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1.
iScience ; 27(9): 110585, 2024 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-39228787

RESUMEN

Intimate partner violence (IPV) is a significant public health concern whose neurological/behavioral sequelae remain to be mechanistically explained. Using a mouse model recapitulating an IPV scenario, we evaluated the female brain neuroendocrine alterations produced by a reiterated male-to-female violent interaction (RMFVI). RMFVI prompted anxiety-like behavior in female mice whose hippocampus displayed a marked neuronal loss and hampered neurogenesis, namely reduced BrdU-DCX-positive nuclei and diminished dendritic arborization in the dentate gyrus (DG): effects paralleled by a substantial downregulation of the estrogen receptor ß (ERß). After RMFVI, the DG harbored reduced brain-derived neurotrophic factor (BDNF) pools and tyrosine kinase receptor B (TrkB) phosphorylation. Accordingly, ERß knockout (KO) mice had heightened anxiety and curtailed BDNF levels at baseline while dying prematurely during the RMFVI procedure. Strikingly, injecting an ERß antagonist or agonist into the wild-type (WT) female hippocampus enhanced or reduced anxiety, respectively. Thus, reiterated male-to-female violence jeopardizes hippocampal homeostasis, perturbing the ERß/BDNF axis and ultimately instigating anxiety and chronic stress.

3.
Acta Physiol (Oxf) ; 240(4): e14124, 2024 04.
Artículo en Inglés | MEDLINE | ID: mdl-38436094

RESUMEN

AIM: Exercise intolerance is the central symptom in patients with heart failure with preserved ejection fraction. In the present study, we investigated the adrenergic reserve both in vivo and in cardiomyocytes of a murine cardiometabolic HFpEF model. METHODS: 12-week-old male C57BL/6J mice were fed regular chow (control) or a high-fat diet and L-NAME (HFpEF) for 15 weeks. At 27 weeks, we performed (stress) echocardiography and exercise testing and measured the adrenergic reserve and its modulation by nitric oxide and reactive oxygen species in left ventricular cardiomyocytes. RESULTS: HFpEF mice (preserved left ventricular ejection fraction, increased E/e', pulmonary congestion [wet lung weight/TL]) exhibited reduced exercise capacity and a reduction of stroke volume and cardiac output with adrenergic stress. In ventricular cardiomyocytes isolated from HFpEF mice, sarcomere shortening had a higher amplitude and faster relaxation compared to control animals. Increased shortening was caused by a shift of myofilament calcium sensitivity. With addition of isoproterenol, there were no differences in sarcomere function between HFpEF and control mice. This resulted in a reduced inotropic and lusitropic reserve in HFpEF cardiomyocytes. Preincubation with inhibitors of nitric oxide synthases or glutathione partially restored the adrenergic reserve in cardiomyocytes in HFpEF. CONCLUSION: In this murine HFpEF model, the cardiac output reserve on adrenergic stimulation is impaired. In ventricular cardiomyocytes, we found a congruent loss of the adrenergic inotropic and lusitropic reserve. This was caused by increased contractility and faster relaxation at rest, partially mediated by nitro-oxidative signaling.


Asunto(s)
Insuficiencia Cardíaca , Función Ventricular Izquierda , Humanos , Masculino , Animales , Ratones , Volumen Sistólico , Función Ventricular Izquierda/fisiología , Adrenérgicos , Modelos Animales de Enfermedad , Óxido Nítrico , Ratones Endogámicos C57BL
4.
bioRxiv ; 2023 Sep 23.
Artículo en Inglés | MEDLINE | ID: mdl-37790349

RESUMEN

Women are the main target of intimate partner violence (IPV), which is escalating worldwide. Mechanisms subtending IPV-related disorders, such as anxiety, depression and PTSD, remain unclear. We employed a mouse model molded on an IPV scenario (male vs. female prolonged violent interaction) to unearth the neuroendocrine alterations triggered by an aggressive male mouse on the female murine brain. Experimental IPV (EIPV) prompted marked anxiety-like behavior in young female mice, coincident with high circulating/cerebral corticosterone levels. The hippocampus of EIPV-inflicted female animals displayed neuronal loss, reduced BrdU-DCX-positive nuclei, decreased mature DCX-positive cells, and diminished dendritic arborization level in the dentate gyrus (DG), features denoting impaired neurogenesis and neuronal differentiation. These hallmarks were associated with marked down-regulation of estrogen receptor ß (ERß) density in the hippocampus, especially in the DG and dependent prosurvival ERK signaling. Conversely, ERα expression was unchanged. After EIPV, the DG harbored lowered local BDNF pools, diminished TrkB phosphorylation, and elevated glucocorticoid receptor phosphorylation. In unison, ERß KO mice had heightened anxiety-like behavior and curtailed BDNF levels at baseline, despite enhanced circulating estradiol levels, while dying prematurely during EIPV. Thus, reiterated male-to-female violence jeopardizes hippocampal homeostasis in the female brain, perturbing ERß/BDNF signaling, thus instigating anxiety and chronic stress.

