Autophagy protects human brain microvascular endothelial cells against methylglyoxal-induced injuries, reproducible in a cerebral ischemic model in diabetic rats
Autophagy protects human brain microvascular endothelial cells against methylglyoxal-induced injuries, reproducible in a cerebral ischemic model in diabetic rats
复制标题
自噬保护人脑微血管内皮细胞免受甲基乙二醛诱导的损伤，这在糖尿病大鼠的脑缺血模型中可重现。
DOI：
10.1111/jnc.13277
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发表时间：
2015-10-01
影响因子：
4.7
通讯作者：
Yan, Min
中科院分区：
文献类型：
--
作者：
Fang, Lili;Li, Xue;Yan, Min
脑微血管内皮细胞（ECs）是脑血管修复和维持的关键细胞，但其生理功能在缺血性脑卒中和糖尿病时可能受损。丙酮醛（MGO）是葡萄糖代谢过程中产生的活性二羰基化合物，可加重缺血诱导的EC损伤和功能障碍。我们研究了自噬对经过MGO处理的培养的人脑微血管内皮细胞（HBMEC）的保护作用。进一步研究了其保护作用的机制。自噬活性通过使用蛋白质印迹评估蛋白质水平来评估。3-甲基腺嘌呤（3-MA）、巴弗洛霉素A1、氯化铵（AC）、Beclin 1 siRNA和氯喹（CQ）用于引起自噬抑制。采用Alarmar蓝法和乳酸脱氢酶释放法检测细胞活力。给药链脲佐菌素诱导大鼠I型糖尿病，并进行永久性大脑中动脉闭塞后引起脑缺血。还评估了血脑屏障通透性。我们的研究发现，MGO以浓度和时间依赖性方式降低HBMEC细胞活力，并触发响应性自噬激活。自噬抑制剂巴弗洛霉素A1、AC、3-MA和BECN 1 siRNA加重了MGO诱导的HBMEC损伤。FAK磷酸化抑制剂PF 573228抑制MGO触发的自噬并增强乳酸脱氢酶释放。同时，在糖尿病大鼠大脑中动脉永久性闭塞诱导的脑缺血期间观察到脑血管内皮细胞中类似的自噬激活，而氯喹诱导的自噬抑制增强血脑屏障通透性。总之，我们的研究表明，由MGO引发的自噬保护HBMEC免受损伤。
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.