scholarly journals Increase in cytosolic Ca2+ induced by elevation of extracellular Ca2+ in skeletal myogenic cells

2003 ◽  
Vol 284 (4) ◽  
pp. C969-C976 ◽  
Author(s):  
Fabio Naro ◽  
Vania De Arcangelis ◽  
Dario Coletti ◽  
Mario Molinaro ◽  
Bianca Zani ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Cell Line ◽  
Satellite Cell ◽  
Arginine Vasopressin ◽  
Inositol Phosphate ◽  
Myoblast Differentiation ◽  
Membrane Hyperpolarization ◽  
Myogenic Potential ◽  
Inositol 1,4,5 Trisphosphate ◽  
Intracellular Ca

Cytoplasmic Ca2+concentration ([Ca2+]i) variation is a key event in myoblast differentiation, but the mechanism by which it occurs is still debated. Here we show that increases of extracellular Ca2+ concentration ([Ca2+]o) produced membrane hyperpolarization and a concentration-dependent increase of [Ca2+]i due to Ca2+influx across the plasma membrane. Responses were not related to inositol phosphate turnover and Ca2+-sensing receptor. [Ca2+]o-induced [Ca2+]i increase was inhibited by Ca2+ channel inhibitors and appeared to be modulated by several kinase activities. [Ca2+]i increase was potentiated by depletion of intracellular Ca2+ stores and depressed by inactivation of the Na+/Ca2+exchanger. The response to arginine vasopressin (AVP), which induces inositol 1,4,5-trisphosphate-dependent [Ca2+]i increase in L6-C5 cells, was not modified by high [Ca2+]o. On the contrary, AVP potentiated the [Ca2+]i increase in the presence of elevated [Ca2+]o. Other clones of the L6 line as well as the rhabdomyosarcoma RD cell line and the satellite cell-derived C2-C12 line expressed similar responses to high [Ca2+]o, and the amplitude of the responses was correlated with the myogenic potential of the cells.

Modeling of Ca2+ flux in pancreatic β-cells: role of the plasma membrane and intracellular stores

2003 ◽  
Vol 285 (1) ◽  
pp. E138-E154 ◽  
Author(s):  
Leonid E. Fridlyand ◽  
Natalia Tamarina ◽  
Louis H. Philipson
Keyword(s):  
Plasma Membrane ◽  
Calcium Oscillations ◽  
Β Cells ◽  
Β Cell ◽  
Pancreatic Β Cells ◽  
Ionic Flux ◽  
Inositol 1,4,5 Trisphosphate ◽  
Intracellular Ca ◽  
Uptake And Release

We have developed a detailed mathematical model of ionic flux in β-cells that includes the most essential channels and pumps in the plasma membrane. This model is coupled to equations describing Ca2+, inositol 1,4,5-trisphosphate (IP3), ATP, and Na+ homeostasis, including the uptake and release of Ca2+ by the endoplasmic reticulum (ER). In our model, metabolically derived ATP activates inward Ca2+ flux by regulation of ATP-sensitive K+ channels and depolarization of the plasma membrane. Results from the simulations support the hypothesis that intracellular Na+ and Ca2+ in the ER can be the main variables driving both fast (2–7 osc/min) and slow intracellular Ca2+ concentration oscillations (0.3–0.9 osc/min) and that the effect of IP3 on Ca2+ leak from the ER contributes to the pattern of slow calcium oscillations. Simulations also show that filling the ER Ca2+ stores leads to faster electrical bursting and Ca2+ oscillations. Specific Ca2+ oscillations in isolated β-cell lines can also be simulated.

scholarly journals Integration of Inositol Phosphate Signaling Pathways via Human ITPK1

2007 ◽  
Vol 282 (38) ◽  
pp. 28117-28125 ◽  
Author(s):  
Philip P. Chamberlain ◽  
Xun Qian ◽  
Amanda R. Stiles ◽  
Jaiesoon Cho ◽  
David H. Jones ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Chloride Channels ◽  
Inositol Phosphates ◽  
Inositol Phosphate ◽  
Structural Features ◽  
Signaling Mechanism ◽  
Metabolic Role ◽  
Inositol 1,4,5 Trisphosphate ◽  
High Resolution Structure ◽  
Substrate Regulation

