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1.
Signal Transduct Target Ther ; 5(1): 186, 2020 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-32883951

RESUMO

Sterol regulatory element binding protein-2 (SREBP-2) is activated by cytokines or pathogen, such as virus or bacteria, but its association with diminished cholesterol levels in COVID-19 patients is unknown. Here, we evaluated SREBP-2 activation in peripheral blood mononuclear cells of COVID-19 patients and verified the function of SREBP-2 in COVID-19. Intriguingly, we report the first observation of SREBP-2 C-terminal fragment in COVID-19 patients' blood and propose SREBP-2 C-terminal fragment as an indicator for determining severity. We confirmed that SREBP-2-induced cholesterol biosynthesis was suppressed by Sestrin-1 and PCSK9 expression, while the SREBP-2-induced inflammatory responses was upregulated in COVID-19 ICU patients. Using an infectious disease mouse model, inhibitors of SREBP-2 and NF-κB suppressed cytokine storms caused by viral infection and prevented pulmonary damages. These results collectively suggest that SREBP-2 can serve as an indicator for severity diagnosis and therapeutic target for preventing cytokine storm and lung damage in severe COVID-19 patients.


Assuntos
Betacoronavirus/patogenicidade , Colesterol/biossíntese , Infecções por Coronavirus/genética , Síndrome da Liberação de Citocina/genética , Interações Hospedeiro-Patógeno/genética , Leucócitos Mononucleares/imunologia , Pneumonia Viral/genética , Proteína de Ligação a Elemento Regulador de Esterol 2/genética , Betacoronavirus/imunologia , Estudos de Casos e Controles , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/mortalidade , Infecções por Coronavirus/virologia , Síndrome da Liberação de Citocina/imunologia , Síndrome da Liberação de Citocina/mortalidade , Síndrome da Liberação de Citocina/virologia , Regulação da Expressão Gênica , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/imunologia , Interações Hospedeiro-Patógeno/imunologia , Humanos , Unidades de Terapia Intensiva , Interleucina-1beta/genética , Interleucina-1beta/imunologia , L-Lactato Desidrogenase/genética , L-Lactato Desidrogenase/imunologia , Leucócitos Mononucleares/metabolismo , Leucócitos Mononucleares/virologia , Pulmão/imunologia , Pulmão/metabolismo , Pulmão/virologia , NF-kappa B/genética , NF-kappa B/imunologia , Pandemias , Pneumonia Viral/imunologia , Pneumonia Viral/mortalidade , Pneumonia Viral/virologia , Cultura Primária de Células , Pró-Proteína Convertase 9/genética , Pró-Proteína Convertase 9/imunologia , Transdução de Sinais , Proteína de Ligação a Elemento Regulador de Esterol 2/imunologia , Análise de Sobrevida , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/imunologia
2.
Life Sci ; 258: 118030, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32739470

RESUMO

The risk of atherosclerosis (AS) ascends among post-menopausal women, while current hormone replacement therapy exerts several adverse effects. Alisol B 23-acetate (AB23A), a tetracyclic triterpenoid isolated from the rhizome of Alisma orientale, was reported to show multiple physiological activities, including regulating lipid metabolism. According to molecular docking analysis, it was predicted to bind with estrogen receptor α (ERα). In this study, we aimed to observe the effect of AB23A on preventing post-menopausal AS and explore whether the mechanism was mediated by ERα. In vitro, free fatty acid (FFA) was applied to induce the abnormal lipid metabolism of L02 cells. In vivo, the ApoE-/- mice were ovariectomized to mimic the cessation of estrogen. The high-fat diet was also given to induce post-menopausal AS. We demonstrated AB23A attenuated the accumulation of total cholesterol and triglyceride induced by free fatty acids in hepatocytes. In high-fat diet-ovariectomy-treated ApoE-/- mice, AB23A eliminated lipids in blood and liver. AB23A not only reduced the synthesis of proprotein convertase subtilisin/kexin type 9 (PCSK9) through sterol-regulatory element binding proteins (SREBPs) but also suppressed the secretion of PCSK9 through silent information regulator 1 (SIRT1). Notably, AB23A promoted the expression of ERα in vivo and in vitro. The both ERα inhibitor and ERα siRNA were also applied in confirming whether the hepatic protective effect of AB23A was mediated by ERα. We found that AB23A significantly promoted the expression of ERα. AB23A could inhibit the synthesis and secretion of PCSK9 through ERα, lower the accumulation of triglyceride and cholesterol, and prevent post-menopausal AS.


Assuntos
Aterosclerose/patologia , Colestenonas/farmacologia , Receptor alfa de Estrogênio/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Pós-Menopausa/efeitos dos fármacos , Animais , Aterosclerose/genética , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Colestenonas/química , Dieta Hiperlipídica , Ácidos Graxos/metabolismo , Feminino , Lipoproteínas LDL/metabolismo , Camundongos , Ovariectomia , Regiões Promotoras Genéticas/genética , Pró-Proteína Convertase 9/genética , Pró-Proteína Convertase 9/metabolismo , Receptores de LDL/genética , Receptores de LDL/metabolismo , Sirtuína 1/metabolismo , Proteínas de Ligação a Elemento Regulador de Esterol/genética , Proteínas de Ligação a Elemento Regulador de Esterol/metabolismo , Regulação para Cima/efeitos dos fármacos
3.
Medicine (Baltimore) ; 99(34): e21754, 2020 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-32846800

