UCL Researchers Uncover Body's Natural Inflammation 'Off Switch' Using Epoxy-Oxylipins

Breakthrough in Understanding Inflammation Resolution

University College London (UCL) researchers have made a groundbreaking discovery by identifying the body's natural 'off switch' for inflammation, mediated by tiny fat-derived molecules known as epoxy-oxylipins. Published in the prestigious journal Nature Communications, this study marks the first comprehensive mapping of epoxy-oxylipin activity in humans during the inflammatory process. Unlike traditional approaches that suppress inflammation broadly, this mechanism promotes resolution—the active process where the body calms the immune response and begins healing—offering hope for safer treatments for chronic conditions.

The research, led by Dr. Olivia V. Bracken from UCL's Department of Ageing, Rheumatology and Regenerative Medicine, demonstrates how boosting these molecules can rapidly reduce pain and curb harmful immune cells without disrupting visible signs like swelling or redness. This precision could transform how we manage diseases where unchecked inflammation leads to tissue damage and prolonged suffering.

The Double-Edged Sword of Inflammation

Inflammation is the body's essential defense mechanism against injury or infection, recruiting immune cells like monocytes to fight pathogens and initiate repair. Classical monocytes (CD14⁺CD16^-) start this response, but they can differentiate into intermediate (CD14⁺CD16⁺) and non-classical monocytes, which sustain inflammation if not properly regulated. When resolution fails, chronic inflammation ensues, contributing to major UK health burdens.

In the United Kingdom, rheumatoid arthritis (RA) affects around 400,000 people, inflammatory bowel disease (IBD) impacts nearly 500,000, and cardiovascular diseases—often fueled by low-grade inflammation—claim over 160,000 lives annually. These conditions not only cause pain and disability but also strain the NHS, with RA alone costing £2.7 billion yearly in healthcare and lost productivity.

Decoding Epoxy-Oxylipins: The Body's Hidden Regulators

Epoxy-oxylipins are specialized lipid mediators derived from polyunsaturated fatty acids like linoleic acid (LA) and arachidonic acid (AA) via cytochrome P450 (CYP450) enzymes, such as CYP2J2 and CYP2C. These molecules are produced at inflammation sites and peak during the resolution phase, around 14 hours post-onset in the UCL study.

Normally, soluble epoxide hydrolase (sEH) breaks them down into less active diols (e.g., 12,13-EpOME to 12,13-DiHOME). By inhibiting sEH, levels of protective epoxy-oxylipins like 12,13-EpOME and 14,15-EET rise, directing immune responses toward healing rather than persistence.

• CYP450 enzymes oxygenate fatty acids to form epoxy-oxylipins.
• sEH catabolizes them to diols, reducing activity.
• Inhibition preserves epoxy-oxylipins for resolution signaling.

The UCL Human Study Design: Mimicking Real Inflammation

To test this in humans, researchers induced acute inflammation in healthy male volunteers (aged 18-50) via intradermal injection of UV-killed Escherichia coli (UVKEc) into the forearm. This safe model replicates infection-like responses: pain, redness, heat, and swelling resolving within 48 hours.

Forty-eight participants were randomized into prophylactic (drug 2 hours pre-injection) and therapeutic (drug 4 hours post-injection) arms, each with 12 treated (15mg oral GSK2256294, an sEH inhibitor) and 12 placebo. This design assessed prevention versus treatment, using blood, blister fluid, and pain scores for analysis.

Striking Results: Faster Pain Relief and Immune Rebalance

Both arms showed accelerated pain resolution—24 hours prophylactically and 24-48 hours therapeutically—without altering heat, redness, or swelling. Crucially, GSK2256294 slashed intermediate monocyte expansion in blood (up to 50% reduction) and tissue, confirmed via flow cytometry and UMAP clustering.

Plasma epoxy-oxylipin levels spiked (e.g., 12,13-EpOME ratios increased), linking directly to monocyte control. A follow-up with p38 MAPK inhibitor losmapimod replicated these effects, validating the pathway.

Unraveling the Mechanism: p38 MAPK and Monocyte Fate

Step-by-step, 12,13-EpOME inhibits p38 mitogen-activated protein kinase (MAPK) phosphorylation in classical monocytes, halting their shift to pro-inflammatory intermediate forms. This p38-dependent block prevents downstream T-cell activation (fewer CD4⁺ T cells, more cell death), curbing chronicity drivers.

1. Inflammation triggers classical monocyte recruitment.
2. p38 MAPK activates, promoting intermediate differentiation.
3. 12,13-EpOME binds, suppresses p38, maintains resolving monocytes.
4. Reduced intermediates limit tissue damage and T-cell persistence.

In vitro co-cultures confirmed intermediate monocytes drive CD4 T-cell survival, amplifying inflammation.

UCL's Stellar Team Driving Resolution Pharmacology

Dr. Olivia Bracken, first author and rising star in regenerative medicine, spearheaded this human-centric work. Professor Derek Gilroy, corresponding author from UCL Division of Medicine, emphasized its translational potential. Collaborators spanned UCL, Queen Mary University of London (QMUL), King's College London, University of Oxford, and US NIEHS, showcasing UK higher education's collaborative prowess.

Funded by Arthritis UK, this reflects UCL's leadership in immunology. Gilroy noted: "This was an entirely human-based study with direct relevance to autoimmune diseases." For aspiring researchers, UCL offers prime opportunities in higher ed research jobs, fostering breakthroughs like this.

Transforming Treatment for UK Chronic Inflammation Sufferers

Chronic inflammation underlies RA (1 in 100 UK adults), IBD (3 in 1,000), and contributes to 7 million CVD cases. Current steroids/NSAIDs suppress symptoms but risk side effects like immunosuppression. sEH inhibitors like GSK2256294, already trialed safely, could resolve flares precisely.Read the full study

• RA: Prevent joint damage alongside DMARDs.
• IBD: Reduce flares, improve remission.
• CVD: Lower monocyte-driven atherosclerosis.

Arthritis UK praises its pain focus, vital as arthritis pain disrupts daily life for 10 million Britons.

Advantages Over Traditional Anti-Inflammatories

This shift to 'resolution pharmacology' avoids immune compromise, as seen in prior animal studies on pro-resolving mediators.

Looking Ahead: Clinical Trials and UK Research Horizon

GSK2256294's safety profile positions it for Phase II trials in RA and CVD. UCL plans expanded studies on diverse populations. UK universities like QMUL and Oxford lead in lipid mediators, bolstered by UKRI funding. This aligns with national priorities amid rising chronic disease rates.UCL News Release

Bracken envisions: "sEH inhibitors trialled alongside existing medications to prevent joint damage."

UCL's Role in Elevating UK Biomedical Innovation

UCL, consistently top-ranked globally, exemplifies UK higher education's research impact. This study highlights interdisciplinary teams tackling grand challenges, attracting talent and funding. With UK university rankings emphasizing translational medicine, such work secures grants and partnerships, vital for post-Brexit competitiveness.

For academics, explore career advice to join labs like Gilroy's, advancing resolution biology.

Photo by Joel Ambass on Unsplash

Careers in Inflammation Resolution Research

This discovery spotlights demand for experts in lipidomics, immunology, and clinical pharmacology. UK universities offer lecturer jobs and postdoc positions at UCL, QMUL. PhDs in regenerative medicine thrive here, with actionable steps:

• Pursue MSc in immunology at UCL.
• Apply for Arthritis UK fellowships.
• Network via Rate My Professor for mentors.

Check higher ed jobs for openings in this burgeoning field, positioning UK unis as resolution therapy leaders.