Degree Of Myocardial Fibrosis Research Articles

Human umbilical cord-derived mesenchymal stromal cells improve myocardial fibrosis and restore miRNA-133a expression in diabetic cardiomyopathy

BackgroundDiabetic cardiomyopathy (DCM) is a serious health-threatening complication of diabetes mellitus characterized by myocardial fibrosis and abnormal cardiac function. Human umbilical cord mesenchymal stromal cells (hUC-MSCs) are a potential therapeutic tool for DCM and myocardial fibrosis via mechanisms such as the regulation of microRNA (miRNA) expression and inflammation. It remains unclear, however, whether hUC-MSC therapy has beneficial effects on cardiac function following different durations of diabetes and which mechanistic aspects of DCM are modulated by hUC-MSC administration at different stages of its development. This study aimed to investigate the therapeutic effects of intravenous administration of hUC-MSCs on DCM following different durations of hyperglycemia in an experimental male model of diabetes and to determine the effects on expression of candidate miRNAs, target mRNA and inflammatory mediators.MethodsA male mouse model of diabetes was induced by multiple low-dose streptozotocin injections. The effects on severity of DCM of intravenous injections of hUC-MSCs and saline two weeks previously were compared at 10 and 18 weeks after diabetes induction. At both time-points, biochemical assays, echocardiography, histopathology, polymerase chain reaction (PCR), immunohistochemistry and enzyme-linked immunosorbent assays (ELISA) were used to analyze blood glucose, body weight, cardiac structure and function, degree of myocardial fibrosis and expression of fibrosis-related mRNA, miRNA and inflammatory mediators.ResultsSaline-treated diabetic male mice had impaired cardiac function and increased cardiac fibrosis after 10 and 18 weeks of diabetes. At both time-points, cardiac dysfunction and fibrosis were improved in hUC-MSC-treated mice. Pro-fibrotic indicators (α-SMA, collagen I, collagen III, Smad3, Smad4) were reduced and anti-fibrotic mediators (FGF-1, miRNA-133a) were increased in hearts of diabetic animals receiving hUC-MSCs compared to saline. Increased blood levels of pro-inflammatory cytokines (IL-6, TNF, IL-1β) and increased cardiac expression of IL-6 were also observed in saline-treated mice and were reduced by hUC-MSCs at both time-points, but to a lesser degree at 18 weeks.ConclusionIntravenous injection of hUC-MSCs ameliorated key functional and structural features of DCM in male mice with diabetes of shorter and longer duration. Mechanistically, these effects were associated with restoration of intra-myocardial expression of miRNA-133a and its target mRNA COL1AI as well as suppression of systemic and localized inflammatory mediators.

Interleukin-1β polarization in M1 macrophage mediates myocardial fibrosis in diabetes

BackgroundDiabetes is a global health problem whose common complication is diabetic cardiomyopathy, characterized by chronic inflammation of the heart muscle. Macrophages are the main white blood cells found in the resting heart. Therefore, we investigated the underling mechanism of macrophage on myocardial fibrosis in diabetes. MethodsHere, echocardiography was utilized to evaluate cardiac function, and the degree of myocardial fibrosis was assessed using Masson's trichrome staining, followed by single-cell RNA sequencing (scRNA-seq) to analyze the phenotype, function, developmental trajectory, and interactions between immune cells, endothelial cells (ECs), and fibroblasts (FBs) in the hearts of db/db mice at different stages of diabetes. Macrophages and cardiac fibroblasts were also co-cultured in order to study the signaling between macrophages and fibroblasts. ResultsWe found that with the development of diabetes mellitus, myocardial hypertrophy and fibrosis occurred that was accompanied by cardiac dysfunction. A significant proportion of immune cells, endothelial cells, and fibroblasts were identified by RNA sequencing. The most significant changes observed were in macrophages, which undergo M1 polarization and are critical for oxidative stress and extracellular matrix (ECM) formation. We further found that M1 macrophages secreted interleukin-1β (IL-1β), which interacted with the receptor on the surface of fibroblasts, to cause myocardial fibrosis. In addition, crosstalk between M1 macrophages and endothelial cells also plays a key role in fibrosis and immune response regulation through IL-1β and corresponding receptors. ConclusionsM1 macrophages mediate diabetic myocardial fibrosis through interleukin-1β interaction with fibroblasts.

Abstract 14254: Myocarditis in Athletes and Non-Athletes: Evaluating the Persistence and Degree of Myocardial Fibrosis at Follow Up

