RESUMO
Proprotein convertase subtilisin/kexin 9 (PCSK9) is a protein that plays a key role in the metabolism of low-density lipoprotein (LDL) cholesterol. The gain-of-function mutations of the PCSK9 gene lead to a reduced number of surface LDL receptors by binding to them, eventually leading to endosomal degradation. This, in turn, is the culprit of hypercholesterolemia, resulting in accelerated atherogenesis. The modern treatment for hypercholesterolemia encompasses the use of biological drugs against PCSK9, like monoclonal antibodies and gene expression modulators such as inclisiran-a short, interfering RNA (siRNA). Peptide nucleic acid (PNA) is a synthetic analog of nucleic acid that possesses a synthetic peptide skeleton instead of a phosphate-sugar one. This different structure determines the unique properties of PNA (e.g., neutral charge, enzymatic resistance, and an enormously high affinity with complementary DNA and RNA). Therefore, it might be possible to use PNA against PCSK9 in the treatment of hypercholesterolemia. We sought to explore the impact of three selected PNA oligomers on PCSK9 gene expression. Using a cell-free transcription/translation system, we showed that one of the tested PNA strands was able to reduce the PCSK9 gene expression down to 74%, 64%, and 68%, as measured by RT-real-time PCR, Western blot, and HPLC, respectively. This preliminary study shows the high applicability of a cell-free enzymatic environment as an efficient tool in the initial evaluation of biologically active PNA molecules in the field of hypercholesterolemia research. This cell-free approach allows for the omission of the hurdles associated with transmembrane PNA transportation at the early stage of PNA selection.
Assuntos
Hipercolesterolemia , Inibidores de PCSK9 , Ácidos Nucleicos Peptídicos , Humanos , Expressão Gênica , Hipercolesterolemia/tratamento farmacológico , Hipercolesterolemia/genética , Ácidos Nucleicos Peptídicos/farmacologia , Pró-Proteína Convertase 9/efeitos dos fármacos , Pró-Proteína Convertase 9/genética , Pró-Proteína Convertases/genética , Receptores de LDL/genética , Receptores de LDL/metabolismo , Subtilisina/genética , Inibidores de PCSK9/farmacologiaRESUMO
Familial hypercholesterolemia (FH), an autosomal dominant disorder of LDL metabolism that is characterized by elevated LDL-cholesterol, is commonly encountered in patients with atherosclerotic coronary heart disease. Combinations of cholesterol-lowering therapies are often used to lower LDL-cholesterol in patients with FH; however, current treatment goals for LDL-cholesterol are rarely achieved in patients with homozygous FH (HoFH) and are difficult to achieve in patients with heterozygous FH (HeFH). Therapies that lower LDL-cholesterol through LDL receptor-mediated mechanisms have thus far been largely ineffective in patients with HoFH, particularly in those with negligible (<2%) LDL receptor activity. Among patients with HeFH who were at very high risk for atherosclerotic cardiovascular disease events, combined therapy consisting of a high dose of high-intensity statin, ezetimibe, and proprotein convertase subtilisin Kexin type 9 inhibitor failed to lower LDL-cholesterol to minimal acceptable goals in more than 50%. This article provides a framework for the use of available and emerging treatments that lower LDL-cholesterol in adult patients with HoFH and HeFH. A framework is provided for the use of angiopoietin-like protein 3 inhibitors in the treatment of HoFH and HeFH.
Assuntos
Hipercolesterolemia Familiar HomozigotaRESUMO
Cardiovascular disease (CVD) is the leading cause of death worldwide and is the clinical manifestation of the atherosclerosis. Elevated LDL-cholesterol levels are the first line of therapy but the increasing prevalence in type 2 diabetes mellitus (T2DM) has positioned the cardiometabolic risk as the most relevant parameter for treatment. Therefore, the control of this risk, characterized by dyslipidemia, hypertension, obesity, and insulin resistance, has become a major goal in many experimental and clinical studies in the context of CVD. In the present review, we summarized experimental studies and clinical trials of recent anti-diabetic and lipid-lowering therapies targeted to reduce CVD. Specifically, incretin-based therapies, sodium-glucose co-transporter 2 inhibitors, and proprotein convertase subtilisin kexin 9 inactivating therapies are described. Moreover, the novel molecular mechanisms explaining the CVD protection of the drugs reviewed here indicate major effects on vascular cells, inflammatory cells, and cardiomyocytes, beyond their expected anti-diabetic and lipid-lowering control. The revealed key mechanism is a prevention of acute cardiovascular events by restraining atherosclerosis at early stages, with decreased leukocyte adhesion, recruitment, and foam cell formation, and increased plaque stability and diminished necrotic core in advanced plaques. These emergent cardiometabolic therapies have a promising future to reduce CVD burden.
