Invasion of epithelial cells and proteolysis of cellular focal adhesion components by distinct types of Porphyromonas gingivalis fimbriae
Invasion of epithelial cells and proteolysis of cellular focal adhesion components by distinct types of Porphyromonas gingivalis fimbriae
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DOI：
10.1128/iai.01902-05
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发表时间：
2006-07-01
影响因子：
3.1
通讯作者：
Amano, Atsuo
中科院分区：
文献类型：
--
作者：
Nakagawa, Ichiro;Inaba, Hiroaki;Amano, Atsuo
牙龈卟啉单胞菌（Porphyromonas gingivalis）菌毛根据其菌毛亚基FimA基因分为6种类型（I ~ V型和Ib型），它们在细菌与宿主组织的相互作用中起着关键作用。在这项研究中，我们比较了牙龈卟啉单胞菌菌株的效率与不同类型的菌毛的上皮细胞的侵袭和降解的细胞粘着斑成分，桩蛋白，粘着斑激酶（FAK）。测试了具有不同类型菌毛的六种代表性菌株，并且具有II型菌毛的牙龈卟啉单胞菌（II型牙龈卟啉单胞菌）以比其他菌株显著更高的水平粘附并侵入上皮细胞。有牙龈卟啉菌蛋白酶的活动之间的六个菌株的差异可以忽略不计，然而，II型牙龈卟啉单胞菌明显降解细胞内桩蛋白与磷酸化的损失30分钟后感染。用细胞松弛素D或在fimA被破坏的突变体中阻断降解。桩蛋白被赖氨酸-牙龈菌蛋白酶破坏的突变体降解，并且通过N α-对甲苯磺酰基-L-赖氨酸氯甲基酮抑制Arg-牙龈菌蛋白酶活性来防止这种降解。FAK也被II型牙龈卟啉单胞菌降解。与绿色荧光蛋白-桩蛋白大聚集体的细胞局灶性粘附被清楚地破坏，这与细胞形态学变化和微管解体有关。在体外伤口闭合测定中，与用其他类型观察到的细胞迁移和增殖相比，II型牙龈卟啉单胞菌显著抑制细胞迁移和增殖。这些结果表明，II型牙龈卟啉单胞菌有效地侵入上皮细胞，并降解与Arg-牙龈卟啉单胞菌蛋白酶的粘着斑成分，这导致伤口愈合和牙周组织再生过程中的细胞损伤。
Porphyromonas gingivalis fimbriae are classified into six types (types I to V and Ib) based on the fimA genes encoding FimA (a subunit of fimbriae), and they play a critical role in bacterial interactions with host tissues. In this study, we compared the efficiencies of P. gingivalis strains with distinct types of fimbriae for invasion of epithelial cells and for degradation of cellular focal adhesion components, paxillin, and focal adhesion kinase (FAK). Six representative strains with the different types of fimbriae were tested, and P. gingivalis with type II fimbriae (type II P. gingivalis) adhered to and invaded epithelial cells at significantly greater levels than the other strains. There were negligible differences in gingipain activities among the six strains; however, type II P. gingivalis apparently degraded intracellular paxillin in association with a loss of phosphorylation 30 min after infection. Degradation was blocked with cytochalasin D or in mutants with fimA disrupted. Paxillin was degraded by the mutant with Lys-gingipain disrupted, and this degradation was prevented by inhibition of Arg-gingipain activity by N alpha-p-tosyl-L-lysine chloromethyl ketone. FAK was also degraded by type II P. gingivalis. Cellular focal adhesions with green fluorescent protein-paxillin macroaggregates were clearly destroyed, and this was associated with cellular morphological changes and microtubule disassembly. In an in vitro wound closure assay, type II P. gingivalis significantly inhibited cellular migration and proliferation compared to the cellular migration and proliferation observed with the other types. These results suggest that type II P. gingivalis efficiently invades epithelial cells and degrades focal adhesion components with Arg-gingipain, which results in cellular impairment during wound healing and periodontal tissue regeneration.