Introduction: Myocarditis is a common acquired cardiac disorder that may lead to persistent scar. Current guidelines recommend follow up cardiac MRI (CMR) in 3-6 months for athletes. Data supporting this recommendation is unfortunately very limited. Aim: The aim of this study was to evaluate the demographic and clinical variables of patients diagnosed with myocarditis. Clinical data for those who had a follow up CMR was also evaluated separately. Methodology: Patients who had a cardiac MRI (CMR) organised between July 2019 till December 2022 because of a MINOCA/Myocarditis hospital admission were retrospectively reviewed. Those with a myocarditis diagnosis were included. An athlete was defined as an individual who engaged in >4 hours of physical activity weekly or underwent organized sport. Results: 105 patients were included (mean age 35.4±15.6 years, 83.8% male). 34.3% were athletes. 12.4% had possible acute myocarditis, 10.5% had likely myocarditis and 77.1% had confirmed myocarditis on cardiac MRI (median 4 days from presentation). ECG was abnormal in 60.0%. 8.6% had arrhythmias. Echocardiography was abnormal in 26.7%. CMR revealed 15.2% reduced LV EF, 57.1% regional wall motion abnormalities, 5.7% reduced RV EF, 25.7% pericardial effusion, 84.5% myocardial oedema. Most (88.5%) had late gadolinium enhancement (LGE). 56.2% were started on anti-heart failure medical therapy. 29.5% had a CMR repeated (interval between scans 14.7±14.2 months). 77.4% showed persistent LGE, less pronounced in most (71.0%). Diffuse LGE at baseline was the only predictor for persistent scar (p=0.004). Scar persisted equally in athletes and non-athletes (p=0.666). Clinical variables were similar in both. At follow-up (24.6±15.3 months), 8.6% had adverse outcomes. The event rate was similar in athletes and non-athletes. A low LV EF on CMR (p=0.011) and abnormal ECHO (p=0.027) were the only variables that could predict outcome. Conclusion: LGE after myocarditis persists in 77.4% of cases, albeit better. No variable could predict the persistence of LGE in this cohort. Athletes and non-athletes had a similar clinical course, suggesting that repeat CMR in non-athletes is reasonable. The diagnostic utility of repeat CMR after myocarditis remains questionable.

Myocardial fibrosis associates with lupus anticoagulant in patients with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that carries increased risk of cardiovascular disease; however, the underlying pathophysiological mechanisms remain poorly understood. We aimed to investigate the prevalence and degree of myocardial fibrosis in SLE patients and associated disease characteristics. Forty-nine SLE patients (89% female, mean age 52 ± 13 years, median disease duration 19 (11–25) years) and 79 sex-and age-matched healthy controls were included. CMR with T1 mapping was performed on SLE patients and healthy controls. Fifty-one SLE patients received gadolinium contrast for the evaluation of late gadolinium enhancement (LGE) and extra cellular volume (ECV). Multiple linear regression analyses were performed to investigate the association between markers of myocardial fibrosis on CMR (LGE, T1, ECV) and SLE-related variables [clinical disease activity, lupus nephritis, chronic kidney disease, anti-cardiolipin and/or anti-beta-2 glycoprotein I antibodies, and lupus anticoagulant (LAC)] with adjustment for traditional risk factors. T1 values were elevated in SLE patients compared to healthy controls (1031 ± 36 ms vs. 1019 ± 25 ms, p = 0.01). LGE was present in 20% of SLE patients who received gadolinium contrast. On multivariable analysis, LAC was associated with LGE in SLE patients (β = 3.87, p = 0.02). Neither T1 nor ECV associated with SLE disease characteristics; however, there was a trend towards an association between LAC and T1 (β = 16.9, p = 0.08). SLE patients displayed signs of myocardial fibrosis on CMR that were associated with the presence of LAC. These findings support the pathophysiological understanding of LAC as a mediator of microvascular and subsequent myocardial dysfunction.Graphical abstract

MRNA Expression Profile Changes in Angiotensin-Ⅱ-Induced Atrial Myocardial Fibrosis in Rats

To study the differences between the mRNA expression profile in angiotensin Ⅱ (Ang Ⅱ)-induced fibrotic cardiomyocytes and that of normal cardiomyocytes and the relevant signaling pathways. Six 8-week-old male Sprague-Dawley (SD) rats were randomly assigned to a control group and an Ang Ⅱ group, with 3 rats in each group. Rats in the control group were injected via caudal vein with 0.9% normal saline at 2 mg/kg per day, while rats in the Ang Ⅱ group were injected with Ang Ⅱ via caudal vein at 2 mg/kg per day. The medications were continuously administered in the two groups for 14 days. The degree of myocardial fibrosis was determined by Masson's Trichrome staining and the content of collagen Ⅰ was determined by immunohistochemistry. High throughput sequencing was performed to measure the mRNA expression of rat cardiomyocytes in the two groups and to screen for differentially-expressed mRNAs. The differentially-expressed mRNAs were analyzed by Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Compared with those of the control group, the degree of myocardial fibrosis and the content of collagen Ⅰ in Ang Ⅱ group were significantly higher ( P<0.05). Through sequencing, 313 differentially-expressed mRNAs were identified, with 201 being up-regulated and 112 being down-regulated. Go and KEGG analyses showed that these differentially-expressed mRNA were involved in a variety of biological regulatory functions and pathways of myocardial fibrosis. Ang Ⅱ can cause myocardial fibrosis in rats. There are significant differences in mRNA expression between fibrotic cardiomyocytes and normal cardiomyocytes. The differentially expressed mRNAs may play an important role in biological processes, including immune response, cell remodeling, and extracellular matrix deposition.

