The neuro-cardiac junction defines an extracellular microdomain required for neurotrophic signaling

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
M Mongillo ◽  
M Franzoso ◽  
V Prando ◽  
L Dokshokova ◽  
A Di Bona ◽  
...  

Abstract Background Sympathetic neurons (SNs) innervate the myocardium with a defined topology that allows physiological modulation of cardiac activity. Neurotrophins released by cardiac cells control SN viability and myocardial distribution, which are impaired in heart diseases with reduced (e.g. heart failure) or heterogenous sympathetic stimulation (e.g. arrhythmias). We previously demonstrated that SNs interact directly with cardiomyocytes (CMs) at neuro-cardiac junctions (NCJ), and such structured contact sites allow neurons to efficiently activate β-adrenoceptors on the myocyte membrane. Aims We here asked whether NCJs are functional for retrograde (myocyte to neuron) neurotrophic signaling. Methods and results Electron microscopy and immunofluorescence on mouse heart slices and SN/CM co-cultures showed that the NGF receptor, TrkA, is preferentially found in correspondence of the NCJ. Consistently, neurons taking structured contact with CMs showed fast TrkA activation and its retrograde transport to the soma, which was monitored using live confocal imaging in cells expressing TrkA-RFP. In accord with NGF dependent effects, CM-contacted SN showed larger synaptic varicosities and did not require NGF supplementation in the culture medium. In support that NGF locally released at NCJs sustains SN viability, the neurotrophin concentration in the culture medium was 1.61 pg/mL, and did not suffice to maintain neuronal viability, which was also perturbed (66% decrease of neuronal density) by silencing NGF expression in CMs. These results support that the NCJ is essential for intercellular neurotrophin signaling. Consistently, by applying competitive inhibition of TrkA with increasing doses of K252a, we estimated NGF concentration at the contact site to be about 1000-fold higher than that released by CM in the culture medium. To seek for the structural determinants of the NCJ, we focused on dystrophin, based on the finding that the protein accumulates on the CM membrane portion contacted by SNs, as observed in mouse heart slices, and co-cultured CMs. In support of a role of CM-expressed dystrophin in neurotrophic signaling, hearts from dystrophin-KO (mdx) mice showed 74.36% decrease of innervation, with no significant changes of NGF expression. In line with the purported role of NCJs, in co-cultures between wild type SNs and mdx CMs, TrkA activation (TrkA movements toward SN soma (%): WTCM-WTSN=18±4; MDXCM-WTSN= 12±3; p<0,05) and neuronal survival were reduced. Conclusions Taken together, our results suggest that NGF-dependent signaling to SNs requires a direct and specialized interaction with myocytes, and that loss of dystrophin at the CM membrane impairs retrograde signaling to the neurons leading to cardiac sympathetic dys-innervation. Funding Acknowledgement Type of funding source: Public Institution(s). Main funding source(s): University of Padova

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
N Tmoyan ◽  
O Afanasieva ◽  
M Ezhov ◽  
U Chubykina ◽  
E Klesareva ◽  
...  

Abstract Background Lipoprotein(a) [Lp(a)] is an independent risk factor of cardiovascular disease. The role of Lp(a) and its autoantibodies in the development of atherosclerosis, depending on the severity of lesion, is uncertain. Purpose To define the relationship of Lp(a) level and autoantibodies to Lp(a) with atherosclerosis of different vascular beds. Methods The study included 1288 patients older than 18 years with instrumental examination of three vascular beds (coronary, carotid and lower limbs arteries). Patients were divided according to the number of affected vascular beds (stenosis ≥50%): 0 (n=339), 1 (n=470), 2 (n=315), 3 (n=164). Levels of lipids, Lp(a) and autoantibodies to Lp(a) were measured in serum of all patients. Results Lp(a) concentration steadily increased and the level of IgM autoantibodies decreased with the number of affected vascular beds (Figure). There was no any association between IgG autoantibodies to Lp(a) and stenotic atherosclerosis. In logistic regression analysis adjusted for age, sex, hypertension, diabetes mellitus, smoking, elevated Lp(a) level was an independent predictor of stenotic atherosclerosis and it was associated with severity of lesions (table). Conclusions Lipoprotein(a) is an independent risk factor of stenotic atherosclerosis and its concentration increases with the number of affected vascular beds, while IgM autoantibodies to Lp(a) possess cardioprotective properties. Funding Acknowledgement Type of funding source: Public Institution(s). Main funding source(s): National Medical Research Center of Cardiology of Ministry of Health of the Russian Federation


