title: Analysis for apoptosis and necrosis on adipocytes, stromal vascular fraction, and adipose-derived stem cells in human lipoaspirates after liposuction.
abstract: BACKGROUND
  Adipose-derived stem cells have become the most studied adult stem cells. The authors examined the apoptosis and necrosis rates for adipocyte, stromal vascular fraction, and adipose-derived stem cells in fresh human lipoaspirates.
  
  
  METHODS
  Human lipoaspirate (n = 8) was harvested using a standard liposuction technique. Stromal vascular fraction cells were separated from adipocytes and cultured to obtain purified adipose-derived stem cells. A panel of stem cell markers was used to identify the surface phenotypes of cultured adipose-derived stem cells. Three distinct stem cell subpopulations (CD90/CD45, CD105/CD45, and CD34/CD31) were selected from the stromal vascular fraction. Apoptosis and necrosis were determined by annexin V/propidium iodide assay and analyzed by flow cytometry.
  
  
  RESULTS
  The cultured adipose-derived stem cells demonstrated long-term proliferation and differentiation evidenced by cell doubling time and positive staining with oil red O and alkaline phosphatase. Isolated from lipoaspirates, adipocytes exhibited 19.7 ± 3.7 percent apoptosis and 1.1 ± 0.3 percent necrosis; stromal vascular fraction cells revealed 22.0 ± 6.3 percent of apoptosis and 11.2 ± 1.9 percent of necrosis; stromal vascular fraction cells had a higher rate of necrosis than adipocytes (p < 0.05). Among the stromal vascular fraction cells, 51.1 ± 3.7 percent expressed CD90/CD45, 7.5 ± 1.0 percent expressed CD105/CD45, and 26.4 ± 3.8 percent expressed CD34/CD31. CD34/CD31 adipose-derived stem cells had lower rates of apoptosis and necrosis compared with CD105/CD45 adipose-derived stem cells (p < 0.05).
  
  
  CONCLUSIONS
  Adipose-derived stem cells had a higher rate of apoptosis and necrosis than adipocytes. However, the extent of apoptosis and necrosis was significantly different among adipose-derived stem cell subpopulations.
authors.affiliation: Las Vegas, Nev. From the Department of Surgery, Division of Plastic Surgery, University of Nevada School of Medicine.
authors.forename: Wei Z
authors.initials: WZ
authors.lastname: Wang
authors.forename: Xin-Hua
authors.initials: XH
authors.lastname: Fang
authors.forename: Shelley J
authors.initials: SJ
authors.lastname: Williams
authors.forename: Linda L
authors.initials: LL
authors.lastname: Stephenson
authors.forename: Richard C
authors.initials: RC
authors.lastname: Baynosa
authors.forename: Nancy
authors.initials: N
authors.lastname: Wong
authors.forename: Kayvan T
authors.initials: KT
authors.lastname: Khiabani
authors.forename: William A
authors.initials: WA
authors.lastname: Zamboni
mesh_terms: D052438:Adipocytes, White / Q000166:cytology / Q000473:pathology*; D000328:Adult; D053687:Adult Stem Cells / Q000166:cytology / Q000378:metabolism / Q000473:pathology*; D015703:Antigens, CD / Q000378:metabolism; D017209:Apoptosis; D015415:Biomarkers / Q000378:metabolism; D002454:Cell Differentiation; D002478:Cells, Cultured; D002498:Centrifugation; D005260:Female; D005434:Flow Cytometry; D006412:Hematopoietic Stem Cells / Q000378:metabolism; D006801:Humans; D015187:Lipectomy; D008297:Male; D059630:Mesenchymal Stem Cells / Q000378:metabolism; D008875:Middle Aged; D009336:Necrosis; D010006:Osteoblasts / Q000166:cytology; D010641:Phenotype; D050151:Subcutaneous Fat / Q000473:pathology* / Q000601:surgery
chemical_list: D015703:Antigens, CD; D015415:Biomarkers