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1.
Circulation ; 148(24): 1945-1957, 2023 12 12.
Artículo en Inglés | MEDLINE | ID: mdl-37830208

RESUMEN

BACKGROUND: Apparent treatment-resistant hypertension (aTRH) is prevalent and associated with adverse outcomes in heart failure with mildly reduced or preserved ejection fraction. Less is known about the potential role of sodium-glucose co-transporter 2 inhibition in this high-risk population. In this post hoc analysis of the DELIVER trial (Dapagliflozin Evaluation to Improve the Lives of Patients with Preserved Ejection Fraction Heart Failure), we evaluated clinical profiles and treatment effects of dapagliflozin among participants with aTRH. METHODS: DELIVER participants were categorized on the basis of baseline blood pressure (BP), with aTRH defined as BP ≥140/90 mm Hg (≥130/80 mm Hg if diabetes) despite treatment with 3 antihypertensive drugs including a diuretic. Nonresistant hypertension was defined as BP above threshold but not meeting aTRH criteria. Controlled BP was defined as BP under threshold. Incidence of the primary outcome (cardiovascular death or worsening heart failure event), key secondary outcomes, and safety events was assessed by baseline BP category. RESULTS: Among 6263 DELIVER participants, 3766 (60.1%) had controlled BP, 1779 (28.4%) had nonresistant hypertension, and 718 (11.5%) had aTRH at baseline. Participants with aTRH had more cardiometabolic comorbidities and tended to have higher left ventricular ejection fraction and worse kidney function. Rates of the primary outcome were 8.7 per 100 patient-years in those with controlled BP, 8.5 per 100 patient-years in the nonresistant hypertension group, and 9.5 per 100 patient-years in the aTRH group. Relative treatment benefits of dapagliflozin versus placebo on the primary outcome were consistent across BP categories (Pinteraction=0.114). Participants with aTRH exhibited the greatest absolute reduction in the rate of primary events with dapagliflozin (4.1 per 100 patient-years) compared with nonresistant hypertension (2.7 per 100 patient-years) and controlled BP (0.8 per 100 patient-years). Irrespective of assigned treatment, participants with aTRH experienced a higher rate of reported vascular events, including myocardial infarction and stroke, over study follow-up. Dapagliflozin modestly reduced systolic BP (by ≈1 to 3 mm Hg) without increasing risk of hypotension, hypovolemia, or other serious adverse events, irrespective of BP category, but did not improve the proportion of participants with aTRH attaining goal BP over time. CONCLUSIONS: aTRH was identified in >1 in 10 patients with heart failure and left ventricular ejection fraction >40% in DELIVER. Dapagliflozin consistently improved clinical outcomes and was well-tolerated, including among those with aTRH. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03619213.


Asunto(s)
Insuficiencia Cardíaca , Hipertensión , Humanos , Volumen Sistólico , Función Ventricular Izquierda , Compuestos de Bencidrilo/efectos adversos
2.
JAMA ; 331(21): 1824-1833, 2024 06 04.
Artículo en Inglés | MEDLINE | ID: mdl-38734952

RESUMEN

Importance: Individual cohort studies concur that the amyloidogenic V142I variant of the transthyretin (TTR) gene, present in 3% to 4% of US Black individuals, increases heart failure (HF) and mortality risk. Precisely defining carrier risk across relevant clinical outcomes and estimating population burden of disease are important given established and emerging targeted treatments. Objectives: To better define the natural history of disease in carriers across mid to late life, assess variant modifiers, and estimate cardiovascular burden to the US population. Design, Setting, and Participants: A total of 23 338 self-reported Black participants initially free from HF were included in 4 large observational studies across the US (mean [SD], 15.5 [8.2] years of follow-up). Data analysis was performed between May 2023 and February 2024. Exposure: V142I carrier status (n = 754, 3.2%). Main Outcomes and Measures: Hospitalizations for HF (including subtypes of reduced and preserved ejection fraction) and all-cause mortality. Outcomes were analyzed by generating 10-year hazard ratios for each age between 50 and 90 years. Using actuarial methods, mean survival by carrier status was estimated and applied to the 2022 US population using US Census data. Results: Among the 23 338 participants, the mean (SD) age at baseline was 62 (9) years and 76.7% were women. Ten-year carrier risk increased for HF hospitalization by age 63 years, predominantly driven by HF with reduced ejection fraction, and 10-year all-cause mortality risk increased by age 72 years. Only age (but not sex or other select variables) modified risk with the variant, with estimated reductions in longevity ranging from 1.9 years (95% CI, 0.6-3.1) at age 50 to 2.8 years (95% CI, 2.0-3.6) at age 81. Based on these data, 435 851 estimated US Black carriers between ages 50 and 95 years are projected to cumulatively lose 957 505 years of life (95% CI, 534 475-1 380 535) due to the variant. Conclusions and Relevance: Among self-reported Black individuals, male and female V142I carriers faced similar and substantial risk for HF hospitalization, predominantly with reduced ejection fraction, and death, with steep age-dependent penetrance. Delineating the individual contributions of, and complex interplay among, the V142I variant, ancestry, the social construct of race, and biological or social determinants of health to cardiovascular disease merits further investigation.


