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Biology subjects

Sock, E.

Publications and source records attributed to Sock, E..

4 recordsLinked to original sources

The neuronal fate determinants SOX4/11 control mitotic fidelity of adult hippocampal precursor cells

In adult hippocampal neurogenesis, fast dividing intermediate progenitor cells (IPCs) ensure the production of a larger number of neurons from a limited pool of slow dividing radial-glia-like neural stem cells. Here, we demonstrate that the neuronal fate determining and lineage-specific transcription factors SOX4 and SOX11 are essential to faithfully execute mitosis in IPCs. In vivo, combined deletion of SOX4 and SOX11 results in death of IPCs and abolishes the generation of new neurons. In vitro analyses of SOX4/11-deficient precursors revealed mitosis defects including chromosome segregation errors, centrosomal errors and cytokinesis defects. SOX4/11-deficient precursors frequently featured micronuclei and DNA bridges and showed a pro-inflammatory signaling profile, suggesting the induction of death by mitotic catastrophe. Importantly, analysis of the developing mouse spinal cord and of human pluripotent stem cell-derived brain organoids indicate that SOXC transcription factors are essential for mitotic fidelity of neural precursor cells across ontogeny and species. The data raise the interesting possibility that mitotic programs in precursor cells are controlled in a lineage-specific manner.

cell biology↗

The chloride cotransporter NKCC1 regulates self-renewal of hippocampal neural stem cells via the transcription factor Sox11

The GABAergic-mediated depolarization plays a key role in controlling stem cell fate and neurogenesis within the dentate gyrus of the hippocampal formation. This depolarization effect is highly dependent on the balance between the chloride co-transporters NKCC1 and KCC2. It is not known how changes in NKCC1 modulate the fate of Nestin-positive stem cells (NSCs) in the hippocampus during adult neurogenesis. In our study, we demonstrate that a knockout of Nkcc1 in NSCs increase their proliferation by symmetric self-renewal and expand the stem cell pool. Using single-cell RNA sequencing, we identified Sox11 as a key transcription factor that is significantly downregulated following Nkcc1 knockout. In agreement with this finding, we found that Sox11 knockout enhances proliferation and self-renewal of NSCs, which is also marked by an increase in symmetric stem cell division. Based on these findings, we propose that altering Nkcc1 expression in NSCs shifts their fate from neurogenesis towards self-renewal via Sox11 regulation. Furthermore, we observed that NKCC1 levels decline in NSCs during aging, which correlates with a further increase in self-renewal. Our data strongly suggest that the age-related decline in NKCC1 levels promote symmetric division and self-renewal contributing to the age-dependent decrease in neurogenesis. NKCC1 via Sox11 is a key regulator of NSCs fate decision, critically balancing self-renewal and neuronal differentiation in the adult hippocampus. HighlightsNKCC1 is a key factor in regulating the Nestin-positive neural stem cell symmetric self-renewal. Sox11 is a downstream effector of NKCC1 in Nestin-positive stem cells and is involved in expansion of the stem cell pool. Aging reduces NKCC1 expression in Nestin-positive stem cells and increases their self-renewal. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=170 HEIGHT=200 SRC="FIGDIR/small/662334v1_ufig1.gif" ALT="Figure 1000"> View larger version (38K): org.highwire.dtl.DTLVardef@1babdcforg.highwire.dtl.DTLVardef@1038bfborg.highwire.dtl.DTLVardef@1db105corg.highwire.dtl.DTLVardef@10f2cde_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

scRNA-Sequencing uncovers a TCF-4-dependent transcription factor network regulating commissure development

Intercortical connectivity is important for higher cognitive brain functions by providing the basis for integrating information from both hemispheres. We show that ablation of the neurodevelopmental disorder associated bHLH factor Tcf4 results in complete loss of forebrain commissural systems in mice. Applying a new bioinformatic strategy integrating transcription factor expression levels and regulon activities from single cell RNA-sequencing data predicted a TCF-4 interacting transcription factor network in intercortical projection neurons regulating commissure formation. This network comprises a number of regulators previously linked to the pathogenesis of intellectual disability, autism-spectrum disorders and schizophrenia, e.g. Foxg1, Sox11 and Brg1. Furthermore, we demonstrate that TCF-4 and SOX11 biochemically interact and cooperatively control commissure formation in vivo, and regulate the transcription of genes implied in this process. Our study provides a regulatory transcriptional network for the development of interhemispheric connectivity with potential pathophysiological relevance in neurodevelopmental disorders.

genomics↗

Deciphering the Regulatory Landscape of γδ T Cell Development by Single-Cell RNA-Sequencing

Recent studies have established{gamma}{delta} T cells as critical players in a broad range of infections, antitumor surveillance, autoimmune diseases and tissue homeostasis. However, differentiation of{gamma}{delta} T cells in the adult thymus remains poorly understood, due to the rare frequency of this lineage. Here, we infer high-resolution developmental trajectories of this rare population by single-cell RNA-sequencing. We reveal previously unknown subtypes and identify the transcription factor c-MAF as a novel key regulator of IL-17-producing{gamma}{delta} T cell ({gamma}{delta}T17) differentiation. c-MAF knockout mice exhibit a complete block in{gamma}{delta} T17 differentiation, absence of these cells from peripheral organs, and protection from an autoimmune phenotype in a psoriasis model. Single-cell RNA-sequencing of Sox13 and Rorc knockout mice pinpoints c-MAF as an essential missing link between these lineage-specifying factors. These findings significantly enhance our understanding of{gamma}{delta} T cell ontogeny. Our experimental strategy provides a blueprint for deciphering differentiation of rare cell types.

immunology↗