title: Enrichment of Adipose-Derived Stromal Cells for BMPR1A Facilitates Enhanced Adipogenesis.
abstract: BACKGROUND
  Reconstruction of soft tissue defects has traditionally relied on the use of grafts and flaps, which may be associated with variable resorption and/or significant donor site morbidity. Cell-based strategies employing adipose-derived stromal cells (ASCs), found within the stromal vascular fraction (SVF) of adipose tissue, may offer an alternative strategy for soft tissue reconstruction. In this study, we investigated the potential of a bone morphogenetic protein receptor type 1A (BMPR1A)(+) subpopulation of ASCs to enhance de novo adipogenesis.
  
  
  METHODS
  Human lipoaspirate was enzymatically digested to isolate SVF and magnetic-activated cell separation was utilized to obtain BMPR1A(+) and BMPR1A(-) cells. These cells, along with unenriched cells, were expanded in culture and evaluated for adipogenic gene expression and in vitro adipocyte formation. Cells from each group were also labeled with a green fluorescent protein (GFP) lentivirus and transplanted into the inguinal fat pads, an adipogenic niche, of immunocompromised mice to determine their potential for de novo adipogenesis. Confocal microscopy along with staining of lipid droplets and vasculature was performed to evaluate the formation of mature adipocytes by transplanted cells.
  
  
  RESULTS
  In comparison to BMPR1A(-) and unenriched ASCs, BMPR1A(+) cells demonstrated significantly enhanced adipogenesis when cultured in an adipogenic differentiation medium, as evidenced by increased staining with Oil Red O and increased expression of peroxisome proliferator-activating receptor gamma (PPAR-γ) and fatty acid-binding protein 4 (FABP4). BMPR1A(+) cells also formed significantly more adipocytes in vivo, as demonstrated by quantification of GFP+ adipocytes. Minimal formation of mature adipocytes was appreciated by BMPR1A(-) cells.
  
  
  CONCLUSIONS
  BMPR1A(+) ASCs show an enhanced ability for adipogenesis in vitro, as shown by gene expression and histological staining. Furthermore, within an adipogenic niche, BMPR1A(+) cells possessed an increased capacity to generate de novo fat compared to BMPR1A(-) and unenriched cells. This suggests utility for the BMPR1A(+) subpopulation in cell-based strategies for soft tissue reconstruction.
authors.affiliation: 1 Hagey Laboratory for Pediatric Regenerative Medicine, Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine , Stanford, California.
authors.forename: Elizabeth R
authors.initials: ER
authors.lastname: Zielins
authors.affiliation: 1 Hagey Laboratory for Pediatric Regenerative Medicine, Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine , Stanford, California.
authors.forename: Kevin
authors.initials: K
authors.lastname: Paik
authors.affiliation: 1 Hagey Laboratory for Pediatric Regenerative Medicine, Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine , Stanford, California.
authors.forename: Ryan C
authors.initials: RC
authors.lastname: Ransom
authors.affiliation: 1 Hagey Laboratory for Pediatric Regenerative Medicine, Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine , Stanford, California.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Brett
authors.affiliation: 1 Hagey Laboratory for Pediatric Regenerative Medicine, Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine , Stanford, California.
authors.forename: Charles P
authors.initials: CP
authors.lastname: Blackshear
authors.affiliation: 1 Hagey Laboratory for Pediatric Regenerative Medicine, Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine , Stanford, California.
authors.forename: Anna
authors.initials: A
authors.lastname: Luan
authors.affiliation: 1 Hagey Laboratory for Pediatric Regenerative Medicine, Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine , Stanford, California.|2 Institute for Stem Cell Biology and Regenerative Medicine, Stanford University , Stanford, California.
authors.forename: Graham G
authors.initials: GG
authors.lastname: Walmsley
authors.affiliation: 1 Hagey Laboratory for Pediatric Regenerative Medicine, Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine , Stanford, California.
authors.forename: David A
authors.initials: DA
authors.lastname: Atashroo
authors.affiliation: 1 Hagey Laboratory for Pediatric Regenerative Medicine, Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine , Stanford, California.
authors.forename: Kshemendra
authors.initials: K
authors.lastname: Senarath-Yapa
authors.affiliation: 1 Hagey Laboratory for Pediatric Regenerative Medicine, Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine , Stanford, California.
authors.forename: Arash
authors.initials: A
authors.lastname: Momeni
authors.affiliation: 1 Hagey Laboratory for Pediatric Regenerative Medicine, Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine , Stanford, California.
authors.forename: Robert
authors.initials: R
authors.lastname: Rennert
authors.affiliation: 1 Hagey Laboratory for Pediatric Regenerative Medicine, Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine , Stanford, California.
authors.forename: Michael
authors.initials: M
authors.lastname: Sorkin
authors.affiliation: 2 Institute for Stem Cell Biology and Regenerative Medicine, Stanford University , Stanford, California.
authors.forename: Eun Young
authors.initials: EY
authors.lastname: Seo
authors.affiliation: 2 Institute for Stem Cell Biology and Regenerative Medicine, Stanford University , Stanford, California.
authors.forename: Charles K
authors.initials: CK
authors.lastname: Chan
authors.affiliation: 1 Hagey Laboratory for Pediatric Regenerative Medicine, Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine , Stanford, California.
authors.forename: Geoffrey C
authors.initials: GC
authors.lastname: Gurtner
authors.affiliation: 1 Hagey Laboratory for Pediatric Regenerative Medicine, Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine , Stanford, California.|2 Institute for Stem Cell Biology and Regenerative Medicine, Stanford University , Stanford, California.
authors.forename: Michael T
authors.initials: MT
authors.lastname: Longaker
authors.affiliation: 1 Hagey Laboratory for Pediatric Regenerative Medicine, Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine , Stanford, California.
authors.forename: Derrick C
authors.initials: DC
authors.lastname: Wan
mesh_terms: D017667:Adipocytes / Q000166:cytology / Q000378:metabolism*; D050156:Adipogenesis; D000273:Adipose Tissue / Q000166:cytology / Q000378:metabolism*; D000328:Adult; D000818:Animals; D052005:Bone Morphogenetic Protein Receptors, Type I / Q000096:biosynthesis* / Q000235:genetics; D002478:Cells, Cultured; D005260:Female; D006801:Humans; D016086:Lentivirus; D051379:Mice; D008875:Middle Aged; D017154:Stromal Cells / Q000166:cytology / Q000378:metabolism; D014161:Transduction, Genetic
chemical_list: C498211:BMPR1A protein, human; D052005:Bone Morphogenetic Protein Receptors, Type I