Regulation of osteogenic differentiation of rat bone marrow stromal cells on 2D nanorod substrates.
Regulation of osteogenic differentiation of rat bone marrow stromal cells on 2D nanorod substrates.
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DOI：
10.1016/j.biomaterials.2009.11.041
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发表时间：
2010-03
期刊：
影响因子：
14
通讯作者：
Wang Q
中科院分区：
文献类型：
--
作者：
Kaur G;Valarmathi MT;Potts JD;Jabbari E;Sabo-Attwood T;Wang Q
骨髓基质细胞（BMSCs）具有多向分化潜能，在化学和环境因素的正确组合下可被诱导分化为各种细胞类型。尽管它们在治疗和医学应用中显示出巨大的前景，但对其在模拟细胞外基质（ECM）的纳米表面上的行为知之甚少。在这份报告中，我们采用了二维基板涂有烟草花叶病毒（TMV）纳米棒，研究骨髓基质细胞分化成骨样细胞的过程。TMV是一种杆状植物病毒，平均长度为300 nm，直径为18 nm。在TMV上的BMSCs的成骨分化在7、14和21天的时间点上进行了研究。我们通过真实的时间定量PCR（RT-qPCR）分析检测了这些时间点期间的时间基因表达变化。正如预期的那样，骨特异性基因（骨钙素，骨桥蛋白和骨连接素）上调，并显示在TMV上的表达在14天的最大变化，这比组织培养塑料（TCP）早7天。基于RT-qPCR实验产生的基因表达谱，我们提出细胞与TMV的早期相互作用触发了信号通路，该信号通路反过来调节骨钙素的快速表达，导致细胞的早期矿化。为了进一步研究这些调节因子，我们研究了纳米基质上成骨分化过程中基因表达的总体变化（DNA微阵列分析）。在纳米棒基底上培养细胞会影响许多基因，这证实了我们最初的PCR发现。微阵列分析进一步揭示了受表面上纳米棒存在影响的其他靶点，其中骨形态发生蛋白2（BMP 2）的表达特别令人感兴趣。对BMP 2的时间变化的进一步研究表明，它作为一个主要的启动子，在TMV包被的基底上的骨钙素的早期调节信号。
Bone marrow stromal cells (BMSCs) possess multi-lineage differentiation potential and can be induced to undergo differentiation into various cell types with the correct combination of chemical and environmental factors. Although, they have shown great prospects in therapeutic and medical applications, less is known about their behavior on nanosurfaces mimicking the extra cellular matrix (ECM). In this report we have employed 2D substrates coated with tobacco mosaic virus (TMV) nanorods to study the differentiation process of BMSCs into osteoblast-like cells. TMV is a rod-shaped plant virus with an average length of 300 nm and diameter of 18 nm. The osteogenic differentiation of BMSCs on TMV was studied over time points of 7, 14 and 21 days. We examined the temporal gene expression changes during these time points by real time quantitative PCR (RT-qPCR) analysis. As expected, osteo-specific genes (osteocalcin, osteopontin and osteonectin) were upregulated and showed a maximum change in expression on TMV at 14 days which was 7 days earlier than on tissue culture plastic (TCP). Based on the genes expression profile generated by RT-qPCR experiments, we proposed that the early interaction of cells with TMV triggers on signaling pathways which regulate speedy expression of osteocalcin in turn, resulting in early mineralization of the cells. To further investigate these regulating factors we studied global changes in gene expression (DNA microarray analyses) during osteogenic differentiation on the nanosubstrate. Multitudes of genes were affected by culturing cells on nanorod substrate, which corroborated our initial PCR findings. Microarray analysis further revealed additional targets influenced by the presence of nanorods on the surface, of which, the expression of bone morphogenetic protein 2 (BMP2) was of particular interests. Further investigation into the temporal change of BMP2, revealed that it acts as a major promoter in signaling the early regulation of osteocalcin on TMV coated substrates.