Assuntos
Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/terapia , Diabetes Mellitus Tipo 2/complicações , Suscetibilidade a Doenças , Dislipidemias/complicações , Animais , Biomarcadores , Doenças Cardiovasculares/metabolismo , Estudos Clínicos como Assunto , Diabetes Mellitus Tipo 2/metabolismo , Gerenciamento Clínico , Desenho de Fármacos , Desenvolvimento de Medicamentos , Avaliação Pré-Clínica de Medicamentos , Dislipidemias/metabolismo , Humanos , Incretinas/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Terapia de Alvo Molecular , Inibidores de PCSK9 , Medição de Risco , Fatores de RiscoRESUMO
Familial hypercholesterolemia (FH) is a common genetic condition characterized by elevated plasma levels of low-density lipoprotein cholesterol (LDL-C), premature atherosclerotic cardiovascular disease, and considerable unmet medical need with conventional LDL-C-lowering therapies. Between 2012 and 2015, the US Food and Drug Administration approved four novel LDL-C-lowering agents for use in patients with FH based on the pronounced LDL-C-lowering efficacy of these medicines. We review the four novel approved agents, as well as promising LDL-C-lowering agents in clinical development, with a focus on their mechanism of action, efficacy in FH cohorts, and safety.
Assuntos
Anticolesterolemiantes/uso terapêutico , Hiperlipoproteinemia Tipo II/terapia , Proteínas Semelhantes a Angiopoietina/antagonistas & inibidores , Anticorpos Monoclonais/uso terapêutico , Anticorpos Monoclonais Humanizados , Benzimidazóis/uso terapêutico , Caproatos/uso terapêutico , Proteínas de Transferência de Ésteres de Colesterol/antagonistas & inibidores , Ácidos Dicarboxílicos/uso terapêutico , Ácidos Graxos/uso terapêutico , Terapia Genética , Humanos , Oligonucleotídeos/uso terapêutico , RNA Interferente Pequeno/uso terapêutico , Receptores de LDL/genética , Resultado do TratamentoRESUMO
BACKGROUND: Low-density lipoprotein (LDL) levels are increased by proprotein convertase subtilisin kexin 9 (PCSK9) which targets the LDL receptor. We recently reported that PCSK9 ameliorates dendritic cell (DC) activation by oxidized LDL (OxLDL), which is abundant in atherosclerotic plaques and is also associated with cardiovascular disease (CVD) in systemic lupus erythematosus (SLE). Here, we investigated the role of PCSK9 in SLE. METHODS: PCSK9 levels were determined by ELISA among SLE patients (N = 109) and age- and sex-matched population-based controls (N = 91). Common carotid intima-media thickness (IMT) and plaque occurrence were determined by B-mode ultrasound. Plaques were graded by echogenicity. Human peripheral blood monocytes from SLE patients or controls were differentiated into DCs. The effects of PCSK9 and its inhibition by silencing were studied. RESULTS: PCSK9 levels were non-significantly higher among SLE-patients compared to controls but significantly associated with SLE disease activity, as determined by the Systemic Lupus Activity Measure (p = 0.020) or the SLE Disease Activity Index (p = 0.0178). There was no association between PCSK9 levels and atherosclerosis as determined by IMT, prevalence of plaques or echolucent (potentially vulnerable) plaques. PCSK9 levels were significantly associated with CVD among SLE patients but not after adjusting for age. OxLDL induced PCSK9 in DCs and DC maturation with increased expression of CD86 and HLA-DR. The effects were significantly stronger in DCs from SLE patients than from controls. Silencing of PCSK9 abolished OxLDL-induced DC maturation. CONCLUSIONS: PCSK9 is associated with disease activity in SLE. One underlying cause could be OxLDL promoting DC activation which depends on PCSK9. OxLDL induces PCSK9 - an effect which is higher among SLE patients. PCSK9 could play an unexpected immunological role in SLE.
