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1.
Cardiovasc Res ; 2021 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-34849650

RESUMO

AIMS: Genetic studies have implicated the ARHGEF26 locus in the risk of coronary artery disease (CAD). However, the causal pathways by which DNA variants at the ARHGEF26 locus confer risk for CAD are incompletely understood. We sought to elucidate the mechanism responsible for the enhanced risk of CAD associated with the ARHGEF26 locus. METHODS AND RESULTS: In a conditional analysis of the ARHGEF26 locus, we show that the sentinel CAD-risk signal is significantly associated with various non-lipid vascular phenotypes. In human endothelial cell (EC), ARHGEF26 promotes the angiogenic capacity, and interacts with known angiogenic factors and pathways. Quantitative mass spectrometry showed that one CAD-risk coding variant, rs12493885 (p.Val29Leu), resulted in a gain-of-function ARHGEF26 that enhances proangiogenic signaling and displays enhanced interactions with several proteins partially related to the angiogenic pathway. ARHGEF26 is required for endothelial angiogenesis by promoting macropinocytosis of VEGFR2 on cell membrane and is crucial to VEGF-dependent murine vessel sprouting ex vivo. In vivo, global or tissue-specific deletion of ARHGEF26 in EC, but not in vascular smooth muscle cells, significantly reduced atherosclerosis in mice, with enhanced plaque stability. CONCLUSIONS: Our results demonstrate that ARHGEF26 is an angiogenic factor, and that DNA variants within ARHGEF26 that are associated with CAD risk could affect angiogenic pathways by promoting VEGF signaling. TRANSLATIONAL PERSPECTIVE: Understanding the genetic architecture of coronary artery disease (CAD) is critical to developing new therapeutics. Here, we present work that revealed the causal mechanism by which DNA variants at the ARHGEF26 locus confer risk for CAD. Angiogenesis-related vascular phenotypes are associated with the ARHGEF26 locus, and ARHGEF26 promotes the angiogenic capacity of human endothelial cells.Together, our work demonstrates that ARHGEF26 is a novel angiogenic factor, and endothelial-specific inhibition of ARHGEF26 may be beneficial to treating CAD. The causal pathway and the actionable therapeutic hypotheses from our work will facilitate the development of new therapeutics for CAD.

3.
Nat Metab ; 3(11): 1476-1483, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34750571

RESUMO

Cardiometabolic diseases are frequently polygenic in architecture, comprising a large number of risk alleles with small effects spread across the genome1-3. Polygenic scores (PGS) aggregate these into a metric representing an individual's genetic predisposition to disease. PGS have shown promise for early risk prediction4-7 and there is an open question as to whether PGS can also be used to understand disease biology8. Here, we demonstrate that cardiometabolic disease PGS can be used to elucidate the proteins underlying disease pathogenesis. In 3,087 healthy individuals, we found that PGS for coronary artery disease, type 2 diabetes, chronic kidney disease and ischaemic stroke are associated with the levels of 49 plasma proteins. Associations were polygenic in architecture, largely independent of cis and trans protein quantitative trait loci and present for proteins without quantitative trait loci. Over a follow-up of 7.7 years, 28 of these proteins associated with future myocardial infarction or type 2 diabetes events, 16 of which were mediators between polygenic risk and incident disease. Twelve of these were druggable targets with therapeutic potential. Our results demonstrate the potential for PGS to uncover causal disease biology and targets with therapeutic potential, including those that may be missed by approaches utilizing information at a single locus.

4.
Nat Genet ; 53(10): 1504-1516, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34611364

RESUMO

Fine-mapping to plausible causal variation may be more effective in multi-ancestry cohorts, particularly in the MHC, which has population-specific structure. To enable such studies, we constructed a large (n = 21,546) HLA reference panel spanning five global populations based on whole-genome sequences. Despite population-specific long-range haplotypes, we demonstrated accurate imputation at G-group resolution (94.2%, 93.7%, 97.8% and 93.7% in admixed African (AA), East Asian (EAS), European (EUR) and Latino (LAT) populations). Applying HLA imputation to genome-wide association study data for HIV-1 viral load in three populations (EUR, AA and LAT), we obviated effects of previously reported associations from population-specific HIV studies and discovered a novel association at position 156 in HLA-B. We pinpointed the MHC association to three amino acid positions (97, 67 and 156) marking three consecutive pockets (C, B and D) within the HLA-B peptide-binding groove, explaining 12.9% of trait variance.


