Do elevated ApoB-containing lipoproteins promote atherosclerotic vascular inflammation?

Atherogenesis is fundamentally driven by the physical entry and entrapment of circulating apolipoprotein B (ApoB)-containing lipoproteins within the arterial wall, initiating a complex inflammatory cascade that underpins cardiovascular disease.

Subendothelial retention and oxidative modification

• ApoB-containing lipoproteins, including low-density lipoprotein (LDL) and lipoprotein(a) [Lp(a)], cross the endothelium and bind to extracellular matrix proteoglycans in the arterial intima.
• This subendothelial retention traps the particles in an enzymatically active, highly pro-oxidant environment, rendering them highly susceptible to lipid peroxidation.
• The trapped particles undergo oxidative modification to form minimally modified (mmLDL) and fully oxidized (oxLDL) species, a transition directly driven by high circulating particle concentrations (ApoB or LDL-P).

Endothelial immune activation and monocyte recruitment

• The accumulation of modified lipoproteins and the oxidized phospholipid cargo of Lp(a) activate endothelial cells via NF-kB signaling pathways, even prior to major inflammatory cell infiltration.
• Activated endothelial cells upregulate key cell adhesion molecules (including VCAM-1, ICAM-1, and selectins) and secrete chemotactic cytokines (such as MCP-1, IL-6, and IL-8).
• These molecular signals coordinate the recruitment, rolling, and firm adhesion of circulating monocytes to the vascular wall.
• Upon transmigrating into the intima, these monocytes differentiate into macrophages, engulf oxidized lipoproteins via scavenger receptors, and transform into foam cells, driving chronic vascular inflammation and plaque progression.

Bottom line

• Elevated concentrations of ApoB-containing lipoproteins promote subendothelial retention and oxidative modification, directly triggering the endothelial immune activation and monocyte recruitment that initiate and perpetuate atherosclerotic vascular inflammation.