RESUMEN
Faulkes et al. recently showed that naked mole-rats (NMRs) have a very distinctive cardiac gene expression profile among other African mole-rats, as well as metabolic variations that result from their chronic exposure to a hypoxic environment. These adaptations might underlie their resistance to cardiac ischemic injuries.
RESUMEN
Ischemic heart diseases and cardiomyopathies are characterized by hypoxia, energy starvation and mitochondrial dysfunction. HIF-1 acts as a cellular oxygen sensor, tuning the balance of metabolic and oxidative stress pathways to provide ATP and sustain cell survival. Acting on mitochondria, HIF-1 regulates different processes such as energy substrate utilization, oxidative phosphorylation and mitochondrial dynamics. In turn, mitochondrial homeostasis modifications impact HIF-1 activity. This underlies that HIF-1 and mitochondria are tightly interconnected to maintain cell homeostasis. Despite many evidences linking HIF-1 and mitochondria, the mechanistic insights are far from being understood, particularly in the context of cardiac diseases. Here, we explore the current understanding of how HIF-1, reactive oxygen species and cell metabolism are interconnected, with a specific focus on mitochondrial function and dynamics. We also discuss the divergent roles of HIF in acute and chronic cardiac diseases in order to highlight that HIF-1, mitochondria and oxidative stress interaction deserves to be deeply investigated. While the strategies aiming at stabilizing HIF-1 have provided beneficial effects in acute ischemic injury, some deleterious effects were observed during prolonged HIF-1 activation. Thus, deciphering the link between HIF-1 and mitochondria will help to optimize HIF-1 modulation and provide new therapeutic perspectives for the treatment of cardiovascular pathologies.
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Cardiopatías , Estrés Oxidativo , Especies Reactivas de Oxígeno , Humanos , Cardiopatías/metabolismo , Cardiopatías/patología , Cardiopatías/genética , Animales , Especies Reactivas de Oxígeno/metabolismo , Factor 1 Inducible por Hipoxia/metabolismo , Factor 1 Inducible por Hipoxia/genética , Mitocondrias Cardíacas/metabolismo , Mitocondrias Cardíacas/patología , Mitocondrias/metabolismo , Mitocondrias/patología , Mitocondrias/genética , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Fosforilación Oxidativa , Isquemia Miocárdica/metabolismo , Isquemia Miocárdica/patología , Isquemia Miocárdica/genéticaRESUMEN
BACKGROUND: Duchenne muscular dystrophy (DMD) is an X-linked disorder characterized by progressive muscle weakness due to the absence of functional dystrophin. DMD patients also develop dilated cardiomyopathy (DCM). We have previously shown that DMD (mdx) mice and a canine DMD model (GRMD) exhibit abnormal intracellular calcium (Ca2+) cycling related to early-stage pathological remodelling of the ryanodine receptor intracellular calcium release channel (RyR2) on the sarcoplasmic reticulum (SR) contributing to age-dependent DCM. METHODS: Here, we used hiPSC-CMs from DMD patients selected by Speckle-tracking echocardiography and canine DMD cardiac biopsies to assess key early-stage Duchenne DCM features. RESULTS: Dystrophin deficiency was associated with RyR2 remodelling and SR Ca2+ leak (RyR2 Po of 0.03 ± 0.01 for HC vs. 0.16 ± 0.01 for DMD, P < 0.01), which led to early-stage defects including senescence. We observed higher levels of senescence markers including p15 (2.03 ± 0.75 for HC vs. 13.67 ± 5.49 for DMD, P < 0.05) and p16 (1.86 ± 0.83 for HC vs. 10.71 ± 3.00 for DMD, P < 0.01) in DMD hiPSC-CMs and in the canine DMD model. The fibrosis was increased in DMD hiPSC-CMs. We observed cardiac hypocontractility in DMD hiPSC-CMs. Stabilizing RyR2 pharmacologically by S107 prevented most of these pathological features, including the rescue of the contraction amplitude (1.65 ± 0.06 µm for DMD vs. 2.26 ± 0.08 µm for DMD + S107, P < 0.01). These data were confirmed by proteomic analyses, in particular ECM remodelling and fibrosis. CONCLUSIONS: We identified key cellular damages that are established earlier than cardiac clinical pathology in DMD patients, with major perturbation of the cardiac ECC. Our results demonstrated that cardiac fibrosis and premature senescence are induced by RyR2 mediated SR Ca2+ leak in DMD cardiomyocytes. We revealed that RyR2 is an early biomarker of DMD-associated cardiac damages in DMD patients. The progressive and later DCM onset could be linked with the RyR2-mediated increased fibrosis and premature senescence, eventually causing cell death and further cardiac fibrosis in a vicious cycle leading to further hypocontractility as a major feature of DCM. The present study provides a novel understanding of the pathophysiological mechanisms of the DMD-induced DCM. By targeting RyR2 channels, it provides a potential pharmacological treatment.
