Abstract |
Cerebral microvascular endothelial cells (ECs) are crucial for brain vascular repair and maintenance, but their physiological function may be impaired during ischemic stroke and diabetes. Methylglyoxal (MGO), a reactive dicarbonyl produced during glucose metabolism, could exacerbate ischemia-induced EC injury and dysfunction. We investigated the protective effect of autophagy on cultured human brain microvascular endothelial cells (HBMEC) that underwent MGO treatment. A further study was conducted to explore the underlying mechanisms of the protective effect. Autophagic activity was assessed by evaluating protein levels, using western blot. 3-methyladenine (3-MA), bafilomycin A1, ammonium chloride (AC), Beclin 1 siRNA, and chloroquine (CQ) were used to cause autophagy inhibition. Alarmar blue assay and lactate dehydrogenase release assay were used to evaluate cell viability. Streptozotocin was administered to induce type I diabetes in rats and post-permanent middle cerebral artery occlusion was performed to elicit cerebral ischemia. Blood-brain barrier permeability was also assessed. Our study found that MGO reduced HBMEC cell viability in a concentration- and time-dependent manner, and triggered the responsive autophagy activation. Autophagy inhibitors bafilomycin A1, AC, 3-MA, and BECN1 siRNA exacerbated MGO-induced HBMEC injury. FAK phosphorylation inhibitor PF573228 inhibited MGO-triggered autophagy and enhanced lactate dehydrogenase release. Meanwhile, similar autophagy activation in brain vascular ECs was observed during permanent middle cerebral artery occlusion-induced cerebral ischemia in diabetic rats, while chloroquine-induced autophagy inhibition enhanced blood-brain barrier permeability. Taken together, our study indicates that autophagy triggered by MGO defends HBMEC against injuries.
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Authors | Lili Fang, Xue Li, Yinbo Zhong, Jing Yu, Lina Yu, Haibin Dai, Min Yan |
Journal | Journal of neurochemistry
(J Neurochem)
Vol. 135
Issue 2
Pg. 431-40
(Oct 2015)
ISSN: 1471-4159 [Electronic] England |
PMID | 26251121
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Copyright | © 2015 International Society for Neurochemistry. |
Chemical References |
- Pyruvaldehyde
- Focal Adhesion Kinase 1
|
Topics |
- Animals
- Autophagy
(drug effects)
- Blood-Brain Barrier
(drug effects)
- Brain Ischemia
(chemically induced, drug therapy)
- Capillaries
(cytology, drug effects)
- Cell Line
- Cell Survival
(drug effects)
- Diabetes Mellitus, Experimental
(pathology)
- Diabetes Mellitus, Type 1
(chemically induced, pathology)
- Diabetic Angiopathies
(pathology)
- Endothelial Cells
(drug effects)
- Focal Adhesion Kinase 1
(metabolism)
- Humans
- Male
- Middle Cerebral Artery
(pathology)
- Pyruvaldehyde
(toxicity)
- RNA Interference
(drug effects)
- Rats
- Rats, Sprague-Dawley
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