Inositol 1,3,4-trisphosphate 5/6-kinase (ITPK1) is a reversible, poly-specific inositol phosphate kinase that has been implicated as a modifier gene in cystic fibrosis. Upon activation of phospholipase C at the plasma membrane, inositol 1,4,5-trisphosphate enters the cytosol and is inter-converted by an array of kinases and phosphatases into other inositol phosphates with diverse and critical cellular activities. In mammals it has been established that inositol 1,3,4-trisphosphate, produced from inositol 1,4,5-trisphosphate, lies in a branch of the metabolic pathway that is separate from inositol 3,4,5,6-tetrakisphosphate, which inhibits plasma membrane chloride channels. We have determined the molecular mechanism for communication between these two pathways, showing that phosphate is transferred between inositol phosphates via ITPK1-bound nucleotide. Intersubstrate phosphate transfer explains how competing substrates are able to stimulate each others' catalysis by ITPK1. We further show that these features occur in the human protein, but not in plant or protozoan homologues. The high resolution structure of human ITPK1 identifies novel secondary structural features able to impart substrate selectivity and enhance nucleotide binding, thereby promoting intersubstrate phosphate transfer. Our work describes a novel mode of substrate regulation and provides insight into the enzyme evolution of a signaling mechanism from a metabolic role.

scholarly journals Thyrotropin Stimulates the Generation of Inositol 1,4,5-Trisphosphate in Human Thyroid Cells

2006 ◽  
Vol 91 (3) ◽  
pp. 1099-1107 ◽  
Author(s):  
Jacqueline Van Sande ◽  
Didier Dequanter ◽  
Philippe Lothaire ◽  
Claude Massart ◽  
Jacques E. Dumont ◽  
...  
Keyword(s):  
Phospholipase C ◽  
Cell Line ◽  
Inositol Phosphates ◽  
Inositol Phosphate ◽  
Human Cells ◽  
Human Thyroid ◽  
Fresh Tissue ◽  
Thyroid Cells ◽  
Thyroid Stimulating Antibodies ◽  
Inositol 1,4,5 Trisphosphate

Abstract Context: Dual activation by TSH of the phospholipase C and cAMP cascades has been reported in human thyroid cells. In contrast, Singh et al. reported convincing data in FRTL-5 thyrocytes arguing against such an effect in this model. Their data in FRTL-5 cells indicated no increase in inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] in response to TSH. Therefore, the authors questioned results previously obtained on human cells by cruder methodology. Objective: We investigated the formation of inositol phosphates by HPLC techniques in human thyroid slices to separate the inositol phosphate isomers. Results: Ins(1,4,5)P3, inositol 1,3,4-trisphosphate, and inositol 1,3,4,5-tetrakisphosphate were increased after TSH stimulation. The effect of TSH in human thyroid cells was reproduced by recombinant TSH and prevented by antibodies blocking the TSH receptor. Thyroid-stimulating antibodies at concentrations eliciting a cAMP response equivalent to TSH failed to stimulate inositol phosphate generation. Conclusions: TSH, but not thyroid-stimulating antibodies, activates both cAMP and the phospholipase C cascade in human thyroid as now demonstrated by an increase in Ins(1,4,5)P3 and its inositol phosphate metabolites. Therefore, this effect cannot be extrapolated to the FRTL-5 cell line. The apparent discrepancy may be due to a difference between species (human vs. rat) or to the loss of the fresh tissue properties in a cell line. The dual effect of TSH in human cells, through cAMP on secretion of thyroid hormones and through the diacylglycerol, Ins(1,4,5)P3 Ca2+ pathway on thyroid hormone synthesis, implies the possible separation of these effects in thyroid disease.

scholarly journals The store-operated Ca2+ entry complex comprises a small cluster of STIM1 associated with one Orai1 channel

2021 ◽  
Vol 118 (10) ◽  
pp. e2010789118
Author(s):  
Yihan Shen ◽  
Nagendra Babu Thillaiappan ◽  
Colin W. Taylor
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Fluorescence Intensity ◽  
Small Cluster ◽  
Store Depletion ◽  
Inositol 1,4,5 Trisphosphate ◽  
Cytosolic Domains ◽  
Intracellular Ca ◽  
The Many ◽  
Orai Channels

