1
|
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
|
2
|
Parkkinen I, Their A, Asghar MY, Sree S, Jokitalo E, Airavaara M. Pharmacological Regulation of Endoplasmic Reticulum Structure and Calcium Dynamics: Importance for Neurodegenerative Diseases. Pharmacol Rev 2023; 75:959-978. [PMID: 37127349 DOI: 10.1124/pharmrev.122.000701] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 03/27/2023] [Accepted: 04/04/2023] [Indexed: 05/03/2023] Open
Abstract
The endoplasmic reticulum (ER) is the largest organelle of the cell, composed of a continuous network of sheets and tubules, and is involved in protein, calcium (Ca2+), and lipid homeostasis. In neurons, the ER extends throughout the cell, both somal and axodendritic compartments, and is highly important for neuronal functions. A third of the proteome of a cell, secreted and membrane-bound proteins, are processed within the ER lumen and most of these proteins are vital for neuronal activity. The brain itself is high in lipid content, and many structural lipids are produced, in part, by the ER. Cholesterol and steroid synthesis are strictly regulated in the ER of the blood-brain barrier protected brain cells. The high Ca2+ level in the ER lumen and low cytosolic concentration is needed for Ca2+-based intracellular signaling, for synaptic signaling and Ca2+ waves, and for preparing proteins for correct folding in the presence of high Ca2+ concentrations to cope with the high concentrations of extracellular milieu. Particularly, ER Ca2+ is controlled in axodendritic areas for proper neurito- and synaptogenesis and synaptic plasticity and remodeling. In this review, we cover the physiologic functions of the neuronal ER and discuss it in context of common neurodegenerative diseases, focusing on pharmacological regulation of ER Ca2+ Furthermore, we postulate that heterogeneity of the ER, its protein folding capacity, and ensuring Ca2+ regulation are crucial factors for the aging and selective vulnerability of neurons in various neurodegenerative diseases. SIGNIFICANCE STATEMENT: Endoplasmic reticulum (ER) Ca2+ regulators are promising therapeutic targets for degenerative diseases for which efficacious drug therapies do not exist. The use of pharmacological probes targeting maintenance and restoration of ER Ca2+ can provide restoration of protein homeostasis (e.g., folding of complex plasma membrane signaling receptors) and slow down the degeneration process of neurons.
Collapse
Affiliation(s)
- Ilmari Parkkinen
- Neuroscience Center (I.P., A.T., M.A.), Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy (I.P., M.A.), Cell and Tissue Dynamics Research Program, Institute of Biotechnology, Helsinki Institute of Life Sciences (M.Y.A., S.S., E.J.), and Electron Microscopy Unit, Institute of Biotechnology, Helsinki Institute of Life Sciences (E.J.), University of Helsinki, Helsinki, Finland
| | - Anna Their
- Neuroscience Center (I.P., A.T., M.A.), Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy (I.P., M.A.), Cell and Tissue Dynamics Research Program, Institute of Biotechnology, Helsinki Institute of Life Sciences (M.Y.A., S.S., E.J.), and Electron Microscopy Unit, Institute of Biotechnology, Helsinki Institute of Life Sciences (E.J.), University of Helsinki, Helsinki, Finland
| | - Muhammad Yasir Asghar
- Neuroscience Center (I.P., A.T., M.A.), Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy (I.P., M.A.), Cell and Tissue Dynamics Research Program, Institute of Biotechnology, Helsinki Institute of Life Sciences (M.Y.A., S.S., E.J.), and Electron Microscopy Unit, Institute of Biotechnology, Helsinki Institute of Life Sciences (E.J.), University of Helsinki, Helsinki, Finland
| | - Sreesha Sree
- Neuroscience Center (I.P., A.T., M.A.), Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy (I.P., M.A.), Cell and Tissue Dynamics Research Program, Institute of Biotechnology, Helsinki Institute of Life Sciences (M.Y.A., S.S., E.J.), and Electron Microscopy Unit, Institute of Biotechnology, Helsinki Institute of Life Sciences (E.J.), University of Helsinki, Helsinki, Finland
| | - Eija Jokitalo
- Neuroscience Center (I.P., A.T., M.A.), Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy (I.P., M.A.), Cell and Tissue Dynamics Research Program, Institute of Biotechnology, Helsinki Institute of Life Sciences (M.Y.A., S.S., E.J.), and Electron Microscopy Unit, Institute of Biotechnology, Helsinki Institute of Life Sciences (E.J.), University of Helsinki, Helsinki, Finland
