Mechanical stretch to neurons results in a strain rate and magnitude-dependent increase in plasma membrane permeability
Mechanical stretch to neurons results in a strain rate and magnitude-dependent increase in plasma membrane permeability
复制标题
DOI：
10.1089/089771503770195885
复制
发表时间：
2003-10-01
影响因子：
4.2
通讯作者：
LaPlaca, MC
中科院分区：
文献类型：
--
作者：
Geddes, DM;Cargill, RS;LaPlaca, MC
对脑组织的机械冲击转换为神经元损伤的机制仍然知之甚少。使用神经元拉伸的体外模型，我们发现神经元的机械拉伸导致了短暂的质膜通透性增加。初级皮质神经元，接种在硅基板上，受到一个定义的速率和幅度的应变脉冲通过拉伸基板超过一个固定的圆柱形。为了鉴定质膜缺陷，在损伤前即刻或损伤后1、2、5或10分钟将各种大小的荧光分子加入到浴介质中，并在1分钟后除去。细胞吸收染料的百分比取决于施加的应变速率、应变大小和分子大小。剧烈拉伸（10秒（-1），0.30）导致所有测试分子（半径范围在0.5和8.9 nm之间）的显著摄取，高达60%的细胞被阳性染色。此外，神经元保持可渗透的最小分子（羧基荧光素，380 Da）后5分钟，严重的拉伸，但仅可渗透较大的分子（大于或等于10 kDa）后立即拉伸。这些瞬时形成的膜缺陷可能是将机械拉伸转化为细胞功能障碍的起始机制。
The mechanism by which mechanical impact to brain tissue is transduced to neuronal impairment remains poorly understood. Using an in vitro model of neuronal stretch, we found that mechanical stretch of neurons resulted in a transient plasma membrane permeability increase. Primary cortical neurons, seeded on silicone substrates, were subjected to a defined rate and magnitude strain pulse by stretching the substrates over a fixed cylindrical form. To identify plasma membrane defects, various sized fluorescent molecules were added to the bathing media either immediately before injury or 1, 2, 5, or 10 min after injury and removed one minute later. The percent of cells that took up dye depended on the applied strain rate, strain magnitude and molecular size. Severe stretch (10 sec(-1), 0.30) resulted in significant uptake of all tested molecules (ranging between 0.5 and 8.9 nm radii) with up to 60% of cells positively stained. Furthermore, the neurons remained permeable to the smallest molecule (carboxyfluorescein, 380 Da) up to 5 min after severe stretch but were only permeable to larger molecules (greater than or equal to10 kDa) immediately after stretch. These transiently formed membrane defects may be the initiating mechanism that translates mechanical stretch to cellular dysfunction.