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1.
Clin Sci (Lond) ; 2020 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-33034619

RESUMO

Heart failure (HF) is associated with impaired L-arginine transport. In the present study, we tested the hypothesis that augmented L-arginine transport prevents the loss of kidney function in HF. Renal function was assessed in wild-type mice (WT), transgenic mice with HF (DCM) and double transgenic mice (HFCAT-1) with HF and endothelial specific overexpression of the predominant L-arginine transporter, cationic amino acid transporter-1 (CAT-1) (n=8/group). Cardiac function was assessed via echocardiography and left ventricular catheterization. Renal function was assessed via quantification of albuminuria and creatinine clearance. Plasma nitrate and nitrite levels together with renal fibrosis and inflammatory markers were also quantified at study end. Albumin/creatinine ratio was 2 fold greater in DCM mice than in WT mice (P=0.002), and tubulointerstitial and glomerular fibrosis were  Ì´ 8 and 3 fold greater, respectively, in DCM mice than in WT mice (P ≤ 0.02). Critically, urinary albumin/creatinine ratio and tubulointerstitial and glomerular fibrosis were less in HFCAT-1 mice than in DCM mice (P < 0.05). Renal CAT-1 expression and plasma nitrate and nitrite levels were less in DCM mice compared to WT (P ≤ 0.03) but was greater in HFCAT-1 mice than in DCM mice (P ≤ 0.009). Renal expression of IL-10 was less in DCM mice compared to WT (P < 0.001) but was greater in HFCAT-1 mice compared to DCM mice (P=0.02). Our data provide direct evidence that augmented L-arginine transport prevents renal fibrosis, inflammation and loss of renal function in HF.

2.
BMC Cardiovasc Disord ; 20(1): 409, 2020 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-32912149

RESUMO

BACKGROUND: Cardiac rupture (CR) is a fatal complication of ST-elevation myocardial infarction (STEMI) with its incidence markedly declined in the recent decades. However, clinical features of CR patients now and the effect of reperfusion therapy to CR remain unclear. We investigated the clinical features of CR in STEMI patients and the effect of reperfusion therapy to CR in mice. METHODS: Two studies were conducted. In clinical study, data of 1456 STEMI patients admitted to the First Hospital, Xi'an Jiaotong University during 2015.12. ~ 2018.12. were analyzed. In experimental study, 83 male C57BL/6 mice were operated to induce MI. Of them, 39 mice were permanent MI (group-1), and remaining mice received reperfusion after 1 h ischemia (21 mice, group-2) or 4 h ischemia (23 mice, group-3). All operated mice were monitored up to day-10. Animals were inspected three times daily for the incidence of death and autopsy was done for all mice found died to determine the cause of death. RESULTS: CR was diagnosed in 40 patients: free-wall rupture in 17, ventricular septal rupture in 20, and combined locations in 3 cases. CR presented in 19 patients at admission and diagnosed in another 21 patients during 1 ~ 14 days post-STEMI, giving an in-hospital incidence of 1.4%. The mortality of CR patients was high during hospitalization accounting for 39% of total in-hospital death. By multivariate logistic regression analysis, older age, peak CK-MB and peak hs-CRP were independent predictors of CR post-STEMI. In mice with non-reperfused MI, 17 animals (43.6%) died of CR that occurred during 3-6 days post-MI. In MI mice received early or delayed reperfusion, all mice survived to the end of experiment except one mouse died of acute heart failure. CONCLUSION: CR remains as a major cause of in-hospital death in STEMI patients. CR patients are characterized of being elderly, having larger infarct and more server inflammation. Experimentally, reperfusion post-MI prevented CR.

3.
Med Hypotheses ; 144: 109938, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32570160

RESUMO

Left ventricular thrombus (LVT) after acute myocardial infarction (AMI) remains to be a common complication bearing adverse prognostic implication. Majority of LVT occurs within the first week after AMI. Over decades, the regional stasis of blood flow is regarded as the main reason for LVT formation. Here we hypothesize that LVT developed within the first week after AMI is the consequence of an incomplete wall rupture. Endocardial rupture with exposure of infarcted tissues triggers platelet thrombosis within the rupture site and then the thrombus grows towards the ventricular chamber forming LVT. This hypothesis is implicated by the comparable clinical features of patients with LVT or with cardiac rupture, and supported by experimental findings in murine model of AMI revealing the mechanistic link between rupture and LVT. This hypothesis, if confirmed, would improve our understanding on the pathophysiology of both rupture and LVT as two pivotal mechanical complications after AMI, and the role of platelets in the setting of AMI and hence the use of anti-platelet therapies. Future studies are warranted to test this hypothesis by serial cardiac imaging on AMI patients with high risk of LVT.

