Effects Of Ipriflavone And Estradiol On Biological Characteristics Of Osteoblasts Derived From Osteoporotic Rats' Mandibles

Many studies have shown that osteoporosis can lead to the reduce of jaw and may be one important reason of implant failure,therefore,effective prevention and treatment of osteoporosis become a hot oral medical research.Although the Systemic drugs can increase the jaw bone density,improve the success rate of implants,but also have significant drawbacks.So,LIU Hong-chen' artificial implant drug delivery system may be a good way for the prevention and treatment of osteoporosis and improving the success rate of implants.In drugs treating osteoporosis,ipriflavone and estradiol may be expected to become the ideal combination of the drugs.Therefore,this experiment will study osteoporotic mandible osteoblasts -- target cells around the implant from biological characteristics and impact of ipriflavone combined with estradiol on it,and provide certain experimental research base for the artificial implant drug delivery system.PartⅠAnimal Model of Osteoporosis and the Relationship of Systemic Osteoporosis and Mandibular OsteoporosisObjective:To establish the postmenopausal osteoporosis mandible animal model and study the influence of osteoporosis on different parts of the body.Methods: Bilateral ovary removal surgery was used to establish animal model of osteoporosis.By detecting weight,lumbar spine and femur bone mineral density, serum indicators,the time of mandible osteoporosis model was determined.Jaws' osteoporosis was judgemented by the jaw bone mineral density and biopsy of jaws.Results:The mandible osteoporosis animal model was established successfully.The weight of ovx group was higher than the sham group in 4w,12w and 20w after surgery.The appearance order of lower BMD in different parts of the body was not the same in ovx group:the lower of BMD in the lumbar spine and femur was after four weeks;the mandible BMD was higher in ovx group than sham group,though maxllia did not appear the statistical lower throughout the experiment,the jaws showed a decreasing trend.Serum calcium, phosphorus,magnesium had decreased and the ALP and OC had increased in ovx group,comparing with sham group,which meeted the performance of animal model of osteoporosis.HE biopsy revealed that trabecular bone of mandibulat in ovx group decreased and were sparsed.Conclusion:Animal model of osteoporosis was established.And the jaws also appeared osteoporotic changes.PartⅡChanges of Proliferation and Differentiation Ability of Mandible Osteoblasts of ovx RatsObjective:To explore the changes of mandible osteoblasts' biological characteristics between the ovx group and the sham group in the 4 weeks and 12 weeks after surgery.Methods:Osteoblasts from the mandible tissue and enzyme isolation were cultured,osteoblasts were identified by ALP staining,I collagen staining and Alizarin S Red nodules.The proliferation of osteoblasts,assay of ALP activity,osteocalcin were detected and acquired.By RT-PCR and Western Blot methods,the gene and protein changes in PCNA were detected.The mocrostructure changes of osteoporotic osteoblasts and sham group' osteoblasts in 12w after surgery were observed by TEM.Results:The stain of ALP,I collagen and Alizarin S Red nodules was positive.In 4 weeks of ovx group,the proliferation and ALP ability had a significant increase,and in 12 weeks osteocalcin and PCNA expression were also higher than that from sham group.The TEM results showed that the mitochondria and heterochromatin in osteoporotic osteoblasts increased,but the black lysosomal particles and white small foam in the osteoblasts from the sham group increased.Conclusions:The osteoblasts capacity of proliferation and differentiation from the ovx group had increased,in comparison to osteoblasts from the sham group.PartⅢChanges of ER and UCP2 in Mandible Osteoblasts of ovx Rats Objective:To explore the osteoblasts changes in ER and UCP2 in 4w and 12w after surgery.Methods:By RT-PCR and Western Blot methods,the gene and protein changes in ER and UCP2 were detected.Results:The expression of UCP2 in osteoblasts from ovx group was lower than that from sham group significantly.ERαand ERβexpression in ovx group were higher than that in sham group.Conclusions:Osteoporotic osteoblasts in ER and UCP2 expression had changed,and the changes may have relation with osteoporotic osteoblasts' proliferation and differentiation mechanism.PartⅣEffects of Ipriflavone and Estradiol on Biological Characteristics of Osteoporotic OsteoblastsObjective:To explore the impact of joint application Of estradiol and Ipriflavone to osteoporotic osteoblasts on the biological characteristics and related genes or proteins.Methods:Detecting of two drugs' different concentrations on proliferation and differentiation of osteoporotic osteoblasts,the best concentration was determined.The UCP2,PCNA,ERαand ERβexpression were measured by RT-PCR and Western Blot methods.Results:Selected concentrations of estradiol and Ipriflavone increased proliferation and differentiation of osteoporotic osteoblasts.And both drugs promoted the expression of UCP2 and PCNA, however,when two drugs combined did not mutually reinforcing.Ipriflavone inhibited the expression of ERα,but promoted the expression of ERβ,when two drugs combined had no obvious role in the expression of ER.Conclusions: Selected concentrations of estradiol and Ipriflavone increased proliferation and differentiation of osteoporotic osteoblasts,no inhibition.Estradiol and ipriflavone may play a role in the expression of PCNA,UCP2,ERαand ERβ,but between the two drugs specific mechanism was not clear.