Lineage conversion from one somatic cell type to another is an attractive approach for deriving specific therapeutic cell generation. In order to bypass inducing pluripotent stage, transdifferentiation/direct conversion technologies have been recently developed. We report the development of a direct conversion methodology in which cells are transdifferentiated through a plastic intermediate state induced by exposure to non-integrative minicircle DNA (MCDNA)-based reprogramming factors, followed by differentiation into myoblasts. In order to increase the MCDNA delivery efficiency, reprogramming factors were delivered into the chondrocytes via electroporation followed by poly (β-amino esters) (PBAE) transfection. We used this approach to convert human chondrocytes to myoblast, and with treatment of SB-431542, an inhibitor of the activin receptor-like kinase receptors, to enhance myogenic commitment. Differentiated cells exhibited expression of myogenic markers such as MyoD and Myog. This methodology for direct lineage conversion from chondrocytes to myoblast represents a novel non-viral Method to convert hard-to-transfect cells to other lineage.
