Immunocytochemical localization of inflammatory cytokines and vascular adhesion receptors in radicular cysts

Abstract

Odontogenic cysts are one of the commonest bone destroying lesions of the maxillofacial skeleton, with the inflammatory radicular cyst being the commonest jaw cyst. Explants of radicular cysts produce an interleukin-1-like activity which could explain the osteolysis seen with these tumours though the cellular source of this osteolytic activity is unknown. In the present study, cytokines with known inflammatory and osteolytic activity: interleukin-1 (IL-1), tumour necrosis factor (TNF), interleukin-6 (IL-6), and the chemotactic cytokine interleukin-8 (IL-8) have been localized immunocytochemically in radicular cysts. The cellular adhesion receptors ICAM-1 and ELAM-1 have also been immunolocalized. All specimens showed positive staining for IL-1 (alpha and beta) and IL-6, with these cytokines being located in epithelial and vascular endothelial cells. Only two specimens demonstrated TNF and IL-8 staining, which was located in macrophages. All specimens demonstrated ELAM-1 staining in endothelium and ICAM-1 staining in epithelium, endothelium and mononuclear cells. These findings show that radicular cysts contain two bone-modulating cytokines, IL-1 and IL-6, and that these appear to be synthesized mainly by the epithelial cells. Cysts also contain a proportion of activated blood vessels whose endothelial cells express the cellular adhesion receptors ICAM-1 and ELAM-1.

Immunohistochemical comparison of cyclin D1 expression in amelobelastoma, odontogenic keratocyst and radicular cyst

“…Bando et al showed that cytokines and growth factors released by inflammatory cells present in connective tissue can stimulate epithelial proliferation in RC and more intense inflammation may cause greater proliferative activity (16).While we did not find any statistical association in staining pattern among studied groups, it's noticeable that in one case of radicular cyst cyclin D1 expression was also seen in all layers of epithelial part. Therefore, according to Bando et al results,cyclin D1 expression in all layers may be related to the intensity of inflammation in cyst wall.…”

Aseptic loosening

“…19,20 These cytokines provide activation signals to lymphocytes, 21 and in turn, the lymphocyte-derived cytokines interleukin 2 (IL-2), interleukin 6 (IL-6) and gamma interferon (IFN-g) may influence osteoclastic activity and bone remodeling. 22 Studies using an in vitro osteoclast model have suggested that the response to PMMA may directly contribute to the process of bone resorption. 23 UHMWPE wear has been significantly correlated with frequency and size of osteolytic lesions 24 and may also act to inhibit biosynthetic pathways of bone and mesenchymal tissue.…”

Cyclin d1 expression in odontogenic cysts

“…Other studies by evaluation of P53, P63, Ki-67, COX-2, IPO-38 and PCNA immunostaining in odontogenic cysts "to compare their proliferative activity" have also shown the higher expression of mentioned markers in parabasal layer of OKCs in contrast to DCs, RCs or normal mucosa seen in basal layer (18,19,20,21,22,23,24,25).…”

“…Bando et al showed that cytokines and growth factors released by infl ammatory cells present in connective tissue can stimulate epithelial proliferation in RC and more intense infl ammation may cause greater proliferative activity (19). Th erefore, cyclin D1 expression in all layers may be related to the intensity of infl ammation in cyst wall.…”