1
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Ferguson R, van Es MA, van den Berg LH, Subramanian V. Neural stem cell homeostasis is affected in cortical organoids carrying a mutation in Angiogenin. J Pathol 2024; 262:410-426. [PMID: 38180358 DOI: 10.1002/path.6244] [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: 04/12/2023] [Revised: 11/07/2023] [Accepted: 11/28/2023] [Indexed: 01/06/2024]
Abstract
Mutations in Angiogenin (ANG) and TARDBP encoding the 43 kDa transactive response DNA binding protein (TDP-43) are associated with amyotrophic lateral sclerosis and frontotemporal dementia (ALS-FTD). ANG is neuroprotective and plays a role in stem cell dynamics in the haematopoietic system. We obtained skin fibroblasts from members of an ALS-FTD family, one with mutation in ANG, one with mutation in both TARDBP and ANG, and one with neither mutation. We reprogrammed these fibroblasts to induced pluripotent stem cells (iPSCs) and generated cortical organoids as well as induced stage-wise differentiation of the iPSCs to neurons. Using these two approaches we investigated the effects of FTD-associated mutations in ANG and TARDBP on neural precursor cells, neural differentiation, and response to stress. We observed striking neurodevelopmental defects such as abnormal and persistent rosettes in the organoids accompanied by increased self-renewal of neural precursor cells. There was also a propensity for differentiation to later-born neurons. In addition, cortical neurons showed increased susceptibility to stress, which is exacerbated in neurons carrying mutations in both ANG and TARDBP. The cortical organoids and neurons generated from patient-derived iPSCs carrying ANG and TARDBP gene variants recapitulate dysfunctions characteristic of frontotemporal lobar degeneration observed in FTD patients. These dysfunctions were ameliorated upon treatment with wild type ANG. In addition to its well-established role during the stress response of mature neurons, ANG also appears to play a role in neural progenitor dynamics. This has implications for neurogenesis and may indicate that subtle developmental defects play a role in disease susceptibility or onset. © 2024 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.
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Affiliation(s)
- Ross Ferguson
- Department of Life Sciences, University of Bath, Bath, UK
| | - Michael A van Es
- Department of Neurology, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Leonard H van den Berg
- Department of Neurology, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht, The Netherlands
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2
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Chen YL, Feng XL, Tam KW, Fan CY, Cheung MPL, Yang YT, Wong S, Shum DKY, Chan YS, Cheung CW, Cheung M, Liu JA. Intrinsic and extrinsic actions of human neural progenitors with SUFU inhibition promote tissue repair and functional recovery from severe spinal cord injury. NPJ Regen Med 2024; 9:13. [PMID: 38519518 PMCID: PMC10959923 DOI: 10.1038/s41536-024-00352-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Accepted: 02/06/2024] [Indexed: 03/25/2024] Open
Abstract
Neural progenitor cells (NPCs) derived from human pluripotent stem cells(hPSCs) provide major cell sources for repairing damaged neural circuitry and enabling axonal regeneration after spinal cord injury (SCI). However, the injury niche and inadequate intrinsic factors in the adult spinal cord restrict the therapeutic potential of transplanted NPCs. The Sonic Hedgehog protein (Shh) has crucial roles in neurodevelopment by promoting the formation of motorneurons and oligodendrocytes as well as its recently described neuroprotective features in response to the injury, indicating its essential role in neural homeostasis and tissue repair. In this study, we demonstrate that elevated SHH signaling in hNPCs by inhibiting its negative regulator, SUFU, enhanced cell survival and promoted robust neuronal differentiation with extensive axonal outgrowth, counteracting the harmful effects of the injured niche. Importantly, SUFU inhibition in NPCs exert non-cell autonomous effects on promoting survival and neurogenesis of endogenous cells and modulating the microenvironment by reducing suppressive barriers around lesion sites. The combined beneficial effects of SUFU inhibition in hNPCs resulted in the effective reconstruction of neuronal connectivity with the host and corticospinal regeneration, significantly improving neurobehavioral recovery in recipient animals. These results demonstrate that SUFU inhibition confers hNPCs with potent therapeutic potential to overcome extrinsic and intrinsic barriers in transplantation treatments for SCI.
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Affiliation(s)
- Yong-Long Chen
- Department of Anaesthesiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Xiang-Lan Feng
- Department of Anaesthesiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Kin-Wai Tam
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Chao-Yang Fan
- Department of Neuroscience, Tat Chee Avenue, City University of Hong Kong, Hong Kong, China
| | - May Pui-Lai Cheung
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Yong-Ting Yang
- Department of Neuroscience, Tat Chee Avenue, City University of Hong Kong, Hong Kong, China
| | - Stanley Wong
- Department of Anaesthesiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Daisy Kwok-Yan Shum
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Ying-Shing Chan
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Chi-Wai Cheung
- Department of Anaesthesiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
- Hong Kong sanatorium hospital, Hong Kong, China
| | - Martin Cheung
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Jessica Aijia Liu
- Department of Anaesthesiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China.
- Department of Neuroscience, Tat Chee Avenue, City University of Hong Kong, Hong Kong, China.
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3
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Cai E, Barba MG, Ge X. Hedgehog Signaling in Cortical Development. Cells 2023; 13:21. [PMID: 38201225 PMCID: PMC10778342 DOI: 10.3390/cells13010021] [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: 11/15/2023] [Revised: 12/14/2023] [Accepted: 12/19/2023] [Indexed: 01/12/2024] Open
Abstract
The Hedgehog (Hh) pathway plays a crucial role in embryonic development, acting both as a morphogenic signal that organizes tissue formation and a potent mitogenic signal driving cell proliferation. Dysregulated Hh signaling leads to various developmental defects in the brain. This article aims to review the roles of Hh signaling in the development of the neocortex in the mammalian brain, focusing on its regulation of neural progenitor proliferation and neuronal production. The review will summarize studies on genetic mouse models that have targeted different components of the Hh pathway, such as the ligand Shh, the receptor Ptch1, the GPCR-like transducer Smo, the intracellular transducer Sufu, and the three Gli transcription factors. As key insights into the Hh signaling transduction mechanism were obtained from mouse models displaying neural tube defects, this review will also cover some studies on Hh signaling in neural tube development. The results from these genetic mouse models suggest an intriguing hypothesis that elevated Hh signaling may play a role in the gyrification of the brain in certain species. Additionally, the distinctive production of GABAergic interneurons in the dorsal cortex in the human brain may also be linked to the extension of Hh signaling from the ventral to the dorsal brain region. Overall, these results suggest key roles of Hh signaling as both a morphogenic and mitogenic signal during the forebrain development and imply the potential involvement of Hh signaling in the evolutionary expansion of the neocortex.
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Affiliation(s)
| | | | - Xuecai Ge
- Department of Molecular and Cell Biology, School of Natural Sciences, University of California Merced, Merced, CA 95340, USA
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4
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Guo MG, Reynolds DL, Ang CE, Liu Y, Zhao Y, Donohue LKH, Siprashvili Z, Yang X, Yoo Y, Mondal S, Hong A, Kain J, Meservey L, Fabo T, Elfaki I, Kellman LN, Abell NS, Pershad Y, Bayat V, Etminani P, Holodniy M, Geschwind DH, Montgomery SB, Duncan LE, Urban AE, Altman RB, Wernig M, Khavari PA. Integrative analyses highlight functional regulatory variants associated with neuropsychiatric diseases. Nat Genet 2023; 55:1876-1891. [PMID: 37857935 PMCID: PMC10859123 DOI: 10.1038/s41588-023-01533-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 09/15/2023] [Indexed: 10/21/2023]
Abstract
Noncoding variants of presumed regulatory function contribute to the heritability of neuropsychiatric disease. A total of 2,221 noncoding variants connected to risk for ten neuropsychiatric disorders, including autism spectrum disorder, attention deficit hyperactivity disorder, bipolar disorder, borderline personality disorder, major depression, generalized anxiety disorder, panic disorder, post-traumatic stress disorder, obsessive-compulsive disorder and schizophrenia, were studied in developing human neural cells. Integrating epigenomic and transcriptomic data with massively parallel reporter assays identified differentially-active single-nucleotide variants (daSNVs) in specific neural cell types. Expression-gene mapping, network analyses and chromatin looping nominated candidate disease-relevant target genes modulated by these daSNVs. Follow-up integration of daSNV gene editing with clinical cohort analyses suggested that magnesium transport dysfunction may increase neuropsychiatric disease risk and indicated that common genetic pathomechanisms may mediate specific symptoms that are shared across multiple neuropsychiatric diseases.
