Low density lipoproteins interact with acidic fibroblast growth factor and modify its function.

Area of Science:

• Cardiovascular Biology
• Atherosclerosis Research
• Molecular Medicine

Background:

• Oxidized low-density lipoprotein (oxLDL) is a key component in atherosclerotic lesions.
• Acidic fibroblast growth factor (FGF-1) release is triggered by oxLDL.
• Simultaneous presence of oxLDL and FGF-1 in atherosclerotic lesions suggests potential interaction.

Purpose of the Study:

• To investigate the interaction between oxLDL and FGF-1.
• To determine if this interaction affects FGF-1 functionality.
• To elucidate the role of this interaction in atherogenesis.

Main Methods:

• Molecular sieve assays to detect complex formation.
• Electrophoretic mobility shift assays (EMSA) to confirm binding.
• Immunohistochemistry to localize FGF-1 and oxLDL in human atherosclerotic lesions.
• Assessment of cell proliferation (PCNA) in relation to oxLDL deposition patterns.

Main Results:

• FGF-1 forms a complex with oxLDL in vitro, with low affinity for native LDL.
• The FGF-1/oxLDL complex exhibits significantly reduced heparin-binding ability and is nonmitogenic to smooth muscle cells.
• FGF-1 immunoreactivity is highest in macrophages within atherosclerotic lesions.
• Mitogenic activity of FGF-1 is confined to regions with intracellular oxLDL and inhibited in areas with extracellular oxLDL deposition.

Conclusions:

• Oxidized LDL (oxLDL) interacts with acidic fibroblast growth factor (FGF-1), forming a complex.
• This complex formation inhibits the growth-promoting function of FGF-1.
• OxLDL may exert pathogenicity during atherogenesis by complexing and inactivating FGF-1.