Increases in cytosolic Ca2+ concentration regulate diverse cellular activities and are usually evoked by opening of Ca2+ channels in intracellular Ca2+ stores and the plasma membrane (PM). For the many signals that evoke formation of inositol 1,4,5-trisphosphate (IP3), IP3 receptors coordinate the contributions of these two Ca2+ sources by mediating Ca2+ release from the endoplasmic reticulum (ER). Loss of Ca2+ from the ER then activates store-operated Ca2+ entry (SOCE) by causing dimers of STIM1 to cluster and unfurl cytosolic domains that interact with the PM Ca2+ channel, Orai1, causing its pore to open. The relative concentrations of STIM1 and Orai1 are important, but most analyses of their interactions use overexpressed proteins that perturb the stoichiometry. We tagged endogenous STIM1 with EGFP using CRISPR/Cas9. SOCE evoked by loss of ER Ca2+ was unaffected by the tag. Step-photobleaching analysis of cells with empty Ca2+ stores revealed an average of 14.5 STIM1 molecules within each sub-PM punctum. The fluorescence intensity distributions of immunostained Orai1 puncta were minimally affected by store depletion, and similar for Orai1 colocalized with STIM1 puncta or remote from them. We conclude that each native SOCE complex is likely to include only a few STIM1 dimers associated with a single Orai1 channel. Our results, demonstrating that STIM1 does not assemble clusters of interacting Orai channels, suggest mechanisms for digital regulation of SOCE by local depletion of the ER.

Effect of erythromycin on ATP-induced intracellular calcium response in A549 cells

2000 ◽  
Vol 278 (4) ◽  
pp. L726-L736 ◽  
Author(s):  
Dong-Mei Zhao ◽  
Hai-Hui Xue ◽  
Kingo Chida ◽  
Takafumi Suda ◽  
Yutaka Oki ◽  
...  
Keyword(s):  
Intracellular Calcium ◽  
Cell Line ◽  
G Protein ◽  
Extracellular Space ◽  
A549 Cells ◽  
Rt Pcr ◽  
Calcium Response ◽  
Store Depletion ◽  
Inositol 1,4,5 Trisphosphate ◽  
Intracellular Ca

ATP induced a biphasic increase in the intracellular Ca2+concentration ([Ca2+]i), an initial spike, and a subsequent plateau in A549 cells. Erythromycin (EM) suppressed the ATP-induced [Ca2+]i spike but only in the presence of extracellular calcium ([Formula: see text]). It was ineffective against ATP- and UTP-induced inositol 1,4,5-trisphosphate [Ins(1,4,5) P 3] formation and UTP-induced [Ca2+]i spike, implying that EM perturbs Ca2+ influx from the extracellular space rather than Ca2+release from intracellular Ca2+ stores via the G protein-phospholipase C-Ins(1,4,5) P 3 pathway. A verapamil-sensitive, KCl-induced increase in [Ca2+]i and the Ca2+ influx activated by Ca2+ store depletion were insensitive to EM. 3′- O-(4-benzoylbenzoyl)-ATP evoked an[Formula: see text]-dependent [Ca2+]i response even in the presence of verapamil or the absence of extracellular Na+, and this response was almost completely abolished by EM pretreatment. RT-PCR analyses revealed that P2X4 as well as P2Y2, P2Y4, and P2Y6 are coexpressed in this cell line. These results suggest that in A549 cells 1) the coexpressed P2X4 and P2Y2/P2Y4 subtypes contribute to the ATP-induced [Ca2+]i spike and 2) EM selectively inhibits Ca2+ influx through the P2X channel. This action of EM may underlie its clinical efficacy in the treatment of airway inflammation.

Transduction of arginine vasopressin signal in skeletal myogenic cells

1993 ◽  
Vol 265 (1) ◽  
pp. C113-C121 ◽  
Author(s):  
A. Teti ◽  
F. Naro ◽  
M. Molinaro ◽  
S. Adamo
Keyword(s):  
Arginine Vasopressin ◽  
Inositol Phosphate ◽  
Cell Types ◽  
Anion Transport ◽  
Myogenic Cells ◽  
Myogenic Potential ◽  
Kinase C ◽  
Inositol Phosphate Production ◽  
Protein Kinase C Inhibitor ◽  
Stimulation Of

Arginine vasopressin (AVP) induced concentration-dependent (10(-9) to 10(-6) M) stimulation of inositol phosphate production and a biphasic increment of cytosolic free Ca2+ concentration ([Ca2+]i) in skeletal myogenic cells in culture. These effects were almost completely abolished when the cells were pretreated with the AVP antagonist [deamino-Pen1,Val4,D-Arg8]-vasopressin before stimulation with AVP, thus confirming a V1 receptor-mediated effect. Inositol 1,4,5-trisphosphate production was maximally stimulated within 2-3 s of treatment with AVP, immediately followed by release of Ca2+ from intracellular deposits. Both effects were inhibited by treatment with 12-O-tetradecanoyl phorbol 13-acetate (TPA). Such effect of TPA was reversed by the protein kinase C inhibitor staurosporine. Vasopressin also regulated the intracellular pH of responsive cells with mechanisms involving both Na+ and anion transport across the plasma membrane. However, unlike in other cell types, AVP stimulated the Na(+)-H+ antiport only simultaneously with a dramatic cell acidification or after treatment with TPA. Response to AVP was observed in L6 and L5 and, to a lesser extent, in chick embryo myogenic cells, regardless of the stage of differentiation (myoblast or myotube). Comparison of different subclones of the L6 cell line demonstrated that the responsiveness to AVP correlated positively with their myogenic potential.

