51
|
Tiwari D, Peariso K, Gross C. MicroRNA-induced silencing in epilepsy: Opportunities and challenges for clinical application. Dev Dyn 2018; 247:94-110. [PMID: 28850760 PMCID: PMC5740004 DOI: 10.1002/dvdy.24582] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 07/20/2017] [Accepted: 08/10/2017] [Indexed: 12/25/2022] Open
Abstract
MicroRNAs are master regulators of gene expression. Single microRNAs influence multiple proteins within diverse molecular pathways and networks. Therefore, changes in levels or activity of microRNAs can have profound effects on cellular function. This makes dysregulated microRNA-induced silencing an attractive potential disease mechanism in complex disorders like epilepsy, where numerous cellular pathways and processes are affected simultaneously. Indeed, several years of research in rodent models have provided strong evidence that acute or recurrent seizures change microRNA expression and function. Moreover, altered microRNA expression has been observed in brain and blood from patients with various epilepsy disorders, such as tuberous sclerosis. MicroRNAs can be easily manipulated using sense or antisense oligonucleotides, opening up opportunities for therapeutic intervention. Here, we summarize studies using these techniques to identify microRNAs that modulate seizure susceptibility, describe protein targets mediating some of these effects, and discuss cellular pathways, for example neuroinflammation, that are controlled by epilepsy-associated microRNAs. We critically assess current gaps in knowledge regarding target- and cell-specificity of microRNAs that have to be addressed before clinical application as therapeutic targets or biomarkers. The recent progress in understanding microRNA function in epilepsy has generated strong momentum to encourage in-depth mechanistic studies to develop microRNA-targeted therapies. Developmental Dynamics 247:94-110, 2018. © 2017 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Durgesh Tiwari
- Cincinnati Children’s Hospital Medical Center, Division of Neurology, Cincinnati, Ohio
| | - Katrina Peariso
- Cincinnati Children’s Hospital Medical Center, Division of Neurology, Cincinnati, Ohio
- University of Cincinnati, Department of Pediatrics, Cincinnati, Ohio
| | - Christina Gross
- Cincinnati Children’s Hospital Medical Center, Division of Neurology, Cincinnati, Ohio
- University of Cincinnati, Department of Pediatrics, Cincinnati, Ohio
| |
Collapse
|
52
|
Rodriguez AS, Engel T, Palfi A, Farrar GJ, Henshall DC, Jimenez-Mateos EM. Tubby-like protein 1 (Tulp1) is a target of microRNA-134 and is down-regulated in experimental epilepsy. INTERNATIONAL JOURNAL OF PHYSIOLOGY, PATHOPHYSIOLOGY AND PHARMACOLOGY 2017; 9:178-187. [PMID: 29348794 PMCID: PMC5770514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 12/13/2017] [Indexed: 06/07/2023]
Abstract
MicroRNAs are important determinants of gene expression via post-transcriptional control of the protein levels of their mRNA targets. MicroRNA-134 (miR-134) has emerged as an important brain-specific microRNA which has been implicated in the control of dendritic spine morphology, neuronal differentiation and apoptosis. Here we show that Tubby-like protein 1 (Tulp1) is a target of miR-134. Tulp1 protein showed a similar cellular distribution pattern in the hippocampus to miR-134 and displayed an inverse expression pattern in the mouse retina. Bioinformatics analyses identified a conserved miR-134 binding site in the 3' untranslated region of both mouse and human Tulp1 and luciferase reporter assays confirmed miR-134 targets Tulp1 in vitro. Induction of prolonged seizures in mice resulted in upregulation of miR-134 and downregulation of protein levels of Tulp1 which were reversed in animals injected with locked nucleic acid-modified antagomirs targeting miR-134. Finally, knockdown of Tulp1 in human neurons caused an increase in vulnerability to excitotoxicity. These data identify Tulp1/TULP1 as a novel target of miR-134, which may contribute to underlying pathomechanisms in epilepsy.
