Fallah Asghar, Beke Alexander, Oborn Connor, Soltys Carrie-Lynn, Kannu Peter
Department of Medical Genetics, University of Alberta, Edmonton, CanadaT6G 2H7.
Stem Cells Transl Med. 2024 Apr 15;13(4):362-370. doi: 10.1093/stcltm/szad093.
Direct reprogramming (DR) is an emerging technique that can be applied to convert fibroblasts into osteoblast-like cells, promoting bone formation and regeneration. We review the current methodology of DR in relation to the creation of induced osteoblasts, including a comparison of transcription factor-mediated reprogramming and nontranscription factor-mediated reprogramming. We review the selection of reprogramming factors and delivery systems required. Transcription factor cocktails, such as the RXOL cocktail (Runx2, Osx, OCT3/4, and L-MYC), have shown promise in inducing osteogenic differentiation in fibroblasts. Alterations to the original cocktail, such as the addition of Oct9 and N-myc, have resulted in improved reprogramming efficiency. Transcription factor delivery includes integrative and nonintegrative systems which encompass viral vectors and nonviral methods such as synthetic RNA. Recently, an integrative approach using self-replicating RNA has been developed to achieve a longer and more sustained transcription factor expression. Nontranscription factor-mediated reprogramming using small molecules, proteins, inhibitors, and agonists has also been explored. For example, IGFBP7 protein supplementation and ALK5i-II inhibitor treatment have shown potential in enhancing osteoblast reprogramming. Direct reprogramming methods hold great promise for advancing bone regeneration and tissue repair, providing a potential therapeutic approach for fracture healing and the repair of bone defects. Multiple obstacles and constraints need to be addressed before a clinically significant level of cell therapy will be reached. Further research is needed to optimize the efficiency of the reprogramming cocktails, delivery methods, and safety profile of the reprogramming process.
直接重编程（DR）是一种新兴技术，可用于将成纤维细胞转化为成骨样细胞，促进骨形成和再生。我们综述了与诱导成骨细胞生成相关的直接重编程的当前方法，包括转录因子介导的重编程和非转录因子介导的重编程的比较。我们还综述了重编程因子和所需递送系统的选择。转录因子组合，如RXOL组合（Runx2、Osx、OCT3/4和L-MYC），已显示出在诱导成纤维细胞成骨分化方面的潜力。对原始组合的改变，如添加Oct9和N-myc，已提高了重编程效率。转录因子递送包括整合和非整合系统，其中涵盖病毒载体和非病毒方法，如合成RNA。最近，已开发出一种使用自我复制RNA的整合方法，以实现更长时间和更持续的转录因子表达。也已探索了使用小分子、蛋白质、抑制剂和激动剂进行的非转录因子介导的重编程。例如，补充IGFBP7蛋白和用ALK5i-II抑制剂治疗已显示出在增强成骨细胞重编程方面的潜力。直接重编程方法在推进骨再生和组织修复方面具有巨大潜力，为骨折愈合和骨缺损修复提供了一种潜在的治疗方法。在达到具有临床意义的细胞治疗水平之前，需要解决多个障碍和限制。需要进一步研究以优化重编程组合的效率、递送方法以及重编程过程的安全性。