Calcium influx and intracellular stores in angiotensin II stimulation of normal and hyperplastic pituitary cells

1999 ◽  
Vol 277 (3) ◽  
pp. E455-E463 ◽  
Author(s):  
Arturo Gonzalez Iglesias ◽  
Graciela Diaz-Torga ◽  
Victoria Lux-Lantos ◽  
Carlos Libertun ◽  
Damasia Becu-Villalobos
Keyword(s):  
Plasma Membrane ◽  
Angiotensin Ii ◽  
Calcium Influx ◽  
Pituitary Cells ◽  
Ang Ii ◽  
Rat Pituitary ◽  
Inositol 1,4,5 Trisphosphate ◽  
Intracellular Ca ◽  
Rat Pituitary Cells ◽  
Stimulation Of

In rat pituitary cells from estrogen-induced hyperplasia, angiotensin II (ANG II) does not evoke a clear spike elevation of intracellular Ca2+concentration ([Ca2+]i) but induces a plateau increase. The present work was undertaken to establish whether this difference was related to a differential participation of intracellular and/or plasma membrane Ca2+ channels. We first tested the effect of 10 nM ANG II on [Ca2+]iin the absence of extracellular Ca2+ in cells depolarized with 25 mM K+ or in the presence of blockers of L-type voltage-sensitive Ca2+ channels (VSCC). These treatments did not alter spike elevation in [Ca2+]iin controls but reduced plateau levels in hyperplastic cells. Intracellular Ca2+ stores were similar in both groups, as assessed by thapsigargin treatment, but this drug abolished spike increase in controls and scarcely modified plateau levels in hyperplastic cells. Finally, inositol trisphosphate (InsP3) production in response to ANG II was significantly higher in control cells. We conclude that the observed plateau rise in hyperplastic cells results mainly from Ca2+ influx through VSCC. In contrast, in control cells, the ANG II-induced spike increase in [Ca2+]iresults from mobilization of Ca2+from thapsigargin-sensitive internal channels, activated by higher inositol 1,4,5-trisphosphate generation.

scholarly journals Electrophysiological engineering of heart-derived cells with calcium-dependent potassium channels improves cell therapy efficacy for cardioprotection

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Patrick Vigneault ◽  
Sandrine Parent ◽  
Pushpinder Kanda ◽  
Connor Michie ◽  
Darryl R. Davis ◽  
...  
Keyword(s):  
Cell Therapy ◽  
Therapeutic Potential ◽  
Resting Potential ◽  
Intramyocardial Injection ◽  
Membrane Hyperpolarization ◽  
Calcium Dependent ◽  
Cell Functions ◽  
Kca Channels ◽  
Therapy Effectiveness ◽  
Intracellular Ca

AbstractWe have shown that calcium-activated potassium (KCa)-channels regulate fundamental progenitor-cell functions, including proliferation, but their contribution to cell-therapy effectiveness is unknown. Here, we test the participation of KCa-channels in human heart explant-derived cell (EDC) physiology and therapeutic potential. TRAM34-sensitive KCa3.1-channels, encoded by the KCNN4 gene, are exclusively expressed in therapeutically bioactive EDC subfractions and maintain a strongly polarized resting potential; whereas therapeutically inert EDCs lack KCa3.1 channels and exhibit depolarized resting potentials. Somatic gene transfer of KCNN4 results in membrane hyperpolarization and increases intracellular [Ca2+], which boosts cell-proliferation and the production of pro-healing cytokines/nanoparticles. Intramyocardial injection of EDCs after KCNN4-gene overexpression markedly increases the salutary effects of EDCs on cardiac function, viable myocardium and peri-infarct neovascularization in a well-established murine model of ischemic cardiomyopathy. Thus, electrophysiological engineering provides a potentially valuable strategy to improve the therapeutic value of progenitor cells for cardioprotection and possibly other indications.

Sign in / Sign up

Export Citation Format

Share Document