scholarly journals Analysis of Ca(2+)signaling mechanisms – our experience on the intercellular communication in muscle remodeling

2019 ◽  
pp. 325-328 ◽  
Author(s):  
S. Filip ◽  
J. Mokrý ◽  
O. Forostyak ◽  
G. Dayanithi
Keyword(s):  
Glutamate Receptors ◽  
Cell Function ◽  
Ryanodine Receptors ◽  
Cyclopiazonic Acid ◽  
C2c12 Cells ◽  
Ionotropic Glutamate Receptors ◽  
Effect Analysis ◽  
Calcium Blockers ◽  
Cell Diversity ◽  
Intracellular Ca

The aim of this study was to evaluate cell diversity by considering how Ca(2+) signaling has been adapted in skeletal muscle cell function. We characterized single C2C12 myoblasts through intracellular Ca(2+) signaling kinetics after exposure to specific drugs and calcium blockers using fast fluorescence microspectrofluorimetry followed by ATP effect analysis, which confirmed the expression of functional purinergic adenosine and P2 receptors. Further, we found that glutamate sensitivity of C2C12 cells was mediated by ionotropic glutamate receptors; on the other hand, most cells were responsive to cyclopiazonic acid, which inhibits the sarco-endoplasmic reticulum Ca(2+)-ATPase pump. These results suggest that C2C12 cells possess functional L- and P/Q-type voltage-operated Ca2+ channels, ryanodine receptors and functional sarcoplasmic reticulum Ca2+ stores (typical for muscle cells), adenosine and P2 purinergic receptors, as well as ionotropic glutamate receptors. The evaluation of intracellular Ca2+ signaling is a promising approach towards a better understanding and control of the physiopathological properties of myogenic cells that could be used as a predictive factor in the selection of optimal cells for scaffold recellularization or for tissue engineered constructs used in stem cell therapy.

scholarly journals Dust from hog confinement facilities impairs Ca2+ mobilization from sarco(endo)plasmic reticulum by inhibiting ryanodine receptors

2013 ◽  
Vol 114 (5) ◽  
pp. 665-674
Author(s):  
Chengju Tian ◽  
Caronda J. Moore ◽  
Puttappa Dodmane ◽  
Chun Hong Shao ◽  
Debra J. Romberger ◽  
...  
Keyword(s):  
Binding Sites ◽  
Molecular Mechanisms ◽  
Ryanodine Receptors ◽  
Cell Types ◽  
C2c12 Cells ◽  
Common Element ◽  
Plasmic Reticulum ◽  
Skeletal Muscle Weakness ◽  
Intracellular Ca ◽  
Phosphate Buffered Saline

Individuals working in commercial hog confinement facilities have elevated incidences of headaches, depression, nausea, skeletal muscle weakness, fatigue, gastrointestinal disorders, and cardiovascular diseases, and the molecular mechanisms for these nonrespiratory ailments remain incompletely undefined. A common element underlying these diverse pathophysiologies is perturbation of intracellular Ca2+ homeostasis. This study assessed whether the dust generated inside hog confinement facilities contains compounds that alter Ca2+ mobilization via ryanodine receptors (RyRs), key intracellular channels responsible for mobilizing Ca2+ from internal stores to elicit an array of physiologic functions. Hog barn dust (HBD) was extracted with phosphate-buffered saline, sterile-filtered (0.22 μm), and size-separated using Sephadex G-100 resin. Fractions (F) 1 through 9 (Mw >10,000 Da) had no measurable effects on RyR isoforms. However, F10 through F17, which contained compounds of Mw ≤2,000 Da, modulated the [3H]ryanodine binding to RyR1, RyR2, and RyR3 in a biphasic (Gaussian) manner. The Ki values for F13, the most potent fraction, were 3.8 ± 0.2 μg/ml for RyR1, 0.2 ± 0.01 μg/ml and 19.1 ± 2.8 μg/ml for RyR2 (two binding sites), and 44.9 ± 2.8 μg/ml and 501.6 ± 9.2 μg/ml for RyR3 (two binding sites). In lipid bilayer assays, F13 dose-dependently decreased the open probabilities of RyR1, RyR2, and RyR3. Pretreating differentiated mouse skeletal myotubes (C2C12 cells) with F13 blunted the amplitudes of ryanodine- and K+-induced Ca2+ transients. Because RyRs are present in many cell types, impairment in Ca2+ mobilization from internal stores via these channels is a possible mechanism by which HBD may trigger these seemingly unrelated pathophysiologies.

