A novel investigation has identified that inflammatory diseases may be exacerbated by an irregular body clock, signifying the importance of a consistent sleeping pattern.
A study conducted by researchers from RCSI University of Medicine and Health Sciences has illuminated the essential role that an erratic body clock performs in enhancing inflammation in the body’s immune cells, having dire consequences for the most severe and prevalent human diseases.
The research, which is published in Frontiers in Immunology, was led by RCSI’s School of Pharmacy and Biomolecular Sciences, with experts from Swansea University, Trinity College Dublin, and the University of Bristol collaborating on the project.
Understanding the body clock
The circadian body clock is an essential aspect of the body’s daily functions, generating 24-hour rhythms that help humans maintain their health in time with the day/night cycle. One of the essential roles it performs is regulating the rhythm of the body’s innate immune cells, called macrophages.
However, when these cell rhythms are disrupted by an erratic eating and sleeping pattern or shift work, the cells produce molecules that cause inflammation. Subsequently, this can lead to chronic inflammatory diseases such as heart disease, obesity, arthritis, diabetes, and cancer and reduce the body’s ability to combat infection.
Impacts on inflammation
For their investigation, the team analysed macrophages with and without a body clock under laboratory conditions, looking to determine if macrophages without a body clock metabolise fuel differently and if this is the reason these cells produce more inflammatory products.
The researchers discovered that macrophages without a body clock used far more glucose and broke it down quicker than normal cells. In addition, the team observed that in the mitochondria (where the cell’s energy originates), the pathways in which glucose was further broken down to produce energy were extremely different in macrophages without a clock. This resulted in the production of reactive oxygen species (ROS), which further fuelled inflammation.
Dr George Timmons, the lead author on the study, said: “Our results add to the growing body of work showing why disruption of our body clock leads to inflammatory and infectious disease, and one of the aspects is fuel usage at the level of key immune cells such as macrophages.”
Dr Annie Curtis, Senior Lecturer at RCSI School of Pharmacy and Biomolecular Sciences and senior author on the paper, added: “This study also shows that anything which negatively impacts on our body clocks, such as insufficient sleep and not enough daylight, can impact on the ability of our immune system to work effectively.”