scholarly journals 80K-H Interacts with Inositol 1,4,5-Trisphosphate (IP3) Receptors and Regulates IP3-induced Calcium Release Activity

2008 ◽  
Vol 284 (1) ◽  
pp. 372-380 ◽  
Author(s):  
Katsuhiro Kawaai ◽  
Chihiro Hisatsune ◽  
Yukiko Kuroda ◽  
Akihiro Mizutani ◽  
Tomoko Tashiro ◽  
...  
1997 ◽  
Vol 272 (1) ◽  
pp. L1-L7 ◽  
Author(s):  
M. S. Kannan ◽  
Y. S. Prakash ◽  
D. E. Johnson ◽  
G. C. Sieck

In the present study, effects of the nitric oxide donor, S-nitroso-N-acetylpenicillamine (SNAP), on sarcoplasmic reticulum (SR) Ca2+ release were examined in freshly dissociated porcine tracheal smooth muscle (TSM) cells. Fura 2-loaded TSM cells were imaged using video fluorescence microscopy. SR Ca2+ release was induced by acetylcholine (ACh), which acts principally through inositol 1,4,5-trisphosphate (IP3) receptors, and by caffeine, which acts principally through ryanodine receptors (RyR). SNAP inhibited ACh-induced SR Ca2+ release at both 0 and 2.5 mM extracellular Ca2+. Degraded SNAP had no effect on ACh-induced SR Ca2+ release. SNAP also inhibited caffeine-induced SR Ca2+ release. ACh-induced Ca2+ influx was not affected by SNAP when SR reloading was blocked by thapsigargin. SNAP also did not affect SR Ca2+ reuptake. The membrane-permeant analogue of guanosine 3',5'-cyclic monophosphate (cGMP), 8-bromo-cGMP, mimicked the effects of SNAP. These results suggest that, in porcine TSM cells, SNAP reduces the intracellular Ca2+ response to ACh and caffeine by inhibiting SR Ca2+ release through both IP3 and RyR, but not by inhibiting influx or repletion of the SR Ca2+ stores. These effects are likely mediated via cGMP-dependent mechanisms.


2009 ◽  
Vol 297 (5) ◽  
pp. C1133-C1145 ◽  
Author(s):  
Ludivine Mondin ◽  
Haouaria Balghi ◽  
Bruno Constantin ◽  
Christian Cognard ◽  
Stéphane Sebille

Evidence for a modulatory effect of cyclosporin A (CsA) on calcium signaling and cell survival in dystrophin-deficient cells is presented. Our previous works strongly supported the hypothesis of an overactivation of Ca2+ release via inositol 1,4,5-trisphosphate (IP3) receptors (IP3R) in dystrophin-deficient cells, both during membrane depolarization and at rest, through spontaneous Ca2+ release events. Forced expression of mini-dystrophin in these cells contributed, during stimulation and in resting condition, to the recovery of a controlled calcium homeostasis. In the present work, we demonstrate that CsA exposure displayed a dual-modulator effect on calcium signaling in dystrophin-deficient cells. Short-time incubation induced a decrease of IP3-dependent calcium release, leading to patterns of release similar to those observed in myotubes expressing mini-dystrophin, whereas long-time incubation reduced the expression of the type I of IP3 receptors (IP3R-1) RNA levels. Moreover, both IP3R-1 knockdown and blockade through 2-aminoethoxydiphenyle borate or CsA induced improved survival of dystrophin-deficient myotubes, demonstrating the cell death dependence on the IP3-dependent calcium signaling as well as the protective effect of CsA. Inhibition of the IP3 pathway could be a very interesting approach for reducing the natural cell death of dystrophin-deficient cells in development.


2008 ◽  
Vol 108 (2) ◽  
pp. 251-260 ◽  
Author(s):  
Huafeng Wei ◽  
Ge Liang ◽  
Hui Yang ◽  
Qiujun Wang ◽  
Brian Hawkins ◽  
...  

Background Isoflurane induces cell apoptosis by an unknown mechanism. The authors hypothesized that isoflurane activates inositol 1,4,5-trisphosphate (IP3) receptors on the endoplasmic reticulum (ER) membrane, causing excessive calcium release, triggering apoptosis. Methods The authors determined isoflurane-induced cytotoxicity by measuring caspase-3 activity, lactate dehydrogenase release, MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt) reduction, and imaging analysis of cell damage markers (annexin V and propidium iodide staining) in different cell types. The authors used the chicken B lymphocyte with a total knock-out of IP3 receptors, PC12 cells with elevated IP3 receptor activity (transfected with L286V presenilin 1), striatal cells with a knock-in of Q111 Huntingtin, and each cell line's corresponding wild-type controls. The authors also measured the isoflurane-evoked changes of calcium concentration in cytosol and/or mitochondria in these cells. Results Isoflurane induced apoptosis concentration- and time-dependently, and sequentially elevated cytosolic and then mitochondrial calcium in the chicken B-lymphocyte wild-type but not the IP3 receptor total knock-out cells. Thapsigargin, a calcium adenosine triphosphatase inhibitor on ER membranes, induced apoptosis and elevations of calcium in cytosol and mitochondria in both chicken B-lymphocyte wild-type and IP3 receptor total knock-out cells. Isoflurane induced significantly more neurotoxicity and greater calcium release from the ER in L286V PC12 and Q111 Huntingtin striatal cells than in their corresponding wild-type controls, both of which were significantly inhibited by the IP3 receptor antagonist xestospongin C. Conclusion These findings suggest that isoflurane activates the ER membrane IP3 receptor, producing excessive calcium release and triggering apoptosis. Neurons with enhanced IP3 receptor activity, as in certain cases of familial Alzheimer or Huntington disease, may be especially vulnerable to isoflurane cytotoxicity.