Assuntos
Lúpus Eritematoso Sistêmico/sangue , Pró-Proteína Convertase 9/sangue , Adulto , Espessura Intima-Media Carotídea , Estudos de Casos e Controles , Feminino , Humanos , Lipoproteínas LDL/sangue , Lúpus Eritematoso Sistêmico/imunologia , Masculino , Pessoa de Meia-Idade , Placa Aterosclerótica/diagnóstico por imagem , Pró-Proteína Convertase 9/imunologia , Fatores de RiscoRESUMO
BACKGROUND: The present study was designed to test the hypothesis that in the liver, excessive fat accumulation impairs cholesterol metabolism mainly by altering the low-density lipoprotein-receptor (LDL-R) pathway. METHOD: Young male Wistar rats were fed standard (SD), high fat (HFD; 60% kcal) or Western (WD; 40% fat + 35% sucrose (17.5% fructose)) diets for 2 or 6 weeks. RESULTS: Weight gain (~ 40 g) was observed only following 6 weeks of the obesogenic diets (P < 0.01). Compared to the 2-week treatment, obesogenic diets tripled fat pad weight (~ 20 vs 7 g) after 6 weeks. Hepatic triglyceride (TG) levels were greater in response to both the WD and HFD compared to the SD (P < 0.01) at 2 and 6 weeks and their concentrations were greater (P < 0.05) in WD than HFD at 2 weeks. Plasma total cholesterol levels were higher (P < 0.05) in animals submitted to WD. After 2 and 6 weeks, liver expression of LDL-R, proprotein convertase subtilisin/kexin 9 (PCSKk9) and sterol regulatory element binding protein 2 (SREBP2), involved in LDL-cholesterol uptake, was lower in animals submitted to WD than in others treated with HFD or SD (P < 0.01). Similarly, low-density lipoprotein-receptor-related protein 1 (LRP1) and acyl-CoA cholesterol acyltransferase-2 (ACAT-2) mRNA levels were lower (P < 0.01) among WD compared to SD-fed rats. Expression of the gene coding the main regulator of endogenous cholesterol synthesis, 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMGCoAR) was reduced in response to WD compared to SD and HFD at 2 (P < 0.001) and 6 (P < 0.05) weeks. Being enriched in fructose, the WD strongly promoted the expression of carbohydrate-response element binding protein (ChREBP) and acetyl-CoA carboxylase (ACC), two key regulators of de novo lipogenesis. CONCLUSION: These results show that the WD promptly increased TG levels in the liver by potentiating fat storage. This impaired the pathway of hepatic cholesterol uptake via the LDL-R axis, promoting a rapid increase in plasma total cholesterol levels. These results indicate that liver fat content is a factor involved in the regulation of plasma cholesterol.
Assuntos
Colesterol/sangue , Dieta Ocidental/efeitos adversos , Metabolismo dos Lipídeos/efeitos dos fármacos , Animais , Fígado Gorduroso/sangue , Masculino , Ratos , Ratos Wistar , Subtilisina/sangueRESUMO
BACKGROUND: Recent studies have shown that alcohol use affects the regulation and expression of proprotein convertase subtilisin/kexin 9 (PCSK9). While a major role of PCSK9 in hepatic function and lipid regulation has been clearly established, other pleiotropic effects remain poorly understood. Existing research suggests a positive association between PCSK9 expression in the brain and psychopathology, with increased levels of PCSK9 in the cerebrospinal fluid (CSF) of individuals with dementia and epigenetic modifications of PCSK9 associated with alcohol use disorder (AUD). In this study, we hypothesized that chronic alcohol use would increase PCSK9 expression in CSF. METHODS: PCSK9 levels in CSF were measured in individuals with AUD (n = 42) admitted to an inpatient rehabilitation program and controls (n = 25). CSF samples in AUD were assessed at 2 time points, at day 5 and day 21 after admission. Furthermore, plasma samples were collected and measured from the individuals with AUD. RESULTS: PCSK9 in CSF was significantly increased in the AUD group at day 5 and day 21 compared to the controls (p < 0.0001). Plasma PCSK9 levels were correlated positively with CSF PCSK9 levels in AUD (p = 0.0493). CONCLUSIONS: Our data suggest that PCSK9 is elevated in the CSF of individuals with AUD, which may indicate a potential role of PCSK9 in AUD. Additional studies are necessary to further elucidate the functions of PCSK9 in the brain.
Assuntos
Alcoolismo/líquido cefalorraquidiano , Pró-Proteína Convertase 9/líquido cefalorraquidiano , Adulto , Alcoolismo/sangue , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pró-Proteína Convertase 9/sangueRESUMO
Diabetic dyslipidaemia, characterized by quantitative, qualitative and kinetic changes in all major circulating lipids, contributes to the increased cardiovascular risk in patients with type 2 diabetes mellitus (T2DM). A promising therapeutic avenue is the inhibition of the proprotein convertase subtilisin kexin 9 (PCSK9) with human monoclonal antibodies (mAbs) that potently reduce plasma low-density lipoprotein cholesterol (LDL-C) levels on top of statin treatment. The aim of this review is to evaluate the efficacy of PCSK9 inhibitors to lower the residual cardiovascular risk of T2DM patients and to discuss the safety of PCSK9 inhibition in these patients. PCSK9 inhibitors potently lower plasma LDL-C levels in T2DM patients and reduce risk for the development of cardiovascular disease. Anti-PCSK9 mAbs are generally not more or less effective in T2DM patients compared to a general high-risk population. Nevertheless, due to their higher cardiovascular risk, the absolute risk reduction of major cardiovascular events is more significant in T2DM patients. This suggests that treatment of T2DM patients with anti-PCSK9 mAbs could be attractive from a cost-effectiveness perspective. Treatment with anti-PCSK9 mAbs did not result in significant treatment-emergent adverse effects. While genetic studies suggest a potential link between PCSK9 inhibition and glucose homeostasis, anti-PCSK9 mAbs did not worsen glycaemic control in T2DM patients, but their safety should be verified after a longer-term follow-up.
Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Diabetes Mellitus Tipo 2/complicações , Dislipidemias/tratamento farmacológico , Hipolipemiantes/uso terapêutico , Inibidores de PCSK9 , Adulto , Idoso , LDL-Colesterol/sangue , Diabetes Mellitus Tipo 2/sangue , Dislipidemias/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do TratamentoRESUMO
Proprotein convertase subtilisin/kexin 9 (PCSK9), a protein regulating the number of cell-surface LDL receptors (LDLR), circulates partially associated to plasma lipoproteins. How this interaction alters PCSK9 plasma levels is still unclear. In the present study, we took advantage of the availability of a large cohort of carriers of genetic HDL disorders to evaluate how HDL defects affect plasma PCSK9 levels and its distribution among lipoproteins. Plasma PCSK9 concentrations were determined by ELISA in carriers of mutations in LCAT, ABCA1, or APOAI genes, and lipoprotein distribution was analyzed by FPLC. Carriers of one or two mutations in the LCAT gene show plasma PCSK9 levels comparable to that of unaffected family controls (homozygotes, 159.4â¯ng/mL (124.9;243.3); heterozygotes, 180.3â¯ng/mL (127.6;251.5) and controls, 190.4â¯ng/mL (146.7;264.4); P for trendâ¯=â¯0.33). Measurement of PCSK9 in plasma of subjects carrying mutations in ABCA1 or APOAI genes confirmed normal values. When fractionated by FPLC, PCSK9 peaked in a region between LDL and HDL in control subjects. In carriers of all HDL defects, lipoprotein profile shows a strong reduction of HDL, but the distribution of PCSK9 was superimposable to that of controls. In conclusion, the present study demonstrates that in genetically determined low HDL states plasma PCSK9 concentrations and lipoprotein distribution are preserved, thus suggesting that HDL may not be involved in PCSK9 transport in plasma.
Assuntos
Transportador 1 de Cassete de Ligação de ATP/sangue , Apolipoproteína A-I/sangue , Hipolipoproteinemias/sangue , Fosfatidilcolina-Esterol O-Aciltransferase/sangue , Pró-Proteína Convertase 9/sangue , Transportador 1 de Cassete de Ligação de ATP/deficiência , Transportador 1 de Cassete de Ligação de ATP/genética , Adulto , Idoso , Apolipoproteína A-I/deficiência , Apolipoproteína A-I/genética , Estudos de Casos e Controles , Feminino , Regulação da Expressão Gênica , Heterozigoto , Homozigoto , Humanos , Hipolipoproteinemias/genética , Hipolipoproteinemias/patologia , Lipoproteínas HDL/sangue , Lipoproteínas HDL/genética , Lipoproteínas LDL/sangue , Lipoproteínas LDL/genética , Masculino , Pessoa de Meia-Idade , Fosfatidilcolina-Esterol O-Aciltransferase/genética , Pró-Proteína Convertase 9/genéticaRESUMO
PURPOSE OF REVIEW: Clinical trials with PCSK9 inhibitors have shown a robust decrease in plasma LDL levels and a significant reduction in the incidence of cardiovascular atherosclerotic events. However, the role of PCSK9 in atherosclerosis is not well investigated and it remains unclear whether PCSK9 inhibition has direct, LDL-independent, anti-atherosclerotic effects. This review outlines the molecular pathways and targets of PCSK9 in atherosclerosis and summarizes the experimental and clinical data supporting the anti-atherosclerotic (pleiotropic) actions of PCSK9 inhibitors. RECENT FINDINGS: PCSK9 is expressed by various cell types that are involved in atherosclerosis (e.g., endothelial cell, smooth muscle cell, and macrophage) and is detected inside human atherosclerotic plaque. Preclinical studies have shown that inhibition of PCSK9 can attenuate atherogenesis and plaque inflammation. Besides increasing plasma LDL, PCSK9 appears to promote the initiation and progression of atherosclerosis. Inhibition of PCSK9 may confer atheroprotection that extends beyond its lipid-lowering effects.
