Circadian Rhythm is Health Factor
Disruptions to the circadian rhythm can affect the growth of blood vessels in the body, thus causing illnesses such as diabetes, obesity, and cancer
The circadian rhythm is regulated by a “clock” that reacts to both incoming light and genetic factors, according to a new study from Linköping University and Karolinska Institutet.
The article is being published in the scientific journal Cell Reports.
For the first time it has been demonstrated
that disruption of the circadian rhythm immediately
inhibits blood vessel growth in zebra fish embryos.
Professor Yihai Cao leads a research group,
which has demonstrated that the breaking point is
the production of a very important signalling substance:
vascular endothelial growth factor (VEGF).
The formation of VEGF requires
a normal circadian rhythm.
During experiments with hours-old zebra fish embryos, the researchers manipulated their circadian rhythm by exposing them to lighting conditions varying from constant darkness to constant light. The growth of blood vessels in the various groups was then studied. The results showed that exposure to constant light (1800 lux) markedly impaired blood vessel growth; additionally, it affected the expression of genes that regulate the circadian clock.
“The results can definitely be translated into clinical circumstances. Individuals with disrupted circadian rhythms for example, shift workers who work under artificial lights at night, people with sleep disorders or a genetic predisposition should be on guard against illnesses associated with disrupted blood vessel growth,” says Lasse Dahl Jensen (pictured), researcher in Cardiovascular Physiology at Linköping University (LiU), and lead writer of the article.
Such diseases include heart attack, stroke, chronic inflammation, and cancer. Disruptions in blood vessel growth can also affect foetal development, women’s reproductive cycles, and the healing of wounds.
Opposing Effects of Circadian Clock Genes Bmal1 and Period2 in Regulation of VEGF-Dependent Angiogenesis in Developing Zebrafish by L D Jensen, Z Cao, M Nakamura, Y Yang, L Bräutigam, P Andersson, Y Zhang, E Wahlberg, T Länne, K Hosaka and Y Cao. Cell Reports Online Now 9 Aug 2012.
Lasse Dahl Jensen, postdoc, Department of Medical and Health Sciences,
+46 (0) 101 033 674, +46 (0) 709 982 096
Cardiovascular Physiology at LiU
Department of Medical and Health Sciences at LiU
Åke Hjelm 2012-08-16
Original article: http://www.liu.se/forskning/forskningsnyheter/1.356215?l=en