Ayako Ban

Publications (2)2.31 Total impact

• Article: In vivo gene transfer of PPAR gamma is insufficient to induce adipogenesis in skeletal muscle.

  Ayako Ban, Keitaro Yamanouchi, Takashi Matsuwaki, Masugi Nishihara
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  ABSTRACT: Skeletal muscle contains several progenitor/stem cells with myogenicity as well as adipogenicity such as satellite cells. Our previous study demonstrated that forced expression of PPAR gamma is sufficient to induce transdifferentiation of predetermined myoblasts in vitro. In the present study, we examined whether introduction of PPAR gamma gene could induce adipogenesis of satellite cells in vivo. A plasmid vector containing enhanced green fluorescent protein (EGFP) or PPAR gamma gene was introduced into rat tibialis anterior muscle by electroporation. Histological analyses revealed that electroporation induces degenerative/regenerative response in skeletal muscle, including activation of satellite cells. When EGFP gene was introduced, newly formed myotubes resulted from fusion of activated satellite cells, showed EGFP expression, indicating that electroporation could transfect satellite cells with exogenously introduced gene. Gene transfer of PPAR gamma resulted in an increase of PPAR gamma-positive mononucleated cells on day 3 after electroporation but failed to induce adipogenesis thereafter. These results suggested that, in addition to an expression of PPAR gamma, niches that support adipogenesis are required for satellite cells to enter adipogenesis in vivo.
  Journal of Veterinary Medical Science 09/2008; 70(8):761-7. · 0.85 Impact Factor
• Article: Both PPARgamma and C/EBPalpha are sufficient to induce transdifferentiation of goat fetal myoblasts into adipocytes.

  Keitaro Yamanouchi, Ayako Ban, Shingo Shibata, Tohru Hosoyama, Yousuke Murakami, Masugi Nishihara
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  ABSTRACT: The present study was conducted to investigate whether goat fetal myoblasts with no inherent adipogenic potential can be induced to transdifferentiate into adipocytes. Goat fetal myoblasts were transiently transfected by the adipogenic transcription factors, peroxisome proliferator-activated receptor-gamma (PPARgamma) and CCAAT/enhancer-binding protein-alpha (C/EBPalpha). Both PPARgamma and C/EBPalpha were capable of inducing adipogenic transdifferentiation as indicated by the appearance of mature adipocytes when the transfected cells were cultured in adipogenic differentiation medium (ADM). Ectopic expression of PPARgamma induced endogenous C/EBPalpha expression and vice versa only when the cells were cultured in ADM. Removal of troglitazone, a PPARgamma agonist, from the ADM resulted in a dramatic decline in the number of adipocytes, indicating that PPARgamma stimulation is necessary to induce adipogenic transdifferentiation of goat fetal myoblasts. These results demonstrate for the first time that primary cultured myoblasts can be transdifferentiated into adipocytes.
  Journal of Reproduction and Development 07/2007; 53(3):563-72. · 1.46 Impact Factor