Macrophage phenotypes and their modulation in atherosclerosis.

Area of Science:

• Cardiovascular biology
• Immunology
• Cell biology

Background:

• Atherosclerosis involves chronic arterial wall inflammation driven by lipid-laden macrophages.
• Macrophages, key in tissue homeostasis and inflammation, exist on a spectrum from M1 (pro-inflammatory) to M2 (anti-inflammatory) phenotypes.
• M2 macrophages display subtypes (M2a-d) with distinct markers and functions.

Purpose of the Study:

• To provide an overview of macrophage phenotype complexity in cardiovascular diseases, specifically atherosclerosis.
• To highlight the plasticity of macrophages within atherosclerotic lesions.
• To discuss the various subpopulations and their modulators.

Main Methods:

• Literature review of macrophage phenotypes in atherosclerosis.
• Analysis of factors influencing macrophage polarization.
• Synthesis of current understanding on macrophage plasticity in cardiovascular disease.

Main Results:

• Macrophages in atherosclerotic lesions exhibit plasticity, forming subpopulations like Mox, Mhem, M(Hb), and M4.
• Numerous factors modulate the balance between M1 and M2 macrophage phenotypes.
• These modulators include lesion characteristics, miRNAs, transcription factors (PPARγ, KLF4, NR4A), lipoproteins, and signaling pathways (mTOR1).

Conclusions:

• Macrophage phenotype diversity is a critical factor in atherosclerosis.
• Understanding macrophage plasticity is essential for unraveling cardiovascular disease mechanisms.
• Further research into these complex subpopulations may offer therapeutic insights.