Assuntos
Anticolesterolemiantes/uso terapêutico , Aterosclerose/tratamento farmacológico , Aterosclerose/genética , Inibidores de PCSK9 , Pró-Proteína Convertase 9/genética , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais/uso terapêutico , Anticolesterolemiantes/farmacologia , Aterosclerose/metabolismo , LDL-Colesterol/antagonistas & inibidores , LDL-Colesterol/sangue , LDL-Colesterol/metabolismo , Expressão Gênica , Humanos , Inflamação/tratamento farmacológico , Inflamação/genética , Inflamação/metabolismo , Placa Aterosclerótica/tratamento farmacológico , Placa Aterosclerótica/genética , Placa Aterosclerótica/metabolismo , Pró-Proteína Convertase 9/metabolismo , RNA Interferente Pequeno/genética , Vacinas/farmacologia , Vacinas/uso terapêuticoRESUMO
OBJECTIVE: To propose and verify a hypothesis that miR-17-5p knockdown may mitigate atherosclerotic lesions using atherosclerotic ApoE-/- mice as serum microRNA-17-5p (miR-17-5p) is elevated in patients with atherosclerosis. RESULTS: The level of miR-17-5p was higher while the level of very low density lipoprotein receptor (VLDLR), a predicted target of miR-17-5p, was lower in the peripheral blood lymphocytes (PBLs) of atherosclerosis patients as compared with control PBLs. ApoE-/- mice fed with a high-cholesterol diet displayed marked atherosclerotic vascular lesions, which were ameliorated after treatment with antagomiR-17-5p. Moreover, the decreased VLDLR in atherosclerotic mice was partly restored when miR-17-5p was antagonized. Further, luciferase assay confirmed VLDLR as a direct target of miR-17-5p in vascular smooth muscle cells (VSMCs). In addition, the elevated expression of proprotein convertase subtilisin kexin 9 (PCSK9), a secreted protease that binds to and promotes VLDLR degradation, in the atherosclerotic mice was suppressed by antagomiR-17-5p. CONCLUSIONS: A novel interaction between miR-17-5p and VLDLR is revealed and suggests that miR-17-5p may be a potential therapeutic target for AS.
Assuntos
Apolipoproteínas E/deficiência , Aterosclerose/patologia , MicroRNAs/biossíntese , Receptores de LDL/biossíntese , Animais , Células Cultivadas , Modelos Animais de Doenças , Técnicas de Silenciamento de Genes , Genes Reporter , Humanos , Leucócitos Mononucleares/química , Luciferases/análise , Camundongos Knockout para ApoERESUMO
Objective: To assess the expression and significance of proprotein convertase subtilisin kexin 9 (PCSK9) in patients with rheumatoid arthritis (RA). Methods: Sixty-five RA patients and forty-seven healthy controls were recruited in this study. The body mass index (BMI) and serum total cholesterol(TC), triglyceride(TG), high density lipoprotein(HDL), lipoprotein a, low density lipoprotein(LDL), very low density lipoprotein(VLDL), apolipoprotein A(ApoA), apolipoprotein B(ApoB) and the ratio of LDL-C/HDL-C were tested. Other parameters included disease activity score 28(DAS28), rheumatoid factor (RF), anti-cyclic citrullinated peptide (CCP) antibody, erythrocyte sedimentation rate (ESR), c-reactive protein (CRP). Serum PCSK9 level was measured by ELISA and compared between RA patients and healthy controls. Results: (1) The serum PCSK9 levels in RA patients were higher than those in healthy controls[(409.36±223.52) µg/L vs (292.19±109.79) µg/L, P<0.05]. (2) Compared with subgroup of moderate and low active disease and patients in remission, PCSK9 was significantly higher in patients with highly active disease (P<0.05). (3) The serum PCSK9 levels were positively correlated with RF, TC, TG, LDL, very low density lipoprotein (VLDL), ApoB, with r values as 0.303, 0.490, 0.320, 0.451, 0.319, 0.463, respectively (P<0.05). (4) Multiple stepwise regression analysis showed that DAS28, RF, TC and LDL-C/HDL-C were relevant factors for PCSK9 in RA patients. Conclusions: The serum PCSK9 level is elevated in RA patients, which is related to RF, disease activity, TC, TG, LDL, VLDL, ApoB. This suggests that PCSK9 is potentially linked to inflammatory reaction and lipid metabolism in rheumatoid arthritis.
Assuntos
Pró-Proteína Convertase 9/fisiologia , Artrite Reumatoide/sangue , Artrite Reumatoide/metabolismo , Artrite Reumatoide/fisiopatologia , Estudos de Casos e Controles , LDL-Colesterol/sangue , Humanos , Pró-Proteína Convertase 9/sangue , Pró-Proteína Convertase 9/metabolismoRESUMO
Considerable evidence suggests that "the lower the better" is a reasonable approach for reducing cardiovascular risk by lowering LDL cholesterol levels. Despite the reduction in cardiovascular events and mortality achieved by statin therapy, significant residual risk remains, especially in severe hereditary hypercholesterolemia, such as familial hypercholesterolemia. Some new strategies to achieve even lower LDL levels are now available, including the addition of cholesterol absorption inhibitor ezetimibe, and the recently available Proprotein convertase subtilisin/kexin type 9 monoclonal antibodies. In addition, new LDL drugs may be effectively administrated in those individuals who are unable to tolerate statins. The authors summarize the efficacy and clinical indications of these new agents and review the currently available guidelines. Orv. Hetil., 2016, 157(31), 1219-1223.
