title: Induction of IL-6 and IL-8 by activation of thermosensitive TRP channels in human PDL cells.
abstract: OBJECTIVE
  The oral cavity is often exposed to not only diverse external pathogens but also dramatic temperature changes. In this study, we investigated the effect of thermal stress on PDL cells with a focus on the inflammatory responses and bone homeostasis.
  
  
  METHODS
  The PDL cells were isolated from healthy premolar extracted for orthodontic reasons, and examined using intracellular calcium concentration ([Ca(2+)]i) measurement and reverse transcription-polymerase chain reaction for pro-inflammatory cytokines and bone remodelling mediators.
  
  
  RESULTS
  We detected the expression of thermosensitive transient receptor potential (TRP) channels, such as TRPV1, TRPV2, TRPV3, TRPM8, and TRPA1. Functional activation of the channels by thermal stress and their specific agonists increased [Ca(2+)]i and interleukin (IL)-6 and IL-8 mRNA expression. A selective Ca(2+) chelator, BAPTA-AM, prevented TRP channel agonists-mediated IL-6 and IL-8 induction. Unlike pro-inflammatory cytokines, the expression of bone remodelling mediators, including receptor activator of nuclear factor-kappa B ligand and osteoprotegerin, was not altered by treatment with TRP channel agonists.
  
  
  CONCLUSIONS
  The activation of thermosensitive TRP channels induced IL-6 and IL-8 expression by increasing [Ca(2+)]i in human PDL cells. Therefore, thermal stress may play a critical role in the inflammatory responses of PDL cells.
authors.affiliation: Department of Oral Biology, Yonsei University College of Dentistry, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Republic of Korea; BK21 PLUS Project, Yonsei University College of Dentistry, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Republic of Korea.
authors.forename: Ga-Yeon
authors.initials: GY
authors.lastname: Son
authors.affiliation: Department of Physiology, Graduate School of Medicine, Gachon University, Incheon 406-799, Republic of Korea.
authors.forename: Jeong Hee
authors.initials: JH
authors.lastname: Hong
authors.affiliation: Department of Oral Biology, Yonsei University College of Dentistry, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Republic of Korea.
authors.forename: Inik
authors.initials: I
authors.lastname: Chang
authors.affiliation: Department of Oral Biology, Yonsei University College of Dentistry, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Republic of Korea; BK21 PLUS Project, Yonsei University College of Dentistry, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Republic of Korea. Electronic address: dmshin@yuhs.ac.
authors.forename: Dong Min
authors.initials: DM
authors.lastname: Shin
mesh_terms: D016723:Bone Remodeling; D002118:Calcium / Q000378:metabolism*; D018929:Cell Culture Techniques; D004533:Egtazic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D006358:Hot Temperature; D006801:Humans; D007249:Inflammation / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism*; D016209:Interleukin-8 / Q000378:metabolism*; D010513:Periodontal Ligament / Q000166:cytology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D050051:Transient Receptor Potential Channels / Q000378:metabolism*
chemical_list: D015850:Interleukin-6; D016209:Interleukin-8; D050051:Transient Receptor Potential Channels; C070379:1,2-bis(2-aminophenoxy)ethane N,N,N',N'-tetraacetic acid acetoxymethyl ester; D004533:Egtazic Acid; D002118:Calcium
keywords: Inflammation; Interleukins (IL); Periodontal ligament (PDL); Periodontitis; Transient receptor potential (TRP) channels