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Affiliation(s)
- Margaret G Guo
- Stanford Program in Biomedical Informatics, Stanford University, Stanford, CA, USA
- Program in Epithelial Biology, Stanford University, Stanford, CA, USA
| | - David L Reynolds
- Program in Epithelial Biology, Stanford University, Stanford, CA, USA
| | - Cheen E Ang
- Department of Pathology, Stanford University, Stanford, CA, USA
- Department of Bioengineering, Stanford University, Stanford, CA, USA
- Institute for Stem Cell Biology & Regenerative Medicine, Stanford University, Stanford, CA, USA
| | - Yingfei Liu
- Institute for Stem Cell Biology & Regenerative Medicine, Stanford University, Stanford, CA, USA
- Institute of Neurobiology, Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Yang Zhao
- Program in Epithelial Biology, Stanford University, Stanford, CA, USA
| | - Laura K H Donohue
- Program in Epithelial Biology, Stanford University, Stanford, CA, USA
- Department of Genetics, Stanford University, Stanford, CA, USA
| | - Zurab Siprashvili
- Program in Epithelial Biology, Stanford University, Stanford, CA, USA
| | - Xue Yang
- Program in Epithelial Biology, Stanford University, Stanford, CA, USA
- Stanford Program in Cancer Biology, Stanford University, Stanford, CA, USA
| | - Yongjin Yoo
- Institute for Stem Cell Biology & Regenerative Medicine, Stanford University, Stanford, CA, USA
| | - Smarajit Mondal
- Program in Epithelial Biology, Stanford University, Stanford, CA, USA
| | - Audrey Hong
- Program in Epithelial Biology, Stanford University, Stanford, CA, USA
| | - Jessica Kain
- Department of Genetics, Stanford University, Stanford, CA, USA
| | | | - Tania Fabo
- Program in Epithelial Biology, Stanford University, Stanford, CA, USA
- Department of Genetics, Stanford University, Stanford, CA, USA
| | - Ibtihal Elfaki
- Program in Epithelial Biology, Stanford University, Stanford, CA, USA
- Department of Genetics, Stanford University, Stanford, CA, USA
| | - Laura N Kellman
- Program in Epithelial Biology, Stanford University, Stanford, CA, USA
- Stanford Program in Cancer Biology, Stanford University, Stanford, CA, USA
| | - Nathan S Abell
- Department of Genetics, Stanford University, Stanford, CA, USA
| | - Yash Pershad
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | | | | | - Mark Holodniy
- Public Health Surveillance and Research, Department of Veterans Affairs, Washington, DC, USA
- Division of Infectious Disease & Geographic Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Daniel H Geschwind
- Program in Neurobehavioral Genetics, Semel Institute, UCLA, Los Angeles, CA, USA
| | - Stephen B Montgomery
- Department of Pathology, Stanford University, Stanford, CA, USA
- Department of Genetics, Stanford University, Stanford, CA, USA
| | - Laramie E Duncan
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA
| | - Alexander E Urban
- Department of Genetics, Stanford University, Stanford, CA, USA
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA
| | - Russ B Altman
- Stanford Program in Biomedical Informatics, Stanford University, Stanford, CA, USA
- Department of Bioengineering, Stanford University, Stanford, CA, USA
- Department of Genetics, Stanford University, Stanford, CA, USA
| | - Marius Wernig
- Department of Pathology, Stanford University, Stanford, CA, USA
- Institute for Stem Cell Biology & Regenerative Medicine, Stanford University, Stanford, CA, USA
| | - Paul A Khavari
- Program in Epithelial Biology, Stanford University, Stanford, CA, USA.
- Stanford Program in Cancer Biology, Stanford University, Stanford, CA, USA.
- Veterans Affairs Palo Alto Healthcare System, Palo Alto, CA, USA.
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5
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Spice DM, Dierolf J, Kelly GM. Suppressor of Fused Regulation of Hedgehog Signaling is Required for Proper Astrocyte Differentiation. Stem Cells Dev 2022; 31:741-755. [PMID: 36103394 DOI: 10.1089/scd.2022.0131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Hedgehog signaling is essential for vertebrate development; however, less is known about the negative regulators that influence this pathway. Using the mouse P19 embryonal carcinoma cell model, suppressor of fused (SUFU), a negative regulator of the Hedgehog (Hh) pathway, was investigated during retinoic acid (RA)-induced neural differentiation. We found Hh signaling increased activity in the early phase of differentiation, but was reduced during terminal differentiation of neurons and astrocytes. This early increase in pathway activity was required for neural differentiation; however, it alone was not sufficient to induce neural lineages. SUFU, which regulates signaling at the level of Gli, remained relatively unchanged during differentiation, but its loss through CRISPR-Cas9 gene editing resulted in ectopic expression of Hh target genes. Interestingly, these SUFU-deficient cells were unable to differentiate toward neural lineages without RA, and when directed toward these lineages, they showed delayed and decreased astrocyte differentiation; neuron differentiation was unaffected. Ectopic activation of Hh target genes in SUFU-deficient cells remained throughout RA-induced differentiation and this was accompanied by the loss of Gli3, despite the presence of the Gli3 message. Thus, the study indicates the proper timing and proportion of astrocyte differentiation requires SUFU, likely acting through Gli3, to reduce Hh signaling during late-stage differentiation.
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Affiliation(s)
- Danielle M Spice
- Molecular Genetics Unit, Department of Biology, Western University, London, Ontario, Canada.,Children's Health Research Institute, London, Ontario, Canada
| | - Joshua Dierolf
- Department of Physiology and Pharmacology, Western University, London, Ontario, Canada
| | - Gregory M Kelly
- Molecular Genetics Unit, Department of Biology, Western University, London, Ontario, Canada.,Children's Health Research Institute, London, Ontario, Canada.,Department of Physiology and Pharmacology, Western University, London, Ontario, Canada
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6
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Manuel M, Tan KB, Kozic Z, Molinek M, Marcos TS, Razak MFA, Dobolyi D, Dobie R, Henderson BEP, Henderson NC, Chan WK, Daw MI, Mason JO, Price DJ. Pax6 limits the competence of developing cerebral cortical cells to respond to inductive intercellular signals. PLoS Biol 2022; 20:e3001563. [PMID: 36067211 PMCID: PMC9481180 DOI: 10.1371/journal.pbio.3001563] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 09/16/2022] [Accepted: 07/08/2022] [Indexed: 12/13/2022] Open
Abstract
The development of stable specialized cell types in multicellular organisms relies on mechanisms controlling inductive intercellular signals and the competence of cells to respond to such signals. In developing cerebral cortex, progenitors generate only glutamatergic excitatory neurons despite being exposed to signals with the potential to initiate the production of other neuronal types, suggesting that their competence is limited. Here, we tested the hypothesis that this limitation is due to their expression of transcription factor Pax6. We used bulk and single-cell RNAseq to show that conditional cortex-specific Pax6 deletion from the onset of cortical neurogenesis allowed some progenitors to generate abnormal lineages resembling those normally found outside the cortex. Analysis of selected gene expression showed that the changes occurred in specific spatiotemporal patterns. We then compared the responses of control and Pax6-deleted cortical cells to in vivo and in vitro manipulations of extracellular signals. We found that Pax6 loss increased cortical progenitors’ competence to generate inappropriate lineages in response to extracellular factors normally present in developing cortex, including the morphogens Shh and Bmp4. Regional variation in the levels of these factors could explain spatiotemporal patterns of fate change following Pax6 deletion in vivo. We propose that Pax6’s main role in developing cortical cells is to minimize the risk of their development being derailed by the potential side effects of morphogens engaged contemporaneously in other essential functions. The development of stable specialized cell types in multicellular organisms relies on mechanisms controlling inductive intercellular signals and the competence of cells to respond. This study shows that cortical development is stabilized by the protective actions of the transcription factor Pax6, which adjusts the ability of cortical cells to respond to potentially destabilizing signals present in their local environment.
