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Costello SM, Cheney AM, Waldum A, Tripet B, Cotrina-Vidal M, Kaufmann H, Norcliffe-Kaufmann L, Lefcort F, Copié V. A Comprehensive NMR Analysis of Serum and Fecal Metabolites in Familial Dysautonomia Patients Reveals Significant Metabolic Perturbations. Metabolites 2023; 13:metabo13030433. [PMID: 36984872 PMCID: PMC10057143 DOI: 10.3390/metabo13030433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 03/06/2023] [Accepted: 03/14/2023] [Indexed: 03/18/2023] Open
Abstract
Central metabolism has a profound impact on the clinical phenotypes and penetrance of neurological diseases such as Alzheimer’s (AD) and Parkinson’s (PD) diseases, Amyotrophic Lateral Sclerosis (ALS) and Autism Spectrum Disorder (ASD). In contrast to the multifactorial origin of these neurological diseases, neurodevelopmental impairment and neurodegeneration in Familial Dysautonomia (FD) results from a single point mutation in the ELP1 gene. FD patients represent a well-defined population who can help us better understand the cellular networks underlying neurodegeneration, and how disease traits are affected by metabolic dysfunction, which in turn may contribute to dysregulation of the gut–brain axis of FD. Here, 1H NMR spectroscopy was employed to characterize the serum and fecal metabolomes of FD patients, and to assess similarities and differences in the polar metabolite profiles between FD patients and healthy relative controls. Findings from this work revealed noteworthy metabolic alterations reflected in energy (ATP) production, mitochondrial function, amino acid and nucleotide catabolism, neurosignaling molecules, and gut-microbial metabolism. These results provide further evidence for a close interconnection between metabolism, neurodegeneration, and gut microbiome dysbiosis in FD, and create an opportunity to explore whether metabolic interventions targeting the gut–brain–metabolism axis of FD could be used to redress or slow down the progressive neurodegeneration observed in FD patients.
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Affiliation(s)
- Stephanann M. Costello
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
| | - Alexandra M. Cheney
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
| | - Annie Waldum
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
| | - Brian Tripet
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
| | - Maria Cotrina-Vidal
- Department of Neurology, New York University School of Medicine, New York, NY 10017, USA
| | - Horacio Kaufmann
- Department of Neurology, New York University School of Medicine, New York, NY 10017, USA
| | | | - Frances Lefcort
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT 59717, USA
| | - Valérie Copié
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
- Correspondence: ; Tel.: +1-406-994-7244
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2
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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.
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Yun T, Ko HR, Jo DG, Park KW, Cho SW, Kim J, Ahn JY. Inhibitor of DNA binding 2 (Id2) mediates microtubule polymerization in the brain by regulating αK40 acetylation of α-tubulin. Cell Death Discov 2021; 7:257. [PMID: 34548475 PMCID: PMC8455547 DOI: 10.1038/s41420-021-00652-4] [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: 05/19/2021] [Revised: 08/22/2021] [Accepted: 09/07/2021] [Indexed: 12/03/2022] Open
Abstract
Acetylation of α-tubulin lysine 40 (αK40) contributes to microtubule (MT) stability and is essential for neuronal development and function, whereas excessive αK40 deacetylation is observed in neurodegenerative disorders including Alzheimer’s disease (AD). Here we identified inhibitor of DNA binding 2 (Id2) as a novel MT-binding partner that interacts with α-tubulin and enhances αK40 acetylation, leading to MT polymerization in the neurons. Commensurate with our finding that the low levels of Id2 expression along with a reduced αK40 acetylation in the postmortem human AD patient and 5X-FAD, AD model mice brain, Id2 upregulation in the hippocampus of 5X-FAD, which exhibit high levels of Sirt2 expression, increased αK40 acetylation and reconstitutes axon growth. Hence our study suggests that Id2 is critical for maintaining MT stability during neural development and the potential of Id2 to counteract pathogenic Sirt2 activity in AD.
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Affiliation(s)
- Taegwan Yun
- Department of Molecular Cell Biology, University School of Medicine, 16419, Suwon, Korea
| | - Hyo Rim Ko
- Department of Molecular Cell Biology, University School of Medicine, 16419, Suwon, Korea.,Single Cell Network Research Center Sungkyunkwan, University School of Medicine, 16419, Suwon, Korea
| | - Dong-Gyu Jo
- Department of Health Science and Technology, Samsung Advanced Institute for Health Science and Technology, Sungkyunkwan University, 06351, Seoul, Korea.,School of Pharmacy, Sungkyunkwan University, 16419, Suwon, Korea
| | - Kye Won Park
- Department of Food Science and Biotechnology, Sungkyunkwan University, 16419, Suwon, Korea
| | - Sung-Woo Cho
- Department of Biochemistry and Molecular Biology, University of Ulsan, College of Medicine, 05505, Seoul, Korea
| | - Jihoe Kim
- Department of Medical Biotechnology, Yeungnam University, 38541, Gyeongsan, Republic of Korea
| | - Jee-Yin Ahn
- Department of Molecular Cell Biology, University School of Medicine, 16419, Suwon, Korea. .,Single Cell Network Research Center Sungkyunkwan, University School of Medicine, 16419, Suwon, Korea. .,Department of Health Science and Technology, Samsung Advanced Institute for Health Science and Technology, Sungkyunkwan University, 06351, Seoul, Korea. .,Samsung Biomedical Research Institute, Samsung Medical Center, 06351, Seoul, Korea.
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4
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Toral-Lopez J, Huerta LMG, Messina-Baas O, Cuevas-Covarrubias SA. Submicroscopic 11p13 deletion including the elongator acetyltransferase complex subunit 4 gene in a girl with language failure, intellectual disability and congenital malformations: A case report. World J Clin Cases 2020; 8:5296-5303. [PMID: 33269262 PMCID: PMC7674752 DOI: 10.12998/wjcc.v8.i21.5296] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 09/08/2020] [Accepted: 09/17/2020] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND We described the main features of an infant diagnosed with facial dysmorphic, language failure, intellectual disability and congenital malformations to strengthen our understanding of the disease. Currently, treatment is only rehabilitation and surgery for cleft lip and palate.
CASE SUMMARY The proband was a 2-years-8-months-old girl. Familial history was negative for congenital malformations or intellectual disability. The patient had microcephaly, upward-slanting palpebral fissures, depressed nasal bridge, bulbous nose and bilateral cleft lip and palate. Brain magnetic resonance imaging showed cortical atrophy and band heterotopia. Her motor and intellectual development is delayed. A submicroscopic deletion in 11p13 involving the elongator acetyltransferase complex subunit 4 gene (ELP4) and a loss of heterozygosity in Xq25-q26.3 were detected.
CONCLUSION There is no treatment for the ELP4 deletion caused by a submicroscopic 11p3 deletion. We describe a second case of deletion of the ELP4 gene without aniridia, which confirms the association between ELP4 gene with several defects and absence of this ocular defect. Additional clinical data in the deletion of the ELP4 gene as cleft palate, facial dysmorphism, and changes at level brain could be associated to this gene or be part of the effect of the recessives genes involved in the loss of heterozygosity region of Xq25-26.3.
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Affiliation(s)
- Jaime Toral-Lopez
- Departamento de Genética Medica, Centro Medico Ecatepec, ISSEMYM, Ecatepec 55000, México
- Programa de Maestría y Doctorado en Ciencias Médicas, Odontológicas y de la Salud/Hospital Infantil de México, Universidad Nacional Autónoma de México, México 06720, México
| | | | - Olga Messina-Baas
- Departamento de Oftalmología, Hospital General de México, Cuauhtémoc 06720, México
| | - Sergio A Cuevas-Covarrubias
- Genetica, Hospital General de México, Cuauhtémoc 06726, Mexico
- Programa de Maestría y Doctorado en Ciencias Médicas, Odontológicas y de la Salud, Universidad Nacional Autónoma de México, México 06720, Mexico
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Rojas-Benítez D, L. Allende M. Elongator Subunit 3 (Elp3) Is Required for Zebrafish Trunk Development. Int J Mol Sci 2020; 21:E925. [PMID: 32023806 PMCID: PMC7036906 DOI: 10.3390/ijms21030925] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 11/02/2019] [Accepted: 11/06/2019] [Indexed: 12/15/2022] Open
Abstract
Transfer RNAs (tRNAs) are the most post-transcriptionally modified RNA species. Some of these modifications, especially the ones located in the anti-codon loop, are required for decoding capabilities of tRNAs. Such is the case for 5-methoxy-carbonyl-methyl-2-thio-uridine (mcm5s2U), synthetized by the Elongator complex. Mutants for its sub-units display pleiotropic phenotypes. In this paper, we analyze the role of elp3 (Elongator catalytic sub-unit) in zebrafish development. We found that it is required for trunk development; elp3 knock-down animals presented diminished levels of mcm5s2U and sonic hedgehog (Shh) signaling activity. Activation of this pathway was sufficient to revert the phenotype caused by elp3 knockdown, indicating a functional relationship between Elongator and Shh through a yet unknown molecular mechanism.
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Affiliation(s)
- Diego Rojas-Benítez
- FONDAP Center for Genome Regulation (CGR), Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Ñuñoa, Santiago 7800003, Chile;
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Freeman S, Mateo Sánchez S, Pouyo R, Van Lerberghe P, Hanon K, Thelen N, Thiry M, Morelli G, Van Hees L, Laguesse S, Chariot A, Nguyen L, Delacroix L, Malgrange B. Proteostasis is essential during cochlear development for neuron survival and hair cell polarity. EMBO Rep 2019; 20:e47097. [PMID: 31321879 PMCID: PMC6726910 DOI: 10.15252/embr.201847097] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 06/13/2019] [Accepted: 06/22/2019] [Indexed: 01/23/2023] Open
Abstract
Protein homeostasis is essential to cell function, and a compromised ability to reduce the load of misfolded and aggregated proteins is linked to numerous age-related diseases, including hearing loss. Here, we show that altered proteostasis consequent to Elongator complex deficiency also impacts the proper development of the cochlea and results in deafness. In the absence of the catalytic subunit Elp3, differentiating spiral ganglion neurons display large aggresome-like structures and undergo apoptosis before birth. The cochlear mechanosensory cells are able to survive proteostasis disruption but suffer defects in polarity and stereociliary bundle morphogenesis. We demonstrate that protein aggregates accumulate at the apical surface of hair cells, where they cause a local slowdown of microtubular trafficking, altering the distribution of intrinsic polarity proteins and affecting kinocilium position and length. Alleviation of protein misfolding using the chemical chaperone 4-phenylbutyric acid during embryonic development ameliorates hair cell polarity in Elp3-deficient animals. Our study highlights the importance of developmental proteostasis in the cochlea and unveils an unexpected link between proteome integrity and polarized organization of cellular components.
