentally involved in these diseases. Although their reflex arcs are not completely understood, we identified the activation of specific sensory neurons or receptor cells to which barrier endothelial cells respond as effectors that regulate gateways for immune cells to enter the nervous tissue. We explain this novel mechanism and describe its role in neuroinflammatory conditions, including models of multiple sclerosis and posterior autoimmune uveitis.
Collapse
Affiliation(s)
- Andrea Stofkova
- 1Department of Physiology, Third Faculty of Medicine, Charles University, Prague, Czech Republic
- 2Division of Molecular Psychoimmunology, Institute for Genetic Medicine, Hokkaido University, Kita-15, Nishi-7, Kita-ku, Sapporo, 060-0815 Japan
| | - Masaaki Murakami
- 2Division of Molecular Psychoimmunology, Institute for Genetic Medicine, Hokkaido University, Kita-15, Nishi-7, Kita-ku, Sapporo, 060-0815 Japan
| |
Collapse
|
10
|
Resveratrol Directly Controls the Activity of Neuronal Ryanodine Receptors at the Single-Channel Level. Mol Neurobiol 2019; 57:422-434. [PMID: 31376069 DOI: 10.1007/s12035-019-01705-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2019] [Accepted: 07/10/2019] [Indexed: 01/14/2023]
Abstract
Calcium ion dyshomeostasis contributes to the progression of many neurodegenerative diseases and represents a target for the development of neuroprotective therapies, as reported by Duncan et al. (Molecules 15(3):1168-95, 2010), LaFerla (Nat Rev Neurosci 3(11):862-72, 2002), and Niittykoshi et al. (Invest Ophthalmol Vis Sci 51(12):6387-93, 2010). Dysfunctional ryanodine receptors contribute to calcium ion dyshomeostasis and potentially to the pathogenesis of neurodegenerative diseases by generating abnormal calcium ion release from the endoplasmic reticulum, according to Bruno et al. (Neurobiol Aging 33(5):1001 e1-6, 2012) and Stutzmann et al. (J Neurosci 24(2):508-13, 2004). Since ryanodine receptors share functional and structural similarities with potassium channels, as reported by Lanner et al. (Cold Spring Harb Perspect Biol 2(11):a003996, 2010), and small molecules with anti-oxidant properties, such as resveratrol (3,5,4'-trihydroxy-trans-stilbene), directly control the activity of potassium channels, according to Wang et al. (J Biomed Sci 23(1):47, 2016), McCalley et al. (Molecules 19(6):7327-40, 2014), Novakovic et al. (Mol Hum Reprod 21(6):545-51, 2015), Li et al. (Cardiovasc Res 45(4):1035-45, 2000), Gopalakrishnan et al. (Br J Pharmacol 129(7):1323-32, 2000), and Hambrock et al. (J Biol Chem 282(5):3347-56, 2007), we hypothesized that trans-resveratrol can modulate intracellular calcium signaling through direct binding and functional regulation of ryanodine receptors. The goal of our study was to identify and measure the control of ryanodine receptor activity by trans-resveratrol. Mechanisms of calcium signaling mediated by the direct interaction between trans-resveratrol and ryanodine receptors were identified and measured with single-channel electrophysiology. Addition of trans-resveratrol to the cytoplasmic face of the ryanodine receptor increased single-channel activity at physiological and elevated pathophysiological cytoplasmic calcium ion concentrations. The open probability of the channel increases after interacting with the small molecule in a dose-dependent manner, but remains also dependent on the concentration of its physiological ligand, cytoplasmic-free calcium ions. This study provides the first evidence of a direct functional interaction between trans-resveratrol and ryanodine receptors. Such functional control of ryanodine receptors by trans-resveratrol as a novel mechanism of action could provide additional rationales for the development of novel therapeutic strategies to treat and prevent neurodegenerative diseases.
Collapse
|
11
|
Ca v3.2 T-Type Calcium Channels Are Physiologically Mandatory for the Auditory System. Neuroscience 2019; 409:81-100. [PMID: 31029730 DOI: 10.1016/j.neuroscience.2019.04.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2018] [Revised: 04/11/2019] [Accepted: 04/12/2019] [Indexed: 02/07/2023]
Abstract
Voltage-gated Ca2+ channels (VGCCs) play key roles in auditory perception and information processing within the inner ear and brainstem. Pharmacological inhibition of low voltage-activated (LVA) T-type Ca2+ channels is related to both age- and noise induced hearing loss in experimental animals and may represent a promising approach to the treatment of auditory impairment of various etiologies. Within the LVA Ca2+ channel subgroup, Cav3.2 is the most prominently expressed T-type channel entity in the cochlea and auditory brainstem. Thus, we performed a complete gender specific click and tone burst based auditory brainstem response (ABR) analysis of Cav3.2+/- and Cav3.2-/- mice, including i.a. temporal progression in hearing loss, amplitude growth function and wave latency analysis as well as a cochlear qPCR based evaluation of other VGCCs transcripts. Our results, based on a self-programmed automated wavelet approach, demonstrate that both heterozygous and Cav3.2 null mutant mice exhibit age-dependent increases in hearing thresholds at 5 months of age. In addition, complex alterations in WI-IV amplitudes and latencies were detected that were not attributable to alterations in the expression of other VGCCs in the auditory tract. Our results clearly demonstrate the important physiological role of Cav3.2 VGCCs in the spatiotemporal organization of auditory processing in young adult mice and suggest potential pharmacological targets for interventions in the future.
Collapse
|
12
|
Dakik P, Medkour Y, Mohammad K, Titorenko VI. Mechanisms Through Which Some Mitochondria-Generated Metabolites Act as Second Messengers That Are Essential Contributors to the Aging Process in Eukaryotes Across Phyla. Front Physiol 2019; 10:461. [PMID: 31057428 PMCID: PMC6482166 DOI: 10.3389/fphys.2019.00461] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 04/02/2019] [Indexed: 12/21/2022] Open
Abstract
Recent studies have revealed that some low-molecular weight molecules produced in mitochondria are essential contributing factors to aging and aging-associated pathologies in evolutionarily distant eukaryotes. These molecules are intermediates or products of certain metabolic reactions that are activated in mitochondria in response to specific changes in the nutrient, stress, proliferation, or age status of the cell. After being released from mitochondria, these metabolites directly or indirectly change activities of a distinct set of protein sensors that reside in various cellular locations outside of mitochondria. Because these protein sensors control the efficiencies of some pro- or anti-aging cellular processes, such changes in their activities allow to create a pro- or anti-aging cellular pattern. Thus, mitochondria can function as signaling platforms that respond to certain changes in cell stress and physiology by remodeling their metabolism and releasing a specific set of metabolites known as "mitobolites." These mitobolites then define the pace of cellular and organismal aging because they regulate some longevity-defining processes taking place outside of mitochondria. In this review, we discuss recent progress in understanding mechanisms underlying the ability of mitochondria to function as such signaling platforms in aging and aging-associated diseases.
