1
|
Chaverra M, Cheney AM, Scheel A, Miller A, George L, Schultz A, Henningsen K, Kominsky D, Walk H, Kennedy WR, Kaufmann H, Walk S, Copié V, Lefcort F. ELP1, the Gene Mutated in Familial Dysautonomia, Is Required for Normal Enteric Nervous System Development and Maintenance and for Gut Epithelium Homeostasis. J Neurosci 2024; 44:e2253232024. [PMID: 39138000 DOI: 10.1523/jneurosci.2253-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 07/31/2024] [Accepted: 08/04/2024] [Indexed: 08/15/2024] Open
Abstract
Familial dysautonomia (FD) is a rare sensory and autonomic neuropathy that results from a mutation in the ELP1 gene. Virtually all patients report gastrointestinal (GI) dysfunction and we have recently shown that FD patients have a dysbiotic gut microbiome and altered metabolome. These findings were recapitulated in an FD mouse model and moreover, the FD mice had reduced intestinal motility, as did patients. To understand the cellular basis for impaired GI function in FD, the enteric nervous system (ENS; both female and male mice) from FD mouse models was analyzed during embryonic development and adulthood. We show here that not only is Elp1 required for the normal formation of the ENS, but it is also required in adulthood for the regulation of both neuronal and non-neuronal cells and for target innervation in both the mucosa and in intestinal smooth muscle. In particular, CGRP innervation was significantly reduced as was the number of dopaminergic neurons. Examination of an FD patient's gastric biopsy also revealed reduced and disoriented axons in the mucosa. Finally, using an FD mouse model in which Elp1 was deleted exclusively from neurons, we found significant changes to the colon epithelium including reduced E-cadherin expression, perturbed mucus layer organization, and infiltration of bacteria into the mucosa. The fact that deletion of Elp1 exclusively in neurons is sufficient to alter the intestinal epithelium and perturb the intestinal epithelial barrier highlights a critical role for neurons in regulating GI epithelium homeostasis.
Collapse
Affiliation(s)
- Marta Chaverra
- Departments of Microbiology and Cell Biology, Montana State University, Bozeman, Montana 59717
| | - Alexandra M Cheney
- Biochemistry and Chemistry, Montana State University, Bozeman, Montana 59717
| | - Alpha Scheel
- Departments of Microbiology and Cell Biology, Montana State University, Bozeman, Montana 59717
| | - Alessa Miller
- Departments of Microbiology and Cell Biology, Montana State University, Bozeman, Montana 59717
| | - Lynn George
- Department of Biological and Physical Sciences, Montana State University, Billings, Montana 59101
| | - Anastasia Schultz
- Departments of Microbiology and Cell Biology, Montana State University, Bozeman, Montana 59717
| | - Katelyn Henningsen
- Departments of Microbiology and Cell Biology, Montana State University, Bozeman, Montana 59717
| | - Douglas Kominsky
- Departments of Microbiology and Cell Biology, Montana State University, Bozeman, Montana 59717
| | - Heather Walk
- Departments of Microbiology and Cell Biology, Montana State University, Bozeman, Montana 59717
| | - William R Kennedy
- Department of Neurology, University of Minnesota, Minneapolis, Minnesota 55455
| | - Horacio Kaufmann
- Department of Neurology, New York University School of Medicine, New York, New York 10016
| | - Seth Walk
- Departments of Microbiology and Cell Biology, Montana State University, Bozeman, Montana 59717
| | - Valérie Copié
- Biochemistry and Chemistry, Montana State University, Bozeman, Montana 59717
| | - Frances Lefcort
- Departments of Microbiology and Cell Biology, Montana State University, Bozeman, Montana 59717
| |
Collapse
|
2
|
Arnskötter F, da Silva PBG, Schouw ME, Lukasch C, Bianchini L, Sieber L, Garcia-Lopez J, Ahmad ST, Li Y, Lin H, Joshi P, Spänig L, Radoš M, Roiuk M, Sepp M, Zuckermann M, Northcott PA, Patrizi A, Kutscher LM. Loss of Elp1 in cerebellar granule cell progenitors models ataxia phenotype of Familial Dysautonomia. Neurobiol Dis 2024; 199:106600. [PMID: 38996985 DOI: 10.1016/j.nbd.2024.106600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Revised: 06/25/2024] [Accepted: 07/08/2024] [Indexed: 07/14/2024] Open
Abstract
Familial Dysautonomia (FD) is an autosomal recessive disorder caused by a splice site mutation in the gene ELP1, which disproportionally affects neurons. While classically characterized by deficits in sensory and autonomic neurons, neuronal defects in the central nervous system have also been described. Although ELP1 expression remains high in the normal developing and adult cerebellum, its role in cerebellar development is unknown. To explore the role of Elp1 in the cerebellum, we knocked out Elp1 in cerebellar granule cell progenitors (GCPs) and examined the outcome on animal behavior and cellular composition. We found that GCP-specific conditional knockout of Elp1 (Elp1cKO) resulted in ataxia by 8 weeks of age. Cellular characterization showed that the animals had smaller cerebella with fewer granule cells. This defect was already apparent as early as 7 days after birth, when Elp1cKO animals also had fewer mitotic GCPs and shorter Purkinje dendrites. Through molecular characterization, we found that loss of Elp1 was associated with an increase in apoptotic cell death and cell stress pathways in GCPs. Our study demonstrates the importance of ELP1 in the developing cerebellum, and suggests that loss of Elp1 in the GC lineage may also play a role in the progressive ataxia phenotypes of FD patients.
Collapse
Affiliation(s)
- Frederik Arnskötter
- Developmental Origins of Pediatric Cancer Junior Research Group, German Cancer Research Center (DKFZ), Heidelberg, Germany; Hopp Children's Cancer Center (KiTZ), Heidelberg, Germany; National Center for Tumor Diseases (NCT), NCT Heidelberg, A partnership between DKFZ and Heidelberg University Hospital, Germany; Faculty of Biosciences, Heidelberg University, Heidelberg, Germany
| | - Patricia Benites Goncalves da Silva
- Developmental Origins of Pediatric Cancer Junior Research Group, German Cancer Research Center (DKFZ), Heidelberg, Germany; Hopp Children's Cancer Center (KiTZ), Heidelberg, Germany; National Center for Tumor Diseases (NCT), NCT Heidelberg, A partnership between DKFZ and Heidelberg University Hospital, Germany
| | - Mackenna E Schouw
- Developmental Origins of Pediatric Cancer Junior Research Group, German Cancer Research Center (DKFZ), Heidelberg, Germany; Hopp Children's Cancer Center (KiTZ), Heidelberg, Germany; National Center for Tumor Diseases (NCT), NCT Heidelberg, A partnership between DKFZ and Heidelberg University Hospital, Germany
| | - Chiara Lukasch
- Developmental Origins of Pediatric Cancer Junior Research Group, German Cancer Research Center (DKFZ), Heidelberg, Germany; Hopp Children's Cancer Center (KiTZ), Heidelberg, Germany; National Center for Tumor Diseases (NCT), NCT Heidelberg, A partnership between DKFZ and Heidelberg University Hospital, Germany
| | - Luca Bianchini
- Developmental Origins of Pediatric Cancer Junior Research Group, German Cancer Research Center (DKFZ), Heidelberg, Germany; Hopp Children's Cancer Center (KiTZ), Heidelberg, Germany; National Center for Tumor Diseases (NCT), NCT Heidelberg, A partnership between DKFZ and Heidelberg University Hospital, Germany; Faculty of Biosciences, Heidelberg University, Heidelberg, Germany
| | - Laura Sieber
- Developmental Origins of Pediatric Cancer Junior Research Group, German Cancer Research Center (DKFZ), Heidelberg, Germany; Hopp Children's Cancer Center (KiTZ), Heidelberg, Germany; National Center for Tumor Diseases (NCT), NCT Heidelberg, A partnership between DKFZ and Heidelberg University Hospital, Germany
| | - Jesus Garcia-Lopez
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA; Center of Excellence in Neuro-Oncology Sciences (CENOS), St. Jude Children's Research Hospital, Memphis, TN, USA; Department of In vivo Pharmacology-Immunology, Tempest Therapeutics, Brisbane, CA, USA
| | - Shiekh Tanveer Ahmad
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA; Center of Excellence in Neuro-Oncology Sciences (CENOS), St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Yiran Li
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA; Center of Excellence in Neuro-Oncology Sciences (CENOS), St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Hong Lin
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA; Center of Excellence in Neuro-Oncology Sciences (CENOS), St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Piyush Joshi
- Developmental Origins of Pediatric Cancer Junior Research Group, German Cancer Research Center (DKFZ), Heidelberg, Germany; Hopp Children's Cancer Center (KiTZ), Heidelberg, Germany; National Center for Tumor Diseases (NCT), NCT Heidelberg, A partnership between DKFZ and Heidelberg University Hospital, Germany
| | - Lisa Spänig
- Developmental Origins of Pediatric Cancer Junior Research Group, German Cancer Research Center (DKFZ), Heidelberg, Germany; Hopp Children's Cancer Center (KiTZ), Heidelberg, Germany; National Center for Tumor Diseases (NCT), NCT Heidelberg, A partnership between DKFZ and Heidelberg University Hospital, Germany; Faculty of Biosciences, Heidelberg University, Heidelberg, Germany
| | - Magdalena Radoš
- Developmental Origins of Pediatric Cancer Junior Research Group, German Cancer Research Center (DKFZ), Heidelberg, Germany; Hopp Children's Cancer Center (KiTZ), Heidelberg, Germany; National Center for Tumor Diseases (NCT), NCT Heidelberg, A partnership between DKFZ and Heidelberg University Hospital, Germany
| | - Mykola Roiuk
- Signal Transduction in Cancer and Metabolism, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Mari Sepp
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Marc Zuckermann
- Hopp Children's Cancer Center (KiTZ), Heidelberg, Germany; National Center for Tumor Diseases (NCT), NCT Heidelberg, A partnership between DKFZ and Heidelberg University Hospital, Germany; Division of Pediatric Neuro-Oncology, Preclinical Modeling Group, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Paul A Northcott
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA; Center of Excellence in Neuro-Oncology Sciences (CENOS), St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Annarita Patrizi
- Schaller Research Group, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Lena M Kutscher
- Developmental Origins of Pediatric Cancer Junior Research Group, German Cancer Research Center (DKFZ), Heidelberg, Germany; Hopp Children's Cancer Center (KiTZ), Heidelberg, Germany; National Center for Tumor Diseases (NCT), NCT Heidelberg, A partnership between DKFZ and Heidelberg University Hospital, Germany.
| |
Collapse
|
3
|
Yovchev I, Maayan C, Simanovsky N, Foldes AJ, Brooks R, Kaplan L, Meiner Z, Cheishvili D. The Relationship Between Scoliosis, Spinal Bone Density, and Truncal Muscle Strength in Familial Dysautonomia Patients. Calcif Tissue Int 2024; 114:222-227. [PMID: 38030713 DOI: 10.1007/s00223-023-01164-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 11/09/2023] [Indexed: 12/01/2023]
Abstract
This combined retrospective and prospective study aimed to investigate the relationship between scoliosis, spinal bone mineral density (BMD), and truncal muscle strength in patients with familial dysautonomia (FD). A total of 79 FD patients (40 male, 39 female) aged 5-44 years were included. The severity of scoliosis, lumbar spine BMD (Z-score), and truncal muscle strength were assessed. Correlations were analyzed using Pearson's correlation coefficient. Inverse correlations were observed between scoliosis severity and BMD (r = - 0.328, p = 0.001), as indicated by increasingly negative Z-score values with worsening osteoporosis. There were also inverse correlations between scoliosis and truncal muscle strength (r = - 0.595, p < 0.001). The correlation between scoliosis and age was notable up to 22 years (r = 0.421, p = 0.01), but not in the older age group (22-44 years). Our study identified inverse correlations between osteoporosis and scoliosis, as well as between scoliosis and truncal muscle strength, in FD patients. These findings suggest that there may be a relationship between bone density, muscle strength, and the severity of spinal curvature in this population. While our results highlight the potential importance of early diagnosis and management of osteoporosis, and possibly the benefits of physical therapy to strengthen truncal muscles, further research is needed to determine the direct impact of these interventions on preventing the progression of scoliosis and its associated complications in FD patients. A long-term longitudinal study could provide more insights into these relationships and inform treatment strategies for FD patients.
Collapse
Affiliation(s)
- I Yovchev
- Department of Rehabilitation, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - Ch Maayan
- Department of Pediatrics, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - N Simanovsky
- Department of Medical Imaging, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - A J Foldes
- Osteoporosis Center, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - R Brooks
- Department of Pediatrics, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - L Kaplan
- Osteoporosis Center, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - Z Meiner
- Department of Rehabilitation, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - D Cheishvili
- Department of Pediatrics, Hadassah Hebrew University Medical Center, Jerusalem, Israel.
- Gerald Bronfman Department of Oncology, McGill University, Montréal, QC, Canada.
- HKG Epitherapeutics, Unit 313-315, 3/F Biotech Center 2, 11 Science Park West Avenue, Shatin, Hong Kong.
| |
Collapse
|
4
|
Macefield VG, Smith LJ, Norcliffe‐Kaufmann L, Palma J, Kaufmann H. Sensorimotor control in the congenital absence of functional muscle spindles. Exp Physiol 2024; 109:27-34. [PMID: 37029664 PMCID: PMC10988665 DOI: 10.1113/ep090768] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Accepted: 03/22/2023] [Indexed: 04/09/2023]
Abstract
Hereditary sensory and autonomic neuropathy type III (HSAN III), also known as familial dysautonomia or Riley-Day syndrome, results from an autosomal recessive genetic mutation that causes a selective loss of specific sensory neurones, leading to greatly elevated pain and temperature thresholds, poor proprioception, marked ataxia and disturbances in blood pressure control. Stretch reflexes are absent throughout the body, which can be explained by the absence of functional muscle spindle afferents - assessed by intraneural microelectrodes inserted into peripheral nerves in the upper and lower limbs. This also explains the greatly compromised proprioception at the knee joint, as assessed by passive joint-angle matching. Moreover, there is a tight correlation between loss of proprioceptive acuity at the knee and the severity of gait impairment. Surprisingly, proprioception is normal at the elbow, suggesting that participants are relying more on sensory cues from the overlying skin; microelectrode recordings have shown that myelinated tactile afferents in the upper and lower limbs appear to be normal. Nevertheless, the lack of muscle spindles does affect sensorimotor control in the upper limb: in addition to poor performance in the finger-to-nose test, manual performance in the Purdue pegboard task is much worse than in age-matched healthy controls. Unlike those rare individuals with large-fibre sensory neuropathy, in which both muscle spindle and cutaneous afferents are absent, those with HSAN III present as a means of assessing sensorimotor control following the selective loss of muscle spindle afferents.