Assuntos
Variação Genética , Genética Populacional , Infecções por HIV/genética , Antígenos HLA/genética , Interações Hospedeiro-Patógeno/genética , Mapeamento Físico do Cromossomo , Alelos , Aminoácidos/genética , Frequência do Gene/genética , HIV-1/genética , Haplótipos/genética , Humanos , Desequilíbrio de Ligação/genética , Padrões de Referência , Seleção Genética , Carga Viral
5.
Circ Genom Precis Med ; 14(5): e003399, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34592835

RESUMO

BACKGROUND: Corin is a protease expressed in cardiomyocytes that plays a key role in salt handling and intravascular volume homeostasis via activation of natriuretic peptides. It is unknown if Corin loss-of-function (LOF) is causally associated with risk of coronary artery disease (CAD). METHODS: We analyzed all coding CORIN variants in an Italian case-control study of CAD. We functionally tested all 64 rare missense mutations in Western Blot and Mass Spectroscopy assays for proatrial natriuretic peptide cleavage. An expanded rare variant association analysis for Corin LOF mutations was conducted in whole exome sequencing data from 37 799 CAD cases and 212 184 controls. RESULTS: We observed LOF variants in CORIN in 8 of 1803 (0.4%) CAD cases versus 0 of 1725 controls (P, 0.007). Of 64 rare missense variants profiled, 21 (33%) demonstrated <30% of wild-type activity and were deemed damaging in the 2 functional assays for Corin activity. In a rare variant association study that aggregated rare LOF and functionally validated damaging missense variants from the Italian study, we observed no association with CAD-21 of 1803 CAD cases versus 12 of 1725 controls with adjusted odds ratio of 1.61 ([95% CI, 0.79-3.29]; P=0.17). In the expanded sequencing dataset, there was no relationship between rare LOF variants with CAD was also observed (odds ratio, 1.15 [95% CI, 0.89-1.49]; P=0.30). Consistent with the genetic analysis, we observed no relationship between circulating Corin concentrations with incident CAD events among 4744 participants of a prospective cohort study-sex-stratified hazard ratio per SD increment of 0.96 ([95% CI, 0.87-1.07], P=0.48). CONCLUSIONS: Functional testing of missense mutations improved the accuracy of rare variant association analysis. Despite compelling pathophysiology and a preliminary observation suggesting association, we observed no relationship between rare damaging variants in CORIN or circulating Corin concentrations with risk of CAD.

7.
Aging Cell ; 20(6): e13366, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34050697

RESUMO

Clonal hematopoiesis of indeterminate potential (CHIP) is a common precursor state for blood cancers that most frequently occurs due to mutations in the DNA-methylation modifying enzymes DNMT3A or TET2. We used DNA-methylation array and whole-genome sequencing data from four cohorts together comprising 5522 persons to study the association between CHIP, epigenetic clocks, and health outcomes. CHIP was strongly associated with epigenetic age acceleration, defined as the residual after regressing epigenetic clock age on chronological age, in several clocks, ranging from 1.31 years (GrimAge, p < 8.6 × 10-7 ) to 3.08 years (EEAA, p < 3.7 × 10-18 ). Mutations in most CHIP genes except DNA-damage response genes were associated with increases in several measures of age acceleration. CHIP carriers with mutations in multiple genes had the largest increases in age acceleration and decrease in estimated telomere length. Finally, we found that ~40% of CHIP carriers had acceleration >0 in both Hannum and GrimAge (referred to as AgeAccelHG+). This group was at high risk of all-cause mortality (hazard ratio 2.90, p < 4.1 × 10-8 ) and coronary heart disease (CHD) (hazard ratio 3.24, p < 9.3 × 10-6 ) compared to those who were CHIP-/AgeAccelHG-. In contrast, the other ~60% of CHIP carriers who were AgeAccelHG- were not at increased risk of these outcomes. In summary, CHIP is strongly linked to age acceleration in multiple clocks, and the combination of CHIP and epigenetic aging may be used to identify a population at high risk for adverse outcomes and who may be a target for clinical interventions.

