The following abstract was to have been included in Volume 65, Issue Supplement s1 of the American Journal of Reproductive Immunology, which was a special issue featuring the Abstracts of the 31st Annual Meeting of the American Society for Reproductive Immunology, published online in June 2011.


Synergistic effects of caffeine or nicotine and Porphyromonas gingivalis-derived LPS on matrigel invasion of an immortalized human first trimester trophoblast cell line

Shihoko Komine-Aizawa1, Yoshimitsu Abiko2, Satoshi Hayakawa1

1Department of Pathology and Microbiology, Division of Microbiology, Nihon University School of Medicine

2Department of Biochemistry and Molecular Biology, Nihon University School of Dentistry at Matsudo

Problem Periodontitis is a chronic infectious disease in subgingival cavities. Among several anaerobic gram-negative bacteriae, Porphyromonas gingivalis is the most frequent pathogen. Epidemiological studies suggest the significant association of periodontitis with systemic diseases including diabetes mellitus, atherosclerosis, and ischemic cardiovascular disorders. In pregnant women, periodontitis is believed to increase the risk of preterm delivery and intrauterine growth retardation (IUGR) as well as pre-eclampsia. However, the mechanism of periodontitis-associated pregnancy complications is so far unknown. As women with juvenile periodontitis tend to have other high-risk behaviors such as smoking and excess caffeine consumption, we examined the synergistic effects of LPS purified from P. gingivalis (PGLPS) and caffeine or nicotine on invasion activity of an immortalized human first trimester trophoblast cell line HTR8.

Materials and methods The trophoblast cell line HTR8 plated on matrigel chambers with or without PGLPS (0.1–10 μg/mL), caffeine (50 μg/mL), and/or nicotine (1 μg/mL) for 24 hr. Invasive activity was estimated by direct counting of invaded cells under a pair of stereomicroscope or colormetry. MMP-2 and MMP-9 activities were determined using gelatin zymography.

Results We observed no reduction in invasion activity by PGLPS alone. Simultaneous treatment of caffeine/nicotine with PGLPS reduced significantly the invasive activity. Furthermore, MMP-2 and MMP-9 activities were reduced by the combination of caffeine/nicotine and PGLPS. Treatment with caffeine or nicotine alone was not enough to suppress invasion up to cytotoxic concentrations.

Conclusion Our results suggest although direct pathogenic effects of P. gingivalis alone on trophoblast invasion may be limited, other high-risk behaviors including smoking and excess caffeine consumption reduce the trophoblast invasion into myometrium and inhibit maternal vascular reconstruction.