RESUMO

RATIONALE: Proprotein convertase subtilisin/kexin 9 or PCSK9 is a protein whose main function is to regulate the number of low-density lipoprotein receptors (LDLR) present on the cell surface. Loss-of-function mutations in PCSK9 have been related to low LDL-cholesterol levels and a decrease in the risk of cardiovascular events. PATIENT CONCERNS: We present the case of a 27-year-old woman, offspring of a patient with familial homozygous hypercholesterolemia, who presented with mild-moderate hypercholesterolemia. DIAGNOSIS: Genetic analysis was performed by next generation sequencing using a customized panel of 198 genes. Sanger sequencing was used to confirm the presence of the variants of interest. The genetic analysis showed a pathogenic heterozygous mutation in LDLR [exon 6:c.902A>G:p(Asp301Gly)], as well as a loss-of-function heterozygous variant in PCSK9 [exon1:c.137 G>T:p.(Arg46Leu)]. The genetic analysis of the index case's mother revealed compound heterozygosity for 2 different mutations in LDLR [c.902A>G:p.(Asp301Gly); c.1646G>T:p.(Gly549Val)] in exon 6 and in exon 11, respectively, and the same loss-of-function variant in PCSK9 that had been found in her daughter [(PCSK9:exon1:c.137G>T:p.(Arg46Leu)]. The maternal grandfather of the index case presented the same genetic variants as his granddaughter. INTERVENTIONS: The index case did not receive any specific treatment for hypercholesterolemia. The loss-of-function variant in PCSK9 protected her from higher LDL-cholesterol levels, provided she kept partial activity of the LDLR. In her mother, instead, a PCSK9 inhibitor was tried but failed to achieve lipid control. The reason for this may be the complete absence in LDL receptor activity. LDL apheresis was started afterwards, resulting in adequate lipid level control. OUTCOMES: To the date, the index case has achieved to maintain adequate total and LDL-cholesterol levels without any other intervention. She has had no known cardiovascular complication. LESSONS: Loss-of-function mutations in PCSK9 could protect from developing more severe forms of hypercholesterolemia. The finding of these mutations (LDLR-PCSK9) in three consecutive generations could imply an adaptive mechanism against the development of hypercholesterolemia.


Assuntos
Hiperlipoproteinemia Tipo II/genética , Pró-Proteína Convertase 9/genética , Adulto , LDL-Colesterol/sangue , Feminino , Humanos
4.
PLoS Genet ; 16(7): e1008903, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32678846

RESUMO

Genome wide association studies (GWAS) of human diseases have generally identified many loci associated with risk with relatively small effect sizes. The omnigenic model attempts to explain this observation by suggesting that diseases can be thought of as networks, where genes with direct involvement in disease-relevant biological pathways are named 'core genes', while peripheral genes influence disease risk via their interactions or regulatory effects on core genes. Here, we demonstrate a method for identifying candidate core genes solely from genes in or near disease-associated SNPs (GWAS hits) in conjunction with protein-protein interaction network data. Applied to 1,381 GWAS studies from 5 ancestries, we identify a total of 1,865 candidate core genes in 343 GWAS studies. Our analysis identifies several well-known disease-related genes that are not identified by GWAS, including BRCA1 in Breast Cancer, Amyloid Precursor Protein (APP) in Alzheimer's Disease, INS in A1C measurement and Type 2 Diabetes, and PCSK9 in LDL cholesterol, amongst others. Notably candidate core genes are preferentially enriched for disease relevance over GWAS hits and are enriched for both Clinvar pathogenic variants and known drug targets-consistent with the predictions of the omnigenic model. We subsequently use parent term annotations provided by the GWAS catalog, to merge related GWAS studies and identify candidate core genes in over-arching disease processes such as cancer-where we identify 109 candidate core genes.


Assuntos
Doença de Alzheimer/genética , Neoplasias da Mama/genética , Diabetes Mellitus Tipo 2/genética , Estudo de Associação Genômica Ampla , Mapas de Interação de Proteínas/genética , Doença de Alzheimer/patologia , Precursor de Proteína beta-Amiloide/genética , Proteína BRCA1/genética , Neoplasias da Mama/patologia , Diabetes Mellitus Tipo 2/patologia , Feminino , Humanos , Insulina/genética , Polimorfismo de Nucleotídeo Único/genética , Pró-Proteína Convertase 9/genética , Fatores de Risco
5.
Arterioscler Thromb Vasc Biol ; 40(9): 2227-2243, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32640901

RESUMO

OBJECTIVE: Perivascular adipose tissue (PVAT) surrounding arteries supports healthy vascular function. During obesity, PVAT loses its vasoprotective effect. We study pathological conversion of PVAT, which involves molecular changes in protein profiles and functional changes in adipocytes. Approach and Results: C57BL6/J mice were fed a 60% high-fat diet for 12 weeks or a cardioprotective 30% calorie-restricted diet for 5 weeks. Proteomic analysis identified PVAT as a molecularly distinct adipose depot, and novel markers for thermogenic adipocytes, such as GRP75 (stress-70 protein, mitochondrial), were identified. High-fat diet increased the similarity of protein signatures in PVAT and brown adipose, suggesting activation of a conserved whitening pathway. The whitening phenotype was characterized by suppression of UCP1 (uncoupling protein 1) and increased lipid deposition, leptin, and inflammation, and specifically in PVAT, elevated Notch signaling. Conversely, PVAT from calorie-restricted mice had decreased Notch signaling and less lipid. Using the Adipoq-Cre strain, we constitutively activated Notch1 signaling in adipocytes, which phenocopied the changes in PVAT caused by a high-fat diet, even on a standard diet. Preadipocytes from mouse PVAT expressed Sca1, CD140a, Notch1, and Notch2, but not CD105, showing differences compared with preadipocytes from other depots. Inhibition of Notch signaling during differentiation of PVAT-derived preadipocytes reduced lipid deposition and adipocyte marker expression. CONCLUSIONS: PVAT shares features with other adipose depots, but has a unique protein signature that is regulated by dietary stress. Increased Notch signaling in PVAT is sufficient to initiate the pathological conversion of PVAT by promoting adipogenesis and lipid accumulation and may thus prime the microenvironment for vascular disease.