8.
Nature ; 593(7859): 429-434, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-34012082

RESUMO

Gene-editing technologies, which include the CRISPR-Cas nucleases1-3 and CRISPR base editors4,5, have the potential to permanently modify disease-causing genes in patients6. The demonstration of durable editing in target organs of nonhuman primates is a key step before in vivo administration of gene editors to patients in clinical trials. Here we demonstrate that CRISPR base editors that are delivered in vivo using lipid nanoparticles can efficiently and precisely modify disease-related genes in living cynomolgus monkeys (Macaca fascicularis). We observed a near-complete knockdown of PCSK9 in the liver after a single infusion of lipid nanoparticles, with concomitant reductions in blood levels of PCSK9 and low-density lipoprotein cholesterol of approximately 90% and about 60%, respectively; all of these changes remained stable for at least 8 months after a single-dose treatment. In addition to supporting a 'once-and-done' approach to the reduction of low-density lipoprotein cholesterol and the treatment of atherosclerotic cardiovascular disease (the leading cause of death worldwide7), our results provide a proof-of-concept for how CRISPR base editors can be productively applied to make precise single-nucleotide changes in therapeutic target genes in the liver, and potentially in other organs.


Assuntos
Sistemas CRISPR-Cas , LDL-Colesterol/sangue , Edição de Genes , Modelos Animais , Pró-Proteína Convertase 9/genética , Adenina/metabolismo , Animais , Células Cultivadas , Feminino , Hepatócitos/metabolismo , Humanos , Fígado/enzimologia , Mutação com Perda de Função , Macaca fascicularis/sangue , Macaca fascicularis/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mutagênese Sítio-Dirigida , Pró-Proteína Convertase 9/sangue , Pró-Proteína Convertase 9/metabolismo , Fatores de Tempo
9.
Genet Med ; 23(9): 1689-1696, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33976420

RESUMO

PURPOSE: To evaluate the diagnostic yield and clinical relevance of clinical genome sequencing (cGS) as a first genetic test for patients with suspected monogenic disorders. METHODS: We conducted a prospective randomized study with pediatric and adult patients recruited from genetics clinics at Massachusetts General Hospital who were undergoing planned genetic testing. Participants were randomized into two groups: standard-of-care genetic testing (SOC) only or SOC and cGS. RESULTS: Two hundred four participants were enrolled, 202 were randomized to one of the intervention arms, and 99 received cGS. In total, cGS returned 16 molecular diagnoses that fully or partially explained the indication for testing in 16 individuals (16.2% of the cohort, 95% confidence interval [CI] 8.9-23.4%), which was not significantly different from SOC (18.2%, 95% CI 10.6-25.8%, P = 0.71). An additional eight molecular diagnoses reported by cGS had uncertain relevance to the participant's phenotype. Nevertheless, referring providers considered 20/24 total cGS molecular diagnoses (83%) to be explanatory for clinical features or worthy of additional workup. CONCLUSION: cGS is technically suitable as a first genetic test. In our cohort, diagnostic yield was not significantly different from SOC. Further studies addressing other variant types and implementation challenges are needed to support feasibility and utility of broad-scale cGS adoption.


