A small molecule accelerates neuronal differentiation in the adult rat
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ABSTRACT: Adult neurogenesis occurs in mammals and provides a mechanism for continuous neural plasticity in the brain.However, little is known about the molecular mechanisms regulating hippocampal neural progenitor cells (NPCs) and whether their fate can be pharmacologically modulated to improve neural plasticity and regeneration. Here, we report the characterization of a unique small molecule (KHS101) that selectively induces a neuronal differentiation phenotype. Mechanism of action studies revealed a link of KHS101 to cell cycle exit and specific binding to the TACC3 protein, whose knockdown in NPCs recapitulates the KHS101-induced phenotype. Upon systemic administration, KHS101 distributed to the brainandresulted in a significant increase in neuronal differentiation in vivo. Our findings indicate that KHS101 accelerates neuronal differentiation by interaction with TACC3 and may provide a basis for pharmacological intervention.directed at endogenous NPCs. Compare expression profile of KHS101-treated hippocampal progenitor cells (2 concentrations) vs. DMSO (negative control), retinoic acid (positive control)
Project description:Analysis of dopaminergic neuronal gene expression changes by Nurr1 and/or Foxa2 overexpression. Result provides that Foxa2 potentiates Nurr1-induced DA neuronal phenotype gene expression. To identify the syergism of Nurr1 and Foxa2 for developing DA neural precursors, neural precusor cells (NPCs) isolated from embryonic brain were treated control, Nurr1, Foxa2 and Nurr1-Foxa2 retrovirus. After treatment of retroviruses, NPCs were cultrued in N2 media withdrawn mitogen (bFGF, EGF) for differetiation of DA neuron. Total RNA was obtained from NPCs in differentiation day 2.
Project description:Adult neurogenesis occurs in mammals and provides a mechanism for continuous neural plasticity in the brain.However, little is known about the molecular mechanisms regulating hippocampal neural progenitor cells (NPCs) and whether their fate can be pharmacologically modulated to improve neural plasticity and regeneration. Here, we report the characterization of a unique small molecule (KHS101) that selectively induces a neuronal differentiation phenotype. Mechanism of action studies revealed a link of KHS101 to cell cycle exit and specific binding to the TACC3 protein, whose knockdown in NPCs recapitulates the KHS101-induced phenotype. Upon systemic administration, KHS101 distributed to the brainandresulted in a significant increase in neuronal differentiation in vivo. Our findings indicate that KHS101 accelerates neuronal differentiation by interaction with TACC3 and may provide a basis for pharmacological intervention.directed at endogenous NPCs.
Project description:Cell-based models of many neurological and psychiatric diseases, established by reprogramming patient somatic cells into human induced pluripotent stem cells (hiPSCs), have now been reported. While numerous reports have demonstrated that neuronal cells differentiated from hiPSCs are electrophysiologically active mature neurons, the “age” of these cells relative to cells in the human brain remains unresolved. Comparisons of gene expression profiles of hiPSC-derived neural progenitor cells (NPCs) and neurons to the Allen BrainSpan Atlas indicate that hiPSC neural cells most resemble first trimester neural tissue. Consequently, we posit that hiPSC-derived neural cells may most accurately be used to model the early developmental defects that contribute to disease predisposition rather than the late features of the disease. Though the characteristic symptoms of schizophrenia (SCZD) generally appear late in adolescence, it is now thought to be a neurodevelopmental condition, often predated by a prodromal period that can appear in early childhood. Postmortem studies of SCZD brain tissue typically describe defects in mature neurons, such as reduced neuronal size and spine density in the prefrontal cortex and hippocampus, but abnormalities of neuronal organization, particularly in the cortex, have also been reported. We postulated that defects in cortical organization in SCZD might result from abnormal migration of neural cells. To test this hypothesis, we directly reprogrammed fibroblasts from SCZD patients into hiPSCs and subsequently differentiated these disorder-specific hiPSCs into NPCs. SCZD hiPSC differentiated into forebrain NPCs have altered expression of a number of cellular adhesion genes, reduced WNT signaling and aberrant cellular migration. 3 independent differentiations (biological replicates) for each of four control and four schizophrenic patients were analyzed.
