Recently, a report published on the Director’s Blog at the National Institutes of Health website discussed new microRNA research on cholesterol.  Cardiovascular disease is one of the most common medical issues today, and cardiovascular health is heavily influenced by cholesterol levels.  There are two types of cholesterol, high-density lipoprotein (HDL) also known as “good” cholesterol, and low-density lipoprotein (LDL) known as “bad” cholesterol.  One of the strongest markers of cardiovascular health is the ratio of HDL to LDL.  Oftentimes statins are prescribed to adjust unhealthy HDL to LDL ratios.  These statins work by lowering LDL levels.

Researchers have explored different types of medications that work by increasing HDL rather than lowering LDL.  One new approach to increase HDL levels involves targeting microRNA (miRNA) which regulate protein production by disabling specific RNA templates called mRNA.  This theory was tested in mice; researchers blocked a specific miRNA and the animals’ HDL rose.  In humans however, HDL production is also regulated by another miRNA, so a team of researchers designed an anti-miRNA molecule that could inhibit both.  This treatment was tested in monkeys, and showed a 40% increase in HDL levels, without any major side effects.  Researchers are now evaluating its safety in preparation for possible human clinical trials.

This research is not only significant as a cholesterol therapy, additionally it is the first time that a single anit-miRNA molecule has been used to induce a therapeutic effect in primates.  This lays the groundwork for future development of therapies targeting other families of miRNA.  The author of this report, Dr. Francis Collins, stated that “one thing is clear: miRNAs are powerful regulartory molecules and may open the door to new treatments for cardiovascular disease, as well as many other conditions.”