Division of Medical Microbiology, Department of Clinical and Experimental Medicine, Linköping University, SE-58185 Linköping, Sweden.
Eur J Cell Biol. 2010 Aug;89(8):584-97. doi: 10.1016/j.ejcb.2010.03.002.
In Pseudomonas aeruginosa, cell-cell communication based on acyl-homoserine lactone (HSL) quorum sensing molecules is known to coordinate the production of virulence factors and biofilms by the bacterium. Incidentally, these bacterial signals can also modulate mammalian cell behaviour. We demonstrate here that 3O-C(12)-HSL can induce changes in calcium signalling through influx and release of calcium from thapsigargin-sensitive stores and delocalization of inositol 1,4,5-trisphosphate receptors (IP(3)R), but not of ryanodine receptors (RyR). In parallel, P. aeruginosa 3O-C(12)-HSL disrupts junctions in human Caco-2 cells as evidenced by a reduction of the expression and distribution of ZO-3 and JAM-A. Using co-immunoprecipitation we also found an alteration in the binding of ZO-3 to JAM-A in protein complexes. Moreover, 3O-C(12)-HSL-treatment resulted in tyrosine hyperphosphorylation of ZO-3 and JAM-A. On the contrary, serine and threonine residues of ZO-1 and JAM-A became less phosphorylated after exposition of 3O-C(12)-HSL. The 3O-C(12)-HSL-induced intracellular calcium signalling and alteration in the phosphorylation status of junction proteins furthermore correlated with changes in the association between JAM-A-ZO-3. The calcium inhibitors thapsigargin, xestospongin C, and dantrolene partly prevented the 3O-C(12)-HSL-induced decreases in TER and increases in the paracellular flux of 10kDa dextran. These findings clearly suggest that P. aeruginosa 3O-C(12)-HSL can cause the loss of epithelial barrier function via calcium signalling and further alteration in the phosphorylation status of junction proteins; and that bacterial quorum sensing signals represent inter-kingdom signalling.
在铜绿假单胞菌中，基于酰基高丝氨酸内酯 (HSL) 群体感应分子的细胞间通讯被认为可以协调细菌产生毒力因子和生物膜。顺便说一句，这些细菌信号也可以调节哺乳动物细胞的行为。我们在这里证明，3O-C(12)-HSL 可以通过钙从 thapsigargin 敏感储存库的内流和释放以及肌醇 1,4,5-三磷酸受体 (IP(3)R) 的去定位来诱导钙信号的变化，但不会引起肌醇 1,4,5-三磷酸受体 (IP(3)R) 的变化。同时，铜绿假单胞菌 3O-C(12)-HSL 破坏了人 Caco-2 细胞的连接，这表现为 ZO-3 和 JAM-A 的表达和分布减少。通过共免疫沉淀，我们还发现 ZO-3 与 JAM-A 在蛋白质复合物中的结合发生了改变。此外，3O-C(12)-HSL 处理导致 ZO-3 和 JAM-A 的酪氨酸过度磷酸化。相反，暴露于 3O-C(12)-HSL 后，ZO-1 和 JAM-A 的丝氨酸和苏氨酸残基的磷酸化程度降低。3O-C(12)-HSL 诱导的细胞内钙信号和连接蛋白磷酸化状态的改变与 JAM-A-ZO-3 之间的关联变化进一步相关。钙抑制剂 thapsigargin、xestospongin C 和 dantrolene 部分阻止了 3O-C(12)-HSL 诱导的 TER 降低和 10kDa 葡聚糖的细胞旁通量增加。这些发现清楚地表明，铜绿假单胞菌 3O-C(12)-HSL 可以通过钙信号和进一步改变连接蛋白的磷酸化状态导致上皮屏障功能丧失；并且细菌群体感应信号代表了种间信号。