| | - Mikko Airavaara
- Neuroscience Center (I.P., A.T., M.A.), Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy (I.P., M.A.), Cell and Tissue Dynamics Research Program, Institute of Biotechnology, Helsinki Institute of Life Sciences (M.Y.A., S.S., E.J.), and Electron Microscopy Unit, Institute of Biotechnology, Helsinki Institute of Life Sciences (E.J.), University of Helsinki, Helsinki, Finland
| |
Collapse
|
3
|
Abid NB, Naseer MI, Kim MO. Comparative Gene-Expression Analysis of Alzheimer's Disease Progression with Aging in Transgenic Mouse Model. Int J Mol Sci 2019; 20:ijms20051219. [PMID: 30862043 PMCID: PMC6429175 DOI: 10.3390/ijms20051219] [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: 02/01/2019] [Revised: 03/03/2019] [Accepted: 03/06/2019] [Indexed: 12/12/2022] Open
Abstract
Alzheimer’s disease (AD) is a multifactorial neurodegenerative disorder characterized by progressive memory dysfunction and a decline in cognition. One of the biggest challenges to study the pathological process at a molecular level is that there is no simple, cost-effective, and comprehensive gene-expression analysis tool. The present study provides the most detailed (Reverse transcription polymerase chain reaction) RT-PCR-based gene-expression assay, encompassing important genes, based on the Kyoto Encyclopedia of Genes and Genomes (KEGG) disease pathway. This study analyzed age-dependent disease progression by focusing on pathological events such as the processing of the amyloid precursor protein, tau pathology, mitochondrial dysfunction, endoplasmic reticulum stress, disrupted calcium signaling, inflammation, and apoptosis. Messenger RNA was extracted from the cortex and hippocampal region of APP/PS1 transgenic mice. Samples were divided into three age groups, six-, nine-, and 12-month-old transgenic mice, and they were compared with normal C57BL/6J mice of respective age groups. Findings of this study provide the opportunity to design a simple, effective, and accurate clinical analysis tool that can not only provide deeper insight into the disease, but also act as a clinical diagnostic tool for its better diagnosis.
Collapse
Affiliation(s)
- Noman Bin Abid
- Division of Life Science and Applied Life Science (BK 21), College of Natural Sciences, Gyeongsang National University, Jinju 660-701, Korea.
| | - Muhammad Imran Naseer
- Center of Excellence in Genomic Medicine Research, Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah 21589, Saudi Arabia.
| | - Myeong Ok Kim
- Division of Life Science and Applied Life Science (BK 21), College of Natural Sciences, Gyeongsang National University, Jinju 660-701, Korea.
| |
Collapse
|
4
|
Rcom-H'cheo-Gauthier AN, Osborne SL, Meedeniya ACB, Pountney DL. Calcium: Alpha-Synuclein Interactions in Alpha-Synucleinopathies. Front Neurosci 2016; 10:570. [PMID: 28066161 PMCID: PMC5167751 DOI: 10.3389/fnins.2016.00570] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 11/25/2016] [Indexed: 11/20/2022] Open
Abstract
Aggregation of the pre-synaptic protein, α-synuclein (α-syn), is the key etiological factor in Parkinson's disease (PD) and other alpha-synucleinopathies, such as multiple system atrophy (MSA) and Dementia with Lewy bodies (DLB). Various triggers for pathological α-syn aggregation have been elucidated, including post-translational modifications, oxidative stress, and binding of metal ions, such as calcium. Raised neuronal calcium levels in PD may occur due to mitochondrial dysfunction and/or may relate to calcium channel dysregulation or the reduced expression of the neuronal calcium buffering protein, calbindin-D28k. Recent results on human tissue and a mouse oxidative stress model show that neuronal calbindin-D28k expression excludes α-syn inclusion bodies. Previously, cell culture model studies have shown that transient increases of intracellular free Ca(II), such as by opening of the voltage-gated plasma calcium channels, could induce cytoplasmic aggregates of α-syn. Raised intracellular free calcium and oxidative stress also act cooperatively to promote α-syn aggregation. The association between raised neuronal calcium, α-syn aggregation, oxidative stress, and neurotoxicity is reviewed in the context of neurodegenerative α-syn disease and potential mechanism-based therapies.