Olfactory Nerve Stimulation-Evoked mGluR1 Slow Potentials, Oscillations, and Calcium Signaling in Mouse Olfactory Bulb Mitral Cells

2006 ◽  
Vol 95 (5) ◽  
pp. 3097-3104 ◽  
Author(s):  
Q. Yuan ◽  
T. Knöpfel
Keyword(s):  
Glutamate Receptors ◽  
High Frequency ◽  
Metabotropic Glutamate Receptor ◽  
Olfactory Nerve ◽  
Ionotropic Glutamate Receptors ◽  
Mitral Cells ◽  
Slow Potential ◽  
Metabotropic Glutamate ◽  
Metabotropic Glutamate Receptor 1 ◽  
Intracellular Ca

Fast synaptic transmission between olfactory receptor neurons and mitral cells (MCs) is mediated through AMPA and NMDA ionotropic glutamate receptors. MCs also express high levels of metabotropic glutamate receptor 1 (mGluR1) whose functional significance is less understood. Here we characterized a slow mGluR1-mediated potential that was evoked by high-frequency (100-Hz) olfactory nerve (ON) stimulation in the presence of NBQX and d-APV, blockers of ionotropic glutamate receptors, and that was associated with a local Ca2+ transient in the MC dendritic tuft. High-frequency ON stimulation in the presence of NBQX and d-APV also evoked a slow, nearly 2-Hz oscillation of MC membrane potential that was abolished by the mGluR1 antagonist LY367385 (50 μM). Both mGluR slow potential and slow oscillation persisted in the presence of gabazine (10 μM), a GABAA receptor antagonist, and intracellular QX-314 (10 mM), a Na+ channel blocker. In contrast to a slow mGluR1 potential in cerebellar Purkinje neurons, the MC mGluR1 potential was not depressed by SKF96365 (≤250 μM) and thus is likely not mediated by TRPC1 cation channels, nor was it potentiated by an elevation of intracellular Ca2+ level. Imaging with the Na+ indicator SBFI revealed a Na+ transient in the MC dendrite accompanying the mGluR1 slow potential. We conclude that the MC mGluR1 potential triggered by glutamate released from the ON supports oscillations and synchronizations of MCs associated within one glomerulus.

Glycine agonism in ionotropic glutamate receptors

2021 ◽  
pp. 108631
Author(s):  
David Stroebel ◽  
Laetitia Mony ◽  
Pierre Paoletti
Keyword(s):  
Glutamate Receptors ◽  
Ionotropic Glutamate Receptors

scholarly journals Effect of memantine, an anti-Alzheimer’s drug, on rodent microglial cells in vitro

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Toru Murakawa-Hirachi ◽  
Yoshito Mizoguchi ◽  
Masahiro Ohgidani ◽  
Yoshinori Haraguchi ◽  
Akira Monji
Keyword(s):  
Neuronal Death ◽  
Phagocytic Activity ◽  
Microglial Cell ◽  
Cell Function ◽  
Microglial Cells ◽  
Phagocytosis Assay ◽  
Intracellular Ca ◽  
Β Amyloid ◽  
The Brain

