1
|
Clancy S, Xie N, Eluvathingal Muttikkal T, Wang J, Fateh E, Smith M, Wilson P, Smith M, Hogan A, Sutherland A, Lu X. Rac1 and Nectin3 are essential for PCP-directed axon guidance in the peripheral auditory system. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.05.597585. [PMID: 38895287 PMCID: PMC11185701 DOI: 10.1101/2024.06.05.597585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Our sense of hearing is critically dependent on the spiral ganglion neurons (SGNs) that connect the sound receptors in the organ of Corti (OC) to the cochlear nuclei of the hindbrain. Type I SGNs innervate inner hair cells (IHCs) to transmit sound signals, while type II SGNs (SGNIIs) innervate outer hair cells (OHCs) to detect moderate-to-intense sound. During development, SGNII afferents make a characteristic 90-degree turn toward the base of the cochlea and innervate multiple OHCs. It has been shown that the Planar Cell Polarity (PCP) pathway acts non-autonomously to mediate environmental cues in the cochlear epithelium for SGNII afferent turning towards the base. However, the underlying mechanisms are unknown. Here, we present evidence that PCP signaling regulates multiple downstream effectors to influence cell adhesion and the cytoskeleton in cochlear supporting cells (SCs), which serve as intermediate targets of SGNII afferents. We show that the core PCP gene Vangl2 regulates the localization of the small GTPase Rac1 and the cell adhesion molecule Nectin3 at SC-SC junctions through which SGNII afferents travel. Through in vivo genetic analysis, we also show that loss of Rac1 or Nectin3 partially phenocopied SGNII peripheral afferent turning defects in Vangl2 mutants, and that Rac1 plays a non-autonomous role in this process in part by regulating PCP protein localization at the SC-SC junctions. Additionally, epistasis analysis indicates that Nectin3 and Rac1 likely act in the same genetic pathway to control SGNII afferent turning. Together, these experiments identify Nectin3 and Rac1 as novel regulators of PCP-directed SGNII axon guidance in the cochlea. Significance statement Planar Cell Polarity (PCP) signaling plays a non-autonomous role in the guidance of type II spiral ganglion neuron (SGNII) afferent projections that innervate cochlear hair cells. However, little is known about the underlying mechanisms. Here, we identify the small GTPase Rac1 and the cell adhesion molecule Nectin3 as two downstream effectors of PCP signaling in SGNII afferent guidance. We show that PCP signaling regulates Rac1 and Nectin3 localization in cochlear supporting cells that serve as intermediate targets for SGNII afferents and that Rac1 and Nectin3 likely act in the same genetic pathway to non-autonomously regulate SGNII afferent guidance. These findings significantly advance our understanding of auditory circuit assembly and shed light on PCP-directed axon guidance mechanisms.
Collapse
|
2
|
Nakamura T, Sakaguchi H, Mohri H, Ninoyu Y, Goto A, Yamaguchi T, Hishikawa Y, Matsuda M, Saito N, Ueyama T. Dispensable role of Rac1 and Rac3 after cochlear hair cell specification. J Mol Med (Berl) 2023; 101:843-854. [PMID: 37204479 PMCID: PMC10300165 DOI: 10.1007/s00109-023-02317-4] [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: 11/07/2022] [Revised: 04/03/2023] [Accepted: 04/11/2023] [Indexed: 05/20/2023]
Abstract
Rac small GTPases play important roles during embryonic development of the inner ear; however, little is known regarding their function in cochlear hair cells (HCs) after specification. Here, we revealed the localization and activation of Racs in cochlear HCs using GFP-tagged Rac plasmids and transgenic mice expressing a Rac1-fluorescence resonance energy transfer (FRET) biosensor. Furthermore, we employed Rac1-knockout (Rac1-KO, Atoh1-Cre;Rac1flox/flox) and Rac1 and Rac3 double KO (Rac1/Rac3-DKO, Atoh1-Cre;Rac1flox/flox;Rac3-/-) mice, under the control of the Atoh1 promoter. However, both Rac1-KO and Rac1/Rac3-DKO mice exhibited normal cochlear HC morphology at 13 weeks of age and normal hearing function at 24 weeks of age. No hearing vulnerability was observed in young adult (6-week-old) Rac1/Rac3-DKO mice even after intense noise exposure. Consistent with prior reports, the results from Atoh1-Cre;tdTomato mice confirmed that the Atoh1 promoter became functional only after embryonic day 14 when the sensory HC precursors exit the cell cycle. Taken together, these findings indicate that although Rac1 and Rac3 contribute to the early development of sensory epithelia in cochleae, as previously shown, they are dispensable for the maturation of cochlear HCs in the postmitotic state or for hearing maintenance following HC maturation. KEY MESSAGES: Mice with Rac1 and Rac3 deletion were generated after HC specification. Knockout mice exhibit normal cochlear hair cell morphology and hearing. Racs are dispensable for hair cells in the postmitotic state after specification. Racs are dispensable for hearing maintenance after HC maturation.
