Myocardial Tissue Of Patients Research Articles

Effects of NLRP3 Inflammasome Mediated Pyroptosis on Cardiovascular Diseases and Intervention Mechanism of Chinese Medicine.

Activation of the NOD-like receptor protein 3 (NLRP3) inflammasome signaling pathway is an important mechanism underlying myocardial pyroptosis and plays an important role in inflammatory damage to myocardial tissue in patients with cardiovascular diseases (CVDs), such as diabetic cardiomyopathy, ischemia/reperfusion injury, myocardial infarction, heart failure and hypertension. Noncoding RNAs (ncRNAs) are important regulatory factors. Many Chinese medicine (CM) compounds, including their effective components, can regulate pyroptosis and exert myocardium-protecting effects. The mechanisms underlying this protection include inhibition of inflammasome protein expression, Toll-like receptor 4-NF-κB signal pathway activation, oxidative stress, endoplasmic reticulum stress (ERS), and mixed lineage kinase 3 expression and the regulation of silent information regulator 1. The NLRP3 protein is an important regulatory target for CVD prevention and treatment with CM. Exploring the effects of the interventions mediated by CM and the related mechanisms provides new ideas and perspectives for CVD prevention and treatment.

Myocardial Tissue Characterization in Patients with Hypertensive Crisis, Positive Troponin, and Unobstructed Coronary Arteries: A Cardiovascular Magnetic Resonance-Based Study.

Hypertensive crisis can present with cardiac troponin elevation and unobstructed coronary arteries. We used cardiac magnetic resonance (CMR) imaging to characterize the myocardial tissue in patients with hypertensive crisis, elevated cardiac troponin, and unobstructed coronary arteries. Patients with hypertensive crisis and elevated cardiac troponin with coronary artery stenosis <50% were enrolled. Patients with troponin-negative hypertensive crisis served as controls. All participants underwent CMR imaging at 1.5 Tesla. Imaging biomarkers and tissue characteristics were compared between the groups. There were 19 patients (63% male) with elevated troponin and 24 (33% male) troponin-negative controls. The troponin-positive group was older (57 ± 11 years vs. 47 ± 14 years, p = 0.015). The groups had similar T2-weighted signal intensity ratios and native T1 times. T2 relaxation times were longer in the troponin-positive group, and the difference remained significant after excluding infarct-pattern late gadolinium enhancement (LGE) from the analysis. Extracellular volume (ECV) was higher in the troponin-positive group (25 ± 4 ms vs. 22 ± 3 ms, p = 0.008) and correlated strongly with T2 relaxation time (rs = 0.701, p = 0.022). Late gadolinium enhancement was 32% more prevalent in the troponin-positive group (82% vs. 50%, p = 0.050), with 29% having infarct-pattern LGE. T2 relaxation time was independently associated with troponin positivity (OR 2.1, p = 0.043), and both T2 relaxation time and ECV predicted troponin positivity (C-statistics: 0.71, p = 0.009; and 0.77, p = 0.006). Left ventricular end-diastolic and left atrial volumes were the strongest predictors of troponin positivity (C-statistics: 0.80, p = 0.001; and 0.82, p < 0.001). The increased T2 relaxation time and ECV and their significant correlation in the troponin-positive group suggest myocardial injury with oedema, while the non-ischaemic LGE could be due to myocardial fibrosis or acute necrosis. These CMR imaging biomarkers provide important clinical indices for risk stratification and prognostication in patients with hypertensive crisis.

Clinical and morphological myocardial changes in patients with post-COVID-19 syndrome

Aim. To characterize the clinical manifestations and myocardial morphological changes in patients with cardiovascular complications of post-Covid syndrome.Material and methods. A total of 38 patients (Group I) with cardiac symptoms in the post-COVID-19 period underwent endomyocardial biopsy (EMB). Patients from group I were divided into 2 subgroups depending on the presence of morphologically verified myocarditis. For morphological comparison, group II was formed (41 patients without COVID-19 and with EMB performed before 2019). Group II was also divided into two subgroups with and without morphologically verified myocarditis. In addition to the analysis of clinical and paraclinical data, a histological and immunohistochemical study of myocardial tissue was carried out with anti-CD3, CD68, CD16, HLA-DR, MHC1, C1q, enterovirus VP1, SARS-CoV-2 spike protein, ACE2, Ang1, von Willebrand factor, VEGF antibodies, as well as a PCR of myocardial tissue after reverse transcription. Additionally, an immunofluorescent study of myocardial tissue was performed using antibody cocktails to SARS-CoV-2/ CD16 spike protein, SARS-CoV-2/CD68 spike protein, CD80/CD163. Statistical processing was performed using the NumPy, SciPy, Pandas and Matplotlib libraries in the Python programming language.Results. Among patients in group I, 65% had morphologically verified lymphocytic myocarditis (subgroup 1, n=29). Other 35% of patients had no signs of myocardial inflammation (subgroup 2, n=9). The comparison group (group II) included 33 patients with myocarditis (80%) and 8 patients (20%) without it. There was a pronounced expression of CD68+ macrophages in the myocardial tissue in patients with postCOVID-19 syndrome in comparison with group II, both with morphological criteria for myocarditis (p=0,014) and without it (p=0,007), mainly due to M2 macrophages. More pronounced expression of CD68+ macrophages was observed when EMB was performed at earlier stages. If SARS-CoV-2 spike protein was detected in group I on the endothelium and inflammatory infiltrate by the immunohistochemistry, PCR of myocardial tissue for SARS-CoV-2 (n=5) was performed, which did not reveal SARS-CoV-2 particles in any of the analyzed samples.Conclusion. Cardiac symptoms of post-COVID-19 syndrome are caused by myocardial remodeling, including in patients without morphologically verified myocarditis. The direct involvement of SARS-CoV-2 in the development of myocarditis in the post-acute period of COVID-19 has not been proven.