Project description:Congenital human cytomegalovirus (HCMV) infection is one of the leading prenatal causes of mental retardation and congenital deformities world-wide. Access to cultured human neuronal lineages, necessary to understand the species specific pathogenic effects of HCMV has been limited by difficulties in sustaining primary cultures. Neuronal cells derived from human induced pluripotent stem (iPS) cells now provide a novel opportunity to investigate HCMV pathogenesis. We derived iPS cells from human adult fibroblasts and induced neural lineages to investigate their permissiveness to infection with HCMV strain Ad169. Analysis of iPS cells and nearly pure populations of iPS-derived neural stem cells (NSCs), neuroprogenitor cells (NPCs) and neurons suggests that (i) iPS cells are not permissive to HCMV infection; (ii) Neural stem cells have impaired differentiation when infected by HCMV; (iii) NPCs are fully permissive for HCMV infection; the supernatant from infected neural stem cells and NPCs (but not mock infected cells) induced cytopathic effects in human fibroblasts; (iv) most iPS-derived neurons are not permissive to HCMV infection; and (v) infected neurons have impaired calcium influx in response to glutamate. Our approach offers powerful cellular models to investigate the effect of neurotropic viral agents on human neurodevelopment. Adherent monolayer culture of neural progenitor cells (NPCs) were either infected with HCMV Ad169 in triplicate, with each individual sample harvested separately to provide biological replicates for expression analysis. Infected and mock-infected cells were harvested 24 h p.i. RNA. NPCs were 70-80% confluence.
Project description:Exposure to lead (Pb) during childhood can result in learning disabilities and behavioral problems. Although described in animal models, whether Pb exposure also alters neuronal differentiation in the developing brains of exposed children is unknown. Here, we investigated the effects of physiologically relevant concentrations of Pb (from 0.4 to 1.9 M-BM-5M or 0 to 40M-BM-5g/dl) on the capacity of human embryonic stem cells (hESCs) to progress to a neuronal fate. We found that neither acute nor chronic exposure to Pb prevented hESCs from generating neural precursor cells (NPCs). NPCs derived from hESCs chronically exposed to 1.9 M-BM-5M or 40M-BM-5g/dl Pb throughout the neural differentiation process generated 2.5 times more TUJ1-positive neurons than those derived from control hESCs. Pb exposure of hESCs during the stage of neural rosette formation resulted in a significant decrease in the expression levels of the neural marker genes PAX6 and MSI1. Furthermore, the resulting NPCs differentiated into neurons with shorter neurites and less branching than control neurons, as assessed by Sholl analysis. DNA methylation studies of control, acutely treated hESCs and NPCs derived from chronically exposed hESCs using the Illumina HumanMethylation450 BeadChipM-BM-. demonstrated that Pb exposure induced changes in the methylation status of genes involved in neurogenetic signaling pathways. In summary, our study shows that exposure to Pb subtly alters the neuronal differentiation of exposed hESCs and that these changes could be partly mediated by modifications in the DNA methylation status of genes crucial to brain development. We analyzed the methylation profile of undifferentiated (n=2 independent experiments) and differentiating (n=2 independent experiments) human embryonic stem cells (hESCs) acutely exposed to losed to lead (Pb) and neural precursor cells derived from hESCs chronically exposed to Pb throughout the neural differentiation process (n=3 independent experiments).
Project description:To connect the neuronal developmental disorders associated GWAS signal to their target effector genes, we performed an integrated analysis of transcriptomics, epigenomics and chromatin conformation changes in an in vitro cellular model. Induced human pluripotent stem cell–derived neural progenitor cells (NPCs) were differentiated into neurons and then subjected to a combination of high-resolution promoter-focused Capture C, ATAC-seq and RNA-seq.