5.
J Cardiovasc Comput Tomogr ; 17(5): 310-317, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37541910

RESUMEN

BACKGROUND: The coronary atheroma burden drives major adverse cardiovascular events (MACE) in patients with suspected coronary heart disease (CHD). However, a consensus on how to grade disease burden for effective risk stratification is lacking. The purpose of this study was to compare the effectiveness of common CHD grading tools to risk stratify symptomatic patients. METHODS: We analyzed the 5-year outcome of 381 prospectively enrolled patients in the CORE320 international, multicenter study using baseline clinical and cardiac computer-tomography (CT) imaging characteristics, including coronary artery calcium score (CACS), percent atheroma volume, "high-risk" plaque, disease severity grading using the CAD-RADS, and two simplified CAD staging systems. We applied Cox proportional hazard models and area under the curve (AUC) analysis to predict MACE or hard MACE, defined as death, myocardial infarction, or stroke. Analyses were stratified by a history of CHD. Additional forward selection analysis was performed to evaluate incremental value of metrics. RESULTS: Clinical characteristics were the strongest predictors of MACE in the overall cohort. In patients without history of CHD, CACS remained the only independent predictor of MACE yielding an AUC of 73 (CI 67-79) vs. 64 (CI 57-70) for clinical characteristics. Noncalcified plaque volume did not add prognostic value. Simple CHD grading schemes yielded similar risk stratification as the CAD-RADS classification. Forward selection analysis confirmed prominent role of CACS and revealed usefulness of functional testing in subgroup with known CHD. CONCLUSION: In patients referred for invasive angiography, a history of CHD was the strongest predictor of MACE. In patients without history of CHD, a coronary calcium score yielded at least equal risk stratification vs. more complex CHD grading.


Asunto(s)
Angina Estable , Enfermedad de la Arteria Coronaria , Placa Aterosclerótica , Humanos , Angina Estable/diagnóstico por imagen , Angina Estable/terapia , Calcio , Angiografía por Tomografía Computarizada/métodos , Angiografía Coronaria/métodos , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Enfermedad de la Arteria Coronaria/terapia , Tomografía Computarizada Multidetector , Valor Predictivo de las Pruebas , Pronóstico , Medición de Riesgo , Factores de Riesgo
6.
Basic Res Cardiol ; 118(1): 9, 2023 03 20.
Artículo en Inglés | MEDLINE | ID: mdl-36939901

RESUMEN

Precision-based molecular phenotyping of heart failure must overcome limited access to cardiac tissue. Although epigenetic alterations have been found to underlie pathological cardiac gene dysregulation, the clinical utility of myocardial epigenomics remains narrow owing to limited clinical access to tissue. Therefore, the current study determined whether patient plasma confers indirect phenotypic, transcriptional, and/or epigenetic alterations to ex vivo cardiomyocytes to mirror the failing human myocardium. Neonatal rat ventricular myocytes (NRVMs) and single-origin human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) and were treated with blood plasma samples from patients with dilated cardiomyopathy (DCM) and donor subjects lacking history of cardiovascular disease. Following plasma treatments, NRVMs and hiPSC-CMs underwent significant hypertrophy relative to non-failing controls, as determined via automated high-content screening. Array-based DNA methylation analysis of plasma-treated hiPSC-CMs and cardiac biopsies uncovered robust, and conserved, alterations in cardiac DNA methylation, from which 100 sites were validated using an independent cohort. Among the CpG sites identified, hypo-methylation of the ATG promoter was identified as a diagnostic marker of HF, wherein cg03800765 methylation (AUC = 0.986, P < 0.0001) was found to out-perform circulating NT-proBNP levels in differentiating heart failure. Taken together, these findings support a novel approach of indirect epigenetic testing in human HF.


Asunto(s)
Insuficiencia Cardíaca , Células Madre Pluripotentes Inducidas , Humanos , Ratas , Animales , Miocitos Cardíacos/patología , Metilación de ADN , Epigenómica , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/genética , Insuficiencia Cardíaca/patología , Epigénesis Genética
7.
JAMA ; 328(20): 2058-2059, 2022 11 22.
Artículo en Inglés | MEDLINE | ID: mdl-36315193

RESUMEN

A patient in his 40s presented to the emergency department with chest pain and diaphoresis, which had also occurred 2 days earlier. He had a 20 pack-year history of smoking but no family history of cardiovascular disease. The patient's electrocardiogram showed biphasic T waves in leads V2 and V3. What would you do next?