Collapse
Affiliation(s)
- Takashi Nakamura
- Laboratory of Molecular Pharmacology, Biosignal Research Center, Kobe University, Kobe, 657-8501, Japan
- Department of Otolaryngology-Head and Neck Surgery, Kyoto Prefectural University of Medicine, Kyoto, 602-8566, Japan
| | - Hirofumi Sakaguchi
- Department of Otolaryngology-Head and Neck Surgery, Kyoto Prefectural University of Medicine, Kyoto, 602-8566, Japan
| | - Hiroaki Mohri
- Laboratory of Molecular Pharmacology, Biosignal Research Center, Kobe University, Kobe, 657-8501, Japan
| | - Yuzuru Ninoyu
- Laboratory of Molecular Pharmacology, Biosignal Research Center, Kobe University, Kobe, 657-8501, Japan
| | - Akihiro Goto
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8315, Japan
| | - Taro Yamaguchi
- Laboratory of Pharmacology, Faculty of Pharmaceutical Sciences, Setsunan University, Hirakata, 573-0101, Japan
| | - Yoshitaka Hishikawa
- Department of Anatomy, Histochemistry and Cell Biology, Faculty of Medicine, University of Miyazaki, Miyazaki, 889-1692, Japan
| | - Michiyuki Matsuda
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8315, Japan
| | - Naoaki Saito
- Laboratory of Molecular Pharmacology, Biosignal Research Center, Kobe University, Kobe, 657-8501, Japan
| | - Takehiko Ueyama
- Laboratory of Molecular Pharmacology, Biosignal Research Center, Kobe University, Kobe, 657-8501, Japan.
| |
Collapse
|
3
|
Dock4 Is Required for the Maintenance of Cochlear Hair Cells and Hearing Function. FUNDAMENTAL RESEARCH 2022. [DOI: 10.1016/j.fmre.2022.04.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
|
4
|
Li P, Jiang X, Zhang G, Trabucco JT, Raciti D, Smith C, Ringwald M, Marai GE, Arighi C, Shatkay H. Utilizing image and caption information for biomedical document classification. Bioinformatics 2021; 37:i468-i476. [PMID: 34252939 PMCID: PMC8346654 DOI: 10.1093/bioinformatics/btab331] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/06/2021] [Indexed: 11/15/2022] Open
Abstract
Motivation Biomedical research findings are typically disseminated through publications. To simplify access to domain-specific knowledge while supporting the research community, several biomedical databases devote significant effort to manual curation of the literature—a labor intensive process. The first step toward biocuration requires identifying articles relevant to the specific area on which the database focuses. Thus, automatically identifying publications relevant to a specific topic within a large volume of publications is an important task toward expediting the biocuration process and, in turn, biomedical research. Current methods focus on textual contents, typically extracted from the title-and-abstract. Notably, images and captions are often used in publications to convey pivotal evidence about processes, experiments and results. Results We present a new document classification scheme, using both image and caption information, in addition to titles-and-abstracts. To use the image information, we introduce a new image representation, namely Figure-word, based on class labels of subfigures. We use word embeddings for representing captions and titles-and-abstracts. To utilize all three types of information, we introduce two information integration methods. The first combines Figure-words and textual features obtained from captions and titles-and-abstracts into a single larger vector for document representation; the second employs a meta-classification scheme. Our experiments and results demonstrate the usefulness of the newly proposed Figure-words for representing images. Moreover, the results showcase the value of Figure-words, captions and titles-and-abstracts in providing complementary information for document classification; these three sources of information when combined, lead to an overall improved classification performance. Availability and implementation Source code and the list of PMIDs of the publications in our datasets are available upon request.
