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1.
Int J Mol Sci ; 22(15)2021 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-34360742

RESUMO

Sodium-glucose co-transporter 2 inhibitors (SGLT2i) are emerging as a new treatment strategy for heart failure with reduced ejection fraction (HFrEF) and-depending on the wistfully awaited results of two clinical trials (DELIVER and EMPEROR-Preserved)-may be the first drug class to improve cardiovascular outcomes in patients suffering from heart failure with preserved ejection fraction (HFpEF). Proposed mechanisms of action of this class of drugs are diverse and include metabolic and hemodynamic effects as well as effects on inflammation, neurohumoral activation, and intracellular ion homeostasis. In this review we focus on the growing body of evidence for SGLT2i-mediated effects on cardiac intracellular Na+ as an upstream mechanism. Therefore, we will first give a short overview of physiological cardiomyocyte Na+ handling and its deterioration in heart failure. On this basis we discuss the salutary effects of SGLT2i on Na+ homeostasis by influencing NHE1 activity, late INa as well as CaMKII activity. Finally, we highlight the potential relevance of these effects for systolic and diastolic dysfunction as well as arrhythmogenesis.


Assuntos
Arritmias Cardíacas/tratamento farmacológico , Cardiotônicos/uso terapêutico , Miocárdio/metabolismo , Miócitos Cardíacos/metabolismo , Inibidores do Transportador 2 de Sódio-Glicose/uso terapêutico , Transportador 2 de Glucose-Sódio/metabolismo , Animais , Arritmias Cardíacas/metabolismo , Arritmias Cardíacas/patologia , Humanos , Miocárdio/patologia , Miócitos Cardíacos/patologia
2.
PLoS One ; 16(8): e0255976, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34411149

RESUMO

BACKGROUND: Cardiac injury associated with cytokine release frequently occurs in SARS-CoV-2 mediated coronavirus disease (COVID19) and mortality is particularly high in these patients. The mechanistic role of the COVID19 associated cytokine-storm for the concomitant cardiac dysfunction and associated arrhythmias is unclear. Moreover, the role of anti-inflammatory therapy to mitigate cardiac dysfunction remains elusive. AIMS AND METHODS: We investigated the effects of COVID19-associated inflammatory response on cardiac cellular function as well as its cardiac arrhythmogenic potential in rat and induced pluripotent stem cell derived cardiomyocytes (iPS-CM). In addition, we evaluated the therapeutic potential of the IL-1ß antagonist Canakinumab using state of the art in-vitro confocal and ratiometric high-throughput microscopy. RESULTS: Isolated rat ventricular cardiomyocytes were exposed to control or COVID19 serum from intensive care unit (ICU) patients with severe ARDS and impaired cardiac function (LVEF 41±5%; 1/3 of patients on veno-venous extracorporeal membrane oxygenation; CK 154±43 U/l). Rat cardiomyocytes showed an early increase of myofilament sensitivity, a decrease of Ca2+ transient amplitudes and altered baseline [Ca2+] upon exposure to patient serum. In addition, we used iPS-CM to explore the long-term effect of patient serum on cardiac electrical and mechanical function. In iPS-CM, spontaneous Ca2+ release events were more likely to occur upon incubation with COVID19 serum and nuclear as well as cytosolic Ca2+ release were altered. Co-incubation with Canakinumab had no effect on pro-arrhythmogenic Ca2+ release or Ca2+ signaling during excitation-contraction coupling, nor significantly influenced cellular automaticity. CONCLUSION: Serum derived from COVID19 patients exerts acute cardio-depressant and chronic pro-arrhythmogenic effects in rat and iPS-derived cardiomyocytes. Canakinumab had no beneficial effect on cellular Ca2+ signaling during excitation-contraction coupling. The presented method utilizing iPS-CM and in-vitro Ca2+ imaging might serve as a novel tool for precision medicine. It allows to investigate cytokine related cardiac dysfunction and pharmacological approaches useful therein.


Assuntos
Anticorpos Monoclonais Humanizados/farmacologia , Arritmias Cardíacas , COVID-19 , Sinalização do Cálcio/efeitos dos fármacos , Miócitos Cardíacos , SARS-CoV-2/metabolismo , Adulto , Idoso , Animais , Arritmias Cardíacas/etiologia , Arritmias Cardíacas/metabolismo , Arritmias Cardíacas/patologia , COVID-19/complicações , COVID-19/tratamento farmacológico , COVID-19/metabolismo , COVID-19/patologia , Cálcio/metabolismo , Avaliação Pré-Clínica de Medicamentos , Feminino , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Células-Tronco Pluripotentes Induzidas/patologia , Masculino , Pessoa de Meia-Idade , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Ratos , Ratos Sprague-Dawley , Disfunção Ventricular Esquerda/tratamento farmacológico , Disfunção Ventricular Esquerda/etiologia , Disfunção Ventricular Esquerda/metabolismo , Disfunção Ventricular Esquerda/patologia
3.
Nat Commun ; 12(1): 4722, 2021 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-34354059

RESUMO

Mutations in the LaminA gene are a common cause of monogenic dilated cardiomyopathy. Here we show that mice with a cardiomyocyte-specific Lmna deletion develop cardiac failure and die within 3-4 weeks after inducing the mutation. When the same Lmna mutations are induced in mice genetically deficient in the LINC complex protein SUN1, life is extended to more than one year. Disruption of SUN1's function is also accomplished by transducing and expressing a dominant-negative SUN1 miniprotein in Lmna deficient cardiomyocytes, using the cardiotrophic Adeno Associated Viral Vector 9. The SUN1 miniprotein disrupts binding between the endogenous LINC complex SUN and KASH domains, displacing the cardiomyocyte KASH complexes from the nuclear periphery, resulting in at least a fivefold extension in lifespan. Cardiomyocyte-specific expression of the SUN1 miniprotein prevents cardiomyopathy progression, potentially avoiding the necessity of developing a specific therapeutic tailored to treating each different LMNA cardiomyopathy-inducing mutation of which there are more than 450.


