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Yang A, Chidiac R, Russo E, Steenland H, Pauli Q, Bonin R, Blazer LL, Adams JJ, Sidhu SS, Goeva A, Salahpour A, Angers S. Exploiting spatiotemporal regulation of FZD5 during neural patterning for efficient ventral midbrain specification. Development 2024; 151:dev202545. [PMID: 38358799 PMCID: PMC10946437 DOI: 10.1242/dev.202545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 02/06/2024] [Indexed: 02/16/2024]
Abstract
The Wnt/β-catenin signaling governs anterior-posterior neural patterning during development. Current human pluripotent stem cell (hPSC) differentiation protocols use a GSK3 inhibitor to activate Wnt signaling to promote posterior neural fate specification. However, GSK3 is a pleiotropic kinase involved in multiple signaling pathways and, as GSK3 inhibition occurs downstream in the signaling cascade, it bypasses potential opportunities for achieving specificity or regulation at the receptor level. Additionally, the specific roles of individual FZD receptors in anterior-posterior patterning are poorly understood. Here, we have characterized the cell surface expression of FZD receptors in neural progenitor cells with different regional identity. Our data reveal unique upregulation of FZD5 expression in anterior neural progenitors, and this expression is downregulated as cells adopt a posterior fate. This spatial regulation of FZD expression constitutes a previously unreported regulatory mechanism that adjusts the levels of β-catenin signaling along the anterior-posterior axis and possibly contributes to midbrain-hindbrain boundary formation. Stimulation of Wnt/β-catenin signaling in hPSCs, using a tetravalent antibody that selectively triggers FZD5 and LRP6 clustering, leads to midbrain progenitor differentiation and gives rise to functional dopaminergic neurons in vitro and in vivo.
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Affiliation(s)
- Andy Yang
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON M5S 3E1, Canada
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, ON M5S 3M2, Canada
| | - Rony Chidiac
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON M5S 3E1, Canada
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, ON M5S 3M2, Canada
| | - Emma Russo
- Department of Pharmacology and Toxicology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Hendrik Steenland
- Department of Pharmacology and Toxicology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
- NeuroTek Innovative Technology, Toronto, ON M6C 3A2, Canada
| | - Quinn Pauli
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, ON M5S 3M2, Canada
| | - Robert Bonin
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, ON M5S 3M2, Canada
| | - Levi L. Blazer
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON M5S 3E1, Canada
| | - Jarrett J. Adams
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON M5S 3E1, Canada
| | - Sachdev S. Sidhu
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON M5S 3E1, Canada
- Department of Molecular Genetics, Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Aleksandrina Goeva
- Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA 02142, USA
| | - Ali Salahpour
- Department of Pharmacology and Toxicology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Stephane Angers
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON M5S 3E1, Canada
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, ON M5S 3M2, Canada
- Department of Biochemistry, Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
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Torene RI, Guillen Sacoto MJ, Millan F, Zhang Z, McGee S, Oetjens M, Heise E, Chong K, Sidlow R, O'Grady L, Sahai I, Martin CL, Ledbetter DH, Myers SM, Mitchell KJ, Retterer K. Systematic analysis of variants escaping nonsense-mediated decay uncovers candidate Mendelian diseases. Am J Hum Genet 2024; 111:70-81. [PMID: 38091987 PMCID: PMC10806863 DOI: 10.1016/j.ajhg.2023.11.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 11/17/2023] [Accepted: 11/19/2023] [Indexed: 01/07/2024] Open
Abstract
Protein-truncating variants (PTVs) near the 3' end of genes may escape nonsense-mediated decay (NMD). PTVs in the NMD-escape region (PTVescs) can cause Mendelian disease but are difficult to interpret given their varying impact on protein function. Previously, PTVesc burden was assessed in an epilepsy cohort, but no large-scale analysis has systematically evaluated these variants in rare disease. We performed a retrospective analysis of 29,031 neurodevelopmental disorder (NDD) parent-offspring trios referred for clinical exome sequencing to identify PTVesc de novo mutations (DNMs). We identified 1,376 PTVesc DNMs and 133 genes that were significantly enriched (binomial p < 0.001). The PTVesc-enriched genes included those with PTVescs previously described to cause dominant Mendelian disease (e.g., SEMA6B, PPM1D, and DAGLA). We annotated ClinVar variants for PTVescs and identified 948 genes with at least one high-confidence pathogenic variant. Twenty-two known Mendelian PTVesc-enriched genes had no prior evidence of PTVesc-associated disease. We found 22 additional PTVesc-enriched genes that are not well established to be associated with Mendelian disease, several of which showed phenotypic similarity between individuals harboring PTVesc variants in the same gene. Four individuals with PTVesc mutations in RAB1A had similar phenotypes including NDD and spasticity. PTVesc mutations in IRF2BP1 were found in two individuals who each had severe immunodeficiency manifesting in NDD. Three individuals with PTVesc mutations in LDB1 all had NDD and multiple congenital anomalies. Using a large-scale, systematic analysis of DNMs, we extend the mutation spectrum for known Mendelian disease-associated genes and identify potentially novel disease-associated genes.
