Changes in enteric cellular environment of the rotenone-induced parkinsonian mice that reproduce central and enteric neurodegenerative features

We previously established an animal model of Parkinson's disease (PD) induced by chronic low-dose rotenone as an environmental neurotoxic pesticide that reproducible central and enteric neurodegenerative features of PD, and also found that rotenone-induced enteric neurodegeneration is caused by dysfunction of enteric glia using primary cultured enteric cells. However, the mechanism of enteric neurodegeneration and inflammation are still obscure. In this study, we examined changes in enteric cellular environment in the enteric epithelium and myenteric plexus of the rotenone-induced PD model mice. Chronic subcutaneous administration with low-dose rotenone (2.5 mg/kg/day) for 4 weeks using an osmotic mini pump reduced the number of dopamine neurons in the substantia nigra and the intestinal myenteric neurons and glial cells of mice. Furthermore, it produced disruption of mucosal epithelial barrier and marked translocation of HMGB1 to the cytosol beside nuclear membrane towards the apical lumen side. These results suggest that the rotenone-induced dysfunctions of epithelial barrier and HMGB1 transportation are involved in the inflammatory reactions and dysfunction of enteric glia and consequent enteric neurodegeneration.