4.
Cardiovasc Res ; 2020 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-32531044

RESUMO

AIMS: Despite numerous reports documenting an important role of hypertension in the development of atrial fibrillation (AF), the detailed mechanism underlying the pathological process remains incompletely understood. Here, we aim to test the hypothesis that diastolic sarcoplasmic reticulum (SR) Ca2+ leak in atrial myocytes, induced by mechanical stretch due to elevated pressure in the left atrium (LA), plays an essential role in the AF development in pressure-overloaded hearts. METHODS AND RESULTS: Isolated mouse atrial myocytes subjected to acute axial stretch displayed an immediate elevation of SR Ca2+ leak. Using a mouse model of transverse aortic constriction (TAC), the relation between stretch, SR Ca2+ leak and AF susceptibility was further tested. At 36 hours post TAC, SR Ca2+ leak in cardiomyocytes from the LA (with hemodynamic stress), but not right atrium (without hemodynamic stress), significantly increased, which was further elevated at 4 weeks post TAC. Accordingly, AF susceptibility to atrial burst pacing in the 4-week TAC mice were also significantly increased, which was unaffected by inhibition of atrial fibrosis or inflammation via deletion of galectin-3. Western blotting revealed that type 2 ryanodine receptor (RyR2) in LA myocytes of TAC mice was oxidized due to activation and upregulation of Nox2 and Nox4. Direct rescue of dysfunctional RyR2 with dantrolene or rycal S107 reduced diastolic SR Ca2+ leak in LA myocytes and prevented atrial burst pacing stimulated AF. CONCLUSION: Our study demonstrated for the first time the increased SR Ca2+ leak mediated by enhanced oxidative stress in LA myocytes that is causatively associated with higher AF susceptibility in pressure-overloaded hearts. TRANSLATIONAL PERSPECTIVE: RyR2 is the major Ca2+ channel in cardiac myocytes, strongly affecting cellular activities. Several types of heart diseases, including heart failure and ventricular arrhythmias, are related to RyR2 dysfunction in ventricular myocytes. The present study expands RyR2 dysfunction as a critical contributor in pressure-overload associated AF. As AF is usually accompanied with cardiac remodeling and dysfunction in the setting of hypertension, which is a common risk factor for different cardiovascular diseases, the convergence of several pathological processes on the dysfunctional RyR2 makes it a common therapeutic target in these diseased settings.

5.
J Cell Mol Med ; 24(15): 8505-8517, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32578931

RESUMO

Activation of the sympatho-ß-adrenergic receptors (ß-ARs) system is a hallmark of heart failure, leading to fibrosis and arrhythmias. Connexin 43 (Cx43) is the most abundant gap junctional protein in the myocardium. Current knowledge is limited regarding Cx43 remodelling in diverse cell types in the diseased myocardium and the underlying mechanism. We studied cell type-dependent changes in Cx43 remodelling due to ß-AR overactivation and molecular mechanisms involved. Mouse models of isoproterenol stimulation or transgenic cardiomyocyte overexpression of ß2 -AR were used, which exhibited cardiac fibrosis and up-regulated total Cx43 abundance. In both models, whereas Cx43 expression in cardiomyocytes was reduced and more laterally distributed, fibroblasts exhibited elevated Cx43 expression and enhanced gap junction communication. Mechanistically, activation of ß2 -AR in fibroblasts in vitro elevated Cx43 expression, which was abolished by the ß2 -antagonist ICI-118551 or protein kinase A inhibitor H-89, but simulated by the adenylyl cyclase activator forskolin. Our in vitro and in vivo data showed that ß-AR activation-induced production of IL-18 sequentially stimulated Cx43 expression in fibroblasts in a paracrine fashion. In summary, our findings demonstrate a pivotal role of ß-AR in mediating distinct and cell type-dependent changes in the expression and distribution of Cx43, leading to pathological gap junction remodelling in the myocardium.