Collapse
Affiliation(s)
| | - Lyndon J. Smith
- School of MedicineWestern Sydney UniversitySydneyNew South WalesAustralia
| | - Lucy Norcliffe‐Kaufmann
- Dysautonomia Center, Department of NeurologyNew York University School of MedicineNew YorkNYUSA
| | - Jose‐Alberto Palma
- Dysautonomia Center, Department of NeurologyNew York University School of MedicineNew YorkNYUSA
| | - Horacio Kaufmann
- Dysautonomia Center, Department of NeurologyNew York University School of MedicineNew YorkNYUSA
| |
Collapse
|
5
|
Pereira M, Ribeiro DR, Berg M, Tsai AP, Dong C, Nho K, Kaiser S, Moutinho M, Soares AR. Amyloid pathology reduces ELP3 expression and tRNA modifications leading to impaired proteostasis. Biochim Biophys Acta Mol Basis Dis 2024; 1870:166857. [PMID: 37640114 DOI: 10.1016/j.bbadis.2023.166857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 08/09/2023] [Accepted: 08/22/2023] [Indexed: 08/31/2023]
Abstract
Alzheimer's Disease (AD) is a neurodegenerative disorder characterized by accumulation of β-amyloid aggregates and loss of proteostasis. Transfer RNA (tRNA) modifications play a crucial role in maintaining proteostasis, but their impact in AD remains unclear. Here, we report that expression of the tRNA modifying enzyme ELP3 is reduced in the brain of AD patients and amyloid mouse models and negatively correlates with amyloid plaque mean density. We further show that SH-SY5Y neuronal cells carrying the amyloidogenic Swedish familial AD mutation (SH-SWE) display reduced ELP3 levels, tRNA hypomodifications and proteostasis impairments when compared to cells not carrying the mutation (SH-WT). Additionally, exposing SH-WT cells to the secretome of SH-SWE cells led to reduced ELP3 expression, wobble uridine tRNA hypomodification, and increased protein aggregation. Importantly, correcting tRNA deficits due to ELP3 reduction reverted proteostasis impairments. These findings suggest that amyloid pathology dysregulates proteostasis by reducing ELP3 expression and tRNA modification levels, and that targeting tRNA modifications may be a potential therapeutic avenue to restore neuronal proteostasis in AD and preserve neuronal function.
Collapse
Affiliation(s)
- Marisa Pereira
- Institute of Biomedicine (iBiMED), Department of Medical Sciences, University of Aveiro, Aveiro, Portugal
| | - Diana R Ribeiro
- Institute of Biomedicine (iBiMED), Department of Medical Sciences, University of Aveiro, Aveiro, Portugal
| | - Maximilian Berg
- Institute of Pharmaceutical Chemistry, Goethe-University, Frankfurt, 60438, Germany
| | - Andy P Tsai
- Wu Tsai Neurosciences Institute, Stanford University School of Medicine, Stanford, CA, USA
| | - Chuanpeng Dong
- Department of Medical and Molecular Genetics, Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Kwangsik Nho
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Stefanie Kaiser
- Institute of Pharmaceutical Chemistry, Goethe-University, Frankfurt, 60438, Germany
| | - Miguel Moutinho
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Ana R Soares
- Institute of Biomedicine (iBiMED), Department of Medical Sciences, University of Aveiro, Aveiro, Portugal.
| |
Collapse
|
6
|
Schultz A, Cheng SY, Kirchner E, Costello S, Miettinen H, Chaverra M, King C, George L, Zhao X, Narasimhan J, Weetall M, Slaugenhaupt S, Morini E, Punzo C, Lefcort F. Reduction of retinal ganglion cell death in mouse models of familial dysautonomia using AAV-mediated gene therapy and splicing modulators. Sci Rep 2023; 13:18600. [PMID: 37903840 PMCID: PMC10616160 DOI: 10.1038/s41598-023-45376-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2023] [Accepted: 10/18/2023] [Indexed: 11/01/2023] Open
Abstract
Familial dysautonomia (FD) is a rare neurodevelopmental and neurodegenerative disease caused by a splicing mutation in the Elongator Acetyltransferase Complex Subunit 1 (ELP1) gene. The reduction in ELP1 mRNA and protein leads to the death of retinal ganglion cells (RGCs) and visual impairment in all FD patients. Currently patient symptoms are managed, but there is no treatment for the disease. We sought to test the hypothesis that restoring levels of Elp1 would thwart the death of RGCs in FD. To this end, we tested the effectiveness of two therapeutic strategies for rescuing RGCs. Here we provide proof-of-concept data that gene replacement therapy and small molecule splicing modifiers effectively reduce the death of RGCs in mouse models for FD and provide pre-clinical foundational data for translation to FD patients.
Collapse
Affiliation(s)
- Anastasia Schultz
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Shun-Yun Cheng
- Department of Ophthalmology, Neurobiology and Gene Therapy Center, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Emily Kirchner
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Boston, MA, USA
| | - Stephanann Costello
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Heini Miettinen
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Marta Chaverra
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Colin King
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Lynn George
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
- Department of Biological and Physical Science, Montana State University Billings, Billings, MT, USA
| | - Xin Zhao
- PTC Therapeutics, Inc., South Plainfield, NJ, 07080, USA
| | | | - Marla Weetall
- PTC Therapeutics, Inc., South Plainfield, NJ, 07080, USA
| | - Susan Slaugenhaupt
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Boston, MA, USA
- Department of Neurology, Massachusetts General Hospital Research Institute and Harvard Medical School, Boston, MA, USA
| | - Elisabetta Morini
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Boston, MA, USA
- Department of Neurology, Massachusetts General Hospital Research Institute and Harvard Medical School, Boston, MA, USA
| | - Claudio Punzo
- Department of Ophthalmology, Neurobiology and Gene Therapy Center, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Frances Lefcort
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA.
| |
Collapse
|
7
|
Roshandel D, Semnani F, Rayati Damavandi A, Masoudi A, Baradaran-Rafii A, Watson SL, Morgan WH, McLenachan S. Genetic predisposition to ocular surface disorders and opportunities for gene-based therapies. Ocul Surf 2023; 29:150-165. [PMID: 37192706 DOI: 10.1016/j.jtos.2023.05.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 04/24/2023] [Accepted: 05/09/2023] [Indexed: 05/18/2023]
Abstract
The ocular surface, comprised of the corneal and conjunctival epithelium, innervation system, immune components, and tear-film apparatus, plays a key role in ocular integrity as well as comfort and vision. Gene defects may result in congenital ocular or systemic disorders with prominent ocular surface involvement. Examples include epithelial corneal dystrophies, aniridia, ectrodactyly-ectodermal dysplasia-clefting (EEC) syndrome, xeroderma pigmentosum (XP), and hereditary sensory and autonomic neuropathy. In addition, genetic factors may interact with environmental risk factors in the development of several multifactorial ocular surface disorders (OSDs) such as autoimmune disorders, allergies, neoplasms, and dry eye disease. Advanced gene-based technologies have already been introduced in disease modelling and proof-of-concept gene therapies for monogenic OSDs. For instance, patient-derived induced pluripotent stem cells have been used for modelling aniridia-associated keratopathy (AAK), XP, and EEC syndrome. Moreover, CRISPR/Cas9 genome editing has been used for disease modelling and/or gene therapy for AAK and Meesmann's epithelial corneal dystrophy. A better understanding of the role of genetic factors in OSDs may be helpful in designing personalized disease models and treatment approaches. Gene-based approaches in monogenic OSDs and genetic predisposition to multifactorial OSDs such as immune-mediated disorders and neoplasms with known or possible genetic risk factors has been seldom reviewed. In this narrative review, we discuss the role of genetic factors in monogenic and multifactorial OSDs and potential opportunities for gene therapy.
Collapse
Affiliation(s)
- Danial Roshandel
- Lions Eye Institute, Perth, WA, Australia; Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, WA, Australia
| | - Farbod Semnani
- School of Public Health, Tehran University of Medical Sciences (TUMS), Tehran, Iran; School of Medicine, Tehran University of Medical Sciences (TUMS), Tehran, Iran
| | - Amirmasoud Rayati Damavandi
- School of Public Health, Tehran University of Medical Sciences (TUMS), Tehran, Iran; School of Medicine, Tehran University of Medical Sciences (TUMS), Tehran, Iran
| | - Ali Masoudi
- Stein Eye Institute, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Alireza Baradaran-Rafii
- Department of Ophthalmology, Research Institute for Ophthalmology and Vision Science, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Department of Ophthalmology, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Stephanie L Watson
- The University of Sydney, Save Sight Institute, Discipline of Ophthalmology, Sydney Medical School, Sydney, New South Wales, Australia
| | - William H Morgan
- Lions Eye Institute, Perth, WA, Australia; Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, WA, Australia
| | - Samuel McLenachan
- Lions Eye Institute, Perth, WA, Australia; Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, WA, Australia.
| |
Collapse
|
8
|
Schultz A, Cheng SY, Kirchner E, Costello S, Miettinen H, Chaverra M, King C, George L, Zhao X, Narasimhan J, Weetall M, Slaugenhaupt S, Morini E, Punzo C, Lefcort F. Reduction of retinal ganglion cell death in mouse models of familial dysautonomia using AAV-mediated gene therapy and splicing modulators. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.22.541535. [PMID: 37293016 PMCID: PMC10245894 DOI: 10.1101/2023.05.22.541535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Familial dysautonomia (FD) is a rare neurodevelopmental and neurodegenerative disease caused by a splicing mutation in the Elongator Acetyltransferase Complex Subunit 1 ( ELP1 ) gene. The reduction in ELP1 mRNA and protein leads to the death of retinal ganglion cells (RGCs) and visual impairment in all FD patients. Currently, patient symptoms are managed, but there is no treatment for the disease. We sought to test the hypothesis that restoring levels of Elp1 would thwart the death of RGCs in FD. To this end, we tested the effectiveness of two therapeutic strategies for rescuing RGCs. Here we provide proof-of-concept data that gene replacement therapy and small molecule splicing modifiers effectively reduce the death of RGCs in mouse models for FD and provide pre-clinical data foundation for translation to FD patients.
Collapse
|
9
|
Tassinari V, La Rosa P, Guida E, Colopi A, Caratelli S, De Paolis F, Gallo A, Cenciarelli C, Sconocchia G, Dolci S, Cesarini V. Contribution of A-to-I RNA editing, M6A RNA Methylation, and Alternative Splicing to physiological brain aging and neurodegenerative diseases. Mech Ageing Dev 2023; 212:111807. [PMID: 37023929 DOI: 10.1016/j.mad.2023.111807] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/31/2023] [Accepted: 04/03/2023] [Indexed: 04/08/2023]
Abstract
Aging is a physiological and progressive phenomenon in all organisms' life cycle, characterized by the accumulation of degenerative processes triggered by several alterations within molecular pathways. These changes compromise cell fate, resulting in the loss of functions in tissues throughout the body, including the brain. Physiological brain aging has been linked to structural and functional alterations, as well as to an increased risk of neurodegenerative diseases. Post-transcriptional RNA modifications modulate mRNA coding properties, stability, translatability, expanding the coding capacity of the genome, and are involved in all cellular processes. Among mRNA post-transcriptional modifications, the A-to-I RNA editing, m6A RNA Methylation and Alternative Splicing play a critical role in all the phases of a neuronal cell life cycle and alterations in their mechanisms of action significantly contribute to aging and neurodegeneration. Here we review our current understanding of the contribution of A-to-I RNA editing, m6A RNA Methylation, and Alternative Splicing to physiological brain aging process and neurodegenerative diseases.
Collapse
Affiliation(s)
- Valentina Tassinari
- Department of Molecular Medicine, Sapienza University of Rome, Rome, Italy; Department of Experimental Medicine, University of Rome Tor Vergata, Rome, Italy.
| | - Piergiorgio La Rosa
- Division of Neuroscience, Department of Psychology, Sapienza University of Rome, Rome, Italy; European Center for Brain Research, IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Eugenia Guida
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
| | - Ambra Colopi
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
| | - Sara Caratelli
- Department of Biomedicine, Institute of Translational Pharmacology (IFT), National Research Council (CNR), Rome, Italy
| | - Francesca De Paolis
- Department of Biomedicine, Institute of Translational Pharmacology (IFT), National Research Council (CNR), Rome, Italy
| | - Angela Gallo
- RNA Editing Lab., Oncohaematology Department, Cellular and Gene Therapy Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Carlo Cenciarelli
- Department of Biomedicine, Institute of Translational Pharmacology (IFT), National Research Council (CNR), Rome, Italy
| | - Giuseppe Sconocchia
- Department of Biomedicine, Institute of Translational Pharmacology (IFT), National Research Council (CNR), Rome, Italy
| | - Susanna Dolci
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
| | - Valeriana Cesarini
- Department of Biomedicine, Institute of Translational Pharmacology (IFT), National Research Council (CNR), Rome, Italy.
| |
Collapse
|
10
|
Chan ACY, Kumar S, Tan G, Wong HY, Ong JJY, Chandra B, Huang H, Sharma VK, Lai PS. Expanding the genetic causes of small-fiber neuropathy: SCN genes and beyond. Muscle Nerve 2023; 67:259-271. [PMID: 36448457 DOI: 10.1002/mus.27752] [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: 04/27/2022] [Revised: 10/31/2022] [Accepted: 11/06/2022] [Indexed: 12/05/2022]
Abstract
Small-fiber neuropathy (SFN) is a disorder that exclusively affects the small nerve fibers, sparing the large nerve fibers. Thinly myelinated Aδ-fibers and unmyelinated C-fibers are damaged, leading to development of neuropathic pain, thermal dysfunction, sensory symptoms, and autonomic disturbances. Although many SFNs are secondary and due to immunological causes or metabolic disturbances, the etiology is unknown in up to half of the patients. Over the years, this proportion of "idiopathic SFN" has decreased, as familial and genetic causes have been discovered, thus shifting a proportion of once "idiopathic" cases to the genetic category. After the discovery of SCN9A-gene variants in 2012, SCN10A and SCN11A variants have been found to be pathogenic in SFN. With improved accessibility of SFN diagnostic tools and genetic tests, many non-SCN variants and genetically inherited systemic diseases involving the small nerve fibers have also been described, but only scattered throughout the literature. There are 80 SCN variants described as causing SFN, 8 genes causing hereditary sensory autonomic neuropathies (HSAN) described with pure SFN, and at least 7 genes involved in genetically inherited systemic diseases associated with SFN. This systematic review aims to consolidate and provide an updated overview on the genetic variants of SFN to date---SCN genes and beyond. Awareness of these genetic causes of SFN is imperative for providing treatment directions, prognostication, and management of expectations for patients and their health-care providers.
Collapse
Affiliation(s)
- Amanda C Y Chan
- Division of Neurology, Department of Medicine, National University Hospital, Singapore, Singapore
- Yong Loo Ling School of Medicine, National University of Singapore, Singapore, Singapore
| | - Shivaram Kumar
- Yong Loo Ling School of Medicine, National University of Singapore, Singapore, Singapore
| | - Grace Tan
- Yong Loo Ling School of Medicine, National University of Singapore, Singapore, Singapore
| | - Hiu Yi Wong
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Hong Kong, China
- Hong Kong Center for Neurodegenerative Diseases, Hong Kong Science Park, Hong Kong, China
| | - Jonathan J Y Ong
- Division of Neurology, Department of Medicine, National University Hospital, Singapore, Singapore
- Yong Loo Ling School of Medicine, National University of Singapore, Singapore, Singapore
| | - Bharatendu Chandra
- Division of Neurology, Department of Medicine, National University Hospital, Singapore, Singapore
- Yong Loo Ling School of Medicine, National University of Singapore, Singapore, Singapore
- Division of Medical Genetics, University of Iowa, Iowa City, Iowa, USA
| | - Hua Huang
- Yong Loo Ling School of Medicine, National University of Singapore, Singapore, Singapore
| | - Vijay Kumar Sharma
- Division of Neurology, Department of Medicine, National University Hospital, Singapore, Singapore
- Yong Loo Ling School of Medicine, National University of Singapore, Singapore, Singapore
| | - Poh San Lai
- Yong Loo Ling School of Medicine, National University of Singapore, Singapore, Singapore
- Adjunct Faculty, Genome Institute of Singapore, Singapore, Singapore
| |
Collapse
|
11
|
Jaciuk M, Scherf D, Kaszuba K, Gaik M, Rau A, Kościelniak A, Krutyhołowa R, Rawski M, Indyka P, Graziadei A, Chramiec-Głąbik A, Biela A, Dobosz D, Lin TY, Abbassi NEH, Hammermeister A, Rappsilber J, Kosinski J, Schaffrath R, Glatt S. Cryo-EM structure of the fully assembled Elongator complex. Nucleic Acids Res 2023; 51:2011-2032. [PMID: 36617428 PMCID: PMC10018365 DOI: 10.1093/nar/gkac1232] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 11/22/2022] [Accepted: 12/09/2022] [Indexed: 01/10/2023] Open
Abstract
Transfer RNA (tRNA) molecules are essential to decode messenger RNA codons during protein synthesis. All known tRNAs are heavily modified at multiple positions through post-transcriptional addition of chemical groups. Modifications in the tRNA anticodons are directly influencing ribosome decoding and dynamics during translation elongation and are crucial for maintaining proteome integrity. In eukaryotes, wobble uridines are modified by Elongator, a large and highly conserved macromolecular complex. Elongator consists of two subcomplexes, namely Elp123 containing the enzymatically active Elp3 subunit and the associated Elp456 hetero-hexamer. The structure of the fully assembled complex and the function of the Elp456 subcomplex have remained elusive. Here, we show the cryo-electron microscopy structure of yeast Elongator at an overall resolution of 4.3 Å. We validate the obtained structure by complementary mutational analyses in vitro and in vivo. In addition, we determined various structures of the murine Elongator complex, including the fully assembled mouse Elongator complex at 5.9 Å resolution. Our results confirm the structural conservation of Elongator and its intermediates among eukaryotes. Furthermore, we complement our analyses with the biochemical characterization of the assembled human Elongator. Our results provide the molecular basis for the assembly of Elongator and its tRNA modification activity in eukaryotes.
