Tiny RNA Molecules in Blood can Act as Markers for Heart Problems

Certain microRNAs in the blood can be used as a marker for heart disease, a new study suggests.

The study, conducted by researchers at the Rockefeller University and Columbia University, shows that tiny molecules in the blood can be used to gain valuable information about the heart's health.

MicroRNAs are non-coding RNAs and help regulate the activity of genes in the cells. The current study adds to the knowledge of these small RNA molecules.

Blood has low levels of these microRNAs. In the study, researchers used highly sensitive RNA sequencing techniques to detect these molecules.

"When we profiled the small RNAs circulating in the blood of healthy people versus heart failure patients, we found increases in levels of certain microRNAs expressed by muscle, including three known to originate only in the heart," said Kemal Akat, the first author and a postdoc in the lab. "Our research suggests these three microRNAs could be used as indicators of injury produced by anything from heart attack to an impact in a car accident."

For the study, researchers looked at microRNA in samples of blood and heart tissue from people suffering from heart failure as well as from healthy individuals.

The team then compared the microRNA profile to the levels of protein called cardiac troponin, which is currently used to detect heart damage. Healthy hearts have cardiac troponin, but it starts leaking into the bloodstream during a heart diseases. Researchers found that the levels of microRNA also increased in the blood samples of heart failure patients, but not in the heart tissue samples.

The team is confident about microRNAs ability to act as a marker for heart disease. Also, researchers say that these tiny molecules might be even better than cardiac troponin.

"Cells contain a small pool of soluble cardiac troponin, but the majority is bound to heart muscle filaments. By contrast, the protein complexes that contain microRNA within the cell are fully soluble. For this reason, we suspect microRNAs may be more readily released into circulation and their levels may increase faster than cardiac troponin upon tissue injury," Akat said in a news release.

The study is published in the journal Proceedings of the National Academy of Sciences.