6.
Clin Exp Pharmacol Physiol ; 47(7): 1193-1202, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32027390

RESUMO

Direct evidence is limited for the association between heart rate variability (HRV) indices and ventricular tachyarrhythmias (VTAs). While galectin-3 (Gal-3) is regarded as a causal factor for cardiac remodelling and a biomarker for arrhythmias, its regulation on VTAs and HVR is unknown. Using aged transgenic (TG) mice with cardiac overexpression of ß2 -adrenoceptors and spontaneous VTAs, we studied whether changes in HRV indices correlated with the severity of VTAs, and whether Gal-3 gene knockout (KO) in TG mice might limit VTA. Body-surface ECG was recorded (10-minute period) in 9- to 10-month-old mice of non-transgenic (nTG), TG and TG × Gal-3 knockout (TG/KO). Time-domain, frequency-domain and nonlinear-domain HRV indices were calculated using the R-R intervals extracted from ECG signals and compared with frequency of VTAs. TG and TG/KO mice developed frequent VTAs and showed significant changes in certain time-domain and nonlinear-domain HRV indices relative to nTG mice. The severity of VTAs in TG and TG/KO mice in combination, estimated by VTA counts and arrhythmia score, was significantly correlated with certain time-domain and nonlinear-domain HRV indices. In conclusion, significant changes in HRV indices were evident and correlated with the severity of spontaneous VTAs in TG mice. The frequency of VTA and HRV indices were largely comparable between TG and TG/KO mice. Deletion of Gal-3 in TG mice altered certain HRV indices implying influence by neuronally localized Gal-3 on autonomic nervous activity.

7.
Circulation ; 141(17): 1393-1403, 2020 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-32093510

RESUMO

BACKGROUND: High blood pressure (BP) continues to be a major, poorly controlled but modifiable risk factor for cardiovascular death. Among key Western lifestyle factors, a diet poor in fiber is associated with prevalence of high BP. The impact of lack of prebiotic fiber and the associated mechanisms that lead to higher BP are unknown. Here we show that lack of prebiotic dietary fiber leads to the development of a hypertensinogenic gut microbiota, hypertension and its complications, and demonstrate a role for G-protein coupled-receptors (GPCRs) that sense gut metabolites. METHODS: One hundred seventy-nine mice including C57BL/6J, gnotobiotic C57BL/6J, and knockout strains for GPR41, GPR43, GPR109A, and GPR43/109A were included. C57BL/6J mice were implanted with minipumps containing saline or a slow-pressor dose of angiotensin II (0.25 mg·kg-1·d-1). Mice were fed diets lacking prebiotic fiber with or without addition of gut metabolites called short-chain fatty acids ([SCFA)] produced during fermentation of prebiotic fiber in the large intestine), or high prebiotic fiber diets. Cardiac histology and function, BP, sodium and potassium excretion, gut microbiome, flow cytometry, catecholamines and methylation-wide changes were determined. RESULTS: Lack of prebiotic fiber predisposed mice to hypertension in the presence of a mild hypertensive stimulus, with resultant pathological cardiac remodeling. Transfer of a hypertensinogenic microbiota to gnotobiotic mice recapitulated the prebiotic-deprived hypertensive phenotype, including cardiac manifestations. Reintroduction of SCFAs to fiber-depleted mice had protective effects on the development of hypertension, cardiac hypertrophy, and fibrosis. The cardioprotective effect of SCFAs were mediated via the cognate SCFA receptors GPR43/GPR109A, and modulated L-3,4-dihydroxyphenylalanine levels and the abundance of T regulatory cells regulated by DNA methylation. CONCLUSIONS: The detrimental effects of low fiber Westernized diets may underlie hypertension, through deficient SCFA production and GPR43/109A signaling. Maintaining a healthy, SCFA-producing microbiota is important for cardiovascular health.

8.
Hypertension ; 75(2): 393-404, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31838908

RESUMO

Heart failure is associated with sympatho-ßAR (ß-adrenoceptor) activation and cardiac fibrosis. Gal-3 (galectin-3) and KCa3.1 channels that are upregulated in diverse cells of diseased heart are implicated in mediating myocardial inflammation and fibrosis. It remains unclear whether Gal-3 interacts with KCa3.1 leading to cardiac fibrosis in the setting of ßAR activation. We tested the effect of KCa3.1 blocker TRAM-34 on cardiac fibrosis and inflammation in cardiac-restricted ß2-TG (ß2AR overexpressed transgenic) mice and determined KCa3.1 expression in ß2-TG×Gal-3-/- mouse hearts. Mechanisms of KCa3.1 in mediating Gal-3 induced fibroblast activation were studied ex vivo. Expression of Gal-3 and KCa3.1 was elevated in ß2-TG hearts. Gal-3 gene deletion in ß2-TG mice decreased KCa3.1 expression in inflammatory cells but not in fibroblasts. Treatment of ß2-TG mice with TRAM-34 for 1 or 2 months significantly ameliorated cardiac inflammation and fibrosis and reduced Gal-3 level. In cultured fibroblasts, Gal-3 upregulated KCa3.1 expression and channel currents with enhanced membrane potential and Ca2+ entry through TRPV4 (transient receptor potential V4) and TRPC6 (transient receptor potential C6) channels leading to fibroblast activation. In conclusion, ßAR stimulation promotes Gal-3 production that upregulates KCa3.1 channels in noncardiomyocyte cells and activates KCa3.1 channels in fibroblasts leading to hyperpolarization of membrane potential and Ca2+ entry via TRP channels. Gal-3-KCa3.1 signaling mobilizes diverse cells facilitating regional inflammation and fibroblast activation and hence myocardial fibrosis.

