Metformin attenuates the effect of Staphylococcus aureus on airway tight junctions by increasing PKCζ-mediated phosphorylation of occludin.
Metformin attenuates the effect of Staphylococcus aureus on airway tight junctions by increasing PKCζ-mediated phosphorylation of occludin.
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二甲双胍通过增加 PKC 介导的 occludin 磷酸化来减弱金黄色葡萄球菌对气道紧密连接的影响。
DOI：
10.1111/jcmm.13929
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发表时间：
2019-01
影响因子：
5.3
通讯作者：
Baines DL
中科院分区：
文献类型：
--
作者：
Kalsi KK;Garnett JP;Patkee W;Weekes A;Dockrell ME;Baker EH;Baines DL
气道上皮紧密连接 (TJ) 蛋白形成对外部环境的抵抗屏障，然而，在呼吸道细菌感染期间，TJ 会被破坏，从而损害屏障功能。这促进了葡萄糖流入/积累到管腔中，作为细菌生长的营养源。用于治疗糖尿病的二甲双胍会增加跨上皮阻力（TEER）并部分阻止细菌的作用，但作用机制尚不清楚。我们研究了二甲双胍和金黄色葡萄球菌对人气道上皮细胞 (H441) 中 TJ 蛋白、小带闭合蛋白 (ZO)-1 和闭合蛋白的影响。我们还探讨了 AMP 激活蛋白激酶 (AMPK) 和 PKCδ 在二甲双胍诱导作用中的作用。二甲双胍预处理可防止金黄色葡萄球菌诱导的 ZO-1 和 occludin 变化。二甲双胍还促进全长丰度比较小的切割闭合蛋白增加。非特异性 PKC 抑制剂星形孢菌素可降低 TEER，但不能阻止二甲双胍的作用，表明该途径可能涉及非典型 PKC 亚型。钙消耗后 TJ 重新组装的研究表明，二甲双胍更快地增加 TEER，并促进 TJ 上 Occludin 的丰度和定位。这些作用可被 AMPK 抑制剂、化合物 C 和 PKC z 假底物抑制剂 (PSI) 抑制。二甲双胍增加了occludin和乙酰辅酶A羧化酶的磷酸化，但PSI仅阻止前者。这项研究表明，二甲双胍通过促进 TJ 处全长 Occludin 的丰度和组装来改善 TJ 屏障功能，并且该过程涉及通过 AMPK-PKCζ 途径对该蛋白质进行磷酸化。
Airway epithelial tight junction (TJ) proteins form a resistive barrier to the external environment, however, during respiratory bacterial infection TJs become disrupted compromising barrier function. This promotes glucose flux/accumulation into the lumen which acts as a nutrient source for bacterial growth. Metformin used for the treatment of diabetes increases transepithelial resistance (TEER) and partially prevents the effect of bacteria but the mechanisms of action are unclear. We investigated the effect of metformin and Staphylococcus aureus on TJ proteins, zonula occludins (ZO)‐1 and occludin in human airway epithelial cells (H441). We also explored the role of AMP‐activated protein kinase (AMPK) and PKCζ in metformin‐induced effects. Pretreatment with metformin prevented the S. aureus‐induced changes in ZO‐1 and occludin. Metformin also promoted increased abundance of full length over smaller cleaved occludin proteins. The nonspecific PKC inhibitor staurosporine reduced TEER but did not prevent the effect of metformin indicating that the pathway may involve atypical PKC isoforms. Investigation of TJ reassembly after calcium depletion showed that metformin increased TEER more rapidly and promoted the abundance and localization of occludin at the TJ. These effects were inhibited by the AMPK inhibitor, compound C and the PKCζ pseudosubstrate inhibitor (PSI). Metformin increased phosphorylation of occludin and acetyl‐coA‐carboxylase but only the former was prevented by PSI. This study demonstrates that metformin improves TJ barrier function by promoting the abundance and assembly of full length occludin at the TJ and that this process involves phosphorylation of the protein via an AMPK‐PKCζ pathway.
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影响因子：
4.5
作者：
Kalsi, Kameljit K.;Baker, Emma H.;Baines, Deborah L.
通讯作者：
Baines, Deborah L.
影响因子：
--
作者：
ATISOOK, K;CARLSON, S;MADARA, JL
通讯作者：
MADARA, JL
影响因子：
6.4
作者：
Malik, Zacki;Roscioli, Eugene;Vreugde, Sarah
通讯作者：
Vreugde, Sarah
通过表达突变型紧密连接膜蛋白，细胞旁通透性和跨上皮电阻的功能性分离以及顶端-基底外侧膜内扩散屏障的破坏。
影响因子：
7.8
作者：
Balda, M S;Whitney, J A;Flores, C;Gonzalez, S;Cereijido, M;Matter, K
通讯作者：
Matter, K
单个基因产物Claudin -1或-2，在成纤维细胞中重构紧密结合的连接链和新兵。
影响因子：
7.8
作者：
Furuse, M;Sasaki, H;Fujimoto, K;Tsukita, S
通讯作者：
Tsukita, S