Ezetimibe increases resistance to oxidative stress and extends lifespan mimicking dietary restriction in Caenorhabditis elegans

Ezetimibe is an approved drug for lowering plasma LDL (low-density lipoprotein) level via inhibition of cholesterol absorption. Derivatives of ezetimibe reduce inflammatory response and oxidative stress. In the present study, we investigated the effect of dietary supplementation with ezetimibe in response to environmental stressors and found that ezetimibe increases resistance to oxidative stress and ultraviolet irradiation. Ezetimibe also significantly extended lifespan accompanying reduced fertility, which is a common trade-off for longevity in C. elegans. Cellular level of reactive oxygen species was increased and the expression of stress-responsive genes, hsp-16.2 and sod-3, was induced by dietary supplementation with ezetimibe, suggesting a hormetic effect on oxidative stress response and lifespan. Ezetimibe also significantly prevented amyloid beta-induced toxicity and completely reversed increased mortality by high-glucose diet. Nuclear localization of DAF-16 required for the prevention of amyloid beta-induced toxicity was enhanced by ezetimibe supplementation. Lifespan assay using known long-lived mutants, age-1, clk-1, and eat-2, revealed that lifespan extension by ezetimibe specifically overlapped with that of eat-2 mutants, which are genetic models of dietary restriction. Effect of ezetimibe on lifespan of worms fed with diluted bacteria suggested that ezetimibe mimics the effect of dietary restriction on lifespan. These findings suggest that ezetimibe exhibits anti-oxidative and anti-aging effects through hormesis and works as a dietary-restriction mimetic on lifespan extension.

Reporte de manejo exitoso con simvastatina y ezetimibe en alopecia areata / A report of successful management with simvastatin plus ezetimibe in alopecia areata

La alopecia areata es un tipo común de alopecia no cicatricial. Aunque la patogénesis exacta permanece sin dilucidar, se piensa que la alopecia areata tiene una etiología multifactorial en donde se interrelacionan predisposición genética y factores ambientales. En pacientes susceptibles, se han documentado que el estrés, infecciones y microtraumas disminuyen las citoquinas inmunosupresoras que normalmente mantienen el privilegio inmune del folículo piloso. Actualmente no hay terapia curativa para la alopecia areata, aunque ciertos tratamientos pueden inducir el crecimiento del cabello en un porcentaje de pacientes. Se postula que la simvastatina restablece el privilegio inmune y ezetimibe aportaría un efecto inmunomodulador y antiinflamatorio. Se presenta el caso de una mujer de 23 años con alopecia areata, exitosamente tratada con simvastatina y ezetimibe.

Alopecia areata is a common type of non-scarring alo¬pecia. Although the exact pathogenesis remains elusive, alopecia areata is thought to have a multifactorial etiology described as an interplay of genetic predisposition and environmental exposures. In patients with genetic susceptibility, stress, infection, and microtrauma have been documented to decrease immunosuppressive cytokines that generally maintain the hair follicle's immune privilege. There is currently no curative therapy for alopecia areata, although some treatments can induce hair growth in a percentage of patients. It has been postulated that simvastatin reestablishes the immune privilege, and ezetimibe would provide an immunomodulatory and anti-inflammatory effect. We report a case of a 23 years-old woman with alopecia areata successfully treated with simvastatin/ezetimibe.

Lipid-lowering drug prescriptions in a group of Colombian patients / Patrones de prescripción de hipolipemiantes en pacientes de Colombia

Introduction. Lipid-lowering drugs, especially statins, have shown great relevance in preventing and treating cardiovascular diseases. Objective. To determine the prescription patterns of lipid-lowering drugs and the variables associated with their use in a Colombian population. Materials and methods. This is a cross-sectional descriptive study. From a drugdispensing database of approximately 4.5 million Colombian health system affiliates, patients of all ages and both sexes treated with lipid-lowering agents (statins, fibrates, ezetimibe) were identified between January and March, 2017. Demographic, pharmacological and co-medication variables were included. Results. In total, 103,624 patients were identified as being treated with lipid-lowering agents. The average age was 67.5 years, and 49.8% were 65 years or older. Women comprised 58.0% of the patients. Statins were the most used (n=96,910; 93.5%), and atorvastatin (n=80,812; 78.0%) and lovastatin (n=12,621; 12.2%) were the most frequent. The mean atorvastatin dose was 30.3 mg/day, and 49.9% of its users received presentations of 40 mg or more. A total of 9,258 (8.9%) patients received fibrates, and only 780 (0.8%) were taking ezetimibe. Of this population, 94.9% were treated with lipid-lowering monotherapy, and 97.3% (n=100,813) had co-medication for their comorbidities, with the most frequent being antihypertensive (89.1%), antiplatelet (57.8%), antidiabetic (31.5%) and antiulcerative agents (34.2%). Conclusions. Atorvastatin is currently the most frequently used lipid-lowering drug in this group of Colombian patients, especially in monotherapy and at doses close to the defined daily dose. Only half received high-intensity doses. New studies are required to verify the efficacy of these therapies.