Assuntos
Adipócitos Brancos/metabolismo , Adipogenia , Tecido Adiposo Branco/metabolismo , Lipogênese , Obesidade/metabolismo , Receptores Notch/metabolismo , Adipócitos Brancos/patologia , Tecido Adiposo Branco/patologia , Adiposidade , Animais , Ataxina-1/metabolismo , Aterosclerose/genética , Aterosclerose/metabolismo , Aterosclerose/patologia , Restrição Calórica , Dieta Hiperlipídica , Modelos Animais de Doenças , Endoglina/metabolismo , Feminino , Masculino , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Obesidade/genética , Obesidade/patologia , Fenótipo , Pró-Proteína Convertase 9/genética , Pró-Proteína Convertase 9/metabolismo , Proteômica , Receptor Notch1/genética , Receptor Notch1/metabolismo , Receptor Notch2/metabolismo , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/metabolismo , Receptores Notch/genética , Transdução de Sinais
6.
Arterioscler Thromb Vasc Biol ; 40(9): 2084-2094, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32673528

RESUMO

OBJECTIVE: Increased postprandial lipemia (PPL) is an independent risk factor for atherosclerotic cardiovascular diseases. PCSK9 (Proprotein convertase subtilisin kexin type 9) is an endogenous inhibitor of the LDLR (low-density lipoprotein receptor) pathway. We previously showed that PCSK9 inhibition in mice reduces PPL. However, the relative contribution of intracellular intestinal PCSK9 or liver-derived circulating PCSK9 to this effect is still unclear. Approach and Results: To address this issue, we generated the first intestine-specific Pcsk9-deficient (i-Pcsk9-/-) mouse model. PPL was measured in i-Pcsk9-/- as well as in wild-type and streptozotocin-induced diabetic mice following treatment with a PCSK9 monoclonal antibody (alirocumab). Blocking the circulating form of PCSK9 with alirocumab significantly reduced PPL, while overexpressing human PCSK9 in the liver of full Pcsk9-/- mice had the opposite effect. Alirocumab regulated PPL in a LDLR-dependent manner as this effect was abolished in Ldlr-/- mice. In contrast, i-Pcsk9-/- mice did not exhibit alterations in plasma lipid parameters nor in PPL. Finally, PPL was highly exacerbated by streptozotocin-induced diabetes mellitus in Pcsk9+/+ but not in Pcsk9-/- mice, an effect that was mimicked by the use of alirocumab in streptozotocin-treated Pcsk9+/+ mice. CONCLUSIONS: Taken together, our data demonstrate that PPL is significantly altered by full but not intestinal PCSK9 deficiency. Treatment with a PCSK9 monoclonal antibody mimics the effect of PCSK9 deficiency on PPL suggesting that circulating PCSK9 rather than intestinal PCSK9 is a critical regulator of PPL. These data validate the clinical relevance of PCSK9 inhibitors to reduce PPL, especially in patients with type 2 diabetes mellitus.


Assuntos
Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Tipo 2/sangue , Hiperlipidemias/sangue , Intestinos/enzimologia , Lipídeos/sangue , Pró-Proteína Convertase 9/sangue , Animais , Anticorpos Monoclonais Humanizados/farmacologia , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/enzimologia , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/enzimologia , Hiperlipidemias/enzimologia , Hiperlipidemias/genética , Hiperlipidemias/prevenção & controle , Hipolipemiantes/farmacologia , Intestinos/efeitos dos fármacos , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Período Pós-Prandial , Pró-Proteína Convertase 9/antagonistas & inibidores , Pró-Proteína Convertase 9/deficiência , Pró-Proteína Convertase 9/genética , Receptores de LDL/genética , Receptores de LDL/metabolismo
7.
PLoS One ; 15(6): e0234131, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32502216

RESUMO

BACKGROUND: Low plasma testosterone, either spontaneous or as a result of androgen deprivation therapy for prostate cancer, is associated with an increased risk of cardiovascular events. The underlying mechanism in humans is not understood. Experimental studies in mice have shown that castration facilitates atherogenesis and may increase signs of plaque vulnerability. Pigs used for translational atherosclerosis research have frequently been castrated for practical or commercial reasons, but the effect of castration on atherosclerosis has never been systematically evaluated in pigs. OBJECTIVE: To study the effect of castration on atherosclerotic plaque burden and type in genetically modified minipigs with hypercholesterolemia. METHODS: Newborn male Yucatan minipigs with transgenic overexpression of a human gain-of-function mutant of proprotein convertase subtilisin/kexin type 9 were randomized to undergo orchiectomy (n = 8) or serve as controls (n = 6). Minipigs were started on high-fat diet at 3 months of age and the amount and composition of atherosclerotic lesions were analyzed at 12 months of age. Plasma lipid profiles and behavioral parameters were also assessed. RESULTS: Plasma lipids were slightly affected to a more atherogenic profile by orchiectomy, but atherosclerotic lesion size was unaltered in the LAD, thoracic aorta, abdominal aorta, and iliac arteries. The distribution of lesion types (xanthomas, pathological intimal thickening and fibroatheromas) were also not statistically different between groups in any of the examined vascular territories. The abdominal aorta developed the most advanced stages of disease with reproducible fibroatheroma formation, and here it was found that the area of necrotic core was significantly increased in orchiectomized pigs compared with controls. Orchiectomy also reduced aggressive behavior. CONCLUSIONS: Castration does not alter the burden of atherosclerosis in hypercholesterolemic Yucatan minipigs, but may increase necrotic core area in fibroatheromas.


