ABSTRACT
OBJECTIVE@#To investigate autophagy-related mechanisms of electroacupuncture (EA) action in improving gastrointestinal motility in mice with functional constipation (FC).@*METHODS@#According to a random number table, the Kunming mice were divided into the normal control, FC and EA groups in Experiment I. The autophagy inhibitor 3-methyladenine (3-MA) was used to observe whether it antagonized the effects of EA in Experiment II. An FC model was established by diphenoxylate gavage. Then the mice were treated with EA stimulation at Tianshu (ST 25) and Shangjuxu (ST 37) acupoints. The first black stool defecation time, the number, weight, and water content of 8-h feces, and intestinal transit rate were used to assess intestinal transit. Colonic tissues underwent histopathological assessment, and the expressions of autophagy markers microtubule-associated protein 1 light chain 3 (LC3) and Beclin-1 were detected by immunohistochemical staining. The expressions of phosphoinositide 3-kinases (PI3K)-protein kinase B (AKT)-mammalian target of rapamycin (mTOR) signaling pathway members were investigated by Western blot and quantitative reverse transcription-polymerase chain reaction, respectively. The relationship between enteric glial cells (EGCs) and autophagy was observed by confocal immunofluorescence microscopy, localization analysis, and electron microscopy.@*RESULTS@#EA treatment shortened the first black stool defecation time, increased the number, weight, and water content of 8-h feces, and improved the intestinal transit rate in FC mice (P<0.01). In terms of a putative autophagy mechanism, EA treatment promoted the expressions of LC3 and Beclin-1 proteins in the colonic tissue of FC mice (P<0.05), with glial fibrillary acidic protein (GFAP) and LC3 significantly colocalized. Furthermore, EA promoted colonic autophagy in FC mice by inhibiting PI3K/AKT/mTOR signaling (P<0.05 or P<0.01). The positive effect of EA on intestinal motility in FC mice was blocked by 3-MA.@*CONCLUSION@#EA treatment can inhibit PI3K/AKT/mTOR signaling in the colonic tissues of FC mice, thereby promoting EGCs autophagy to improve intestinal motility.
Subject(s)
Mice , Animals , Proto-Oncogene Proteins c-akt/metabolism , Phosphatidylinositol 3-Kinases/metabolism , Electroacupuncture , Beclin-1 , Signal Transduction , Constipation/therapy , TOR Serine-Threonine Kinases/metabolism , Autophagy , Neuroglia/metabolism , Mammals/metabolismABSTRACT
Glial cell line-derived neurotrophic factor (GDNF) is an important functional protein derived from enteric glial cells. It plays an important role in the enteric nervous system, such as nutritional neurons, promoting synaptic remodeling and anti-inflammation. The role of GDNF in the progression of gastrointestinal diseases has received more attention gradually. This article reviewed GDNF and its ligands, related signaling pathway, correlation with intestinal homeostasis and clinical application.
ABSTRACT
Objective To investigate the roles of neuroinflammation and pathology of peripheral nervous system in the pathogenesis of Parkinson's disease (PD).Methods Immunohistochemical staining was performed to examine the nodose ganglia (containing vagus nerve) and intestine of an autopsy case of PD.The neuroinflammation and morphological changes of vagus nerve and enteric nervous system were observed.Results The expressions and distributions of glial fibrillary acidic protein and ionized calcium binding adapter molecule 1,two typical glia cell biomarkers,were different in vagus nerve and intestinal mucosa.Tumor necrosis factor α and inducible nitric oxide synthase were expressed in intestinal mucosa and myenteric plexus of the PD patient.There was a strong inflammatory reaction in the myenteric plexus,which distributed diffusely.Conclusion Satellite glial cells and intestinal inflammatory response may play a role in the pathogenesis of PD.