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Tanjore Ramanathan J, Zárybnický T, Filppu P, Monzo HJ, Monni O, Tervonen TA, Klefström J, Kerosuo L, Kuure S, Laakkonen P. Immunoglobulin superfamily member 3 is required for the vagal neural crest cell migration and enteric neuronal network organization. Sci Rep 2023; 13:17162. [PMID: 37821496 PMCID: PMC10567708 DOI: 10.1038/s41598-023-44093-8] [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: 03/07/2023] [Accepted: 10/03/2023] [Indexed: 10/13/2023] Open
Abstract
The immunoglobulin (Ig) superfamily members are involved in cell adhesion and migration, complex multistep processes that play critical roles in embryogenesis, wound healing, tissue formation, and many other processes, but their specific functions during embryonic development remain unclear. Here, we have studied the function of the immunoglobulin superfamily member 3 (IGSF3) by generating an Igsf3 knockout (KO) mouse model with CRISPR/Cas9-mediated genome engineering. By combining RNA and protein detection methodology, we show that during development, IGSF3 localizes to the neural crest and a subset of its derivatives, suggesting a role in normal embryonic and early postnatal development. Indeed, inactivation of Igsf3 impairs the ability of the vagal neural crest cells to migrate and normally innervate the intestine. The small intestine of Igsf3 KO mice shows reduced thickness of the muscularis externa and diminished number of enteric neurons. Also, misalignment of neurons and smooth muscle cells in the developing intestinal villi is detected. Taken together, our results suggest that IGSF3 functions contribute to the formation of the enteric nervous system. Given the essential role of the enteric nervous system in maintaining normal gastrointestinal function, our study adds to the pool of information required for further understanding the mechanisms of gut innervation and etiology behind bowel motility disorders.
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Affiliation(s)
| | - Tomáš Zárybnický
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Pauliina Filppu
- Translational Cancer Medicine Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Hector J Monzo
- Translational Cancer Medicine Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Outi Monni
- Applied Tumor Genomics Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Topi A Tervonen
- Translational Cancer Medicine Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- Finnish genome editing center (FinGEEC), Helsinki Institute of Life Science (HiLIFE), University of Helsinki, Helsinki, Finland
| | - Juha Klefström
- Translational Cancer Medicine Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- Finnish Cancer Institute & FICAN South, Helsinki University Hospital (HUS), Helsinki, Finland
| | - Laura Kerosuo
- Neural Crest Development and Disease Unit, Department of Health and Human Services, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, 20892, USA.
| | - Satu Kuure
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland.
- GM-unit, Helsinki Institute of Life Science (HiLIFE), University of Helsinki, Helsinki, Finland.
| | - Pirjo Laakkonen
- Translational Cancer Medicine Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland.
- iCAN Flagship Program, University of Helsinki, Helsinki, Finland.
- Laboratory Animal Centre, Helsinki Institute of Life Science (HiLIFE), University of Helsinki, Helsinki, Finland.
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2
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Panebianco CJ, Dave A, Charytonowicz D, Sebra R, Iatridis JC. Single-cell RNA-sequencing atlas of bovine caudal intervertebral discs: Discovery of heterogeneous cell populations with distinct roles in homeostasis. FASEB J 2021; 35:e21919. [PMID: 34591994 DOI: 10.1096/fj.202101149r] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 08/19/2021] [Accepted: 08/31/2021] [Indexed: 12/25/2022]
Abstract
Back and neck pain are significant healthcare burdens that are commonly associated with pathologies of the intervertebral disc (IVD). The poor understanding of the cellular heterogeneity within the IVD makes it difficult to develop regenerative IVD therapies. To address this gap, we developed an atlas of bovine (Bos taurus) caudal IVDs using single-cell RNA-sequencing (scRNA-seq). Unsupervised clustering resolved 15 unique clusters, which we grouped into the following annotated partitions: nucleus pulposus (NP), outer annulus fibrosus (oAF), inner AF (iAF), notochord, muscle, endothelial, and immune cells. Analyzing the pooled gene expression profiles of the NP, oAF, and iAF partitions allowed us to identify novel markers for NP (CP, S100B, H2AC18, SNORC, CRELD2, PDIA4, DNAJC3, CHCHD7, and RCN2), oAF (IGFBP6, CTSK, LGALS1, and CCN3), and iAF (MGP, COMP, SPP1, GSN, SOD2, DCN, FN1, TIMP3, WDR73, and GAL) cells. Network analysis on subpopulations of NP and oAF cells determined that clusters NP1, NP2, NP4, and oAF1 displayed gene expression profiles consistent with cell survival, suggesting these clusters may uniquely support viability under the physiological stresses of the IVD. Clusters NP3, NP5, oAF2, and oAF3 expressed various extracellular matrix (ECM)-associated genes, suggesting their role in maintaining IVD structure. Lastly, transcriptional entropy and pseudotime analyses found that clusters NP3 and NP1 had the most stem-like gene expression signatures of the NP partition, implying these clusters may contain IVD progenitor cells. Overall, results highlight cell type diversity within the IVD, and these novel cell phenotypes may enhance our understanding of IVD development, homeostasis, degeneration, and regeneration.
