title: Neuropeptide release from dental pulp cells by RgpB via proteinase-activated receptor-2 signaling.
abstract: Dental pulp inflammation often results from dissemination of periodontitis caused mostly by Porphyromonas gingivalis infection. Calcitonin gene-related peptide and substance P are proinflammatory neuropeptides that increase in inflamed pulp tissue. To study an involvement of the periodontitis pathogen and neuropeptides in pulp inflammation, we investigated human dental pulp cell neuropeptide release by arginine-specific cysteine protease (RgpB), a cysteine proteinase of P. gingivalis, and participating signaling pathways. RgpB induced neuropeptide release from cultured human pulp cells (HPCs) in a proteolytic activity-dependent manner at a range of 12.5-200 nM. HPCs expressed both mRNA and the products of calcitonin gene-related peptide, substance P, and proteinase-activated receptor-2 (PAR-2) that were also found in dental pulp fibroblast-like cells. The PAR-2 agonists, SLIGKV and trypsin, also induced neuropeptide release from HPCs, and HPC PAR-2 gene knockout by transfection of PAR-2 antisense oligonucleotides inhibited significantly the RgpB-elicited neuropeptide release. These results indicated that RgpB-induced neuropeptide release was dependent on PAR-2 activation. The kinase inhibitor profile on the RgpB-neuropeptide release from HPC revealed a new PAR-2 signaling pathway that was mediated by p38 MAPK and activated transcription factor-2 activation, in addition to the PAR-2-p44/42 p38MAPK and -AP-1 pathway. This new RgpB activity suggests a possible link between periodontitis and pulp inflammation, which may be modulated by neuropeptides released in the lesion.
authors.affiliation: Department of Restorative Dentistry and Endodontology, Laboratory of Vascular Medicine, Kagoshima University Graduate School of Medical and Dental Science, Japan.
authors.forename: Salunya
authors.initials: S
authors.lastname: Tancharoen
authors.forename: Krishna Pada
authors.initials: KP
authors.lastname: Sarker
authors.forename: Takahisa
authors.initials: T
authors.lastname: Imamura
authors.forename: Kamal Krishna
authors.initials: KK
authors.lastname: Biswas
authors.forename: Kenji
authors.initials: K
authors.lastname: Matsushita
authors.forename: Shoko
authors.initials: S
authors.lastname: Tatsuyama
authors.forename: James
authors.initials: J
authors.lastname: Travis
authors.forename: Jan
authors.initials: J
authors.lastname: Potempa
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Torii
authors.forename: Ikuro
authors.initials: I
authors.lastname: Maruyama
mesh_terms: D051698:Activating Transcription Factor 2; D018829:Adhesins, Bacterial; D015740:Calcitonin Gene-Related Peptide / Q000096:biosynthesis / Q000378:metabolism; D045744:Cell Line, Tumor; D002474:Cell-Free System / Q000378:metabolism; D002478:Cells, Cultured; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D003546:Cysteine Endopeptidases / Q000502:physiology*; D003782:Dental Pulp / Q000166:cytology / Q000201:enzymology* / Q000378:metabolism*; D004789:Enzyme Activation / Q000502:physiology; D000080867:Gingipain Cysteine Endopeptidases; D006388:Hemagglutinins / Q000502:physiology*; D006801:Humans; D020935:MAP Kinase Signaling System / Q000502:physiology*; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D009479:Neuropeptides / Q000096:biosynthesis / Q000378:metabolism*; D016966:Porphyromonas gingivalis / Q000502:physiology*; D044464:Receptor, PAR-2 / Q000819:agonists / Q000096:biosynthesis / Q000172:deficiency / Q000502:physiology*; D013373:Substance P / Q000096:biosynthesis / Q000378:metabolism; D018808:Transcription Factor AP-1 / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D051698:Activating Transcription Factor 2; D018829:Adhesins, Bacterial; D017362:Cyclic AMP Response Element-Binding Protein; D000080867:Gingipain Cysteine Endopeptidases; D006388:Hemagglutinins; D009479:Neuropeptides; D044464:Receptor, PAR-2; D018808:Transcription Factor AP-1; D014157:Transcription Factors; D013373:Substance P; D019950:Mitogen-Activated Protein Kinase 1; D048051:p38 Mitogen-Activated Protein Kinases; D003546:Cysteine Endopeptidases; D015740:Calcitonin Gene-Related Peptide