Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, B-57, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan.
Biomaterials. 2012 Jan;33(2):515-23. doi: 10.1016/j.biomaterials.2011.09.070. Epub 2011 Oct 20.
The establishment of cardiomyocyte differentiation of embryonic stem cells (ESCs) is a useful strategy for cardiovascular regenerative medicine. Here, we report a strategy for cardiomyocyte differentiation of ESCs using substrate immobilization of insulin-like growth factor binding protein 4 (IGFBP4) with elastin-like polypeptides. Recently, IGFBP4 was reported to promote cardiomyocyte differentiation of ESCs through inhibition of the Wnt/β-catenin signaling. However, high amounts of IGFBP4 (approximately 1 μg/mL) were required to inhibit the Wnt/β-catenin signaling and induce differentiation to cardiomyocytes. We report herein induction of cardiomyocyte differentiation using IGFBP4-immobilized substrates. IGFBP4-immobilized substrates were created by fusion with elastin-like polypeptides. IGFBP4 was stably immobilized to polystyrene dishes through fusion of elastin-like polypeptides. Cardiomyocyte differentiation of ESCs was effectively promoted by strong and continuous inhibition of Wnt/β-catenin signaling with IGFBP4-immobilized substrates. These results demonstrated that IGFBP4 could be immobilized using fusion of elastin-like polypeptides. Our results also demonstrate that substrate immobilization of IGFBP4 is a powerful tool for differentiation of ESCs into cardiomyocytes. These findings suggest that substrate immobilization of soluble factors is a useful technique for differentiation of ESCs in regenerative medicine and tissue engineering.
胚胎干细胞（ESCs）心肌细胞分化的建立是心血管再生医学的一种有用策略。在这里，我们报告了一种使用胰岛素样生长因子结合蛋白 4（IGFBP4）与弹性蛋白样多肽的基质固定化来诱导 ESCs 心肌细胞分化的策略。最近，有报道称 IGFBP4 通过抑制 Wnt/β-catenin 信号通路来促进 ESCs 的心肌细胞分化。然而，需要高浓度的 IGFBP4（约 1μg/mL）来抑制 Wnt/β-catenin 信号通路并诱导其向心肌细胞分化。本文报告了使用 IGFBP4 固定化底物诱导心肌细胞分化的方法。IGFBP4 固定化底物是通过与弹性蛋白样多肽融合而创建的。通过与弹性蛋白样多肽融合，IGFBP4 被稳定地固定在聚苯乙烯培养皿上。IGFBP4 固定化底物通过强烈且持续抑制 Wnt/β-catenin 信号通路，有效地促进了 ESCs 的心肌细胞分化。这些结果表明，可以通过与弹性蛋白样多肽融合来固定 IGFBP4。我们的结果还表明，IGFBP4 的基质固定化是将 ESCs 分化为心肌细胞的有力工具。这些发现表明，可溶性因子的基质固定化是再生医学和组织工程中 ESCs 分化的一种有用技术。
