Figure 7.

Bone morphogenetic proteins, and particularly BMP4, mediate MSC-driven induction of rat GFAP expression in cocultures; quantitative reverse transcription-polymerase chain reaction. (A): Both nestin and GFAP were strongly induced by MSCs, whereas MSC-CM mediated weak induction of GFAP and strong induction of nestin. (B): Recombinant noggin or human BMP4-specific neutralizing antibody inhibited GFAP increase. (C): Silencing of BMP4 in MSCs decreased GFAP induction in cocultures. MSCs transfected with either BMP4- or control-siRNA were cocultured with neural cells for 5 days followed by gene expression analysis. Expression levels are shown relative to levels in control cocultures, which are set as 1. In cocultures with BMP4-siRNA transfectants, human BMP4 expression was knocked down and rat GFAP expression was lowered, whereas human FGF2 and human GAP expression were unchanged, compared with control. Abbreviations: BMP4, bone morphogenetic protein; CM, mesenchymal stromal cell-conditioned medium; GFAP, glial fibrillary acidic protein; huBMP4, human bone morphogenetic protein 4; huFGF2, human fibroblast growth factor 2; huGAP, human glyceraldehyde-3-phosphate dehydrogenase; MSC, mesenchymal stromal cell; N, neural cells; Nes, nestin; Rel., relative; rGFAP, rat glial fibrillary acidic protein; siBMP4-MSC, mesenchymal stromal cells transfected with bone morphogenetic protein 4-targeted small interfering RNA; siContr-MSC, mesenchymal stromal cells transfected with negative control small interfering RNA.