Asunto(s)
Amiloidosis , Negro o Afroamericano , Cardiomiopatías , Insuficiencia Cardíaca , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Amiloidosis/etnología , Amiloidosis/genética , Negro o Afroamericano/genética , Cardiomiopatías/etnología , Cardiomiopatías/genética , Progresión de la Enfermedad , Insuficiencia Cardíaca/etnología , Insuficiencia Cardíaca/genética , Insuficiencia Cardíaca/mortalidad , Heterocigoto , Hospitalización/estadística & datos numéricos , Prealbúmina/genética , Volumen Sistólico , Estados Unidos/epidemiología , Costo de Enfermedad
3.
Circulation ; 146(11): 808-818, 2022 09 13.
Artículo en Inglés | MEDLINE | ID: mdl-35603596

RESUMEN

BACKGROUND: Sodium-glucose cotransporter-2 inhibitors are foundational therapy in patients with heart failure with reduced ejection fraction (HFrEF), but underlying mechanisms of benefit are not well defined. We sought to investigate the relationships between sodium-glucose cotransporter-2 inhibitor treatment, changes in metabolic pathways, and outcomes using targeted metabolomics. METHODS: DEFINE-HF (Dapagliflozin Effects on Biomarkers, Symptoms and Functional Status in Patients With HF With Reduced Ejection Fraction) was a placebo-controlled trial of dapagliflozin in HFrEF. We performed targeted mass spectrometry profiling of 63 metabolites (45 acylcarnitines [markers of fatty acid oxidation], 15 amino acids, and 3 conventional metabolites) in plasma samples at randomization and 12 weeks. Using mixed models, we identified principal components analysis-defined metabolite clusters that changed differentially with treatment and examined the relationship between change in metabolite clusters and change in Kansas City Cardiomyopathy Questionnaire scores and NT-proBNP (N-terminal probrain natriuretic peptide). Models were adjusted for relevant clinical covariates and nominal P<0.05 with false discovery rate-adjusted P<0.10 was used to determine statistical significance. RESULTS: Among the 234 DEFINE-HF participants with targeted metabolomic data, the mean age was 62.0±11.1 years, 25% were women, 38% were Black, and mean ejection fraction was 27±8%. Dapagliflozin increased ketone-related and short-chain acylcarnitine as well as medium-chain acylcarnitine principal components analysis-defined metabolite clusters compared with placebo (nominal P=0.01, false discovery rate-adjusted P=0.08 for both clusters). However, ketosis (ß-hydroxybutyrate levels >500 µmol/L) was achieved infrequently (3 [2.5%] in dapagliflozin arm versus 1 [0.9%] in placebo arm) and supraphysiologic levels were not observed. Increases in long-chain acylcarnitine, long-chain dicarboxylacylcarnitine, and aromatic amino acid metabolite clusters were associated with decreases in Kansas City Cardiomyopathy Questionnaire scores (ie, worse quality of life) and increases in NT-proBNP levels, without interaction by treatment group. CONCLUSIONS: In this study of targeted metabolomics in a placebo-controlled trial of sodium-glucose cotransporter-2 inhibitors in HFrEF, we observed effects of dapagliflozin on key metabolic pathways, supporting a role for altered ketone and fatty acid biology with sodium-glucose cotransporter-2 inhibitors in patients with HFrEF. Only physiologic levels of ketosis were observed. In addition, we identified several metabolic biomarkers associated with adverse HFrEF outcomes. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT02653482.