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Affiliation(s)
- Martine Manuel
- Simons Initiative for the Developing Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, United Kingdom
| | - Kai Boon Tan
- Simons Initiative for the Developing Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, United Kingdom
| | - Zrinko Kozic
- Simons Initiative for the Developing Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, United Kingdom
| | - Michael Molinek
- Simons Initiative for the Developing Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, United Kingdom
| | - Tiago Sena Marcos
- Simons Initiative for the Developing Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, United Kingdom
| | - Maizatul Fazilah Abd Razak
- Simons Initiative for the Developing Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, United Kingdom
| | - Dániel Dobolyi
- Simons Initiative for the Developing Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, United Kingdom
| | - Ross Dobie
- Centre for Inflammation Research, University of Edinburgh, Queen’s Medical Research Institute, Edinburgh, United Kingdom
| | - Beth E. P. Henderson
- Centre for Inflammation Research, University of Edinburgh, Queen’s Medical Research Institute, Edinburgh, United Kingdom
| | - Neil C. Henderson
- Centre for Inflammation Research, University of Edinburgh, Queen’s Medical Research Institute, Edinburgh, United Kingdom
| | - Wai Kit Chan
- Simons Initiative for the Developing Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, United Kingdom
| | - Michael I. Daw
- Simons Initiative for the Developing Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, United Kingdom
- Zhejiang University-University of Edinburgh Institute, Zhejiang University, Haining, Zhejiang, People’s Republic of China
| | - John O. Mason
- Simons Initiative for the Developing Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, United Kingdom
| | - David J. Price
- Simons Initiative for the Developing Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, United Kingdom
- * E-mail:
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7
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Shimada IS, Kato Y. Ciliary signaling in stem cells in health and disease: Hedgehog pathway and beyond. Semin Cell Dev Biol 2022; 129:115-125. [PMID: 35466055 DOI: 10.1016/j.semcdb.2022.04.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 04/11/2022] [Accepted: 04/12/2022] [Indexed: 11/29/2022]
Abstract
The primary cilium is a hair-like sensory compartment that protrudes from the cellular surface. The primary cilium is enriched in a variety of signaling molecules that regulate cellular activities. Stem cells have primary cilia. They reside in a specialized environment, called the stem cell niche. This niche contains a variety of secreted factors, and some of their receptors are localized in the primary cilia of stem cells. Here, we summarize the current understanding of the function of cilia in compartmentalized signaling in stem cells. We describe how ciliary signaling regulates stem cells and progenitor cells during development, tissue homeostasis and tumorigenesis. We summarize our understanding of cilia regulated signaling -primary involving the hedgehog pathway- in stem cells in diverse settings that include neuroepithelial cells, radial glia, cerebellar granule neuron precursors, hematopoietic stem cells, hair follicle stem cells, bone marrow mesenchymal stem cells and mammary gland stem cells. Overall, our review highlights a variety of roles that ciliary signaling plays in regulating stem cells throughout life.
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Affiliation(s)
- Issei S Shimada
- Department of Cell Biology, Graduate School of Medical Sciences, Nagoya City University, 1 Azakawasumi, Mizuzho-cho, Mizuho-ku, Nagoya, 467-8601 Aichi, Japan.
| | - Yoichi Kato
- Department of Cell Biology, Graduate School of Medical Sciences, Nagoya City University, 1 Azakawasumi, Mizuzho-cho, Mizuho-ku, Nagoya, 467-8601 Aichi, Japan.
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8
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Makamte S, Thureau A, Jabrani A, Paquelin A, Plessis A, Sanial M, Rudenko O, Oteri F, Baaden M, Biou V. A large disordered region confers a wide spanning volume to vertebrate Suppressor of Fused as shown in a trans-species solution study. J Struct Biol 2022; 214:107853. [DOI: 10.1016/j.jsb.2022.107853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 03/10/2022] [Accepted: 03/24/2022] [Indexed: 10/18/2022]
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9
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Thomas DC, Moorthy JD, Prabhakar V, Ajayakumar A, Pitchumani PK. Role of primary cilia and Hedgehog signaling in craniofacial features of Ellis-van Creveld syndrome. AMERICAN JOURNAL OF MEDICAL GENETICS. PART C, SEMINARS IN MEDICAL GENETICS 2022; 190:36-46. [PMID: 35393766 DOI: 10.1002/ajmg.c.31969] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 03/13/2022] [Accepted: 03/22/2022] [Indexed: 06/14/2023]
Abstract
Ellis-van Creveld syndrome (EvC) is an autosomal recessive genetic disorder involving pathogenic variants of EVC and EVC2 genes and classified as a ciliopathy. The syndrome is caused by mutations in the EVC gene on chromosome 4p16, and EVC2 gene, located close to the EVC gene, in a head-to-head configuration. Regardless of the affliction of EVC or EVC2, the clinical features of Ellis-van Creveld syndrome are similar. Both these genes are expressed in tissues such as, but not limited to, the heart, liver, skeletal muscle, and placenta, while the predominant expression in the craniofacial tissues is that of EVC2. Biallelic mutations of EVC and EVC2 affect Hedgehog signaling and thereby ciliary function, crucial factors in vertebrate development, culminating in the phenotypical features characteristic of EvC. The clinical features of Ellis-van Creveld syndrome are consistent with significant abnormalities in morphogenesis and differentiation of the affected tissues. The robust role of primary cilia in histodifferentiation and morphodifferentiation of oral, perioral, and craniofacial tissues is becoming more evident in the most recent literature. In this review, we give a summary of the mechanistic role of primary cilia in craniofacial development, taking Ellis-van Creveld syndrome as a representative example.
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Affiliation(s)
- Davis C Thomas
- Center for TMD and Orofacial Pain, Rutgers School of Dental Medicine, Newark, New Jersey, USA
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10
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Hou S, Ho WL, Wang L, Kuo B, Park JY, Han YG. Biphasic Roles of Hedgehog Signaling in the Production and Self-Renewal of Outer Radial Glia in the Ferret Cerebral Cortex. Cereb Cortex 2021; 31:4730-4741. [PMID: 34002221 DOI: 10.1093/cercor/bhab119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The neocortex, the center for higher brain function, emerged in mammals and expanded in the course of evolution. The expansion of outer radial glia (oRGs) and intermediate progenitor cells (IPCs) plays key roles in the expansion and consequential folding of the neocortex. Therefore, understanding the mechanisms of oRG and IPC expansion is important for understanding neocortical development and evolution. By using mice and human cerebral organoids, we previously revealed that hedgehog (HH) signaling expands oRGs and IPCs. Nevertheless, it remained to be determined whether HH signaling expanded oRGs and IPCs in vivo in gyrencephalic species, in which oRGs and IPCs are naturally expanded. Here, we show that HH signaling is necessary and sufficient to expand oRGs and IPCs in ferrets, a gyrencephalic species, through conserved cellular mechanisms. HH signaling increases oRG-producing division modes of ventricular radial glia (vRGs), oRG self-renewal, and IPC proliferation. Notably, HH signaling affects vRG division modes only in an early restricted phase before superficial-layer neuron production peaks. Beyond this restricted phase, HH signaling promotes oRG self-renewal. Thus, HH signaling expands oRGs and IPCs in two distinct but continuous phases during cortical development.
