scholarly journals MicroRNA-9a-5p Alleviates Ischemia Injury After Focal Cerebral Ischemia of the Rat by Targeting ATG5-Mediated Autophagy

2017 ◽  
Vol 45 (1) ◽  
pp. 78-87 ◽  
Author(s):  
Ning Wang ◽  
Lei Yang ◽  
Huixue Zhang ◽  
Xiaoyu Lu ◽  
Jianjian Wang ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Focal Cerebral Ischemia ◽  
Infarct Volume ◽  
Mrna Level ◽  
Critical Role ◽  
Cerebrovascular Diseases ◽  
Artery Occlusion ◽  
Pathological Process ◽  
Luciferase Assay ◽  
Repressive Effect

Background/Aims: Previous studies have suggested that autophagy is activated in distinct cerebrovascular diseases, including stroke. However, the underlying regulatory mechanism of autophagy under stroke remained elusive. Accumulating evidence indicates that dysfunctions of microRNAs (miRNAs) are involved in the pathological process of stroke. Therefore, this study was taken to identify the effect of microRNA-9a-5p (miR-9a-5p) on autophagy in rats following stroke. Methods: The rat model of focal cerebral ischemia was established by middle cerebral artery occlusion (MCAO) surgery; The neurological outcomes were defined by neurological evaluation and infarct volume; The western blotting and immunofluorescence assays were used to detected the protein levels of microtubule-associated protein 1 light chain 3 (LC3) and autophagy related 5 (ATG5); The mRNA level of miR-9a-5p, LC3 and ATG5 were quantified by real-time RT-PCR; The luciferase activities of ATG5 and miR-9a-5p was detected by luciferase assay. Results: We showed here that the level of miR-9a-5p was decreased in the ischemic region of rats after MCAO. Overexpression of miR-9a-5p by miR-9a-5p agomir reduced infarct volume and alleviated neurological deficit. Moreover, we found that autophagy was activated by miR-9a-5p inhibition and inactivated by miR-9a-5p overexpression both in the MCAO rat and in SY-5Y cell lines, and unchanged by miR-masks as indicated by LC3 expression. Furthermore, the protein level of ATG5 was decreased by miR-9a-5p overexpression, but increased by miR-9a-5p inhibition and unchanged by miR-masks transfection. In addition, the luciferase assay data showed that miR-9a-5p suppressed the luciferase activity of 3’UTR of ATG5, whereas the repressive effect was relieved by mutation of binding sites. Conclusion: Our study demonstrated that miR-9a-5p may play a critical role in regulating the process of autophagy through targeting ATG5 expression, and overexpression of miR-9a-5p may be a potential approach in alleviating ischemia injury induced by MCAO.

scholarly journals Inhibition of MicroRNA-383 Ameliorates Injury After Focal Cerebral Ischemia via Targeting PPARγ

2016 ◽  
Vol 39 (4) ◽  
pp. 1339-1346 ◽  
Author(s):  
Lichun Pei ◽  
Songyan Meng ◽  
Weigang Yu ◽  
Qiujun Wang ◽  
Fangfang Song ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Middle Cerebral Artery ◽  
Middle Cerebral Artery Occlusion ◽  
Cerebral Artery ◽  
Protein Level ◽  
Focal Cerebral Ischemia ◽  
Infarct Volume ◽  
Artery Occlusion ◽  
Luciferase Assay ◽  
Cerebral Artery Occlusion

Background: Peroxisome proliferator-activated receptor gamma (PPARγ) plays a critical role in protecting against distinct brain damages, including ischemia. Our previous data have shown that the protein level of PPARγ is increased in the cortex after middle cerebral artery occlusion (MCAO); PPARγ up-regulation contributes to PPARγ activation and is effective in reducing ischemic damage to brain. However, the regulatory mechanism of PPARγ after focal cerebral ischemia in rats is still unclear. In this study, we evaluated the effect of microRNA on PPARγ in rats subjected to MCAO. Methods: Focal cerebral ischemia was established by surgical middle cerebral artery occlusion; the protein level of PPARγ was detected by Western blotting; the level of microRNA-383 (miR-383) was quantified by real-time PCR; the neurological outcomes were defined by infarct volume and neurological deficits. Luciferase assay was used to identify the luciferase activities of PPARγ and miR-383. Results: We showed here that miR-383 level was down-regulated in the ischemic hemisphere of rats 24h after MCAO. Overexpression of miR-383 by miR-383 agomir increased infarct volume and aggravated neurological damage. Administration of miR-383 antagomir had the opposite effects. Furthermore, we found that PPARγ protein was down-regulated by miR-383 overexpression, and up-regulated by miR-383 inhibition both in rat model of MCAO and in primary culture cells. Finally, we found that miR-383 suppressed the luciferase activity of the vector carrying the 3'UTR of PPARγ, whereas mutation of the binding sites relived the repressive effect of miR-383. Conclusion: Our study demonstrated that miR-383 may play a key role in focal cerebral ischemia by regulating PPARγ expression at the post-transcriptional level, and miR-383 may be a potential therapeutic target for stroke.