Collapse
Affiliation(s)
- Pengyuan Li
- Department of Computer and Information Sciences, University of Delaware, Newark, DE 19716, USA
| | - Xiangying Jiang
- Department of Computer and Information Sciences, University of Delaware, Newark, DE 19716, USA.,Amazon, Seattle, WA 98109, USA
| | - Gongbo Zhang
- Department of Computer and Information Sciences, University of Delaware, Newark, DE 19716, USA.,Google, Mountain View, CA 94043, USA
| | - Juan Trelles Trabucco
- Department of Computer Science, The University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Daniela Raciti
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | | | | | - G Elisabeta Marai
- Department of Computer Science, The University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Cecilia Arighi
- Department of Computer and Information Sciences, University of Delaware, Newark, DE 19716, USA
| | - Hagit Shatkay
- Department of Computer and Information Sciences, University of Delaware, Newark, DE 19716, USA
| |
Collapse
|
5
|
Pellegatta M, Berti C, Hurley E, Palmisano M, de Curtis I, Feltri ML, Frick LR. Rac1 and Rac3 have opposite functions in Schwann cells during developmental myelination. Neurosci Lett 2021; 753:135868. [PMID: 33812927 DOI: 10.1016/j.neulet.2021.135868] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 03/14/2021] [Accepted: 03/29/2021] [Indexed: 11/15/2022]
Abstract
Small Rho GTPases such as Cdc42 and Rac1 regulate peripheral myelination during development. Deletion of Rac1 in Schwann cell conditional knockout mice causes a delay in the process of radial sorting, followed by hypomyelination as well as defective PAK1 activation and high number of immature Oct6+ Schwann cells. Rac3 has been shown to have redundant, specific and even opposite functions to Rac1 depending on the cell type, age and other factors. In neuronal cells, evidence suggests that Rac3 may oppose Rac1 by disrupting PAK1-GIT1-Paxillin signaling thus preventing cell differentiation and extension of lamellipodia. Therefore, we tested if these Rho GTPases have similar or opposite functions in Schwann cells, by deleting the genes for both proteins in mice during peripheral myelination. At P30, global deletion of Rac3 alleviates the developmental defects on axonal sorting and hypomyelination that are caused by Schwann cell conditional ablation of Rac1. Moreover, Rac3 deletion also reverses the arrest of Schwann cells at the Oct6+ stage and ameliorates the defects in PAK1 phosphorylation observed in Rac1 deficient mice. This partial rescue of the phenotype declines later on with aging. Since double transgenic animals showed dysmyelination without axonal degeneration at P60, we postulate that this deterioration is not likely due to loss of Rac3 in neurons, but it seems to be a Schwann cell-specific defect in the maintenance of myelin.
Collapse
Affiliation(s)
- Marta Pellegatta
- Hunter James Kelly Research Institute, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, 14203, United States; Departments of Biochemistry Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, 14203, United States
| | - Caterina Berti
- Hunter James Kelly Research Institute, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, 14203, United States; Departments of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, 14203, United States
| | - Edward Hurley
- Hunter James Kelly Research Institute, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, 14203, United States; Departments of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, 14203, United States
| | - Marilena Palmisano
- Hunter James Kelly Research Institute, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, 14203, United States; Departments of Biochemistry Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, 14203, United States
| | - Ivan de Curtis
- San Raffaele Hospital, Division of Neuroscience, Milano, 20132, Italy
| | - M Laura Feltri
- Hunter James Kelly Research Institute, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, 14203, United States; Departments of Biochemistry Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, 14203, United States; Departments of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, 14203, United States
| | - Luciana R Frick
- Hunter James Kelly Research Institute, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, 14203, United States; Departments of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, 14203, United States.
