https://ogma.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 Heterogeneity of Notch signaling in astrocytes and the effects of GFAP and vimentin deficiency https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:27422 POS or Aldh1L1POS 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.]]> Sat 24 Mar 2018 07:35:23 AEDT ]]> Nestin regulates neurogenesis in mice through notch signaling from astrocytes to neural stem cells https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:47756 Nes-/-) mice. We found that the proliferation of Nes-/- neural stem cells was not altered, but neurogenesis in the hippocampal dentate gyrus of Nes-/- mice was increased. Surprisingly, the proneurogenic effect of nestin deficiency was mediated by its function in the astrocyte niche. Through its role in Notch signaling from astrocytes to neural stem cells, nestin negatively regulates neuronal differentiation and survival; however, its expression in neural stem cells is not required for normal neurogenesis. In behavioral studies, nestin deficiency in mice did not affect associative learning but was associated with impaired long-term memory.]]> Fri 27 Jan 2023 10:25:04 AEDT ]]>