Collapse
Affiliation(s)
| | | | | | - Dean L. Pountney
- Menzies Health Institute Queensland, Griffith UniversityGold Coast, QLD, Australia
| |
Collapse
|
5
|
Rinnerthaler M, Duschl J, Steinbacher P, Salzmann M, Bischof J, Schuller M, Wimmer H, Peer T, Bauer JW, Richter K. Age-related changes in the composition of the cornified envelope in human skin. Exp Dermatol 2013; 22:329-35. [DOI: 10.1111/exd.12135] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/12/2013] [Indexed: 11/28/2022]
Affiliation(s)
- Mark Rinnerthaler
- Department of Cell Biology; Division of Genetics; University of Salzburg; Salzburg Austria
| | - Jutta Duschl
- Department of Cell Biology; Division of Genetics; University of Salzburg; Salzburg Austria
| | - Peter Steinbacher
- Department of Organismic Biology; Division of Zoology; University of Salzburg; Salzburg Austria
| | - Manuel Salzmann
- Department of Cell Biology; Division of Genetics; University of Salzburg; Salzburg Austria
| | - Johannes Bischof
- Department of Cell Biology; Division of Genetics; University of Salzburg; Salzburg Austria
| | - Markus Schuller
- Department of Cell Biology; Division of Genetics; University of Salzburg; Salzburg Austria
| | - Herbert Wimmer
- Department of Cell Biology; Division of Genetics; University of Salzburg; Salzburg Austria
| | - Thomas Peer
- Department of Organismic Biology; Division of Zoology; University of Salzburg; Salzburg Austria
| | - Johann W. Bauer
- Department of Dermatology; Division of Molecular Dermatology and EB House Austria; Paracelsus Medical University; Salzburg Austria
| | - Klaus Richter
- Department of Cell Biology; Division of Genetics; University of Salzburg; Salzburg Austria
| |
Collapse
|
6
|
Duncan C, Mueller S, Simon E, Renger JJ, Uebele VN, Hogan QH, Wu HE. Painful nerve injury decreases sarco-endoplasmic reticulum Ca²⁺-ATPase activity in axotomized sensory neurons. Neuroscience 2012; 231:247-57. [PMID: 23219911 DOI: 10.1016/j.neuroscience.2012.11.055] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Revised: 11/28/2012] [Accepted: 11/29/2012] [Indexed: 12/15/2022]
Abstract
The sarco-endoplasmic reticulum Ca(2+)-ATPase (SERCA) is a critical pathway by which sensory neurons sequester cytosolic Ca(2+) and thereby maintain intracellular Ca(2+) homeostasis. We have previously demonstrated decreased intraluminal endoplasmic reticulum Ca(2+) concentration in traumatized sensory neurons. Here we examine SERCA function in dissociated sensory neurons using Fura-2 fluorometry. Blocking SERCA with thapsigargin (1 μM) increased resting [Ca(2+)](c) and prolonged recovery (τ) from transients induced by neuronal activation (elevated bath K(+)), demonstrating SERCA contributes to control of resting [Ca(2+)](c) and recovery from transient [Ca(2+)](c) elevation. To evaluate SERCA in isolation, plasma membrane Ca(2+) ATPase was blocked with pH 8.8 bath solution and mitochondrial buffering was avoided by keeping transients small (≤ 400 nM). Neurons axotomized by spinal nerve ligation (SNL) showed a slowed rate of transient recovery compared to control neurons, representing diminished SERCA function, whereas neighboring non-axotomized neurons from SNL animals were unaffected. Injury did not affect SERCA function in large neurons. Repeated depolarization prolonged transient recovery, showing that neuronal activation inhibits SERCA function. These findings suggest that injury-induced loss of SERCA function in small sensory neurons may contribute to the generation of pain following peripheral nerve injury.
Collapse
Affiliation(s)
- C Duncan
- Medical College of Wisconsin, Department of Anesthesiology, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
| | | | | | | | | | | | | |
Collapse
|
7
|
Li D, Nikiforova N, Lu CJ, Wannop K, McMenamin M, Lee CW, Buckler KJ, Paterson DJ. Targeted neuronal nitric oxide synthase transgene delivery into stellate neurons reverses impaired intracellular calcium transients in prehypertensive rats. Hypertension 2012; 61:202-7. [PMID: 23172925 DOI: 10.1161/hypertensionaha.111.00105] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Hypertension is associated with the early onset of cardiac sympathetic hyperresponsiveness and enhanced intracellular Ca(2+) concentration [Ca(2+)](i) in sympathetic neurons from both prehypertensive and hypertensive, spontaneously hypertensive rats (SHRs). Oxidative stress is a hallmark of hypertension, therefore, we tested the hypothesis that the inhibitory action of the nitric oxide-cGMP pathway on [Ca(2+)](i) transients is impaired in cardiac sympathetic neurons from the SHR. Stellate ganglia were isolated from young prehypertensive SHRs and age-matched normotensive Wistar-Kyoto rats. [Ca(2+)](i) was measured by ratiometric fluorescence imaging. Neurons from the prehypertensive SHR ganglia had a significantly higher depolarization evoked [Ca(2+)](i) transient that was also associated with decreased expression of neuronal nitric oxide synthase (nNOS), β1 subunit of soluble guanylate cyclase and cGMP when compared with the Wistar-Kyoto rat ganglia. Soluble guanylate cyclase inhibition or nNOS inhibition increased [Ca(2+)](i) in the Wistar-Kyoto rats but had no effect in SHR neurons. A nitric oxide donor decreased [Ca(2+)](i) in both sets of neurons, although this was markedly less in the SHR. A novel noradrenergic cell specific vector (Ad.PRSx8-nNOS/Cherry) or its control vector (Ad.PRSx8-Cherry) was expressed in sympathetic neurons. In the SHR, Ad.PRSx8-nNOS/Cherry-treated neurons had a significantly reduced peak [Ca(2+)](i) transient that was associated with increased tissue levels of nNOS protein and cGMP concentration compared with gene transfer of Ad.PRSx8-Cherry alone. nNOS inhibition significantly increased [Ca(2+)](i) after Ad.PRSx8-nNOS/Cherry expression. We conclude that artificial upregulation of stellate sympathetic nNOS via targeted gene transfer can directly attenuate intracellular Ca(2+) and may provide a novel method for decreasing enhanced cardiac sympathetic neurotransmission.
