gene expression pathways associated with plasma levels of 17-HDHA in classical and intermediate monocytes in people with osteoarthritis pain. Monocyte gene expression in people with osteoarthritis pain

Lower circulating levels of the specialised pro-resolving mediator pre-cursor, 17-hydroxy-docosahexaenoic acid (17-HDHA), are associated with increased osteoarthritis (OA) pain. The aim of this study was to probe the potential genetic basis for the association between levels of 17-HDHA and OA pain. Intermediate (CD14++/CD16+/CD66b-/HLA-DR+) and classical (CD14++/CD16-/CD66b-/HLA-DR+) monocytes were sorted by fluorescence-activated cell sorting (FACS) from blood samples collected from 30 people with OA pain. Participants were stratified into four groups based on their plasma/serum levels of 17-HDHA and self-reported pain scores. RNA was extracted from these monocyte populations for next-generation RNA sequencing. RNA sequencing of the classical and intermediate monocytes identified a number of mRNAs which were differentially expressed between the 4 groups. Pathway analysis identified canonical biological pathways which were enriched in our comparison of interest. These data provide new insight into the biological pathways which may contribute to the association between 17-HDHA and chronic OA pain, and may provide novel analgesic strategies.