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ABSTRACT: It has recently been hypothesized that a sub-lethal ischemic insult induced in one organ is able to protect from a harmful ischemia occurring in a different organ. Objective of this study is to identify new putative mechanisms of neuroprotection elicited by remote ischemic femoral postconditioning. A 50% reduction in the infarct volume was observed when 100 minutes of middle cerebral artery occlusion were followed,10 minutes later, by the remote postconditioning stimulus represented by 20 minutes of femoral artery occlusion. The use of in vivo silencing strategy allowed to demonstrate that NO production through nNOS mediates part of the neuroprotection. Indeed, whereas CNS nNOS expression was up-regulated by remote postconditioning, the pharmacological inhibition of nNOS or its silencing-mediated knocking-down partially prevented this neuroprotective effect. This nNOS overexpression seemed to be p-ERK dependent. In fact, p-ERK expression increased in brain cortex after remote postconditioning, and its pharmacological inhibition prevented both nNOS overexpression and remote postconditioning-mediated neuroprotection. Interestingly, neuroprotection induced by remote postconditioning was partially prevented when ganglion transmission was pharmacologically interrupted by hexamethonium, thus showing that neural factors are involved in this phenomenon. Collectively, the present study demonstrates that p-ERK and nNOS take part to the complex cascade of events triggered by ischemic remote postconditioning.
Neurobiology of Disease 02/2013; · 5.40 Impact Factor
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Pasquale Molinaro,
Mauro Cataldi, Ornella Cuomo,
Davide Viggiano,
Giuseppe Pignataro,
Rossana Sirabella,
Agnese Secondo,
Francesca Boscia,
Anna Pannaccione,
Antonella Scorziello,
Sophie Sokolow,
André Herchuelz,
Gianfranco Di Renzo,
Lucio Annunziato
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ABSTRACT: Because no isoform-specific blocker of NCX has ever been synthesized, a more selective strategy to identify the role of each antiporter isoform in the brain was represented by the generation of knockout and knockin mice for the different isoforms of the antiporter.Experiments performed in NCX2 and NCX3 knockout mice provided evidence that these two isoforms participate in spatial learning and memory consolidation, although in an opposite manner. These new data from ncx2-/- and ncx3-/- mice may open new experimental avenues for the development of effective therapeutic compounds that, by selectively inhibiting or activating these molecular targets, could treat patients affected by cognitive impairment including Alzheimer's, Parkinson's, Huntington's diseases, and infarct dementia.More importantly, knockout and knockin mice also provided new relevant information on the role played by NCX in maintaining the intracellular Na(+) and Ca(2+) homeostasis and in protecting neurons during brain ischemia. In particular, both ncx2-/- and ncx3-/- mice showed an increased neuronal vulnerability after the ischemic insult induced by transient middle cerebral artery occlusion.As the ubiquitous deletion of NCX1 brings about to an early death of embryos because of a lack of heartbeat, this strategy could not be successfully pursued. However, information on the role of NCX1 in normal and ischemic brain could be obtained by developing conditional knockout mice lacking NCX1 in the brain. Preliminarily results obtained in these conditional mice suggest that also NCX1 protects neurons from ischemic cell death.Overall, the use of genetic-modified mice for NCX1, NCX2, and NCX3 represents a fruitful strategy to characterize the physiological role exerted by NCX in CNS and to identify the isoforms of the antiporter as potential molecular targets for therapeutic intervention in cerebral ischemia.
Advances in experimental medicine and biology 01/2013; 961:213-22. · 1.09 Impact Factor
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ABSTRACT: Ischemic preconditioning is a neuroprotective mechanism in which a brief non-injurious episode of ischemia protects the brain from a subsequent lethal insult. Recently, it has been reported that modified reperfusion subsequent to a prolonged ischemic episode may also confer neuroprotection, a phenomenon termed postconditioning. Mitogen-activated protein kinases (MAPK) play a key role in these two neuroprotective mechanisms. The aim of this study was to evaluate whether Na(+)/Ca(2+) exchangers (NCXs), a family of ionic transporters that contribute to the maintenance of intracellular ionic homeostasis, contribute to the neuroprotection elicited by ischemic preconditioning and postconditioning.Results of this study indicated that (1) NCX1 and NCX3 are upregulated in those brain regions protected by preconditioning, while (2) postconditioning treatment induces an upregulation only in NCX3 expression. (3) NCX1 upregulation and NCX3 upregulation are mediated by p-AKT since its inhibition reverted the neuroprotective effect of preconditioning and postconditioning and prevented NCXs overexpression. (4) The involvement of NCX in preconditioning and postconditioning neuroprotection is further supported by the results of experiments showing that a partial reversion of the protective effect induced by preconditioning was obtained by silencing NCX1 or NCX3, while the silencing of NCX3 was able to mitigate the protection induced by ischemic postconditioning.Altogether, the data presented here suggest that NCX1 and NCX3 -represent two promising druggable targets for setting on new strategies in stroke therapy.
