Metalomics Revealed That Changes of Serum Elements Were Associated with Oxidative Stress-Induced Inflammation of Cortex in a Mouse Model of Autism

Autism spectrum disorder (ASD) is a neurodevelopmental disorder emerging during early childhood. However, the mechanism underlying the pathogenesis of ASD remains unclear. This study investigated the alterations of elements in serum and prefrontal cortex of BTBR T + tf/J (BTBR) mice and potential mechanisms. The male BTBR mice were used for experimental group and C57BL/6 J (C57) mice were used for control group (n = 15). After behavioral tests were monitored, serum and prefrontal cortex of mice were analyzed by ICP-MS. The results demonstrated that the level of copper (Cu) was increased, and the levels of calcium (Ca), magnesium (Mg), selenium (Se), cobalt (Co), iron (Fe) and zinc (Zn) were decreased in BTBR mice compared to C57 mice (p < 0.01). The levels of above differential elements in serum demonstrated positive correlations with those in prefrontal cortex. Meanwhile, differential elements in prefrontal cortex had correlations with the total distance traveled (open field test) and the number of marbles buried (marble burying test) in BTBR mice (p < 0.05 or p < 0.01). The abnormally changed elements in serum might cross blood-brain-barrier into the brain and lead to oxidative stress, causing inflammation. Furtherly, the levels of inflammation-related indicators including tumor necrosis factor-alpha (TNF-α), nuclear factor kappa-B (NF-κB), interleukin-6 (IL-6) and interleukin-1β (IL-1β) were increased in prefrontal cortex of BTBR mice (p < 0.01), which were consistent with the aforementioned results. Our study suggested that the abnormal elements in the serum of BTBR mice may cause oxidative stress and inflammation in prefrontal cortex, which might contribute to increase the understanding of ASD pathogenesis.