ABSTRACT
BACKGROUND:Various studies confirm that smoking can contribute to the resorption of periodontal alveolar bone. OBJECTIVE:To observe the effect of smoking in alveolar bone resorption of periodontitis rat models. METHODS:A total of 24 rats were randomly divided into three groups. Normal group:rats were normal y fed without any other pre-treatment;Control group:experimental periodontitis model was established using wire ligation method in rats;Experimental group:rat models were given passive smoking during experimental modeling period. Al rats were sacrificed after 8 weeks of modeling, periodontal tissue were removed. Hematoxylin-eosin staining was used for examining pathological changes in periodontal tissue, and immunohistochemical analysis was done for observing receptor activator of nuclear factor-κB ligand and osteoprotegrin expression. RESULTS AND CONCLUSION:After 8 weeks of modeling, expression of receptor activator of nuclear factor-κB ligand factor was significantly higher in alveolar bone of rats from experimental group in comparison to control group (P<0.05), whereas expression of osteoprotegerin in alveolar bone was significantly greater in rats from control group when compared to experimental group (P<0.05). This finding suggests that smoking can increase the expression of receptor activator of nuclear factor-κB ligand protein and reduce osteoprotegrin expression in periodontal rats, thus increasing the resorption of periodontal alveolar bone.
ABSTRACT
BACKGROUND:Studies concerning how estrogen receptorβparticipates in bone metabolism are few now. OBJECTIVE:To investigate the effect of estrogen receptorβon the expression of osteoprotegerin and receptor activator of nuclear factor-κB ligand in human osteblast-like cells. METHODS:The retrovirus with the most effective interference sequence and non-specific short hairpin RNA was used to transfect human osteoblast-like cellMG63 in order to screen out the stable colon, and then amplified and cultured. The blank control and non-specific short hairpin RNA were used as control, and the stable inhibition rate of estrogen receptorβwas detected. The 17β-estradiol was added into the cells in three groups, that were MG63 cells, short hairpin RNA retrovirus estrogen receptorβ-mediated MG63 cells and negative control short hairpin RNA retrovirus-medicated MG63 cells, in order to detect the expressions of osteoprotegerin and receptor activator of nuclear factor-κB ligand mRNA in human osteoblast-like cells. RESULTS AND CONCLUSION: The human osteoblast-like MG63 cellline was further stably transfected with pRNAT-H1.4/Retro-estrogen receptorβshort hairpin RNA3, and then compared with the blank control and negative control, and found that estrogen receptorβcould express the stable inhibited human osteoblast-like cellline. The inhibition rate of estrogen receptorβmRNA was (88.17±1.17)%(P<0.05), and the inhibition rate of estrogen receptorβprotein was (89.01±1.22)%(P<0.05), indicating that estrogen receptorβgene knockdown human osteoblast-like cellmodels were constructed successful y. After estrogen intervention for 48 hours, the inhibition of MG63 cells with estrogen receptorβcould up-regulate the osteoprotegerin mRNA and protein expression in the blank control group and the negative control group (P<0.05), down-regulate the receptor activator of nuclear factor-κB ligand mRNA and protein expression (P<0.05), and up-regulate the osteoprotegerin receptor activator of nuclear factor-κB ligand expression. The results indicate that estrogen receptorβmay play an important role in bone metabolism through regulating osteoprotegerin/receptor activator of nuclear factor-κB ligand ratio.