Assuntos
Testes Genéticos , Patologia Molecular , Adulto , Criança , Mapeamento Cromossômico , Humanos , Técnicas de Diagnóstico Molecular , Estudos Prospectivos
12.
Arterioscler Thromb Vasc Biol ; 41(1): 465-474, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33115266

RESUMO

OBJECTIVE: Lp(a) (lipoprotein[a]) concentrations are associated with atherosclerotic cardiovascular disease (ASCVD), and new therapies that enable potent and specific reduction are in development. In the largest study conducted to date, we address 3 areas of uncertainty: (1) the magnitude and shape of ASCVD risk conferred across the distribution of lipoprotein(a) concentrations; (2) variation of risk across racial and clinical subgroups; (3) clinical importance of a high lipoprotein(a) threshold to guide therapy. Approach and Results: Relationship of lipoprotein(a) to incident ASCVD was studied in 460 506 middle-aged UK Biobank participants. Over a median follow-up of 11.2 years, incident ASCVD occurred in 22 401 (4.9%) participants. Median lipoprotein(a) concentration was 19.6 nmol/L (25th-75th percentile 7.6-74.8). The relationship between lipoprotein(a) and ASCVD appeared linear across the distribution, with a hazard ratio of 1.11 (95% CI, 1.10-1.12) per 50 nmol/L increment. Substantial differences in concentrations were noted according to race-median values for white, South Asian, black, and Chinese individuals were 19, 31, 75, and 16 nmol/L, respectively. However, risk per 50 nmol/L appeared similar-hazard ratios of 1.11, 1.10, and 1.07 for white, South Asian, and black individuals, respectively. A high lipoprotein(a) concentration defined as ≥150 nmol/L was present in 12.2% of those without and 20.3% of those with preexisting ASCVD and associated with hazard ratios of 1.50 (95% CI, 1.44-1.56) and 1.16 (95% CI, 1.05-1.27), respectively. CONCLUSIONS: Lipoprotein(a) concentrations predict incident ASCVD among middle-aged adults within primary and secondary prevention contexts, with a linear risk gradient across the distribution. Concentrations are variable across racial subgroups, but the associated risk appears similar.


Assuntos
Aterosclerose/sangue , Aterosclerose/epidemiologia , Lipoproteína(a)/sangue , Adulto , Idoso , Aterosclerose/diagnóstico , Aterosclerose/prevenção & controle , Bancos de Espécimes Biológicos , Biomarcadores/sangue , Feminino , Fatores de Risco de Doenças Cardíacas , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Prevenção Primária , Prognóstico , Fatores Raciais , Medição de Risco , Prevenção Secundária , Fatores de Tempo , Reino Unido
14.
Gastroenterology ; 160(5): 1620-1633.e13, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33310085

RESUMO

BACKGROUND & AIMS: In contrast to most other common diseases, few genetic variants have been identified that impact risk of cirrhosis. We aimed to identify new genetic variants that predispose to cirrhosis, to test whether such variants, aggregated into a polygenic score, enable genomic risk stratification, and to test whether alcohol intake or body mass index interacts with polygenic predisposition. METHODS: We conducted a multi-trait genome-wide association study combining cirrhosis and alanine aminotransferase levels performed in 5 discovery studies (UK Biobank, Vanderbilt BioVU, Atherosclerosis Risk in Communities study, and 2 case-control studies including 4829 individuals with cirrhosis and 72,705 controls and 362,539 individuals with alanine aminotransferase levels). Identified variants were replicated in 3 studies (Partners HealthCare Biobank, FinnGen, and Biobank Japan including 3554 individuals with cirrhosis and 343,826 controls). A polygenic score was tested in Partners HealthCare Biobank. RESULTS: Five previously reported and 7 newly identified genetic variants were associated with cirrhosis in both the discovery studies multi-trait genome-wide association study (P < 5 × 10-8) and the replication studies (P < .05), including a missense variant in the APOE gene and a noncoding variant near EFN1A. These 12 variants were used to generate a polygenic score. Among Partners HealthCare Biobank individuals, high polygenic score-defined as the top quintile of the distribution-was associated with significantly increased risk of cirrhosis (odds ratio, 2.26; P < .001) and related comorbidities compared with the lowest quintile. Risk was even more pronounced among those with extreme polygenic risk (top 1% of the distribution, odds ratio, 3.16; P < .001). The impact of extreme polygenic risk was substantially more pronounced in those with elevated alcohol consumption or body mass index. Modeled as risk by age 75 years, probability of cirrhosis with extreme polygenic risk was 13.7%, 20.1%, and 48.2% among individuals with no or modest, moderate, and increased alcohol consumption, respectively (Pinteraction < .001). Similarly, probability among those with extreme polygenic risk was 6.5%, 10.3%, and 19.5% among individuals with normal weight, overweight, and obesity, respectively (Pinteraction < .001). CONCLUSIONS: Twelve independent genetic variants, 7 of which are newly identified in this study, conferred risk for cirrhosis. Aggregated into a polygenic score, these variants identified a subset of the population at substantially increased risk who are most susceptible to the hepatotoxic effects of excess alcohol consumption or obesity.


