RESUMEN
BACKGROUND: Hydrogen sulfide is a critical endogenous signaling molecule that exerts protective effects in the setting of heart failure. Cystathionine γ-lyase (CSE), 1 of 3 hydrogen-sulfide-producing enzyme, is predominantly localized in the vascular endothelium. The interaction between the endothelial CSE-hydrogen sulfide axis and endothelial-mesenchymal transition, an important pathological process contributing to the formation of fibrosis, has yet to be investigated. METHODS: Endothelial-cell-specific CSE knockout and Endothelial cell-CSE overexpressing mice were subjected to transverse aortic constriction to induce heart failure with reduced ejection fraction. Cardiac function, vascular reactivity, and treadmill exercise capacity were measured to determine the severity of heart failure. Histological and gene expression analyses were performed to investigate changes in cardiac fibrosis and the activation of endothelial-mesenchymal transition. RESULTS: Endothelial-cell-specific CSE knockout mice exhibited increased endothelial-mesenchymal transition and reduced nitric oxide bioavailability in the myocardium, which was associated with increased cardiac fibrosis, impaired cardiac and vascular function, and worsened exercise performance. In contrast, genetic overexpression of CSE in endothelial cells led to increased myocardial nitric oxide, decreased endothelial-mesenchymal transition and cardiac fibrosis, preserved cardiac and endothelial function, and improved exercise capacity. CONCLUSIONS: Our data demonstrate that endothelial CSE modulates endothelial-mesenchymal transition and ameliorate the severity of pressure-overload-induced heart failure, in part, through nitric oxide-related mechanisms. These data further suggest that endothelium-derived hydrogen sulfide is a potential therapeutic for the treatment of heart failure with reduced ejection fraction.
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Insuficiencia Cardíaca , Sulfuro de Hidrógeno , Disfunción Ventricular Izquierda , Ratones , Animales , Sulfuro de Hidrógeno/metabolismo , Células Endoteliales/metabolismo , Óxido Nítrico/metabolismo , Ratones Noqueados , Endotelio Vascular/metabolismo , FibrosisRESUMEN
Heart failure (HF) is a global pandemic with a poor prognosis after hospitalization. Despite HF syndrome complexities, evidence of significant sympathetic overactivity in the manifestation and progression of HF is universally accepted. Confirmation of this dogma is observed in guideline-directed use of neurohormonal pharmacotherapies as a standard of care in HF. Despite reductions in morbidity and mortality, a growing patient population is resistant to these medications, while off-target side effects lead to dismal patient adherence to lifelong drug regimens. Novel therapeutic strategies, devoid of these limitations, are necessary to attenuate the progression of HF pathophysiology while continuing to reduce morbidity and mortality. Renal denervation is an endovascular procedure, whereby the ablation of renal nerves results in reduced renal afferent and efferent sympathetic nerve activity in the kidney and globally. In this review, we discuss the current state of preclinical and clinical research related to renal sympathetic denervation to treat HF.
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Insuficiencia Cardíaca/terapia , Simpatectomía/métodos , Animales , Progresión de la Enfermedad , Insuficiencia Cardíaca/fisiopatología , Humanos , Riñón/fisiopatologíaRESUMEN
Smoking and high-fat diet (HFD) consumption are two modifiable risk factors for cardiovascular (CV) diseases, and individuals who are overweight or obese due to unhealthy diet are more likely to use tobacco products. In this study, we aim to investigate the combined effects of nicotine (the addictive component of all tobacco products) and HFD on CV health, which are poorly understood. C57BL/6N male mice were placed on either HFD (60 kcal% fat) or regular diet (22 kcal% fat) and exposed to air or nicotine vapor for 10-12 wk. CV function was monitored by echocardiography and radiotelemetry, with left ventricular (LV) catheterization and aortic ring vasoreactivity assays performed at end point. Mice on HFD exhibited increased heart rate and impaired parasympathetic tone, whereas nicotine exposure increased sympathetic vascular tone as evidenced by increased blood pressure (BP) response to ganglionic blockade. Although neither nicotine nor HFD alone or in combination significantly altered BP, nicotine exposure disrupted circadian BP regulation with reduced BP dipping. LV catheterization revealed that combined exposure to nicotine and HFD led to LV diastolic dysfunction with increased LV end-diastolic pressure (LVEDP). Moreover, combined exposure resulted in increased inhibitory phosphorylation of endothelial nitric oxide synthase and greater impairment of endothelium-dependent vasodilation. Finally, a small cohort of C57BL/6N females with combined exposure exhibited similar increases in LVEDP, indicating that both sexes are susceptible to the combined effect of nicotine and HFD. In summary, combined exposure to nicotine and HFD leads to greater CV harm, including both additive and new-onset CV dysfunction.NEW & NOTEWORTHY Nicotine product usage and high-fat diet consumption are two modifiable risk factors for cardiovascular diseases. Here, we demonstrate that in mice, combined exposure to inhaled nicotine and high-fat diet results in unique cardiovascular consequences compared with either treatment alone, including left ventricular diastolic dysfunction, dysregulation of blood pressure, autonomic dysfunction, and greater impairment of endothelium-dependent vasorelaxation. These findings indicate that individuals who consume both nicotine products and high-fat diet have distinctive cardiovascular risks.