| |
Collapse
|
6
|
Landin Malt A, Hogan AK, Smith CD, Madani MS, Lu X. Wnts regulate planar cell polarity via heterotrimeric G protein and PI3K signaling. J Cell Biol 2021; 219:152025. [PMID: 32805026 PMCID: PMC7659710 DOI: 10.1083/jcb.201912071] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 04/15/2020] [Accepted: 07/13/2020] [Indexed: 12/16/2022] Open
Abstract
In the mammalian cochlea, the planar cell polarity (PCP) pathway aligns hair cell orientation along the plane of the sensory epithelium. Concurrently, multiple cell intrinsic planar polarity (referred to as iPCP) modules mediate planar polarization of the hair cell apical cytoskeleton, including the kinocilium and the V-shaped hair bundle essential for mechanotransduction. How PCP and iPCP are coordinated during development and the roles of Wnt ligands in this process remain unresolved. Here we show that genetic blockade of Wnt secretion in the cochlear epithelium resulted in a shortened cochlear duct and misoriented and misshapen hair bundles. Mechanistically, Wnts stimulate Gi activity by regulating the localization of Daple, a guanine nucleotide exchange factor (GEF) for Gαi. In turn, the Gβγ complex signals through phosphoinositide 3-kinase (PI3K) to regulate kinocilium positioning and asymmetric localizations of a subset of core PCP proteins, thereby coordinating PCP and iPCP. Thus, our results identify a putative Wnt/heterotrimeric G protein/PI3K pathway for PCP regulation.
Collapse
Affiliation(s)
- Andre Landin Malt
- Department of Cell Biology, University of Virginia Health System, Charlottesville, VA
| | - Arielle K Hogan
- Department of Cell Biology, University of Virginia Health System, Charlottesville, VA
| | - Connor D Smith
- Department of Cell Biology, University of Virginia Health System, Charlottesville, VA
| | - Maxwell S Madani
- Department of Cell Biology, University of Virginia Health System, Charlottesville, VA
| | - Xiaowei Lu
- Department of Cell Biology, University of Virginia Health System, Charlottesville, VA
| |
Collapse
|
7
|
Lagresle-Peyrou C, Olichon A, Sadek H, Roche P, Tardy C, Da Silva C, Garrigue A, Fischer A, Moshous D, Collette Y, Picard C, Casanova JL, André I, Cavazzana M. A gain-of-function RAC2 mutation is associated with bone-marrow hypoplasia and an autosomal dominant form of severe combined immunodeficiency. Haematologica 2021; 106:404-411. [PMID: 31919089 PMCID: PMC7849581 DOI: 10.3324/haematol.2019.230250] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 01/08/2020] [Indexed: 01/08/2023] Open
Abstract
Severe combined immunodeficiencies (SCIDs) constitute a heterogeneous group of life-threatening genetic disorders that typically present in the first year of life. They are defined by the absence of autologous T cells and the presence of an intrinsic or extrinsic defect in the B-cell compartment. In three newborns presenting with frequent infections and profound leukopenia, we identified a private, heterozygous mutation in the RAC2 gene (p.G12R). This mutation was de novo in the index case, who had been cured by hematopoietic stem cell transplantation but had transmitted the mutation to her sick daughter. Biochemical assays showed that the mutation was associated with a gain of function. The results of in vitro differentiation assays showed that RAC2 is essential for the survival and differentiation of hematopoietic stem/progenitor cells. Therefore, screening for RAC2 gain-of-function mutations should be considered in patients with a SCID phenotype and who lack a molecular diagnosis.
Collapse
Affiliation(s)
- Chantal Lagresle-Peyrou
- Laboratory of Human Lymphohematopoiesis, INSERM UMR 1163, Imagine Institute, F-75015 Paris, France
- Paris Descartes University – Sorbonne Paris Cité, Imagine Institute UMR1163, F-75015Paris, France
- Biotherapy Clinical Investigation Center, Groupe Hospitalier Universitaire Ouest, Assistance Publique-Hôpitaux de Paris, INSERM CIC 1416, F-75015 Paris, France
| | - Aurélien Olichon
- Cancer Research Center of Toulouse, CRCT, University of Toulouse, UPS, INSERM U1037, F-31037 Toulouse, France
| | - Hanem Sadek
- Biotherapy Clinical Investigation Center, Groupe Hospitalier Universitaire Ouest, Assistance Publique-Hôpitaux de Paris, INSERM CIC 1416, F-75015 Paris, France
| | - Philippe Roche
- Marseille Cancer Research Center, CRCM, Aix Marseille University, Institut Paoli-Calmettes, CNRS, INSERM, Team ISCB, F-13273 Marseille, France
| | - Claudine Tardy
