title: Effective gene delivery into adipose-derived stem cells: transfection of cells in suspension with the use of a nuclear localization signal peptide-conjugated polyethylenimine.
abstract: OBJECTIVE
  Adipose-derived stem cells have the ability to turn into several clinically important cell types. However, it is difficult to transfect these cells with the use of conventional cationic lipid-based reagents. Polyethylenimine (PEI) is considered to be an inexpensive and effective tool for delivery of nucleic acids into mammalian cells.
  
  
  METHODS
  We used a linear PEI conjugated with the nuclear localization signal (NLS) peptide of Simian vacuolating virus 40 large T antigen (PEI-NLS) for transfection of plasmid DNA into adipose-derived cells. We also tested if transfection of cells in suspension might improve the degree and duration of exogenous gene expression.
  
  
  RESULTS
  Transfection of cells in suspension with the use of a PEI conjugated with an NLS peptide resulted in high levels of reporter gene expression for an extended period of time in clonal 3T3-L1 preadipocytes and native human adipose-derived stem cells. The reporter gene expression increased for 3 days after the addition of the PEI-NLS peptide-DNA mixture in cell suspension and remained significant for at least 7 days. Cell density did not influence the level of reporter gene expression. Thus, the suspension method with the use of an NLS peptide-conjugated PEI leads to a robust and sustained expression of exogenous genes in adipose-derived cells.
  
  
  CONCLUSIONS
  The devised transfection method may be useful for reprogramming of adipose-derived stem cells and cell-based therapy.
authors.affiliation: Department of Bioengineering, Nagaoka University of Technology, Nagaoka, Niigata, Japan.
authors.forename: Eulsoon
authors.initials: E
authors.lastname: Park
authors.affiliation: Extreme Energy-Density Research Institute, Nagaoka University of Technology, Nagaoka, Niigata, Japan.
authors.forename: Hong-Baek
authors.initials: HB
authors.lastname: Cho
authors.affiliation: Department of Bioengineering, Nagaoka University of Technology, Nagaoka, Niigata, Japan. Electronic address: koichi@vos.nagaokaut.ac.jp.
authors.forename: Koichi
authors.initials: K
authors.lastname: Takimoto
mesh_terms: D041721:3T3-L1 Cells; D000273:Adipose Tissue / Q000166:cytology*; D000595:Amino Acid Sequence; D000818:Animals; D016466:CHO Cells; D002452:Cell Count; D006224:Cricetinae; D003412:Cricetulus; D015870:Gene Expression; D017930:Genes, Reporter; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D019913:Nuclear Localization Signals / Q000737:chemistry / Q000378:metabolism*; D010455:Peptides / Q000737:chemistry / Q000378:metabolism*; D011094:Polyethyleneimine / Q000737:chemistry*; D013234:Stem Cells / Q000378:metabolism*; D014162:Transfection / Q000379:methods*
chemical_list: D019913:Nuclear Localization Signals; D010455:Peptides; D011094:Polyethyleneimine
keywords: adipose tissue; adult stem cell; polyethylenimine; transfection