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Affiliation(s)
- Stephen Freeman
- GIGA‐NeurosciencesInterdisciplinary Cluster for Applied Genoproteomics (GIGA‐R)C.H.U. Sart TilmanUniversity of LiègeLiègeBelgium
| | - Susana Mateo Sánchez
- GIGA‐NeurosciencesInterdisciplinary Cluster for Applied Genoproteomics (GIGA‐R)C.H.U. Sart TilmanUniversity of LiègeLiègeBelgium
| | - Ronald Pouyo
- GIGA‐NeurosciencesInterdisciplinary Cluster for Applied Genoproteomics (GIGA‐R)C.H.U. Sart TilmanUniversity of LiègeLiègeBelgium
| | - Pierre‐Bernard Van Lerberghe
- GIGA‐NeurosciencesInterdisciplinary Cluster for Applied Genoproteomics (GIGA‐R)C.H.U. Sart TilmanUniversity of LiègeLiègeBelgium
| | - Kevin Hanon
- GIGA‐NeurosciencesInterdisciplinary Cluster for Applied Genoproteomics (GIGA‐R)C.H.U. Sart TilmanUniversity of LiègeLiègeBelgium
| | - Nicolas Thelen
- GIGA‐NeurosciencesInterdisciplinary Cluster for Applied Genoproteomics (GIGA‐R)C.H.U. Sart TilmanUniversity of LiègeLiègeBelgium
| | - Marc Thiry
- GIGA‐NeurosciencesInterdisciplinary Cluster for Applied Genoproteomics (GIGA‐R)C.H.U. Sart TilmanUniversity of LiègeLiègeBelgium
| | - Giovanni Morelli
- GIGA‐NeurosciencesInterdisciplinary Cluster for Applied Genoproteomics (GIGA‐R)C.H.U. Sart TilmanUniversity of LiègeLiègeBelgium
- UHasseltBIOMEDHasseltBelgium
| | - Laura Van Hees
- GIGA‐NeurosciencesInterdisciplinary Cluster for Applied Genoproteomics (GIGA‐R)C.H.U. Sart TilmanUniversity of LiègeLiègeBelgium
| | - Sophie Laguesse
- GIGA‐NeurosciencesInterdisciplinary Cluster for Applied Genoproteomics (GIGA‐R)C.H.U. Sart TilmanUniversity of LiègeLiègeBelgium
| | - Alain Chariot
- GIGA‐NeurosciencesInterdisciplinary Cluster for Applied Genoproteomics (GIGA‐R)C.H.U. Sart TilmanUniversity of LiègeLiègeBelgium
- GIGA‐Molecular Biology of DiseasesInterdisciplinary Cluster for Applied Genoproteomics (GIGA‐R)C.H.U. Sart TilmanUniversity of LiègeLiègeBelgium
- Walloon Excellence in Life Sciences and Biotechnology (WELBIO)WavreBelgium
| | - Laurent Nguyen
- GIGA‐NeurosciencesInterdisciplinary Cluster for Applied Genoproteomics (GIGA‐R)C.H.U. Sart TilmanUniversity of LiègeLiègeBelgium
| | - Laurence Delacroix
- GIGA‐NeurosciencesInterdisciplinary Cluster for Applied Genoproteomics (GIGA‐R)C.H.U. Sart TilmanUniversity of LiègeLiègeBelgium
| | - Brigitte Malgrange
- GIGA‐NeurosciencesInterdisciplinary Cluster for Applied Genoproteomics (GIGA‐R)C.H.U. Sart TilmanUniversity of LiègeLiègeBelgium
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7
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Vijayakumar UG, Milla V, Cynthia Stafford MY, Bjourson AJ, Duddy W, Duguez SMR. A Systematic Review of Suggested Molecular Strata, Biomarkers and Their Tissue Sources in ALS. Front Neurol 2019; 10:400. [PMID: 31139131 PMCID: PMC6527847 DOI: 10.3389/fneur.2019.00400] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 04/02/2019] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS), also known as motor neuron disease, is an incurable neurodegenerative condition, characterized by the loss of upper and lower motor neurons. It affects 1-1.8/100,000 individuals worldwide, and the number of cases is projected to increase as the population ages. Thus, there is an urgent need to identify both therapeutic targets and disease-specific biomarkers-biomarkers that would be useful to diagnose and stratify patients into different sub-groups for therapeutic strategies, as well as biomarkers to follow the efficacy of any treatment tested during clinical trials. There is a lack of knowledge about pathogenesis and many hypotheses. Numerous "omics" studies have been conducted on ALS in the past decade to identify a disease-signature in tissues and circulating biomarkers. The first goal of the present review was to group the molecular pathways that have been implicated in monogenic forms of ALS, to enable the description of patient strata corresponding to each pathway grouping. This strategy allowed us to suggest 14 strata, each potentially targetable by different pharmacological strategies. The second goal of this review was to identify diagnostic/prognostic biomarker candidates consistently observed across the literature. For this purpose, we explore previous biomarker-relevant "omics" studies of ALS and summarize their findings, focusing on potential circulating biomarker candidates. We systematically review 118 papers on biomarkers published during the last decade. Several candidate markers were consistently shared across the results of different studies in either cerebrospinal fluid (CSF) or blood (leukocyte or serum/plasma). Although these candidates still need to be validated in a systematic manner, we suggest the use of combinations of biomarkers that would likely reflect the "health status" of different tissues, including motor neuron health (e.g., pNFH and NF-L, cystatin C, Transthyretin), inflammation status (e.g., MCP-1, miR451), muscle health (miR-338-3p, miR-206) and metabolism (homocysteine, glutamate, cholesterol). In light of these studies and because ALS is increasingly perceived as a multi-system disease, the identification of a panel of biomarkers that accurately reflect features of pathology is a priority, not only for diagnostic purposes but also for prognostic or predictive applications.
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Affiliation(s)
| | | | | | | | | | - Stephanie Marie-Rose Duguez
- Northern Ireland Center for Stratified Medicine, Biomedical Sciences Research Institute, Londonderry, United Kingdom
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Xu CP, Qi Y, Cui Z, Yang YJ, Wang J, Hu YJ, Yu B, Wang FZ, Yang QP, Sun HT. Discovery of novel elongator protein 2 inhibitors by compound library screening using surface plasmon resonance. RSC Adv 2019; 9:1696-1704. [PMID: 35518050 PMCID: PMC9059734 DOI: 10.1039/c8ra09640f] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Accepted: 12/26/2018] [Indexed: 12/13/2022] Open
Abstract
Tumour necrosis factor-α (TNF-α) is a pleiotropic cytokine that becomes elevated in chronic inflammatory states, including slowing down osteogenic differentiation, which leads to bone dysplasia in long-term inflammatory microenvironments. The elongator complex plays a role in gene regulation and association with various cellular activities, including the downstream signal transduction of TNF-α in osteogenic cells. To find an inhibitor of Elongator Protein 2 (Elp2), we performed a compound library screen and verified the pharmaceutical effects of candidate compounds on the mouse myoblast cell (C2C12) and mouse osteoblastic cells (MC3T3-E1). The commercial FDA-approved drug (FD) library and the bioactive compound (BC) library were used as candidate libraries. After a label-free, high-throughput affinity measurement with surface plasmon resonance (SPRi), seven kinds of compounds showed binding affinity with mouse Elp2 protein. The seven candidates were then used to perform an inhibition test with TNF-α-induced C2C12 and MC3T3-E1 cell lines. One candidate compound reduced the differentiation suppression caused by TNF-α with resuscitated alkaline phosphatase (ALP) activity, mineralization intensity and expression of osteogenic differentiation marker genes. The results of our study provide a competitive candidate to mitigate the TNF-α-induced osteogenic differentia.
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Affiliation(s)
- Chang-Peng Xu
- Department of Orthopaedics, Guangdong Second Provincial General Hospital Guangzhou Guangdong P. R. China
| | - Yong Qi
- Department of Orthopaedics, Guangdong Second Provincial General Hospital Guangzhou Guangdong P. R. China
| | - Zhuang Cui
- Department of Orthopaedics and Traumatology, Nanfang Hospital, Southern Medical University Guangzhou Guangdong P. R. China
| | - Ya-Jun Yang
- Department of Pharmacology, Guangdong Medical College Zhanjiang Guangdong P. R. China
| | - Jian Wang
- Department of Orthopaedics, The Inner Mongolia People's Hospital Hohhot Inner Mongolia P. R. China
| | - Yan-Jun Hu
- Department of Orthopaedics and Traumatology, Nanfang Hospital, Southern Medical University Guangzhou Guangdong P. R. China
| | - Bin Yu
- Department of Orthopaedics and Traumatology, Nanfang Hospital, Southern Medical University Guangzhou Guangdong P. R. China
| | - Fa-Zheng Wang
- Department of Orthopaedics, The First People's Hospital of Kashgar Prefecture Kashgar Xinjiang P. R. China
| | - Qing-Po Yang
- Department of Orthopaedics, The First People's Hospital of Kashgar Prefecture Kashgar Xinjiang P. R. China
| | - Hong-Tao Sun
- Department of Orthopaedics, Guangdong Second Provincial General Hospital Guangzhou Guangdong P. R. China
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Ueki Y, Shchepetkina V, Lefcort F. Retina-specific loss of Ikbkap/Elp1 causes mitochondrial dysfunction that leads to selective retinal ganglion cell degeneration in a mouse model of familial dysautonomia. Dis Model Mech 2018; 11:dmm.033746. [PMID: 29929962 PMCID: PMC6078410 DOI: 10.1242/dmm.033746] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 06/12/2018] [Indexed: 12/26/2022] Open
Abstract
Familial dysautonomia (FD) is an autosomal recessive disorder marked by developmental and progressive neuropathies. It is caused by an intronic point-mutation in the IKBKAP/ELP1 gene, which encodes the inhibitor of κB kinase complex-associated protein (IKAP, also called ELP1), a component of the elongator complex. Owing to variation in tissue-specific splicing, the mutation primarily affects the nervous system. One of the most debilitating hallmarks of FD that affects patients' quality of life is progressive blindness. To determine the pathophysiological mechanisms that are triggered by the absence of IKAP in the retina, we generated retina-specific Ikbkap conditional knockout (CKO) mice using Pax6-Cre, which abolished Ikbkap expression in all cell types of the retina. Although sensory and autonomic neuropathies in FD are known to be developmental in origin, the loss of IKAP in the retina did not affect its development, demonstrating that IKAP is not required for retinal development. The loss of IKAP caused progressive degeneration of retinal ganglion cells (RGCs) by 1 month of age. Mitochondrial membrane integrity was breached in RGCs, and later in other retinal neurons. In Ikbkap CKO retinas, mitochondria were depolarized, and complex I function and ATP were significantly reduced. Although mitochondrial impairment was detected in all Ikbkap-deficient retinal neurons, RGCs were the only cell type to degenerate; the survival of other retinal neurons was unaffected. This retina-specific FD model is a useful in vivo model for testing potential therapeutics for mitigating blindness in FD. Moreover, our data indicate that RGCs and mitochondria are promising targets. Summary: The elongator subunit IKBKAP/ELP1 is not required for development, but is essential for maintaining mitochondrial function and retina morphology. Loss of this subunit causes progressive, selective degeneration of retinal ganglion cells.
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Affiliation(s)
- Yumi Ueki
- Department of Cell Biology and Neuroscience, Montana State University, Bozeman, MT 59717, USA
| | - Veronika Shchepetkina
- Department of Cell Biology and Neuroscience, Montana State University, Bozeman, MT 59717, USA
| | - Frances Lefcort
- Department of Cell Biology and Neuroscience, Montana State University, Bozeman, MT 59717, USA
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10
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Heras-Garvin A. Basic research and model systems in familial dysautonomia: What do we know and what's next? Clin Auton Res 2017; 27:211-212. [PMID: 28707017 DOI: 10.1007/s10286-017-0448-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 07/01/2017] [Indexed: 01/05/2023]
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11
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Bednářová A, Hanna M, Durham I, VanCleave T, England A, Chaudhuri A, Krishnan N. Lost in Translation: Defects in Transfer RNA Modifications and Neurological Disorders. Front Mol Neurosci 2017; 10:135. [PMID: 28536502 PMCID: PMC5422465 DOI: 10.3389/fnmol.2017.00135] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 04/20/2017] [Indexed: 11/13/2022] Open
Abstract
Transfer RNAs (tRNAs) are key molecules participating in protein synthesis. To augment their functionality they undergo extensive post-transcriptional modifications and, as such, are subject to regulation at multiple levels including transcription, transcript processing, localization and ribonucleoside base modification. Post-transcriptional enzyme-catalyzed modification of tRNA occurs at a number of base and sugar positions and influences specific anticodon-codon interactions and regulates translation, its efficiency and fidelity. This phenomenon of nucleoside modification is most remarkable and results in a rich structural diversity of tRNA of which over 100 modified nucleosides have been characterized. Most often these hypermodified nucleosides are found in the wobble position of tRNAs, where they play a direct role in codon recognition as well as in maintaining translational efficiency and fidelity, etc. Several recent studies have pointed to a link between defects in tRNA modifications and human diseases including neurological disorders. Therefore, defects in tRNA modifications in humans need intensive characterization at the enzymatic and mechanistic level in order to pave the way to understand how lack of such modifications are associated with neurological disorders with the ultimate goal of gaining insights into therapeutic interventions.