- Cancer Research Center of Toulouse, CRCT, University of Toulouse, UPS, INSERM U1037, F-31037 Toulouse, France
| | - Cindy Da Silva
- Biotherapy Clinical Investigation Center, Groupe Hospitalier Universitaire Ouest, Assistance Publique-Hôpitaux de Paris, INSERM CIC 1416, F-75015 Paris, France
| | - Alexandrine Garrigue
- Biotherapy Clinical Investigation Center, Groupe Hospitalier Universitaire Ouest, Assistance Publique-Hôpitaux de Paris, INSERM CIC 1416, F-75015 Paris, France
| | - Alain Fischer
- Paris Descartes University – Sorbonne Paris Cité, Imagine Institute UMR1163, F-75015Paris, France
- Department of Pediatric Immunology, Hematology and Rheumatology, Necker-Enfants Malades University Hospital, APHP, F- 75015 Paris, France
- College de France, F-75231 Paris, France
| | - Despina Moshous
- Department of Pediatric Immunology, Hematology and Rheumatology, Necker-Enfants Malades University Hospital, APHP, F- 75015 Paris, France
| | - Yves Collette
- Marseille Cancer Research Center, CRCM, Aix Marseille University, Institut Paoli-Calmettes, CNRS, INSERM, Team ISCB, F-13273 Marseille, France
| | - Capucine Picard
- Paris Descartes University – Sorbonne Paris Cité, Imagine Institute UMR1163, F-75015Paris, France
- Department of Pediatric Immunology, Hematology and Rheumatology, Necker-Enfants Malades University Hospital, APHP, F- 75015 Paris, France
- Study Center for Primary Immunodeficiencies, Assistance Publique–Hôpitaux de Paris (AP-HP), Necker- Enfants Malades University Hospital, F-75015 Paris, France
- Laboratory of Lymphocyte Activation and Susceptibility to EBV, INSERM UMR 1163, Imagine Institute, F-75015 Paris, France
| | - Jean Laurent Casanova
- Paris Descartes University – Sorbonne Paris Cité, Imagine Institute UMR1163, F-75015Paris, France
- Department of Pediatric Immunology, Hematology and Rheumatology, Necker-Enfants Malades University Hospital, APHP, F- 75015 Paris, France
- Laboratory of Human Genetics of Infectious Diseases, Necker Branch INSERM UMR 1163, Imagine Institute, F-75015 Paris, France
- St. Giles Laboratory of Human Genetics of Infectious Diseases, Rockefeller Branch, Rockefeller University, New York, NY, USA
- Howard Hughes Medical Institute, New York, NY, USA
| | - Isabelle André
- Laboratory of Human Lymphohematopoiesis, INSERM UMR 1163, Imagine Institute, F-75015 Paris, France
- Paris Descartes University – Sorbonne Paris Cité, Imagine Institute UMR1163, F-75015Paris, France
| | - Marina Cavazzana
- Laboratory of Human Lymphohematopoiesis, INSERM UMR 1163, Imagine Institute, F-75015 Paris, France
- Paris Descartes University – Sorbonne Paris Cité, Imagine Institute UMR1163, F-75015Paris, France
- Biotherapy Clinical Investigation Center, Groupe Hospitalier Universitaire Ouest, Assistance Publique-Hôpitaux de Paris, INSERM CIC 1416, F-75015 Paris, France
| |
Collapse
|
8
|
Yamamoto R, Ohnishi H, Omori K, Yamamoto N. In silico analysis of inner ear development using public whole embryonic body single-cell RNA-sequencing data. Dev Biol 2020; 469:160-171. [PMID: 33131705 DOI: 10.1016/j.ydbio.2020.10.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 10/19/2020] [Accepted: 10/20/2020] [Indexed: 02/02/2023]
Abstract
The inner ear comprises four epithelial domains: the cochlea, vestibule, semicircular canals, and endolymphatic duct/sac. These structures are segregated at embryonic day 13.5 (E13.5). However, these four anatomical structures remain undefined at E10.5. Here, we aimed to identify lineage-specific genes in the early developing inner ear using published data obtained from single-cell RNA-sequencing (scRNA-seq) of embryonic mice. We downloaded 5000 single-cell transcriptome data, named 'auditory epithelial trajectory', from the Mouse Organogenesis Cell Atlas. The dataset was supposed to include otic epithelial cells at E9.5-13.5. We projected the 5000 cells onto a two-dimensional space encoding the transcriptional state and visualised the pattern of otic epithelial cell differentiation. We identified 15 clusters, which were annotated as one of the four components of the inner ear epithelium using known genes that characterise the four different tissues. Additionally, we classified 15 clusters into sub-regions of the four inner ear components. By comparing transcriptomes between these 15 clusters, we identified several candidates of lineage-specific genes. Characterising these new candidate genes will help future studies about inner ear development.
