EFFECT OF HYPERTHERMIA ON BRAIN ENDOTHELIAL CELLS - IN VITRO STUDY -

高温对脑内皮细胞的影响 - 体外研究 -

• 批准号: 03670676
• 负责人: TAKEUCHI Shigekazu
• 金额: $ 1.28万
• 依托单位: NIIGATA UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1991
• 资助国家: 日本
• 起止时间: 1991 至 1992
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-03670676/
• 关键词: Endothelial cell; Brain; Hyperthermia; Blood-brain barrier; Actin; Albumin; Dextran; Survival; endothelium; bloodーbrain barrier; hyperthermia; in vitro

The role of physical and functional barrier between the blood and brain is played by endothelial cell layer. There have been few laboratory studies about the effect of hyperthermia to the endothelial barrier integrity. The aim of the present study was to investigate the effect of temperature on endothelial cells and the barrier function. We used endothelial cells isolated from rat brain in our laboratory. In each experiments, endothelial cell monolayers were heated at 42, 43, 44ﾟC for 60 min with water bath. Morphological study of endothelial cells heated at 44ﾟC revealed a lot of cell deaths within 24 hrs. At 43ﾟC, cellular atrophies and microvacuolations were sometimes shown. However, at 42ﾟC, no morphological changes were observed.Survival of heated endothelial cells were investigated by colony forming assays. Heating at 42ﾟC of endothelial cells did not influence cell survival. Over 43ﾟC, survival curve was depressed, depending on temperature and the time of heating. To determine the permeability of endothelial monolayers, we examined a transport of albumin or dextran (M.W.70000) labeled by fluorescein, using double chamber systems.The transport of albumin through endothelial monolayers was increased only by heating at 44ﾟC. However,that of dextran was not changed at any heating conditions. It was considered that gap formations between endothelial cells could explain the increase of albumin transport. Also, the distribution of actins stained by rhodamine-phalloidin in endothelial cells was changed by hyperthermia. At 44ﾟC, almost all actins immediately disappeared. At 43ﾟC, an transient accumulation of actins around the nucleus was observed within 24 hrs after heating. These phenomenon could be considered some cell protective responses, such as heat shock proteins. Our study indicates that endothelial cells are influenced by hyperthermia over 43ﾟC, then, the barrier function is collapsed at 44ﾟC.

内皮细胞层在血液和脑之间起着物理和功能屏障的作用。关于高温对内皮屏障完整性影响的实验室研究很少。本研究旨在探讨温度对内皮细胞及其屏障功能的影响。我们在实验室中使用从大鼠脑中分离的内皮细胞。在每个实验中，用水浴在42、43、44 ℃下加热内皮细胞单层60 min。44 ℃热处理的内皮细胞在24小时内大量死亡。在43 ℃时，有时会出现细胞萎缩和微空泡。然而，在42 ℃下，没有观察到形态学变化。在42 ℃加热内皮细胞不影响细胞存活。43 ℃以上，存活曲线下降，随温度升高和加热时间延长而下降。为了确定内皮细胞单层的通透性，我们用双室系统检测了荧光素标记的白蛋白或葡聚糖（M.W.70000）的转运，只有在44 ℃加热时，白蛋白通过内皮细胞单层的转运才增加。然而，在任何加热条件下，右旋糖酐的含量都没有改变。认为内皮细胞之间间隙的形成可以解释白蛋白转运的增加。此外，肌动蛋白染色罗丹明鬼笔环肽在内皮细胞的分布被高温改变。在44 ℃时，几乎所有肌动蛋白立即消失。在43 ℃时，在加热后24小时内观察到肌动蛋白在细胞核周围的瞬时积累。这些现象可以被认为是某些细胞的保护性反应，如热休克蛋白。我们的研究表明，内皮细胞受到超过43 ℃的高温的影响，然后，屏障功能在44 ℃时崩溃。