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Affiliation(s)
- Andrea Bednářová
- Department of Biochemistry and Physiology, Institute of Entomology, Biology Centre, Academy of SciencesČeské Budějovice, Czechia.,Laboratory of Molecular Biology and Biochemistry, Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State UniversityMississippi State, MS, USA
| | - Marley Hanna
- Molecular Biosciences Program, Arkansas State UniversityJonesboro, AR, USA
| | - Isabella Durham
- Department of Wildlife, Fisheries and Aquaculture, Mississippi State UniversityMississippi State, MS, USA
| | - Tara VanCleave
- Laboratory of Molecular Biology and Biochemistry, Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State UniversityMississippi State, MS, USA
| | - Alexis England
- Laboratory of Molecular Biology and Biochemistry, Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State UniversityMississippi State, MS, USA
| | | | - Natraj Krishnan
- Laboratory of Molecular Biology and Biochemistry, Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State UniversityMississippi State, MS, USA
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Laguesse S, Close P, Van Hees L, Chariot A, Malgrange B, Nguyen L. Loss of Elp3 Impairs the Acetylation and Distribution of Connexin-43 in the Developing Cerebral Cortex. Front Cell Neurosci 2017; 11:122. [PMID: 28507509 PMCID: PMC5410572 DOI: 10.3389/fncel.2017.00122] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 04/12/2017] [Indexed: 12/19/2022] Open
Abstract
The Elongator complex is required for proper development of the cerebral cortex. Interfering with its activity in vivo delays the migration of postmitotic projection neurons, at least through a defective α-tubulin acetylation. However, this complex is already expressed by cortical progenitors where it may regulate the early steps of migration by targeting additional proteins. Here we report that connexin-43 (Cx43), which is strongly expressed by cortical progenitors and whose depletion impairs projection neuron migration, requires Elongator expression for its proper acetylation. Indeed, we show that Cx43 acetylation is reduced in the cortex of Elp3cKO embryos, as well as in a neuroblastoma cell line depleted of Elp1 expression, suggesting that Cx43 acetylation requires Elongator in different cellular contexts. Moreover, we show that histones deacetylase 6 (HDAC6) is a deacetylase of Cx43. Finally, we report that acetylation of Cx43 regulates its membrane distribution in apical progenitors of the cerebral cortex.
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Affiliation(s)
- Sophie Laguesse
- GIGA-Neurosciences, University of LiègeLiège, Belgium.,Interdisciplinary Cluster for Applied Genoproteomics (GIGA-R), University of LiègeLiège, Belgium
| | - Pierre Close
- Interdisciplinary Cluster for Applied Genoproteomics (GIGA-R), University of LiègeLiège, Belgium.,GIGA-Molecular Biology of Diseases, University of LiègeLiège, Belgium
| | - Laura Van Hees
- GIGA-Neurosciences, University of LiègeLiège, Belgium.,Interdisciplinary Cluster for Applied Genoproteomics (GIGA-R), University of LiègeLiège, Belgium
| | - Alain Chariot
- Interdisciplinary Cluster for Applied Genoproteomics (GIGA-R), University of LiègeLiège, Belgium.,GIGA-Molecular Biology of Diseases, University of LiègeLiège, Belgium.,Walloon Excellence in Lifesciences and Biotechnology (WELBIO)Wallonia, Belgium
| | - Brigitte Malgrange
- GIGA-Neurosciences, University of LiègeLiège, Belgium.,Interdisciplinary Cluster for Applied Genoproteomics (GIGA-R), University of LiègeLiège, Belgium
| | - Laurent Nguyen
- GIGA-Neurosciences, University of LiègeLiège, Belgium.,Interdisciplinary Cluster for Applied Genoproteomics (GIGA-R), University of LiègeLiège, Belgium
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13
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Chaverra M, George L, Mergy M, Waller H, Kujawa K, Murnion C, Sharples E, Thorne J, Podgajny N, Grindeland A, Ueki Y, Eiger S, Cusick C, Babcock AM, Carlson GA, Lefcort F. The familial dysautonomia disease gene IKBKAP is required in the developing and adult mouse central nervous system. Dis Model Mech 2017; 10:605-618. [PMID: 28167615 PMCID: PMC5451171 DOI: 10.1242/dmm.028258] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 01/23/2017] [Indexed: 02/06/2023] Open
Abstract
Hereditary sensory and autonomic neuropathies (HSANs) are a genetically and clinically diverse group of disorders defined by peripheral nervous system (PNS) dysfunction. HSAN type III, known as familial dysautonomia (FD), results from a single base mutation in the gene IKBKAP that encodes a scaffolding unit (ELP1) for a multi-subunit complex known as Elongator. Since mutations in other Elongator subunits (ELP2 to ELP4) are associated with central nervous system (CNS) disorders, the goal of this study was to investigate a potential requirement for Ikbkap in the CNS of mice. The sensory and autonomic pathophysiology of FD is fatal, with the majority of patients dying by age 40. While signs and pathology of FD have been noted in the CNS, the clinical and research focus has been on the sensory and autonomic dysfunction, and no genetic model studies have investigated the requirement for Ikbkap in the CNS. Here, we report, using a novel mouse line in which Ikbkap is deleted solely in the nervous system, that not only is Ikbkap widely expressed in the embryonic and adult CNS, but its deletion perturbs both the development of cortical neurons and their survival in adulthood. Primary cilia in embryonic cortical apical progenitors and motile cilia in adult ependymal cells are reduced in number and disorganized. Furthermore, we report that, in the adult CNS, both autonomic and non-autonomic neuronal populations require Ikbkap for survival, including spinal motor and cortical neurons. In addition, the mice developed kyphoscoliosis, an FD hallmark, indicating its neuropathic etiology. Ultimately, these perturbations manifest in a developmental and progressive neurodegenerative condition that includes impairments in learning and memory. Collectively, these data reveal an essential function for Ikbkap that extends beyond the peripheral nervous system to CNS development and function. With the identification of discrete CNS cell types and structures that depend on Ikbkap, novel strategies to thwart the progressive demise of CNS neurons in FD can be developed. Summary:Ikbkap is essential for normal CNS development, neuronal survival and behavior, adding to our understanding of the role of the Elongator complex in the mammalian CNS.
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Affiliation(s)
- Marta Chaverra
- Department of Cell Biology and Neuroscience, Montana State University, Bozeman, MT 59717, USA
| | - Lynn George
- Department of Cell Biology and Neuroscience, Montana State University, Bozeman, MT 59717, USA.,Department of Biological and Physical Sciences, Montana State University Billings, Billings, MT 59101, USA
| | - Marc Mergy
- Department of Cell Biology and Neuroscience, Montana State University, Bozeman, MT 59717, USA
| | - Hannah Waller
- Department of Cell Biology and Neuroscience, Montana State University, Bozeman, MT 59717, USA
| | - Katharine Kujawa
- Department of Psychology, Montana State University, Bozeman, MT 59717, USA
| | - Connor Murnion
- Department of Cell Biology and Neuroscience, Montana State University, Bozeman, MT 59717, USA
| | - Ezekiel Sharples
- Department of Cell Biology and Neuroscience, Montana State University, Bozeman, MT 59717, USA
| | - Julian Thorne
- Department of Cell Biology and Neuroscience, Montana State University, Bozeman, MT 59717, USA.,University of Washington, School of Medicine, Seattle, WA 98195, USA
| | - Nathaniel Podgajny
- Department of Cell Biology and Neuroscience, Montana State University, Bozeman, MT 59717, USA
| | | | - Yumi Ueki
- Department of Cell Biology and Neuroscience, Montana State University, Bozeman, MT 59717, USA
| | - Steven Eiger
- Department of Cell Biology and Neuroscience, Montana State University, Bozeman, MT 59717, USA
| | - Cassie Cusick
- Department of Cell Biology and Neuroscience, Montana State University, Bozeman, MT 59717, USA
| | - A Michael Babcock
- Department of Psychology, Montana State University, Bozeman, MT 59717, USA
| | | | - Frances Lefcort
- Department of Cell Biology and Neuroscience, Montana State University, Bozeman, MT 59717, USA
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14
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Kolaj-Robin O, Séraphin B. Structures and Activities of the Elongator Complex and Its Cofactors. RNA MODIFICATION 2017; 41:117-149. [DOI: 10.1016/bs.enz.2017.03.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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15
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Naftelberg S, Abramovitch Z, Gluska S, Yannai S, Joshi Y, Donyo M, Ben-Yaakov K, Gradus T, Zonszain J, Farhy C, Ashery-Padan R, Perlson E, Ast G. Phosphatidylserine Ameliorates Neurodegenerative Symptoms and Enhances Axonal Transport in a Mouse Model of Familial Dysautonomia. PLoS Genet 2016; 12:e1006486. [PMID: 27997532 PMCID: PMC5172536 DOI: 10.1371/journal.pgen.1006486] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 11/15/2016] [Indexed: 12/03/2022] Open
Abstract
Familial Dysautonomia (FD) is a neurodegenerative disease in which aberrant tissue-specific splicing of IKBKAP exon 20 leads to reduction of IKAP protein levels in neuronal tissues. Here we generated a conditional knockout (CKO) mouse in which exon 20 of IKBKAP is deleted in the nervous system. The CKO FD mice exhibit developmental delays, sensory abnormalities, and less organized dorsal root ganglia (DRGs) with attenuated axons compared to wild-type mice. Furthermore, the CKO FD DRGs show elevated HDAC6 levels, reduced acetylated α-tubulin, unstable microtubules, and impairment of axonal retrograde transport of nerve growth factor (NGF). These abnormalities in DRG properties underlie neuronal degeneration and FD symptoms. Phosphatidylserine treatment decreased HDAC6 levels and thus increased acetylation of α-tubulin. Further PS treatment resulted in recovery of axonal outgrowth and enhanced retrograde axonal transport by decreasing histone deacetylase 6 (HDAC6) levels and thus increasing acetylation of α-tubulin levels. Thus, we have identified the molecular pathway that leads to neurodegeneration in FD and have demonstrated that phosphatidylserine treatment has the potential to slow progression of neurodegeneration. We create a novel FD mouse model, in which exon 20 of IKBKAP was deleted in the nervous system, to study the role of IKAP in the neurodegeneration process. The lack of IKBKAP exon 20 impaired retrograde nerve growth factor (NGF) transport and axonal outgrowth. Reduction of IKAP levels resulted in elevated HDAC6 levels and thus reduced acetylated α-tubulin levels. Phosphatidylserine down-regulated HDAC6 levels, furthermore phosphatidylserine treatment facilitated axonal transport and stabilized microtubules. In brief: Naftelberg et al. identify the molecular pathway leading to neurodegeneration using a mouse model of familial dysautonomia and suggest that phosphatidylserine acts as an HDAC6 inhibitor to improve neurologic function.
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Affiliation(s)
- Shiran Naftelberg
- Department of Human Molecular Genetics and Biochemestry. Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ziv Abramovitch
- Department of Human Molecular Genetics and Biochemestry. Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Shani Gluska
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Sivan Yannai
- Department of Human Molecular Genetics and Biochemestry. Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Yuvraj Joshi
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Maya Donyo
- Department of Human Molecular Genetics and Biochemestry. Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Keren Ben-Yaakov
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Tal Gradus
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Jonathan Zonszain
- Department of Human Molecular Genetics and Biochemestry. Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Chen Farhy
- Department of Human Molecular Genetics and Biochemestry. Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ruth Ashery-Padan
- Department of Human Molecular Genetics and Biochemestry. Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Eran Perlson
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- * E-mail: (EP); (GA)
| | - Gil Ast
- Department of Human Molecular Genetics and Biochemestry. Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- * E-mail: (EP); (GA)
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16
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Kojic M, Wainwright B. The Many Faces of Elongator in Neurodevelopment and Disease. Front Mol Neurosci 2016; 9:115. [PMID: 27847465 PMCID: PMC5088202 DOI: 10.3389/fnmol.2016.00115] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2016] [Accepted: 10/18/2016] [Indexed: 12/02/2022] Open
Abstract
Development of the nervous system requires a variety of cellular activities, such as proliferation, migration, axonal outgrowth and guidance and synapse formation during the differentiation of neural precursors into mature neurons. Malfunction of these highly regulated and coordinated events results in various neurological diseases. The Elongator complex is a multi-subunit complex highly conserved in eukaryotes whose function has been implicated in the majority of cellular activities underlying neurodevelopment. These activities include cell motility, actin cytoskeleton organization, exocytosis, polarized secretion, intracellular trafficking and the maintenance of neural function. Several studies have associated mutations in Elongator subunits with the neurological disorders familial dysautonomia (FD), intellectual disability (ID), amyotrophic lateral sclerosis (ALS) and rolandic epilepsy (RE). Here, we review the various cellular activities assigned to this complex and discuss the implications for neural development and disease. Further research in this area has the potential to generate new diagnostic tools, better prevention strategies and more effective treatment options for a wide variety of neurological disorders.