Introducción. Los fármacos hipolipemiantes, especialmente las estatinas, han demostrado gran relevancia para la prevención y el tratamiento de las enfermedades cardiovasculares. Objetivo. Determinar los patrones de prescripción de los fármacos hipolipemiantes y las variables asociadas con su uso en una población de Colombia. Materiales y métodos. Se trata de un estudio descriptivo y transversal. A partir de una base de datos de dispensación de medicamentos de 4,5 millones de afiliados al sistema de salud de Colombia, se identificaron los pacientes de cualquier edad y sexo en tratamiento con hipolipemiantes (estatinas, fibratos, ezetimibe), entre enero y marzo de 2017. Se incluyeron variables demográficas, farmacológicas y de comedicaciones. Resultados. Se identificaron 103.624 pacientes en tratamiento con hipolipemiantes. La edad promedio fue de 67,5 años y el 49,8 % tenía 65 o más años. El 58,0 % eran mujeres. Las estatinas fueron los más utilizados (n=96.910; 93,5 %), siendo la atorvastatina (n=80.812; 78,0 %) y la lovastatina (n=12.621; 12,2 %) las más frecuentes. La dosis promedio de atorvastatina fue de 30,3 mg/día y el 49,9 % de sus usuarios recibía presentaciones de 40 mg o más. Un total de 9.258 (8,9 %) pacientes recibían fibratos y solo 780 (0,8 %) tomaban ezetimibe. El 94,9 % de casos recibió tratamiento en monoterapia hipolipemiante y el 97,3 % (n=100.813) tenía comedicaciones para comorbilidades, siendo las más frecuentes antihipertensivos (89,1 %), antiagregantes plaquetarios (57,8 %), antidiabéticos (31,5 %) y antiulcerosos (34,2 %). Conclusiones. La atorvastatina es actualmente el medicamento hipolipemiante más utilizado en este grupo de pacientes de Colombia, especialmente en monoterapia y a dosis cercanas a las definidas, aunque solo la mitad recibían dosis recibían dosis de alta intensidad. Se requieren nuevos estudios que verifiquen la efectividad de estos tratamientos.

Elegibilidad para la indicación de inhibidores de PCSK9 según las recomendaciones de diferentes sociedades científicas / Eligibility for the indication of PCSK9 inhibitors according to the recommendations of different scientific societies

La reducción del colesterol-LDL (C-LDL) es un objetivo primordial en prevención cardiovascular. Estudios recientes demostraron beneficio clínico al administrar inhibidores de la proprotein convertase subtilisin/kexin-9 (iPCSK9) a pacientes que no habían logrado la meta de C-LDL con estatinas de alta intensidad y ezetimibe, sin embargo el uso de estos fármacos está limitado por su costo. El American College of Cardiology, la Sociedad Argentina de Cardiología y la European Society of Cardiology recomiendan una meta de C-LDL menor a 70 mg/dl en prevención secundaria, determinando umbrales de C-LDL de 70, 100 o 140 mg/dl respectivamente, para iniciar el tratamiento con iPCSK9. Con el objetivo de evaluar el esquema hipolipemiante prescripto en internados por síndrome coronario agudo o revascularización coronaria y analizar la proporción de elegibles para ser tratados con iPCSK9 en un escenario real y simulado, realizamos un estudio que incluyó 351 pacientes con enfermedad coronaria, tomados de una base de datos electrónica de un hospital universitario. El 48.4% recibió estatinas de elevada intensidad, 11.4% ezetimibe y 54.7% no logró la meta de C-LDL menor a 70 mg/dl. Utilizando un modelo de simulación en el que todos serían medicados con estatinas de elevada intensidad y ezetimibe, la elegibilidad para prescribir iPCSK9 fue de 31.1%, 12.8% y 9.1% según los umbrales de C-LDL determinados por las tres sociedades científicas. Nuestro estudio demostró una brecha entre las recomendaciones de los consensos para reducir el colesterol y la práctica habitual que debería ser minimizada para optimizar la relación costo/efectividad en prevención secundaria.