Collapse
Affiliation(s)
- Dan Li
- Department of Physiology, Anatomy and Genetics, University of Oxford, Burdon Sanderson Cardiac Science Centre and BHF Centre of Research Excellence, Oxford, United Kingdom.
| | | | | | | | | | | | | | | |
Collapse
|
8
|
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
|
9
|
Abstract
The cause(s) of sporadic Alzheimer’s disease (sAD) are complex and currently poorly understood. They likely result from a combination of genetic, environmental, proteomic and lipidomic factors that crucially occur only in the aged brain. Age-related changes in calcium levels and dynamics have the potential to increase the production and accumulation of both amyloid-β peptide (Aβ) and τ pathologies in the AD brain, although these two pathologies themselves can induce calcium dyshomeostasis, particularly at synaptic membranes. This review discuses the evidence for a role for calcium dyshomeostasis in the initiation of pathology, as well as the evidence for these pathologies themselves disrupting normal calcium homeostasis, which lead to synaptic and neuronal dysfunction, synaptotoxicity and neuronal loss, underlying the dementia associated with the disease.
Collapse
Affiliation(s)
- Kim N Green
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA 92697-4545, USA.
| |
Collapse
|
10
|
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
|
11
|
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
|
12
|
Goyal R, Angermann JE, Ostrovskaya O, Buchholz JN, Smith GD, Wilson SM. Enhanced capacitative calcium entry and sarcoplasmic-reticulum calcium storage capacity with advanced age in murine mesenteric arterial smooth muscle cells. Exp Gerontol 2008; 44:201-7. [PMID: 19017540 DOI: 10.1016/j.exger.2008.10.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2008] [Revised: 10/18/2008] [Accepted: 10/21/2008] [Indexed: 11/16/2022]
Abstract
Intracellular Ca(2+) signaling is important to perfusion pressure related arterial reactivity and to vascular disorders including hypertension, angina and ischemic stroke. We have recently shown that advancing-age leads to calcium signaling adaptations in mesenteric arterial myocytes from C57 BL/6 mice [Corsso, C.D., Ostrovskaya, O., McAllister, C.E., Murray, K., Hatton, W.J., Gurney, A.M., Spencer, N.J., Wilson, S.M., 2006. Effects of aging on Ca(2+) signaling in murine mesenteric arterial smooth muscle cells. Mech. Ageing Dev. 127, 315-323)] which may contribute to decrements in perfusion pressure related arterial contractility others have shown occur. Even still, the mechanisms underlying the changes in Ca(2+) signaling and arterial reactivity are unresolved. Ca(2+) transport and storage capabilities are thought to contribute to age-related Ca(2+) signaling dysfunctions in other cell types. The present studies were therefore designed to test the hypothesis that cytosolic and compartmental Ca(2+) homeostasis in mesenteric arterial myocytes changes with advanced age. The hypothesis was tested by performing digitalized fluorescence microscopy on mesenteric arterial myocytes isolated from 5- to 6-month and 29- to 30-month-old C57Bl/6 mice. The data provide evidence that with advanced age capacitative Ca(2+) entry and sarcoplasmic reticulum Ca(2+) storage are increased although sarcoplasmic reticulum Ca(2+) uptake and plasma membrane Ca(2+) extrusion are unaltered. Overall, the studies begin to resolve the mechanisms associated with age-related alterations in mesenteric arterial smooth muscle Ca(2+) signaling and their physiological consequences.