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Cardiomiopatías , Cardiomiopatía Dilatada , Humanos , Ratones , Animales , Perros , Cardiomiopatía Dilatada/etiología , Distrofina/genética , Distrofina/metabolismo , Canal Liberador de Calcio Receptor de Rianodina/genética , Canal Liberador de Calcio Receptor de Rianodina/metabolismo , Ratones Endogámicos mdx , Calcio/metabolismo , Proteómica , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/patología , FibrosisRESUMEN
Doxorubicin (Dox) is an effective anticancer molecule, but its clinical efficacy is limited by strong cardiotoxic side effects. Lysosomal dysfunction has recently been proposed as a new mechanism of Dox-induced cardiomyopathy. However, to date, there is a paucity of therapeutic approaches capable of restoring lysosomal acidification and function in the heart. Methods: We designed novel poly(lactic-co-glycolic acid) (PLGA)-grafted silica nanoparticles (NPs) and investigated their therapeutic potential in the primary prevention of Dox cardiotoxicity in cardiomyocytes and mice. Results: We showed that NPs-PLGA internalized rapidly in cardiomyocytes and accumulated inside the lysosomes. Mechanistically, NPs-PLGA restored lysosomal acidification in the presence of doxorubicin or bafilomycin A1, thereby improving lysosomal function and autophagic flux. Importantly, NPs-PLGA mitigated Dox-related mitochondrial dysfunction and oxidative stress, two main mechanisms of cardiotoxicity. In vivo, inhalation of NPs-PLGA led to effective and rapid targeting of the myocardium, which prevented Dox-induced adverse remodeling and cardiac dysfunction in mice. Conclusion: Our findings demonstrate a pivotal role for lysosomal dysfunction in Dox-induced cardiomyopathy and highlight for the first time that pulmonary-driven NPs-PLGA administration is a promising strategy against anthracycline cardiotoxicity.
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Cardiomiopatías , Nanopartículas , Ratones , Animales , Cardiotoxicidad/tratamiento farmacológico , Cardiotoxicidad/prevención & control , Doxorrubicina/farmacología , Miocitos Cardíacos/metabolismo , Cardiomiopatías/metabolismo , Estrés Oxidativo , Lisosomas/metabolismoRESUMEN
Gene-transfer methods are useful to study the structural or functional roles of recombinant proteins in vitro. In particular, adenovirus-mediated gene transduction results in strong efficiency and high level of expression in primary cells such as cardiomyocytes, which are difficult to transfect with classical methods. Here, we describe a protocol that enables efficient expression of MAO A in both primary cells and cell lines. Following expression of recombinant MAO A, substrate-induced activation of the enzyme can be assessed by measuring production of reactive oxygen species and downstream signal transduction pathways in cells. This model allows to decipher the biological function of MAO A on metabolism, mitochondrial fitness, cell death/survival, and proliferation.
