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001-es BibID:	BIBFORM057717
Első szerző:	González Rodríguez, Estela
Cím:	Phosphoinositide substrates of myotubularin affect voltage-activated Ca2+ release in skeletal muscle / Estela González Rodríguez, Romain Lefebvre, Dóra Bodnár, Claude Legrand, Peter Szentesi, János Vincze, Karine Poulard, Justine Bertrand-Michel, Laszlo Csernoch, Anna Buj-Bello, Vincent Jacquemond
Dátum:	2014
ISSN:	0031-6768
Megjegyzések:	Skeletal muscle excitation?contraction (E?C) couplingis altered in several models of phosphatidylinositol phosphate(PtdInsP) phosphatase deficiency and ryanodine receptoractivity measured in vitro was reported to be affected by certainPtdInsPs, thus prompting investigation of the physiologicalrole of PtdInsPs in E?C coupling. We measured intracellularCa2+ transients in voltage-clamped mouse muscle fibresmicroinjected with a solution containing a PtdInsP substrate(PtdIns(3,5)P2 or PtdIns(3)P) or product (PtdIns(5)P orPtdIns) of the myotubularin phosphatase MTM1. No significantchange was observed in the presence of either PtdIns(5)Por PtdIns but peak SR Ca2+ release was depressed by ~30%and50% in fibres injected with PtdIns(3,5)P2 and PtdIns(3)P,respectively, with no concurrent alteration in the membranecurrent signals associated with the DHPR function as well asin the voltage dependence of Ca2+ release inactivation. Inpermeabilized muscle fibres, the frequency of spontaneousCa2+ release events was depressed in the presence of the threetested phosphorylated forms of PtdInsP with PtdIns(3,5)P2being the most effective, leading to an almost complete disappearanceof Ca2+ release events. Results support the possibilitythat pathological accumulation of MTM1 substrates mayacutely depress ryanodine receptor-mediated Ca2+ release.Overexpression of a mCherry-tagged form of MTM1 in musclefibres revealed a striated pattern consistent with the triadicarea. Ca2+ release remained although unaffected by MTM1overexpression and was also unaffected by the PtdIns-3-kinaseinhibitor LY2940002, suggesting that the 3-phosphorylatedPtdIns lipids active on voltage-activated Ca2+ release are inherentlymaintained at a low level, inefficient on Ca2+ releasein normal conditions.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban Calcium homeostasis Excitation-contraction coupling Ryanodine receptor Sarcoplasmic reticulum Ca2+ release Phosphatidylinositol phosphate
Megjelenés:	Pflugers Archiv-European Journal Of Physiology. - 466 : 5 (2014), p. 973-985. -
További szerzők:	Lefebvre, Romain Bodnár Dóra (1987-) (molekuláris biológus) Legrand, Claude Szentesi Péter (1967-) (élettanász) Vincze János (1988-) (orvos) Poulard, Karine Bertrand-Michel, Justine Csernoch László (1961-) (élettanász) Buj-Bello, Anna Jacquemond, Vincent
Pályázati támogatás:	OTKA-K107765 OTKA
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001-es BibID:	BIBFORM078604
035-os BibID:	(WOS)000469204700012 (Scopus)85064219867
Első szerző:	Kutchukian, Candice
Cím:	Ca2+-induced sarcoplasmic reticulum Ca2+ release in myotubularin-deficient muscle fibers / Candice Kutchukian, Peter Szentesi, Bruno Allard, Anna Buj-Bello, Laszlo Csernoch, Vincent Jacquemond
Dátum:	2019
ISSN:	0143-4160
Megjegyzések:	Skeletal muscle deficiency in the 3-phosphoinositide (PtdInsP) phosphatase myotubularin (MTM1) causes myotubular myopathy which is associated with severe depression of voltage-activated sarcoplasmic reticulum Ca2+ release through ryanodine receptors. In the present study we aimed at further understanding how Ca2+ release is altered in MTM1-deficient muscle fibers, at rest and during activation. While in wild-type muscle fibers, SR Ca2+ release exhibits fast stereotyped kinetics of activation and decay throughout the voltage range of activation, Ca2+ release in MTM1-deficient muscle fibers exhibits slow and unconventional kinetics at intermediate voltages, suggestive of