Assuntos
Cardiomiopatia Dilatada/genética , Lamina Tipo A/genética , Lamina Tipo A/metabolismo , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Animais , Cardiomiopatia Dilatada/patologia , Cardiomiopatia Dilatada/fisiopatologia , Dependovirus/genética , Feminino , Humanos , Lamina Tipo A/deficiência , Masculino , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas Associadas aos Microtúbulos/deficiência , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Transdução Genética
4.
Nat Commun ; 12(1): 4808, 2021 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-34376683

RESUMO

Myocardial regeneration is restricted to early postnatal life, when mammalian cardiomyocytes still retain the ability to proliferate. The molecular cues that induce cell cycle arrest of neonatal cardiomyocytes towards terminally differentiated adult heart muscle cells remain obscure. Here we report that the miR-106b~25 cluster is higher expressed in the early postnatal myocardium and decreases in expression towards adulthood, especially under conditions of overload, and orchestrates the transition of cardiomyocyte hyperplasia towards cell cycle arrest and hypertrophy by virtue of its targetome. In line, gene delivery of miR-106b~25 to the mouse heart provokes cardiomyocyte proliferation by targeting a network of negative cell cycle regulators including E2f5, Cdkn1c, Ccne1 and Wee1. Conversely, gene-targeted miR-106b~25 null mice display spontaneous hypertrophic remodeling and exaggerated remodeling to overload by derepression of the prohypertrophic transcription factors Hand2 and Mef2d. Taking advantage of the regulatory function of miR-106b~25 on cardiomyocyte hyperplasia and hypertrophy, viral gene delivery of miR-106b~25 provokes nearly complete regeneration of the adult myocardium after ischemic injury. Our data demonstrate that exploitation of conserved molecular programs can enhance the regenerative capacity of the injured heart.


Assuntos
MicroRNAs/genética , Infarto do Miocárdio/genética , Miócitos Cardíacos/metabolismo , Regeneração/genética , Animais , Animais Recém-Nascidos , Cardiomegalia/genética , Células Cultivadas , Ecocardiografia , Regulação da Expressão Gênica , Humanos , Hiperplasia/genética , Camundongos , Infarto do Miocárdio/patologia , Infarto do Miocárdio/fisiopatologia , Ratos , Reação em Cadeia da Polimerase Via Transcriptase Reversa
5.
Life Sci ; 283: 119866, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34352257

RESUMO

AIMS: Morphine, a commonly used drug for anesthesia, affects lipid metabolism in different tissues, but the mechanism is currently unclear. Adipose triglyceride lipase (ATGL) is the rate-limiting enzyme responsible for the first step of triglyceride (TG) hydrolysis. Here we aim to investigate whether ATGL phosphorylation is involved in morphine-induced TG accumulation. MAIN METHODS: Oil red O staining and TG content analysis were used to detect the effect of morphine on lipid storage. A series of ATGL phosphoamino acid site mutant plasmids were constructed by gene synthesis and transfected to HL-1 cells to evaluate the phosphorylation levels of ATGL phosphoamino acid in morphine-treated HL-1 cells with immunoprecipitation and immunoblotting assay. KEY FINDINGS: Morphine acute treatment induced excessive accumulation of TG and decreased the phosphorylation level of ATGL Ser406 in HL-1 cells. Of note, the phosphorylation positive mutation of ATGL Ser406 to aspartic acid effectively reversed morphine-induced excessive accumulation of TG in HL-1 cells. SIGNIFICANCE: This discovery will help to fully understand the lipid regulation function of morphine in a new scope. In addition, it will expand the phosphorylation research of ATGL more comprehensively and provide powerful clues for lipid metabolism regulation.


Assuntos
Lipase/metabolismo , Morfina/farmacologia , Miocárdio/metabolismo , Miócitos Cardíacos/metabolismo , Triglicerídeos/biossíntese , Animais , Linhagem Celular , Masculino , Camundongos , Morfina/farmacocinética , Miocárdio/patologia , Miócitos Cardíacos/patologia , Fosforilação/efeitos dos fármacos
6.
Int J Mol Sci ; 22(15)2021 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-34360813

RESUMO

Proper cardiac function depends on the coordinated expression of multiple gene networks related to fuel utilization and mitochondrial ATP production, heart contraction, and ion transport. Key transcriptional regulators that regulate these gene networks have been identified. Among them, estrogen-related receptors (ERRs) have emerged as crucial modulators of cardiac function by regulating cellular metabolism and contraction machinery. Consistent with this role, lack of ERRα or ERRγ results in cardiac derangements that lead to functional maladaptation in response to increased workload. Interestingly, metabolic inflexibility associated with diabetic cardiomyopathy has been recently associated with increased mitochondrial fatty acid oxidation and expression of ERRγ, suggesting that sustained expression of this nuclear receptor could result in a cardiac pathogenic outcome. Here, we describe the generation of mice with cardiac-specific overexpression of ERRγ, which die at young ages due to heart failure. ERRγ transgenic mice show signs of dilated cardiomyopathy associated with cardiomyocyte hypertrophy, increased cell death, and fibrosis. Our results suggest that ERRγ could play a role in mediating cardiac pathogenic responses.