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Dieta Alta en Grasa , Disfunción Ventricular Izquierda , Humanos , Femenino , Ratones , Masculino , Animales , Dieta Alta en Grasa/efectos adversos , Nicotina/toxicidad , Ratones Endogámicos C57BL , Vasodilatación , Presión Sanguínea , Disfunción Ventricular Izquierda/inducido químicamenteRESUMEN
BACKGROUND: Hydrogen sulfide (H2S) exerts mitochondria-specific actions that include the preservation of oxidative phosphorylation, biogenesis, and ATP synthesis, while inhibiting cell death. 3-MST (3-mercaptopyruvate sulfurtransferase) is a mitochondrial H2S-producing enzyme whose functions in the cardiovascular disease are not fully understood. In the current study, we investigated the effects of global 3-MST deficiency in the setting of pressure overload-induced heart failure. METHODS: Human myocardial samples obtained from patients with heart failure undergoing cardiac surgeries were probed for 3-MST protein expression. 3-MST knockout mice and C57BL/6J wild-type mice were subjected to transverse aortic constriction to induce pressure overload heart failure with reduced ejection fraction. Cardiac structure and function, vascular reactivity, exercise performance, mitochondrial respiration, and ATP synthesis efficiency were assessed. In addition, untargeted metabolomics were utilized to identify key pathways altered by 3-MST deficiency. RESULTS: Myocardial 3-MST was significantly reduced in patients with heart failure compared with nonfailing controls. 3-MST KO mice exhibited increased accumulation of branched-chain amino acids in the myocardium, which was associated with reduced mitochondrial respiration and ATP synthesis, exacerbated cardiac and vascular dysfunction, and worsened exercise performance following transverse aortic constriction. Restoring myocardial branched-chain amino acid catabolism with 3,6-dichlorobenzo1[b]thiophene-2-carboxylic acid (BT2) and administration of a potent H2S donor JK-1 ameliorates the detrimental effects of 3-MST deficiency in heart failure with reduced ejection fraction. CONCLUSIONS: Our data suggest that 3-MST derived mitochondrial H2S may play a regulatory role in branched-chain amino acid catabolism and mediate critical cardiovascular protection in heart failure.
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Insuficiencia Cardíaca , Sulfuro de Hidrógeno , Disfunción Ventricular Izquierda , Adenosina Trifosfato/metabolismo , Aminoácidos de Cadena Ramificada/metabolismo , Animales , Insuficiencia Cardíaca/metabolismo , Humanos , Sulfuro de Hidrógeno/metabolismo , Ratones , Ratones Endogámicos C57BL , Mitocondrias/metabolismo , Miocardio/metabolismo , Disfunción Ventricular Izquierda/metabolismoRESUMEN
Cigarette smoking remains the leading modifiable risk factor for cardiopulmonary diseases; however, the effects of nicotine alone on cardiopulmonary function remain largely unknown. Previously, we have shown that chronic nicotine vapor inhalation in mice leads to the development of pulmonary hypertension (PH) with right ventricular (RV) remodeling. The present study aims to further examine the cardiopulmonary effects of nicotine and the role of the α7 nicotinic acetylcholine receptor (α7-nAChR), which is widely expressed in the cardiovascular system. Wild-type (WT) and α7-nAChR knockout (α7-nAChR-/-) mice were exposed to room air (control) or nicotine vapor daily for 12 weeks. Consistent with our previous study, echocardiography and RV catheterization reveal that male WT mice developed increased RV systolic pressure with RV hypertrophy and dilatation following 12-week nicotine vapor exposure; in contrast, these changes were not observed in male α7-nAChR-/- mice. In addition, chronic nicotine inhalation failed to induce PH and RV remodeling in female mice regardless of genotype. The effects of nicotine on the vasculature were further examined in male mice. Our results show that chronic nicotine inhalation led to impaired acetylcholine-mediated vasodilatory response in both thoracic aortas and pulmonary arteries, and these effects were accompanied by altered endothelial nitric oxide synthase phosphorylation (enhanced inhibitory phosphorylation at threonine 495) and reduced plasma nitrite levels in WT but not α7-nAChR-/- mice. Finally, RNA sequencing revealed up-regulation of multiple inflammatory pathways in thoracic aortas from WT but not α7-nAChR-/- mice. We conclude that the α7-nAChR mediates chronic nicotine inhalation-induced PH, RV remodeling and vascular dysfunction.
