Role of complement activation in atherosclerosis

Area of Science:

• Immunology
• Cardiovascular Research
• Inflammation Biology

Background:

• Atherosclerosis involves significant inflammation within the arterial intima.
• The complement system is a critical component of the innate immune system implicated in inflammatory processes.

Purpose of the Study:

• To review recent advancements in understanding the complement system's role in atherogenesis.
• To explore the connection between complement activation and the development of atherosclerotic lesions.

Main Methods:

• Review of current literature on complement system activation in atherosclerosis.
• Analysis of findings from human atherosclerotic lesions.
• Evaluation of experimental data from genetically engineered hyperlipidemic mouse models.

Main Results:

• The complement system is demonstrably activated in human atherosclerotic lesions.
• Triggers include immunocomplexes, C-reactive protein, modified lipoproteins, apoptotic cells, and cholesterol crystals.
• Anaphylatoxin receptors are present in human lesions, but mouse models show limited complement involvement in experimental atherogenesis.

Conclusions:

• Human studies provide substantial circumstantial evidence linking complement to atherosclerosis.
• Recent findings in hyperlipidemic mouse models present a contrasting view, indicating a modest or negative role for complement in experimental atherogenesis.