Miller T A, Smith G S, Banan A, Kokoska E R
Theodore Cooper Surgical Research Institute, Department of Surgery, Saint Louis University Health Sciences Center, St. Louis, Missouri 63104, USA.
Microsc Res Tech. 2000 Oct 15;51(2):149-55. doi: 10.1002/1097-0029(20001015)51:2<149::AID-JEMT6>3.0.CO;2-M.
This report summarizes the findings of a series of studies undertaken to discern the role of the cytoskeleton in intestinal injury and defense. Two established cell lines were used for these studies. IEC-6 cells (a rat intestinal cell line) were incubated in Eagle's minimal essential medium with and without 16, 16 dimethyl prostaglandin E(2) (dmPGE(2); 2.6 microM) for 15 minutes and subsequently incubated in medium containing 10% ethanol (EtOH). The effects on cell viability and the actin cytoskeleton were then determined. Using a similar protocol, Caco-2 cells (a human colonic cell line) were employed to assess the microtubule cytoskeleton under these conditions. In both cell lines, EtOH extensively disrupted the cytoskeletal component being evaluated coincident with adversely affecting cell viability. Pretreatment with dmPGE(2) increased cell viability and abolished the disruptive effects on both the actin and microtubule cytoskeleton in cells exposed to EtOH. Prior incubation with cytochalasin D, an actin disruptive agent, prevented the protective capabilities of dmPGE(2) in IEC-6 cells challenged with EtOH. Phalloidin, an actin stabilizing agent, demonstrated similar effects to that of dmPGE(2) by stabilizing the actin cytoskeleton and preserving cellular viability in IEC-6 cells in response to EtOH. In Caco-2 cells, taxol, a microtubule stabilizing agent, mimicked the effects of dmPGE(2) by increasing cell viability in cells exposed to EtOH and enhancing microtubular integrity. In contrast, pretreatment with colchicine, an inhibitor of microtubule integrity, prevented the protective effects of dmPGE(2). These findings support the hypothesis that the cytoskeleton may be a major target for injury in damaged intestinal epithelium, and that the protective action of dmPGE(2) is orchestrated through preservation of this target.
本报告总结了一系列旨在探讨细胞骨架在肠道损伤与防御中作用的研究结果。这些研究使用了两种已建立的细胞系。IEC - 6细胞（一种大鼠肠道细胞系）在含有和不含16,16 - 二甲基前列腺素E(2)（dmPGE(2)；2.6微摩尔）的伊格尔最低必需培养基中孵育15分钟，随后在含有10%乙醇（EtOH）的培养基中孵育。然后测定其对细胞活力和肌动蛋白细胞骨架的影响。采用类似方案，使用Caco - 2细胞（一种人结肠细胞系）来评估在这些条件下的微管细胞骨架。在这两种细胞系中，乙醇广泛破坏所评估的细胞骨架成分，同时对细胞活力产生不利影响。用dmPGE(2)预处理可提高细胞活力，并消除乙醇对细胞肌动蛋白和微管细胞骨架的破坏作用。预先用细胞松弛素D（一种肌动蛋白破坏剂）孵育，可阻止dmPGE(2)对受乙醇攻击的IEC - 6细胞的保护能力。鬼笔环肽（一种肌动蛋白稳定剂）通过稳定肌动蛋白细胞骨架并在IEC - 6细胞中维持细胞活力以应对乙醇，表现出与dmPGE(2)类似的效果。在Caco - 2细胞中，紫杉醇（一种微管稳定剂）通过提高受乙醇攻击的细胞的活力并增强微管完整性，模拟了dmPGE(2)的作用。相反，用秋水仙碱（一种微管完整性抑制剂）预处理可阻止dmPGE(2)的保护作用。这些发现支持了以下假设：细胞骨架可能是受损肠道上皮损伤的主要靶点，并且dmPGE(2)的保护作用是通过保护这一靶点来协调的。
