1
|
Droppelmann CA, Campos-Melo D, Noches V, McLellan C, Szabla R, Lyons TA, Amzil H, Withers B, Kaplanis B, Sonkar KS, Simon A, Buratti E, Junop M, Kramer JM, Strong MJ. Mitigation of TDP-43 toxic phenotype by an RGNEF fragment in amyotrophic lateral sclerosis models. Brain 2024; 147:2053-2068. [PMID: 38739752 PMCID: PMC11146434 DOI: 10.1093/brain/awae078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 01/24/2024] [Accepted: 02/08/2024] [Indexed: 05/16/2024] Open
Abstract
Aggregation of the RNA-binding protein TAR DNA binding protein (TDP-43) is a hallmark of TDP-proteinopathies including amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). As TDP-43 aggregation and dysregulation are causative of neuronal death, there is a special interest in targeting this protein as a therapeutic approach. Previously, we found that TDP-43 extensively co-aggregated with the dual function protein GEF (guanine exchange factor) and RNA-binding protein rho guanine nucleotide exchange factor (RGNEF) in ALS patients. Here, we show that an N-terminal fragment of RGNEF (NF242) interacts directly with the RNA recognition motifs of TDP-43 competing with RNA and that the IPT/TIG domain of NF242 is essential for this interaction. Genetic expression of NF242 in a fruit fly ALS model overexpressing TDP-43 suppressed the neuropathological phenotype increasing lifespan, abolishing motor defects and preventing neurodegeneration. Intracerebroventricular injections of AAV9/NF242 in a severe TDP-43 murine model (rNLS8) improved lifespan and motor phenotype, and decreased neuroinflammation markers. Our results demonstrate an innovative way to target TDP-43 proteinopathies using a protein fragment with a strong affinity for TDP-43 aggregates and a mechanism that includes competition with RNA sequestration, suggesting a promising therapeutic strategy for TDP-43 proteinopathies such as ALS and FTD.
Collapse
Affiliation(s)
- Cristian A Droppelmann
- Molecular Medicine Group, Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, Ontario N6A 5C1, Canada
| | - Danae Campos-Melo
- Molecular Medicine Group, Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, Ontario N6A 5C1, Canada
| | - Veronica Noches
- Molecular Medicine Group, Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, Ontario N6A 5C1, Canada
| | - Crystal McLellan
- Molecular Medicine Group, Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, Ontario N6A 5C1, Canada
| | - Robert Szabla
- Department of Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, Ontario N6A 5C1, Canada
| | - Taylor A Lyons
- Molecular Medicine Group, Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, Ontario N6A 5C1, Canada
| | - Hind Amzil
- Molecular Medicine Group, Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, Ontario N6A 5C1, Canada
| | - Benjamin Withers
- Molecular Medicine Group, Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, Ontario N6A 5C1, Canada
| | - Brianna Kaplanis
- Department of Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, Ontario N6A 5C1, Canada
| | - Kirti S Sonkar
- International Centre for Genetic Engineering and Biotechnology (ICGEB), AREA Science Park, 34149 Trieste, Italy
| | - Anne Simon
- Department of Biology, Faculty of Science, Western University, London, Ontario N6A 5B7, Canada
| | - Emanuele Buratti
- International Centre for Genetic Engineering and Biotechnology (ICGEB), AREA Science Park, 34149 Trieste, Italy
| | - Murray Junop
- Department of Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, Ontario N6A 5C1, Canada
| | - Jamie M Kramer
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Michael J Strong
- Molecular Medicine Group, Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, Ontario N6A 5C1, Canada
- Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University, London, Ontario N6A 5C1, Canada
| |
Collapse
|
2
|
Zamani A, Walker AK, Rollo B, Ayers KL, Farah R, O'Brien TJ, Wright DK. Early and progressive dysfunction revealed by in vivo neurite imaging in the rNLS8 TDP-43 mouse model of ALS. Neuroimage Clin 2022; 34:103016. [PMID: 35483133 PMCID: PMC9125783 DOI: 10.1016/j.nicl.2022.103016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 03/29/2022] [Accepted: 04/19/2022] [Indexed: 11/26/2022]
Abstract
Are neurite density and dispersion altered in amyotropic lateral sclerosis (ALS)? Both measures are affected in the rNLS8 TDP-43 mouse model of ALS. Diffusion tensor imaging metrics were also affected. Group-wise changes were observed early in the disease course. Together these diffusion imaging metrics may aid in the timelier diagnosis of ALS.
Amyotrophic lateral sclerosis (ALS) is characterized by transactive response DNA-binding protein 43 (TDP-43) pathology, progressive loss of motor neurons and muscle dysfunction. Symptom onset can be insidious and diagnosis challenging. Conventional neuroimaging is used to exclude ALS mimics, however more advanced neuroimaging techniques may facilitate an earlier diagnosis. Here, we investigate the potential for neurite orientation dispersion and density imaging and diffusion tensor imaging (DTI) to detect microstructural changes in an experimental model of ALS with neuronal doxycycline (Dox)-suppressible overexpression of human TDP-43 (hTDP-43). In vivo diffusion-weighted imaging (DWI) was acquired 1- and 3- weeks following the initiation of hTDP-43 expression (post-Dox) to investigate whether neurite density imaging (NDI) and orientation dispersion imaging (ODI) are affected early in this preclinical model of ALS and if so, how these metrics compare to those derived from the diffusion tensor. Tract-based spatial statistics at 1-week post-Dox, i.e. very early in the disease stage, demonstrated increased NDI in TDP-43 mice but no change in ODI or DTI metrics. At 3-weeks post-Dox, a reduced pattern of increased NDI was observed along with widespread increases in ODI, and decreased fractional anisotropy (FA), apparent diffusion coefficient (ADC) and axial diffusivity (AD). A hypothesis driven analysis of the bilateral corticospinal tracts demonstrated that at 1-week post-Dox, ODI was significantly increased caudally but decreased in the motor cortex of TDP-43 mice. Decreased cortical ODI had normalized by 3-weeks post-Dox and only significant increases were observed. A similar, but inverse pattern in FA was also observed. Together, these results suggest a non-monotonic relationship between DWI metrics and pathophysiological progression with TDP-43 mice exhibiting significantly altered diffusion metrics consistent with early inflammation followed by progressive axonal degeneration. Importantly, significant group-wise changes were observed in the earliest stages of disease when subtle pathology may be more elusive to traditional structural imaging techniques.
Collapse
Affiliation(s)
- Akram Zamani
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia
| | - Adam K Walker
- Queensland Brain Institute, The University of Queensland, QLD 4072, Australia
| | - Ben Rollo
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia
| | - Katie L Ayers
- The Murdoch Children's Research Institute, The Royal Children's Hospital, Parkville, VIC 3052, Australia; Department of Pediatrics, The University of Melbourne, Parkville, VIC 3052, Australia
| | - Raysha Farah
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia
| | - Terence J O'Brien
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia; Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC 3052, Australia
| | - David K Wright
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia.
| |
Collapse
|