Assuntos
Aterosclerose/patologia , Hipercolesterolemia/patologia , Animais , Animais Geneticamente Modificados , Aorta/patologia , Aterosclerose/complicações , Dieta Hiperlipídica , Modelos Animais de Doenças , Humanos , Hipercolesterolemia/complicações , Hipercolesterolemia/genética , Artéria Ilíaca/patologia , Lipídeos/sangue , Masculino , Necrose , Orquiectomia , Pró-Proteína Convertase 9/genética , Pró-Proteína Convertase 9/metabolismo , Suínos , Porco Miniatura , Testosterona/sangue
9.
Curr Opin Cardiol ; 35(4): 423-427, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32452920

RESUMO

PURPOSE OF REVIEW: Low cholesterol syndromes were considered curiosities. The present article reviews some hypolipidaemic disorders and the drugs developed from the insights they provided. RECENT FINDINGS: Abetalipopoproteinaemia and hypobetalipoproteinaemia are associated with low cholesterol concentrations and caused by mutations in apolipoprotein (apo) B or microsomal transfer protein. This led to the development of mipomersen and lomitapide which are used to treat homozygous familial hypercholesterolaemia. Mutations in proprotein convertase subtilisin kexin-9 (PCSK9) can cause either high or low cholesterol. Loss of function PCSK9 mutations prompted the development of antibody therapies to PCSK9 which are now widely used to treat hypercholesterolaemia. Mutations in apolipoprotein C-3 and angiopoietin-like protein 3 (ANGPTL3) cause hypolipoproteinaemia and reduced triglycerides. Antisense therapies to apolipoprotein C-3 and antibodies to ANGPTL3 are in development to treat familial chylomicronaemia syndrome. Activating mutations in apoA-1 result in hyper-functioning high-density lipoprotein (HDL) and suggest that modifying HDL turnover may reduce cardiovascular disease (CVD) risk. SUMMARY: Orphan lipid disorders have provided insights into mechanisms involved in lowering cholesterol levels and the potential safety and efficacy of interventional processes. They have been not only enabled development of drugs to treat rare lipid disorders but also those finding wider use in general lowering of CVD risk.


Assuntos
Anticolesterolemiantes/uso terapêutico , Pró-Proteína Convertase 9/genética , Proteínas Semelhantes a Angiopoietina , Colesterol , Desenvolvimento de Medicamentos , Humanos , Síndrome
10.
Nature ; 581(7809): 434-443, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32461654

RESUMO

Genetic variants that inactivate protein-coding genes are a powerful source of information about the phenotypic consequences of gene disruption: genes that are crucial for the function of an organism will be depleted of such variants in natural populations, whereas non-essential genes will tolerate their accumulation. However, predicted loss-of-function variants are enriched for annotation errors, and tend to be found at extremely low frequencies, so their analysis requires careful variant annotation and very large sample sizes1. Here we describe the aggregation of 125,748 exomes and 15,708 genomes from human sequencing studies into the Genome Aggregation Database (gnomAD). We identify 443,769 high-confidence predicted loss-of-function variants in this cohort after filtering for artefacts caused by sequencing and annotation errors. Using an improved model of human mutation rates, we classify human protein-coding genes along a spectrum that represents tolerance to inactivation, validate this classification using data from model organisms and engineered human cells, and show that it can be used to improve the power of gene discovery for both common and rare diseases.


Assuntos
Exoma/genética , Genes Essenciais/genética , Variação Genética/genética , Genoma Humano/genética , Adulto , Encéfalo/metabolismo , Doenças Cardiovasculares/genética , Estudos de Coortes , Bases de Dados Genéticas , Feminino , Predisposição Genética para Doença/genética , Estudo de Associação Genômica Ampla , Humanos , Mutação com Perda de Função/genética , Masculino , Taxa de Mutação , Pró-Proteína Convertase 9/genética , RNA Mensageiro/genética , Reprodutibilidade dos Testes , Sequenciamento Completo do Exoma , Sequenciamento Completo do Genoma
11.
J Cardiovasc Pharmacol ; 75(5): 410-420, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32379108

RESUMO

Atherosclerotic cardiovascular disease (ASCVD) remains the leading cause of death worldwide. Low-density lipoprotein cholesterol (LDL-C) is the primary cause of ASCVD and reducing LDL-C levels with statin therapy significantly reduces ASCVD risk; however, significant residual risk remains. Two monoclonal antibodies (mAbs), alirocumab and evolocumab, that target proprotein convertase subtilisin/kexin-type 9 (PCSK9), reduce LDL-C levels by up to 60% when used in combination with statins and significantly reduce the risk of recurrent ASCVD events in both stable secondary prevention and acute coronary syndrome populations. Prespecified analyses of recent randomized controlled trials have shed light on how best to prioritize these therapies to maximize their value in select high-risk groups. These data have also informed recent clinical practice guidelines and scientific statements resulting in an expanded role for PCSK9-mAbs compared with previous guidelines, albeit there are notable differences between these recommendations. Ongoing research is exploring the long-term safety of PCSK9-mAbs and their role in the acute setting and patients without prior myocardial infarction or stroke. Novel therapies that inhibit PCSK9 synthesis via small interfering RNA, such as inclisiran, are also in development and may reduce LDL-C levels similar to PCSK9-mAbs, but with less frequent administration. Nonetheless, the PCSK9-mAbs are a breakthrough therapy and warrant consideration in very high-risk patients who are most likely to benefit. Such a personalized approach can help to ensure cost-effectiveness and maximize their value.


Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Anticolesterolemiantes/uso terapêutico , Doenças Cardiovasculares/prevenção & controle , LDL-Colesterol/sangue , Dislipidemias/tratamento farmacológico , Medicina de Precisão , Pró-Proteína Convertase 9/antagonistas & inibidores , Prevenção Secundária , Inibidores de Serino Proteinase/uso terapêutico , Animais , Anticorpos Monoclonais Humanizados/efeitos adversos , Anticolesterolemiantes/efeitos adversos , Biomarcadores/sangue , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/epidemiologia , Tomada de Decisão Clínica , Dislipidemias/sangue , Dislipidemias/diagnóstico , Dislipidemias/epidemiologia , Humanos , Pró-Proteína Convertase 9/genética , Pró-Proteína Convertase 9/metabolismo , Recidiva , Medição de Risco , Fatores de Risco , Inibidores de Serino Proteinase/efeitos adversos , Resultado do Tratamento
12.
Gen Physiol Biophys ; 39(2): 123-134, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32329440

RESUMO

The upregulation of proprotein convertase subtilisin/kexin type 9 (PCSK9) was reported to be involved in regulating the levels of inflammatory markers and apoptosis in macrophages. This study aims to investigate the function and regulation of PCSK9 in myocardial ischaemia. The results of our study showed dramatically increased expression of PCSK9 induced by hypoxia/reoxygenation (H/R) stress rather than by apoptosis in primary murine cardiomyocytes and HL-1 cells. Moreover, PCSK9 promoted H/R-induced pro-inflammatory cytokine release from macrophages, while silencing of PCSK9 inhibited the expression of the pro-inflammatory cytokines TNF-α, IL-6 and IL-1ß. Additionally, PCSK9 facilitated the release of pro-inflammatory cytokines from macrophages under H/R conditions, which decreased cardiomyocyte viability and promoted apoptosis of cardiomyocytes. For the underlying mechanisms, we identified PCSK9-induced NF-κB activation as being involved in the cardiomyocyte apoptosis, which was blocked by the NF-κB inhibitor BAY 11-7082. Collectively, this study provides new insights into the therapeutic possibility of regulating PCSK9 in cardiomyocytes for the treatment of ischaemic cardiomyopathy.


Assuntos
Citocinas/metabolismo , Macrófagos/citologia , Miócitos Cardíacos/citologia , NF-kappa B/metabolismo , Pró-Proteína Convertase 9/metabolismo , Animais , Apoptose , Hipóxia Celular , Linhagem Celular , Inativação Gênica , Camundongos , Pró-Proteína Convertase 9/genética , Transdução de Sinais
13.
Intern Med ; 59(6): 783-787, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32173689

RESUMO

We present the first case of a Japanese patient with familial hypobetalipoproteinemia (FHBL) caused by a protein-truncating variant in the proprotein convertase subtilisin/kexin type 9 (PCSK9) gene. A 34-year-old woman was referred to our hospital due to her low low-density lipoprotein (LDL)-cholesterolemia (34 mg/dL). She did not have any secondary causes of hypobetalipoproteinemia. Her father and her younger sister also exhibited low LDL cholesterol levels. We identified a protein-truncating variant in the PCSK9 gene (c.1090_1091del/p.Pro364ArgfsTer62) among them. None of them exhibited atherosclerotic cardiovascular diseases nor any other complications associated with low LDL cholesterol, including fatty liver, neurocognitive disorders, or cerebral hemorrhaging.


Assuntos
Hipobetalipoproteinemias/genética , Pró-Proteína Convertase 9/genética , Adulto , LDL-Colesterol/sangue , Feminino , Deleção de Genes , Humanos
14.
PLoS One ; 15(2): e0229098, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32084179

RESUMO

Non-communicable diseases, including cardiovascular diseases (CVDs), are increasing in African populations. High serum low density lipoprotein cholesterol (LDL-cholesterol) levels are a known risk factor for CVDs in European populations, but the link remains poorly understood among Africans. This study investigated the associations between serum LDL-cholesterol levels and selected variants in the low density lipoprotein receptor (LDLR), apolipoprotein B (APOB), proprotein convertase subtilisin/kexin type 9 (PCSK9) and low density lipoprotein receptor adaptor protein 1 (LDLRAP1) genes in some selected African populations. Nineteen SNPs were selected from publicly available African whole genome sequence data based on functional prediction and allele frequency. SNPs were genotyped in 1000 participants from the AWI-Gen, study selected from the extremes of LDL-cholesterol level distribution (500 with LDL-cholesterol>3.5 mmol/L and 500 with LDL-cholesterol<1.1 mmol/L). The minor alleles at five of the six associated SNPs were significantly associated (P<0.05) with lower LDL-cholesterol levels: LDLRAP1 rs12071264 (OR 0.56, 95% CI: 0.39-0.75, P = 2.73x10-4) and rs35910270 (OR 0.78, 95% CI: 0.64-0.94, P = 0.008); APOB rs6752026 (OR 0. 55, 95% CI: 0.41-0.72, P = 2.82x10-5); LDLR: rs72568855 (OR 0.47, 95% CI: 0.27-0.82, P = 0.008); and PCSK9 rs45613943 (OR = 0.72, 95% CI: 0.58-0.88, P = 0.001). The minor allele of the sixth variant was associated with higher LDL-cholesterol levels: APOB rs679899 (OR 1.41, 95% CI: 1.06-1.86, P = 0.016). A replication analysis in the Africa America Diabetes Mellitus (AADM) study found the PCSK9 variant to be significantly associated with low LDL-cholesterol levels (Beta = -0.10). Since Africans generally have lower LDL-cholesterol levels, these LDL-cholesterol associated variants may be involved in adaptation due to unique gene-environment interactions. In conclusion, using a limited number of potentially functional variants in four genes, we identified significant associations with lower LDL-cholesterol levels in sub-Saharan Africans.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Apolipoproteínas B/genética , Pró-Proteína Convertase 9/genética , Receptores de LDL/genética , Alelos , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único/genética
15.
Arterioscler Thromb Vasc Biol ; 40(3): 819-829, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32078365

