Dissociable and nondissociable forms of platelet-activating factor acetylhydrolase in human plasma LDL: implications for LDL oxidative susceptibility

McCall, Mark R.; Belle, Michael La; Forte, Trudy M.; Krauss, Ronald M.; Takanami, Yoichi

doi:10.1016/s0005-2760(98)00177-5

Cited by 45 publications

(32 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Western blot in GGE ( Figure 4) and PAF-AH activity of LDL subfractions separated from total LDL isolated by gel filtration showed a patent increase in PAF-AH associated with both LDL fractions compared with samples isolated by ultracentrifugation [PAF-AH activity (mol · min Ϫ1 · mL Ϫ1 ) of total LDL isolated by chromatography, LDL(ϩ)0.55, LDL(Ϫ)9.75; total LDL isolated by ultracentrifugation, LDL(ϩ) 0.35, LDL(Ϫ) 4.50], in accordance with previous reports. 12 However, this decrease does not modify the basic observation that most PAF-AH is bound to LDL(Ϫ).…”

Section: Resultsmentioning

confidence: 87%

“…It was described that ultracentrifugation results in the loss of PAF-AH in LDL and a parallel enrichment of PAF-AH in HDL and lipoprotein-deficient serum, 12 but a redistribution of PAF-AH from LDL(ϩ) to LDL(Ϫ) is highly improbable because both fractions are of very similar density. Nevertheless, we tested this possibility.…”

Section: Discussionmentioning

confidence: 99%

“…11 Composition of LDL fractions, including total and free cholesterol, triglyceride, phospholipid, apolipoprotein (apo) B, and NEFA, was determined as described previously. 7 Because ultracentrifugation was reported to promote the displacement of PAF-AH from LDL to HDL or lipoprotein-deficient serum, 12 an alternative method to ultracentrifugation was used. Total LDL from human NL plasma was isolated by gel filtration chromatography, as described previously.…”

Section: Lipoprotein Isolationmentioning

confidence: 99%

See 2 more Smart Citations

Platelet-Activating Factor Acetylhydrolase Is Mainly Associated With Electronegative Low-Density Lipoprotein Subfraction

et al. 2003

View full text Add to dashboard Cite

Background-Electronegative LDL [LDL(Ϫ)], a modified subfraction of LDL present in plasma, induces the release of interleukin-8 and monocyte chemotactic protein-1 from cultured endothelial cells. Methods and Results-We demonstrate that platelet-activating factor acetylhydrolase (PAF-AH) is mainly associated with LDL(Ϫ). LDL(Ϫ) had 5-fold higher PAF-AH activity than the nonelectronegative LDL subfraction [LDL(ϩ)] in both normolipemic and familial hypercholesterolemic subjects. Western blot analysis after SDS-PAGE confirmed these results, because a single band of 44 kDa corresponding to PAF-AH appeared in LDL(Ϫ) but not in LDL(ϩ).Nondenaturing polyacrylamide gradient gel electrophoresis demonstrated that PAF-AH was bound to LDL(Ϫ) regardless of LDL size. In accordance with the above findings, nonesterified fatty acids, a cleavage product of PAF-AH, were increased in LDL(Ϫ) compared with LDL(ϩ). Conclusions-The

show abstract

Section: Resultsmentioning

confidence: 87%

Section: Discussionmentioning

confidence: 99%

Section: Lipoprotein Isolationmentioning

confidence: 99%

See 1 more Smart Citation

Platelet-Activating Factor Acetylhydrolase Is Mainly Associated With Electronegative Low-Density Lipoprotein Subfraction

et al. 2003

View full text Add to dashboard Cite

show abstract

“…1 are bar graphs representing the total protein profile of apoBcontaining lipoprotein subspecies as well as the profiles of the Lp-PLA 2 activity, mass, and specific activity in plasma from a phenotype non-A person. We next studied the distribution of Lp-PLA 2 among the apoAI-containing lipoproteins, using apoB-depleted plasma to avoid any contamination by HDL-Lp-PLA 2 of the LDL-associated enzyme during ultracentrifugation (29,32 ). The Lp-PLA 2 activity and mass were preferentially associated with the HDL-3c subfraction in persons of either phenotype (A or non-A).…”

Section: Lp-pla 2 Activity and Mass In Lipoprotein Subfractionsmentioning

confidence: 99%

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

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

show abstract

“…In plasma, PAF is hydrolyzed and inactivated by PAFacetylhydrolase (PAF-AH) (EC 3.1.1.47), an enzyme associated mainly with the apolipoprotein B (apoB)-containing lipoproteins and primarily with LDL (2). A small proportion of circulating enzyme activity is also associated with HDL (2,3). PAF-AH exhibits a ␣ / ␤ hydrolase conformation (4) and has broad substrate specificity toward lipid esters containing short acyl chains (5).…”

mentioning

confidence: 99%

Fenofibrate induces HDL-associated PAF-AH but attenuates enzyme activity associated with apoB-containing lipoproteins

Tsimihodimos

Kakafika

Tambaki

et al. 2003

Journal of Lipid Research

121

View full text Add to dashboard Cite

Human plasma platelet-activating factor acetylhydrolase (PAF-AH) is an enzyme associated mainly with the apolipoprotein B (apoB)-containing lipoproteins and primarily with LDL. A small proportion of enzymatic activity is also associated with HDL. Plasma paraoxonase 1 (PON1) is an esterase exclusively associated with HDL. The effect of fenofibrate on PAF-AH and PON1 activities in patients with dyslipidemias of Types IIA, IIB, and IV were studied. Fenofibrate reduced plasma PAF-AH activity in all patient groups. In Type IIA patients, this reduction was mainly due to a fall in enzyme activity associated with the dense LDL subspecies, whereas in Type IIB and Type IV patients, it was due to the decrease in PAF-AH activity associated with both the VLDL ؉ IDL and dense LDL subspecies. Drug therapy in Type IIB and Type IV patients significantly increased the HDL-associated PAF-AH activity due to the increase in enzyme activity associated with the HDL-3c subfraction. Fenofibrate did not affect serum PON1 activities toward paraoxon and phenylacetate in either patient group.The fenofibrate-induced elevation of HDL-associated PAF-AH activity in dyslipidemic patients of Type IIB and Type IV, as well as the reduction in enzyme activity associated with atherogenic apoBcontaining lipoproteins in all patient groups, may represent a new and important antiatherogenic effect of this potent lipid-modulating agent.

show abstract

Dissociable and nondissociable forms of platelet-activating factor acetylhydrolase in human plasma LDL: implications for LDL oxidative susceptibility

Cited by 45 publications

References 31 publications

Platelet-Activating Factor Acetylhydrolase Is Mainly Associated With Electronegative Low-Density Lipoprotein Subfraction

Platelet-Activating Factor Acetylhydrolase Is Mainly Associated With Electronegative Low-Density Lipoprotein Subfraction

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

Fenofibrate induces HDL-associated PAF-AH but attenuates enzyme activity associated with apoB-containing lipoproteins

Contact Info

Product

Resources

About