Collapse
Affiliation(s)
- Ravi Goyal
- Department of Pharmacology, University of Mississippi School of Pharmacy and Research Institute of Pharmaceutical Sciences, MS 38677, USA
| | | | | | | | | | | |
Collapse
|
13
|
Buchholz JN, Behringer EJ, Pottorf WJ, Pearce WJ, Vanterpool CK. Age-dependent changes in Ca2+ homeostasis in peripheral neurones: implications for changes in function. Aging Cell 2007; 6:285-96. [PMID: 17517039 PMCID: PMC1974774 DOI: 10.1111/j.1474-9726.2007.00298.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Calcium ions represent universal second messengers within neuronal cells integrating multiple cellular functions, such as release of neurotransmitters, gene expression, proliferation, excitability, and regulation of cell death or apoptotic pathways. The magnitude, duration and shape of stimulation-evoked intracellular calcium ([Ca2+]i) transients are determined by a complex interplay of mechanisms that modulate stimulation-evoked rises in [Ca2+]i that occur with normal neuronal function. Disruption of any of these mechanisms may have implications for the function and health of peripheral neurones during the aging process. This review focuses on the impact of advancing age on the overall function of peripheral adrenergic neurones and how these changes in function may be linked to age-related changes in modulation of [Ca2+]i regulation. The data in this review suggest that normal aging in peripheral autonomic neurones is a subtle process and does not always result in dramatic deterioration in their function. We present studies that support the idea that in order to maintain cell viability peripheral neurones are able to compensate for an age-related decline in the function of at least one of the neuronal calcium-buffering systems, smooth endoplasmic reticulum calcium ATPases, by increased function of other calcium-buffering systems, namely, the mitochondria and plasmalemma calcium extrusion. Increased mitochondrial calcium uptake may represent a 'weak point' in cellular compensation as this over time may contribute to cell death. In addition, we present more recent studies on [Ca2+]i regulation in the form of the modulation of release of calcium from smooth endoplasmic reticulum calcium stores. These studies suggest that the contribution of the release of calcium from smooth endoplasmic reticulum calcium stores is altered with age through a combination of altered ryanodine receptor levels and modulation of these receptors by neuronal nitric oxide containing neurones.
Collapse
Affiliation(s)
- John N Buchholz
- Department of Physiology and Pharmacology, Loma Linda University, School of Medicine, Loma Linda, CA 92350, USA.
| | | | | | | | | |
Collapse
|
14
|
Görlach A, Klappa P, Kietzmann T. The endoplasmic reticulum: folding, calcium homeostasis, signaling, and redox control. Antioxid Redox Signal 2006; 8:1391-418. [PMID: 16986999 DOI: 10.1089/ars.2006.8.1391] [Citation(s) in RCA: 493] [Impact Index Per Article: 27.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The endoplasmic reticulum (ER) plays a major role in regulating synthesis, folding, and orderly transport of proteins. It is also essentially involved in various cellular signaling processes, primarily by its function as a dynamic Ca(2+) store. Compared to the cytosol, oxidizing conditions are found in the ER that allow oxidation of cysteine residues in nascent polypeptide chains to form intramolecular disulfide bonds. However, compounds and enzymes such as PDI that catalyze disulfide bonds become reduced and have to be reoxidized for further catalytic cycles. A number of enzymes, among them products of the ERO1 gene, appear to provide oxidizing equivalents, and oxygen appears to be the final oxidant in aerobic living organisms. Thus, protein oxidation in the ER is connected with generation of reactive oxygen species (ROS). Changes in the redox state and the presence of ROS also affect the Ca(2+) homeostasis by modulating the functionality of ER-based channels and buffering chaperones. In addition, a close relationship exists between oxidative stress and ER stress, which both may activate signaling events leading to a rebalance of folding capacity and folding demand or to cell death. Thus, redox homeostasis appears to be a prerequisite for proper functioning of the ER.
Collapse
Affiliation(s)
- Agnes Görlach
- Experimental Pediatric Cardiology, Department of Pediatric Cardiology and Congenital Heart Disease, German Heart Center Munich at the Technical University Munich, Munich, Germany
| | | | | |
Collapse
|
15
|
Vanterpool C.K, Vanterpool EA, Pearce WJ, Buchholz. JN. Advancing age alters the expression of the ryanodine receptor 3 isoform in adult rat superior cervical ganglia. J Appl Physiol (1985) 2006; 101:392-400. [PMID: 16645194 PMCID: PMC1569677 DOI: 10.1152/japplphysiol.00167.2006] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Sympathetic nerves arising from the superior cervical ganglion (SCG) protect the cerebrovasculature during periods of acute hypertension and may play a role in homeostasis of target organs. The functions of these nerves depend on calcium release triggered by activation of ryanodine receptor (RyR) channels. The function of RyR channels is in part dependent on genetic expression and regulation by numerous protein modulators such as neuronal nitric oxide synthase (nNOS) neurons also found in the SCG. We have shown that release of calcium in SCG cells is altered during late maturation and advancing age. However, the underlying molecular mechanisms that may in part account for these data are elusive. Therefore we used molecular techniques to test the hypothesis that advancing age alters the pattern of genetic expression and/or protein levels of RyRs and their modulation by nNOS in the SCG in F344 rats aged 6, 12, and 24 mo. Surprisingly, ryr1 expression was undetectable in all age groups and ryr2 and ryr3 are the predominantly transcribed isoforms in the adult rat SCG. mRNA and protein levels for RyR2 isoform did not change with advancing age. However, ryr3 mRNA levels increased from 6 to 12 mo and declined from 12 to 24 mo. Similarly, RyR3 receptor protein levels also increased from 6 to 12 mo and declined from 12 to 24 mo. Because nNOS and the phosphorylation of the RyRs have been shown to modulate the function of RyRs, total phosphorylation and nNOS protein levels were analyzed in all age groups. Phosphorylation levels of the RyRs were similar in all age groups. However, nNOS protein levels increased from 6 to 12 mo followed by decline from 12 to 24 mo. These data suggest that advancing age selectively impacts the genetic expression and protein levels of RyR3 as well as modulatory nNOS protein levels. In addition, these data may part provide some insight into the possible changes in the function of RyRs that may occur with the normal aging process.