RESUMO

OBJECTIVE: To clarify the association between PCSK9 (proprotein convertase subtilisin/kexin type 9) and Lp(a) (lipoprotein [a]), we studied Lp(a) kinetics in patients with loss-of-function and gain-of-function PCSK9 mutations and in patients in whom extended-release niacin reduced Lp(a) and PCSK9 concentrations. Approach and Results: Six healthy controls, 9 heterozygous patients with familial hypercholesterolemia (5 with low-density lipoprotein receptor [LDLR] mutations and 4 with PCSK9 gain-of-function mutations) and 3 patients with heterozygous dominant-negative PCSK9 loss-of-function mutations were included in the preliminary study. Eight patients were enrolled in a second study assessing the effects of 2 g/day extended-release niacin. Apolipoprotein kinetics in VLDL (very-low-density lipoprotein), LDL (low-density lipoprotein), and Lp(a) were studied using stable isotope techniques. Plasma Lp(a) concentrations were increased in PCSK9-gain-of-function and familial hypercholesterolemia-LDLR groups compared with controls and PCSK9-loss-of-function groups (14±12 versus 5±4 mg/dL; P=0.04), but no change was observed in Lp(a) fractional catabolic rate. Subjects with PCSK9-loss-of-function mutations displayed reduced apoE (apolipoprotein E) concentrations associated with a VLDL-apoE absolute production rate reduction. Lp(a) and VLDL-apoE absolute production rates were correlated (r=0.50; P<0.05). ApoE-to-apolipoprotein (a) molar ratios in Lp(a) increased with plasma Lp(a) (r=0.96; P<0.001) but not with PCSK9 levels. Extended-release niacin-induced reductions in Lp(a) and VLDL-apoE absolute production rate were correlated (r=0.83; P=0.015). In contrast, PCSK9 reduction (-35%; P=0.008) was only correlated with that of VLDL-apoE absolute production rate (r=0.79; P=0.028). CONCLUSIONS: VLDL-apoE production could determine Lp(a) production and/or assembly. As PCSK9 inhibitors reduce plasma apoE and Lp(a) concentrations, apoE could be the link between PCSK9 and Lp(a).


Assuntos
Apolipoproteínas E/sangue , Hiperlipoproteinemia Tipo II/sangue , Lipoproteína(a)/sangue , Lipoproteínas VLDL/sangue , Adolescente , Adulto , Anticolesterolemiantes/uso terapêutico , Biomarcadores/sangue , Estudos de Casos e Controles , Preparações de Ação Retardada , Feminino , Predisposição Genética para Doença , Heterozigoto , Humanos , Hiperlipoproteinemia Tipo II/diagnóstico , Hiperlipoproteinemia Tipo II/tratamento farmacológico , Hiperlipoproteinemia Tipo II/genética , Cinética , Lipoproteína(a)/biossíntese , Masculino , Pessoa de Meia-Idade , Mutação , Niacina/uso terapêutico , Fenótipo , Pró-Proteína Convertase 9/genética , Ensaios Clínicos Controlados Aleatórios como Assunto , Receptores de LDL/genética , Resultado do Tratamento , Adulto Jovem
16.
JAMA ; 323(7): 646-655, 2020 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-32068819

RESUMO

Importance: Preclinical and epidemiological studies indicate a potential chemopreventive role of statins in epithelial ovarian cancer risk. Objective: To evaluate the association of genetically proxied inhibition of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase (ie, genetic variants related to lower function of HMG-CoA reductase, target of statins) with epithelial ovarian cancer among the general population and in BRCA1/2 mutation carriers. Design, Setting, and Participants: Single-nucleotide polymorphisms (SNPs) in HMGCR, NPC1L1, and PCSK9 associated with low-density lipoprotein (LDL) cholesterol in a genome-wide association study (GWAS) meta-analysis (N ≤196 475) were used to proxy therapeutic inhibition of HMG-CoA reductase, Niemann-Pick C1-Like 1 (NPC1L1) and proprotein convertase subtilisin/kexin type 9 (PCSK9), respectively. Summary statistics were obtained for these SNPs from a GWAS meta-analysis of case-control analyses of invasive epithelial ovarian cancer in the Ovarian Cancer Association Consortium (OCAC; N = 63 347) and from a GWAS meta-analysis of retrospective cohort analyses of epithelial ovarian cancer among BRCA1/2 mutation carriers in the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA; N = 31 448). Across the 2 consortia, participants were enrolled between 1973 and 2014 and followed up through 2015. OCAC participants came from 14 countries and CIMBA participants came from 25 countries. SNPs were combined into multi-allelic models and mendelian randomization estimates representing lifelong inhibition of targets were generated using inverse-variance weighted random-effects models. Exposures: Primary exposure was genetically proxied inhibition of HMG-CoA reductase and secondary exposures were genetically proxied inhibition of NPC1L1 and PCSK9 and genetically proxied circulating LDL cholesterol levels. Main Outcomes and Measures: Overall and histotype-specific invasive epithelial ovarian cancer (general population) and epithelial ovarian cancer (BRCA1/2 mutation carriers), measured as ovarian cancer odds (general population) and hazard ratio (BRCA1/2 mutation carriers). Results: The OCAC sample included 22 406 women with invasive epithelial ovarian cancer and 40 941 control individuals and the CIMBA sample included 3887 women with epithelial ovarian cancer and 27 561 control individuals. Median ages for the cohorts ranged from 41.5 to 59.0 years and all participants were of European ancestry. In the primary analysis, genetically proxied HMG-CoA reductase inhibition equivalent to a 1-mmol/L (38.7-mg/dL) reduction in LDL cholesterol was associated with lower odds of epithelial ovarian cancer (odds ratio [OR], 0.60 [95% CI, 0.43-0.83]; P = .002). In BRCA1/2 mutation carriers, genetically proxied HMG-CoA reductase inhibition was associated with lower ovarian cancer risk (hazard ratio, 0.69 [95% CI, 0.51-0.93]; P = .01). In secondary analyses, there were no significant associations of genetically proxied inhibition of NPC1L1 (OR, 0.97 [95% CI, 0.53-1.75]; P = .91), PCSK9 (OR, 0.98 [95% CI, 0.85-1.13]; P = .80), or circulating LDL cholesterol (OR, 0.98 [95% CI, 0.91-1.05]; P = .55) with epithelial ovarian cancer. Conclusions and Relevance: Genetically proxied inhibition of HMG-CoA reductase was significantly associated with lower odds of epithelial ovarian cancer. However, these findings do not indicate risk reduction from medications that inhibit HMG-CoA reductase; further research is needed to understand whether there is a similar association with such medications.


