Involvement of TRPV1 and AQP2 in hypertonic stress by xylitol in odontoblast cells.
OBJECTIVE
To examine the responses of mouse odontoblast-lineage cell line (OLC) cultures to xylitol-induced hypertonic stress.


METHODS
OLCs were treated with xylitol, sucrose, sorbitol, mannitol, arabinose and lyxose. Cell viability was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium assay. The expression of transient receptor potential vanilloids (TRPV) 1, 3 and 4 was detected using a reverse transcriptase-polymerase chain reaction (RT-PCR) assay. The expression of aquaporin (AQP) 2 was detected using immunofluorescence and Western blotting analysis. The expression of interleukin-6 (IL-6) under xylitol-induced hypertonic stress was assessed using an enzyme-linked immunosorbent assay (ELISA). Small interfering ribonucleic acid (siRNA) for AQP-2 was used to inhibition assay.


RESULTS
Xylitol-induced hypertonic stress did not decrease OLC viability, unlike the other sugars tested. OLCs expressed TRPV1, 3 and 4 as well as AQP2. Xylitol inhibited lipopolysaccharide (LPS)-induced IL-6 expression after 3 h of hypertonic stress. TRPV1 mRNA expression was upregulated by xylitol. Costimulation with HgCl2 (AQP inhibitor) and Ruthenium red (TRPV1 inhibitor) decreased cell viability with xylitol stimulation. OLCs treated with siRNA against TRPV1 exhibited decreased cell viability with xylitol stimulation.


CONCLUSIONS
OLCs have high-cell viability under xylitol-induced hypertonic stress, which may be associated with TRPV1 and AQP2 expressions.
Department of Restorative Dentistry and Endodontology, Kagoshima University Graduate School of Medical and Dental Sciences , Kagoshima , Japan.
M
M
Tokuda
M
M
Fujisawa
K
K
Miyashita
Y
Y
Kawakami
Y
Y
Morimoto-Yamashita
M
M
Torii
D000818:Animals; D051399:Aquaporin 2 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D006982:Hypertonic Solutions / Q000494:pharmacology; D015850:Interleukin-6 / Q000378:metabolism; D007700:Kinetics; D008070:Lipopolysaccharides / Q000494:pharmacology; D051379:Mice; D009804:Odontoblasts / Q000187:drug effects / Q000378:metabolism*; D009997:Osmotic Pressure / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D050916:TRPV Cation Channels / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D013997:Time Factors; D014993:Xylitol / Q000494:pharmacology*
D051399:Aquaporin 2; D006982:Hypertonic Solutions; D015850:Interleukin-6; D008070:Lipopolysaccharides; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D050916:TRPV Cation Channels; C494484:TRPV1 receptor; D014993:Xylitol
AQP2; TRPV1; hypertonic stress; odontoblast cells; xylitol