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Affiliation(s)
- Marija Kojic
- Genomics of Development and Disease Division, Institute for Molecular Bioscience, The University of Queensland Brisbane, QLD, Australia
| | - Brandon Wainwright
- Genomics of Development and Disease Division, Institute for Molecular Bioscience, The University of Queensland Brisbane, QLD, Australia
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17
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Ganai SA, Banday S, Farooq Z, Altaf M. Modulating epigenetic HAT activity for reinstating acetylation homeostasis: A promising therapeutic strategy for neurological disorders. Pharmacol Ther 2016; 166:106-22. [DOI: 10.1016/j.pharmthera.2016.07.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 06/28/2016] [Indexed: 01/30/2023]
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18
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Tielens S, Huysseune S, Godin JD, Chariot A, Malgrange B, Nguyen L. Elongator controls cortical interneuron migration by regulating actomyosin dynamics. Cell Res 2016; 26:1131-1148. [PMID: 27670698 DOI: 10.1038/cr.2016.112] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Revised: 06/27/2016] [Accepted: 08/11/2016] [Indexed: 12/20/2022] Open
Abstract
The migration of cortical interneurons is a fundamental process for the establishment of cortical connectivity and its impairment underlies several neurological disorders. During development, these neurons are born in the ganglionic eminences and they migrate tangentially to populate the cortical layers. This process relies on various morphological changes that are driven by dynamic cytoskeleton remodelings. By coupling time lapse imaging with molecular analyses, we show that the Elongator complex controls cortical interneuron migration in mouse embryos by regulating nucleokinesis and branching dynamics. At the molecular level, Elongator fine-tunes actomyosin forces by regulating the distribution and turnover of actin microfilaments during cell migration. Thus, we demonstrate that Elongator cell-autonomously promotes cortical interneuron migration by controlling actin cytoskeletal dynamics.
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Affiliation(s)
- Sylvia Tielens
- GIGA-Neurosciences, 4000 Liège, Belgium.,Interdisciplinary Cluster for Applied Genoproteomics (GIGA-R), 4000 Liège, Belgium
| | - Sandra Huysseune
- GIGA-Neurosciences, 4000 Liège, Belgium.,Interdisciplinary Cluster for Applied Genoproteomics (GIGA-R), 4000 Liège, Belgium
| | - Juliette D Godin
- GIGA-Neurosciences, 4000 Liège, Belgium.,Interdisciplinary Cluster for Applied Genoproteomics (GIGA-R), 4000 Liège, Belgium
| | - Alain Chariot
- Interdisciplinary Cluster for Applied Genoproteomics (GIGA-R), 4000 Liège, Belgium.,GIGA-Molecular Biology of Diseases, 4000 Liège, Belgium.,Walloon Excellence in Lifesciences and Biotechnology (WELBIO), University of Liège, CHU Sart Tilman, 4000 Liège, Belgium
| | - Brigitte Malgrange
- GIGA-Neurosciences, 4000 Liège, Belgium.,Interdisciplinary Cluster for Applied Genoproteomics (GIGA-R), 4000 Liège, Belgium
| | - Laurent Nguyen
- GIGA-Neurosciences, 4000 Liège, Belgium.,Interdisciplinary Cluster for Applied Genoproteomics (GIGA-R), 4000 Liège, Belgium
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19
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Wieczorek E, Kędracka–Krok S, Sołtys K, Jankowska U, Hołubowicz R, Seliga J, Ożyhar A. Is Transthyretin a Regulator of Ubc9 SUMOylation? PLoS One 2016; 11:e0160536. [PMID: 27501389 PMCID: PMC4976990 DOI: 10.1371/journal.pone.0160536] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 07/20/2016] [Indexed: 12/21/2022] Open
Abstract
Ageing and mutations of transthyretin (TTR), the thyroid hormones and retinol transporting protein lead to amyloidosis by destabilizing the structure of TTR. Because protein structure is regulated through posttranslational modifications, we investigated the Small Ubiquitin-like Modifier (SUMO)ylation of TTR. We chose the widely used Ubc9 fusion-directed SUMOylation system, which is based on a fusion of the SUMOylation substrate of interest with Ubc9, a sole SUMO conjugating enzyme. Surprisingly, despite our presumptions, we found that Ubc9 fused to TTR was SUMOylated at a unique set of lysine residues. Three unknown SUMOylation sites of Ubc9-K154, K18 and K65-were revealed by mass spectrometry (MS). The previously reported SUMOylation at K49 of Ubc9 was also observed. SUMOylation of the lysine residues of TTR fused to Ubc9 was hardly detectable. However, non-fused TTR was SUMOylated via trans-SUMOylation by Ubc9 fused to TTR. Interestingly, mutating the catalytic residue of Ubc9 fused to TTR did not result in complete loss of the SUMOylation signal, suggesting that Ubc9 linked to TTR is directly cross-SUMOylated by the SUMO-activating enzyme E1. Ubc9, TTR or fusion proteins composed of TTR and Ubc9 specifically affected the global SUMOylation of cellular proteins. TTR or Ubc9 alone increased global SUMOylation, whereas concomitant presence of TTR and Ubc9 did not further increase the amount of high-molecular weight (HMW) SUMO conjugates. Our data suggest that TTR may influence the SUMOylation of Ubc9, thereby altering signalling pathways in the cell.
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Affiliation(s)
- Elżbieta Wieczorek
- Department of Biochemistry, Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, Wrocław, Poland
- * E-mail:
| | - Sylwia Kędracka–Krok
- Department of Physical Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - Katarzyna Sołtys
- Department of Biochemistry, Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, Wrocław, Poland
| | - Urszula Jankowska
- Department of Structural Biology, Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland
| | - Rafał Hołubowicz
- Department of Biochemistry, Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, Wrocław, Poland
| | - Justyna Seliga
- Department of Biochemistry, Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, Wrocław, Poland
| | - Andrzej Ożyhar
- Department of Biochemistry, Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, Wrocław, Poland
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20
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Dietrich P, Dragatsis I. Familial Dysautonomia: Mechanisms and Models. Genet Mol Biol 2016; 39:497-514. [PMID: 27561110 PMCID: PMC5127153 DOI: 10.1590/1678-4685-gmb-2015-0335] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Accepted: 03/16/2016] [Indexed: 11/22/2022] Open
Abstract
Hereditary Sensory and Autonomic Neuropathies (HSANs) compose a heterogeneous group of genetic disorders characterized by sensory and autonomic dysfunctions. Familial Dysautonomia (FD), also known as HSAN III, is an autosomal recessive disorder that affects 1/3,600 live births in the Ashkenazi Jewish population. The major features of the disease are already present at birth and are attributed to abnormal development and progressive degeneration of the sensory and autonomic nervous systems. Despite clinical interventions, the disease is inevitably fatal. FD is caused by a point mutation in intron 20 of the IKBKAP gene that results in severe reduction in expression of IKAP, its encoded protein. In vitro and in vivo studies have shown that IKAP is involved in multiple intracellular processes, and suggest that failed target innervation and/or impaired neurotrophic retrograde transport are the primary causes of neuronal cell death in FD. However, FD is far more complex, and appears to affect several other organs and systems in addition to the peripheral nervous system. With the recent generation of mouse models that recapitulate the molecular and pathological features of the disease, it is now possible to further investigate the mechanisms underlying different aspects of the disorder, and to test novel therapeutic strategies.
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Affiliation(s)
- Paula Dietrich
- Department of Physiology, The University of Tennessee, Memphis, TN, USA
| | - Ioannis Dragatsis
- Department of Physiology, The University of Tennessee, Memphis, TN, USA
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21
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Xu S, Panikker P, Iqbal S, Elefant F. Tip60 HAT Action Mediates Environmental Enrichment Induced Cognitive Restoration. PLoS One 2016; 11:e0159623. [PMID: 27454757 PMCID: PMC4959735 DOI: 10.1371/journal.pone.0159623] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 07/06/2016] [Indexed: 12/14/2022] Open
Abstract
Environmental enrichment (EE) conditions have beneficial effects for reinstating cognitive ability in neuropathological disorders like Alzheimer's disease (AD). While EE benefits involve epigenetic gene control mechanisms that comprise histone acetylation, the histone acetyltransferases (HATs) involved remain largely unknown. Here, we examine a role for Tip60 HAT action in mediating activity- dependent beneficial neuroadaptations to EE using the Drosophila CNS mushroom body (MB) as a well-characterized cognition model. We show that flies raised under EE conditions display enhanced MB axonal outgrowth, synaptic marker protein production, histone acetylation induction and transcriptional activation of cognition linked genes when compared to their genotypically identical siblings raised under isolated conditions. Further, these beneficial changes are impaired in both Tip60 HAT mutant flies and APP neurodegenerative flies. While EE conditions provide some beneficial neuroadaptive changes in the APP neurodegenerative fly MB, such positive changes are significantly enhanced by increasing MB Tip60 HAT levels. Our results implicate Tip60 as a critical mediator of EE-induced benefits, and provide broad insights into synergistic behavioral and epigenetic based therapeutic approaches for treatment of cognitive disorder.
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Affiliation(s)
- Songjun Xu
- Department of Biology, Drexel University, Philadelphia, PA, United States of America
| | - Priyalakshmi Panikker
- Department of Biology, Drexel University, Philadelphia, PA, United States of America
| | - Sahira Iqbal
- Department of Biology, Drexel University, Philadelphia, PA, United States of America
| | - Felice Elefant
- Department of Biology, Drexel University, Philadelphia, PA, United States of America
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22
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Laguesse S, Creppe C, Godin JD, Nguyen L. [Unveiling the role of endoplasmic reticulum stress and unfolded protein response in cortical neurogenesis]. Med Sci (Paris) 2016; 32:568-71. [PMID: 27406761 DOI: 10.1051/medsci/20163206014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Sophie Laguesse
- GIGA-Neurosciences, université de Liège, CHU Sart Tilman, Avenue de l'Hopital, 1, Liège 4020, Belgique - Interdisciplinary cluster for applied genoproteomics (GIGA-R), université de Liège, CHU Sart Tilman, Liège 4000, Belgique
| | - Catherine Creppe
- GIGA-Neurosciences, université de Liège, CHU Sart Tilman, Avenue de l'Hopital, 1, Liège 4020, Belgique - Interdisciplinary cluster for applied genoproteomics (GIGA-R), université de Liège, CHU Sart Tilman, Liège 4000, Belgique
| | - Juliette D Godin
- Institut de génétique et de biologie moléculaire et cellulaire (IGBMC), Inserm U964, CNRS UMR7104, université de Strasbourg, Illkirch, France
| | - Laurent Nguyen
- GIGA-Neurosciences, université de Liège, CHU Sart Tilman, Avenue de l'Hopital, 1, Liège 4020, Belgique - Interdisciplinary cluster for applied genoproteomics (GIGA-R), université de Liège, CHU Sart Tilman, Liège 4000, Belgique
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23
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Norcliffe-Kaufmann L, Slaugenhaupt SA, Kaufmann H. Familial dysautonomia: History, genotype, phenotype and translational research. Prog Neurobiol 2016; 152:131-148. [PMID: 27317387 DOI: 10.1016/j.pneurobio.2016.06.003] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 06/10/2016] [Accepted: 06/11/2016] [Indexed: 01/30/2023]
Abstract
Familial dysautonomia (FD) is a rare neurological disorder caused by a splice mutation in the IKBKAP gene. The mutation arose in the 1500s within the small Jewish founder population in Eastern Europe and became prevalent during the period of rapid population expansion within the Pale of Settlement. The carrier rate is 1:32 in Jews descending from this region. The mutation results in a tissue-specific deficiency in IKAP, a protein involved in the development and survival of neurons. Patients homozygous for the mutations are born with multiple lesions affecting mostly sensory (afferent) fibers, which leads to widespread organ dysfunction and increased mortality. Neurodegenerative features of the disease include progressive optic atrophy and worsening gait ataxia. Here we review the progress made in the last decade to better understand the genotype and phenotype. We also discuss the challenges of conducting controlled clinical trials in this rare medically fragile population. Meanwhile, the search for better treatments as well as a neuroprotective agent is ongoing.