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Adenoviridae , Estrés Oxidativo , Adenoviridae/genética , Adenoviridae/metabolismo , Monoaminooxidasa/metabolismo , Estrés Oxidativo/fisiología , Especies Reactivas de Oxígeno/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismoRESUMEN
Bladder cancer is the 10th most common cancer in the world and has a high risk of recurrence and metastasis. In order to sustain high energetic needs, cancer cells undergo complex metabolic adaptations, such as a switch toward aerobic glycolysis, that can be exploited therapeutically. Reactive oxygen species (ROS) act as key regulators of cancer metabolic reprogramming and tumorigenesis, but the sources of ROS remain unidentified. Monoamine oxidases (MAOs) are mitochondrial enzymes that generate H2O2 during the breakdown of catecholamines and serotonin. These enzymes are particularly important in neurological disorders, but recently, a new link between MAOs and cancer has been uncovered, involving their production of ROS. At present, the putative role of MAOs in bladder cancer has never been evaluated. We observed that human urothelial tumor explants and the bladder cancer cell line AY27 expressed both MAO-A and MAO-B isoforms. Selective inhibition of MAO-A or MAO-B limited mitochondrial ROS accumulation, cell cycle progression and proliferation of bladder cancer cells, while only MAO-A inhibition prevented cell motility. To test whether ROS contributed to MAO-induced tumorigenesis, we used a mutated form of MAO-A which was unable to produce H2O2. Adenoviral transduction of the WT MAO-A stimulated the proliferation and migration of AY27 cells while the Lys305Met MAO-A mutant was inactive. This was consistent with the fact that the antioxidant Trolox strongly impaired proliferation and cell cycle progression. Most interestingly, AY27 cells were highly dependent on glucose metabolism to sustain their growth, and MAO inhibitors potently reduced glycolysis and oxidative phosphorylation, due to pyruvate depletion. Accordingly, MAO inhibitors decreased the expression of proteins involved in glucose transport (GLUT1) and transformation (HK2). In conclusion, urothelial cancer cells are characterized by a metabolic shift toward glucose-dependent metabolism, which is important for cell growth and is under the regulation of MAO-dependent oxidative stress.
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Carcinoma , Neoplasias de la Vejiga Urinaria , Antioxidantes/metabolismo , Carcinogénesis/metabolismo , Carcinoma/metabolismo , Catecolaminas/metabolismo , Proliferación Celular , Glucosa/metabolismo , Transportador de Glucosa de Tipo 1/metabolismo , Humanos , Peróxido de Hidrógeno/metabolismo , Peróxido de Hidrógeno/farmacología , Monoaminooxidasa/genética , Monoaminooxidasa/metabolismo , Inhibidores de la Monoaminooxidasa/metabolismo , Inhibidores de la Monoaminooxidasa/farmacología , Estrés Oxidativo , Piruvatos/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Serotonina/metabolismo , Vejiga Urinaria/metabolismo , Neoplasias de la Vejiga Urinaria/metabolismoRESUMEN
BACKGROUND: Mechanical circulatory supports are used in case of cardiogenic shock (CS) refractory to conventional therapy. Several devices can be employed, but are limited by their availability, benefit risk-ratio, and/or cost. AIMS: To investigate the feasibility, safety, and effectiveness of a long-term support by a new available device (IVAC2L) in pigs. METHODS: Experiments were carried out in male pigs, divided into healthy (n = 6) or ischemic CS (n = 4) groups for a median support time of 34 and 12 h, respectively. IVAC2L was implanted under fluoroscopic and TTE guidance under general anesthesia. CS was induced by surgical ligation of the left anterior descending artery. An ipsilateral lower limb reperfusion was created with the Solopath® system. Reperfusion was started after 1 h of support in healthy pigs and upon IVAC2L insertion in CS pigs. Hemodynamic and biological parameters were monitored before and during the whole period of support in each group. RESULTS: Occurrence of an ipsilateral lower limb ischemia was systematic in healthy and CS pigs in a few minutes after IVAC2L implantation, and could be reversed by the arterial reperfusion, as demonstrated by distal transcutaneous pressure in oxygen (TcPO2) and lactate normalization. IVAC2L support decreased pulmonary capillary wedge pressure (PCWP) (15.3 ± 0.3 vs. 7.5 ± 0.9 mmHg, p < 0.001), increased systolic blood pressure (SBP) (70 ± 4.5 vs. 101.3 ± 3.1 mmHg, p < 0.01), and cardiac output (CO) (4.0 ± 0.3 vs. 5.2 ± 0.6 l/min, p < 0.05) in CS pigs; at CS onset and after 12 h of support, without effects on heart rate or pulmonary artery pressure (PAP). Non-sustained ventricular arrhythmias were frequent at implantation (50%). A non-significant hemolysis was observed under support in CS pigs. Bleedings were frequent at the insertion and/or operating sites (30%). CONCLUSION: Long-term support by IVAC2L is feasible and associated with a significant hemodynamic improvement in a porcine model. These preclinical data open the door for a study of IVAC2L in human ischemic CS, keeping in mind the need for systematic reperfusion of the lower limb and the associated risk of bleeding.