partial loss of the normal control of ryanodine receptor Ca2+ channel activity. In addition, the diseased muscle fibers at rest exhibit spontaneous elementary Ca2+ release events at a frequency 30 times greater than that of control fibers. Eighty percent of the events have spatiotemporal properties of archetypal Ca2+ sparks while the rest take either the form of lower amplitude, longer duration Ca2+ release events or of a combination thereof. The events occur at preferred locations in the fibers, indicating spatially uneven distribution of the parameters determining spontaneous ryanodine receptor 1 opening. Spatially large Ca2+ release sources were obviously involved in some of these events, suggesting that opening of ryanodine receptors in one cluster can activate opening of ryanodine receptors in a neighboring one. Overall results demonstrate that opening of Ca2+-activated ryanodine receptors is promoted both at rest and during excitation-contraction coupling in MTM1-deficient muscle fibers. Because access to this activation mode is denied to ryanodine receptors in healthy skeletal muscle, this may play an important role in the associated disease situation.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk Skeletal muscle Ryanodine receptor Sarcoplasmic reticulum Ca2+ release Myotubular myopathy
Megjelenés:	Cell Calcium. - 80 (2019), p. 91-100. -
További szerzők:	Szentesi Péter (1967-) (élettanász) Allard, Bruno Buj-Bello, Anna Csernoch László (1961-) (élettanász) Jacquemond, Vincent
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001-es BibID:	BIBFORM106457
035-os BibID:	(scopus)85144071015 (wos)000895116500001
Első szerző:	Szentesi Péter (élettanász)
Cím:	Disrupted T-tubular network accounts for asynchronous calcium release in MTM1-deficient skeletal muscle / Szentesi Peter, Dienes Beatrix, Kutchukian Candice, Czirjak Tamas, Buj-Bello Anna, Jacquemond Vincent, Csernoch László
Dátum:	2023
ISSN:	0022-3751 1469-7793
Megjegyzések:	In mammalian skeletal muscle, the propagation of surface membrane depolarization into the interior of the muscle fibre along the transverse (T) tubular network is essential for the synchronized release of calcium from the sarcoplasmic reticulum (SR) via ryanodine receptors (RyRs) in response to the conformational change in the voltage-sensor dihydropyridine receptors. Deficiency in 3-phosphoinositide phosphatase myotubularin (MTM1) has been reported to disrupt T-tubules, resulting in impaired SR calcium release. Here confocal calcium transients recorded in muscle fibres of MTM1-deficient mice were compared with the results from a model where propagation of the depolarization along the T-tubules was modelled mathematically with disruptions in the network assumed to modify the access and transmembrane resistance as well as the capacitance. If, in simulations, T-tubules were assumed to be partially or completely inaccessible to the depolarization and RyRs at these points to be prime for calcium-induced calcium release, all the features of measured SR calcium release could be reproduced. We conclude that the inappropriate propagation of the depolarization into the fibre interior is the initial critical cause of severely impaired SR calcium release in MTM1 deficiency, while the Ca2+-triggered opening of RyRs provides an alleviating support to the diseased process.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk calcium release ryanodine receptor sarcoplasmic reticulum MTM1 T-tubule
Megjelenés:	Journal Of Physiology-London. - 601 : 1 (2023), p. 99-121. -
További szerzők:	Dienes Beatrix (1972-) (élettanász, molekuláris biológus) Kutchukian, Candice Czirják Tamás Buj-Bello, Anna Jacquemond, Vincent Csernoch László (1961-) (élettanász)
Pályázati támogatás:	NKFIH K_137600 Egyéb TKP2020-NKA-04 Egyéb 2020?4.1.1-TKP2020 Egyéb
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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