Collapse
|
13
|
Murgia M, Toniolo L, Nagaraj N, Ciciliot S, Vindigni V, Schiaffino S, Reggiani C, Mann M. Single Muscle Fiber Proteomics Reveals Fiber-Type-Specific Features of Human Muscle Aging. Cell Rep 2018; 19:2396-2409. [PMID: 28614723 DOI: 10.1016/j.celrep.2017.05.054] [Citation(s) in RCA: 175] [Impact Index Per Article: 29.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 04/10/2017] [Accepted: 05/17/2017] [Indexed: 12/20/2022] Open
Abstract
Skeletal muscle is a key tissue in human aging, which affects different muscle fiber types unequally. We developed a highly sensitive single muscle fiber proteomics workflow to study human aging and show that the senescence of slow and fast muscle fibers is characterized by diverging metabolic and protein quality control adaptations. Whereas mitochondrial content declines with aging in both fiber types, glycolysis and glycogen metabolism are upregulated in slow but downregulated in fast muscle fibers. Aging mitochondria decrease expression of the redox enzyme monoamine oxidase A. Slow fibers upregulate a subset of actin and myosin chaperones, whereas an opposite change happens in fast fibers. These changes in metabolism and sarcomere quality control may be related to the ability of slow, but not fast, muscle fibers to maintain their mass during aging. We conclude that single muscle fiber analysis by proteomics can elucidate pathophysiology in a sub-type-specific manner.
Collapse
Affiliation(s)
- Marta Murgia
- Max-Planck-Institute of Biochemistry, Martinsried 82152, Germany; Department of Biomedical Science, University of Padova, Padua 35121, Italy.
| | - Luana Toniolo
- Department of Biomedical Science, University of Padova, Padua 35121, Italy
| | | | - Stefano Ciciliot
- Venetian Institute of Molecular Medicine, Padua 35129, Italy; Department of Medicine, University of Padua, Padua 35128, Italy
| | - Vincenzo Vindigni
- Department of Neurosciences, University of Padova, Padua 35128, Italy
| | | | - Carlo Reggiani
- Department of Biomedical Science, University of Padova, Padua 35121, Italy
| | - Matthias Mann
- Max-Planck-Institute of Biochemistry, Martinsried 82152, Germany.
| |
Collapse
|
14
|
Behringer EJ, Segal SS. Impact of Aging on Calcium Signaling and Membrane Potential in Endothelium of Resistance Arteries: A Role for Mitochondria. J Gerontol A Biol Sci Med Sci 2017; 72:1627-1637. [PMID: 28510636 DOI: 10.1093/gerona/glx079] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 04/21/2017] [Indexed: 12/20/2022] Open
Abstract
Impaired blood flow to peripheral tissues during advanced age is associated with endothelial dysfunction and diminished bioavailability of nitric oxide (NO). However, it is unknown whether aging impacts coupling between intracellular calcium ([Ca2+]i) signaling and small- and intermediate K+ channel (SKCa/IKCa) activity during endothelium-derived hyperpolarization (EDH), a signaling pathway integral to dilation of the resistance vasculature. To address the potential impact of aging on EDH, Fura-2 photometry and intracellular recording were applied to evaluate [Ca2+]i and membrane potential of intact endothelial tubes (width, 60 µm; length, 1-3 mm) freshly isolated from superior epigastric arteries of young (4-6 mo) and old (24-26 mo) male C57BL/6 mice. In response to acetylcholine, intracellular release of Ca2+ from the endoplasmic reticulum (ER) was enhanced with aging. Further, treatment with the mitochondrial uncoupler FCCP evoked a significant increase of [Ca2+]i with membrane hyperpolarization in an SKCa/IKCa-dependent manner in the endothelium of old but not young mice. We conclude that the ability of resistance artery endothelium to release Ca2+ from intracellular stores (ie, ER and mitochondria) and hyperpolarize Vm via SKCa/IKCa activation is augmented as compensation for reduced NO bioavailability during advanced age.
Collapse
Affiliation(s)
- Erik J Behringer
- Department of Basic Sciences, Loma Linda University, California.,Department of Medical Pharmacology and Physiology, University of Missouri, Columbia
| | - Steven S Segal
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia.,Dalton Cardiovascular Research Center, Columbia, Missouri
| |
Collapse
|
15
|
Berridge MJ. Vitamin D deficiency accelerates ageing and age-related diseases: a novel hypothesis. J Physiol 2017; 595:6825-6836. [PMID: 28949008 DOI: 10.1113/jp274887] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 09/11/2017] [Indexed: 12/24/2022] Open
Abstract
Ageing can occur at different rates, but what controls this variable rate is unknown. Here I have developed a hypothesis that vitamin D may act to control the rate of ageing. The basis of this hypothesis emerged from studyng the various cellular processes that control ageing. These processes such as autophagy, mitochondrial dysfunction, inflammation, oxidative stress, epigenetic changes, DNA disorders and alterations in Ca2+ and reactive oxygen species (ROS) signalling are all known to be regulated by vitamin D. The activity of these processes will be enhanced in individuals that are deficient in vitamin D. Not only will this increase the rate of ageing, but it will also increase the probability of developing age-related diseases such as Alzheimer's disease, Parkinson's disease, multiple sclerosis and cardiovascular disease. In individual with normal vitamin D levels, these ageing-related processes will occur at lower rates resulting in a reduced rate of ageing and enhanced protection against these age-related diseases.
Collapse
|
16
|
Bhat AH, Dar KB, Anees S, Zargar MA, Masood A, Sofi MA, Ganie SA. Oxidative stress, mitochondrial dysfunction and neurodegenerative diseases; a mechanistic insight. Biomed Pharmacother 2015; 74:101-10. [PMID: 26349970 DOI: 10.1016/j.biopha.2015.07.025] [Citation(s) in RCA: 605] [Impact Index Per Article: 67.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 07/26/2015] [Indexed: 12/23/2022] Open
Abstract
Mitochondria is one of the main source of oxidative stress (ROS), as it utilizes the oxygen for the energy production. ROS and RNS are normally generated by tightly regulated enzymes. Excessive stimulation of NAD(P)H and electron transport chain leads to the overproduction of ROS, results in oxidative stress, which is a good mediator to injure the cell structures, lipids, proteins, and DNA. Various oxidative events implicated in many diseases due to oxidative stress include alteration in mitochondrial proteins, mitochondrial lipids and mitochondrial DNA, Which in turn leads to the damage to nerve cell as they are metabolically very active. ROS/RNS at moderate concentrations also play roles in normal physiology of many processes like signaling pathways, induction of mitogenic response and in defense against infectious pathogens. Oxidative stress has been considered to be the main cause in the etiology of many diseases, which includes Parkinson's and Alzheimer diseases. Several PD associated genes have been found to be involved in mitochondrial function, dynamics and morphology as well. This review includes source of free radical generation, chemistry and biochemistry of ROS/RNS and mitochondrial dysfunction and the mechanism involved in neurodegenerative diseases.
