BERLIN, Aug. 10 (UPI) -- A key muscle protein was found to be one of the drivers of muscle loss in heart failure patients, which makes the disease so difficult for doctors to treat, researchers said in a new study.
Scientists already know that some portion of the muscle loss is caused by the renin-angiotensin-aldosterone system, which regulates blood pressure and the salt-water balance in the body. In patients with heart failure, this system results in an increase of the effector protein angiotensin II and leads directly to a loss of muscle mass and strength.
Treatments to rein in this system can slow muscle loss for a period of time, however they are less effective the longer they're used. While studying this process, the researchers found angiotensin II increases the production of a protein called muscle RING-finger 1, or MuRF1, which is key to muscle loss.
"We have been able to identify and characterize the function of a new transcription factor that regulates this process," said Dr. Jens Fielitz, a professor and cardiologist at the Charite University of Medicine in Berlin, in a press release. "Our experiments have also revealed the specific mechanisms that either activate or inhibit the production of MuRF1 protein, that is to say that either reduce or increase muscle loss."
In a study published in Circulation Researcher, scientists worked with mice to find the effects of blocking angiotensin II production, which in some cases reversed the process of muscle loss.
"Our findings can now provide insights into important unanswered questions in that they delineate a new signal pathway that is important in the emergence of cardiac cachexia," Fielitz said.