Doxorubicin inhibits cholesterol efflux through the miR-33/ABCA1 pathway

Area of Science:

• Cardiovascular Biology
• Molecular Oncology
• Pharmacology

Background:

• Doxorubicin (DOX) is a widely used chemotherapy agent with known cardiovascular toxicity.
• The mechanism by which DOX contributes to cardiac dysfunction, specifically through atherosclerosis, remains unclear.

Purpose of the Study:

• To investigate the role of Doxorubicin (DOX) in regulating lipid deposition within macrophages.
• To elucidate the molecular mechanisms underlying DOX-induced changes in macrophage lipid metabolism.

Main Methods:

• Utilized the RAW 264.7 macrophage cell line, stimulating with DOX and low-density lipoprotein (LDL).
• Assessed changes in miR-33 expression, ATP binding cassette transporter A1 (ABCA1) protein levels, and cholesterol efflux.
• Employed miR-33 mimics and inhibitors to confirm the role of miR-33 in regulating ABCA1 and lipid accumulation.

Main Results:

• DOX treatment led to increased miR-33 levels and decreased ABCA1 protein expression in macrophages.
• DOX suppressed cholesterol efflux, an effect exacerbated under high-cholesterol conditions.
• Modulation of miR-33 levels directly impacted ABCA1 expression and intracellular lipid accumulation.

Conclusions:

• Doxorubicin (DOX) promotes intracellular lipid deposition in macrophages by upregulating miR-33, consequently suppressing ABCA1 protein expression and cholesterol efflux.
• These findings suggest DOX contributes to early atherosclerosis, providing insights for clinical monitoring of its cardiovascular side effects.