Collapse
Affiliation(s)
- Marcin Jaciuk
- Malopolska Centre of Biotechnology (MCB), Jagiellonian University, Krakow 30-387, Poland
| | - David Scherf
- Institute for Biology, Department for Microbiology, University of Kassel, Kassel 34132, Germany
| | - Karol Kaszuba
- European Molecular Biology Laboratory Hamburg, Hamburg 22607, Germany
- Centre for Structural Systems Biology (CSSB), Hamburg 22607, Germany
| | - Monika Gaik
- Malopolska Centre of Biotechnology (MCB), Jagiellonian University, Krakow 30-387, Poland
| | - Alexander Rau
- Bioanalytics, Institute of Biotechnology, Technische Universität Berlin, Berlin 13355, Germany
| | - Anna Kościelniak
- Malopolska Centre of Biotechnology (MCB), Jagiellonian University, Krakow 30-387, Poland
| | - Rościsław Krutyhołowa
- Malopolska Centre of Biotechnology (MCB), Jagiellonian University, Krakow 30-387, Poland
| | - Michał Rawski
- Malopolska Centre of Biotechnology (MCB), Jagiellonian University, Krakow 30-387, Poland
- National Synchrotron Radiation Centre SOLARIS, Jagiellonian University, Krakow 30-387, Poland
| | - Paulina Indyka
- Malopolska Centre of Biotechnology (MCB), Jagiellonian University, Krakow 30-387, Poland
- National Synchrotron Radiation Centre SOLARIS, Jagiellonian University, Krakow 30-387, Poland
| | - Andrea Graziadei
- Bioanalytics, Institute of Biotechnology, Technische Universität Berlin, Berlin 13355, Germany
| | | | - Anna Biela
- Malopolska Centre of Biotechnology (MCB), Jagiellonian University, Krakow 30-387, Poland
| | - Dominika Dobosz
- Malopolska Centre of Biotechnology (MCB), Jagiellonian University, Krakow 30-387, Poland
| | - Ting-Yu Lin
- Malopolska Centre of Biotechnology (MCB), Jagiellonian University, Krakow 30-387, Poland
| | - Nour-el-Hana Abbassi
- Malopolska Centre of Biotechnology (MCB), Jagiellonian University, Krakow 30-387, Poland
- Postgraduate School of Molecular Medicine, Medical University of Warsaw, Warsaw 02-091, Poland
| | - Alexander Hammermeister
- Malopolska Centre of Biotechnology (MCB), Jagiellonian University, Krakow 30-387, Poland
- Institute for Biology, Department for Microbiology, University of Kassel, Kassel 34132, Germany
| | - Juri Rappsilber
- Bioanalytics, Institute of Biotechnology, Technische Universität Berlin, Berlin 13355, Germany
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Jan Kosinski
- European Molecular Biology Laboratory Hamburg, Hamburg 22607, Germany
- Centre for Structural Systems Biology (CSSB), Hamburg 22607, Germany
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg 69117, Germany
| | - Raffael Schaffrath
- Institute for Biology, Department for Microbiology, University of Kassel, Kassel 34132, Germany
| | - Sebastian Glatt
- To whom correspondence should be addressed. Tel: +48 12 664 6321; Fax: +48 12 664 6902;
| |
Collapse
|
12
|
A novel ELP1 mutation impairs the function of the Elongator complex and causes a severe neurodevelopmental phenotype. J Hum Genet 2023. [PMID: 36864284 DOI: 10.1038/s10038-023-01135-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
BACKGROUND Neurodevelopmental disorders (NDDs) are heterogeneous, debilitating conditions that include motor and cognitive disability and social deficits. The genetic factors underlying the complex phenotype of NDDs remain to be elucidated. Accumulating evidence suggest that the Elongator complex plays a role in NDDs, given that patient-derived mutations in its ELP2, ELP3, ELP4 and ELP6 subunits have been associated with these disorders. Pathogenic variants in its largest subunit ELP1 have been previously found in familial dysautonomia and medulloblastoma, with no link to NDDs affecting primarily the central nervous system. METHODS Clinical investigation included patient history and physical, neurological and magnetic resonance imaging (MRI) examination. A novel homozygous likely pathogenic ELP1 variant was identified by whole-genome sequencing. Functional studies included in silico analysis of the mutated ELP1 in the context of the holo-complex, production and purification of the ELP1 harbouring the identified mutation and in vitro analyses using microscale thermophoresis for tRNA binding assay and acetyl-CoA hydrolysis assay. Patient fibroblasts were harvested for tRNA modification analysis using HPLC coupled to mass spectrometry. RESULTS We report a novel missense mutation in the ELP1 identified in two siblings with intellectual disability and global developmental delay. We show that the mutation perturbs the ability of ELP123 to bind tRNAs and compromises the function of the Elongator in vitro and in human cells. CONCLUSION Our study expands the mutational spectrum of ELP1 and its association with different neurodevelopmental conditions and provides a specific target for genetic counselling.
Collapse
|
13
|
Haga CL, Phinney DG. Strategies for targeting RNA with small molecule drugs. Expert Opin Drug Discov 2023; 18:135-147. [PMID: 35934990 DOI: 10.1080/17460441.2022.2111414] [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: 02/07/2023]
Abstract
INTRODUCTION Historically, therapeutic treatment of disease has been restricted to targeting proteins. Of the approximately 20,000 translated human proteins, approximately 1600 are associated with diseases. Strikingly, less than 15% of disease-associated proteins are predicted or known to be 'druggable.' While the concept and narrative of protein druggability continue to evolve with the development of novel technological and pharmacological advances, most of the human proteome remains undrugged. Recent genomic studies indicate that less than 2% of the human genome encodes for proteins, and while as much as 75% of the genome is transcribed, RNA has largely been ignored as a druggable target for therapeutic interventions. AREAS COVERED This review delineates the theory and techniques involved in the development of small molecule inhibitors of RNAs from brute force, high-throughput screening technologies to de novo molecular design using computational machine and deep learning. We will also highlight the potential pitfalls and limitations of targeting RNA with small molecules. EXPERT OPINION Although significant advances have recently been made in developing systems to identify small molecule inhibitors of RNAs, many challenges remain. Focusing on RNA structure and ligand binding sites may help bring drugging RNA in line with traditional protein drug targeting.
Collapse
Affiliation(s)
- Christopher L Haga
- Department of Molecular Medicine, UF Scripps Biomedical Research, Jupiter, FL, USA
| | - Donald G Phinney
- Department of Molecular Medicine, UF Scripps Biomedical Research, Jupiter, FL, USA
| |
Collapse
|
14
|
Cheney AM, Costello SM, Pinkham NV, Waldum A, Broadaway SC, Cotrina-Vidal M, Mergy M, Tripet B, Kominsky DJ, Grifka-Walk HM, Kaufmann H, Norcliffe-Kaufmann L, Peach JT, Bothner B, Lefcort F, Copié V, Walk ST. Gut microbiome dysbiosis drives metabolic dysfunction in Familial dysautonomia. Nat Commun 2023; 14:218. [PMID: 36639365 PMCID: PMC9839693 DOI: 10.1038/s41467-023-35787-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 12/18/2022] [Indexed: 01/15/2023] Open
Abstract
Familial dysautonomia (FD) is a rare genetic neurologic disorder caused by impaired neuronal development and progressive degeneration of both the peripheral and central nervous systems. FD is monogenic, with >99.4% of patients sharing an identical point mutation in the elongator acetyltransferase complex subunit 1 (ELP1) gene, providing a relatively simple genetic background in which to identify modifiable factors that influence pathology. Gastrointestinal symptoms and metabolic deficits are common among FD patients, which supports the hypothesis that the gut microbiome and metabolome are altered and dysfunctional compared to healthy individuals. Here we show significant differences in gut microbiome composition (16 S rRNA gene sequencing of stool samples) and NMR-based stool and serum metabolomes between a cohort of FD patients (~14% of patients worldwide) and their cohabitating, healthy relatives. We show that key observations in human subjects are recapitulated in a neuron-specific Elp1-deficient mouse model, and that cohousing mutant and littermate control mice ameliorates gut microbiome dysbiosis, improves deficits in gut transit, and reduces disease severity. Our results provide evidence that neurologic deficits in FD alter the structure and function of the gut microbiome, which shifts overall host metabolism to perpetuate further neurodegeneration.
Collapse
Affiliation(s)
- Alexandra M Cheney
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT, USA
| | - Stephanann M Costello
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT, USA
| | - Nicholas V Pinkham
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Annie Waldum
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT, USA
| | - Susan C Broadaway
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Maria Cotrina-Vidal
- Department of Neurology, New York University School of Medicine, New York, NY, USA
| | - Marc Mergy
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Brian Tripet
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT, USA
| | - Douglas J Kominsky
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Heather M Grifka-Walk
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Horacio Kaufmann
- Department of Neurology, New York University School of Medicine, New York, NY, USA
| | | | - Jesse T Peach
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT, USA
| | - Brian Bothner
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT, USA
| | - Frances Lefcort
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA.
| | - Valérie Copié
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT, USA.
| | - Seth T Walk
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA.
| |
Collapse
|
15
|
Younger DS. Autonomic failure: Clinicopathologic, physiologic, and genetic aspects. HANDBOOK OF CLINICAL NEUROLOGY 2023; 195:55-102. [PMID: 37562886 DOI: 10.1016/b978-0-323-98818-6.00020-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/12/2023]
Abstract
Over the past century, generations of neuroscientists, pathologists, and clinicians have elucidated the underlying causes of autonomic failure found in neurodegenerative, inherited, and antibody-mediated autoimmune disorders, each with pathognomonic clinicopathologic features. Autonomic failure affects central autonomic nervous system components in the α-synucleinopathy, multiple system atrophy, characterized clinically by levodopa-unresponsive parkinsonism or cerebellar ataxia, and pathologically by argyrophilic glial cytoplasmic inclusions (GCIs). Two other central neurodegenerative disorders, pure autonomic failure characterized clinically by deficits in norepinephrine synthesis and release from peripheral sympathetic nerve terminals; and Parkinson's disease, with early and widespread autonomic deficits independent of the loss of striatal dopamine terminals, both express Lewy pathology. The rare congenital disorder, hereditary sensory, and autonomic neuropathy type III (or Riley-Day, familial dysautonomia) causes life-threatening autonomic failure due to a genetic mutation that results in loss of functioning baroreceptors, effectively separating afferent mechanosensing neurons from the brain. Autoimmune autonomic ganglionopathy caused by autoantibodies targeting ganglionic α3-acetylcholine receptors instead presents with subacute isolated autonomic failure affecting sympathetic, parasympathetic, and enteric nervous system function in various combinations. This chapter is an overview of these major autonomic disorders with an emphasis on their historical background, neuropathological features, etiopathogenesis, diagnosis, and treatment.
Collapse
Affiliation(s)
- David S Younger
- Department of Clinical Medicine and Neuroscience, CUNY School of Medicine, New York, NY, United States; Department of Medicine, Section of Internal Medicine and Neurology, White Plains Hospital, White Plains, NY, United States.
| |
Collapse
|
16
|
Younger DS. Neonatal and infantile hypotonia. HANDBOOK OF CLINICAL NEUROLOGY 2023; 195:401-423. [PMID: 37562880 DOI: 10.1016/b978-0-323-98818-6.00011-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/12/2023]
Abstract
The underlying etiology of neonatal and infantile hypotonia can be divided into primary peripheral and central nervous system and acquired or genetic disorders. The approach to identifying the likeliest cause of hypotonia begins with a bedside assessment followed by a careful review of the birth history and early development and family pedigree and obtaining available genetic studies and age- and disease-appropriate laboratory investigations. Until about a decade ago, the main goal was to identify the clinical signs and a battery of basic investigations including electrophysiology to confirm or exclude a given neuromuscular disorder, however the availability of whole-exome sequencing and next generation sequencing and transcriptome sequencing has simplified the identification of specific underlying genetic defect and improved the accuracy of diagnosis in many related Mendelian disorders.
Collapse
Affiliation(s)
- David S Younger
- Department of Clinical Medicine and Neuroscience, CUNY School of Medicine, New York, NY, United States; Department of Medicine, Section of Internal Medicine and Neurology, White Plains Hospital, White Plains, NY, United States.
| |
Collapse
|
17
|
Shilian M, Even A, Gast H, Nguyen L, Weil M. Elongator promotes neuritogenesis via regulation of tau stability through acly activity. Front Cell Dev Biol 2022; 10:1015125. [PMID: 36393857 PMCID: PMC9644021 DOI: 10.3389/fcell.2022.1015125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 10/05/2022] [Indexed: 11/23/2022] Open
Abstract
The six subunits (Elp1 to Elp6) Elongator complex promotes specific uridine modifications in tRNA’s wobble site. Moreover, this complex has been indirectly involved in the regulation of α-tubulin acetylation in microtubules (MTs) via the stabilization of ATP-Citrate Lyase (Acly), the main cytosolic source of acetyl-CoA production in cells, a key substrate used for global protein acetylation. Here, we report additional evidence that Elongator activity is important for proper cytoskeleton remodeling as cells lacking expression of Elp1 show morphology impairment; including distinct neurite process formation and disorganization and instability of MTs. Here, we show that loss of Elongator results in a reduction of expression of the microtubule associated protein Tau (MAPT). Tau, is a well-known key MT regulator in neurons whose lysines can be competitively acetylated or ubiquitylated. Therefore, we tested whether Tau is an indirect acetylation target of Elongator. We found that a reduction of Elongator activity leads to a decrease of lysine acetylation on Tau that favors its proteasomal degradation. This phenotype was prevented by using selective deacetylase or proteasomal inhibitors. Moreover, our data demonstrate that Acly’s activity regulates the mechanism underlying Tau mediated neurite morphology defects found in Elp1 KD since both Tau levels and neurites morphology are restored due to Acly overexpression. This suggests a possible involvement of both Tau and Acly dysfunction in Familial Dysautonomia (FD), which is an autosomal recessive peripheral neuropathy caused by mutation in the ELP1 gene that severely affects Elp1 expression levels in the nervous system in FD patients in a similar way as found previously in Elp1 KD neuroblastoma cells.
