New studies have revealed how the body’s biological clock affects the immune system’s inflammatory processes. The findings indicate that immune cells known as macrophages operate differently at various times throughout the day, potentially leading to treatments for inflammatory disorders like arthritis that are timed for optimal effectiveness.
Recent research conducted by RCSI University of Medicine and Health Sciences has shed light on how the body’s internal clock impacts the inflammatory actions of the immune system. It demonstrates that macrophages, which are immune cells, function differently at different times of the day, opening up possibilities for time-specific therapies aimed at inflammatory diseases such as arthritis.
The researchers investigated the connection between the immune system and the body’s circadian rhythms, which are commonly known as the biological clock. Macrophages, the immune cells responsible for recognizing and responding to harmful substances, can induce inflammation as a protective mechanism by forming large complexes called inflammasomes. Essentially, inflammasomes act like ‘smoke detectors’ that alert the immune system to potential threats.
The study found that the activation of an inflammasome known as NLRP3 does not remain constant throughout the day; instead, it is regulated by the body’s 24-hour circadian clock. This daily rhythm dictates when macrophages are most adept at spotting dangers and when their energy levels are at their highest to respond effectively. The research also emphasizes a crucial role for mitochondria, the energy-producing components of cells, in driving these daily fluctuations in immune function.
“When macrophages perceive it as morning, they activate their inflammasomes more quickly and vigorously,” stated Professor Annie Curtis, the lead investigator of the study at RCSI School of Pharmacy and Biomolecular Sciences. “As a result, the immune response is stronger early in the day, coinciding with a time when we are awake and more likely to face environmental challenges, such as injuries or infections.”
The implications of this study are significant for understanding and addressing inflammatory diseases like arthritis, where overactive inflammasomes are crucial. Symptoms related to such conditions often exacerbate in the morning, a phenomenon that this research may help clarify.
“These insights provide an opportunity to enhance treatments for inflammatory disorders,” noted Dr. James O’Siorain, the lead author of the study. “For instance, new therapies targeting inflammasomes may yield better results if administered during specific times of the day when macrophage activity is at its peak.”
‘Time of day control of mitochondria regulates NLRP3 inflammasome activation in macrophages’ is published in The FASEB Journal. The study received support from Taighde Éireann — Research Ireland.