scholarly journals Cortical Spreading Depression Protects against Subsequent Focal Cerebral Ischemia in Rats

1996 ◽  
Vol 16 (2) ◽  
pp. 221-226 ◽  
Author(s):  
Kazushi Matsushima ◽  
Matthew J. Hogan ◽  
Antoine M. Hakim
Keyword(s):  
Cerebral Ischemia ◽  
Cortical Spreading Depression ◽  
Spreading Depression ◽  
Focal Cerebral Ischemia ◽  
Infarct Volume ◽  
Occipital Cortex ◽  
Artery Occlusion ◽  
Microdialysis Probe ◽  
Cerebral Artery Occlusion ◽  
Subcortical Infarct

The possibility that cortical spreading depression (CSD) may have neuroprotective action during subsequent focal cerebral ischemia was examined in rats. Three days before the imposition of focal cerebral ischemia CSDs were elicited by applying potassium chloride (KCl) for 2 h through a microdialysis probe implanted in the occipital cortex. Control animals were handled identically except that saline was infused instead of KCl. Focal ischemia was produced by the intraluminal suture method and cortical and subcortical infarct volumes were measured 7 days later. Neocortical infarct volume was reduced from 124.8 ± 49.5 mm3 in the controls to 62.9 ± 59.5 mm3 in the animals preconditioned with CSD (p = 0.012). There was no difference between the two groups in the subcortical infarct volume or in CBF, measured by the hydrogen clearance method, during or immediately after the ischemic interval. Our data indicate that preconditioning CSD applied 3 days before middle cerebral artery occlusion may increase the brain's resistance to focal ischemic damage and may be used as a model to explore the neuroprotective molecular responses of neuronal and glial cells.

VWF-Cleaving Protease ADAMTS13 Reduces Brain Injury Following Ischemic Stroke in Mice: Essential Role for VWF in Stroke

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 259-259
Author(s):  
Bing-Qiao Zhao ◽  
Anil kumar Chauhan ◽  
Ian S. Patten ◽  
Michael Dockal ◽  
Friedrich Scheiflinger ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Cerebral Ischemia ◽  
Essential Role ◽  
Focal Cerebral Ischemia ◽  
Infarct Volume ◽  
Recombinant Tissue Plasminogen Activator ◽  
Protective Role ◽  
Artery Occlusion ◽  
Type I ◽  
Deficient Mice

Abstract Ischemic stroke is the second leading cause of death and disability. The only approved therapy available is recombinant tissue plasminogen activator (tPA), but its use remains limited. Therefore, there is a need for an alternative drug. Platelets and their adhesion receptors play a crucial role in modulating infarct size during ischemic stroke. ADAMTS13 (A Disintegrin-like And Metalloprotease with Thrombospondin type I repeats-13) is a plasma metalloprotease that cleaves von Willebrand factor (VWF) an important adhesion molecule for platelets at sites of vascular injury. In patients, an increase in circulating levels of VWF and a decrease in ADAMTS13 activity are considered risk factors for ischemic stroke. By using genetically-modified mice we have previously shown that ADAMTS13 down regulates both thrombosis and inflammation and recombinant human ADAMTS13 down regulates platelet thrombi in injured arterioles. All these processes were dependent on VWF. We therefore hypothesize that ADAMTS13 has a protective role after ischemic stroke. In this study, we show that VWF deficiency or VWF heterozygosity in mice reduces infarct volume by two-fold after focal cerebral ischemia compared to wild-type (WT) in the middle cerebral artery occlusion (MCAO) stroke model. Furthermore, infusion of recombinant human VWF in WT mice not only accelerates thrombosis in the ferric-chloride injured artery model, but also increases infarct volume compared to vehicle-treated controls. These findings suggest an essential role of VWF in modulating infarction after stroke. We also show that ADAMTS13 deficiency in mice results in approximately 20% larger infarcts after cerebral ischemia compared to WT. The larger infarcts observed in ADAMTS13 deficient mice were due to VWF because mice deficient in both ADAMTS13 and VWF had infarct sizes similar to VWF deficient mice. Importantly, infusion of r-human ADAMTS13 immediately before reperfusion (two hour after occlusion) significantly reduced infarct volume (106.2 ± 9.7 mm3 vs 75.8 ± 6.9 mm3, P<0.05). Of note, we observed that ADAMTS13 protein was induced in the ischemic penumbra region of brain after ischemic stroke. Our findings reveal an important role for VWF in modulating infarct volume after ischemic stroke. In addition, recombinant-ADAMTS13 could become a new therapeutic agent for stroke therapy.