1989 ◽  
Vol 262 (1) ◽  
pp. 83-89 ◽  
Author(s):  
K J Föhr ◽  
J Scott ◽  
G Ahnert-Hilger ◽  
M Gratzl

The inositol 1,4,5-trisphosphate (IP3)-sensitive Ca2+ compartment of endocrine cells was studied with alpha-toxin- and digitonin-permeabilized rat insulinoma (RINA2) and rat pheochromocytoma (PC12) cells. The Ca2+ uptake was ATP-dependent, and submicromolar concentrations of IP3 specifically released the stored Ca2+. Half-maximal Ca2+ release was observed with 0.25-0.5 mumol of IP3/l, and the amount of Ca2+ released due to IP3 could be enhanced by additional loading of the Ca2+ compartment. Consecutive additions of the same concentration of IP3 for 1-2 h always released the same amount of Ca2+ without desensitization, providing an ideal basis to further characterize the IP3-induced Ca2+ release. Here we describe for the first time a reversible inhibitory effect of decavanadate on the IP3-induced Ca2+ release. Among the vanadium species tested (decavanadate, oligovanadate and monovanadate), only decavanadate was inhibitory, with a half-maximal effect at 5 mumol/l in both cell types. The effect of decavanadate could be overcome by increasing the amount of sequestered Ca2+ or added IP3. Decavanadate did not affect the ATP-driven Ca2+ uptake but oligovanadate was inhibitory on Ca2+ uptake. p-Hydroxymercuribenzoate (pHMB) at concentrations between 10 and 30 mumol/l also inhibited the Ca2+ release due to IP3. Thiol compounds such as dithiothreitol (DTT; 1 mmol/l) added before pHMB removed all its inhibitory effect on the IP3-induced Ca2+ release, whereas the inhibition caused by decavanadate was unaffected by DTT. Thus, the decavanadate-dependent inhibition functions by a distinctly different mechanism than pHMB and could serve as a specific tool to analyse various aspects of the IP3-induced Ca2+ release within endocrine cells.


1999 ◽  
Vol 276 (5) ◽  
pp. C1115-C1120 ◽  
Author(s):  
Karl Dreja ◽  
Per Hellstrand

To investigate the Ca2+-dependent plasticity of sarcoplasmic reticulum (SR) function in vascular smooth muscle, transient responses to agents releasing intracellular Ca2+ by either ryanodine (caffeine) ord- myo-inositol 1,4,5-trisphosphate [IP3; produced in response to norepinephrine (NE), 5-hydroxytryptamine (5-HT), arginine vasopressin (AVP)] receptors in rat tail arterial rings were evaluated after 4 days of organ culture. Force transients induced by all agents were increased compared with those induced in fresh rings. Stimulation by 10% FCS during culture further potentiated the force and Ca2+ responses to caffeine (20 mM) but not to NE (10 μM), 5-HT (10 μM), or AVP (0.1 μM). The effect was persistent, and SR capacity was not altered after reversible depletion of stores with cyclopiazonic acid. The effects of serum could be mimicked by culture in depolarizing medium (30 mM K+) and blocked by the addition of verapamil (1 μM) or EGTA (1 mM) to the medium, lowering intracellular Ca2+ concentration ([Ca2+]i) during culture. These results show that modulation of SR function can occur in vitro by a mechanism dependent on long-term levels of basal [Ca2+]iand involving ryanodine- but not IP3 receptor-mediated Ca2+release.


1997 ◽  
Vol 325 (3) ◽  
pp. 661-666 ◽  
Author(s):  
Ludwig MISSIAEN ◽  
Jan B. PARYS ◽  
Humbert DE SMEDT ◽  
Ilse SIENAERT ◽  
Henk SIPMA ◽  
...  

The effects of a whole series of adenine nucleotides on Ins(1,4,5)P3-induced Ca2+ release were characterized in permeabilized A7r5 smooth-muscle cells. Several adenine nucleotides activated the Ins(1,4,5)P3 receptor. It was observed that 3′-phosphoadenosine 5′-phosphosulphate, CoA, di(adenosine-5′)tetraphosphate (Ap4A) and di(adenosine-5′)pentaphosphate (Ap5A) were more effective than ATP. Ap4A and Ap5A also interacted with a lower EC50 than ATP. In order to find out how these adenine nucleotides affected Ins(1,4,5)P3-induced Ca2+ release, we have measured their effect on the response of permeabilized A7r5 cells to a progressively increasing Ins(1,4,5)P3 concentration. Stimulatory ATP and Ap5A concentrations had no effect on the threshold Ins(1,4,5)P3 concentration for initiating Ca2+ release, but they stimulated Ca2+ release in the presence of supra-threshold Ins(1,4,5)P3 concentrations by increasing the co-operativity of the release process. Inhibition of the Ins(1,4,5)P3-induced Ca2+ release at higher ATP concentrations was associated with a further increase in co-operativity and also with a shift in threshold towards higher Ins(1,4,5)P3 concentrations. ATP had no effect on the non-specific Ca2+ leak in the absence of Ins(1,4,5)P3. We conclude that the adenine-nucleotide-binding site can be activated by many different adenine nucleotides. Binding of these compounds to the transducing domain of the Ins(1,4,5)P3 receptor increases the efficiency of transmitting Ins(1,4,5)P3 binding to channel opening. The inhibition by high ATP concentrations is exerted at a different site, related to Ins(1,4,5)P3 binding.


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