Assuntos
Anticolesterolemiantes/uso terapêutico , Doenças Cardiovasculares/prevenção & controle , LDL-Colesterol/sangue , Hiperlipoproteinemia Tipo II/tratamento farmacológico , Inibidores de PCSK9 , Anticolesterolemiantes/farmacologia , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/etiologia , LDL-Colesterol/efeitos dos fármacos , Quimioterapia Combinada , Ezetimiba/uso terapêutico , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêuticoRESUMO
Despite significant reduction of cardiovascular events by statin treatment, substantial residual risk persists, driving emerging needs for the development of new therapies. We identified a novel cholesteryl ester transfer protein (CETP) inhibitor, K-312, that raises HDL and lowers LDL cholesterol levels in animals. K-312 also suppresses hepatocyte expression of proprotein convertase subtilisin/kexin 9 (PCSK9), a molecule that increases LDL cholesterol. We explored the underlying mechanism for the reduction of PCSK9 expression by K-312. K-312 inhibited in vitro human plasma CETP activity (IC50; 0.06 µM). Administration of K-312 to cholesterol-fed New Zealand White rabbits for 18 wk raised HDL cholesterol, decreased LDL cholesterol, and attenuated aortic atherosclerosis. Our search for additional beneficial characteristics of this compound revealed that K-312 decreases PCSK9 expression in human primary hepatocytes and in the human hepatoma cell line HepG2. siRNA silencing of CETP in HepG2 did not compromise the suppression of PCSK9 by K-312, suggesting a mechanism independent of CETP. In HepG2 cells, K-312 treatment decreased the active forms of sterol regulatory element-binding proteins (SREBP-1 and -2) that regulate promoter activity of PCSK9. Chromatin immunoprecipitation assays demonstrated that K-312 decreased the occupancy of SREBP-1 and SREBP-2 on the sterol regulatory element of the PCSK9 promoter. PCSK9 protein levels decreased by K-312 treatment in the circulating blood of cholesterol-fed rabbits, as determined by two independent mass spectrometry approaches, including the recently developed, highly sensitive parallel reaction monitoring method. New CETP inhibitor K-312 decreases LDL cholesterol and PCSK9 levels, serving as a new therapy for dyslipidemia and cardiovascular disease.
Assuntos
Anticolesterolemiantes/farmacologia , Proteínas de Transferência de Ésteres de Colesterol/antagonistas & inibidores , LDL-Colesterol/metabolismo , Pró-Proteína Convertases/genética , Serina Endopeptidases/genética , Animais , Células Cultivadas , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Células Hep G2 , Humanos , Metabolismo dos Lipídeos/efeitos dos fármacos , Metabolismo dos Lipídeos/genética , Masculino , Camundongos , Pró-Proteína Convertase 9 , Pró-Proteína Convertases/metabolismo , Coelhos , Ratos , Ratos Sprague-Dawley , Serina Endopeptidases/metabolismoAssuntos
Anticolesterolemiantes/uso terapêutico , Doenças Cardiovasculares/prevenção & controle , Dislipidemias/tratamento farmacológico , Metabolismo dos Lipídeos/efeitos dos fármacos , Inibidores de PCSK9 , Inibidores de Serina Proteinase/uso terapêutico , Anticolesterolemiantes/efeitos adversos , Biomarcadores/sangue , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/genética , LDL-Colesterol/sangue , Dislipidemias/sangue , Dislipidemias/epidemiologia , Dislipidemias/genética , Medicina Baseada em Evidências/métodos , Humanos , Metabolismo dos Lipídeos/genética , Oligonucleotídeos Antissenso/uso terapêutico , Pró-Proteína Convertase 9/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Terapêutica com RNAi , Ensaios Clínicos Controlados Aleatórios como Assunto/métodos , Projetos de Pesquisa , Fatores de Risco , Inibidores de Serina Proteinase/efeitos adversos , Resultado do TratamentoRESUMO
Schisandra chinensis extract (SCE) protects against hypocholesterolemia by inhibiting proprotein convertase subtilisin/kexin 9 (PCSK9) protein stabilization. We hypothesized that the hypocholesterolemic activity of SCE can be attributable to upregulation of the PCSK9 inhibition-associated low-density lipoprotein receptor (LDLR). Male mice were fed a low-fat diet or a Western diet (WD) containing SCE at 1% for 12 weeks. WD increased final body weight and blood LDL cholesterol levels as well as alanine transaminase and aspartate aminotransferase expression. However, SCE supplementation significantly attenuated the increase in blood markers caused by WD. SCE also attenuated WD-mediated increases in hepatic LDLR protein expression in the obese mice. In addition, SCE increased LDLR protein expression and attenuated cellular PCSK9 levels in HepG2 cells supplemented with delipidated serum (DLPS). Non-toxic concentrations of schisandrin A (SA), one of the active components of SCE, significantly increased LDLR expression and tended to decrease PCSK9 protein levels in DLPS-treated HepG2 cells. High levels of SA-mediated PCSK9 attenuation was not attributable to reduced PCSK9 gene expression, but was associated with free PCSK9 protein degradation in this cell model. Our findings show that PCSK9 secretion can be significantly reduced by SA treatment, contributing to reductions in free cholesterol levels.