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Affiliation(s)
- Christopher J Panebianco
- Leni and Peter W. May Department of Orthopaedics, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Arpit Dave
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Daniel Charytonowicz
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Robert Sebra
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA.,Icahn Institute for Data Science and Genomics Technology, Icahn School of Medicine at Mount Sinai, New York, New York, USA.,Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA.,Sema4, a Mount Sinai venture, Stamford, Connecticut, USA
| | - James C Iatridis
- Leni and Peter W. May Department of Orthopaedics, Icahn School of Medicine at Mount Sinai, New York, New York, USA
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3
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Fazilaty H, Brügger MD, Valenta T, Szczerba BM, Berkova L, Doumpas N, Hausmann G, Scharl M, Basler K. Tracing colonic embryonic transcriptional profiles and their reactivation upon intestinal damage. Cell Rep 2021; 36:109484. [PMID: 34348153 DOI: 10.1016/j.celrep.2021.109484] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 05/25/2021] [Accepted: 07/13/2021] [Indexed: 12/12/2022] Open
Abstract
We lack a holistic understanding of the genetic programs orchestrating embryonic colon morphogenesis and governing damage response in the adult. A window into these programs is the transcriptomes of the epithelial and mesenchymal cell populations in the colon. Performing unbiased single-cell transcriptomic analyses of the developing mouse colon at different embryonic stages (embryonic day 14.5 [E14.5], E15.5, and E18.5), we capture cellular and molecular profiles of the stages before, during, and after the appearance of crypt structures, as well as in a model of adult colitis. The data suggest most adult lineages are established by E18.5. We find embryonic-specific gene expression profiles and cell populations that reappear in response to tissue damage. Comparison of the datasets from mice and human colitis suggests the processes are conserved. In this study, we provide a comprehensive single-cell atlas of the developing mouse colon and evidence for the reactivation of embryonic genes in disease.
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Affiliation(s)
- Hassan Fazilaty
- Department of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Michael David Brügger
- Department of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Tomas Valenta
- Department of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland; Institute of Molecular Genetics of the ASCR, v. v. i., Vídeňská 1083, 142 20 Prague 4, Czech Republic.
| | - Barbara M Szczerba
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Rämistrasse 100, 8091 Zurich, Switzerland
| | - Linda Berkova
- Institute of Molecular Genetics of the ASCR, v. v. i., Vídeňská 1083, 142 20 Prague 4, Czech Republic
| | - Nikolaos Doumpas
- Department of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - George Hausmann
- Department of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Michael Scharl
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Rämistrasse 100, 8091 Zurich, Switzerland
| | - Konrad Basler
- Department of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.
