RESUMO
BACKGROUND AND AIMS: Research on the biologic activities of HDL, such as cholesterol efflux capacity and HDL composition, has allowed the understanding of the effect of interventions directed to improve cardiovascular risk. Previously, statin therapy has shown conflicting results about its effects on cholesterol efflux capacity of HDL; the underlying mechanisms are unclear but studies with positive effects are associated with an increase of HDL-cholesterol levels. We investigated if 10 weeks of atorvastatin therapy changes HDL efflux capacity and the chemical composition of its subpopulations. METHODS: In a before-after design basis, HDL-cholesterol levels, chemical composition and cholesterol efflux capacity from HDL subpopulations isolated by isophynic ultracentrifugation were assessed in plasma samples from 60 patients with type 2 diabetes mellito (T2DM) at baseline and after 10 weeks of treatment with 20â¯mg atorvastatin. Cholesterol efflux was measured from human THP-1â¯cells using large, light HDL2b and small, dense 3c subpopulations as well as total HDL as acceptors. Changes of cholesterol efflux and chemical composition of HDL after treatment were analyzed. Correlations among variables potentially involved in cholesterol efflux were evaluated. RESULTS: A significant decrease of 4% in HDL-cholesterol levels was observed from 47 (42-54) to 45 (39-56) mg/dL, pâ¯=â¯0.02. Cholesterol efflux from total-HDL and HDL2b and 3c subfractions was maintained unchanged after treatment. The total mass of HDL remained unaffected, except for the HDL3a subpopulation accounted for by a significant increase in total protein content. No significant correlations for variables previously known to be associated with cholesterol efflux were found in our study. CONCLUSIONS: Short therapy of 10 weeks with 20â¯mg of atorvastatin does not modify the cholesterol efflux capacity neither the total mass of HDL2b, HDL3c and total HDL. The discrepancy with previous reports may be due to the selective effects among different classes of statins or differences in the approaches to measure cellular cholesterol efflux.
Assuntos
Atorvastatina/uso terapêutico , HDL-Colesterol/sangue , Diabetes Mellitus Tipo 2/tratamento farmacológico , Dislipidemias/tratamento farmacológico , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Adulto , Idoso , Atorvastatina/efeitos adversos , Biomarcadores/sangue , Estudos Controlados Antes e Depois , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/diagnóstico , Dislipidemias/sangue , Dislipidemias/diagnóstico , Feminino , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/efeitos adversos , Macrófagos/metabolismo , Masculino , México , Pessoa de Meia-Idade , Células THP-1 , Fatores de Tempo , Resultado do Tratamento , Adulto JovemRESUMO
BACKGROUND: Low plasma levels of high-density lipoprotein-cholesterol (HDL-C) are typical of acute myocardial infarction (MI) and predict risk of recurrent cardiovascular events. The potential relationships between modifications in the molecular composition and the functionality of HDL subpopulations in acute MI however remain indeterminate. METHODS AND RESULTS: ST segment elevation MI (STEMI) patients were recruited within 24h after diagnosis (n=16) and featured low HDL-C (-31%, p<0.05) and acute-phase inflammation (determined as marked elevations in C-reactive protein, serum amyloid A (SAA) and interleukin-6) as compared to age- and sex-matched controls (n=10). STEMI plasma HDL and its subpopulations (HDL2b, 2a, 3a, 3b, 3c) displayed attenuated cholesterol efflux capacity from THP-1 cells (up to -32%, p<0.01, on a unit phospholipid mass basis) vs. CONTROLS: Plasma HDL and small, dense HDL3b and 3c subpopulations from STEMI patients exhibited reduced anti-oxidative activity (up to -68%, p<0.05, on a unit HDL mass basis). HDL subpopulations in STEMI were enriched in two proinflammatory bioactive lipids, lysophosphatidylcholine (up to 3.0-fold, p<0.05) and phosphatidic acid (up to 8.4-fold, p<0.05), depleted in apolipoprotein A-I (up to -23%, p<0.05) and enriched in SAA (up to +10.2-fold, p<0.05); such changes were most marked in the HDL3b subfraction. In vitro HDL enrichment in both lysophosphatidylcholine and phosphatidic acid exerted deleterious effects on HDL functionality. CONCLUSIONS: In the early phase of STEMI, HDL particle subpopulations display marked, concomitant alterations in both lipidome and proteome which are implicated in impaired HDL functionality. Such modifications may act synergistically to confer novel deleterious biological activities to STEMI HDL. SIGNIFICANCE: Our present data highlight complex changes in the molecular composition and functionality of HDL particle subpopulations in the acute phase of STEMI, and for the first time, reveal that concomitant modifications in both the lipidome and proteome contribute to functional deficiencies in cholesterol efflux and antioxidative activities of HDL particles. These findings may provide new biomarkers and new insights in therapeutic strategy to reduce cardiovascular risk in this clinical setting where such net deficiency in HDL function, multiplied by low circulating HDL concentrations, can be expected to contribute to accelerated atherogenesis.
