The role of miR-135-modified adipose-derived mesenchymal stem cells in bone regeneration
The role of miR-135-modified adipose-derived mesenchymal stem cells in bone regeneration
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miR-135修饰的脂肪间充质干细胞在骨再生中的作用
DOI：
10.1016/j.biomaterials.2015.10.042
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发表时间：
2016
期刊：
影响因子：
14
通讯作者：
Fan Xianqun
中科院分区：
文献类型：
--
作者：
Xie Qing;Wang Zi;Zhou Huifang;Yu Zhang;Huang Yazhuo;Sun Hao;Bi Xiaoping;Wang Yefei;Shi Wodong;Gu Ping;Fan Xianqun
组织工程技术采用基因修饰的间充质干细胞结合适当的支架是一个有前途的策略，骨再生。阐明间充质干细胞成骨的潜在机制将使人们更深入地了解其调控模式，并提供更有效的方法来增强骨再生。在这项研究中，miR-135被鉴定为成骨相关的microRNA，在大鼠脂肪干细胞（ADSCs）的成骨过程中上调。使用慢病毒表达系统进行的功能获得和丧失实验表明，同源框A2（Hoxa 2）受miR-135负调控，荧光素酶报告基因检测进一步表明，miR-135通过与Hoxa 2 mRNA的3′-非翻译区（3′-UTR）结合抑制Hoxa 2的表达。miR-135显著增强了骨标志物的表达和细胞外基质钙沉积，而miR-135的敲低抑制了这些过程。然后将转导的ADSCs与聚（癸二酰甘油二酯）（PSeD）支架组合以修复大鼠中临界尺寸的颅骨缺损。结果显示，miR-135的过表达显著促进新骨形成，骨密度（BMD）和骨小梁数量（Tb.N）增加，四环素、钙黄绿素和茜素红标记的新骨和矿化面积增加。相反，miR-135的敲低减弱了这些过程。此外，免疫组织化学分析显示，转导的ADSC参与新骨形成，miR-135/Hoxa 2/Runx 2通路可能有助于调节ADSC成骨和骨再生。综上所述，我们的数据表明，miR-135在体外和体内均正向调节ADSCs的成骨和骨再生。因此，miR-135修饰的ADSCs和PSeD支架的组合可以作为修复临界尺寸骨缺损的有希望和有效的方法。
Tissue-engineering technology employing genetically-modified mesenchymal stem cells combined with proper scaffolds represents a promising strategy for bone regeneration. Elucidating the underlying mechanisms that govern the osteogenesis of mesenchymal stem cells will give deeper insights into the regulatory patterns, as well as provide more effective methods to enhance bone regeneration. In this study, miR-135 was identified as an osteogenesis-related microRNA that was up-regulated during the osteogenesis of rat adipose-derived stem cells (ADSCs). Gain- and loss-of-function experiments using a lentiviral expression system showed that Homeobox A2 (Hoxa2) was negatively regulated by miR-135, and luciferase reporter assay further indicated that miR-135 repressed Hoxa2 expression through binding to the 3′-untranslated region (3′-UTR) of the Hoxa2 mRNA.In vitroanalyses showed that the overexpression of miR-135 significantly enhanced the expression of bone markers and extracellular matrix calcium deposition, whereas the knockdown of miR-135 suppressed these processes. Transduced ADSCs were then combined with poly(sebacoyl diglyceride) (PSeD) scaffold to repair a critical-sized calvarial defects in rats. The results showed that the overexpression of miR-135 significantly promoted new bone formation with higher bone mineral density (BMD) and number of trabeculae (Tb.N), as well as larger areas of newly formed bone and mineralization labeled by tetracycline, calcein and alizarin red. In contrast, the knockdown of miR-135 attenuated these processes. Additionally, immunohistochemical analyses showed that transduced ADSCs participated in new bone formation and a miR-135/Hoxa2/Runx2 pathway might contribute to the regulation of ADSC osteogenesis and bone regeneration. Taken together, our data suggested that miR-135 positively regulated the osteogenesis and bone regeneration of ADSCs bothin vitroandin vivo. Thus, the combination of miR-135-modified ADSCs and the PSeD scaffold may serve as a promising and effective method to repair critical-sized bone defects.