Malondialdehyde-modified low-density lipoprotein (MDA-modified LDL)

Malondialdehyde-modified low-density lipoprotein is a pathologically modified form of LDL that plays a central role in atherosclerosis development. Malondialdehyde (MDA) is generated during lipid peroxidation in oxidized LDL and forms covalent adducts with lysine residues in the apolipoprotein B component of LDL. The degree of modification determines receptor recognition: when less than 15% of lysine residues are modified, the lipoprotein is recognized by normal LDL receptors, but further modification results in recognition by scavenger receptors on macrophages. This scavenger receptor-mediated uptake leads to foam cell formation, a hallmark of atherosclerotic lesions. MDA-modified LDL is highly immunogenic, eliciting antibody responses including IgM, IgG, IgG1, and IgG2 anti-MDA antibodies. These antibodies have emerged as important biomarkers for cardiovascular disease, with high levels of certain isotypes (particularly IgG1 and IgM) associated with protection against CVD, especially in men. MDA itself can promote further LDL oxidation, creating a cycle of oxidative damage. The molecule forms stable compounds such as dihydropyridine with lysine, which are believed to contribute to atherosclerosis and chronic inflammatory conditions. MDA-modified LDL functions as a danger-associated molecular pattern (DAMP), triggering immune responses that contribute to vascular inflammation and disease progression.

Other names

MDA-modified LDLMDA-LDLMalondialdehyde-modified low density lipoproteinMalondialdehyde-modified lipoproteinsMDA-modified lipoproteins

Not applicable as a drug target; however, the molecule itself acts through: Recognition by scavenger receptors when more than 15% of lysine residues are modified; Recognition by LDL receptors when less than 15% of lysine residues are modified; Uptake by macrophages via scavenger receptor-mediated endocytosis; Formation of covalent protein adducts that are immunogenic.