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Jahncke JN, Miller DS, Krush M, Schnell E, Wright KM. Inhibitory CCK+ basket synapse defects in mouse models of dystroglycanopathy. eLife 2024; 12:RP87965. [PMID: 38179984 PMCID: PMC10942650 DOI: 10.7554/elife.87965] [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] [Indexed: 01/06/2024] Open
Abstract
Dystroglycan (Dag1) is a transmembrane glycoprotein that links the extracellular matrix to the actin cytoskeleton. Mutations in Dag1 or the genes required for its glycosylation result in dystroglycanopathy, a type of congenital muscular dystrophy characterized by a wide range of phenotypes including muscle weakness, brain defects, and cognitive impairment. We investigated interneuron (IN) development, synaptic function, and associated seizure susceptibility in multiple mouse models that reflect the wide phenotypic range of dystroglycanopathy neuropathology. Mice that model severe dystroglycanopathy due to forebrain deletion of Dag1 or Pomt2, which is required for Dystroglycan glycosylation, show significant impairment of CCK+/CB1R+ IN development. CCK+/CB1R+ IN axons failed to properly target the somatodendritic compartment of pyramidal neurons in the hippocampus, resulting in synaptic defects and increased seizure susceptibility. Mice lacking the intracellular domain of Dystroglycan have milder defects in CCK+/CB1R+ IN axon targeting, but exhibit dramatic changes in inhibitory synaptic function, indicating a critical postsynaptic role of this domain. In contrast, CCK+/CB1R+ IN synaptic function and seizure susceptibility was normal in mice that model mild dystroglycanopathy due to partially reduced Dystroglycan glycosylation. Collectively, these data show that inhibitory synaptic defects and elevated seizure susceptibility are hallmarks of severe dystroglycanopathy, and show that Dystroglycan plays an important role in organizing functional inhibitory synapse assembly.
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Affiliation(s)
- Jennifer N Jahncke
- Neuroscience Graduate Program, Oregon Health & Science UniversityPortlandUnited States
| | - Daniel S Miller
- Neuroscience Graduate Program, Oregon Health & Science UniversityPortlandUnited States
| | - Milana Krush
- Neuroscience Graduate Program, Oregon Health & Science UniversityPortlandUnited States
| | - Eric Schnell
- Operative Care Division, Portland VA Health Care SystemPortlandUnited States
- Anesthesiology and Perioperative Medicine, Oregon Health & Science UniversityPortlandUnited States
| | - Kevin M Wright
- Vollum Institute, Oregon Health & Science UniversityPortlandUnited States
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Huang X, Tan D, Zhang Z, Ge L, Liu J, Ding J, Yang H, Wei C, Chang X, Yuan Y, Yan C, Xiong H. Unique genotype-phenotype correlations within LAMA2-related limb girdle muscular dystrophy in Chinese patients. Front Neurol 2023; 14:1158094. [PMID: 37206914 PMCID: PMC10190595 DOI: 10.3389/fneur.2023.1158094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 03/21/2023] [Indexed: 05/21/2023] Open
Abstract
Background LAMA2-related limb girdle muscular dystrophy (LGMD R23) is rare. The detailed clinical phenotypes and genetic information associated with LGMD R23 are unknown. Methods We conducted a retrospective cross-sectional and longitudinal study on 19 LGMD R23 patients. Results Normal early motor development was observed in 84.2% patients. Mild orthopedic complications were observed in 42.1% patients. 36.8% patients had seizures, which is unusually frequent in LGMD. Epilepsy was eventually diagnosed in 26.3% patients. 46.7% patients presented with motor neuropathy. Genetic analysis identified 29 pathogenic variants, with missense and frameshift variants being the most common. The mutant sites were mainly distributed in the N-terminal and G-like domains of laminin. The missense variants are distributed near the N-terminus (exons 3-11), whereas frameshift variants are distributed in exons 12-65. Five patients were diagnosed with epilepsy and all of them harbor at least one missense variants in exon 4. 71.4% variants of patients with motor neuropathy located in the LN domain. Conclusions Missense variants in exon 4 maybe correlated with epilepsy and variants in the LN domain maybe correlated with motor neuropathy in Chinese patients. Our study expands the clinical and genetic spectrum caused by LAMA2 variations and provides novel genotype-phenotype correlations of LGMD R23.
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Affiliation(s)
- Xiuli Huang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Dandan Tan
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Zaiqiang Zhang
- Department of Neurology, China National Clinical Research Center for Neurological Diseases, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Lin Ge
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Jieyu Liu
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Juan Ding
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Haipo Yang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Cuijie Wei
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Xingzhi Chang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Yun Yuan
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Chuanzhu Yan
- Department of Neurology, Research Institute of Neuromuscular and Neurodegenerative Disease, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Hui Xiong
- Department of Pediatrics, Peking University First Hospital, Beijing, China
- Beijing Key Laboratory of Molecular Diagnosis and Study on Pediatric Genetic Diseases, Beijing, China
- *Correspondence: Hui Xiong
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