title: Partial characterization of the Sox2+ cell population in an adult murine model of digit amputation.
abstract: Tissue regeneration in response to injury in adult mammals is generally limited to select tissues. Nonmammalian species such as newts and axolotls undergo regeneration of complex tissues such as limbs and digits via recruitment and accumulation of local and circulating multipotent progenitors preprogrammed to recapitulate the missing tissue. Directed recruitment and activation of progenitor cells at a site of injury in adult mammals may alter the default wound-healing response from scar tissue toward regeneration. Bioactive molecules derived from proteolytic degradation of extracellular matrix (ECM) proteins have been shown to recruit a variety of progenitor cells in vitro and in vivo to the site of injury. The present study further characterized the population of cells accumulating at the site of injury after treatment with ECM degradation products in a well-established model of murine digit amputation. After a mid-second phalanx digit amputation in 6-8-week-old adult mice, treatment with ECM degradation products resulted in the accumulation of a heterogeneous population of cells, a subset of which expressed the transcription factor Sox2, a marker of pluripotent and adult progenitor cells. Sox2+ cells were localized lateral to the amputated P2 bone and coexpressed progenitor cell markers CD90 and Sca1. Transgenic Sox2 eGFP/+ and bone marrow chimeric mice showed that the bone marrow and blood circulation did not contribute to the Sox2+ cell population. The present study showed that, in addition to circulating progenitor cells, resident tissue-derived cells also populate at the site of injury after treatment with ECM degradation products. Although future work is necessary to determine the contribution of Sox2+ cells to functional tissue at the site of injury, recruitment and/or activation of local tissue-derived cells may be a viable approach to tissue engineering of more complex tissues in adult mammals.
authors.affiliation: McGowan Institute for Regenerative Medicine, University of Pittsburgh, 450 Technology Drive, Pittsburgh, PA 15213, USA. badylaks@upmc.edu
authors.forename: Vineet
authors.initials: V
authors.lastname: Agrawal
authors.forename: Bernard F
authors.initials: BF
authors.lastname: Siu
authors.forename: Hsu
authors.initials: H
authors.lastname: Chao
authors.forename: Karen K
authors.initials: KK
authors.lastname: Hirschi
authors.forename: Eric
authors.initials: E
authors.lastname: Raborn
authors.forename: Scott A
authors.initials: SA
authors.lastname: Johnson
authors.forename: Stephen
authors.initials: S
authors.lastname: Tottey
authors.forename: Katherine B
authors.initials: KB
authors.lastname: Hurley
authors.forename: Chris J
authors.initials: CJ
authors.lastname: Medberry
authors.forename: Stephen F
authors.initials: SF
authors.lastname: Badylak
mesh_terms: D000375:Aging / Q000378:metabolism*; D000671:Amputation, Surgical; D000818:Animals; D001854:Bone Marrow Cells / Q000473:pathology; D016026:Bone Marrow Transplantation; D001842:Bone and Bones / Q000473:pathology; D002452:Cell Count; D005109:Extracellular Matrix / Q000378:metabolism; D005121:Extremities / Q000601:surgery*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D023421:Models, Animal; D015203:Reproducibility of Results; D055748:SOXB1 Transcription Factors / Q000378:metabolism*
chemical_list: D055748:SOXB1 Transcription Factors; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins