miR-155 Regulated Inflammation Response by the SOCS1-STAT3-PDCD4 Axis in Atherogenesis

Area of Science:

• Cardiovascular Biology
• Molecular Medicine
• Immunology

Background:

• Inflammation is central to atherosclerosis (AS) development and progression.
• MicroRNA-155 (miR-155) is implicated in macrophage-mediated inflammation, promoting AS plaque formation and rupture.
• The exact molecular mechanism of miR-155 in AS remains incompletely understood.

Purpose of the Study:

• To elucidate the precise mechanism by which miR-155 contributes to inflammation in atherosclerosis.
• To investigate the role of miR-155 in regulating key inflammatory mediators and signaling pathways in AS.
• To evaluate the therapeutic potential of targeting miR-155 in an AS model.

Main Methods:

• Quantification of miR-155, PDCD4, and SOCS1 expression in aortic tissues of atherosclerotic mice and ox-LDL treated RAW264.7 cells.
• Analysis of miR-155's direct inhibition of SOCS1 expression.
• Assessment of downstream effects on p-STAT, PDCD4, IL-6, and TNF-α levels.
• In vivo studies involving inhibition of miR-155 in atherosclerotic mice.

Main Results:

• miR-155 and PDCD4 were upregulated in atherosclerotic tissues and cells.
• miR-155 directly inhibited SOCS1, leading to increased p-STAT and PDCD4, and elevated IL-6 and TNF-α production.
• Downregulation of miR-155 and PDCD4, alongside SOCS1 upregulation, reduced pro-inflammatory cytokine expression.
• Inhibition of miR-155 in vivo decreased plasma and aortic IL-6 and TNF-α, with corresponding changes in SOCS1, p-STAT3, and PDCD4.

Conclusions:

• miR-155 mediates inflammation in atherosclerosis through the SOCS1-STAT3-PDCD4 axis.
• Targeting intracellular miR-155 presents a promising therapeutic strategy for anti-atherosclerotic interventions.