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Affiliation(s)
- Shirui Hou
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Wan-Ling Ho
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.,School of Medicine, College of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan.,Department of Pediatrics, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan.,Department of Pediatrics, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.,Taipei Cancer Center, Taipei Medical University, Taipei, Taiwan.,Department of Pediatrics, Taipei Medical University Hospital, Taipei, Taiwan
| | - Lei Wang
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Bryan Kuo
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Jun Young Park
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Young-Goo Han
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
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11
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Zhang Y, Liu G, Guo T, Liang XG, Du H, Yang L, Bhaduri A, Li X, Xu Z, Zhang Z, Li Z, He M, Tsyporin J, Kriegstein AR, Rubenstein JL, Yang Z, Chen B. Cortical Neural Stem Cell Lineage Progression Is Regulated by Extrinsic Signaling Molecule Sonic Hedgehog. Cell Rep 2021; 30:4490-4504.e4. [PMID: 32234482 PMCID: PMC7197103 DOI: 10.1016/j.celrep.2020.03.027] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 12/07/2019] [Accepted: 03/11/2020] [Indexed: 02/07/2023] Open
Abstract
Neural stem cells (NSCs) in the prenatal neocortex progressively generate different subtypes of glutamatergic projection neurons. Following that, NSCs have a major switch in their progenitor properties and produce γ-aminobutyric acid (GABAergic) interneurons for the olfactory bulb (OB), cortical oligodendrocytes, and astrocytes. Herein, we provide evidence for the molecular mechanism that underlies this switch in the state of neocortical NSCs. We show that, at around E16.5, mouse neocortical NSCs start to generate GSX2-expressing (GSX2+) intermediate progenitor cells (IPCs). In vivo lineage-tracing study revealed that GSX2+ IPC population gives rise not only to OB interneurons but also to cortical oligodendrocytes and astrocytes, suggesting that they are a tri-potential population. We demonstrated that Sonic hedgehog signaling is both necessary and sufficient for the generation of GSX2+ IPCs by reducing GLI3R protein levels. Using single-cell RNA sequencing, we identify the transcriptional profile of GSX2+ IPCs and the process of the lineage switch of cortical NSCs. Zhang et al. reveal that cortical radial glia-derived GSX2+ cells at the late embryonic stage are tri-potential intermediate progenitors, which give rise to a subset of cortical oligodendrocytes, astrocytes, and olfactory bulb interneurons. SHH signaling is crucial for the generation of GSX2+ cells by reducing GLI3R protein level.
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Affiliation(s)
- Yue Zhang
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | - Guoping Liu
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute for Translational Brain Research, Institutes of Brain Science, Department of Neurology, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Teng Guo
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute for Translational Brain Research, Institutes of Brain Science, Department of Neurology, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Xiaoyi G Liang
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | - Heng Du
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute for Translational Brain Research, Institutes of Brain Science, Department of Neurology, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Lin Yang
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute for Translational Brain Research, Institutes of Brain Science, Department of Neurology, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Aparna Bhaduri
- Eli and Edythe Broad Center for Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Xiaosu Li
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute for Translational Brain Research, Institutes of Brain Science, Department of Neurology, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Zhejun Xu
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute for Translational Brain Research, Institutes of Brain Science, Department of Neurology, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Zhuangzhi Zhang
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute for Translational Brain Research, Institutes of Brain Science, Department of Neurology, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Zhenmeiyu Li
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute for Translational Brain Research, Institutes of Brain Science, Department of Neurology, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Miao He
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute for Translational Brain Research, Institutes of Brain Science, Department of Neurology, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Jeremiah Tsyporin
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | - Arnold R Kriegstein
- Eli and Edythe Broad Center for Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94143, USA
| | - John L Rubenstein
- Nina Ireland Laboratory of Developmental Neurobiology, Department of Psychiatry, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Zhengang Yang
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute for Translational Brain Research, Institutes of Brain Science, Department of Neurology, Zhongshan Hospital, Fudan University, Shanghai 200032, China.
| | - Bin Chen
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064, USA.
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12
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Zhou J, Lin Y, Huynh T, Noguchi H, Bush JO, Pleasure SJ. NMDA receptors control development of somatosensory callosal axonal projections. eLife 2021; 10:59612. [PMID: 33661095 PMCID: PMC7959694 DOI: 10.7554/elife.59612] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 02/22/2021] [Indexed: 11/25/2022] Open
Abstract
Callosal projections from primary somatosensory cortex (S1) are key for processing somatosensory inputs and integrating sensory-motor information. How the callosal innervation pattern in S1 is formed during early postnatal development is not clear. We found that the normal termination pattern of these callosal projections is disrupted in cortex specific NMDAR mutants. Rather than projecting selectively to the primary/secondary somatosensory cortex (S1/S2) border, axons were uniformly distributed throughout S1. In addition, the density of this projection increased over postnatal life until the mice died by P30. By combining genetic and antibody-mediated loss of function, we demonstrated that it is GluN2B-containing NMDA receptors in target S1 that mediate this guidance phenotype, thus playing a central role in interhemispheric connectivity. Furthermore, we found that this function of NMDA receptors in callosal circuit formation is independent of ion channel function and works with the EPHRIN-B/EPHB system. Thus, NMDAR in target S1 cortex regulates the formation callosal circuits perhaps by modulating EPH-dependent repulsion.
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Affiliation(s)
- Jing Zhou
- Department of Neurology, University of California, San Francisco, San Francisco, United States.,Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, United States
| | - Yong Lin
- Department of Neurology, University of California, San Francisco, San Francisco, United States.,Department of Neurological Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Trung Huynh
- Department of Neurology, University of California, San Francisco, San Francisco, United States.,Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, United States
| | - Hirofumi Noguchi
- Department of Neurology, University of California, San Francisco, San Francisco, United States.,Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, United States
| | - Jeffrey O Bush
- Department of Cell and Tissue Biology, Program in Craniofacial Biology and Institute for Human Genetics, University of California, San Francisco, San Francisco, United States.,Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, United States
| | - Samuel J Pleasure
- Department of Neurology, University of California, San Francisco, San Francisco, United States.,Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, United States.,Programs in Neuroscience and Developmental Stem Cell Biology, Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, Kavli Institute for Fundamental Neuroscience, San Francisco, United States
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13
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Yan Z, Cheng M, Hu G, Wang Y, Zeng S, Huang A, Xu L, Liu Y, Shi C, Deng L, Lu Q, Rao H, Lu H, Chen YG, Luo S. Positive feedback of SuFu negating protein 1 on Hedgehog signaling promotes colorectal tumor growth. Cell Death Dis 2021; 12:199. [PMID: 33608498 PMCID: PMC7896051 DOI: 10.1038/s41419-021-03487-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 01/27/2021] [Accepted: 01/28/2021] [Indexed: 12/15/2022]
Abstract
Hedgehog (Hh) signaling plays a critical role in embryogenesis and tissue homeostasis, and its deregulation has been associated with tumor growth. The tumor suppressor SuFu inhibits Hh signaling by preventing the nuclear translocation of Gli and suppressing cell proliferation. Regulation of SuFu activity and stability is key to controlling Hh signaling. Here, we unveil SuFu Negating Protein 1 (SNEP1) as a novel Hh target, that enhances the ubiquitination and proteasomal degradation of SuFu and thus promotes Hh signaling. We further show that the E3 ubiquitin ligase LNX1 plays a critical role in the SNEP1-mediated degradation of SuFu. Accordingly, SNEP1 promotes colorectal cancer (CRC) cell proliferation and tumor growth. High levels of SNEP1 are detected in CRC tissues and are well correlated with poor prognosis in CRC patients. Moreover, SNEP1 overexpression reduces sensitivity to anti-Hh inhibitor in CRC cells. Altogether, our findings demonstrate that SNEP1 acts as a novel feedback regulator of Hh signaling by destabilizing SuFu and promoting tumor growth and anti-Hh resistance.