LDL-cholesterol (LDL-C) lowering is a primary objective in cardiovascular prevention. Recent studies demonstrated clinical benefit when proprotein convertase subtilisin/kexin-9 inhibitors (PCSK9i) were added to the treatment in patients who had not achieved the LDL-C goal despite being treated with high intensity statins and ezetimibe, however the use of these drugs is limited by their cost. The American College of Cardiology, the Argentine Society of Cardiology and the European Society of Cardiology recommend an LDL-C goal less than 70 mg/dl in secondary prevention, determining thresholds of LDL-C to start treatment with PCSK9i of 70, 100 or 140 mg/dl respectively. In order to evaluate the lipid-lowering regimen prescribed in patients hospitalized for acute coronary syndrome or coronary revascularization and analyze the proportion of eligible to be treated with PCSK9i in a real and simulated scenario, we conducted a study that included 351 patients with coronary disease collected from an electronic database of a university hospital. The 48.4% received high intensity statins, 11.4% ezetimibe and 54.7% did not achieve the LDL-C goal of less than 70 mg/dL. Using a simulation model in which all would be treated with high intensity statins and ezetimibe, the eligibility to prescribe PCSK9i was 31.1%, 12.8% and 9.1% according to the C- LDL thresholds determined by the three scientific societies. Our study demonstrated a gap between the consensus recommendations for LDL-C lowering and the current practice that should be minimized to optimize the cost/effectiveness ratio in secondary prevention.

Simultaneous determination of atorvastatin and ezetimibe from combined pharmaceutical products by micellar electrokinetic capillary chromatography

Abstract A rapid and sensitive micellar electrokinetic capillary chromatography method with UV photodiode-array detection was developed for the simultaneous determination of atorvastatin and ezetimibe in fixed dose drug combination. Experimental conditions such as buffer concentration and pH, surfactant concentration, system temperature, applied voltage, injection parameters were optimized in order to improve the efficiency of the separation. The best results were obtained when using fused silica capillary (48 cm length X 50 µm ID) and 25 mM borate buffer electrolyte at pH 9.3 containing 25 mM SDS, + 30 kV applied voltage, 20 ºC system temperature. The separation was achieved in approximately 2 minutes, with a resolution of 7.02, the order of migration being atorvastatin followed by ezetimibe. The analytical performance of the method was verified with regard to linearity, precision, robustness and the limit of detection and quantification were calculated.

Endothelial Effect of Statin Therapy at a High Dose Versus Low Dose Associated with Ezetimibe / Efeito Endotelial da Terapia com Estatina em Alta Dose versus Baixa Dose Associada à Ezetimiba

Abstract Background: The effect of statins on the endothelial function in humans remains under discussion. Particularly, it is still unclear if the improvement in endothelial function is due to a reduction in LDL-cholesterol or to an arterial pleiotropic effect. Objective: To test the hypothesis that modulation of the endothelial function promoted by statins is primarily mediated by the degree of reduction in LDL-cholesterol, independent of the dose of statin administered. Methods: Randomized clinical trial with two groups of lipid-lowering treatment (16 patients/each) and one placebo group (14 patients). The two active groups were designed to promote a similar degree of reduction in LDL-cholesterol: the first used statin at a high dose (80 mg, simvastatin 80 group) and the second used statin at a low dose (10 mg) associated with ezetimibe (10 mg, simvastatin 10/ezetimibe group) to optimize the hypolipidemic effect. The endothelial function was assessed by flow-mediated vasodilation (FMV) before and 8 weeks after treatment. Results: The decrease in LDL-cholesterol was similar between the groups simvastatin 80 and simvastatin 10/ezetimibe (27% ± 31% and 30% ± 29%, respectively, p = 0.75). The simvastatin 80 group presented an increase in FMV from 8.4% ± 4.3% at baseline to 11% ± 4.2% after 8 weeks (p = 0.02). Similarly, the group simvastatin 10/ezetimibe showed improvement in FMV from 7.3% ± 3.9% to 12% ± 4.4% (p = 0.001). The placebo group showed no variation in LDL-cholesterol level or endothelial function. Conclusion: The improvement in endothelial function with statin seems to depend more on a reduction in LDL-cholesterol levels, independent of the dose of statin administered, than on pleiotropic mechanisms.

