Quantification of apo[a] and apoB in human atherosclerotic lesions.

      This paper is only available as a PDF. To read, Please Download here.
      Lipoprotein[a] or Lp[a] is a cholesterol-rich plasma lipoprotein that is associated with increased risk for cardiovascular disease. To better understand this association we determined the amount of apo[a] and apoB as possible estimates for Lp[a] and low density lipoprotein (LDL) accumulation in atherosclerotic lesions and in plasma, from patients undergoing vascular surgery, using specific radioimmunoassays for apolipoprotein[a] and apolipoprotein B. Apo[a] and apoB were operationally divided into a loosely bound fraction obtained by extracting minced samples of plaque with phosphate-buffered saline (PBS), and a tightly bound fraction obtained by extracting the residual tissue with 6 M guanidine-HCl (GuHCl). We found that 83% of all apo[a] but only 32% of all apoB in lesions was in the tightly bound fraction. When normalized for corresponding plasma levels, apo[a] accumulation in plaques was more than twice that of apoB. All fractions of tissue apo[a], loosely bound, tightly bound, and total, correlated significantly with plasma apo[a]. However, no significant correlations were found between any of the tissue fractions and plasma apoB. If all apo[a] and apoB had been associated with intact Lp[a] or LDL particles, the calculated mass of tightly bound Lp[a] would actually have exceeded that of tightly bound LDL in five cases with plasma Lp[a] levels above 5 mg apo[a] protein/dl. When PBS and GuHCl extracts of lesions were subjected to one-dimensional electrophoresis, the major band stained for lipid and immunoblotted positively for apo[a] and apoB, suggesting the presence of some intact Lp[a] in these extracts. These results suggest that Lp[a] accumulates preferentially to LDL in plaques, and that plaque apo[a] is directly associated with plasma apo[a] levels and is in a form that is less easily removable than most of the apoB. This preferential accumulation of apo[a] as a tightly bound fraction in lesions, could be responsible for the independent association of Lp[a] with cardiovascular disease in humans.


        • Utermann G
        The mysteries of lipoprotein [a].
        Science. 1989; 246: 904-910
        • Fless G.M.
        • ZumMallen M.E.
        • Scanu A.M.
        Physiochemical properties of apolipoprotein [a] and lipoprotein[a-] derived from the dissociation of human plasma lipoprotein[a].
        J. Biol. Chem. 1986; 261: 8712-8718
        • Gaubatz J.W.
        • Heideman C.
        • Gotto A.M.
        • Morrisett J.D.
        • Dahlen G.H.
        Human plasma lipoprotein[a]. Structural properties.
        J. Biol. Chem. 1983; 258: 4582-4589
        • Armstrong V.W.
        • Cremer P.
        • Eberle E.
        • Manke A.
        • Schulze F.
        • Wieland H.
        • Kreuzer H.
        • Seidel D.
        The association between serum Lp[a] concentrations and angio-graphically assessed coronary atherosclerosis. Dependence on serum LDL levels.
        Atherosclerosis. 1986; 62: 249-257
        • Dahlen G.H.
        • Guyton J.R.
        • Attar M.
        • Farmer J.A.
        • Kautz J.A.
        • Gotto A.M.
        Association of levels of lipoprotein Lp[a], plasma lipids, and other lipoproteins with coronary artery disease documented by angiography.
        Circulation. 1986; 74: 758-765
        • Koltringer P.
        • Jurgens G.
        A dominant role of lipoprotein[a] in the investigation and evaluation of parameters indicating the development of cervical atherosclerosis.
        Atherosclerosis. 1985; 58: 187-198
        • Murai A.
        • Miyahar T.
        • Fujimoto N.
        • Matsuda M.
        • Kameyama M.
        Lp[a] lipoprotein as a risk factor for coronary heart disease and cerebral infarction.
        Atherosclerosis. 1986; 59: 199-204
        • Hoff H.E.
        • Beck G.J.
        • Skibinski C.I.
        • Jürgens G.
        • O'Neil J.A.
        • Kramer J.
        • Lytic B.
        Serum Lp[a] levels as a predictor of vein graft stenosis after coronary artery bypass surgery in patients.
