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Autophagy protects human brain microvascular endothelial cells against methylglyoxal‐induced injuries, reproducible in a cerebral ischemic model in diabetic rats
Author(s) -
Fang Lili,
Li Xue,
Zhong Yinbo,
Yu Jing,
Yu Lina,
Dai Haibin,
Yan Min
Publication year - 2015
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/jnc.13277
Subject(s) - autophagy , bafilomycin , ischemia , lactate dehydrogenase , viability assay , pharmacology , methylglyoxal , blood–brain barrier , endothelial stem cell , streptozotocin , medicine , biology , chemistry , endocrinology , diabetes mellitus , cell , biochemistry , central nervous system , apoptosis , enzyme , in vitro
Cerebral microvascular endothelial cells ( EC s) 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 si RNA , 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 BECN 1 si RNA exacerbated MGO ‐induced HBMEC injury. FAK phosphorylation inhibitor PF 573228 inhibited MGO ‐triggered autophagy and enhanced lactate dehydrogenase release. Meanwhile, similar autophagy activation in brain vascular EC s 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.Cerebral microvascular endothelial cells ( EC s) are crucial for brain vascular repair and maintenance, but their physiological function is impaired during ischemic stroke and diabetes. In this study, we found methylglyoxal (MGO) decreased human brain microvascular endothelial cells ( HBMEC ) cell viability in a concentration and time dependent manner, which was accompanied by the responsive autophagy activation. Autophagy inhibitors exacerbated ( MGO )‐induced HBMEC injury. FAK phosphorylation inhibitor PF 573228 inhibited MGO ‐triggered autophagy and enhanced LDH release. Meanwhile, the similar autophagy activation in brain vascular EC s was observed during permanent middle cerebral artery occlusion ( pMCAO )‐induced cerebral ischemia in diabetic rats, and chloroquine ‐induced autophagy inhibition enhanced BBB permeability. This study indicates that autophagy triggered by MGO defends HBMEC against injuries.