Assuntos
Carcinoma Epitelial do Ovário/prevenção & controle , Hidroximetilglutaril-CoA Redutases/genética , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Neoplasias Ovarianas/prevenção & controle , Polimorfismo de Nucleotídeo Único , Adulto , Carcinoma Epitelial do Ovário/genética , Estudos de Casos e Controles , LDL-Colesterol/sangue , Feminino , Genes BRCA1 , Genes BRCA2 , Humanos , Proteínas de Membrana Transportadoras/genética , Análise da Randomização Mendeliana , Pessoa de Meia-Idade , Mutação , Razão de Chances , Neoplasias Ovarianas/genética , Pró-Proteína Convertase 9/genética , Estudos Retrospectivos , Risco
17.
EBioMedicine ; 52: 102650, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32058941

RESUMO

BACKGROUND: Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a secreted protein that down-regulates hepatic low-density lipoprotein receptor (LDLR) by binding and shuttling LDLR to lysosomes for degradation. The development of therapy that inhibits PCSK9 has attracted considerable attention for the management of cardiovascular disease risk. However, only monoclonal antibodies of PCSK9 have reached the clinic use. Oral administration of small-molecule transcriptional inhibitors has the potential to become a therapeutic option. METHODS: Here, we developed a cell-based small molecule screening platform to identify transcriptional inhibitors of PCSK9. Through high-throughput screening and a series of evaluation, we found several active compounds. After detailed investigation on the pharmacological effect and molecular mechanistic characterization, 7030B-C5 was identified as a potential small-molecule PCSK9 inhibitor. FINDINGS: Our data showed that 7030B-C5 down-regulated PCSK9 expression and increased the total cellular LDLR protein and its mediated LDL-C uptake by HepG2 cells. In both C57BL/6 J and ApoE KO mice, oral administration of 7030B-C5 reduced hepatic and plasma PCSK9 level and increased hepatic LDLR expression. Most importantly, 7030B-C5 inhibited lesions in en face aortas and aortic root in ApoE KO mice with a slight amelioration of lipid profiles. We further provide evidences suggesting that transcriptional regulation of PCSK9 by 7030B-C5 mostly depend on the transcriptional factor HNF1α and FoxO3. Furthermore, FoxO1 was found to play an important role in 7030B-C5 mediated integration of hepatic glucose and lipid metabolism. INTERPRETATION: 7030B-C5 with potential suppressive effect of PCSK9 expression may serve as a promising lead compound for drug development of cholesterol/glucose homeostasis and cardiovascular disease therapy. FUND: This work was supported by grants from the National Natural Science Foundation of China (81473214, 81402929, and 81621064), the Drug Innovation Major Project of China (2018ZX09711001-003-006, 2018ZX09711001-007 and 2018ZX09735001-002), CAMS Innovation Fund for Medical Sciences (2016-I2M-2-002, 2016-I2M-1-011 and 2017-I2M-1-008), Beijing Natural Science Foundation (7162129).


Assuntos
Aterosclerose/etiologia , Aterosclerose/metabolismo , Proteína Forkhead Box O1/genética , Proteína Forkhead Box O3/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Pró-Proteína Convertase 9/antagonistas & inibidores , Pró-Proteína Convertase 9/genética , Inibidores de Proteases/farmacologia , Animais , Apolipoproteínas E/genética , Aterosclerose/patologia , Proteína Forkhead Box O1/metabolismo , Proteína Forkhead Box O3/metabolismo , Glucose/metabolismo , Células Hep G2 , Fator 1-alfa Nuclear de Hepatócito , Humanos , Masculino , Camundongos , Camundongos Knockout , Modelos Biológicos , Inibidores de Proteases/química
18.
Artigo em Inglês | MEDLINE | ID: mdl-32058034

RESUMO

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a secretory protein that promotes low-density lipoprotein receptor (LDLR) degradation and thereby regulating plasma levels of LDL cholesterol. Previous studies have revealed the role of the C-terminal domain (CTD) of PCSK9 in its secretion, however, how CTD regulates PCSK9 secretion is not completely understood. Additionally, SEC24A, the cargo adaptor protein of the coat protein complex II, has been implicated in the secretion of mouse PCSK9. Here, we investigated how CTD and SEC24 regulated PCSK9 secretion in humans. We found that mutant PCSK91-528, in which amino acids from 529 to the end (amino acid 692) were deleted, was maturated and secreted from cells as effectively as the wild-type protein. On the other hand, lacking amino acids 454 to 692 in mutant PCSK91-453 significantly reduced its maturation and secretion, but to a lesser extent when compared to mutants PCSK91-446, PCSK91-445 and PCSK91-444, that all markedly impaired PCSK9 maturation. However, mutant PCSK91-444 virtually eliminated PCSK9 secretion while PCSK91-446 and PCSK91-445 could still be adequately detected in culture medium. Interestingly, mutation of Pro445 to other amino acid residues considerably impaired the secretion of mutant PCSK91-445 but not the full-length protein. We also found that natural variants in CTD including S462P, S465L, E482G, R495Q and A522T impaired PCSK9 secretion. Further, the knockdown of SEC24A, SEC24B, SEC24C but not SEC24D reduced secretion of the full-length PCSK9 but not mutant PCSK91-446. Therefore, SEC24A, SEC24B, and SEC24C facilitate endogenous PCSK9 secretion from cultured human hepatocytes, that are most likely mediated by the CTD of PCSK9. Our studies also indicate that the CTD of PCSK9 may allosterically and independently modulate the stability of the hinge region. Collectively, these data revealed that the CTD of PCSK9 and the hinge region play a critical role in PCSK9 maturation and secretion.