Asunto(s)
Cardiomiopatías , Insuficiencia Cardíaca , Cetosis , Inhibidores del Cotransportador de Sodio-Glucosa 2 , Disfunción Ventricular Izquierda , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Compuestos de Bencidrilo/efectos adversos , Biomarcadores , Cardiomiopatías/complicaciones , Ácidos Grasos , Glucósidos , Cetonas/uso terapéutico , Calidad de Vida , Inhibidores del Cotransportador de Sodio-Glucosa 2/farmacología , Inhibidores del Cotransportador de Sodio-Glucosa 2/uso terapéutico , Volumen Sistólico/fisiología , Disfunción Ventricular Izquierda/complicaciones
4.
Int J Mol Sci ; 24(22)2023 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-38003551

RESUMEN

The leptin-melanocortin pathway is pivotal in appetite and energy homeostasis. Pathogenic variants in genes involved in this pathway lead to severe early-onset monogenic obesity (MO). The MC4R gene plays a central role in leptin-melanocortin signaling, and heterozygous variants in this gene are the most common cause of MO. A targeted gene panel consisting of 52 obesity-related genes was used to screen for variants associated with obesity. Variants were analyzed and filtered to identify potential disease-causing activity and validated using Sanger sequencing. We identified two novel heterozygous variants, c.253A>G p.Ser85Gly and c.802T>C p.Tyr268His, in the MC4R gene in two unrelated patients with morbid obesity and evaluated the functional impact of these variants. The impact of the variants on the MC4R gene was assessed using in silico prediction tools and molecular dynamics simulation. To further study the pathogenicity of the identified variants, GT1-7 cells were transfected with plasmid DNA encoding either wild-type or mutant MC4R variants. The effects of allelic variations in the MC4R gene on cAMP synthesis, MC4R protein level, and activation of PKA, ERB, and CREB signaling pathways in both stimulated and unstimulated ɑ-MSH paradigms were determined for their functional implications. In silico analysis suggested that the variants destabilized the MC4R structure and affected the overall dynamics of the MC4R protein, possibly leading to intracellular receptor retention. In vitro analysis of the functional impact of these variants showed a significant reduction in cell surface receptor expression and impaired extracellular ligand binding activity, leading to reduced cAMP production. Our analysis shows that the variants do not affect total protein expression; however, they are predicted to affect the post-translational localization of the MC4R protein to the cell surface and impair downstream signaling cascades such as PKA, ERK, and CREB signaling pathways. This finding might help our patients to benefit from the novel therapeutic advances for monogenic forms of obesity.


Asunto(s)
Leptina , Obesidad Mórbida , Humanos , Leptina/genética , Obesidad Mórbida/genética , Qatar , Alelos , alfa-MSH/farmacología , Receptor de Melanocortina Tipo 4/genética , Receptor de Melanocortina Tipo 4/metabolismo , Mutación
5.
Hum Mutat ; 43(4): 499-510, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35112413

RESUMEN

Despite recent biomedical breakthroughs and large genomic studies growing momentum, the Middle Eastern population, home to over 400 million people, is underrepresented in the human genome variation databases. Here we describe insights from Phase 1 of the Qatar Genome Program with whole genome sequenced 6047 individuals from Qatar. We identified more than 88 million variants of which 24 million are novel and 23 million are singletons. Consistent with the high consanguinity and founder effects in the region, we found that several rare deleterious variants were more common in the Qatari population while others seem to provide protection against diseases and have shaped the genetic architecture of adaptive phenotypes. These results highlight the value of our data as a resource to advance genetic studies in the Arab and neighboring Middle Eastern populations and will significantly boost the current efforts to improve our understanding of global patterns of human variations, human history, and genetic contributions to health and diseases in diverse populations.


Asunto(s)
Genoma Humano , Genómica , Consanguinidad , Genética de Población , Genoma Humano/genética , Genómica/métodos , Humanos , Medio Oriente , Qatar/epidemiología
6.
J Card Fail ; 28(7): 1128-1136, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-34965472

RESUMEN

BACKGROUND: ß-Amyloid has recently been discovered in the myocardium of patients with Alzheimer's disease (AD). Whether genetic variation in apolipoprotein E (APOE) ɛ4, a common variant associated with Alzheimer's disease, is associated with incident heart failure (HF), N-terminal pro-B-type natriuretic peptide (NT-proBNP), and cardiac structure and function is unknown. METHODS AND RESULTS: We studied 15,064 White and Black participants in the Atherosclerosis Risk in Communities, relating genotype status at visit 1 (1987-1989) to incident HF hospitalization using Cox regression. At visits 2, 4, and 5, we assessed NT-proBNP levels by genotype. At visits 3 and 5, we related Aß peptides to incident HF. At visit 5 (2011-2013, n = 6251), we assessed the relationship of genotype with prevalent HF and echocardiographic parameters. The mean participant age was 54.7 ± 5.8 years, 45% were men, and 73% were White. At visit 5, there was no difference in prevalent HF by genotype. The APOE ε4 carriers did not have increased risk for HF hospitalization. The APOE ε4 genotype was not associated with cardiac structure and function or NT-proBNP levels. The Aß peptides were not associated with incident HF after multivariable adjustment. CONCLUSIONS: A genetic predisposition to Alzheimer's disease through APOE ε4 is not associated with an increased prevalence of HF, HF hospitalization, myocardial remodeling, or biochemical evidence of HF.