Collapse
Affiliation(s)
| | - Elaine A. Vanterpool
- Department of Microbiology and Molecular Genetics, Loma Linda University, School of Medicine, Loma Linda, CA 92350, USA
| | | | - John N. Buchholz.
- Department of Physiology and Pharmacology
- *Corresponding author: John Buchholz, Department of Physiology and Pharmacology, Loma Linda University, School of Medicine, Loma Linda, CA 92350, E-mail:
| |
Collapse
|
16
|
del Corsso C, Ostrovskaya O, McAllister CE, Murray K, Hatton WJ, Gurney AM, Spencer NJ, Wilson SM. Effects of aging on Ca2+ signaling in murine mesenteric arterial smooth muscle cells. Mech Ageing Dev 2006; 127:315-23. [PMID: 16413046 DOI: 10.1016/j.mad.2005.12.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2005] [Revised: 11/23/2005] [Accepted: 12/07/2005] [Indexed: 11/21/2022]
Abstract
Pathophysiological changes in arterial smooth muscle structure and function occur with aging and there are a number of reports illustrating reductions in vascular responsiveness with aging. While much is known about arterial remodeling and functional adaptations with aging, very little is known about the biophysical adaptations in individual arterial myocytes. Cytosolic Ca2+ signaling, involving activation of L-type Ca2+ channels on the plasma membrane as well as InsP3 and ryanodine receptors on the sarcoplasmic reticulum, is integral to vascular tone and reactivity. Thus, we tested the hypothesis that aging results in reductions in the functional expression of L-type channels and temporal aspects of ryanodine receptor and InsP3 receptor Ca2+ signaling, in mesenteric arterial smooth muscle cells isolated from 6 and 30 months old C57Bl/6 mice. Comparisons of L-type current activity were made using dialyzed, whole-cell voltage-clamp techniques and Ba2+ as charge carrier. Ca2+ signaling was measured using fura-2 fluorescence microscopy techniques. Cell morphological changes were also investigated using electrophysiological and immunocytochemical approaches. The amplitudes of L-type Ca2+ currents were increased in older mice, but this was associated with membrane surface area increases of approximately 50%, due to increases in cell length not cell width. Consequently, L-type Ca2+ current densities were preserved with age, indicating functional channel expression was unchanged. In contrast, aging was associated with decrements in Ca2+ signaling in response to either ryanodine receptor stimulation by caffeine or InsP3 receptor activation with phenylephrine. These changes with aging may be related to the previously reported depression in myogenic reactivity.
Collapse
Affiliation(s)
- Cristiane del Corsso
- Department of Physiology, University of Nevada School of Medicine, Reno, NV 89557, USA
| | | | | | | | | | | | | | | |
Collapse
|
17
|
Vanterpool CK, Pearce WJ, Buchholz JN. Advancing age alters rapid and spontaneous refilling of caffeine-sensitive calcium stores in sympathetic superior cervical ganglion cells. J Appl Physiol (1985) 2005; 99:963-71. [PMID: 15845773 PMCID: PMC1188236 DOI: 10.1152/japplphysiol.00343.2005] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Intracellular calcium concentration ([Ca2+]i) release from smooth endoplasmic reticulum (SER) stores plays an important role in cell signaling. These stores are rapidly refilled via influx through voltage-gated calcium channels or spontaneously via store-operated calcium channels and subsequent pumping by SER Ca2+-ATPases. We measured [Ca2+]i transients in isolated fura 2-loaded superior cervical ganglion cells from 6-, 12-, 20-, and 24-mo-old Fischer 344 rats. For rapid refilling, [Ca2+]i transients were elicited by a 1) 5-s exposure to K+, 2) caffeine to release Ca2+ from SER stores, 3) K+ to refill SER Ca2+ stores, and 4) caffeine. The percent difference between the peak and rate of rise of the first and second caffeine-evoked [Ca2+]i transient significantly declined over the age range of 12-24 mo. To estimate spontaneous refilling, cells were depolarized for 5 s with 68 mM K+ (control), followed by a 10-s exposure to 10 mM caffeine "conditioning stimulus" to deplete [Ca2+]i stores. Caffeine was then rapidly applied for 5 s at defined intervals from 60 to 300 s. Integrated caffeine-evoked [Ca2+]i transients were measured and plotted as a percentage of the K+ response vs. time. The derivative of the refilling time curves significantly declined over the age range from 12-24 mo. Overall, these data suggest that the ability of superior cervical ganglion cells to sustain release of [Ca2+]i following rapid or spontaneous refilling declines with advancing age. Compromised ability to sustain calcium signaling may possibly alter the overall function of adrenergic neurons innervating the cerebrovasculature.
