Dicarbonyl stress and mitochondrial dysfunction in the aged heart

Aging; Cardiomyocytes; MitochondriaEnvejecimiento; Cardiomiocitos; MitocondriasEnvelliment; Cardiomiòcits; Mitocondri

Efficacy of a cysteine protease inhibitor compared with enalapril in murine heart failure models

Cardiovascular medicine; Cell biologyMedicina cardiovascular; Biologia cel·lularMedicina cardiovascular; Biología celularCysteine proteases calpains contribute to heart failure (HF), but it remains unknown whether their inhibition provides any benefit compared to standard pharmacological treatment for HF. Here, we characterize the pharmacological properties of NPO-2270 (NPO) as a potent inhibitor of cysteine proteases. Then, we describe that acute administration of NPO in rodent models of transient ischemia at the time of reperfusion reduces myocardial infarction, while its chronic oral administration attenuates adverse remodeling and cardiac dysfunction induced by ischemic and non-ischemic pathological stimuli more effectively than enalapril when given at the same dose. Finally, we provide evidence showing that the effects of NPO correlate with calpain inhibition and the preservation of the T-tubule morphology, due at least in part to reduced cleavage of the calpain substrate junctophilin-2. Together, our data highlight the potential of cysteine protease inhibition with NPO as a therapeutic strategy for the treatment of heart failure.This work was funded by Instituto de Salud Carlos III, Spain, through the projects AES PI20/01681 and AES PI23/00068; and the research network CIBERCV (CB16/11/00479), both cofunded by European Regional Development Fund; Sociedad Española de Cardiología (SEC/FEC-INV-BAS 22/013); Fundació la Marató de TV3 (FLMTV3/202321-30-31) and PERIS STL/484/2023. Long-Sheng Song is supported by the National Institutes of Health of USA

TRPV4 Channels Promote Pathological, but Not Physiological, Cardiac Remodeling through the Activation of Calcineurin/NFAT and TRPC6

Calcium; Heart failure; Pathological remodelingCalci; Insuficiència cardíaca; Remodelació patològicaCalcio; Insuficiencia cardiaca; Remodelación patológicaTRPV4 channels, which respond to mechanical activation by permeating Ca2+ into the cell, may play a pivotal role in cardiac remodeling during cardiac overload. Our study aimed to investigate TRPV4 involvement in pathological and physiological remodeling through Ca2+-dependent signaling. TRPV4 expression was assessed in heart failure (HF) models, induced by isoproterenol infusion or transverse aortic constriction, and in exercise-induced adaptive remodeling models. The impact of genetic TRPV4 inhibition on HF was studied by echocardiography, histology, gene and protein analysis, arrhythmia inducibility, Ca2+ dynamics, calcineurin (CN) activity, and NFAT nuclear translocation. TRPV4 expression exclusively increased in HF models, strongly correlating with fibrosis. Isoproterenol-administered transgenic TRPV4−/− mice did not exhibit HF features. Cardiac fibroblasts (CFb) from TRPV4+/+ animals, compared to TRPV4−/−, displayed significant TRPV4 overexpression, elevated Ca2+ influx, and enhanced CN/NFATc3 pathway activation. TRPC6 expression paralleled that of TRPV4 in all models, with no increase in TRPV4−/− mice. In cultured CFb, the activation of TRPV4 by GSK1016790A increased TRPC6 expression, which led to enhanced CN/NFATc3 activation through synergistic action of both channels. In conclusion, TRPV4 channels contribute to pathological remodeling by promoting fibrosis and inducing TRPC6 upregulation through the activation of Ca2+-dependent CN/NFATc3 signaling. These results pose TRPV4 as a primary mediator of the pathological response.This research was funded by the Instituto de Salud Carlos III—Fondo de Investigación Sanitaria [PI16/00619]; the Sociedad Española de Cardiología [SEC/FEC-INV-BAS 20/016]; and the Societat Catalana de Cardiologia 2021

