Relationship between the levels of tumor necrosis factor alpha, interleukin-1beta and interleukin 6 of bone tissue and osteoporosis in ovariectomized rats / 中国组织工程研究

ABSTRACT

BACKGROUND:It has found that secretions of tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β) and interleukin 6 (IL-6) are closely related to osteoporosis OBJECTIVE:To further investigate the levels of TNF-α, IL-1β and IL-6 of bone tissue in ovariectomized rats and their relationship with osteoporosis. METHODS: Sixty 3-month-old female Sprague-Dawley rats were randomly divided into control group and test group (n=30 per group). In the test group osteoporosis model was induced by ovariectomy folowed by intraperitoneal injection of aluminum nitride solution; while rats in the control group were given intraperitoneal injection of normal saline without ovariectomy. The experiment cycle was 12 weeks. One week after modeling, serum level of estradiol was tested, and the bone mineral density of rats measured with bone densitometry. In the meanwhile, the levels of TNF-α, IL-1β and IL-6 in bone tissue were detected to analyze the correlation between cytokines and bone mineral density. RESULTS AND CONCLUSION: The level of serum estradiol in the test group was significantly lower than that in the control group (P=0.007); the bone mineral density of the lumbar spine and femur in the test group was significantly lower than that in the control group (P=0.006, 0.004). Compared with the control group, the percentages of trabecular bone and osteoblast area within the visual field in the test group were significantly lower, while the osteoclast area within the visual field was significantly higher (P=0.037, 0.029, 0.044). Compared with the control group, the levels of TNF-α, IL-1β and IL-6 in the test group significantly increased (P=0.032, 0.031, 0.025). And the bone mineral density of the lumbar spine and femur was negatively correlated with the levels of TNF-α, IL-1β and IL-6 in the test group (P < 0.05). In conclusion, the osteoclast activity is enhanced by elevating the levels of TNF-α, IL-1β and IL-6 of bone tissue of ovariectomized rats, and increasing the percentage of osteoclast area within the visual field. Moreover, the percentages of trabecular bone and osteoblast area within the visual field have a decline, which accelerates the process of bone resorption and leads to the formation of osteoporosis. Subject headingsOvary; Cytokines; Osteoporosis; Tissue Engineering