The role of CD34 expression and cellular fusion in the regeneration capacity of myogenic progenitor cells

Abstract

Characterization of myogenic subpopulations has traditionally been performed independently of their functional performance following transplantation. Using the preplate technique, which separates cells based on their variable adhesion characteristics, we investigated the use of cell surface proteins to potentially identify progenitors with enhanced regeneration capabilities. Based on previous studies, we used cell sorting to investigate stem cell antigen-1 (Sca-1) and CD34 expression on myogenic populations with late adhesion characteristics. We compared the regeneration efficiency of these sorted progenitors, as well as those displaying early adhesion characteristics, by quantifying their ability to regenerate skeletal muscle and restore dystrophin following transplantation into allogenic dystrophic host muscle. Identification and utilization of late adhering populations based on CD34 expression led to differential regeneration, with CD34-positive populations exhibiting significant improvements in dystrophin restoration compared with both their CD34-negative counterparts and early adhering cell populations. Regenerative capacity was found to correspond to the level of myogenic commitment, defined by myogenic regulatory factor expression, and the rate and degree of induced cell differentiation and fusion. These results demonstrate the ability to separate definable subpopulations of myogenic progenitors based on CD34 expression and reveal the potential implications of defining myogenic cell behavioral and phenotypic characteristics in relation to their regenerative capacity in vivo.

Myo/Endothelial Differentiation of Human Umbilical Cord Blood-Derived Stem Cells in Ischemic Limb Tissues

“…In addition, it is possible that only a subset of CD34 ϩ cells is capable of myogenic conversion. Altogether, the results of the present study support the hypothesis that, analogous to the muscle regenerating activity of mesenchymal stem cells 48 or muscle derived stem cells in dystrophic mice (for a review, see Jankowski et al 49 ), muscle regeneration after ischemia is induced through a certain degree of direct differentiation of UCB CD34 ϩ cell into myogenic cells.…”

Mechanical Loading of Stem Cells for Improvement of Transplantation Outcome in a Model of Acute Myocardial Infarction: The Role of Loading History

“…33 Cells were plated on 24-well plates after mechanical stimulation, and 24 h later the medium was changed to DMEM containing 2% serum, which induces myotube differentiation. At 10 days, the plates were stained with a mouse primary antibody for anti-fast skeletal myosin heavy chain (fsMHC) (1:500; Sigma), Alexafluor 488 donkey anti-mouse secondary antibody (1:400; Molecular Probes), and 4¢,6-diamidino-2-phenylindole (DAPI, for nuclei).…”

Regenerative medicine in orthopaedic surgery

“…In fact, murine skeletal muscle contains a population of stem cells termed muscle-derived stem cells (MDSCs), which demonstrate a capacity for long-term proliferation, selfrenewal, and immune-privileged behavior. 16,19 Furthermore, they can undergo multilineage differentiation toward skeletal muscle, bone, cartilage, and neural, endothelial, and hematopoietic tissues. 15,16,[20][21][22][23][24][25][26] They are found in murine skeletal muscle at a ratio of 1 in 100,000 cells, 16 a ratio similar to that of adult mesenchymal stem cells (MSCs) isolated from bone marrow aspirates.…”