Assuntos
Ciclo-Octanos , Fígado Gorduroso , Lignanas , Compostos Policíclicos , Schisandra , Masculino , Camundongos , Animais , Humanos , Pró-Proteína Convertase 9/genética , Pró-Proteína Convertase 9/metabolismo , Schisandra/metabolismo , Serina Endopeptidases/genética , Subtilisina , Pró-Proteína Convertases/genética , Pró-Proteína Convertases/metabolismo , Receptores de LDL/genética , Receptores de LDL/metabolismo , Células Hep G2RESUMO
AIMS: PCSK9 inhibition intensively lowers low density lipoprotein cholesterol and is well tolerated in adults and paediatric patients with familial hypercholesterolaemia (FH). HAUSER-RCT showed that 24 weeks of treatment with evolocumab in paediatric patients did not affect cognitive function. This study determined the effects of 80 additional weeks of evolocumab treatment on cognitive function in paediatric patients with heterozygous FH. METHODS AND RESULTS: HAUSER-OLE was an 80-week open-label extension of HAUSER-RCT, a randomized, double-blind, 24-week trial evaluating the efficacy and safety of evolocumab in paediatric patients (ages 10-17 years) with FH. During the OLE, all patients received monthly 420â mg subcutaneous evolocumab injections. Tests of psychomotor function, attention, visual learning, and executive function were administered at baseline and Weeks 24 and 80 of the OLE. Changes over time were analysed descriptively and using analysis of covariance. Cohen's d statistic was used to evaluate the magnitude of treatment effects. Analysis of covariance results indicated no decrease in performance across visits during 80 weeks of evolocumab treatment for Groton Maze Learning, One Card Learning accuracy, Identification speed, or Detection speed (all P > 0.05). Performance on all tasks was similar for those who received placebo or evolocumab in the RCT (all P > 0.05). For all tests, the least square mean differences between patients who received placebo vs. evolocumab in the parent study were trivial (all Cohen's d magnitude < 0.2). CONCLUSION: In paediatric patients with FH, 80 weeks of open-label evolocumab treatment had no negative impact on cognitive function. REGISTRATION: ClinicalTrials.gov identifier: NCT02624869.
Some children are born with a genetic disorder that causes high cholesterol, which leads to heart disease. Children with high cholesterol can be treated with evolocumab, a medication that lowers blood cholesterol. Because cholesterol is important for development and adequate function of the brain, there is a concern that lowering cholesterol in children may affect mental ability. In this study, we tested whether treating children with evolocumab for 80 weeks affected mental ability in performing several tasks. A battery of tests that measure executive function (Groton Maze Learning Test), visual learning (One Card Learning Test), visual attention (Identification Test), and psychomotor function (Detection Test) showed no decrease in performance across visits during 80 weeks of evolocumab treatment. Performance on all tasks was similar for the children who received placebo for the first 24 weeks then received evolocumab for an additional 80 weeks (placebo/evolocumab) and those who received evolocumab for 24 weeks then received evolocumab for an additional 80 weeks (evolocumab/evolocumab).