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Affiliation(s)
- Zhengwei Yan
- Center for Experimental Medicine, The First Affiliated Hospital of Nanchang University, 330006, Nanchang, Jiangxi, China
| | - Minzhang Cheng
- Center for Experimental Medicine, The First Affiliated Hospital of Nanchang University, 330006, Nanchang, Jiangxi, China
| | - Guohui Hu
- Center for Experimental Medicine, The First Affiliated Hospital of Nanchang University, 330006, Nanchang, Jiangxi, China
| | - Yao Wang
- Center for Experimental Medicine, The First Affiliated Hospital of Nanchang University, 330006, Nanchang, Jiangxi, China
- Guangzhou Jinan Biomedicine Research and Development Center, College of Life Science and Technology, Jinan University, 510632, Guangzhou, Guangdong, China
| | - Shaopeng Zeng
- Center for Experimental Medicine, The First Affiliated Hospital of Nanchang University, 330006, Nanchang, Jiangxi, China
| | - Aidi Huang
- Center for Experimental Medicine, The First Affiliated Hospital of Nanchang University, 330006, Nanchang, Jiangxi, China
| | - Linlin Xu
- Center for Experimental Medicine, The First Affiliated Hospital of Nanchang University, 330006, Nanchang, Jiangxi, China
| | - Yuan Liu
- The State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, 100084, Beijing, China
| | - Chao Shi
- Center for Experimental Medicine, The First Affiliated Hospital of Nanchang University, 330006, Nanchang, Jiangxi, China
| | - Libin Deng
- Basic Medical College, Nanchang University, 330006, Nanchang, Jiangxi, China
| | - Quqin Lu
- Department of Biostatistics and Epidemiology, School of Public Health, Nanchang University, 330006, Nanchang, Jiangxi, China
| | - Hai Rao
- Department of Molecular Medicine, The University of Texas Health, San Antonio, TX, 78229, USA
| | - Hua Lu
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, New Orleans, LA, 70112, USA
- Tulane Cancer Center, Tulane University School of Medicine, New Orleans, LA, 70112, USA
| | - Ye-Guang Chen
- The State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, 100084, Beijing, China.
| | - Shiwen Luo
- Center for Experimental Medicine, The First Affiliated Hospital of Nanchang University, 330006, Nanchang, Jiangxi, China.
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14
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Hasenpusch-Theil K, Theil T. The Multifaceted Roles of Primary Cilia in the Development of the Cerebral Cortex. Front Cell Dev Biol 2021; 9:630161. [PMID: 33604340 PMCID: PMC7884624 DOI: 10.3389/fcell.2021.630161] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 01/11/2021] [Indexed: 12/12/2022] Open
Abstract
The primary cilium, a microtubule based organelle protruding from the cell surface and acting as an antenna in multiple signaling pathways, takes center stage in the formation of the cerebral cortex, the part of the brain that performs highly complex neural tasks and confers humans with their unique cognitive capabilities. These activities require dozens of different types of neurons that are interconnected in complex ways. Due to this complexity, corticogenesis has been regarded as one of the most complex developmental processes and cortical malformations underlie a number of neurodevelopmental disorders such as intellectual disability, autism spectrum disorders, and epilepsy. Cortical development involves several steps controlled by cell–cell signaling. In fact, recent findings have implicated cilia in diverse processes such as neurogenesis, neuronal migration, axon pathfinding, and circuit formation in the developing cortex. Here, we will review recent advances on the multiple roles of cilia during cortex formation and will discuss the implications for a better understanding of the disease mechanisms underlying neurodevelopmental disorders.
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Affiliation(s)
- Kerstin Hasenpusch-Theil
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom.,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, United Kingdom
| | - Thomas Theil
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom.,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, United Kingdom
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15
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Andreu-Cervera A, Catala M, Schneider-Maunoury S. Cilia, ciliopathies and hedgehog-related forebrain developmental disorders. Neurobiol Dis 2020; 150:105236. [PMID: 33383187 DOI: 10.1016/j.nbd.2020.105236] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 12/18/2020] [Accepted: 12/26/2020] [Indexed: 02/07/2023] Open
Abstract
Development of the forebrain critically depends on the Sonic Hedgehog (Shh) signaling pathway, as illustrated in humans by the frequent perturbation of this pathway in holoprosencephaly, a condition defined as a defect in the formation of midline structures of the forebrain and face. The Shh pathway requires functional primary cilia, microtubule-based organelles present on virtually every cell and acting as cellular antennae to receive and transduce diverse chemical, mechanical or light signals. The dysfunction of cilia in humans leads to inherited diseases called ciliopathies, which often affect many organs and show diverse manifestations including forebrain malformations for the most severe forms. The purpose of this review is to provide the reader with a framework to understand the developmental origin of the forebrain defects observed in severe ciliopathies with respect to perturbations of the Shh pathway. We propose that many of these defects can be interpreted as an imbalance in the ratio of activator to repressor forms of the Gli transcription factors, which are effectors of the Shh pathway. We also discuss the complexity of ciliopathies and their relationships with forebrain disorders such as holoprosencephaly or malformations of cortical development, and emphasize the need for a closer examination of forebrain defects in ciliopathies, not only through the lens of animal models but also taking advantage of the increasing potential of the research on human tissues and organoids.
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Affiliation(s)
- Abraham Andreu-Cervera
- Sorbonne Université, Centre National de la Recherche Scientifique (CNRS) UMR7622, Institut national pour la Santé et la Recherche Médicale (Inserm) U1156, Institut de Biologie Paris Seine - Laboratoire de Biologie du Développement (IBPS-LBD), 9 Quai Saint-Bernard, 75005 Paris, France; Instituto de Neurociencias, Universidad Miguel Hernández - CSIC, Campus de San Juan; Avda. Ramón y Cajal s/n, 03550 Alicante, Spain
| | - Martin Catala
- Sorbonne Université, Centre National de la Recherche Scientifique (CNRS) UMR7622, Institut national pour la Santé et la Recherche Médicale (Inserm) U1156, Institut de Biologie Paris Seine - Laboratoire de Biologie du Développement (IBPS-LBD), 9 Quai Saint-Bernard, 75005 Paris, France.
| | - Sylvie Schneider-Maunoury
- Sorbonne Université, Centre National de la Recherche Scientifique (CNRS) UMR7622, Institut national pour la Santé et la Recherche Médicale (Inserm) U1156, Institut de Biologie Paris Seine - Laboratoire de Biologie du Développement (IBPS-LBD), 9 Quai Saint-Bernard, 75005 Paris, France.