2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Polina Goichberg ◽  
Maria Cimini ◽  
Antonio Cannata ◽  
Sergio Signore ◽  
Kanako Waight ◽  
...  

The delivery of adult cardiac progenitor cells (CPCs) or their activation in situ constitute an evolving approach for the treatment of heart failure. CPCs are endowed with regenerative capacity, producing differentiating myocytes and vascular structures in the course of homeostasis and upon injury. The regenerative function of CPCs is contingent to their ability to migrate to and engraft within the wounded area. Yet, the mechanisms governing CPC trafficking in the diseased myocardium are largely unknown. The lymphatic system is vital for tissue repair, and the role of the lymphatic vasculature in the trafficking of hematopoietic and cancer cells is well documented. We examined whether cardiac lymphatic vessels mediate the translocation of CPCs in the infarcted myocardium. By imaging of the heart from transgenic c-kit-GFP reporter mice, we found that as early as 4 hours after myocardial infarction (MI), uncommitted lineage-negative progenitors accumulated in the vicinity of the lymphatic vessels located in the region bordering the necrotic area. Histologically, extensive lymphangiogenesis was documented in the mouse heart in the acute (8-48 hours) and chronic (15-35 days) phases of infarct healing and scar formation. CPCs were detected traversing the wall of lymphatic vessels at different stages after MI, indicative of the functional role of the lymphatic circulation in the recruitment of primitive cells to the site of injury. Furthermore, isolated human CPCs exhibited chemotaxis and specific binding to the human lymphatic endothelial cells (LECs) in steady-state conditions and, increasingly, after exposure to an inflammatory cytokine, TNFα. CPCs performed trans-endothelial migration in vitro, and actively intravasated into the lumen of microvessels formed by LECs in three-dimensional matrices. Finally, our data suggest that sphingosine-1-phosphate (S1P)-stimulated signaling governs the interactions of CPCs with LECs. These findings on the direct role of lymphatic vasculature in CPC trafficking may contribute to the development of novel therapeutic modalities to increase mobilization of endogenous or transplanted CPCs, promoting myocardial repair in patients with ischemic heart diseases.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
I Kutya ◽  
Y Hilova ◽  
J Rodionova ◽  
M Kopytsya ◽  
O Petyunina

Abstract   One of the promising parameter for the prognosis in patients with STEMI can be suggested the VEGF-A gene polymorphism. Purpose Estimate the role of the VEGF-A gene polymorphism in the prediction of outcomes in patients with STEMI. Methods The study involved 135 STEMI patients (80.7% male and 19.3% female) with an average age of 59.21±8.92 years. Control group of 30 healthy volunteers included. Patients were divided into two groups: the first one – “case” group, those who reached the end point, and the second group – “control”, those who did not reached. The combined endpoint included cardiovascular death, recurrent myocardial infarction, the occurrence / progression of heart failure that required hospitalization. The study of the VEGF-A gene polymorphism (rs 2010963) was carried out by polymerase chain reaction (PCR). Follow-up period was 6 month. VEGF-A level was measured by ELISA. Results The patients from the “case” group had significantly elevated VEGF-A levels compared to controls (217.40 [102.54–473.78] pg/ml; 311.45 [204.20–680.86] pg/ml; p=0.046). Multivariate linear regression analyses demonstrated that polymorphism G634C (rs2010963) of VEGF-A gene (G634C+C634C) – β=0.8079, CI [1.1907 to 5.6490] p=0.0465; and LVEF <50.60% – β=0.0488 CI [0.9179 to 0.9882], p=0.0096 are significantly associated with negative outcomes (combined endpoints). Conclusions STEMI patients with G634C+C634C polymorphism G634C (rs2010963) of VEGF-A gene, and with LVEF <50.60% have greater chances for adverse outcomes. Further investigations of the VEGF-A gene polymorphism are the perspective direction in the development of prevention and treatment of STEMI. Funding Acknowledgement Type of funding source: Public Institution(s). Main funding source(s): GI “L.T. Malaya Therapy National Institute NAMSU”


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
J Barc ◽  
R Trados ◽  
C Glinge ◽  
F Simonet ◽  
D Chiang ◽  
...  

