Department of Biomedical Science, College of Life Science, CHA University, 3F, Yatap Ace-Core Building, 502 Yatap-Dong, Bundang-Gu, Seongnam-Si, Gyeonggi-Do 135-081, Republic of Korea.
School of Integrative Engineering, Chung-Ang Univeristy, 221 Heukseok-dong, Dongjak-gu, Seoul 156-756, Republic of Korea.
Biomaterials. 2014 Sep;35(28):8236-48. doi: 10.1016/j.biomaterials.2014.05.092. Epub 2014 Jun 23.
During stem cell differentiation, various cellular responses occur that are mediated by transcription factors and proteins. This study evaluated the abilities of SOX9, a crucial protein during the early stage of chondrogenesis, and siRNA targeting Cbfa-1, a transcription factor that promotes osteogenesis, to stimulate chondrogenesis. Non-toxic poly-(d,l-lactide-co-glycolide) (PLGA) nanoparticles (NPs) were coated with Cbfa-1-targeting siRNA and loaded with SOX9 protein. Coomassie blue staining and circular dichroism revealed that the loaded SOX9 protein maintained its stability and bioactivity. These NPs easily entered human mesenchymal stem cells (hMSCs) in vitro and caused them to differentiate into chondrocytes. Markers that are typically expressed in mature chondrocytes were examined. These markers were highly expressed at the mRNA and protein levels in hMSCs treated with PLGA NPs coated with Cbfa-1-targeting siRNA and loaded with SOX9 protein. By contrast, these cells did not express osteogenesis-related markers. hMSCs were injected into mice following internalization of PLGA NPs coated with Cbfa-1-targeting siRNA and loaded with SOX9 protein. When the injection site was excised, markers of chondrogenesis were found to be highly expressed at the mRNA and protein levels, similar to the in vitro results. When hMSCs internalized these NPs and were then cultured in vitro or injected into mice, chondrogenesis-related extracellular matrix components were highly expressed.
在干细胞分化过程中，会发生各种由转录因子和蛋白质介导的细胞反应。本研究评估了 SOX9（软骨形成早期的关键蛋白）和靶向 Cbfa-1（促进成骨的转录因子）的 siRNA 的能力，以刺激软骨形成。无毒的聚（D，L-丙交酯-co-乙交酯）（PLGA）纳米颗粒（NPs）被靶向 Cbfa-1 的 siRNA 包裹，并负载 SOX9 蛋白。考马斯亮蓝染色和圆二色性显示负载的 SOX9 蛋白保持其稳定性和生物活性。这些 NPs 很容易进入人骨髓间充质干细胞（hMSCs）并使其分化为软骨细胞。检查了通常在成熟软骨细胞中表达的标志物。在用 PLGA NPs 处理的 hMSCs 中，用靶向 Cbfa-1 的 siRNA 包裹并负载 SOX9 蛋白，这些标志物在 mRNA 和蛋白水平上均高度表达。相比之下，这些细胞不表达成骨相关标志物。在 hMSCs 内化靶向 Cbfa-1 的 siRNA 和负载 SOX9 蛋白的 PLGA NPs 后，将其注入小鼠体内。当切除注射部位时，在 mRNA 和蛋白水平上发现软骨形成标志物高度表达，与体外结果相似。当 hMSCs 内化这些 NPs 然后在体外培养或注入小鼠体内时，软骨形成相关的细胞外基质成分高度表达。