Collapse
Affiliation(s)
- Ryosuke Yamamoto
- Department of Otolaryngology, Head and Neck Surgery, Graduate School of Medicine, Kyoto University, 54, Shogoin Kawahara-cho, Sakyo-ku, Kyoto, 6068507, Japan.
| | - Hiroe Ohnishi
- Department of Otolaryngology, Head and Neck Surgery, Graduate School of Medicine, Kyoto University, 54, Shogoin Kawahara-cho, Sakyo-ku, Kyoto, 6068507, Japan.
| | - Koichi Omori
- Department of Otolaryngology, Head and Neck Surgery, Graduate School of Medicine, Kyoto University, 54, Shogoin Kawahara-cho, Sakyo-ku, Kyoto, 6068507, Japan.
| | - Norio Yamamoto
- Department of Otolaryngology, Head and Neck Surgery, Graduate School of Medicine, Kyoto University, 54, Shogoin Kawahara-cho, Sakyo-ku, Kyoto, 6068507, Japan.
| |
Collapse
|
9
|
Ueyama T. Rho-Family Small GTPases: From Highly Polarized Sensory Neurons to Cancer Cells. Cells 2019; 8:cells8020092. [PMID: 30696065 PMCID: PMC6406560 DOI: 10.3390/cells8020092] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 01/19/2019] [Accepted: 01/23/2019] [Indexed: 12/22/2022] Open
Abstract
The small GTPases of the Rho-family (Rho-family GTPases) have various physiological functions, including cytoskeletal regulation, cell polarity establishment, cell proliferation and motility, transcription, reactive oxygen species (ROS) production, and tumorigenesis. A relatively large number of downstream targets of Rho-family GTPases have been reported for in vitro studies. However, only a small number of signal pathways have been established at the in vivo level. Cumulative evidence for the functions of Rho-family GTPases has been reported for in vivo studies using genetically engineered mouse models. It was based on different cell- and tissue-specific conditional genes targeting mice. In this review, we introduce recent advances in in vivo studies, including human patient trials on Rho-family GTPases, focusing on highly polarized sensory organs, such as the cochlea, which is the primary hearing organ, host defenses involving reactive oxygen species (ROS) production, and tumorigenesis (especially associated with RAC, novel RAC1-GSPT1 signaling, RHOA, and RHOBTB2).
Collapse
Affiliation(s)
- Takehiko Ueyama
- Laboratory of Molecular Pharmacology, Biosignal Research Center, Kobe University, Kobe 657-8501, Japan.
| |
Collapse
|
10
|
Zhu C, Cheng C, Wang Y, Muhammad W, Liu S, Zhu W, Shao B, Zhang Z, Yan X, He Q, Xu Z, Yu C, Qian X, Lu L, Zhang S, Zhang Y, Xiong W, Gao X, Xu Z, Chai R. Loss of ARHGEF6 Causes Hair Cell Stereocilia Deficits and Hearing Loss in Mice. Front Mol Neurosci 2018; 11:362. [PMID: 30333726 PMCID: PMC6176010 DOI: 10.3389/fnmol.2018.00362] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 09/13/2018] [Indexed: 11/13/2022] Open
Abstract
ARHGEF6 belongs to the family of guanine nucleotide exchange factors (GEFs) for Rho GTPases, and it specifically activates Rho GTPases CDC42 and RAC1. Arhgef6 is the X-linked intellectual disability gene also known as XLID46, and clinical features of patients carrying Arhgef6 mutations include intellectual disability and, in some cases, sensorineural hearing loss. Rho GTPases act as molecular switches in many cellular processes. Their activities are regulated by binding or hydrolysis of GTP, which is facilitated by GEFs and GTPase-activating proteins, respectively. RAC1 and CDC42 have been shown to play important roles in hair cell (HC) stereocilia development. However, the role of ARHGEF6 in inner ear development and hearing function has not yet been investigated. Here, we found that ARHGEF6 is expressed in mouse cochlear HCs, including the HC stereocilia. We established Arhgef6 knockdown mice using the clustered regularly interspaced short palindromic repeat-associated Cas9 nuclease (CRISPR-Cas9) genome editing technique. We showed that ARHGEF6 was indispensable for the maintenance of outer hair cell (OHC) stereocilia, and loss of ARHGEF6 in mice caused HC stereocilia deficits that eventually led to progressive HC loss and hearing loss. However, the loss of ARHGEF6 did not affect the synapse density and did not affect the mechanoelectrical transduction currents in OHCs at postnatal day 3. At the molecular level, the levels of active CDC42 and RAC1 were dramatically decreased in the Arhgef6 knockdown mice, suggesting that ARHGEF6 regulates stereocilia maintenance through RAC1/CDC42.