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Affiliation(s)
| | | | | | | | | | - Matthew Oetjens
- Geisinger, Danville, PA, USA; Geisinger Autism & Developmental Medicine Institute, Lewisburg, PA, USA
| | | | | | | | | | | | - Christa L Martin
- Geisinger, Danville, PA, USA; Geisinger Autism & Developmental Medicine Institute, Lewisburg, PA, USA
| | - David H Ledbetter
- University of Florida, College of Medicine-Jacksonville, Jacksonville, FL, USA
| | - Scott M Myers
- Geisinger, Danville, PA, USA; Geisinger Autism & Developmental Medicine Institute, Lewisburg, PA, USA
| | - Kevin J Mitchell
- Smurfit Institute of Genetics and Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland
| | - Kyle Retterer
- GeneDx, Gaithersburg, MD, USA; Geisinger, Danville, PA, USA.
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Pal S, Dwivedi D, Pramanik T, Godbole G, Iwasato T, Jabaudon D, Bhalla US, Tole S. An Early Cortical Progenitor-Specific Mechanism Regulates Thalamocortical Innervation. J Neurosci 2021; 41:6822-6835. [PMID: 34193558 PMCID: PMC8360687 DOI: 10.1523/jneurosci.0226-21.2021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 05/29/2021] [Accepted: 06/08/2021] [Indexed: 11/21/2022] Open
Abstract
The cortical subplate is critical in regulating the entry of thalamocortical sensory afferents into the cortex. These afferents reach the subplate at embryonic day (E)15.5 in the mouse, but "wait" for several days, entering the cortical plate postnatally. We report that when transcription factor LHX2 is lost in E11.5 cortical progenitors, which give rise to subplate neurons, thalamocortical afferents display premature, exuberant ingrowth into the E15.5 cortex. Embryonic mutant subplate neurons are correctly positioned below the cortical plate, but they display an altered transcriptome and immature electrophysiological properties during the waiting period. The sensory thalamus in these cortex-specific Lhx2 mutants displays atrophy and by postnatal day (P) 7, sensory innervation to the cortex is nearly eliminated leading to a loss of the somatosensory barrels. Strikingly, these phenotypes do not manifest if LHX2 is lost in postmitotic subplate neurons, and the transcriptomic dysregulation in the subplate resulting from postmitotic loss of LHX2 is vastly distinct from that seen when LHX2 is lost in progenitors. These results demonstrate a mechanism operating in subplate progenitors that has profound consequences on the growth of thalamocortical axons into the cortex.SIGNIFICANCE STATEMENT Thalamocortical nerves carry sensory information from the periphery to the cortex. When they first grow into the embryonic cortex, they "wait" at the subplate, a structure critical for the guidance and eventual connectivity of thalamic axons with their cortical targets. How the properties of subplate neurons are regulated is unclear. We report that transcription factor LHX2 is required in the progenitor "mother" cells of the cortical primordium when they are producing their "daughter" subplate neurons, in order for the thalamocortical pathway to wait at the subplate. Without LHX2 function in subplate progenitors, thalamocortical axons grow past the subplate, entering the cortical plate prematurely. This is followed by their eventual attrition and, consequently, a profound loss of sensory innervation of the mature cortex.
