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MiR-146a inhibits oxidized low-density lipoprotein-induced lipid accumulation and inflammatory response via targeting

Ke Yang1, Yu Song He, Xiao Qun Wang

  • 1Department of Cardiology, Rui Jin Hospital, Jiaotong University School of Medicine, Shanghai 200025, People's Republic of China.

FEBS Letters
|February 19, 2011
PubMed

Insights

MicroRNA-146a (miR-146a) plays a key role in atherosclerosis by reducing oxidized low-density lipoprotein (oxLDL) accumulation and inflammation. Its upregulation may offer a therapeutic strategy for preventing and treating this cardiovascular disease.

Area of Science:

  • Cardiovascular Biology
  • Molecular Medicine
  • Immunology

Background:

  • Atherosclerosis is characterized by chronic inflammation driven by oxidized low-density lipoprotein (oxLDL) accumulation in macrophages.
  • MicroRNAs (miRNAs) are emerging as critical regulators of cellular processes involved in atherosclerosis.

Purpose of the Study:

  • To investigate the role of miR-146a in regulating oxLDL accumulation and inflammatory responses within macrophages.
  • To identify the molecular targets and signaling pathways modulated by miR-146a in the context of atherosclerosis.

Main Methods:

  • Assessed miR-146a expression levels in macrophages stimulated with oxLDL.
  • Quantified the effects of miR-146a modulation on intracellular LDL cholesterol content and inflammatory cytokine secretion (IL-6, IL-8, CCL2, MMP-9).
  • Investigated the interaction between miR-146a and Toll-like receptor 4 (TLR4) signaling pathways.

Main Results:

  • miR-146a expression was significantly downregulated upon oxLDL stimulation.
  • Overexpression of miR-146a markedly reduced intracellular LDL cholesterol and the secretion of key inflammatory mediators.
  • miR-146a directly targets TLR4, inhibiting TLR4-dependent signaling pathways crucial for lipid uptake and inflammation.

Conclusions:

  • miR-146a acts as a negative regulator of both oxLDL accumulation and inflammatory responses in macrophages by targeting TLR4.
  • Modulating miR-146a expression, particularly through overexpression, holds potential therapeutic value for atherosclerosis prevention and treatment.

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