title: The Alu neurodegeneration hypothesis: A primate-specific mechanism for neuronal transcription noise, mitochondrial dysfunction, and manifestation of neurodegenerative disease.
abstract: It is hypothesized that retrotransposons have played a fundamental role in primate evolution and that enhanced neurologic retrotransposon activity in humans may underlie the origin of higher cognitive function. As a potential consequence of this enhanced activity, it is likely that neurons are susceptible to deleterious retrotransposon pathways that can disrupt mitochondrial function. An example is observed in the TOMM40 gene, encoding a β-barrel protein critical for mitochondrial preprotein transport. Primate-specific Alu retrotransposons have repeatedly inserted into TOMM40 introns, and at least one variant associated with late-onset Alzheimer's disease originated from an Alu insertion event. We provide evidence of enriched Alu content in mitochondrial genes and postulate that Alus can disrupt mitochondrial populations in neurons, thereby setting the stage for progressive neurologic dysfunction. This Alu neurodegeneration hypothesis is compatible with decades of research and offers a plausible mechanism for the disruption of neuronal mitochondrial homeostasis, ultimately cascading into neurodegenerative disease.
authors.affiliation: Department of Biology, Duke University, Durham, NC, USA. Electronic address: peter.larsen@duke.edu.
authors.forename: Peter A
authors.initials: PA
authors.lastname: Larsen
authors.affiliation: Department of Neurology, Duke University School of Medicine, Durham, NC, USA.
authors.forename: Michael W
authors.initials: MW
authors.lastname: Lutz
authors.affiliation: Department of Biology, Duke University, Durham, NC, USA.
authors.forename: Kelsie E
authors.initials: KE
authors.lastname: Hunnicutt
authors.affiliation: Department of Neurology, Duke University School of Medicine, Durham, NC, USA.
authors.forename: Mirta
authors.initials: M
authors.lastname: Mihovilovic
authors.affiliation: Department of Neurology, Duke University School of Medicine, Durham, NC, USA.
authors.forename: Ann M
authors.initials: AM
authors.lastname: Saunders
authors.affiliation: Department of Biology, Duke University, Durham, NC, USA; Duke Lemur Center, Duke University, Durham, NC, USA.
authors.forename: Anne D
authors.initials: AD
authors.lastname: Yoder
authors.affiliation: Department of Neurology, Duke University School of Medicine, Durham, NC, USA; Zinfandel Pharmaceuticals, Inc, Durham, NC, USA.
authors.forename: Allen D
authors.initials: AD
authors.lastname: Roses
mesh_terms: D020087:Alu Elements; D000818:Animals; D006801:Humans; D007438:Introns; D026901:Membrane Transport Proteins / Q000235:genetics; D008928:Mitochondria / Q000235:genetics*; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D019636:Neurodegenerative Diseases / Q000503:physiopathology*; D011323:Primates
chemical_list: D026901:Membrane Transport Proteins; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; C400783:TOMM40 protein, human
keywords: A-to-I editing; Alternative splicing; Alzheimer's disease; Epigenetics; H3K9; Inflammation; LINE; Neuroepigenetics; Nonsense-mediated decay; Parkinson's disease; Retrotransposon; SINE; Somatic mosaicism; Somatic mutation; Spliceosome