Assuntos
Interação Gene-Ambiente , Variação Genética , Cirrose Hepática/genética , Adulto , Fatores Etários , Idoso , Consumo de Bebidas Alcoólicas/efeitos adversos , Consumo de Bebidas Alcoólicas/epidemiologia , Estudos de Casos e Controles , Comorbidade , Feminino , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Humanos , Cirrose Hepática/diagnóstico , Cirrose Hepática/epidemiologia , Masculino , Pessoa de Meia-Idade , Herança Multifatorial , Obesidade/epidemiologia , Fenótipo , Medição de Risco , Fatores de Risco
15.
Nature ; 586(7831): 769-775, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-33057200

RESUMO

Myeloproliferative neoplasms (MPNs) are blood cancers that are characterized by the excessive production of mature myeloid cells and arise from the acquisition of somatic driver mutations in haematopoietic stem cells (HSCs). Epidemiological studies indicate a substantial heritable component of MPNs that is among the highest known for cancers1. However, only a limited number of genetic risk loci have been identified, and the underlying biological mechanisms that lead to the acquisition of MPNs remain unclear. Here, by conducting a large-scale genome-wide association study (3,797 cases and 1,152,977 controls), we identify 17 MPN risk loci (P < 5.0 × 10-8), 7 of which have not been previously reported. We find that there is a shared genetic architecture between MPN risk and several haematopoietic traits from distinct lineages; that there is an enrichment for MPN risk variants within accessible chromatin of HSCs; and that increased MPN risk is associated with longer telomere length in leukocytes and other clonal haematopoietic states-collectively suggesting that MPN risk is associated with the function and self-renewal of HSCs. We use gene mapping to identify modulators of HSC biology linked to MPN risk, and show through targeted variant-to-function assays that CHEK2 and GFI1B have roles in altering the function of HSCs to confer disease risk. Overall, our results reveal a previously unappreciated mechanism for inherited MPN risk through the modulation of HSC function.


Assuntos
Predisposição Genética para Doença/genética , Células-Tronco Hematopoéticas/patologia , Transtornos Mieloproliferativos/genética , Transtornos Mieloproliferativos/patologia , Neoplasias/genética , Neoplasias/patologia , Linhagem da Célula/genética , Autorrenovação Celular , Quinase do Ponto de Checagem 2/genética , Feminino , Humanos , Leucócitos/patologia , Masculino , Proteínas Proto-Oncogênicas/genética , Proteínas Repressoras/genética , Risco , Homeostase do Telômero
16.
Circulation ; 142(17): 1633-1646, 2020 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-32981348