9.
FASEB J ; 33(12): 14760-14771, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31690106

RESUMO

Chronic islet inflammation is associated with development of type 2 diabetes mellitus (T2DM). Intermediate-conductance calcium-activated K+ (KCa3.1) channel plays an important role in inflammatory diseases. However, the role and regulation of KCa3.1 in pancreatic ß cells in progression of T2DM remain unclarified. In the present study, we evaluated the effect of the specific KCa3.1 channel blocker 1-[(2-chlorophenyl)diphenylmethyl]-1H-pyrazole (TRAM-34) on diabetic phenotype in the db/db model. In diabetic mice, blockade of KCa3.1 significantly improved glucose tolerance, enhanced secretion of postprandial insulin level, and reduced loss of ß-cell mass through attenuating the expression and secretion of inflammatory mediators. Furthermore, in cultured pancreatic ß cells, exposure to high levels of glucose or palmitic acid significantly increased expression and current density of the KCa3.1 channel as well as secretion of proinflammatory chemokines, and the effects were similarly reversed by preincubation with TRAM-34 or a NF-κB inhibitor pyrrolidinedithiocarbamate. Additionally, expression of KCa3.1 in pancreas islet cells was up-regulated by activation of NF-κB with IL-1ß stimulation. In summary, up-regulated KCa3.1 due to activation of NF-κB pathway leads to pancreatic inflammation via expression and secretion of chemokines and cytokines by pancreatic ß cells, thereby facilitating progression of T2DM.-Pang, Z.-D., Wang, Y., Wang, X.-J., She, G., Ma, X.-Z., Song, Z., Zhao, L.-M., Wang, H.-F., Lai, B.-C., Gou, W., Du, X.-J., Deng, X.-L. KCa3.1 channel mediates inflammatory signaling of pancreatic ß cells and progression of type 2 diabetes mellitus.

10.
Can J Cardiol ; 35(10): 1366-1376, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31495686

RESUMO

BACKGROUND: The purpose of the study was to assess the value of admission macrophage migration inhibitory factor (MIF) levels in predicting clinical outcomes in ST-elevation myocardial infarction (STEMI) patients. METHODS: For this study we recruited 498 STEMI patients after they received percutaneous coronary intervention (PCI), 40 with stable angina pectoris and 137 healthy participants. Plasma MIF levels were measured at admission and after PCI. The primary end points were in-hospital mortality and major adverse cardio-and/or cerebrovascular events (MACCE) during hospitalization and 3.2-year follow-up period. RESULTS: Admission MIF levels were elevated in 88.4% of STEMI patients over the upper reference limit of healthy controls and it was 3- to 7-fold higher than that in stable angina pectoris and control groups (122 ± 61 vs 39 ± 19 vs 17 ± 8 ng/mL; P < 0.001). Admission MIF levels were significantly higher in patients who died after myocardial infarction vs survivors. For predicting in-hospital mortality using the optimal cutoff value (127.8 ng/mL) of MIF, the area under the receiver operating characteristic curve for MIF was 0.820, similar area under the receiver operating characteristic curve values for predicting short-term outcomes were observed for high-sensitivity troponin T, CK-MB, N-terminal probrain natriuretic peptide, and Global Registry of Acute Coronary Events (GRACE) score. Although peak high-sensitivity troponin T and N-terminal probrain natriuretic peptide also predicted MACCE during the follow-up period, only higher admission MIF levels predicted in-hospital mortality and MACCE during the 3.2-year follow-up. Multivariate regression analysis showed the independent predictive value of a higher admission MIF level (≥ 127.8 ng/mL) on in-hospital mortality (odds ratio, 9.1; 95% confidence interval, 1.7-47.2) and 3.2-year MACCE (hazard ratio, 2.8; 95% confidence interval, 1.5-5.6). CONCLUSIONS: A higher admission MIF level is an independent predictor for in-hospital mortality and long-term MACCE in STEMI patients who underwent PCI.


