Proteomic study of plasma and L1CAM-captured exosomal proteins in children with autism spectrum disorders

Autism spectrum disorder (ASD) has become a neurodevelopmental disorder that seriously endangers the health of infants and children. In order to explore the pathogenesis of the disease and search for early diagnostic biomarkers. In this study, plasma exosomes (PEs) and neural cell adhesion molecule L1 (L1CAM)-captured exosomes (LCEs) of ASD and controls were extracted and lysed to obtain proteins. Isobaric tags for relative and absolute quantitation (iTRAQ) proteomics were applied to investigate the differences in the expression of PEs and LCEs proteins between the two groups. Twenty-eight plasma exosomal differentially expressed proteins (DEPs) were identified, which were mainly associated with immunity, inflammation, complement and coagulation, and lipoprotein metabolism and transport. Twenty L1CAM-captured exosomal DEPs were identified, which were mainly involved in cytoskeleton, tight junctions, focal adhesion, and platelet-associated pathways. Meanwhile, our results suggested that processes or signaling pathways associated with the DEPs from plasma exosomes may be activated, whereas those associated with L1CAM-captured exosome may be inhibited. These processes or signaling pathways have been reported to be associated with ASD in previous studies. These DEPs have the potential to be diagnostic markers. This study provides new insights into disease mechanisms and diagnostic markers of ASD.