NCX1 is a new rest target gene: role in cerebral ischemia.
The Na(+)-Ca(2+) exchanger 1 (NCX1), a bidirectional transporter that mediates the electrogenic exchange of one calcium ion for three sodium ions across the plasma membrane, is known to be involved in brain ischemia. Since the RE1-silencing transcription factor (REST) is a key modulator of neuronal gene expression in several neurological conditions, we studied the possible involvement of REST in regulating NCX1 gene expression and activity in stroke. We found that: (1) REST binds in a sequence specific manner and represses through H4 deacetylation, ncx1 gene in neuronal cells by recruting CoREST, but not mSin3A. (2) In neurons and in SH-SY5Y cells REST silencing by siRNA and site-direct mutagenesis of REST consensus sequence on NCX1 brain promoter determined an increase in NCX1 promoter activity. (3) By contrast, REST overexpression caused a reduction in NCX1 protein expression and activity. (4) Interestingly, in rats subjected to transient middle cerebral artery occlusion (tMCAO) and in organotypic hippocampal slices or SH-SY5Y cells exposed to oxygen and glucose deprivation (OGD) plus reoxygenation (RX), the increase in REST was associated with a decrease in NCX1. However, this reduction was reverted by REST silencing. (5) REST knocking down, along with the deriving NCX1 overexpression in the deep V and VIb cortical layers caused a marked reduction in infarct volume after tMCAO. Double silencing of REST and NCX1 completely abolished neuroprotection induced by siREST administration. Collectively, these results demonstrate that REST, by regulating NCX1 expression, may represent a potential druggable target for the treatment of brain ischemia.
Department of Neuroscience, School of Medicine Division of Pharmacology, Federico II University of Naples, Naples, Italy.
Luigi
L
Formisano
Natascia
N
Guida
Valeria
V
Valsecchi
Giuseppe
G
Pignataro
Antonio
A
Vinciguerra
Anna
A
Pannaccione
Agnese
A
Secondo
Francesca
F
Boscia
Pasquale
P
Molinaro
Maria Jose
MJ
Sisalli
Rossana
R
Sirabella
Antonella
A
Casamassa
Lorella M T
LM
Canzoniero
Gianfranco
G
Di Renzo
Lucio
L
Annunziato
D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D002545:Brain Ischemia / Q000235:genetics* / Q000378:metabolism; D047369:Chromatin Immunoprecipitation; D024202:Electrophoretic Mobility Shift Assay; D005455:Fluorescent Antibody Technique; D005786:Gene Expression Regulation / Q000235:genetics*; D006624:Hippocampus / Q000378:metabolism; D006801:Humans; D018613:Microscopy, Confocal; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009474:Neurons / Q000378:metabolism*; D009924:Organ Culture Techniques; D051381:Rats; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar; D060888:Real-Time Polymerase Chain Reaction; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism; D019831:Sodium-Calcium Exchanger / Q000235:genetics* / Q000378:metabolism; D014162:Transfection; D000099229:RE1-Silencing Transcription Factor
D012097:Repressor Proteins; D019831:Sodium-Calcium Exchanger; D000099229:RE1-Silencing Transcription Factor; C110374:sodium-calcium exchanger 1