Cytochalasin B modulation of Caco-2 tight junction barrier: role of myosin light chain kinase
Cytochalasin B modulation of Caco-2 tight junction barrier: role of myosin light chain kinase
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DOI：
10.1152/ajpgi.2000.279.5.g875
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发表时间：
2000-11-01
影响因子：
4.5
通讯作者：
Merryfield, M
中科院分区：
文献类型：
--
作者：
Ma, TY;Hoa, NT;Merryfield, M
细胞松弛素介导的肠上皮紧密连接（TJ）通透性增加的细胞内机制尚不清楚。在这项研究中，我们研究了肌球蛋白轻链激酶（MLCK）在这个过程中的参与，使用过滤生长的Caco-2肠上皮细胞单层。细胞松弛素B（Cyto B）（5 μ g/ml）导致Caco-2 MLCK活性增加，这与Caco-2 TJ渗透性增加相关。抑制Cyto B诱导的MLCK活化可防止Caco-2 TJ渗透性增加。此外，肌球蛋白-Mg 2 +-ATP酶抑制剂和代谢抑制剂（抑制MLCK诱导的肌动蛋白-肌球蛋白收缩）也阻止了Cyto B诱导的Caco-2 TJ渗透性增加。Cyto B引起后期（15-30分钟）肌动蛋白片段聚集成大的肌动蛋白团块，这也被MLCK抑制剂抑制。Cyto B产生ZO-1 TJ蛋白的形态学紊乱，视觉上与Caco-2 TJ渗透性的功能性增加相关。MLCK和肌球蛋白-Mg 2 + AT-ATP抑制剂阻止TJ通透性的功能性增加和ZO-1蛋白的破坏。这些结果表明，Cyto B诱导的Caco-2 TJ渗透性增加受MLCK激活调节。
The intracellular mechanisms that mediate cytochalasin-induced increase in intestinal epithelial tight junction (TJ) permeability are unclear. In this study, we examined the involvement of myosin light chain kinase (MLCK) in this process, using the filter-grown Caco-2 intestinal epithelial monolayers. Cytochalasin B (Cyto B) (5 mug/ml) produced an increase in Caco-2 MLCK activity, which correlated with the increase in Caco-2 TJ permeability. The inhibition of Cyto B-induced MLCK activation prevented the increase in Caco-2 TJ permeability. Additionally, myosin-Mg2+-ATPase inhibitor and metabolic inhibitors (which inhibit MLCK induced actin-myosin contraction) also prevented the Cyto B-induced increase in Caco-2 TJ permeability. Cyto B caused a late-phase (15-30 min) aggregation of actin fragments into large actin clumps, which was also inhibited by MLCK inhibitors. Cyto B produced a morphological disturbance of the ZO-1 TJ proteins, visually correlating with the functional increase in Caco-2 TJ permeability. The MLCK and myosin-Mg2+ AT-Pase inhibitors prevented both the functional increase in TJ permeability and disruption of ZO-1 proteins. These findings suggested that Cyto B-induced increase in Caco-2 TJ permeability is regulated by MLCK activation.