RESUMEN
Cyclic adenosine monophosphate (cAMP) is a master regulator of mitochondrial metabolism but its precise mechanism of action yet remains unclear. Here, we found that a dietary saturated fatty acid (FA), palmitate increased intracellular cAMP synthesis through the palmitoylation of soluble adenylyl cyclase in cardiomyocytes. cAMP further induced exchange protein directly activated by cyclic AMP 1 (Epac1) activation, which was upregulated in the myocardium of obese patients. Epac1 enhanced the activity of a key enzyme regulating mitochondrial FA uptake, carnitine palmitoyltransferase 1. Consistently, pharmacological or genetic Epac1 inhibition prevented lipid overload, increased FA oxidation (FAO), and protected against mitochondrial dysfunction in cardiomyocytes. In addition, analysis of Epac1 phosphoproteome led us to identify two key mitochondrial enzymes of the the ß-oxidation cycle as targets of Epac1, the long-chain FA acyl-CoA dehydrogenase (ACADL) and the 3-ketoacyl-CoA thiolase (3-KAT). Epac1 formed molecular complexes with the Ca2+/calmodulin-dependent protein kinase II (CaMKII), which phosphorylated ACADL and 3-KAT at specific amino acid residues to decrease lipid oxidation. The Epac1-CaMKII axis also interacted with the α subunit of ATP synthase, thereby further impairing mitochondrial energetics. Altogether, these findings indicate that Epac1 disrupts the balance between mitochondrial FA uptake and oxidation leading to lipid accumulation and mitochondrial dysfunction, and ultimately cardiomyocyte death.
Asunto(s)
AMP Cíclico/metabolismo , Factores de Intercambio de Guanina Nucleótido/metabolismo , Ácido Palmítico/toxicidad , Adenilil Ciclasas/metabolismo , Secuencia de Aminoácidos , Animales , Animales Recién Nacidos , Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina/metabolismo , Catecolaminas/metabolismo , Factores de Intercambio de Guanina Nucleótido/química , Humanos , L-Lactato Deshidrogenasa/metabolismo , Lipoilación/efectos de los fármacos , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Modelos Biológicos , Miocitos Cardíacos/metabolismo , Oxidación-Reducción , Fosfoproteínas/metabolismo , Ratas Sprague-Dawley , Transducción de Señal/efectos de los fármacos , Solubilidad , Estrés Fisiológico/efectos de los fármacosRESUMEN
Accumulation of senescent cells in tissues during normal or accelerated aging has been shown to be detrimental and to favor the outcomes of age-related diseases such as heart failure (HF). We have previously shown that oxidative stress dependent on monoamine oxidase A (MAOA) activity in cardiomyocytes promotes mitochondrial damage, the formation of telomere-associated foci, senescence markers, and triggers systolic cardiac dysfunction in a model of transgenic mice overexpressing MAOA in cardiomyocytes (Tg MAOA). However, the impact of cardiomyocyte oxidative stress on the cardiac microenvironment in vivo is still unclear. Our results showed that systolic cardiac dysfunction in Tg MAOA mice was strongly correlated with oxidative stress induced premature senescence of cardiac stromal cells favoring the recruitment of CCR2+ monocytes and the installation of cardiac inflammation. Understanding the interplay between oxidative stress induced premature senescence and accelerated cardiac dysfunction will help to define new molecular pathways at the crossroad between cardiac dysfunction and accelerated aging, which could contribute to the increased susceptibility of the elderly to HF.
