Calcitonin Gene-related Peptide Receptor Expression in Alternatively Activated Monocytes/Macrophages During Irreversible Pulpitis

The purpose of this study was to quantify the percentage and the mean fluorescence intensity of viable alternatively activated monocytes/macrophages (AAMø) CD163+ positive for calcitonin gene-related peptide receptor (CGRPr) within the total AAMø population in human dental pulp. Pulp tissue samples were collected from teeth with a clinical diagnosis of irreversible pulpitis (n = 13), pulps with induced inflammation (n = 13), and normal pulps (n = 13). All samples were labeled to identify positive cells for CGRPr and CD163 using a flow cytometry assay. Results demonstrated that a high percentage of total viable AAMø CD163+ expressed CGRPr on their membranes (72.12% in healthy pulp, 62.20% in irreversible pulpitis, and 58.01% in induced pulpitis). Significant differences were found between mean AAMø CD163+ fluorescence for CGRPr according to pulp condition, being greater in irreversible pulpitis. It can be concluded that AAMø CD163+ are expressed during normal and inflammatory processes, supporting the hypothesis that they could exercise an anti-inflammatory action that could be controlled by CGRP signaling after its binding.