Collapse
Affiliation(s)
- Michal Shilian
- Laboratory for Neurodegenerative Diseases and Personalized Medicine, The Shmunis School of Biomedicine and Cancer Research, The George S. Wise Faculty for Life Sciences, Sagol School of Neurosciences, Tel Aviv University, Tel Aviv, Israel
| | - Aviel Even
- Laboratory for Neurodegenerative Diseases and Personalized Medicine, The Shmunis School of Biomedicine and Cancer Research, The George S. Wise Faculty for Life Sciences, Sagol School of Neurosciences, Tel Aviv University, Tel Aviv, Israel
| | - Hila Gast
- Laboratory for Neurodegenerative Diseases and Personalized Medicine, The Shmunis School of Biomedicine and Cancer Research, The George S. Wise Faculty for Life Sciences, Sagol School of Neurosciences, Tel Aviv University, Tel Aviv, Israel
| | - Laurent Nguyen
- GIGA-Stem Cells and GIGA-Neurosciences, Interdisciplinary Cluster for Applied Genoproteomics (GIGAR), University of Liège, C.H.U. Sart Tilman, Belgium, BIOMED Research Institute, Hasselt, Belgium
| | - Miguel Weil
- Laboratory for Neurodegenerative Diseases and Personalized Medicine, The Shmunis School of Biomedicine and Cancer Research, The George S. Wise Faculty for Life Sciences, Sagol School of Neurosciences, Tel Aviv University, Tel Aviv, Israel
- *Correspondence: Miguel Weil,
| |
Collapse
|
18
|
McAfee JC, Bell JL, Krupa O, Matoba N, Stein JL, Won H. Focus on your locus with a massively parallel reporter assay. J Neurodev Disord 2022; 14:50. [PMID: 36085003 PMCID: PMC9463819 DOI: 10.1186/s11689-022-09461-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 09/01/2022] [Indexed: 01/01/2023] Open
Abstract
A growing number of variants associated with risk for neurodevelopmental disorders have been identified by genome-wide association and whole genome sequencing studies. As common risk variants often fall within large haplotype blocks covering long stretches of the noncoding genome, the causal variants within an associated locus are often unknown. Similarly, the effect of rare noncoding risk variants identified by whole genome sequencing on molecular traits is seldom known without functional assays. A massively parallel reporter assay (MPRA) is an assay that can functionally validate thousands of regulatory elements simultaneously using high-throughput sequencing and barcode technology. MPRA has been adapted to various experimental designs that measure gene regulatory effects of genetic variants within cis- and trans-regulatory elements as well as posttranscriptional processes. This review discusses different MPRA designs that have been or could be used in the future to experimentally validate genetic variants associated with neurodevelopmental disorders. Though MPRA has limitations such as it does not model genomic context, this assay can help narrow down the underlying genetic causes of neurodevelopmental disorders by screening thousands of sequences in one experiment. We conclude by describing future directions of this technique such as applications of MPRA for gene-by-environment interactions and pharmacogenetics.
Collapse
Affiliation(s)
- Jessica C McAfee
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
- UNC Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Jessica L Bell
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
- UNC Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Oleh Krupa
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
- UNC Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Nana Matoba
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
- UNC Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Jason L Stein
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
- UNC Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
| | - Hyejung Won
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
- UNC Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
| |
Collapse
|
19
|
Rescue of a familial dysautonomia mouse model by AAV9-Exon-specific U1 snRNA. Am J Hum Genet 2022; 109:1534-1548. [PMID: 35905737 PMCID: PMC9388384 DOI: 10.1016/j.ajhg.2022.07.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 06/30/2022] [Indexed: 02/06/2023] Open
Abstract
Familial dysautonomia (FD) is a currently untreatable, neurodegenerative disease caused by a splicing mutation (c.2204+6T>C) that causes skipping of exon 20 of the elongator complex protein 1 (ELP1) pre-mRNA. Here, we used adeno-associated virus serotype 9 (AAV9-U1-FD) to deliver an exon-specific U1 (ExSpeU1) small nuclear RNA, designed to cause inclusion of ELP1 exon 20 only in those cells expressing the target pre-mRNA, in a phenotypic mouse model of FD. Postnatal systemic and intracerebral ventricular treatment in these mice increased the inclusion of ELP1 exon 20. This also augmented the production of functional protein in several tissues including brain, dorsal root, and trigeminal ganglia. Crucially, the treatment rescued most of the FD mouse mortality before one month of age (89% vs 52%). There were notable improvements in ataxic gait as well as renal (serum creatinine) and cardiac (ejection fraction) functions. RNA-seq analyses of dorsal root ganglia from treated mice and human cells overexpressing FD-ExSpeU1 revealed only minimal global changes in gene expression and splicing. Overall then, our data prove that AAV9-U1-FD is highly specific and will likely be a safe and effective therapeutic strategy for this debilitating disease.
Collapse
|
20
|
Willems M, Wells CF, Coubes C, Pequignot M, Kuony A, Michon F. Hypolacrimia and Alacrimia as Diagnostic Features for Genetic or Congenital Conditions. Invest Ophthalmol Vis Sci 2022; 63:3. [PMID: 35925585 PMCID: PMC9363675 DOI: 10.1167/iovs.63.9.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
As part of the lacrimal apparatus, the lacrimal gland participates in the maintenance of a healthy eye surface by producing the aqueous part of the tear film. Alacrimia and hypolacrimia, which are relatively rare during childhood or young adulthood, have their origin in a number of mechanisms which include agenesia, aplasia, hypoplasia, or incorrect maturation of the gland. Moreover, impaired innervation of the gland and/or the cornea and alterations of protein secretion pathways can lead to a defective tear film. In most conditions leading to alacrimia or hypolacrimia, however, the altered tear film is only one of numerous defects that arise and therefore is commonly disregarded. Here, we have systematically reviewed all of those genetic conditions or congenital disorders that have alacrimia or hypolacrimia as a feature. Where it is known, we describe the mechanism of the defect in question. It has been possible to clearly establish the physiopathology of only a minority of these conditions. As hypolacrimia and alacrimia are rare features, this review could be used as a tool in clinical genetics to perform a quick diagnosis, necessary for appropriate care and counseling.
Collapse
Affiliation(s)
- Marjolaine Willems
- Institute for Neurosciences of Montpellier, University of Montpellier, INSERM, Montpellier, France.,Medical Genetic Department for Rare Diseases and Personalized Medicine, Reference Center AD SOOR, AnDDI-RARE, Montpellier University Hospital Center, Montpellier, France
| | - Constance F Wells
- Medical Genetic Department for Rare Diseases and Personalized Medicine, Reference Center AD SOOR, AnDDI-RARE, Montpellier University Hospital Center, Montpellier, France
| | - Christine Coubes
- Medical Genetic Department for Rare Diseases and Personalized Medicine, Reference Center AD SOOR, AnDDI-RARE, Montpellier University Hospital Center, Montpellier, France
| | - Marie Pequignot
- Institute for Neurosciences of Montpellier, University of Montpellier, INSERM, Montpellier, France
| | - Alison Kuony
- Institute for Neurosciences of Montpellier, University of Montpellier, INSERM, Montpellier, France.,Université Paris Cité, CNRS, Institut Jacques Monod, Paris, France
| | - Frederic Michon
- Institute for Neurosciences of Montpellier, University of Montpellier, INSERM, Montpellier, France
| |
Collapse
|
21
|
Gaik M, Kojic M, Stegeman MR, Öncü‐Öner T, Kościelniak A, Jones A, Mohamed A, Chau PYS, Sharmin S, Chramiec‐Głąbik A, Indyka P, Rawski M, Biela A, Dobosz D, Millar A, Chau V, Ünalp A, Piper M, Bellingham MC, Eichler EE, Nickerson DA, Güleryüz H, Abbassi NEH, Jazgar K, Davis MJ, Mercimek‐Andrews S, Cingöz S, Wainwright BJ, Glatt S. Functional divergence of the two Elongator subcomplexes during neurodevelopment. EMBO Mol Med 2022; 14:e15608. [PMID: 35698786 PMCID: PMC9260213 DOI: 10.15252/emmm.202115608] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 05/20/2022] [Accepted: 05/23/2022] [Indexed: 12/11/2022] Open
Abstract
The highly conserved Elongator complex is a translational regulator that plays a critical role in neurodevelopment, neurological diseases, and brain tumors. Numerous clinically relevant variants have been reported in the catalytic Elp123 subcomplex, while no missense mutations in the accessory subcomplex Elp456 have been described. Here, we identify ELP4 and ELP6 variants in patients with developmental delay, epilepsy, intellectual disability, and motor dysfunction. We determine the structures of human and murine Elp456 subcomplexes and locate the mutated residues. We show that patient-derived mutations in Elp456 affect the tRNA modification activity of Elongator in vitro as well as in human and murine cells. Modeling the pathogenic variants in mice recapitulates the clinical features of the patients and reveals neuropathology that differs from the one caused by previously characterized Elp123 mutations. Our study demonstrates a direct correlation between Elp4 and Elp6 mutations, reduced Elongator activity, and neurological defects. Foremost, our data indicate previously unrecognized differences of the Elp123 and Elp456 subcomplexes for individual tRNA species, in different cell types and in different key steps during the neurodevelopment of higher organisms.
Collapse
|
22
|
Morini E, Gao D, Logan EM, Salani M, Krauson AJ, Chekuri A, Chen YT, Ragavendran A, Chakravarty P, Erdin S, Stortchevoi A, Svejstrup JQ, Talkowski ME, Slaugenhaupt SA. Developmental regulation of neuronal gene expression by Elongator complex protein 1 dosage. J Genet Genomics 2022; 49:654-665. [PMID: 34896608 PMCID: PMC9254147 DOI: 10.1016/j.jgg.2021.11.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 10/27/2021] [Accepted: 11/04/2021] [Indexed: 01/21/2023]
Abstract
Familial dysautonomia (FD), a hereditary sensory and autonomic neuropathy, is caused by a mutation in the Elongator complex protein 1 (ELP1) gene that leads to a tissue-specific reduction of ELP1 protein. Our work to generate a phenotypic mouse model for FD headed to the discovery that homozygous deletion of the mouse Elp1 gene leads to embryonic lethality prior to mid-gestation. Given that FD is caused by a reduction, not loss, of ELP1, we generated two new mouse models by introducing different copy numbers of the human FD ELP1 transgene into the Elp1 knockout mouse (Elp1-/-) and observed that human ELP1 expression rescues embryonic development in a dose-dependent manner. We then conducted a comprehensive transcriptome analysis in mouse embryos to identify genes and pathways whose expression correlates with the amount of ELP1. We found that ELP1 is essential for the expression of genes responsible for nervous system development. Further, gene length analysis of the differentially expressed genes showed that the loss of Elp1 mainly impacts the expression of long genes and that by gradually restoring Elongator, their expression is progressively rescued. Finally, through evaluation of co-expression modules, we identified gene sets with unique expression patterns that depended on ELP1 expression.
Collapse
Affiliation(s)
- Elisabetta Morini
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Boston, MA, USA; Department of Neurology, Massachusetts General Hospital Research Institute and Harvard Medical School, Boston, MA, USA
| | - Dadi Gao
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Boston, MA, USA; Department of Neurology, Massachusetts General Hospital Research Institute and Harvard Medical School, Boston, MA, USA; Program in Medical and Population Genetics and Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA, USA
| | - Emily M Logan
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Boston, MA, USA
| | - Monica Salani
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Boston, MA, USA
| | - Aram J Krauson
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Boston, MA, USA
| | - Anil Chekuri
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Boston, MA, USA; Department of Neurology, Massachusetts General Hospital Research Institute and Harvard Medical School, Boston, MA, USA
| | - Yei-Tsung Chen
- Department of Life Sciences and Institute of Genome Sciences, National Yang Ming Chiao Tung University, Taiwan
| | - Ashok Ragavendran
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Boston, MA, USA; Program in Medical and Population Genetics and Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA, USA
| | - Probir Chakravarty
- Bioinformatics and Biostatistics, The Francis Crick Institute, London, UK
| | - Serkan Erdin
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Boston, MA, USA; Program in Medical and Population Genetics and Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA, USA
| | - Alexei Stortchevoi
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Boston, MA, USA; Program in Medical and Population Genetics and Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA, USA
| | - Jesper Q Svejstrup
- Mechanisms of Transcription Laboratory, The Francis Crick Institute, London, UK; Department of Cellular and Molecular Medicine, Panum Institute, University of Copenhagen, Copenhagen, Denmark
| | - Michael E Talkowski
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Boston, MA, USA; Department of Neurology, Massachusetts General Hospital Research Institute and Harvard Medical School, Boston, MA, USA; Program in Medical and Population Genetics and Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA, USA
| | - Susan A Slaugenhaupt
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Boston, MA, USA; Department of Neurology, Massachusetts General Hospital Research Institute and Harvard Medical School, Boston, MA, USA.
| |
Collapse
|
23
|
Elongator regulates the melanocortin satiety pathway. Biochem Biophys Res Commun 2022; 613:73-80. [DOI: 10.1016/j.bbrc.2022.04.128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 04/27/2022] [Indexed: 11/19/2022]
|
24
|
Lischka A, Lassuthova P, Çakar A, Record CJ, Van Lent J, Baets J, Dohrn MF, Senderek J, Lampert A, Bennett DL, Wood JN, Timmerman V, Hornemann T, Auer-Grumbach M, Parman Y, Hübner CA, Elbracht M, Eggermann K, Geoffrey Woods C, Cox JJ, Reilly MM, Kurth I. Genetic pain loss disorders. Nat Rev Dis Primers 2022; 8:41. [PMID: 35710757 DOI: 10.1038/s41572-022-00365-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/10/2022] [Indexed: 01/05/2023]
Abstract
Genetic pain loss includes congenital insensitivity to pain (CIP), hereditary sensory neuropathies and, if autonomic nerves are involved, hereditary sensory and autonomic neuropathy (HSAN). This heterogeneous group of disorders highlights the essential role of nociception in protecting against tissue damage. Patients with genetic pain loss have recurrent injuries, burns and poorly healing wounds as disease hallmarks. CIP and HSAN are caused by pathogenic genetic variants in >20 genes that lead to developmental defects, neurodegeneration or altered neuronal excitability of peripheral damage-sensing neurons. These genetic variants lead to hyperactivity of sodium channels, disturbed haem metabolism, altered clathrin-mediated transport and impaired gene regulatory mechanisms affecting epigenetic marks, long non-coding RNAs and repetitive elements. Therapies for pain loss disorders are mainly symptomatic but the first targeted therapies are being tested. Conversely, chronic pain remains one of the greatest unresolved medical challenges, and the genes and mechanisms associated with pain loss offer new targets for analgesics. Given the progress that has been made, the coming years are promising both in terms of targeted treatments for pain loss disorders and the development of innovative pain medicines based on knowledge of these genetic diseases.