Collapse
Affiliation(s)
- Aashiq Hussain Bhat
- Department of Clinical Biochemistry, University of Kashmir, Srinagar 190006, India
| | - Khalid Bashir Dar
- Department of Clinical Biochemistry, University of Kashmir, Srinagar 190006, India
| | - Suhail Anees
- Department of Clinical Biochemistry, University of Kashmir, Srinagar 190006, India
| | | | - Akbar Masood
- Department of Biochemistry, University of Kashmir, Srinagar 190006, India
| | - Manzoor Ahmad Sofi
- Department of Clinical Biochemistry, University of Kashmir, Srinagar 190006, India
| | - Showkat Ahmad Ganie
- Department of Clinical Biochemistry, University of Kashmir, Srinagar 190006, India.
| |
Collapse
|
17
|
Ren HM, Ren J, Liu W. Recognition and control of the progression of age-related hearing loss. Rejuvenation Res 2014; 16:475-86. [PMID: 23915327 DOI: 10.1089/rej.2013.1435] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Recent breakthroughs have provided notable insights into both the pathogenesis and therapeutic strategies for age-related hearing loss (ARHL). Simultaneously, these breakthroughs enhance our knowledge about this neurodegenerative disease and raise the question of whether the disorder is preventable or even treatable. Discoveries relating to ARHL have revealed a unique link between ARHL and the underlying pathologies. Therefore, we need to better understand the pathogenesis or the mechanism of ARHL and learn how to take full advantage of various therapeutic strategies to prevent the progression of ARHL.
Collapse
Affiliation(s)
- Hong Miao Ren
- Department of Otolaryngology Head and Neck Surgery, the Second Xiangya Hospital, Central South University , Changsha, Hunan, P.R. China
| | | | | |
Collapse
|
18
|
Leonov A, Titorenko VI. A network of interorganellar communications underlies cellular aging. IUBMB Life 2013; 65:665-74. [PMID: 23818261 DOI: 10.1002/iub.1183] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2013] [Accepted: 04/19/2013] [Indexed: 01/07/2023]
Abstract
Organelles within a eukaryotic cell respond to age-related intracellular stresses and environmental factors by altering their functional states to generate, direct and process the flow of interorganellar information that is essential for establishing a pro- or antiaging cellular pattern. The scope of this review is to critically analyze recent progress in understanding how various intercompartmental (i.e., organelle-organelle and organelle-cytosol) communications regulate cellular aging in evolutionarily distant eukaryotes. Our analysis suggests a model for an intricate network of intercompartmental communications that underly cellular aging in eukaryotic organisms across phyla. This proposed model posits that the numerous directed, coordinated and regulated organelle-organelle and organelle-cytosol communications integrated into this network define the long-term viability of a eukaryotic cell and, thus, are critical for regulating cellular aging.
Collapse
Affiliation(s)
- Anna Leonov
- Department of Biology, Concordia University, Montreal, QC, Canada
| | | |
Collapse
|
19
|
Santos RX, Correia SC, Zhu X, Smith MA, Moreira PI, Castellani RJ, Nunomura A, Perry G. Mitochondrial DNA oxidative damage and repair in aging and Alzheimer's disease. Antioxid Redox Signal 2013; 18:2444-57. [PMID: 23216311 PMCID: PMC3671662 DOI: 10.1089/ars.2012.5039] [Citation(s) in RCA: 116] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
SIGNIFICANCE Mitochondria are fundamental to the life and proper functioning of cells. These organelles play a key role in energy production, in maintaining homeostatic levels of second messengers (e.g., reactive oxygen species and calcium), and in the coordination of apoptotic cell death. The role of mitochondria in aging and in pathophysiological processes is constantly being unraveled, and their involvement in neurodegenerative processes, such as Alzheimer's disease (AD), is very well known. RECENT ADVANCES A considerable amount of evidence points to oxidative damage to mitochondrial DNA (mtDNA) as a determinant event that occurs during aging, which may cause or potentiate mitochondrial dysfunction favoring neurodegenerative events. Concomitantly to reactive oxygen species production, an inefficient mitochondrial base excision repair (BER) machinery has also been pointed to favor the accumulation of oxidized bases in mtDNA during aging and AD progression. CRITICAL ISSUES The accumulation of oxidized mtDNA bases during aging increases the risk of sporadic AD, an event that is much less relevant in the familial forms of the disease. This aspect is critical for the interpretation of data arising from tissue of AD patients and animal models of AD, as the major part of animal models rely on mutations in genes associated with familial forms of the disease. FUTURE DIRECTIONS Further investigation is important to unveil the role of mtDNA and BER in aging brain and AD in order to design more effective preventive and therapeutic strategies.
Collapse
Affiliation(s)
- Renato X Santos
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | | | | | | | | | | | | | | |
Collapse
|
20
|
Ermer J, Haffey MB, Richards C, Lasseter K, Adeyi B, Corcoran M, Stanton B, Martin P. Double-blind, placebo-controlled, two-period, crossover trial to examine the pharmacokinetics of lisdexamfetamine dimesylate in healthy older adults. Neuropsychiatr Dis Treat 2013; 9:219-29. [PMID: 23431065 PMCID: PMC3575217 DOI: 10.2147/ndt.s38377] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Pharmacokinetic and safety data on stimulants in older adults are limited. The objective of this study was to characterize the pharmacokinetics of lisdexamfetamine dimesylate (LDX), a d-amphetamine prodrug, in older adults. METHODS In this two-period crossover trial, healthy adults (n = 47) stratified by age (55-64, 65-74, and ≥ 75 years) and gender received randomized, double-blind, single doses of LDX 50 mg or placebo. Baseline creatinine clearance, d-amphetamine and intact LDX pharmacokinetics, and safety were assessed. RESULTS Mean (±standard deviation) baseline creatinine clearance in participants aged 55-64, 65-74, and ≥ 75 years was 102.5 ± 26.1, 105.3 ± 23.1, and 94.9 ± 27.3 mL per minute, respectively. In the groups aged 55-64, 65-74, and ≥ 75 years, the mean maximum plasma d-amphetamine concentration in men was 44.2 ± 11.1, 47.7 ± 7.0, and 53.4 ± 19.4 ng/mL, respectively; area under the concentration time curve from time 0 extrapolated to infinity (AUC(0-inf)) was 915.0 ± 164.9, 1123.0 ± 227.0, and 1325.0 ± 464.4 nghour/mL; median time to reach peak plasma concentration was 4.5, 3.5, and 5.5 hours; in women, mean maximum plasma d-amphetamine concentration was 51.0 ± 6.7, 50.2 ± 6.8, and 64.3 ± 12.1 ng/mL, AUC(0-inf) was 1034.5 ± 154.6, 988.4 ± 80.5, and 1347.8 ± 198.9 ng hour/mL, and median time to reach peak plasma concentration was 3.5, 4.1, and 5.5 hours, respectively. d-Amphetamine clearance was unrelated to baseline creatinine clearance. Five participants aged 55-64 years reported treatment-emergent adverse events (versus one each aged 65-74 and ≥ 75 years), and as did six women (versus one man). No trends in blood pressure or pulse changes were seen with LDX according to age. In participants aged 55-64, 65-74, and ≥ 75 years, the mean change from time-matched baseline pulse ranged from -5.0 to 14.7, -4.3 to 9.5, and -3.0 to 14.7 beats per minute; for systolic blood pressure, from -3.9 to 18.5 mmHg, -2.1 to 14.5 mmHg, and -5.9 to 16.0 mmHg; for diastolic blood pressure from -2.5 to 8.3 mmHg, from -0.8 to 9.4 mmHg, and -0.6 to 9.5 mmHg. Vital sign changes were similar between men and women. CONCLUSION Clearance of d-amphetamine decreased with age and was unrelated to creatinine clearance. No trends in pulse or blood pressure changes with LDX were seen according to age. The safety profile of LDX was consistent with prior observations in younger adult study participants.