Assuntos
Cardiomiopatia Dilatada/metabolismo , Miocárdio/metabolismo , Miócitos Cardíacos/metabolismo , Receptores de Estrogênio/fisiologia , Animais , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Miocárdio/patologia , Miócitos Cardíacos/patologia
7.
Life Sci ; 283: 119857, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34339715

RESUMO

AIM: Diabetic cardiomyopathy (DCM) accomodates a spectrum of cardiac abnormalities. This study aims to investigate whether DCM is associated with changes in cyclic adenosine 3'-5' monophosphate (cAMP) signaling, particularly cyclic nucleotide phosphodiesterases (PDEs). MAIN METHODS: Type 1 diabetes (T1D) was induced in rats by streptozotocin (STZ, 65 mg/kg) injection. Myocardial remodeling, structure and function were evaluated by histology and echocardiography, respectively. We delineated the sequential changes affecting cAMP signaling and characterized the expression pattern of the predominant cardiac PDE isoforms (PDE 1-5) and ß-adrenergic (ß-AR) receptors at 4, 8 and 12 weeks following diabetes induction, by real-time quantitative PCR and Western blot. cAMP levels were measured by immunoassays. KEY FINDINGS: T1D-induced DCM was associated with cardiac remodeling, steatosis and fibrosis. Upregulation of ß1-AR receptor transcripts was noted in diabetic hearts at 4 weeks along with an increase in cAMP levels and an upregulation in the ejection fraction and fraction shortening. However, ß2-AR receptors expression remained unchanged regardless of the disease stage. Moreover, we noted an early and specific upregulation of cardiac PDE1A, PDE2A, PDE4B, PDE4D and PDE5A expression at week 4, followed by increases in PDE3A levels in diabetic hearts at week 8. However, DCM was not associated with changes in PDE4A gene expression irrespective of the disease stage. SIGNIFICANCE: We show for the first time differential and time-specific regulations in cardiac PDEs, data that may prove useful in proposing new therapeutic approaches in T1D-induced DCM.


Assuntos
3',5'-AMP Cíclico Fosfodiesterases/metabolismo , Cardiomiopatias Diabéticas/fisiopatologia , Diester Fosfórico Hidrolases/metabolismo , Animais , AMP Cíclico/metabolismo , Diabetes Mellitus Experimental/fisiopatologia , Cardiomiopatias Diabéticas/metabolismo , Masculino , Miocárdio/metabolismo , Miócitos Cardíacos/metabolismo , Diester Fosfórico Hidrolases/fisiologia , Ratos , Ratos Wistar , Receptores Adrenérgicos beta/metabolismo , Transdução de Sinais , Estreptozocina/farmacologia
8.
Theranostics ; 11(16): 7879-7895, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34335970

RESUMO

Rationale: Previous studies have shown that human embryonic stem cell-derived cardiomyocytes improved myocardial recovery when administered to infarcted pig and non-human primate hearts. However, the engraftment of intramyocardially delivered cells is poor and the effectiveness of clinically relevant doses of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) in large animal models of myocardial injury remains unknown. Here, we determined whether thymosin ß4 (Tb4) could improve the engraftment and reparative potency of transplanted hiPSC-CMs in a porcine model of myocardial infarction (MI). Methods: Tb4 was delivered from injected gelatin microspheres, which extended the duration of Tb4 administration for up to two weeks in vitro. After MI induction, pigs were randomly distributed into 4 treatment groups: the MI Group was injected with basal medium; the Tb4 Group received gelatin microspheres carrying Tb4; the CM Group was treated with 1.2 × 108 hiPSC-CMs; and the Tb4+CM Group received both the Tb4 microspheres and hiPSC-CMs. Myocardial recovery was assessed by cardiac magnetic resonance imaging (MRI), arrhythmogenesis was monitored with implanted loop recorders, and tumorigenesis was evaluated via whole-body MRI. Results: In vitro, 600 ng/mL of Tb4 protected cultured hiPSC-CMs from hypoxic damage by upregulating AKT activity and BcL-XL and promoted hiPSC-CM and hiPSC-EC proliferation. In infarcted pig hearts, hiPSC-CM transplantation alone had a minimal effect on myocardial recovery, but co-treatment with Tb4 significantly enhanced hiPSC-CM engraftment, induced vasculogenesis and the proliferation of cardiomyocytes and endothelial cells, improved left ventricular systolic function, and reduced infarct size. hiPSC-CM implantation did not increase incidence of ventricular arrhythmia and did not induce tumorigenesis in the immunosuppressed pigs. Conclusions: Co-treatment with Tb4-microspheres and hiPSC-CMs was safe and enhanced the reparative potency of hiPSC-CMs for myocardial repair in a large-animal model of MI.