Collapse
Affiliation(s)
- Annette Lischka
- Institute of Human Genetics, Medical Faculty, Uniklinik RWTH Aachen University, Aachen, Germany
| | - Petra Lassuthova
- Department of Paediatric Neurology, 2nd Faculty of Medicine, Charles University in Prague and Motol University Hospital, Prague, Czech Republic
| | - Arman Çakar
- Neuromuscular Unit, Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Christopher J Record
- Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, UK
| | - Jonas Van Lent
- Peripheral Neuropathy Research Group, Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium.,Laboratory of Neuromuscular Pathology, Institute Born Bunge, Antwerp, Belgium
| | - Jonathan Baets
- Laboratory of Neuromuscular Pathology, Institute Born Bunge, Antwerp, Belgium.,Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium.,Neuromuscular Reference Centre, Department of Neurology, Antwerp University Hospital, Antwerp, Belgium
| | - Maike F Dohrn
- Department of Neurology, Medical Faculty, Uniklinik RWTH Aachen University, Aachen, Germany.,Dr. John T. Macdonald Foundation, Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami, Miller School of Medicine, Miami, FL, USA
| | - Jan Senderek
- Friedrich-Baur-Institute, Department of Neurology, Ludwig-Maximilians-University, Munich, Germany
| | - Angelika Lampert
- Institute of Physiology, Medical Faculty, Uniklinik RWTH Aachen University, Aachen, Germany
| | - David L Bennett
- Nuffield Department of Clinical Neuroscience, Oxford University, Oxford, UK
| | - John N Wood
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, London, UK
| | - Vincent Timmerman
- Peripheral Neuropathy Research Group, Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium.,Laboratory of Neuromuscular Pathology, Institute Born Bunge, Antwerp, Belgium
| | - Thorsten Hornemann
- Department of Clinical Chemistry, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Michaela Auer-Grumbach
- Department of Orthopedics and Trauma Surgery, Medical University of Vienna, Vienna, Austria
| | - Yesim Parman
- Neuromuscular Unit, Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | | | - Miriam Elbracht
- Institute of Human Genetics, Medical Faculty, Uniklinik RWTH Aachen University, Aachen, Germany
| | - Katja Eggermann
- Institute of Human Genetics, Medical Faculty, Uniklinik RWTH Aachen University, Aachen, Germany
| | - C Geoffrey Woods
- Cambridge Institute for Medical Research, Keith Peters Building, Cambridge Biomedical Campus, Cambridge, UK
| | - James J Cox
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, London, UK
| | - Mary M Reilly
- Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, UK
| | - Ingo Kurth
- Institute of Human Genetics, Medical Faculty, Uniklinik RWTH Aachen University, Aachen, Germany.
| |
Collapse
|
25
|
Anderson SL, Fasih-Ahmad F, Evans AJ, Rubin BY. Carnosol, a diterpene present in rosemary, increases ELP1 levels in familial Dysautonomia (FD) patient-derived cells and healthy adults: a possible therapy for FD. Hum Mol Genet 2022; 31:3521-3538. [PMID: 35708500 DOI: 10.1093/hmg/ddac133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 05/12/2022] [Accepted: 06/01/2022] [Indexed: 11/13/2022] Open
Abstract
Recent research on Familial Dysautonomia (FD) has focused on the development of therapeutics that facilitate the production of the correctly spliced, exon 20-containing, transcript in cells and individuals bearing the splice-altering, FD-causing, mutation in the ELP1 gene. We report here the ability of carnosol, a diterpene present in plant species of the Lamiaceae family, including rosemary, to enhance the cellular presence of the correctly spliced ELP1 transcript in FD patient-derived fibroblasts by upregulating transcription of the ELP1 gene and correcting the aberrant splicing of the ELP1 transcript. Carnosol treatment also elevates the level of the RBM24 and RBM38 proteins., two multifunctional RNA binding proteins. Transfection-mediated expression of either of these RBMs facilitates the inclusion of exon 20 sequence into the transcript generated from a minigene bearing ELP1 genomic sequence containing the FD-causing mutation. Suppression of the carnosol-mediated induction of either of these RBMs, using targeting siRNAs, limited the carnosol-mediated inclusion of the ELP1 exon 20 sequence. Carnosol treatment of FD patient PBMCs facilitates the inclusion of exon 20 into the ELP1 transcript. Increased levels of the ELP1 and RBM38 transcripts and the alternative splicing of the SIRT2 transcript, a sentinel for exon 20 inclusion in the FD-derived ELP1 transcript, are observed in RNA isolated from whole blood of healthy adults following the ingestion of carnosol-containing rosemary extract. These findings and the excellent safety profile of rosemary together justify an expedited clinical study of the impact of carnosol on the FD patient population.
Collapse
Affiliation(s)
- Sylvia L Anderson
- Laboratory for Familial Dysautonomia Research, Department of Biological Sciences, Fordham University, Bronx, NY 10458, USA
| | - Faaria Fasih-Ahmad
- Laboratory for Familial Dysautonomia Research, Department of Biological Sciences, Fordham University, Bronx, NY 10458, USA
| | - Anthony J Evans
- Laboratory for Familial Dysautonomia Research, Department of Biological Sciences, Fordham University, Bronx, NY 10458, USA
| | - Berish Y Rubin
- Laboratory for Familial Dysautonomia Research, Department of Biological Sciences, Fordham University, Bronx, NY 10458, USA
| |
Collapse
|
26
|
Chekuri A, Logan EM, Krauson AJ, Salani M, Ackerman S, Kirchner EG, Bolduc JM, Wang X, Dietrich P, Dragatsis I, Vandenberghe LH, Slaugenhaupt SA, Morini E. Selective retinal ganglion cell loss and optic neuropathy in a humanized mouse model of familial dysautonomia. Hum Mol Genet 2022; 31:1776-1787. [PMID: 34908112 PMCID: PMC9169455 DOI: 10.1093/hmg/ddab359] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 12/09/2021] [Accepted: 12/10/2021] [Indexed: 11/21/2022] Open
Abstract
Familial dysautonomia (FD) is an autosomal recessive neurodegenerative disease caused by a splicing mutation in the gene encoding Elongator complex protein 1 (ELP1, also known as IKBKAP). This mutation results in tissue-specific skipping of exon 20 with a corresponding reduction of ELP1 protein, predominantly in the central and peripheral nervous system. Although FD patients have a complex neurological phenotype caused by continuous depletion of sensory and autonomic neurons, progressive visual decline leading to blindness is one of the most problematic aspects of the disease, as it severely affects their quality of life. To better understand the disease mechanism as well as to test the in vivo efficacy of targeted therapies for FD, we have recently generated a novel phenotypic mouse model, TgFD9; IkbkapΔ20/flox. This mouse exhibits most of the clinical features of the disease and accurately recapitulates the tissue-specific splicing defect observed in FD patients. Driven by the dire need to develop therapies targeting retinal degeneration in FD, herein, we comprehensively characterized the progression of the retinal phenotype in this mouse, and we demonstrated that it is possible to correct ELP1 splicing defect in the retina using the splicing modulator compound (SMC) BPN-15477.
Collapse
Affiliation(s)
- Anil Chekuri
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Boston, MA, USA
- Department of Neurology, Massachusetts General Hospital Research Institute and Harvard Medical School, Boston, MA, USA
- Grousbeck Gene Therapy Center, Schepens Eye Research Institute and Massachusetts Eye and Ear Infirmary, Boston, MA, USA
| | - Emily M Logan
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Boston, MA, USA
| | - Aram J Krauson
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Boston, MA, USA
| | - Monica Salani
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Boston, MA, USA
| | - Sophie Ackerman
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Boston, MA, USA
| | - Emily G Kirchner
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Boston, MA, USA
| | - Jessica M Bolduc
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Boston, MA, USA
| | - Xia Wang
- Grousbeck Gene Therapy Center, Schepens Eye Research Institute and Massachusetts Eye and Ear Infirmary, Boston, MA, USA
| | - Paula Dietrich
- Department of Physiology, The University of Tennessee, Health Science Center, Memphis, TN, USA
| | - Ioannis Dragatsis
- Department of Physiology, The University of Tennessee, Health Science Center, Memphis, TN, USA
| | - Luk H Vandenberghe
- Grousbeck Gene Therapy Center, Schepens Eye Research Institute and Massachusetts Eye and Ear Infirmary, Boston, MA, USA
| | - Susan A Slaugenhaupt
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Boston, MA, USA
- Department of Neurology, Massachusetts General Hospital Research Institute and Harvard Medical School, Boston, MA, USA
| | - Elisabetta Morini
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Boston, MA, USA
- Department of Neurology, Massachusetts General Hospital Research Institute and Harvard Medical School, Boston, MA, USA
| |
Collapse
|
27
|
Wang N, Xi J, Lan C, Wu Y, Zhu Y, Zuo X, Zhang Y. Association between IKBKAP polymorphisms and Hirschsprung's disease susceptibility in Chinese children. Transl Pediatr 2022; 11:789-796. [PMID: 35800263 PMCID: PMC9253937 DOI: 10.21037/tp-21-550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 04/22/2022] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Hirschsprung's disease (HSCR) is a rare congenital disease in which enteric nervous system (ENS) in the distal intestine is absent. HSCR is a disease involving genetic factors and environmental factors. Despite a series of genes have been revealed to contribute to HSCR, many HSCR associated genes were yet not identified. Previous studies had identified that a potential susceptibility gene of HSCR was an inhibitor of kappa light polypeptide gene enhancer in B-cells, kinase complex-associated protein (IKBKAP). The study aimed to explore the association of genetic variants in IKBKAP and HSCR susceptibility in southern Chinese children. METHODS Single nucleotide polymorphism (SNPs) were genotyped by the Mass ARRAY iPLEX Gold system (Sequenom, San Diego, CA, USA) on all samples, which included 1,470 HSCR children (cases) and 1,473 healthy children (controls). The associations between SNPs and HSCR or clinical subtypes were assessed by comparing their allele frequencies in corresponding case and control samples. Different genetic models, including additive, recessive, and dominant models, were tested using PLINK 1.9 software. RESULTS Further subgroup analysis revealed rs2275630 as a total colonic aganglionosis (TCA)-specific susceptibility locus. The present study is the first to indicate that IKBKAP rs2275630 were associated with HSCR susceptibility, especially in TCA patients. CONCLUSIONS We conclude that IKBKAP rs2275630 is a susceptibility gene of HSCR.
Collapse
Affiliation(s)
- Ning Wang
- Department of Pediatric Surgery, Guangzhou Institute of Pediatrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Jiaojiao Xi
- Department of Pediatric Surgery, Guangzhou Institute of Pediatrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Chaoting Lan
- Department of Pediatrics, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Yuxin Wu
- Department of Pediatrics, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Yun Zhu
- Department of Pediatric Surgery, Guangzhou Institute of Pediatrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Xiaoyu Zuo
- Department of Pediatric Surgery, Guangzhou Institute of Pediatrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Yan Zhang
- Department of Pediatric Surgery, Guangzhou Institute of Pediatrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| |
Collapse
|
28
|
Turan B, Yitik Tonkaz G, Selçuk Esin İ, Burak Dursun O. A Closer Look at Familial Dysautonomia from a Social Communication Perspective: A Case Report and Review of Literature. PSYCHIAT CLIN PSYCH 2022; 32:178-180. [PMID: 38764866 PMCID: PMC11099645 DOI: 10.5152/pcp.2022.21210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 11/04/2021] [Indexed: 05/21/2024] Open
Abstract
Familial dysautonomia (Riley-Day syndrome) is a rare but fatal autosomal recessive peripheral neuropathy caused by a point mutation in I-κ-B kinase complex-associated protein gene. The disease, which affects primarily people of Ashkenazi Jewish origin, prejudices the development of primary sensory neurons determining the depletion of autonomic and sensory neurons. In this study, we report a 5-year-old girl with familial dysautonomia, and how her different psychiatric aspects may lead to genetic vulnerability. Obviously, the gene, the reason for this syndrome, and overreactions to different kinds of emotions, maybe a risk factor for having any mood disorders. From another perspective, this "genetic vulnerability" may be protective or related to the syndromes that affect social communication like autism.
Collapse
Affiliation(s)
- Bahadır Turan
- Turkish Ministry of Health, Ağrı State Hospital, Child and Adolescent Psychiatry Unit, Ağrı, Turkey
| | - Gülsüm Yitik Tonkaz
- University of Health Sciences, Erzurum Region Training and Research Hospital, Child and Adolescent Psychiatry Unit, Erzurum, Turkey
| | - İbrahim Selçuk Esin
- Department of Child and Adolescent Psychiatry, Atatürk University, School of Medicine, Erzurum, Turkey
| | - Onur Burak Dursun
- Department of Child and Adolescent Psychiatry, University of Health Sciences, Trabzon Kanuni Training and Research Hospital, Trabzon, Turkey
| |
Collapse
|
29
|
Funk H, DiVita DJ, Sizemore HE, Wehrle K, Miller CLW, Fraley ME, Mullins AK, Guy AR, Phizicky EM, Guy MP. Identification of a Trm732 Motif Required for 2'- O-methylation of the tRNA Anticodon Loop by Trm7. ACS OMEGA 2022; 7:13667-13675. [PMID: 35559166 PMCID: PMC9088939 DOI: 10.1021/acsomega.1c07231] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 03/31/2022] [Indexed: 06/15/2023]
Abstract
Posttranscriptional tRNA modifications are essential for proper gene expression, and defects in the enzymes that perform tRNA modifications are associated with numerous human disorders. Throughout eukaryotes, 2'-O-methylation of residues 32 and 34 of the anticodon loop of tRNA is important for proper translation, and in humans, a lack of these modifications results in non-syndromic X-linked intellectual disability. In yeast, the methyltransferase Trm7 forms a complex with Trm732 to 2'-O-methylate tRNA residue 32 and with Trm734 to 2'-O-methylate tRNA residue 34. Trm732 and Trm734 are required for the methylation activity of Trm7, but the role of these auxiliary proteins is not clear. Additionally, Trm732 and Trm734 homologs are implicated in biological processes not directly related to translation, suggesting that these proteins may have additional cellular functions. To identify critical amino acids in Trm732, we generated variants and tested their ability to function in yeast cells. We identified a conserved RRSAGLP motif in the conserved DUF2428 domain of Trm732 that is required for tRNA modification activity by both yeast Trm732 and its human homolog, THADA. The identification of Trm732 variants that lack tRNA modification activity will help to determine if other biological functions ascribed to Trm732 and THADA are directly due to tRNA modification or to secondary effects due to other functions of these proteins.
Collapse
Affiliation(s)
- Holly
M. Funk
- Department
of Chemistry & Biochemistry, Northern
Kentucky University, Highland
Heights, Kentucky 41076, United States
| | - Daisy J. DiVita
- Department
of Chemistry & Biochemistry, Northern
Kentucky University, Highland
Heights, Kentucky 41076, United States
| | - Hannah E. Sizemore
- Department
of Chemistry & Biochemistry, Northern
Kentucky University, Highland
Heights, Kentucky 41076, United States
| | - Kendal Wehrle
- Department
of Chemistry & Biochemistry, Northern
Kentucky University, Highland
Heights, Kentucky 41076, United States
| | - Catherine L. W. Miller
- Department
of Biochemistry and Biophysics, University
of Rochester School of Medicine, Rochester, New York 14642, United States
| | - Morgan E. Fraley
- Department
of Chemistry & Biochemistry, Northern
Kentucky University, Highland
Heights, Kentucky 41076, United States
| | - Alex K. Mullins
- Department
of Chemistry & Biochemistry, Northern
Kentucky University, Highland
Heights, Kentucky 41076, United States
| | - Adrian R. Guy
- Department
of Chemistry & Biochemistry, Northern
Kentucky University, Highland
Heights, Kentucky 41076, United States
| | - Eric M. Phizicky
- Department
of Biochemistry and Biophysics, University
of Rochester School of Medicine, Rochester, New York 14642, United States
| | - Michael P. Guy
- Department
of Chemistry & Biochemistry, Northern
Kentucky University, Highland
Heights, Kentucky 41076, United States
- Department
of Biochemistry and Biophysics, University
of Rochester School of Medicine, Rochester, New York 14642, United States
| |
Collapse
|
30
|
Dalwadi U, Mannar D, Zierhut F, Yip CK. Biochemical and Structural Characterization of Human Core Elongator and Its Subassemblies. ACS OMEGA 2022; 7:3424-3433. [PMID: 35128251 PMCID: PMC8811885 DOI: 10.1021/acsomega.1c05719] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 12/31/2021] [Indexed: 06/14/2023]
Abstract
Conserved from yeast to humans and composed of six core subunits (Elp1-Elp6), Elongator is a multiprotein complex that catalyzes the modification of the anticodon loop of transfer RNAs (tRNAs) and in turn regulates messenger RNA decoding efficiency. Previous studies showed that yeast Elongator consists of two subassemblies (yElp1/2/3 and yElp4/5/6) and adopts an asymmetric overall architecture. Yet, much less is known about the structural properties of the orthologous human Elongator. Furthermore, the order in which the different Elongator subunits come together to form the full assembly as well as how they coordinate with one another to catalyze tRNA modification is not fully understood. Here, we purified recombinant human Elongator subunits and subassemblies and examined them by single-particle electron microscopy. We found that the human Elongator complex is assembled from two subcomplexes that share similar overall morphologies as their yeast counterparts. Complementary co-purification and pulldown assays revealed that the scaffolding subunit human ELP1 (hELP1) has stabilizing effects on the human ELP3 catalytic subunit. Furthermore, the peripheral hELP2 subunit appears to enhance the integrity and substrate-binding ability of the dimeric hELP1/2/3. Lastly, we found that hELP4/5/6 is recruited to hELP1/2/3 via hELP3. Collectively, our work generated insights into the assembly process of core human Elongator and the coordination of different subunits within this complex.