Asunto(s)
Dolor en el Pecho , Humanos , Persona de Mediana Edad , Dolor en el Pecho/etiología , Angiografía Coronaria , Electrocardiografía , Tórax
8.
Life Sci Alliance ; 5(6)2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35288456

RESUMEN

Tuberous sclerosis complex-2 (TSC2) negatively regulates mammalian target of rapamycin complex 1 (mTORC1), and its activity is reduced by protein kinase B (Akt) and extracellular response kinase (ERK1/2) phosphorylation to activate mTORC1. Serine 1364 (human) on TSC2 bidirectionally modifies mTORC1 activation by pathological growth factors or hemodynamic stress but has no impact on resting activity. We now show this modification biases to ERK1/2 but not Akt-dependent TSC2-mTORC1 activation. Endothelin-1-stimulated mTORC1 requires ERK1/2 activation and is bidirectionally modified by phospho-mimetic (S1364E) or phospho-silenced (S1364A) mutations. However, mTORC1 activation by Akt-dependent stimuli (insulin or PDGF) is unaltered by S1364 modification. Thrombin stimulates both pathways, yet only the ERK1/2 component is modulated by S1364. S1364 also has negligible impact on mTORC1 regulation by energy or nutrient status. In vivo, diet-induced obesity, diabetes, and fatty liver couple to Akt activation and are also unaltered by TSC2 S1364 mutations. This contrasts to prior reports showing a marked impact of both on pathological pressure-stress. Thus, S1364 provides ERK1/2-selective mTORC1 control and a genetic means to modify pathological versus physiological mTOR stimuli.


Asunto(s)
Sistema de Señalización de MAP Quinasas , Diana Mecanicista del Complejo 1 de la Rapamicina , Proteína 2 del Complejo de la Esclerosis Tuberosa , Humanos , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Serina/metabolismo , Proteína 2 del Complejo de la Esclerosis Tuberosa/genética , Proteína 2 del Complejo de la Esclerosis Tuberosa/metabolismo , Proteínas Supresoras de Tumor/metabolismo
9.
J Clin Invest ; 131(21)2021 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-34618683

RESUMEN

Central obesity with cardiometabolic syndrome (CMS) is a major global contributor to human disease, and effective therapies are needed. Here, we show that cyclic GMP-selective phosphodiesterase 9A inhibition (PDE9-I) in both male and ovariectomized female mice suppresses preestablished severe diet-induced obesity/CMS with or without superimposed mild cardiac pressure load. PDE9-I reduces total body, inguinal, hepatic, and myocardial fat; stimulates mitochondrial activity in brown and white fat; and improves CMS, without significantly altering activity or food intake. PDE9 localized at mitochondria, and its inhibition in vitro stimulated lipolysis in a PPARα-dependent manner and increased mitochondrial respiration in both adipocytes and myocytes. PPARα upregulation was required to achieve the lipolytic, antiobesity, and metabolic effects of PDE9-I. All these PDE9-I-induced changes were not observed in obese/CMS nonovariectomized females, indicating a strong sexual dimorphism. We found that PPARα chromatin binding was reoriented away from fat metabolism-regulating genes when stimulated in the presence of coactivated estrogen receptor-α, and this may underlie the dimorphism. These findings have translational relevance given that PDE9-I is already being studied in humans for indications including heart failure, and efficacy against obesity/CMS would enhance its therapeutic utility.


Asunto(s)
3',5'-AMP Cíclico Fosfodiesterasas/metabolismo , Tejido Adiposo/embriología , Síndrome Metabólico/enzimología , Obesidad/enzimología , 3',5'-AMP Cíclico Fosfodiesterasas/genética , Animales , Femenino , Masculino , Síndrome Metabólico/genética , Ratones , Ratones Transgénicos , Mitocondrias/enzimología , Mitocondrias/genética , Obesidad/genética , PPAR alfa/genética , PPAR alfa/metabolismo
10.
Int J Mol Sci ; 22(11)2021 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-34073033