Collapse
|
21
|
Behringer EJ, Segal SS. Spreading the signal for vasodilatation: implications for skeletal muscle blood flow control and the effects of ageing. J Physiol 2012; 590:6277-84. [PMID: 22890708 DOI: 10.1113/jphysiol.2012.239673] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Blood flow control requires coordinated contraction and relaxation of smooth muscle cells (SMCs) along and among the arterioles and feed arteries that comprise vascular resistance networks. Whereas smooth muscle contraction of resistance vessels is enhanced by noradrenaline release along perivascular sympathetic nerves, the endothelium is integral to coordinating smooth muscle relaxation. Beyond producing nitric oxide in response to agonists and shear stress, endothelial cells (ECs) provide an effective conduit for conducting hyperpolarization along vessel branches and into surrounding SMCs through myoendothelial coupling. In turn, bidirectional signalling from SMCs into ECs enables the endothelium to moderate adrenergic vasoconstriction in response to sympathetic nerve activity. This review focuses on the endothelium as the cellular pathway that coordinates spreading vasodilatation. We discuss the nature and regulation of cell-to-cell coupling through gap junctions, bidirectional signalling between ECs and SMCs, and how oxidative stress during ageing may influence respective signalling pathways. Our recent findings illustrate the role of small (SK(Ca)) and intermediate (IK(Ca)) Ca(2+) activated K(+) channels as modulators of electrical conduction along the endothelium. Gaps in current understanding indicate the need to determine mechanisms that regulate intracellular Ca(2+) homeostasis and ion channel activation in the resistance vasculature with advancing age.
Collapse
Affiliation(s)
- Erik J Behringer
- Medical Pharmacology and Physiology, University of Missouri, Columbia, MO 65212, USA
| | | |
Collapse
|
22
|
Kidd Iii AR, Bao J. Recent advances in the study of age-related hearing loss: a mini-review. Gerontology 2012; 58:490-6. [PMID: 22710288 PMCID: PMC3766364 DOI: 10.1159/000338588] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Accepted: 04/02/2012] [Indexed: 11/19/2022] Open
Abstract
Hearing loss is a common age-associated affliction that can result from the loss of hair cells and spiral ganglion neurons (SGNs) in the cochlea. Although hair cells and SGNs are typically lost in the same cochlea, recent analysis suggests that they can occur independently, via unique mechanisms. Research has identified both environmental and genetic factors that contribute to degeneration of cochlear cells. Additionally, molecular analysis has identified multiple cell-signaling mechanisms that likely contribute to pathological changes that result in hearing deficiencies. These analyses should serve as useful primers for future work, including genomic and proteomic analysis, to elucidate the mechanisms driving cell loss in the aging cochlea. Significant progress in this field has occurred in the past decade. As our understanding of aging-induced cochlear changes continues to improve, our ability to offer medical intervention will surely benefit the growing elderly population.
Collapse
Affiliation(s)
- Ambrose R Kidd Iii
- Department of Otolaryngology, Center for Aging, Washington University School of Medicine, St. Louis, Mo., USA
| | | |
Collapse
|
23
|
Li D, Lee CW, Buckler K, Parekh A, Herring N, Paterson DJ. Abnormal intracellular calcium homeostasis in sympathetic neurons from young prehypertensive rats. Hypertension 2012; 59:642-9. [PMID: 22252398 DOI: 10.1161/hypertensionaha.111.186460] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Hypertension is associated with cardiac noradrenergic hyperactivity, although it is not clear whether this precedes or follows the development of hypertension itself. We hypothesized that Ca(2+) homeostasis in postganglionic sympathetic neurons is impaired in spontaneously hypertensive rats (SHRs) and may occur before the development of hypertension. The depolarization-induced rise in intracellular free calcium concentration ([Ca(2+)](i); measured using fura-2-acetoxymethyl ester) was significantly larger in cultured sympathetic neurons from prehypertensive SHRs than in age matched normotensive Wistar-Kyoto rats. The decay of the [Ca(2+)](i) transient was also faster in SHRs. The endoplasmic reticulum Ca(2+) content and caffeine-induced [Ca(2+)](i) amplitude were significantly greater in the young SHRs. Lower protein levels of phospholamban and more copies of ryanodine receptor mRNA were also observed in the young SHRs. Depleting the endoplasmic reticulum Ca(2+) store did not alter the difference of the evoked [Ca(2+)](i) transient and decay time between young SHRs and Wistar-Kyoto rats. However, removing mitochondrial Ca(2+) buffering abolished these differences. A lower mitochondrial membrane potential was also observed in young SHR sympathetic neurons. This resulted in impaired mitochondrial Ca(2+) uptake and release, which might partly be responsible for the increased [Ca(2+)](i) transient and faster decay in SHR sympathetic neurons. This Ca(2+) phenotype seen in early development in cardiac stellate and superior cervical ganglion neurons may contribute to the sympathetic hyperresponsiveness that precedes the onset of hypertension.
Collapse
Affiliation(s)
- Dan Li
- Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy, and Genetics, Oxford, UK.
| | | | | | | | | | | |
Collapse
|
24
|
Martiáñez T, Carrascal M, Lamarca A, Segura M, Durany N, Masgrau R, Abian J, Gella A. UTP affects the Schwannoma cell line proteome through P2Y receptors leading to cytoskeletal reorganisation. Proteomics 2011; 12:145-56. [PMID: 22065602 DOI: 10.1002/pmic.201100187] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2011] [Revised: 09/09/2011] [Accepted: 10/19/2011] [Indexed: 12/23/2022]
Abstract
Glial cells in the peripheral nervous system, such as Schwann cells, respond to nucleotides, which play an important role in axonal regeneration and myelination. Metabotropic P2Y receptor agonists are promising therapeutic molecules for peripheral neuropathies. Nevertheless, the proteomic mechanisms involved in nucleotide action on Schwann cells remain unknown. Here, we studied intracellular protein changes in RT4-D6P2T Schwann cells after treatment with nucleotides and Nucleo CMP Forte (CMPF), a nucleotide-based drug. After treatment with CMPF, 2-D DIGE revealed 11 differential gel spots, which were all upregulated. Among these, six different proteins were identified by MS. Some of these proteins are involved in actin remodelling (actin-related protein, Arp3), membrane vesicle transport (Rab GDP dissociation inhibitor β, Rab GDI), and the endoplasmic reticulum stress response (protein disulfide isomerase A3, PDI), which are hallmarks of a possible P2Y receptor signalling pathway. Expression of P2Y receptors in RT4-D6P2T cells was demonstrated by RT-PCR and a transient elevation of intracellular calcium measured in response to UTP. Actin reorganisation was visualized after UTP treatment using phalloidin-FITC staining and was blocked by the P2Y antagonist suramin, which also inhibited Arp3, Rab GDI, and PDI protein upregulation. Our data indicate that extracellular UTP interacts with Schwann P2Y receptors and activates molecular machinery that induces changes in the glial cell cytoskeleton.
