PAF-acether-degrading acetylhydrolase in plasma LDL is inactivated by copper- and cell-mediated oxidation.

Dentan, Christine; Lesnik, Philippe; Chapman, M. John; Ninio, Ewa

doi:10.1161/01.atv.14.3.353

Cited by 49 publications

(28 citation statements)

References 46 publications

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“…The possibility that the above phenomenon may be attributable to any influence of plasma factors on the Lp-PLA 2 mass assay can be excluded because we obtained similar results when we measured the enzyme mass either in total plasma or in lipoprotein subfractions completely separated from the other plasma components. Another possibility could be the well-known increased susceptibility of sdLDL to oxidation (33 ) because, according to data published previously by our group and others, during lipoprotein oxidation the enzyme activity is significantly reduced (34,35 ). We found no evidence of oxidation in any lipoprotein subfraction, however.…”

Section: Discussionsupporting

confidence: 58%

Lipoprotein-Associated Phospholipase A2 Activity Is a Marker of Small, Dense LDL Particles in Human Plasma

Gazi¹,

Lourida

Filippatos³

et al. 2005

Clinical Chemistry

159

101

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Background:Recent clinical studies showed that lipoprotein-associated phospholipase A 2 (Lp-PLA 2 ) is a predictor for incident atherosclerotic disease. We have previously shown that among the LDL subfractions, Lp-PLA 2 activity is preferentially associated with the atherogenic small, dense (sdLDL) particles in vitro. We investigated whether Lp-PLA 2 could be a marker of sdLDL in human plasma. Methods: One hundred and seventy-six individuals participated in the study. LDL subclass analysis was performed by polyacrylamide gel electrophoresis. Lp-PLA 2 activity and mass were determined in total plasma and in apolipoprotein B-depleted plasma (HDL-Lp-PLA 2 ). Non-HDL-Lp-PLA 2 activity and mass were calculated by subtracting the HDL-Lp-PLA 2 from total plasma Lp-PLA 2 . Results: On the basis of the LDL subclass analysis, participants were categorized into phenotype A and non-A (total cholesterol mass of the sdLDL subfractions <0.155 and >0.155 mmol/L, respectively). Unlike total plasma Lp-PLA 2 mass, total plasma Lp-PLA 2 activity and non-HDL-Lp-PLA 2 activity and mass were significantly higher in persons with phenotype non-A compared with persons with phenotype A, whereas HDLLp-PLA 2 activity and mass were lower in persons with phenotype non-A compared with phenotype A. Total plasma activity and non-HDL-Lp-PLA 2 activity and mass, but not Lp-PLA 2 mass, were correlated with sdLDL-cholesterol mass, proportion, and mean LDL

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Section: Discussionsupporting

confidence: 58%

Lipoprotein-Associated Phospholipase A2 Activity Is a Marker of Small, Dense LDL Particles in Human Plasma

Gazi¹,

Lourida

Filippatos³

et al. 2005

Clinical Chemistry

159

101

View full text Add to dashboard Cite

show abstract

“…The increase in biological activity of oxidatively modified DFP * LDL we observe may be attributable to an increase in the amount of biologically active phospholipids, due to the loss of the initial hydrolytic activity provided by LDL-associated PAF-AH. It has previously been shown that oxidation depletes LDL of PAF hydrolytic activity (24,48,49).…”

Section: Discussionmentioning

confidence: 99%

Effect of platelet activating factor-acetylhydrolase on the formation and action of minimally oxidized low density lipoprotein.

Watson¹,

Navab²,

Hama³

et al. 1995

J. Clin. Invest.

383

242

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Mildly oxidized low density lipoprotein (MM-LDL) HPLC analysis also revealed that the active oxidized phospholipid species in MM-LDL had been destroyed after PAF-AH treatment. In addition, treatment of MM-LDL with albumin removed polar phospholipids that, when reisolated, induced monocyte binding to endothelial cells. These polar phospholipids, when treated with PAF-AH, lost biological activity and were no longer detected by HPLC. These results suggest that PAF-AH in HDL protects against the production and activity of MM-LDL by facilitating hydrolysis of active oxidized phospholipids to lysolipids, thereby destroying the biologically active lipids in MM-LDL. (J. Clin. Invest. 1995. 95:774-782)

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“…(2) The lipid peroxidation products transferred from oxidized LDL may directly inactivate the PAF-AH activity in HDL 2 . Dentan and colleagues 40 have demonstrated that 4-hydroxynonenal generated during LDL oxidation may inhibit PAF-AH activity, either by a direct modification of amino acid side chains in PAF-AH or by a modification of the phospholipid environment of the enzyme at the surface of the lipoprotein particle. In conclusion, our study demonstrates that HDL 2 from subjects with poorly controlled NIDDM, in both fasting and postprandial states, exhibits decreased protection against macrophage-mediated LDL oxidation, and this may contribute to accelerated atherosclerosis in type 2 diabetes.…”

Section: Gowri Et Al Decreased Protective Function Of Hdl In Niddm 2231mentioning

confidence: 99%

Decreased Protection by HDL From Poorly Controlled Type 2 Diabetic Subjects Against LDL Oxidation May Be Due to the Abnormal Composition of HDL

Gowri

Westhuyzen

Bridges

et al. 1999

ATVB

150

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Abstract-High plasma triglyceride concentrations in diabetic subjects increase their risk for developing coronary heart disease. Numerous studies have shown that the high density lipoprotein (HDL) composition is abnormal in type 2 diabetic subjects. One study has shown that HDL (lipoprotein A-I) isolated from subjects with non-insulin-dependent diabetes mellitus exhibits a decreased capacity to induce cholesterol efflux. The current study examined the effect of HDL 2 and HDL 3 subfractions from poorly controlled type 2 diabetic and control subjects on THP-1 macrophagemediated low density lipoprotein (LDL) oxidation. The composition and protective effects of HDL 2 , but not of HDL 3 , differed significantly between control and diabetic subjects. HDL 2 from diabetics were triglyceride enriched and cholesterol depleted compared with those from controls. Control HDL 2 inhibited LDL oxidation, as assessed by lipid peroxides and electrophoretic mobility, significantly (PϽ0.05) more than did diabetic HDL 2 in both the fasting and postprandial state. In addition, HDL 2 from diabetics did not protect against apolipoprotein B-100 fragmentation in LDL. Cross-linking in apolipoprotein A-I, oxidized in the presence of LDL, was extensive in HDL 2 from diabetics compared with that from controls. Serum triglyceride concentrations were negatively correlated with protection by HDL 2 (rϭϪ0.673, PϽ0.05) in diabetic but not in control subjects. HDL 2 -associated platelet-activating factor acetylhydrolase activity was positively correlated with protection by HDL 2 in control (rϭ0.872, PϽ0.002) but not in diabetic subjects.In conclusion, compositional alterations in HDL 2 from poorly controlled type 2 diabetic subjects may reduce its antiatherogenic properties.

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PAF-acether-degrading acetylhydrolase in plasma LDL is inactivated by copper- and cell-mediated oxidation.

Cited by 49 publications

References 46 publications

Lipoprotein-Associated Phospholipase A2 Activity Is a Marker of Small, Dense LDL Particles in Human Plasma

Lipoprotein-Associated Phospholipase A2 Activity Is a Marker of Small, Dense LDL Particles in Human Plasma

Effect of platelet activating factor-acetylhydrolase on the formation and action of minimally oxidized low density lipoprotein.

Decreased Protection by HDL From Poorly Controlled Type 2 Diabetic Subjects Against LDL Oxidation May Be Due to the Abnormal Composition of HDL

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