Direct Conversion of Human Umbilical Vein Endothelial Cells into Osteoblasts Using Cell Penetrating Peptide, 30Kc19

Along with the growing senior population, diseases related to aging, especially bone-related diseases have become more prominent in the global population. This urges more studies on osteo-diseases to be conducted, which results in a surge of demand for cellular resources. Direct reprogramming seems to be a promising solution to meet these standards, incorporating viral and nonviral methods. Because the viral methods have the risk of cytotoxicity and tumorigenesis, non-viral methods, more specifically Cell-Penetrating-Peptide (CPP) can be employed to directly reprogram Human Umbilical Vein Endothelial Cells (HUVEC) into Osteoblasts.

In this study, osteogenic transcription factors, Osterix (Osx), and Core-Binding Factor Beta (Cbfb), are individually attached to a CPP, 30Kc19, to transdifferentiate HUVEC into osteoblasts. Osx and Cbfb are key ostegenic transcription factors known for their roles in osteoblast maturation, bone calcification, and bone homeostasis. In order to attach 30Kc19 to these transcription factors, gene cloning via recombinant technology and mass production using BL21 Escherichia coli are employed. Further promoting transdifferentation, Bone Morphogenic Protein 4 (BMP4) is incorporated to induce osteogenesis from different cell types, such as HUVEC. Prior to the peptide treatments, direct reprogramming efficacies in HUVEC and Adipocyte Derived Stem Cell (ADSC) are examined via electroporation of Osx plasmid. When transfected HUVEC and ADSC are analyzed, calcification and up-regulation of osteoblast-specific genes are observed, indicating that transdifferentiation occurred.