El impacto de la obesidad sobre el lipidoma cardíaco y sus consecuencias en el daño cardíaco en ratas obesas

To explore the impact of obesity on the cardiac lipid profile in rats with diet-induced obesity, as well as to evaluate whether or not the specific changes in lipid species are associated with cardiac fibrosis. Methods: Male Wistar rats were fed either a high-fat diet (HFD, 35% fat) or standard diet (3.5% fat) for 6 weeks. Cardiac lipids were analyzed using by liquid chromatography-tandem mass spectrometry. Results: HFD rats showed cardiac fibrosis and enhanced levels of cardiac superoxide anion (O 2 ), HOMA index, adiposity, and plasma leptin, as well as a reduction in those of cardiac glucose transporter (GLUT 4), compared with control animals. Cardiac lipid profile analysis showed a significant increase in triglycerides, especially those enriched with palmitic, stearic, and arachidonic acid. An increase in levels of diacylglycerol (DAG) was also observed. No changes in cardiac levels of diacyl phosphatidylcholine, or even a reduction in total levels of diacyl phosphatidylethanolamine, diacyl phosphatidylinositol, and sphingomyelins (SM) was observed in HFD, as compared with control animals. After adjustment for other variables (oxidative stress, HOMA, cardiac hypertrophy), total levels of DAG were independent predictors of cardiac fibrosis while the levels of total SM were independent predictors of the cardiac levels of GLUT 4. Conclusions: These data suggest that obesity has a significant impact on cardiac lipid composition, although it does not modulate the different species in a similar manner. Nonetheless, these changes are likely to participate in the cardiac damage in the context of obesity, since total DAG levels can facilitate the development of cardiac fibrosis, and SM levels predict GLUT4 levelsThis work was supported by funds from the Sociedad Española de Arteriosclerosis (Basic Research Award 2015), from Plan Estatal I+D+I 2013-2016: PI15/01060 and SAF2016-81063. The study was cofunded by Fondo Europeo de Desarrollo Regional (FEDER), a way to build Europ

Toll-like receptor 4 contributes to vascular remodelling and endothelial dysfunction in angiotensin II-induced hypertension

This is the peer-reviewed version of the following article: "Toll-like receptor 4 contributes to vascular remodelling and endothelial dysfunction in angiotensin II-induced hypertension", British Journal of Pharmacology 172.12 (2015): 3159-76 which has been published in final form at http://dx.doi.org/10.1111/bph.13117 This article may be used for non-commercial purposes in accordance with Wiley-VCH Terms and Conditions for Self-ArchivingBackground and Purpose Toll-like receptor 4 (TLR4) signalling contributes to inflammatory cardiovascular diseases, but its role in hypertension and the associated vascular damage is not known. We investigated whether TLR4 activation contributed to angiotensin II (AngII)-induced hypertension and the associated vascular structural, mechanical and functional alterations. Experimental Approach AngII was infused (1.44 mg·kg−1·day−1, s.c.) for 2 weeks in C57BL6 mice, treated with a neutralizing anti-TLR4 antibody or IgG (1 μg·day−1); systolic BP (SBP) and aortic cytokine levels were measured. Structural, mechanical and contractile properties of aortic and mesenteric arterial segments were measured with myography and histology. RT-PCR and Western blotting were used to analyse these tissues and cultured vascular smooth muscle cells (VSMC) from hypertensive rats (SHR). Key Results Aortic TLR4 mRNA levels were raised by AngII infusion. Anti-TLR4 antibody treatment of AngII-treated mice normalised: (i) increased SBP and TNF-α, IL-6 and CCL2 levels; (ii) vascular structural and mechanical changes; (iii) altered aortic phenylephrine- and ACh-induced responses; (iv) increased NOX-1 mRNA levels, superoxide anion production and NAD(P)H oxidase activity and effects of catalase, apocynin, ML-171 and Mito-TEMPO on vascular responses; and (v) reduced NO release and effects of L-NAME on phenylephrine-induced contraction. In VSMC, the MyD88 inhibitor ST-2825 reduced AngII-induced NAD(P)H oxidase activity. The TLR4 inhibitor CLI-095 reduced AngII-induced increased phospho-JNK1/2 and p65 NF-κB subunit nuclear protein expression. Conclusions and Implications TLR4 up-regulation by AngII contributed to the inflammation, endothelial dysfunction, vascular remodelling and stiffness associated with hypertension by mechanisms involving oxidative stress. MyD88-dependent activation and JNK/NF-κB signalling pathways participated in these alterationsThis work was supported by Ministerio de Economía y Competitividad (SAF2012-36400), Instituto de Salud Carlos III (Red de Investigación Cardiovascular RD12/0042/0024 and RD12/0042/0033) and URJC (PRIN13_CS12). AMB was supported by the Ramón y Cajal Program (RYC-2010-06473)