Asunto(s)
Enfermedad de Alzheimer , Apolipoproteína E4 , Insuficiencia Cardíaca , Enfermedad de Alzheimer/complicaciones , Apolipoproteína E4/genética , Apolipoproteínas E/genética , Biomarcadores , Femenino , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/epidemiología , Insuficiencia Cardíaca/genética , Humanos , Masculino , Persona de Mediana Edad , Péptido Natriurético Encefálico , Fragmentos de Péptidos , Remodelación Ventricular/genética
7.
Circulation ; 141(22): 1800-1812, 2020 06 02.
Artículo en Inglés | MEDLINE | ID: mdl-32479196

RESUMEN

Despite existing therapy, patients with heart failure (HF) experience substantial morbidity and mortality, highlighting the urgent need to identify novel pathophysiological mechanisms and therapies, as well. Traditional models for pharmacological intervention have targeted neurohormonal axes and hemodynamic disturbances in HF. However, several studies have now highlighted the potential for ketone metabolic modulation as a promising treatment paradigm. During the pathophysiological progression of HF, the failing heart reduces fatty acid and glucose oxidation, with associated increases in ketone metabolism. Recent studies indicate that enhanced myocardial ketone use is adaptive in HF, and limited data demonstrate beneficial effects of exogenous ketone therapy in studies of animal models and humans with HF. This review will summarize current evidence supporting a salutary role for ketones in HF including (1) normal myocardial ketone use, (2) alterations in ketone metabolism in the failing heart, (3) effects of therapeutic ketosis in animals and humans with HF, and (4) the potential significance of ketosis associated with sodium-glucose cotransporter 2 inhibitors. Although a number of important questions remain regarding the use of therapeutic ketosis and mechanism of action in HF, current evidence suggests potential benefit, in particular, in HF with reduced ejection fraction, with theoretical rationale for its use in HF with preserved ejection fraction. Although it is early in its study and development, therapeutic ketosis across the spectrum of HF holds significant promise.


Asunto(s)
Insuficiencia Cardíaca/metabolismo , Cetonas/metabolismo , Cetosis/metabolismo , Animales , Biomarcadores , Gasto Cardíaco Bajo/etiología , Gasto Cardíaco Bajo/metabolismo , Cardiotónicos/uso terapéutico , Dieta Cetogénica , Metabolismo Energético , Ácidos Grasos/metabolismo , Glucosa/metabolismo , Insuficiencia Cardíaca/complicaciones , Insuficiencia Cardíaca/dietoterapia , Insuficiencia Cardíaca/tratamiento farmacológico , Humanos , Cuerpos Cetónicos/metabolismo , Cetonas/administración & dosificación , Cetonas/uso terapéutico , Hígado/metabolismo , Ratones , Daño por Reperfusión Miocárdica/tratamiento farmacológico , Daño por Reperfusión Miocárdica/etiología , Ratas Endogámicas Dahl , Inhibidores del Cotransportador de Sodio-Glucosa 2/uso terapéutico , Volumen Sistólico
8.
Curr Opin Cardiol ; 36(4): 413-419, 2021 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-33709982

RESUMEN

PURPOSE OF REVIEW: Hypertension remains a leading risk factor for heart failure with preserved ejection fraction (HFpEF), and elevated blood pressure (BP) portends an adverse prognosis in patients with established HFpEF. We summarize current evidence for mechanisms linking hypertension to HFpEF and management of hypertension in HFpEF. RECENT FINDINGS: Data suggest a complex, multifactorial pathophysiology driving the association between hypertension and HFpEF, including left ventricular hypertrophy, diastolic dysfunction, atrial dysfunction, coronary microvascular disease, endothelial dysfunction, myocardial injury and fibrosis. Although intensive BP control may attenuate these processes, this hypothesis has not been tested on clinical outcomes in a dedicated randomized controlled trial (RCT) in HFpEF. Antihypertensive therapies variably improve key surrogate markers in HFpEF, though BP reduction generally does not account for these benefits. Accordingly, BP targets are extrapolated from observational studies and RCTs testing heart failure therapies that affect BP in addition to dedicated RCT data in patients at elevated risk (without heart failure). SUMMARY: Clinicians should recognize the risk of disease progression and poor outcomes associated with uncontrolled hypertension in HFpEF. Intensive BP control, preferably by therapies known to improve outcomes in heart failure, may slow key pathways in disease progression. Future RCTs testing intensified BP control strategies in HFpEF are warranted.


