title: Whole cigarette smoke increased the expression of TLRs, HBDs, and proinflammory cytokines by human gingival epithelial cells through different signaling pathways.
abstract: The gingival epithelium is becoming known as a regulator of the oral innate immune responses to a variety of insults such as bacteria and chemicals, including those chemicals found in cigarette smoke. We investigated the effects of whole cigarette smoke on cell-surface-expressed Toll-like receptors (TLR)-2, -4 and -6, human β-defensin (HBD) and proinflammatory cytokine expression and production in primary human gingival epithelial cells. Whole cigarette smoke was shown to increase TLR2, TLR4 and TLR6 expression. Cigarette smoke led to ERK1/2, p38 and JNK phosphorylation in conjunction with nuclear factor-κB (NFκB) translocation into the nucleus. TLR expression following cigarette smoke exposure was down regulated by the use of ERK1/2, p38, JNK MAP kinases, and NFκB inhibitors, suggesting the involvement of these signaling pathways in the cellular response against cigarette smoke. Cigarette smoke also promoted HBD2, HBD3, IL-1β, and IL-6 expression through the ERK1/2 and NFκB pathways. Interestingly, the modulation of TLR, HBD, and cytokine expression was maintained long after the gingival epithelial cells were exposed to smoke. By promoting TLR, HBDs, and proinflammatory cytokine expression and production, cigarette smoke may contribute to innate immunity dysregulation, which may have a negative effect on human health.
authors.affiliation: Groupe de Recherche en Écologie Buccale, Département de Stomatologie, Faculté de Médecine Dentaire, Université Laval, Québec, Québec, Canada.
authors.forename: Abdelhabib
authors.initials: A
authors.lastname: Semlali
authors.forename: Chmielewski
authors.initials: C
authors.lastname: Witoled
authors.forename: Mohammed
authors.initials: M
authors.lastname: Alanazi
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Rouabhia
mesh_terms: D002478:Cells, Cultured; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D015870:Gene Expression; D005881:Gingiva / Q000166:cytology; D006801:Humans; D007113:Immunity, Innate; D018836:Inflammation Mediators / Q000378:metabolism; D053583:Interleukin-1beta / Q000235:genetics / Q000378:metabolism*; D015850:Interleukin-6 / Q000235:genetics / Q000378:metabolism*; D020935:MAP Kinase Signaling System; D016328:NF-kappa B / Q000378:metabolism; D010766:Phosphorylation; D028321:Plant Preparations / Q000494:pharmacology; D011499:Protein Processing, Post-Translational; D012906:Smoke; D012907:Smoking / Q000276:immunology; D014026:Nicotiana / Q000737:chemistry; D051193:Toll-Like Receptors / Q000235:genetics / Q000378:metabolism*; D023083:beta-Defensins / Q000235:genetics / Q000378:metabolism*
chemical_list: C422950:DEFB103A protein, human; C106641:DEFB4A protein, human; C508585:IL1B protein, human; C508600:IL6 protein, human; D018836:Inflammation Mediators; D053583:Interleukin-1beta; D015850:Interleukin-6; D016328:NF-kappa B; D028321:Plant Preparations; D012906:Smoke; D051193:Toll-Like Receptors; D023083:beta-Defensins; D048049:Extracellular Signal-Regulated MAP Kinases