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Nicotina , Receptor Nicotínico de Acetilcolina alfa 7 , Acetilcolina/metabolismo , Administración por Inhalación , Animales , Aorta Torácica/efectos de los fármacos , Femenino , Masculino , Ratones , Nicotina/administración & dosificación , Arteria Pulmonar/efectos de los fármacos , Regulación hacia Arriba , Vasodilatación/efectos de los fármacos , Receptor Nicotínico de Acetilcolina alfa 7/genética , Receptor Nicotínico de Acetilcolina alfa 7/metabolismoRESUMEN
Ischemic heart diseases such as myocardial infarction (MI) are the largest contributors to cardiovascular disease worldwide. The resulting cardiac cell death impairs function of the heart and can lead to heart failure and death. Reperfusion of the ischemic tissue is necessary but causes damage to the surrounding tissue by reperfusion injury. Cortical bone stem cells (CBSCs) have been shown to increase pump function and decrease scar size in a large animal swine model of MI. To investigate the potential mechanism for these changes, we hypothesized that CBSCs were altering cardiac cell death after reperfusion. To test this, we performed TUNEL staining for apoptosis and antibody-based immunohistochemistry on tissue from Göttingen miniswine that underwent 90 min of lateral anterior descending coronary artery ischemia followed by 3 or 7 days of reperfusion to assess changes in cardiomyocyte and noncardiomyocyte cell death. Our findings indicate that although myocyte apoptosis is present 3 days after ischemia and is lower in CBSC-treated animals, myocyte apoptosis accounts for <2% of all apoptosis in the reperfused heart. In addition, nonmyocyte apoptosis trends toward decreased in CBSC-treated hearts, and although CBSCs increase macrophage and T-cell populations in the infarct region, the occurrence of apoptosis in CD45+ cells in the myocardium is not different between groups. From these data, we conclude that CBSCs may be influencing cardiomyocyte and noncardiomyocyte cell death and immune cell recruitment dynamics in the heart after MI, and these changes may account for some of the beneficial effects conferred by CBSC treatment.NEW & NOTEWORTHY The following research explores aspects of cell death and inflammation that have not been previously studied in a large animal model. In addition, apoptosis and cell death have not been studied in the context of cell therapy and myocardial infarction. In this article, we describe interactions between cell therapy and inflammation and the potential implications for cardiac wound healing.
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Apoptosis , Infarto del Miocardio/cirugía , Daño por Reperfusión Miocárdica/cirugía , Miocitos Cardíacos/patología , Trasplante de Células Madre , Células Madre , Tibia/citología , Animales , Células Cultivadas , Modelos Animales de Enfermedad , Femenino , Células Madre Hematopoyéticas/inmunología , Células Madre Hematopoyéticas/metabolismo , Antígenos Comunes de Leucocito/metabolismo , Macrófagos/inmunología , Macrófagos/metabolismo , Masculino , Infarto del Miocardio/inmunología , Infarto del Miocardio/metabolismo , Infarto del Miocardio/patología , Daño por Reperfusión Miocárdica/metabolismo , Daño por Reperfusión Miocárdica/patología , Miocitos Cardíacos/inmunología , Porcinos , Porcinos Enanos , Linfocitos T/inmunología , Linfocitos T/metabolismo , Factores de TiempoRESUMEN
Enthusiasm for cell therapy for myocardial injury has waned due to equivocal benefits in clinical trials. In an attempt to improve efficacy, we investigated repeated cell therapy and adjunct renal denervation (RDN) as strategies for augmenting cardioprotection with cardiosphere-derived cells (CDCs). We hypothesized that combining CDC post-conditioning with repeated CDC doses or delayed RDN therapy would result in superior function and remodeling. Wistar-Kyoto (WKY) rats or spontaneously hypertensive rats (SHR) were subjected to 45 min of coronary artery ligation followed by reperfusion for 12-14 weeks. In the first study arm, SHR were treated with CDCs (0.5 × 106 i.c.) or PBS 20 min following reperfusion, or additionally treated with CDCs (1.0 × 106 i.v.) at 2, 4, and 8 weeks. In the second arm, at 4 weeks following myocardial infarction (MI), SHR received CDCs (0.5 × 106 i.c.) or CDCs + RDN. In the third arm, WKY rats were treated with i.c. CDCs administered 20 min following reperfusion and RDN or a sham at 4 weeks. Early i.c. + multiple i.v. dosing, but not single i.c. dosing, of CDCs improved long-term left ventricular (LV) function, but not remodeling. Delayed CDC + RDN therapy was not superior to single-dose delayed CDC therapy. Early CDC + delayed RDN therapy improved LV ejection fraction and remodeling compared to both CDCs alone and RDN alone. Given that both RDN and CDCs are currently in the clinic, our findings motivate further translation targeting a heart failure indication with combined approaches.
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Desnervación Autonómica/métodos , Daño por Reperfusión Miocárdica , Trasplante de Células Madre/métodos , Animales , Insuficiencia Cardíaca , Riñón/inervación , Riñón/cirugía , Masculino , Infarto del Miocardio , Ratas , Ratas Endogámicas SHR , Ratas Endogámicas WKY , Remodelación Ventricular/fisiologíaRESUMEN
RATIONALE: Cortical bone stem cells (CBSCs) have been shown to reduce ventricular remodeling and improve cardiac function in a murine myocardial infarction (MI) model. These effects were superior to other stem cell types that have been used in recent early-stage clinical trials. However, CBSC efficacy has not been tested in a preclinical large animal model using approaches that could be applied to patients. OBJECTIVE: To determine whether post-MI transendocardial injection of allogeneic CBSCs reduces pathological structural and functional remodeling and prevents the development of heart failure in a swine MI model. METHODS AND RESULTS: Female Göttingen swine underwent left anterior descending coronary artery occlusion, followed by reperfusion (ischemia-reperfusion MI). Animals received, in a randomized, blinded manner, 1:1 ratio, CBSCs (n=9; 2×107 cells total) or placebo (vehicle; n=9) through NOGA-guided transendocardial injections. 5-ethynyl-2'deoxyuridine (EdU)-a thymidine analog-containing minipumps were inserted at the time of MI induction. At 72 hours (n=8), initial injury and cell retention were assessed. At 3 months post-MI, cardiac structure and function were evaluated by serial echocardiography and terminal invasive hemodynamics. CBSCs were present in the MI border zone and proliferating at 72 hours post-MI but had no effect on initial cardiac injury or structure. At 3 months, CBSC-treated hearts had significantly reduced scar size, smaller myocytes, and increased myocyte nuclear density. Noninvasive echocardiographic measurements showed that left ventricular volumes and ejection fraction were significantly more preserved in CBSC-treated hearts, and invasive hemodynamic measurements documented improved cardiac structure and functional reserve. The number of EdU+ cardiac myocytes was increased in CBSC- versus vehicle- treated animals. CONCLUSIONS: CBSC administration into the MI border zone reduces pathological cardiac structural and functional remodeling and improves left ventricular functional reserve. These effects reduce those processes that can lead to heart failure with reduced ejection fraction.
