Coronary artery disease develops when plaque builds up in arteries, reducing blood flow to the heart. Credit: 7activestudio / iStock / Getty Images Plus

Low serum level of a class of small non-coding RNAs or microRNAs is strongly linked to the risk of coronary artery disease (CAD)1.

To test if certain miRNAs could be used as markers for CAD in an Indian cohort, researchers at the CSIR-Institute of Genomics and Integrative Biology and All India Institute of Medical Sciences in Delhi looked at the expression level of miR-128-3p and miR-195-5p. They looked at 124 cases, including CAD patients and control subjects.

Extensive literature review pointed to validated targets of miR-128-3p and miR-195-5p with a possible role in the disease. The researchers then ran a quantitative Real Time-Polymerase Chain Reaction, a molecular biology technique for amplifying circulating miRNAs.

Levels of miR-195-5p did not show a marked change, but miR-128-3p was significantly decreased in the CAD patients. ROC curve analysis revealed that miR-128-3p distinguishes CAD patients from controls with 66% accuracy.

The researchers demonstrated that miR-128-3p increases cholesterol levels in macrophages, a type of white blood cell, by preventing cholesterol from getting out. This change disrupts the normal cholesterol balance in the cells, forming foam cells which speeds up CAD progression. The microRNA could be a non-invasive and precise marker for CAD.