Advances in experimental medicine and biology 01/2013; 961:223-40. · 1.09 Impact Factor
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Pasquale Molinaro,
Maria Cantile, Ornella Cuomo,
Agnese Secondo,
Anna Pannaccione,
Paolo Ambrosino,
Giuseppe Pignataro,
Ferdinando Fiorino,
Beatrice Severino,
Elena Gatta,
Maria Jose Sisalli,
Marco Milanese,
Antonella Scorziello,
Giambattista Bonanno,
Mauro Robello,
Vincenzo Santagada,
Giuseppe Caliendo,
Gianfranco Di Renzo,
Lucio Annunziato
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ABSTRACT: Previous studies have demonstrated that the knock-down or knock-out of the three Na(+)/Ca(2+) exchanger (NCX) isoforms, NCX1, NCX2 and NCX3, worsens ischemic brain damage. This suggests that the activation of these antiporters exerts a neuroprotective action against stroke damage. However, drugs able to increase the activity of NCXs are not yet available. We have here succeeded in synthesizing a new compound, named neurounina-1 (7-nitro-5-phenyl-1-(pyrrolidin-1-ylmethyl)-1H-benzo[e][1,4]diazepin-2(3H)-one), provided with an high lipophilicity index and able to increase NCX activity. Ca(2+)-radiotracer, Fura-2-microfluorimetry, and patch-clamp techniques revealed that neurounina-1 stimulated NCX1 and NCX2 activities with an EC(50) in the picomolar-low-nanomolar range, whereas it did not affect NCX3 activity. Furthermore, by using chimera strategy and site-directed mutagenesis, three specific molecular determinants of NCX1 responsible for neurounina-1 activity were identified in the α-repeats. Interestingly, NCX3 became responsive to neurounina-1 when both α-repeats were replaced with the corresponding regions of NCX1. In vitro studies showed that 10nM neurounina-1 reduced cell death of primary cortical neurons exposed to oxygen-glucose deprivation followed by reoxygenation. Moreover, in vitro, neurounina-1 also reduced GABA release, enhanced GABA(A)-currents, and inhibited both glutamate release and NMDA receptors. More important, neurounina-1 proved to have a wide therapeutic window in vivo. Indeed, when administered i.p. at doses ranging 0.003-30 μg/kg, it was able to reduce the infarct volume of mice subjected to transient middle cerebral artery occlusion even up to 3-5h after stroke onset. Collectively, the present study shows that neurounina-1 exerts a remarkable neuroprotective effect during stroke and increases NCX1 and NCX2 activities.
Molecular pharmacology 10/2012; · 4.53 Impact Factor
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ABSTRACT: Nuclear factor-kappaB (NF-κB) p50/RelA is a key molecule with a dual effect in the progression of ischemic stroke. In harmful ischemia, but not in preconditioning insult, neurotoxic activation of p50/RelA is characterized by RelA-specific acetylation at Lys310 (K310) and deacetylation at other Lys residues. The derangement of RelA acetylation is associated with activation of Bim promoter. OBJECTIVE: With the aim of producing neuroprotection by correcting altered acetylation of RelA in brain ischemia, we combined the pharmacological inhibition of histone deacetylase (HDAC) 1-3, the enzymes known to reduce global RelA acetylation, and the activation of sirtuin 1, endowed with a specific deacetylase activity on the K310 residue of RelA. To afford this aim, we tested the clinically used HDAC 1-3 inhibitor entinostat (MS-275) and the sirtuin 1 activator resveratrol. METHODS: We used the mouse model of transient middle cerebral artery occlusion (MCAO) and primary cortical neurons exposed to oxygen glucose deprivation (OGD). RESULTS: The combined use of MS-275 and resveratrol, by restoring normal RelA acetylation, elicited a synergistic neuroprotection in neurons exposed to OGD. This effect correlated with MS-275 capability to increase total RelA acetylation and resveratrol capability to reduce RelA K310 acetylation through the activation of an AMP-activated protein kinase-sirtuin 1 pathway. The synergistic treatment reproduced the acetylation state of RelA peculiar of preconditioning ischemia. Neurons exposed to the combined drugs totally recovered the optimal histone H3 acetylation. Neuroprotection was reproduced in mice subjected to MCAO and treated with MS-275 (20μg/kg and 200μg/kg) or resveratrol (6800μg/kg) individually. However, the administration of lowest doses of MS-275 (2μg/kg) and resveratrol (68μg/kg) synergistically reduced infarct volume and neurological deficits. Importantly, the treatment was effective even when administered 7h after the stroke onset. Chromatin immunoprecipitation analysis of cortices harvested from treated mice showed that the RelA binding and histone acetylation increased at the Bcl-x(L) promoter and decreased at the Bim promoter. CONCLUSION: Our study reveals that epigenetic therapy shaping acetylation of both RelA and histones may be a promising strategy to limit post-ischemic injury with an extended therapeutic window.
