MitoKATP opener, diazoxide, reduces neuronal damage after middle cerebral artery occlusion in the rat

2002 ◽  
Vol 283 (3) ◽  
pp. H1005-H1011 ◽  
Author(s):  
Katsuyoshi Shimizu ◽  
Zsombor Lacza ◽  
Nishadi Rajapakse ◽  
Takashi Horiguchi ◽  
James Snipes ◽  
...  

We investigated effects of diazoxide, a selective opener of mitochondrial ATP-sensitive K+ (mitoKATP) channels, against brain damage after middle cerebral artery occlusion (MCAO) in male Wistar rats. Diazoxide (0.4 or 2 mM in 30 μl saline) or saline (sham) was infused into the right lateral ventricle 15 min before MCAO. Neurological score was improved 24 h later in the animals treated with 2 mM diazoxide (13.8 ± 0.7, n = 13) compared with sham treatment (9.5 ± 0.2, n = 6, P < 0.01). The total percent infarct volume (MCAO vs. contralateral side) of sham treatment animals was 43.6 ± 3.6% ( n = 12). Treatment with 2 mM diazoxide reduced the infarct volume to 20.9 ± 4.8% ( n = 13, P < 0.05). Effects of diazoxide were prominent in the cerebral cortex. The protective effect of diazoxide was completely prevented by the pretreatment with 5-hydroxydecanoate (100 mM in 10 μl saline), a selective blocker of mitoKATP channels ( n = 6). These results indicate that selective opening of the mitoKATP channel has neuroprotective effects against ischemia-reperfusion injury in the rat brain.

Stroke ◽  
2021 ◽  
Vol 52 (3) ◽  
pp. 1053-1064
Author(s):  
Shuaishuai Gong ◽  
Guosheng Cao ◽  
Fang Li ◽  
Zhuo Chen ◽  
Xuewei Pan ◽  
...  

Background and Purpose: In ischemic stroke, breakdown of the blood-brain barrier (BBB) aggravates brain damage. Endothelial detachment contributes to BBB disruption and neurovascular dysfunction, but its regulation in stroke has yet to be clarified. We investigated the function of NMMHC IIA (nonmuscle myosin heavy chain IIA) in the endothelium on BBB breakdown and its potential mechanisms. Methods: Endothelial conditional knockdown NMMHC IIA ( Myh9 ECKD ) was constructed in vivo and in vitro, and its role was explored in middle cerebral artery occlusion/reperfusion–injured mice and oxygen-glucose deprivation/reoxygenation–injured brain microvascular endothelial cells. The degree of brain injury was analyzed using staining (2,3,5-triphenyltetrazolium chloride, hematoxylin, and eosin) and electron microscopy. BBB breakdown was investigated with leakage of Evans Blue dye and expression of TJs (tight junctions) and MMP (matrix metallopeptidase)-2/9. Transcriptomics for enrichment analysis was adopted to explore the potential downstream signaling pathways of NMMHC IIA involved in middle cerebral artery occlusion/reperfusion–induced BBB dysfunction. Results: NMMHC IIA expression was upregulated in endothelial cells after cerebral ischemia/reperfusion injury. Myh9 ECKD mice exhibited improvement in endothelial barrier hyperpermeability and TJs integrity stimulated by cerebral ischemia/reperfusion. Blebbistatin (NMMHC II inhibitor) treatment exerted the same effect. Transcriptomics showed that NMMHC IIA was involved in regulating various BBB-related genomic changes in the middle cerebral artery occlusion/reperfusion model, and NMMHC IIA was confirmed to significantly modulate Hippo and peroxisome proliferator-activated receptor gamma/nuclear factor-kappa B signaling pathways, which are closely related to BBB damage. Conclusions: Our findings provide some new insights into how NMMHC IIA contributes to maintaining the integrity of the cerebral endothelial barrier. NMMHC IIA could be a potential therapeutic target for ischemic stroke.


Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4124
Author(s):  
Maozhu Liu ◽  
Mengyuan Chen ◽  
Ying Luo ◽  
Hong Wang ◽  
Haifeng Huang ◽  
...  

Celastrol, a pentacyclic triterpene isolated from the traditional Chinese medicine Tripterygium wilfordii Hook. F., exhibits effectiveness in protection against multiple central nervous system (CNS) diseases such as cerebral ischemia, but its influence on lipidomics still remains unclear. Therefore, in the present study, the efficacy and potential mechanism of celastrol against cerebral ischemia/reperfusion (I/R) injury were investigated based on lipidomics. Middle cerebral artery occlusion (MCAO) followed by reperfusion was operated in mice to set up a cerebral I/R model. TTC staining and TUNEL staining were used to evaluate the therapeutic effect of celastrol. Ultra-performance liquid chromatography-tandem mass spectrometry (UPLC/MS) was employed for lipidomics analysis in ipsilateral hemisphere and plasma. Celastrol remarkably reduced cerebral infarct volume and apoptosis positive cells in tMCAO mice. Furthermore, lipidomics analysis showed that 14 common differentially expressed lipids (DELs) were identified in brain and five common DELs were identified in plasma between the Sham, tMCAO and Celastrol-treated tMCAO groups. Through enrichment analysis, sphingolipid metabolism and glycerophospholipid metabolism were demonstrated to be significantly enriched in all the comparison groups. Among the DELs, celastrol could reverse cerebral I/R injury-induced alteration of phosphatidylcholine, phosphatidylethanolamine and sulfatide, which may be responsible for the neuroprotective effect of celastrol. Our findings suggested the neuroprotection of celastrol on cerebral I/R injury may be partially associated with its regulation of lipid metabolism.


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