Assuntos
Infarto do Miocárdio/terapia , Miócitos Cardíacos/metabolismo , Timosina/farmacologia , Animais , Diferenciação Celular , Proliferação de Células , Células Cultivadas , China , Modelos Animais de Doenças , Células Endoteliais/patologia , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Infarto do Miocárdio/metabolismo , Miocárdio/patologia , Regeneração , Transplante de Células-Tronco/métodos , Suínos , Timosina/metabolismo , Timosina/fisiologia
9.
Oxid Med Cell Longev ; 2021: 1058872, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34457109

RESUMO

Reperfusion therapy is the most effective treatment for acute myocardial infarction, but it can damage cardiomyocytes through a mechanism known as myocardial ischemia/reperfusion injury (MIRI). In this study, we investigated whether the large tumor suppressor kinase 2 (LATS2) contributes to the development of myocardial MIRI by disrupting mitochondrial biogenesis. Our in vitro data demonstrate that cardiomyocyte viability was reduced and apoptosis was increased in response to hypoxia/reoxygenation (H/R) injury. However, suppression of LATS2 by shRNA sustained cardiomyocyte viability by maintaining mitochondrial function. Compared to H/R-treated control cardiomyocytes, cardiomyocytes transfected with LATS2 shRNA exhibited increased mitochondrial respiration, improved mitochondrial ATP generation, and more stable mitochondrial membrane potential. LATS2 suppression increased cardiomyocyte viability and mitochondrial biogenesis in a manner dependent on PGC1α, a key regulator of mitochondrial metabolism. These results identify LATS2 as a new inducer of mitochondrial damage and myocardial MIRI and suggest that approaches targeting LATS2 or mitochondrial biogenesis may be beneficial in the clinical management of cardiac MIRI.


Assuntos
Potencial da Membrana Mitocondrial , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Miócitos Cardíacos/citologia , Biogênese de Organelas , Proteínas Serina-Treonina Quinases/deficiência , Animais , Células Cultivadas , Traumatismo por Reperfusão Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/patologia , Miócitos Cardíacos/metabolismo , Ratos
10.
Oxid Med Cell Longev ; 2021: 2989974, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34457111

RESUMO

In the present study, we used lipopolysaccharide- (LPS-) stimulated H9C2 cardiomyocytes to investigate whether irisin treatment attenuates septic cardiomyopathy via Fundc1-related mitophagy. Fundc1 levels and mitophagy were significantly reduced in LPS-stimulated H9C2 cardiomyocytes but were significantly increased by irisin treatment. Irisin significantly increased ATP production and the activities of mitochondrial complexes I and III in the LPS-stimulated cardiomyocytes. Irisin also improved glucose metabolism and significantly reduced LPS-induced levels of reactive oxygen species by increasing the activities of antioxidant enzymes, glutathione peroxidase (GPX), and superoxide dismutase (SOD), as well as levels of reduced glutathione (GSH). TUNEL assays showed that irisin significantly reduced LPS-stimulated cardiomyocyte apoptosis by suppressing the activation of caspase-3 and caspase-9. However, the beneficial effects of irisin on oxidative stress, mitochondrial metabolism, and viability of LPS-stimulated H9C2 cardiomyocytes were abolished by silencing Fundc1. These results demonstrate that irisin abrogates mitochondrial dysfunction, oxidative stress, and apoptosis through Fundc1-related mitophagy in LPS-stimulated H9C2 cardiomyocytes. This suggests irisin is a potentially useful treatment for septic cardiomyopathy, though further investigations are necessary to confirm our findings.


Assuntos
Apoptose , Cardiomiopatias/patologia , Fibronectinas/metabolismo , Proteínas de Membrana/metabolismo , Mitocôndrias/patologia , Proteínas Mitocondriais/metabolismo , Miócitos Cardíacos/patologia , Estresse Oxidativo , Sepse/patologia , Animais , Cardiomiopatias/etiologia , Cardiomiopatias/metabolismo , Células Cultivadas , Fibronectinas/genética , Proteínas de Membrana/genética , Mitocôndrias/metabolismo , Proteínas Mitocondriais/genética , Mitofagia , Miócitos Cardíacos/metabolismo , Ratos , Sepse/etiologia , Sepse/metabolismo
11.
Int J Mol Sci ; 22(15)2021 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-34360639

RESUMO

LMNA-related dilated cardiomyopathy is an inherited heart disease caused by mutations in the LMNA gene encoding for lamin A/C. The disease is characterized by left ventricular enlargement and impaired systolic function associated with conduction defects and ventricular arrhythmias. We hypothesized that LMNA-mutated patients' induced Pluripotent Stem Cell-derived cardiomyocytes (iPSC-CMs) display electrophysiological abnormalities, thus constituting a suitable tool for deciphering the arrhythmogenic mechanisms of the disease, and possibly for developing novel therapeutic modalities. iPSC-CMs were generated from two related patients (father and son) carrying the same E342K mutation in the LMNA gene. Compared to control iPSC-CMs, LMNA-mutated iPSC-CMs exhibited the following electrophysiological abnormalities: (1) decreased spontaneous action potential beat rate and decreased pacemaker current (If) density; (2) prolonged action potential duration and increased L-type Ca2+ current (ICa,L) density; (3) delayed afterdepolarizations (DADs), arrhythmias and increased beat rate variability; (4) DADs, arrhythmias and cessation of spontaneous firing in response to ß-adrenergic stimulation and rapid pacing. Additionally, compared to healthy control, LMNA-mutated iPSC-CMs displayed nuclear morphological irregularities and gene expression alterations. Notably, KB-R7943, a selective inhibitor of the reverse-mode of the Na+/Ca2+ exchanger, blocked the DADs in LMNA-mutated iPSC-CMs. Our findings demonstrate cellular electrophysiological mechanisms underlying the arrhythmias in LMNA-related dilated cardiomyopathy.