Collapse
Affiliation(s)
- Tánia Martiáñez
- Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Josep Trueta s/n, Sant Cugat del Vallès, Spain
| | | | | | | | | | | | | | | |
Collapse
|
25
|
Age-associated loss of selectivity in human olfactory sensory neurons. Neurobiol Aging 2011; 33:1913-9. [PMID: 22074806 DOI: 10.1016/j.neurobiolaging.2011.09.036] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Revised: 09/23/2011] [Accepted: 09/30/2011] [Indexed: 11/23/2022]
Abstract
We report a cross-sectional study of olfactory impairment with age based on both odorant-stimulated responses of human olfactory sensory neurons (OSNs) and tests of olfactory threshold sensitivity. A total of 621 OSNs from 440 subjects in 2 age groups of younger (≤ 45 years) and older (≥ 60 years) subjects were investigated using fluorescence intensity ratio fura-2 imaging. OSNs were tested for responses to 2 odorant mixtures, as well as to subsets of and individual odors in those mixtures. Whereas cells from younger donors were highly selective in the odorants to which they responded, cells from older donors were more likely to respond to multiple odor stimuli, despite a loss in these subjects' absolute olfactory sensitivity, suggesting a loss of specificity. This degradation in peripheral cellular specificity may impact odor discrimination and olfactory adaptation in the elderly. It is also possible that chronic adaptation as a result of reduced specificity contributes to observed declines in absolute sensitivity.
Collapse
|
26
|
Lei D, Gao X, Perez P, Ohlemiller KK, Chen CC, Campbell KP, Hood AY, Bao J. Anti-epileptic drugs delay age-related loss of spiral ganglion neurons via T-type calcium channel. Hear Res 2011; 278:106-12. [PMID: 21640179 PMCID: PMC3152691 DOI: 10.1016/j.heares.2011.05.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2010] [Revised: 04/29/2011] [Accepted: 05/11/2011] [Indexed: 12/26/2022]
Abstract
Loss of spiral ganglion neurons is a major cause of age-related hearing loss (presbycusis). Despite being the third most prevalent condition afflicting elderly persons, there are no known medications to prevent presbycusis. Because calcium signaling has long been implicated in age-related neuronal death, we investigated T-type calcium channels. This family is comprised of three members (Ca(v)3.1, Ca(v)3.2, and Ca(v)3.3), based on their respective main pore-forming alpha subunits: α1G, α1H, and α1I. In the present study, we report a significant delay of age-related loss of cochlear function and preservation of spiral ganglion neurons in α1H null and heterozygous mice, clearly demonstrating an important role for Ca(v)3.2 in age-related neuronal loss. Furthermore, we show that anticonvulsant drugs from a family of T-type calcium channel blockers can significantly preserve spiral ganglion neurons during aging. To our knowledge, this is the first report of drugs capable of diminishing age-related loss of spiral ganglion neurons.
Collapse
MESH Headings
- Aging/drug effects
- Aging/metabolism
- Aging/pathology
- Animals
- Anticonvulsants/pharmacology
- Base Sequence
- Calcium Channel Blockers/pharmacology
- Calcium Channels, T-Type/deficiency
- Calcium Channels, T-Type/genetics
- Calcium Channels, T-Type/metabolism
- Evoked Potentials, Auditory, Brain Stem/drug effects
- Hair Cells, Auditory, Inner/pathology
- Hair Cells, Auditory, Outer/pathology
- Mice
- Mice, Congenic
- Mice, Knockout
- Neurons/drug effects
- Neurons/metabolism
- Neurons/pathology
- Presbycusis/metabolism
- Presbycusis/pathology
- Presbycusis/prevention & control
- RNA/genetics
- RNA/metabolism
- Spiral Ganglion/drug effects
- Spiral Ganglion/innervation
- Spiral Ganglion/metabolism
- Spiral Ganglion/pathology
Collapse
Affiliation(s)
- Debin Lei
- Department of Otolaryngology, Washington University School of Medicine, St. Louis, Missouri, 63110, USA
- Center for Aging, Washington University School of Medicine, St. Louis, Missouri, 63110, USA
| | - Xia Gao
- Department of Otolaryngology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China 210008
| | - Philip Perez
- Department of Otolaryngology, Washington University School of Medicine, St. Louis, Missouri, 63110, USA
- Center for Aging, Washington University School of Medicine, St. Louis, Missouri, 63110, USA
| | - Kevin K Ohlemiller
- Department of Otolaryngology, Washington University School of Medicine, St. Louis, Missouri, 63110, USA
| | - Chien-Chang Chen
- Howard Hughes Medical Institute, University of Iowa, Iowa City, Iowa, 60153, USA
| | - Kevin P. Campbell
- Howard Hughes Medical Institute, University of Iowa, Iowa City, Iowa, 60153, USA
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, Iowa, 60153, USA
- Department of Neurology, University of Iowa, Iowa City, Iowa, 60153, USA
- Department of Internal Medicine, University of Iowa, Iowa City, Iowa, 60153, USA
| | - Aizhen Yang Hood
- Department of Otolaryngology, Washington University School of Medicine, St. Louis, Missouri, 63110, USA
- Center for Aging, Washington University School of Medicine, St. Louis, Missouri, 63110, USA
| | - Jianxin Bao
- Department of Otolaryngology, Washington University School of Medicine, St. Louis, Missouri, 63110, USA
- Center for Aging, Washington University School of Medicine, St. Louis, Missouri, 63110, USA
- The Division of Biology & Biomedical Science and Neuroscience Program, Washington University School of Medicine, St. Louis, Missouri, 63110, USA
| |
Collapse
|
27
|
Mikhelson VM, Gamaley IA. Telomere shortening: The main mechanism of natural and radiation aging. Biophysics (Nagoya-shi) 2010. [DOI: 10.1134/s0006350910050295] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
|
28
|
Wang D, Liu P, Yang Y, Shen L. Formation of a combined Ca/Cd toxicity on lifespan of nematode Caenorhabditis elegans. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2010; 73:1221-1230. [PMID: 20580433 DOI: 10.1016/j.ecoenv.2010.05.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2010] [Revised: 04/24/2010] [Accepted: 05/01/2010] [Indexed: 05/29/2023]
Abstract
We investigated the possible formation of combined toxicity from Ca/Cd exposure on nematode lifespan. Ca exposure at concentrations more than 1.56 mM significantly reduced lifespan, accelerated aging-related declines, and induced severe stress response in wild-type nematodes. Combined Ca (25 mM)/Cd (200 microM) exposure decreased the lifespans compared to Cd (200 microM) exposure; whereas no lifespan differences were found between Ca (1.56 mM)/Cd (200 microM) exposure and Cd (200 microM) exposure. Combined Ca (25 mM)/Cd (200 microM) exposure caused a more significant induction of hsp-16.2::gfp expression, and a more severe increase in oxidative damage than Cd (200 microM) exposure. Moreover, mutation of mev-1, encoding a subunit of succinate dehydrogenase cytochrome b, enhanced the combined Ca/Cd toxicity on lifespan. Furthermore, mutation of daf-16, encoding a fork-head-family transcription factor, enhanced the combined Ca/Cd toxicity on lifespan, and mutation of daf-2, encoding an insulin receptor-like protein, alleviated the combined Ca/Cd toxicity on lifespan.