New protein-protein interactions of mitochondrial connexin 43 in mouse heart

Connexin 43 (Cx43), the gap junction protein involved in cell-to-cell coupling in the heart, is also present in the subsarcolemmal fraction of cardiomyocyte mitochondria. It has been described to regulate mitochondrial potassium influx and respiration and to be important for ischaemic preconditioning protection, although the molecular effectors involved are not fully characterized. In this study, we looked for potential partners of mitochondrial Cx43 in an attempt to identify new molecular pathways for cardioprotection. Mass spectrometry analysis of native immunoprecipitated mitochondrial extracts showed that Cx43 interacts with several proteins related with mitochondrial function and metabolism. Among them, we selected for further analysis only those present in the subsarcolemmal mitochondrial fraction and known to be related with the respiratory chain. Apoptosis-inducing factor () and the beta-subunit of the electron-transfer protein (), two proteins unrelated to date with Cx43, fulfilled these conditions, and their interaction with Cx43 was proven by direct and reverse co-immunoprecipitation. Furthermore, a previously unknown molecular interaction between and was established, and protein content and sub-cellular localization appeared to be independent from the presence of Cx43. Our results identify new protein-protein interactions between -Cx43, -Cx43 and - as possible players in the regulation of the mitochondrial redox state

Defective dimerization of FoF1-ATP synthase secondary to glycation favors mitochondrial energy deficiency in cardiomyocytes during aging

Aging; Dicarbonyl stress; MitochondriaEnvelliment; Estrès dicarbonílic; MitocondrisEnvejecimiento; Estrés dicarbonílico; MitocondriasAged cardiomyocytes develop a mismatch between energy demand and supply, the severity of which determines the onset of heart failure, and become prone to undergo cell death. The FoF1-ATP synthase is the molecular machine that provides >90% of the ATP consumed by healthy cardiomyocytes and is proposed to form the mitochondrial permeability transition pore (mPTP), an energy-dissipating channel involved in cell death. We investigated whether aging alters FoF1-ATP synthase self-assembly, a fundamental biological process involved in mitochondrial cristae morphology and energy efficiency, and the functional consequences this may have. Purified heart mitochondria and cardiomyocytes from aging mice displayed an impaired dimerization of FoF1-ATP synthase (blue native and proximity ligation assay), associated with abnormal mitochondrial cristae tip curvature (TEM). Defective dimerization did not modify the in vitro hydrolase activity of FoF1-ATP synthase but reduced the efficiency of oxidative phosphorylation in intact mitochondria (in which membrane architecture plays a fundamental role) and increased cardiomyocytes’ susceptibility to undergo energy collapse by mPTP. High throughput proteomics and fluorescence immunolabeling identified glycation of 5 subunits of FoF1-ATP synthase as the causative mechanism of the altered dimerization. In vitro induction of FoF1-ATP synthase glycation in H9c2 myoblasts recapitulated the age-related defective FoF1-ATP synthase assembly, reduced the relative contribution of oxidative phosphorylation to cell energy metabolism, and increased mPTP susceptibility. These results identify altered dimerization of FoF1-ATP synthase secondary to enzyme glycation as a novel pathophysiological mechanism involved in mitochondrial cristae remodeling, energy deficiency, and increased vulnerability of cardiomyocytes to undergo mitochondrial failure during aging.This work was supported by the Instituto de Salud Carlos III of the Spanish Ministry of Health (FIS-PI19-01196) and a grant from the Sociedad Española de Cardiología (SEC/FEC-INV-BAS 217003

Differential features in composition of coronary thrombus of women with ST-segment elevation myocardial infarction