RESUMEN

Atrial fibrillation (AF) is the most common sustained (atrial) arrhythmia, a considerable global health burden and often associated with heart failure. Perturbations of redox signalling in cardiomyocytes provide a cellular substrate for the manifestation and maintenance of atrial arrhythmias. Several clinical trials have shown that treatment with sodium-glucose linked transporter inhibitors (SGLTi) improves mortality and hospitalisation in heart failure patients independent of the presence of diabetes. Post hoc analysis of the DECLARE-TIMI 58 trial showed a 19% reduction in AF in patients with diabetes mellitus (hazard ratio, 0.81 (95% confidence interval: 0.68-0.95), n = 17.160) upon treatment with SGLTi, regardless of pre-existing AF or heart failure and independent from blood pressure or renal function. Accordingly, ongoing experimental work suggests that SGLTi not only positively impact heart failure but also counteract cellular ROS production in cardiomyocytes, thereby potentially altering atrial remodelling and reducing AF burden. In this article, we review recent studies investigating the effect of SGLTi on cellular processes closely interlinked with redox balance and their potential effects on the onset and progression of AF. Despite promising insight into SGLTi effect on Ca2+ cycling, Na+ balance, inflammatory and fibrotic signalling, mitochondrial function and energy balance and their potential effect on AF, the data are not yet conclusive and the importance of individual pathways for human AF remains to be established. Lastly, an overview of clinical studies investigating SGLTi in the context of AF is provided.


Asunto(s)
Fibrilación Atrial/tratamiento farmacológico , Miocitos Cardíacos , Oxidación-Reducción/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Transportador 1 de Sodio-Glucosa/antagonistas & inhibidores , Inhibidores del Cotransportador de Sodio-Glucosa 2/farmacología , Animales , Calcio/metabolismo , Células Cultivadas , Humanos , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/patología , Especies Reactivas de Oxígeno/metabolismo
11.
Cardiovasc Diabetol ; 20(1): 7, 2021 01 07.
Artículo en Inglés | MEDLINE | ID: mdl-33413413

RESUMEN

BACKGROUND: Sodium-glucose linked transporter type 2 (SGLT-2) inhibition has been shown to reduce cardiovascular mortality in heart failure independently of glycemic control and prevents the onset of atrial arrhythmias, a common co-morbidity in heart failure with preserved ejection fraction (HFpEF). The mechanism behind these effects is not fully understood, and it remains unclear if they could be further enhanced by additional SGLT-1 inhibition. We investigated the effects of chronic treatment with the dual SGLT-1&2 inhibitor sotagliflozin on left atrial (LA) remodeling and cellular arrhythmogenesis (i.e. atrial cardiomyopathy) in a metabolic syndrome-related rat model of HFpEF. METHODS: 17 week-old ZSF-1 obese rats, a metabolic syndrome-related model of HFpEF, and wild type rats (Wistar Kyoto), were fed 30 mg/kg/d sotagliflozin for 6 weeks. At 23 weeks, LA were imaged in-vivo by echocardiography. In-vitro, Ca2+ transients (CaT; electrically stimulated, caffeine-induced) and spontaneous Ca2+ release were recorded by ratiometric microscopy using Ca2+-sensitive fluorescent dyes (Fura-2) during various experimental protocols. Mitochondrial structure (dye: Mitotracker), Ca2+ buffer capacity (dye: Rhod-2), mitochondrial depolarization (dye: TMRE) and production of reactive oxygen species (dye: H2DCF) were visualized by confocal microscopy. Statistical analysis was performed with 2-way analysis of variance followed by post-hoc Bonferroni and student's t-test, as applicable. RESULTS: Sotagliflozin ameliorated LA enlargement in HFpEF in-vivo. In-vitro, LA cardiomyocytes in HFpEF showed an increased incidence and amplitude of arrhythmic spontaneous Ca2+ release events (SCaEs). Sotagliflozin significantly reduced the magnitude of SCaEs, while their frequency was unaffected. Sotagliflozin lowered diastolic [Ca2+] of CaT at baseline and in response to glucose influx, possibly related to a ~ 50% increase of sodium sodium-calcium exchanger (NCX) forward-mode activity. Sotagliflozin prevented mitochondrial swelling and enhanced mitochondrial Ca2+ buffer capacity in HFpEF. Sotagliflozin improved mitochondrial fission and reactive oxygen species (ROS) production during glucose starvation and averted Ca2+ accumulation upon glycolytic inhibition. CONCLUSION: The SGLT-1&2 inhibitor sotagliflozin ameliorated LA remodeling in metabolic HFpEF. It also improved distinct features of Ca2+-mediated cellular arrhythmogenesis in-vitro (i.e. magnitude of SCaEs, mitochondrial Ca2+ buffer capacity, diastolic Ca2+ accumulation, NCX activity). The safety and efficacy of combined SGLT-1&2 inhibition for the treatment and/or prevention of atrial cardiomyopathy associated arrhythmias should be further evaluated in clinical trials.


