Heat shock protein 27 expression in the epithelium of periapical lesions

Heat shock protein (HSP) 27 is a member of the small HSP family that plays a part in the regulation of epithelial cell growth and differentiation, wou nd healing, apoptosis and cell protection against inflammatory cytotoxicity mediators. Thus the expression of HSP27 was investigated immunohistochemic ally in periapical granulomas with epithelial rests of Malassez and in radi cular cysts. Anti-HSP27 mouse monoclonal antibody and peroxidase-labeled st reptavidin-biotin standard technique were used to study the expression of H SP27, proliferating epithelial cell rests, and islands of epithelium and ep ithelial lining of microcysts strongly reacted throughout all layers, where as radicular cysts epithelial lining presented mainly a moderate suprabasal staining pattern. However both the proliferating epithelial cell rests and the radicular cysts shared an over-expression of HSP27 immunostaining inte nsity in coincidence with the presence of local infiltration of immune cell s. HSP27 may play several roles in periapical lesions that include contribu ting to the migration of epithelial cell rests and an increased resistance both to necrotic and apoptotic cell deaths.