title: The absence of dystrophin rather than muscle degeneration causes acetylcholine receptor cluster defects in dystrophic muscle.
abstract: Duchenne muscular dystrophy is the most common genetic muscle disease. Affected muscles are characterized by abnormal acetylcholine receptor (AChR) clustering. Some studies have suggested that changes in AChR clusters are secondary to degenerative processes. In this study, we demonstrate that AChR cluster fragmentation and muscle degeneration are separate events. We compared AChR clusters and pathological features in mdx mice (mutated dystrophin) and dko mice (mutated dystrophin and utrophin). AChR clusters were identified by binding with α-bungarotoxin, and pathological features were observed by classical immunohistochemical techniques. AChR clusters in mdx and dko mice were reduced in number and exhibited structural fragmentation. However, AChR cluster fragmentation was not significantly different in mdx and dko mice, although more severe inflammatory infiltration and degeneration were observed in dko mice. Furthermore, neuronal nitric oxide synthase, which interacts with dystrophin to anchor itself at the sarcolemma, was notably reduced in mdx and dko mice. Fragmentation of AChR and muscle degeneration are separate events, and both are secondary results of destabilization on the sarcolemma and the cytoskeleton.
authors: The First Affiliated Hospital, Sun Yet-sen University, Guangdong Province, People's Republic of China. kongjie1939@hotmail.com
authors: Jie
authors: J
authors: Kong
authors: Liqing
authors: L
authors: Yang
authors: Qiuling
authors: Q
authors: Li
authors: Jiqing
authors: J
authors: Cao
authors: Juan
authors: J
authors: Yang
authors: Fei
authors: F
authors: Chen
authors: Yanyun
authors: Y
authors: Wang
authors: Cheng
authors: C
authors: Zhang
mesh_terms: D000818:Animals; D016189:Dystrophin / Q000172:deficiency* / Q000235:genetics; D051379:Mice; D018101:Mice, Inbred mdx; D018345:Mice, Knockout; D018482:Muscle, Skeletal / Q000473:pathology*; D009137:Muscular Dystrophy, Animal / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D011950:Receptors, Cholinergic / Q000648:ultrastructure*; D049411:Utrophin / Q000235:genetics
chemical_list: D016189:Dystrophin; D011950:Receptors, Cholinergic; D049411:Utrophin