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4
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Fawkner-Corbett D, Antanaviciute A, Parikh K, Jagielowicz M, Gerós AS, Gupta T, Ashley N, Khamis D, Fowler D, Morrissey E, Cunningham C, Johnson PRV, Koohy H, Simmons A. Spatiotemporal analysis of human intestinal development at single-cell resolution. Cell 2021; 184:810-826.e23. [PMID: 33406409 PMCID: PMC7864098 DOI: 10.1016/j.cell.2020.12.016] [Citation(s) in RCA: 224] [Impact Index Per Article: 74.7] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 10/10/2020] [Accepted: 12/10/2020] [Indexed: 12/11/2022]
Abstract
Development of the human intestine is not well understood. Here, we link single-cell RNA sequencing and spatial transcriptomics to characterize intestinal morphogenesis through time. We identify 101 cell states including epithelial and mesenchymal progenitor populations and programs linked to key morphogenetic milestones. We describe principles of crypt-villus axis formation; neural, vascular, mesenchymal morphogenesis, and immune population of the developing gut. We identify the differentiation hierarchies of developing fibroblast and myofibroblast subtypes and describe diverse functions for these including as vascular niche cells. We pinpoint the origins of Peyer’s patches and gut-associated lymphoid tissue (GALT) and describe location-specific immune programs. We use our resource to present an unbiased analysis of morphogen gradients that direct sequential waves of cellular differentiation and define cells and locations linked to rare developmental intestinal disorders. We compile a publicly available online resource, spatio-temporal analysis resource of fetal intestinal development (STAR-FINDer), to facilitate further work. Multimodal atlas of human intestinal development maps 101 cell types onto tissue Charts developmental origins of diverse cellular compartments and their progenitors Functional diversity of fibroblasts in stem cell, vasculature, and GALT formation Resource applied to interrogate pathology of in utero intestinal diseases
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Affiliation(s)
- David Fawkner-Corbett
- Medical Research Council (MRC) Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine (WIMM), John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, UK; Translational Gastroenterology Unit, John Radcliffe Hospital, Oxford OX3 9DU, UK; Academic Paediatric Surgery Unit (APSU), Nuffield Department of Surgical Sciences, University of Oxford, Oxford OX3 9DU, UK
| | - Agne Antanaviciute
- Medical Research Council (MRC) Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine (WIMM), John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, UK; MRC WIMM Centre For Computational Biology, MRC Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, UK
| | - Kaushal Parikh
- Medical Research Council (MRC) Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine (WIMM), John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, UK; Translational Gastroenterology Unit, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - Marta Jagielowicz
- Medical Research Council (MRC) Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine (WIMM), John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, UK; Translational Gastroenterology Unit, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - Ana Sousa Gerós
- Medical Research Council (MRC) Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine (WIMM), John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, UK; Translational Gastroenterology Unit, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - Tarun Gupta
- Medical Research Council (MRC) Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine (WIMM), John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, UK; Translational Gastroenterology Unit, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - Neil Ashley
- MRC Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, UK
| | - Doran Khamis
- MRC WIMM Centre For Computational Biology, MRC Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, UK
| | - Darren Fowler
- Paediatric Pathology, Department of Cellular Pathology, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK
| | - Edward Morrissey
- MRC WIMM Centre For Computational Biology, MRC Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, UK
| | - Chris Cunningham
- Colorectal Surgery Department, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK
| | - Paul R V Johnson
- Academic Paediatric Surgery Unit (APSU), Nuffield Department of Surgical Sciences, University of Oxford, Oxford OX3 9DU, UK
| | - Hashem Koohy
- Medical Research Council (MRC) Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine (WIMM), John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, UK; MRC WIMM Centre For Computational Biology, MRC Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, UK.
| | - Alison Simmons
- Medical Research Council (MRC) Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine (WIMM), John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, UK; Translational Gastroenterology Unit, John Radcliffe Hospital, Oxford OX3 9DU, UK.
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5
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Abstract
The hedgehog (Hh) signaling pathway plays several diverse regulatory and patterning roles during organogenesis of the intestine and in the regulation of adult intestinal homeostasis. In the embryo, fetus, and adult, intestinal Hh signaling is paracrine: Hh ligands are expressed in the endodermally derived epithelium, while signal transduction is confined to the mesenchymal compartment, where at least a dozen distinct cell types are capable of responding to Hh signals. Epithelial Hh ligands not only regulate a variety of mesenchymal cell behaviors, but they also direct these mesenchymal cells to secrete additional soluble factors (e.g., Wnts, Bmps, inflammatory mediators) that feed back to regulate the epithelial cells themselves. Evolutionary conservation of the core Hh signaling pathway, as well as conservation of epithelial/mesenchymal cross talk in the intestine, has meant that work in many diverse model systems has contributed to our current understanding of the role of this pathway in intestinal organogenesis, which is reviewed here.
