Calcium oscillations in gingival epithelial cells infected with Porphyromonas gingivalis

• Published in: Microbes and infection 2004-04, Vol.6 (5), p.440-447
• Main Authors: Belton, Carol M., Goodwin, Paul C., Fatherazi, Sahba, Schubert, Mark M., Lamont, Richard J., Izutsu, Kenneth T.
• Format: Article
• Language: English
• Subjects: Bacteriology; Biological and medical sciences; Biological Transport - drug effects; Boron Compounds - pharmacology; Calcium; Calcium - analysis; Calcium - metabolism; Calcium Channel Blockers - pharmacology; Calcium Signaling; Cell Nucleus - chemistry; Cells, Cultured; Cytoplasm - chemistry; Epithelial; Epithelial Cells - metabolism; Epithelial Cells - microbiology; Fundamental and applied biological sciences. Psychology; Fura-2 - metabolism; Gingiva - cytology; Gingiva - metabolism; Gingiva - microbiology; Gingivalis; Humans; Invasion; Keratinocyte; Lanthanum - pharmacology; Microbiology; Microscopy, Fluorescence; Oscillations; Pathogenicity, virulence, toxins, bacteriocins, pyrogens, host-bacteria relations, miscellaneous strains; Porphyromonas gingivalis; Porphyromonas gingivalis - physiology; Staining and Labeling
• ISSN: 1286-4579; 1769-714X
• DOI: 10.1016/j.micinf.2004.01.007

The periodontal pathogen Porphyromonas gingivalis modulates epithelial cell signal transduction pathways including Ca 2+ signaling, and internalizes within the host cell cytoplasm. Since nuclear and cytoplasmic [Ca 2+] increases can induce different host cell responses, P. gingivalis-related [Ca 2+] changes in these compartments were measured by digital fluorescent imaging microscopy. Non-deconvolved and deconvolved fura-2 images showed that P. gingivalis exposure caused human gingival epithelial cells cultured in physiologic [Ca 2+] levels to undergo sustained oscillations of [Ca 2+] in nuclear and cytoplasmic spaces. However, P. gingivalis invasion was not tightly correlated with intracellular [Ca 2+] oscillations, since invasion could significantly precede, or even occur in the absence of, oscillations. [Ca 2+] oscillations required a Ca 2+ influx, which was completely inhibited by La 3+ or 2-APB (2-aminoethoxydiphenyl borate), indicating Ca 2+ entry was via a Ca 2+-permeable channel. Ca 2+ entry was likely not via a store-operated channel, since Ca 2+ release from intracellular stores was not observed during cellular uptake of P. gingivalis. Hence, uptake of P. gingivalis in gingival epithelial cells induces oscillations in nuclear and cytoplasmic spaces by activating a Ca 2+ influx through Ca 2+ channels.