AB0080 Differential effects of tr14 versus diclofenac on pro-resolving lipid mediators revealed by rnaseq

Background Anti-inflammatory agents are used widely in treating numerous pain and inflammatory conditions. With a focus on the specialised pro-resolving mediators (SPM) pathways in cutaneous wound repair in mice, the therapeutic activities of Tr14 (Traumeel), a multicomponent/multitarget natural product, and diclofenac (NSAID), a non-selective cyclooxygenase (COX) inhibitor were compared. COX inhibitors can block the synthesis of prostaglandins and thromboxanes from arachidonic acid, and can have important effects on the synthesis of resolvins and protectins produced by similar enzymes from eicosopentanoic and docosohexanoic acid substrates. Differential effects were identified via transcriptome analysis (RNAseq). Objectives To compare the transcriptomic changes after administration of Tr14 or diclofenac in a mouse cutaneous wound healing model, with particular emphasis on the SPM pathways, which include resolvins and protectins. Methods After abrasive wounding, the wounds were treated with topical Tr14 (34 mg/ml) in combination with subcutaneous Tr14 injections (9.5 mg/ml), or with subcutaneous Tr14 injections only, or topical diclofenac at clinically relevant doses (2 mg/ml). Skin samples were analysed for RNA transcript profiling by RNAseq at specific times (12 hour, 24 hour, 36 hour, 72 hour, 96 hour, 120 hour, 192 hour) after injury. Differentially expressed genes (DEGs) were computed at each time point between diclofenac vs control or Tr14 vs control, using EdgeR. Results At early time points (12–36 hour), Tr14-treated wounds, and to a lesser extent diclofenac-treated wounds, showed marked induction of 3 lipoxygenase enzyme mRNAs involved in SPM synthesis. Even more striking was a pronounced effect of Tr14 at 12–36 hours on Fpr1 and Fpr2 mRNAs, which are the transmembrane receptors for the SPM lipid mediators. Consistent with elevated levels of enzymes regulating SPM synthesis, and SPR receptors, there was a noticeable decrease in the mRNA levels of the p65/RelA subunit of NFkB at 72–96 hours. NFkB is a critical transcription factor in inflammation, regulating numerous cytokines and chemokines. Conclusions Tr14 and diclofenac had very different effects on the SPM synthetic pathway after cutaneous wounding. Tr14 stimulated mRNA levels of several key regulators of SPM synthesis, and had a marked effect on the mRNA levels of the SPM receptors. Tr14, not diclofenac, suppressed mRNA levels for NFkB subunit p65/RelA, which may explain some of the anti-inflammatory and proresolving properties of Tr14. Disclosure of Interest None declared