Stem cells from umbilical cord blood do have myogenic potential, with and without differentiation induction in vitro

The dystrophin gene, located at Xp21, codifies dystrophin, which is part of a protein complex responsible for the membrane stability of muscle cells. Its absence on muscle causes Duchenne Muscular Dystrophy (DMD), a severe disorder, while a defect of muscle dystrophin causes Becker Muscular Dystrophy (DMB), a milder disease. The replacement of the defective muscle through stem cells transplantation is a possible future treatment for these patients. Our objective was to analyze the potential of CD34+ stem cells from umbilical cord blood to differentiate in muscle cells and express dystrophin, in vitro. Protein expression was analyzed by Immunofluorescence, Western Blotting (WB) and Reverse Transcriptase – Polymerase Chain Reaction (RT-PCR). CD34+ stem cells and myoblasts from a DMD affected patient started to fuse with muscle cells immediately after co-cultures establishment. Differentiation in mature myotubes was observed after 15 days and dystrophin-positive regions were detected through Immunofluorescence analysis. However, WB or RT-PCR analysis did not detect the presence of normal dystrophin in co-cultures of CD34+ and DMD or DMB affected patients' muscle cells. In contrast, some CD34+ stem cells differentiated in dystrophin producers' muscle cells, what was observed by WB, reinforcing that this progenitor cell has the potential to originate muscle dystrophin in vitro, and not just in vivo like reported before.

The collaboration of the following persons is gratefully acknowledged: Hospital Israelita Albert Einstein, São Paulo, Brazil, especially Dr Andresa Ribeiro and Dr Eurípides Ferreira. Marta Cánovas and Antonia Cerqueira, for technical assistance; L.V.B. Anderson, who kindly provided specific antibodies. This work was supported by grants from Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESPCEPID), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), PRONEX, and Associação Brasileira de Distrofia Muscular (ABDIM).

The collaboration of the following persons is gratefully acknowledged: Hospital Israelita Albert Einstein, São Paulo, Brazil, especially Dr Andresa Ribeiro and Dr Eurípides Ferreira. Marta Cánovas and Antonia Cerqueira, for technical assistance; L.V.B. Anderson, who kindly provided specific antibodies. This work was supported by grants from Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP-CEPID), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), PRONEX, and Associação Brasileira de Distrofia Muscular (ABDIM).