Vitamin D3 suppresses astrocyte activation and ameliorates coal dust-induced mood disorders in mice.

BACKGROUND:Pneumoconiosis patients exhibit significantly more anxiety and depression than healthy individuals. However, the mechanism of coal dust-induced anxiety and depression remains unclear. METHODS:A pneumoconiosis mouse model with anxiety- and depression-like behaviors were established after 28 days of exposure to coal dust. Vitamin D3 treatment (1200 IU/kg/week) was administered intraperitoneally for 3 months starting from the first coal exposure. Tail suspension test (TST), open field test (OFT), and elevated plus-maze (EPM) test were used to assess anxiety- and depression-like behaviors. Theserum concentration of 25(OH)D3 and fibrillary acid protein (GFAP) expression were determined. In addition, the morphology and distribution of GFAP and neurogenic differentiation factor1 expression (NeuroD1) in different cerebral hippocampus were observed. RESULTS:In coal dust-exposed mice, immobility time decreased in OFT and increased in TST,and the frequency of entering the open arm decreased in the EPM compared with the control mice. Coal dust increased hippocampal GFAP expression and astrocyte activation and reduced neurogenic differentiation factor1 expression (NeuroD1). In addition, Vitamin D3 significantly alleviated anxiety- and depressive-like behaviors in TST and EPM test, decreased GFAP expression level, modified hippocampal astrocyte activation pattern, and advanced brain-derived neurotrophic factor (BDNF) distribution and expression in CA1 and CA3 of the hippocampus. CONCLUSIONS:Taken together, our results suggest that, by inhibiting the over-activation of astrocytes and increasing BDNF and neuron protection, vitamin D treatment ameliorates coal-dust-induced depressive and anxiety-like behavior, which is the first evidence that vitamin D may be a new approach for treating mood disorders caused by particulate matter.