Looking at the micro could mend broken hearts

Ribonucleic acid (RNA) could hold the key to treating heart disease.

Researchers have completed the first comprehensive survey of the tiny cellular molecules found in the heart and which are essential for its healthy function. The breakthrough could lead to the development of targeted therapeutic treatments for heart disease.

Professor Thomas Preiss and Jennifer Clancy and their team commenced the research at Sydney’s Victor Chang Cardiac Research Institute in 2008 and completed it at The John Curtin School of Medical Research at ANU. They used the latest sequencing technology to capture and identify thousands of microRNAs found in the cells of the heart.

MicroRNAs are short ribonucleic acid molecules, which in turn are one of three building blocks of all life. Even though they are tiny molecules, microRNAs are abundant in cells and act like an army of ants - individually making small changes to the expression of many genes, but in combination resulting in large changes to the cell. When these molecules are deregulated, or ’not co-ordinating their efforts’, they can cause disease.

Professor Preiss said that microRNAs are important regulators influencing which genes get used in each cell and that every cell type has its own particular suite of microRNAs that enable specific cellular functions.

"This suite of microRNAs changes during heart disease and microRNA-based therapies aim to revert a cell to its former function by resetting microRNA levels," she said.

"A number of these therapies are already in pre-clinical development. However, the knowledge of which microRNAs were present in the heart and what they actually looked like may not be good enough for the development of appropriate therapies.

"That’s why we conducted this survey. Using next-generation sequencing technology, we were able to visually identify tens of thousands of heart microRNAs and describe them fully.