Heat stress activates interleukin-8 and the antioxidant system via Nrf2 pathways in human dental pulp cells.
ABSTRACT This study tested whether heat stress (42 degrees C for 30 minutes) induces reactive oxygen species (ROS), proinflammatory cytokines, Nrf2 activation, and Nrf2 target genes such as antioxidant enzymes in human dental pulp (HDP) cells.
ROS was evaluated by using flow cytometry. Proteins and messenger RNA levels for cytokines and antioxidant genes were determined by using Western blotting and reverse transcription-polymerase chain reaction (RT-PCR) analysis, respectively.
Heat stress induced the production of ROS and the increased expression of the interleukin (IL)-8 and IL-8 receptor genes. Exposure of cells to heat stress resulted in the nuclear translocation of Nrf2 and increased expression of Nrf2 target genes including heme oxygenase-1. Pretreatment with an exogenous antioxidant inhibited the heat-induced expression of IL-8 and Nrf2 target genes and Nrf2 translocation.
Collectively, these results show that heat-induced Nrf2 activation is the major regulatory pathway of cytoprotective gene expression against oxidative stress in HDP cells.
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ABSTRACT: Introduction The objective of this study was to evaluate the biocompatibility, inflammatory response, and odontoblastic potential of Biodentine (Septodont, Saint Maur des Fosses, France), Ortho-MTA (OMTA; BioMTA, Seoul, Korea), Angelus-MTA (AMTA; Angelus, Londrina, Brazil), and IRM (Dentsply Tulsa Dental, Tulsa, OK) in human dental pulp cells. The underlying signaling mechanisms were also investigated. Methods Biocompatibilities were examined by the 3-(4,5-dimethylthiazolyl-2-yl)-2,5-diphenyltetrazolium bromide assay. Differentiation was assessed by alkaline phosphatase activity, alizarin red S staining, and reverse-transcription polymerase chain reaction for marker genes. The levels of inflammatory mediators and cytokines were measured by reverse-transcription polymerase chain reaction and enzyme-linked immunosorbent assay. Signal transduction analysis was performed by Western blotting. Results Biodentine, OMTA, and AMTA showed favorable cell proliferation, alkaline phosphatase activity, formation of mineralized nodules, and expression of odontoblastic marker genes that were similar to those of IRM. The levels of proinflammatory mediators including nitric oxide, prostaglandin E2, inducible nitric oxide synthase, and cyclooxygenase-2 were lower for Biodentine, OMTA, and AMTA compared with the IRM group. All test materials induced reactive oxygen species production and the expression of hemeoxygenase-1, nuclear factor–E2-related factor-2, and mitogen-activated protein kinases. Conclusions These data indicate for the first time that the biocompatibility, inflammatory response, and odontoblastic differentiation of Biodentine were similar to that of OMTA and AMTA in HDPCs, which suggests that Biodentine could be good alternative pulp capping agent.Journal of Endodontics 02/2014; DOI:10.1016/j.joen.2014.01.001 · 2.79 Impact Factor
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ABSTRACT: To determine whether chemokines such as SDF-1 and monocyte chemoattractant protein-1 (MCP-1) are responsible for hydrogen peroxide (H2 O2 )-induced extracellular matrix (ECM) degradation and to identify the underlying mechanism in human dental pulp cells (HDPCs). Human dental pulp cells were exposed to 0.4 mmol H2 O2 for 48 h. mRNA expression and protein expression were examined by RT-PCR and Western blot analysis, respectively. The mRNA expression of chemokine (SDF-1 and MCP-1), their receptors (CXCR4 and CXCR2) and extracellular matrix proteins was evaluated by reverse transcriptase-polymerase chain reaction. The production of SDF-1, MCP-1, CXCR4 and CCR2 in the culture medium was determined by enzyme-linked immunosorbent assay. Signal transduction pathway was examined by Western blotting. Hydrogen peroxide provoked the activation of MCP-1 and SDF-1 mRNA and their respective receptors, CXCR4 and CXCR2. H2 O2 treatment concomitantly downregulated the expression of ECM molecules, such as type I collagen, elastin and fibronectin, and upregulated the mRNA expression of matrix metalloproteinase-1 (MMP-1), MMP-2, MMP-8 and MMP-9. Hydrogen peroxide-induced ECM degradation and MMP upregulation were blocked by neutralizing antibodies and siRNAs directed against SDF-1 and MCP-1. Inhibition of SDF-1 and MCP-1 blocked the H2 O2 -induced activation of Akt, p38, ERK and NF-kB. Inhibition of SDF and MCP-1 is a potent component of reducing release reactive oxygen species-induced ECM degradation in HDPCs and may play an important role in pulpal and periapical inflammation.International Endodontic Journal 06/2013; DOI:10.1111/iej.12147 · 2.27 Impact Factor
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ABSTRACT: OBJECTIVES: Heme oxygenase-1 (HO-1) is contributed to odontoblast differentiation in human dental pulp cells (HDPCs). In this study, pachymic acid from mushroom Formitopsis niagra is examined to determine whether it affects pulpal inflammation and promotes odontogenesis via HO-1 gene expression. MATERIALS AND METHODS: The HDPCs were given H(2) O(2) for inflammation. The anti-inflammatory character and odontoblast differentiation by pachymic acid were analyzed by Western blotting, alkaline phosphatase activity, and alizarin red S staining. To understand the mechanism of pachymic acid via HO-1 induction, the cells were treated with zinc protoporphyrin IX (ZnPP: HO-1 inhibitor). RESULTS: H(2) O(2) induced pulp inflammation and disturbed odontoblast differentiation. However, the HDPCs treated with pachymic acid affected anti-inflammatory effect and induction of odontoblast differentiation through increasing HO-1 expression. In addition, pachymic acid has potent cytoprotection and mineralization under H(2) O(2) treatment. Furthermore, pachymic acid significantly suppressed nuclear factor-kappa B (NF-κB) translocation into nucleus and induced NE-E2-related factor-2 (Nrf2) translocation into nucleus. Overall, NF-κB and Nrf2 translocation were regulated by the HO-1 pathway. CONCLUSIONS: The pachymic acid showed anti-inflammatory function and odontoblast differentiation via HO-1 pathway. These results suggested that pachymic acid may be applicable for prevention of oral inflammation or to improve dentin mineralization against several stresses.Oral Diseases 07/2012; DOI:10.1111/j.1601-0825.2012.01970.x · 2.40 Impact Factor