Genetic pathway behind body clock disturbance and arthritis link identified

Washington, June 11 (ANI): Scientists have identified a genetic pathway responsible for link between body clock disturbance and worsening arthritis.

They have found that the genes, which regulate human circadian rhythm, or 'the body clock', are significantly disturbed in individuals with arthritis.

In a sample of 200 rheumatoid arthritis (RA) patients, sleep was determined to be significantly disturbed in over 61 percent.

The researchers further looked into the expression patterns of certain genes in mice with arthritis.

Here, researchers identified a novel biochemical pathway in which the circadian regulatory gene CRY was found to up-regulate expression of a gene which promotes the activation of TNF-alpha (tumour necrosis factor-alpha, a pro-inflammatory cytokine used by the body to boost the immune system) by two fold, when comparing mice with the CRY gene removed to those with a normal copy of the gene.

"Our study has shown that arthritis interferes with the genetics behind an individual's circadian rhythm and, specifically, that certain body clock genes may play a part in the activation of TNF-alpha, a signaling molecule that has an important role in the inflammation commonly seen in a number of rheumatologic conditions," Professor Shunichi Shiozawa of Kobe University Graduate School of Medicine and University Hospital, Japan, who led the research said.

"The identification of this curious pathway may help to explain the 24-hour symptom cycle seen by many patients who experience worsening of joint pain and stiffness in the mornings, and lead to further research into new approaches for improving daily quality of life," Shiozawa added.

The study has been presented at EULAR 2009, the Annual Congress of the European League Against Rheumatism in Copenhagen, Denmark. (ANI)