Assuntos
Arritmias Cardíacas/patologia , Cálcio/metabolismo , Cardiomiopatia Dilatada/patologia , Células-Tronco Pluripotentes Induzidas/patologia , Lamina Tipo A/genética , Mutação , Miócitos Cardíacos/patologia , Potenciais de Ação , Adulto , Arritmias Cardíacas/genética , Arritmias Cardíacas/metabolismo , Cardiomiopatia Dilatada/genética , Cardiomiopatia Dilatada/metabolismo , Diferenciação Celular , Fenômenos Eletrofisiológicos , Feminino , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Masculino , Pessoa de Meia-Idade , Miócitos Cardíacos/metabolismo , Linhagem
12.
Theranostics ; 11(16): 7995-8007, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34335976

RESUMO

Rationale: The conserved long non-coding RNA (lncRNA) myocardial infarction associate transcript (Miat) was identified for its multiple single-nucleotide polymorphisms that are strongly associated with susceptibility to MI, but its role in cardiovascular biology remains elusive. Here we investigated whether Miat regulates cardiac response to pathological hypertrophic stimuli. Methods: Both an angiotensin II (Ang II) infusion model and a transverse aortic constriction (TAC) model were used in adult WT and Miat-null knockout (Miat-KO) mice to induce pathological cardiac hypertrophy. Heart structure and function were evaluated by echocardiography and histological assessments. Gene expression in the heart was evaluated by RNA sequencing (RNA-seq), quantitative real-time RT-PCR (qRT-PCR), and Western blotting. Primary WT and Miat-KO mouse cardiomyocytes were isolated and used in Ca2+ transient and contractility measurements. Results: Continuous Ang II infusion for 4 weeks induced concentric hypertrophy in WT mice, but to a lesser extent in Miat-KO mice. Surgical TAC for 6 weeks resulted in decreased systolic function and heart failure in WT mice but not in Miat-KO mice. In both models, Miat-KO mice displayed reduced heart-weight to tibia-length ratio, cardiomyocyte cross-sectional area, cardiomyocyte apoptosis, and cardiac interstitial fibrosis and a better-preserved capillary density, as compared to WT mice. In addition, Ang II treatment led to significantly reduced mRNA and protein expression of the Ca2+ cycling genes Sarcoplasmic/endoplasmic reticulum Ca2+ ATPase 2a (SERCA2a) and ryanodine receptor 2 (RyR2) and a dramatic increase in global RNA splicing events in the left ventricle (LV) of WT mice, and these changes were largely blunted in Miat-KO mice. Consistently, cardiomyocytes isolated from Miat-KO mice demonstrated more efficient Ca2+ cycling and greater contractility. Conclusions: Ablation of Miat attenuates pathological hypertrophy and heart failure, in part, by enhancing cardiomyocyte contractility.


Assuntos
Insuficiência Cardíaca/genética , Miócitos Cardíacos/metabolismo , RNA Longo não Codificante/genética , Angiotensina II/farmacologia , Animais , Apoptose , Cardiomegalia/genética , Modelos Animais de Doenças , Ecocardiografia , Fibrose , Masculino , Camundongos , Camundongos Knockout , Infarto do Miocárdio/patologia , RNA Longo não Codificante/metabolismo
13.
Int Rev Cell Mol Biol ; 363: 203-269, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34392930

RESUMO

An increase in intracellular Ca2+ concentration ([Ca2+]i) regulates a plethora of functions in the cardiovascular (CV) system, including contraction in cardiomyocytes and vascular smooth muscle cells (VSMCs), and angiogenesis in vascular endothelial cells and endothelial colony forming cells. The sarco/endoplasmic reticulum (SR/ER) represents the largest endogenous Ca2+ store, which releases Ca2+ through ryanodine receptors (RyRs) and/or inositol-1,4,5-trisphosphate receptors (InsP3Rs) upon extracellular stimulation. The acidic vesicles of the endolysosomal (EL) compartment represent an additional endogenous Ca2+ store, which is targeted by several second messengers, including nicotinic acid adenine dinucleotide phosphate (NAADP) and phosphatidylinositol 3,5-bisphosphate [PI(3,5)P2], and may release intraluminal Ca2+ through multiple Ca2+ permeable channels, including two-pore channels 1 and 2 (TPC1-2) and Transient Receptor Potential Mucolipin 1 (TRPML1). Herein, we discuss the emerging, pathophysiological role of EL Ca2+ signaling in the CV system. We describe the role of cardiac TPCs in ß-adrenoceptor stimulation, arrhythmia, hypertrophy, and ischemia-reperfusion injury. We then illustrate the role of EL Ca2+ signaling in VSMCs, where TPCs promote vasoconstriction and contribute to pulmonary artery hypertension and atherosclerosis, whereas TRPML1 sustains vasodilation and is also involved in atherosclerosis. Subsequently, we describe the mechanisms whereby endothelial TPCs promote vasodilation, contribute to neurovascular coupling in the brain and stimulate angiogenesis and vasculogenesis. Finally, we discuss about the possibility to target TPCs, which are likely to mediate CV cell infection by the Severe Acute Respiratory Disease-Coronavirus-2, with Food and Drug Administration-approved drugs to alleviate the detrimental effects of Coronavirus Disease-19 on the CV system.