Asunto(s)
Arritmias Cardíacas/prevención & control , Función del Atrio Izquierdo/efectos de los fármacos , Remodelación Atrial/efectos de los fármacos , Glicósidos/farmacología , Atrios Cardíacos/efectos de los fármacos , Insuficiencia Cardíaca/tratamiento farmacológico , Transportador 1 de Sodio-Glucosa/antagonistas & inhibidores , Inhibidores del Cotransportador de Sodio-Glucosa 2/farmacología , Transportador 2 de Sodio-Glucosa/metabolismo , Animales , Arritmias Cardíacas/etiología , Arritmias Cardíacas/metabolismo , Arritmias Cardíacas/fisiopatología , Señalización del Calcio/efectos de los fármacos , Modelos Animales de Enfermedad , Atrios Cardíacos/metabolismo , Atrios Cardíacos/fisiopatología , Insuficiencia Cardíaca/etiología , Insuficiencia Cardíaca/metabolismo , Insuficiencia Cardíaca/fisiopatología , Síndrome Metabólico/complicaciones , Mitocondrias Cardíacas/efectos de los fármacos , Mitocondrias Cardíacas/metabolismo , Mitocondrias Cardíacas/patología , Dinámicas Mitocondriales/efectos de los fármacos , Dilatación Mitocondrial/efectos de los fármacos , Ratas Endogámicas WKY , Ratas Zucker , Especies Reactivas de Oxígeno/metabolismo , Intercambiador de Sodio-Calcio/metabolismo , Transportador 1 de Sodio-Glucosa/metabolismo
12.
Circ Res ; 128(5): 639-651, 2021 03 05.
Artículo en Inglés | MEDLINE | ID: mdl-33401933

RESUMEN

RATIONALE: The mTORC1 (mechanistic target of rapamycin complex-1) controls metabolism and protein homeostasis and is activated following ischemia reperfusion (IR) injury and by ischemic preconditioning (IPC). However, studies vary as to whether this activation is beneficial or detrimental, and its influence on metabolism after IR is little reported. A limitation of prior investigations is their use of broad gain/loss of mTORC1 function, mostly applied before ischemic stress. This can be circumvented by regulating one serine (S1365) on TSC2 (tuberous sclerosis complex) to achieve bidirectional mTORC1 modulation but only with TCS2-regulated costimulation. OBJECTIVE: We tested the hypothesis that reduced TSC2 S1365 phosphorylation protects the myocardium against IR and is required for IPC by amplifying mTORC1 activity to favor glycolytic metabolism. METHODS AND RESULTS: Mice with either S1365A (TSC2SA; phospho-null) or S1365E (TSC2SE; phosphomimetic) knockin mutations were studied ex vivo and in vivo. In response to IR, hearts from TSC2SA mice had amplified mTORC1 activation and improved heart function compared with wild-type and TSC2SE hearts. The magnitude of protection matched IPC. IPC requited less S1365 phosphorylation, as TSC2SE hearts gained no benefit and failed to activate mTORC1 with IPC. IR metabolism was altered in TSC2SA, with increased mitochondrial oxygen consumption rate and glycolytic capacity (stressed/maximal extracellular acidification) after myocyte hypoxia-reperfusion. In whole heart, lactate increased and long-chain acylcarnitine levels declined during ischemia. The relative IR protection in TSC2SA was lost by lowering glucose in the perfusate by 36%. Adding fatty acid (palmitate) compensated for reduced glucose in wild type and TSC2SE but not TSC2SA which had the worst post-IR function under these conditions. CONCLUSIONS: TSC2-S1365 phosphorylation status regulates myocardial substrate utilization, and its decline activates mTORC1 biasing metabolism away from fatty acid oxidation to glycolysis to confer protection against IR. This pathway is also engaged and reduced TSC2 S1365 phosphorylation required for effective IPC. Graphic Abstract: A graphic abstract is available for this article.


Asunto(s)
Glucólisis , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Daño por Reperfusión Miocárdica/metabolismo , Miocitos Cardíacos/metabolismo , Animales , Carnitina/análogos & derivados , Carnitina/metabolismo , Células Cultivadas , Glucosa/metabolismo , Precondicionamiento Isquémico , Ácido Láctico/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Mitocondrias Cardíacas/metabolismo , Mutación , Daño por Reperfusión Miocárdica/terapia , Oxígeno/metabolismo , Fosforilación , Ratas , Proteína 2 del Complejo de la Esclerosis Tuberosa/genética , Proteína 2 del Complejo de la Esclerosis Tuberosa/metabolismo
13.
Nat Commun ; 11(1): 5237, 2020 10 20.
Artículo en Inglés | MEDLINE | ID: mdl-33082318