Project description:Cell-based models of many neurological and psychiatric diseases, established by reprogramming patient somatic cells into human induced pluripotent stem cells (hiPSCs), have now been reported. While numerous reports have demonstrated that neuronal cells differentiated from hiPSCs are electrophysiologically active mature neurons, the âageâ of these cells relative to cells in the human brain remains unresolved. Comparisons of gene expression profiles of hiPSC-derived neural progenitor cells (NPCs) and neurons to the Allen BrainSpan Atlas indicate that hiPSC neural cells most resemble first trimester neural tissue. Consequently, we posit that hiPSC-derived neural cells may most accurately be used to model the early developmental defects that contribute to disease predisposition rather than the late features of the disease. Though the characteristic symptoms of schizophrenia SZ generally appear late in adolescence, it is now thought to be a neurodevelopmental condition, often predated by a prodromal period that can appear in early childhood. Postmortem studies of SZ brain tissue typically describe defects in mature neurons, such as reduced neuronal size and spine density in the prefrontal cortex and hippocampus, but abnormalities of neuronal organization, particularly in the cortex, have also been reported. We postulated that defects in cortical organization in SZ might result from abnormal migration of neural cells. To test this hypothesis, we directly reprogrammed fibroblasts from SZ patients into hiPSCs and subsequently differentiated these disorder-specific hiPSCs into NPCs. SZ hiPSC differentiated into forebrain NPCs have altered expression of a number of cellular adhesion genes and WNT signaling. Methods: We compared global transcription of forebrain NPCs from six control and four SZ patients by RNAseq. Results: Multi-dimensional scaling (MDS) resolved most SZ and control hiPSC NPC samples; 848 genes were significantly differentially expressed (FDR<0.01) Conclusions: The WNT signaling pathway was enriched 2-fold (fisher exact test p-value = 0.031). 1-2 independent differentiations (biological replicates) for each of four control and four schizophrenia patients were analyzed; samples were generated in parallel to neuron RNAseq data.
Project description:To connect the neuronal developmental disorders associated GWAS signal to their target effector genes, we performed an integrated analysis of transcriptomics, epigenomics and chromatin conformation changes in an in vitro cellular model. Induced human pluripotent stem cell–derived neural progenitor cells (NPCs) were differentiated into neurons and then subjected to a combination of high-resolution promoter-focused Capture C, ATAC-seq and RNA-seq.
Project description:Understanding evolutionary mechanisms underlying expansion and reorganization of the human brain represents an important aspect in analyzing the emergence of cognitive abilities typical of our species. Comparative analyses of neuronal phenotypes in closest living relatives (Pan troglodytes; the common chimpanzee) can shed the light into changes in neuronal morphology compared to the last common ancestor (LCA), opening possibilities for analyses of the timing of their appearance, and the role of evolutionary mechanisms favoring a particular type of information processing in humans. Here, we use induced pluripotent stem cell (iPSC) technology to model neural progenitor cell migration and early development of cortical pyramidal neurons in humans and chimpanzees. In addition, we provide morphological characterization of the early stages of neuronal development in human and chimpanzee transplanted cells, and examine the role of developmental mechanisms previously proposed for the evolutionary expansions of the human brain on the early development of pyramidal neurons in the two species. The strategy proposed here lay down the basis for further comparative analysis between human and non-human primates and opens new avenues for understanding cognitive capability and neurological disease susceptibility differences between species. PolyA RNA-Seq profiling of neural progenitor cells (NPCs) and neurons differentiated from human and chimpanzee iPSCs.
Project description:To connect the neuronal developmental disorders associated GWAS signal to their target effector genes, we performed an integrated analysis of transcriptomics, epigenomics and chromatin conformation changes in an in vitro cellular model. Induced human pluripotent stem cell–derived neural progenitor cells (NPCs) were differentiated into neurons and then subjected to a combination of high-resolution promoter-focused Capture C, ATAC-seq and RNA-seq.