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Envejecimiento/patología , Efecto Espectador , Senescencia Celular , Monoaminooxidasa/fisiología , Miocitos Cardíacos/patología , Estrés Oxidativo , Células del Estroma/patología , Envejecimiento/metabolismo , Animales , Células Cultivadas , Daño del ADN , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Miocitos Cardíacos/metabolismo , Células del Estroma/metabolismoRESUMEN
Population aging is one of the most significant social changes of the twenty-first century. This increase in longevity is associated with a higher prevalence of chronic diseases, further rising healthcare costs. At the molecular level, cellular senescence has been identified as a major process in age-associated diseases, as accumulation of senescent cells with aging leads to progressive organ dysfunction. Of particular importance, mitochondrial oxidative stress and consequent organelle alterations have been pointed out as key players in the aging process, by both inducing and maintaining cellular senescence. Monoamine oxidases (MAOs), a class of enzymes that catalyze the degradation of catecholamines and biogenic amines, have been increasingly recognized as major producers of mitochondrial ROS. Although well-known in the brain, evidence showing that MAOs are also expressed in a variety of peripheral organs stimulated a growing interest in the extra-cerebral roles of these enzymes. Besides, the fact that MAO-A and/or MAO-B are frequently upregulated in aged or dysfunctional organs has uncovered new perspectives on their roles in pathological aging. In this review, we will give an overview of the major results on the regulation and function of MAOs in aging and age-related diseases, paying a special attention to the mechanisms linked to the increased degradation of MAO substrates or related to MAO-dependent ROS formation.
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Monoaminooxidasa , Estrés Oxidativo , Senescencia Celular , Mitocondrias/metabolismo , Monoaminooxidasa/metabolismoRESUMEN
The incidence of disorders associated with low inflammatory state, such as chronic kidney disease, increases in the elderly. The accumulation of senescent cells during aging and the senescence-associated secretory phenotype, which leads to inflammaging, is known to be deleterious and account for progressive organ dysfunction. To date, the cellular actors implicated in chronic inflammation in the kidney during aging are still not well characterized. Using the DECyt method, based on hierarchical clustering of flow cytometry data, we showed that aging was associated with significant changes in stromal cell diversity in the kidney. In particular, we identified two cell populations up-regulated with aging, the mesenchymal stromal cell subset (kMSC) expressing CD73 and the monocyte-derived Ly6C+ CCR2+ macrophage subset expressing pro-inflammatory cytokines. Aged CD73+ kMSCs depicted senescence associated features with low proliferation rate, increased DNA damage foci and Ccl2 expression. Using co-cultures experiments, we showed that aged CD73+ kMSC promoted monocyte activation and secretion of inflammatory cytokines albeit less efficiently than young CD73+ kMSCs. In the context of ageing, increased frequency of CD73+ kMSC subpopulations could provide additional niche factors to newly recruited monocytes favoring a positive regulatory loop in response to local inflammation. Interfering with such partnership during aging could be a valuable approach to regulate kidney inflammaging and to limit the risk of developing chronic kidney disease in the elderly.
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Microambiente Celular/inmunología , Senescencia Celular/inmunología , Inflamación/inmunología , Riñón/inmunología , Macrófagos/inmunología , Monocitos/inmunología , Receptores CCR2/metabolismo , Animales , Receptor 1 de Quimiocinas CX3C/genética , Receptor 1 de Quimiocinas CX3C/metabolismo , Citocinas/metabolismo , Inflamación/metabolismo , Inflamación/patología , Riñón/metabolismo , Riñón/patología , Macrófagos/metabolismo , Macrófagos/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Monocitos/metabolismo , Monocitos/patologíaRESUMEN
Cellular senescence is a state of cell cycle arrest induced by repetitive cell mitoses or different stresses, which is implicated in various physiological or pathological processes. The beneficial or adverse effects of senescent cells depend on their transitory or persistent state. Transient senescence has major beneficial roles promoting successful post-injury repair and inhibiting malignant transformation. On the other hand, persistent accumulation of senescent cells has been associated with chronic diseases and age-related illnesses like renal/urinary tract disorders. The deleterious effects of persistent senescent cells have been related, in part, to their senescence-associated secretory phenotype (SASP) characterized by the release of a variety of factors responsible for chronic inflammation, extracellular matrix adverse remodeling, and fibrosis. Recently, an increase in senescent cell burden has been reported in renal, prostate, and bladder disorders. In this review, we will summarize the molecular mechanisms of senescence and their implication in renal and urinary tract diseases. We will also discuss the differential impacts of transient versus persistent status of cellular senescence, as well as the therapeutic potential of senescent cell targeting in these diseases.