Collapse
Affiliation(s)
- Chengwen Zhu
- Department of Otolaryngology Head and Neck Surgery, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, China.,Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, China.,Research Institute of Otolaryngology, Nanjing, China
| | - Cheng Cheng
- Department of Otolaryngology Head and Neck Surgery, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, China.,Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, China.,Research Institute of Otolaryngology, Nanjing, China.,Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Yanfei Wang
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, China.,Shandong Provincial Collaborative Innovation Center of Cell Biology, Shandong Normal University, Jinan, China
| | - Waqas Muhammad
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, China.,Department of Biotechnology, Federal Urdu University of Arts, Science and Technology, Karachi, Pakistan
| | - Shuang Liu
- School of Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing, China
| | - Weijie Zhu
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, China
| | - Buwei Shao
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, China
| | - Zhong Zhang
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, China
| | - Xiaoqian Yan
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, China
| | - Qingqing He
- Department of Otolaryngology Head and Neck Surgery, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, China
| | - Zhengrong Xu
- Department of Otolaryngology Head and Neck Surgery, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, China
| | - Chenjie Yu
- Department of Otolaryngology Head and Neck Surgery, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, China
| | - Xiaoyun Qian
- Department of Otolaryngology Head and Neck Surgery, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, China
| | - Ling Lu
- Department of Otolaryngology Head and Neck Surgery, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, China
| | - Shasha Zhang
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, China.,Research Institute of Otolaryngology, Nanjing, China.,Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China.,Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
| | - Yuan Zhang
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, China
| | - Wei Xiong
- School of Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing, China
| | - Xia Gao
- Department of Otolaryngology Head and Neck Surgery, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, China.,Research Institute of Otolaryngology, Nanjing, China
| | - Zhigang Xu
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, China.,Shandong Provincial Collaborative Innovation Center of Cell Biology, Shandong Normal University, Jinan, China
| | - Renjie Chai
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, China.,Research Institute of Otolaryngology, Nanjing, China.,Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China.,Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China.,Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China
| |
Collapse
|
11
|
Abstract
The hair bundle—the sensory organelle of inner-ear hair cells of vertebrates—exemplifies the ability of a cell to assemble complex, elegant structures. Proper construction of the bundle is required for proper mechanotransduction in response to external forces and to transmit information about sound and movement. Bundles contain tightly controlled numbers of actin-filled stereocilia, which are arranged in defined rows of precise heights. Indeed, many deafness mutations that disable hair-cell cytoskeletal proteins also disrupt bundles. Bundle assembly is a tractable problem in molecular and cellular systems biology; the sequence of structural changes in stereocilia is known, and a modest number of proteins may be involved.
