| First Author | Horiuchi M | Year | 2024 |
| Journal | Acta Neuropathol Commun | Volume | 12 |
| Issue | 1 | Pages | 184 |
| PubMed ID | 39605053 | Mgi Jnum | J:358922 |
| Mgi Id | MGI:7783869 | Doi | 10.1186/s40478-024-01893-x |
| Citation | Horiuchi M, et al. (2024) ALS-linked mutant TDP-43 in oligodendrocytes induces oligodendrocyte damage and exacerbates motor dysfunction in mice. Acta Neuropathol Commun 12(1):184 |
| abstractText | Nuclear clearance and cytoplasmic aggregation of TAR DNA-binding protein of 43 kDa (TDP-43) are pathological hallmarks of amyotrophic lateral sclerosis (ALS) and its pathogenic mechanism is mediated by both loss-of-function and gain-of-toxicity of TDP-43. However, the role of TDP-43 gain-of-toxicity in oligodendrocytes remains unclear. To investigate the impact of excess TDP-43 on oligodendrocytes, we established transgenic mice overexpressing the ALS-linked mutant TDP-43(M337V) in oligodendrocytes through crossbreeding with Mbp-Cre mice. Two-step crossbreeding of floxed TDP-43(M337V) and Mbp-Cre mice resulted in the heterozygous low-level systemic expression of TDP-43(M337V) with (Cre-positive) or without (Cre-negative) oligodendrocyte-specific overexpression of TDP-43(M337V). Although Cre-negative mice also exhibit subtle motor dysfunction, TDP-43(M337V) overexpression in oligodendrocytes aggravated clasping signs and gait disturbance accompanied by myelin pallor in the corpus callosum and white matter of the lumbar spinal cord in Cre-positive mice. RNA sequencing analysis of oligodendrocyte lineage cells isolated from whole brains of 12-month-old transgenic mice revealed downregulation of myelinating oligodendrocyte marker genes and cholesterol-related genes crucial for myelination, along with marked upregulation of apoptotic pathway genes. Immunofluorescence staining showed cleaved caspase 3-positive apoptotic oligodendrocytes surrounded by activated microglia and astrocytes in aged transgenic mice. Collectively, our findings demonstrate that an excess amount of ALS-linked mutant TDP-43 expression in oligodendrocytes exacerbates motor dysfunction in mice, likely through oligodendrocyte dysfunction and neuroinflammation. Therefore, targeting oligodendrocyte protection, particularly through ameliorating TDP-43 pathology, could represent a potential therapeutic approach for ALS. |
