title: Distinct progenitor populations in skeletal muscle are bone marrow derived and exhibit different cell fates during vascular regeneration.
abstract: Vascular progenitors were previously isolated from blood and bone marrow; herein, we define the presence, phenotype, potential, and origin of vascular progenitors resident within adult skeletal muscle. Two distinct populations of cells were simultaneously isolated from hindlimb muscle: the side population (SP) of highly purified hematopoietic stem cells and non-SP cells, which do not reconstitute blood. Muscle SP cells were found to be derived from, and replenished by, bone marrow SP cells; however, within the muscle environment, they were phenotypically distinct from marrow SP cells. Non-SP cells were also derived from marrow stem cells and contained progenitors with a mesenchymal phenotype. Muscle SP and non-SP cells were isolated from Rosa26 mice and directly injected into injured muscle of genetically matched recipients. SP cells engrafted into endothelium during vascular regeneration, and non-SP cells engrafted into smooth muscle. Thus, distinct populations of vascular progenitors are resident within skeletal muscle, are derived from bone marrow, and exhibit different cell fates during injury-induced vascular regeneration.
authors.affiliation: Department of Pediatrics, Children's Nutrition Research Center, Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, Texas 77030, USA.
authors.forename: Susan M
authors.initials: SM
authors.lastname: Majka
authors.forename: Kathyjo A
authors.initials: KA
authors.lastname: Jackson
authors.forename: Kirsten A
authors.initials: KA
authors.lastname: Kienstra
authors.forename: Mark W
authors.initials: MW
authors.lastname: Majesky
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Goodell
authors.forename: Karen K
authors.initials: KK
authors.lastname: Hirschi
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology*; D019070:Cell Lineage; D002469:Cell Separation; D004727:Endothelium / Q000166:cytology; D004730:Endothelium, Vascular / Q000502:physiology; D005434:Flow Cytometry; D007150:Immunohistochemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D018482:Muscle, Skeletal / Q000166:cytology*; D032389:Myocytes, Smooth Muscle; D010641:Phenotype; D012038:Regeneration; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013234:Stem Cells / Q000166:cytology*; D014945:Wound Healing