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Deciphering the Role of Emx1 in Neurogenesis: A Neuroproteomics Approach

Emx1 has long been implicated in embryonic brain development. Previously we found that mice null of Emx1 gene had smaller dentate gyri and reduced neurogenesis, although the molecular mechanisms underlying this defect was not well understood. To decipher the role of Emx1 gene in neural regeneration...

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Autores principales: Kobeissy, Firas H., Hansen, Katharina, Neumann, Melanie, Fu, Shuping, Jin, Kulin, Liu, Jialing
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5065984/
https://www.ncbi.nlm.nih.gov/pubmed/27799894
http://dx.doi.org/10.3389/fnmol.2016.00098
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author Kobeissy, Firas H.
Hansen, Katharina
Neumann, Melanie
Fu, Shuping
Jin, Kulin
Liu, Jialing
author_facet Kobeissy, Firas H.
Hansen, Katharina
Neumann, Melanie
Fu, Shuping
Jin, Kulin
Liu, Jialing
author_sort Kobeissy, Firas H.
collection PubMed
description Emx1 has long been implicated in embryonic brain development. Previously we found that mice null of Emx1 gene had smaller dentate gyri and reduced neurogenesis, although the molecular mechanisms underlying this defect was not well understood. To decipher the role of Emx1 gene in neural regeneration and the timing of its involvement, we determine the frequency of neural stem cells (NSCs) in embryonic and adult forebrains of Emx1 wild type (WT) and knock out (KO) mice in the neurosphere assay. Emx1 gene deletion reduced the frequency and self-renewal capacity of NSCs of the embryonic brain but did not affect neuronal or glial differentiation. Emx1 KO NSCs also exhibited a reduced migratory capacity in response to serum or vascular endothelial growth factor (VEGF) in the Boyden chamber migration assay compared to their WT counterparts. A thorough comparison between NSC lysates from Emx1 WT and KO mice utilizing 2D-PAGE coupled with tandem mass spectrometry revealed 38 proteins differentially expressed between genotypes, including the F-actin depolymerization factor Cofilin. A global systems biology and cluster analysis identified several potential mechanisms and cellular pathways implicated in altered neurogenesis, all involving Cofilin1. Protein interaction network maps with functional enrichment analysis further indicated that the differentially expressed proteins participated in neural-specific functions including brain development, axonal guidance, synaptic transmission, neurogenesis, and hippocampal morphology, with VEGF as the upstream regulator intertwined with Cofilin1 and Emx1. Functional validation analysis indicated that apart from the overall reduced level of phosphorylated Cofilin1 (p-Cofilin1) in the Emx1 KO NSCs compared to WT NSCs as demonstrated in the western blot analysis, VEGF was able to induce more Cofilin1 phosphorylation and FLK expression only in the latter. Our results suggest that a defect in Cofilin1 phosphorylation induced by VEGF or other growth factors might contribute to the reduced neurogenesis in the Emx1 null mice during brain development.
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spelling pubmed-50659842016-10-31 Deciphering the Role of Emx1 in Neurogenesis: A Neuroproteomics Approach Kobeissy, Firas H. Hansen, Katharina Neumann, Melanie Fu, Shuping Jin, Kulin Liu, Jialing Front Mol Neurosci Neuroscience Emx1 has long been implicated in embryonic brain development. Previously we found that mice null of Emx1 gene had smaller dentate gyri and reduced neurogenesis, although the molecular mechanisms underlying this defect was not well understood. To decipher the role of Emx1 gene in neural regeneration and the timing of its involvement, we determine the frequency of neural stem cells (NSCs) in embryonic and adult forebrains of Emx1 wild type (WT) and knock out (KO) mice in the neurosphere assay. Emx1 gene deletion reduced the frequency and self-renewal capacity of NSCs of the embryonic brain but did not affect neuronal or glial differentiation. Emx1 KO NSCs also exhibited a reduced migratory capacity in response to serum or vascular endothelial growth factor (VEGF) in the Boyden chamber migration assay compared to their WT counterparts. A thorough comparison between NSC lysates from Emx1 WT and KO mice utilizing 2D-PAGE coupled with tandem mass spectrometry revealed 38 proteins differentially expressed between genotypes, including the F-actin depolymerization factor Cofilin. A global systems biology and cluster analysis identified several potential mechanisms and cellular pathways implicated in altered neurogenesis, all involving Cofilin1. Protein interaction network maps with functional enrichment analysis further indicated that the differentially expressed proteins participated in neural-specific functions including brain development, axonal guidance, synaptic transmission, neurogenesis, and hippocampal morphology, with VEGF as the upstream regulator intertwined with Cofilin1 and Emx1. Functional validation analysis indicated that apart from the overall reduced level of phosphorylated Cofilin1 (p-Cofilin1) in the Emx1 KO NSCs compared to WT NSCs as demonstrated in the western blot analysis, VEGF was able to induce more Cofilin1 phosphorylation and FLK expression only in the latter. Our results suggest that a defect in Cofilin1 phosphorylation induced by VEGF or other growth factors might contribute to the reduced neurogenesis in the Emx1 null mice during brain development. Frontiers Media S.A. 2016-10-17 /pmc/articles/PMC5065984/ /pubmed/27799894 http://dx.doi.org/10.3389/fnmol.2016.00098 Text en Copyright © 2016 Kobeissy, Hansen, Neumann, Fu, Jin and Liu. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Neuroscience
Kobeissy, Firas H.
Hansen, Katharina
Neumann, Melanie
Fu, Shuping
Jin, Kulin
Liu, Jialing
Deciphering the Role of Emx1 in Neurogenesis: A Neuroproteomics Approach
title Deciphering the Role of Emx1 in Neurogenesis: A Neuroproteomics Approach
title_full Deciphering the Role of Emx1 in Neurogenesis: A Neuroproteomics Approach
title_fullStr Deciphering the Role of Emx1 in Neurogenesis: A Neuroproteomics Approach
title_full_unstemmed Deciphering the Role of Emx1 in Neurogenesis: A Neuroproteomics Approach
title_short Deciphering the Role of Emx1 in Neurogenesis: A Neuroproteomics Approach
title_sort deciphering the role of emx1 in neurogenesis: a neuroproteomics approach
topic Neuroscience
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5065984/
https://www.ncbi.nlm.nih.gov/pubmed/27799894
http://dx.doi.org/10.3389/fnmol.2016.00098
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