Chemokine expression of oral fibroblasts and epithelial cells in response to artificial saliva.
OBJECTIVE
Artificial saliva is widely used to overcome reduced natural salivary flow. Natural saliva provokes the expression of chemokines in oral fibroblasts in vitro. However, if artificial saliva changes the expression of chemokines remains unknown.


METHODS
Here, we investigated the ability of Saliva Orthana®, Aldiamed®, Glandosane®, and Saliva Natura® to change the expression of chemokines in human oral fibroblasts and the human oral epithelial cell line HSC-2 by means of reverse transcription polymerase chain reaction and immunoassays. Mucins isolated from bovine submaxillary glands and recombinant human mucin 1 were included in the bioassay. Formazan formation and LIVE/DEAD® staining determined the impact of artificial saliva on cell viability. The involvement of signaling pathways was determined by pharmacologic inhibitors and Western blotting.


RESULTS
In gingival fibroblasts, Saliva Orthana®-containing mucins provoked a significantly increased expression of CXC ligand 8 (CXCL8, or interleukin 8), CXCL1, and CXCL2. Immunoassays for CXCL8 and CXCL1 confirmed the translation at the protein level. The respective dilution of artificial saliva had no impact on formazan formation and LIVE/DEAD® staining. Mucins isolated from bovine submaxillary glands also increased the panel of chemokine expression in gingival fibroblasts. BAY 11-7082, a nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) inhibitor, but also TAK-242, an inhibitor of toll-like receptor 4 signaling, blocked chemokine expression of Saliva Orthana® and bovine mucins. In HSC-2 cells, Glandosane® significantly increased CXCL8 expression.


CONCLUSIONS
Saliva Orthana® stimulated chemokine expression in gingival fibroblasts. Mammalian mucins, but also possible contaminations with endotoxins, might contribute to the respective changes in gene expression. Epithelial cells have a differential response to artificial saliva with Glandosane® changing CXCL8 expression.


CONCLUSIONS
Artificial saliva can incite a cellular response, if however the changing expression of chemokines by isolated fibroblasts and epithelial cells in vitro translates into a clinical condition, is not clear.
Department of Preventive, Restorative and Pediatric Dentistry, School of Dental Medicine, University of Bern, Freiburgstrasse 7, 3010, Bern, Switzerland.|Laboratory of Oral Cell Biology, School of Dental Medicine, University of Bern, Bern, Switzerland.
Heinz-Dieter
HD
Müller
Department of Preventive, Restorative and Pediatric Dentistry, School of Dental Medicine, University of Bern, Freiburgstrasse 7, 3010, Bern, Switzerland.|Department of Conservative Dentistry and Periodontology, Medical University of Vienna, Vienna, Austria.
Barbara
B
Cvikl
Department of Preventive, Restorative and Pediatric Dentistry, School of Dental Medicine, University of Bern, Freiburgstrasse 7, 3010, Bern, Switzerland.
Adrian
A
Lussi
Department of Preventive, Restorative and Pediatric Dentistry, School of Dental Medicine, University of Bern, Freiburgstrasse 7, 3010, Bern, Switzerland. reinhard.gruber@zmk.unibe.ch.|Laboratory of Oral Cell Biology, School of Dental Medicine, University of Bern, Bern, Switzerland. reinhard.gruber@zmk.unibe.ch.|Department of Oral Biology, Medical University of Vienna, Sensengasse 2a, 1090, Vienna, Austria. reinhard.gruber@zmk.unibe.ch.
Reinhard
R
Gruber
D000818:Animals; D015153:Blotting, Western; D002266:Carboxymethylcellulose Sodium / Q000494:pharmacology*; D002417:Cattle; D002460:Cell Line; D002478:Cells, Cultured; D018925:Chemokines / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism; D005347:Fibroblasts / Q000378:metabolism*; D005881:Gingiva / Q000166:cytology; D006801:Humans; D009077:Mucins / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012464:Saliva, Artificial / Q000494:pharmacology*; D013194:Staining and Labeling; D013449:Sulfonamides / Q000494:pharmacology
D018925:Chemokines; C000623316:Glandosane; D009077:Mucins; D012464:Saliva, Artificial; D013449:Sulfonamides; C507035:ethyl 6-(N-(2-chloro-4-fluorophenyl)sulfamoyl)cyclohex-1-ene-1-carboxylate; D002266:Carboxymethylcellulose Sodium
Artificial saliva; Chemokines; Gingival; Inflammation