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Hueso Cortical/citología , Infarto del Miocardio/cirugía , Daño por Reperfusión Miocárdica/cirugía , Miocardio/patología , Células Madre/fisiología , Función Ventricular Izquierda , Remodelación Ventricular , Animales , Apoptosis , Arritmias Cardíacas/fisiopatología , Arritmias Cardíacas/prevención & control , Proliferación Celular , Células Cultivadas , Modelos Animales de Enfermedad , Femenino , Hemodinámica , Contracción Miocárdica , Infarto del Miocardio/patología , Infarto del Miocardio/fisiopatología , Daño por Reperfusión Miocárdica/patología , Daño por Reperfusión Miocárdica/fisiopatología , Fenotipo , Volumen Sistólico , Sus scrofa , Factores de TiempoRESUMEN
Cardiac fibroblasts are critical mediators of fibrotic remodeling in the failing heart and transform into myofibroblasts in the presence of profibrotic factors such as transforming growth factor-ß. Myocardial fibrosis worsens cardiac function, accelerating the progression to decompensated heart failure (HF). We investigated the effects of a novel inhibitor (NM922; NovoMedix, San Diego, CA) of the conversion of normal fibroblasts to the myofibroblast phenotype in the setting of pressure overload-induced HF. NM922 inhibited fibroblast-to-myofibroblast transformation in vitro via a reduction of activation of the focal adhesion kinase-Akt-p70S6 kinase and STAT3/4E-binding protein 1 pathways as well as via induction of cyclooxygenase-2. NM922 preserved left ventricular ejection fraction ( P < 0.05 vs. vehicle) and significantly attenuated transverse aortic constriction-induced LV dilation and hypertrophy ( P < 0.05 compared with vehicle). NM922 significantly ( P < 0.05) inhibited fibroblast activation, as evidenced by reduced myofibroblast counts per square millimeter of tissue area. Picrosirius red staining demonstrated that NM922 reduced ( P < 0.05) interstitial fibrosis compared with mice that received vehicle. Similarly, NM922 hearts had lower mRNA levels ( P < 0.05) of collagen types I and III, lysyl oxidase, and TNF-α at 16 wk after transverse aortic constriction. Treatment with NM922 after the onset of cardiac hypertrophy and HF resulted in attenuated myocardial collagen formation and adverse remodeling with preservation of left ventricular ejection fraction. Future studies are aimed at further elucidation of the molecular and cellular mechanisms by which this novel antifibrotic agent protects the failing heart. NEW & NOTEWORTHY Our data demonstrated that a novel antifibrotic agent, NM922, blocks the activation of fibroblasts, reduces the formation of cardiac fibrosis, and preserves cardiac function in a murine model of heart failure with reduced ejection fraction.
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Cardiotónicos/farmacología , Insuficiencia Cardíaca/tratamiento farmacológico , Miofibroblastos/efectos de los fármacos , Sulfonamidas/farmacología , Remodelación Ventricular/efectos de los fármacos , Animales , Cardiotónicos/uso terapéutico , Células Cultivadas , Colágeno/metabolismo , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Miofibroblastos/metabolismo , Proteína-Lisina 6-Oxidasa/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Proteínas Quinasas S6 Ribosómicas 70-kDa/metabolismo , Factor de Transcripción STAT3/metabolismo , Sulfonamidas/química , Sulfonamidas/uso terapéutico , Factor de Crecimiento Transformador beta/metabolismoRESUMEN
RATIONALE: Catecholamines increase cardiac contractility, but exposure to high concentrations or prolonged exposures can cause cardiac injury. A recent study demonstrated that a single subcutaneous injection of isoproterenol (ISO; 200 mg/kg) in mice causes acute myocyte death (8%-10%) with complete cardiac repair within a month. Cardiac regeneration was via endogenous cKit(+) cardiac stem cell-mediated new myocyte formation. OBJECTIVE: Our goal was to validate this simple injury/regeneration system and use it to study the biology of newly forming adult cardiac myocytes. METHODS AND RESULTS: C57BL/6 mice (n=173) were treated with single injections of vehicle, 200 or 300 mg/kg ISO, or 2 daily doses of 200 mg/kg ISO for 6 days. Echocardiography revealed transiently increased systolic function and unaltered diastolic function 1 day after single ISO injection. Single ISO injections also caused membrane injury in ≈10% of myocytes, but few of these myocytes appeared to be necrotic. Circulating troponin I levels after ISO were elevated, further documenting myocyte damage. However, myocyte apoptosis was not increased after ISO injury. Heart weight to body weight ratio and fibrosis were also not altered 28 days after ISO injection. Single- or multiple-dose ISO injury was not associated with an increase in the percentage of 5-ethynyl-2'-deoxyuridine-labeled myocytes. Furthermore, ISO injections did not increase new myocytes in cKit(+/Cre)×R-GFP transgenic mice. CONCLUSIONS: A single dose of ISO causes injury in ≈10% of the cardiomyocytes. However, most of these myocytes seem to recover and do not elicit cKit(+) cardiac stem cell-derived myocyte regeneration.
