title: Prion protein and its ligand stress inducible protein 1 regulate astrocyte development.
abstract: Prion protein (PrP(C)) interaction with stress inducible protein 1 (STI1) mediates neuronal survival and differentiation. However, the function of PrP(C) in astrocytes has not been approached. In this study, we show that STI1 prevents cell death in wild-type astrocytes in a protein kinase A-dependent manner, whereas PrP(C)-null astrocytes were not affected by STI1 treatment. At embryonic day 17, cultured astrocytes and brain extracts derived from PrP(C)-null mice showed a reduced expression of glial fibrillary acidic protein (GFAP) and increased vimentin and nestin expression when compared with wild-type, suggesting a slower rate of astrocyte maturation in PrP(C)-null animals. Furthermore, PrP(C)-null astrocytes treated with STI1 did not differentiate from a flat to a process-bearing morphology, as did wild-type astrocytes. Remarkably, STI1 inhibited proliferation of both wild-type and PrP(C)-null astrocytes in a protein kinase C-dependent manner. Taken together, our data show that PrP(C) and STI1 are essential to astrocyte development and act through distinct signaling pathways.
authors.affiliation: Ludwig Institute for Cancer Research, Hospital Alemão Oswaldo Cruz, São Paulo, Brazil.
authors.forename: Camila
authors.initials: C
authors.lastname: Arantes
authors.forename: Regina
authors.initials: R
authors.lastname: Nomizo
authors.forename: Marilene H
authors.initials: MH
authors.lastname: Lopes
authors.forename: Glaucia N M
authors.initials: GN
authors.lastname: Hajj
authors.forename: Flavia R S
authors.initials: FR
authors.lastname: Lima
authors.forename: Vilma R
authors.initials: VR
authors.lastname: Martins
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000166:cytology / Q000502:physiology*; D001921:Brain / Q000502:physiology; D002454:Cell Differentiation / Q000502:physiology*; D049109:Cell Proliferation; D002470:Cell Survival / Q000502:physiology; D002478:Cells, Cultured; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000378:metabolism*; D007381:Intermediate Filament Proteins / Q000378:metabolism; D020935:MAP Kinase Signaling System; D051379:Mice; D018345:Mice, Knockout; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D008959:Models, Neurological; D009419:Nerve Tissue Proteins / Q000378:metabolism; D064231:Nestin; D018621:PrPC Proteins / Q000235:genetics / Q000378:metabolism*; D011493:Protein Kinase C / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D015398:Signal Transduction; D014746:Vimentin / Q000378:metabolism
chemical_list: D005904:Glial Fibrillary Acidic Protein; D006360:Heat-Shock Proteins; D007381:Intermediate Filament Proteins; D009419:Nerve Tissue Proteins; C577485:Nes protein, mouse; D064231:Nestin; D018621:PrPC Proteins; D011994:Recombinant Proteins; C489791:Stip1 protein, mouse; D014746:Vimentin; D017868:Cyclic AMP-Dependent Protein Kinases; D011493:Protein Kinase C; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3