Teaching the modes of Ca2+ transport between the plasma membrane and endoplasmic reticulum using a classic paper by Kwan et al.

2009 ◽  
Vol 33 (3) ◽  
pp. 169-174 ◽  
Author(s):  
Willmann Liang
Keyword(s):  
Endoplasmic Reticulum ◽  
Teaching And Learning ◽  
Inhibitory Effects ◽  
New Graduate ◽  
Intracellular Ca ◽  
Upper Level ◽  
Lacrimal Acinar Cells ◽  
Learning Points ◽  
Classic Paper

This teaching article uses the report by Kwan et al., “Effects of methacholine, thapsigargin, and La3+ on plasmalemmal and intracellular Ca2+ transport in lacrimal acinar cells,” where the effects of Ca2+-mobilizing agents in regulating Ca2+ fluxes were examined under various conditions. Upper-level undergraduate and new graduate students in physiology are the targe audience. Teaching and learning points are put forth in this article to illustrate 1) the characteristics of methacholine- and thapsigargin-induced Ca2+ responses, 2) the different endoplasmic reticulum Ca2+ stores accessible to methacholine and thapsigargin, 3) the inhibitory effects of La3+ on Ca2+ extrusion and Ca2+ influx, and 4) the facilitatory role of La3+ on endoplasmic reticulum Ca2+ recycling. Each of the above concepts is first explained with references to the figures adapted from the original article. A list of student learning questions then follows, where the answers are found in the teaching notes for the instructors. It is the objective of this article to make both teaching and learning Ca2+ regulation a rewarding experience for all.

Discovering the mechanism of capacitative calcium entry

2006 ◽  
Vol 291 (6) ◽  
pp. C1104-C1106 ◽  
Author(s):  
Juan A. Rosado
Keyword(s):  
Acinar Cells ◽  
Calcium Entry ◽  
Capacitative Calcium Entry ◽  
Historical Significance ◽  
Intracellular Ca ◽  
Lacrimal Acinar Cells ◽  
Classic Paper

This essay examines the historical significance of an APS classic paper that is freely available online: Kwan CY, Takemura H, Obie JF, Thastrup O, and Putney JW Jr. Effects of MeCh, thapsigargin, and La3+ on plasmalemmal and intracellular Ca2+ transport in lacrimal acinar cells. Am J Physiol Cell Physiol 258: C1006–C1015, 1990. ( http://ajpcell.physiology.org/cgi/reprint/258/6/C1006 )

Activation of Phosphatidylinositol-Linked Novel D1 Dopamine Receptors Inhibits High-Voltage-Activated Ca2+ Currents in Primary Cultured Striatal Neurons

2009 ◽  
Vol 101 (5) ◽  
pp. 2230-2238 ◽  
Author(s):  
Li-Qun Ma ◽  
Chao Liu ◽  
Fang Wang ◽  
Na Xie ◽  
Jun Gu ◽  
...  
Keyword(s):  
Dopamine Receptor ◽  
High Voltage ◽  
Dependent Manner ◽  
Striatal Neurons ◽  
Inhibitory Effects ◽  
Patch Clamp Technique ◽  
Whole Cell Patch Clamp ◽  
Intracellular Ca ◽  
Dose Dependent

Recent evidences indicate the existence of a putative novel phosphatidylinositol (PI)-linked D1 dopamine receptor that mediates excellent anti-Parkinsonian but less severe dyskinesia action. To further understand the basic physiological function of this receptor in brain, the effects of a PI-linked D1 dopamine receptor-selective agonist 6-chloro-7,8-dihydroxy-3-methyl-1-(3-methylphenyl)-2,3,4,5-tetrahydro-1H-3-benzazepine (SKF83959) on high-voltage activated (HVA) Ca2+ currents in primary cultured striatal neurons were investigated by whole cell patch-clamp technique. The results indicated that stimulation by SKF83959 induced an inhibition of HVA Ca2+ currents in a dose-dependent manner in substance-P (SP)-immunoreactive striatal neurons. Application of D1 receptor, but not D2, α1 adrenergic, 5-HT receptor, or cholinoceptor antagonist prevented SKF83959-induced reduction, indicating that a D1 receptor-mediated event assumed via PI-linked D1 receptor. SKF83959-induced inhibitory modulation was mediated by activation of phospholipase C (PLC), mobilization of intracellular Ca2+ stores and activation of calcineurin. Furthermore, the inhibitory effects were attenuated significantly by the L-type calcium channel antagonist nifedipine, suggesting that L-type calcium channels involved in the regulation induced by SKF83959. These findings may help to further understand the functional role of the PI-linked dopamine receptor in brain.