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Isoproterenol/administración & dosificación , Isoproterenol/toxicidad , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/patología , Regeneración/efectos de los fármacos , Animales , Catecolaminas/administración & dosificación , Catecolaminas/toxicidad , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Miocitos Cardíacos/fisiología , Regeneración/fisiologíaRESUMEN
Hypertrophic cardiomyopathy (HCM) is one of the most common genetic cardiac diseases and among the leading causes of sudden cardiac death (SCD) in the young. The cellular mechanisms leading to SCD in HCM are not well known. Prolongation of the action potential (AP) duration (APD) is a common feature predisposing hypertrophied hearts to SCD. Previous studies have explored the roles of inward Na+ and Ca2+ in the development of HCM, but the role of repolarizing K+ currents has not been defined. The objective of this study was to characterize the arrhythmogenic phenotype and cellular electrophysiological properties of mice with HCM, induced by myosin-binding protein C (MyBPC) knockout (KO), and to test the hypothesis that remodeling of repolarizing K+ currents causes APD prolongation in MyBPC KO myocytes. We demonstrated that MyBPC KO mice developed severe hypertrophy and cardiac dysfunction compared with wild-type (WT) control mice. Telemetric electrocardiographic recordings of awake mice revealed prolongation of the corrected QT interval in the KO compared with WT control mice, with overt ventricular arrhythmias. Whole cell current- and voltage-clamp experiments comparing KO with WT mice demonstrated ventricular myocyte hypertrophy, AP prolongation, and decreased repolarizing K+ currents. Quantitative RT-PCR analysis revealed decreased mRNA levels of several key K+ channel subunits. In conclusion, decrease in repolarizing K+ currents in MyBPC KO ventricular myocytes contributes to AP and corrected QT interval prolongation and could account for the arrhythmia susceptibility.NEW & NOTEWORTHY Ventricular myocytes isolated from the myosin-binding protein C knockout hypertrophic cardiomyopathy mouse model demonstrate decreased repolarizing K+ currents and action potential and QT interval prolongation, linking cellular repolarization abnormalities with arrhythmia susceptibility and the risk for sudden cardiac death in hypertrophic cardiomyopathy.
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Proteínas Portadoras/metabolismo , Frecuencia Cardíaca , Miocitos Cardíacos/metabolismo , Canales de Potasio/metabolismo , Potasio/metabolismo , Taquicardia Ventricular/metabolismo , Complejos Prematuros Ventriculares/metabolismo , Potenciales de Acción , Animales , Cardiomegalia/genética , Cardiomegalia/metabolismo , Cardiomegalia/patología , Proteínas Portadoras/genética , Modelos Animales de Enfermedad , Electrocardiografía Ambulatoria , Fibrosis , Predisposición Genética a la Enfermedad , Cinética , Masculino , Ratones de la Cepa 129 , Ratones Noqueados , Contracción Miocárdica , Miocitos Cardíacos/patología , Técnicas de Placa-Clamp , Fenotipo , Canales de Potasio/genética , ARN Mensajero/genética , ARN Mensajero/metabolismo , Taquicardia Ventricular/genética , Taquicardia Ventricular/patología , Taquicardia Ventricular/fisiopatología , Telemetría , Complejos Prematuros Ventriculares/genética , Complejos Prematuros Ventriculares/patología , Complejos Prematuros Ventriculares/fisiopatologíaRESUMEN
RATIONALE: Adoptive transfer of multiple stem cell types has only had modest effects on the structure and function of failing human hearts. Despite increasing the use of stem cell therapies, consensus on the optimal stem cell type is not adequately defined. The modest cardiac repair and functional improvement in patients with cardiac disease warrants identification of a novel stem cell population that possesses properties that induce a more substantial improvement in patients with heart failure. OBJECTIVE: To characterize and compare surface marker expression, proliferation, survival, migration, and differentiation capacity of cortical bone stem cells (CBSCs) relative to mesenchymal stem cells (MSCs) and cardiac-derived stem cells (CDCs), which have already been tested in early stage clinical trials. METHODS AND RESULTS: CBSCs, MSCs, and CDCs were isolated from Gottingen miniswine or transgenic C57/BL6 mice expressing enhanced green fluorescent protein and were expanded in vitro. CBSCs possess a unique surface marker profile, including high expression of CD61 and integrin ß4 versus CDCs and MSCs. In addition, CBSCs were morphologically distinct and showed enhanced proliferation capacity versus CDCs and MSCs. CBSCs had significantly better survival after exposure to an apoptotic stimuli when compared with MSCs. ATP and histamine induced a transient increase of intracellular Ca(2+) concentration in CBSCs versus CDCs and MSCs, which either respond to ATP or histamine only further documenting the differences between the 3 cell types. CONCLUSIONS: CBSCs are unique from CDCs and MSCs and possess enhanced proliferative, survival, and lineage commitment capacity that could account for the enhanced protective effects after cardiac injury.