Abstract   The Brugada Syndrome (BrS) is characterized by ST-segment elevation in the right precordial leads and is associated with an increased risk of sudden cardiac death. The disorder was initially described as a monogenic primary cardiac electrical disease. However, mutations in SCN5A, encoding the cardiac sodium channel (NaV1.5), which is the major gene associated with the disorder are found in only around 20% of cases and are associated with low penetrance. Furthermore many cases did not display familial aggregation. Based on a previous GWAS conducted on 312 BrS patients and the discovery of the unexpected strong effect of 3 common variants, we proposed that the BrS may comprise a more complex inheritance model. We conducted a genome-wide association study on 2820 individuals with BrS and 10001 ancestry-matched controls to uncover additional genetic loci that modulate susceptibility to BrS, to characterize further the BrS genetic architecture and to uncover new molecular mechanisms. We identified 21 susceptibility variants that passed the genome-wide statistical significance threshold (P<5.10–8), of which 18 were novel. Eight were located at the SCN5A-SCN10A locus, illustrating the central role of NaV1.5 in the disease. Interestingly, 9 occur in the vicinity of genes known to play a crucial role in cardiac development (HEY2, TBX20, GATA4, ZFPM2, WT1, TBX5, IRX3, IRX5) and / or control cardiac ion channel expression. Of note, 2 others signals occurred in the vicinity of microtubule / cytoskeleton associated proteins (MAPRE2 and MYO18B). Through studies in zebrafish and in human iPSC-derived cardiomyocytes, we demonstrate a role of MAPRE2 on NaV1.5 function. We identified 18 new susceptibility variants associated with BrS and uncovered a new pathophysiological molecular mechanism underlying BrS susceptibility. We provided further support for a complex genetic architecture underlying susceptibility for the disorder. Funding Acknowledgement Type of funding source: Public Institution(s). Main funding source(s): H2020 - Marie Sklodowska Curie IF grant, Rising star grant from the Pays de la Loire regional council


2016 ◽  
Vol 86 (3-4) ◽  
pp. 127-151 ◽  
Author(s):  
Zeshan Ali ◽  
Zhenbin Wang ◽  
Rai Muhammad Amir ◽  
Shoaib Younas ◽  
Asif Wali ◽  
...  

While the use of vinegar to fi ght against infections and other crucial conditions dates back to Hippocrates, recent research has found that vinegar consumption has a positive effect on biomarkers for diabetes, cancer, and heart diseases. Different types of vinegar have been used in the world during different time periods. Vinegar is produced by a fermentation process. Foods with a high content of carbohydrates are a good source of vinegar. Review of the results of different studies performed on vinegar components reveals that the daily use of these components has a healthy impact on the physiological and chemical structure of the human body. During the era of Hippocrates, people used vinegar as a medicine to treat wounds, which means that vinegar is one of the ancient foods used as folk medicine. The purpose of the current review paper is to provide a detailed summary of the outcome of previous studies emphasizing the role of vinegar in treatment of different diseases both in acute and chronic conditions, its in vivo mechanism and the active role of different bacteria.


1991 ◽  
Vol 125 (3) ◽  
pp. 280-285 ◽  
Author(s):  
J. Alan Talbot ◽  
Ann Lambert ◽  
Robert Mitchell ◽  
Marek Grabinski ◽  
David C. Anderson ◽  
...  