Dapagliflozin attenuates myocardial hypertrophy via activating the SIRT1/HIF-1α signaling pathway

As a sodium-glucose transporter 2 inhibitor (SGLT2i), the cardioprotective benefits of Dapagliflozin (DAPA) are now widely appreciated. However, the underlying mechanism of DAPA on angiotensin II (Ang II)-induced myocardial hypertrophy has never been evaluated. In this study, we not only investigated the effects of DAPA on Ang II-induced myocardial hypertrophy, but explored its underlying mechanisms. Mice were injected with Ang II (500 ng /kg/min) or saline solution as control, followed by intragastric administration DAPA (1.5 mg/kg/day) or saline for four weeks. DAPA treatment alleviated the condition of decrease in left ventricular ejection fraction (LVEF) and fractional shortening (LVFS) caused by Ang II. In addition, DAPA treatment significantly alleviated Ang II-induced elevation of the ratio of heart weight to tibia length, as well as cardiac injury and hypertrophy. In mice stimulated with Ang II, the degree of myocardial fibrosis and upregulation of the markers of cardiac hypertrophy (atrial natriuretic peptide, ANP and B-type natriuretic peptide, BNP) were attenuated by DAPA. What’s more, DAPA partially reversed the Ang II-induced upregulation of HIF-1α and the decrease in levels of SIRT1. Taken together, activating the SIRT1/HIF-1α signaling pathway was found to confer a protective effect against experimental myocardial hypertrophy in mice induced by Ang II, demonstrating its potential as an effective therapeutic target for pathological cardiac hypertrophy.

CHI3L1 promotes myocardial fibrosis via regulating lncRNA TUG1/miR-495-3p/ETS1 axis.

Abnormal levels of CHI3L1 and lnc TUG1 are often associated with myocardial fibrosis, and their specific expressions may be closely related to the process of myocardial fibrosis. In addition, CHI3L1 was found to significantly up-regulate the expression of lncTUG1. Therefore, this study further explored the major role of CHI3L1 in regulating the progression of myocardial fibrosis. Myocardial fibrosis in mice was established using an angiotensin (Ang II) model, and the degree of myocardial fibrosis was assessed by qPCR, western blot and pathological techniques. HL-1 cells with overexpression and silencing of CHI3L1 were constructed, and the cell migration ability was detected using the Transwell method. Biological information was used to predict the potential target miRNA of lnc TUG1, and the interaction between them was verified by dual luciferase reporter assay. Using functional rescue assay and the rAAV9 technique, CHI3L1 was verified to affect the fibrotic process of myocardial cells by regulating the lnc TUG1/miR-495-3p/ETS1 axis in vitro and in vivo. The myocardial fibrosis index in the model group was significantly upregulated, and expression of both CHI3L1 and lnc TUG1 was upregulated. Pathological results revealed fibrosis and collagen deposition in the myocardium. Overexpression of lnc TUG1 reversed the inhibitory effect of CHI3L1 silencing on myocardial fibrosis. Mechanistically, CH3L1 upregulates the expression of lnc TUG1, and lnc TUG1 weakens the inhibition of ETS1 through sponge absorption of miR-495-3p, promoting the process of myocardial fibrosis.

Effects of Sacubitril/Valsartan on Exercise Capacity in Patients with Heart Failure with Reduced Ejection Fraction and the Role of Percentage of Delayed Enhancement Measured by Cardiac Magnetic Resonance in Predicting Therapeutic Response: A Multicentre Study.

Background: This study aims to evaluate the cardiopulmonary effects of sacubitril/valsartan therapy in patients with heart failure with reduced ejection fraction (HFrEF), investigating a possible correlation with the degree of myocardial fibrosis, as assessed by cardiac magnetic resonance. Methods: A total of 134 outpatients with HFrEF were enrolled. Results: After a mean follow-up of 13.3 ± 6.6 months, an improvement in ejection fraction and a reduction in E/A ratio, inferior vena cava size and N-terminal pro-B-type natriuretic peptide levels were observed. At follow-up, we observed an increase in VO2 peak of 16% (p<0.0001) and in O2 pulse of 13% (p=0.0002) as well as an improvement in ventilatory response associated with a 7% reduction in the VE/VCO2 slope (p=0.0001). An 8% increase in the ΔVO2/Δ work ratio and an 18% increase in exercise tolerance were also observed. Multivariate logistic regression analysis showed that the main predictors of events during follow-up were VE/VCO2 slope >34 (OR 3.98; 95% CI [1.59-10.54]; p=0.0028); ventilatory oscillatory pattern (OR 4.65; 95% CI [1.55-16.13]; p=0.0052); and haemoglobin level (OR 0.35; 95% CI [0.21-0.55]; p<0.0001). In patients who had cardiac magnetic resonance, when delayed enhancement >4.6% was detected, a lower response after sacubitril/valsartan therapy was observed as expressed by improvement in ΔVO2 peak, O2 pulse, LVEF and N-terminal pro-B-type natriuretic peptide. No significant differences were observed in ΔVO2/Δ work and VE/VCO2 slope. Conclusion:Sacubitril/valsartan improves cardiopulmonary functional capacity in HFrEF patients. The presence of myocardial fibrosis on cardiac magnetic resonance is a predictor of response to therapy.

