MicroRNA-141 regulates the expression level of ICAM-1 on endothelium to decrease myocardial ischemia-reperfusion...

Area of Science:

• Molecular Biology
• Cardiovascular Research
• MicroRNA Therapeutics

Background:

• MicroRNAs (miRNAs) are implicated in myocardial ischemia-reperfusion (MI/R) injury.
• The specific roles of miRNAs targeting endothelial cells (ECs) and their interaction with ICAM-1 in MI/R are not well understood.

Purpose of the Study:

• To investigate the role of endogenous miRNAs, particularly miR-141, in endothelial cells during MI/R injury.
• To identify novel targets of miR-141 and elucidate its mechanism in modulating ICAM-1 expression and subsequent inflammatory responses.

Main Methods:

• Microarray analysis and real-time PCR to identify differentially expressed miRNAs in ECs.
• Bioinformatic analysis (Target Scan) and reporter gene assays to confirm ICAM-1 as a miR-141 target.
• In vitro assays assessing leukocyte adhesion to ECs and in vivo murine MI/R models with miR-141 mimic treatment.

Main Results:

• miR-141 was significantly downregulated in ECs challenged with TNF-α.
• miR-141 directly targets and inhibits ICAM-1 expression, reducing leukocyte adhesion to ECs in vitro.
• In vivo, miR-141 mimic pretreatment attenuated MI/R injury, decreasing infarct size and cardiac enzyme levels, associated with reduced inflammatory cell infiltration.

Conclusions:

• miR-141 acts as a novel repressor of ICAM-1, playing a protective role in MI/R injury.
• The cardioprotective effects of miR-141 involve the downregulation of ICAM-1 and reduced inflammatory cell infiltration.
• miR-141 represents a promising therapeutic target for treating ischemic heart disease.