Dental and Craniofacial Research Institute and Section of Orthodontics, School of Dentistry, University of California, Los Angeles, CA 90095-1759, USA.
Biomaterials. 2012 Aug;33(24):5821-31. doi: 10.1016/j.biomaterials.2012.04.049. Epub 2012 May 21.
Pluripotent and/or multipotent stem cell-based therapeutics are a vital component of tissue engineering and regenerative medicine. The generation or isolation of safer and readily available stem cell sources will significantly aid clinical applications. We report here a technique using a single molecule, recombinant human fibromodulin protein (FMOD), to reprogram human fibroblasts into multipotent cells. Like virally-induced pluripotent stem (iPS) cells, FMOD reprogrammed (FReP) cells express pluripotency markers, form embryoid bodies (EBs), and differentiate into ectoderm, mesoderm, and endoderm derivatives in vitro. Notably, FReP cells regenerate muscle and bone tissues but do not generate teratomas in vivo. Unlike iPS cells, undifferentiated FReP cells proliferate slowly and express low proto-oncogene c-MYC and unexpectedly high levels of cyclin-dependent kinase inhibitors p15(Ink4B) and p21(WAF1/Cip1). Remarkably, in a fashion reminiscent of quiescent stem cells, the slow replicative phenotype of undifferentiated FReP cells reverses after differentiation induction, with differentiating FReP cells proliferating faster and expressing less p15(Ink4B) and p21(WAF1/Cip1) than differentiating iPS cells. Overall, single protein, FMOD-based, cell reprograming bypasses the risks of mutation, gene instability, and malignancy associated with genetically-modified iPS cells, and provides an alternative strategy for engineering patient-specific multipotent cells for basic research and therapeutic application.
基于多能性和/或多能干细胞的治疗方法是组织工程和再生医学的重要组成部分。更安全、更易于获得的干细胞来源的产生或分离将极大地促进临床应用。我们在此报告了一种使用单个分子、重组人纤维调蛋白蛋白（FMOD）将人成纤维细胞重编程为多能细胞的技术。与病毒诱导的多能干细胞（iPS）一样，FMOD 重编程（FReP）细胞表达多能性标志物，形成胚状体（EBs），并在体外分化为外胚层、中胚层和内胚层衍生物。值得注意的是，FReP 细胞再生肌肉和骨骼组织，但在体内不会产生畸胎瘤。与 iPS 细胞不同，未分化的 FReP 细胞增殖缓慢，表达低原癌基因 c-MYC，出人意料地高水平表达细胞周期蛋白依赖性激酶抑制剂 p15(Ink4B)和 p21(WAF1/Cip1)。值得注意的是，未分化的 FReP 细胞的缓慢复制表型在分化诱导后以类似于静止干细胞的方式逆转，分化的 FReP 细胞增殖更快，表达的 p15(Ink4B)和 p21(WAF1/Cip1)低于分化的 iPS 细胞。总的来说，基于单一蛋白质 FMOD 的细胞重编程绕过了与基因修饰的 iPS 细胞相关的突变、基因不稳定性和恶性肿瘤的风险，并为工程化患者特异性多能细胞提供了一种替代策略，用于基础研究和治疗应用。