PO-02-241 CARDIAC SYMPATHETIC REMODELING AND SK CHANNELS UPREGULATION, THE POSSIBLE MECHANISMS OF NOISE EXPOSURE ASSOCIATED ATRIAL ARRHYTHMOGENESIS

Environmental noise exposure may increase sympathetic tone and lead to atrial fibrillation (AF) and mortality. The small conductance Ca2+- activated K+ (SK) channels play important roles in the repolarization of atria. The regulation of SK channels might be involved in modulating cardiac electrophysiology via the autonomic nervous system (ANS). Apamin blocks SK channels specifically and is used for evaluating the roles of SK channels regulation related to noise exposure. To determine how ANS regulates SK channels under noise exposure. We used a noise exposure (NOE) mice model with broad-band noise 20-20k Hz for 28 days to induce atrial myopathy. A total of 12 NOE and 9 control mice were used in the study. Dual optical mapping was performed via Langendorff perfused intact hearts to measure the baseline and post-apamin atrial action potential duration (APD), calcium transient duration (CaTD) and conduction velocity (CV) in the NOE and control mice. The expression of SK channel proteins (SK1-3), tyrosine hydroxylase (TH) and growth-associated protein 43 (GAP43) was detected by immunohistochemistry. The degree of myocardial fibrosis in the atria was detected by Masson's trichrome staining. Optical mapping study showed no APD difference (26.26±3.69 vs 27.76±2.36 ms, p=0.69) but prolonged CaTD (52.67±1.91 vs 49.65±3.4 ms, p=0.03) in NOE compared with control mice atria at baseline. The ratio of ΔAPD (the difference in the APD after and before apamin) and baseline was higher in NOE than in control mice (0.221±0.231 vs 0.011±0.52, p=0.015), meaning that noise exposure contributed to the upregulation of SK channels. Atrial CV was higher in NOE than in control mice (44.9±4 vs 39.2±3.5 cm/s, p=0.019); after apamin administration, it was significantly lower in NOE than in control mice (30.9±4.8 vs 34.2±3.5 cm/s, p=0.045). IHC study showed SK1-3, TH, GAP43 and trichrome staining were significantly higher in NOE than in control atria (18445.3±2527.9 vs 11228.4±2276.9 μm2/ mm2, 16063.6±1974 vs 9760.17±2576.8 μm2/mm2, 9304.3±633.1 vs 5994.7±1131.8 μm2/ mm2, 1019.9±189.8 vs 622.6±252.3 μm2/ mm2, 733.5±449.1 vs 117.4±53.4 μm2/ mm2, 7449.9±4274.7 vs 492.6±353.9 μm2/ mm2, all p≤0.01). Additionally, AF can be induced in 17% (2/12) of NOE but never in control mice (p=0.14). Noise exposure induces cardiac ANS remodeling, fibrosis and SK currents upregulation. It partially explains the mechanism of noise-induced atrial arrhythmia.

Aortic valve calcification and myocardial fibrosis determine outcome following transcatheter aortic valve replacement.

There is evidence to suggest that the subtype of aortic stenosis (AS), the degree of myocardial fibrosis (MF), and level of aortic valve calcification (AVC) are associated with adverse cardiac outcome in AS. Because little is known about their respective contribution, we sought to investigate their relative importance and interplay as well as their association with adverse cardiac events following transcatheter aortic valve replacement (TAVR). One hundred consecutive patients with severe AS and indication for TAVR were prospectively enrolled between January 2017 and October 2018. Patients underwent transthoracic echocardiography, multidetector computed tomography, and left ventricular endomyocardial biopsies at the time of TAVR. The final study cohort consisted of 92 patients with a completed study protocol, 39 (42.4%) of whom showed a normal ejection fraction (EF) high-gradient (NEFHG) AS, 13 (14.1%) a low EF high-gradient (LEFHG) AS, 25 (27.2%) a low EF low-gradient (LEFLG) AS, and 15 (16.3%) a paradoxical low-flow, low-gradient (PLFLG) AS. The high-gradient phenotypes (NEFHG and LEFHG) showed the largest amount of AVC (807±421 and 813±281mm3 , respectively) as compared with the low-gradient phenotypes (LEFLG and PLFLG; 503±326 and 555±594mm3 , respectively, P<0.05). Conversely, MF was most prevalent in low-output phenotypes (LEFLG>LEFHG>PLFLG>NEFHG, P<0.05). This was paralleled by a greater cardiovascular (CV) mortality within 600days after TAVR (LEFLG 28%>PLFLG 26.7%>LEFHG 15.4%>NEFHG 2.5%; P=0.023). In patients with a high MF burden, a higher AVC was associated with a lower mortality following TAVR (P=0.045, hazard ratio 0.261, 95% confidence interval 0.07-0.97). MF is associated with adverse CV outcome following TAVR, which is most prevalent in low EF situations. In the presence of large MF burden, patients with large AVC have better outcome following TAVR. Conversely, worse outcome in large MF and relatively little AVC may be explained by a relative prominence of an underlying cardiomyopathy. The better survival rates in large AVC patients following TAVR indicate TAVR induced relief of severe AS-associated pressure overload with subsequently improved outcome.