Collapse
Affiliation(s)
| | | | - John N. Buchholz
- Department of Physiology and Pharmacology, Loma Linda University, School of Medicine, Loma Linda, California, 92354
| |
Collapse
|
18
|
Pande J, Mallhi KK, Grover AK. Role of third extracellular domain of plasma membrane Ca2+-Mg2+-ATPase based on the novel inhibitor caloxin 3A1. Cell Calcium 2005; 37:245-50. [PMID: 15670871 DOI: 10.1016/j.ceca.2004.10.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2004] [Revised: 10/12/2004] [Accepted: 10/24/2004] [Indexed: 11/20/2022]
Abstract
The plasma membrane Ca2+ pump (PMCA) is a Ca2+-Mg2+-ATPase that expels Ca2+ from cells to help them maintain low concentrations of cytosolic Ca2+ ([Ca2+]i). It contains five putative extracellular domains (PEDs). Earlier we had reported that binding to PED2 leads to PMCA inhibition. Mutagenesis of residues in transmembrane domain 6 leads to loss of PMCA activity. PED3 connects transmembrane domains 5 and 6. PED3 is only five amino acid residues long. By screening a phage display library, we obtained a peptide sequence that binds this target. After examining a number of peptides related to this original sequence, we selected one that inhibits the PMCA pump (caloxin 3A1). Caloxin 3A1 inhibits PMCA but not the sarcoplasmic reticulum Ca2+-pump. Caloxin 3A1 did not inhibit formation of the 140 kDa acylphosphate intermediate from ATP or its degradation. Thus, PEDs play a role in the reaction cycle of PMCA even though sites for binding to the substrates Ca2+ and Mg-ATP2-, and the activator calmodulin are all in the cytosolic domains of PMCA. In endothelial cells exposed to low concentration of a Ca2+-ionophore, caloxin 3A1 caused a further increase in [Ca2+]i proving its ability to inhibit PMCA pump extracellularly. Thus, even though PED3 is the shortest PED, it plays key role in the PMCA function.
Collapse
Affiliation(s)
- Jyoti Pande
- Department of Medicine, McMaster University, 1200 Main Street West, Hamilton, Ont., L8N 3Z5, Canada
| | | | | |
Collapse
|
19
|
Toescu EC, Verkhratsky A. Neuronal ageing from an intraneuronal perspective: roles of endoplasmic reticulum and mitochondria. Cell Calcium 2003; 34:311-23. [PMID: 12909078 DOI: 10.1016/s0143-4160(03)00142-8] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The nature of brain ageing and the age-dependent decline in cognitive functions remains poorly understood. Physiological brain ageing is characterised by mild mental dysfunctions, whereas age-dependent neurodegeneration, as illustrated by Alzheimer disease (AD), results rapidly in severe dementia. These two states of the aged brain, the physiological and the pathological, are fundamentally different as the latter stems from significant neuronal loss, whereas the former develops without significant neuronal demise. In this paper, we review the changes in neuronal Ca(2+) homeostasis that occur during brain ageing, and conclude that normal, physiological ageing is characterised mainly by a decrease of neuronal homeostatic reserve, defined as the capacity to respond effectively to functional and metabolic stressors, but does not reach the trigger required to induce neuronal death. In contrast, during neurodegenerative states, Ca(2+) homeostasis is affected early during the pathological process and result in significant neuronal demise. We also review recent evidence suggesting that the endoplasmic reticulum (ER) might play an important role in controlling the balance between healthy and pathological neuronal ageing.
