Modification of brain lipids but not phenotype in α-synucleinopathy transgenic mice by long-term dietary n-3 fatty acids

Transgenic mice expressing both wild mouse α-synuclein and the Parkinson's disease associated A53T mutated human α-synuclein were subjected to long-term diets impoverished in n-3 or diets impoverished in n-3 and supplemented with docosahexaenoic acid (DHA) for 6 months. Transgenic mice evidenced mild phenotype characterized by increased total α-synuclein expression, truncated α-synuclein forms, and abnormal solubility and aggregation, in the absence of Lewy bodies and neurites, and lack of apparent neuronal loss, astrocytosis and microgliosis. These diets produced a reduction in the content of linolenic, n-3 docosapentaenoic and total polyunsaturated fatty acids, leading to significantly lower double bond and peroxidizability indexes as well as to lower protein oxidative damage, with no effects in α-synuclein expression and with no modifications in the number of cortical astrocytes and microglial cells. The present results show that diets may modify brain lipid composition and susceptibility to oxidative damage that do not interfere with phenotype in models with a genetic susceptibility to develop α-synucleinopathy.