The Characterization of Cardiac Explants Reveals Unique Fibrosis Patterns and a Predominance of CD8+ T Cell Subpopulations in Patients with Chronic Chagas Cardiomyopathy.

The present study aimed to characterize the histopathological findings and the phenotype of inflammatory cells in the myocardial tissue of patients with end-stage heart failure (ESHF) secondary to CCC in comparison with ESHF secondary to non-Chagas cardiomyopathies (NCC). A total of 32 explanted hearts were collected from transplanted patients between 2014 and 2017. Of these, 21 were classified as CCC and 11 as other NCC. A macroscopic analysis followed by a microscopic analysis were performed. Finally, the phenotypes of the inflammatory infiltrates were characterized using flow cytometry. Microscopic analysis revealed more extensive fibrotic involvement in patients with CCC, with more frequent foci of fibrosis, collagen deposits, and degeneration of myocardial fibers, in addition to identifying foci of inflammatory infiltrate of greater magnitude. Finally, cell phenotyping identified more memory T cells, mainly CD8+CD45RO+ T cells, and fewer transitioning T cells (CD45RA+/CD45RO+) in patients with CCC compared with the NCC group. CCC represents a unique form of myocardial involvement characterized by abundant inflammatory infiltrates, severe interstitial fibrosis, extensive collagen deposits, and marked cardiomyocyte degeneration. The structural myocardial changes observed in late-stage Chagas cardiomyopathy appear to be closely related to the presence of cardiac fibrosis and the colocalization of collagen fibers and inflammatory cells, a finding that serves as a basis for the generation of new hypotheses aimed at better understanding the role of inflammation and fibrogenesis in the progression of CCC. Finally, the predominance of memory T cells in CCC compared with NCC hearts highlights the critical role of the parasite-specific lymphocytic response in the course of the infection.

Molecular Imaging of Fibroblast Activity in Radiation-Induced Acute Myocardial Damage Using a [18F]AlF-Labeled Fibroblast Activation Protein Inhibitor, FAPI-04

<h3>Purpose/Objective(s)</h3> A previous retrospective analysis revealed increased [¹⁸F]AlF-NOTA-FAPI uptake in myocardial tissue of patients with esophageal squamous cell cancer (ESCC) treated with concurrent chemoradiotherapy (CCRT). The present study investigated and verified the feasibility of [¹⁸F]AlF-NOTA-FAPI positron emission tomography (PET)/computed tomography (CT) imaging for detecting radiation-induced myocardial damage (RIMD). <h3>Materials/Methods</h3> Myocardial FAPI uptake was analyzed before radiotherapy and during radiotherapy (36–50 Gy) in 13 ESCC patients treated with CCRT. In an animal study, a single dose of 50 Gy was delivered to the cardiac apex of female Wistar rats using conformal radiotherapy. RIMD model rats were scanned with [¹⁸F]AlF-NOTA-FAPI PET/CT weekly for 12 weeks, and then MRI was conducted. Dynamic, competition, and [¹⁸F]FDG PET/CT studies were performed on RIMD rats at 5 weeks post-radiation, and histopathological analyses were conducted. <h3>Results</h3> Three patients showed potentially increased FAPI uptake in myocardial tissue after radiotherapy. In the RIMD rat model, a significant increase in FAPI uptake in the damaged myocardium was observed from the 2nd week post-radiation exposure, with peak values observed in the 5th week. Significantly more intense tracer accumulation was observed in the damaged myocardial region than in remote myocardial tissue, as identified by decreased [¹⁸F]FDG uptake and confirmed by autoradiography, Masson's trichrome staining and immunohistochemical staining. The left ventricular ejection fraction (LVEF) remained unchanged from baseline at the 3rd week post-radiation exposure but was remarkably decreased compared with that in the control group at the 8th week. <h3>Conclusion</h3> An increase in myocardial uptake of [¹⁸F]AlF-NOTA-FAPI occurred in patients with ESCC after radiotherapy. These results indicated that FAPI PET/CT imaging can detect RIMD noninvasively and before a decrease in LVEF is detected, indicating the clinical potential of FAPI as a radiotracer for in vivo imaging of RIMD.