Collapse
Affiliation(s)
- Amaya Sanz Rodriguez
- Department of Physiology & Medical Physics, Royal College of Surgeons in IrelandDublin 2, Ireland
| | - Tobias Engel
- Department of Physiology & Medical Physics, Royal College of Surgeons in IrelandDublin 2, Ireland
| | - Arpad Palfi
- Smurfit Institute of Genetics, School of Genetics and Microbiology and Trinity College Institute of Neuroscience, Trinity College DublinDublin 2, Ireland
| | - G Jane Farrar
- Smurfit Institute of Genetics, School of Genetics and Microbiology and Trinity College Institute of Neuroscience, Trinity College DublinDublin 2, Ireland
| | - David C Henshall
- Department of Physiology & Medical Physics, Royal College of Surgeons in IrelandDublin 2, Ireland
| | - Eva M Jimenez-Mateos
- Department of Physiology & Medical Physics, Royal College of Surgeons in IrelandDublin 2, Ireland
| |
Collapse
|
53
|
Steward CA, Parker APJ, Minassian BA, Sisodiya SM, Frankish A, Harrow J. Genome annotation for clinical genomic diagnostics: strengths and weaknesses. Genome Med 2017; 9:49. [PMID: 28558813 PMCID: PMC5448149 DOI: 10.1186/s13073-017-0441-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The Human Genome Project and advances in DNA sequencing technologies have revolutionized the identification of genetic disorders through the use of clinical exome sequencing. However, in a considerable number of patients, the genetic basis remains unclear. As clinicians begin to consider whole-genome sequencing, an understanding of the processes and tools involved and the factors to consider in the annotation of the structure and function of genomic elements that might influence variant identification is crucial. Here, we discuss and illustrate the strengths and weaknesses of approaches for the annotation and classification of important elements of protein-coding genes, other genomic elements such as pseudogenes and the non-coding genome, comparative-genomic approaches for inferring gene function, and new technologies for aiding genome annotation, as a practical guide for clinicians when considering pathogenic sequence variation. Complete and accurate annotation of structure and function of genome features has the potential to reduce both false-negative (from missing annotation) and false-positive (from incorrect annotation) errors in causal variant identification in exome and genome sequences. Re-analysis of unsolved cases will be necessary as newer technology improves genome annotation, potentially improving the rate of diagnosis.
Collapse
Affiliation(s)
- Charles A Steward
- Congenica Ltd, Wellcome Genome Campus, Hinxton, Cambridge, CB10 1DR, UK. .,The Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, CB10 1SA, UK.
| | | | - Berge A Minassian
- Department of Pediatrics (Neurology), University of Texas Southwestern, Dallas, TX, USA.,Program in Genetics and Genome Biology and Department of Paediatrics (Neurology), The Hospital for Sick Children and University of Toronto, Toronto, Canada
| | - Sanjay M Sisodiya
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, WC1N 3BG, UK.,Chalfont Centre for Epilepsy, Chesham Lane, Chalfont St Peter, Buckinghamshire, SL9 0RJ, UK
| | - Adam Frankish
- The Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, CB10 1SA, UK.,European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge, CB10 1SD, UK
| | - Jennifer Harrow
- The Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, CB10 1SA, UK.,Illumina Inc, Great Chesterford, Essex, CB10 1XL, UK
| |
Collapse
|
54
|
Abstract
Epilepsy is a common and devastating neurological disorder characterized by recurrent and unprovoked spontaneous seizures. One leading hypothesis for the development and progression of epilepsy is that large-scale changes in gene transcription and protein expression contribute to aberrant network restructuring and hyperexcitability, resulting in the genesis of repeated seizures. Current research shows that epigenetic mechanisms, including posttranslational alterations to the proteins around which DNA is coiled, chemical modifications to DNA, and the activity of various noncoding RNA molecules exert important influences on these gene networks in experimental epilepsy. Key findings from animal models have been replicated in humans using brain tissue obtained from living patients at the time of neurosurgical resection for pharmacoresistant epilepsy. These findings have spurred efforts to target epigenetic processes to disrupt or modify epilepsy in experimental models with varying degrees of success. In this review, we will (1) summarize the epigenetic mechanisms implicated in epileptogenesis and epilepsy, (2) explore the influence of metabolic factors on epigenetic mechanisms, and (3) assess the potential of using epigenetic markers to support diagnosis and prognosis. Translation of these findings may guide the development of molecular biomarkers and novel therapeutics for prevention or modification of epileptic disorders.
Collapse
Affiliation(s)
- Rebecca M. Hauser
- Evelyn F. McKnight Brain Institute, Department of Neurobiology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - David C. Henshall
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Farah D. Lubin
- Evelyn F. McKnight Brain Institute, Department of Neurobiology, The University of Alabama at Birmingham, Birmingham, AL, USA
| |
Collapse
|