Circadian rhythms are biological processes
that follow a roughly 24-hour cycle; they involve physical, mental and
behavioural changes. They are found in most living beings, including animals,
plants and micro-organisms. Circadian rhythms are moderated by light and
darkness in the environment. Disruptions of the rhythms profoundly influence
the health of people. The day-night pattern of
circadian rhythms regulate up to 15 percent of human genes.
The early online edition of Proceedings of the National
Academy of Sciences
reports the latest study that sheds more light
in to the intricacies of circadian rhythms. Researchers suggest that these
rhythms can boost the body's ability to combat intestinal bacterial infections,
notably those caused by salmonella.
Studies conducted on mice
infected with salmonella show that circadian-controlled genes govern the immune
response to the invading pathogen. Infection potential and the immune system's
ability to deal with pathogens differ between day and night. "We think these
findings may be broadly applicable to other infectious diseases in the gut, and
possibly in other organs controlled by circadian patterns," says Raffatellu,
Assistant Professor of Microbiology & Molecular Genetics who lead the study
along with UC Irvine's Paolo Sassone-Corsi, one of the world's leading
researchers on circadian rhythm genetics.
It is true that mice, which
are nocturnal creatures, have circadian rhythms opposite to those of humans.
But the results do provide clues regarding the influence that
circadian-controlled intestinal genes have
on the human immune system.
Sassone-Corsi believes that learning more about the
circadian genetics is vital. "This
gives us the ability to target treatments that supplement the power of the body
clock to boost immune response," he said.
Reference: Proceedings of the National Academy of Sciences.