Assuntos
Oxirredutases Intramoleculares/sangue , Fatores Inibidores da Migração de Macrófagos/sangue , Intervenção Coronária Percutânea , Infarto do Miocárdio com Supradesnível do Segmento ST/sangue , Infarto do Miocárdio com Supradesnível do Segmento ST/cirurgia , Idoso , Feminino , Mortalidade Hospitalar , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prognóstico , Estudos Prospectivos , Infarto do Miocárdio com Supradesnível do Segmento ST/mortalidade , Resultado do Tratamento
11.
Exp Cell Res ; 383(2): 111552, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31415760

RESUMO

Elevated plasma free fatty acids level has been implicated in the development of insulin resistance, inflammation, and endothelial dysfunction in diabetic and nondiabetic individuals. However, the underlying mechanisms still remain to be defined. Herein, we investigated the effect of palmitic acid (PA), the most abundant saturated fatty acid in the human body, on small-conductance Ca2+-activated potassium channels (KCa2.3)-mediated relaxation in rodent resistance arteries and the underlying molecular mechanism. The effect of PA on KCa2.3 in endothelium was evaluated using real-time PCR, Western blotting, whole-cell patch voltage-clamp, wire and pressure myograph system, and reactive oxygen species (ROS) were measured by using dihydroethidium and 2', 7'-dichlorofluorescein diacetate. KCa2.3-mediated vasodilatation responses to acetylcholine and NS309 (agonist of KCa2.3 and KCa3.1) were impaired by incubation of normal mesenteric arteries with 100 µM PA for 24 h. In cultured human umbilical vein endothelial cells (HUVECs), PA decreased KCa2.3 current and expression at mRNA and protein levels. Incubation with the NADPH oxidase (Nox) inhibitor dibenziodolium (DPI) partly inhibited the PA-induced ROS production and restored KCa2.3 expression. Inhibition of either p38-MAPK or NF-κB using specific inhibitors (SB203580, SB202190 or Bay11-7082, pyrrolidinedithiocarbamate) attenuated PA-induced downregulation of KCa2.3 and inhibition of p38-MAPK also attenuated PA-induced phosphorylation of NF-κB p65. Furthermore, DPI reversed the increment of phospho-p38-MAPK by PA. These results demonstrated that PA downregulated KCa2.3 expressions via Nox/ROS/p38-MAPK/NF-κB signaling leading to endothelial vasodilatory dysfunction.

12.
iScience ; 17: 288-301, 2019 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-31323475

RESUMO

In the heart, primary microRNA-208b (pri-miR-208b) and Myheart (Mhrt) are long non-coding RNAs (lncRNAs) encoded by the cardiac myosin heavy chain genes. Although preclinical studies have shown that lncRNAs regulate gene expression and are protective for pathological hypertrophy, the mechanism underlying sex-based differences remains poorly understood. In this study, we examined DNA- and RNA-methylation-dependent regulation of pri-miR-208b and Mhrt. Expression of pri-miR-208b is elevated in the left ventricle of the female heart. Despite indistinguishable DNA methylation between sexes, the interaction of MeCP2 on chromatin is subject to RNase digestion, highlighting that affinity of the methyl-CG reader is broader than previously thought. A specialized procedure to isolate RNA from soluble cardiac chromatin emphasizes sex-based affinity of an MeCP2 co-repressor complex with Rest and Hdac2. Sex-specific Mhrt methylation chromatinizes MeCP2 at the pri-miR-208b promoter and extends the functional relevance of default transcriptional suppression in the heart.

13.
Basic Res Cardiol ; 114(4): 30, 2019 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-31218471

RESUMO

Microvascular obstruction (MVO) and leakage (MVL) forms a pivotal part of microvascular damage following cardiac ischemia-reperfusion (IR). We tested the effect of relaxin therapy on MVO and MVL in mice following cardiac IR injury including severity of MVO and MVL, opening capillaries, infarct size, regional inflammation, cardiac function and remodelling, and permeability of cultured endothelial monolayer. Compared to vehicle group, relaxin treatment (50 µg/kg) reduced no-reflow area by 38% and the content of Evans blue as a permeability tracer by 56% in jeopardized myocardium (both P < 0.05), effects associated with increased opening capillaries. Relaxin also decreased leukocyte density, gene expression of cytokines, and mitigated IR-induced decrease in protein content of VE-cadherin and relaxin receptor. Infarct size was comparable between the two groups. At 2 weeks post-IR, relaxin treatment partially preserved cardiac contractile function and limited chamber dilatation versus untreated controls by echocardiography. Endothelial cell permeability assay demonstrated that relaxin attenuated leakage induced by hypoxia-reoxygenation, H2O2, or cytokines, action that was independent of nitric oxide but associated with the preservation of VE-cadherin. In conclusion, relaxin therapy attenuates IR-induced MVO and MVL and endothelial leakage. This protection was associated with reduced regional inflammatory responses and consequently led to alleviated adverse cardiac remodeling.