Collapse
Affiliation(s)
- Peter-G Barr-Gillespie
- Oregon Hearing Research Center and Vollum Institute, Oregon Health and Science University, Portland, OR 97239
| |
Collapse
|
12
|
Yamada M, Clark J, Iulianella A. MLLT11/AF1q is differentially expressed in maturing neurons during development. Gene Expr Patterns 2014; 15:80-7. [PMID: 24839873 DOI: 10.1016/j.gep.2014.05.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Revised: 04/03/2014] [Accepted: 05/05/2014] [Indexed: 12/13/2022]
Abstract
Myeloid/lymphoid or mixed-lineage leukemia; translocated to chromosome 11 or ALL1 fused from chromosome 1q (MLLT11/AF1q) is a highly conserved 90 amino acid protein that functions in hematopoietic differentiation. Its translocation to the Trithorax locus has been implicated in malignancies of the hematopoietic system. However, the spatio-temporal profile of MLLT11 expression during embryonic development has not been characterized. Here we show that MLLT11 has a remarkably specific expression pattern in the developing central and peripheral nervous system. We find high levels of MLLT11 transcript and protein expression in the developing marginal zone of the cortex and spinal cord. MLLT11 co-localized with Tbr2 in the developing subplate region of the cortex and expanded to encompass the cortical plate at late fetal stages. Expression in the peripheral nervous system initiated at E9.5 in the facio-acoustic cranial ganglia and elaborated to identify all the cranio-facial and dorsal root ganglia by E10.5. We also observed expression in the eye and gastrointestinal tract, where MLLT11 transcripts localized to Tuj1-positive inner retinal layer and autonomic neurons, respectively. Altogether these results show that MLLT11 is a pan-neuronal marker, suggesting a role in neural differentiation in the central nervous system and neural crest-cell derived peripheral ganglia.
Collapse
Affiliation(s)
- Makiko Yamada
- Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
| | - Jessica Clark
- Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
| | - Angelo Iulianella
- Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada.
| |
Collapse
|
13
|
An alteration in ELMOD3, an Arl2 GTPase-activating protein, is associated with hearing impairment in humans. PLoS Genet 2013; 9:e1003774. [PMID: 24039609 PMCID: PMC3764207 DOI: 10.1371/journal.pgen.1003774] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Accepted: 07/24/2013] [Indexed: 12/30/2022] Open
Abstract
Exome sequencing coupled with homozygosity mapping was used to identify a transition mutation (c.794T>C; p.Leu265Ser) in ELMOD3 at the DFNB88 locus that is associated with nonsyndromic deafness in a large Pakistani family, PKDF468. The affected individuals of this family exhibited pre-lingual, severe-to-profound degrees of mixed hearing loss. ELMOD3 belongs to the engulfment and cell motility (ELMO) family, which consists of six paralogs in mammals. Several members of the ELMO family have been shown to regulate a subset of GTPases within the Ras superfamily. However, ELMOD3 is a largely uncharacterized protein that has no previously known biochemical activities. We found that in rodents, within the sensory epithelia of the inner ear, ELMOD3 appears most pronounced in the stereocilia of cochlear hair cells. Fluorescently tagged ELMOD3 co-localized with the actin cytoskeleton in MDCK cells and actin-based microvilli of LLC-PK1-CL4 epithelial cells. The p.Leu265Ser mutation in the ELMO domain impaired each of these activities. Super-resolution imaging revealed instances of close association of ELMOD3 with actin at the plasma membrane of MDCK cells. Furthermore, recombinant human GST-ELMOD3 exhibited GTPase activating protein (GAP) activity against the Arl2 GTPase, which was completely abolished by the p.Leu265Ser mutation. Collectively, our data provide the first insights into the expression and biochemical properties of ELMOD3 and highlight its functional links to sound perception and actin cytoskeleton. Autosomal recessive nonsyndromic hearing loss is a genetically heterogeneous disorder. Here, we report a severe-to-profound mixed hearing loss locus, DFNB88 on chromosome 2p12-p11.2. Exome enrichment followed by massive parallel sequencing revealed a c.794T>C transition mutation in ELMOD3 that segregated with DFNB88-associated hearing loss in a large Pakistani family. This transition mutation is predicted to substitute a highly invariant leucine residue with serine (p.Leu265Ser) in the engulfment and cell motility (ELMO) domain of the protein. No biological activity has been described previously for the ELMOD3 protein. We investigated the biochemical properties and ELMOD3 expression to gain mechanistic insights into the function of ELMOD3 in the inner ear. In rodent inner ears, ELMOD3 immunoreactivity was observed in the cochlear and vestibular hair cells and supporting cells. However, ELMOD3 appears most pronounced in the stereocilia of cochlear hair cells. Ex vivo, ELMOD3 is associated with actin-based structures, and this link is impaired by the DFNB88 mutation. ELMOD3 exhibited GAP activity against Arl2, a small GTPase, providing a potential functional link between Arf family signaling and stereocilia actin-based cytoskeletal architecture. Our study provides new insights into the molecules that are necessary for the development and/or function of inner ear sensory cells.
Collapse
|