Cytotoxic Effects of Periodontopathic Bacteria on Human Gingival Epithelial Cell Cultured in Serum-Free Medium.

本研究旨在探讨牙周病原菌在体外对细胞增殖、蛋白质合成及细胞损伤的影响。从微生物中提取的超声波提取物包括伴生放线菌、牙龈假单胞菌、中间假单胞菌、金黄色葡萄球菌、腐蚀性葡萄球菌、核假单胞菌、粘性金黄色葡萄球菌和变形链球菌。以无血清培养的角质形成细胞SCC9和牙周角质形成细胞为靶细胞。结果表明，腐蚀性假单胞菌对SCC9的细胞增殖和蛋白质合成速率有强烈的抑制作用，在相似浓度下，伴生放线菌、牙龈假单胞菌和芽孢杆菌对SCC9细胞的增殖和蛋白质合成也有明显的抑制作用，而中间假单胞菌、核假单胞菌、粘性假单胞菌和变形杆菌的作用较小。这些结果表明，角质形成细胞的功能可能受到牙周病原菌的调节。细胞分离试验是用A…的多形核白细胞和/或细菌超声提取液进行的更多。放线菌伴生放线菌、福氏放线菌、核型放线菌、斯氏放线菌和腐蚀性放线菌。细菌提取物本身不会对角质形成细胞单层造成细胞破坏。单用多形核白细胞仅可引起微小的细胞脱离。相反，当细菌提取物加入角质形成细胞和多形核白细胞的共培养中时，除腐蚀性细菌提取物外，角质形成细胞均有细胞脱落。伴生放线菌的作用最强。这种作用不能被多粘菌素B抑制，但能被α1-抗胰蛋白酶抑制，但不能被过氧化氢酶和超氧化物歧化酶抑制。过氧化氢和白细胞弹性蛋白酶也可引起角质形成细胞脱离，未见角质形成细胞溶解。这些结果表明，中性粒细胞在接触某些细菌时会引起牙周角质形成细胞的非溶解细胞脱离，从而可能导致角质形成细胞层通透性的增加。较少

The purpose of this investigation was to study the effects of selected periodontal pathogens on cell proliferation, protein synthesis and cell injury in vitro.The ultrasonic extracts from microorganisms included A. actinomycetemcomitans, P. gingivalis, P. intermedia, C. sputigena, E. corrodens, F. nucleatum, A. viscosus and St. mutans. Target cells were keratinocytes SCC9 and gingival keratinocytes cultured in serum-free medium. The results showed that cell proliferation and rate of protein synthesis by SCC9 were strongly inhibited by E. corrodens ; at similar concentrations A. actinomycetemcomitans, P. gingivalis and C. sputigena also significantly reduced the proliferation and synthesis whereas P. intez-media, F. nucleatum, A. viscosus and St. mutans had only minor ef f ects. These results indicate that keratinocyte function may be modulated by periodontopathic bacteria.The cell detachment assay was subjected by polymorphonuclear leukocytes and/or bacterial ultrasonic extracts from A … More . actinomycetemcomitans, B. forsythus, F. nucleatum, C. sputigena and E. corrodens. The bacterial extracts alone caused no cell disruption of the keratinocyte monolayers. Polymorphonuclear leukocyte alone caused only a minimal cell detachment. On the contrary, when the bacterial extracts were added to the co-culture of keratinocytes and polymorphonuclear leukocytes, cell detachment of keratinocytes was observed except for the bacterial extract f rom E. corrodens. The effect of A. actinomycetemcomitans was strongest. This effect was heat labile and not inhibited by polymyxin B. Cell detachment was inhibited by alpha 1-antitrypsin but not by catalase and superoxide dismutase. Hydrogen peroxide and leukocyte elastase also caused keratinocyte detachment, and keratinocyte lysis was not observed. These results indicate that polymorphonuclear leukocyte can cause non-lytic cell detachment of the gingival keratinocytes when encountering some bacteria, which may lead to the increase of the permeability of the keratinocyte layers. Less