Assuntos
Anti-Inflamatórios/farmacologia , Vasos Coronários/efeitos dos fármacos , Microvasos/efeitos dos fármacos , Infarto do Miocárdio/tratamento farmacológico , Traumatismo por Reperfusão Miocárdica/tratamento farmacológico , Fragmentos de Peptídeos/farmacologia , Relaxina/farmacologia , Animais , Antígenos CD/metabolismo , Caderinas/metabolismo , Linhagem Celular , Vasos Coronários/metabolismo , Vasos Coronários/patologia , Modelos Animais de Doenças , Fibrose , Mediadores da Inflamação/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Microvasos/metabolismo , Microvasos/patologia , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/patologia , Traumatismo por Reperfusão Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/patologia , Miocárdio/metabolismo , Miocárdio/patologia , Receptores Acoplados a Proteínas-G/metabolismo , Remodelação Ventricular/efeitos dos fármacos
15.
Br J Pharmacol ; 176(14): 2465-2481, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30932177

RESUMO

BACKGROUND AND PURPOSE: Expression of the pro-fibrotic galectin-3 and the pro-apoptotic BIM is elevated in diseased heart or after ß-adrenoceptor stimulation, but the underlying mechanisms are unclear. This question was addressed in the present study. EXPERIMENTAL APPROACH: Wild-type mice and mice with cardiac transgenic expression of ß2 -adrenoceptors, mammalian sterile-20 like kinase 1 (Mst1) or dominant-negative Mst1, and non-specific galectin-3 knockout mice were used. Effects of the ß-adrenoceptor agonist isoprenaline or ß-adrenoceptor antagonists were studied. Rat cardiomyoblasts (H9c2) were used for mechanistic exploration. Biochemical assays were performed. KEY RESULTS: Isoprenaline treatment up-regulated expression of galectin-3 and BIM, and this was inhibited by non-selective or selective ß-adrenoceptor antagonists (by 60-70%). Cardiac expression of galectin-3 and BIM was increased in ß2 -adrenoceptor transgenic mice. Isoprenaline-induced up-regulation of galectin-3 and BIM was attenuated by Mst1 inactivation, but isoprenaline-induced galectin-3 expression was exaggerated by transgenic Mst1 activation. Pharmacological or genetic activation of ß-adrenoceptors induced Mst1 expression and yes-associated protein (YAP) phosphorylation. YAP hyper-phosphorylation was also evident in Mst1 transgenic hearts with up-regulated expression of galectin-3 (40-fold) and BIM as well as up-regulation of many YAP-target genes by RNA sequencing. In H9c2 cells, isoprenaline induced YAP phosphorylation and expression of galectin-3 and BIM, effects simulated by forskolin but abolished by PKA inhibitors, and YAP knockdown induced expression of galectin-3 and BIM. CONCLUSIONS AND IMPLICATIONS: Stimulation of cardiac ß-adrenoceptors activated the Mst1/Hippo pathway leading to YAP hyper-phosphorylation with enhanced expression of galectin-3 and BIM. This signalling pathway would have therapeutic potential. LINKED ARTICLES: This article is part of a themed section on Adrenoceptors-New Roles for Old Players. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.14/issuetoc.

16.
Front Pharmacol ; 10: 269, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31001111

RESUMO

The anti-inflammatory, pro-resolving annexin-A1 protein acts as an endogenous brake against exaggerated cardiac necrosis, inflammation, and fibrosis following myocardial infarction (MI) in vivo. Little is known, however, regarding the cardioprotective actions of the N-terminal-derived peptide of annexin A1, Ac2-26, particularly beyond its anti-necrotic actions in the first few hours after an ischemic insult. In this study, we tested the hypothesis that exogenous Ac2-26 limits cardiac injury in vitro and in vivo. Firstly, we demonstrated that Ac2-26 limits cardiomyocyte death both in vitro and in mice subjected to ischemia-reperfusion (I-R) injury in vivo (Ac2-26, 1 mg/kg, i.v. just prior to post-ischemic reperfusion). Further, Ac2-26 (1 mg/kg i.v.) reduced cardiac inflammation (after 48 h reperfusion), as well as both cardiac fibrosis and apoptosis (after 7-days reperfusion). Lastly, we investigated whether Ac2-26 preserved cardiac function after MI. Ac2-26 (1 mg/kg/day s.c., osmotic pump) delayed early cardiac dysfunction 1 week post MI, but elicited no further improvement 4 weeks after MI. Taken together, our data demonstrate the first evidence that Ac2-26 not only preserves cardiomyocyte survival in vitro, but also offers cardioprotection beyond the first few hours after an ischemic insult in vivo. Annexin-A1 mimetics thus represent a potential new therapy to improve cardiac outcomes after MI.