Neurobiology of Disease 08/2012; 49C:177-189. · 5.40 Impact Factor
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ABSTRACT: Substantial evidence has established that a short sub-lethal brain ischemia applied before a prolonged harmful ischemic episode confers ischemic neuroprotection, a phenomenon named ischemic preconditioning. Na(+)/Ca(2+) exchanger (NCX) isoforms, NCX1, NCX2, and NCX3, are plasmamembrane ionic transporters widely distributed in the brain, where they are involved in the control of Na(+) and Ca(2+) homeostasis and in the progression of stroke damage. The objective of this study was to evaluate the role of these three proteins in the preconditioning-induced neuroprotection. NCX protein expression was evaluated at different time points in the ischemic temporoparietal cortex of rats subjected to ischemia alone, to ischemic preconditioning alone, or to ischemic preconditioning plus ischemia. NCX1 and NCX3 were up-regulated in those brain regions protected by preconditioning treatment. These changes were mediated by p-AKT, since the p-AKT inhibition prevented the up-regulation of both isoforms. The relevant role of NCX1 and NCX3 during preconditioning was further confirmed when NCX1 and NCX3 silencing, induced by icv infusion of siRNA, partially reverted the preconditioning-induced neuroprotection. The enhancement of NCX1 and NCX3 expression and activity might represent a reasonable strategy to reduce the infarct extension after stroke.
Neurobiology of Disease 01/2012; 45(1):616-23. · 5.40 Impact Factor
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Luca Lignitto,
Annalisa Carlucci,
Maria Sepe,
Eduard Stefan, Ornella Cuomo,
Robert Nisticò,
Antonella Scorziello,
Claudia Savoia,
Corrado Garbi,
Lucio Annunziato,
Antonio Feliciello
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ABSTRACT: Activation of G-protein-coupled receptors (GPCRs) mobilizes compartmentalized pulses of cyclic AMP. The main cellular effector of cAMP is protein kinase A (PKA), which is assembled as an inactive holoenzyme consisting of two regulatory (R) and two catalytic (PKAc) subunits. cAMP binding to R subunits dissociates the holoenzyme and releases the catalytic moiety, which phosphorylates a wide array of cellular proteins. Reassociation of PKAc and R components terminates the signal. Here we report that the RING ligase praja2 controls the stability of mammalian R subunits. Praja2 forms a stable complex with, and is phosphorylated by, PKA. Rising cAMP levels promote praja2-mediated ubiquitylation and subsequent proteolysis of compartmentalized R subunits, leading to sustained substrate phosphorylation by the activated kinase. Praja2 is required for efficient nuclear cAMP signalling and for PKA-mediated long-term memory. Thus, praja2 regulates the total concentration of R subunits, tuning the strength and duration of PKA signal output in response to cAMP.
Nature Cell Biology 03/2011; 13(4):412-22. · 19.49 Impact Factor
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ABSTRACT: It has been recently shown that a short sublethal brain ischemia subsequent to a prolonged harmful ischemic episode may confer ischemic neuroprotection, a phenomenon termed ischemic postconditioning. Na(+)/Ca(2+) exchanger (NCX) isoforms, NCX1, NCX2, and NCX3, are plasma membrane ionic transporters widely distributed in the brain and involved in the control of Na(+) and Ca(2+) homeostasis and in the progression of stroke damage. The objective of this study was to evaluate the role of these three proteins in the postconditioning-induced neuroprotection. The NCX protein and mRNA expression was evaluated at different time points in the ischemic temporoparietal cortex of rats subjected to tMCAO alone or to tMCAO plus ischemic postconditioning. The results of this study showed that NCX3 protein and ncx3 mRNA were upregulated in those brain regions protected by postconditioning treatment. These changes in NCX3 expression were mediated by the phosphorylated form of the ubiquitously expressed serine/threonine protein kinase p-AKT, as the p-AKT inhibition prevented NCX3 upregulation. The relevant role of NCX3 during postconditioning was further confirmed by results showing that NCX3 silencing, induced by intracerebroventricular infusion of small interfering RNA (siRNA), partially reverted the postconditioning-induced neuroprotection. The results of this study support the idea that the enhancement of NCX3 expression and activity might represent a reasonable strategy to reduce the infarct extension after stroke.