Dynamic evolution and mechanism of myocardial glucose metabolism in different functional phenotypes of diabetic cardiomyopathy — a study based on 18 F-FDG microPET myocardial metabolic imaging

PurposeTo use 18 F-FDG microPET dynamic imaging to preliminarily identify the changes of myocardial glucose metabolism corresponding to different functional phenotypes of diabetic cardiomyopathy (DCM) in mice and elucidate their relationships.MethodsLeft ventricular function was measured by echocardiography in C57BL/KsJ-db/db (db/db) mice and their controls at 8, 12, 16, and 20 weeks of age to divide DCM stages and functional phenotypes. Myocardial histopathology was used to verify the staging accuracy and list-mode microPET dynamic imaging was conducted. The myocardial metabolic rate of glucose (MRglu) and the glucose uptake rate constant (Ki) were derived via Patlak graphical analysis, and the differences in myocardial glucose metabolism levels in different DCM stages were compared. The key proteins involved in myocardial glucose metabolism signaling pathway were analyzed by Western blotting to elucidate the underlying mechanism of abnormal glucose metabolism in DCM.ResultsCompared with the controls, the ratio of early diastolic transmitral flow velocity to early diastolic mitral annular tissue velocity (E/e’) of db/db mice was significantly increased from the age of 12 weeks, while the left ventricular ejection fraction (LVEF) was significantly decreased from the age of 16 weeks (all P < 0.05). Based on the staging criteria, 8 and 12 weeks (8/12w) db/db mice were in DCM stage 1 (diastolic dysfunction with normal LVEF), and 16 and 20 weeks (16/20w) db/db mice were in DCM stage 2/3 (diastolic and systolic dysfunction). The degree of myocardial fibrosis, glycogen deposition and ultrastructural damage in 16/20w db/db mice were more obvious than those in 8/12w group. The myocardial MRglu, Ki of db/db mice in 8/12w group or 16/20w group were significantly lower than those in the control group (all P < 0.05), while the myocardial standard uptake value (SUV) was not significantly reduced in the 8/12w group compared with the control group (P > 0.05). MRglu and SUV were moderately negatively correlated with the E/e’ ratio (r=-0.539 and − 0.512, P = 0.007 and 0.011), which were not significantly correlated with LVEF (P > 0.05). Meanwhile, Ki was not significantly correlated with LVEF or E/e’ ratio. The decreased expression of glucose transporter (GLUT) -4 in db/db mice preceded GLUT-1 and was accompanied by decreased phosphorylated AMP-activated protein kinase (p-AMPK) expression. Myocardial MRglu, Ki and SUV were significantly positively correlated with the expression of GLUT-4 (MRglu: r = 0.537; Ki: r = 0.818; SUV: r = 0.491; P = 0.000 ~ 0.046), but there was no significant correlation with GLUT-1 expression (P = 0.238 ~ 0.780).ConclusionsDuring the progression of DCM, with the changes of left ventricular functional phenotype, abnormal and dynamic changes of myocardial glucose metabolism can occur in the early stage.

Effect of Extracellular Matrix Stiffness on Candesartan Efficacy in Anti-Fibrosis and Antioxidation.

Myocardial fibrosis progression and imbalanced redox state are closely associated with increased extracellular matrix (ECM) stiffness. Candesartan (CAN), an angiotensin II (Ang II) receptor inhibitor, has shown promising anti-fibrosis and antioxidant efficacy in previous cardiovascular disease studies. However, the effect of ECM stiffness on CAN efficacy remains elusive. In this study, we constructed rat models with three different degrees of myocardial fibrosis and treated them with CAN, and then characterized the stiffness, cardiac function, and NADPH oxidase-2 (NOX2) expression of the myocardial tissues. Based on the obtained stiffness of myocardial tissues, we used polyacrylamide (PA) gels with three different stiffness to mimic the ECM stiffness of cardiac fibroblasts (CFs) at the early, middle, and late stages of myocardial fibrosis as the cell culture substrates and then constructed CFs mechanical microenvironment models. We studied the effects of PA gel stiffness on the migration, proliferation, and activation of CFs without and with CAN treatment, and characterized the reactive oxygen species (ROS) and glutathione (GSH) levels of CFs using fluorometry and scanning electrochemical microscopy (SECM). We found that CAN has the best amelioration efficacy in the cardiac function and NOX2 levels in rats with medium-stiffness myocardial tissue, and the most obvious anti-fibrosis and antioxidant efficacy in CFs on the medium-stiffness PA gels. Our work proves the effect of ECM stiffness on CAN efficacy in myocardial anti-fibrosis and antioxidants for the first time, and the results demonstrate that the effect of ECM stiffness on drug efficacy should also be considered in the treatment of cardiovascular diseases.

Characterization of volatile organic compounds with anti-atherosclerosis effects in Allium macrostemon Bge. and Allium chinense G. Don by head space solid phase microextraction coupled with gas chromatography tandem mass spectrometry.

