New research reveals how the body clock regulates inflammation

RCSI research reveals how the body clock regulates inflammation

Tuesday, 17 December 2024: New research from RCSI University of Medicine and Health Sciences has explained how the body’s internal clock influences the inflammatory process of the immune system. The findings describe how immune cells, called macrophages, work differently at various times of the day and could pave the way for time-targeted treatments for inflammatory diseases such as arthritis.

The researchers explored the link between the immune system and the body’s circadian rhythms often referred to as the body clock. Macrophages, immune cells that detect and respond to harmful substances, are able to trigger inflammation as a defense mechanism by assembling large complexes known as inflammasomes. Inflammasomes could be compared to ‘smoke detectors’ that will then alert the immune system of danger.

Activation of an inflammasome called NLRP3 was not found to be constant throughout the day but was regulated by the body’s 24-hour circadian clock. This daily rhythm determines when macrophages are most efficient at detecting threats and when their energy levels peak to mount a response. The research also highlights a key role for mitochondria, the cell’s energy producers, in driving these daily changes in immune activity.

“When macrophages ‘think’ it’s morning, their inflammasome activation is quicker and more robust,” explained Professor Annie Curtis, Principal investigator for the study at RCSI School of Pharmacy and Biomolecular Sciences. “This means the immune response is heightened during the early part of the day, a time when we are awake and more likely to encounter environmental challenges, such as injuries or infections.”

The study has significant implications for understanding and treating inflammatory diseases, such as arthritis, where overactive inflammasomes play a key role. Symptoms of such diseases often worsen in the morning, something this research may help explain.

“With these findings, there’s potential to refine treatments for inflammatory conditions,” said Dr James O’Siorain, lead author of the study. “For instance, new therapies targeting inflammasomes could be more effective if administered at specific times of the day when macrophage activity peaks.”

‘Time of day control of mitochondria regulates NLRP3 inflammasome activation in macrophages’ is published in The FASEB Journal. The research was supported by funding from Taighde Éireann – Research Ireland. 

ENDS

For further information:

Laura Anderson, Communications Officer, RCSI 

087 199 0399/ lauraanderson@rcsi.ie

About RCSI University of Medicine and Health Sciences 

RCSI University of Medicine and Health Sciences is ranked fifth in the world for its contribution to UN Sustainable Development Goal 3, Good Health and Well-being, in the Times Higher Education (THE) University Impact Rankings 2024. 

Founded in 1784 as the Royal College of Surgeons in Ireland with responsibility for training surgeons in Ireland, today RCSI is an innovative, not-for-profit, international university exclusively focused on driving improvements in human health worldwide through education, research and engagement.

RCSI is among the top 300 universities worldwide in the World University Rankings (2025) and has been awarded Athena Swan Bronze accreditation for positive gender practice in higher education.

In 2026, RCSI will open a new public engagement space, dedicated to health and well-being, at 118 St Stephen’s Green in Dublin city centre. The space is designed to engage the public in dialogue about living longer, healthier and happier lives through dynamic events and exhibitions. Our aim is to bridge the gap between health sciences research, professional expertise, and public understanding, empowering people to make informed decisions about their health. 

Visit the RCSI MyHealth Expert Directory to find the details of our experts across a range of healthcare issues and concerns. Recognising their responsibility to share their knowledge and discoveries to empower people with information that leads them to better health, these clinicians and researchers are willing to engage with the media in their area of expertise.