Kasai Hironori, Yamamoto Kozo, Koseki Takeyoshi, Yokota Makoto, Nishihara Tatsuji
Department of Oral Microbiology, Kyushu Dental College, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu 803-8580, Japan.
FEMS Microbiol Lett. 2004 Apr 1;233(1):29-35. doi: 10.1016/j.femsle.2004.01.034.
We previously reported that infection with the periodontopathic bacterium Actinobacillus actinomycetemcomitans induced apoptosis in a mouse macrophage cell line J774.1. In the present study, we examined the involvement of cytochrome c and caspases in the induction of apoptosis in A. actinomycetemcomitans-infected J774.1 cells. Following infection, the expression levels of cytochrome c, and cleaved forms of caspase-3 and caspase-9 in the cells were examined using immunoblot analysis. Cytochrome c was released from mitochondria into the cytoplasm after A. actinomycetemcomitans-infected J774.1 cells were cultured for 6 h, and caspase-3 and caspase-9 were found to be cleaved forms in the cells. Further, caspase-9 activity was markedly increased, and phosphorylated p53 was detected in the cells 30 h following infection. These results suggest that apoptosis in A. actinomycetemcomitans-infected J774.1 cells is regulated by the release of cytochrome c from mitochondria into cytoplasm and the subsequent activation of caspases through phosphorylation of p53.
我们之前报道过，牙周病原菌伴放线放线杆菌感染可诱导小鼠巨噬细胞系J774.1发生凋亡。在本研究中，我们检测了细胞色素c和半胱天冬酶在伴放线放线杆菌感染的J774.1细胞凋亡诱导过程中的作用。感染后，使用免疫印迹分析检测细胞中细胞色素c以及半胱天冬酶-3和半胱天冬酶-9的裂解形式的表达水平。伴放线放线杆菌感染的J774.1细胞培养6小时后，细胞色素c从线粒体释放到细胞质中，并且发现细胞中的半胱天冬酶-3和半胱天冬酶-9为裂解形式。此外，感染后30小时，细胞中的半胱天冬酶-9活性显著增加，并且检测到磷酸化的p53。这些结果表明，伴放线放线杆菌感染的J774.1细胞中的凋亡是由细胞色素c从线粒体释放到细胞质中以及随后通过p53磷酸化激活半胱天冬酶来调节的。
