Downregulation of MicroRNA-9 in iPSC-Derived Neurons of FTD/ALS Patients with TDP-43 Mutations

• Published in: PloS one Vol. 8; no. 10; p. e76055
• Main Authors: Zhang, Zhijun, Almeida, Sandra, Lu, Yubing, Nishimura, Agnes L., Peng, Lingtao, Sun, Danqiong, Wu, Bei, Karydas, Anna M., Tartaglia, Maria C., Fong, Jamie C., Miller, Bruce L., Farese, Robert V., Moore, Melissa J., Shaw, Christopher E., Gao, Fen-Biao
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 15.10.2013; Public Library of Science (PLoS)
• Subjects: Aged; Aging; Amyotrophic lateral sclerosis; Amyotrophic Lateral Sclerosis - genetics; Amyotrophic Lateral Sclerosis - pathology; Analysis; Animal models; Antibiotics; Base Sequence; Biopsy; Brain research; Cardiovascular disease; Cell Differentiation; Cytoplasm; Dementia; Dementia disorders; Deoxyribonucleic acid; DNA; DNA-binding protein; DNA-Binding Proteins - genetics; Down-Regulation; Fibroblasts; Frontotemporal dementia; Frontotemporal Dementia - genetics; Frontotemporal Dementia - pathology; Gene expression; Genetic aspects; Humans; Induced Pluripotent Stem Cells - pathology; Male; Medical schools; Memory; MicroRNA; MicroRNAs; MicroRNAs - genetics; miRNA; Molecular chains; Mutation; Neurodegeneration; Neurogenesis; Neurology; Neurons; Neurons - metabolism; Neurons - pathology; Neurosciences; Pathology; Patients; Phenotype; Pluripotency; Protein binding; Proteins; Ribonucleic acid; RNA; Skin; Staurosporine; Stem cells; Stress; Stresses; San Francisco California; California; United Kingdom > UK; United States > US; Massachusetts
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0076055

Transactive response DNA-binding protein 43 (TDP-43) is a major pathological protein in frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS). There are many disease-associated mutations in TDP-43, and several cellular and animal models with ectopic overexpression of mutant TDP-43 have been established. Here we sought to study altered molecular events in FTD and ALS by using induced pluripotent stem cell (iPSC) derived patient neurons. We generated multiple iPSC lines from an FTD/ALS patient with the TARDBP A90V mutation and from an unaffected family member who lacked the mutation. After extensive characterization, two to three iPSC lines from each subject were selected, differentiated into postmitotic neurons, and screened for relevant cell-autonomous phenotypes. Patient-derived neurons were more sensitive than control neurons to 100 nM straurosporine but not to other inducers of cellular stress. Three disease-relevant cellular phenotypes were revealed under staurosporine-induced stress. First, TDP-43 was localized in the cytoplasm of a higher percentage of patient neurons than control neurons. Second, the total TDP-43 level was lower in patient neurons with the A90V mutation. Third, the levels of microRNA-9 (miR-9) and its precursor pri-miR-9-2 decreased in patient neurons but not in control neurons. The latter is likely because of reduced TDP-43, as shRNA-mediated TDP-43 knockdown in rodent primary neurons also decreased the pri-miR-9-2 level. The reduction in miR-9 expression was confirmed in human neurons derived from iPSC lines containing the more pathogenic TARDBP M337V mutation, suggesting miR-9 downregulation might be a common pathogenic event in FTD/ALS. These results show that iPSC models of FTD/ALS are useful for revealing stress-dependent cellular defects of human patient neurons containing rare TDP-43 mutations in their native genetic contexts.