scholarly journals Intraventricular Brain-Derived Neurotrophic Factor Reduces Infarct Size after Focal Cerebral Ischemia in Rats

1997 ◽  
Vol 17 (5) ◽  
pp. 500-506 ◽  
Author(s):  
Wolf-R. Schäbitz ◽  
Stefan Schwab ◽  
Matthias Spranger ◽  
Werner Hacke
Keyword(s):  
Cerebral Ischemia ◽  
Infarct Size ◽  
Middle Cerebral Artery ◽  
Middle Cerebral Artery Occlusion ◽  
Neurotrophic Factor ◽  
Cortical Neurons ◽  
Focal Cerebral Ischemia ◽  
Infarct Volume ◽  
Artery Occlusion ◽  
Cerebral Artery Occlusion

Brain-derived neurotrophic factor (BDNF), acting through the high-affinity receptor tyrosine kinase (TrkB), is widely distributed throughout the central nervous system and displays in vitro trophic effects on a wide range of neuronal cells, including hippocampal, cerebellar, and cortical neurons. In vivo, BDNF rescues motorneurons, hippocampal, and substantia nigral dopaminergic cells from traumatic and toxic brain injury. After transient middle cerebral artery occlusion (MCAO), upregulation of BDNF-mRNA in cortical neurons suggests that BDNF potentially plays a neuroprotective role in focal cerebral ischemia. In the current study, BDNF (2.1 μg/d) in vehicle or vehicle alone (controls) was delivered intraventricularly for 8 days, beginning 24 hours before permanent middle cerebral artery occlusion by intraluminal suture in Wistar rats (n = 13 per group). There were no differences in physiological variables recorded during surgery for the two groups. Neurological deficit (0 to 4 scale), which was assessed on a daily basis, improved in BDNF-treated animals compared with controls ( P < 0.05; analysis of variance and Scheffe's test). There were no significant differences in weight in BDNF-treated animals and controls during the experiment. After elective killing on day 7 after MCAO, brains underwent 2,3,5-triphenyltetrazolium chloride staining for calculation of the infarct volume and for histology (hematoxylin and eosin and glial fibrillary acid protein). The mean total infarct volume was 83.1 ± 27.1 mm3 in BDNF-treated animals and 139.2 ± 56.4 mm3 in controls (mean ± SD; P < 0.01, unpaired, two-tailed t-test). The cortical infarct volume was 10.8 ± 7.1 mm3 in BDNF-treated animals and 37.9 ± 19.8 mm3 in controls (mean ± SD; P < 0.05; unpaired, two-tailed t-test), whereas ischemic lesion volume in caudoputaminal infarction was not significantly different. These results show that pretreatment with intraventricular BDNF reduces infarct size after focal cerebral ischemia in rats and support the hypothesis of a neuroprotective role for BDNF in stoke.

Effect of intermittent reperfusion and nitric oxide synthase inhibition on infarct volume during reversible focal cerebral ischemia

1995 ◽  
Vol 83 (3) ◽  
pp. 491-495 ◽  
Author(s):  
Brian A. Iuliano ◽  
Robert E. Anderson ◽  
Fredric B. Meyer
Keyword(s):  
Nitric Oxide ◽  
Cerebral Ischemia ◽  
Nitric Oxide Synthase ◽  
Focal Cerebral Ischemia ◽  
Infarct Volume ◽  
Vascular Occlusion ◽  
Artery Occlusion ◽  
Content Type ◽  
Infarction Size ◽  
Oxide Synthase

