CD14⁺-Monocytes Exposed to Apolipoprotein CIII Express Tissue Factor

Area of Science:

• Cardiovascular Biology
• Lipid Metabolism
• Immunology

Background:

• Apolipoprotein CIII (ApoCIII) is a critical regulator of plasma lipid metabolism and a risk factor for cardiovascular diseases.
• ApoCIII contributes to endothelial dysfunction and monocyte recruitment in atherothrombosis.

Purpose of the Study:

• To investigate whether ApoCIII induces tissue factor (TF) expression in monocytes.
• To explore the role of ApoCIII in monocyte activation and its link to atherothrombosis.

Main Methods:

• Human CD14+ monocytes and neutrophils were incubated with purified ApoCIII and human sera.
• Gene expression (RT-qPCR) and protein production (ELISA) of inflammatory cytokines and TF were measured.
• TF surface expression on monocytes was analyzed by flow cytometry.
• The effect of ApoCIII-neutralizing antibodies on TF expression was assessed.

Main Results:

• ApoCIII exposure significantly increased mRNA and protein levels of TNFα, IL-1β, IL-6, and TF in CD14+ monocytes, but not neutrophils.
• Monocytes rapidly expressed cell-surface TF upon incubation with ApoCIII or ApoCIII-containing sera.
• ApoCIII-neutralizing antibodies partially inhibited TF upregulation and cytokine release in monocytes.

Conclusions:

• Apolipoprotein CIII activates human CD14+ monocytes to express tissue factor.
• This mechanism connects circulating apolipoproteins to inflammation and atherothrombosis, highlighting a novel pathway in cardiovascular risk.