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Affiliation(s)
- Suranjana Pal
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, 400005, India
| | - Deepanjali Dwivedi
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bengaluru, 560001, India
| | - Tuli Pramanik
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, 400005, India
| | - Geeta Godbole
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, 400005, India
| | - Takuji Iwasato
- Laboratory of Mammalian Neural Circuits, National Institute of Genetics, Mishima, 411-8540, Japan
- Department of Genetics, SOKENDAI (Graduate University for Advanced Studies), Mishima, 411-8540, Japan
| | - Denis Jabaudon
- Department of Basic Neurosciences, University of Geneva, 1211 Geneva, Switzerland; Department of Neurology, Geneva University Hospital, 1205 Geneva, Switzerland
| | - Upinder S Bhalla
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bengaluru, 560001, India
| | - Shubha Tole
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, 400005, India
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Ohnishi T, Kiyama Y, Arima‐Yoshida F, Kadota M, Ichikawa T, Yamada K, Watanabe A, Ohba H, Tanaka K, Nakaya A, Horiuchi Y, Iwayama Y, Toyoshima M, Ogawa I, Shimamoto‐Mitsuyama C, Maekawa M, Balan S, Arai M, Miyashita M, Toriumi K, Nozaki Y, Kurokawa R, Suzuki K, Yoshikawa A, Toyota T, Hosoya T, Okuno H, Bito H, Itokawa M, Kuraku S, Manabe T, Yoshikawa T. Cooperation of LIM domain-binding 2 (LDB2) with EGR in the pathogenesis of schizophrenia. EMBO Mol Med 2021; 13:e12574. [PMID: 33656268 PMCID: PMC8033514 DOI: 10.15252/emmm.202012574] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 01/21/2021] [Accepted: 01/25/2021] [Indexed: 01/15/2023] Open
Abstract
Genomic defects with large effect size can help elucidate unknown pathologic architecture of mental disorders. We previously reported on a patient with schizophrenia and a balanced translocation between chromosomes 4 and 13 and found that the breakpoint within chromosome 4 is located near the LDB2 gene. We show here that Ldb2 knockout (KO) mice displayed multiple deficits relevant to mental disorders. In particular, Ldb2 KO mice exhibited deficits in the fear-conditioning paradigm. Analysis of the amygdala suggested that dysregulation of synaptic activities controlled by the immediate early gene Arc is involved in the phenotypes. We show that LDB2 forms protein complexes with known transcription factors. Consistently, ChIP-seq analyses indicated that LDB2 binds to > 10,000 genomic sites in human neurospheres. We found that many of those sites, including the promoter region of ARC, are occupied by EGR transcription factors. Our previous study showed an association of the EGR family genes with schizophrenia. Collectively, the findings suggest that dysregulation in the gene expression controlled by the LDB2-EGR axis underlies a pathogenesis of subset of mental disorders.
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Sensational developments in somatosensory development? Curr Opin Neurobiol 2021; 66:212-223. [PMID: 33454646 DOI: 10.1016/j.conb.2020.12.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 12/10/2020] [Accepted: 12/12/2020] [Indexed: 12/25/2022]
Abstract
This is an overview of the most recent advances pertaining to the development of the cardinal components of the somatosensory system: the peripheral sensory neurons that perceive somatosensory stimuli, the first line central nervous system circuits that modulate them, and the higher structures such as the somatosensory cortex that eventually compute a motor response to them. Here, I also review the most recent findings concerning the role of neuronal activity in somatosensory development, formation of somatotopic maps, insights into human somatosensory development and the link between aberrant somatosensation and neurodevelopmental disorders.
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Jones I, Hägglund AC, Carlsson L. Reduced mTORC1-signalling in retinal progenitor cells leads to visual pathway dysfunction. Biol Open 2019; 8:bio.044370. [PMID: 31285269 PMCID: PMC6737973 DOI: 10.1242/bio.044370] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Development of the vertebrate central nervous system involves the co-ordinated differentiation of progenitor cells and the establishment of functional neural networks. This neurogenic process is driven by both intracellular and extracellular cues that converge on the mammalian target of rapamycin complex 1 (mTORC1). Here we demonstrate that mTORC1-signalling mediates multi-faceted roles during central nervous system development using the mouse retina as a model system. Downregulation of mTORC1-signalling in retinal progenitor cells by conditional ablation of Rptor leads to proliferation deficits and an over-production of retinal ganglion cells during embryonic development. In contrast, reduced mTORC1-signalling in postnatal animals leads to temporal deviations in programmed cell death and the consequent production of asymmetric retinal ganglion cell mosaics and associated loss of axonal termination topographies in the dorsal lateral geniculate nucleus of adult mice. In combination these developmental defects induce visually mediated behavioural deficits. These collective observations demonstrate that mTORC1-signalling mediates critical roles during visual pathway development and function. Summary: Conditional deletion of Rptor in retinal progenitor cells demonstrates that mTORC1-signalling is critical for visual pathway development and function.
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Affiliation(s)
- Iwan Jones
- Umeå Center for Molecular Medicine (UCMM), Umeå University, 901 87 Umeå, Sweden
| | - Anna-Carin Hägglund
- Umeå Center for Molecular Medicine (UCMM), Umeå University, 901 87 Umeå, Sweden
| | - Leif Carlsson
- Umeå Center for Molecular Medicine (UCMM), Umeå University, 901 87 Umeå, Sweden
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