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16
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Ferent J, Zaidi D, Francis F. Extracellular Control of Radial Glia Proliferation and Scaffolding During Cortical Development and Pathology. Front Cell Dev Biol 2020; 8:578341. [PMID: 33178693 PMCID: PMC7596222 DOI: 10.3389/fcell.2020.578341] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 09/08/2020] [Indexed: 01/14/2023] Open
Abstract
During the development of the cortex, newly generated neurons migrate long-distances in the expanding tissue to reach their final positions. Pyramidal neurons are produced from dorsal progenitors, e.g., radial glia (RGs) in the ventricular zone, and then migrate along RG processes basally toward the cortex. These neurons are hence dependent upon RG extensions to support their migration from apical to basal regions. Several studies have investigated how intracellular determinants are required for RG polarity and subsequent formation and maintenance of their processes. Fewer studies have identified the influence of the extracellular environment on this architecture. This review will focus on extracellular factors which influence RG morphology and pyramidal neuronal migration during normal development and their perturbations in pathology. During cortical development, RGs are present in different strategic positions: apical RGs (aRGs) have their cell bodies located in the ventricular zone with an apical process contacting the ventricle, while they also have a basal process extending radially to reach the pial surface of the cortex. This particular conformation allows aRGs to be exposed to long range and short range signaling cues, whereas basal RGs (bRGs, also known as outer RGs, oRGs) have their cell bodies located throughout the cortical wall, limiting their access to ventricular factors. Long range signals impacting aRGs include secreted molecules present in the embryonic cerebrospinal fluid (e.g., Neuregulin, EGF, FGF, Wnt, BMP). Secreted molecules also contribute to the extracellular matrix (fibronectin, laminin, reelin). Classical short range factors include cell to cell signaling, adhesion molecules and mechano-transduction mechanisms (e.g., TAG1, Notch, cadherins, mechanical tension). Changes in one or several of these components influencing the RG extracellular environment can disrupt the development or maintenance of RG architecture on which neuronal migration relies, leading to a range of cortical malformations. First, we will detail the known long range signaling cues impacting RG. Then, we will review how short range cell contacts are also important to instruct the RG framework. Understanding how RG processes are structured by their environment to maintain and support radial migration is a critical part of the investigation of neurodevelopmental disorders.
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Affiliation(s)
- Julien Ferent
- Inserm, U 1270, Paris, France.,Sorbonne University, UMR-S 1270, IFM, Paris, France.,Institut du Fer á Moulin, Paris, France
| | - Donia Zaidi
- Inserm, U 1270, Paris, France.,Sorbonne University, UMR-S 1270, IFM, Paris, France.,Institut du Fer á Moulin, Paris, France
| | - Fiona Francis
- Inserm, U 1270, Paris, France.,Sorbonne University, UMR-S 1270, IFM, Paris, France.,Institut du Fer á Moulin, Paris, France
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17
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The Neocortical Progenitor Specification Program Is Established through Combined Modulation of SHH and FGF Signaling. J Neurosci 2020; 40:6872-6887. [PMID: 32737167 DOI: 10.1523/jneurosci.2888-19.2020] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 06/22/2020] [Accepted: 07/18/2020] [Indexed: 12/21/2022] Open
Abstract
Neuronal progenitors in the developing forebrain undergo dynamic competence states to ensure timely generation of specific excitatory and inhibitory neuronal subtypes from distinct neurogenic niches of the dorsal and ventral forebrain, respectively. Here we show evidence of progenitor plasticity when Sonic hedgehog (SHH) signaling is left unmodulated in the embryonic neocortex of the mammalian dorsal forebrain. We found that, at early stages of corticogenesis, loss of Suppressor of Fused (Sufu), a potent inhibitor of SHH signaling, in neocortical progenitors, altered the transcriptomic landscape of male mouse embryos. Ectopic activation of SHH signaling occurred, via degradation of Gli3R, resulting in significant upregulation of fibroblast growth factor 15 (FGF15) gene expression in all E12.5 Sufu-cKO neocortex regardless of sex. Consequently, activation of FGF signaling, and its downstream effector the MAPK signaling, facilitated expression of genes characteristic of ventral forebrain progenitors. Our studies identify the importance of modulating extrinsic niche signals such as SHH and FGF15, to maintain the competency and specification program of neocortical progenitors throughout corticogenesis.SIGNIFICANCE STATEMENT Low levels of FGF15 control progenitor proliferation and differentiation during neocortical development, but little is known on how FGF15 expression is maintained. Our studies identified SHH signaling as a critical activator of FGF15 expression during corticogenesis. We found that Sufu, via Gli3R, ensured low levels of FGF15 was expressed to prevent abnormal specification of neocortical progenitors. These studies advance our knowledge on the molecular mechanisms guiding the generation of specific neocortical neuronal lineages, their implications in neurodevelopmental diseases, and may guide future studies on how progenitor cells may be used for brain repair.
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18
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Suciu SK, Caspary T. Cilia, neural development and disease. Semin Cell Dev Biol 2020; 110:34-42. [PMID: 32732132 DOI: 10.1016/j.semcdb.2020.07.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 07/17/2020] [Accepted: 07/18/2020] [Indexed: 12/16/2022]
Abstract
Neural development requires a series of cellular events starting with cell specification, proliferation, and migration. Subsequently, axons and dendrites project from the cell surface to form connections to other neurons, interneurons and glia. Anomalies in any one of these steps can lead to malformation or malfunction of the nervous system. Here we review the critical role the primary cilium plays in the fundamental steps of neurodevelopment. By highlighting human diseases caused by mutations in cilia-associated proteins, it is clear that cilia are essential to multiple neural processes. Furthermore, we explore whether additional aspects of cilia regulation, most notably post-translational modification of the tubulin scaffold in cilia, play underappreciated roles in neural development. Finally, we discuss whether cilia-associated proteins function outside the cilium in some aspects of neurodevelopment. These data underscore both the importance of cilia in the nervous system and some outstanding questions in the field.
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Affiliation(s)
- Sarah K Suciu
- Genetics and Molecular Biology Graduate Program, USA; Department of Human Genetics, Emory University, Atlanta, GA 30322, Georgia
| | - Tamara Caspary
- Department of Human Genetics, Emory University, Atlanta, GA 30322, Georgia.
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19
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The Elegance of Sonic Hedgehog: Emerging Novel Functions for a Classic Morphogen. J Neurosci 2019; 38:9338-9345. [PMID: 30381425 DOI: 10.1523/jneurosci.1662-18.2018] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 09/27/2018] [Accepted: 09/28/2018] [Indexed: 12/12/2022] Open
Abstract
Sonic Hedgehog (SHH) signaling has been most widely known for its role in specifying region and cell-type identity during embryonic morphogenesis. This mini-review accompanies a 2018 SFN mini-symposium that addresses an emerging body of research focused on understanding the diverse roles for Shh signaling in a wide range of contexts in neurodevelopment and, more recently, in the mature CNS. Such research shows that Shh affects the function of brain circuits, including the production and maintenance of diverse cell types and the establishment of wiring specificity. Here, we review these novel and unexpected functions and the unanswered questions regarding the role of SHH and its signaling pathway members in these cases.