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Affiliation(s)
| | - Susan A Slaugenhaupt
- Center for Human Genetic Research, Massachusetts General Hospital Research Institute and Department of Neurology, Harvard Medical School, Boston, MA, USA
| | - Horacio Kaufmann
- Department of Neurology, New York University School of Medicine, New York, NY, USA.
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24
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Laguesse S, Creppe C, Nedialkova DD, Prévot PP, Borgs L, Huysseune S, Franco B, Duysens G, Krusy N, Lee G, Thelen N, Thiry M, Close P, Chariot A, Malgrange B, Leidel SA, Godin JD, Nguyen L. A Dynamic Unfolded Protein Response Contributes to the Control of Cortical Neurogenesis. Dev Cell 2016; 35:553-567. [PMID: 26651292 DOI: 10.1016/j.devcel.2015.11.005] [Citation(s) in RCA: 146] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 10/07/2015] [Accepted: 11/09/2015] [Indexed: 12/21/2022]
Abstract
The cerebral cortex contains layers of neurons sequentially generated by distinct lineage-related progenitors. At the onset of corticogenesis, the first-born progenitors are apical progenitors (APs), whose asymmetric division gives birth directly to neurons. Later, they switch to indirect neurogenesis by generating intermediate progenitors (IPs), which give rise to projection neurons of all cortical layers. While a direct lineage relationship between APs and IPs has been established, the molecular mechanism that controls their transition remains elusive. Here we show that interfering with codon translation speed triggers ER stress and the unfolded protein response (UPR), further impairing the generation of IPs and leading to microcephaly. Moreover, we demonstrate that a progressive downregulation of UPR in cortical progenitors acts as a physiological signal to amplify IPs and promotes indirect neurogenesis. Thus, our findings reveal a contribution of UPR to cell fate acquisition during mammalian brain development.
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Affiliation(s)
- Sophie Laguesse
- GIGA-Neurosciences, University of Liège, C.H.U. Sart Tilman, Liège 4000, Belgium; Interdisciplinary Cluster for Applied Genoproteomics (GIGA-R), University of Liège, C.H.U. Sart Tilman, Liège 4000, Belgium
| | - Catherine Creppe
- GIGA-Neurosciences, University of Liège, C.H.U. Sart Tilman, Liège 4000, Belgium; Interdisciplinary Cluster for Applied Genoproteomics (GIGA-R), University of Liège, C.H.U. Sart Tilman, Liège 4000, Belgium
| | - Danny D Nedialkova
- Max Planck Research Group for RNA Biology, Max Planck Institute for Molecular Biomedicine, Von-Esmarch-Strasse 54, 48149 Muenster, Germany; Cells-in-Motion Cluster of Excellence, University of Muenster, Albert-Schweitzer-Campus 1, 48129 Muenster, Germany
| | - Pierre-Paul Prévot
- GIGA-Neurosciences, University of Liège, C.H.U. Sart Tilman, Liège 4000, Belgium; Interdisciplinary Cluster for Applied Genoproteomics (GIGA-R), University of Liège, C.H.U. Sart Tilman, Liège 4000, Belgium
| | - Laurence Borgs
- GIGA-Neurosciences, University of Liège, C.H.U. Sart Tilman, Liège 4000, Belgium; Interdisciplinary Cluster for Applied Genoproteomics (GIGA-R), University of Liège, C.H.U. Sart Tilman, Liège 4000, Belgium
| | - Sandra Huysseune
- GIGA-Neurosciences, University of Liège, C.H.U. Sart Tilman, Liège 4000, Belgium; Interdisciplinary Cluster for Applied Genoproteomics (GIGA-R), University of Liège, C.H.U. Sart Tilman, Liège 4000, Belgium
| | - Bénédicte Franco
- GIGA-Neurosciences, University of Liège, C.H.U. Sart Tilman, Liège 4000, Belgium; Interdisciplinary Cluster for Applied Genoproteomics (GIGA-R), University of Liège, C.H.U. Sart Tilman, Liège 4000, Belgium
| | - Guérin Duysens
- GIGA-Neurosciences, University of Liège, C.H.U. Sart Tilman, Liège 4000, Belgium; Interdisciplinary Cluster for Applied Genoproteomics (GIGA-R), University of Liège, C.H.U. Sart Tilman, Liège 4000, Belgium
| | - Nathalie Krusy
- GIGA-Neurosciences, University of Liège, C.H.U. Sart Tilman, Liège 4000, Belgium; Interdisciplinary Cluster for Applied Genoproteomics (GIGA-R), University of Liège, C.H.U. Sart Tilman, Liège 4000, Belgium
| | - Gabsang Lee
- Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Nicolas Thelen
- GIGA-Neurosciences, University of Liège, C.H.U. Sart Tilman, Liège 4000, Belgium; Interdisciplinary Cluster for Applied Genoproteomics (GIGA-R), University of Liège, C.H.U. Sart Tilman, Liège 4000, Belgium
| | - Marc Thiry
- GIGA-Neurosciences, University of Liège, C.H.U. Sart Tilman, Liège 4000, Belgium; Interdisciplinary Cluster for Applied Genoproteomics (GIGA-R), University of Liège, C.H.U. Sart Tilman, Liège 4000, Belgium
| | - Pierre Close
- GIGA-Signal Transduction, University of Liège, C.H.U. Sart Tilman, Liège 4000, Belgium; Interdisciplinary Cluster for Applied Genoproteomics (GIGA-R), University of Liège, C.H.U. Sart Tilman, Liège 4000, Belgium
| | - Alain Chariot
- GIGA-Signal Transduction, University of Liège, C.H.U. Sart Tilman, Liège 4000, Belgium; Interdisciplinary Cluster for Applied Genoproteomics (GIGA-R), University of Liège, C.H.U. Sart Tilman, Liège 4000, Belgium; Walloon Excellence in Lifesciences and Biotechnology (WELBIO), University of Liège, C.H.U. Sart Tilman, Liège 4000, Belgium
| | - Brigitte Malgrange
- GIGA-Neurosciences, University of Liège, C.H.U. Sart Tilman, Liège 4000, Belgium; Interdisciplinary Cluster for Applied Genoproteomics (GIGA-R), University of Liège, C.H.U. Sart Tilman, Liège 4000, Belgium
| | - Sebastian A Leidel
- Max Planck Research Group for RNA Biology, Max Planck Institute for Molecular Biomedicine, Von-Esmarch-Strasse 54, 48149 Muenster, Germany; Faculty of Medicine, University of Muenster, 48129 Muenster, Germany; Cells-in-Motion Cluster of Excellence, University of Muenster, Albert-Schweitzer-Campus 1, 48129 Muenster, Germany
| | - Juliette D Godin
- GIGA-Neurosciences, University of Liège, C.H.U. Sart Tilman, Liège 4000, Belgium; Interdisciplinary Cluster for Applied Genoproteomics (GIGA-R), University of Liège, C.H.U. Sart Tilman, Liège 4000, Belgium.
| | - Laurent Nguyen
- GIGA-Neurosciences, University of Liège, C.H.U. Sart Tilman, Liège 4000, Belgium; Interdisciplinary Cluster for Applied Genoproteomics (GIGA-R), University of Liège, C.H.U. Sart Tilman, Liège 4000, Belgium; Walloon Excellence in Lifesciences and Biotechnology (WELBIO), University of Liège, C.H.U. Sart Tilman, Liège 4000, Belgium.
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Donyo M, Hollander D, Abramovitch Z, Naftelberg S, Ast G. Phosphatidylserine enhances IKBKAP transcription by activating the MAPK/ERK signaling pathway. Hum Mol Genet 2016; 25:1307-17. [PMID: 26769675 DOI: 10.1093/hmg/ddw011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 01/11/2016] [Indexed: 01/04/2023] Open
Abstract
Familial dysautonomia (FD) is a genetic disorder manifested due to abnormal development and progressive degeneration of the sensory and autonomic nervous system. FD is caused by a point mutation in the IKBKAP gene encoding the IKAP protein, resulting in decreased protein levels. A promising potential treatment for FD is phosphatidylserine (PS); however, the manner by which PS elevates IKAP levels has yet to be identified. Analysis of ChIP-seq results of the IKBKAP promoter region revealed binding of the transcription factors CREB and ELK1, which are regulated by the mitogen-activated protein kinase (MAPK)/extracellular-regulated kinase (ERK) signaling pathway. We show that PS treatment enhanced ERK phosphorylation in cells derived from FD patients. ERK activation resulted in elevated IKBKAP transcription and IKAP protein levels, whereas pretreatment with the MAPK inhibitor U0126 blocked elevation of the IKAP protein level. Overexpression of either ELK1 or CREB activated the IKBKAP promoter, whereas downregulation of these transcription factors resulted in a decrease of the IKAP protein. Additionally, we show that PS improves cell migration, known to be enhanced by MAPK/ERK activation and abrogated in FD cells. In conclusion, our results demonstrate that PS activates the MAPK/ERK signaling pathway, resulting in activation of transcription factors that bind the promoter region of IKBKAP and thus enhancing its transcription. Therefore, compounds that activate the MAPK/ERK signaling pathway could constitute potential treatments for FD.
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Affiliation(s)
- Maya Donyo
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv 69978, Israel
| | - Dror Hollander
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv 69978, Israel
| | - Ziv Abramovitch
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv 69978, Israel
| | - Shiran Naftelberg
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv 69978, Israel
| | - Gil Ast
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv 69978, Israel
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26
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Addis L, Ahn JW, Dobson R, Dixit A, Ogilvie CM, Pinto D, Vaags AK, Coon H, Chaste P, Wilson S, Parr JR, Andrieux J, Lenne B, Tumer Z, Leuzzi V, Aubell K, Koillinen H, Curran S, Marshall CR, Scherer SW, Strug LJ, Collier DA, Pal DK. Microdeletions of ELP4 Are Associated with Language Impairment, Autism Spectrum Disorder, and Mental Retardation. Hum Mutat 2015; 36:842-50. [PMID: 26010655 DOI: 10.1002/humu.22816] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Accepted: 05/15/2015] [Indexed: 12/13/2022]
Abstract
Copy-number variations (CNVs) are important in the aetiology of neurodevelopmental disorders and show broad phenotypic manifestations. We compared the presence of small CNVs disrupting the ELP4-PAX6 locus in 4,092 UK individuals with a range of neurodevelopmental conditions, clinically referred for array comparative genomic hybridization, with WTCCC controls (n = 4,783). The phenotypic analysis was then extended using the DECIPHER database. We followed up association using an autism patient cohort (n = 3,143) compared with six additional control groups (n = 6,469). In the clinical discovery series, we identified eight cases with ELP4 deletions, and one with a partial duplication of ELP4 and PAX6. These cases were referred for neurological phenotypes including language impairment, developmental delay, autism, and epilepsy. Six further cases with a primary diagnosis of autism spectrum disorder (ASD) and similar secondary phenotypes were identified with ELP4 deletions, as well as another six (out of nine) with neurodevelopmental phenotypes from DECIPHER. CNVs at ELP4 were only present in 1/11,252 controls. We found a significant excess of CNVs in discovery cases compared with controls, P = 7.5 × 10(-3) , as well as for autism, P = 2.7 × 10(-3) . Our results suggest that ELP4 deletions are highly likely to be pathogenic, predisposing to a range of neurodevelopmental phenotypes from ASD to language impairment and epilepsy.
