title: Expression and possible immune-regulatory function of ghrelin in oral epithelium.
abstract: Originally found in stomach mucosa, ghrelin is a peptide appetite hormone that has been implicated as an immuno-modulatory factor. Ghrelin has also been found in salivary glands and saliva; however, its expression patterns and biological properties in the oral cavity remain unclear. Therefore, we investigated the expression patterns of ghrelin in saliva, gingival crevicular fluid (GCF), and gingival tissue, as well as its in vitro effects on IL-8 production by TNF-α or LPS-stimulated oral epithelial cells. In the clinical samples obtained from 12 healthy volunteers, the concentration of ghrelin in GCF remarkably exceeded that detected in saliva. The expression of ghrelin mRNAs and growth hormone secretagogue (GHS) receptors could be detected in human oral epithelial cells. Immunohistochemical analysis revealed the expression of ghrelin in gingival epithelium, as well as in fibroblasts in the lamina propria. Ghrelin increased intracellular calcium mobilization and cAMP levels in oral epithelial cells, suggesting that ghrelin acts on epithelial cells to induce cell signaling. Furthermore, synthetic ghrelin inhibited the production of IL-8 from TNF-α or LPS-stimulated oral epithelial cells. These results indicate that ghrelin produced in the oral cavity appears to play a regulatory role in innate immune responses to inflammatory infection.
authors.affiliation: Department of Immunology, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA, USA.
authors.forename: K
authors.initials: K
authors.lastname: Ohta
authors.forename: N J
authors.initials: NJ
authors.lastname: Laborde
authors.forename: M
authors.initials: M
authors.lastname: Kajiya
authors.forename: J
authors.initials: J
authors.lastname: Shin
authors.forename: T
authors.initials: T
authors.lastname: Zhu
authors.forename: A K
authors.initials: AK
authors.lastname: Thondukolam
authors.forename: C
authors.initials: C
authors.lastname: Min
authors.forename: N
authors.initials: N
authors.lastname: Kamata
authors.forename: N Y
authors.initials: NY
authors.lastname: Karimbux
authors.forename: P
authors.initials: P
authors.lastname: Stashenko
authors.forename: T
authors.initials: T
authors.lastname: Kawai
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D020013:Calcium Signaling; D002461:Cell Line, Transformed; D045744:Cell Line, Tumor; D000242:Cyclic AMP / Q000378:metabolism; D004847:Epithelial Cells / Q000378:metabolism; D005260:Female; D005347:Fibroblasts / Q000378:metabolism; D054439:Ghrelin / Q000276:immunology* / Q000378:metabolism*; D005881:Gingiva / Q000378:metabolism*; D005883:Gingival Crevicular Fluid / Q000737:chemistry*; D018922:HL-60 Cells; D006801:Humans; D016209:Interleukin-8 / Q000378:metabolism; D008070:Lipopolysaccharides; D008297:Male; D008875:Middle Aged; D009061:Mouth Mucosa / Q000276:immunology / Q000378:metabolism; D016966:Porphyromonas gingivalis / Q000276:immunology; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism; D054440:Receptors, Ghrelin / Q000378:metabolism; D012463:Saliva / Q000737:chemistry; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D055815:Young Adult
chemical_list: D054439:Ghrelin; D016209:Interleukin-8; D008070:Lipopolysaccharides; D043562:Receptors, G-Protein-Coupled; D054440:Receptors, Ghrelin; D014409:Tumor Necrosis Factor-alpha; D000242:Cyclic AMP