title: Aggregatibacter actinomycetemcomitans Invasion Induces Interleukin-1β Production Through Reactive Oxygen Species and Cathepsin B.
abstract: Interleukin-1 (IL-1) cytokines, IL-1α, IL-1β, and IL-18 play a crucial role in inflammatory responses in a variety of diseases including periodontitis. In this study, the periodontopathic bacterial pathogen, Aggregatibacter actinomycetemcomitans, induced cell death and cytokine release in macrophages. Cell viability was reduced by A. actinomycetemcomitans invasion using (3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide assay. The production of IL-1β in A. actinomycetemcomitans-invaded macrophage cells was detected by real-time reverse transcriptase-polymerase chain reaction, western blotting, and enzyme-linked immunosorbent assay. Treatment with a caspase-1 inhibitor and silencing of the caspase-1 gene had no effect on IL-1β secretion induced by A. actinomycetemcomitans invasion. Pattern recognition receptor, NLRP3 was upregulated in A. actinomycetemcomitans-invaded macrophages. However, NLRP3 knockdown had no effect on the secretion of IL-1β in A. actinomycetemcomitans-invaded RAW 264 cells. In addition, A. actinomycetemcomitans invasion induced the generation of reactive oxygen species (ROS) and the release of cathepsin B in RAW 264 cells. Interestingly, CA074-Me, a cathepsin B inhibitor, and N-Acetyl-l-cysteine, a ROS inhibitor, prevented the production of IL-1β induced by A. actinomycetemcomitans. Taken together, these results suggest A. actinomycetemcomitans induce IL-1β production in RAW 264 cells through the production of ROS and cathepsin B, but not through the NLRP3/caspase-1 pathway.
authors: Division of Infections and Molecular Biology, Department of Health Promotion, Kyushu Dental University , Kitakyushu, Japan .
authors: Toshinori
authors: T
authors: Okinaga
authors: Division of Infections and Molecular Biology, Department of Health Promotion, Kyushu Dental University , Kitakyushu, Japan .
authors: Wataru
authors: W
authors: Ariyoshi
authors: Division of Infections and Molecular Biology, Department of Health Promotion, Kyushu Dental University , Kitakyushu, Japan .
authors: Tatsuji
authors: T
authors: Nishihara
mesh_terms: D016976:Aggregatibacter actinomycetemcomitans / Q000472:pathogenicity / Q000502:physiology*; D000818:Animals; D001854:Bone Marrow Cells / Q000378:metabolism / Q000382:microbiology / Q000473:pathology; D002352:Carrier Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D020170:Caspase 1 / Q000235:genetics / Q000378:metabolism; D002401:Cathepsin B / Q000235:genetics / Q000378:metabolism*; D016923:Cell Death; D002460:Cell Line; D002470:Cell Survival; D005786:Gene Expression Regulation; D054884:Host-Pathogen Interactions; D006801:Humans; D058847:Inflammasomes / Q000378:metabolism; D053583:Interleukin-1beta / Q000235:genetics / Q000378:metabolism*; D008264:Macrophages / Q000378:metabolism* / Q000382:microbiology / Q000473:pathology; D008297:Male; D051379:Mice; D000071199:NLR Family, Pyrin Domain-Containing 3 Protein; D061251:Primary Cell Culture; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D015843:Serpins / Q000494:pharmacology; D015398:Signal Transduction; D014764:Viral Proteins / Q000494:pharmacology
chemical_list: D002352:Carrier Proteins; D058847:Inflammasomes; D053583:Interleukin-1beta; D000071199:NLR Family, Pyrin Domain-Containing 3 Protein; C492716:Nlrp3 protein, mouse; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species; D015843:Serpins; D014764:Viral Proteins; C074641:interleukin-1beta-converting enzyme inhibitor; D002401:Cathepsin B; D020170:Caspase 1