Assuntos
COVID-19/complicações , COVID-19/tratamento farmacológico , Sinalização do Cálcio/fisiologia , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/metabolismo , Sistema Cardiovascular/metabolismo , Lisossomos/metabolismo , SARS-CoV-2 , ADP-Ribosil Ciclase 1/metabolismo , Animais , Encéfalo/irrigação sanguínea , Encéfalo/metabolismo , COVID-19/metabolismo , Canais de Cálcio/metabolismo , Doenças Cardiovasculares/tratamento farmacológico , Retículo Endoplasmático/metabolismo , Células Endoteliais/metabolismo , Humanos , Modelos Cardiovasculares , Miócitos Cardíacos/metabolismo , NADP/análogos & derivados , NADP/metabolismo , Receptores Adrenérgicos beta/metabolismo , Retículo Sarcoplasmático/metabolismo , Canais de Potencial de Receptor Transitório/metabolismo
14.
Nat Commun ; 12(1): 4442, 2021 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-34290256

RESUMO

The forward genetic screen is a powerful, unbiased method to gain insights into biological processes, yet this approach has infrequently been used in vivo in mammals because of high resource demands. Here, we use in vivo somatic Cas9 mutagenesis to perform an in vivo forward genetic screen in mice to identify regulators of cardiomyocyte (CM) maturation, the coordinated changes in phenotype and gene expression that occur in neonatal CMs. We discover and validate a number of transcriptional regulators of this process. Among these are RNF20 and RNF40, which form a complex that monoubiquitinates H2B on lysine 120. Mechanistic studies indicate that this epigenetic mark controls dynamic changes in gene expression required for CM maturation. These insights into CM maturation will inform efforts in cardiac regenerative medicine. More broadly, our approach will enable unbiased forward genetics across mammalian organ systems.


Assuntos
Epigênese Genética , Miócitos Cardíacos/fisiologia , Ubiquitina-Proteína Ligases/metabolismo , Animais , Animais Recém-Nascidos , Sistemas CRISPR-Cas , Regulação da Expressão Gênica no Desenvolvimento , Histonas/metabolismo , Camundongos , Mutagênese , Miócitos Cardíacos/metabolismo , Fenótipo , Reprodutibilidade dos Testes , Ubiquitina-Proteína Ligases/genética , Ubiquitinação
15.
Int J Mol Sci ; 22(12)2021 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-34205318

RESUMO

Low-density lipoprotein receptor-related protein 5 (LRP5) has been studied as a co-receptor for Wnt/ß-catenin signaling. However, its role in the ischemic myocardium is largely unknown. Here, we show that LRP5 may act as a negative regulator of ischemic heart injury via its interaction with prolyl hydroxylase 2 (PHD2), resulting in hypoxia-inducible factor-1α (HIF-1α) degradation. Overexpression of LRP5 in cardiomyocytes promoted hypoxia-induced apoptotic cell death, whereas LRP5-silenced cardiomyocytes were protected from hypoxic insult. Gene expression analysis (mRNA-seq) demonstrated that overexpression of LRP5 limited the expression of HIF-1α target genes. LRP5 promoted HIF-1α degradation, as evidenced by the increased hydroxylation and shorter stability of HIF-1α under hypoxic conditions through the interaction between LRP5 and PHD2. Moreover, the specific phosphorylation of LRP5 at T1492 and S1503 is responsible for enhancing the hydroxylation activity of PHD2, resulting in HIF-1α degradation, which is independent of Wnt/ß-catenin signaling. Importantly, direct myocardial delivery of adenoviral constructs, silencing LRP5 in vivo, significantly improved cardiac function in infarcted rat hearts, suggesting the potential value of LRP5 as a new target for ischemic injury treatment.


Assuntos
Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Prolina Dioxigenases do Fator Induzível por Hipóxia/metabolismo , Proteína-5 Relacionada a Receptor de Lipoproteína de Baixa Densidade/metabolismo , Isquemia Miocárdica/metabolismo , Miócitos Cardíacos/metabolismo , Animais , Animais Recém-Nascidos , Regulação da Expressão Gênica , Hidroxilação , Hipóxia/metabolismo , Proteína-6 Relacionada a Receptor de Lipoproteína de Baixa Densidade/metabolismo , Cultura Primária de Células , Ratos , Via de Sinalização Wnt
16.
Mol Cell Biol ; 41(9): e0058020, 2021 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-34228494

RESUMO

Cardiac fibrosis is a hallmark of various heart diseases and ultimately leads to heart failure. Although long noncoding RNA (lncRNA) SNHG20 has been reported to play important roles in various cancers, its function in cardiac fibrosis remains unclear. The expression of SNHG20 and microRNA 335 (miR-335) in heart tissues of angiotensin II-induced mice and angiotensin II-stimulated mouse cardiomyocyte cell line HL-1 were detected by quantitative real-time PCR (qRT-PCR). Cell viability was evaluated by cell counting kit-8 assay. The expression of galectin-3, fibrosis-related proteins (fibronectin, collagen IaI, and α-SMA), and apoptosis-related proteins [cleaved caspase-3 and cleaved poly(ADP-ribose) polymerase (PARP)] was detected by Western blotting. Bioinformatics prediction, luciferase reporter assay, and RNA pulldown assay were performed to determine the relationship between SNHG20 and miR-335 as well as miR-335 and Galectin-3. Gain- and loss-function assays were performed to determine the role of SNHG20/miR-335/Galectin-3 in cardiac fibrosis. SNHG20 was significantly upregulated and miR-335 was downregulated in heart tissues of angiotensin II-treated mice and angiotensin II-stimulated HL-1 cells. Downregulation of SNHG20 effectively enhanced cell viability and decreased cell size of HL-1 cells and the expression levels of fibrosis-related proteins (fibronectin, collagen IaI, and α-SMA) and apoptosis-related proteins (cleaved caspase-3 and cleaved PARP), which were induced by angiotensin II treatment. Furthermore, SNHG20 elevated the expression levels of Galectin-3 by directly regulating miR-335. Our study revealed that downregulation of SNHG20 improved angiotensin II-induced cardiac fibrosis by targeting the miR-335/Galectin-3 axis, suggesting that SNHG20 is a therapeutic target for cardiac fibrosis and hypertrophy.


