A decrease in membrane tension precedes successful cell-membrane repair
A decrease in membrane tension precedes successful cell-membrane repair
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DOI：
10.1091/mbc.11.12.4339
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发表时间：
2000-12-01
影响因子：
3.3
通讯作者：
Steinhardt, RA
中科院分区：
文献类型：
--
作者：
Togo, T;Krasieva, TB;Steinhardt, RA
我们假设Ca2+依赖性胞外分泌在tell-membrane修复中的要求是提供足够的降低膜张力，以允许膜重新密封。我们使用激光镊子形成膜系索，并测量这些系索的力，以估计Swiss 3T3成纤维细胞在膜破裂和重新密封期间的膜张力。这些测量表明，在正常Ca2+林格溶液中损伤的成纤维细胞，在损伤和重新密封后，膜张力急剧下降，其下降幅度与对照组系绳力值的60%相似。然而，如果细胞在低Ca2+林格氏溶液中受伤，张力不会降低，这抑制了膜的再密封和胞外分泌。当细胞在正常的Ca2+林格溶液中损伤两次时，第二次伤口的张力下降速度是第一次伤口的2.3倍，与重复伤口的两倍快的重封率密切相关。促进重新密封到第二个伤口需要一个新的囊泡池，这是通过蛋白激酶C （PKC）依赖和brefeldin a （BFA）敏感的过程产生的。PKC抑制剂或BFA可减缓或抑制第二伤口的张力下降。细胞松弛素D处理降低膜张力可以代替胞外分泌，恢复低Ca2+林格氏溶液中的膜重封。
We hypothesized that the requirement for Ca2+-dependent exocytosis in tell-membrane repair is to provide an adequate lowering of membrane tension to permit membrane resealing. We used laser tweezers to form membrane tethers and measured the force of those tethers to estimate the membrane tension of Swiss 3T3 fibroblasts after membrane disruption and during resealing. These measurements show that, for fibroblasts wounded in normal Ca2+ Ringer's solution, the membrane tension decreased dramatically after the wounding and resealing coincided with a decrease of similar to 60% of control tether force values. However, the tension did not decrease if cells were wounded in a low Ca2+ Ringer's solution that inhibited both membrane resealing and exocytosis. When cells were wounded twice in normal Ca2+ Ringer's solution, deceases in tension at the second wound were 2.3 times faster than at the first wound, correlating well with twofold faster resealing rates for repeated wounds. The facilitated resealing to a second wound requires a new vesicle pool, which is generated via a protein kinase C (PKC)-dependent and brefeldin A (BFA)-sensitive process. Tension decrease at the second wound was slowed or inhibited by PKC inhibitor or BFA. Lowering membrane tension by cytochalasin D treatment could substitute for exocytosis and could restore membrane resealing in low Ca2+ Ringer's solution.