17.
Eur J Heart Fail ; 21(3): 272-285, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30714667

RESUMO

Fibrosis is a pivotal player in heart failure development and progression. Measurements of (markers of) fibrosis in tissue and blood may help to diagnose and risk stratify patients with heart failure, and its treatment may be effective in preventing heart failure and its progression. A lack of pathophysiological insights and uniform definitions has hampered the research in fibrosis and heart failure. The Translational Research Committee of the Heart Failure Association discussed several aspects of fibrosis in their workshop. Early insidious perturbations such as subclinical hypertension or inflammation may trigger first fibrotic events, while more dramatic triggers such as myocardial infarction and myocarditis give rise to full blown scar formation and ongoing fibrosis in diseased hearts. Aging itself is also associated with a cardiac phenotype that includes fibrosis. Fibrosis is an extremely heterogeneous phenomenon, as several stages of the fibrotic process exist, each with different fibrosis subtypes and a different composition of various cells and proteins - resulting in a very complex pathophysiology. As a result, detection of fibrosis, e.g. using current cardiac imaging modalities or plasma biomarkers, will detect only specific subforms of fibrosis, but cannot capture all aspects of the complex fibrotic process. Furthermore, several anti-fibrotic therapies are under investigation, but such therapies generally target aspecific aspects of the fibrotic process and suffer from a lack of precision. This review discusses the mechanisms and the caveats and proposes a roadmap for future research.


Assuntos
Proteínas da Matriz Extracelular/sangue , Fibrose , Insuficiência Cardíaca , Miocárdio , Biomarcadores/sangue , Técnicas de Imagem Cardíaca/métodos , Gerenciamento Clínico , Europa (Continente) , Fibrose/classificação , Fibrose/diagnóstico , Fibrose/fisiopatologia , Fibrose/terapia , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/fisiopatologia , Insuficiência Cardíaca/terapia , Humanos , Miocárdio/metabolismo , Miocárdio/patologia , Prognóstico , Pesquisa , Sociedades Médicas , Pesquisa Médica Translacional
18.
Br J Pharmacol ; 176(14): 2449-2464, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30756388

RESUMO

Myocardial fibrosis is a key histopathological component that drives the progression of heart disease leading to heart failure and constitutes a therapeutic target. Recent preclinical and clinical studies have implicated galectin-3 (Gal-3) as a pro-fibrotic molecule and a biomarker of heart disease and fibrosis. However, our knowledge is poor on the mechanism(s) that determine the blood level or regulate cardiac expression of Gal-3. Recent studies have demonstrated that enhanced ß-adrenoceptor activity is a determinant of both circulating concentration and cardiac expression of Gal-3. Pharmacological or transgenic activation of ß-adrenoceptors leads to increased blood levels of Gal-3 and up-regulated cardiac Gal-3 expression, effect that can be reversed with the use of ß-adrenoceptor antagonists. Conversely, Gal-3 gene deletion confers protection against isoprenaline-induced cardiotoxicity and fibrogenesis. At the transcription level, ß-adrenoceptor stimulation activates cardiac mammalian sterile-20-like kinase 1, a pivotal kinase of the Hippo signalling pathway, which is associated with Gal-3 up-regulation. Recent studies have suggested a role for the ß-adrenoceptor-Hippo signalling pathway in the regulation of cardiac Gal-3 expression thereby contributing to the onset and progression of heart disease. This implies a therapeutic potential of the suppression of Gal-3 expression. In this review, we discuss the effects of ß-adrenoceptor activity on Gal-3 as a biomarker and causative mediator in the setting of heart disease and point out pivotal knowledge gaps. LINKED ARTICLES: This article is part of a themed section on Adrenoceptors-New Roles for Old Players. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.14/issuetoc.