Urocortin induces positive inotropic effect in rat heart

9 páginas, 6 figuras.Aims The aim of this study is to evaluate the positive inotropic effect of urocortin (Ucn) and to characterize its signalling pathways. Methods and results Contractility was measured in ex vivo Langendorff-perfused hearts isolated from Wistar rats. Isolated ventricular cardiomyocytes were used to analyse intracellular calcium ([Ca2+]i) transients evoked by electrical stimulation and L-type Ca2+ current by confocal microscopy and whole-cell patch-clamping, respectively. The application of Ucn to perfused hearts induced progressive, sustained, and potent inotropic and lusitropic effects that were dose-dependent with an EC50 of approximately 8 nM. Ucn effects were independent of protein kinase A (PKA) activation but were significantly reduced by protein kinase C (PKC) and mitogen-activated protein kinase (MAPK) inhibitors and by brefeldin A, an antagonist of guanine nucleotide exchange factor, suggested to be an inhibitor of exchange protein activated by cAMP (Epac). These whole-organ effects were correlated with the inotropic effects observed in isolated cells: Ucn increased ICaL density, [Ca2+]i transients, cell shortening and Ca2+ content of sarcoplasmic reticulum. Conclusion Our results show that Ucn evokes potent positive inotropic and lusitropic effects mediated, at least in part, by an increase in ICaL and [Ca2+]i transient amplitude. These effects may involve the activation of Epac, PKC, and MAPK signalling pathways.This study was supported by ‘Red Cardiovascular RECAVA’ of Instituto Carlos III (grant number: RD06-0014-0020, RD06-0014-0007, PI06-0133), Consejerías de Salud, de Innovación Ciencia y Empresa de la Junta de Andalucía (grant numbers: 174/2006, P06-CTS-01711), Inserm, and by Agence Nationale pour la Recherche (grant: Physio2006Epac). T.S is a ‘Ramon y Cajal’ Researcher and E.C is a fellow student from RECAVA.Peer reviewe

Mineralocorticoid Receptor and Leptin: A Dangerous Liaison in the Obese Heart

Multiple factors have been proposed as being responsible for cardiac damage in the context of obesity, including aldosterone/mineralocorticoid receptor and leptin. Aldosterone exerts proinflammatory, prooxidant and profibrotic actions, which can play a key role in the development of cardiac damage associated with different pathologies, through binding of mineralocorticoid receptor (MR). Moreover, its pharmacological blockade has demonstrated to improve these situations. Different studies have demonstrated that aldosterone is inappropriately elevated in obesity and MR antagonism improves left ventricle function and reduces circulating procollagen levels in patients with obesity without other comorbidities. Leptin is locally produced in the myocardium and its production is up-regulated in obesity. This adipokine is a proinflammatory, prooxidant and profibrotic factor that can participate in the cardiac damage associated with obesity. Interactions among leptin and aldosterone have previously been reported in different scenarios and at different levels, supporting a link between leptin and MR and that could result in the potentiation of the cardiac damage associated with obesity. Therefore, the aim of this review is to discuss whether MR activation can mediate the deleterious effects of leptin in the heart in the context of obesity, as well as the potential mechanisms involved in this process

Oxidative Stress in Obesity

Obesity is defined by the World Health Organization (WHO) as abnormal or excessive fat accumulation that presents a health risk [...

