
PAR-1 and PAR-2 Expression Is Enhanced in Inflamed Odontoblast Cells
2017; SAGE Publishing; Volume: 96; Issue: 13 Linguagem: Inglês
10.1177/0022034517719415
ISSN1544-0591
AutoresMarcela Maciel Palacio Alvarez, Gioconda Emanuella Diniz de Dantas Moura, Maurício F.M. Machado, Gustavo Monteiro Viana, Carlos Alberto de Souza Costa, Leo Tjäderhane, Helena B. Nader, Ivarne L.S. Tersariol, Fábio Dupart Nascimento,
Tópico(s)Signaling Pathways in Disease
ResumoProtease-activated receptors (PARs) are G protein–coupled receptors, which are activated by proteolytical cleavage of the amino-terminus and act as sensors for extracellular proteases. We hypothesized that PAR-1 and PAR-2 can be modulated by inflammatory stimulus in human dental pulp cells. PAR-1 and PAR-2 gene expression in human pulp tissue and MDPC-23 cells were analyzed by quantitative polymerase chain reaction. Monoclonal PAR-1 and PAR-2 antibodies were used to investigate the cellular expression of these receptors using Western blot, flow cytometry, and confocal microscopy in MDPC-23 cells. Immunofluorescence assays of human intact and carious teeth were performed to assess the presence of PAR-1 and PAR-2 in the dentin-pulp complex. The results show for the first time that human odontoblasts and MDPC-23 cells constitutively express PAR-1 and PAR-2. PAR-2 activation increased significantly the messenger RNA expression of matrix metalloproteinase (MMP)–2, MMP-9, MMP-13, and MMP-14 in MDPC-23 cells (P < 0.05), while the expression of these enzymes decreased significantly in the PAR-1 agonist group (P < 0.05). The high-performance liquid chromatography and matrix-assisted laser desorption/ionization–time-of-flight mass spectrometry analysis showed the presence of MMP-13 activity cleaving PAR-1 at specific, noncanonical site TLDPRS42↓F43LL in human dental pulp tissues. Also, we detected a presence of a trypsin-like activity cleaving PAR-2 at canonical site SKGR20↓S21LIGRL in pulp tissues. Confocal microscopy analysis of human dentin-pulp complex showed intense positive staining of PAR-1 and PAR-2 in the odontoblast processes in dentinal tubules of carious teeth compared to intact ones. The present results support the hypothesis of activation of the upregulated PAR-1 and PAR-2 by endogenous proteases abundant during the inflammatory response in dentin-pulp complex.
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