TFAP2A inhibits microRNA-126 expression at a transcriptional level to aggravate ischemic neuronal injury

2020 ◽  
Author(s):  
Zhiqiang Gao ◽  
Jiang Zhang ◽  
Yunxia Wu
Keyword(s):  
Cerebral Ischemia ◽  
Pc12 Cells ◽  
Cell Model ◽  
Pathological Condition ◽  
Neuronal Injury ◽  
Global Cerebral Ischemia ◽  
Transcriptional Level ◽  
Mechanistic Investigation ◽  
Brain Tissues

Neuronal injury induced by cerebral ischemia poses a serious risk to health worldwide, which lacks effective clinical therapies currently. This study was performed to investigate the effect of transcription factor AP-2 alpha (TFAP2A) and the underlying mechanism in oxygen-glucose deprivation (OGD) cell model and transient global cerebral ischemia (tGCI) rat model. Based on CCK-8 and Hoechst staining results, silencing of TFAP2A could enhance the viability of OGD-treated PC12 cells and decrease the apoptotic rate of cells. ChIP assay was performed to detect the binding of TFAP2A to the promoter region of microRNA (miR)-126, and we found that TFAP2A could inhibit miR-126 expression. Further mechanistic investigation showed that miR-126 targeted polo like kinase 2 (PLK2), while overexpression of PLK2 activated the IκBα/NF-κB pathway and further suppressed the growth of OGD-treated PC12 cells. As for in vivo assay, proportion of infarction area in brain tissues of rats was analyzed by TTC staining, whereas Nissl staining was applied to evaluate the number of surviving brain neurons. The pathological condition of neuronal injury in rat brain tissues was monitored using HE staining. Results suggested that TFAP2A downregulated miR-126 to upregulate PLK2 and activate IκBα/NF-κB pathway, which deteriorated neuronal injury following ischemia in vivo.

scholarly journals A Model of Global Cerebral Ischemia in C57 BL/6 Mice

2004 ◽  
Vol 24 (2) ◽  
pp. 151-158 ◽  
Author(s):  
Ichiro Yonekura ◽  
Nobutaka Kawahara ◽  
Hirofumi Nakatomi ◽  
Kazuhide Furuya ◽  
Takaaki Kirino
Keyword(s):  
Cerebral Ischemia ◽  
Genetic Background ◽  
Neuronal Degeneration ◽  
Neuronal Damage ◽  
Neuronal Injury ◽  
Genetically Engineered ◽  
Global Cerebral Ischemia ◽  
Vessel Occlusion ◽  
Bilateral Carotid ◽  
The Mean

A reproducible model of global cerebral ischemia in mice is essential for elucidating the molecular mechanism of ischemic neuronal injury. Such a model is particularly important in the mouse because many genetically engineered mutant animals are available. In C57BL/6 and SV129/EMS mice, we evaluated a three-vessel occlusion model. Occlusion of the basilar artery with a miniature clip was followed by bilateral carotid occlusion. The mean cortical cerebral blood flow was reduced to less than 10% of the preischemic value, and the mean anoxic depolarization was attained within 1 minute. In C57BL/6 mice, there was CA1 hippocampal neuronal degeneration 4 days after ischemia. Neuronal damage depended upon ischemic duration: the surviving neuronal count was 78.5 ± 8.5% after 8-minute ischemia and 8.4 ± 12.7% after 14-minute ischemia. In SV129/EMS mice, similar neuronal degeneration was not observed after 14-minute ischemia. The global ischemia model in C57BL/6 mice showed high reproducibility and consistent neuronal injury in the CA1 sector, indicating that comparison of ischemic outcome between wild-type and mutant mice could provide meaningful data using the C57BL/6 genetic background. Strain differences in this study highlight the need for consideration of genetic background when evaluating ischemia experiments in mice.

scholarly journals Up-regulation of miR-499a-5p decreases cerebral ischemia/reperfusion injury by targeting PDCD4

2021 ◽  
Author(s):  
Weifeng Shan ◽  
Huifeng Ge ◽  
Bingquan Chen ◽  
Linger Huang ◽  
Shaojun Zhu ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Cerebral Ischemia ◽  
Ischemia Reperfusion Injury ◽  
Cell Model ◽  
Ischemia Reperfusion ◽  
Glucose Deprivation ◽  
Artery Occlusion ◽  
Tunel Staining ◽  
Cerebral Ischemia Reperfusion

Abstract MiR-499a-5p was significantly down-regulated in degenerative tissues and correlated with apoptosis. Nonetheless, the biological function of miR-499a-5p in acute ischemic stroke has been still unclear. In this study, we found the plasma levels of miR-499a-5p were significantly down-regulated in 64 ischemic stroke patients and negatively correlated with the National Institutes of Health Stroke Scale score. Then, we constructed cerebral ischemia/reperfusion (I/R) injury in rats after middle cerebral artery occlusion and subsequent reperfusion and oxygen-glucose deprivation and reoxygenation (OGD/R) treated SH-SY5Y cell model. Transfection with miR-499a-5p mimic was accomplished by intracerebroventricular injection in the in vivo I/R injury model. We further found miR-499a-5p overexpression decreased infarct volumes and cell apoptosis in the in vivo I/R stroke model using TTC and TUNEL staining. PDCD4 was a direct target of miR-499a-5p by luciferase report assay and western blotting. Knockdown of PDCD4 reduced the infarct damage and cortical neuron apoptosis caused by I/R injury. MiR-499a-5p exerted neuroprotective roles mainly through inhibiting PDCD4-mediated apoptosis by CCK-8 assay, LDH release assay and flow cytometry analysis. These findings suggest that miR-499a-5p might represent a novel target that regulates brain injury by inhibiting PDCD4-mediating apoptosis.

