Department of Medical Research, MacKay Memorial Hospital, New Taipei City, Taiwan.
Department of Bioscience Technology, Chung Yuan Christian University, Taoyuan City, Taiwan.
Cell Mol Neurobiol. 2019 Jul;39(5):591-604. doi: 10.1007/s10571-019-00665-9. Epub 2019 Mar 9.
It is known that cerebral ischemia can cause brain inflammation and adiposome can serve as a depot of inflammatory mediators. In the study, the pro-inflammatory and pro-death role of adiposome in ischemic microglia and ischemic brain was newly investigated. The contribution of PPARγ to adiposome formation was also evaluated for the first time in ischemic microglia. Focal cerebral ischemia/reperfusion (I/R) animal model and the in vitro glucose-oxygen-serum deprivation (GOSD) cell model were both applied in the study. GOSD- or I/R-induced adiposome formation, inflammatory activity, cell death of microglia, and brain infarction were, respectively, determined, in the absence or presence of NS-398 (adiposome inhibitor) or GW9662 (PPARγ antagonist). GOSD-increased adiposome formation played a critical role in stimulating the inflammatory activity (production of TNF-α and IL-1β) and cell death of microglia. Similar results were also found in ischemic brain tissues. GOSD-induced PPARγ partially contributed to the increase of adiposomes and adiposome-mediated inflammatory responses of microglia. Blockade of adiposome formation with NS-398 or GW9662 significantly reduced not only the inflammatory activity and death rate of GOSD-treated microglia but also the brain infarct volume and motor function deficit of ischemic rats. The pathological role of microglia-derived adiposome in cerebral ischemia has been confirmed and attributed to its pro-inflammatory and/or pro-death effect upon ischemic brain cells and tissues. Adiposome and its upstream regulator PPARγ were therefore as potential targets for the treatment of ischemic stroke. Therapeutic values of NS-398 and GW9662 have been suggested.
已知脑缺血可引起脑炎症,脂肪体可作为炎症介质的储存库。在这项研究中,新研究了脂肪体在缺血性小胶质细胞和缺血性脑中的促炎和促死作用。还首次评估了 PPARγ 在缺血性小胶质细胞中对脂肪体形成的贡献。研究中同时应用了局灶性脑缺血再灌注(I/R)动物模型和体外葡萄糖-氧-血清剥夺(GOSD)细胞模型。分别在不存在或存在 NS-398(脂肪体抑制剂)或 GW9662(PPARγ 拮抗剂)的情况下,测定了 GOSD 或 I/R 诱导的脂肪体形成、小胶质细胞的炎症活性、细胞死亡和脑梗死。GOSD 增加的脂肪体形成在刺激小胶质细胞的炎症活性(TNF-α和 IL-1β的产生)和细胞死亡中起关键作用。在缺血性脑组织中也发现了类似的结果。GOSD 诱导的 PPARγ 部分有助于增加脂肪体和脂肪体介导的小胶质细胞炎症反应。用 NS-398 或 GW9662 阻断脂肪体形成不仅显著降低了 GOSD 处理的小胶质细胞的炎症活性和死亡率,而且还降低了缺血大鼠的脑梗死体积和运动功能缺陷。已经证实了小胶质细胞衍生的脂肪体在脑缺血中的病理作用,并归因于其对缺血性脑细胞和组织的促炎和/或促死亡作用。因此,脂肪体及其上游调节剂 PPARγ 是治疗缺血性中风的潜在靶点。已经提出了 NS-398 和 GW9662 的治疗价值。