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Senescencia Celular , Enfermedades Renales/patología , Enfermedades Urológicas/patología , Animales , Humanos , Enfermedades Renales/fisiopatología , Enfermedades Renales/terapia , Especificidad de Órganos , Transducción de Señal , Enfermedades Urológicas/fisiopatología , Enfermedades Urológicas/terapiaRESUMEN
A key component of cardiac ischemia-reperfusion injury (IRI) is the increased generation of reactive oxygen species, leading to enhanced inflammation and tissue dysfunction in patients following intervention for myocardial infarction. In this study, we hypothesized that oxidative stress, due to ischemia-reperfusion, induces senescence which contributes to the pathophysiology of cardiac IRI. We demonstrate that IRI induces cellular senescence in both cardiomyocytes and interstitial cell populations and treatment with the senolytic drug navitoclax after ischemia-reperfusion improves left ventricular function, increases myocardial vascularization, and decreases scar size. SWATH-MS-based proteomics revealed that biological processes associated with fibrosis and inflammation that were increased following ischemia-reperfusion were attenuated upon senescent cell clearance. Furthermore, navitoclax treatment reduced the expression of pro-inflammatory, profibrotic, and anti-angiogenic cytokines, including interferon gamma-induced protein-10, TGF-ß3, interleukin-11, interleukin-16, and fractalkine. Our study provides proof-of-concept evidence that cellular senescence contributes to impaired heart function and adverse remodeling following cardiac ischemia-reperfusion. We also establish that post-IRI the SASP plays a considerable role in the inflammatory response. Subsequently, senolytic treatment, at a clinically feasible time-point, attenuates multiple components of this response and improves clinically important parameters. Thus, cellular senescence represents a potential novel therapeutic avenue to improve patient outcomes following cardiac ischemia-reperfusion.
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Senescencia Celular/fisiología , Daño por Reperfusión/metabolismo , Femenino , Humanos , MasculinoRESUMEN
The compartmentation of signaling processes is accomplished by the assembly of protein complexes called signalosomes. These signaling platforms colocalize enzymes, substrates, and anchoring proteins into specific subcellular compartments. Exchange protein directly activated by cAMP 1 (EPAC1) is an effector of the second messenger, 3',5'-cyclic adenosine monophosphate (cAMP) that is associated with multiple roles in several pathologies including cardiac diseases. Both EPAC1 intracellular localization and molecular partners are key players in the regulation of cell fate, which may have important therapeutic potential. In this review, we summarize the recent findings on EPAC1 structure, regulation, and pharmacology. We describe the importance of EPAC1 subcellular distribution in its biological action, paying special attention to its nuclear localization and mechanism of action leading to cardiomyocyte hypertrophy. In addition, we discuss the role of mitochondrial EPAC1 in the regulation of cell death. Depending on the cell type and stress condition, we present evidence that supports either a protective or detrimental role of EPAC1 activation.
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Muerte Celular/efectos de los fármacos , Factores de Intercambio de Guanina Nucleótido/metabolismo , Diferenciación Celular , Humanos , Transducción de SeñalRESUMEN
Cardiac senescence is a typical chronic frailty condition in the elderly population, and cellular aging is often associated with oxidative stress. The mitochondrial-membrane flavoenzyme monoamine oxidase A (MAO A) catalyzes the oxidative deamination of neurotransmitters, and its expression increases in aged hearts. We produced recombinant human MAO A variants at Lys305 that play a key role in O2 reactivity leading to H2O2 production. The K305Q variant is as active as the wild-type enzyme, whereas K305M and K305S have 200-fold and 100-fold lower kcat values and similar Km. Under anaerobic conditions, K305M MAO A was normally reduced by substrate, whereas reoxidation by O2 was much slower but could be accomplished by quinone electron acceptors. When overexpressed in cardiomyoblasts by adenoviral vectors, the K305M variant showed enzymatic turnover similar to that of the wild-type but displayed decreased ROS levels and senescence markers. These results might translate into pharmacological treatments as MAO inhibitors may attenuate cardiomyocytes aging.