Abstract We have investigated the role of Ca2+ in the control of FSH-induced estradiol secretion by Sertoli cells isolated from 8-10 days old rats. Exogenous Ca2+ (4-8 mmol/1) inhibited FSH-stimulated E2 secretion such that, with 8 mmol/l Ca2+ and FSH (8 IU/l) E2 secretion decreased from 2091±322 to 1480±84 pmol/l (p<0.002), whilst chelation of Ca2+ in the culture medium with EGTA (3 mmol/l) increased E2 secretion from 360±45 to 1242±133 pmol/l) in the absence of FSH. Further, EGTA (3 mmol/l) markedly potentiated FSH (8 IU/l), forskolin (1 μmol/l) and dibutyryl cAMP (1 mmol/l)-stimulated E2 secretion. Addition of the Ca2+ ionophores, ionomycin (2-5 μmol/l) and A23187 (2 μmol/l), inhibited FSH (8 IU/l)-stimulated E2 secretion by >80%. The effect of ionomycin was totally reversible, whereas that of A23187 was irreversible. Ionomycin (5 μmol/l) had no effect on EGTA-induced E2 secretion in the absence of FSH, but reduced EGTA-provoked E2 secretion by 59% in the presence of FSH (8 IU/l). Similarly, forskolin- and dibutyryl cAMP-provoked E2 production was inhibited 46-50% by ionomycin (5 μmol/l). We conclude that FSH-induced E2 secretion from immature rat Sertoli cells is modulated by intra- and extracellular Ca2+.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
H Hara ◽  
K Takahashi ◽  
D Klaveren ◽  
M Ono ◽  
H Kawashima ◽  
...  

Abstract Background In patients with complex coronary artery disease (CAD), women favored coronary artery bypass grafting surgery (CABG) compared to percutaneous coronary intervention (PCI) at 5 years in the SYNTAX trial, whereas mortality rates after PCI and CABG were not different in men. On the other hand, poor outcomes of women undergoing PCI were not observed in the PRECOMBAT and BEST trials. The long-term optimal revascularization strategy according to gender has not been fully evaluated. Purpose In the SYNTAX Extended Survival (SYNTAXES) study, no significant difference existed in all-cause death between PCI and CABG at 10 years. This study aimed to assess treatment effect of PCI and CABG for 10-year all-cause death according to gender. Methods The SYNTAXES study evaluated vital status up to 10 years in 1,800 patients with de novo three-vessel disease (3VD) and/or left main coronary artery disease (LMCAD) randomized to treatment with CABG or PCI in the SYNTAX trial, and the pre-specified primary endpoint was all-cause death at 10 years. In this prespecified analysis, all-cause death at 10 years according to gender in patients undergoing PCI or CABG was evaluated. Results Of 1800 patients, 402 (22.3%) were women and 1398 (77.7%) were men. In women, the rate of mortality was significantly higher in the PCI arm at 5 years than in the CABG arm (19.3% vs. 10.3%; Log-rank p=0.010, Figure A), but the rates of mortality were not different at 10 years between the PCI and CABG arms (33.0% vs. 32.5%; Log-rank p=0.600, Figure A). In men, the mortality rate tended to be higher in the PCI arm at 10 years than in the CABG arm (27.0% vs. 22.5%; Log-rank p=0.082, Figure B), although the mortality rates were not different at 5 years between the PCI and CABG arms (12.4% vs. 12.3%; Log-rank p=0.957, Figure B). Conclusion The efficacy of CABG observed at 5 years disappeared at 10 years in women, whereas the efficacy of CABG became apparent after 5 years in men. Figure 1 Funding Acknowledgement Type of funding source: Public Institution(s). Main funding source(s): Erasmus University Medical Centre, Rotterdam, Netherlands, reference: MEC-2016-716


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
H Kohjitani ◽  
A Kashiwa ◽  
T Makiyama ◽  
F Toyoda ◽  
Y Yamamoto ◽  
...  