Resumo Fundamento: O efeito das estatinas na função endotelial em seres humanos permanece em discussão. Particularmente, ainda carece resposta se a melhora na função endotelial deve-se à redução do LDL-colesterol ou a um efeito pleiotrópico arterial. Objetivo: Testar a hipótese de que a modulação da função endotelial promovida por estatinas é prioritariamente mediada pelo grau de redução do LDL-colesterol, independente da dose de estatina utilizada. Métodos: Ensaio clínico randomizado com dois grupos de tratamento hipolipemiante (16 pacientes/cada) e um grupo placebo (14 pacientes). Os dois grupos ativos foram desenhados para promover graus semelhantes de redução de LDL-colesterol: o primeiro utilizou estatina em alta dose (80 mg, grupo sinvastatina 80) e o segundo em baixa dose (10 mg) associada a ezetimiba (10 mg, grupo sinvastatina 10/ezetimiba) para otimizar o efeito hipolipemiante. A função endotelial foi analisada pela vasodilatação mediada por fluxo (VMF) antes e após 8 semanas de tratamento. Resultados: A redução no LDL-colesterol foi semelhante entre os grupos sinvastatina 80 e sinvastatina 10/ezetimiba (27% ± 31% e 30% ± 29%, respectivamente, p = 0,75). O grupo sinvastatina 80 apresentou incremento da VMF de 8,4% ± 4,3% no basal para 11% ± 4,2% após 8 semanas (p = 0,02). Da mesma forma, o grupo sinvastatina 10/ezetimiba apresentou melhora da VMF de 7,3% ± 3,9% para 12% ± 4,4% (p = 0,001). O grupo placebo não apresentou variação no nível de LDL-colesterol ou da função endotelial. Conclusão: A melhora da função endotelial com uso de estatina parece depender mais da redução do LDL-colesterol, independente da dose de estatina utilizada, do que de mecanismos pleiotrópicos.

Dislipidemias: ¿qué hay de nuevo? / Dyslipidemia: what's new?

En los últimos años han surgido algunas investigaciones y guías de práctica clínica relacionadas con el diagnóstico y tratamiento de las dislipidemias, que aportaron nuevos conocimientos (y controversias) sobre dicha problemática. En este resumen se describen, en primer lugar, las características de las "nuevas guías" norteamericanas para el manejo del colesterol publicadas a fines de 2013 y se comparan con las recomendaciones tradicionales. En segundo lugar, se analizan los últimos estudios que evaluaron el impacto cardiovascular de otros fármacos hipolipemiantes (ezetimibe y ácido nicotínico) en pacientes en prevención secundaria tratados con estatinas. Finalmente, se mencionan las nuevas drogas hipolipemiantes desarrolladas en los últimos años, como el lomitapide, el mipomersen y los inhibidores de la PCSK9, y se comentan el mecanismo de acción, su eficacia, sus efectos colaterales y los escenarios clínicos en donde podrían utilizarse. (AU)

In recent years, some research and clinical practice guidelines related to the diagnosis and treatment of dyslipidemia, which provided new knowledge (and controversy) about this problem have emerged. In this review, the characteristics of the American "new guidelines" for cholesterol management published by the end of 2013 are described, and they are compared with the traditional recommendations. In addition, recent studies assessing the cardiovascular impact of other lipid-lowering drugs (ezetimibe and nicotinic acid) in patients in secondary prevention treated with statins are analyzed. Finally, new hypolipidemic drugs developed in recent years are mentioned (lomitapide, mipomersen and PCSK9 inhibitors), discussing the mechanism of action, efficacy, side effects and clinical settings where they could be used. (AU)

Papel de inibidores da síntese e absorção do colesterol na modulação de biomarcadores de inflamação e adesão celular in vivo e in vitro / Role of inhibitors of the cholesterol synthesis and absorption on modulation of inflammation and cell adhesion biomarkers in vivo and in vitro

