title: Effect of lyso-phosphatidylcholine and Schnurri-3 on osteogenic transdifferentiation of vascular smooth muscle cells to calcifying vascular cells in 3D culture.
abstract: BACKGROUND
  In vitro cell culture is a widely used technique for investigating a range of processes such as stem cell behavior, regenerative medicine, tissue engineering, and drug discovery. Conventional cell culture is performed in Petri dishes or flasks where cells typically attach to a flat glass or plastic surface as a cell monolayer. However, 2D cell monolayers do not provide a satisfactory representation of in vivo conditions. A 3D culture could be a much better system for representing the conditions that prevail in vivo.
  
  
  RESULTS
  To simulate 3D conditions, vascular smooth muscle cells (VSMCs) were loaded with gold-polyvmer-iron oxide hydrogel, enabling levitation of the cells by using spatially varying magnetic fields. These magnetically levitated 3D cultures appeared as freely suspended, clustered cells which proliferated 3-4 times faster than cells in conventional 2D cultures. When the levitated cells were treated with 10nM lysophosphatidylcholine (LPC), for 3days, cell clusters exhibited translucent extensions/rods 60-80μm wide and 200-250μm long. When 0.5μg/μl Schnurri-3 was added to the culture containing LPC, these extensions were smaller or absent. When excited with 590-650nm light, these extensions emitted intrinsic fluorescence at >667nm. When the 3D cultures were treated with a fluorescent probe specific for calcium hydroxyapatite (FITC-HABP-19), the cell extensions/rods emitted intensely at 518nm, the λmax for FITC emission. Pellets of cells treated with LPC were more enriched in calcium, phosphate, and glycosaminoglycans than cells treated with LPC and Schnurri-3.
  
  
  CONCLUSIONS
  In 3D cultures, VSMCs grow more rapidly and form larger calcification clusters than cells in 2D cultures. Transdifferentiation of VSMC into calcifying vascular cells is enhanced by LPC and attenuated by Schnurri-3.
  
  
  CONCLUSIONS
  The formation of calcified structures in 3D VSMC cultures suggests that similar structures may be formed in vivo.
authors.affiliation: Department of Medicine, Baylor College of Medicine, Houston, TX, USA.
authors.forename: Fernando
authors.initials: F
authors.lastname: Castro-Chavez
authors.forename: Kasey C
authors.initials: KC
authors.lastname: Vickers
authors.forename: Jae Sam
authors.initials: JS
authors.lastname: Lee
authors.forename: Ching-Hsuan
authors.initials: CH
authors.lastname: Tung
authors.forename: Joel D
authors.initials: JD
authors.lastname: Morrisett
mesh_terms: D002114:Calcinosis / Q000139:chemically induced / Q000378:metabolism* / Q000473:pathology; D018929:Cell Culture Techniques; D002460:Cell Line; D054338:Cell Transdifferentiation / Q000187:drug effects*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D006801:Humans; D008244:Lysophosphatidylcholines / Q000633:toxicity*; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000378:metabolism* / Q000473:pathology; D032389:Myocytes, Smooth Muscle / Q000378:metabolism* / Q000473:pathology; D010012:Osteogenesis / Q000187:drug effects*
chemical_list: D004268:DNA-Binding Proteins; C425103:HIVEP3 protein, human; D008244:Lysophosphatidylcholines