title: Heterogeneity of Notch signaling in astrocytes and the effects of GFAP and vimentin deficiency.
abstract: Astrocytes have multiple roles in the CNS including control of adult neurogenesis. We recently showed that astrocyte inhibition of neurogenesis through Notch signaling depends on the intermediate filament proteins glial fibrillary acidic protein (GFAP) and vimentin. Here, we used real-time quantitative PCR to analyze gene expression in individual mouse astrocytes in primary cultures and in GFAP(POS) or Aldh1L1(POS) astrocytes freshly isolated from uninjured, contralesional and lesioned hippocampus 4 days after entorhinal cortex lesion. To determine the Notch signaling competence of individual astrocytes, we measured the mRNA levels of Notch ligands and Notch1 receptor. We found that whereas most cultured and freshly isolated astrocytes were competent to receive Notch signals, only a minority of astrocytes were competent to send Notch signals. Injury increased the fraction of astrocyte subpopulation unable to send and receive Notch signals, thus resembling primary astrocytes in vitro. Astrocytes deficient of GFAP and vimentin showed decreased Notch signal sending competence and altered expression of Notch signaling pathway-related genes Dlk2, Notch1, and Sox2. Furthermore, we identified astrocyte subpopulations based on their mRNA and protein expression of nestin and HB-EGF. This study improves our understanding of astrocyte heterogeneity, and points to astrocyte cytoplasmic intermediate filaments as targets for neural cell replacement strategies.
authors.affiliation: Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.
authors.forename: Isabell
authors.initials: I
authors.lastname: Lebkuechner
authors.affiliation: Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.
authors.forename: Ulrika
authors.initials: U
authors.lastname: Wilhelmsson
authors.affiliation: Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.
authors.forename: Elin
authors.initials: E
authors.lastname: Möllerström
authors.affiliation: Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.|Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia.|University of Newcastle, New South Wales, Australia.
authors.forename: Marcela
authors.initials: M
authors.lastname: Pekna
authors.affiliation: Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.|Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia.|University of Newcastle, New South Wales, Australia.
authors.forename: Milos
authors.initials: M
authors.lastname: Pekny
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000502:physiology*; D004815:Epidermal Growth Factor / Q000235:genetics; D005904:Glial Fibrillary Acidic Protein / Q000172:deficiency* / Q000235:genetics*; D006624:Hippocampus / Q000166:cytology; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000502:physiology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D061251:Primary Cell Culture; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D051881:Receptor, Notch1; D051880:Receptors, Notch / Q000235:genetics* / Q000502:physiology*; D055748:SOXB1 Transcription Factors; D015398:Signal Transduction / Q000235:genetics* / Q000502:physiology*; D014746:Vimentin / Q000172:deficiency* / Q000235:genetics*
chemical_list: C559657:Dlk2 protein, mouse; D005904:Glial Fibrillary Acidic Protein; D036341:Intercellular Signaling Peptides and Proteins; C497762:Notch1 protein, mouse; D012333:RNA, Messenger; D051881:Receptor, Notch1; D051880:Receptors, Notch; D055748:SOXB1 Transcription Factors; C527783:Sox2 protein, mouse; D014746:Vimentin; D004815:Epidermal Growth Factor
keywords: GFAP; Notch signaling; astrocytes; single-cell gene expression profiling; vimentin