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Affiliation(s)
- Laura Addis
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
- Neuroscience Discovery Research, Eli Lilly and Company, Erl Wood, Surrey, UK
| | - Joo Wook Ahn
- Department of Cytogenetics, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Richard Dobson
- Department of Biostatistics and NIHR BRC for Mental Health, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Abhishek Dixit
- Department of Biostatistics and NIHR BRC for Mental Health, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Caroline M Ogilvie
- Department of Cytogenetics, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Dalila Pinto
- Departments of Psychiatry, and Genetics and Genomic Sciences, Seaver Autism Center, The Mindich Child Health & Development Institute, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Andrea K Vaags
- The Centre for Applied Genomics, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Hilary Coon
- Department of Psychiatry, University of Utah School of Medicine, Salt Lake City, Utah
| | - Pauline Chaste
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Scott Wilson
- Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
- Department of Endocrinology and Diabetes, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia
- School of Medicine and Pharmacology, University of Western Australia, Nedlands, Western Australia, Australia
| | - Jeremy R Parr
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Joris Andrieux
- Institut de Génétique Médicale, Hopital Jeanne de Flandre, CHRU de Lille, France
| | - Bruno Lenne
- Centre de Génétique Chromosomique, GHICL, Hôpital Saint Vincent de Paul, Lille, France
| | - Zeynep Tumer
- Applied Human Molecular Genetics, Kennedy Center, Department of Clinical Genetics, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Vincenzo Leuzzi
- Department of Pediatrics, Child Neurology and Psychiatry, Sapienza Università di Roma, Rome, Italy
| | - Kristina Aubell
- Institute of Human Genetics, Medical University of Graz, Graz, Austria
| | - Hannele Koillinen
- Department of Clinical Genetics, Helsinki University Hospital, Helsinki, Finland
| | - Sarah Curran
- Department of Cytogenetics, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Christian R Marshall
- The Centre for Applied Genomics, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Molecular Genetics, Paediatric Laboratory Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Stephen W Scherer
- The Centre for Applied Genomics, The Hospital for Sick Children, Toronto, Ontario, Canada
- McLaughlin Centre and Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Lisa J Strug
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Division of Biostatistics, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
| | - David A Collier
- Neuroscience Discovery Research, Eli Lilly and Company, Erl Wood, Surrey, UK
- Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Deb K Pal
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
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Lin S, Nazif K, Smith A, Baas PW, Smith GM. Histone acetylation inhibitors promote axon growth in adult dorsal root ganglia neurons. J Neurosci Res 2015; 93:1215-28. [PMID: 25702820 DOI: 10.1002/jnr.23573] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Revised: 01/13/2015] [Accepted: 01/26/2015] [Indexed: 12/24/2022]
Abstract
Intrinsic mechanisms that guide damaged axons to regenerate following spinal cord injury remain poorly understood. Manipulation of posttranslational modifications of key proteins in mature neurons could reinvigorate growth machinery after injury. One such modification is acetylation, a reversible process controlled by two enzyme families, the histone deacetylases (HDACs) and the histone acetyl transferases (HATs), acting in opposition. Whereas acetylated histones in the nucleus are associated with upregulation of growth-promoting genes, deacetylated tubulin in the axoplasm is associated with more labile microtubules, conducive to axon growth. This study investigates the effects of HAT and HDAC inhibitors on cultured adult dorsal root ganglia (DRG) neurons and shows that inhibition of HATs by anacardic acid or CPTH2 improves axon outgrowth, whereas inhibition of HDACs by TSA or tubacin inhibits axon growth. Anacardic acid increased the number of axons able to cross an inhibitory chondroitin sulfate proteoglycan border. Histone acetylation but not tubulin acetylation level was affected by HAT inhibitors, whereas tubulin acetylation levels were increased in the presence of the HDAC inhibitor tubacin. Although the microtubule-stabilizing drug taxol did not have an effect on the lengths of DRG axons, nocodazole decreased axon lengths. Determining the mechanistic basis will require future studies, but this study shows that inhibitors of HAT can augment axon growth in adult DRG neurons, with the potential of aiding axon growth over inhibitory substrates produced by the glial scar.
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Affiliation(s)
- Shen Lin
- Department of Neuroscience, Shriners Hospitals for Pediatric Research Center, Temple University, Philadelphia, Pennsylvania
| | - Kutaiba Nazif
- Department of Neuroscience, Shriners Hospitals for Pediatric Research Center, Temple University, Philadelphia, Pennsylvania
| | - Alexander Smith
- Department of Neuroscience, Shriners Hospitals for Pediatric Research Center, Temple University, Philadelphia, Pennsylvania
| | - Peter W Baas
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania
| | - George M Smith
- Department of Neuroscience, Shriners Hospitals for Pediatric Research Center, Temple University, Philadelphia, Pennsylvania
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28
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Rectifier of aberrant mRNA splicing recovers tRNA modification in familial dysautonomia. Proc Natl Acad Sci U S A 2015; 112:2764-9. [PMID: 25675486 DOI: 10.1073/pnas.1415525112] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Familial dysautonomia (FD), a hereditary sensory and autonomic neuropathy, is caused by missplicing of exon 20, resulting from an intronic mutation in the inhibitor of kappa light polypeptide gene enhancer in B cells, kinase complex-associated protein (IKBKAP) gene encoding IKK complex-associated protein (IKAP)/elongator protein 1 (ELP1). A newly established splicing reporter assay allowed us to visualize pathogenic splicing in cells and to screen small chemicals for the ability to correct the aberrant splicing of IKBKAP. Using this splicing reporter, we screened our chemical libraries and identified a compound, rectifier of aberrant splicing (RECTAS), that rectifies the aberrant IKBKAP splicing in cells from patients with FD. Here, we found that the levels of modified uridine at the wobble position in cytoplasmic tRNAs are reduced in cells from patients with FD and that treatment with RECTAS increases the expression of IKAP and recovers the tRNA modifications. These findings suggest that the missplicing of IKBKAP results in reduced tRNA modifications in patients with FD and that RECTAS is a promising therapeutic drug candidate for FD.
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Abdel-Fattah W, Jablonowski D, Di Santo R, Thüring KL, Scheidt V, Hammermeister A, ten Have S, Helm M, Schaffrath R, Stark MJR. Phosphorylation of Elp1 by Hrr25 is required for elongator-dependent tRNA modification in yeast. PLoS Genet 2015; 11:e1004931. [PMID: 25569479 PMCID: PMC4287497 DOI: 10.1371/journal.pgen.1004931] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Accepted: 12/01/2014] [Indexed: 12/26/2022] Open
Abstract
Elongator is a conserved protein complex comprising six different polypeptides that has been ascribed a wide range of functions, but which is now known to be required for modification of uridine residues in the wobble position of a subset of tRNAs in yeast, plants, worms and mammals. In previous work, we showed that Elongator's largest subunit (Elp1; also known as Iki3) was phosphorylated and implicated the yeast casein kinase I Hrr25 in Elongator function. Here we report identification of nine in vivo phosphorylation sites within Elp1 and show that four of these, clustered close to the Elp1 C-terminus and adjacent to a region that binds tRNA, are important for Elongator's tRNA modification function. Hrr25 protein kinase directly modifies Elp1 on two sites (Ser-1198 and Ser-1202) and through analyzing non-phosphorylatable (alanine) and acidic, phosphomimic substitutions at Ser-1198, Ser-1202 and Ser-1209, we provide evidence that phosphorylation plays a positive role in the tRNA modification function of Elongator and may regulate the interaction of Elongator both with its accessory protein Kti12 and with Hrr25 kinase. tRNA molecules function as adapters in protein synthesis, bringing amino acids to the ribosome and reading the genetic code through codon-anticodon base pairing. When the tRNA contains a uridine residue in the “wobble position” of its anticodon, which base-pairs with purine residues in the third position of a cognate codon, it is almost always chemically modified and modification is required for efficient decoding. In eukaryotic cells, these wobble uridine modifications require a conserved protein complex called Elongator. Our work shows that Elp1, Elongator's largest subunit, is phosphorylated on several sites. By blocking phosphorylation at these positions using mutations, we identified four phosphorylation sites that are important for Elongator's role in tRNA modification. We have also shown that Hrr25 protein kinase, a member of the casein kinase I (CKI) family, is responsible for modification of two of the sites that are important for Elongator function. Phosphorylation appears to affect interaction of the Elongator complex both with its kinase (Hrr25) and with Kti12, an accessory protein previously implicated in Elongator function. Our studies imply that Elp1 phosphorylation plays a positive role in Elongator-mediated tRNA modification and raise the possibility that wobble uridine modification may be regulated, representing a potential translational control mechanism.
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Affiliation(s)
- Wael Abdel-Fattah
- Centre for Gene Regulation & Expression, College of Life Sciences, University of Dundee, Dundee, United Kingdom
- Institut für Biologie, FG Mikrobiologie, Universität Kassel, Germany
| | | | - Rachael Di Santo
- Centre for Gene Regulation & Expression, College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Kathrin L. Thüring
- Institut für Pharmazie und Biochemie, Johannes Gutenberg-Universität Mainz, Germany
| | - Viktor Scheidt
- Institut für Biologie, FG Mikrobiologie, Universität Kassel, Germany
| | | | - Sara ten Have
- Centre for Gene Regulation & Expression, College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Mark Helm
- Institut für Pharmazie und Biochemie, Johannes Gutenberg-Universität Mainz, Germany
| | - Raffael Schaffrath
- Institut für Biologie, FG Mikrobiologie, Universität Kassel, Germany
- Department of Genetics, University of Leicester, Leicester, United Kingdom
- * E-mail: (RS); (MJRS)
| | - Michael J. R. Stark
- Centre for Gene Regulation & Expression, College of Life Sciences, University of Dundee, Dundee, United Kingdom
- * E-mail: (RS); (MJRS)
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30
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Torres AG, Batlle E, Ribas de Pouplana L. Role of tRNA modifications in human diseases. Trends Mol Med 2014; 20:306-14. [PMID: 24581449 DOI: 10.1016/j.molmed.2014.01.008] [Citation(s) in RCA: 296] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Revised: 01/17/2014] [Accepted: 01/23/2014] [Indexed: 12/22/2022]
Abstract
Transfer RNAs (tRNAs) are key for efficient and accurate protein translation. To be fully active, tRNAs need to be heavily modified post-transcriptionally. Growing evidence indicates that tRNA modifications and the enzymes catalyzing such modifications may play important roles in complex human pathologies. Here, we have compiled current knowledge that directly link tRNA modifications to human diseases such as cancer, type 2 diabetes (T2D), neurological disorders, and mitochondrial-linked disorders. The molecular mechanisms behind these connections remain, for the most part, unknown. As we progress towards the understanding of the roles played by hypomodified tRNAs in human disease, novel areas of therapeutic intervention may be discovered.
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Affiliation(s)
- Adrian Gabriel Torres
- Institute for Research in Biomedicine (IRB), Parc Cientific de Barcelona, 08028 Catalunya, Spain
| | - Eduard Batlle
- Institute for Research in Biomedicine (IRB), Parc Cientific de Barcelona, 08028 Catalunya, Spain; Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, 08010 Catalunya, Spain
| | - Lluis Ribas de Pouplana
- Institute for Research in Biomedicine (IRB), Parc Cientific de Barcelona, 08028 Catalunya, Spain; Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, 08010 Catalunya, Spain.