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Cardiopatías/terapia , Trasplante de Células Madre Mesenquimatosas/métodos , Células Madre Mesenquimatosas/fisiología , Animales , Gatos , Diferenciación Celular/fisiología , Células Cultivadas , Técnicas de Cocultivo , Femenino , Cardiopatías/patología , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Miocitos Cardíacos/fisiología , Miocitos Cardíacos/trasplante , Porcinos , Porcinos EnanosRESUMEN
RATIONALE: Sorafenib is an effective treatment for renal cell carcinoma, but recent clinical reports have documented its cardiotoxicity through an unknown mechanism. OBJECTIVE: Determining the mechanism of sorafenib-mediated cardiotoxicity. METHODS AND RESULTS: Mice treated with sorafenib or vehicle for 3 weeks underwent induced myocardial infarction (MI) after 1 week of treatment. Sorafenib markedly decreased 2-week survival relative to vehicle-treated controls, but echocardiography at 1 and 2 weeks post MI detected no differences in cardiac function. Sorafenib-treated hearts had significantly smaller diastolic and systolic volumes and reduced heart weights. High doses of sorafenib induced necrotic death of isolated myocytes in vitro, but lower doses did not induce myocyte death or affect inotropy. Histological analysis documented increased myocyte cross-sectional area despite smaller heart sizes after sorafenib treatment, further suggesting myocyte loss. Sorafenib caused apoptotic cell death of cardiac- and bone-derived c-kit+ stem cells in vitro and decreased the number of BrdU+ (5-bromo-2'-deoxyuridine+) myocytes detected at the infarct border zone in fixed tissues. Sorafenib had no effect on infarct size, fibrosis, or post-MI neovascularization. When sorafenib-treated animals received metoprolol treatment post MI, the sorafenib-induced increase in post-MI mortality was eliminated, cardiac function was improved, and myocyte loss was ameliorated. CONCLUSIONS: Sorafenib cardiotoxicity results from myocyte necrosis rather than from any direct effect on myocyte function. Surviving myocytes undergo pathological hypertrophy. Inhibition of c-kit+ stem cell proliferation by inducing apoptosis exacerbates damage by decreasing endogenous cardiac repair. In the setting of MI, which also causes large-scale cell loss, sorafenib cardiotoxicity dramatically increases mortality.
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Antineoplásicos/efectos adversos , Antineoplásicos/farmacología , Corazón/efectos de los fármacos , Infarto del Miocardio/mortalidad , Niacinamida/análogos & derivados , Compuestos de Fenilurea/efectos adversos , Compuestos de Fenilurea/farmacología , Animales , Apoptosis/efectos de los fármacos , Gatos , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Técnicas In Vitro , Masculino , Metoprolol/farmacología , Ratones , Ratones Endogámicos C57BL , Infarto del Miocardio/patología , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/patología , Niacinamida/efectos adversos , Niacinamida/farmacología , Proteínas Proto-Oncogénicas c-kit/efectos de los fármacos , Proteínas Proto-Oncogénicas c-kit/metabolismo , SorafenibRESUMEN
BAG3 is a cellular protein that is expressed predominantly in skeletal and cardiac muscle but can also be found in the brain and in the peripheral nervous system. BAG3 functions in the cell include: serving as a co-chaperone with members of the heat-shock protein family of proteins to facilitate the removal of misfolded and degraded proteins, inhibiting apoptosis by interacting with Bcl2 and maintaining the structural integrity of the Z-disk in muscle by binding with CapZ. The importance of BAG3 in the homeostasis of myocytes and its role in the development of heart failure was evidenced by the finding that single allelic mutations in BAG3 were associated with familial dilated cardiomyopathy. Furthermore, significant decreases in the level of BAG3 have been found in end-stage failing human heart and in animal models of heart failure including mice with heart failure secondary to trans-aortic banding and in pigs after myocardial infarction. Thus, it becomes relevant to understand the cellular biology and molecular regulation of BAG3 expression in order to design new therapies for the treatment of patients with both hereditary and non-hereditary forms of dilated cardiomyopathy.
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Proteínas Adaptadoras Transductoras de Señales/genética , Proteínas Reguladoras de la Apoptosis/genética , Apoptosis/genética , Autofagia/genética , Insuficiencia Cardíaca/genética , Animales , Corazón , Humanos , MutaciónRESUMEN
RATIONALE: Autologous bone marrow-derived or cardiac-derived stem cell therapy for heart disease has demonstrated safety and efficacy in clinical trials, but functional improvements have been limited. Finding the optimal stem cell type best suited for cardiac regeneration is the key toward improving clinical outcomes. OBJECTIVE: To determine the mechanism by which novel bone-derived stem cells support the injured heart. METHODS AND RESULTS: Cortical bone-derived stem cells (CBSCs) and cardiac-derived stem cells were isolated from enhanced green fluorescent protein (EGFP+) transgenic mice and were shown to express c-kit and Sca-1 as well as 8 paracrine factors involved in cardioprotection, angiogenesis, and stem cell function. Wild-type C57BL/6 mice underwent sham operation (n=21) or myocardial infarction with injection of CBSCs (n=67), cardiac-derived stem cells (n=36), or saline (n=60). Cardiac function was monitored using echocardiography. Only 2/8 paracrine factors were detected in EGFP+ CBSCs in vivo (basic fibroblast growth factor and vascular endothelial growth factor), and this expression was associated with increased neovascularization of the infarct border zone. CBSC therapy improved survival, cardiac function, regional strain, attenuated remodeling, and decreased infarct size relative to cardiac-derived stem cells- or saline-treated myocardial infarction controls. By 6 weeks, EGFP+ cardiomyocytes, vascular smooth muscle, and endothelial cells could be identified in CBSC-treated, but not in cardiac-derived stem cells-treated, animals. EGFP+ CBSC-derived isolated myocytes were smaller and more frequently mononucleated, but were functionally indistinguishable from EGFP- myocytes. CONCLUSIONS: CBSCs improve survival, cardiac function, and attenuate remodeling through the following 2 mechanisms: (1) secretion of proangiogenic factors that stimulate endogenous neovascularization, and (2) differentiation into functional adult myocytes and vascular cells.
