title: Oct-2 transcription factor binding activity and expression up-regulation in rat cerebral ischaemia is associated with a diminution of neuronal damage in vitro.
abstract: Brain plasticity provides a mechanism to compensate for lesions produced as a result of stroke. The present study aims to identify new transcription factors (TFs) following focal cerebral ischaemia in rat as potential therapeutic targets. A transient focal cerebral ischaemia model was used for TF-binding activity and TF-TF interaction profile analysis. A permanent focal cerebral ischaemia model was used for the transcript gene analysis and for the protein study. The identification of TF variants, mRNA analysis, and protein study was performed using conventional polymerase chain reaction (PCR), qPCR, and Western blot and immunofluorescence, respectively. Rat cortical neurons were transfected with small interfering RNA against the TF in order to study its role. The TF-binding analysis revealed a differential binding activity of the octamer family in ischaemic brain in comparison with the control brain samples both in acute and late phases. In this study, we focused on Oct-2 TF. Five of the six putative Oct-2 transcript variants are expressed in both control and ischaemic rat brain, showing a significant increase in the late phase of ischaemia. Oct-2 protein showed neuronal localisation both in control and ischaemic rat brain cortical slices. Functional studies revealed that Oct-2 interacts with TFs involved in important brain processes (neuronal and vascular development) and basic cellular functions and that Oct-2 knockdown promotes neuronal injury. The present study shows that Oct-2 expression and binding activity increase in the late phase of cerebral ischaemia and finds Oct-2 to be involved in reducing ischaemic-mediated neuronal injury.
authors.affiliation: Servei de Neurologia, Institut d'Investigació Biomèdica de Girona (IdIBGi), Hospital Universitari de Girona Dr. Josep Trueta, Av. França s/n, 17007, Girona, Spain.
authors.forename: Susanna
authors.initials: S
authors.lastname: Camós
authors.forename: Carme
authors.initials: C
authors.lastname: Gubern
authors.forename: Mónica
authors.initials: M
authors.lastname: Sobrado
authors.forename: Rocío
authors.initials: R
authors.lastname: Rodríguez
authors.forename: Víctor G
authors.initials: VG
authors.lastname: Romera
authors.forename: María Ángeles
authors.initials: MÁ
authors.lastname: Moro
authors.forename: Ignacio
authors.initials: I
authors.lastname: Lizasoain
authors.forename: Joaquín
authors.initials: J
authors.lastname: Serena
authors.forename: Judith
authors.initials: J
authors.lastname: Mallolas
authors.forename: Mar
authors.initials: M
authors.lastname: Castellanos
mesh_terms: D000818:Animals; D001925:Brain Damage, Chronic / Q000209:etiology / Q000235:genetics / Q000473:pathology / Q000517:prevention & control; D002540:Cerebral Cortex / Q000378:metabolism / Q000473:pathology; D002544:Cerebral Infarction / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D047369:Chromatin Immunoprecipitation; D018450:Disease Progression; D020869:Gene Expression Profiling; D020244:Infarction, Middle Cerebral Artery / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D002546:Ischemic Attack, Transient / Q000235:genetics / Q000378:metabolism; D008297:Male; D023421:Models, Animal; D009419:Nerve Tissue Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D009474:Neurons / Q000378:metabolism; D050813:Octamer Transcription Factor-2 / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D011485:Protein Binding; D034622:RNA Interference; D012333:RNA, Messenger / Q000096:biosynthesis; D034741:RNA, Small Interfering / Q000494:pharmacology; D051381:Rats; D011916:Rats, Inbred F344; D014158:Transcription, Genetic; D015854:Up-Regulation
chemical_list: D009419:Nerve Tissue Proteins; D050813:Octamer Transcription Factor-2; C489205:Pou2f2 protein, rat; D012333:RNA, Messenger; D034741:RNA, Small Interfering