MicroRNAs have attracted interest as potential blood biomarkers for various cardiovascular diseases, but researchers haven’t quite figured out how they avoid destruction while in the bloodstream. Sort of like tiny outlaws on the run, while traveling the circulatory super-highway miRNAs must nimbly evade the RNAases that might catch them in order to reach their destination safely. New research reveals that certain vesicles that pinch off of cells, called microparticles, shield the miRNAs and help them reach their target cells.
The new paper from Karlheinz Peter and colleagues at the Baker IDI Heart & Diabetes Institute in Australia determined that blood miRNAs were predominantly packaged in microparticles in conventional plasma preparations. They then applied next generation sequencing to study a wide range of miRNAs in microparticles derived either from human umbilical vein endothelial cells or a type of leukemia cell line. The microparticle miRNA profiles differed from those in the original cells.
The Peter group also ran qRT-PCR on miRNAs associated with cardiovascular diseases and discovered differences in their profiles between platelets and the corresponding microparticles.
In samples taken from patients with stable and unstable coronary artery disease, the miRNA profiles were also different between the two disease types. From their results, the investigators concluded that:
- Microparticles act as vehicles for microRNAs associated with cardiovascular diseases.
- Because the microparticle microRNA profiles differed from that found in the original cells, there probably is mechanism that selectively packages certain microRNAs into microparticles from cells.
- Microparticles may serve as a way for the cells releasing miRNAs in order to manipulate the gene expression of other cells.
Get on the road to the full article at Cardiovascular Research, January 2012.