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20
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Gomez HG, Noguchi H, Castillo JG, Aguilar D, Pleasure SJ, Yabut OR. Suppressor of Fused regulates the proliferation of postnatal neural stem and precursor cells via a Gli3-dependent mechanism. Biol Open 2019; 8:bio.039248. [PMID: 31142467 PMCID: PMC6602331 DOI: 10.1242/bio.039248] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The ventricular-subventricular zone (V-SVZ) of the forebrain is the source of neurogenic stem/precursor cells for adaptive and homeostatic needs throughout the life of most mammals. Here, we report that Suppressor of Fused (Sufu) plays a critical role in the establishment of the V-SVZ at early neonatal stages by controlling the proliferation of distinct subpopulations of stem/precursor cells. Conditional deletion of Sufu in radial glial progenitor cells (RGCs) at E13.5 resulted in a dramatic increase in the proliferation of Sox2+ Type B1 cells. In contrast, we found a significant decrease in Gsx2+ and a more dramatic decrease in Tbr2+ transit amplifying cells (TACs) indicating that innate differences between dorsal and ventral forebrain derived Type B1 cells influence Sufu function. However, many precursors accumulated in the dorsal V-SVZ or failed to survive, demonstrating that despite the over-proliferation of Type B1 cells, they are unable to transition into functional differentiated progenies. These defects were accompanied by reduced Gli3 expression and surprisingly, a significant downregulation of Sonic hedgehog (Shh) signaling. Therefore, these findings indicate a potential role of the Sufu-Gli3 regulatory axis in the neonatal dorsal V-SVZ independent of Shh signaling in the establishment and survival of functional stem/precursor cells in the postnatal dorsal V-SVZ. Summary: Conditional deletion of Sufu causes dramatic expansion of neural stem/precursor cells in the neonatal ventricular-subventricular (SVZ) zone. This defect occurs through a Gli3-dependent mechanism resulting in the downregulation of Shh signaling.
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Affiliation(s)
| | | | | | | | - Samuel J Pleasure
- Department of Neurology .,Programs in Neuroscience and Developmental Biology, Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, California 94143, USA
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21
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Noguchi H, Castillo JG, Nakashima K, Pleasure SJ. Suppressor of fused controls perinatal expansion and quiescence of future dentate adult neural stem cells. eLife 2019; 8:42918. [PMID: 30973324 PMCID: PMC6459675 DOI: 10.7554/elife.42918] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 03/28/2019] [Indexed: 12/18/2022] Open
Abstract
Adult hippocampal neurogenesis requires the quiescent neural stem cell (NSC) pool to persist lifelong. However, establishment and maintenance of quiescent NSC pools during development is not understood. Here, we show that Suppressor of Fused (Sufu) controls establishment of the quiescent NSC pool during mouse dentate gyrus (DG) development by regulating Sonic Hedgehog (Shh) signaling activity. Deletion of Sufu in NSCs early in DG development decreases Shh signaling activity leading to reduced proliferation of NSCs, resulting in a small quiescent NSC pool in adult mice. We found that putative adult NSCs proliferate and increase their numbers in the first postnatal week and subsequently enter a quiescent state towards the end of the first postnatal week. In the absence of Sufu, postnatal expansion of NSCs is compromised, and NSCs prematurely become quiescent. Thus, Sufu is required for Shh signaling activity ensuring expansion and proper transition of NSC pools to quiescent states during DG development.
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Affiliation(s)
- Hirofumi Noguchi
- Department of Neurology, University of California, San Francisco, San Francisco, United States
| | - Jesse Garcia Castillo
- Department of Neurology, University of California, San Francisco, San Francisco, United States
| | - Kinichi Nakashima
- Department of Stem Cell Biology and Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Samuel J Pleasure
- Programs in Neuroscience and Developmental Biology, Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, United States
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22
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Derepression of sonic hedgehog signaling upon Gpr161 deletion unravels forebrain and ventricular abnormalities. Dev Biol 2019; 450:47-62. [PMID: 30914320 DOI: 10.1016/j.ydbio.2019.03.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Revised: 03/12/2019] [Accepted: 03/17/2019] [Indexed: 11/24/2022]
Abstract
Inverse gradients of transcriptional repressors antagonize the transcriptional effector response to morphogens. However, the role of such inverse regulation might not manifest solely from lack of repressors. Sonic hedgehog (Shh) patterns the forebrain by being expressed ventrally; however, absence of antagonizing Gli3 repressor paradoxically cause insufficient pathway activation. Interestingly, lack of the primary cilia-localized G-protein-coupled receptor, Gpr161 increases Shh signaling in the mouse neural tube from coordinated lack of Gli3 repressor and Smoothened-independent activation. Here, by deleting Gpr161 in mouse neuroepithelial cells and radial glia at early mid-gestation we detected derepression of Shh signaling throughout forebrain, allowing determination of the pathophysiological consequences. Accumulation of cerebrospinal fluid (hydrocephalus) was apparent by birth, although usual causative defects in multiciliated ependymal cells or aqueduct were not seen. Rather, the ventricular surface was expanded (ventriculomegaly) during embryogenesis from radial glial overproliferation. Cortical phenotypes included polymicrogyria in the medial cingulate cortex, increased proliferation of intermediate progenitors and basal radial glia, and altered neocortical cytoarchitectonic structure with increased upper layer and decreased deep layer neurons. Finally, periventricular nodular heterotopia resulted from disrupted neuronal migration, while the radial glial scaffold was unaffected. Overall, suppression of Shh pathway during early mid-gestation prevents ventricular overgrowth, and regulates cortical gyration and neocortical/periventricular cytoarchitecture.
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23
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Yabut OR, Pleasure SJ. Sonic Hedgehog Signaling Rises to the Surface: Emerging Roles in Neocortical Development. Brain Plast 2018; 3:119-128. [PMID: 30151337 PMCID: PMC6091060 DOI: 10.3233/bpl-180064] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The mammalian neocortex is composed of a diverse population of neuronal and glial cells that are crucial for cognition and consciousness. Orchestration of molecular events that lead to the production of distinct cell lineages is now a major research focus. Recent studies in mammalian animal models reveal that Sonic Hedgehog (Shh) signaling plays crucial roles in this process. In this review, we will evaluate these studies and provide insights on how Shh signaling specifically influence cortical development, beyond its established roles in telencephalic patterning, by specifically focusing on its impact on cells derived from the cortical radial glial (RG) cells. We will also assess how these findings further advance our knowledge of neurological diseases and discuss potential roles of targeting Shh signaling in therapies.
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Affiliation(s)
- Odessa R Yabut
- Department of Neurology, University of California San Francisco, San Francisco, CA, USA.,Weill Institute for Neurosciences, University of California San Francisco, San Francisco, CA, USA
| | - Samuel J Pleasure
- Department of Neurology, University of California San Francisco, San Francisco, CA, USA.,Weill Institute for Neurosciences, University of California San Francisco, San Francisco, CA, USA.,Programs in Neuroscience and Developmental Biology, Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, Kavli Institute for Fundamental Neuroscience, University of California San Francisco, CA, USA
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24
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The Dorsal Wave of Neocortical Oligodendrogenesis Begins Embryonically and Requires Multiple Sources of Sonic Hedgehog. J Neurosci 2018; 38:5237-5250. [PMID: 29739868 DOI: 10.1523/jneurosci.3392-17.2018] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 04/23/2018] [Accepted: 04/26/2018] [Indexed: 01/06/2023] Open
Abstract
Neural progenitor cells in the developing dorsal forebrain give rise to excitatory neurons, astrocytes, and oligodendrocytes for the neocortex. While we are starting to gain a better understanding about the mechanisms that direct the formation of neocortical neurons and astrocytes, far less is known about the molecular mechanisms that instruct dorsal forebrain progenitors to make oligodendrocytes. In this study, we show that Sonic hedgehog (Shh) signaling is required in dorsal progenitors for their late embryonic transition to oligodendrogenesis. Using genetic lineage-tracing in mice of both sexes, we demonstrate that most oligodendrocytes in the embryonic neocortex derive from Emx1+ dorsal forebrain progenitors. Deletion of the Shh signaling effector Smo specifically in Emx1+ progenitors led to significantly decreased oligodendrocyte numbers in the embryonic neocortex. Conversely, knock-out of the Shh antagonist Sufu was sufficient to increase neocortical oligodendrogenesis. Using conditional knock-out strategies, we found that Shh ligand is supplied to dorsal progenitors through multiple sources. Loss of Shh from Dlx5/6+ interneurons caused a significant reduction in oligodendrocytes in the embryonic neocortex. This phenotype was identical to that observed upon Shh deletion from the entire CNS using Nestin-Cre, indicating that interneurons migrating into the neocortex from the subpallium are the primary neural source of Shh for dorsal oligodendrogenesis. Additionally, deletion of Shh from migrating interneurons together with the choroid plexus epithelium led to a more severe loss of oligodendrocytes, suggesting that the choroid plexus is an important non-neural source of Shh ligand. Together, our studies demonstrate that the dorsal wave of neocortical oligodendrogenesis occurs earlier than previously appreciated and requires highly regulated Shh signaling from multiple embryonic sources.SIGNIFICANCE STATEMENT Most neocortical oligodendrocytes are made by neural progenitors in the dorsal forebrain, but the mechanisms that specify this fate are poorly understood. This study identifies Sonic hedgehog (Shh) signaling as a critical pathway in the transition from neurogenesis to oligodendrogenesis in dorsal forebrain progenitors during late embryonic development. The timing of this neuron-to-glia "switch" coincides with the arrival of migrating interneurons into the dorsal germinal zone, which we identify as a critical source of Shh ligand, which drives oligodendrogenesis. Our data provide evidence for a new model in which Shh signaling increases in the dorsal forebrain late in embryonic development to provide a temporally regulated mechanism that initiates the third wave of neocortical oligodendrogenesis.
