The anti-inflammatory action of a biological clock protein could prevent the onset of fulminant hepatitis, by alleviating symptoms and increasing survival rates.
‘Regulation of the circadian rhythm may be an effective method of reducing the severity of inflammatory diseases because the severity of these diseases depends on the time of disease occurrence.’
A research team conducted research on human immune cells and mice and found that the seriousness and mortality associated with fulminant hepatitis were dependent on the time at which the disease was induced
Fulminant hepatitis is a serious disease which leads to rapid deterioration of tissue and liver function in the patient, associated with blood coagulation disorders and irreparable brain damage. Although fulminant hepatitis can be caused by different factors, overdose with medications containing acetaminophen continues to be the main cause of the disease.
Accumulation of acetaminophen in the body can cause cellular stress, which gives rise to an abnormal immune system response. This is expressed by excessive inflammation, which destroys hepatocytes and the liver. Until now, no specific treatment for fulminant hepatitis has been identified, and the only solution is liver transplant within 24 hours following onset of symptoms. Researchers from Inserm, Institut Pasteur de Lille and Universite de Lille are focusing on the mechanisms underlying inflammation specifically in fulminant hepatitis, with a view to identifying potential avenues of treatment.
Starting from the observation that immune functions vary during the day, the researchers examined a biological clock protein called Rev-erb-alpha and its potential role in regulating inflammation in fulminant hepatitis. This protein notably targets adipose tissue, together with liver, skeletal muscle and brain cells. It plays a major role in developing and regulating their circadian rhythm, i.e. the repetition of their biological cycle every 24 hours.
The research, conducted on human immune system cells and on mice, showed that the inflammation also follows a circadian rhythm. The researchers also observed that injecting a molecule potentiating the action of Rev-erb-alpha reduced the inflammatory response which causes hepatocyte death in fulminant hepatitis.
Mice having received the Rev-erb-alpha-activating treatment demonstrated less severe forms of the disease, together with a higher survival rate. As the same results were observed in vitro on human cells, these data indicate new avenues to be explored with a view to potentially developing a treatment for acute fulminant hepatitis or able to slow the progression of symptoms in patients awaiting transplantation.
Fulminant hepatitis is not the only disease involving the circadian molecular mechanism inhibited by Rev-erb-alpha. Other diseases such as peritonitis, diabetes or even atherosclerosis display a similar imbalance in the inflammatory response due to the abnormal accumulation of toxins in the body
Helene Duez, researcher at Inserm, affirms that: "the results of this study could open up new prospects in preventing these diseases. They also offer new avenues for researchers, notably in terms of potential improvements in quality of life and longevity among patients suffering from chronic inflammatory disease."
This research is published in the journal Gastroenterology