Allium macrostemon Bge. (AMB) and Allium chinense G. Don (ACGD) are both edible Allium vegetables and named officinal Xiebai (or Allii Macrostemonis Bulbus) in East Asia. Their medicinal qualities involve in lipid lowering and anti-atherosclerosis effects. And steroidal saponins, nitrogenous compounds and sulfur compounds are like the beneficial components responsible for medicinal functions. Sulfur compounds are the recognized main components both in the volatile oils of AMB and ACGD. Besides, few researches were reported about their holistic chemical profiles of volatile organic compounds (VOCs) and pharmacodynamic effects. In this study, we first investigated the lipid-lowering and anti-atherosclerotic effects of volatile oils derived from AMB and ACGD in ApoE -/- mice with high fat and high cholesterol diets. The results showed the volatile oils of AMB and ACGD both could markedly reduce serum levels of TG, TC, and LDL-C (p < 0.05), and had no alterations of HDL-C, ALT, and AST levels (p > 0.05). Pathological results displayed they both could obviously improve the morphology of cardiomyocytes and the degree of myocardial fibrosis in model mice. Meanwhile, oil red O staining results also proved they could apparently decrease the lesion areas of plaques in the aortic intima (p < 0.05). Furthermore, head space solid phase microextraction coupled with gas chromatography tandem mass spectrometry combined with metabolomics analysis was performed to characterize the VOCs profiles of AMB and ACGD, and screen their differential VOCs. A total of 121 and 115 VOCs were identified or tentatively characterized in the volatile oils of AMB and ACGD, respectively. Relative-quantification results also confirmed sulfur compounds, aldehydes, and heterocyclic compounds accounted for about 85.6% in AMB bulbs, while approximately 86.6% in ACGD bulbs were attributed to sulfur compounds, ketones, and heterocyclic compounds. Multivariate statistical analysis showed 62 differentially expressed VOCs were observed between AMB and ACGD, of which 17 sulfur compounds were found to be closely associated with the garlic flavor and efficacy. Taken together, this study was the first analysis of holistic chemical profiles and anti-atherosclerosis effects of AMB and ACGD volatile oils, and would benefit the understanding of effective components in AMB and ACGD.

Bone Marrow Mesenchymal Stem Cell Modified with A Disintegrin and Metalloproteinase with Thrombospondin Motifs 1 Inhibitor Regulates Myocardial Fibrosis in Myocarditis

This study assesses the mechanism of BMSC modified with ADAMTS-1 inhibitor in regulating the myocardial fibrosis in myocarditis through TGFβ1/MMP9/TIMP1 pathway and collagen metabolism. Model of viral myocarditis (VMC) rats was established and then assigned into control set, carrier set, inhibitor set and carrier and inhibitor set randomly followed by analysis of CVF% in atrial tissue, ADAMTS-1 level by RT-PCR and TGFβ1, MMP9 and TIMP1 level by IHC. ADAMTS-1 mRNA level in control set was highest and lowest in inhibitor set. There was fibrosis in every set inordinately. The degree of myocardial fibrosis was reduced in inhibitor set and carrier and inhibitor set. The quantity of inflammatory cells was also reduced significantly. There was no or sporadic mall focal necrosis. The level of TGFβ1, MMP9 and TIMP1 in the treated three sets was significant decreased compared with control set with more significant changes in the inhibitor set and carrier and inhibitor set. Collagen metabolism in VMC rats was restrained by BMSC modified with ADAMTS-1 inhibitor and therefore the myocardial fibrosis was ameliorated with the possible mechanism being through regulation of the TGFβ1/MMP9/TIMP1 signaling pathway.

Association of electrocardiographic spatial heterogeneity of repolarization and spatial heterogeneity of atrial depolarization with left ventricular fibrosis.

To evaluate the relationship between spatial heterogeneity of electrocardiographic repolarization and spatial heterogeneity of atrial depolarization with arrhythmic substrate represented by left ventricular fibrosis. We assessed the associations of T- and P-wave morphology parameters analysed from the standard 12-lead electrocardiograms with left ventricular fibrosis in 378 victims of unexpected sudden cardiac death (SCD) who underwent medico-legal autopsy. Based on autopsy findings, the SCD victims were categorized into four different groups according to different stages of severity of left ventricular fibrosis (substantial fibrosis, moderate patchy fibrosis, scattered mild fibrosis, no fibrosis). T-wave and P-wave area dispersion (TWAd: 0.0841 ± 0.496, 0.170 ± 0.492, 0.302 ± 404, 0.296 ± 0.476, P = 0.008; PWAd: 0.574 ± 0.384, 0.561 ± 0.367, 0.654 ± 0.281, 0.717 ± 0.257, P = 0.011, respectively; low values abnormal), non-dipolar components of T-wave and P-wave morphology (T_NonDipolarABS: 0.0496 ± 0.0377, 0.0571 ± 0.0487, 0.0432 ± 0.0476, 0.0380 ± 0.0377, P = 0.027; P_NonDipolarABS: 0.0132 ± 0.0164, 0.0130 ± 0.0135, 0.0092 ± 0.0117, 0.0069 ± 0.00472, P = 0.005, respectively, high values abnormal), T-wave morphology dispersion (TMD: 45.9 ± 28.3, 40.5 ± 25.8, 35.5 ± 24.9, 33.0 ± 24.6, P = 0.030, respectively, high values abnormal), and P-wave heterogeneity (PWH: 20.0 ± 9.44, 19.7 ± 8.87, 17.9 ± 9.78, 15.4 ± 4.60, P = 0.019, respectively, high values abnormal) differed significantly between the groups with different stages of left ventricular fibrosis. After adjustment with heart weight, T_NonDipolarABS [standardized β (sβ) = 0.131, P = 0.014], PWAd (sβ = -0.161, P = 0.003), P_NonDipolarABS (sβ = 0.174, P = 0.001), and PWH (sβ = 0.128, P = 0.015) retained independent association, and TWAd (sβ = -0.091, P = 0.074) and TMD (sβ = 0.097, P = 0.063) tended to retain their association with the degree of myocardial fibrosis. Our findings suggest that abnormal values of T- and P-wave morphology are associated with arrhythmic substrate represented by ventricular fibrosis partly explaining the mechanism behind their prognostic significance.