Collapse
|
31
|
Leonard CE, Quiros J, Lefcort F, Taneyhill LA. Loss of Elp1 disrupts trigeminal ganglion neurodevelopment in a model of familial dysautonomia. eLife 2022; 11:71455. [PMID: 35713404 PMCID: PMC9273214 DOI: 10.7554/elife.71455] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Accepted: 06/17/2022] [Indexed: 01/28/2023] Open
Abstract
Familial dysautonomia (FD) is a sensory and autonomic neuropathy caused by mutations in elongator complex protein 1 (ELP1). FD patients have small trigeminal nerves and impaired facial pain and temperature perception. These signals are relayed by nociceptive neurons in the trigeminal ganglion, a structure that is composed of both neural crest- and placode-derived cells. Mice lacking Elp1 in neural crest derivatives ('Elp1 CKO') are born with small trigeminal ganglia, suggesting Elp1 is important for trigeminal ganglion development, yet the function of Elp1 in this context is unknown. We demonstrate that Elp1, expressed in both neural crest- and placode-derived neurons, is not required for initial trigeminal ganglion formation. However, Elp1 CKO trigeminal neurons exhibit abnormal axon outgrowth and deficient target innervation. Developing nociceptors expressing the receptor TrkA undergo early apoptosis in Elp1 CKO, while TrkB- and TrkC-expressing neurons are spared, indicating Elp1 supports the target innervation and survival of trigeminal nociceptors. Furthermore, we demonstrate that specific TrkA deficits in the Elp1 CKO trigeminal ganglion reflect the neural crest lineage of most TrkA neurons versus the placodal lineage of most TrkB and TrkC neurons. Altogether, these findings explain defects in cranial gangliogenesis that may lead to loss of facial pain and temperature sensation in FD.
Collapse
Affiliation(s)
- Carrie E Leonard
- Department of Avian and Animal Sciences, University of Maryland, College ParkCollege ParkUnited States
| | - Jolie Quiros
- Department of Avian and Animal Sciences, University of Maryland, College ParkCollege ParkUnited States
| | - Frances Lefcort
- Department of Microbiology and Cell Biology, Montana State UniversityBozemanUnited States
| | - Lisa A Taneyhill
- Department of Avian and Animal Sciences, University of Maryland, College ParkCollege ParkUnited States
| |
Collapse
|
32
|
Wang DO. Epitranscriptomic regulation of cognitive development and decline. Semin Cell Dev Biol 2021; 129:3-13. [PMID: 34857470 DOI: 10.1016/j.semcdb.2021.11.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Revised: 11/16/2021] [Accepted: 11/19/2021] [Indexed: 11/24/2022]
Abstract
Functional genomics and systems biology have opened new doors to previously inaccessible genomic information and holistic approaches to study complex networks of genes and proteins in the central nervous system. The advances are revolutionizing our understanding of the genetic underpinning of cognitive development and decline by facilitating identifications of novel molecular regulators and physiological pathways underlying brain function, and by associating polymorphism and mutations to cognitive dysfunction and neurological diseases. However, our current understanding of these complex gene regulatory mechanisms has yet lacked sufficient mechanistic resolution for further translational breakthroughs. Here we review recent findings from the burgeoning field of epitranscriptomics in association of cognitive functions with a special focus on the epitranscritomic regulation in subcellular locations such as chromosome, synapse, and mitochondria. Although there are important gaps in knowledge, current evidence is suggesting that this layer of RNA regulation may be of particular interest for the spatiotemporally coordinated regulation of gene networks in developing and maintaining brain function that underlie cognitive changes.
Collapse
Affiliation(s)
- Dan Ohtan Wang
- Center for Biosystems Dynamics Research, RIKEN, 2-2-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047, Japan; Graduate School of Biostudies, Kyoto University, Yoshida Hon-machi, Kyoto 606-8501, Japan.
| |
Collapse
|
33
|
Chen WT, Tseng HY, Jiang CL, Lee CY, Chi P, Chen LY, Lo KY, Wang IC, Lin FJ. Elp1 facilitates RAD51-mediated homologous recombination repair via translational regulation. J Biomed Sci 2021; 28:81. [PMID: 34819065 PMCID: PMC8613991 DOI: 10.1186/s12929-021-00773-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 11/02/2021] [Indexed: 11/25/2022] Open
Abstract
Background RAD51-dependent homologous recombination (HR) is one of the most important pathways for repairing DNA double-strand breaks (DSBs), and its regulation is crucial to maintain genome integrity. Elp1 gene encodes IKAP/ELP1, a core subunit of the Elongator complex, which has been implicated in translational regulation. However, how ELP1 contributes to genome maintenance is unclear. Methods To investigate the function of Elp1, Elp1-deficient mouse embryonic fibroblasts (MEFs) were generated. Metaphase chromosome spreading, immunofluorescence, and comet assays were used to access chromosome abnormalities and DSB formation. Functional roles of Elp1 in MEFs were evaluated by cell viability, colony forming capacity, and apoptosis assays. HR-dependent DNA repair was assessed by reporter assay, immunofluorescence, and western blot. Polysome profiling was used to evaluate translational efficiency. Differentially expressed proteins and signaling pathways were identified using a label-free liquid chromatography–tandem mass spectrometry (LC–MS/MS) proteomics approach. Results Here, we report that Elp1 depletion enhanced genomic instability, manifested as chromosome breakage and genotoxic stress-induced genomic DNA fragmentation upon ionizing radiation (IR) exposure. Elp1-deficient cells were hypersensitive to DNA damage and exhibited impaired cell proliferation and defective HR repair. Moreover, Elp1 depletion reduced the formation of IR-induced RAD51 foci and decreased RAD51 protein levels. Polysome profiling analysis revealed that ELP1 regulated RAD51 expression by promoting its translation in response to DNA damage. Notably, the requirement for ELP1 in DSB repair could be partially rescued in Elp1-deficient cells by reintroducing RAD51, suggesting that Elp1-mediated HR-directed repair of DSBs is RAD51-dependent. Finally, using proteome analyses, we identified several proteins involved in cancer pathways and DNA damage responses as being differentially expressed upon Elp1 depletion. Conclusions Our study uncovered a molecular mechanism underlying Elp1-mediated regulation of HR activity and provides a novel link between translational regulation and genome stability. Supplementary Information The online version contains supplementary material available at 10.1186/s12929-021-00773-z.
Collapse
Affiliation(s)
- Wei-Ting Chen
- Department of Biochemical Science and Technology, National Taiwan University, No.1, Sec.4, Roosevelt Rd., Taipei, 10617, Taiwan
| | - Huan-Yi Tseng
- Department of Biochemical Science and Technology, National Taiwan University, No.1, Sec.4, Roosevelt Rd., Taipei, 10617, Taiwan
| | - Chung-Lin Jiang
- Department of Biochemical Science and Technology, National Taiwan University, No.1, Sec.4, Roosevelt Rd., Taipei, 10617, Taiwan
| | - Chih-Ying Lee
- Institute of Biochemical Sciences, National Taiwan University, Taipei, 10617, Taiwan
| | - Peter Chi
- Institute of Biochemical Sciences, National Taiwan University, Taipei, 10617, Taiwan.,Institute of Biological Chemistry, Academia Sinica, Taipei, 11529, Taiwan
| | - Liuh-Yow Chen
- Institute of Molecular Biology, Academia Sinica, Taipei, 11529, Taiwan
| | - Kai-Yin Lo
- Department of Agricultural Chemistry, National Taiwan University, Taipei, 10617, Taiwan
| | - I-Ching Wang
- Institute of Biotechnology, National Tsing Hua University, Hsinchu, 30013, Taiwan
| | - Fu-Jung Lin
- Department of Biochemical Science and Technology, National Taiwan University, No.1, Sec.4, Roosevelt Rd., Taipei, 10617, Taiwan. .,Research Center for Development Biology and Regenerative Medicine, National Taiwan University, Taipei, 10617, Taiwan.
| |
Collapse
|
34
|
Vahidi G, Flook H, Sherk V, Mergy M, Lefcort F, Heveran CM. Bone biomechanical properties and tissue-scale bone quality in a genetic mouse model of familial dysautonomia. Osteoporos Int 2021; 32:2335-2346. [PMID: 34036438 PMCID: PMC8563419 DOI: 10.1007/s00198-021-06006-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 05/11/2021] [Indexed: 10/21/2022]
Abstract
PURPOSE Familial dysautonomia (FD) is associated with a high prevalence of bone fractures, but the impacts of the disease on bone mass and quality are unclear. The purpose of this study was to evaluate tissue through whole-bone scale bone quality in a mouse model of FD. METHODS Femurs from mature adult Tuba1a-Cre; Elp1LoxP/LoxP conditional knockouts (CKO) (F = 7, M = 4) and controls (F = 5, M = 6) were evaluated for whole-bone flexural material properties, trabecular microarchitecture and cortical geometry, and areal bone mineral density (BMD). Adjacent maps spanning the thickness of femur midshaft cortical bone assessed tissue-scale modulus (nanoindentation), bone mineralization, mineral maturity, and collagen secondary structure (Raman spectroscopy). RESULTS Consistent with prior studies on this mouse model, the Elp1 CKO mouse model recapitulated several key hallmarks of human FD, with one difference being the male mice tended to have a more severe phenotype than females. Deletion of Elp1 in neurons (using the neuronal-specific Tuba1a-cre) led to a significantly reduced whole-bone toughness but not strength or modulus. Elp1 CKO female mice had reduced trabecular microarchitecture (BV/TV, Tb.Th, Conn.D.) but not cortical geometry. The mutant mice also had a small but significant reduction in cortical bone nanoindentation modulus. While bone tissue mineralization and mineral maturity were not impaired, FD mice may have altered collagen secondary structure. Changes in collagen secondary structure were inversely correlated with bone toughness. BMD from dual-energy x-ray absorptiometry (DXA) was unchanged with FD. CONCLUSION The deletion of Elp1 in neurons is sufficient to generate a mouse line which demonstrates loss of whole-bone toughness, consistent with the poor bone quality suspected in the clinical setting. The Elp1 CKO model, as with human FD, impacts the nervous system, gut, kidney function, mobility, gait, and posture. The bone quality phenotype of Elp1 CKO mice, which includes altered microarchitecture and tissue-scale material properties, is complex and likely influenced by these multisystemic changes. This mouse model may provide a useful platform to not only investigate the mechanisms responsible for bone fragility in FD, but also a powerful model system with which to evaluate potential therapeutic interventions for bone fragility in FD patients.
Collapse
Affiliation(s)
- G Vahidi
- Department of Mechanical & Industrial Engineerings, Montana State University, Bozeman, MT, USA
| | - H Flook
- Department of Mechanical & Industrial Engineerings, Montana State University, Bozeman, MT, USA
| | - V Sherk
- Department of Orthopaedics, University of Colorado School of Medicine, Aurora, CO, USA
| | - M Mergy
- Department of Microbiology & Immunology, Montana State University, Bozeman, MT, USA
| | - F Lefcort
- Department of Microbiology & Immunology, Montana State University, Bozeman, MT, USA
| | - C M Heveran
- Department of Mechanical & Industrial Engineerings, Montana State University, Bozeman, MT, USA.
| |
Collapse
|
35
|
ATP-citrate lyase promotes axonal transport across species. Nat Commun 2021; 12:5878. [PMID: 34620845 PMCID: PMC8497606 DOI: 10.1038/s41467-021-25786-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 08/24/2021] [Indexed: 01/22/2023] Open
Abstract
Microtubule (MT)-based transport is an evolutionary conserved process finely tuned by posttranslational modifications. Among them, α-tubulin acetylation, primarily catalyzed by a vesicular pool of α-tubulin N-acetyltransferase 1 (Atat1), promotes the recruitment and processivity of molecular motors along MT tracks. However, the mechanism that controls Atat1 activity remains poorly understood. Here, we show that ATP-citrate lyase (Acly) is enriched in vesicles and provide Acetyl-Coenzyme-A (Acetyl-CoA) to Atat1. In addition, we showed that Acly expression is reduced upon loss of Elongator activity, further connecting Elongator to Atat1 in a pathway regulating α-tubulin acetylation and MT-dependent transport in projection neurons, across species. Remarkably, comparable defects occur in fibroblasts from Familial Dysautonomia (FD) patients bearing an autosomal recessive mutation in the gene coding for the Elongator subunit ELP1. Our data may thus shine light on the pathophysiological mechanisms underlying FD. Microtubule tracks are important for the transport of molecules within axons. Here, the authors show that ATAT1, the enzyme responsible for acetylating a-tubulin, receives acetyl groups from ATP citrate lyase whose stability is regulated by Elongator, a protein mutated in the neuronal disease Familial dysautonomia.
Collapse
|
36
|
Lombardi S, Leo G, Merlin S, Follenzi A, McVey JH, Maestri I, Bernardi F, Pinotti M, Balestra D. Dissection of pleiotropic effects of variants in and adjacent to F8 exon 19 and rescue of mRNA splicing and protein function. Am J Hum Genet 2021; 108:1512-1525. [PMID: 34242570 DOI: 10.1016/j.ajhg.2021.06.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 06/14/2021] [Indexed: 12/11/2022] Open
Abstract
The pathogenic significance of nucleotide variants commonly relies on nucleotide position within the gene, with exonic changes generally attributed to quantitative or qualitative alteration of protein biosynthesis, secretion, activity, or clearance. However, these changes may exert pleiotropic effects on both protein biology and mRNA splicing due to the overlapping of the amino acid and splicing codes, thus shaping the disease phenotypes. Here, we focused on hemophilia A, in which the definition of F8 variants' causative role and association to bleeding phenotypes is crucial for proper classification, genetic counseling, and management of affected individuals. We extensively characterized a large panel of hemophilia A-causing variants (n = 30) within F8 exon 19 by combining and comparing in silico and recombinant expression analyses. We identified exonic variants with pleiotropic effects and dissected the altered protein features of all missense changes. Importantly, results from multiple prediction algorithms provided qualitative results, while recombinant assays allowed us to correctly infer the likely phenotype severity for 90% of variants. Molecular characterization of pathogenic variants was also instrumental for the development of tailored correction approaches to rescue splicing affecting variants or missense changes impairing protein folding. A single engineered U1snRNA rescued mRNA splicing of nine different variants and the use of a chaperone-like drug resulted in improved factor VIII protein secretion for four missense variants. Overall, dissection of the molecular mechanisms of a large panel of HA variants allowed precise classification of HA-affected individuals and favored the development of personalized therapeutic approaches.
Collapse
Affiliation(s)
- Silvia Lombardi
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara 44121, Italy
| | - Gabriele Leo
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara 44121, Italy
| | - Simone Merlin
- Department of Health Sciences, University of Piemonte Orientale, Novara 28100, Italy
| | - Antonia Follenzi
- Department of Health Sciences, University of Piemonte Orientale, Novara 28100, Italy
| | - John H McVey
- School of Bioscience and Medicine, University of Surrey, Guildford GU2 7XH, UK
| | - Iva Maestri
- Department of Experimental and Diagnostic Medicine, University of Ferrara, Ferrara 44123, Italy
| | - Francesco Bernardi
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara 44121, Italy
| | - Mirko Pinotti
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara 44121, Italy.
| | - Dario Balestra
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara 44121, Italy.
| |
Collapse
|
37
|
The case of a patient with MIRAGE syndrome with familial dysautonomia-like symptoms. Hum Genome Var 2021; 8:27. [PMID: 34253717 PMCID: PMC8275606 DOI: 10.1038/s41439-021-00158-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 05/25/2021] [Accepted: 06/18/2021] [Indexed: 11/08/2022] Open
Abstract
We describe a case of posthumously diagnosed MIRAGE syndrome (Myelodysplasia, Infection, Restriction of growth, Adrenal hypoplasia, Genital problems, and Enteropathy) in a girl with a new pathogenic SAMD9 variant (p.F437S), who was initially considered to have familial dysautonomia (FD)-like disease due to increased levels of catecholamine metabolites. Functional analyses of F437S-SAMD9 were performed, showing characteristics of disease-causing variants. This new SAMD9 variant (p.F437S) also causes MIRAGE syndrome.
