骨髓脂肪细胞向成骨细胞的转分化  

Transdifferentiation of bone marrow adipocytes into osteoblasts

作　　者：康鹏德[1] 裴福兴[1] 杨静[1] 沈彬[1] 周宗科[1] 

机构地区：[1]四川大学华西医院骨科,四川省成都市610041

出　　处：《中国组织工程研究与临床康复》2011年第1期17-22,共6页Journal of Clinical Rehabilitative Tissue Engineering Research

基　　金：国家自然科学基金面上项目(30772202/C1607);教育部博士点基金新教师基金(850-20070610005)~~

摘　　要：背景:骨髓脂肪细胞、成骨细胞共同来源于骨髓基质细胞,二者存在基因同源性,在一定的条件下可以相互转分化。目的:观察骨髓细胞源性脂肪细胞在成骨诱导分化培养条件下转分化为成骨细胞的活性,探索股骨头坏死细胞水平治疗的新途径。方法:将前脂肪细胞3T3-L1分别进行成骨诱导培养和成脂诱导培养。培养后不同时间点观察细胞形态的变化;并于诱导培养后5,21d分别进行实时定量-聚合酶链反应检测成骨、成脂分化过程中,细胞中Runt相关基因转录因子2、氧化物增殖体激活物受体γ2、骨钙素和Ⅰ型胶原mRNA表达。并于成骨、成脂培养21d后采用Wertern-blot法检测相关蛋白的表达。培养细胞爬片,分别进行碱性磷酸酶、钙结节茜素红、油红O染色,观察3T3-L1成骨转分化情况以及成骨细胞活性表达。结果与结论:3T3-L1在成骨诱导培养5d后,细胞由圆形逐渐演变成纺锤形和梭形;实时定量-聚合酶链反应检测结果与对照组相比,氧化物增殖体激活物受体γ2mRNA表达减弱,而Runt相关基因转录因子2、骨钙素和Ⅰ型胶原mRNA表达微量增强。至21d时,这种表达改变更加明显;Western-blot显示,Runt相关基因转录因子2、骨钙素和Ⅰ型胶原蛋白量增加,而氧化物增殖体激活物受体γ2微量甚至无表达;碱性磷酸酶染色阳性表达较多,茜素红钙结节染色可见多个散在分布的钙结节;油红O染色微量脂滴。提示小鼠骨髓基质细胞源性前脂肪细胞3T3-L1在成骨诱导培养下,可在一定程度上转分化为有生物活性的成骨细胞;小鼠骨髓基质细胞的脂肪细胞和成骨细胞二者之间存在着可塑性。BACKGROUND：Bone marrow adipocytes and osteoblasts are derived from bone marrow stromal cells. Both of them have homology and have transdifferentiation each other under a certain condition. OBJECTIVE：To investigate the activity of bone marrow adipocytes differentiation into osteoblasts and to explore the new treatment method for the steroid-induced osteonecrosis of the femoral head. METHODS：Osteogenic and adipogenic differentiation of confluent preadipocytes 3T3-L1 was performed. Changes in cell morphology were observed at various time points following culture. The levels of peroxisome proliferators activated receptor γ2 （PPARγ2）,runt-related transcription factor 2 （Runx2）,osteocalcin （OCN） and collagen type I （Col I） mRNA expression were investigated by RT-PCR at days 5 and 21 following culture. Western blotting was used to evaluate cellular PPARγ2,Runx2,OCN and Col I production on day 21 following osteogenic and adipogenic culture. Cultured cells received alkaline phosphatase staining,alizarin red staining and oil red O staining. 3T3-L1 osteogenic transdifferentiation and activity expression of osteoblasts were observed. RESULTS AND CONCLUSION：On day 5 following osteogenic induction,3T3-L1 cells became spindle shape. Compared with control group,real-time quantity-PCR results demonstrated that PPARγ2 mRNA expression was reduced,but Runx2,OCN and Col I mRNA expression was slightly increased. On day 21,these changes were more significant. Western blot exhibited that Runx2,OCN and Col I expression was increased,but no PPARγ2 expression was detected. Positive expression of alkaline phosphatase staining was more. Alizarin red staining showed many scattered calcified nodes. Oil red O staining showed slight lipid droplet. Results indicated that mouse bone marrow stromal cells-derived preadipocytes 3T3-L1 can differentiate into osteoblasts with bioactivity to a certain degree following culture. There is the plasticity between adipocytes and osteoblasts.

关 键 词：脂肪细胞 成骨细胞 骨髓 转分化 股骨头坏死 

分 类 号：R394.2[医药卫生—医学遗传学]