AbstractThe pathophysiology of Alzheimer’s disease (AD) is related to neuroinflammatory responses mediated by microglia. Memantine, an antagonist of N-methyl-d-aspartate (NMDA) receptors used as an anti-Alzheimer’s drug, protects from neuronal death accompanied by suppression of proliferation and activation of microglial cells in animal models of AD. However, it remains to be tested whether memantine can directly affect microglial cell function. In this study, we examined whether pretreatment with memantine affects intracellular NO and Ca2+ mobilization using DAF-2 and Fura-2 imaging, respectively, and tested the effects of memantine on phagocytic activity by human β-Amyloid (1–42) phagocytosis assay in rodent microglial cells. Pretreatment with memantine did not affect production of NO or intracellular Ca2+ elevation induced by TNF in rodent microglial cells. Pretreatment with memantine also did not affect the mRNA expression of pro-inflammatory (TNF, IL-1β, IL-6 and CD45) or anti-inflammatory (IL-10, TGF-β and arginase) phenotypes in rodent microglial cells. In addition, pretreatment with memantine did not affect the amount of human β-Amyloid (1–42) phagocytosed by rodent microglial cells. Moreover, we observed that pretreatment with memantine did not affect 11 major proteins, which mainly function in the phagocytosis and degradation of β-Amyloid (1–42), including TREM2, DAP12 and neprilysin in rodent microglial cells. To the best of our knowledge, this is the first report to suggest that memantine does not directly modulate intracellular NO and Ca2+ mobilization or phagocytic activity in rodent microglial cells. Considering the neuroinflammation hypothesis of AD, the results might be important to understand the effect of memantine in the brain.

Preparation of domoic acid analogues using a bioconversion system, and their toxicity in mice

2021 ◽  
Author(s):  
Yukari Maeno ◽  
Yuichi Kotaki ◽  
Ryuta Terada ◽  
Masafumi Hidaka ◽  
Yuko Cho ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Chemical Synthesis ◽  
Glutamate Receptors ◽  
Domoic Acid ◽  
Ionotropic Glutamate Receptors ◽  
The Central Nervous System ◽  
Potent Agonist

Domoic acid (1, DA), a member of the natural kainoid family, is a potent agonist of ionotropic glutamate receptors in the central nervous system. The chemical synthesis of DA and...

scholarly journals NMDA and AMPA Receptor Autoantibodies in Brain Disorders: From Molecular Mechanisms to Clinical Features

Cells ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 77
Author(s):  
Fabrizio Gardoni ◽  
Jennifer Stanic ◽  
Diego Scheggia ◽  
Alberto Benussi ◽  
Barbara Borroni ◽  
...  
Keyword(s):  
Glutamate Receptors ◽  
Ampa Receptor ◽  
Molecular Mechanisms ◽  
Clinical Symptoms ◽  
In Vivo Studies ◽  
Ionotropic Glutamate Receptors ◽  
Brain Disorders ◽  
Functional Impairments ◽  
Different Types

The role of autoimmunity in central nervous system (CNS) disorders is rapidly expanding. In the last twenty years, different types of autoantibodies targeting subunits of ionotropic glutamate receptors have been found in a variety of patients affected by brain disorders. Several of these antibodies are directed against NMDA receptors (NMDAR), mostly in autoimmune encephalitis, whereas a growing field of research has identified antibodies against AMPA receptor (AMPAR) subunits in patients with different types of epilepsy or frontotemporal dementia. Several in vitro and in vivo studies performed in the last decade have dramatically improved our understanding of the molecular and functional effects induced by both NMDAR and AMPAR autoantibodies at the excitatory glutamatergic synapse and, consequently, their possible role in the onset of clinical symptoms. In particular, the method by which autoantibodies can modulate the localization at synapses of specific target subunits leading to functional impairments and behavioral alterations has been well addressed in animal studies. Overall, these preclinical studies have opened new avenues for the development of novel pharmacological treatments specifically targeting the synaptic activation of ionotropic glutamate receptors.

scholarly journals Illuminating Ionotropic Glutamate Receptors: Characterization of Fluorescent Antagonists Based on Polyamine Toxins

2013 ◽  
Vol 104 (2) ◽  
pp. 272a
Author(s):  
Christel B. Jensen ◽  
Niels G. Nørager ◽  
Anders S. Kristensen ◽  
Kristian Strømgaard
Keyword(s):  
Glutamate Receptors ◽  
Ionotropic Glutamate Receptors ◽  
Polyamine Toxins
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