Expression level of miR-155 in peripheral blood

Area of Science:

• Cardiovascular Biology
• Molecular Medicine
• Atherosclerosis Research

Background:

• Coronary heart disease (CHD) involves complex molecular mechanisms.
• MicroRNAs (miRNAs) are implicated in cardiovascular disease pathogenesis.
• The role of miR-155 in atherosclerosis requires further elucidation.

Purpose of the Study:

• To investigate the association between miR-155 expression levels and coronary lesion severity.
• To explore the underlying mechanism of miR-155 in the context of atherosclerosis.

Main Methods:

• Isolation of peripheral blood mononuclear cells (PBMCs) from patients with varying CHD statuses (AMI, UAP, SAP, CPS).
• Quantitative reverse transcription polymerase chain reaction (RT-PCR) to measure miR-155 expression in PBMCs, plasma, and RAW264.7 macrophages.
• MTT assay to assess the viability of OxLDL-treated RAW264.7 macrophages.

Main Results:

• miR-155 expression was significantly lower in CHD patients compared to non-CHD individuals.
• miR-155 levels were elevated in PBMCs and plasma of the chest pain syndrome (CPS) group.
• Oxidized low-density lipoprotein (OxLDL) induced miR-155 expression in macrophages, reducing their viability, but high miR-155 expression conferred protection against OxLDL-induced apoptosis.

Conclusions:

• miR-155 demonstrates a protective role in atherosclerosis progression.
• This protective effect may be mediated by reducing OxLDL-induced apoptosis in macrophages.