The role of flavor and fragrance chemicals in TRPA1 (transient receptor potential cation channel, member A1) activity associated with allergies

TRPA1 has been proposed to be associated with diverse sensory allergic reactions, including thermal (cold) nociception, hearing and allergic inflammatory conditions. Some naturally occurring compounds are known to activate TRPA1 by forming a Michael addition product with a cysteine residue of TRPA1 through covalent protein modification and, in consequence, to cause allergic reactions. The anti-allergic property of TRPA1 agonists may be due to the activation and subsequent desensitization of TRPA1 expressed in sensory neurons. In this review, naturally occurring TRPA1 antagonists, such as camphor, 1,8-cineole, menthol, borneol, fenchyl alcohol and 2-methylisoborneol, and TRPA1 agonists, including thymol, carvacrol, 1’S-1’- acetoxychavicol acetate, cinnamaldehyde, α-n-hexyl cinnamic aldehyde and thymoquinone as well as isothiocyanates and sulfides are discussed

Direct Effect of Intracanal Medicaments on Survival of Stem Cells of the Apical Papilla

Introduction: Regenerative endodontic procedures are an alternative treatment for immature teeth with necrotic pulps. Typically, intracanal medicaments such as triple antibiotic paste (TAP) or double antibiotic paste (DAP) and calcium hydroxide (Ca[OH](2)) are used for disinfection. However, their effect on human stem cells of the apical papilla (SCAPs) is unknown. We hypothesized that intracanal medicaments at high concentrations are toxic to SCAPs. To test this hypothesis, a cell culture assay was used. Methods: Briefly, SCAPs were cultured and subjected to either no drug treatment or various concentrations including TAP, DAP, modified TAP (ciprofloxacin, metronidazole and cefaclor), Augmentin (Champs Pharmacy, San Antonio, TX), or Ca(OH)(2). Viable stem cells counts were obtained using an automated method of detecting trypan blue dye at 3 days after treatment. Results: All 4 antibiotics significantly reduced SCAP survival in a concentration-dependent fashion. Interestingly, Ca(OH)(2) was conducive with SCAP survival at all concentrations. Conclusions: Collectively, our data show that high concentrations of antibiotics have a detrimental effect on SCAP survival, whereas lower concentrations as well as Ca(OH)(2) at all tested concentrations are conducive with SCAP survival and proliferation. These studies highlight the clinically important point that intracanal medicaments must be used at concentrations that are bactericidal while having minimal effects on stem cell viability. (J Endod 2012;38:1372-1375)38101372137

Characterization of a Stem Cell of Apical Papilla Cell Line: Effect of Passage on Cellular Phenotype

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Introduction: Stem cells of the apical papilla (SCAP) have been identified as an important population of mesenchymal stem cells (MSCs) in regenerative endodontics. Preclinical studies that evaluate the various aspects of the regenerative process must use fully characterized MSCs. The phenotype of these cells when maintained in culture is crucial for the translational applicability of these studies. Thus, in this study, we aimed to characterize a SCAP cell line that preferentially expressed and maintained the required MSCs markers in culture, namely the RP-89 cell line. Methods: Apical papillae from extracted mandibular third molars from a single donor were processed for immunohistochemistry, cell culture, and,RT-PCR. SCAP were successfully cultured and maintained in culture for up to 20 passages. The expression of MSC-related molecular markers was analyzed by laser confocal microscopy, flow cytometry, and real-time RT-PCR arrays. Results: Cells within the apical papillae tissue had a widespread expression of CD90, whereas the expression of CD105 and CD73 was compartmentalized to the blood vessels and periphery, respectively. The RP-89 cell line population coexpressed CD73, CD90, and CD105 in all passages evaluated. There was a dramatic change in gene expression when cells were cultured and maintained in culture with the up-regulation of MSCs markers, inhibitors of differentiation, and sternness markers. Conversely, genes involved in the differentiation of MSCs were suppressed. Conclusions: Collectively, these results highlight the need to use fully characterized cell lines in regenerative studies and provide the foundational knowledge of gene expression modulation that occurs in cultured SCAP. (J Endod 2013;39:357-363)393357363University of Texas Health Science Center at San AntonioDepartment of EndodonticsCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)CAPES [BEX3563/103