Effect of estrogen deficiency on the expression levels of nuclear factor-kappa B and interleukin-17 in periodontal tissues / 中国组织工程研究

ABSTRACT

BACKGROUND:There is a very close relationship between osteoporosis and periodontal disease in postmenopausal women, but the mechanism remains unclear. OBJECTIVE:To investigate the expression of nuclear factor-κB in the alveolar bone andinterleukin-17 in the serum and gingiva in the mouse model of osteoporosis caused by ovariectomy. METHODS:Female mice aged 3 months were randomly divided into ovariectomy and sham operation groups. At 6 months after surgery, the mouse models were evaluated histologically on the submandibular bone and thigh bone stained with hematoxylin and eosin. In the submandibular bone, the expression levels of OCN and Runx2 were detected by RT-PCR, and the expression level of nuclear factor-κB was detected by immunohistochemical staining and western blot assay. Besides, the expression level of interleukin-17 in the serum and gingival homogenate was evaluated using Cytometric Beads Array. RESULTS AND CONCLUSION:The thigh bone in the ovariectomy group revealed the thin cortical bone, enlarged marrow cavity, and increased resorption lacunae, as well as fewer, thinner trabeculae with lower density and irregular structure. Compared with the sham operation group, the expression levels of OCN and Runx2 in the alveolar bone were decreased in the ovariectomy group. The activation of nuclear factor-κB (P65)appeared with P65 positive expression in the submandibular bone in the ovariectomy group, and the relative expression level was higher than that in the sham operation group. The serum level of interleukin-17 in the ovariectomy group was higher than that in the sham operation group, but the level in the gingival tissue showed no significant difference between the two groups. These results indicate that estrogen deficiency after ovariectomy can activate nuclear factor-κB signal pathway to play a role in periodontal osteolysis. However interleukin-17 in the local periodontal tissue may not be a key cytokine to damage the periodontal tissue.