RESUMEN

Proteotoxicity from insufficient clearance of misfolded/damaged proteins underlies many diseases. Carboxyl terminus of Hsc70-interacting protein (CHIP) is an important regulator of proteostasis in many cells, having E3-ligase and chaperone functions and often directing damaged proteins towards proteasome recycling. While enhancing CHIP functionality has broad therapeutic potential, prior efforts have all relied on genetic upregulation. Here we report that CHIP-mediated protein turnover is markedly post-translationally enhanced by direct protein kinase G (PKG) phosphorylation at S20 (mouse, S19 human). This increases CHIP binding affinity to Hsc70, CHIP protein half-life, and consequent clearance of stress-induced ubiquitinated-insoluble proteins. PKG-mediated CHIP-pS20 or expressing CHIP-S20E (phosphomimetic) reduces ischemic proteo- and cytotoxicity, whereas a phospho-silenced CHIP-S20A amplifies both. In vivo, depressing PKG activity lowers CHIP-S20 phosphorylation and protein, exacerbating proteotoxicity and heart dysfunction after ischemic injury. CHIP-S20E knock-in mice better clear ubiquitinated proteins and are cardio-protected. PKG activation provides post-translational enhancement of protein quality control via CHIP.


Asunto(s)
Proteínas Quinasas Dependientes de GMP Cíclico/metabolismo , Isquemia/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Secuencias de Aminoácidos , Animales , Proteínas Quinasas Dependientes de GMP Cíclico/genética , Femenino , Corazón/fisiopatología , Humanos , Isquemia/enzimología , Isquemia/genética , Isquemia/fisiopatología , Masculino , Ratones , Miocardio/metabolismo , Fosforilación , Ubiquitina-Proteína Ligasas/química , Ubiquitina-Proteína Ligasas/genética
14.
Front Physiol ; 11: 858, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32848832

RESUMEN

Impaired or insufficient protein kinase G (PKG) signaling and protein quality control (PQC) are hallmarks of most forms of cardiac disease, including heart failure. Their dysregulation has been shown to contribute to and exacerbate cardiac hypertrophy and remodeling, reduced cell survival and disease pathogenesis. Enhancement of PKG signaling and PQC are associated with improved cardiac function and survival in many pre-clinical models of heart disease. While many clinically used pharmacological approaches exist to stimulate PKG, there are no FDA-approved therapies to safely enhance cardiomyocyte PQC. The latter is predominantly due to our lack of knowledge and identification of proteins regulating cardiomyocyte PQC. Recently, multiple studies have demonstrated that PKG regulates PQC in the heart, both during physiological and pathological states. These studies tested already FDA-approved pharmacological therapies to activate PKG, which enhanced cardiomyocyte PQC and alleviated cardiac disease. This review examines the roles of PKG and PQC during disease pathogenesis and summarizes the experimental and clinical data supporting the utility of stimulating PKG to target cardiac proteotoxicity.

15.
Circ Res ; 127(4): 522-533, 2020 07 31.
Artículo en Inglés | MEDLINE | ID: mdl-32393148

RESUMEN

RATIONALE: Stimulated PKG1α (protein kinase G-1α) phosphorylates TSC2 (tuberous sclerosis complex 2) at serine 1365, potently suppressing mTORC1 (mechanistic [mammalian] target of rapamycin complex 1) activation by neurohormonal and hemodynamic stress. This reduces pathological hypertrophy and dysfunction and increases autophagy. PKG1α oxidation at cysteine-42 is also induced by these stressors, which blunts its cardioprotective effects. OBJECTIVE: We tested the dependence of mTORC1 activation on PKG1α C42 oxidation and its capacity to suppress such activation by soluble GC-1 (guanylyl cyclase 1) activation. METHODS AND RESULTS: Cardiomyocytes expressing wild-type (WT) PKG1α (PKG1αWT) or cysteine-42 to serine mutation redox-dead (PKG1αCS/CS) were exposed to ET-1 (endothelin 1). Cells expressing PKG1αWT exhibited substantial mTORC1 activation (p70 S6K [p70 S6 kinase], 4EBP1 [elF4E binding protein-1], and Ulk1 [Unc-51-like kinase 1] phosphorylation), reduced autophagy/autophagic flux, and abnormal protein aggregation; all were markedly reversed by PKG1αCS/CS expression. Mice with global knock-in of PKG1αCS/CS subjected to pressure overload (PO) also displayed markedly reduced mTORC1 activation, protein aggregation, hypertrophy, and ventricular dysfunction versus PO in PKG1αWT mice. Cardioprotection against PO was equalized between groups by co-treatment with the mTORC1 inhibitor everolimus. TSC2-S1365 phosphorylation increased in PKG1αCS/CS more than PKG1αWT myocardium following PO. TSC2S1365A/S1365A (TSC2 S1365 phospho-null, created by a serine to alanine mutation) knock-in mice lack TSC2 phosphorylation by PKG1α, and when genetically crossed with PKG1αCS/CS mice, protection against PO-induced mTORC1 activation, cardiodepression, and mortality in PKG1αCS/CS mice was lost. Direct stimulation of GC-1 (BAY-602770) offset disparate mTORC1 activation between PKG1αWT and PKG1αCS/CS after PO and blocked ET-1 stimulated mTORC1 in TSC2S1365A-expressing myocytes. CONCLUSIONS: Oxidation of PKG1α at C42 reduces its phosphorylation of TSC2, resulting in amplified PO-stimulated mTORC1 activity and associated hypertrophy, dysfunction, and depressed autophagy. This is ameliorated by direct GC-1 stimulation.


