LIM矿化蛋白1/低氧诱导因子1α慢病毒载体转染脂肪源性干细胞的成骨分化

Osteogenic differentiation of adipose-derived stem cells transfected by lentivirus vector carrying LIM mineralization protein-1 and hypoxia-inducible factor-1alpha

背景:LIM矿化蛋白1及低氧诱导因子1α作为胞内蛋白,可分别从诱导成骨分化及促进血管再生两个方面促进成骨,联合二者高效诱导脂肪源性干细胞成骨分化具有重要的意义。目的:探讨慢病毒载体介导的LIM矿化蛋白1及低氧诱导因子1α双基因转染的脂肪源性干细胞成骨分化的情况。方法:应用反转录PCR技术克隆目的基因LIM矿化蛋白1及低氧诱导因子1α片段,并分别克隆于慢病毒骨架质粒p LVX-EF1α-DsR ed-Hyg和p LVX-EF1α-IRES2-AcG FP1中,构建慢病毒载体主体质粒p LVX-EF1α-DsR ed-Hyg-RLMP-1和p LVX-EF1α-AcG FP-RHIF-1α,随即与辅助质粒和包装质粒共转染Lenti-X 293T细胞,包装慢病毒载体;采用组织块加酶消化法分离培养大鼠脂肪源性干细胞,使用流式细胞仪对其进行鉴定。分别在慢病毒转染脂肪源性干细胞3,7,14 d后,应用反转录PCR方法检测脂肪源性干细胞中成骨基因骨形态发生蛋白2、Runx-2、碱性磷酸酶、骨钙蛋白表达水平的同时检测血管内皮生长因子的表达水平。结果与结论:pL VX-EF1α-DsR ed-Hyg-RLMP-1和p LVX-EF1α-Ac GFP-RHIF-1α可有效地转染入大鼠脂肪源性干细胞;反转录PCR结果显示成骨基因骨形态发生蛋白2、Runx-2、碱性磷酸酶、骨钙蛋白在LIM矿化蛋白1及低氧诱导因子1α双基因转染后第7天都开始明显过表达,并且可持续到14 d。说明LIM矿化蛋白1及低氧诱导因子1α双基因转染脂肪源性干细胞可提高其成骨活性。

BACKGROUND：LIM mineralization protein-1 （LMP-1） and hypoxia-inducible factor-1α （HIF-1α） as intracelular proteins can induce osteogenic differentiation and promote angiogenesis, respectively. Therefore, their combination is of great significance for effectively inducing the osteogenic differentiation of adipose-derived stem cels. OBJECTIVE：To study the osteogenic differentiation of adipose-derived stem cels transfected by lentivirus vector carrying LMP-1 and HIF-1α. METHODS：Reverse transcription-PCR technology was employed to clone LMP-1 and HIF-1α genes, and thegenes were cloned to lentivirus vectors pLVX-EF1α-DsRed-Hyg and pLVX-EF1α-IRES2-AcGFP1 to construct main lentiviral vectors pLVX-EF1α-DsRed-Hyg-RLMP-1 and pLVX-EF1α-IRES2-AcGFP1-RHIF-1α. Then, Lenti-X 293T cels were transfected with main vectors pLVX-EF1α-DsRed-Hyg-RLMP-1 and pLVX-EF1α-IRES2-AcGFP1-RHIF-1α, packaging plasmid and coated plasmid. After that, lentiviral vectors were packaged to transfect adipose-derived stem cels from rats that were obtained by tissue explants culture and enzyme digestion methods. At 3, 7, 14 days after transfection, reverse transcription-PCR technology was adopted to detect the expression of osteogeic genes, such as bone morphogenetic protein 2, Runx-2, alkaline phosphatase, osteocalcin as wel as to detect the expression of vascular endothelial growth factor. RESULTS AND CONCLUSION：Lentiviral vectors pLVX-EF1α-DsRed-Hyg-RLMP-1 and pLVX-EF1α-IRES2-AcGFP1-RHIF-1α were effectively transfected into adipose-derived stem cels. Reverse transcription-PCR results showed that from the 7th day to the 14th day after lentivirus transfection, bone morphogenetic protein 2, Runx-2, alkaline phosphatase and osteocalcin al over-expressed. These findings indicate that the combination of LMP-1 and HIF-1α can enhance the osteogenic activity of adipose-derived stem cels.