Journal of cerebral blood flow and metabolism: official journal of the International Society of Cerebral Blood Flow and Metabolism 01/2011; 31(1):362-70. · 5.46 Impact Factor
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ABSTRACT: Acid-sensing ion channels, ASICs, are proton-gated cation channels widely expressed in peripheral sensory neurons and in neurons of the central nervous system that play an important role in a variety of physiological and pathological processes. To further confirm the role played by ASIC1a in cerebral ischemia, here we examined the involvement of this channel in two endogenous recently characterized neuroprotective strategies: brain ischemic preconditioning and postconditioning. The main aim of this study was to elucidate whether ASIC1a might take part as effector in the neuroprotection evoked by brain ischemic preconditioning and postconditioning. For this purpose we investigated the effect of ischemic preconditioning and postconditioning on (1) ASIC1a mRNA and protein expression in the temporoparietal cortex of rats at different time intervals; and (2) the effect of p-AKT inhibition on ASIC1a expression during ischemic preconditioning and postconditioning. Ischemic preconditioning and postconditioning were experimentally induced in adult male rats by subjecting them to different protocols of middle cerebral artery occlusion and reperfusion. ASIC1a expression was dramatically reduced in both the neuroprotective processes. These changes in ASIC expression were p-AKT mediated, since LY-294002, a specific p-AKT inhibitor, was able to prevent variations in ASIC1a expression. The results of the present study support the idea that the downregulation of ASIC1a expression and activity might be a reasonable strategy to reduce the infarct extension after stroke.
International Journal of Physiology, Pathophysiology and Pharmacology 01/2011; 3(1):1-8.
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Lucio Annunziato,
Pasquale Molinaro,
Agnese Secondo,
Anna Pannaccione,
Antonella Scorziello,
Giuseppe Pignataro, Ornella Cuomo,
Rossana Sirabella,
Francesca Boscia,
Alessandra Spinali,
Gianfranco Di Renzo
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ABSTRACT: The Na+/Ca2+ exchanger (NCX) belongs to the superfamily of Ca2+/cation antiporter (CaCA) membrane proteins comprising the following members: (1) the NCX family, which exchanges three Na+ ions for one Ca2+ ion (Reeves and Hale, 1984; Fujioka et al., 2000; Kang and Hilgemann, 2004); (2) the Na+/Ca2+ exchanger K+-dependent family (NCKX), which exchanges four Na+ for one Ca2+ plus one K+ ion [1, 2]; (3) the bacterial family which probably promotes Ca2+/H+ exchange (YRBG) [3]; (4) the nonbacterial Ca2+/H+ exchange family (CAX), which is also the Ca2+ exchanger of yeast vacuoles [4]; and (5) the Ca2+/cation exchanger family (CCX), which contains the partially characterized molecule previously called Na+/Ca2+–Li+ exchanger (NCLX or NCKX6).
11/2009: pages 65-87;
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ABSTRACT: A-kinase anchor protein 121 (AKAP121) assembles a multivalent signalling complex on the outer mitochondrial membrane that controls persistence and amplitude of cAMP and src signalling to mitochondria, and plays an essential role in oxidative metabolism and cell survival. Here, we show that AKAP121 levels are regulated post-translationally by the ubiquitin/proteasome pathway. Seven In-Absentia Homolog 2 (Siah2), an E3-ubiquitin ligase whose expression is induced in hypoxic conditions, formed a complex and degraded AKAP121. In addition, we show that overexpression of Siah2 or oxygen and glucose deprivation (OGD) promotes Siah2-mediated ubiquitination and proteolysis of AKAP121. Upregulation of Siah2, by modulation of the cellular levels of AKAP121, significantly affects mitochondrial activity assessed as mitochondrial membrane potential and oxidative capacity. Also during cerebral ischaemia, AKAP121 is degraded in a Siah2-dependent manner. These findings reveal a novel mechanism of attenuation of cAMP/PKA signaling, which occurs at the distal sites of signal generation mediated by proteolysis of an AKAP scaffold protein. By regulating the stability of AKAP121-signalling complex at mitochondria, cells efficiently and rapidly adapt oxidative metabolism to fluctuations in oxygen availability.
