Inflammation is essential for survival. It helps the immune system fight infections and repair injuries. However, when inflammatory responses persist, they can contribute to serious conditions, including cardiovascular disease, diabetes and autoimmune disorders.

Johns Hopkins researchers identified how human resistin activates a powerful inflammatory pathway, potentially explaining amplified inflammation and offering a future treatment target.

A Protein That Activates Inflammation

The discovery centres on human resistin, a protein associated with several inflammatory diseases.

Researchers found that resistin helps activate the NLRP3 inflammasome, a molecular complex inside immune cells that plays an important role in inflammatory responses.

The process occurs in macrophages, specialised immune cells that recognise threats and coordinate the body's defences.

Resistin performs two important functions. First, it prepares macrophages for an inflammatory response by increasing the production of proteins required for inflammasome activity. It then helps activate the molecular machinery that releases inflammatory substances, including IL-1β and IL-18.

When produced excessively, these substances can contribute to tissue damage and prolonged inflammation.

How Researchers Uncovered The Mechanism

The scientists examined cultured human macrophages using molecular techniques, including gene-expression analysis and protein testing.

They discovered that resistin stimulates the release of HMGB1, a protein that prepares the NLRP3 inflammasome for activation.

Resistin also interacts with an enzyme called Bruton’s tyrosine kinase, or BTK. This interaction activates BTK, which subsequently modifies NLRP3 and enables the inflammatory complex to assemble.

The resulting molecular cascade activates caspase-1 and promotes the release of IL-1β and IL-18.

Experiments using inhibitors and genetically modified cells helped establish the importance of these individual steps.

Evidence From Patients With Lung Disease

To investigate whether this mechanism is relevant beyond laboratory experiments, researchers examined lung tissue from patients with pulmonary hypertension.

This serious condition involves abnormally high blood pressure in the blood vessels supplying the lungs.

The researchers identified increased activity involving resistin and the NLRP3 inflammasome in affected tissue.

They also studied mice with experimentally induced pulmonary hypertension, finding evidence that the corresponding inflammatory pathway contributes to changes in pulmonary blood vessels.

Professor Roger Anthony Johns explained that observing increased pathway activity in patients' lung tissue strengthens the evidence that the mechanism is relevant to human disease, rather than being limited to laboratory experiments.

A Potential Target For New Treatments

The team also investigated whether blocking resistin could interrupt the inflammatory process.

In laboratory experiments, a targeted monoclonal antibody reduced activation of the NLRP3 inflammasome and the associated inflammatory response.

Johns explained that identifying resistin as an important regulator could create opportunities to develop therapies that interrupt harmful immune signalling more precisely.

However, the research does not establish that blocking resistin is an effective treatment for patients. Additional studies will be necessary to assess its safety, clinical benefits and suitability for different inflammatory conditions.

A Potential Target For New Treatments

The team also investigated whether blocking resistin could interrupt the inflammatory process.

In laboratory experiments, a targeted monoclonal antibody reduced activation of the NLRP3 inflammasome and the associated inflammatory response.

Johns explained that identifying resistin as an important regulator could create opportunities to develop therapies that interrupt harmful immune signalling more precisely.

However, the research does not establish that blocking resistin is an effective treatment for patients. Additional studies will be necessary to assess its safety, clinical benefits and suitability for different inflammatory conditions.

Why The Discovery Matters

Chronic inflammation contributes to numerous diseases, but understanding its individual molecular triggers remains challenging.

This research provides a more detailed explanation of how resistin prepares and activates immune cells, connecting a previously recognised inflammatory protein with a specific molecular pathway.

Although clinical applications remain some distance away, the findings identify a promising direction for developing treatments that reduce damaging inflammation without unnecessarily suppressing the body's essential immune defences.