Lin Y C, Ho C H, Grinnell F
Department of Cell Biology and Neuroscience, University of Texas Southwestern Medical School, Dallas 75235, USA.
Mol Biol Cell. 1997 Jan;8(1):59-71. doi: 10.1091/mbc.8.1.59.
When fibroblasts contract collagen matrices, the cells activate a Ca(2+)-dependent cyclic AMP signaling pathway. We have found that contraction also stimulates uptake of fluorescein isothiocyanate-dextran molecules from the medium. Our results indicate that fluorescein isothiocyanate-dextran enters directly into the cell cytoplasm through 3- to 5-nm plasma membrane passages. These passages, which reseal in less than 5 s in the presence of divalent cations, also are likely sites of Ca2+ uptake during contraction and the first step in contraction-activated cyclic AMP signaling. The formation of plasma membrane passages during fibroblast contraction may reflect a general cellular response to rapid mechanical changes.
当成纤维细胞收缩胶原基质时，细胞会激活一条依赖钙离子的环磷酸腺苷信号通路。我们发现，收缩还会刺激细胞从培养基中摄取异硫氰酸荧光素标记的葡聚糖分子。我们的结果表明，异硫氰酸荧光素标记的葡聚糖通过3至5纳米的质膜通道直接进入细胞质。这些通道在二价阳离子存在的情况下不到5秒就能重新封闭，它们也可能是收缩过程中钙离子摄取的位点以及收缩激活的环磷酸腺苷信号传导的第一步。成纤维细胞收缩过程中质膜通道的形成可能反映了细胞对快速机械变化的一种普遍反应。