Collapse
Affiliation(s)
- Dayong Wang
- Key Laboratory of Developmental Genes and Human Disease in Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing 210009, China.
| | | | | | | |
Collapse
|
29
|
Santos RX, Correia SC, Wang X, Perry G, Smith MA, Moreira PI, Zhu X. Alzheimer's disease: diverse aspects of mitochondrial malfunctioning. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2010; 3:570-581. [PMID: 20661404 PMCID: PMC2907118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Received: 06/13/2010] [Accepted: 06/21/2010] [Indexed: 05/29/2023]
Abstract
Alzheimer's disease is a progressive neurodegenerative disorder, either assuming a sporadic, age-associated, late-onset form, or a familial form, with early onset, in a smaller fraction of the cases. Whereas in the familial cases several mutations have been identified in genes encoding proteins related with the pathogenesis of the disease, for the sporadic form several causes have been proposed and are currently under debate. Mitochondrial dysfunction has surfaced as one of the most discussed hypotheses acting as a trigger for the pathogenesis of Alzheimer's disease. Mitochondria assume central functions in the cell, including ATP production, calcium homeostasis, reactive oxygen species generation, and apoptotic signaling. Although their role as the cause of the disease may be controversial, there is no doubt that mitochondrial dysfunction, abnormal mitochondrial dynamics and degradation by mitophagy occur during the disease process, contributing to its onset and progression.
Collapse
Affiliation(s)
- Renato X Santos
- Center for Neuroscience and Cell Biology of Coimbra, University of CoimbraCoimbra, Portugal
- Faculty of Sciences and Technology, Department of Life Sciences, University of CoimbraCoimbra, Portugal
- Department of Pathology, Case Western Reserve UniversityCleveland, Ohio, USA
| | - Sónia C Correia
- Center for Neuroscience and Cell Biology of Coimbra, University of CoimbraCoimbra, Portugal
- Faculty of Sciences and Technology, Department of Life Sciences, University of CoimbraCoimbra, Portugal
- Department of Pathology, Case Western Reserve UniversityCleveland, Ohio, USA
| | - Xinglong Wang
- Department of Pathology, Case Western Reserve UniversityCleveland, Ohio, USA
| | - George Perry
- Department of Pathology, Case Western Reserve UniversityCleveland, Ohio, USA
- UTSA Neurosciences Institute and Department of Biology, University of Texas at San AntonioSan Antonio, Texas, USA
| | - Mark A Smith
- Department of Pathology, Case Western Reserve UniversityCleveland, Ohio, USA
| | - Paula I Moreira
- Center for Neuroscience and Cell Biology of Coimbra, University of CoimbraCoimbra, Portugal
- Faculty of Medicine, Institute of Physiology, University of CoimbraCoimbra, Portugal
| | - Xiongwei Zhu
- Department of Pathology, Case Western Reserve UniversityCleveland, Ohio, USA
| |
Collapse
|
30
|
Pessah IN, Cherednichenko G, Lein PJ. Minding the calcium store: Ryanodine receptor activation as a convergent mechanism of PCB toxicity. Pharmacol Ther 2010; 125:260-85. [PMID: 19931307 PMCID: PMC2823855 DOI: 10.1016/j.pharmthera.2009.10.009] [Citation(s) in RCA: 172] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2009] [Accepted: 10/30/2009] [Indexed: 11/24/2022]
Abstract
Chronic low-level polychlorinated biphenyl (PCB) exposures remain a significant public health concern since results from epidemiological studies indicate that PCB burden is associated with immune system dysfunction, cardiovascular disease, and impairment of the developing nervous system. Of these various adverse health effects, developmental neurotoxicity has emerged as a particularly vulnerable endpoint in PCB toxicity. Arguably the most pervasive biological effects of PCBs could be mediated by their ability to alter the spatial and temporal fidelity of Ca2+ signals through one or more receptor-mediated processes. This review will focus on our current knowledge of the structure and function of ryanodine receptors (RyRs) in muscle and nerve cells and how PCBs and related non-coplanar structures alter these functions. The molecular and cellular mechanisms by which non-coplanar PCBs and related structures alter local and global Ca2+ signaling properties and the possible short and long-term consequences of these perturbations on neurodevelopment and neurodegeneration are reviewed.
Collapse
Affiliation(s)
- Isaac N Pessah
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
| | | | | |
Collapse
|
31
|
Kumar A, Bodhinathan K, Foster TC. Susceptibility to Calcium Dysregulation during Brain Aging. Front Aging Neurosci 2009; 1:2. [PMID: 20552053 PMCID: PMC2874411 DOI: 10.3389/neuro.24.002.2009] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2009] [Accepted: 10/27/2009] [Indexed: 01/06/2023] Open
Abstract
Calcium (Ca(2+)) is a highly versatile intracellular signaling molecule that is essential for regulating a variety of cellular and physiological processes ranging from fertilization to programmed cell death. Research has provided ample evidence that brain aging is associated with altered Ca(2+) homeostasis. Much of the work has focused on the hippocampus, a brain region critically involved in learning and memory, which is particularly susceptible to dysfunction during senescence. The current review takes a broader perspective, assessing age-related changes in Ca(2+) sources, Ca(2+) sequestration, and Ca(2+) binding proteins throughout the nervous system. The nature of altered Ca(2+) homeostasis is cell specific and may represent a deficit or a compensatory mechanism, producing complex patterns of impaired cellular function. Incorporating the knowledge of the complexity of age-related alterations in Ca(2+) homeostasis will positively shape the development of highly effective therapeutics to treat brain disorders.
