Fluoxetine inhibits matrix metalloprotease activation and prevents disruption of blood-spinal cord barrier after spinal cord injury
Fluoxetine inhibits matrix metalloprotease activation and prevents disruption of blood-spinal cord barrier after spinal cord injury
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DOI：
10.1093/brain/aws171
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发表时间：
2012-08-01
期刊：
影响因子：
14.5
通讯作者：
Yune, Tae Y.
中科院分区：
文献类型：
--
作者：
Lee, Jee Y.;Kim, Hwang S.;Yune, Tae Y.
脊髓损伤后，基质金属蛋白酶的激活破坏血脊髓屏障是导致血细胞浸润、炎症反应和神经细胞死亡的关键事件，从而导致永久性神经功能障碍。最近的证据表明，抗抑郁药物氟西汀在缺血性脑损伤中具有神经保护作用，但其保护作用的确切机制在很大程度上尚不清楚。在这里，我们表明，氟西汀通过抑制脊髓损伤后基质金属蛋白酶的激活来防止血脊髓屏障的破坏。无限水平冲击器致小鼠T9节段脊髓中度挫伤后，给予氟西汀(10 mg/kg)腹腔注射，1次/d，持续给药时间。氟西汀治疗可显著抑制脊髓损伤后基质金属蛋白酶2、9和12的信使RNA表达。通过酶谱和荧光酶活性测定，氟西汀还显著降低了创伤后基质金属蛋白酶2和9的活性。此外，氟西汀还抑制缺氧-葡萄糖剥夺/复氧后脑血管内皮细胞系bEnd.3核因子-kappaB依赖的基质金属蛋白酶9的表达。在体内和bEnd培养中，氟西汀还可以减轻损伤后紧密连接分子的丢失，如闭锁小带1和闭锁蛋白。通过免疫荧光染色，氟西汀可阻止损伤后血管内皮细胞紧密连接完整性的破坏。此外，氟西汀还可抑制Groα、MIP1α和1β等趋化因子的信使RNA表达，阻止中性粒细胞和巨噬细胞的浸润，减少损伤后炎症介质的表达。最后，氟西汀减轻了损伤后细胞的死亡，改善了损伤后的运动功能。因此，我们的结果表明，氟西汀促进脊髓损伤后功能恢复的部分机制是通过抑制基质金属蛋白酶的激活和防止血脊髓屏障的破坏。此外，我们的研究表明，氟西汀可能是一种潜在的治疗药物，用于保护人类缺血性脑损伤和脊髓损伤后血脑屏障的完整性。
After spinal cord injury, the disruption of blood-spinal cord barrier by activation of matrix metalloprotease is a critical event leading to infiltration of blood cells, inflammatory responses and neuronal cell death, contributing to permanent neurological disability. Recent evidence indicates that fluoxetine, an anti-depressant drug, is shown to have neuroprotective effects in ischaemic brain injury, but the precise mechanism underlying its protective effects is largely unknown. Here, we show that fluoxetine prevented blood-spinal cord barrier disruption via inhibition of matrix metalloprotease activation after spinal cord injury. After a moderate contusion injury at the T9 level of spinal cord with an infinite horizon impactor in the mouse, fluoxetine (10 mg/kg) was injected intraperitoneally and further administered once a day for indicated time points. Fluoxetine treatment significantly inhibited messenger RNA expression of matrix metalloprotease 2, 9 and 12 after spinal cord injury. By zymography and fluorimetric enzyme activity assay, fluoxetine also significantly reduced matrix metalloprotease 2 and matrix metalloprotease 9 activities after injury. In addition, fluoxetine inhibited nuclear factor kappa B-dependent matrix metalloprotease 9 expression in bEnd.3, a brain endothelial cell line, after oxygen-glucose deprivation/reoxygenation. Fluoxetine also attenuated the loss of tight junction molecules such as zona occludens 1 and occludin after injury in vivo as well as in bEnd.3 cultures. By immunofluorescence staining, fluoxetine prevented the breakdown of the tight junction integrity in endothelial cells of blood vessel after injury. Furthermore, fluoxetine inhibited the messenger RNA expression of chemokines such as Gro alpha, MIP1 alpha and 1 beta, and prevented the infiltration of neutrophils and macrophages, and reduced the expression of inflammatory mediators after injury. Finally, fluoxetine attenuated apoptotic cell death and improved locomotor function after injury. Thus, our results indicate that fluoxetine improved functional recovery in part by inhibiting matrix metalloprotease activation and preventing blood-spinal cord barrier disruption after spinal cord injury. Furthermore, our study suggests that fluoxetine may represent a potential therapeutic agent for preserving blood-brain barrier integrity following ischaemic brain injury and spinal cord injury in humans.