Genetic variants in CCNB1 associated with differential gene transcription and risk of coronary in-stent restenosis.

BACKGROUND: The development of diagnostic tools to assess restenosis risk after stent deployment may enable the intervention to be tailored to the individual patient, for example, by targeting the use of drug-eluting stent to high-risk patients, with the goal of improving safety and reducing costs. The CCNB1 gene (encoding cyclin B1) positively regulates cell proliferation, a key component of in-stent restenosis. Therefore, we hypothesized that single-nucleotide polymorphisms in CCNB1 may serve as useful tools in risk stratification for in-stent restenosis. METHODS AND RESULTS: We identified 3 single-nucleotide polymorphisms in CCNB1 associated with increased restenosis risk in a cohort of 284 patients undergoing coronary angioplasty and stent placement (rs350099: TT versus CC+TC; odds ratio [OR], 1.82; 95% confidence interval [CI], 1.09-3.03; P=0.023; rs350104: CC versus CT+TT; OR, 1.82; 95% CI, 1.02-3.26; P=0.040; and rs164390: GG versus GT+TT; OR, 2.27; 95% CI, 1.33-3.85; P=0.002). These findings were replicated in another cohort study of 715 patients (rs350099: TT versus CC+TC; OR, 1.88; 95% CI, 0.92-3.81; P=0.080; rs350104: CC versus CT+TT; OR, 2.23; 95% CI, 1.18-4.25; P=0.016; and rs164390: GG versus GT+TT; OR, 1.87; 95% CI, 1.03-3.47; P=0.040). Moreover, the haplotype containing all 3 risk alleles is associated with higher CCNB1 mRNA expression in circulating lymphocytes and increased in-stent restenosis risk (OR, 1.43; 95% CI, 1.00-1.823; P=0.039). The risk variants of rs350099, rs350104, and rs164390 are associated with increased reporter gene expression through binding of transcription factors nuclear factor-Y, activator protein 1, and specificity protein 1, respectively. CONCLUSIONS: Allele-dependent transcriptional regulation of CCNB1 associated with rs350099, rs350104, and rs164390 affects the risk of in-stent restenosis. These findings reveal these common genetic variations as attractive diagnostic tools in risk stratification for restenosis.

Apolipoprotein E gene mutations in subjects with mixed hyperlipidemia and a clinical diagnosis of familial combined hyperlipidemia.

OBJECTIVE: Rare mutations in the APOE gene, undetectable with the usual genotyping technique, are responsible for dominant familial dysbetalipoproteinemia (FD) and therefore could be easily misclassified as familial combined hyperlipidemia (FCHL). We aimed to identify APOE mutations associated with dominant combined hyperlipoproteinemia and to establish their frequency in subjects with a clinical diagnosis of FCHL. METHODS AND RESULTS: In 279 unrelated subjects with FCHL in whom a functional LDLR mutation was excluded, sequencing of the entire APOE gene detected 9 carriers of a rare mutation: 5 subjects (1.8%) with the R136S mutation (arginine at residue 136 changed to serine) and 4 subjects (1.4%) with the p.Leu149del mutation, a 3-bp inframe deletion that results in the loss of leucine at position 149. Both genetic defects were detected with similar frequency (2.5% and 1.3%, respectively) in an independent group of 160 FCHL subjects from other locations in Spain. Family studies demonstrated cosegregation of these APOE mutations with hyperlipoproteinemia. R136S carriers showed dysbetalipoproteinemia, while the lipid phenotype of p.Leu149del carriers was IIa or IIb. CONCLUSIONS: Rare APOE mutations are responsible for approximately 3.5% of FCHL cases in our population. APOE R136S and p.Leu149del induce autosomal dominant FD and a phenotype indistinguishable from FCHL, respectively.

Iron deposits and dietary patterns in familial combined hyperlipidemia and familial hypertriglyceridemia