RESUMO

BACKGROUND: Abdominal aortic aneurysm (AAA) is an important cause of cardiovascular mortality; however, its genetic determinants remain incompletely defined. In total, 10 previously identified risk loci explain a small fraction of AAA heritability. METHODS: We performed a genome-wide association study in the Million Veteran Program testing ≈18 million DNA sequence variants with AAA (7642 cases and 172 172 controls) in veterans of European ancestry with independent replication in up to 4972 cases and 99 858 controls. We then used mendelian randomization to examine the causal effects of blood pressure on AAA. We examined the association of AAA risk variants with aneurysms in the lower extremity, cerebral, and iliac arterial beds, and derived a genome-wide polygenic risk score (PRS) to identify a subset of the population at greater risk for disease. RESULTS: Through a genome-wide association study, we identified 14 novel loci, bringing the total number of known significant AAA loci to 24. In our mendelian randomization analysis, we demonstrate that a genetic increase of 10 mm Hg in diastolic blood pressure (odds ratio, 1.43 [95% CI, 1.24-1.66]; P=1.6×10-6), as opposed to systolic blood pressure (odds ratio, 1.06 [95% CI, 0.97-1.15]; P=0.2), likely has a causal relationship with AAA development. We observed that 19 of 24 AAA risk variants associate with aneurysms in at least 1 other vascular territory. A 29-variant PRS was strongly associated with AAA (odds ratioPRS, 1.26 [95% CI, 1.18-1.36]; PPRS=2.7×10-11 per SD increase in PRS), independent of family history and smoking risk factors (odds ratioPRS+family history+smoking, 1.24 [95% CI, 1.14-1.35]; PPRS=1.27×10-6). Using this PRS, we identified a subset of the population with AAA prevalence greater than that observed in screening trials informing current guidelines. CONCLUSIONS: We identify novel AAA genetic associations with therapeutic implications and identify a subset of the population at significantly increased genetic risk of AAA independent of family history. Our data suggest that extending current screening guidelines to include testing to identify those with high polygenic AAA risk, once the cost of genotyping becomes comparable with that of screening ultrasound, would significantly increase the yield of current screening at reasonable cost.


Assuntos
Aneurisma da Aorta Abdominal/genética , Humanos , Veteranos
17.
Arterioscler Thromb Vasc Biol ; 40(11): 2738-2746, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32957805

RESUMO

OBJECTIVE: To determine the relationship of a genome-wide polygenic score for coronary artery disease (GPSCAD) with lifetime trajectories of CAD risk, directly compare its predictive capacity to traditional risk factors, and assess its interplay with the Pooled Cohort Equations (PCE) clinical risk estimator. Approach and Results: We studied GPSCAD in 28 556 middle-aged participants of the Malmö Diet and Cancer Study, of whom 4122 (14.4%) developed CAD over a median follow-up of 21.3 years. A pronounced gradient in lifetime risk of CAD was observed-16% for those in the lowest GPSCAD decile to 48% in the highest. We evaluated the discriminative capacity of the GPSCAD-as assessed by change in the C-statistic from a baseline model including age and sex-among 5685 individuals with PCE risk estimates available. The increment for the GPSCAD (+0.045, P<0.001) was higher than for any of 11 traditional risk factors (range +0.007 to +0.032). Minimal correlation was observed between GPSCAD and 10-year risk defined by the PCE (r=0.03), and addition of GPSCAD improved the C-statistic of the PCE model by 0.026. A significant gradient in lifetime risk was observed for the GPSCAD, even among individuals within a given PCE clinical risk stratum. We replicated key findings-noting strikingly consistent results-in 325 003 participants of the UK Biobank. CONCLUSIONS: GPSCAD-a risk estimator available from birth-stratifies individuals into varying trajectories of clinical risk for CAD. Implementation of GPSCAD may enable identification of high-risk individuals early in life, decades in advance of manifest risk factors or disease.


Assuntos
Doença da Artéria Coronariana/genética , Herança Multifatorial , Adulto , Idoso , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/epidemiologia , Feminino , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Fatores de Risco de Doenças Cardíacas , Hereditariedade , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Fenótipo , Prognóstico , Medição de Risco , Suécia/epidemiologia , Fatores de Tempo , Reino Unido/epidemiologia
18.
Circ Genom Precis Med ; 13(5): 417-423, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32862661

