Mechanisms and consequences of efferocytosis in advanced atherosclerosis

Area of Science:

• Cardiovascular Biology
• Immunology
• Pathology

Background:

• Macrophages undergo apoptosis during atherosclerotic lesion development, typically preventing necrosis.
• In advanced lesions, apoptotic macrophages undergo secondary necrosis, forming the necrotic core of vulnerable plaques.
• Necrotic core formation promotes plaque disruption and acute atherothrombotic vascular disease.

Purpose of the Study:

• To understand the cellular and molecular mechanisms of efferocytosis in atherosclerosis.
• To elucidate why efferocytosis becomes defective in advanced atherosclerotic lesions.
• To identify potential therapeutic targets for atherothrombotic vascular disease.

Main Methods:

• Utilized molecular-genetic causation studies in mouse models of advanced atherosclerosis.
• Investigated the roles of key molecules involved in efferocytosis, including TG2, MFG-E8, complement C1q, Mertk, lysoPC, and Fas.
• Examined the clearance of apoptotic cells within advanced atherosclerotic plaques.

Main Results:

• Several molecules (TG2, MFG-E8, C1q, Mertk, lysoPC, Fas) are crucial for apoptotic cell clearance in advanced plaques.
• Evidence suggests defective efferocytosis contributes to secondary macrophage necrosis.
• Defective efferocytosis is linked to the formation of the necrotic core in vulnerable plaques.

Conclusions:

• Understanding defective efferocytosis mechanisms is critical for addressing atherothrombotic vascular disease.
• Insights into molecular mechanisms may lead to novel therapeutic strategies.
• Targeting efferocytosis pathways could offer new treatments for the leading cause of death globally.