✓ The authors examined the effects of both intermittent reperfusion and nitric oxide synthase (NOS) inhibition, caused by NG-nitro-l-arginine methyl ester (l-NAME) during episodes of focal cerebral ischemia induced to simulate the neurosurgical setting. Seventy-eight Wistar rats underwent single (60 minutes of ischemia) or repetitive (four 15-minute periods of ischemia separated by 5 minutes of reperfusion) episodes of middle cerebral artery occlusion while under anesthesia (1.0% halothane). Twenty-four hours after the procedure, the animals were given neurological examinations and then sacrificed for histological preparation and examination. The intermittent reperfusion groups tended to have smaller mean cortical infarctions. There was also a trend showing a decrease in infarction size in groups given l-NAME. The combination of intermittent reperfusion and preischemic administration ofl-NAME (10 mg/kg) resulted in a 65% reduction in infarction size (p < 0.05) when compared to that caused by 60 minutes of single occlusion without l-NAME. The use of NOS inhibition combined with intermittent reperfusion may be a technique to provide intraoperative cerebral protection during neurovascular procedures that require temporary vascular occlusion.

scholarly journals Effect of combined therapy with hyperbaric oxygen and an antioxidant on infarct volume after permanent focal cerebral ischemia

2007 ◽  
pp. 369-373
Author(s):  
G Acka ◽  
A Sen ◽  
Z Canakci ◽  
S Yildiz ◽  
A Akin ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Hyperbaric Oxygen ◽  
Focal Cerebral Ischemia ◽  
Infarct Volume ◽  
Combined Therapy ◽  
Artery Occlusion ◽  
Control Group ◽  
Male Wistar Rats ◽  
Cerebral Artery Occlusion ◽  
Reduce Infarct Volume

The aim of the present study was to evaluate the efficiency of combination of hyperbaric oxygen (HBO) and an antioxidant on permanent focal cerebral ischemia. Male Wistar rats underwent permanent middle cerebral artery occlusion (MCAO). Then, animals were randomly assigned to one of four groups: the control group (n=9) received no treatment, HBO group (n=9) was treated for 90 min at 2.5 absolute atmosphere for 3 days, the U-74389G group (n=8) received single U-74389G injection (3 mg/kg), the HBO + U-74389G group (n=8) received both HBO and U-74389G treatments. Treatments were initiated within the first 10 min after MCAO. After 3 days, the infarct volumes in rat brains were measured. The infarct ratios were 25.6+/-6.5 % for the control group, 21.9+/-6.4 % for the HBO group, 15.7+/-5.7 % for U-74389G group and 12.5+/-3.8 % for HBO + U74389G group. The infarct volumes were significantly reduced in rats treated with U-74389G (p<0.05) and combination therapy (p<0.05). HBO failed to reduce infarct volume significantly. We concluded that 1) U-74389G is more beneficial than HBO on permanent MCAO in rats, and 2) a combined therapy failed to significantly improve infarct volume more than either single treatment.

Abstract TP109: Impact of ATP-Induced Mild Hypothermia on Focal Cerebral Ischemia in Rats

Stroke ◽  
2013 ◽  
Vol 44 (suppl_1) ◽  
Author(s):  
Meijuan Zhang ◽  
Wenjin Li ◽  
Rehana K Leak ◽  
Jun Chen ◽  
Feng Zhang
Keyword(s):  
Brain Injury ◽  
Cerebral Ischemia ◽  
Body Temperature ◽  
Mild Hypothermia ◽  
Focal Cerebral Ischemia ◽  
Infarct Volume ◽  
Neuroprotective Effect ◽  
Core Body Temperature ◽  
Artery Occlusion ◽  
Dependent Manner

Brain ischemia is a devastating disorder without effective therapies. One of the most promising approaches to attenuate ischemic brain injury is mild hypothermia. Recent studies show that adenosine nucleotides can induce hypothermia in mice. The purpose of the present study was to test the hypothesis that ATP, a common form of energy currency, induces mild hypothermia in rats and reduces brain injury following focal cerebral ischemia. ATP solution was dissolved in water and intraperitoneally injected; and focal stroke was induced by a suture model of middle cerebral artery occlusion and ischemic outcomes were evaluated within 24 hr. We found that injections of ATP lowered core body temperature in a dose-dependent manner; the dose appropriate for subsequent experiments was 2 g/kg as it reduced temperature to the range of mild hypothermia for approximately 7 hours. While intravenous injection of ATP was less effective in lowering body temperature. However, when ATP-induced hypothermia was applied to stroke, a neuroprotective effect was not observed. In contrast, the infarct volume grew even larger in ATP-treated rats. Not surprisingly, this was accompanied by an increased rate of seizure events, hemorrhagic transformation, and higher mortality. Continuous monitoring of physiological parameters revealed that ATP severely reduced heartbeat rate and blood pressure. ATP also raised blood glucose to dangerous levels and this was accompanied by severe acidosis and hypocalcemia. Western blotting showed that ATP treatment decreased levels of both phospho-Akt and total-Akt in the ischemic cortex. Our results reveal that, despite inducing hypothermia, ATP is not appropriate for protecting the brain against stroke, as it is associated with exaggerated ischemic outcomes and dangerous systemic side effects.

