The expression of MCP-1 and CCR2 in induced rats periapical lesions.

OBJECTIVE

Monocyte chemotatic protein-1 (MCP-1) has been found to promote chemotaxis, differentiation, and activation of osteoclasts. The aim of this study is to detect and localize the expressions of MCP-1 and its receptor CCR2 in a rat model of apical periodontitis.

DESIGN

After exposing the pulp of the first mandibular molars, 25 Wistar rats were killed on days 0, 7, 14, 21, 28, and 35. Rat jaws containing the first molar were obtained and routinely prepared for histological analysis, immunohistochemistry, enzyme histochemistry and immunofluorescence staining.

RESULTS

Lesions expanded from day 0 to day 28, and stabilized thereafter. Most of the MCP-1-positive cells were inflammatory cells, and their amount increased from day 7 to day 28. Aside from inflammatory cells, CCR2 was also detected in osteoclasts in the lesions. From day 7 to day 14, the number of osteoclasts increased. From day 21 to day 35, fewer osteoclasts could be observed, and the number of osteoclast was negatively correlated with positive MCP-1 expression.

CONCLUSION

These findings showed that MCP-1/CCR2 could be observed and might possibly be involved in the development of periapical lesions.