Year: 2026
Type: preprint
Abstract: Nuclear depletion of TDP-43 is a defining pathological feature of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), leading to widespread RNA misprocessing, including the formation of cryptic exons. Here, we identified TDP-43 as a regulator of circular RNA (circRNA) biogenesis in multiple human neuronal cell models, and showed that its dysfunction induces the de novo formation of cryptic circular RNAs (c-circRNAs). Analysis of post-mortem brain transcriptomic data identified a subset of c-circRNAs which are specific for ALS and FTD cases with TDP-43 pathology. Further, we developed highly sensitive rolling-circle amplification-based circRNA detection assays that allow to distinguish TDP-43 pathology in human CNS tissues with a 0.99 AUC. We found that c-circRNAs can co-occur with cryptic linear splicing events, uncovering complex RNA misprocessing hotspots that induce loss of disease-relevant proteins, including RPTOR and EHMT1 . Notably, one of these c-circRNAs originates from UNC13A , a gene whose cryptic exon has previously been linked to one of the major GWAS hits in ALS/FTD and that is being pursued as a therapeutic target through splice-switching ASOs. We showed that c-circUNC13A is co-regulated with the linear cryptic transcript and suppression of UNC13A cryptic exon results in c-circUNC13A reduction in cultured neurons and in vivo, highlighting its potential as a target engagement biomarker for emerging UNC13A-directed therapies. Overall, this work identifies a novel molecular mechanism for TDP-43 dysfunction, opening novel avenues for understanding disease pathogenesis and developing much needed pathology biomarkers.
Authors: Dario Dattilo, Flaminia Pellegrini, Simone Barattucci, Anna-Leigh Brown, Jose Norberto S. Vargas, Ariana Gatt, Ryan Morrie, Georgiana Miller, Iris Bachmutsky, Zachary McEachin, Mingee Chung, Matthew J. Keuss, Eugeni Ryadnov, Matteo Zanovello, Puja R. Mehta, Francesca Mattedi, Michela Barioglio, Shubha Kamath, Sarah E Kargbo-Hill, Joanna Palade, Isabelle Kowal, Jonathan Glass, Marla Gearing, Edward B Lee, Melissa E Murray, Dennis W Dickson, Eric M Green, Nicholas T Seyfried, Sanjay Chandriani, Michael Ward, Pietro Fratta
Institutions: The Francis Crick Institute, National Hospital for Neurology and Neurosurgery, UCL Queen Square Institute of Neurology, University College London, Emory University, University of Michigan, National Institute of Neurological Disorders and Stroke, University of Pennsylvania, Mayo Clinic, Mayo Clinic in Florida
Language: English
Subfield: Neurology
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W7213780656
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