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Muscular dystrophies are inherited myopathic disorders characterized by progressive muscle weakness. Recently, several gene therapies have been developed; however, the treatment options are still limited. Resveratrol, an activator of SIRT1, ameliorates muscular function in muscular dystrophy patients and dystrophin-deficient mdx mice, although its mechanism is still not fully elucidated. Here, we investigated the effects of resveratrol on membrane resealing. We found that resveratrol promoted membrane repair in C2C12 cells via the activation of SIRT1. To elucidate the mechanism by which resveratrol promotes membrane resealing, we focused on the reorganization of the cytoskeleton, which occurs in the early phase of membrane repair. Treatment with resveratrol promoted actin accumulation at the injured site. We also examined the role of cortactin in membrane resealing. Cortactin accumulated at the injury site, and cortactin knockdown suppressed membrane resealing and reorganization of the cytoskeleton. Additionally, SIRT1 deacetylated cortactin and promoted the interaction between cortactin and F-actin, thus possibly enhancing the accumulation of cortactin at the injury site. Finally, we performed a membrane repair assay using single fiber myotubes from control and resveratrol-fed mice, where the oral treatment with resveratrol promoted membrane repair ex vivo. These findings suggest that resveratrol promotes membrane repair via the SIRT1/cortactin axis. [ABSTRACT FROM AUTHOR]

We assessed the clinicopathological features of nine patients with pure autonomic neuropathy, that is, neuropathy without sensory or motor deficits. The duration from symptom onset to diagnosis ranged from 1 month to 13 years. Of eight patients in whom serum antiganglionic acetylcholine receptor antibody was determined, four were positive. All patients who tested positive for this antibody manifested widespread autonomic dysfunction, with the exception of one patient who only experienced orthostatic hypotension. However, patients who were negative for the antiganglionic acetylcholine receptor antibody presented with partial autonomic failure. One of these patients had diffuse parasympathetic failure and generalized hypohidrosis but no orthostatic hypotension, which is clinically compatible with postganglionic cholinergic dysautonomia. Electron microscopic examination revealed a variable degree of reduction in unmyelinated fibers. Compared with normal controls, the patients had a significantly increased density of collagen pockets ( p < 0.05). Additionally, the percentage of Schwann cell subunits with axons (out of the total number of Schwann cell subunits associated with unmyelinated fibers) was significantly decreased ( p < 0.01). The density of unmyelinated fibers tended to decrease with increasing time between the onset of autonomic symptoms and biopsy ( p < 0.05). In conclusion, the clinical and pathological features of pure autonomic neuropathy vary in terms of progression, autonomic involvement, presence of the antiganglionic acetylcholine receptor antibody, and loss of unmyelinated fibers. [ABSTRACT FROM AUTHOR]