title: Isolation and characterization of human anterior cruciate ligament-derived vascular stem cells.
abstract: The anterior cruciate ligament (ACL) usually fails to heal after rupture mainly due to the inability of the cells within the ACL tissue to establish an adequate healing process, making graft reconstruction surgery a necessity. However, some reports have shown that there is a healing potential of ACL with primary suture repair. Although some reports showed the existence of mesenchymal stem cell-like cells in human ACL tissues, their origin still remains unclear. Recently, blood vessels have been reported to represent a rich supply of stem/progenitor cells with a characteristic expression of CD34 and CD146. In this study, we attempted to validate the hypothesis that CD34- and CD146-expressing vascular cells exist in hACL tissues, have a potential for multi-lineage differentiation, and are recruited to the rupture site to participate in the intrinsic healing of injured ACL. Immunohistochemistry and flow cytometry analysis of hACL tissues demonstrated that it contains significantly more CD34 and CD146-positive cells in the ACL ruptured site compared with the noninjured midsubstance. CD34+CD45- cells isolated from ACL ruptured site showed higher expansionary potentials than CD146+CD45- and CD34-CD146-CD45- cells, and displayed higher differentiation potentials into osteogenic, adipogenic, and angiogenic lineages than the other cell populations. Immunohistochemistry of fetal and adult hACL tissues demonstrated a higher number of CD34 and CD146-positive cells in the ACL septum region compared with the midsubstance. In conclusion, our findings suggest that the ACL septum region contains a population of vascular-derived stem cells that may contribute to ligament regeneration and repair at the site of rupture.
authors: Stem Cell Research Center, Children's Hospital of Pittsburgh, and Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania 15219, USA.
authors: Tomoyuki
authors: T
authors: Matsumoto
authors: Sheila M
authors: SM
authors: Ingham
authors: Yutaka
authors: Y
authors: Mifune
authors: Aki
authors: A
authors: Osawa
authors: Alison
authors: A
authors: Logar
authors: Arvydas
authors: A
authors: Usas
authors: Ryosuke
authors: R
authors: Kuroda
authors: Masahiro
authors: M
authors: Kurosaka
authors: Freddie H
authors: FH
authors: Fu
authors: Johnny
authors: J
authors: Huard
mesh_terms: D016118:Anterior Cruciate Ligament / Q000098:blood supply*; D018952:Antigens, CD34 / Q000032:analysis; D001808:Blood Vessels / Q000166:cytology*; D051929:CD146 Antigen / Q000032:analysis; D002454:Cell Differentiation; D005434:Flow Cytometry; D006801:Humans; D007150:Immunohistochemistry; D013234:Stem Cells / Q000166:cytology*; D014945:Wound Healing
chemical_list: D018952:Antigens, CD34; D051929:CD146 Antigen; C497902:MCAM protein, human