Effect of antiatherogenic high density lipoprotein (HDL) and apolipoprotein AI (apoAI) on production of prostaglandin E2 (PGE2) by human monocyte-derived macrophages was investigated. Macrophages were loaded with acetylated low density lipoprotein followed by incubation with HDL3 or apoAI. PGE2 produced and secreted in culture supernatant was quantified by enzyme immunoassay. HDL3 induced production of PGE2 by macrophages in a time-dependent manner. 24 h after incubation, PGE2 production by HDL3-treated macrophages increased 3.7-fold of that by control cells. ApoAI also induced PGE2 secretion to 2.1-fold, which was significantly less than HDL3. The data indicate that both HDL3 and lipid-free apoAI enhance PGE2 synthesis and secretion by human macrophages and this may further contribute to the protection from atherosclerosis.
Apolipoprotein A-I ; pharmacology ; Arteriosclerosis ; prevention & control ; Culture Media, Conditioned ; Dinoprostone ; biosynthesis ; Humans ; Lipoproteins, HDL ; pharmacology ; Lipoproteins, HDL3 ; Macrophages ; cytology ; metabolism ; Monocytes ; metabolism

BACKGROUND: Recent studies have suggested that high density lipoprotein (HDL) cholesterol is inversely associated with the development of hypertension. We aimed to determine the association between different HDL cholesterol subclasses and risk of future hypertension. METHODS: A total of 270 Japanese Americans (130 men, 140 women) without hypertension between the ages of 34 to 75 years were enrolled. Blood pressure was measured with a mercury sphygmomanometer, and average blood pressure was calculated. Incident hypertension was determined 5 to 6 and 10 to 11 years after enrollment. HDL2, HDL3, and total HDL cholesterol were measured at baseline. RESULTS: During 10 years of follow-up, the cumulative incidence of hypertension was 28.1% (76/270). In univariate analysis, age, diabetes, waist circumference, systolic and diastolic blood pressure, fasting glucose, insulin resistance index, total and low density lipoprotein cholesterol, and visceral adipose tissue were significant predictors for incident hypertension. Among the HDL cholesterol subclass, HDL2 cholesterol was inversely associated with hypertension incidence, but both total and HDL3 cholesterol were not. In addition, HDL2/HDL cholesterol was inversely associated with future hypertension risk. In multivariate analysis, age (odds ratio [OR], 1.71; 95% confidence interval [CI], 1.26 to 2.31; P=0.001), systolic blood pressure (OR, 1.83; 95% CI, 1.31 to 2.56; P < 0.001), and HDL2/HDL cholesterol (OR, 0.71; 95% CI, 0.52 to 0.98; P=0.035), were associated with future development of hypertension. CONCLUSION: A higher proportion of HDL2 cholesterol among total HDL cholesterol predicted a lower risk for incident hypertension. However, concentrations of total HDL, HDL2, and HDL3 cholesterol were not independent predictors of incident hypertension.
Asian Americans ; Blood Pressure ; Cholesterol ; Cholesterol, HDL ; Cholesterol, LDL ; Fasting ; Follow-Up Studies ; Glucose ; Humans ; Hypertension ; Incidence ; Insulin Resistance ; Intra-Abdominal Fat ; Lipoproteins ; Lipoproteins, HDL2 ; Lipoproteins, HDL3 ; Male ; Multivariate Analysis ; Sphygmomanometers ; Waist Circumference