Stretch-induced injury alters mitochondrial membrane potential and cellular ATP in cultured astrocytes and neurons
Stretch-induced injury alters mitochondrial membrane potential and cellular ATP in cultured astrocytes and neurons
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DOI：
10.1046/j.1471-4159.2000.741951000000000.x
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发表时间：
2000-05-01
影响因子：
4.7
通讯作者：
Ellis, EF
中科院分区：
文献类型：
--
作者：
Ahmed, SM;Rzigalinski, BA;Ellis, EF
创伤性脑损伤（TBI）后的能量缺乏可能会改变离子稳态、神经传递、生物合成和细胞转运。使用TBI的体外模型，我们测试了牵张诱导的损伤改变星形胶质细胞和神经元中的线粒体膜电位（Δ psi（m））和ATP的假设。星形胶质细胞，纯神经元培养物，和混合神经元加上神经胶质细胞培养物上生长的硅橡胶膜进行轻度，中度和严重的拉伸。在损伤后，使用罗丹明-123测量Δ psi（m），并且用荧光素酶测定定量ATP。在星形胶质细胞中，Δ psi（m）在轻度或中度牵张后15 min显著下降，ATP含量下降43-52%，但在24 h时恢复。在纯神经元中，仅在严重拉伸组中，Delta psi（m）在15 min时下降。伤后48 h，重度牵张神经元的Δ psi（m）仍呈下降趋势，中度牵张神经元的Δ psi（m）也呈下降趋势。细胞内ATP含量没有改变任何组的损伤纯神经元。我们还发现星形胶质细胞和神经元在损伤后细胞外释放ATP。与纯神经元相比，神经元加胶质细胞混合培养的神经元中的Δ psi（m）在轻度、中度或重度牵张后15分钟下降，并在24-48小时恢复。轻度至重度牵张后，混合培养物中ATP含量下降22-28%，24 h后恢复。我们的研究结果表明，损伤导致星形胶质细胞线粒体功能障碍，并表明星形胶质细胞损伤改变局部神经元线粒体功能。
Energy deficit after traumatic brain injury (TBI) may alter ionic homeostasis, neurotransmission, biosynthesis, and cellular transport. Using an in vitro model for TBI, we tested the hypothesis that stretch-induced injury alters mitochondrial membrane potential (Delta psi(m)) and ATP in astrocytes and neurons. Astrocytes, pure neuronal cultures, and mixed neuronal plus glial cultures grown on Silastic membranes were subjected to mild, moderate, and severe stretch. After injury, Delta psi(m), was measured using rhodamine-123, and ATP was quantified with a luciferin-luciferase assay. In astrocytes, Delta psi(m) dropped significantly, and ATP content declined 43-52% 15 min after mild or moderate stretch but recovered by 24 h. In pure neurons, Delta psi(m) declined at 15 min only in the severely stretched group. At 48 h postinjury, Delta psi(m) remained decreased in severely stretched neurons and dropped in moderately stretched neurons. Intracellular ATP content did not change in any group of injured pure neurons. We also found that astrocytes and neurons release ATP extracellularly following injury. In contrast to pure neurons, Delta psi(m) in neurons of mixed neuronal plus glial cultures declined 15 min after mild, moderate, or severe stretch and recovered by 24-48 h. ATP content in mixed cultures declined 22-28% after mild to severe stretch with recovery by 24 h. Our findings demonstrate that injury causes mitochondrial dysfunction in astrocytes and suggest that astrocyte injury alters mitochondrial function in local neurons.