Quercetin Inhibits Pyroptosis in Diabetic Cardiomyopathy through the Nrf2 Pathway.

The present study investigated whether quercetin promotes the nuclear translocation of nuclear factor erythroid-2-related factor 2 (Nrf2) to inhibit pyroptosis progression and ameliorate diabetic cardiomyopathy. We evaluated the protective effects of quercetin against diabetic cardiomyopathy by analyzing the expression of pyroptosis pathway proteins, myocardial cell apoptosis rate, degree of myocardial fibrosis, and serum inflammatory indices in the hearts of model rats with diabetes. We evaluated the expression of Nrf2 in the nucleus of cardiomyocytes and H9C2 cells to clarify the role of quercetin in promoting the nuclear translocation of Nrf2. In addition, we coincubated cardiomyocytes with the Nrf2 inhibitor ML385 to confirm that quercetin inhibits the diabetes-induced cardiomyocyte pyroptosis via the Nrf2 pathway. We found that quercetin promoted the nuclear translocation of Nrf2 in cardiac cells of diabetic rats, increased the expression of the antioxidant proteins HO-1, GCLC, and SOD, reduced the accumulation of ROS and the degree of cardiomyocyte apoptosis, and alleviated diabetes-induced cardiac fibrosis. The therapeutic effects of quercetin were further validated in H9C2 cardiomyocytes. Interestingly, ML385 prevented the beneficial effects of quercetin on diabetic cardiomyopathy, further indicating that the quercetin-mediated inhibition of pyroptosis requires the participation of the Nrf2 pathway. In conclusion, quercetin promoted the nuclear translocation of Nrf2, increased the expression of antioxidant factors in cells, and inhibited the progression of cell pyroptosis, thereby alleviating diabetic cardiomyopathy.

Intact Fibroblast Growth Factor 23 Regulates Chronic Kidney Disease-Induced Myocardial Fibrosis by Activating the Sonic Hedgehog Signaling Pathway.

Background Clinically, myocardial fibrosis is one of the most common complications caused by chronic kidney disease (CKD). However, the potential mechanisms of CKD-induced myocardial fibrosis have not been clarified. Methods and Results In our in vivo study, a rat model of CKD with 5/6 nephrectomy was established. The CKD model was treated with the glioma 1 (Gli-1) inhibitor GANT-61, and myocardial fibrosis and serum intact fibroblast growth factor 23 levels were assessed 16 weeks after nephrectomy. Finally, we found that Gli-1 and Smoothened in the Sonic Hedgehog (Shh) signaling pathway were activated and that collagen-1 and collagen-3, which constitute the fibrotic index, were expressed in CKD myocardial tissue. After administering the Gli-1 inhibitor GANT-61, the degree of myocardial fibrosis was reduced, and Gli-1 expression was also inhibited. We also measured blood pressure, cardiac biomarkers, and other indicators in rats and performed hematoxylin-eosin staining of myocardial tissue. Furthermore, in vitro studies showed that intact fibroblast growth factor 23 promoted cardiac fibroblast proliferation and transdifferentiation into myofibroblasts by activating the Shh signaling pathway, thereby promoting cardiac fibrosis, as manifested by increased expression of the Shh, Patch 1, and Gli-1 mRNAs and Shh, Smoothened, and Gli-1 proteins in the Shh signaling pathway. The protein and mRNA levels of other fibrosis indicators, such as α-smooth muscle actin, which are also markers of transdifferentiation, collagen-1, and collagen-3, were increased. Conclusions On the basis of these results, intact fibroblast growth factor 23 promotes CKD-induced myocardial fibrosis by activating the Shh signaling pathway.