Collapse
Affiliation(s)
- Ashok Kumar
- Department of Neuroscience, McKnight Brain Institute, University of Florida Gainesville, FL, USA
| | | | | |
Collapse
|
32
|
Behringer EJ, Leite LD, Buchholz NE, Keeney MG, Pearce WJ, Vanterpool CK, Wilson SM, Buchholz JN. Maturation and long-term hypoxia alters Ca2+-induced Ca2+ release in sheep cerebrovascular sympathetic neurons. J Appl Physiol (1985) 2009; 107:1223-34. [PMID: 19644029 PMCID: PMC2763832 DOI: 10.1152/japplphysiol.00363.2009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2009] [Accepted: 07/24/2009] [Indexed: 11/22/2022] Open
Abstract
The contribution of sympathetic nerves arising from the superior cervical ganglia (SCG) toward the growth and function of cerebral blood vessels is pertinent throughout maturation as well as in response to cardiovascular stress imposed by high-altitude long-term hypoxia (LTH). The function of SCG sympathetic neurons is dependent on intracellular Ca2+ concentration ([Ca2+]i) signaling, which is strongly influenced by a process known as Ca(2+)-induced Ca2+ release (CICR) from the smooth endoplasmic reticulum (SER). In this study, we used the sheep SCG neuronal model to test the hypotheses that maturation decreases CICR and high-altitude LTH depresses CICR in fetal SCG neurons but not in those of the adult. We found that the contribution of CICR to electric field stimulation (EFS)-evoked [Ca2+]i transients was greatest in SCG cells from normoxic fetuses and was abolished by LTH. The decline in CICR was associated with a reduction in sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA) function in fetal SCG cells during LTH, reducing SER Ca2+ levels below the threshold needed for the coupling of Ca2+ influx and CICR. With respect to the maturation from the fetus to adult, the decrease in CICR may reflect both a reduction in the levels of ryanodine receptor isoforms 2 and 3 and SERCA function. In response to LTH and in contrast to the fetus, CICR function in adult SCG cells is maintained and may reflect alterations in other mechanisms that modulate the CICR process. As CICR is instrumental in the function of sympathetic neurons within the cerebrovasculature, the loss of this signaling mechanism in the fetus may have consequences for the adaptation to LTH in terms of fetal susceptibility to vascular insults.
Collapse
Affiliation(s)
- Erik J Behringer
- Department of Physiology and Pharmacology, Loma Linda Univ. School of Medicine, Loma Linda, CA 92350, USA
| | | | | | | | | | | | | | | |
Collapse
|
33
|
Wang LY, Wang DH, Zou XY, Xu CM. Mitochondrial functions on oocytes and preimplantation embryos. J Zhejiang Univ Sci B 2009; 10:483-92. [PMID: 19585665 DOI: 10.1631/jzus.b0820379] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Oocyte quality has long been considered as a main limiting factor for in vitro fertilization (IVF). In the past decade, extensive observations demonstrated that the mitochondrion plays a vital role in the oocyte cytoplasm, for it can provide adenosine triphosphate (ATP) for fertilization and preimplantation embryo development and also act as stores of intracellular calcium and proapoptotic factors. During the oocyte maturation, mitochondria are characterized by distinct changes of their distribution pattern from being homogeneous to heterogeneous, which is correlated with the cumulus apoptosis. Oocyte quality decreases with the increasing maternal age. Recent studies have shown that low quality oocytes have some age-related dysfunctions, which include the decrease in mitochondrial membrane potential, increase of mitochondrial DNA (mtDNA) damages, chromosomal aneuploidies, the incidence of apoptosis, and changes in mitochondrial gene expression. All these dysfunctions may cause a high level of developmental retardation and arrest of preimplantation embryos. It has been suggested that these mitochondrial changes may arise from excessive reactive oxygen species (ROS) that is closely associated with the oxidative energy production or calcium overload, which may trigger permeability transition pore opening and subsequent apoptosis. Therefore, mitochondria can be seen as signs for oocyte quality evaluation, and it is possible that the oocyte quality can be improved by enhancing the physical function of mitochondria. Here we reviewed recent advances in mitochondrial functions on oocytes.
Collapse
Affiliation(s)
- Li-ya Wang
- Department of Biotechnology, Dalian Medical University, Dalian 116044, China
| | | | | | | |
Collapse
|
34
|
Yang XP, Pei ZH, Ren J. MAKING UP OR BREAKING UP: THE TORTUOUS ROLE OF PLATELET-DERIVED GROWTH FACTOR IN VASCULAR AGEING. Clin Exp Pharmacol Physiol 2009; 36:739-47. [DOI: 10.1111/j.1440-1681.2009.05182.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
|
35
|
Finley LW, Haigis MC. The coordination of nuclear and mitochondrial communication during aging and calorie restriction. Ageing Res Rev 2009; 8:173-88. [PMID: 19491041 DOI: 10.1016/j.arr.2009.03.003] [Citation(s) in RCA: 144] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2009] [Revised: 02/27/2009] [Accepted: 03/04/2009] [Indexed: 12/24/2022]
Abstract
Mitochondria are dynamic organelles that integrate environmental signals to regulate energy production, apoptosis and Ca(2+) homeostasis. Not surprisingly, mitochondrial dysfunction is associated with aging and the pathologies observed in age-related diseases. The vast majority of mitochondrial proteins are encoded in the nuclear genome, and so communication between the nucleus and mitochondria is essential for maintenance of appropriate mitochondrial function. Several proteins have emerged as major regulators of mitochondrial gene expression, capable of increasing transcription of mitochondrial genes in response to the physiological demands of the cell. In this review, we will focus on PGC-1alpha, SIRT1, AMPK and mTOR and discuss how these proteins regulate mitochondrial function and their potential involvement in aging, calorie restriction and age-related disease. We will also discuss the pathways through which mitochondria signal to the nucleus. Although such retrograde signaling is not well studied in mammals, there is growing evidence to suggest that it may be an important area for future aging research. Greater understanding of the mechanisms by which mitochondria and the nucleus communicate will facilitate efforts to slow or reverse the mitochondrial dysfunction that occurs during aging.
Collapse
|
36
|
Puzianowska-Kuznicka M, Kuznicki J. The ER and ageing II: calcium homeostasis. Ageing Res Rev 2009; 8:160-72. [PMID: 19427411 DOI: 10.1016/j.arr.2009.05.002] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2009] [Revised: 04/30/2009] [Accepted: 05/01/2009] [Indexed: 11/29/2022]
Abstract
Increase in intracellular Ca(2+) concentration occurs by Ca(2+) influx through the plasma membrane and by Ca(2+) release from intracellular stores. The ER is the most important Ca(2+) store. Its stress, characterized by the impairment of Ca(2+) homeostasis and by the accumulation of misfolded proteins, can be induced by different factors. In turn, it induces defense mechanisms such as unfolded protein response, and when it is severe and prolonged, activation of the apoptotic pathway. Damage to the ER, impairment of its function, and a decreased level of its Ca(2+)-handling proteins might all play a role in physiological ageing by handicapping the ER stress response. Thus, healthy ageing is accompanied by subtle alterations of Ca(2+) homeostasis and signaling, including alterations in the ER Ca(2+) load and release. The expression and/or function of ryanodine receptors, IP3 receptors, and SERCA Ca(2+) pumps located in the ER membrane, and Ca(2+)-binding proteins within ER lumen all seem to be affected in aged cells. Data are presented on age-dependent, tissue-specific changes in ER-related Ca(2+) homeostasis in skeletal, cardiac and smooth muscles, as well as in the nervous and immune systems. Disturbances of Ca(2+) homeostasis and of signaling are potential targets for intervention in aged humans.