Assuntos
Cardiomegalia/genética , Galectina 3/genética , Regulação da Expressão Gênica , MicroRNAs/genética , Miocárdio/patologia , RNA Longo não Codificante/metabolismo , Angiotensina II , Animais , Sequência de Bases , Cardiotônicos/metabolismo , Linhagem Celular , Regulação para Baixo/genética , Fibrose , Galectina 3/metabolismo , Camundongos Endogâmicos C57BL , MicroRNAs/metabolismo , Miócitos Cardíacos/metabolismo , RNA Longo não Codificante/genética , Regulação para Cima/genética
17.
Arterioscler Thromb Vasc Biol ; 41(9): 2454-2468, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34261327

RESUMO

Objective: Extracellular vesicles (EVs) facilitate molecular transport across extracellular space, allowing local and systemic signaling during homeostasis and in disease. Extensive studies have described functional roles for EV populations, including during cardiovascular disease, but the in vivo characterization of endogenously produced EVs is still in its infancy. Because of their genetic tractability and live imaging amenability, zebrafish represent an ideal but under-used model to investigate endogenous EVs. We aimed to establish a transgenic zebrafish model to allow the in vivo identification, tracking, and extraction of endogenous EVs produced by different cell types. Approach and Results: Using a membrane-tethered fluorophore reporter system, we show that EVs can be fluorescently labeled in larval and adult zebrafish and demonstrate that multiple cell types including endothelial cells and cardiomyocytes actively produce EVs in vivo. Cell-type specific EVs can be tracked by high spatiotemporal resolution light-sheet live imaging and modified flow cytometry methods allow these EVs to be further evaluated. Additionally, cryo electron microscopy reveals the full morphological diversity of larval and adult EVs. Importantly, we demonstrate the utility of this model by showing that different cell types exchange EVs in the adult heart and that ischemic injury models dynamically alter EV production. Conclusions: We describe a powerful in vivo zebrafish model for the investigation of endogenous EVs in all aspects of cardiovascular biology and pathology. A cell membrane fluorophore labeling approach allows cell-type specific tracing of EV origin without bias toward the expression of individual protein markers and will allow detailed future examination of their function.


Assuntos
Sistema Cardiovascular/metabolismo , Vesículas Extracelulares/metabolismo , Proteínas de Peixe-Zebra/metabolismo , Peixe-Zebra/metabolismo , Animais , Animais Geneticamente Modificados , Sistema Cardiovascular/embriologia , Separação Celular , Microscopia Crioeletrônica , Modelos Animais de Doenças , Células Endoteliais/metabolismo , Células Endoteliais/ultraestrutura , Vesículas Extracelulares/genética , Vesículas Extracelulares/ultraestrutura , Citometria de Fluxo , Regulação da Expressão Gênica no Desenvolvimento , Larva/metabolismo , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Infarto do Miocárdio/genética , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/patologia , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/ultraestrutura , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Fatores de Tempo , Peixe-Zebra/embriologia , Peixe-Zebra/genética , Proteínas de Peixe-Zebra/genética
18.
Biophys J ; 120(16): 3261-3271, 2021 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-34297964

RESUMO

Mitochondria exhibit unstable inner membrane potentials (ΔΨm) when subjected to stress, such as during ischemia/reperfusion (I/R). Understanding the mechanism of ΔΨm instability involves characterizing and quantifying this phenomenon in an unbiased and reproducible manner. Here, we describe a simple analytical workflow called "MitoWave" that combines wavelet transform methods and image segmentation to unravel dynamic ΔΨm changes in the cardiac mitochondrial network during I/R. In vitro ischemia was affected by placing a glass coverslip on a monolayer of neonatal mouse ventricular myocytes for 1 h and removing the coverslip to allow for reperfusion, revealing complex oscillatory ΔΨm. MitoWave analysis was then used to identify individual mitochondrial clusters within the cells and track their intrinsic oscillation frequencies over the course of reperfusion. Responses segregated into five typical behaviors were quantified by MitoWave that were corroborated by visual inspection of the time series. Statistical analysis of the distribution of oscillating mitochondrial clusters during reperfusion showed significant differences between the five different outcomes. Features such as the time point of ΔΨm depolarization during I/R, area of mitochondrial clusters, and time-resolved frequency components during reperfusion were determined per cell and per mitochondrial cluster. Mitochondria from neonatal mouse ventricular myocytes subjected to I/R oscillate in the frequency range of 8.6-45 mHz, with a mean of 8.73 ± 4.35 mHz. Oscillating clusters had smaller areas ranging from 49.8 ± 1.2 µm2, whereas nonoscillating clusters had larger areas 66 ± 1.5 µm2. A negative correlation between frequency and mitochondrial cluster area was observed. We also observed that late ΔΨm loss during ischemia correlated with early ΔΨm stabilization after oscillation on reperfusion. Thus, MitoWave analysis provides a semiautomated method to quantify complex time-resolved mitochondrial behavior in an easy-to-follow workflow, enabling unbiased, reproducible quantitation of complex nonstationary cellular phenomena.