Assuntos
Anticorpos Monoclonais Humanizados , Anticolesterolemiantes , Hiperlipoproteinemia Tipo II , Adulto , Humanos , Criança , Pró-Proteína Convertase 9 , Anticolesterolemiantes/efeitos adversos , Anticorpos Monoclonais/uso terapêutico , Hiperlipoproteinemia Tipo II/diagnóstico , Hiperlipoproteinemia Tipo II/tratamento farmacológico , Cognição , Resultado do Tratamento , Método Duplo-CegoRESUMO
Purpose: This study investigated the influence of plasma proprotein convertase subtilisin/kexin 9 (PCSK9) levels on the degree of atherosclerosis and major adverse cardiovascular and cerebrovascular events (MACCE) in older adults with non-alcoholic fatty liver disease. Methods: The degree of atherosclerosis severity was assessed by the standard Gensini score quartile method. According to the degree of atherosclerosis, patients were divided into mild (0-24 points; n=84), moderate (25-53 points; n=86), and severe groups (≥54 points; n=84) and then categorized as MACCE (n=30) or non-MACCE (n=224) according to 6-month follow-up data. The patients' age, sex, smoking history, medical history, and early morning fasting venous blood, for measuring biochemical indexes, were collected. Clinical data were compared between groups and the relationship between Gensini scores and PCSK9 was evaluated. Results: Compared with the mild group, the moderate and severe groups had higher high-sensitivity C-reactive protein(hs-CRP), PCSK9, triglycerides(TG), low-density lipoprotein cholesterol (LDL-C), and lipoprotein(a)[Lp(a)] levels and lower high-density lipoprotein cholesterol(HDL-C) levels (all P<0.05). Moreover, PCSK9 positively correlated with Gensini scores (r=0.657, P<0.01). The MACCE and non-MACCE groups had significantly different ages, statin use, Gensini scores, PCSK9, and LDL-C (all P<0.05). Multi-factorial Cox risk regression analysis showed the Gensini score (HR=1.018, 95% CI: 1.006~1.029) and PCSK9 (HR=1.147, 95% CI: 1.038~1.287) were independent risk factors for MACCE. Conclusion: The Gensini score and PCSK9 levels can be used as predictive indicators for the degree of illness and occurrence of MACCE in older NAFLD patients.
RESUMO
T cells play important roles in antitumor immunity. However, given that the hepatocellular carcinoma (HCC) tumor microenvironment confers resistance to T cell-based immunotherapies, novel strategies to boost T cell-mediated antitumor efficacy are urgently needed for the treatment of HCC. Here, we show that high proprotein convertase subtilisin/kexin type9 (PCSK9) expression was negatively associated with HCC patient's overall survival and markers of CD8+ T cells. Pharmacological inhibition of PCSK9 enhanced tumor-specific killing and downregulated PD-1 expression of AFP-specific TCR-T. Inhibition of PCSK9 significantly enhances the anti-HCC efficacy of TCR-T cells and anti-PD-1 immunotherapy in vivo. Moreover, PCSK9 inhibitor suppressed HCC growth dependent on CD8+ T cells. Mechanically, pharmacological inhibition of PCSK9 promoted low-density lipoprotein receptor (LDLR)-mediated activation of mTORC1 signaling in CD8+ T cells. LDLR deficiency was shown to impair cellular mTORC1 signaling and the anti-HCC function of CD8 T cells. On the basis of our findings in this study, we propose a potential metabolic intervention strategy that could be used to enhance the antitumor effects of immunotherapy for HCC.
Assuntos
Linfócitos T CD8-Positivos , Carcinoma Hepatocelular , Imunoterapia , Neoplasias Hepáticas , Pró-Proteína Convertase 9 , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/imunologia , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/imunologia , Neoplasias Hepáticas/metabolismo , Pró-Proteína Convertase 9/metabolismo , Humanos , Animais , Imunoterapia/métodos , Camundongos , Receptor de Morte Celular Programada 1/metabolismo , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Linhagem Celular Tumoral , Microambiente Tumoral , Inibidores de PCSK9 , Camundongos Endogâmicos C57BL , Receptores de Antígenos de Linfócitos T/metabolismo , MasculinoRESUMO
Proprotein convertase subtilisin-kexin-9 (PCSK9) inhibition markedly augments the LDL lowering action of statins. The combination is being evaluated for long-term effects on atherosclerotic disease outcomes. However, effects of combined treatment on hepatic cholesterol and bile acid metabolism have not yet been reported. To study this, PCSK9-Y119X mutant (knockout) and wild-type mice were treated with or without atorvastatin for 12 weeks. Atorvastatin progressively lowered plasma LDL in each group, but no differences in liver cholesterol, cholesterol ester, or total bile acid concentrations, or in plasma total bile acid levels were seen. In contrast, atorvastatin increased fecal total bile acids (≈ 2-fold, P < 0.01) and cholesterol concentrations (≈ 3-fold, P < 0.01) versus controls for both PCSK9-Y119X and wild-type mice. All 14 individual bile acids resolved by LC-MS, including primary, secondary, and conjugated species, reflected similar increases. Expression of key liver bile acid synthesis genes CYP7A1 and CYP8B1 were ≈ 2.5-fold higher with atorvastatin in both strains, but mRNA for liver bile acid export and reuptake transporters and conjugating enzymes were not unaffected. The data suggest that hepatocyte cholesterol and bile acid homeostasis is maintained with combined PCSK9 and HMG-CoA reductase inhibition through efficient liver enzymatic conversion of LDL-derived cholesterol into bile acids and excretion of both, with undisturbed enterohepatic recycling.