Asunto(s)
Cardiomegalia/metabolismo , Proteína Quinasa Dependiente de GMP Cíclico Tipo I/metabolismo , Guanilato Ciclasa/metabolismo , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Miocitos Cardíacos/metabolismo , Animales , Aorta , Autofagia/fisiología , Benzoatos/metabolismo , Compuestos de Bifenilo/metabolismo , Constricción Patológica , Proteína Quinasa Dependiente de GMP Cíclico Tipo I/genética , Cisteína/metabolismo , Endotelina-1/farmacología , Activación Enzimática , Everolimus/farmacología , Técnicas de Sustitución del Gen , Hidrocarburos Fluorados/metabolismo , Diana Mecanicista del Complejo 1 de la Rapamicina/antagonistas & inhibidores , Ratones , Ratones Endogámicos C57BL , Miocitos Cardíacos/efectos de los fármacos , Oxidación-Reducción , Estrés Oxidativo , Fosforilación , Presión , Proteostasis , Ratas , Proteína 2 del Complejo de la Esclerosis Tuberosa/genética , Proteína 2 del Complejo de la Esclerosis Tuberosa/metabolismo
17.
Nature ; 566(7743): 264-269, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30700906

RESUMEN

The mechanistic target of rapamycin complex-1 (mTORC1) coordinates regulation of growth, metabolism, protein synthesis and autophagy1. Its hyperactivation contributes to disease in numerous organs, including the heart1,2, although broad inhibition of mTORC1 risks interference with its homeostatic roles. Tuberin (TSC2) is a GTPase-activating protein and prominent intrinsic regulator of mTORC1 that acts through modulation of RHEB (Ras homologue enriched in brain). TSC2 constitutively inhibits mTORC1; however, this activity is modified by phosphorylation from multiple signalling kinases that in turn inhibits (AMPK and GSK-3ß) or stimulates (AKT, ERK and RSK-1) mTORC1 activity3-9. Each kinase requires engagement of multiple serines, impeding analysis of their role in vivo. Here we show that phosphorylation or gain- or loss-of-function mutations at either of two adjacent serine residues in TSC2 (S1365 and S1366 in mice; S1364 and S1365 in humans) can bidirectionally control mTORC1 activity stimulated by growth factors or haemodynamic stress, and consequently modulate cell growth and autophagy. However, basal mTORC1 activity remains unchanged. In the heart, or in isolated cardiomyocytes or fibroblasts, protein kinase G1 (PKG1) phosphorylates these TSC2 sites. PKG1 is a primary effector of nitric oxide and natriuretic peptide signalling, and protects against heart disease10-13. Suppression of hypertrophy and stimulation of autophagy in cardiomyocytes by PKG1 requires TSC2 phosphorylation. Homozygous knock-in mice that express a phosphorylation-silencing mutation in TSC2 (TSC2(S1365A)) develop worse heart disease and have higher mortality after sustained pressure overload of the heart, owing to mTORC1 hyperactivity that cannot be rescued by PKG1 stimulation. However, cardiac disease is reduced and survival of heterozygote Tsc2S1365A knock-in mice subjected to the same stress is improved by PKG1 activation or expression of a phosphorylation-mimicking mutation (TSC2(S1365E)). Resting mTORC1 activity is not altered in either knock-in model. Therefore, TSC2 phosphorylation is both required and sufficient for PKG1-mediated cardiac protection against pressure overload. The serine residues identified here provide a genetic tool for bidirectional regulation of the amplitude of stress-stimulated mTORC1 activity.


