Supplementary Material for: Pretreatment with 17β-Estradiol Attenuates Cerebral Ischemia-Induced Blood-Brain Barrier Disruption in Aged Rats: Involvement of Antioxidant Signaling

<b><i>Background/Aims:</i></b> Blood-brain barrier (BBB) disruption is often induced in brain injury and particularly associated with cerebral ischemia in stroke. Estradiol (17β-estradiol 3-benzoate, E2), an endogenous steroid hormone, has been reported to play a protective role against cerebrovascular pathologies. Here we aimed to determine the potential effects of E2 on the integrity of BBB and brain damage following middle cerebral artery occlusion (MCAO). <b><i>Methods:</i></b> Aged (24- month-old) ovariectomized female rats were administered E2 for 2 months through daily intraperitoneal injections prior to induction of MCAO. <b><i>Results:</i></b> Compared to vehicle controls, E2 had a dose-dependent effect in reducing the severity of brain injuries while maintaining the integrity of the BBB in aged rats. The neuroprotective effects of E2 were associated with the rescued tight junction loss, decreased oxidative stress, and attenuated ERK activation in the ischemic brains. <b><i>Conclusion:</i></b> Our data suggest a beneficial role of E2 in aged stroke patients, associated with a protective effect of E2 against BBB disruption in aging-related brain ischemia.

<b><i>背景与目的：</i></b> 血脑屏障（Blood-brain barrier, BBB）破坏常继发于脑损伤，且与脑卒中后的脑缺血病变密切相关。雌二醇（17β-雌二醇3-苯甲酸酯，E2）作为一种内源性甾体激素，既往研究已证实其可对脑血管病理过程发挥保护作用。本研究旨在探讨E2对大脑中动脉闭塞（middle cerebral artery occlusion, MCAO）模型大鼠的血脑屏障完整性及脑损伤的潜在影响。<b><i>方法：</i></b> 选取24月龄去卵巢雌性大鼠，在构建大脑中动脉闭塞模型前，通过每日腹腔注射的方式给予E2，持续给药2个月。<b><i>结果：</i></b> 与溶剂对照组相比，E2可呈剂量依赖性减轻老年大鼠的脑损伤程度，同时维持血脑屏障的完整性。E2的神经保护作用与缺血脑组织中紧密连接丢失得到挽救、氧化应激水平降低以及细胞外调节蛋白激酶（Extracellular Regulated Protein Kinases, ERK）激活减弱密切相关。<b><i>结论：</i></b> 本研究数据表明，E2对老年脑卒中患者具有有益作用，其保护机制与E2可缓解衰老相关脑缺血中的血脑屏障破坏有关。