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Iron deposits are associated with lipid phenotype in familial hypertriglyceridemias, mainly familial combined hyperlipidemia (FCH) and familial hypertriglyceridemia (FHTG). In turn, diet plays an important role in hypertriglyceridemias although it is not known if dietary patterns are associated with iron concentration in these disorders. The objective was to determine the relationship between diet and iron deposits, measured through serum ferritin concentration, in patients with FCH and FHTG. The study was composed of 140 patients, 107 with FCH and 33 with FHTG. Subjects completed a validated 137-item food frequency questionnaire. Dividing subjects by ferritin tertiles adjusted by sex, there were no significant differences in dietary patterns except in dairy products consumption which was lower in the highest ferritin tertile. Subjects were also divided by triglycerides tertiles adjusted by sex. Those subjects in the highest tertile had lower HDL cholesterol and higher ferritin concentrations. Regarding to dietary parameters, there were significant differences in marine omega three fatty acids and vegetables presenting higher and lower consumption, respectively, those patients in the highest tertile of triglycerides. Moreover, there was not a significant correlation between dietary iron intake and any parameter, both biochemical and dietary, including ferritin concentrations. In conclusion, in patients with primary hypertriglyceridemia, triglycerides are associated with ferritin concentrations but dietary patterns are not related to iron deposits. Our results highly support the concept that the genetic mechanisms driven tohypertriglyceridemia also favor iron overload (AU)

Iron deposits and dietary patterns in familial combined hyperlipidemia and familial hypertriglyceridemia.

Iron deposits are associated with lipid phenotype in familial hypertriglyceridemias, mainly familial combined hyperlipidemia (FCH) and familial hypertriglyceridemia (FHTG). In turn, diet plays an important role in hypertriglyceridemias although it is not known if dietary patterns are associated with iron concentration in these disorders. The objective was to determine the relationship between diet and iron deposits, measured through serum ferritin concentration, in patients with FCH and FHTG. The study was composed of 140 patients, 107 with FCH and 33 with FHTG. Subjects completed a validated 137-item food frequency questionnaire. Dividing subjects by ferritin tertiles adjusted by sex, there were no significant differences in dietary patterns except in dairy products consumption which was lower in the highest ferritin tertile. Subjects were also divided by triglycerides tertiles adjusted by sex. Those subjects in the highest tertile had lower HDL cholesterol and higher ferritin concentrations. Regarding to dietary parameters, there were significant differences in marine omega three fatty acids and vegetables presenting higher and lower consumption, respectively, those patients in the highest tertile of triglycerides. Moreover, there was not a significant correlation between dietary iron intake and any parameter, both biochemical and dietary, including ferritin concentrations. In conclusion, in patients with primary hypertriglyceridemia, triglycerides are associated with ferritin concentrations but dietary patterns are not related to iron deposits. Our results highly support the concept that the genetic mechanisms driven to hypertriglyceridemia also favor iron overload.

Mutations in HFE causing hemochromatosis are associated with primary hypertriglyceridemia.

CONTEXT: Most cases of primary hypertriglyceridemia (HTG) are caused by the interaction of unknown polygenes and environmental factors. Elevated iron storage is associated with metabolic syndrome, diabetes, and obesity, and all of them are associated with HTG. OBJECTIVE: The aim of the study was to analyze whether HFE mutations causing hereditary hemochromatosis (HH) are associated with primary HTG. DESIGN: Genetic predisposition to HH was analyzed in a case-control study. SETTING: The study was conducted at University Hospital Lipid Clinic. PARTICIPANTS: We studied two groups: 1) the HTG group, composed of 208 patients; and 2) the control group, composed of 215 normolipemic subjects and 161 familial hypercholesterolemia patients. INTERVENTION: Two HFE mutations (C282Y and H63D) were analyzed. MAIN OUTCOME MEASURE: We measured HH genetic predisposition difference between groups. RESULTS: HH genetic predisposition was 5.9 and 4.4 times higher in the HTG group than in the normolipemic (P = 0.02) and FH (P = 0.05) subjects, respectively. There were 35 cases (16.8%) of iron overload in the primary HTG group, 14 (6.5%) and nine (5.6%) in the normolipidemic and FH groups, respectively. A higher HH genetic predisposition and a different prevalence of iron overload in subjects with HH genetic predisposition among groups contributed to this higher prevalence. None of the four cases with the HFE genotype associated with high risk of HH in the control groups presented iron overload; however, in eight of 11 subjects (72.7%) with primary HTG and HH genetic predisposition, the iron overload was present. CONCLUSION: Mutations in HFE gene, favoring iron overload and causing HH, could play an important role in the development of several phenotypes of primary HTG.

Overexpression of the CXCL3 gene in response to oxidized low-density lipoprotein is associated with the presence of tendon xanthomas in familial hypercholesterolemia.

