title: Can arthroscopically harvested synovial stem cells be preferentially sorted using stage-specific embryonic antigen 4 antibody for cartilage, bone, and adipose regeneration?
abstract: OBJECTIVE
  The aim of this study was to investigate the relation between stage-specific embryonic antigen 4 (SSEA4) expression and synovium-derived stem cell (SDSC) lineage differentiation.
  
  
  METHODS
  Human SDSCs were collected during arthroscopic surgery from 4 young patients with anterior cruciate ligament injuries. Passage 2 SDSCs were sorted by fluorescence-activated cell sorting using phycoerythrin-conjugated monoclonal antibody against SSEA4 into 3 groups: SSEA4(+) cells, SSEA4(-) cells, and unsorted control cells. After 1 more passage, expanded cells from each group were evaluated for SSEA4 expression by use of flow cytometry as well as multilineage differentiation capacities, including chondrogenesis, adipogenesis, and osteogenesis, using biochemical analysis, histologic analysis, immunostaining, and real-time polymerase chain reaction.
  
  
  RESULTS
  After cell sorting, 1 more passage expansion decreased SSEA4(+) cells from 99.8% to 79.2% and increased SSEA4(-) cells from 4.4% to 53.3% compared with 70.3% in the unsorted cell population. SSEA4(-) SDSCs with a lower cell proliferation exhibited higher chondrogenic potential (in terms of the ratio of glycosaminoglycan to DNA [P < .001] and COL2A1 [type II collagen] messenger RNA [mRNA] [P < .001]) and adipogenic potential (in terms of oil red O staining and quantitative assay [P = .007], LPL [lipoprotein lipase] mRNA [P = .005], and CEBP [CCAAT/enhancer-binding protein alpha] mRNA [P = .010]). In contrast, SSEA4(+) SDSCs retained cell expansion and enhanced osteogenic capacity, as evidenced by intense calcium deposition stained by alizarin red S and a significantly elevated expression of OPN (osteopontin) mRNA (P = .007).
  
  
  CONCLUSIONS
  In this study, for the first time, we showed the benefit of using the surface marker SSEA4 in SDSCs to preferentially sort a mixed population of cells. SSEA4(+) SDSCs indicated a strong potential for osteogenesis rather than chondrogenesis and adipogenesis.
  
  
  CONCLUSIONS
  SDSC-based mesenchymal tissue regeneration can be easily achieved by arthroscopic harvesting followed by quick cell sorting.
authors.affiliation: Stem Cell and Tissue Engineering Laboratory, Department of Orthopaedics, West Virginia University, Morgantown, West Virginia, U.S.A.; Department of Exercise Physiology, West Virginia University, Morgantown, West Virginia, U.S.A.
authors.forename: Jingting
authors.initials: J
authors.lastname: Li
authors.affiliation: Stem Cell and Tissue Engineering Laboratory, Department of Orthopaedics, West Virginia University, Morgantown, West Virginia, U.S.A.
authors.forename: Douglas D
authors.initials: DD
authors.lastname: Campbell
authors.affiliation: Stem Cell and Tissue Engineering Laboratory, Department of Orthopaedics, West Virginia University, Morgantown, West Virginia, U.S.A.
authors.forename: George K
authors.initials: GK
authors.lastname: Bal
authors.affiliation: Stem Cell and Tissue Engineering Laboratory, Department of Orthopaedics, West Virginia University, Morgantown, West Virginia, U.S.A.; Department of Exercise Physiology, West Virginia University, Morgantown, West Virginia, U.S.A.; Department of Mechanical & Aerospace Engineering, West Virginia University, Morgantown, West Virginia, U.S.A.. Electronic address: mpei@hsc.wvu.edu.
authors.forename: Ming
authors.initials: M
authors.lastname: Pei
mesh_terms: D050156:Adipogenesis; D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D002356:Cartilage / Q000166:cytology / Q000378:metabolism; D002454:Cell Differentiation / Q000235:genetics; D049109:Cell Proliferation; D002469:Cell Separation / Q000379:methods; D020219:Chondrogenesis / Q000235:genetics; D024043:Collagen Type II / Q000235:genetics / Q000378:metabolism; D005260:Female; D005434:Flow Cytometry / Q000379:methods*; D006025:Glycosaminoglycans / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008297:Male; D010012:Osteogenesis; D053495:Osteopontin / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D055746:Stage-Specific Embryonic Antigens / Q000378:metabolism*; D013234:Stem Cells / Q000166:cytology* / Q000378:metabolism; D013583:Synovial Membrane / Q000166:cytology* / Q000378:metabolism; D055815:Young Adult
chemical_list: D015415:Biomarkers; D024043:Collagen Type II; D006025:Glycosaminoglycans; D012333:RNA, Messenger; D055746:Stage-Specific Embryonic Antigens; C066584:stage-specific embryonic antigen-4; D053495:Osteopontin; D002118:Calcium