title: Rac-mediated macropinocytosis is a critical route for naked plasmid DNA transfer in mice.
abstract: We have recently discovered the potential for in vivo naked plasmid DNA (pDNA) transfer into gastric serosal surface cells in mice. As pDNA are huge molecules, the mechanism of gene transfer without carriers and physical forces is of great biological interest. The endocytic route for naked pDNA transfer into gastric mesothelial cells was not clathrin- or caveolae-mediated endocytosis, but macropinocytosis. Naked pDNA transfer required both actin polymerization and myosin-based contraction. Upstream kinases of Rho family GTPases, Syk, Src family kinases and PI-3K were involved in naked pDNA transfer. Furthermore, the intracellular signaling pathway was not mediated via the Rho pathway, but by the Rac pathway. Downstream molecules of Rac, PAK and WAVE2 co-operated with naked pDNA transfer. Overall, it was demonstrated that the Rac signaling pathway regulated the macropinocytosis of naked pDNA. The information in this study would be helpful to clarify in vivo cell functions and to improve in vivo transfection efficiency.
authors.affiliation: Graduate School of Biomedical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan. sfumoto@nagasaki-u.ac.jp
authors.forename: Shintaro
authors.initials: S
authors.lastname: Fumoto
authors.forename: Junya
authors.initials: J
authors.lastname: Nishi
authors.forename: Hiroki
authors.initials: H
authors.lastname: Ishii
authors.forename: Xuan
authors.initials: X
authors.lastname: Wang
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Miyamoto
authors.forename: Naoki
authors.initials: N
authors.lastname: Yoshikawa
authors.forename: Mikiro
authors.initials: M
authors.lastname: Nakashima
authors.forename: Junzo
authors.initials: J
authors.lastname: Nakamura
authors.forename: Koyo
authors.initials: K
authors.lastname: Nishida
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D021941:Caveolae / Q000378:metabolism; D022163:Clathrin-Coated Vesicles / Q000378:metabolism; D004247:DNA / Q000008:administration & dosage*; D004705:Endocytosis; D005753:Gastric Mucosa / Q000378:metabolism*; D018628:Gene Dosage; D018014:Gene Transfer Techniques; D007124:Immunoenzyme Techniques; D008297:Male; D051379:Mice; D009119:Muscle Contraction; D009218:Myosins / Q000378:metabolism; D010873:Pinocytosis / Q000502:physiology*; D010957:Plasmids / Q000235:genetics*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D012704:Serous Membrane / Q000378:metabolism*; D051300:Wiskott-Aldrich Syndrome Protein Family / Q000378:metabolism; D054462:p21-Activated Kinases / Q000378:metabolism; D020741:rho GTP-Binding Proteins / Q000378:metabolism
chemical_list: D000199:Actins; C492303:Wasf2 protein, mouse; D051300:Wiskott-Aldrich Syndrome Protein Family; D004247:DNA; D051057:Proto-Oncogene Proteins c-akt; D054462:p21-Activated Kinases; D009218:Myosins; D020741:rho GTP-Binding Proteins