Collapse
|
37
|
Behringer EJ, Vanterpool CK, Pearce WJ, Wilson SM, Buchholz JN. Advancing age alters the contribution of calcium release from smooth endoplasmic reticulum stores in superior cervical ganglion cells. J Gerontol A Biol Sci Med Sci 2009; 64:34-44. [PMID: 19196634 PMCID: PMC2673896 DOI: 10.1093/gerona/gln053] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
In superior cervical ganglion (SCG) neurons calcium-induced calcium release (CICR), mediated by ryanodine receptors (RyRs), contributes to stimulation-evoked intracellular calcium ([Ca2+]i) transients. Hypothesis: The contribution of CICR to electrical field stimulation (EFS)–evoked [Ca2+]i transients in SCG cells declines with senescence and may be partially recovered in the presence of caffeine. We measured EFS-evoked [Ca2+]i transients in isolated fura-2–loaded SCG cells from Fischer-344 rats aged 6, 12, and 24 months with either the RyR antagonist ryanodine to block the contribution of CICR to [Ca2+]i transients or caffeine to sensitize CICR to EFS. EFS-evoked [Ca2+]i transients increased from 6 to 12 months and declined at 24 months and ryanodine decreased [Ca2+]i transients in SCG cells from 6- and 12-month-old animals only. Caffeine significantly increased EFS-evoked [Ca2+]i transients in all age groups. These data suggest that CICR declines with senescence and residual CICR function may be reclaimed in senescent cells with caffeine.
Collapse
Affiliation(s)
- Erik J Behringer
- Department of Physiology and Pharmacology, Loma Linda University, CA 92354, USA
| | | | | | | | | |
Collapse
|
38
|
Wojda U, Salinska E, Kuznicki J. Calcium ions in neuronal degeneration. IUBMB Life 2008; 60:575-90. [PMID: 18478527 DOI: 10.1002/iub.91] [Citation(s) in RCA: 209] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Neuronal Ca(2+) homeostasis and Ca(2+) signaling regulate multiple neuronal functions, including synaptic transmission, plasticity, and cell survival. Therefore disturbances in Ca(2+) homeostasis can affect the well-being of the neuron in different ways and to various degrees. Ca(2+) homeostasis undergoes subtle dysregulation in the physiological ageing. Products of energy metabolism accumulating with age together with oxidative stress gradually impair Ca(2+) homeostasis, making neurons more vulnerable to additional stress which, in turn, can lead to neuronal degeneration. Neurodegenerative diseases related to aging, such as Alzheimer's disease, Parkinson's disease, or Huntington's disease, develop slowly and are characterized by the positive feedback between Ca(2+) dyshomeostasis and the aggregation of disease-related proteins such as amyloid beta, alfa-synuclein, or huntingtin. Ca(2+) dyshomeostasis escalates with time eventually leading to neuronal loss. Ca(2+) dyshomeostasis in these chronic pathologies comprises mitochondrial and endoplasmic reticulum dysfunction, Ca(2+) buffering impairment, glutamate excitotoxicity and alterations in Ca(2+) entry routes into neurons. Similar changes have been described in a group of multifactorial diseases not related to ageing, such as epilepsy, schizophrenia, amyotrophic lateral sclerosis, or glaucoma. Dysregulation of Ca(2+) homeostasis caused by HIV infection or by sudden accidents, such as brain stroke or traumatic brain injury, leads to rapid neuronal death. The differences between the distinct types of Ca(2+) dyshomeostasis underlying neuronal degeneration in various types of pathologies are not clear. Questions that should be addressed concern the sequence of pathogenic events in an affected neuron and the pattern of progressive degeneration in the brain itself. Moreover, elucidation of the selective vulnerability of various types of neurons affected in the diseases described here will require identification of differences in the types of Ca(2+) homeostasis and signaling among these neurons. This information will be required for improved targeting of Ca(2+) homeostasis and signaling components in future therapeutic strategies, since no effective treatment is currently available to prevent neuronal degeneration in any of the pathologies described here.
Collapse
Affiliation(s)
- Urszula Wojda
- Laboratory of Neurodegeneration, International Institute of Molecular and Cell Biology, Ks. Trojdena 4, 02-109 Warsaw, Poland.
| | | | | |
Collapse
|
39
|
Toescu EC, Verkhratsky A. The importance of being subtle: small changes in calcium homeostasis control cognitive decline in normal aging. Aging Cell 2007; 6:267-73. [PMID: 17517038 DOI: 10.1111/j.1474-9726.2007.00296.x] [Citation(s) in RCA: 140] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Aging is a complex, multifactorial process. One of the features of normal aging of the brain is a decline in cognitive functions and much experimental attention has been devoted to understanding this process. Evidence accumulated in the last decade indicates that such functional changes are not due to gross morphological alterations, but to subtle functional modification of synaptic connectivity and intracellular signalling and metabolism. Such synaptic modifications are compatible with a normal level of activity and allow the maintenance of a certain degree of functional reserve. This is in contrast to the changes in various neurodegenerative diseases, characterized by significant neuronal loss and dramatic and irreversible functional deficit. This whole special issue has been initiated with the intention of focusing on the processes of normal brain aging. In this review, we present data that shows how subtle changes in Ca(2+) homeostasis or in the state of various Ca(2+)-dependent processes or molecules, which occur in aging can have significant functional consequences.
Collapse
Affiliation(s)
- Emil C Toescu
- Department of Physiology, Division of Medical Sciences, The Medical School, University of Birmingham, Birmingham B15 2TT, UK.
| | | |
Collapse
|
40
|
The amyloid beta ion channel hypothesis of Alzheimer's disease. Neuropsychiatr Dis Treat 2007; 3:597-612. [PMID: 19300589 PMCID: PMC2656296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Alzheimer's disease (AD) is a leading cause of chronic dementia in the US. Its incidence is increasing with an attendant increase in associated health care costs. Since its first description in a patient by Dr. Alois Alzheimer over a century ago, a large body of biomedical literature has established a detailed clinical and molecular profile of this disorder. Amyloid beta peptide (Abeta; a 39-42 amino acid molecule) is the major component of senile plaques, the lesions that are one of the pathologic hallmarks of AD (Wong et al 1985). Although many aspects of the biology of amyloid beta have been investigated, several fundamental questions about how this peptide causes AD neuropathology remain unanswered. The key question is: How is Abeta toxic to cerebral neurons? Because plaques are extra-neuronal deposits, it is difficult to imagine a structural basis for their toxicity. As an interesting contrast the other pathognomonic feature of AD, neurofibrillary tangles, are intra-axonal structural anomalies that are composed of the hyperphosphorylated microtubule associated (MAP) protein, tau. This review will assess the current thinking that relates to a recent hypothesis of Abeta toxicity. In 1992, Hardy and Higgins reported findings that suggested a new and intriguing possibility. These authors found that Abeta peptides disrupt Ca(2+) homeostasis in neurons and increase intracellular Ca(2+) [Ca(2+)](i). This was corroborated by Mattson and his colleagues who demonstrated that Abeta exposure to human cortical neurons raised [Ca2(+)](i) (Mattson, Cheng et al 1992); (Hardy and Higgins 1992). Finally, Nelson Arispe's group at the NIH specifically investigated the possibility that Abeta peptides might function like Ca(2+) ion channels (Arispe et al 1993). This and several subsequent studies have laid the foundation for a novel idea: "Abeta peptides are, in part, toxic to neurons because they form aberrant ion channels in neuronal membranes and thereby disrupt neuronal homeostasis". In this review we shall critically examine this theory in light of classic and contemporary literature.
Collapse
|