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Envejecimiento/metabolismo , Senescencia Celular/fisiología , Peróxido de Hidrógeno/metabolismo , Monoaminooxidasa/metabolismo , Miocardio/metabolismo , Animales , Línea Celular , Humanos , Lisina/genética , Monoaminooxidasa/genética , Mutación , Mioblastos Cardíacos/metabolismo , Ingeniería de Proteínas , RatasRESUMEN
Chronic remodeling postmyocardial infarction consists in various maladaptive changes including interstitial fibrosis, cardiomyocyte death and mitochondrial dysfunction that lead to heart failure (HF). Reactive aldehydes such as 4-hydroxynonenal (4-HNE) are critical mediators of mitochondrial dysfunction but the sources of mitochondrial 4-HNE in cardiac diseases together with its mechanisms of action remain poorly understood. Here, we evaluated whether the mitochondrial enzyme monoamine oxidase-A (MAO-A), which generates H2O2 as a by-product of catecholamine metabolism, is a source of deleterious 4-HNE in HF. We found that MAO-A activation increased mitochondrial ROS and promoted local 4-HNE production inside the mitochondria through cardiolipin peroxidation in primary cardiomyocytes. Deleterious effects of MAO-A/4-HNE on cardiac dysfunction were prevented by activation of mitochondrial aldehyde dehydrogenase 2 (ALDH2), the main enzyme for 4-HNE metabolism. Mechanistically, MAO-A-derived 4-HNE bound to newly identified targets VDAC and MCU to promote ER-mitochondria contact sites and MCU higher-order complex formation. The resulting mitochondrial Ca2+ accumulation participated in mitochondrial respiratory dysfunction and loss of membrane potential, as shown with the protective effects of the MCU inhibitor, RU360. Most interestingly, these findings were recapitulated in a chronic model of ischemic remodeling where pharmacological or genetic inhibition of MAO-A protected the mice from 4-HNE accumulation, MCU oligomer formation and Ca2+ overload, thus mitigating ventricular dysfunction. To our knowledge, these are the first evidences linking MAO-A activation to mitoCa2+ mishandling through local 4-HNE production, contributing to energetic failure and postischemic remodeling.
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Aldehídos/metabolismo , Insuficiencia Cardíaca/metabolismo , Mitocondrias Cardíacas/metabolismo , Monoaminooxidasa/metabolismo , Infarto del Miocardio/metabolismo , Miocitos Cardíacos , Animales , Calcio/metabolismo , Células Cultivadas , Humanos , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/patología , Ratas , Remodelación VentricularRESUMEN
Aging is a major risk factor in the development of chronic diseases, especially cardiovascular diseases. Age-related organ dysfunction is strongly associated with the accumulation of senescent cells. Cardiac mesenchymal stromal cells (cMSCs), deemed part of the microenvironment, modulate cardiac homeostasis through their vascular differentiation potential and paracrine activity. Transcriptomic analysis of cMSCs identified age-dependent biological pathways regulating immune responses and angiogenesis. Aged cMSCs displayed a senescence program characterized by Cdkn2a expression, decreased proliferation and clonogenicity, and acquisition of a senescence-associated secretory phenotype (SASP). Increased CCR2-dependent monocyte recruitment by aged cMSCs was associated with increased IL-1ß production by inflammatory macrophages in the aging heart. In turn, IL-1ß induced senescence in cMSCs and mimicked age-related phenotypic changes such as decreased CD90 expression. The CD90+ and CD90- cMSC subsets had biased vascular differentiation potentials, and CD90+ cMSCs were more prone to acquire markers of the endothelial lineage with aging. These features were related to the emergence of a new cMSC subset in the aging heart, expressing CD31 and endothelial genes. These results demonstrate that cMSC senescence and SASP production are supported by the installation of an inflammatory amplification loop, which could sustain cMSC senescence and interfere with their vascular differentiation potentials.
