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Faria TC, Maldonado HL, Santos LC, DeLabio R, Payao SLM, Turecki G, Mechawar N, Santana DA, Gigek CO, Lemos B, Smith MAC, Chen ES. Characterization of Cerebellum-Specific Ribosomal DNA Epigenetic Modifications in Alzheimer's Disease: Should the Cerebellum Serve as a Control Tissue After All? Mol Neurobiol 2020; 57:2563-2571. [PMID: 32232768 DOI: 10.1007/s12035-020-01902-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 03/09/2020] [Indexed: 11/26/2022]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease, known as the most common form of dementia. In AD onset, abnormal rRNA expression has been reported to be linked in pathogenesis. Although region-specific expression patterns have previously been reported in AD, it is not until recently that the cerebellum has come under the spotlight. Specifically, it is unclear whether DNA methylation is the mechanism involved in rRNA expression regulation in AD. Hence, we sought to explore the rDNA methylation pattern of two different brain regions - auditory cortex and cerebellum - from AD and age-/sex-matched controls. Our results showed differential hypermethylation at an upstream CpG region to the rDNA promoter when comparing cerebellum controls to auditory cortex controls. This suggests a possible regulatory region from rDNA expression regulation. Moreover, when comparing between AD and control cerebellum samples, we observed hypermethylation of the rDNA promoter region as well as an increase in rDNA content. In addition, we also observed increased rRNA levels in AD compared to control cerebellum. Although still considered a pathology-free brain region, there are growing findings that continue to suggest otherwise. Indeed, cerebellum from AD has been recently described as affected by the disease, presenting a unique pattern of molecular alterations. Given that we observed that increased rDNA promoter methylation did not silence rDNA gene expression, we suggest that rDNA promoter hypermethylation is playing a protective role in rDNA genomic stability and, therefore, increasing rRNA levels in AD cerebellum.
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Affiliation(s)
- Tathyane C Faria
- Departamento de Morfologia e Genética, Programa de Pós-Graduação em Biologia Estrutural e Funcional da UNIFESP/EPM, Disciplina de Genética, Universidade Federal de São Paulo (UNIFESP/EPM), São Paulo, SP, Brazil
| | - Héctor L Maldonado
- Department of Environmental Health, Program in Molecular and Integrative Physiological Sciences, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Leonardo C Santos
- Departamento de Morfologia e Genética, Programa de Pós-Graduação em Biologia Estrutural e Funcional da UNIFESP/EPM, Disciplina de Genética, Universidade Federal de São Paulo (UNIFESP/EPM), São Paulo, SP, Brazil
| | - Roger DeLabio
- Faculdade de Medicina de Marília (FAMEMA), Marília, SP, Brazil
| | | | - Gustavo Turecki
- Department of Psychiatry, Douglas Hospital Research Center, McGill University, Montreal, QC, Canada
| | - Naguib Mechawar
- Department of Psychiatry, Douglas Hospital Research Center, McGill University, Montreal, QC, Canada
| | - Dalileia A Santana
- Departamento de Morfologia e Genética, Programa de Pós-Graduação em Biologia Estrutural e Funcional da UNIFESP/EPM, Disciplina de Genética, Universidade Federal de São Paulo (UNIFESP/EPM), São Paulo, SP, Brazil
| | - Carolina O Gigek
- Departamento de Morfologia e Genética, Programa de Pós-Graduação em Biologia Estrutural e Funcional da UNIFESP/EPM, Disciplina de Genética, Universidade Federal de São Paulo (UNIFESP/EPM), São Paulo, SP, Brazil
| | - Bernardo Lemos
- Department of Environmental Health, Program in Molecular and Integrative Physiological Sciences, Harvard T.H. Chan School of Public Health, Boston, MA, USA
- Broad Institute of Harvard and MIT, Cambridge, MA, USA
| | - Marilia A C Smith
- Departamento de Morfologia e Genética, Programa de Pós-Graduação em Biologia Estrutural e Funcional da UNIFESP/EPM, Disciplina de Genética, Universidade Federal de São Paulo (UNIFESP/EPM), São Paulo, SP, Brazil
| | - Elizabeth S Chen
- Departamento de Morfologia e Genética, Programa de Pós-Graduação em Biologia Estrutural e Funcional da UNIFESP/EPM, Disciplina de Genética, Universidade Federal de São Paulo (UNIFESP/EPM), São Paulo, SP, Brazil.
- Department of Environmental Health, Program in Molecular and Integrative Physiological Sciences, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
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