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Huesos/citología , Transdiferenciación Celular , Células Endoteliales/citología , Células Madre Multipotentes/fisiología , Infarto del Miocardio/fisiopatología , Miocitos Cardíacos/citología , Comunicación Paracrina/fisiología , Proteínas Angiogénicas/biosíntesis , Proteínas Angiogénicas/genética , Proteínas Angiogénicas/metabolismo , Animales , Antígenos Ly/biosíntesis , Antígenos Ly/genética , Biomarcadores , Células Cultivadas/citología , Células Cultivadas/metabolismo , Regulación de la Expresión Génica , Genes Reporteros , Proteínas de la Membrana/biosíntesis , Proteínas de la Membrana/genética , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Células Madre Multipotentes/citología , Células Madre Multipotentes/metabolismo , Células Madre Multipotentes/trasplante , Infarto del Miocardio/patología , Neovascularización Fisiológica/genética , Proteínas Proto-Oncogénicas c-kit/biosíntesis , Proteínas Proto-Oncogénicas c-kit/genética , Remodelación Ventricular/fisiologíaRESUMEN
BACKGROUND AND PURPOSE: Sodium glucose cotransporter 2 inhibitors (SGLT2i) have emerged as a potent therapy for heart failure with preserved ejection fraction (HFpEF). Hydrogen sulphide (H2S), a well-studied cardioprotective agent, could be beneficial in HFpEF. SGLT2i monotherapy and combination therapy involving an SGLT2i and H2S donor in two preclinical models of cardiometabolic HFpEF was investigated. EXPERIMENTAL APPROACH: Nine-week-old C57BL/6N mice received L-NAME and a 60% high fat diet for five weeks. Mice were then randomized to either control, SGLT2i monotherapy or SGLT2i and H2S donor, SG1002, for five additional weeks. Ten-week-old ZSF1 obese rats were randomized to control, SGLT2i or SGLT2i and SG1002 for 8 weeks. SG1002 monotherapy was investigated in additional animals. Cardiac function (echocardiography and haemodynamics), exercise capacity, glucose handling and multiorgan pathology were monitored during experimental protocols. KEY RESULTS: SGLT2i treatment improved E/e' ratio and treadmill exercise in both models. Combination therapy afforded increases in cardiovascular sulphur bioavailability that coincided with improved left end-diastolic function (E/e' ratio), exercise capacity, metabolic state, cardiorenal fibrosis, and hepatic steatosis. Follow-up studies with SG1002 monotherapy revealed improvements in diastolic function, exercise capacity and multiorgan histopathology. CONCLUSIONS AND IMPLICATIONS: SGLT2i monotherapy remediated pathological complications exhibited by two well-established HFpEF models. Adjunctive H2S therapy resulted in further improvements of cardiometabolic perturbations beyond SGLT2i monotherapy. Follow-up SG1002 monotherapy studies inferred an improved phenotype with combination therapy beyond either monotherapy. These data demonstrate the differing effects of SGLT2i and H2S therapy while also revealing the superior efficacy of the combination therapy in cardiometabolic HFpEF.
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BACKGROUND: The renal sympathetic nervous system modulates systemic blood pressure, cardiac performance, and renal function. Pathological increases in renal sympathetic nerve activity contribute to the pathogenesis of heart failure with preserved ejection fraction (HFpEF). We investigated the effects of renal sympathetic denervation performed at early or late stages of HFpEF progression. METHODS AND RESULTS: Male ZSF1 obese rats were subjected to radiofrequency renal denervation (RF-RDN) or sham procedure at either 8 weeks or 20 weeks of age and assessed for cardiovascular function, exercise capacity, and cardiorenal fibrosis. Renal norepinephrine and renal nerve tyrosine hydroxylase staining were performed to quantify denervation following RF-RDN. In addition, renal injury, oxidative stress, inflammation, and profibrotic biomarkers were evaluated to determine pathways associated with RDN. RF-RDN significantly reduced renal norepinephrine and tyrosine hydroxylase content in both study cohorts. RF-RDN therapy performed at 8 weeks of age attenuated cardiac dysfunction, reduced cardiorenal fibrosis, and improved endothelial-dependent vascular reactivity. These improvements were associated with reductions in renal injury markers, expression of renal NLR family pyrin domain containing 3/interleukin 1ß, and expression of profibrotic mediators. RF-RDN failed to exert beneficial effects when administered in the 20-week-old HFpEF cohort. CONCLUSIONS: Our data demonstrate that early RF-RDN therapy protects against HFpEF disease progression in part due to the attenuation of renal fibrosis and inflammation. In contrast, the renoprotective and left ventricular functional improvements were lost when RF-RDN was performed in later HFpEF progression. These results suggest that RDN may be a viable treatment option for HFpEF during the early stages of this systemic inflammatory disease.
