Direct reprogramming of human dermal fibroblasts into functional osteoblasts using cell-permeable Oct4-30Kc19 and Cbfß-30Kc19
This study aimed to induce the direct reprogramming of human dermal fibroblasts (HDFs) into osteoblast-like cells using the recombinant fusion proteins Oct4-30Kc19 and Cbfß-30Kc19. Oct4 is a transcription factor known to play a crucial role in the direct reprogramming of various cell types, while Cbfß facilitates the differentiation of bone marrow-derived mesenchymal stem cells into osteogenic lineages. To enable intracellular delivery, both transcription factors were fused with 30Kc19, a bombyx mori-derived cell-permeable protein, and expressed using an Escherichia coli system. Oct4-30Kc19 and Cbfß-30Kc19 were successfully delivered into HDFs, and the treated cells exhibited calcium deposition, a hallmark of functional osteoblasts. RNA sequencing was performed on control, treatment, and positive control (osteoblast) groups, revealing that Oct4-30Kc19 and Cbfß-30Kc19 treatment shifted the gene expression profile of HDFs toward an osteoblast-like state. These findings suggest that recombinant fusion protein-based transcription factor delivery may serve as a potential strategy for direct cell reprogramming into osteogenic lineages. Overall design: Oct4-30Kc19 and Cbfß-30Kc19 were applied to induce the direct reprogramming of human dermal fibroblasts (HDFs) into osteoblasts. To achieve this, HDFs (Gibco) were cultured in osteogenic medium supplemented with Oct4-30Kc19 and Cbfß-30Kc19, and their gene expression profiles were analyzed by RNA sequencing (RNA-seq) and compared with those of human osteoblasts.