Colchicine: Emerging therapeutic effects on atrial fibrillation by alleviating myocardial fibrosis in a rat model

Although many research have found that colchicine has general therapeutic effect in cardiovascular disease, the therapeutic mechanism in atrial fibrillation has not been clearly studied. To explore whether colchicine plays a role in the treatment of AF by reducing myocardial fibrosis, we performed a series of studies. Rat models of AF were induced by Ach–CaCl2 to assess the therapeutic effect of colchicine at doses of 0.8 mg/kg on the duration of AF rhythm, degree of myocardial fibrosis, and secretion of inflammatory factors in the serum. RNA-Seq was also performed to elucidate the possible mechanisms by which colchicine might reduce the alleviation of myocardial fibrosis associated with AF. These studies showed that colchicine reduced the duration of AF and the degree of fibrosis in the left atrium and that it significantly reduced the secretion of TGFβ1, activin A, collagen I, and collagen III. These results suggest that colchicine may reduce myocardial fibrosis by (1) inhibiting the TGFβ1/ALK5 and activin A/ALK4 fibrosis pathways; (2) inhibiting the activation, phenotypic transformation, and apoptosis resistance of myocardial fibroblasts; and (3) reducing the synthesis of inflammatory factors and collagen.

Micropatterned conductive elastomer patch based on poly (glycerol sebacate)-graphene for cardiac tissue repair

Preparing a micropatterned elastomer film with characteristics that can simulate the mechanical properties, anisotropy, and electroactivity of natural myocardial tissues is crucial in cardiac tissue engineering after myocardial infarction (MI). Therefore, in this study, we developed several elastomeric films with a surface micropattern based on poly (glycerol sebacate) (PGS) and graphene (Gr). These films have sufficient mechanical strength (0.6 ± 0.1–3.2 ± 0.08 MPa) to withstand heartbeats, and the micropatterned structure also satisfies the natural myocardium anisotropy in the transverse and vertical. Moreover, Gr makes these films conductive (up to 5.80 × 10−7 S m−1), which is necessary for the conduction of electrical signals between cardiomyocytes and the cardiac tissue. Furthermore, they have good cytocompatibility and can promote cell proliferation in H9c2 rat cardiomyocyte cell lines. In vivo test results indicate that these films have good biocompatibility. Notably, a film with 1 wt% Gr content (PGS–Gr1) significantly affects the recovery of myocardial function in rats after MI. This film effectively decreased the infarct size and degree of myocardial fibrosis and reduced collagen deposition. Echocardiographic evaluation showed that after treatment with this film, the left ventricular internal dimension (LVID) in systole and LVID in diastole of rats exhibited a significant downward trend, whereas the fractional shortening and ejection fraction were significantly increased compared with the control group. These data indicate that this electroactive micropatterned anisotropic elastomer film can be applied in cardiac tissue engineering.

Aortic valve calcification and endomyocardial fibrosis determine adverse outcomes following transcatheter aortic valve replacement

Abstract Funding Acknowledgements Type of funding sources: None. Aims There is evidence to suggest that subtype of aortic stenosis (AS), degree of myocardial fibrosis (MF) and level of aortic valve calcification (AVC) are associated with adverse cardiac outcome in AS. Since little is known about their respective contribution, we sought to investigate their relative importance and interplay as well as association with adverse cardiac events. Methods 100 consecutive patients with severe AS and indication for transfemoral transcatheter aortic valve replacement (TAVR) were prospectively enrolled between January 2017 and October 2018. Patients underwent transthoracic echocardiography, multi detector computed tomography (MDCT) and left ventricular endomyocardial biopsy at the time of TAVR. Results The final study cohort consisted of 92 patients with completed study protocol comprising of 39 (42.4 %) normal ejection fraction high gradient (NEFHG), 13 (14.1 %) low EF high gradient (LEFHG), 25 (27.2 %) low EF (flow) low gradient (LEFLG) and 15 (16.3 %) paradoxical low flow low gradient (PLFLG) AS. The high gradient phenotypes (NEFHG and LEFHG) showed the largest amount of AVC (807 ± 421; 813 ± 281 mm³ respectively) as compared to the low gradient phenotypes (LEFLG and PLFLG; 503 ± 326; 555 ± 594 mm³ respectively, p &amp;lt; 0.05). Conversely, MF was most prevalent in low output phenotypes (LEFLG &amp;gt; LEFHG &amp;gt; PLFLG &amp;gt; HEFHG, p &amp;lt; 0.05). This was paralleled by larger cardiovascular mortality within 600 days post TAVR (LEFLG n = 7 &amp;gt; PLFLG n = 4 &amp;gt; LEFHG n = 2 &amp;gt; NEFHG n = 1). In Patients with high MF burden a higher AVC was associated with a lower mortality (p = 0.045, HR = 0.261, 95%CI 0.07-0.97). Within LEFLG AS, patients with larger AVC (&amp;gt;476.8 mm³) had larger MF (40.2%) and higher cardiovascular mortality (n = 5) as compared to patients with lower AVC (£476.8 mm³, 17.1% MF, p = 0.027, cardiovascular mortality n = 2). Conclusion MF is associated with adverse cardiovascular outcome following TAVR which is most prevalent in low ejection fraction situations. In the presence of large MF burden patients with large AVC have better outcome following TAVR. Conversely worse outcome in large MF and relatively little AVC may be explained by a relative prominence of an underlying cardiomyopathy while better survival rates in large AVC patients may indicate severe AS associated pressure overload relief and subsequently improved survival following TAVR.