The EMBO Journal 05/2008; 27(7):1073-84. · 9.20 Impact Factor
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Ornella Cuomo,
Rosaria Gala,
Giuseppe Pignataro,
Francesca Boscia,
Agnese Secondo,
Antonella Scorziello,
Anna Pannaccione,
Davide Viggiano,
Annagrazia Adornetto,
Pasquale Molinaro,
Xiao-Fang Li,
Jonathan Lytton,
Gianfranco Di Renzo,
Lucio Annunziato
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ABSTRACT: The superfamily of cation/Ca2+ plasma-membrane exchangers contains two branches, the K+-independent Na+-Ca2+ exchangers (NCXs) and the K+-dependent Na+-Ca2+ exchangers (NCKXs), widely expressed in mammals. NCKX2 is the major neuronally expressed isoform among NCKX members. Despite its importance in maintaining Na+, Ca2+, and K+ homeostasis in the CNS, the role of NCKX2 during cerebral ischemia, a condition characterized by an alteration of ionic concentrations, has not yet been investigated. The present study examines NCKX2 role in the development of ischemic brain damage in permanent middle cerebral artery occlusion (pMCAO) and transient middle cerebral artery occlusion. Furthermore, to evaluate the effect of nckx2 ablation on neuronal survival, nckx2-/- primary cortical neurons were subjected to oxygen glucose deprivation plus reoxygenation. NCKX2 mRNA and protein expression was evaluated in the ischemic core and surrounding ipsilesional areas, at different time points after pMCAO in rats. In ischemic core and in periinfarctual area, NCKX2 mRNA and protein expression were downregulated. In addition, NCKX2 knock-down by antisense oligodeoxynucleotide and NCKX2 knock-out by genetic disruption dramatically increased infarct volume. Accordingly, nckx2-/- primary cortical neurons displayed a higher vulnerability and a greater [Ca2+]i increase under hypoxic conditions, compared with nckx2+/+ neurons. In addition, NCKX currents both in the forward and reverse mode of operation were significantly reduced in nckx2-/- neurons compared with nckx2+/+ cells. Overall, these results indicate that NCKX2 is involved in brain ischemia, and it may represent a new potential target to be investigated in the study of the molecular mechanisms involved in cerebral ischemia.
Journal of Neuroscience 03/2008; 28(9):2053-63. · 7.11 Impact Factor
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Pasquale Molinaro, Ornella Cuomo,
Giuseppe Pignataro,
Francesca Boscia,
Rossana Sirabella,
Anna Pannaccione,
Agnese Secondo,
Antonella Scorziello,
Annagrazia Adornetto,
Rosaria Gala,
Davide Viggiano,
Sophie Sokolow,
Andre Herchuelz,
Stèphane Schurmans,
Gianfranco Di Renzo,
Lucio Annunziato
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ABSTRACT: Na+/Ca+ exchanger 3 (NCX3), one of the three isoforms of the NCX family, is highly expressed in the brain and is involved in the maintenance of intracellular Na+ and Ca2+ homeostasis. Interestingly, whereas the function of NCX3 under physiological conditions has been determined, its role under anoxia is still unknown. To assess NCX3 role in cerebral ischemia, we exposed ncx3-/- mice to transient middle cerebral artery occlusion followed by reperfusion. In addition, to evaluate the effect of ncx3 ablation on neuronal survival, organotypic hippocampal cultures and primary cortical neurons from ncx3-/- mice were subjected to oxygen glucose deprivation (OGD) plus reoxygenation. Here we report that ncx3 gene suppression leads to a worsening of brain damage after focal ischemia and to a massive neuronal death in all the hippocampal fields of organotypic cultures as well as in cortical neurons from ncx3-/- mice exposed to OGD plus reoxygenation. In addition, in ncx3-/- cortical neurons exposed to hypoxia, NCX currents, recorded in the reverse mode of operation, were significantly lower than those detected in ncx3+/+. From these results, NCX3 protein emerges as a new molecular target that may have a potential therapeutic value in modulating cerebral ischemia.
