PDF(Pubmed)
Abstract：
Mitochondrial integrity and function constitute a prerequisite for cellular function and repair processes. We have previously shown that mitochondria of different cell types exhibit pronounced fragmentation under hypothermic conditions. This fission, accompanied by a decline of cellular ATP content, showed reversibility at 37◦C. However, it is unclear whether other temperatures as currently discussed for reconditioning of organs allow this reconstitution of mitochondria. Therefore, we here study in a model of cultured porcine aortic endothelial cells how different rewarming temperatures affect mitochondrial re-fusion and function. After 48 h cold incubation of endothelial cells in Krebs-Henseleit buffer with glucose (5 mM) and deferoxamine (1 mM) at 4◦C pronounced mitochondrial fission was observed. Following 2 h rewarming in cell culture medium, marked fission was still present after rewarming at 10◦ or 15◦C. At 21◦C some re-fusion was visible, which became more marked at 25◦C. Networks of tubular mitochondria similar to control cells only re-appeared at 37◦C. ATP content decreased at 4◦C from 3.6 ± 0.4 to 1.6 ± 0.4 nmol/106 cells and decreased even further when rewarming cells to 10◦ and 15◦C. Values after rewarming at 21◦C were similar to the values before rewarming while ATP gradually increased at higher rewarming temperatures. Metabolic activity dropped to 5 ± 11% of control values during 4◦C incubation and recovered with increasing temperatures to 36 ± 10% at 25◦C and 78 ± 17% at 37◦C. Integrity of monolayers, largely disturbed at 4◦C (large gaps between endothelial cells; cell injury ≤ 1%), showed partial recovery from 15◦C upwards, complete recovery at 37◦C. Endothelial repair processes (scratch assay) at 25◦C were clearly inferior to those at 37◦C. These data suggest that reconditioning temperatures below 21◦C are not optimal with regard to reconstitution of mitochondrial integrity and function. For this goal, temperatures of at least 25◦C appear required, with 30◦C being superior and 37◦C yielding the best results.
摘要：
线粒体完整性和功能构成细胞功能和修复过程的先决条件。我们先前已经表明，不同细胞类型的线粒体在低温条件下表现出明显的碎片化。这个裂变,伴随着细胞ATP含量的下降，在37°C时显示出可逆性。然而,目前尚不清楚目前讨论的其他器官修复温度是否允许线粒体重建。因此,我们在培养的猪主动脉内皮细胞模型中研究不同复温温度对线粒体再融合和功能的影响.在4℃下用葡萄糖（5mM）和去铁胺（1mM）在Krebs-Henseleit缓冲液中将内皮细胞冷孵育48小时后，观察到明显的线粒体裂变。在细胞培养基中复温2小时后，在重新加温后，仍存在明显的裂变，温度为10°C或15°C。在21°C时，一些重新融合是可见的，在25°C时变得更加明显。与对照细胞相似的管状线粒体网络仅在37°C时重新出现。ATP含量在4°C时从3.6±0.4降低到1.6±0.4nmol/106个细胞，并且在将细胞重新加温到10°C和15°C时进一步降低。在21°C复温后的值与复温前的值相似，而ATP在较高的复温温度下逐渐增加。代谢活性下降到5±11%的对照值在4℃的培养过程中，并随着温度的升高而恢复到36±10%在25℃和78±17%在37℃。单层的完整性，在4°C时受到很大程度的干扰(内皮细胞之间的间隙大；细胞损伤≤1%)，显示从15°C向上的部分恢复，在37°C时完全恢复。25°C时的内皮修复过程（划痕分析）明显低于37°C时的过程。这些数据表明，对于线粒体完整性和功能的重建，低于21°C的修复温度不是最佳的。为了这个目标,至少需要25°C的温度，30°C更优，37°C产生最佳结果。
