AAV2-SYN overexpression induces microRNA-155 in the SNpc. A, B, Multiple microRNAs are increased at 2 weeks and 4 weeks after transduction of AAV2-SYN compared with AAV-GFP-injected animals. miR-155 was found to be increased at both time points. microRNAs were measured and quantified using the Qiagen Inflammatory Response and Autoimmunity miScript miRNA PCR array and miScript PCR Array Data Analysis Tool. Samples were pooled from n = 6 animals per group with four replicates of each group per plate. C, D, Increased miR-155 expression confirmed at 2 weeks after transduction of AAV2-SYN using probes designed for the mature miR-155 sequences. Animals were studied individually using n = 6 animals per group. At 2 weeks, miR-155 was significantly increased (p = 0.0144, Student's t test). At 4 weeks, there was a trend for increased miR-155 that did not reach significance (p = 0.0688, Student's t test).