最近研究表明固醇辅酶A去饱和酶1（SCD1）的高活性与骨质疏松有关。SCD1的高活性提示体内饱和脂肪酸的增加，而大量的饱和脂肪酸能增加骨折的风险。我们先前的研究表明在骨髓间充质干细胞（BM-MSCs）中过表达SCD1能促进体外成骨并增加诱导的内皮细胞表达。至今为止，国内外尚无有关在骨髓间充质干细胞中过表达SCD1与体外成骨及成内皮关系的研究。本课题目的在于研究中过表达SCD1对体外成骨效能与细胞转归方面的影响以及过表达SCD1促进成骨及成内皮的机制。本课题使用慢病毒转染骨髓间充质干细胞并诱导为内皮细胞与成骨细胞，与β-TCP支架复合。拟采用SCD1-GFP荧光序列，通过不同CD标记细胞免疫测定，研究转染诱导的成骨细胞和内皮细胞对组织工程化骨的成骨效能和细胞转归的影响。同时，通过对PPAR、Wnt、ERK、Notch等成骨成内皮通路的检测研究SCD1促进成骨及成内皮的分子水平机制。

Recent study showed that high activity of Stearoyl-CoA desaturase 1 (SCD1) was related to osteoporosis. High SCD1 activity indicated high level of saturated fat acids in vivo, which substantially increased the risk for fractures. Our previous study suggested that overexpression of SCD1 in bone marrow mesenchymal stem cells (BM-MSCs) could increase osteogenesis and the expression of induced endothelial cells in vitro. Up to now, there has been no report in the literature of the relationship between the overexpression of SCD1 and osteogenesis or endothelial cell differentiation in vitro. The goal of this research is to study the influence of overexpression of SCD1 in osteigenicity of tissue engineered bone and fate of BM-MSCs, and the mechanism by which SCD1 increases osteogenesis and endothelial differentiation in BM-MSCs. In our study, the co-culture system would be modified by lenti virus as vector and compounded with β-TCP scaffold. We will observe vascularization, osteogenesis and fate of induced osteoblasts and endothelial cells through SCD1-GFP transfect and CD series detections. And we will study the mechanism in the molecular level by which SCD1 increases osteogenesis and endothelial differentiation in BM-MSCs by detecting the related pathways of osteogenesis and endothelial differentiation such as PPAR, Wnt, ERK and Nothch.

固醇辅酶A去饱和酶1（SCD1）在组织工程化成骨中具有促进成骨成内皮作用，本课题通过在骨髓间充质干细胞（BM-MSCs）中过表达SCD1，结合蛋白质生物化学、细胞生物学、基因芯片等方法与技术，对过表达SCD1促进BM-MSCs成骨成内皮的作用及分子机制进行了研究。首先通过构建pCDH-SCD1慢病毒载体，转染人源骨髓间充质干细胞（hBMSCs），筛选获得稳定过表达SCD1的细胞株；进而进行体外成骨及成内皮诱导分化，通过RT-PCR方法检测分化情况，结果显示成骨指标（ALP、OCN）及成内皮指标（vWF、CD31、CDH5）均高表达，表明过表达SCD1对BM-MSCs成骨成内皮具有促进作用。通过基因芯片及智能通路分析系统（IPA）分析在成骨、成内皮诱导下过表达SCD1对hBMSCs基因及通路表达差异的影响，结果显示Interferon Signaling及NRF2 Signaling信号通路表达差异明显，推测SCD1通过与该信号通路作用促进成骨成内皮。SCD1与PPARγ、Wnt、ERK5、Notch等促成骨成内皮相关通路之间相互关系的工作正在进行。综合上述结果，本研究为探讨过SCD1对调节组织工程化成骨中成骨及成内皮作用的机制奠定了坚实的工作基础，同时对认识SCD1与和hBMSCs分化之间的关系提供了重要的线索。项目资助发表论文1篇，待发表2篇。项目培养在读硕士生2名。项目投入经费65万元，支出27.13万元，各项支出基本与预算相符。剩余经费37.87万元，剩余经费计划用于本项目研究后续支出。