RESUMO

BACKGROUND: Familial sitosterolemia is a rare Mendelian disorder characterized by hyperabsorption and decreased biliary excretion of dietary sterols. Affected individuals typically have complete genetic deficiency-homozygous loss-of-function (LoF) variants-in the ABCG5 or ABCG8 genes and have substantially elevated plasma sitosterol and LDL (low-density lipoprotein) cholesterol (LDL-C) levels. The impact of partial genetic deficiency of ABCG5 or ABCG8-as occurs in heterozygous carriers of LoF variants-on LDL-C and risk of coronary artery disease (CAD) has remained uncertain. METHODS: We first recruited 9 sitosterolemia families, identified causative LoF variants in ABCG5 or ABCG8, and evaluated the associations of these ABCG5 or ABCG8 LoF variants with plasma phytosterols and lipid levels. We next assessed for LoF variants in ABCG5 or ABCG8 in CAD cases (n=29 321) versus controls (n=357 326). We tested the association of rare LoF variants in ABCG5 or ABCG8 with blood lipids and risk for CAD. Rare LoF variants were defined as protein-truncating variants with minor allele frequency <0.1% in ABCG5 or ABCG8. RESULTS: In sitosterolemia families, 7 pedigrees harbored causative LoF variants in ABCG5 and 2 pedigrees in ABCG8. Homozygous LoF variants in either ABCG5 or ABCG8 led to marked elevations in sitosterol and LDL-C. Of those sitosterolemia families, heterozygous carriers of ABCG5 LoF variants exhibited increased sitosterol and LDL-C levels compared with noncarriers. Within large-scale CAD case-control cohorts, prevalence of rare LoF variants in ABCG5 and in ABCG8 was ≈0.1% each. ABCG5 heterozygous LoF variant carriers had significantly elevated LDL-C levels (25 mg/dL [95% CI, 14-35]; P=1.1×10-6) and were at 2-fold increased risk of CAD (odds ratio, 2.06 [95% CI, 1.27-3.35]; P=0.004). By contrast, ABCG8 heterozygous LoF carrier status was not associated with increased LDL-C or risk of CAD. CONCLUSIONS: Although familial sitosterolemia is traditionally considered as a recessive disorder, we observed that heterozygous carriers of an LoF variant in ABCG5 had significantly increased sitosterol and LDL-C levels and a 2-fold increase in risk of CAD.

19.
J Proteome Res ; 19(10): 3968-3980, 2020 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-32786677

RESUMO

Population genetic studies highlight a missense variant (G398S) of A1CF that is strongly associated with higher levels of blood triglycerides (TGs) and total cholesterol (TC). Functional analyses suggest that the mutation accelerates the secretion of very low-density lipoprotein (VLDL) from the liver by an unknown mechanism. Here, we used multiomics approaches to interrogate the functional difference between the WT and mutant A1CF. Using metabolomics analyses, we captured the cellular lipid metabolite changes induced by transient expression of the proteins, confirming that the mutant A1CF is able to relieve the TG accumulation induced by WT A1CF. Using a proteomics approach, we obtained the interactomic data of WT and mutant A1CF. Networking analyses show that WT A1CF interacts with three functional protein groups, RNA/mRNA processing, cytosolic translation, and, surprisingly, mitochondrial translation. The mutation diminishes these interactions, especially with the group of mitochondrial translation. Differential analyses show that the WT A1CF-interacting proteins most significantly different from the mutant are those for mitochondrial translation, whereas the most significant interacting proteins with the mutant are those for cytoskeleton and vesicle-mediated transport. RNA-seq analyses validate that the mutant, but not the WT, A1CF increases the expression of the genes responsible for cellular transport processes. On the contrary, WT A1CF affected the expression of mitochondrial matrix proteins and increased cell oxygen consumption. Thus, our studies confirm the previous hypothesis that A1CF plays broader roles in regulating gene expression. The interactions of the mutant A1CF with the vesicle-mediated transport machinery provide mechanistic insight in understanding the increased VLDL secretion in the A1CF mutation carriers.


Assuntos
Metabolismo dos Lipídeos , Proteínas de Ligação a RNA , Metabolismo dos Lipídeos/genética , Fígado/metabolismo , Edição de RNA , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/metabolismo
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