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Affiliation(s)
- Katherine D Walton
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA; , .,Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA
| | - Deborah L Gumucio
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA; ,
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Wong CY, Chang YM, Tsai YS, Ng WV, Cheong SK, Chang TY, Chung IF, Lim YM. Decoding the differentiation of mesenchymal stem cells into mesangial cells at the transcriptomic level. BMC Genomics 2020; 21:467. [PMID: 32635896 PMCID: PMC7339572 DOI: 10.1186/s12864-020-06868-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 06/23/2020] [Indexed: 02/08/2023] Open
Abstract
Background Mesangial cells play an important role in the glomerulus to provide mechanical support and maintaine efficient ultrafiltration of renal plasma. Loss of mesangial cells due to pathologic conditions may lead to impaired renal function. Mesenchymal stem cells (MSC) can differentiate into many cell types, including mesangial cells. However transcriptomic profiling during MSC differentiation into mesangial cells had not been studied yet. The aim of this study is to examine the pattern of transcriptomic changes during MSC differentiation into mesangial cells, to understand the involvement of transcription factor (TF) along the differentiation process, and finally to elucidate the relationship among TF-TF and TF-key gene or biomarkers during the differentiation of MSC into mesangial cells. Results Several ascending and descending monotonic key genes were identified by Monotonic Feature Selector. The identified descending monotonic key genes are related to stemness or regulation of cell cycle while ascending monotonic key genes are associated with the functions of mesangial cells. The TFs were arranged in a co-expression network in order of time by Time-Ordered Gene Co-expression Network (TO-GCN) analysis. TO-GCN analysis can classify the differentiation process into three stages: differentiation preparation, differentiation initiation and maturation. Furthermore, it can also explore TF-TF-key genes regulatory relationships in the muscle contraction process. Conclusions A systematic analysis for transcriptomic profiling of MSC differentiation into mesangial cells has been established. Key genes or biomarkers, TFs and pathways involved in differentiation of MSC-mesangial cells have been identified and the related biological implications have been discussed. Finally, we further elucidated for the first time the three main stages of mesangial cell differentiation, and the regulatory relationships between TF-TF-key genes involved in the muscle contraction process. Through this study, we have increased fundamental understanding of the gene transcripts during the differentiation of MSC into mesangial cells.
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Affiliation(s)
- Chee-Yin Wong
- Department of Pre-Clinical Sciences, Faculty of Medicine and Health Sciences, Universiti Tunku Abdul Rahman, Jalan Sungai Long, Bandar Sungai Long, 43000 Kajang, Selangor, Malaysia
| | - Yao-Ming Chang
- Institute of Biomedical Sciences, Academia Sinica, 128, Academia Road, Section 2, Nankang, Taipei, Taiwan
| | - Yu-Shuen Tsai
- Center for Systems and Synthetic Biology, National Yang-Ming University, No. 155, Section 2, Linong Street, Taipei, Taiwan
| | - Wailap Victor Ng
- Department of Biotechnology and Laboratory Science in Medicine, National Yang-Ming University, No. 155, Section 2, Linong Street, Taipei, Taiwan
| | - Soon-Keng Cheong
- Department of Pre-Clinical Sciences, Faculty of Medicine and Health Sciences, Universiti Tunku Abdul Rahman, Jalan Sungai Long, Bandar Sungai Long, 43000 Kajang, Selangor, Malaysia
| | - Ting-Yu Chang
- Department of Research, ChangHua Christian Hospital, 135, Nan-Hsiao Street, ChangHua City, Taiwan
| | - I-Fang Chung
- Center for Systems and Synthetic Biology, National Yang-Ming University, No. 155, Section 2, Linong Street, Taipei, Taiwan. .,Institute of Biomedical Informatics, National Yang-Ming University, No. 155, Section 2, Linong Street, Taipei, Taiwan. .,Preventive Medicine Research Center, National Yang-Ming University, No. 155, Section 2, Linong Street, Taipei, Taiwan.
| | - Yang-Mooi Lim
- Department of Pre-Clinical Sciences, Faculty of Medicine and Health Sciences, Universiti Tunku Abdul Rahman, Jalan Sungai Long, Bandar Sungai Long, 43000 Kajang, Selangor, Malaysia.
