title: Calcium oscillations in gingival epithelial cells infected with Porphyromonas gingivalis.
abstract: The periodontal pathogen Porphyromonas gingivalis modulates epithelial cell signal transduction pathways including Ca2+ signaling, and internalizes within the host cell cytoplasm. Since nuclear and cytoplasmic [Ca2+] increases can induce different host cell responses, P. gingivalis-related [Ca2+] 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 [Ca2+] levels to undergo sustained oscillations of [Ca2+] in nuclear and cytoplasmic spaces. However, P. gingivalis invasion was not tightly correlated with intracellular [Ca2+] oscillations, since invasion could significantly precede, or even occur in the absence of, oscillations. [Ca2+] oscillations required a Ca2+ influx, which was completely inhibited by La3+ or 2-APB (2-aminoethoxydiphenyl borate), indicating Ca2+ entry was via a Ca(2+)-permeable channel. Ca2+ entry was likely not via a store-operated channel, since Ca2+ 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 Ca2+ influx through Ca2+ channels.
authors.affiliation: Department of Oral Biology, School of Dentistry, University of Washington, Box 357132, Seattle, WA 98195, USA.
authors.forename: Carol M
authors.initials: CM
authors.lastname: Belton
authors.forename: Paul C
authors.initials: PC
authors.lastname: Goodwin
authors.forename: Sahba
authors.initials: S
authors.lastname: Fatherazi
authors.forename: Mark M
authors.initials: MM
authors.lastname: Schubert
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Lamont
authors.forename: Kenneth T
authors.initials: KT
authors.lastname: Izutsu
mesh_terms: D001692:Biological Transport / Q000187:drug effects; D001896:Boron Compounds / Q000494:pharmacology; D002118:Calcium / Q000032:analysis* / Q000378:metabolism; D002121:Calcium Channel Blockers / Q000494:pharmacology; D020013:Calcium Signaling; D002467:Cell Nucleus / Q000737:chemistry; D002478:Cells, Cultured; D003593:Cytoplasm / Q000737:chemistry; D004847:Epithelial Cells / Q000378:metabolism* / Q000382:microbiology; D016257:Fura-2 / Q000378:metabolism; D005881:Gingiva / Q000166:cytology / Q000378:metabolism / Q000382:microbiology*; D006801:Humans; D007811:Lanthanum / Q000494:pharmacology; D008856:Microscopy, Fluorescence; D016966:Porphyromonas gingivalis / Q000502:physiology*; D013194:Staining and Labeling
chemical_list: D001896:Boron Compounds; D002121:Calcium Channel Blockers; C028521:lanthanum chloride; D007811:Lanthanum; C109986:2-aminoethoxydiphenyl borate; D002118:Calcium; D016257:Fura-2