Asunto(s)
Insuficiencia Cardíaca , Hipertensión , Presión Sanguínea , Objetivos , Humanos , Hipertensión/complicaciones , Hipertensión/tratamiento farmacológico , Ensayos Clínicos Controlados Aleatorios como Asunto , Volumen Sistólico , Función Ventricular Izquierda
9.
J Nucl Cardiol ; 28(3): 981-988, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33083984

RESUMEN

BACKGROUND: The difference in diagnostic accuracy of coronary artery disease (CAD) between vasodilator SPECT and PET myocardial perfusion imaging (MPI) in patients with left bundle branch block (LBBB) or ventricular-paced rhythm (VPR) is unknown. METHODS: We identified patients with LBBB or VPR who underwent either vasodilator SPECT or PET MPI and subsequent coronary angiography. LBBB/VPR-related septal and anteroseptal defects were defined as perfusion defects involving those regions in the absence of obstructive CAD in the left anterior descending artery or left main coronary artery. RESULTS: Of the 55 patients who underwent coronary angiography, 38 (69%) underwent SPECT and 17 patients (31%) underwent PET. PET compared to SPECT demonstrated higher sensitivity (88% vs 60%), specificity (56% vs 14%), positive predictive value (64% vs 20%), negative predictive value (83% vs 50%), and overall superior diagnostic accuracy (AUC .72 (95% CI .50-.93) vs .37 (95% CI .20-.54), P = .01) to detect obstructive CAD. LBBB/VPR-related septal and anteroseptal defects were more common with SPECT compared to PET (septal: 72% vs 17%, P = .001; anteroseptal: 47% vs 8%, P = .02). CONCLUSIONS: PET has higher diagnostic accuracy when compared to SPECT for the detection of obstructive CAD in patients with LBBB or VPR.


Asunto(s)
Bloqueo de Rama/diagnóstico por imagen , Estimulación Cardíaca Artificial , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Imagen de Perfusión Miocárdica , Tomografía de Emisión de Positrones , Tomografía Computarizada de Emisión de Fotón Único , Anciano , Bloqueo de Rama/complicaciones , Angiografía Coronaria , Enfermedad de la Arteria Coronaria/etiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Estudios Retrospectivos , Vasodilatadores
10.
Circulation ; 140(17): 1369-1379, 2019 10 22.
Artículo en Inglés | MEDLINE | ID: mdl-31510768

RESUMEN

BACKGROUND: The contemporary prognostic value of the physical examination- beyond traditional risk factors including natriuretic peptides, risk scores, and symptoms-in heart failure (HF) with reduced ejection fraction is unknown. We aimed to determine the association between physical signs of congestion at baseline and during study follow-up with quality of life and clinical outcomes and to assess the treatment effects of sacubitril/valsartan on congestion. METHODS: We analyzed participants from PARADIGM-HF (Prospective Comparison of Angiotensin Receptor-Neprilysin Inhibitor With Angiotensin Converting Enzyme Inhibitor to Determine Impact on Global Mortality and Morbidity in HF) with an available physical examination at baseline. We examined the association of the number of signs of congestion (jugular venous distention, edema, rales, and third heart sound) with the primary outcome (cardiovascular death or HF hospitalization), its individual components, and all-cause mortality using time-updated, multivariable-adjusted Cox regression. We further evaluated whether sacubitril/valsartan reduced congestion during follow-up and whether improvement in congestion is related to changes in clinical outcomes and quality of life, assessed by Kansas City Cardiomyopathy Questionnaire overall summary scores. RESULTS: Among 8380 participants, 0, 1, 2, and 3+ signs of congestion were present in 70%, 21%, 7%, and 2% of patients, respectively. Patients with baseline congestion were older, more often female, had higher MAGGIC risk scores (Meta-Analysis Global Group in Chronic Heart Failure) and lower Kansas City Cardiomyopathy Questionnaire overall summary scores (P<0.05). After adjusting for baseline natriuretic peptides, time-updated Meta-Analysis Global Group in Chronic Heart Failure score, and time-updated New York Heart Association class, increasing time-updated congestion was associated with all outcomes (P<0.001). Sacubitril/valsartan reduced the risk of the primary outcome irrespective of clinical signs of congestion at baseline (P=0.16 for interaction), and treatment with the drug improved congestion to a greater extent than did enalapril (P=0.011). Each 1-sign reduction was independently associated with a 5.1 (95% CI, 4.7-5.5) point improvement in Kansas City Cardiomyopathy Questionnaire overall summary scores. Change in congestion strongly predicted outcomes even after adjusting for baseline congestion (P<0.001). CONCLUSIONS: In HF with reduced ejection fraction, the physical exam continues to provide significant independent prognostic value even beyond symptoms, natriuretic peptides, and Meta-Analysis Global Group in Chronic Heart Failure risk score. Sacubitril/valsartan improved congestion to a greater extent than did enalapril. Reducing congestion in the outpatient setting is independently associated with improved quality of life and reduced cardiovascular events, including mortality. CLINICAL TRIAL REGISTRATION: https://www.clinicaltrials.gov. Unique identifier: NCT01035255.