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7
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Dong W, Baldwin C, Choi J, Milunsky JM, Zhang J, Bilguvar K, Lifton RP, Milunsky A. Identification of a dominant MYH11 causal variant in chronic intestinal pseudo-obstruction: Results of whole-exome sequencing. Clin Genet 2019; 96:473-477. [PMID: 31389005 DOI: 10.1111/cge.13617] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 07/26/2019] [Accepted: 07/30/2019] [Indexed: 02/06/2023]
Abstract
Chronic Intestinal Pseudo-Obstruction (CIPO) is a rare gastrointestinal disorder, which affects the smooth muscle contractions of the gastrointestinal tract. Dominant mutations in the smooth muscle actin gene, ACTG2, accounts for 44%-50% of CIPO patients. Other recessive or X-linked genes, including MYLK, LMOD1, RAD21, MYH11, MYL9, and FLNA were reported in single cases. In this study, we used Whole-Exome Sequencing (WES) to study 23 independent CIPO families including one extended family with 13 affected members. A dominantly inherited rare mutation, c.5819delC (p.Pro1940HisfsTer91), in the smooth muscle myosin gene, MYH11, was found in the extended family, shared by 7 affected family members but not by 3 unaffected family members with available DNA, suggesting a high probability of genetic linkage. Gene burden analysis indicates that additional genes, COL4A1, FBLN1 and HK2, may be associated with the disease. This study expanded our understanding of CIPO etiology and provided additional genetic evidence to physicians and genetic counselors for CIPO diagnosis.
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Affiliation(s)
- Weilai Dong
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut
| | - Clinton Baldwin
- Center for Human Genetics and Dept. Ob/Gyn, Tufts University School of Medicine, Boston, Massachusetts
| | - Jungmin Choi
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut.,Laboratory of Human Genetics and Genomics, Rockefeller University, New York, New York
| | - Jeff M Milunsky
- Center for Human Genetics and Dept. Ob/Gyn, Tufts University School of Medicine, Boston, Massachusetts
| | - Junhui Zhang
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut
| | - Kaya Bilguvar
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut
| | - Richard P Lifton
- Laboratory of Human Genetics and Genomics, Rockefeller University, New York, New York
| | - Aubrey Milunsky
- Center for Human Genetics and Dept. Ob/Gyn, Tufts University School of Medicine, Boston, Massachusetts
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Abstract
The adult gastrointestinal tract (GI) is a series of connected organs (esophagus, stomach, small intestine, colon) that develop via progressive regional specification of a continuous tubular embryonic organ anlage. This chapter focuses on organogenesis of the small intestine. The intestine arises by folding of a flat sheet of endodermal cells into a tube of highly proliferative pseudostratified cells. Dramatic elongation of this tube is driven by rapid epithelial proliferation. Then, epithelial-mesenchymal crosstalk and physical forces drive a stepwise cascade that results in convolution of the tubular surface into finger-like projections called villi. Concomitant with villus formation, a sharp epithelial transcriptional boundary is defined between stomach and intestine. Finally, flask-like depressions called crypts are established to house the intestinal stem cells needed throughout life for epithelial renewal. New insights into these events are being provided by in vitro organoid systems, which hold promise for future regenerative engineering of the small intestine.
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Affiliation(s)
- Sha Wang
- University of Michigan, Cell and Developmental Biology Department, Ann Arbor, MI, United States
| | - Katherine D Walton
- University of Michigan, Cell and Developmental Biology Department, Ann Arbor, MI, United States.
| | - Deborah L Gumucio
- University of Michigan, Cell and Developmental Biology Department, Ann Arbor, MI, United States
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9
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Abstract
During embryonic development, Hox genes participate in the building of a functional digestive system in metazoans, and genetic conditions involving these genes lead to important, sometimes lethal, growth retardation. Recently, this phenotype was obtained after deletion of Haglr, the Hoxd antisense growth-associated long noncoding RNA (lncRNA) located between Hoxd1 and Hoxd3 In this study, we have analyzed the function of Hoxd genes in delayed growth trajectories by looking at several nested targeted deficiencies of the mouse HoxD cluster. Mutant pups were severely stunted during the suckling period, but many recovered after weaning. After comparing seven distinct HoxD alleles, including CRISPR/Cas9 deletions involving Haglr, we identified Hoxd3 as the critical component for the gut to maintain milk-digestive competence. This essential function could be abrogated by the dominant-negative effect of HOXD10 as shown by a genetic rescue approach, thus further illustrating the importance of posterior prevalence in Hox gene function. A role for the lncRNA Haglr in the control of postnatal growth could not be corroborated.
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