O processo inflamatório tem um papel fundamental na gênese e desenvolvimento da aterosclerose, sendo que a disfunção endotelial é considerada um dos estágios iniciais da aterogênese. Por meio da inibição da enzima hidroxi-metil-glutaril coA redutase (HMGCR), as estatinas reduzem a biossíntese do colesterol e a formação de isoprenóides, produtos intermediários da síntese do colesterol que são importantes na modificação pós-transcricional de GTPases pequenas que estão envolvidas na disfunção endotelial e inflamação vascular. A ezetimiba é um inibidor da absorção do colesterol através da inibição da proteína NPC1L1. Com a finalidade de esclarecer os mecanismos moleculares da inibição da síntese e da absorção do colesterol sobre a modulação de biomarcadores inflamatórios e de adesão celular foram utilizados modelos in vitro com células endoteliais (HUVEC) e monócitos (células THP-1), e in vivo com células mononucleares do sangue periférico (CMSP) de indivíduos hipercolesterolêmicos (HC). O efeito das estatinas, atorvastatina e sinvastatina, e da ezetimiba na expressão de RNAm e proteínas de moléculas de adesão endoteliais e moduladores do processo inflamatório, como citocinas e óxido nítrico (NO), foi estudado em células HUVEC. O efeito desses fármacos sobre a expressão de moléculas de adesão monocitárias foi estudado em células THP-1. O efeito da terapia hipolipemiante sobre essas moléculas foi também estudada em CMSP de HC tratados com ezetimiba (10 mg/dia/4 semanas), sinvastatina (10 mg/dia/8 semanas) e sinvastatina combinada com ezetimiba (10 mg de cada/dia/4 semanas). A expressão de RNAm foi avaliada por RT-qPCR. A expressão de moléculas de adesão na superfície de células THP-1 e HUVEC foi estudada por citometria de fluxo. A quantificação de citocinas secretadas no sobrenadante de células HUVEC e no plasma dos HC foi analisada pela tecnologia Milliplex. A quantificação do perfil lipífico, Proteína C reativa ultra-sensível (PCRus) e NO foi realizada por métodos laboratoriais convencionais. O papel do NO na modulação dos marcadores inflamatórios pelas estatinas foi também estudada, usando modelo de células HUVEC com NOS3 silenciado por interferência de RNAm e também por meio do uso do inibidor da síntese do óxido nítrico, L-NAME. Também foi avaliado o efeito de hipolipemiantes na expressão dos microRNAs (miRs) 221, miR-222 e miR-1303 em células HUVEC por meio do stem-loop RT-qPCR. O tratamento com atorvastatina e sinvastatina reduziu a expressão de RNAm e proteínas das moléculas de adesão LSelectina, PSGL-1 e VLA-4, em células THP-1 pré-tratadas com TNFα por 12 h. A ezetimiba reduziu a expressão de L-Selectina apenas no nível transcricional. Em células HUVEC, as estatinas diminuíram a expressão de RNAm de IL1B e SELP, entretanto aumentaram a de VCAM1. A ezetimiba reduziu a expressão de RNAm do IL1B. Entretanto as expressões de SELE, MMP9, IL6 e MMP9 não foram afetadas pelos tratamentos. A expressão das proteínas ICAM-1 e P-Selectina, na superfície de células HUVEC, foi diminuída pelo tratamento com as estatinas, mas não pela ezetimiba. Da mesma forma, a secreção das citocinas IL-6 e MCP-1 foram reduzidas pelas estatinas, entretanto a secreção de IL-8 não foi modificada por nenhum dos tratamentos. A expressão de NOS3 e a liberação de NO em células HUVEC foi aumentada pelas estatinas, porém não foi estimulada pela ezetimiba. Entretanto, os efeitos antiinflamatórios exercidos pelas estatinas foram independentes dessa via devido a que estes efeitos foram mantidos em células HUVEC com NOS3 silenciado por interferência de RNAm. Apesar de que o efeito sobre ICAM-1 e MCP-1 foi atenuado quando as células foram simultaneamente tratadas com L-NAME, os efeitos das estatinas parecem ser independentes da liberação de NO. As estatinas e a ezetimiba reduziram a expressão do miR-221, em células HUVEC. A expressão do miR-222 foi reduzida só pelo tratamento com atorvastatina. A expressão do miR-1303 não foi modulada pelos tratamentos hipolipemiantes. Em pacientes HC, a terapia de associação da sinvastatina e ezetimiba demonstrou melhorar o perfil lipídico de forma mais efetiva que ambas monoterapias. Da mesma forma, o tratamento combinado resultou em maior beneficio pela redução da expressão de RNAm em CMSP e da concentração plasmática das proteínas IL-1 ß, MCP-1, IL-8 e TNFα. A expressão de ICAM1 foi diminuída apenas no nível transcricional, entretanto a expressão de RNAm mas não da proteína do TNFα foi também reduzida pela sinvastatina em monoterapia. Não houve modulação de RNAm ou proteínas de outros marcadores estudados no modelo in vivo. Por outro lado, os efeitos anti-inflamatórios observados nos indivíduos HC foram independentes da modulação de PCRus e NO que não foram modificados pelos tratamentos hipolipemiantes. Neste estudo, foram confirmados os propostos efeitos pleiotrópicos das estatinas em modelos células de monócito e endotélio vascular in vitro e em pacientes HC. Por outro lado, apesar de ser menos potente que as estatinas foi mostrado que a inibição da absorção do colesterol tem também um efeito anti-inflamatório. A redução adicional do colesterol causado pela combinação das terapias hipolipemiantes outorga um maior beneficio cardiovascular em pacientes hipercolesterolêmicos

