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.

Melatonin and calpeptin synergistically protect against post-reperfusion injury in a rat middle cerebral artery occlusion stroke model

2021 ◽  
Vol 4 (4) ◽  
pp. 592-612
Author(s):  
Ye Feng ◽  
Qian Xu ◽  
Raymond Tak Fai Cheung
Keyword(s):  
Cerebral Ischemia ◽  
Middle Cerebral Artery ◽  
Reperfusion Injury ◽  
Middle Cerebral Artery Occlusion ◽  
Cerebral Artery ◽  
Neurological Deficit ◽  
Infarct Volume ◽  
Artery Occlusion ◽  
Stroke Model ◽  
Cerebral Artery Occlusion

Cerebral ischemia induces oxidative injury and increases the intracellular calcium ion concentration to activate several calcium-dependent proteases such as calpains. Calpain activation leads to various necrotic and apoptotic processes. Calpeptin is a potent, cell-permeable calpain inhibitor. As a strong antioxidant and free radical scavenger, melatonin shows beneficial effect in rodent models of focal cerebral ischemia when given prior to ischemia or reperfusion. This study was focused on the neuroprotective effects of melatonin and/or calpeptin given after onset of reperfusion. For this purpose, right-sided middle cerebral artery occlusion (MCAO) for 90 minutes followed by 24 or 72 hours of reperfusion was performed in male Sprague Dawley rats, then, melatonin 50 or 150 µg/kg, calpeptin 10, 15 or 50 µg/kg or a combination of melatonin 50 µg/kg plus calpeptin 15 or 50 µg/kg were injected via an intracerebroventricular route at 15 minutes after onset of reperfusion. Melatonin or calpeptin tended to reduce the relative infarct volume and significantly decreased the neurological deficit at 24 hours. The combination achieved a greater protection than each of them alone. Melatonin, calpeptin or the combination all decreased Fluoro-Jade B (FJB)+ degenerative neurons and cleaved/total caspase-3 ratio at 24 hours. These treatments did not significantly impact the density of surviving neurons and ED-1+ macrophage/activated microglia. At the 72-hour-reperfusion, melatonin or the combination decreased the relative infarct volume and neurological deficit. Nevertheless, only the combination reduced FJB+ degenerating neurons at 72 hours. In conclusion, a combination of melatonin and calpeptin exerted synergistic protection against post-reperfusion injury in a rat MCAO stroke model.

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.

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