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Envejecimiento/metabolismo , Senescencia Celular , Células Endoteliales/citología , Células Madre Mesenquimatosas/citología , Miocardio/citología , Antígenos Thy-1/metabolismo , Envejecimiento/genética , Animales , Diferenciación Celular , Células Endoteliales/metabolismo , Humanos , Interferón beta/metabolismo , Interleucina-1beta/biosíntesis , Interleucina-1beta/metabolismo , Células Madre Mesenquimatosas/metabolismo , Ratones , Antígenos Thy-1/genéticaRESUMEN
AIMS: Recent studies reported that cAMP-binding protein Epac1-deficient mice were protected against various forms of cardiac stress, suggesting that pharmacological inhibition of Epac1 could be beneficial for the treatment of cardiac diseases. To test this assumption, we characterized an Epac1-selective inhibitory compound and investigated its potential cardioprotective properties. METHODS AND RESULTS: We used the Epac1-BRET (bioluminescence resonance energy transfer) for searching for non-cyclic nucleotide Epac1 modulators. A thieno[2,3-b]pyridine derivative, designated as AM-001 was identified as a non-competitive inhibitor of Epac1. AM-001 has no antagonist effect on Epac2 or protein kinase A activity. This small molecule prevents the activation of the Epac1 downstream effector Rap1 in cultured cells, in response to the Epac1 preferential agonist, 8-CPT-AM. In addition, we found that AM-001 inhibited Epac1-dependent deleterious effects such as cardiomyocyte hypertrophy and death. Importantly, AM-001-mediated inhibition of Epac1 reduces infarct size after mouse myocardial ischaemia/reperfusion injury. Finally, AM-001 attenuates cardiac hypertrophy, inflammation and fibrosis, and improves cardiac function during chronic ß-adrenergic receptor activation with isoprenaline (ISO) in mice. At the molecular level, ISO increased Epac1-G protein-coupled receptor kinase 5 (GRK5) interaction and induced GRK5 nuclear import and histone deacetylase type 5 (HDAC5) nuclear export to promote the activity of the prohypertrophic transcription factor, myocyte enhancer factor 2 (MEF2). Inversely, AM-001 prevented the non-canonical action of GRK5 on HDAC5 cytoplasmic shuttle to down-regulate MEF2 transcriptional activity. CONCLUSION: Our study represents a 'proof-of-concept' for the therapeutic effectiveness of inhibiting Epac1 activity in cardiac disease using small-molecule pharmacotherapy.
Asunto(s)
Fármacos Cardiovasculares/farmacología , Factores de Intercambio de Guanina Nucleótido/antagonistas & inhibidores , Infarto del Miocardio/prevención & control , Daño por Reperfusión Miocárdica/prevención & control , Miocitos Cardíacos/efectos de los fármacos , Disfunción Ventricular Izquierda/tratamiento farmacológico , Función Ventricular Izquierda/efectos de los fármacos , Remodelación Ventricular/efectos de los fármacos , Animales , Muerte Celular/efectos de los fármacos , Enfermedad Crónica , Modelos Animales de Enfermedad , Fibrosis , Quinasa 5 del Receptor Acoplado a Proteína-G/metabolismo , Factores de Intercambio de Guanina Nucleótido/genética , Factores de Intercambio de Guanina Nucleótido/metabolismo , Células HEK293 , Histona Desacetilasas/metabolismo , Humanos , Factores de Transcripción MEF2/metabolismo , Ratones , Ratones de la Cepa 129 , Ratones Endogámicos C57BL , Ratones Noqueados , Infarto del Miocardio/genética , Infarto del Miocardio/metabolismo , Infarto del Miocardio/fisiopatología , Daño por Reperfusión Miocárdica/genética , Daño por Reperfusión Miocárdica/metabolismo , Daño por Reperfusión Miocárdica/fisiopatología , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/patología , Ratas , Transducción de Señal , Disfunción Ventricular Izquierda/genética , Disfunción Ventricular Izquierda/metabolismo , Disfunción Ventricular Izquierda/fisiopatologíaRESUMEN
Ageing is the biggest risk factor for cardiovascular disease. Cellular senescence, a process driven in part by telomere shortening, has been implicated in age-related tissue dysfunction. Here, we address the question of how senescence is induced in rarely dividing/post-mitotic cardiomyocytes and investigate whether clearance of senescent cells attenuates age-related cardiac dysfunction. During ageing, human and murine cardiomyocytes acquire a senescent-like phenotype characterised by persistent DNA damage at telomere regions that can be driven by mitochondrial dysfunction and crucially can occur independently of cell division and telomere length. Length-independent telomere damage in cardiomyocytes activates the classical senescence-inducing pathways, p21CIP and p16INK4a, and results in a non-canonical senescence-associated secretory phenotype, which is pro-fibrotic and pro-hypertrophic. Pharmacological or genetic clearance of senescent cells in mice alleviates detrimental features of cardiac ageing, including myocardial hypertrophy and fibrosis. Our data describe a mechanism by which senescence can occur and contribute to age-related myocardial dysfunction and in the wider setting to ageing in post-mitotic tissues.