{"doi":"10.1101/2023.10.24.563701","title":"RNA aptamer reveals nuclear TDP-43 pathology is an early aggregation event that coincides with <i>STMN-2</i> cryptic splicing and precedes clinical manifestation in ALS","abstract":"Abstract TDP-43 is an aggregation-prone protein which accumulates in the hallmark pathological inclusions of amyotrophic lateral sclerosis (ALS). However, analysis of deeply-phenotyped human post-mortem samples has shown that TDP-43 aggregation, revealed by standard antibody methods, correlates poorly with symptom manifestation. Recent identification of cryptic-splicing events, such as the detection of Stathmin-2 ( STMN-2 ) cryptic exons, are providing evidence implicating TDP-43 loss-of-function as a potential driving pathomechanism, but the temporal nature of TDP-43 loss and its relation to the disease process and clinical phenotype is not known. To address these outstanding questions, we used a novel RNA aptamer, TDP-43 APT , to detect TDP-43 aggregation and used single molecule in situ hybridization to sensitively reveal TDP-43 loss-of-function and applied these in a deeply-phenotyped human post-mortem tissue cohort. We demonstrate that TDP-43 APT identifies pathological TDP-43, detecting aggregation events that cannot be detected by classical antibody stains. We show that nuclear TDP-43 pathology is an early event, occurring prior to cytoplasmic aggregation and is associated with loss-of-function measured by coincident STMN-2 cryptic splicing pathology. Crucially, we show that these pathological features of TDP-43 loss-of-function precede the clinical inflection point and are not required for region specific clinical manifestation. Furthermore, we demonstrate that gain-of-function in the form of extensive cytoplasmic aggregation, but not loss-of-function, is the primary molecular correlate of clinical manifestation. Taken together, our findings demonstrate implications for early diagnostics as the presence of STMN-2 cryptic exons and early TDP-43 aggregation events could be detected prior to symptom onset, holding promise for early intervention in ALS. Short Abstract Recent identification of cryptic-splicing events such as the detection of Stathmin-2 ( STMN-2 ) cryptic exons, are providing evidence implicating TDP-43 loss-of-function as a potential driving pathomechanism in amyotrophic lateral sclerosis (ALS). However, the temporal nature of TDP-43 loss and its relation to clinical phenotype is not known. Here, we used a novel RNA aptamer to detect TDP-43 aggregation and used single molecule ISH to sensitively reveal TDP-43 loss-of-function, applying these methods in a deeply-phenotyped human post-mortem tissue cohort. We show that nuclear TDP-43 pathology is an early event, that coincides with STMN-2 cryptic splicing. Crucially, we show that these pathological features of TDP-43 loss-of-function precede the clinical inflection point and are not required for region specific clinical manifestation. Furthermore, we demonstrate that gain-of-function, but not loss-of-function, is the primary molecular correlate of clinical manifestation. Taken together, our findings demonstrate implications for early diagnostics and intervention prior to symptom onset in ALS. Graphical Abstract","journal":"bioRxiv (Cold Spring Harbor Laboratory)","year":2023,"id":401389,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":1,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9604,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2023-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1052847,"name":"Fergal M. Waldron","orcid":"0000-0003-2622-0776","position":1,"is_corresponding":false},{"id":1067556,"name":"Rebecca S. Saleeb","orcid":"0000-0002-6587-9867","position":2,"is_corresponding":false},{"id":238158,"name":"Anna‐Leigh Brown","orcid":"0000-0003-1493-208X","position":3,"is_corresponding":false},{"id":395267,"name":"Olivia M. Rifai","orcid":"0000-0002-0996-1110","position":4,"is_corresponding":false},{"id":1178354,"name":"Martina Gilodi","orcid":"0000-0003-0969-0637","position":5,"is_corresponding":false},{"id":1178355,"name":"F.L. Read","orcid":"0009-0007-1371-1062","position":6,"is_corresponding":false},{"id":1178850,"name":"Kristine Roberts","orcid":null,"position":7,"is_corresponding":false},{"id":1178356,"name":"Gillian Milne","orcid":"0000-0003-1153-2646","position":8,"is_corresponding":false},{"id":1178357,"name":"D. Wilkinson","orcid":"0000-0003-0237-3807","position":9,"is_corresponding":false},{"id":1052844,"name":"Judi O’Shaughnessy","orcid":"0009-0001-2014-9078","position":10,"is_corresponding":false},{"id":1178358,"name":"Annalisa Pastore","orcid":"0000-0002-3047-654X","position":11,"is_corresponding":false},{"id":238180,"name":"Pietro Fratta","orcid":"0000-0002-8762-8188","position":12,"is_corresponding":false},{"id":550624,"name":"Neil A. Shneider","orcid":"0000-0002-3223-7366","position":13,"is_corresponding":false},{"id":589276,"name":"Gian Gaetano Tartaglia","orcid":"0000-0001-7524-6310","position":14,"is_corresponding":false},{"id":1178359,"name":"Elsa Zacco","orcid":"0000-0002-3593-6023","position":15,"is_corresponding":false},{"id":343939,"name":"Mathew H. Horrocks","orcid":"0000-0001-5495-5492","position":16,"is_corresponding":false},{"id":841914,"name":"Jenna M. Gregory","orcid":"0000-0003-3337-4079","position":17,"is_corresponding":false},{"id":1178353,"name":"Holly Spence","orcid":"0000-0002-1628-6790","position":0,"is_corresponding":true}],"reference_count":28,"raw_metadata":null,"created_at":"2026-07-19T01:20:12.316631Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}