OBJECTIVES: To characterize sex differences in the composition of coronary thrombus in patients with ST-segment elevation myocardial infarction (STEMI), especially in the young (age ≤ 55 years). BACKGROUND: Women have smaller coronary vessels than men and their vascular lesions can be influenced by different exposure to circulating estrogens throughout life. These factors could determine a different composition of the coronary thrombus in women with STEMI. METHODS: A prospective, multicenter study was conducted on patients with STEMI and coronary thrombus was aspirated immediately before percutaneous coronary intervention (PCI) using a suction catheter (ProntoV3® or Export®). Histopathology, immunohistochemistry and ELISA techniques were used for the quantitative determination of fibrin, p-selectin and von Willebrand factor (vWF) within thrombi. RESULTS: Thrombi were collected from 100 patients (50 men and 50 women; 13 women and 13 men of <55 years). Women presented similar baseline characteristics and pain-to-balloon elapsed time than men. Thrombi from women showed a trend to a lower concentration of fibrin than those from men [median = 1.2 ng/mg (IQR 3.5) vs median = 2.2 ng/mg (IQR 5.9), p = 0.102]. No differences were found between sexes in p-selectin and vWF concentration in thrombi. However, thrombi from young women showed lower levels of p-selectin [median = 2.2 ng/mg (IQR 4.5) vs 6.5 ng/mg (IQR 4.8), p = 0.004], fibrin [median = 1.1 ng/mg; (IQR: 3.4) vs 4.1 ng/mg (IQR 15.6), p = 0.014] and vWF [median = 3.2 ng/mg (IQR 10.6) vs 25.8 ng/mg (IQR 15.0), p = 0.003] than those from young men. CONCLUSIONS: Thrombi from young women with STEMI showed a lower content of fibrin, p-selectin and vWF than those from men.European Regional Development Fund grants (ERDF)S

New protein-protein interactions of mitochondrial connexin 43 in mouse heart

Connexin 43 (Cx43), the gap junction protein involved in cell-to-cell coupling in the heart, is also present in the subsarcolemmal fraction of cardiomyocyte mitochondria. It has been described to regulate mitochondrial potassium influx and respiration and to be important for ischaemic preconditioning protection, although the molecular effectors involved are not fully characterized. In this study, we looked for potential partners of mitochondrial Cx43 in an attempt to identify new molecular pathways for cardioprotection. Mass spectrometry analysis of native immunoprecipitated mitochondrial extracts showed that Cx43 interacts with several proteins related with mitochondrial function and metabolism. Among them, we selected for further analysis only those present in the subsarcolemmal mitochondrial fraction and known to be related with the respiratory chain. Apoptosis-inducing factor () and the beta-subunit of the electron-transfer protein (), two proteins unrelated to date with Cx43, fulfilled these conditions, and their interaction with Cx43 was proven by direct and reverse co-immunoprecipitation. Furthermore, a previously unknown molecular interaction between and was established, and protein content and sub-cellular localization appeared to be independent from the presence of Cx43. Our results identify new protein-protein interactions between -Cx43, -Cx43 and - as possible players in the regulation of the mitochondrial redox state

The rs1333049 polymorphism on locus 9p21.3 and extreme longevity in Spanish and Japanese cohorts

The rs1333049 (G/C) polymorphism located on chromosome 9p21.3 is a candidate to influence extreme longevity owing to its association with age-related diseases, notably coronary artery disease (CAD). We compared allele/genotype distributions of rs1333049 in cases (centenarians) and controls (younger adults, without (healthy) or with CAD) in two independent cohorts: Spanish (centenarians: n = 152, 128 women, 100–111 years; healthy controls: n = 343, 212 women, age <50 years; CAD controls: n = 98, 32 women, age ≤65 years) and Japanese (centenarians: n = 742, 623 women, 100–115 years; healthy controls: n = 920, 511 women, < 60 years; CAD controls: n = 395, 45 women, age ≤65 years). The frequency of the “risk” C-allele tended to be lower in Spanish centenarians (47.0 %) than in their healthy (52.9 %, P = 0.088) or CAD controls (55.1 %, P = 0.078), and significant differences were found in genotype distributions (P = 0.034 and P = 0.045), with a higher frequency of the GG genotype in cases than in both healthy and CAD controls as well as a lower proportion of the CG genotype compared with healthy controls. In the Japanese cohort, the main finding was that the frequency of the C-allele did not differ between centenarians (46.4 %) and healthy controls (47.3 %, P = 0.602), but it was significantly lower in the former than in CAD controls (57.2 %, P < 0.001). Although more research is needed, the present and recent pioneer findings (Rejuvenation Res 13:23–26, 2010) suggest that the rs1333049 polymorphism could be among the genetic contributors to exceptional longevity in Southern European populations, albeit this association does not exist in the healthy (CAD-free) Japanese population.3.390 JCR (2014) Q2, 14/50 Geriatrics and gerontologyUE