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Pirooznia SK, Elefant F. Targeting specific HATs for neurodegenerative disease treatment: translating basic biology to therapeutic possibilities. Front Cell Neurosci 2013; 7:30. [PMID: 23543406 PMCID: PMC3610086 DOI: 10.3389/fncel.2013.00030] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Accepted: 03/10/2013] [Indexed: 12/28/2022] Open
Abstract
Dynamic epigenetic regulation of neurons is emerging as a fundamental mechanism by which neurons adapt their transcriptional responses to specific developmental and environmental cues. While defects within the neural epigenome have traditionally been studied in the context of early developmental and heritable cognitive disorders, recent studies point to aberrant histone acetylation status as a key mechanism underlying acquired inappropriate alterations of genome structure and function in post-mitotic neurons during the aging process. Indeed, it is becoming increasingly evident that chromatin acetylation status can be impaired during the lifetime of neurons through mechanisms related to loss of function of histone acetyltransferase (HAT) activity. Several HATs have been shown to participate in vital neuronal functions such as regulation of neuronal plasticity and memory formation. As such, dysregulation of such HATs has been implicated in the pathogenesis associated with age-associated neurodegenerative diseases and cognitive decline. In order to counteract the loss of HAT function in neurodegenerative diseases, the current therapeutic strategies involve the use of small molecules called histone deacetylase (HDAC) inhibitors that antagonize HDAC activity and thus enhance acetylation levels. Although this strategy has displayed promising therapeutic effects, currently used HDAC inhibitors lack target specificity, raising concerns about their applicability. With rapidly evolving literature on HATs and their respective functions in mediating neuronal survival and higher order brain function such as learning and memory, modulating the function of specific HATs holds new promises as a therapeutic tool in neurodegenerative diseases. In this review, we focus on the recent progress in research regarding epigenetic histone acetylation mechanisms underlying neuronal activity and cognitive function. We discuss the current understanding of specific HDACs and HATs in neurodegenerative diseases and the future promising prospects of using specific HAT based therapeutic approaches.
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Bochner R, Ziv Y, Zeevi D, Donyo M, Abraham L, Ashery-Padan R, Ast G. Phosphatidylserine increases IKBKAP levels in a humanized knock-in IKBKAP mouse model. Hum Mol Genet 2013; 22:2785-94. [PMID: 23515154 DOI: 10.1093/hmg/ddt126] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Familial dysautonomia (FD) is a severe neurodegenerative genetic disorder restricted to the Ashkenazi Jewish population. The most common mutation in FD patients is a T-to-C transition at position 6 of intron 20 of the IKBKAP gene. This mutation causes aberrant skipping of exon 20 in a tissue-specific manner, leading to reduction of the IκB kinase complex-associated protein (IKAP) protein in the nervous system. We established a homozygous humanized mouse strain carrying human exon 20 and its two flanking introns; the 3' intron has the transition observed in the IKBKAP gene of FD patients. Although our FD humanized mouse does not display FD symptoms, the unique, tissue-specific splicing pattern of the IKBKAP in these mice allowed us to evaluate the effect of therapies on gene expression and exon 20 splicing. The FD mice were supplemented with phosphatidylserine (PS), a safe food supplement that increases mRNA and protein levels of IKBKAP in cell lines generated from FD patients. Here we demonstrated that PS treatment increases IKBAKP mRNA and IKAP protein levels in various tissues of FD mice without affecting exon 20 inclusion levels. We also observed that genes associated with transcription regulation and developmental processes were up-regulated in the cerebrum of PS-treated mice. Thus, PS holds promise for the treatment of FD.
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Affiliation(s)
- Ron Bochner
- Department of Human Molecular Genetics and Biochemistry
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34
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Godin JD, Thomas N, Laguesse S, Malinouskaya L, Close P, Malaise O, Purnelle A, Raineteau O, Campbell K, Fero M, Moonen G, Malgrange B, Chariot A, Metin C, Besson A, Nguyen L. p27(Kip1) is a microtubule-associated protein that promotes microtubule polymerization during neuron migration. Dev Cell 2012; 23:729-44. [PMID: 23022035 DOI: 10.1016/j.devcel.2012.08.006] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Revised: 05/16/2012] [Accepted: 08/08/2012] [Indexed: 01/28/2023]
Abstract
The migration of cortical interneurons is characterized by extensive morphological changes that result from successive cycles of nucleokinesis and neurite branching. Their molecular bases remain elusive, and the present work describes how p27(Kip1) controls cell-cycle-unrelated signaling pathways to regulate these morphological remodelings. Live imaging reveals that interneurons lacking p27(Kip1) show delayed tangential migration resulting from defects in both nucleokinesis and dynamic branching of the leading process. At the molecular level, p27(Kip1) is a microtubule-associated protein that promotes polymerization of microtubules in extending neurites, thereby contributing to tangential migration. Furthermore, we show that p27(Kip1) controls actomyosin contractions that drive both forward translocation of the nucleus and growth cone splitting. Thus, p27(Kip1) cell-autonomously controls nucleokinesis and neurite branching by regulating both actin and microtubule cytoskeletons.
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Affiliation(s)
- Juliette D Godin
- GIGA-Neurosciences, University of Liège, C.H.U. Sart Tilman, Liège 4000, Belgium
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Close P, Gillard M, Ladang A, Jiang Z, Papuga J, Hawkes N, Nguyen L, Chapelle JP, Bouillenne F, Svejstrup J, Fillet M, Chariot A. DERP6 (ELP5) and C3ORF75 (ELP6) regulate tumorigenicity and migration of melanoma cells as subunits of Elongator. J Biol Chem 2012; 287:32535-45. [PMID: 22854966 PMCID: PMC3463322 DOI: 10.1074/jbc.m112.402727] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Indexed: 12/17/2022] Open
Abstract
The Elongator complex is composed of 6 subunits (Elp1-Elp6) and promotes RNAPII transcript elongation through histone acetylation in the nucleus as well as tRNA modification in the cytoplasm. This acetyltransferase complex directly or indirectly regulates numerous biological processes ranging from exocytosis and resistance to heat shock in yeast to cell migration and neuronal differentiation in higher eukaryotes. The identity of human ELP1 through ELP4 has been reported but human ELP5 and ELP6 have remained uncharacterized. Here, we report that DERP6 (ELP5) and C3ORF75 (ELP6) encode these subunits of human Elongator. We further investigated the importance and function of these two subunits by a combination of biochemical analysis and cellular assays. Our results show that DERP6/ELP5 is required for the integrity of Elongator and directly connects ELP3 to ELP4. Importantly, the migration and tumorigenicity of melanoma-derived cells are significantly decreased upon Elongator depletion through ELP1 or ELP3. Strikingly, DERP6/ELP5 and C3ORF75/ELP6-depleted melanoma cells have similar defects, further supporting the idea that DERP6/ELP5 and C3ORF75/ELP6 are essential for Elongator function. Together, our data identify DERP6/ELP5 and C3ORF75/ELP6 as key players for migration, invasion and tumorigenicity of melanoma cells, as integral subunits of Elongator.
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Affiliation(s)
- Pierre Close
- From the Interdisciplinary Cluster for Applied Genoproteomics (GIGA-R)
- GIGA Signal Transduction and Laboratory of Medical Chemistry
| | - Magali Gillard
- From the Interdisciplinary Cluster for Applied Genoproteomics (GIGA-R)
- GIGA Signal Transduction and Laboratory of Medical Chemistry
| | - Aurélie Ladang
- From the Interdisciplinary Cluster for Applied Genoproteomics (GIGA-R)
- GIGA Signal Transduction and Laboratory of Medical Chemistry
| | - Zheshen Jiang
- From the Interdisciplinary Cluster for Applied Genoproteomics (GIGA-R)
- GIGA Signal Transduction and Laboratory of Medical Chemistry
| | - Jessica Papuga
- From the Interdisciplinary Cluster for Applied Genoproteomics (GIGA-R)
- GIGA Signal Transduction and Laboratory of Medical Chemistry
| | - Nicola Hawkes
- the Mechanisms of Transcription Laboratory, Clare Hall Laboratories, Cancer Research UK London Research Institute, South Mimms EN6 3LD, United Kingdom
| | - Laurent Nguyen
- From the Interdisciplinary Cluster for Applied Genoproteomics (GIGA-R)
- Developmental Neurobiology Unit and GIGA Neurosciences
| | - Jean-Paul Chapelle
- From the Interdisciplinary Cluster for Applied Genoproteomics (GIGA-R)
- GIGA Signal Transduction and Laboratory of Medical Chemistry
| | | | - Jesper Svejstrup
- the Mechanisms of Transcription Laboratory, Clare Hall Laboratories, Cancer Research UK London Research Institute, South Mimms EN6 3LD, United Kingdom
| | - Marianne Fillet
- From the Interdisciplinary Cluster for Applied Genoproteomics (GIGA-R)
- GIGA Signal Transduction and Laboratory of Medical Chemistry
- Laboratory of Analytical Pharmaceutical Chemistry, Department of Pharmacy, CIRM, and
| | - Alain Chariot
- From the Interdisciplinary Cluster for Applied Genoproteomics (GIGA-R)
- GIGA Signal Transduction and Laboratory of Medical Chemistry
- Walloon Excellence in Life Sciences and Biotechnology (WELBIO), GIGA-R, University of Liège, CHU, Sart-Tilman, B-4000 Liège, Belgium and
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Hunnicutt BJ, Chaverra M, George L, Lefcort F. IKAP/Elp1 is required in vivo for neurogenesis and neuronal survival, but not for neural crest migration. PLoS One 2012; 7:e32050. [PMID: 22384137 PMCID: PMC3285659 DOI: 10.1371/journal.pone.0032050] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Accepted: 01/20/2012] [Indexed: 12/18/2022] Open
Abstract
Familial Dysautonomia (FD; Hereditary Sensory Autonomic Neuropathy; HSAN III) manifests from a failure in development of the peripheral sensory and autonomic nervous systems. The disease results from a point mutation in the IKBKAP gene, which encodes the IKAP protein, whose function is still unresolved in the developing nervous system. Since the neurons most severely depleted in the disease derive from the neural crest, and in light of data identifying a role for IKAP in cell motility and migration, it has been suggested that FD results from a disruption in neural crest migration. To determine the function of IKAP during development of the nervous system, we (1) first determined the spatial-temporal pattern of IKAP expression in the developing peripheral nervous system, from the onset of neural crest migration through the period of programmed cell death in the dorsal root ganglia, and (2) using RNAi, reduced expression of IKBKAP mRNA in the neural crest lineage throughout the process of dorsal root ganglia (DRG) development in chick embryos in ovo. Here we demonstrate that IKAP is not expressed by neural crest cells and instead is expressed as neurons differentiate both in the CNS and PNS, thus the devastation of the PNS in FD could not be due to disruptions in neural crest motility or migration. In addition, we show that alterations in the levels of IKAP, through both gain and loss of function studies, perturbs neuronal polarity, neuronal differentiation and survival. Thus IKAP plays pleiotropic roles in both the peripheral and central nervous systems.
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Affiliation(s)
| | | | | | - Frances Lefcort
- Department of Cell Biology and Neuroscience, Montana State University, Bozeman, Montana
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Lin JJ, Riley JD, Hsu DA, Stafstrom CE, Dabbs K, Becker T, Seidenberg M, Hermann BP. Striatal hypertrophy and its cognitive effects in new-onset benign epilepsy with centrotemporal spikes. Epilepsia 2012; 53:677-85. [PMID: 22360313 DOI: 10.1111/j.1528-1167.2012.03422.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
PURPOSE Benign epilepsy with centrotemporal spikes (BECTS), the most common childhood epilepsy syndrome, is a neurodevelopmental disorder with a genetic influence. Despite its signature electroencephalographic pattern and distinct focal motor seizure semiology, little is known about the underlying brain anatomic alteration and the corresponding cognitive consequences. Given the motor manifestations of seizures in BECTS, we hypothesize that anatomic networks in BECTS involve a distributed corticostriatal circuit. METHODS We investigated volumetric differences and shape deformities of caudate, putamen, pallidum, and thalamus in a group of children with new- and recent-onset BECTS (N = 3) compared to healthy controls (N = 54). We correlated specific subcortical volumes in BECTS that were significantly different from those in healthy controls with performances in executive function. KEY FINDINGS Children with BECTS demonstrated significantly hypertrophied putamen, which was selective among the subcortical regions examined. Shape analysis showed dorsoventral elongation of the left caudate and bilateral putamen, with subnuclei expansion in ventral and dorsal striatum. Larger putamen volumes were linked to better cognitive performances on two complementary executive function tests. SIGNIFICANCE Children with BECTS showed aberrant volume and shape in subcortical regions that are critical for both motor processing and executive function. It is of importance to note that the hypertrophy appears to be cognitively adaptive, as enlargement was associated with improved cognitive performances. The anatomic abnormalities and their cognitive effects are evident in a group of children with new- and recent-onset epilepsy, suggesting that the structural brain anomalies occurred before the diagnosis of epilepsy.