Assuntos
Isquemia , Miócitos Cardíacos , Animais , Isquemia/metabolismo , Potencial da Membrana Mitocondrial , Camundongos , Mitocôndrias Cardíacas/metabolismo , Miócitos Cardíacos/metabolismo , Reperfusão , Análise Espaço-Temporal
19.
Biomaterials ; 275: 121000, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34218049

RESUMO

Mesenchymal stem cell (MSC)-derived extracellular vesicles (EVs) with anti-apoptotic and anti-inflammatory properties have been intensively studied. However, rapid clearance by the mononuclear phagocyte system remains a huge barrier for the delivery of extracellular vesicle contents into target organs and restricts its wider application, particularly in the heart. CD47 is a transmembrane protein that enables cancer cells to evade clearance by macrophages through CD47- signal regulatory proteinα binding, which initiates a "don't eat me" signal. This study aimed to explore the biodistribution and delivery efficiency of EVs carrying the membrane protein CD47 and specific anti-apoptotic miRNAs. EVs were isolated from MSCs overexpressing CD47 (CD47-EVs) and identified. Fluorescence-labeled EVs were injected through the tail vein and tracked using fluorescence imaging. In silico analysis was performed to determine miRNA profiles in MSCs and in a heart-derived H9c2 cardiomyoblast cell line under hypoxia vs. normoxia conditions. Electro CD47-EV was constructed by encapsulating purified CD47-EV with miR-21a via electroporation. The effect of miR21-EVs on the pro-apoptotic gene encoding phosphatase and tensin homolog (PTEN) was evaluated by dual-luciferase assay, qPCR, and western blotting. Exogenous miR21 distribution, PTEN protein level, blood vessel density, anti-apoptotic effect by TdT-mediated dUTP nick-end labeling staining, and macrophage and leukocyte infiltration in the myocardium were assessed by immunofluorescence staining. Cardiac functional recovery during the early stage and recovery period was evaluated using echocardiography. The results showed that CD47-EVs were still detectable in the plasma 120 min after the tail vein injection, compared to the detection time of less than 30 min observed with the unmodified EVs. More strikingly, CD47-EVs preferentially accumulated in the heart in the ischemia-reperfusion (I/R) + CD47-EV group [heart total fluorescence radiance ( × 105 Photons/sec/cm2/sr) 51.62 ± 11.30 v.s. 10.08 ± 3.15 in the I/R + unmodified EVs group] 8 h post-injection. Exogenous miR-21 is efficiently internalized into cardiomyocytes, inhibits apoptosis, alleviates inflammation, and improves cardiac function. In conclusion, electro CD47-EVs efficiently improve biodistribution in the heart, shedding new light on the application of a two-step EV delivery method (CD47 genetic modification followed by therapeutic content electrotransfection) as a potential therapeutic tool for myocardial I/R injury that may benefit patients in the future.


Assuntos
Vesículas Extracelulares , MicroRNAs , Infarto do Miocárdio , Traumatismo por Reperfusão Miocárdica , Traumatismo por Reperfusão , Antígeno CD47/metabolismo , Vesículas Extracelulares/metabolismo , Humanos , Macrófagos/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Infarto do Miocárdio/metabolismo , Traumatismo por Reperfusão Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/terapia , Miócitos Cardíacos/metabolismo , Traumatismo por Reperfusão/metabolismo , Distribuição Tecidual
20.
Int J Mol Sci ; 22(14)2021 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-34299159

RESUMO

Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are proteins that contain highly conserved functional domains and sequence motifs that are correlated with their unique biophysical activities, to regulate cardiac pacemaker activity and synaptic transmission. These pacemaker proteins have been studied in mammalian species, but little is known now about their heart distribution in lower vertebrates and c-AMP modulation. Here, we characterized the pacemaker system in the heart of the wild Atlantic cod (Gadus morhua), with respect to primary pacemaker molecular markers. Special focus is given to the structural, ultrastructural and molecular characterization of the pacemaker domain, through the expression of HCN channel genes and the immunohistochemistry of HCN isoforms, including the location of intracardiac neurons that are adjacent to the sinoatrial region of the heart. Similarly to zebrafish and mammals, these neurons are immunoreactive to ChAT, VAChT and nNOS. It has been shown that cardiac pacemaking can be modulated by sympathetic and parasympathetic pathways, and the existence of intracardiac neurons projecting back to the central nervous system provide a plausible link between them.


Assuntos
Gadus morhua/metabolismo , Coração/fisiologia , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização/química , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização/metabolismo , Ativação do Canal Iônico , Miócitos Cardíacos/metabolismo , Animais , Proteínas de Peixes/química , Proteínas de Peixes/genética , Proteínas de Peixes/metabolismo , Gadus morhua/genética , Gadus morhua/crescimento & desenvolvimento , Coração/inervação , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização/genética , Miócitos Cardíacos/citologia , Isoformas de Proteínas , Transmissão Sináptica
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