Department of Biotechnology, Yonsei University, Seoul, Republic of Korea.
Department and Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea.
Nat Biomed Eng. 2018 Jul;2(7):522-539. doi: 10.1038/s41551-018-0260-8. Epub 2018 Jul 11.
Biophysical cues can improve the direct reprogramming of fibroblasts into neurons that can be used for therapeutic purposes. However, the effects of a three-dimensional (3D) environment on direct neuronal reprogramming remain unexplored. Here, we show that brain extracellular matrix (BEM) decellularized from human brain tissue facilitates the plasmid-transfection-based direct conversion of primary mouse embryonic fibroblasts into induced neuronal (iN) cells. We first show that two-dimensional (2D) surfaces modified with BEM significantly increase the generation efficiency of iN cells and enhance neuronal transdifferentiation and maturation. Moreover, in an animal model of ischaemic stroke, iN cells generated on the BEM substrates and transplanted into the brain led to significant improvements in locomotive behaviours. We also show that compared with the 2D BEM substrates, 3D BEM hydrogels recapitulating brain-like microenvironments further promote neuronal conversion and potentiate the functional recovery of the animals. Our findings suggest that 3D microenvironments can boost nonviral direct reprogramming for the generation of therapeutic neuronal cells.
生物物理线索可以改善成纤维细胞向神经元的直接重编程，从而用于治疗目的。然而，三维（3D）环境对直接神经元重编程的影响仍未得到探索。在这里，我们表明，从人脑组织脱细胞化的脑细胞外基质（BEM）有利于基于质粒转染的原代小鼠胚胎成纤维细胞向诱导性神经元（iN）细胞的直接转化。我们首先表明，用 BEM 修饰的二维（2D）表面显著提高了 iN 细胞的生成效率，并增强了神经元的转分化和成熟。此外，在缺血性中风动物模型中，在 BEM 基质上生成并移植到大脑中的 iN 细胞导致运动行为的显著改善。我们还表明，与 2D BEM 基质相比，模拟脑样微环境的 3D BEM 水凝胶进一步促进神经元转化，并增强动物的功能恢复。我们的研究结果表明，3D 微环境可以促进非病毒直接重编程以产生治疗性神经元细胞。