scholarly journals Ornithine Decarboxylase Knockdown Exacerbates Transient Focal Cerebral Ischemia-Induced Neuronal Damage in Rat Brain

2001 ◽  
Vol 21 (8) ◽  
pp. 945-954 ◽  
Author(s):  
Raghavendra Vemuganti L. Rao ◽  
Aclan Dogan ◽  
Kellie K. Bowen ◽  
Robert J. Dempsey
Keyword(s):  
Cerebral Ischemia ◽  
Ornithine Decarboxylase ◽  
Neuronal Damage ◽  
Focal Cerebral Ischemia ◽  
Infarct Volume ◽  
Artery Occlusion ◽  
Motor Deficits ◽  
Spontaneously Hypertensive ◽  
Protein Levels ◽  
Transient Focal Cerebral Ischemia

Transient cerebral ischemia leads to increased expression of ornithine decarboxylase (ODC). Contradicting studies attributed neuroprotective and neurotoxic roles to ODC after ischemia. Using antisense oligonucleotides (ODNs), the current study evaluated the functional role of ODC in the process of neuronal damage after transient focal cerebral ischemia induced by middle cerebral artery occlusion (MCAO) in spontaneously hypertensive rats. Transient MCAO significantly increased the ODC immunoreactive protein levels and catalytic activity in the ipsilateral cortex, which were completely prevented by the infusion of antisense ODN specific for ODC. Transient MCAO in rats infused with ODC antisense ODN increased the infarct volume, motor deficits, and mortality compared with the sense or random ODN-infused controls. Results of the current study support a neuroprotective or recovery role, or both, for ODC after transient focal ischemia.

scholarly journals Acute Treatment with Rosuvastatin Protects Insulin Resistant (C57BL/6J ob/ob) Mice against Transient Cerebral Ischemia

2008 ◽  
Vol 28 (12) ◽  
pp. 1927-1935 ◽  
Author(s):  
Keita Mayanagi ◽  
Prasad V Katakam ◽  
Tamas Gáspár ◽  
Ferenc Domoki ◽  
David W Busija
Keyword(s):  
Cerebral Ischemia ◽  
Focal Cerebral Ischemia ◽  
Infarct Volume ◽  
Artery Occlusion ◽  
Blood Cholesterol ◽  
Doppler Flowmetry ◽  
Insulin Resistant ◽  
Transient Focal Cerebral Ischemia ◽  
Intracellular Adhesion Molecule ◽  
Cerebral Artery Occlusion

The purpose of this study was to investigate the short-term effects of rosuvastatin (RSV), a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, on transient, focal cerebral ischemia in C57BL/6J ob/ob mice with insulin resistance (IR). Male ob/ob, lean, or wild-type (WT) mice were treated with RSV (10 mg/kg per day, i.p.) or vehicle for 3 days. Ischemia was induced by 60 mins of middle cerebral artery occlusion (MCAO) and cortical blood flow (CBF) was monitored by laser-Doppler flowmetry. Infarct volumes were measured 24 h after reperfusion. IR mice exhibited a higher infarct volume compared with Lean or WT mice, and RSV reduced infarct volume only in obese mice (40% ± 3% versus 32% ± 3%, P < 0.05). Blood cholesterol and insulin levels were elevated in ob/ob mice but were unaffected by RSV. The CBF reductions during MCAO were similar in all groups and were not affected by RSV. Although RSV did not increase cortical endothelial NO synthase (eNOS) levels in the ob/ob mice, it attenuated the increased cortical expression of intracellular adhesion molecule-1 (ICAM-1) after MCAO from ob/ob mice. Thus, RSV protects against stroke in IR mice by a mechanism independent of effects on the lipid profile, CBF, or eNOS but dependent on suppression of post-MCAO ICAM-1 expression.

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