Asunto(s)
Proteínas Quinasas Dependientes de GMP Cíclico/metabolismo , Cardiopatías/prevención & control , Cardiopatías/fisiopatología , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Proteína 2 del Complejo de la Esclerosis Tuberosa/química , Proteína 2 del Complejo de la Esclerosis Tuberosa/metabolismo , Animales , Autofagia , Células Cultivadas , Progresión de la Enfermedad , Activación Enzimática , Everolimus/farmacología , Femenino , Técnicas de Sustitución del Gen , Células HEK293 , Cardiopatías/genética , Cardiopatías/patología , Humanos , Hipertrofia/tratamiento farmacológico , Hipertrofia/patología , Masculino , Diana Mecanicista del Complejo 1 de la Rapamicina/antagonistas & inhibidores , Ratones , Mutación , Miocitos Cardíacos/patología , Fosforilación , Fosfoserina/metabolismo , Presión , Ratas , Ratas Wistar , Serina/genética , Serina/metabolismo , Proteína 2 del Complejo de la Esclerosis Tuberosa/genética
18.
Mol Metab ; 5(2): 67-78, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26909315

RESUMEN

OBJECTIVES: Cancer cachexia affects the majority of tumor patients and significantly contributes to high mortality rates in these subjects. Despite its clinical importance, the identity of tumor-borne signals and their impact on specific peripheral organ systems, particularly the heart, remain mostly unknown. METHODS AND RESULTS: By combining differential colon cancer cell secretome profiling with large-scale cardiomyocyte phenotyping, we identified a signature panel of seven "cachexokines", including Bridging integrator 1, Syntaxin 7, Multiple inositol-polyphosphate phosphatase 1, Glucosidase alpha acid, Chemokine ligand 2, Adamts like 4, and Ataxin-10, which were both sufficient and necessary to trigger cardiac atrophy and aberrant fatty acid metabolism in cardiomyocytes. As a prototypical example, engineered secretion of Ataxin-10 from non-cachexia-inducing cells was sufficient to induce cachexia phenotypes in cardiomyocytes, correlating with elevated Ataxin-10 serum levels in murine and human cancer cachexia models. CONCLUSIONS: As Ataxin-10 serum levels were also found to be elevated in human cachectic cancer patients, the identification of Ataxin-10 as part of a cachexokine cocktail now provides a rational approach towards personalized predictive, diagnostic and therapeutic measures in cancer cachexia.

19.
Drug Des Devel Ther ; 7: 297-303, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23630415

RESUMEN

BACKGROUND: Type 2 Diabetes mellitus (T2DM) is a common comorbidity in patients after heart transplantation (HTx) and is associated with adverse long-term outcomes. METHODS: The retrospective study reported here analyzed the effects of vildagliptin therapy in stable patients post-HTx with T2DM and compared these with control patients for matched-pairs analysis. A total of 30 stable patients post-HTx with T2DM were included in the study. Fifteen patients (mean age 58.6 ± 6.0 years, mean time post-HTx 4.9 ± 5.3 years, twelve male and three female) were included in the vildagliptin group (VG) and 15 patients were included in the control group (CG) (mean age 61.2 ± 8.3 years, mean time post-HTx 7.2 ± 6.6 years, all male). RESULTS: Mean glycated hemoglobin (HbA1c) in the VG was 7.4% ± 0.7% before versus 6.8% ± 0.8% after 8 months of vildagliptin therapy (P = 0.002 vs baseline). In the CG, HbA1c was 7.0% ± 0.7% versus 7.3% ± 1.2% at follow-up (P = 0.21). Additionally, there was a significant reduction in mean blood glucose in the VG, from 165.0 ± 18.8 mg/dL to 147.9 ± 22.7 mg/dL (P = 0.002 vs baseline), whereas mean blood glucose increased slightly in the CG from 154.7 ± 19.7 mg/dL to 162.6 ± 35.0 mg/dL (P = 0.21). No statistically significant changes in body weight (from 83.3 ± 10.8 kg to 82.0 ± 10.9 kg, P = 0.20), total cholesterol (1.5%, P = 0.68), or triglyceride levels (8.0%, P = 0.65) were seen in the VG. No significant changes in immunosuppressive drug levels or dosages were observed in either group. CONCLUSION: Vildagliptin therapy significantly reduced HbA1c and mean blood glucose levels in post-HTx patients in this study with T2DM and did not have any negative effects on lipid profile or body weight. Thus, vildagliptin therapy presented an interesting therapeutic approach for this selected patient cohort.


Asunto(s)
Adamantano/análogos & derivados , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Inhibidores de la Dipeptidil-Peptidasa IV/uso terapéutico , Trasplante de Corazón/efectos adversos , Nitrilos/uso terapéutico , Pirrolidinas/uso terapéutico , Adamantano/efectos adversos , Adamantano/uso terapéutico , Anciano , Glucemia/análisis , Peso Corporal/efectos de los fármacos , Diabetes Mellitus Tipo 2/sangre , Femenino , Hemoglobina Glucada/análisis , Humanos , Inmunosupresores/uso terapéutico , Lípidos/sangre , Masculino , Persona de Mediana Edad , Nitrilos/efectos adversos , Pirrolidinas/efectos adversos , Estudios Retrospectivos , Vildagliptina
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