Polyethylene glycols interact with membrane glycerophospholipids: is this part of their mechanism for hypothermic graft protection?
Polyethylene glycols interact with membrane glycerophospholipids: is this part of their mechanism for hypothermic graft protection?
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DOI：
10.1007/s12154-009-0014-x
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发表时间：
2009-03-01
期刊：
影响因子：
--
通讯作者：
Holmsen, Holm
中科院分区：
文献类型：
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作者：
Dutheil, Delphine;Underhaug Gjerde, Anja;Holmsen, Holm
聚乙二醇（PEG）是一种存在于新的器官保存溶液中的高分子量胶体，可防止冷缺血损伤，从而使移植器官具有更好的移植功能。这种保护作用不能完全用免疫抑制特性或信号通路的改变来解释。因此，我们寻求依赖于膜流动性的替代机制。使用朗缪尔-波克尔技术，我们在这里表明，PEG与脂质单层的定义的组合物或构成的肾细胞脂质提取物相互作用。高分子量PEG在低表面压力下稳定脂质单层。奇怪的是，在高表面压力下，PEG使单分子膜不稳定。低温降低饱和单层的不稳定性，而不饱和单层保持不受影响。离子强度和pH的改变诱导PEG 35，000 Da的更强的稳定作用，这可以解释其在器官移植期间对冷诱导损伤的更高有效性的报道。这项研究揭示了一个新的光PEG在器官保存过程中的保护作用不同于所有经典的假设。
Polyethylene glycol (PEG), a high-molecular-weight colloid present in new organ preservation solutions, protects against cold ischemia injuries leading to better graft function of transplanted organs. This protective effect cannot be totally explained by immuno-camouflaging property or signaling-pathway modifications. Therefore, we sought for an alternative mechanism dependent on membrane fluidity. Using the Langmuir-Pockles technique, we show here that PEGs interacted with lipid monolayers of defined composition or constituted by a renal cell lipid extract. High-molecular-weight PEGs stabilized the lipid monolayer at low surface pressure. Paradoxically, at high surface pressure, PEGs destabilized the monolayers. Hypothermia reduced the destabilization of saturated monolayer whereas unsaturated monolayer remained unaffected. Modification of ionic strength and pH induced a stronger stabilizing effect of PEG 35,000 Da which could explain its reported higher effectiveness on cold-induced injuries during organ transplantation. This study sheds a new light on PEG protective effects during organ preservation different from all classical hypotheses.