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Affiliation(s)
- Jack J Lin
- Department of Neurology, University of California, Irvine, California 92697, USA.
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Bolukbasi E, Vass S, Cobbe N, Nelson B, Simossis V, Dunbar DR, Heck MMS. Drosophila poly suggests a novel role for the Elongator complex in insulin receptor-target of rapamycin signalling. Open Biol 2012; 2:110031. [PMID: 22645656 PMCID: PMC3352090 DOI: 10.1098/rsob.110031] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Accepted: 12/21/2011] [Indexed: 01/06/2023] Open
Abstract
Multi-cellular organisms need to successfully link cell growth and metabolism to environmental cues during development. Insulin receptor-target of rapamycin (InR-TOR) signalling is a highly conserved pathway that mediates this link. Herein, we describe poly, an essential gene in Drosophila that mediates InR-TOR signalling. Loss of poly results in lethality at the third instar larval stage, but only after a stage of extreme larval longevity. Analysis in Drosophila demonstrates that Poly and InR interact and that poly mutants show an overall decrease in InR-TOR signalling, as evidenced by decreased phosphorylation of Akt, S6K and 4E-BP. Metabolism is altered in poly mutants, as revealed by microarray expression analysis and a decreased triglyceride : protein ratio in mutant animals. Intriguingly, the cellular distribution of Poly is dependent on insulin stimulation in both Drosophila and human cells, moving to the nucleus with insulin treatment, consistent with a role in InR-TOR signalling. Together, these data reveal that Poly is a novel, conserved (from flies to humans) mediator of InR signalling that promotes an increase in cell growth and metabolism. Furthermore, homology to small subunits of Elongator demonstrates a novel, unexpected role for this complex in insulin signalling.
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Affiliation(s)
| | | | | | | | | | | | - Margarete M. S. Heck
- University of Edinburgh, Queen's Medical
Research Institute, University/BHF Centre for
Cardiovascular Science, 47 Little France Crescent, Edinburgh EH16
4TJ, UK
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Maxwell MM, Tomkinson EM, Nobles J, Wizeman JW, Amore AM, Quinti L, Chopra V, Hersch SM, Kazantsev AG. The Sirtuin 2 microtubule deacetylase is an abundant neuronal protein that accumulates in the aging CNS. Hum Mol Genet 2011; 20:3986-96. [PMID: 21791548 DOI: 10.1093/hmg/ddr326] [Citation(s) in RCA: 146] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Sirtuin 2 (SIRT2) is one of seven known mammalian protein deacetylases homologous to the yeast master lifespan regulator Sir2. In recent years, the sirtuin protein deacetylases have emerged as candidate therapeutic targets for many human diseases, including metabolic and age-dependent neurological disorders. In non-neuronal cells, SIRT2 has been shown to function as a tubulin deacetylase and a key regulator of cell division and differentiation. However, the distribution and function of the SIRT2 microtubule (MT) deacetylase in differentiated, postmitotic neurons remain largely unknown. Here, we show abundant and preferential expression of specific isoforms of SIRT2 in the mammalian central nervous system and find that a previously uncharacterized form, SIRT2.3, exhibits age-dependent accumulation in the mouse brain and spinal cord. Further, our studies reveal that focal areas of endogenous SIRT2 expression correlate with reduced α-tubulin acetylation in primary mouse cortical neurons and suggest that the brain-enriched species of SIRT2 may function as the predominant MT deacetylases in mature neurons. Recent reports have demonstrated an association between impaired tubulin acetyltransferase activity and neurodegenerative disease; viewed in this light, our results showing age-dependent accumulation of the SIRT2 neuronal MT deacetylase in wild-type mice suggest a functional link between tubulin acetylation patterns and the aging brain.
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Affiliation(s)
- Michele M Maxwell
- MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Boston, MA 02115, USA.
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Cohen-Kupiec R, Pasmanik-Chor M, Oron-Karni V, Weil M. Effects of IKAP/hELP1 deficiency on gene expression in differentiating neuroblastoma cells: implications for familial dysautonomia. PLoS One 2011; 6:e19147. [PMID: 21559466 PMCID: PMC3084765 DOI: 10.1371/journal.pone.0019147] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2011] [Accepted: 03/18/2011] [Indexed: 02/05/2023] Open
Abstract
Familial dysautonomia (FD) is a developmental neuropathy of the sensory and autonomous nervous systems. The IKBKAP gene, encoding the IKAP/hELP1 subunit of the RNA polymerase II Elongator complex is mutated in FD patients, leading to a tissue-specific mis-splicing of the gene and to the absence of the protein in neuronal tissues. To elucidate the function of IKAP/hELP1 in the development of neuronal cells, we have downregulated IKBKAP expression in SHSY5Y cells, a neuroblastoma cell line of a neural crest origin. We have previously shown that these cells exhibit abnormal cell adhesion when allowed to differentiate under defined culture conditions on laminin substratum. Here, we report results of a microarray expression analysis of IKAP/hELP1 downregulated cells that were grown on laminin under differentiation or non-differentiation growth conditions. It is shown that under non-differentiation growth conditions, IKAP/hELP1 downregulation affects genes important for early developmental stages of the nervous system, including cell signaling, cell adhesion and neural crest migration. IKAP/hELP1 downregulation during differentiation affects the expression of genes that play a role in late neuronal development, in axonal projection and synapse formation and function. We also show that IKAP/hELP1 deficiency affects the expression of genes involved in calcium metabolism before and after differentiation of the neuroblastoma cells. Hence, our data support IKAP/hELP1 importance in the development and function of neuronal cells and contribute to the understanding of the FD phenotype.
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Affiliation(s)
- Rachel Cohen-Kupiec
- Department of Cell Research and Immunology, Tel Aviv University, Ramat-Aviv, Israel
| | | | | | - Miguel Weil
- Department of Cell Research and Immunology, Tel Aviv University, Ramat-Aviv, Israel
- * E-mail:
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Eschbach J, Dupuis L. Cytoplasmic dynein in neurodegeneration. Pharmacol Ther 2011; 130:348-63. [PMID: 21420428 DOI: 10.1016/j.pharmthera.2011.03.004] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Accepted: 03/01/2011] [Indexed: 12/11/2022]
Abstract
Cytoplasmic dynein 1 (later referred to as dynein) is the major molecular motor moving cargoes such as mitochondria, organelles and proteins towards the minus end of microtubules. Dynein is involved in multiple basic cellular functions, such as mitosis, autophagy and structure of endoplasmic reticulum and Golgi, but also in neuron specific functions in particular retrograde axonal transport. Dynein is regulated by a number of protein complexes, notably by dynactin. Several studies have supported indirectly the involvement of dynein in neurodegeneration associated with Alzheimer's disease, Parkinson's disease, Huntington's disease and motor neuron diseases. First, axonal transport disruption represents a common feature occurring in neurodegenerative diseases. Second, a number of dynein-dependent processes, including autophagy or clearance of aggregation-prone proteins, are found defective in most of these diseases. Third, a number of mutant genes in various neurodegenerative diseases are involved in the regulation of dynein transport. This includes notably mutations in the P150Glued subunit of dynactin that are found in Perry syndrome and motor neuron diseases. Interestingly, gene products that are mutant in Huntington's disease, Parkinson's disease, motor neuron disease or spino-cerebellar ataxia are also involved in the regulation of dynein motor activity or of cargo binding. Despite a constellation of indirect evidence, direct links between the motor itself and neurodegeneration are few, and this might be due to the requirement of fully active dynein for development. Here, we critically review the evidence of dynein involvement in different neurodegenerative diseases and discuss potential underlying mechanisms.
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Affiliation(s)
- Judith Eschbach
- Inserm U692, Laboratoire de Signalisations Moléculaires et Neurodégénérescence, Strasbourg, F-67085, France
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Elongator: an ancestral complex driving transcription and migration through protein acetylation. J Biomed Biotechnol 2011; 2011:924898. [PMID: 21274405 PMCID: PMC3025403 DOI: 10.1155/2011/924898] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2010] [Accepted: 12/05/2010] [Indexed: 11/17/2022] Open
Abstract
Elongator is an evolutionary highly conserved complex. At least two of its cellular functions rely on the intrinsic lysine acetyl-transferase activity of the elongator complex. Its two known substrates--histone H3 and α-tubulin--reflect the different roles of elongator in the cytosol and the nucleus. A picture seems to emerge in which nuclear elongator could regulate the transcriptional elongation of a subset of stress-inducible genes through acetylation of histone H3 in the promoter-distal gene body. In the cytosol, elongator-mediated acetylation of α-tubulin contributes to intracellular trafficking and cell migration. Defects in both functions of elongator have been implicated in neurodegenerative disorders.
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Phosphatidylserine increases IKBKAP levels in familial dysautonomia cells. PLoS One 2010; 5:e15884. [PMID: 21209961 PMCID: PMC3012102 DOI: 10.1371/journal.pone.0015884] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2010] [Accepted: 11/26/2010] [Indexed: 11/19/2022] Open
Abstract
Familial Dysautonomia (FD) is an autosomal recessive congenital neuropathy that results from abnormal development and progressive degeneration of the sensory and autonomic nervous system. The mutation observed in almost all FD patients is a point mutation at position 6 of intron 20 of the IKBKAP gene; this gene encodes the IκB kinase complex-associated protein (IKAP). The mutation results in a tissue-specific splicing defect: Exon 20 is skipped, leading to reduced IKAP protein expression. Here we show that phosphatidylserine (PS), an FDA-approved food supplement, increased IKAP mRNA levels in cells derived from FD patients. Long-term treatment with PS led to a significant increase in IKAP protein levels in these cells. A conjugate of PS and an omega-3 fatty acid also increased IKAP mRNA levels. Furthermore, PS treatment released FD cells from cell cycle arrest and up-regulated a significant number of genes involved in cell cycle regulation. Our results suggest that PS has potential for use as a therapeutic agent for FD. Understanding its mechanism of action may reveal the mechanism underlying the FD disease.
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Sudo H, Baas PW. Strategies for diminishing katanin-based loss of microtubules in tauopathic neurodegenerative diseases. Hum Mol Genet 2010; 20:763-78. [PMID: 21118899 DOI: 10.1093/hmg/ddq521] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
It is commonly stated that microtubules gradually disintegrate as tau becomes dissociated from them in tauopathies such as Alzheimer's disease. However, there has been no compelling evidence to date that such disintegration is due to depolymerization of microtubules from their ends. In recent studies, we have shown that neurons contain sufficient levels of the microtubule-severing protein termed katanin to completely break down the axonal microtubule array if not somehow attenuated. The presence of tau on axonal microtubules renders them notably less sensitive to katanin, prompting us to posit that microtubule disintegration in tauopathies may result from elevated severing of the microtubules as they lose tau. In support of this hypothesis, we demonstrate here that pathogenic tau mutants that bind less strongly to microtubules than wild-type tau provide correspondingly less protection against katanin-based severing. Using cultured rat hippocampal neurons, we pursued two potential therapies for fortifying axonal microtubules against excess severing by katanin, under conditions of tau depletion. We found that either deacetylating the microtubules via overexpression of HDAC6 or treating the neurons with NAP, a microtubule-interacting neuroprotective peptide, resulted in notable protection of the microtubules against katanin-based loss. In both cases, we found that these treatments also diminished the characteristic increase in axonal branching that normally accompanies tau depletion, an effect that is also known to be directly related to the severing of microtubules. These observations may be useful in developing therapeutic regimes for preserving microtubules against loss in the axons of patients suffering from tauopathies.
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Affiliation(s)
- Haruka Sudo
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, 2900 W. Queen Lane, Philadelphia, PA 19129, USA
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Selvi BR, Cassel JC, Kundu TK, Boutillier AL. Tuning acetylation levels with HAT activators: Therapeutic strategy in neurodegenerative diseases. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2010; 1799:840-53. [DOI: 10.1016/j.bbagrm.2010.08.012] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2010] [Revised: 08/24/2010] [Accepted: 08/27/2010] [Indexed: 10/19/2022]
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