摘要
目的研究在不同浓度地塞米松作用下,体外培养的大鼠颅骨成骨细胞能否转分化为脂肪细胞,以进一步探讨糖皮质激素性骨质疏松症发病的具体机制。方法将原代培养的大鼠颅骨成骨细胞分为四组,分别用含不同浓度的地塞米松(0 mol/L、10-8mol/L、10-7mol/L、10-6mol/L)的DMEM(H)培养基培养。于作用后第7天、21 d,采用倒置相差显微镜观察细胞形态的变化,进行细胞化学染色(茜素红钙结节染色、油红O染色),并采用实时荧光定量RT-PCR检测PPARγ-2、LPL及ALP基因mRNA的表达。结果在10-6、10-7mol/L的地塞米松作用下,大鼠成骨细胞矿化能力减弱,胞浆中出现脂滴,RT-PCR结果显示脂肪细胞标志基因PPARγ-2、LPL mRNA表达增高,成骨细胞标志基因ALP mRNA表达减少。而10-8mol/L地塞米松对成骨细胞的分化有促进作用。结论长期、大剂量应用糖皮质激素可促进大鼠颅骨成骨细胞转分化为成熟的脂肪细胞,这可能是糖皮质激素性骨质疏松症的发病机制之一。
Objective To investigate the transdifferentiation of rat calvarial osteoblasts into mature adipocytes induced by dexamethasone with different doses in vitro and to explore the pathogenesis of osteoporosis caused by dexamethasone. Methods Osteoblasts in primary cultures were divided into 4 groups. They were cultured with dexamethasone concentrations of 0 mol/L, 108 mol/L, 10-7 mol/L, and 10-6mol/L in DMEM （H） medium. Cell morphology was observed using an inverted phase contrast microscope in 7 days and 21 days, respectively. Cell chemical staining including Alizarin red staining and oil red 0 staining were performed. The expression of PPARΥ2, LPL, and ALP mRNA were investigated using real-time fluorescence quantitative RT-PCR. Results The mineralization of osteoblasts was obviously decreased and lipid droplets were found in cell plasma with 10-6 and 10-7 mol/L dexamethasone. The results of RT-PCR showed that the expression of PPARΥ-2 and LPL increased and the expression of ALP significantly decreased. Dexamethasone at the concentration of 10-s mol/L promoted osteoblast differentiation. Conclusion High dose and long-term usage of dexamethasone can induce transdi？ erentiation of osteoblasts into adipocytes in rats. This may be the pathogenesis of glucocorticoid-indueed osteoporosis.
出处
《中国骨质疏松杂志》
CAS
CSCD
北大核心
2012年第5期415-419,共5页
Chinese Journal of Osteoporosis
基金
国家自然科学基金面上项目(30872631)
