Probing the Alzheimer’s disease risk gene PTK2B using human-derived induced neurons
| dc.contributor.advisor | Costa, Marcos Romualdo | |
| dc.contributor.advisorLattes | http://lattes.cnpq.br/6118493598074445 | pt_BR |
| dc.contributor.author | Farias, Ana Raquel Melo de | |
| dc.contributor.authorLattes | http://lattes.cnpq.br/9402603894122604 | pt_BR |
| dc.contributor.referees1 | Girault, Jean-Antoine | |
| dc.contributor.referees2 | Crozet, Carole | |
| dc.contributor.referees3 | Lambert, Jean-Charles | |
| dc.contributor.referees4 | Hedin-Pereira, Cecília | |
| dc.contributor.referees5 | Leão, Emelie Katarina Svahn | |
| dc.date.accessioned | 2024-07-16T20:53:29Z | |
| dc.date.issued | 2023-10-20 | |
| dc.description.embargo | 2026-10-20 | |
| dc.description.resumo | Alzheimer's disease (AD) is the main type of dementia and poses a significant global public health challenge. It is characterized by a progressive decline in cognition, memory, and behavioral functions and affects more than 55 million people worldwide. At the molecular level, AD is defined by the presence of aggregated neurofibrillary tangles (NFTs) within neurons and the accumulation of amyloid-β (Aβ) plaques in the brain. These pathological features are associated with alterations in neuronal activity, synapse loss, gliosis, and neuroinflammation, leading to irreversible neurodegeneration. AD etiology and pathophysiology involves a complex interplay between genetic and environmental factors. Genome-Wide Association Studies (GWAS) have successfully identified more than 75 genetic loci carrying single nucleotide polymorphisms (SNPs) associated with AD risk. Among these loci, the one harboring the Protein Tyrosine Kinase 2β (PTK2B) is highlighted in the present work. This gene encodes a protein tyrosine kinase that is involved in calciuminduced regulation of ion channels and activation of numerous signaling pathways, such as MAP kinase. Non-synonymous genetic variations in the PTK2B locus have been associated with an increased risk of AD and are thought to regulate PTK2B expression. However, both the physiological and pathophysiological roles of PTK2B are not fully understood. In the human brain, PTK2B expression is mainly observed in glutamatergic neurons and this expression declines during AD progression. This reduced PTK2B expression in the brain of patients with AD may contribute to neuronal dysfunctions observed in the disease, such as increased electrical excitability and synaptic alterations. Therefore, understanding the role of PTK2B in human neurons may contribute to reveal the mechanisms of neuronal dysfunctions in AD. Considering that, the aims of this thesis are to uncover the cellular processes and molecular pathways regulated by PTK2B in human neurons. To that, we took advantage of isogenic human induced-pluripotent stem cells (hiPSCs) to generate neurons expressing different levels of PTK2B. Next, we employed functional and molecular assays to probe the consequences of altered PTK2B expression both in a physiological and in an AD-like context. We show that reduced PTK2B expression leads to increased TAU phosphorylation at various epitopes associated with AD pathology, suggesting a central role of PTK2B in regulating TAU aggregation. Using single-cell transcriptomics, we also show that reduced PTK2B expression leads to specific transcriptional alterations related to neuronal electrical activity and synaptic transmission mainly in glutamatergic neurons. Calcium imaging experiments indicate that PTK2B downregulation contributes to increased calcium spikes frequency without affecting synchronization, indicating an elevated neuronal electrical activity. Additionally, results from electrophysiological recordings from multi-electrode array (MEA) show increased electrical activity and disrupted bursting patterns in PTK2B mutant neurons. Overall, this work sheds light on the involvement of PTK2B in AD-related cellular processes, providing insights into the molecular mechanisms and functional alterations associated with PTK2B dysregulation in human iPSC-derived neural cells. | pt_BR |
| dc.identifier.citation | FARIAS, Ana Raquel Melo de. Probing the Alzheimer’s disease risk gene PTK2B using human-derived induced neurons. Orientador: Dr. Marcos Romualdo Costa. 2023. 304f. Tese (Doutorado em Neurociências) - Instituto do Cérebro, Universidade Federal do Rio Grande do Norte, Natal, 2023. | pt_BR |
| dc.identifier.uri | https://repositorio.ufrn.br/handle/123456789/58802 | |
| dc.language | pt_BR | pt_BR |
| dc.publisher | Universidade Federal do Rio Grande do Norte | pt_BR |
| dc.publisher.country | Brasil | pt_BR |
| dc.publisher.initials | UFRN | pt_BR |
| dc.publisher.program | PROGRAMA DE PÓS-GRADUAÇÃO EM NEUROCIÊNCIAS | pt_BR |
| dc.rights | Acesso Embargado | pt_BR |
| dc.subject | Alzheimer’s Disease | pt_BR |
| dc.subject | Genetic risk factors | pt_BR |
| dc.subject | PTK2B | pt_BR |
| dc.subject | Human induced neurons | pt_BR |
| dc.subject.cnpq | CNPQ::OUTROS::CIENCIAS | pt_BR |
| dc.title | Probing the Alzheimer’s disease risk gene PTK2B using human-derived induced neurons | pt_BR |
| dc.type | doctoralThesis | pt_BR |