Asunto(s)
Aminobutiratos/uso terapéutico , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Enalapril/uso terapéutico , Insuficiencia Cardíaca/tratamiento farmacológico , Antagonistas de Receptores de Angiotensina/uso terapéutico , Antihipertensivos/uso terapéutico , Femenino , Estudios de Seguimiento , Insuficiencia Cardíaca/diagnóstico , Humanos , Masculino , Persona de Mediana Edad , Examen Físico , Pronóstico , Estudios Prospectivos , Volumen Sistólico/efectos de los fármacos
13.
J Neurosci ; 37(12): 3364-3377, 2017 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-28258168

RESUMEN

Loss of dopaminergic (DA) neurons leads to Parkinson's disease; however, the mechanism(s) for the vulnerability of DA neurons is(are) not fully understood. We demonstrate that TRPC1 regulates the L-type Ca2+ channel that contributes to the rhythmic activity of adult DA neurons in the substantia nigra region. Store depletion that activates TRPC1, via STIM1, inhibits the frequency and amplitude of the rhythmic activity in DA neurons of wild-type, but not in TRPC1-/-, mice. Similarly, TRPC1-/- substantia nigra neurons showed increased L-type Ca2+ currents, decreased stimulation-dependent STIM1-Cav1.3 interaction, and decreased DA neurons. L-type Ca2+ currents and the open channel probability of Cav1.3 channels were also reduced upon TRPC1 activation, whereas increased Cav1.3 currents were observed upon STIM1 or TRPC1 silencing. Increased interaction between Cav1.3-TRPC1-STIM1 was observed upon store depletion and the loss of either TRPC1 or STIM1 led to DA cell death, which was prevented by inhibiting L-type Ca2+ channels. Neurotoxins that mimic Parkinson's disease increased Cav1.3 function, decreased TRPC1 expression, inhibited Tg-mediated STIM1-Cav1.3 interaction, and induced caspase activation. Importantly, restoration of TRPC1 expression not only inhibited Cav1.3 function but increased cell survival. Together, we provide evidence that TRPC1 suppresses Cav1.3 activity by providing an STIM1-based scaffold, which is essential for DA neuron survival.SIGNIFICANCE STATEMENT Ca2+ entry serves critical cellular functions in virtually every cell type, and appropriate regulation of Ca2+ in neurons is essential for proper function. In Parkinson's disease, DA neurons are specifically degenerated, but the mechanism is not known. Unlike other neurons, DA neurons depend on Cav1.3 channels for their rhythmic activity. Our studies show that, in normal conditions, the pacemaking activity in DA neurons is inhibited by the TRPC1-STIM1 complex. Neurotoxins that mimic Parkinson's disease target TRPC1 expression, which leads to an abnormal increase in Cav1.3 activity, thereby causing degeneration of DA neurons. These findings link TRPC1 to Cav1.3 regulation and provide important indications about how disrupting Ca2+ balance could have a direct implication in the treatment of Parkinson's patients.


Asunto(s)
Canales de Calcio Tipo L/metabolismo , Señalización del Calcio/fisiología , Supervivencia Celular/fisiología , Neuronas Dopaminérgicas/patología , Molécula de Interacción Estromal 1/metabolismo , Canales Catiónicos TRPC/metabolismo , Animales , Calcio/metabolismo , Células Cultivadas , Neuronas Dopaminérgicas/citología , Activación del Canal Iónico/fisiología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados
15.
J Cell Sci ; 128(16): 3143-54, 2015 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-26116575

