创伤性损伤在体外引发JNK介导的人星形胶质细胞回缩。
Traumatic injury elicits JNK-mediated human astrocyte retraction in vitro.
作者信息
Augustine C, Cepinskas G, Fraser D D
机构信息
Department of Physiology and Pharmacology, Western University, London, ON, Canada; Children's Health Research Institute, London, ON, Canada; Center for Critical Illness Research, London, ON, Canada.
Center for Critical Illness Research, London, ON, Canada; Department of Medical Biophysics, Western University, London, ON, Canada; Department of Medicine, Western University, London, ON, Canada.
出版信息
Neuroscience. 2014 Aug 22;274:1-10. doi: 10.1016/j.neuroscience.2014.05.009. Epub 2014 May 15.
Brain injury causes dysfunction of the blood-brain barrier (BBB). The BBB is comprised of perivascular astrocytes whose end-feet ensheath brain microvascular endothelial cells. We investigated trauma-induced morphological changes of human astrocytes (HA) and human cerebral microvascular endothelial cells (hCMEC/D3) in vitro, including the potential role of mitogen-activated protein kinase (MAPK) signal-transduction pathways. HA or hCMEC/D3 were grown on flexible culture membranes and subjected to single traumatic injury normalized to 20%, 30% or 55% membrane deformation. Cells were assayed for morphological changes (i.e. retraction) and MAPK phosphorylation and/or expression (c-Jun NH2-terminal kinase (JNK)1/2, extracellular signal-regulated kinase (ERK)1/2, and p38). HA retraction was rapidly elicited with a single traumatic injury (55% membrane deformation; p<0.01). Morphological recovery of HA was observed within 2h (p<0.05). Traumatic injuries increased phospho-JNK1/2 (p<0.05) in HA, indicating MAPK activation. Pre-treatment of HA with structurally distinct JNK inhibitors (25μM), either SP600125 or SU3327, reduced JNK phosphorylation (p<0.05) and trauma-induced HA retraction (P<0.05). In contrast to HA, traumatic injury failed to induce either morphological changes or MAPK activation in hCMEC/D3. In summary, traumatic injury induces JNK-mediated HA retraction in vitro, while sparing morphological changes in cerebral microvascular endothelial cells. Astrocyte retraction from microvascular endothelial cells in vivo may occur after brain trauma, resulting in cellular uncoupling and BBB dysfunction. JNK may represent a potential therapeutic target for traumatic brain injuries.
脑损伤会导致血脑屏障（BBB）功能障碍。血脑屏障由血管周围星形胶质细胞组成，其终足包裹着脑微血管内皮细胞。我们在体外研究了创伤诱导的人星形胶质细胞（HA）和人脑微血管内皮细胞（hCMEC/D3）的形态变化，包括丝裂原活化蛋白激酶（MAPK）信号转导通路的潜在作用。将HA或hCMEC/D3培养在柔性培养膜上，并使其遭受标准化为20%、30%或55%膜变形的单次创伤性损伤。检测细胞的形态变化（即收缩）以及MAPK磷酸化和/或表达（c-Jun氨基末端激酶（JNK）1/2、细胞外信号调节激酶（ERK）1/2和p38）。单次创伤性损伤（55%膜变形；p<0.01）可迅速引发HA收缩。在2小时内观察到HA的形态恢复（p<0.05）。创伤性损伤增加了HA中磷酸化JNK1/2（p<0.05），表明MAPK激活。用结构不同的JNK抑制剂（25μM），即SP600125或SU3327预处理HA，可降低JNK磷酸化（p<0.05）和创伤诱导的HA收缩（P<0.05）。与HA相反，创伤性损伤未能在hCMEC/D3中诱导形态变化或MAPK激活。总之，创伤性损伤在体外诱导JNK介导的HA收缩，同时脑微血管内皮细胞形态变化不受影响。脑外伤后体内星形胶质细胞可能会从微血管内皮细胞收缩，导致细胞解偶联和血脑屏障功能障碍。JNK可能是创伤性脑损伤的一个潜在治疗靶点。
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