Hua Ziyi, Li Shuang, Liu Qianzi, Yu Minxuan, Liao Mengling, Zhang Hongmei, Xiang Xuerong, Wu Qingqing
Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Stomatological Hospital of Chongqing Medical University, Chongqing, China.
Front Bioeng Biotechnol. 2022 May 12;10:841778. doi: 10.3389/fbioe.2022.841778. eCollection 2022.
Induced pluripotent stem cell (iPSC)-derived mesenchymal stem cells (iMSCs) are a promising cell source for bone tissue engineering. However, iMSCs have less osteogenic potential than BMSCs, and the classical iPSC-EB-iMSC process to derive iMSCs from iPSCs is too laborious as it involves multiple steps. Low-intensity pulsed ultrasound (LIPUS) is a safe therapeutic modality used to promote osteogenic differentiation of stem cells. Whether LIPUS can facilitate osteogenic differentiation of iMSCs and simplify the iPSC-EB-iMSC process is unknown. We stimulated iMSCs with LIPUS at different output intensities (20, 40, and 60 mW/cm) and duty cycles (20, 50, and 80%). Results of ALP activity assay, osteogenic gene expression, and mineralization quantification demonstrated that LIPUS was able to promote osteogenic differentiation of iMSCs, and it worked best at the intensity of 40 mW/cm and the duty cycle of 50% (LIPUS40/50). The Wnt/β-catenin signaling pathway was involved in LIPUS40/50-mediated osteogenesis. When cranial bone defects were implanted with iMSCs, LIPUS40/50 stimulation resulted in a significant higher new bone filling rate (72.63 ± 17.04)% than the non-stimulated ones (34.85 ± 4.53)%. Daily exposure to LIPUS40/50 may accelerate embryoid body (EB)-MSC transition, but it failed to drive iPSCs or EB cells to an osteogenic lineage directly. This study is the first to demonstrate the pro-osteogenic effect of LIPUS on iMSCs. Although LIPUS40/50 failed to simplify the classical iPSC-EB-MSC differentiation process, our preliminary results suggest that LIPUS with a more suitable parameter set may achieve the goal. LIPUS is a promising method to establish an efficient model for iPSC application.
诱导多能干细胞（iPSC）来源的间充质干细胞（iMSC）是骨组织工程中一种很有前景的细胞来源。然而，iMSC的成骨潜能低于骨髓间充质干细胞（BMSC），并且从iPSC中获得iMSC的经典iPSC-胚状体（EB）-iMSC方法过于繁琐，因为它涉及多个步骤。低强度脉冲超声（LIPUS）是一种用于促进干细胞成骨分化的安全治疗方式。LIPUS是否能促进iMSC的成骨分化并简化iPSC-EB-iMSC过程尚不清楚。我们用不同输出强度（20、40和60 mW/cm）和占空比（20%、50%和80%）的LIPUS刺激iMSC。碱性磷酸酶（ALP）活性测定、成骨基因表达和矿化定量结果表明，LIPUS能够促进iMSC的成骨分化，并且在强度为40 mW/cm和占空比为50%（LIPUS40/50）时效果最佳。Wnt/β-连环蛋白信号通路参与了LIPUS40/50介导的成骨过程。当颅骨缺损植入iMSC时，LIPUS40/50刺激导致新骨填充率（72.63±17.04）%显著高于未刺激组（34.85±4.53）%。每天暴露于LIPUS40/50可能会加速胚状体（EB）-MSC转变，但它未能直接将iPSC或EB细胞驱动到成骨谱系。本研究首次证明了LIPUS对iMSC的促成骨作用。尽管LIPUS40/50未能简化经典的iPSC-EB-MSC分化过程，但我们的初步结果表明，具有更合适参数设置的LIPUS可能实现这一目标。LIPUS是建立高效iPSC应用模型的一种有前景的方法。