19.
Clin Sci (Lond) ; 133(5): 665-680, 2019 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-30804219

RESUMO

Ischemic preconditioning (IPC) is an endogenous protection strategy against myocardial ischemia-reperfusion (I/R) injury. Macrophage migration inhibitory factor (MIF) released from the myocardium subjected to brief periods of ischemia confers cardioprotection. We hypothesized that MIF plays an essential role in IPC-induced cardioprotection. I/R was induced either ex vivo or in vivo in male wild-type (WT) and MIF knockout (MIFKO) mice with or without proceeding IPC (three cycles of 5-min ischemia and 5-min reperfusion). Indices of myocardial injury, regional inflammation and cardiac function were determined to evaluate the extent of I/R injury. Activations of the reperfusion injury salvage kinase (RISK) pathway, AMP-activated protein kinase (AMPK) and their downstream components were investigated to explore the underlying mechanisms. IPC conferred prominent protection in WT hearts evidenced by reduced infarct size (by 33-35%), myocyte apoptosis and enzymatic markers of tissue injury, ROS production, inflammatory cell infiltration and MCP1/CCR2 expression (all P<0.05). IPC also ameliorated cardiac dysfunction both ex vivo and in vivo These protective effects were abolished in MIFKO hearts. Notably, IPC mediated further activations of RISK pathway, AMPK and the membrane translocation of GLUT4 in WT hearts. Deletion of MIF blunted these changes in response to IPC, which is the likely basis for the absence of protective effects of IPC against I/R injury. In conclusion, MIF plays a critical role in IPC-mediated cardioprotection under ischemic stress by activating RISK signaling pathway and AMPK. These results provide an insight for developing a novel therapeutic strategy that target MIF to protect ischemic hearts.


Assuntos
Oxirredutases Intramoleculares/metabolismo , Precondicionamento Isquêmico Miocárdico/métodos , Fatores Inibidores da Migração de Macrófagos/metabolismo , Infarto do Miocárdio/prevenção & controle , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Miocárdio/metabolismo , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Apoptose , Quimiocina CCL2/metabolismo , Modelos Animais de Doenças , Oxirredutases Intramoleculares/deficiência , Oxirredutases Intramoleculares/genética , Fatores Inibidores da Migração de Macrófagos/deficiência , Fatores Inibidores da Migração de Macrófagos/genética , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Infarto do Miocárdio/genética , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/patologia , Traumatismo por Reperfusão Miocárdica/genética , Traumatismo por Reperfusão Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/patologia , Miocárdio/patologia , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo , Receptores CCR2/metabolismo , Transdução de Sinais , Remodelação Ventricular
20.
J Am Heart Assoc ; 8(1): e010418, 2019 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-30563389

RESUMO

Background Cardiac fibrosis is a core pathological process associated with heart failure. The recruitment and differentiation of primitive fibroblast precursor cells of bone marrow origin play a critical role in pathological interstitial cardiac fibrosis. The KC a3.1 channels are expressed in both ventricular fibroblasts and circulating mononuclear cells in rats and are upregulated by angiotensin II . We hypothesized that KC a3.1 channels mediate the inflammatory microenvironment in the heart, promoting the infiltrated bone marrow-derived circulating mononuclear cells to differentiate into myofibroblasts, leading to myocardial fibrosis. Methods and Results We established a cardiac fibrosis model in rats by infusing angiotensin II to evaluate the impact of the specific KC a3.1 channel blocker TRAM -34 on cardiac fibrosis. At the same time, mouse CD 4+ T cells and rat circulating mononuclear cells were separated to investigate the underlying mechanism of the TRAM -34 anti-cardiac fibrosis effect. TRAM -34 significantly attenuated cardiac fibrosis and the inflammatory reaction and reduced the number of fibroblast precursor cells and myofibroblasts. Inhibition of KC a3.1 channels suppressed angiotensin II -stimulated expression and secretion of interleukin-4 and interleukin-13 in CD 4+ T cells and interleukin-4- or interleukin-13-induced differentiation of monocytes into fibrocytes. Conclusions KC a3.1 channels facilitate myocardial inflammation and the differentiation of bone marrow-derived monocytes into myofibroblasts in cardiac fibrosis caused by angiotensin II infusion.


Assuntos
Cardiomiopatias/genética , Regulação da Expressão Gênica , Inflamação/genética , Canais de Potássio Ativados por Cálcio de Condutância Intermediária/genética , Monócitos/patologia , Miocárdio/metabolismo , Angiotensina II/toxicidade , Animais , Western Blotting , Cardiomiopatias/metabolismo , Cardiomiopatias/patologia , Fibroblastos/metabolismo , Fibroblastos/patologia , Fibrose/genética , Fibrose/metabolismo , Fibrose/patologia , Ventrículos do Coração/metabolismo , Ventrículos do Coração/patologia , Imuno-Histoquímica , Inflamação/metabolismo , Inflamação/patologia , Canais de Potássio Ativados por Cálcio de Condutância Intermediária/biossíntese , Masculino , Monócitos/metabolismo , Miocárdio/patologia , Miofibroblastos/metabolismo , Miofibroblastos/patologia , RNA/genética , Ratos , Ratos Sprague-Dawley
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