Pentoxifylline modulates intestinal tight junction signaling after burn injury: effects on myosin light chain kinase.
Pentoxifylline modulates intestinal tight junction signaling after burn injury: effects on myosin light chain kinase.
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DOI：
10.1097/ta.0b013e318191bb1f
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发表时间：
2009-01
期刊：
影响因子：
--
通讯作者：
Coimbra R
中科院分区：
文献类型：
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作者：
Costantini TW;Loomis WH;Putnam JG;Kroll L;Eliceiri BP;Baird A;Bansal V;Coimbra R
烧伤可导致肠屏障功能丧失，导致全身炎症反应综合征和多器官功能衰竭。肌球蛋白轻链激酶（MLCK）是一种参与屏障功能调节的紧密连接蛋白，激活后可增加肠上皮通透性。先前的研究表明，肿瘤坏死因子（TNF）-α激活MLCK，部分通过核因子（NF）-κ B依赖性途径。我们以前已经证明，戊茶碱（PTX）减少TNF-α的合成和NF-κB激活休克模型。因此，我们推测PTX会减弱紧密连接蛋白MLCK的激活，这可能会降低严重烧伤后肠道紧密连接通透性。将经历严重烧伤的雄性balb/c小鼠随机分配至用生理盐水（NS）或NS + PTX（12.5mg/kg）复苏。采用酶联免疫吸附试验评价肠道TNF-α水平。获得肠道提取物，通过免疫印迹法评估MLCK、磷酸化IKK、IκB-α和NF-κB p65水平。烧伤使NS复苏的动物肠MLCK蛋白水平增加3倍，而接受PTX的动物的MLCK水平与对照组相似（p < 0.01）。PTX治疗减弱了烧伤引起的肠道通透性。PTX使细胞质IKK、IκB-α磷酸化和核NF-κB p65易位降低至假手术水平（p < 0.05 vs. NS）。PTX治疗减弱了紧密连接蛋白MLCK的活化，可能是通过其减少烧伤后局部TNF-α合成和NF-κB活化的能力。PTX可能通过减少烧伤后肠屏障破坏而具有治疗效用。
Burn injury can result in loss of intestinal barrier function, leading to systemic inflammatory response syndrome and multiorgan failure. Myosin light chain kinase (MLCK), a tight junction protein involved in the regulation of barrier function, increases intestinal epithelial permeability when activated. Prior studies have shown that tumor necrosis factor (TNF)-α activates MLCK, in part through a nuclear factor (NF)-κ B-dependent pathway. We have previously shown that pentoxifylline (PTX) decreases both TNF-α synthesis and NF-κB activation in models of shock. Therefore, we postulate that PTX will attenuate activation of the tight junction protein MLCK, which may decrease intestinal tight junction permeability after severe burn. Male balb/c mice undergoing a severe burn were randomized to resuscitation with normal saline (NS) or NS + PTX (12.5 mg/kg). Intestinal TNF-α levels were evaluated using enzyme linked immunosorbent assay. Gut extracts were obtained to assess MLCK, phosphorylated IKK, IκB-α, and NF-κB p65 levels by immunoblotting. Burn injury increased intestinal MLCK protein levels threefold in animals resuscitated with NS, whereas those receiving PTX had MLCK levels similar to control (p < 0.01). Treatment with PTX attenuated burn-induced intestinal permeability. PTX decreased cytoplasmic IKK, IκB-α phosphorylation, and nuclear NF-κB p65 translocation to sham levels (p < 0.05 vs. NS). Treatment with PTX attenuates activation of the tight junction protein MLCK, likely through its ability to decrease local TNF-α synthesis and NF-κB activation after burn. PTX may have therapeutic utility by decreasing intestinal barrier breakdown after burn.