RESUMEN

The key proteins mediating store-operated Ca(2+) entry (SOCE) are the endoplasmic reticulum (ER) Ca(2+) sensor STIM1 and the plasma membrane Ca(2+)-selective channel Orai1. Here, we quantitatively dissect Orai1 trafficking dynamics and show that Orai1 recycles rapidly at the plasma membrane (Kex≃0.1 min(-1)), with ∼40% of the total Orai1 pool localizing to the plasma membrane at steady state. A subset of intracellular Orai1 localizes to a sub-plasmalemal compartment. Store depletion is coupled to Orai1 plasma membrane enrichment in a STIM1-dependent fashion. This is due to trapping of Orai1 into cortical ER STIM1 clusters, leading to its removal from the recycling pool and enrichment at the plasma membrane. Interestingly, upon high STIM1 expression, Orai1 is trapped into STIM1 clusters intracellularly, thus preventing its plasma membrane enrichment following store depletion. Consistent with this, STIM1 knockdown prevents trapping of excess Orai1 into limiting STIM1 clusters in the cortical ER. SOCE-dependent Ca(2+) influx shows a similar biphasic dependence on the Orai1:STIM1 ratio. Therefore, a STIM1-dependent Orai1 'trafficking trap' mechanism controls Orai1 plasma membrane enrichment and SOCE levels, thus modulating the SOCE 'bandwidth' for downstream signaling.


Asunto(s)
Canales de Calcio/genética , Señalización del Calcio/genética , Calcio/metabolismo , Proteínas de la Membrana/genética , Proteínas de Neoplasias/genética , Animales , Células CHO , Canales de Calcio/biosíntesis , Membrana Celular/metabolismo , Cricetulus , Retículo Endoplásmico/genética , Retículo Endoplásmico/metabolismo , Células HEK293 , Humanos , Proteínas de la Membrana/biosíntesis , Proteínas de Neoplasias/biosíntesis , Proteína ORAI1 , Transporte de Proteínas/genética , ARN Interferente Pequeño , Transducción de Señal , Molécula de Interacción Estromal 1
17.
Adv Exp Med Biol ; 976: 85-94, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28508315

RESUMEN

Parkinson's disease (PD) is a common neurodegenerative disorder, which involves degeneration of dopaminergic neurons that are present in the substantia nigra pars compacta (SNpc) region. Many factors have been identified that could lead to Parkinson's disease; however, almost all of them are directly or indirectly dependent on Ca2+ signaling. Importantly, though disturbances in Ca2+ homeostasis have been implicated in Parkinson's disease and other neuronal diseases, the identity of the calcium channel remains elusive. Members of the transient receptor potential canonical (TRPC) channel family have been identified as a new class of Ca2+ channels, and it could be anticipated that these channels could play important roles in neurodegenerative diseases, especially in PD. Thus, in this chapter we have entirely focused on TRPC channels and elucidated its role in PD.


Asunto(s)
Encéfalo/metabolismo , Calcio/metabolismo , Neuronas Dopaminérgicas/patología , Enfermedad de Parkinson/metabolismo , Canales Catiónicos TRPC/metabolismo , Animales , Encéfalo/patología , Neuronas Dopaminérgicas/metabolismo , Humanos , Enfermedad de Parkinson/patología
18.
Circulation ; 131(3): 269-79, 2015 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-25398313

RESUMEN

BACKGROUND: Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous clinical syndrome in need of improved phenotypic classification. We sought to evaluate whether unbiased clustering analysis using dense phenotypic data (phenomapping) could identify phenotypically distinct HFpEF categories. METHODS AND RESULTS: We prospectively studied 397 patients with HFpEF and performed detailed clinical, laboratory, ECG, and echocardiographic phenotyping of the study participants. We used several statistical learning algorithms, including unbiased hierarchical cluster analysis of phenotypic data (67 continuous variables) and penalized model-based clustering, to define and characterize mutually exclusive groups making up a novel classification of HFpEF. All phenomapping analyses were performed by investigators blinded to clinical outcomes, and Cox regression was used to demonstrate the clinical validity of phenomapping. The mean age was 65±12 years; 62% were female; 39% were black; and comorbidities were common. Although all patients met published criteria for the diagnosis of HFpEF, phenomapping analysis classified study participants into 3 distinct groups that differed markedly in clinical characteristics, cardiac structure/function, invasive hemodynamics, and outcomes (eg, phenogroup 3 had an increased risk of HF hospitalization [hazard ratio, 4.2; 95% confidence interval, 2.0-9.1] even after adjustment for traditional risk factors [P<0.001]). The HFpEF phenogroup classification, including its ability to stratify risk, was successfully replicated in a prospective validation cohort (n=107). CONCLUSIONS: Phenomapping results in a novel classification of HFpEF. Statistical learning algorithms applied to dense phenotypic data may allow improved classification of heterogeneous clinical syndromes, with the ultimate goal of defining therapeutically homogeneous patient subclasses.