Collapse
Affiliation(s)
- Emil C Toescu
- Department of Physiology, The University of Birmingham, B15 2TT Edgbaston, UK.
| | | |
Collapse
|
20
|
van der Vlies D, Woudenberg J, Post JA. Protein oxidation in aging: endoplasmic reticulum as a target. Amino Acids 2003; 25:397-407. [PMID: 14661099 DOI: 10.1007/s00726-003-0025-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2002] [Revised: 01/01/2003] [Accepted: 05/08/2003] [Indexed: 10/26/2022]
Abstract
Oxidatively modified proteins have been shown to correlate with the age of an organism or its tissues. An increase in tissue-susceptibility to experimentally induced protein oxidation not only depends on tissue type and age, but also on the maximum lifespan potential of the species. A general, although tissue dependent, decline in anti-oxidative defenses during aging may very well be responsible for this difference in vulnerability. In addition, the level of protein modifications also depends on the nature and the subcellular localization of the proteins involved. Damage to the endoplasmic reticulum (ER), and its subsequent impaired functionality may be involved in the process of aging. This is suggested by; (1) an upregulation of ER stress-response chaperones, (2) a preferential oxidation of ER-resident proteins and, (3) a disturbance of calcium homeostasis. Therefore, this review will focus on the putative involvement of the oxidized endoplasmic reticulum in the process of aging.
Collapse
Affiliation(s)
- D van der Vlies
- Erasmus MC, Department of Internal Oncology - Josephina Nefkens Instituut, Rotterdam, The Netherlands.
| | | | | |
Collapse
|
21
|
Changes in mitochondrial status associated with altered Ca2+ homeostasis in aged cerebellar granule neurons in brain slices. J Neurosci 2003. [PMID: 12486169 DOI: 10.1523/jneurosci.22-24-10761.2002] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
In the present work, we investigated the relationship between mitochondrial function and Ca2+ homeostasis in brain slices obtained from mice that aged normally. In acute preparations, the cerebellar neurons had similar values for intracellular free Ca2+ ([Ca2+]i) regardless of their age (range, 6 weeks to 24 months). However, compared with the young slices, the aged neurons (20-24 months) showed an enhanced rate of [Ca2+]i increases as a function of the time the slices were maintained in vitro. When slices were stimulated (KCl depolarization), there were significant differences in the patterns of [Ca2+]i signal displayed by the young and old cerebellar granule neurons. More importantly, the aged neurons showed a significant delay in their capacity to recover the resting [Ca2+]i. The relationship between [Ca2+]i and mitochondrial membrane potential was assessed by recording both parameters simultaneously, using fura-2 and rhodamine-123. In both young and aged neurons, the cytosolic [Ca2+]i signal was associated with a mitochondrial depolarization response. In the aged neurons, the mitochondria had a significantly longer repolarization response, and quantitative analysis showed a direct correlation between the delays in mitochondrial repolarization and [Ca2+]i recovery, indicating the causal relationship between the two parameters. Thus, the present results show that the reported changes in Ca2+ homeostasis associated with aging, which manifest principally in a decreased capacity of maintaining a stable resting [Ca2+]i or recovering the resting [Ca2+]i values after stimulation, are primarily attributable to a metabolic dysfunction in which the mitochondrial impairment plays an important role.
Collapse
|
22
|
Clodfelter GV, Porter NM, Landfield PW, Thibault O. Sustained Ca2+-induced Ca2+-release underlies the post-glutamate lethal Ca2+ plateau in older cultured hippocampal neurons. Eur J Pharmacol 2002; 447:189-200. [PMID: 12151011 DOI: 10.1016/s0014-2999(02)01843-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Several studies have shown that a prolonged Ca(2+) elevation follows a glutamate-mediated excitotoxic insult in cultured neurons, and may be associated with impending cell death. Recently, we showed that the prolonged Ca(2+) elevation that emerges as neurons age in culture is specifically linked to an age-related increase in excitotoxic vulnerability. However, the multiple sources of Ca(2+) that contribute to Ca(2+) elevation during and after glutamate exposure are not well understood. Here, we examined the Ca(2+) sources of the age-related prolonged Ca(2+) elevation in cultured hippocampal neurons. Studies with caffeine showed that the ryanodine receptor-dependent releasable pool of Ca(2+) from intracellular stores was similar in older and younger neurons. Thapsigargin, which inhibits intracellular store refilling, did not mimic the age-related prolonged Ca(2+) elevation and, in fact, partially reduced it. Ryanodine, which blocks Ca(2+)-induced Ca(2+)-release (CICR) from stores, completely blocked the age-related prolonged Ca(2+) elevation following glutamate exposure but did not alter maximal Ca(2+) elevation during the glutamate exposure. Thus, we conclude that sustained CICR plays a selective and key role in generating the lethal, age-related, prolonged Ca(2+) elevation, and is the likely mechanism underlying age-related, enhanced vulnerability to excitotoxicity in neurons.
Collapse
Affiliation(s)
- Gregory V Clodfelter
- University of Kentucky Medical Center, Department of Molecular and Biomedical Pharmacology, MS-320, 800 Rose Street, Lexington, KY 40536, USA
| | | | | | | |
Collapse
|