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25
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Agirman G, Broix L, Nguyen L. Cerebral cortex development: an outside‐in perspective. FEBS Lett 2017; 591:3978-3992. [DOI: 10.1002/1873-3468.12924] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 11/17/2017] [Accepted: 11/28/2017] [Indexed: 12/18/2022]
Affiliation(s)
- Gulistan Agirman
- GIGA‐Neurosciences Interdisciplinary Cluster for Applied Genoproteomics (GIGA‐R) Liège Belgium
| | - Loïc Broix
- GIGA‐Neurosciences Interdisciplinary Cluster for Applied Genoproteomics (GIGA‐R) Liège Belgium
| | - Laurent Nguyen
- GIGA‐Neurosciences Interdisciplinary Cluster for Applied Genoproteomics (GIGA‐R) Liège Belgium
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26
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The Many Hats of Sonic Hedgehog Signaling in Nervous System Development and Disease. J Dev Biol 2016; 4:jdb4040035. [PMID: 29615598 PMCID: PMC5831807 DOI: 10.3390/jdb4040035] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Revised: 11/17/2016] [Accepted: 11/29/2016] [Indexed: 02/06/2023] Open
Abstract
Sonic hedgehog (Shh) signaling occurs concurrently with the many processes that constitute nervous system development. Although Shh is mostly known for its proliferative and morphogenic action through its effects on neural stem cells and progenitors, it also contributes to neuronal differentiation, axonal pathfinding and synapse formation and function. To participate in these diverse events, Shh signaling manifests differently depending on the maturational state of the responsive cell, on the other signaling pathways regulating neural cell function and the environmental cues that surround target cells. Shh signaling is particularly dynamic in the nervous system, ranging from canonical transcription-dependent, to non-canonical and localized to axonal growth cones. Here, we review the variety of Shh functions in the developing nervous system and their consequences for neurodevelopmental diseases and neural regeneration, with particular emphasis on the signaling mechanisms underlying Shh action.
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27
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Han YG. Sonic hedgehog signaling: A conserved mechanism for the expansion of outer radial glia and intermediate progenitor cells and for the growth and folding of the neocortex. NEUROGENESIS 2016; 3:e1242957. [PMID: 28255571 PMCID: PMC5325666 DOI: 10.1080/23262133.2016.1242957] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 09/12/2016] [Accepted: 09/25/2016] [Indexed: 11/23/2022]
Abstract
The expansion of outer radial glia (oRGs, also called basal RGs) and intermediate progenitor cells (IPCs) has played a key role in the evolutionary expansion and folding of the neocortex, resulting in superior sensorimotor and cognitive abilities. In particular, oRGs, which are critical for both the increased production and lateral dispersion of neurons, are rare in lisencephalic species but vastly expanded in gyrencephalic species. However, the mechanisms that expand oRGs and IPCs are not well understood. We recently identified Sonic hedgehog (Shh) signaling as the first known signaling pathway necessary and sufficient to expand both oRGs and IPCs. Elevated Shh signaling in the embryonic neocortex leads to neocortical expansion and folding with normal cytoarchitecture in otherwise smooth mouse neocortex, whereas the loss of Shh signaling decreases oRGs, IPCs, and neocortical size. We also showed that SHH signaling activity in fetal neocortex is stronger in humans than in mice and that blocking SHH signaling decreases oRGs in human cerebral organoids. Shh signaling may be a conserved mechanism that promotes oRG and IPC expansion, driving neocortical growth and folding in humans and other species. Understanding the mechanisms underlying species-specific differences in Shh signaling activity and how Shh signaling expands oRGs and IPCs will provide insights into the mechanisms of neocortical development and evolution.
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Affiliation(s)
- Young-Goo Han
- Department of Developmental Neurobiology, Neurobiology and Brain Tumor Program, St. Jude Children's Research Hospital , Memphis, TN, USA
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28
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Abstract
Neural progenitors in the embryonic neocortex must be tightly regulated in order to generate the correct number and projection neuron subtypes necessary for the formation of functional neocortical circuits. In this study, we show that the intracellular protein Suppressor of Fused (Sufu) regulates the proliferation of intermediate progenitor (IP) cells at later stages of corticogenesis to affect the number of Cux1+ upper layer neurons in the postnatal neocortex. This correlates with abnormal levels of the repressor form of Gli3 (Gli3R) and the ectopic expression of Patched 1 (Ptch1), a Sonic Hedgehog (Shh) target gene. These studies reveal that the canonical role of Sufu as an inhibitor of Shh signaling is conserved at later stages of corticogenesis and that Sufu plays a crucial role in regulating neuronal number by controlling the cell cycle dynamics of IP cells in the embryonic neocortex.
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29
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Wang L, Hou S, Han YG. Hedgehog signaling promotes basal progenitor expansion and the growth and folding of the neocortex. Nat Neurosci 2016; 19:888-96. [PMID: 27214567 PMCID: PMC4925239 DOI: 10.1038/nn.4307] [Citation(s) in RCA: 119] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 04/27/2016] [Indexed: 12/16/2022]
Abstract
The unique mental abilities of humans are rooted in the immensely expanded and folded neocortex, which reflects the expansion of neural progenitors, especially basal progenitors including basal radial glia (bRGs, also called outer RGs) and intermediate progenitor cells (IPCs). Here, we show that constitutively active Shh signaling expanded bRGs and IPCs and induced folding in the otherwise smooth mouse neocortex, whereas the loss of Shh signaling decreased the number of bRGs and IPCs and the size of the neocortex. SHH signaling was strongly active in the human fetal neocortex but not in the mouse embryonic neocortex, and blocking SHH signaling in human cerebral organoids decreased the number of bRGs. Mechanistically, Shh signaling increased the initial generation and self-renewal of bRGs as well as increasing IPC proliferation. Thus, robust SHH signaling in the human fetal neocortex may contribute to bRG and IPC expansion and neocortical growth and folding.
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Affiliation(s)
- Lei Wang
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA.,Division of Brain Tumor Research, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Shirui Hou
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA.,Division of Brain Tumor Research, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Young-Goo Han
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA.,Division of Brain Tumor Research, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
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