Inflammation but Not Endothelial Dysfunction Is Associated with the Severity of Coronary Artery Disease in Dyslipidemic Subjects

Introduction. Endothelial dysfunction and inflammation play a key role in the development of atherosclerosis. The present study evaluated endothelial function, inflammatory parameters, and carotid intima-media thickness (IMT) in dyslipidemic patients with or without coronary artery disease (CAD). Methods. Metabolic profile and inflammatory parameters were determined in dyslipidemic patients with (+CAD, n = 33) and without (−CAD, n = 69) symptomatic CAD. Endothelial function was evaluated by flow mediated dilatation (FMD) and plasma concentration of nitrites and nitrates. Carotid IMT was measured by ultrasound. Results. No significant differences were observed in anthropometric hemodynamic or metabolic parameters between the groups. After adjusting by age and medication usage, some inflammatory markers were significantly higher in +CAD; however no significant differences in FMD or plasma levels of nitrites were observed. Conclusions. In subjects with dyslipidemia, the presence of CAD is associated with an elevation of certain inflammatory markers and carotid IMT but not with further endothelial dysfunction

Mitochondrial oxidative stress induces cardiac fibrosis in obese rats through modulation of transthyretin

A proteomic approach was used to characterize potential mediators involved in the improvement in cardiac fibrosis observed with the administration of the mitochondrial antioxidant MitoQ in obese rats. Male Wistar rats were fed a standard diet (3.5% fat; CT) or a high-fat diet (35% fat; HFD) and treated with vehicle or MitoQ (200 ¿M) in drinking water for 7 weeks. Obesity modulated the expression of 33 proteins as compared with controls of the more than 1000 proteins identified. These include proteins related to endoplasmic reticulum (ER) stress and oxidative stress. Proteomic analyses revealed that HFD animals presented with an increase in cardiac transthyretin (TTR) protein levels, an effect that was prevented by MitoQ treatment in obese animals. This was confirmed by plasma levels, which were associated with those of cardiac levels of both binding immunoglobulin protein (BiP), a marker of ER stress, and fibrosis. TTR stimulated collagen I production and BiP in cardiac fibroblasts. This upregulation was prevented by the presence of MitoQ. In summary, the results suggest a role of TTR in cardiac fibrosis development associated with obesity and the beneficial effects of treatment with mitochondrial antioxidants.This research was funded by Instituto de Salud Carlos III-Fondo Europeo de Desarrollo Regional (FEDER) (PI18/00257, PI21/00431, CIBERCV, Madrid, Spain)

Secreted phospholipase A2-IIA modulates transdifferentiation of cardiac fibroblast through EGFR transactivation: An inflammation–fibrosis link

Producción CientíficaSecreted phospholipase A2-IIA (sPLA2-IIA) is a pro-inflammatory protein associated with cardiovascular disorders, whose functions and underlying mechanisms in cardiac remodelling are still under investigation. We herein study the role of sPLA2-IIA in cardiac fibroblast (CFs)-to-myofibroblast differentiation and fibrosis, two major features involved in cardiac remodelling, and also explore potential mechanisms involved. In a mice model of dilated cardiomyopathy (DCM) after autoimmune myocarditis, serum and cardiac sPLA2-IIA protein expression were found to be increased, together with elevated cardiac levels of the cross-linking enzyme lysyl oxidase (LOX) and reactive oxygen species (ROS) accumulation. Exogenous sPLA2-IIA treatment induced proliferation and differentiation of adult rat CFs. Molecular studies demonstrated that sPLA2-IIA promoted Src phosphorylation, shedding of the membrane-anchored heparin-binding EGF-like growth factor (HB-EGF) ectodomain and EGFR phosphorylation, which triggered phosphorylation of ERK, P70S6K and rS6. This was also accompanied by an up-regulated expression of the bone morphogenic protein (BMP)-1, LOX and collagen I. ROS accumulation were also found to be increased in sPLA2-IIA-treated CFs. The presence of inhibitors of the Src/ADAMs-dependent HB-EGF shedding/EGFR pathway abolished the CF phenotype induced by sPLA2-IIA. In conclusion, sPLA2-IIA may promote myofibroblast differentiation through its ability to modulate EGFR transactivation and signalling as key mechanisms that underlie its biological and pro-fibrotic effects.Ministerio de Economía, Industria y Competitividad (grants SAF2012-34460 and SAF2016-81063)Instituto de Salud Carlos III (grant PI18/010257729