The Curtis lab from MCT in partnership with the O’Neill lab at Trinity College have revealed insights into how the body clock controls the inflammatory response, which may open up new therapeutic options to treat excess inflammation in conditions such as asthma, arthritis and cardiovascular disease. By understanding how the body clock controls the inflammatory response, we may be able to target these conditions at certain times of the day to have the most benefit. These findings may also shed light on why individuals who experience body clock disruption such as shift workers are more susceptible to these inflammatory conditions.
The body clock, the timing mechanism in each cell in the body, allows the body to anticipate and respond to the 24-hour external environment. Inflammation is normally a protective process that enables the body to clear infection or damage, however, if left unchecked can lead to disease. The new study published in the Proceedings of the National Academy of Sciences (PNAS), a leading international multidisciplinary scientific journal.
Dr Annie Curtis, Research Lecturer in the Department of Molecular and Cellular Therapeutics at RCSI and senior author, explained that: “Macrophages are key immune cells in our bodies which produce this inflammatory response when we are injured or ill. What has become clear in recent years is that these cells react differently depending on the time of day that they face an infection or damage, or when we disrupt the body clock within these cells”.
Dr. Jamie Early, the first author on the study, said: “We have made a number of discoveries into the impact of the body clock in macrophages on inflammatory diseases such as asthma and multiple sclerosis. However, the underlying molecular mechanisms by which the body clock precisely controls the inflammatory response were still unclear. Our study shows that the central clock protein, BMAL1 regulates levels of the antioxidant response protein NRF2 to control the inflammatory response from macrophages.
“The findings although at a preliminary stage, offers new insights into the behaviour of inflammatory conditions such as arthritis and cardiovascular disease which are known to be altered by the body clock”, added Dr Early.
Funded by Science Foundation Ireland, the research was undertaken in collaboration between RCSI, Trinity College Dublin and the Broad Institute in Boston, USA.
She was awarded a prestigious L’Oréal-UNESCO For Women in Science 2017 Fellowship at a ceremony held at the Royal Society in London on May 5th.
She was one of five winners of these fellowships and the only Irish winner this year. The fellowship will support her research into understanding the precise mechanisms by which the body clock restrains inflammation from a key immune cell called the macrophage.
Last week’s departmental talks encompassed a Deep Dive into Clock biology in Macrophages affecting the Inflammatory Response. This area is the focus of the Immune-Clock laboratory of Dr. Annie Curtis, a recent recruit to RCSI.
Jamie Early (PhD student of the Curtis Lab) currently residing in the Luke O’Neill Laboratory presented his findings on the role of the circadian clock in suppressing inflammation in macrophages and if the anti-oxidant transcription factor and redox sensor NRF2 plays a role. His talk was titled ‘The macrophage clock is a key controller of the anti-oxidant and inflammatory response via the transcription factor Nrf2’.
Second up, we had Mariana Cervantes (PhD student and visiting scientist from the Instituto Politecnico Nacional (IPN) in Mexico) present her talk titled ‘The macrophage clock is having a profound impact on mitochondrial dynamics- what are the implications for inflammation?’
Mariana is interested in how mitochondria alter their morphology, either fusing together to form networks or fragmenting into smaller units termed fission. She is trying to uncover if the clock is regulating this process and if so what are the implications for the inflammatory response.
Our Immune-clock laboratory has a real interest in metabolism and how alterations in metabolic pathways termed “metabolic reprogramming” can shape the type of immune response. This area called “Immunometabolism” has exploded in the last 5 years, and the implications are massive. It appears that macrophages use one metabolic pathway to become highly proinflammatory and another metabolic pathway to resolve inflammation and promote wound healing. So why is our laboratory so interested in this? Well, if you think about daily changes in our environment, the two biggest are the sleep/wake cycle and the other is feeding/fasting. It is now clear that clocks in metabolic tissues like the liver/pancreas/adipose tissue prepare the body to deal with this daily rhythm in feeding/fasting. Based on this, our interest is to figure out if the clock within macrophages is somehow altering its metabolism over the course of the day and is that leading to changes in macrophage function, particularly the inflammatory response.
Body clocks tend to garner quite a bit of attention from the media. Folks are obsessed with sleep, either they cant get enough or they are getting too much, and all of us can relate to the symptoms of jet lag and morning versus evening types. Therefore it’s a great topic to discuss with wider audiences. I really enjoy chatting with people about the implications of our internal timing system and that research now shows that living in synchrony with your body clock can improve overall health. For the SFI Science week I was asked to provide an interview to the Daily Star called “The Science of Sleep Explained”. I was also asked to go on the “Alive and Kicking” show on Newstalk Radio with Ciara Kelly, you can listen to the interview: What type of sleeper are you? Are you an owl or a lark?