BACKGROUND We have shown that genetic overexpression of cell cycle proteins can increase the proliferation of transplanted cardiomyocytes derived from human induced-pluripotent stem cells (hiPSC-CMs) in animal models of myocardial infarction (MI). Here, we introduce a new, non-genetic approach to promote hiPSC-CM cell cycle activity and proliferation in transplanted human cardiomyocyte patches (hCMPs). METHODS Mice were randomly distributed into 5 experimental groups (n = 10 per group). One group underwent Sham surgery, and the other 4 groups underwent MI induction surgery followed by treatment with hCMPs composed of hiPSC-CMs and nanoparticles that contained CHIR99021 and FGF1 (the NPCF-hCMP group), with hCMPs composed of hiPSC-CMs and empty nanoparticles (the NPE-hCMP group); with patches containing the CHIR99021/FGF-loaded nanoparticles but lacking hiPSC-CMs (the NPCF-Patch group), or patches lacking both the nanoparticles and cells (the E-Patch group). Cell cycle activity was evaluated via Ki67 and Aurora B expression, bromodeoxyuridine incorporation, and phosphorylated histone 3 levels (immunofluorescence); engraftment via human cardiac troponin T or human nuclear antigen expression (immunofluorescence) and bioluminescence imaging; cardiac function via echocardiography; infarct size and wall thickness via histology; angiogenesis via isolectin B4 expression (immunofluorescence); and apoptosis via TUNEL and caspace 3 expression (immunofluorescence). RESULTS Combined CHIR99021- and FGF1-treatment significantly increased hiPSC-CM cell cycle activity both in cultured cells (by 4- to 6-fold) and in transplanted hCMPs, and compared to treatment with NPE-hCMPs, NPCF-hCMP transplantation increased hiPSC-CM engraftment by ~4-fold and was associated with significantly better measurements of cardiac function, infarct size, wall thickness, angiogenesis, and hiPSC-CM apoptosis four weeks after MI induction. CONCLUSIONS Nanoparticle-mediated CHIR99021 and FGF1 delivery promotes hiPSC-CM cell cycle activity and proliferation, as well as the engraftment and regenerative potency of transplanted hCMPs, in a mouse MI model.

中文翻译：

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CHIR99021 和成纤维细胞生长因子 1 可增强小鼠心肌梗死后人心肌贴片的再生能力。

背景我们已经表明，在心肌梗死 (MI) 的动物模型中，细胞周期蛋白的基因过表达可以增加源自人诱导多能干细胞 (hiPSC-CM) 的移植心肌细胞的增殖。在这里，我们介绍了一种新的非遗传方法来促进移植的人心肌细胞贴片 (hCMPs) 中的 hiPSC-CM 细胞周期活性和增殖。方法 将小鼠随机分为 5 个实验组（每组 n = 10）。一组接受假手术，另外 4 组接受 MI 诱导手术，然后用由 hiPSC-CM 和含有 CHIR99021 和 FGF1 的纳米颗粒组成的 hCMPs 治疗（NPCF-hCMP 组），hCMPs 由 hiPSC-CMs 和空纳米颗粒组成（NPE-hCMP 组）；含有载有 CHIR99021/FGF 的纳米颗粒但缺乏 hiPSC-CM（NPCF-Patch 组）的贴片，或同时缺乏纳米颗粒和细胞的贴片（E-Patch 组）。通过 Ki67 和 Aurora B 表达、溴脱氧尿苷掺入和磷酸化组蛋白 3 水平（免疫荧光）评估细胞周期活性；通过人心肌肌钙蛋白 T 或人核抗原表达（免疫荧光）和生物发光成像进行植入；通过超声心动图检查心脏功能；通过组织学检查梗塞大小和壁厚；通过异凝集素 B4 表达（免疫荧光）进行血管生成；通过 TUNEL 和 caspace 3 表达（免疫荧光）进行细胞凋亡。结果 CHIR99021 和 FGF1 联合处理显着增加了培养细胞（4 到 6 倍）和移植的 hCMPs 中的 hiPSC-CM 细胞周期活性，与 NPE-hCMP 治疗相比，NPCF-hCMP 移植使 hiPSC-CM 植入增加了约 4 倍，并且与 4 周后心脏功能、梗塞面积、壁厚、血管生成和 hiPSC-CM 凋亡的更好测量相关MI 感应。结论 在小鼠 MI 模型中，纳米颗粒介导的 CHIR99021 和 FGF1 递送促进了 hiPSC-CM 细胞周期活性和增殖，以及移植的 hCMPs 的植入和再生效力。