The inflammatory process has a key role in the genesis and development of atherosclerosis and the endothelial disfunction is considered as a first step in atherogenesis. By inhibiting the hydroxyl-methyl-glutaryl coA reductase (HMGCR)m statins reduce the cholesterol synthesis and isoprenoid generation, which are intermediary products of cholesterol synthesis with important role in posttranscriptional modifications of small GTPases that are involved in endothelial disfunction and vascular inflammation. The ezetimibe is an inhibitor of cholesterol absorption by inhibiting the NPC1L1 protein. To clarify the molecular mechanisms of the inhibition of cholesterol synthesis and absorption modulating inflammatory and cell adhesion biomarkers we used in vitro models of endothelial cells (HUVEC) and monocytes (THP-1), and an in vivo model of peripheral blood mononuclear cells (PBMC) from hypercholesterolemic (HC) patients. The effect of the statins, atorvastatin and simvastatin, and the ezetimibe on mRNA and protein expression of endothelial adhesion molecules and modulators of the inflammatory process, as citokynes and nitric oxide (NO), was analyzed in HUVEC. The effect of these drugs on the expression of monocyte adhesion molecules was also studied in THP-1. The influence of hypolipemiant therapy on the adhesion molecules was also analyzed in PBMC from HC treated with ezetimibe (10 mg/day/4-weeks), simvastatin (10 mg/day/8-weeks) and simvastatin combined with ezetimibe (10 mg each/day/4-weeks). The mRNA expression was evaluated by RT-qPCR. The expression of adhesion molecules on the surface of THP-1 and HUVEC cells was analyzed flow cytometry. The citokynes in the supernatants of HUVEC were quantified using the milliplex technology. The Lipid profile, high-sensivity PCR (hsPCR) and NO were determined by conventional laboratory methods. The role of the NO on the statin-modulation of inflammatory markers was also studied using a model with silenced NOS3 by interference of mRNA and by the use of the inhibitor of NO synthesis, L-NAME. The effect of hypolipemiants on the expression of microRNAs (miRs) 221, miR-222 and miR-1303 was also evaluated in HUVEC using the stem-loom RT-qPCR. Atorvastatin and simvastatin reduced the mRNA and protein expression of the adhesion molecules L-Selectin, PSGL-1 and VLA-4 in THP-1 cells pre-treated with TNFα for 12 h. The ezetimibe reduced the L-Selectin expression only at transcriptional level. In HUVEC, statins diminished IL1B and SELP mRNA expression, whereas VCAM1 was increased. The ezetimibe reduced the IL1B mRNA expression. However, SELE, MMP9, IL6 and MMP9 mRNA expressions were not affected by the treatments. The protein expression of ICAM-1 and P-Selectin on the surface of HUVEC was reduced by statins, but not by the ezetimibe. Similarly, IL-6 and MCP-1 secretion were reduced by statins, whereas IL-8 secretion was not modified by the treatments. The NO release and NOS3 expression in HUVEC was increased by the statins, however it was not stimulated by ezetimibe. Moreover, the anti-inflammatory statin effects were independent of this pathway due to statin effects were maintained in HUVEC with silenced NOS3. Although the statin effect on ICAM-1 and MCP-1 were attenuated by L-NAME co treatment, the statin effects seem to be independent of NO release. Statins and ezetimibe reduced miR221 in HUVEC. miR-222 expression was reduced only by atorvastatin. miR-1303 was not affected by the treatments. In HC patients, the improvement of the lipid profile simvastatin combined with ezetimibe was more efficient than both monotherapies. Similarly, the association therapy was better in reducing the mRNA expression in PBMC and plasma concentration of IL-1ß, MCP-1, IL-8 and TNFα. ICAM1 expression was reduced only at transcriptional level, whereas mRNA but not protein expression of TNFα was also reduced by the simvastatin monotherapy. There was no modulation mRNA or protein expression of other studied markers in the in vivo model. Additionally, the anti-inflammatory effects observed in the HC were independent of PCRus or NO modulation, which were not altered by the hypolipemiant treatments. In this study, the proposed plitropic effects of statins were confirmed in monocytes and endothelial cells in vitro and in HC patients. Moreover, although it was less potent than statins, an anti-inflammatory effect was also observed for the inhibition of cholesterol absorption. An additional reduction of the cholesterol caused by combined hypolipemiant therapies gives a greater cardiovascular beneffict in hypercholesterolemic patients