Abstract Background A missense mutation, CACNA1C-E1115K, located in the cardiac L-type calcium channel (LTCC), was recently reported to be associated with diverse arrhythmias. Several studies reported in-vivo and in-vitro modeling of this mutation, but actual mechanism and target drug of this disease has not been clarified due to its complex ion-mechanisms. Objective To reveal the mechanism of this diverse arrhythmogenic phenotype using combination of in-vitro and in-silico model. Methods and results Cell-Engineering Phase: We generated human induced pluripotent stem cell (hiPSC) from a patient carrying heterozygous CACNA1C-E1115K and differentiated into cardiomyocytes. Spontaneous APs were recorded from spontaneously beating single cardiomyocytes by using the perforated patch-clamp technique. Mathematical-Modeling Phase: We newly developed ICaL-mutation mathematical model, fitted into experimental data, including its impaired ion selectivity. Furthermore, we installed this mathematical model into hiPSC-CM simulation model. Collaboration Phase: Mutant in-silico model showed APD prolongation and frequent early afterdepolarization (EAD), which are same as in-vitro model. In-silico model revealed this EAD was mostly related to robust late-mode of sodium current occurred by Na+ overload and suggested that mexiletine is capable of reducing arrhythmia. Afterward, we applicated mexiletine onto hiPSC-CMs mutant model and found mexiletine suppress EADs. Conclusions Precise in-silico disease model can elucidate complicated ion currents and contribute predicting result of drug-testing. Funding Acknowledgement Type of funding source: Public Institution(s). Main funding source(s): Japan Society for the Promotion of Science, Grant-in-Aid for Young Scientists


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
V Montiel ◽  
R Bella ◽  
L Michel ◽  
E Robinson ◽  
J.C Jonas ◽  
...  

Abstract Background Pathological remodeling of the myocardium has long been known to involve oxidant signaling, but so far, strategies using systemic anti-oxidants have generally failed to prevent it. Aquaporins are a family of transmembrane water channels with thirteen isoforms currently known. Some isoforms have been implicated in oxidant signaling. AQP1 is the most abundant aquaporin in cardiovascular tissues but its specific role in cardiac remodeling remains unknown. Purpose We tested the role of AQP1 as a key regulator of oxidant-mediated cardiac remodeling amenable to targeted pharmacological therapy. Methods We used mice with genetic deletion of Aqp1 (and wild-type littermate), as well as primary isolates from the same mice and human iPSC/Engineered Heart Tissue to test the role of AQP1 in pro-hypertrophic signaling. Human cardiac myocyte-specific (PCM1+) expression of AQP's and genes involved in hypertrophic remodeling was studied by RNAseq and bioinformatic GO pathway analysis. Results RNA sequencing from human cardiac myocytes revealed that the archetypal AQP1 is a major isoform. AQP1 expression correlates with the severity of hypertrophic remodeling in patients with aortic stenosis. The AQP1 channel was detected at the plasma membrane of human and mouse cardiac myocytes from hypertrophic hearts, where it colocalizes with the NADPH oxidase-2 (NOX2) and caveolin-3. We show that hydrogen peroxide (H2O2), produced extracellularly, is necessary for the hypertrophic response of isolated cardiac myocytes and that AQP1 facilitates the transmembrane transport of H2O2 through its water pore, resulting in activation of oxidant-sensitive kinases in cardiac myocytes. Structural analysis of the amino acid residues lining the water pore of AQP1 supports its permeation by H2O2. Deletion of Aqp1 or selective blockade of AQP1 intra-subunit pore (with Bacopaside II) inhibits H2O2 transport in mouse and human cells and rescues the myocyte hypertrophy in human induced pluripotent stem cell-derived engineered heart muscle. This protective effect is due to loss of transmembrane transport of H2O2, but not water, through the intra-subunit pore of AQP1. Treatment of mice with clinically-approved Bacopaside extract (CDRI08) inhibitor of AQP1 attenuates cardiac hypertrophy and fibrosis. Conclusion We provide the first demonstration that AQP1 functions as an aqua-peroxiporin in primary rodent and human cardiac parenchymal cells. We show that cardiac hypertrophy is mediated by the transmembrane transport of H2O2 through the AQP1 water channel. Our studies open the way to complement the therapeutic armamentarium with specific blockers of AQP1 for the prevention of adverse remodeling in many cardiovascular diseases leading to heart failure. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): FRS-FNRS, Welbio


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