Collapse
|
38
|
Li D, McIntosh CS, Mastaglia FL, Wilton SD, Aung-Htut MT. Neurodegenerative diseases: a hotbed for splicing defects and the potential therapies. Transl Neurodegener 2021; 10:16. [PMID: 34016162 PMCID: PMC8136212 DOI: 10.1186/s40035-021-00240-7] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 04/23/2021] [Indexed: 12/14/2022] Open
Abstract
Precursor messenger RNA (pre-mRNA) splicing is a fundamental step in eukaryotic gene expression that systematically removes non-coding regions (introns) and ligates coding regions (exons) into a continuous message (mature mRNA). This process is highly regulated and can be highly flexible through a process known as alternative splicing, which allows for several transcripts to arise from a single gene, thereby greatly increasing genetic plasticity and the diversity of proteome. Alternative splicing is particularly prevalent in neuronal cells, where the splicing patterns are continuously changing to maintain cellular homeostasis and promote neurogenesis, migration and synaptic function. The continuous changes in splicing patterns and a high demand on many cis- and trans-splicing factors contribute to the susceptibility of neuronal tissues to splicing defects. The resultant neurodegenerative diseases are a large group of disorders defined by a gradual loss of neurons and a progressive impairment in neuronal function. Several of the most common neurodegenerative diseases involve some form of splicing defect(s), such as Alzheimer's disease, Parkinson's disease and spinal muscular atrophy. Our growing understanding of RNA splicing has led to the explosion of research in the field of splice-switching antisense oligonucleotide therapeutics. Here we review our current understanding of the effects alternative splicing has on neuronal differentiation, neuronal migration, synaptic maturation and regulation, as well as the impact on neurodegenerative diseases. We will also review the current landscape of splice-switching antisense oligonucleotides as a therapeutic strategy for a number of common neurodegenerative disorders.
Collapse
Affiliation(s)
- Dunhui Li
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, Western Australia, Australia.,Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Perth, Western Australia, Australia
| | - Craig Stewart McIntosh
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, Western Australia, Australia.,Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Perth, Western Australia, Australia
| | - Frank Louis Mastaglia
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, Western Australia, Australia.,Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Perth, Western Australia, Australia
| | - Steve Donald Wilton
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, Western Australia, Australia.,Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Perth, Western Australia, Australia
| | - May Thandar Aung-Htut
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, Western Australia, Australia. .,Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Perth, Western Australia, Australia.
| |
Collapse
|
39
|
Kojic M, Gawda T, Gaik M, Begg A, Salerno-Kochan A, Kurniawan ND, Jones A, Drożdżyk K, Kościelniak A, Chramiec-Głąbik A, Hediyeh-Zadeh S, Kasherman M, Shim WJ, Sinniah E, Genovesi LA, Abrahamsen RK, Fenger CD, Madsen CG, Cohen JS, Fatemi A, Stark Z, Lunke S, Lee J, Hansen JK, Boxill MF, Keren B, Marey I, Saenz MS, Brown K, Alexander SA, Mureev S, Batzilla A, Davis MJ, Piper M, Bodén M, Burne THJ, Palpant NJ, Møller RS, Glatt S, Wainwright BJ. Elp2 mutations perturb the epitranscriptome and lead to a complex neurodevelopmental phenotype. Nat Commun 2021; 12:2678. [PMID: 33976153 PMCID: PMC8113450 DOI: 10.1038/s41467-021-22888-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 03/24/2021] [Indexed: 02/03/2023] Open
Abstract
Intellectual disability (ID) and autism spectrum disorder (ASD) are the most common neurodevelopmental disorders and are characterized by substantial impairment in intellectual and adaptive functioning, with their genetic and molecular basis remaining largely unknown. Here, we identify biallelic variants in the gene encoding one of the Elongator complex subunits, ELP2, in patients with ID and ASD. Modelling the variants in mice recapitulates the patient features, with brain imaging and tractography analysis revealing microcephaly, loss of white matter tract integrity and an aberrant functional connectome. We show that the Elp2 mutations negatively impact the activity of the complex and its function in translation via tRNA modification. Further, we elucidate that the mutations perturb protein homeostasis leading to impaired neurogenesis, myelin loss and neurodegeneration. Collectively, our data demonstrate an unexpected role for tRNA modification in the pathogenesis of monogenic ID and ASD and define Elp2 as a key regulator of brain development.
Collapse
Affiliation(s)
- Marija Kojic
- The University of Queensland Diamantina Institute, Translational Research Institute, The University of Queensland, Brisbane, QLD, Australia
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Tomasz Gawda
- Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland
| | - Monika Gaik
- Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland
| | - Alexander Begg
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Anna Salerno-Kochan
- Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland
- Postgraduate School of Molecular Medicine, Warsaw, Poland
| | - Nyoman D Kurniawan
- Centre for Advanced Imaging, The University of Queensland, Brisbane, QLD, Australia
| | - Alun Jones
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Katarzyna Drożdżyk
- Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland
| | - Anna Kościelniak
- Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland
| | | | - Soroor Hediyeh-Zadeh
- Bioinformatics Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia
- Department of Medical Biology, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne, VIC, Australia
| | - Maria Kasherman
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Woo Jun Shim
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | - Enakshi Sinniah
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Laura A Genovesi
- The University of Queensland Diamantina Institute, Translational Research Institute, The University of Queensland, Brisbane, QLD, Australia
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Rannvá K Abrahamsen
- Department of Epilepsy Genetics and Personalized Medicine, Danish Epilepsy Centre, Dianalund, Denmark
| | - Christina D Fenger
- Department of Epilepsy Genetics and Personalized Medicine, Danish Epilepsy Centre, Dianalund, Denmark
| | - Camilla G Madsen
- Centre for Functional and Diagnostic Imaging and Research, Hvidovre Hospital, Hvidovre, Denmark
| | - Julie S Cohen
- Department of Neurology and Developmental Medicine, Division of Neurogenetics, Kennedy Krieger Institute, Baltimore, MD, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Ali Fatemi
- Department of Neurology and Developmental Medicine, Division of Neurogenetics, Kennedy Krieger Institute, Baltimore, MD, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Zornitza Stark
- Department of Paediatrics, The University of Melbourne, Melbourne, VIC, Australia
- Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Melbourne, VIC, Australia
- Australian Genomics Health Alliance, Parkville, VIC, Australia
| | - Sebastian Lunke
- Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Melbourne, VIC, Australia
- Australian Genomics Health Alliance, Parkville, VIC, Australia
- The University of Melbourne, Melbourne, VIC, Australia
| | - Joy Lee
- Department of Paediatrics, The University of Melbourne, Melbourne, VIC, Australia
- Department of Metabolic Medicine, Royal Children's Hospital, Parkville, VIC, Australia
| | - Jonas K Hansen
- Department of Paediatrics, Regional Hospital Viborg, Viborg, Denmark
| | - Martin F Boxill
- Department of Paediatrics, Regional Hospital Viborg, Viborg, Denmark
| | - Boris Keren
- Department of Genetics, Pitié-Salpêtrière Hospital, AP-HP, Paris, France
| | - Isabelle Marey
- Department of Genetics, Pitié-Salpêtrière Hospital, AP-HP, Paris, France
| | - Margarita S Saenz
- The University of Colorado Anschutz, Children's Hospital Colorado, Aurora, CO, USA
| | - Kathleen Brown
- The University of Colorado Anschutz, Children's Hospital Colorado, Aurora, CO, USA
| | - Suzanne A Alexander
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
- Queensland Centre for Mental Health Research, The Park Centre for Mental Health, Brisbane, QLD, Australia
| | - Sergey Mureev
- CSIRO-QUT Synthetic Biology Alliance, Centre for Tropical Crops and Bio-commodities, Queensland University of Technology, Brisbane, QLD, Australia
| | - Alina Batzilla
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
- The Ruprecht Karl University of Heidelberg, Heidelberg, Germany
| | - Melissa J Davis
- Bioinformatics Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia
- Department of Medical Biology, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne, VIC, Australia
- Department of Clinical Pathology, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne, VIC, Australia
| | - Michael Piper
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Mikael Bodén
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | - Thomas H J Burne
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
- Queensland Centre for Mental Health Research, The Park Centre for Mental Health, Brisbane, QLD, Australia
| | - Nathan J Palpant
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Rikke S Møller
- Department of Epilepsy Genetics and Personalized Medicine, Danish Epilepsy Centre, Dianalund, Denmark
- Department for Regional Health Research, The University of Southern Denmark, Odense, Denmark
| | - Sebastian Glatt
- Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland.
| | - Brandon J Wainwright
- The University of Queensland Diamantina Institute, Translational Research Institute, The University of Queensland, Brisbane, QLD, Australia.
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia.
| |
Collapse
|
40
|
RNA-Targeting Splicing Modifiers: Drug Development and Screening Assays. Molecules 2021; 26:molecules26082263. [PMID: 33919699 PMCID: PMC8070285 DOI: 10.3390/molecules26082263] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 04/05/2021] [Accepted: 04/09/2021] [Indexed: 02/06/2023] Open
Abstract
RNA splicing is an essential step in producing mature messenger RNA (mRNA) and other RNA species. Harnessing RNA splicing modifiers as a new pharmacological modality is promising for the treatment of diseases caused by aberrant splicing. This drug modality can be used for infectious diseases by disrupting the splicing of essential pathogenic genes. Several antisense oligonucleotide splicing modifiers were approved by the U.S. Food and Drug Administration (FDA) for the treatment of spinal muscular atrophy (SMA) and Duchenne muscular dystrophy (DMD). Recently, a small-molecule splicing modifier, risdiplam, was also approved for the treatment of SMA, highlighting small molecules as important warheads in the arsenal for regulating RNA splicing. The cellular targets of these approved drugs are all mRNA precursors (pre-mRNAs) in human cells. The development of novel RNA-targeting splicing modifiers can not only expand the scope of drug targets to include many previously considered “undruggable” genes but also enrich the chemical-genetic toolbox for basic biomedical research. In this review, we summarized known splicing modifiers, screening methods for novel splicing modifiers, and the chemical space occupied by the small-molecule splicing modifiers.
Collapse
|
41
|
Ghosh S, Tourtellotte WG. The Complex Clinical and Genetic Landscape of Hereditary Peripheral Neuropathy. ANNUAL REVIEW OF PATHOLOGY-MECHANISMS OF DISEASE 2021; 16:487-509. [PMID: 33497257 DOI: 10.1146/annurev-pathol-030320-100822] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Hereditary peripheral neuropathy (HPN) is a complex group of neurological disorders caused by mutations in genes expressed by neurons and Schwann cells. The inheritance of a single mutation or multiple mutations in several genes leads to disease phenotype. Patients exhibit symptoms during development, at an early age or later in adulthood. Most of the mechanistic understanding about these neuropathies comes from animal models and histopathological analyses of postmortem human tissues. Diagnosis is often very complex due to the heterogeneity and overlap in symptoms and the frequent overlap between various genes and different mutations they possess. Some symptoms in HPN are common through different subtypes such as axonal degeneration, demyelination, and loss of motor and sensory neurons, leading to similar physiologic abnormalities. Recent advances in gene-targeted therapies, genetic engineering, and next-generation sequencing have augmented our understanding of the underlying pathogenetic mechanisms of HPN.
Collapse
Affiliation(s)
- Soumitra Ghosh
- Department of Pathology and Laboratory Medicine, Neurology, and Neurological Surgery, Cedars-Sinai Medical Center, Los Angeles, California 90048, USA;
| | - Warren G Tourtellotte
- Department of Pathology and Laboratory Medicine, Neurology, and Neurological Surgery, Cedars-Sinai Medical Center, Los Angeles, California 90048, USA;
| |
Collapse
|
42
|
The expanding world of tRNA modifications and their disease relevance. Nat Rev Mol Cell Biol 2021; 22:375-392. [PMID: 33658722 DOI: 10.1038/s41580-021-00342-0] [Citation(s) in RCA: 288] [Impact Index Per Article: 96.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/26/2021] [Indexed: 02/08/2023]
Abstract
Transfer RNA (tRNA) is an adapter molecule that links a specific codon in mRNA with its corresponding amino acid during protein synthesis. tRNAs are enzymatically modified post-transcriptionally. A wide variety of tRNA modifications are found in the tRNA anticodon, which are crucial for precise codon recognition and reading frame maintenance, thereby ensuring accurate and efficient protein synthesis. In addition, tRNA-body regions are also frequently modified and thus stabilized in the cell. Over the past two decades, 16 novel tRNA modifications were discovered in various organisms, and the chemical space of tRNA modification continues to expand. Recent studies have revealed that tRNA modifications can be dynamically altered in response to levels of cellular metabolites and environmental stresses. Importantly, we now understand that deficiencies in tRNA modification can have pathological consequences, which are termed 'RNA modopathies'. Dysregulation of tRNA modification is involved in mitochondrial diseases, neurological disorders and cancer.
Collapse
|
43
|
Jacot-Descombes S, Keshav N, Brosch CMS, Wicinski B, Warda T, Norcliffe-Kaufmann L, Kaufmann H, Varghese M, Hof PR. Von Economo Neuron Pathology in Familial Dysautonomia: Quantitative Assessment and Possible Implications. J Neuropathol Exp Neurol 2021; 79:1072-1083. [PMID: 32954436 DOI: 10.1093/jnen/nlaa095] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Von Economo neurons (VENs) and fork cells are principally located in the anterior cingulate cortex (ACC) and the frontoinsular cortex (FI). Both of these regions integrate inputs from the autonomic nervous system (ANS) and are involved in decision-making and perception of the emotional states of self and others. Familial dysautonomia (FD) is an orphan disorder characterized by autonomic dysfunction and behavioral abnormalities including repetitive behavior and emotional rigidity, which are also seen in autism spectrum disorder. To understand a possible link between the ANS and the cortical regions implicated in emotion regulation we studied VENs and fork cells in an autonomic disorder. We determined the densities of VENs, fork cells, and pyramidal neurons and the ratio of VENs and fork cells to pyramidal neurons in ACC and FI in 4 FD patient and 6 matched control brains using a stereologic approach. We identified alterations in densities of VENs and pyramidal neurons and their distributions in the ACC and FI in FD brains. These data suggest that alterations in migration and numbers of VENs may be involved in FD pathophysiology thereby supporting the notion of a functional link between VENs, the ANS and the peripheral nervous system in general.