Efeito de hipolipemiantes sobre a expressão de genes envolvidos no transporte reverso do colesterol / Statin effects on expression of genes involved in reverse cholesterol transport

A eficácia das estatinas em reduzir o risco de eventos coronarianos não é completamente explicada por seus efeitos em diminuir colesterol de lipoproteína de baixa densidade (LDL-C). Um dos seus efeitos adicionais pode ser decorrente da modificação na concentração de lipoproteína de alta densidade (HDL), reconhecida como ateroprotetora, principalmente por seu papel no transporte reverso do colesterol (TRC). Os transportadores de membrana do tipo ATP-binding cassette, ABCA1 e ABCG1, e o scavenger receptor BI (SRBI) são proteínas importantes envolvidas no TRC e seus genes são regulados por vários fatores de transcrição, entre eles os liver-x-receptors (LXRs). Com a finalidade de avaliarmos os efeitos dos hipolipemiantes sobre expressão dos transportadores ABC e do receptor SRBI, a expressão de RNAm do ABCA1, ABCG1, SCARB1, NR1H3 (LXRα) e NR1H2 (LRXß) foi avaliada por PCR em tempo real em células das linhagens HepG2 (origem hepática) e Caco-2 (origem intestinal) tratadas com atorvastatina ou sinvastatina (10 µM) e/ou ezetimiba (até 5 µM) por até 24 horas. Além disso, a expressão desses genes também foi avaliada em células mononucleares do sangue periférico (CMSP) de 50 pacientes normolipidêmicos (NL) e 71 hipercolesterolêmicos (HC) tratados com atorvastatina (10mg/dia/4semanas, n=48) ou sinvastatina e/ou ezetimiba (10mg/dia/4 ou 8 semanas, n=23). A possível associação entre os polimorfismos ABCA1 C-14T e R219K e a expressão de RNAm em CMSP também foi avaliada por PCR-RFLP. O SCARB1 foi o gene mais expresso nas células HepG2 e Caco-2, seguido por NR1H2, NR1H3, ABCG1 e ABCA1 em HepG2 ou por ABCA1 e ABCG1 em Caco-2. O tratamento com estatinas (1 ou 10 µM) ou ezetimiba (5 µM), por 12 ou 24 horas, aumentou a expressão de RNAm do ABCG1, mas não de ABCA1 e SCARB1, em células HepG2. Ainda nesta linhagem, o aumento na transcrição dos genes NR1H2 e NR1H3 foi observado somente com a maior concentração de atorvastatina (10 µM) e, ao contrário, o tratamento com ezetimiba causou redução na transcrição de NR1H2, sem alteração de NR1H3. Em células Caco-2, o tratamento com atorvastatina ou sinvastatina por 12 ou 24 horas reduziu a quantidade do transcrito ABCA1 e não alterou a expressão do SCARB1 e do ABCG1, embora, para este último, tenha havido uma tendência à diminuição da expressão após tratamento com sinvastatina (p=0,07). Após tratamento com ezetimiba isolada (até 5 µM) nenhuma alteração de expressão de RNAm foi observada em células Caco-2; no entanto, após 24 horas de tratamento com sinvastatina e ezetimiba, foi reduzida a taxa de transcrição de ABCA1 e ABCG1, mas não de SCARB1. Ao contrário das linhagens celulares, em CMSP os genes NR1H2 e ABCG1 foram os mais expressos, seguidos pelos genes SCARB1 e ABCA1 e, finalmente, pelo NR1H3. Indivíduos HC tiveram maior expressão basal de NR1H2 e NR1H3, mas não de outros genes, quando comparados aos NL (p<0,05). Além disso, nos indivíduos HC, a expressão basal de ABCA1 foi maior em portadores do alelo -14T do polimorfismo ABCA1 -14C>T quando comparados aos portadores do genótipo -14CC (p=0,034). O tratamento com estatinas, com ezetimiba ou com a terapia combinada diminuiu a transcrição de ABCA1 e ABCG1. Para o SCARB1, NR1H2 e NR1H3, nenhuma alteração de expressão de RNAm em CMSP foi detectada após os tratamentos in vivo. Após todas as fases de tratamento, ABCA1 e ABCG1 e também NR1H2 e NR1H3 foram significativamente correlacionados entre si, mas nenhuma correlação com perfil lipídico sérico foi relevante. Coletivamente, esses resultados dão indícios de que os hipolipemiantes analisados (estatinas e ezetimiba) têm um importante papel na regulação da expressão de genes envolvidos no transporte reverso do colesterol e sugerem a existência de regulação tecido-específica para os dois transportadores ABC. Além disso, o efeito das estatinas ou da ezetimiba sobre a expressão do ABCA1, do ABCG1 ou do SCARB1 não sofreu influencia de alterações diretas da transcrição dos LXRs