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Insuficiencia Cardíaca , Humanos , Masculino , Ratas , Animales , Insuficiencia Cardíaca/metabolismo , Volumen Sistólico , Tirosina 3-Monooxigenasa/metabolismo , Riñón/metabolismo , Simpatectomía/métodos , Inflamación/metabolismo , Norepinefrina , Fibrosis , DesnervaciónRESUMEN
Background Recent studies have suggested that cardiac nitrosative stress mediated by pathological overproduction of nitric oxide (NO) via inducible NO synthase (iNOS) contributes to the pathogenesis of heart failure with preserved ejection fraction (HFpEF). Other studies have suggested that endothelial NO synthase (eNOS) dysfunction and attenuated NO bioavailability contribute to HFpEF morbidity and mortality. We sought to further investigate dysregulated NO signaling and to examine the effects of a NO-based dual therapy (sodium nitrite+hydralazine) following the onset of HFpEF using a "2-hit" murine model. Methods and Results Nine-week-old male C57BL/6 N mice (n=15 per group) were treated concurrently with high-fat diet and N(ω)-nitro-L-arginine methyl ester (L-NAME) (0.5 g/L per day) via drinking water for 10 weeks. At week 5, mice were randomized into either vehicle (normal saline) or combination treatment with sodium nitrite (75 mg/L in the drinking water) and hydralazine (2.0 mg/kg IP, BID). Cardiac structure and function were monitored with echocardiography and invasive hemodynamic measurements. Cardiac mitochondrial respiration, aortic vascular function, and exercise performance were also evaluated. Circulating and myocardial nitrite were measured to determine the bioavailability of NO. Circulating markers of oxidative or nitrosative stress as well as systemic inflammation were also determined. Severe HFpEF was evident by significantly elevated E/E', LVEDP, and Tau in mice treated with L-NAME and HFD, which was associated with impaired NO bioavailability, mitochondrial respiration, aortic vascular function, and exercise capacity. Treatment with sodium nitrite and hydralazine restored NO bioavailability, reduced oxidative and nitrosative stress, preserved endothelial function and mitochondrial respiration, limited the fibrotic response, and improved exercise capacity, ultimately attenuating the severity of "two-hit" HFpEF. Conclusions Our data demonstrate that nitrite, a well-established biomarker of NO bioavailability and a physiological source of NO, is significantly reduced in the heart and circulation in the "2-hit" mouse HFpEF model. Furthermore, sodium nitrite+hydralazine combined therapy significantly attenuated the severity of HFpEF in the "2-hit" cardiometabolic HFpEF. These data suggest that supplementing NO-based therapeutics with a potent antioxidant and vasodilator agent may result in synergistic benefits for the treatment of HFpEF.
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Agua Potable , Insuficiencia Cardíaca , Ratones , Masculino , Animales , Insuficiencia Cardíaca/tratamiento farmacológico , Nitrito de Sodio , Volumen Sistólico/fisiología , NG-Nitroarginina Metil Éster , Modelos Animales de Enfermedad , Ratones Endogámicos C57BL , Hidralazina/farmacología , Óxido Nítrico SintasaRESUMEN
A lack of preclinical large animal models of heart failure with preserved ejection fraction (HFpEF) that recapitulate this comorbid-laden syndrome has led to the inability to tease out mechanistic insights and to test novel therapeutic strategies. This study developed a large animal model that integrated multiple comorbid determinants of HFpEF in a miniswine breed that exhibited sensitivity to obesity, metabolic syndrome, and vascular disease with overt clinical signs of heart failure. The combination of a Western diet and 11-deoxycorticosterone acetate salt-induced hypertension in the Göttingen miniswine led to the development of a novel large animal model of HFpEF that exhibited multiorgan involvement and a full spectrum of comorbidities associated with human HFpEF.
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Background Patients at increased risk for coronary artery disease and adverse prognosis during heart failure exhibit increased levels of circulating trimethylamine N-oxide (TMAO), a metabolite formed in the metabolism of dietary phosphatidylcholine. We investigated the efficacy of dietary withdrawal of TMAO as well as use of a gut microbe-targeted inhibitor of TMAO production, on cardiac function and structure during heart failure. Methods and Results Male C57BLK/6J mice were fed either control diet, a diet containing TMAO (0.12% wt/wt), a diet containing choline (1% wt/wt), or a diet containing choline (1% wt/wt) plus a microbial choline trimethylamine lyase inhibitor, iodomethylcholine (0.06% wt/wt), starting 3 weeks before transverse aortic constriction. At 6 weeks after transverse aortic constriction, a subset of animals in the TMAO group were switched to a control diet for the remainder of the study. Left ventricular structure and function were monitored at 3-week intervals. Withdrawal of TMAO from the diet attenuated adverse ventricular remodeling and improved cardiac function compared with the TMAO group. Similarly, inhibiting gut microbial conversion of choline to TMAO with a choline trimethylamine lyase inhibitor, iodomethylcholine, improved remodeling and cardiac function compared with the choline-fed group. Conclusions These experimental findings are clinically relevant, and they demonstrate that TMAO levels are modifiable following long-term exposure periods with either dietary withdrawal of TMAO or gut microbial blockade of TMAO generation. Furthermore, these therapeutic strategies to reduce circulating TMAO levels mitigate the negative effects of dietary choline and TMAO in heart failure.