Glial cell-derived neurotrophic factor alleviates sepsis-induced neuromuscular dysfunction by decreasing the expression of γ- and α7-nicotinic acetylcholine receptors in an experimental rat model of neuromyopathy

Sepsis-induced neuromuscular dysfunction results from up-regulation of the expression of gamma- and alpha 7 nicotinic acetylcholine receptors (nAChR). Although glial cell derived neurotrophic factor (GDNF) has been implicated in repairing and supporting neurons, little is known about the effects of GDNF on demyelination of nerves in sepsis. In this study, we tested the hypothesis that GDNF could alleviate sepsis-induced neuromuscular dysfunction by decreasing the expression of gamma- and alpha 7-nAChR in an experimental rat model of neuromyopathy. Rats were randomly divided into a sham group and a sepsis group. Levels of inflammatory factors, muscle function, and nicotinic acetylcholine receptors were tested in rats after cecal ligation and puncture (CLP). At 24 h after CLP, GDNF was injected around the sciatic nerve of sepsis rats, cytokines were detected by enzyme-linked immunosorbent assay (ELISA), and immunofluorescence staining was used to detect the expression of nAChRs. GDNF and its downstream effector (Erk1/2 and GFR-alpha), neuregulin-1 (NRG-1) and gamma- and alpha 7-nAChR were measured using Western blot analysis. The expression of GDNF reached a minimum at 24 h after CLP. Compared with the sham group, the release of cytokines and the expression of gamma- and alpha 7-nAChR were significantly increased in the sepsis group. The administration of GDNF significantly alleviated sepsis-induced neuromuscular dysfunction, as well as reducing the expression of gamma- and alpha 7-nAChR. In addition, the expression of Erk1/2, GFR-alpha, NRG-1 were significantly increased after GDNF treatment. GDNF administration may improve patient outcomes by reducing the demyelination of nerves and the expression of gamma- and alpha 7-nAChR. (C) 2018 Published by Elsevier Inc.