The efficacy of statins in reducing the risk of coronary events is not completely explained by their effects in decreasing cholesterol low-density lipoprotein (LDL-C). One of their additional effects may result from the change in concentration of high-density lipoprotein (HDL), recognized as atheroprotective, mainly for the role in reverse cholesterol transport (RCT). The membrane transporters, as ATP-binding cassette, ABCA1 and ABCG1, and scavenger receptor BI (SRBI) are important proteins involved in the RCT and their genes are regulated by various transcription factors, including the liver-X-receptors (LXRs) . In order to evaluate the effects of lipid lowering on expression of ABC transporters and SRBI receptor, the mRNA expression of ABCA1, ABCG1, SCARB1, NR1H3 (LXRα) and NR1H2 (LRXß) was assessed by real time PCR in HepG2 (hepatic origin) and Caco-2 (intestinal origin) cells treated with atorvastatin or simvastatin (10 µM) and/or ezetimibe (up to 5 µM) for 24 hours. Furthermore, the expression of these genes was evaluated in peripheral blood mononuclear cells (PBMC) of 50 normolipidemic (NL) and 71 hypercholesterolemic (HC) patients treated with atorvastatin (10mg/d/4 weeks, n = 48) or simvastatin and/or ezetimibe (10mg/d/4 or 8 weeks, n = 23). The possible association between ABCA1 C-14T and R219K polymorphisms and mRNA expression in PBMC was also evaluated by PCR-RFLP. SCARB1 was the most expressed in HepG2 and Caco-2 cells, followed by NR1H2, NR1H3, ABCG1 and ABCA1 in HepG2 or by ABCG1 and ABCA1 in Caco-2. The treatment with statins (1 or 10 µM) or ezetimibe (5 µM) for 12 or 24 hours, increased mRNA expression of ABCG1 but not ABCA1 and SCARB1 in HepG2 cells. Moreover, in HepG2 cells, atorvastatin also upregulated NR1H2 and NR1H3 only at 10.0 µM, meanwhile ezetimibe downregulated NR1H2 but did not change NR1H3 expression. In Caco-2 cells, atorvastatin or simvastatin treatment for 12 or 24 hours reduced the amount of ABCA1 transcript and did not alter the ABCG1 and SCARB1 expressions, despite the tendency to decrease ABCG1 mRNA expression after simvastatin treatment (p = 0.07). After treatment with ezetimibe alone (up to 5 µM) no change in mRNA expression was observed in Caco-2 cells; however, after 24 hours- simvastatin and ezetimibe treatments decreased the transcription of ABCA1 and ABCG1, but not of SCARB1. Unlike cell lines, in PBMC, NR1H2 and ABCG1 were the most expressed, followed by SCARB1 and ABCA1 and finally by the NR1H3. HC patients showed higher NR1H2 and NR1H3 basal expressions, but not of other genes, compared to NL (p <0.05). Moreover, in HC individuals, the ABCA1 basal expression was higher in individuals carrying -14T allele of -14C> T polymorphism when compared with -14CC carriers (p = 0.034). Treatment with statins, ezetimibe, or combined therapy downregulated ABCA1 and ABCG1 expression. For SCARB1, NR1H2 and NR1H3, no change in mRNA expression in PBMC was detected after treatments. After all phases of treatment, ABCA1 and ABCG1 as well as NR1H2 and NR1H3 were significantly correlated, but no correlation with serum lipid profile was relevant. Collectively, these results provide evidences that the lipid lowering (statins and ezetimibe) have an important role in mRNA expression regulation of genes involved in reverse cholesterol transport and suggest the existence of tissue-specific regulation for the ABC transporters. Furthermore, the effect of statins or ezetimibe on ABCA1, ABCG1 or SCARB1 expression was not directly influenced by changes of LXR transcription