Assuntos
Pró-Proteína Convertase 9/metabolismo , Domínios Proteicos/genética , Proteínas de Transporte Vesicular/metabolismo , Células HEK293 , Humanos , Mutagênese Sítio-Dirigida , Pró-Proteína Convertase 9/genética
19.
J Nutr ; 150(4): 818-825, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-31909809

RESUMO

BACKGROUND: Walnuts have established lipid-/lipoprotein-lowering properties; however, their effect on lipoprotein subclasses has not been investigated. Furthermore, the mechanisms by which walnuts improve lipid/lipoprotein concentrations are incompletely understood. OBJECTIVES: We aimed to examine, as exploratory outcomes of this trial, the effect of replacing SFAs with unsaturated fats from walnuts or vegetable oils on lipoprotein subclasses, cholesterol efflux, and proprotein convertase subtilisin/kexin type 9 (PCSK9). METHODS: A randomized, crossover, controlled-feeding study was conducted in individuals at risk of cardiovascular disease (CVD) (n = 34; 62% men; mean ± SD age 44 ± 10 y; BMI: 30.1 ± 4.9 kg/m2). After a 2-wk run-in diet (12% SFAs, 7% PUFAs, 12% MUFAs), subjects consumed the following diets, in randomized order, for 6 wk: 1) walnut diet (WD) [57-99 g/d walnuts, 7% SFAs, 16% PUFAs [2.7% α-linolenic acid (ALA)], 9% MUFAs]; 2) walnut fatty acid-matched diet [7% SFAs, 16% PUFAs (2.6% ALA), 9% MUFAs]; and 3) oleic acid replaces ALA diet (ORAD) [7% SFAs, 14% PUFAs (0.4% ALA); 12% MUFAs] (all percentages listed are of total kilocalories ). Serum collected after the run-in (baseline) and each diet period was analyzed for lipoprotein classes and subclasses (vertical auto profile), cholesterol efflux, and PCSK9. Linear mixed models were used for data analysis. RESULTS: Compared with the ORAD, total cholesterol (mean ± SEM -8.9± 2.3 mg/dL; -5.1%; P < 0.001), non-HDL cholesterol (-7.4 ± 2.0 mg/dL; -5.4%; P = 0.001), and LDL cholesterol (-6.9 ± 1.9 mg/dL; -6.5%; P = 0.001) were lower after the WD; no other pairwise differences existed. There were no between-diet differences for HDL-cholesterol or LDL-cholesterol subclasses. Lipoprotein(a) [Lp(a)], cholesterol efflux, and PCSK9 were unchanged after the diets. CONCLUSIONS: In individuals at risk of CVD, replacement of SFAs with unsaturated fats from walnuts or vegetable oils improved lipid/lipoprotein classes, including LDL-cholesterol, non-HDL cholesterol, and total cholesterol, without an increase in Lp(a). These improvements were not explained by changes in cholesterol efflux capacity or PCSK9. This trial was registered at clinicaltrials.gov as NCT01235832.


Assuntos
Gorduras Insaturadas/farmacologia , Ácidos Graxos/administração & dosagem , Juglans/química , Lipoproteína(a)/sangue , Óleos Vegetais/química , Adulto , Idoso , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Estudos Cross-Over , Dieta , Gorduras Insaturadas/administração & dosagem , Gorduras Insaturadas/química , Ácidos Graxos/química , Feminino , Análise de Alimentos , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Sobrepeso , Pró-Proteína Convertase 9/genética , Pró-Proteína Convertase 9/metabolismo
20.
Am J Cardiol ; 125(6): 880-886, 2020 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-31932084

RESUMO

Autosomal dominant hypercholesterolemia results from mutations affecting the low-density lipoprotein receptor pathway, including proprotein convertase subtilisin/kexin type 9 (PCSK9) gain-of-function mutations (GoFm) and apolipoprotein B (APOB) loss-of-function mutations (LoFm). This study examined the long-term efficacy and safety of alirocumab in patients with PCSK9 GoFm and APOB LoFm who participated in the open-label extension to a Phase 2 double-blind study (NCT01604824). Of the 23 patients who completed the 14-week double-blind period and 8-week follow-up, 21 opted to continue in the open-label extension (PCSK9 GoFm, n = 15; APOB LoFm, n = 6). Patients received alirocumab 150 mg every 2 weeks from week 32 up to 3 years for PCSK9 GoFm and 2 years for APOB LoFm. Mean duration of alirocumab exposure was 129 weeks (median: 144 weeks). After initiation of alirocumab treatment, low-density lipoprotein cholesterol (LDL-C) decreased in both groups. At week 80, mean percent reduction in LDL-C from baseline was 58.0% and 47.1% for PCSK9 GoFm and APOB LoFm groups, respectively. Treatment-emergent adverse events were reported in 19 patients (90.5%); no patients discontinued treatment due to treatment-emergent adverse events. In patients with autosomal dominant hypercholesterolemia and elevated LDL-C levels despite receiving maximally tolerated lipid-lowering therapies, alirocumab 150 mg every 2 weeks resulted in clinically meaningful reductions in LDL-C, sustained through to 3 years and 2 years for patients with PCSK9 GoFm and APOB LoFm, respectively. Alirocumab was generally well tolerated with no unexpected safety concerns.


Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Apolipoproteína B-100/genética , Mutação com Ganho de Função/genética , Hiperlipoproteinemia Tipo II/tratamento farmacológico , Hiperlipoproteinemia Tipo II/genética , Mutação com Perda de Função/genética , Pró-Proteína Convertase 9/genética , Adulto , Anticorpos Monoclonais Humanizados/efeitos adversos , Anticorpos Monoclonais Humanizados/farmacocinética , Aberrações Cromossômicas , Método Duplo-Cego , Feminino , Genes Dominantes , Genótipo , Humanos , Hiperlipoproteinemia Tipo II/sangue , Assistência de Longa Duração , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
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