Possible role of calcium in parathyroid hormone actions in rabbit renal proximal tubules

1986 ◽  
Vol 250 (5) ◽  
pp. F942-F948
Author(s):  
N. Yanagawa ◽  
O. D. Jo
Keyword(s):  
Parathyroid Hormone ◽  
Proximal Tubules ◽  
Inhibitory Effects ◽  
Renal Proximal Tubules ◽  
Intracellular Ca ◽  
Altered Response ◽  
Isolated Renal Tubule ◽  
Convoluted Tubules

Using a glucose microassay and in vitro isolated renal tubule perfusion technique, we have studied the actions of parathyroid hormone (PTH) on gluconeogenesis (GNG) and fluid (Jv) and phosphate (Jp) transport rates in isolated rabbit renal proximal tubules. In proximal straight tubules (PST), PTH stimulated GNG and inhibited Jv and Jp. In proximal convoluted tubules (PCT), PTH inhibited Jv but failed to affect GNG and Jp. An increase in Ca concentration, however, stimulated GNG and allowed PTH to inhibit Jp in PCT. Addition of the intracellular Ca antagonists trifluoperazine and N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7) abolished the inhibitory effects of PTH on Jv and Jp in both PCT and PST. In conclusion, these studies suggest that Ca-dependent intracellular pathways may be involved in the actions of PTH in rabbit renal proximal tubules. The altered response to PTH in rabbit PCT may be due to alterations in the response of intracellular Ca to the hormone.

Cancer cells with defective oxidative phosphorylation require endoplasmic reticulum–to–mitochondria Ca2+ transfer for survival

2020 ◽  
Vol 13 (640) ◽  
pp. eaay1212 ◽  
Author(s):  
Cesar Cardenas ◽  
Alenka Lovy ◽  
Eduardo Silva-Pavez ◽  
Felix Urra ◽  
Craig Mizzoni ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Oxidative Phosphorylation ◽  
Cancer Cells ◽  
Autophagic Flux ◽  
Release Channel ◽  
Atp Production ◽  
Fusion Inhibition ◽  
Intracellular Ca ◽  
Reductive Carboxylation

Spontaneous Ca2+ signaling from the InsP3R intracellular Ca2+ release channel to mitochondria is essential for optimal oxidative phosphorylation (OXPHOS) and ATP production. In cells with defective OXPHOS, reductive carboxylation replaces oxidative metabolism to maintain amounts of reducing equivalents and metabolic precursors. To investigate the role of mitochondrial Ca2+ uptake in regulating bioenergetics in these cells, we used OXPHOS-competent and OXPHOS-defective cells. Inhibition of InsP3R activity or mitochondrial Ca2+ uptake increased α-ketoglutarate (αKG) abundance and the NAD+/NADH ratio, indicating that constitutive endoplasmic reticulum (ER)–to–mitochondria Ca2+ transfer promoted optimal αKG dehydrogenase (αKGDH) activity. Reducing mitochondrial Ca2+ inhibited αKGDH activity and increased NAD+, which induced SIRT1-dependent autophagy in both OXPHOS-competent and OXPHOS-defective cells. Whereas autophagic flux in OXPHOS-competent cells promoted cell survival, it was impaired in OXPHOS-defective cells because of inhibition of autophagosome-lysosome fusion. Inhibition of αKGDH and impaired autophagic flux in OXPHOS-defective cells resulted in pronounced cell death in response to interruption of constitutive flux of Ca2+ from ER to mitochondria. These results demonstrate that mitochondria play a fundamental role in maintaining bioenergetic homeostasis of both OXPHOS-competent and OXPHOS-defective cells, with Ca2+ regulation of αKGDH activity playing a pivotal role. Inhibition of ER-to-mitochondria Ca2+ transfer may represent a general therapeutic strategy against cancer cells regardless of their OXPHOS status.

