How do macrophages contribute to plaque formation?

Macrophages play a crucial role in the development of atherosclerosis, particularly in plaque formation. In the context of atherosclerotic lesions, macrophages are classified as pro-inflammatory cells. They infiltrate the arterial walls, particularly within areas where low-density lipoproteins (LDL) accumulate. Upon entering these regions, macrophages engulf LDL particles through a process known as phagocytosis.

Once activated, these macrophages release a variety of pro-inflammatory cytokines and chemokines. This release perpetuates an inflammatory response, further attracting other immune cells and contributing to the overall progression of the atherosclerotic plaque. Over time, this leads to the formation of a necrotic core within the plaque, as the accumulated lipids and cellular debris are not efficiently cleared away due to ongoing inflammation.

This cycle of inflammation initiated by macrophages creates an environment conducive to plaque growth. Their presence signifies an ongoing inflammatory process, which is one of the hallmarks of atherosclerosis, impacting the stability and structure of the plaque and ultimately influencing cardiovascular risk. Understanding this role underscores the significance of macrophages in the pathophysiology of atherosclerosis.