Asunto(s)
Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/fisiopatología , Fenotipo , Volumen Sistólico/fisiología , Anciano , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Insuficiencia Cardíaca/sangre , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos
19.
Mol Carcinog ; 55(5): 818-31, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-25917875

RESUMEN

Resveratrol (RSV), a natural polyphenol, has been suggested to induce cell cycle arrest and activate apoptosis-mediated cell death in several cancer cells, including prostate cancer. However, several molecular mechanisms have been proposed on its chemopreventive action, the precise mechanisms by which RSV exerts its anti-proliferative effect in androgen-independent prostate cancer cells remain questionable. In the present study, we show that RSV activates autophagic cell death in PC3 and DU145 cells, which was dependent on stromal interaction molecule 1 (STIM1) expression. RSV treatment decreases STIM1 expression in a time-dependent manner and attenuates STIM1 association with TRPC1 and Orai1. Furthermore, RSV treatment also decreases ER calcium storage and store operated calcium entry (SOCE), which induces endoplasmic reticulum (ER) stress, thereby, activating AMPK and inhibiting the AKT/mTOR pathway. Similarly, inhibition of SOCE by SKF-96365 decreases the survival and proliferation of PC3 and DU145 cells and inhibits AKT/mTOR pathway and induces autophagic cell death. Importantly, SOCE inhibition and subsequent autophagic cell death caused by RSV was reversed by STIM1 overexpression. STIM1 overexpression restored SOCE, prevents the loss of mTOR phosphorylation and decreased the expression of CHOP and LC3A in PC3 cells. Taken together, for the first time, our results revealed that RSV induces autophagy-mediated cell death in PC3 and DU145 cells through regulation of SOCE mechanisms, including downregulating STIM1 expression and trigger ER stress by depleting ER calcium pool.


Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Regulación hacia Abajo , Proteínas de la Membrana/metabolismo , Proteínas de Neoplasias/metabolismo , Neoplasias de la Próstata/metabolismo , Estilbenos/farmacología , Serina-Treonina Quinasas TOR/metabolismo , Autofagia , Calcio/metabolismo , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Estrés del Retículo Endoplásmico/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Imidazoles/farmacología , Masculino , Resveratrol , Transducción de Señal/efectos de los fármacos , Molécula de Interacción Estromal 1
20.
Echocardiography ; 33(3): 386-97, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26525308

RESUMEN

BACKGROUND: Several large epidemiologic studies and clinical trials have included echocardiography, but images were stored in analog format and these studies predated tissue Doppler imaging (TDI) and speckle tracking echocardiography (STE). We hypothesized that digitization of analog echocardiograms, with subsequent quantification of cardiac mechanics using STE, is feasible, reproducible, accurate, and produces clinically valid results. METHODS: In the NHLBI HyperGEN study (N = 2234), archived analog echocardiograms were digitized and subsequently analyzed using STE to obtain tissue velocities/strain. Echocardiograms were assigned quality scores and inter-/intra-observer agreement was calculated. Accuracy was evaluated in: (1) a separate second study (N = 50) comparing prospective digital strain versus post hoc analog-to-digital strain, and (2) in a third study (N = 95) comparing prospectively obtained TDI e' velocities with post hoc STE e' velocities. Finally, we replicated previously known associations between tissue velocities/strain, conventional echocardiographic measurements, and clinical data. RESULTS: Of the 2234 HyperGEN echocardiograms, 2150 (96.2%) underwent successful digitization and STE analysis. Inter/intra-observer agreement was high for all STE parameters, especially longitudinal strain (LS). In accuracy studies, LS performed best when comparing post hoc STE to prospective digital STE for strain analysis. STE-derived e' velocities correlated with, but systematically underestimated, TDI e' velocity. Several known associations between clinical variables and cardiac mechanics were replicated in HyperGEN. We also found a novel independent inverse association between fasting glucose and LS (adjusted ß = -2.4 [95% CI -3.6, -1.2]% per 1-SD increase in fasting glucose; P < 0.001). CONCLUSIONS: Archeological echocardiography, the digitization and speckle tracking analysis of archival echocardiograms, is feasible and generates indices of cardiac mechanics similar to contemporary studies.


Asunto(s)
Conversión Analogo-Digital , Ecocardiografía/métodos , Diagnóstico por Imagen de Elasticidad/métodos , Sistemas de Información Radiológica/organización & administración , Disfunción Ventricular Izquierda/diagnóstico por imagen , Disfunción Ventricular Izquierda/fisiopatología , Minería de Datos/métodos , Humanos , Interpretación de Imagen Asistida por Computador/métodos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Procesamiento de Señales Asistido por Computador
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