Collapse
Affiliation(s)
- Sarah Jacot-Descombes
- Nash Family Department of Neuroscience.,Friedman Brain Institute.,Icahn School of Medicine at Mount Sinai, New York, New York; University Center of Legal Medicine, Lausanne - Geneva, Geneva University Hospitals
| | - Neha Keshav
- Nash Family Department of Neuroscience.,Friedman Brain Institute.,Seaver Autism Center for Research and Treatment
| | - Carla Micaela Santos Brosch
- Nash Family Department of Neuroscience.,Department of Mental Health and Psychiatry, University Hospitals and School of Medicine Geneva, Switzerland
| | - Bridget Wicinski
- Nash Family Department of Neuroscience.,Friedman Brain Institute
| | - Tahia Warda
- Nash Family Department of Neuroscience.,Friedman Brain Institute
| | - Lucy Norcliffe-Kaufmann
- Department of Neurology, Dysautonomia Center, New York University School of Medicine, New York, New York
| | - Horacio Kaufmann
- Department of Neurology, Dysautonomia Center, New York University School of Medicine, New York, New York
| | - Merina Varghese
- Nash Family Department of Neuroscience.,Friedman Brain Institute
| | - Patrick R Hof
- Nash Family Department of Neuroscience.,Friedman Brain Institute.,Seaver Autism Center for Research and Treatment
| |
Collapse
|
44
|
Jonkhout N, Cruciani S, Santos Vieira HG, Tran J, Liu H, Liu G, Pickford R, Kaczorowski D, Franco GR, Vauti F, Camacho N, Abedini SS, Najmabadi H, Ribas de Pouplana L, Christ D, Schonrock N, Mattick JS, Novoa EM. Subcellular relocalization and nuclear redistribution of the RNA methyltransferases TRMT1 and TRMT1L upon neuronal activation. RNA Biol 2021; 18:1905-1919. [PMID: 33499731 DOI: 10.1080/15476286.2021.1881291] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
RNA modifications are dynamic chemical entities that expand the RNA lexicon and regulate RNA fate. The most abundant modification present in mRNAs, N6-methyladenosine (m6A), has been implicated in neurogenesis and memory formation. However, whether additional RNA modifications may be playing a role in neuronal functions and in response to environmental queues is largely unknown. Here we characterize the biochemical function and cellular dynamics of two human RNA methyltransferases previously associated with neurological dysfunction, TRMT1 and its homolog, TRMT1-like (TRMT1L). Using a combination of next-generation sequencing, LC-MS/MS, patient-derived cell lines and knockout mouse models, we confirm the previously reported dimethylguanosine (m2,2G) activity of TRMT1 in tRNAs, as well as reveal that TRMT1L, whose activity was unknown, is responsible for methylating a subset of cytosolic tRNAAla(AGC) isodecoders at position 26. Using a cellular in vitro model that mimics neuronal activation and long term potentiation, we find that both TRMT1 and TRMT1L change their subcellular localization upon neuronal activation. Specifically, we observe a major subcellular relocalization from mitochondria and other cytoplasmic domains (TRMT1) and nucleoli (TRMT1L) to different small punctate compartments in the nucleus, which are as yet uncharacterized. This phenomenon does not occur upon heat shock, suggesting that the relocalization of TRMT1 and TRMT1L is not a general reaction to stress, but rather a specific response to neuronal activation. Our results suggest that subcellular relocalization of RNA modification enzymes may play a role in neuronal plasticity and transmission of information, presumably by addressing new targets.
Collapse
Affiliation(s)
- Nicky Jonkhout
- Garvan Institute of Medical Research, Darlinghurst, NSW, Australia.,School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia.,Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona, Spain
| | - Sonia Cruciani
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona, Spain.,University Pompeu Fabra (UPF), Barcelona, Spain
| | - Helaine Graziele Santos Vieira
- Garvan Institute of Medical Research, Darlinghurst, NSW, Australia.,Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona, Spain
| | - Julia Tran
- Garvan Institute of Medical Research, Darlinghurst, NSW, Australia
| | - Huanle Liu
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona, Spain
| | - Ganqiang Liu
- Garvan Institute of Medical Research, Darlinghurst, NSW, Australia.,Current Address: School of Medicine, Sun Yat-sen University, Shenzhen, Guangdong, China
| | - Russell Pickford
- Bioanalytical Mass Spectrometry Facility, Mark Wainwright Analytical Centre, University of New South Wales, Sydney, NSW, Australia
| | | | - Gloria R Franco
- Departamento De Bioquímica E Imunologia, Universidade Federal De Minas Gerais,Belo Horizonte,Minas Gerais, Brazil
| | - Franz Vauti
- Division of Cellular & Molecular Neurobiology, Zoological Institute, Technische Universität Braunschweig, 38106 Braunschweig, Germany
| | - Noelia Camacho
- Institute for Research in Biomedicine, Barcelona, Catalonia, Spain
| | - Seyedeh Sedigheh Abedini
- Department of Genetics, Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Hossein Najmabadi
- Department of Genetics, Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran.,Kariminejad-Najmabadi Pathology & Genetics Center, Tehran, Iran
| | - Lluís Ribas de Pouplana
- Institute for Research in Biomedicine, Barcelona, Catalonia, Spain.,Catalan Institution for Research and Advanced Studies, Barcelona, Catalonia, Spain
| | - Daniel Christ
- Garvan Institute of Medical Research, Darlinghurst, NSW, Australia.,School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Nicole Schonrock
- Garvan Institute of Medical Research, Darlinghurst, NSW, Australia
| | - John S Mattick
- Garvan Institute of Medical Research, Darlinghurst, NSW, Australia.,School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Eva Maria Novoa
- Garvan Institute of Medical Research, Darlinghurst, NSW, Australia.,School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia.,Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona, Spain.,University Pompeu Fabra (UPF), Barcelona, Spain
| |
Collapse
|
45
|
Li L, Gruner K, Tourtellotte WG. Retrograde nerve growth factor signaling abnormalities in familial dysautonomia. J Clin Invest 2021; 130:2478-2487. [PMID: 32281946 DOI: 10.1172/jci130401] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 01/23/2020] [Indexed: 12/11/2022] Open
Abstract
Familial dysautonomia (FD) is the most prevalent form of hereditary sensory and autonomic neuropathy (HSAN). In FD, a germline mutation in the Elp1 gene leads to Elp1 protein decrease that causes sympathetic neuron death and sympathetic nervous system dysfunction (dysautonomia). Elp1 is best known as a scaffolding protein within the nuclear hetero-hexameric transcriptional Elongator protein complex, but how it functions in sympathetic neuron survival is very poorly understood. Here, we identified a cytoplasmic function for Elp1 in sympathetic neurons that was essential for retrograde nerve growth factor (NGF) signaling and neuron target tissue innervation and survival. Elp1 was found to bind to internalized TrkA receptors in an NGF-dependent manner, where it was essential for maintaining TrkA receptor phosphorylation (activation) by regulating PTPN6 (Shp1) phosphatase activity within the signaling complex. In the absence of Elp1, Shp1 was hyperactivated, leading to premature TrkA receptor dephosphorylation, which resulted in retrograde signaling failure and neuron death. Inhibiting Shp1 phosphatase activity in the absence of Elp1 rescued NGF-dependent retrograde signaling, and in an animal model of FD it rescued abnormal sympathetic target tissue innervation. These results suggest that regulation of retrograde NGF signaling in sympathetic neurons by Elp1 may explain sympathetic neuron loss and physiologic dysautonomia in patients with FD.
Collapse
Affiliation(s)
- Lin Li
- Department of Pathology and Laboratory Medicine
| | | | - Warren G Tourtellotte
- Department of Pathology and Laboratory Medicine.,Department of Neurology.,Department of Neurosurgery, and.,Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA
| |
Collapse
|
46
|
Termathe M, Leidel SA. Urm1: A Non-Canonical UBL. Biomolecules 2021; 11:biom11020139. [PMID: 33499055 PMCID: PMC7911844 DOI: 10.3390/biom11020139] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 01/18/2021] [Accepted: 01/19/2021] [Indexed: 01/10/2023] Open
Abstract
Urm1 (ubiquitin related modifier 1) is a molecular fossil in the class of ubiquitin-like proteins (UBLs). It encompasses characteristics of classical UBLs, such as ubiquitin or SUMO (small ubiquitin-related modifier), but also of bacterial sulfur-carrier proteins (SCP). Since its main function is to modify tRNA, Urm1 acts in a non-canonical manner. Uba4, the activating enzyme of Urm1, contains two domains: a classical E1-like domain (AD), which activates Urm1, and a rhodanese homology domain (RHD). This sulfurtransferase domain catalyzes the formation of a C-terminal thiocarboxylate on Urm1. Thiocarboxylated Urm1 is the sulfur donor for 5-methoxycarbonylmethyl-2-thiouridine (mcm5s2U), a chemical nucleotide modification at the wobble position in tRNA. This thio-modification is conserved in all domains of life and optimizes translation. The absence of Urm1 increases stress sensitivity in yeast triggered by defects in protein homeostasis, a hallmark of neurological defects in higher organisms. In contrast, elevated levels of tRNA modifying enzymes promote the appearance of certain types of cancer and the formation of metastasis. Here, we summarize recent findings on the unique features that place Urm1 at the intersection of UBL and SCP and make Urm1 an excellent model for studying the evolution of protein conjugation and sulfur-carrier systems.
Collapse
Affiliation(s)
- Martin Termathe
- Institute of Biochemistry, Protein Biochemistry and Photobiocatalysis, University of Greifswald, Felix-Hausdorff-Strasse 4, 17489 Greifswald, Germany;
| | - Sebastian A. Leidel
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
- Correspondence:
| |
Collapse
|
47
|
Ghosh S, Li L, Tourtellotte WG. Retrograde nerve growth factor signaling abnormalities and the pathogenesis of familial dysautonomia. Neural Regen Res 2021; 16:1795-1796. [PMID: 33510081 PMCID: PMC8328778 DOI: 10.4103/1673-5374.306081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- Soumitra Ghosh
- Department of Pathology and Laboratory Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Lin Li
- Department of Pathology and Laboratory Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Warren G Tourtellotte
- Department of Pathology and Laboratory Medicine; Department of Neurology; Department of Neurosurgery; Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| |
Collapse
|
48
|
Jiang W, Chen L. Alternative splicing: Human disease and quantitative analysis from high-throughput sequencing. Comput Struct Biotechnol J 2020; 19:183-195. [PMID: 33425250 PMCID: PMC7772363 DOI: 10.1016/j.csbj.2020.12.009] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 11/26/2020] [Accepted: 12/11/2020] [Indexed: 02/07/2023] Open
Abstract
Alternative splicing contributes to the majority of protein diversity in higher eukaryotes by allowing one gene to generate multiple distinct protein isoforms. It adds another regulation layer of gene expression. Up to 95% of human multi-exon genes undergo alternative splicing to encode proteins with different functions. Moreover, around 15% of human hereditary diseases and cancers are associated with alternative splicing. Regulation of alternative splicing is attributed to a set of delicate machineries interacting with each other in aid of important biological processes such as cell development and differentiation. Given the importance of alternative splicing events, their accurate mapping and quantification are paramount for downstream analysis, especially for associating disease with alternative splicing. However, deriving accurate isoform expression from high-throughput RNA-seq data remains a challenging task. In this mini-review, we aim to illustrate I) mechanisms and regulation of alternative splicing, II) alternative splicing associated human disease, III) computational tools for the quantification of isoforms and alternative splicing from RNA-seq.
Collapse
Affiliation(s)
- Wei Jiang
- Quantitative and Computational Biology, Department of Biological Sciences, University of Southern California, 1050 Childs Way, Los Angeles, CA 90089, United States
| | - Liang Chen
- Quantitative and Computational Biology, Department of Biological Sciences, University of Southern California, 1050 Childs Way, Los Angeles, CA 90089, United States
| |
Collapse
|
49
|
Funk HM, Zhao R, Thomas M, Spigelmyer SM, Sebree NJ, Bales RO, Burchett JB, Mamaril JB, Limbach PA, Guy MP. Identification of the enzymes responsible for m2,2G and acp3U formation on cytosolic tRNA from insects and plants. PLoS One 2020; 15:e0242737. [PMID: 33253256 PMCID: PMC7704012 DOI: 10.1371/journal.pone.0242737] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 11/06/2020] [Indexed: 11/18/2022] Open
Abstract
Posttranscriptional modification of tRNA is critical for efficient protein translation and proper cell growth, and defects in tRNA modifications are often associated with human disease. Although most of the enzymes required for eukaryotic tRNA modifications are known, many of these enzymes have not been identified and characterized in several model multicellular eukaryotes. Here, we present two related approaches to identify the genes required for tRNA modifications in multicellular organisms using primer extension assays with fluorescent oligonucleotides. To demonstrate the utility of these approaches we first use expression of exogenous genes in yeast to experimentally identify two TRM1 orthologs capable of forming N2,N2-dimethylguanosine (m2,2G) on residue 26 of cytosolic tRNA in the model plant Arabidopsis thaliana. We also show that a predicted catalytic aspartate residue is required for function in each of the proteins. We next use RNA interference in cultured Drosophila melanogaster cells to identify the gene required for m2,2G26 formation on cytosolic tRNA. Additionally, using these approaches we experimentally identify D. melanogaster gene CG10050 as the corresponding ortholog of human DTWD2, which encodes the protein required for formation of 3-amino-3-propylcarboxyuridine (acp3U) on residue 20a of cytosolic tRNA. We further show that A. thaliana gene AT2G41750 can form acp3U20b on an A. thaliana tRNA expressed in yeast cells, and that the aspartate and tryptophan residues in the DXTW motif of this protein are required for modification activity. These results demonstrate that these approaches can be used to study tRNA modification enzymes.
Collapse
Affiliation(s)
- Holly M. Funk
- Department of Chemistry and Biochemistry, Northern Kentucky University, Highland Heights, Kentucky, United States of America
| | - Ruoxia Zhao
- Rieveschl Laboratories for Mass Spectrometry, Department of Chemistry, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Maggie Thomas
- Department of Chemistry and Biochemistry, Northern Kentucky University, Highland Heights, Kentucky, United States of America
| | - Sarah M. Spigelmyer
- Department of Chemistry and Biochemistry, Northern Kentucky University, Highland Heights, Kentucky, United States of America
| | - Nichlas J. Sebree
- Department of Chemistry and Biochemistry, Northern Kentucky University, Highland Heights, Kentucky, United States of America
| | - Regan O. Bales
- Department of Chemistry and Biochemistry, Northern Kentucky University, Highland Heights, Kentucky, United States of America
| | - Jamison B. Burchett
- Department of Chemistry and Biochemistry, Northern Kentucky University, Highland Heights, Kentucky, United States of America
| | - Justen B. Mamaril
- Department of Chemistry and Biochemistry, Northern Kentucky University, Highland Heights, Kentucky, United States of America
| | - Patrick A. Limbach
- Rieveschl Laboratories for Mass Spectrometry, Department of Chemistry, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Michael P. Guy
- Department of Chemistry and Biochemistry, Northern Kentucky University, Highland Heights, Kentucky, United States of America
| |
Collapse
|
50
|
Fedele L, Brand T. The Intrinsic Cardiac Nervous System and Its Role in Cardiac Pacemaking and Conduction. J Cardiovasc Dev Dis 2020; 7:jcdd7040054. [PMID: 33255284 PMCID: PMC7712215 DOI: 10.3390/jcdd7040054] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 11/19/2020] [Accepted: 11/20/2020] [Indexed: 12/11/2022] Open
Abstract
The cardiac autonomic nervous system (CANS) plays a key role for the regulation of cardiac activity with its dysregulation being involved in various heart diseases, such as cardiac arrhythmias. The CANS comprises the extrinsic and intrinsic innervation of the heart. The intrinsic cardiac nervous system (ICNS) includes the network of the intracardiac ganglia and interconnecting neurons. The cardiac ganglia contribute to the tight modulation of cardiac electrophysiology, working as a local hub integrating the inputs of the extrinsic innervation and the ICNS. A better understanding of the role of the ICNS for the modulation of the cardiac conduction system will be crucial for targeted therapies of various arrhythmias. We describe the embryonic development, anatomy, and physiology of the ICNS. By correlating the topography of the intracardiac neurons with what is known regarding their biophysical and neurochemical properties, we outline their physiological role in the control of pacemaker activity of the sinoatrial and atrioventricular nodes. We conclude by highlighting cardiac disorders with a putative involvement of the ICNS and outline open questions that need to be addressed in order to better understand the physiology and pathophysiology of the ICNS.
Collapse
Affiliation(s)
- Laura Fedele
- Correspondence: (L.F.); (T.B.); Tel.: +44-(0)-207-594-6531 (L.F.); +44-(0)-207-594-8744 (T.B.)
| | - Thomas Brand
- Correspondence: (L.F.); (T.B.); Tel.: +44-(0)-207-594-6531 (L.F.); +44-(0)-207-594-8744 (T.B.)
| |
Collapse
|