Disruption of Tight Junction Structure in Salivary Glands From Sjogren's Syndrome Patients Is Linked to Proinflammatory Cytokine Exposure
Disruption of Tight Junction Structure in Salivary Glands From Sjogren's Syndrome Patients Is Linked to Proinflammatory Cytokine Exposure
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DOI：
10.1002/art.27362
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发表时间：
2010-05-01
影响因子：
--
通讯作者：
Gonzalez, Maria-Julieta
中科院分区：
文献类型：
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作者：
Ewert, Patricia;Aguilera, Sergio;Gonzalez, Maria-Julieta
目标。腺泡细胞顶端微绒毛的紊乱和腺泡腔间质胶原的存在提示干燥综合征患者的唇唾液腺（LSG）屏障功能受损。紧密连接决定细胞极性，调节细胞旁离子和水的流动，是腺泡细胞的重要功能。本研究旨在评估SS患者LSGs中紧密连接蛋白的表达和定位，并在体外确定肿瘤坏死因子α (TNF α)和干扰素γ (IFN γ)对对照组离体腺泡细胞紧密连接完整性的影响。研究了22名患者和15名对照组。采用半定量逆转录聚合酶链反应和Western blotting检测紧密连接组分（claudin-1、claudin-3、claudin-4、occludin和ZO-1）的信使RNA和蛋白水平。免疫组化检测紧密连接蛋白定位。透射电镜观察紧密结的超微结构。对照组分离的腺泡用TNF α和IFN γ处理。SS患者紧密连接蛋白水平差异有统计学意义，ZO-1和occludin强烈下调，而claudin-1和claudin-4过表达。紧密连接蛋白只定位于LSGs的腺泡和导管的顶端结构域。在SS患者中，ZO-1和occludin的顶域存在减少，而claudin-3和claudin-4重新分布到基底外侧质膜。将分离的对照腺泡暴露于TNF α和IFN γ中，在体外再现了这些变化。超微结构分析将紧密连接的破坏与含有电子密集物质的内吞囊泡的存在联系起来，这些电子密集物质可能代表紧密连接的成分。我们的研究结果表明，SS患者LSGs中局部细胞因子的产生可能通过改变上皮细胞紧密连接的完整性，从而降低唾液的质量和数量，从而导致SS患者分泌腺功能障碍。
Objective. Disorganization of acinar cell apical microvilli and the presence of stromal collagen in the acinar lumen suggest that the labial salivary gland (LSG) barrier function is impaired in patients with Sjogren's syndrome. Tight junctions define cell polarity and regulate the paracellular flow of ions and water, crucial functions of acinar cells. This study was undertaken to evaluate the expression and localization of tight junction proteins in LSGs from patients with SS and to determine in vitro the effects of tumor necrosis factor alpha (TNF alpha) and interferon-gamma (IFN gamma) on tight junction integrity of isolated acini from control subjects.Methods. Twenty-two patients and 15 controls were studied. The messenger RNA and protein levels of tight junction components (claudin-1, claudin-3, claudin-4, occludin, and ZO-1) were determined by semiquantitative reverse transcriptase-polymerase chain reaction and Western blotting. Tight junction protein localization was determined by immunohistochemistry. Tight junction ultrastructure was examined by transmission electron microscopy. Isolated acini from control subjects were treated with TNF alpha and IFN gamma.Results. Significant differences in tight junction protein levels were detected in patients with SS. ZO-1 and occludin were strongly down-regulated, while claudin-1 and claudin-4 were overexpressed. Tight junction proteins localized exclusively to apical domains in acini and ducts of LSGs from controls. In SS patients, the ZO-1 and occludin the apical domain presence of decreased, while claudin-3 and claudin-4 was redistributed to the basolateral plasma membrane. Exposure of isolated control acini to TNF alpha and IFN gamma reproduced these alterations in vitro. Ultrastructural analysis associated tight junction disorganization with the presence of endocytic vesicles containing electron-dense material that may represent tight junction components.Conclusion. Our findings indicate that local cytokine production in LSGs from SS patients may contribute to the secretory gland dysfunction observed in SS patients by altering tight junction integrity of epithelial cells, thereby decreasing the quality and quantity of saliva.