        Circulation. 1988; 77: 1238-1244
        • Fless G.M.
        • Rolih C.A.
        • Scanu A.M.
        Heterogeneity of human plasma lipoprotein[a]. Isolation and characterization of the lipoprotein subspecies and their apoproteins.
        J. Biol. Chem. 1984; 254: 11470-11478
        • Enholm C.
        • Garoff H.
        • Renkonen O.
        • Simons K.
        Protein and carbohydrate composition of Lp[a] lipoprotein from human plasma.
        Biochemistry. 1972; 11: 3229-3232
        • Utermann G.
        • Menzel H.J.
        • Kraft H.G.
        • Duba H.C.
        • Kemmler H.G.
        • Seitz C.
        Lp[a] glycoprotein phenotypes.
        J. Clin. Invest. 1987; 80: 458-465
        • Gaubatz J.W.
        • Chari M.V.
        • Nava M.L.
        • Guyton J.R.
        • Morrisett J.D.
        Isolation and characterization of the two major apoproteins in human lipoprotein[a].
        J. Lipid Res. 1987; 28: 69-79
        • Hoff H.F.
        • Heideman C.L.
        • Gaubatz J.W.
        • Scott D.W.
        • Gotto A.M.
        Detergent extraction of tightly bound apoB from extracts of normal aortic intima and plaques.
        Exp. Mol. Pathol. 1978; 28: 290-300
        • Jurgens G.
        • Marth E.
        • Kostner G.M.
        • Holasek A.
        Investigation of the Lp[a] lipoprotein: lipoprotein aggregation and enzymatic activity associated with the Lp[a] polypeptide.
        Artery. 1977; 3: 13-26
        • Hoff H.F.
        • Clevidence B.A.
        Uptake by mouse peritoneal macrophages of large cholesteryl ester-rich particles isolated from human atherosclerotic lesions.
        Exp. Mol. Pathol. 1987; 46: 331-344
        • Hatch F.T.
        • Lees R.S.
        Practical method for plasma lipoprotein analysis.
        Adv. Lipid Res. 1968; 6: 2-63
        • McLean J.W.
        • Tomlinson S.E.
        • Kuang W.J.
        • Eaton D.L.
        • Chen E.Y.
        • Fless G.M.
        • Scanu A.M.
        • Lawn R.M.
        cDNA sequence of human apolipoprotein[a] is homologous to plasminogen.
        Nature. 1987; 330: 132-137
        • Feldkamp C.S.
        • Smith S.W.
        Practical guide to immunoassay method evaluation.
        in: Chan D.W. Perlstein M.T. Immunoassay - A Practical Guide. Academic Press, SanDiego, CA1987: 73-75
        • Rath M.
        • Niendorf A.
        • Reblin T.
        • Dietel M.
        • Krebber H.J.
        • Beisiegel U.
        Detection and quantification of lipoprotein[a] in the arterial wall of 107 coronary bypass patients.
        Arteriosclerosis. 1989; 9: 579-592
        • Smith P.K.
        • Krohn R.I.
        • Hermanson G.T.
        • Mallia A.K.
        • Gartner F.H.
        • Provenzano M.D.
        • Fujimoto E.K.
        • Goeke N.M.
        • Olson B.J.
        • Klenk D.C.
        Measurement of protein using bicinchoninic acid.
        Anal. Biochem. 1985; 150: 76-85
        • Lowry O.H.
        • Rosebrough N.J.
        • Farr A.L.
        • Randall R.J.
        Protein measurement with the Folin phenol reagent.
        J. Biol. Chem. 1951; 193: 265-275
        • Bilheimer D.W.
        • Eisenberg S.
        • Levy R.I.
        The metabolism of very low density lipoprotein proteins. I. Preliminary in vitro and in vivo observations.
        Biochim. Biophys. Acta. 1972; 260: 212-221
        • McFarlane A.S.
        Efficient trace-labeling of proteins with iodine.
        Nature. 1958; 182: 53-57
        • Cushing G.L.
        • Gaubatz J.W.
        • Nava M.L.
        • Burdick B.J.