The Antibiotic Erythromycin Induces Tolerance against Transient Global Cerebral Ischemia in Rats (Pharmacologic Preconditioning)

2006 ◽  
Vol 104 (6) ◽  
pp. 1208-1215 ◽  
Author(s):  
Ansgar M. Brambrink ◽  
Ines P. Koerner ◽  
Kathrin Diehl ◽  
Georg Strobel ◽  
Ruediger Noppens ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Messenger Rna ◽  
Neuronal Cell ◽  
Tolerance Induction ◽  
Ischemic Tolerance ◽  
Global Cerebral Ischemia ◽  
Neuroprotective Effects ◽  
Transient Global Cerebral Ischemia ◽  
Cerebral Ischemic

Background Cerebral ischemic tolerance can be induced by a variety of noxious stimuli, but no clinically applicable regimen for preconditioning has been described. Therefore, the authors tested the ability of a pharmacologic preconditioning strategy using the well-known macrolide antibiotic erythromycin to induce tolerance against transient global cerebral ischemia in vivo. They also investigated whether tolerance induction by erythromycin involves transcriptional and translational changes of cerebral B-cell leukemia/lymphoma-2 (bcl-2) expression. Methods Male Wistar rats were treated with erythromycin (25 mg/kg intramuscularly) or vehicle and subjected to 15 min of transient global cerebral ischemia 6, 12, or 24 h after pretreatment. Neurologic deficit was evaluated once daily, and neuronal cell survival was assessed after 7 days of reperfusion. Additional animals were similarly pretreated, and cerebral bcl-2 messenger RNA (mRNA) and protein expression was analyzed 6 and 24 h later. Results Erythromycin improved postischemic neuronal survival in hippocampal CA1 and CA3 sectors and reduced functional deficit, with 12 h being the most efficient pretreatment interval. Bcl-2 mRNA in hippocampus was transiently up-regulated 6 h after erythromycin, but neuronal Bcl-2 protein remained unchanged. Conclusions Erythromycin can induce cerebral ischemic tolerance in vivo (pharmacologic preconditioning), suggesting a potential clinical strategy of preemptive neuroprotection. Changes in bcl-2 expression after erythromycin were small and transient. The induction of bcl-2-related pathways, although important for other preconditioning regimens, may therefore be less relevant for the neuroprotective effects of pharmacologic preconditioning using erythromycin.

Abstract W P206: Analysis of SUMO3-Modified Proteome in Post-Ischemic Mouse Brain

Stroke ◽  
2014 ◽  
Vol 45 (suppl_1) ◽  
Author(s):  
Wei Yang ◽  
Huaxin Sheng ◽  
Will Thompson ◽  
Shengli Zhao ◽  
Liangli Wang ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Transgenic Mice ◽  
Transgenic Mouse ◽  
Ischemia Reperfusion ◽  
Global Cerebral Ischemia ◽  
Sham Operation ◽  
Dependent Manner ◽  
Ischemic Brain ◽  
Double Transgenic Mice

Background and Purpose: Small ubiquitin-like modifier (SUMO) conjugation modulates many key cellular processes. Transient cerebral ischemia dramatically activates SUMO2/3 conjugation, and this is believed to be a protective stress response. It is, therefore, of tremendous clinical interest to characterize the SUMO-modified proteome regulated by transient ischemia. We generated a novel SUMO transgenic mouse and performed the first SUMO proteomics study using post-ischemic brain samples. Methods: CAG-loxP-STOP-loxP-SUMO (CAG-SUMO) mice were generated in which His-SUMO1, HA-SUMO2, and FLAG-SUMO3 were expressed from a single multicistronic transgene in a Cre-dependent manner. CAG-SUMO mice were mated with Emx1 Cre/Cre mice to generate double transgenic CAG-SUMO/Emx1-Cre mice as experimental mice and Emx1 Cre/+ mice as control mice. Double transgenic mice were subjected to 10 min global cerebral ischemia followed by 1 h reperfusion or sham operation. FLAG-SUMO3-conjugated proteins were enriched from cortical tissues and analyzed. Results: Characterization of double transgenic mice demonstrated that exogenous expressed tagged SUMO paralogues were functionally intact and did not perturb the endogenous SUMOylation machinery in the brain. FLAG pulldown of cortical samples from sham and ischemia mice followed by GeLC-MS/MS analysis identified 91 candidates whose SUMOylation states were up-regulated in ischemic samples. Data analysis revealed several potentially important processes in which SUMO3 conjugation may play a key role during ischemia/reperfusion, including the cross-talk between SUMOylation and ubiquitination, glucocorticoid receptor signaling, and modulation of posttranscriptional mRNA processing. Conclusions: SUMO proteomic analysis identified important processes and pathways modulated by SUMOylation in the post-ischemic brain that warrant future investigations, since they could be the key to understand the overall impact of SUMOylation on the fate and functions of post-ischemic neurons. The conditional SUMO transgenic mouse will be an invaluable tool for in-depth in vivo analysis of the SUMO-modified proteome in various pathological states.

