Using single-cell RNA sequencing, researchers reported successfully demonstrating the characteristics of Myeloid immune cells in coronary plaque, which causes acute coronary syndrome including conditions such as unstable angina and acute myocardial infarction. Based on this study “Single-Cell RNA Sequencing Reveals a Distinct Immune Landscape of Myeloid Cells in Coronary Culprit Plaques Causing AcuteCoronary Syndrome,” published in Circulation, the scientists hope to develop a treatment method that can stabilize coronary plaque.

This study was conducted by a research group from Kobe University Graduate School of Medicine’s Division of Cardiovascular Medicine in the Department of Internal Medicine, in collaboration with Hyogo Brain and Heart Center (one of Kobe University’s collaborative partners).

Single-cell RNA sequencing enables the gene expression of each individual cell to be comprehensively analyzed. This approach has been carried out on the plaque that causes carotid arteries to harden (arteriosclerosis), but no such studies have been conducted on carotid plaque due to its being difficult to obtain a sample.

The formation of artery-hardening plaque has been strongly linked to inflammation. However, two issues need further clarification—what kind of immune cells are found in the carotid plaque of an actual human being, and what characteristics do these cells have, and does carotid plaque act at the onset of acute coronary syndrome?

Research methodology

“Samples for this study were obtained by conducting directional coronary atherectomy procedures on consenting patients at Hyogo Brain and Heart Center between June 2021 and October 2022. Single-cell RNA sequencing was carried out on samples from four cases of chronic coronary syndrome and three cases of acute coronary syndrome,” according to the investigators.

“The results revealed the presence of the following myeloid cells in the plaque: macrophages (three types), monocytes, mast cells, and dendritic cell clusters. In addition, a comparison of the results for the chronic cases with those of acute cases revealed that more monocytes, mast cells, and inflammatory macrophages (the latter of which exhibited higher expression of CXCL3 and IL1B) accumulated in the coronary plaques in acute coronary syndrome cases.

Having revealed the distinct characteristics of myeloid immune cells in the coronary plaque of patients with acute coronary syndrome, the researchers aim to use this data to develop a therapy that can stabilize coronary plaque.