        • Bocan T.M.A.
        • Guyton J.R.
        • Weilbaecher D.
        • DeBakey M.E.
        • Lawrie G.M.
        • Morrisett J.D.
        Quantitation and localization of apolipoproteins [a] and B in coronary artery bypass vein grafts resected at re-operation.
        Arteriosclerosis. 1989; 9: 593-603
        • Hoff H.F.
        • Yamauchi Y.
        • Bond M.G.
        Reduction in tissue LDL accumulation during coronary artery regression in cynomolgus macaques.
        Atherosclerosis. 1985; 56: 51-60
        • Yamauchi Y.
        • Hoff H.F.
        Apolipoprotein B accumulation and development of foam cell lesions in coronary arteries of hypercholesterolemic swine.
        Lab. Invest. 1984; 51: 325-332
        • Hoff H.E.
        • Gerrity R.G.
        • Naito H.K.
        • Dusek D.M.
        Quantitation of apolipoprotein B in aortas of hypercholesterolemic swine.
        Lab. Invest. 1983; 48: 492-504
        • Hoff H.F.
        • Gaubatz J.W.
        Residual apoB in aortic plaques extracted with hydrolytic enzymes.
        Artery. 1979; 6: 89-107
        • Hoff H.F.
        • Heideman C.L.
        • Gaubatz J.W.
        • Gotto A.M.
        • Erickson E.E.
        • Jackson R.L.
        Quantification of apoB in grossly normal human aorta.
        Circ. Res. 1977; 40: 56-63
        • Hoff H.F.
        • Heideman C.L.
        • Gaubatz J.W.
        • Titus J.L.
        • Gotto A.M.
        Quantitation of apoB in human aortic fatty streaks.
        Atherosclerosis. 1978; 30: 263-272
        • Armstrong V.W.
        • Walli A.K.
        • Seidel D.
        Isolation, characterization, and uptake in human fibroblasts of an apo[a]-free lipoprotein obtained on reduction of lipoprotein[a].
        J. Lipid Res. 1985; 26: 1314-1323
        • Kostner G.M.
        • Gavish D.
        • Leopold B.
        • Bolzano K.
        • Weintraub M.S.
        • Breslow J.L.
        HMG-CoA reductase inhibitors lower LDL cholesterol without reducing Lp[a] levels.
        Circulation. 1988; 80: 1313-1319
        • Bihari-Varga M.
        • Gruber E.
        • Rotheneder M.
        • Zechner R.
        • Kostner G.M.
        Interaction of lipoprotein[a] (Lp[a]) and low density lipoprotein with gly-cosaminoglycans from human aorta.
        Arteriosclerosis. 1988; 8: 851-857
        • Dahlen G.H.
        • Ericson C.
        • Berg K.
        In vitro studies of the interaction of isolated Lp[a] lipoprotein and other serum lipoproteins with glycosaminoglycans.
        Clin. Genet. 1978; 14: 36-42
        • Dahlen G.
        • Ericson C.
        • Berg K.
        In vitro studies of the interaction of calcium ions and other divalent cations with the Lp[a] lipoprotein and other isolated serum lipoproteins.
        Clin. Genet. 1978; 14: 115-124
        • McGill Jr, H.C.
        Fatty streaks in the coronary arteries and aorta.
        Lab. Invest. 1968; 18: 560-564
        • Loscalzo J.
        • Weinfeld M.
        • Fless G.M.
        • Scanu A.M.
        Lipoprotein[a], fibrin binding and plasminogen activation.
        Arteriosclerosis. 1990; 10: 240-245
        • Harpel P.C.
        • Gordon B.R.
        • Parker T.S.
        Plasmin catalyzes binding of lipoprotein[a] to immobilized fibrinogen and fibrin.
        Proc. Natl. Acad. Sci. USA. 1989; 86: 3847-3851
        • Gonzalez-Gronow J.
        • Edelberg J.M.
        • Pizzo S.V.
        Further characterization of the cellular plasminogen binding site: evidence that plasminogen 2 and lipoprotein[a] compete for the same site.
        Biochemistry. 1989; 28: 2374-2377