Journal of Neuroscience 02/2008; 28(5):1179-84. · 7.11 Impact Factor
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ABSTRACT: Antithrombin (AT), a glycoprotein belonging to the serpin family, blocks thrombin formation and activity at several steps. Thrombin, beside its relevant role in the coagulation cascade, exerts neurodetrimental effects through the activation of a family of protease-activated receptors, which can be implicated in stroke pathophysiology. The aims of the present study were to evaluate whether AT could reduce brain damage, ameliorate neurologic deficits, and prolong animal survival.
Two different doses of AT (10 and 30 IU/kg IP) were administered 3 hours, 6 hours, or 3 and 6 hours after an ischemic insult to mice and rats subjected to either transient or permanent focal ischemia. Ischemic volume was evaluated 24 hours or 7 days after the ischemic insult. Neurologic deficits were also scored.
In mice, 10 or 30 IU/kg AT administered twice, at 3 and 6 hours after transient ischemia, and 30 IU/kg AT administered 3 hours only after transient ischemia substantially reduced total ischemic volume, significantly improved neurologic deficits evaluated 24 hours after the insult, and prolonged animal survival. In rats, the same doses given at the same time intervals significantly reduced ischemic volume, evaluated 24 hours after permanent ischemia.
These results indicate that AT remarkably reduces infarct volume, ameliorates neurologic deficit scores, and prolongs animal survival in 2 rodent models of brain ischemia. Taken together, our data suggest that AT, delivered via systemic administration, an easily achievable route of administration and in a clinically useful time window, could represent a new therapeutic strategy to be validated for the clinical treatment of human stroke.
Stroke 01/2008; 38(12):3272-9. · 5.73 Impact Factor
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ABSTRACT: Sodium/calcium exchangers are neuronal plasma membrane transporters, which by coupling Ca2+ and Na+ fluxes, may play a relevant role in brain ischemia. The exchanger gene superfamily comprises two arms: the K+-independent (NCX) and K+-dependent (NCKX) exchangers. In the brain, three different NCX (NCX1, NCX2, NCX3) and three NCKX (NCKX2, NCKX3, NCKX4) family members have been described. Up to now, no sutides about the role played by NCKX proteins in cerebral ischemia have been published. The aim of the present study was to investigate the role of NCKX2 in an in vivo model of permanent middle cerebral artery occlusion (pMCAO). The role of this protein in the development of ischemic damage was assessed by knocking-down its expression with an antisense oligodeoxynucleotide (AS-ODN), intracerebroventricularly infused by an osmotic minipump for 48 h, starting from 24 h before pMCAO. The results showed that NCKX2 knocking-down by using antisense strategy increased the extent of the ischemic lesion. The results of this study suggest that NCKX2 could exert a neuroprotective effect during ischemic injury.
Annals of the New York Academy of Sciences 04/2007; 1099:486-9. · 3.15 Impact Factor
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Giuseppe Pignataro,
Rosaria Gala, Ornella Cuomo,
Anna Tortiglione,
Lucia Giaccio,
Pasqualina Castaldo,
Rossana Sirabella,
Carmela Matrone,
Adriana Canitano,
Salvatore Amoroso,
Gianfranco Di Renzo,
Lucio Annunziato
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ABSTRACT: The Na+/Ca2+ exchanger, by mediating Ca2+ and Na+ fluxes in a bidirectional way across the synaptic plasma membrane, may play a pivotal role in the events leading to anoxic damage. In the brain, there are 3 different genes coding for 3 different proteins: NCX1, NCX2, and NCX3. The aim of this study was to determine whether NCX1, NCX2, and NCX3 might play a differential role in the development of cerebral injury induced by permanent middle cerebral artery occlusion (pMCAO).
By means of Western blotting, NCX1, NCX2, and NCX3 protein expression was evaluated in the ischemic core and in the remaining nonischemic area of the slice at different time intervals starting from ischemia induction. The role of each isoform was also assessed with antisense oligodeoxynucleotides (ODNs) targeted for each isoform. These ODNs were continuously intracerebroventricularly infused with an osmotic minipump (1 microL/h) for 48 hours, 24 hours before pMCAO.
The results showed that after pMCAO all 3 NCX proteins were downregulated in ischemic core; NCX3 decreased in periinfarctual area whereas NCX1 and NCX2 were unchanged. The ODNs for NCX1 and NCX3 gene products were capable of inducing an increase in the ischemic lesion and to worsen neurological scores.
The results of this study suggest that in the neuroprotective effect exerted by NCX during ischemic injury, the major role is prevalently exerted by NCX1 and NCX3 gene products.
Stroke 12/2004; 35(11):2566-70. · 5.73 Impact Factor