To examine if overexpression of certain chemokines and proinflammatory cytokines in response to oxidized low-density lipoprotein could be involved in the onset and development of tendon xanthomas (TX), we quantified IL-1beta, TNF-alpha, and IL-8 and compared gene expression of PPAR-gamma, NF-kappaBIA, IL-8, IL-1beta, CXCL3, tryptase, and TNF-alpha in macrophages of familial hypercholesterolemia subjects with and without TX stimulated with oxidized low-density lipoprotein at 1, 3, 6, and 18 h of incubation. We propose that chemokines belonging to the CXC family could play an important role in the etiology of TX, with CXCL3 being a possible biological marker of onset and development of TX.

Sobreexpresión génica de citocinas proinflamatorias en macrófagos de sujetos con hipercolesterolemia familiar y xantomas tendinosos / Proinflammatory cytokine gene overexpression in macrophages of patients with familial hypercholesterolemia and tendon xanthomas

Introducción y objetivo. Entre el 30 y el 50% de los sujetos con diagnóstico genético de hipercolesterolemia familiar (HF) heterocigota presentan xantomas tendinosos (XT), pero el mecanismo por el cual unos sujetos HF desarrollan XT y otros no se desconoce. Previamente, nuestro grupo de investigación ha demostrado que los macrófagos de sujetos HF con y sin XT desarrollan una respuesta inflamatoria diferente frente a lipoproteínas de baja densidad oxidadas (LDLox). Por ello, el objetivo de este trabajo fue analizar la expresión génica de diversas moléculas inflamatorias que podrían estar involucradas en la aparición y desarrollo de XT. Material y métodos. Se seleccionó a 10 pacientes con diagnóstico genético de HF, en los que se midió el diámetro anteroposterior del tendón de Aquiles mediante ecografía de alta resolución. Se aislaron sus monocitos a partir de 40 ml de sangre periférica. Una vez diferenciados a macrófagos, se suplementaron con 50 µg/ml de LDLox durante 1, 3, 6 y 18 h. Mediante RT-PCR en tiempo real, se analizó la expresión de los genes PPAR*, IL-8, IL-1ß, CXCL3, triptasa, NF-*BIA y TNF-*. Resultados y conclusión. Los sujetos HF con XT (HF XT+) mostraron una tendencia a sobreexpresar el gen IL-8 tras 18 h de incubación con LDLox, mientras que el grupo de sujetos HF sin XT (HF XT­) tendió a sobreexpresar el gen TNF-* tras 1 h de incubación con LDLox. El gen CXCL3 se sobreexpresó significativamente en todos los tiempos de incubación en el grupo HF XT+. Además, se halló una correlación positiva entre la expresión de CXCL3 y el tamaño del tendón de Aquiles, que fue máxima a 3 h del tratamiento con LDLox (R = 0,782; p = 0,008). Estos resultados sugieren que CXCL3 podría desempeñar un papel importante en la etiología de los xantomas, y se puede considerar como un posible marcador predictor de estos depósitos lipídicos (AU)

Introduction and objective. Approximately 30%-50% of patients with genetic diagnosis of heterozygous familial hypercholesterolemia (FH) present tendon xanthomas (TX), but the mechanism by which some subjects develop TX and others do not is unknown. Previously, we have shown that macrophages of FH subjects with and without TX develop a different inflammatory response to oxidized LDL (oxLDL). Therefore, the objective of this work was to analyze the gene expression of several inflammatory molecules that could be involved in the onset and development of TX. Material and methods. Ten FH patients were selected, and the antero-posterior Achilles tendon diameter was measured with high resolution sonography. Their monocytes were isolated from 40 ml of peripheral blood. When they were differentiated to macrophages, were supplemented with 50 µg/ml of oxLDL for 1, 3, 6 and 18 hours. The gene expression of PPAR*, IL-8, IL-1ß, CXCL3, tryptase, NF-*BIA and TNF-* was analyzed with real time RT-PCR. Results and conclusion. The FH subjects with TX (FH TX+) showed a tendency to over-express IL-8 gene after 18 h of incubation with oxLDL, while FH subjects without TX (FH TX­) tended to over-express TNF-* gene after 1 h of incubation. CXCL3 gene was significantly over-expressed at all incubation times with oxLDL in FH TX+ group. Furthermore, a positive correlation was found between CXCL3 gene expression and Achilles tendon size, being maximum at 3h of treatment with oxLDL (R = 0.782; p = 0.008). These results would suggest that CXCL3 could play an important role in the ethiology of xanthomas and could be considered as a possible predictor marker of these lipid deposits (AU)