Involvement of intracellular Ca2+ stores in inhibitory effects of NO donor SIN-1 and cGMP

1998 ◽  
Vol 275 (1) ◽  
pp. G159-G168
Author(s):  
Hartmut Franck ◽  
Martin Storr ◽  
Andreas Puschmann ◽  
Volker Schusdziarra ◽  
Hans-Dieter Allescher
Keyword(s):  
Response Curve ◽  
Cyclopiazonic Acid ◽  
Inhibitory Effect ◽  
Repetitive Stimulation ◽  
Bay K 8644 ◽  
Inhibitory Effects ◽  
No Donor ◽  
Intracellular Ca ◽  
The Right

We investigated the role of K+ channels and intracellular Ca2+ stores in the relaxations induced by the NO donor 3-morpholinosydnonimine (SIN-1) and 8-bromo-cGMP (8-BrcGMP), 8-(4-chlorophenylthio)-cGMP (pCPT-cGMP), and α,β-methylene-ATP in isolated segments of rat ileum. The inhibitory responses to SIN-1 and the cGMP analogs were not influenced by the K+ blockers apamin, charybdotoxin, iberiotoxin, or glibenclamide, whereas relaxations induced by α,β-methylene-ATP were abolished by apamin and tetraethylammonium. The NO-donor SIN-1 and the cGMP analogs were able to inhibit contractions induced by activation of L-type Ca2+ channels (BAY-K-8644), by carbachol (CCh), and by cyclopiazonic acid (CPA), a blocker of sarcoplasmic Ca2+-ATPase. However, the inhibition of the combined CPA and CCh response was reduced and the dose-response curve of SIN-1 shifted to the right. Intracellular Ca2+ stores were emptied by incubation in Ca2+-free buffer and repetitive stimulation with CCh or BAY-K-8644. After restoration of extracellular Ca2+, the inhibitory effect of SIN-1 and pCPT-cGMP was only attenuated, whereas in the additional presence of CPA, the inhibitory effect of SIN-1 was blocked and the effect of 8-BrcGMP reduced. Thus depleting intracellular Ca2+ stores attenuated the effect of SIN-1 and 8-BrcGMP, suggesting an involvement of functional Ca2+ stores.

Localization of Intracisternal a Particle Antigens in Neoplastic Cells and Preimplantation Mouse Embryos

1980 ◽  
Vol 38 ◽  
pp. 696-697
Author(s):  
Thomas T.F. Huang ◽  
Patricia G. Calarco
Keyword(s):  
Endoplasmic Reticulum ◽  
Normal Development ◽  
Mouse Embryos ◽  
Neoplastic Cells ◽  
Large Numbers ◽  
Preimplantation Mouse Embryos ◽  
Preimplantation Mouse ◽  
Intracisternal A Particle ◽  
Normal Feature

The stage specific appearance of a retravirus, termed the Intracisternal A particle (IAP) is a normal feature of early preimplantation development. To date, all feral and laboratory strains of Mus musculus and even Asian species such as Mus cervicolor and Mus pahari express the particles during the 2-8 cell stages. IAP form by budding into the endoplasmic reticulum and appear singly or as groups of donut-shaped particles within the cisternae (fig. 1). IAP are also produced in large numbers in several neoplastic cells such as certain plasmacytomas and rhabdomyosarcomas. The role of IAP, either in normal development or in neoplastic behavior, is unknown.

Alignment

2016 ◽  
pp. 33-50
Author(s):  
Pier Giuseppe Rossi
Keyword(s):  
Teaching And Learning ◽  
Enactive Approach ◽  
The World ◽  
Strategic Role ◽  
Education Today ◽  
Current Context ◽  
The Subject

The subject of alignment is not new to the world of education. Today however, it has come to mean different things and to have a heuristic value in education according to research in different areas, not least for neuroscience, and to attention to skills and to the alternation framework.This paper, after looking at the classic references that already attributed an important role to alignment in education processes, looks at the strategic role of alignment in the current context, outlining the shared construction processes and focusing on some of the ways in which this is put into effect.Alignment is part of a participatory, enactive approach that gives a central role to the interaction between teaching and learning, avoiding the limits of behaviourism, which has a greater bias towards teaching, and cognitivism/constructivism, which focus their attention on learning and in any case, on that which separates a teacher preparing the environment and a student working in it.

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