Assuntos
Lipoproteínas HDL3/sangue , Lisofosfatidilcolinas/sangue , Infarto do Miocárdio/sangue , Ácidos Fosfatídicos/sangue , Proteína Amiloide A Sérica/metabolismo , Adulto , Idoso , Apolipoproteína A-I/química , Apolipoproteína A-I/deficiência , Apolipoproteína A-I/metabolismo , Proteína C-Reativa/metabolismo , Estudos de Casos e Controles , Linhagem Celular , Feminino , Humanos , Interleucina-6/sangue , Lipoproteínas HDL3/química , Lisofosfatidilcolinas/química , Masculino , Pessoa de Meia-Idade , Monócitos/metabolismo , Infarto do Miocárdio/patologia , Ácidos Fosfatídicos/química , Proteoma/química , Proteoma/metabolismoRESUMO
Iron overload (IO) has been associated with glucose metabolism alterations and increased risk of cardiovascular disease (CVD). Primary IO is associated with mutations in the HFE gene. To which extent HFE gene mutations and metabolic alterations contribute to the presence of atherogenic lipoprotein modifications in primary IO remains undetermined. The present study aimed to assess small, dense low-density lipoprotein (LDL) levels, chemical composition of LDL and high-density lipoprotein (HDL) particles, and HDL functionality in IO patients. Eighteen male patients with primary IO and 16 sex- and age-matched controls were recruited. HFE mutations (C282Y, H63D and S65C), measures of insulin sensitivity and secretion (calculated from the oral glucose tolerance test), chemical composition and distribution profile of LDL and HDL subfractions (isolated by gradient density ultracentrifugation) and HDL functionality (as cholesterol efflux and antioxidative activity) were studied. IO patients compared with controls exhibited insulin resistance (HOMA-IR (homoeostasis model assessment-estimated insulin resistance): +93%, P< 0.001). Metabolic profiles differed across HFE genotypes. C282Y homozygotes (n=7) presented a reduced ß-cell function and insulin secretion compared with non-C282Y patients (n=11) (-58% and -73%, respectively, P< 0.05). In addition, C282Y homozygotes featured a predominance of large, buoyant LDL particles (C282Y: 43±5; non-C282Y: 25±8; controls: 32±7%; P< 0.001), whereas non-C282Y patients presented higher amounts of small, dense LDL (C282Y: 23±5; non-C282Y: 39±10; controls: 26±4%; P< 0.01). HDL particles were altered in C282Y homozygotes. However, HDL functionality was conserved. In conclusion, metabolic alterations and HFE gene mutations are involved in the presence of atherogenic lipoprotein modifications in primary IO. To what extent such alterations could account for an increase in CVD risk remains to be determined.
Assuntos
Aterosclerose/etiologia , Glicemia/metabolismo , HDL-Colesterol/sangue , Antígenos de Histocompatibilidade Classe I/genética , Insulina/sangue , Sobrecarga de Ferro/sangue , Sobrecarga de Ferro/genética , Proteínas de Membrana/genética , Mutação , Adulto , Idoso , Aterosclerose/sangue , Aterosclerose/genética , Biomarcadores/sangue , Estudos de Casos e Controles , Linhagem Celular , LDL-Colesterol/sangue , Análise Mutacional de DNA , Predisposição Genética para Doença , Teste de Tolerância a Glucose , Proteína da Hemocromatose , Heterozigoto , Homozigoto , Humanos , Resistência à Insulina , Células Secretoras de Insulina/metabolismo , Sobrecarga de Ferro/complicações , Sobrecarga de Ferro/diagnóstico , Masculino , Pessoa de Meia-Idade , Fenótipo , Fatores de RiscoRESUMO
To evaluate functional and compositional properties of HDL in subjects from a kindred of genetic apoA-I deficiency, two homozygotes and six heterozygotes, with a nonsense mutation at APOA1 codon -2, Q[-2]X, were recruited together with age- and sex-matched healthy controls (n = 11). Homozygotes displayed undetectable plasma levels of apoA-I and reduced levels of HDL-cholesterol (HDL-C) and apoC-III (5.4% and 42.6% of controls, respectively). Heterozygotes displayed low HDL-C (21 ± 9 mg/dl), low apoA-I (79 ± 24 mg/dl), normal LDL-cholesterol (132 ± 25 mg/dl), and elevated TG (130 ± 45 mg/dl) levels. Cholesterol efflux capacity of ultracentrifugally isolated HDL subpopulations was reduced (up to -25%, P < 0.01, on a glycerophospholipid [GP] basis) in heterozygotes versus controls. Small, dense HDL3 and total HDL from heterozygotes exhibited diminished antioxidative activity (up to -48%, P < 0.001 on a total mass basis) versus controls. HDL subpopulations from both homozygotes and heterozygotes displayed altered chemical composition, with depletion in apoA-I, GP, and cholesteryl ester; enrichment in apoA-II, free cholesterol, and TG; and altered phosphosphingolipidome. The defective atheroprotective activities of HDL were correlated with altered lipid and apo composition. These data reveal that atheroprotective activities of HDL particles are impaired in homozygous and heterozygous apoA-I deficiency and are intimately related to marked alterations in protein and lipid composition.