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.1471-4159.2000.0741951.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
创伤性脑损伤后能量缺乏可改变离子稳态、神经传递、生物合成和细胞运输。利用体外脑损伤模型，我们验证了牵张损伤改变星形胶质细胞和神经元线粒体膜电位和三磷酸腺苷的假设。生长在硅橡胶膜上的星形胶质细胞、纯神经元培养物以及神经元和神经胶质混合体培养物分别承受轻度、中度和重度拉伸。伤后用罗丹明-123法测定βpsi(M)，用荧光素-荧光素酶法定量测定ATP。在星形胶质细胞中，轻度或中度牵张后15min，Delta psi(M)显著下降，ATP含量下降43-52%，但在24 h后恢复，在纯神经元中，只有重度牵张组的Delta psi(M)在15min时才下降。损伤后48h，重度牵拉神经元的Delta psi(M)持续下降，中度牵张神经元的Delta psi(M)下降。损伤后的纯神经元细胞内ATP含量无明显变化。我们还发现星形胶质细胞和神经元在损伤后释放细胞外的三磷酸腺苷。与单纯神经元相比，神经元和胶质细胞混合培养的神经元在轻、中、重度牵拉后15min，Delta psi(M)下降，24~48h恢复，混合培养细胞中的ATP含量在轻、重度牵拉后24小时下降22~28%，我们的结果表明损伤导致星形胶质细胞线粒体功能障碍，提示星形胶质细胞损伤改变了局部神经元的线粒体功能。
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.