scholarly journals In vivo Binding of [3H]Nimodipine in Rat Brain after Transient Forebrain Ischemia

1994 ◽  
Vol 14 (3) ◽  
pp. 397-405 ◽  
Author(s):  
Shunya Takizawa ◽  
Matthew J. Hogan ◽  
Alastair M. Buchan ◽  
Antoine M. Hakim
Keyword(s):  
Cerebral Ischemia ◽  
Brain Structures ◽  
Brain Regions ◽  
Global Cerebral Ischemia ◽  
Therapeutic Window ◽  
Forebrain Ischemia ◽  
In Vivo Binding ◽  
Transient Forebrain Ischemia ◽  
Ca1 Region

We report the regional variation in relative in vivo binding of the l-type voltage sensitive calcium channel (VSCC) antagonist [3H]nimodipine to brain following transient forebrain ischemia in the rat. At 30-min of reperfusion after 20 min of forebrain ischemia, [3H]nimodipine binding was significantly increased in striatum, CA3 and CA4, and dentate relative to binding in sham-operated rats, suggesting that VSCCs were responding to ischemic depolarization. Two h following ischemia, binding in all brain structures returned to normal levels indicating repolarization of cell membranes. At 24 h of recirculation, increased [3H]nimodipine binding was again observed in striatum and dentate. Binding remained elevated in the striatum and dentate, and increased binding became evident in the CA1 region of the hippocampus after 48 h of reperfusion. With the exception of the dentate gyrus, the second rise in [3H]nimodipine binding anticipated or coincided with the observed regional ischemic cell changes. These observations in global cerebral ischemia support previous work indicating that in vivo binding of [3H]nimodipine to the l-type VSCC may be an early and sensitive indicator of impending ischemic injury. Such measurements may be of use in identifying vulnerable brain regions and defining a therapeutic window of opportunity in models of cerebral ischemia.

Opuntia ficus-indica attenuates neuronal injury in in vitro and in vivo models of cerebral ischemia

2006 ◽  
Vol 104 (1-2) ◽  
pp. 257-262 ◽  
Author(s):  
Jung-Hoon Kim ◽  
Shin-Mi Park ◽  
Hyun-Joo Ha ◽  
Chang-Jong Moon ◽  
Tae-Kyun Shin ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Neuronal Injury ◽  
Opuntia Ficus Indica ◽  
In Vivo Models

scholarly journals Targeting Expression of hsp70i to Discrete Neuronal Populations Using the Lmo-1 Promoter: Assessment of the Neuroprotective Effects of hsp70i In vivo and In vitro

2001 ◽  
Vol 21 (8) ◽  
pp. 972-981 ◽  
Author(s):  
Stephen Kelly ◽  
Alison Bieneman ◽  
Karen Horsburgh ◽  
David Hughes ◽  
Michael V. Sofroniew ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Transgenic Mice ◽  
Caudate Nucleus ◽  
Neuronal Damage ◽  
Global Cerebral Ischemia ◽  
Specific Gene ◽  
Wild Type ◽  
Neuroprotective Effects ◽  
Bilateral Carotid

Transgenic technology provides a powerful means of studying gene regulation and specific gene function with complex mammalian systems. In this study, the authors exploited the specific and discrete neuronal expression pattern mediated by promoter 1 of the Lmo-1 gene to study the neuroprotective effects of the inducible form of heat shock protein 70kD (hsp70i) in primary hippocampal cultures in a mouse model of global cerebral ischemia. Targeting expression of hsp70i to hippocampal neurons protected these cells significantly from toxic levels of glutamate and oxidative stress (for example, exposure to 10 μmol/L free iron produced a 26% increase in lactate dehydrogenase release from neurons cultured from wild-type mice, but a 7% increase in neurons cultured from hsp70i transgenic mice). Bilateral carotid occlusion (25 minutes) produced significantly less neuronal damage in the caudate nucleus and posterior thalamus in hsp70i transgenic mice than in wild-type littermates (for example, 21% ± 9.3% and 12.5% ± 9.0% neuronal damage in lateral caudate nucleus of wild-type and hsp70i transgenic mice, respectively, P < 0.05). The current study highlights the utility of targeted expression of transgenes of interest in cerebral ischemia and demonstrates that expression of hsp70i alone is sufficient to mediate the protection of primary neurons from denaturing stress and that expression of human hsp70i in vivo plays crucial role in determining the fate of neurons after ischemic challenge.

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