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[目的]探讨在去卵巢大鼠骨质疏松模型骨髓微环境中成骨细胞、脂肪细胞和破骨细胞分化的相互关系及其机制。[方法]将3个月龄雌性SD大鼠16只随机分为2组:假手术组(SHAM)和去卵巢组(OVX),每组8只。采用双侧卵巢切除术复制骨质疏松大鼠模型。术后14周,应用双能X线吸收仪法(DXA)测第4腰椎和股骨骨密度(BMD)。qRT-PCR法测量骨髓细胞RUNX2、PPARγ、OPG和RANKL mRNA表达量。石蜡组织切片HE染色测量第3腰椎和胫骨近端骨组织脂肪细胞数目。免疫组织化学染色测定胫骨近端骨组织OPG/RANKL蛋白表达量。[结果]与SHAM比较,OVX组腰椎和股骨BMD下降(P<0.05)。OVX组股骨骨髓细胞成骨分化转录因子RUNX2mRNA水平比SHAM组增高(P<0.05),成脂分化转录因子PPARγmRNA表达水平比SHAM组增高(P<0.05)。OVX组胫骨和第3腰椎脂肪细胞数目比SHMA组增多(P<0.05)。与SHAM组比较,OVX组股骨骨髓细胞RANKLmRNA和胫骨RANKL蛋白表达量增加(P<0.05)且OPG/RANKL的比率都降低(P<0.05),而两者OPG的mR-NA和蛋白表达量无统计学差异(P>0.05)。[结论]去卵巢大鼠骨量丢失可能是骨髓微环境中成骨细胞分化、脂肪细胞分化和破骨细胞分化紊乱导致。
[Objective] To investigate the relationship between osteoblasts, adipocytes and osteoclasts differentiation in the bone marrow microenvironment of osteoporosis model in ovariectomized rats and its mechanism. [Method] Sixteen 3-month-old female Sprague-Dawley rats were randomly divided into 2 groups: sham operation group (OVX) and sham operation group (OVX), 8 in each group. Bilateral ovariectomized rat models of osteoporosis were replicated. At 14 weeks after operation, the fourth lumbar and femur BMD were measured by dual energy X-ray absorptiometry (DXA). The mRNA expression of RUNX2, PPARγ, OPG and RANKL in bone marrow cells was measured by qRT-PCR. Paraffin sections were stained with HE to measure the number of adipocytes in the third lumbar vertebrae and proximal tibia. Immunohistochemical staining was used to detect the OPG / RANKL protein expression in the proximal tibia bone. [Results] Compared with SHAM, BMD of lumbar spine and femur in OVX group decreased (P <0.05). OVX group osteogenic differentiation transcription factor RUNX2 mRNA level increased compared with SHAM group (P <0.05), the adipogenic transcription factor PPARγmRNA expression level increased compared with SHAM group (P <0.05). The number of tibias and third lumbar adipocytes in OVX group was higher than that in SHMA group (P <0.05). Compared with SHAM group, the expression of RANKL mRNA and RANKL protein in femur bone marrow cells increased (P <0.05) and the ratio of OPG / RANKL in OVX group decreased (P <0.05), while the expression of mR-NA and protein in OPG Statistical difference (P> 0.05). [Conclusion] The bone loss in ovariectomized rats may result from osteoblast differentiation, adipocyte differentiation and osteoclast differentiation disorder in bone marrow microenvironment.