Mitochondrial Dysfunction in Cyanotic Congenital Heart Disease: A Promising Therapeutic Approach for the Future.

Congenital heart disease (CHD) is one of the most specific and yet challenging fields of heart surgery. Apart from the known clinical approaches, including surgery, a significant scale of regenerative therapeutic options is available, which increase the number of cardiomyocytes and restore cardiac function. Although it has been revealed in recent years that mitochondrial transplantation can be used as a promising treatment option in this disease group, there is no clinical evidence for the significance of mitochondrial function in myocardial tissue of patients with CHD regarding cardiac surgery. In this study, mitochondrial morphology and function, myocardial fibrosis, and myocyte atypia were evaluated in myocardial biopsy tissue of pediatric patients with cyanotic and acyanotic CHD, five from each group. After histopathological evaluation of myocardial tissue specimens, mitochondrial morphology and network were analyzed by immunofluorescence staining using an anti-Tom20 antibody, electron transport chain complexes of myocardium were examined by cytochrome c oxidase/succinate dehydrogenase staining, and the amount of ATP was measured by bioluminescence assay. In addition, cardiac markers have been tested to be reviewed as a potential indicator for postoperative follow-up. Myocyte atypia and fibrosis were classified on a scale of 1 to 4. In this study, unlike patients with acyanotic CHD, alterations in mitochondrial network and reduction in ATP production were detected in all pediatric patients with cyanotic CHD. A statistically significant correlation was also determined between mitochondrial dysfunction and cardiac markers.These findings may be assumed as a promising pathway for evaluating the relationship between mitochondrial dysfunction and cyanotic CHD.

Construction and Analysis of the lncRNA-miRNA-mRNA Network Based on Competing Endogenous RNA in Atrial Fibrillation.

BackgroundAccumulated studies have revealed that long non-coding RNAs (lncRNAs) play critical roles in human diseases by acting as competing endogenous RNAs (ceRNAs). However, functional roles and regulatory mechanisms of lncRNA-mediated ceRNA in atrial fibrillation (AF) remain unknown. In the present study, we aimed to construct the lncRNA-miRNA-mRNA network based on ceRNA theory in AF by using bioinformatic analyses of public datasets.MethodsMicroarray data sets of GSE115574 and GSE79768 from the Gene Expression Omnibus database were downloaded. Twenty-one AF right atrial appendage (RAA) samples and 22 sinus rhythm (SR) subjects RAA samples were selected for subsequent analyses. After merging all microarray data and adjusting for batch effect, differentially expressed genes were identified. Gene Ontology (GO) categories and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were carried out. A ceRNA network was constructed.ResultA total of 8 lncRNAs and 43 mRNAs were significantly differentially expressed with fold change >1.5 (p < 0.05) in RAA samples of AF patients when compared with SR. GO and KEGG pathway analysis showed that cardiac muscle contraction pathway were involved in AF development. The ceRNA was predicted by co-expressing LOC101928304/ LRRC2 from the constructional network analysis, which was competitively combined with miR-490-3p. The expression of LOC101928304 and LRRC were up-regulated in myocardial tissue of patients with AF, while miR-490-3p was down-regulated.ConclusionWe constructed the LOC101928304/miR-490-3p/LRRC2 network based on ceRNA theory in AF in the bioinformatic analyses of public datasets. The ceRNA network found from this study may help improve our understanding of lncRNA-mediated ceRNA regulatory mechanisms in the pathogenesis of AF.

Altered mRNA Expression of Interleukin-1 Receptors in Myocardial Tissue of Patients with Left Ventricular Assist Device Support.

Serum levels of cytokines interleukin 1 beta ( IL-1β) and interleukin 33 (IL-33) are highly abnormal in heart failure and remain elevated after mechanical circulatory support (MCS). However, local cytokine signaling induction remains elusive. Left (LV) and right ventricular (RV) myocardial tissue specimens of end-stage heart failure (HF) patients without (n = 24) and with MCS (n = 39; 594 ± 57 days) were analyzed for cytokine mRNA expression level of IL-1B, interleukin 1 receptor 1/2 (IL-1R1/2), interleukin 1 receptor-like 1 (IL-1RL1), IL-33 and interleukin-1 receptor accessory protein (IL-1RaP). MCS patients showed significantly elevated IL-1B expression levels (LV: 2.0 fold, p = 0.0058; RV: 3.3 fold, p < 0.0001). Moreover, IL-1R1, IL-1RaP and IL-33 expression levels strongly correlated with each other. IL-1RL1 and IL-1R2 expression levels were significantly higher in RV myocardial tissue (RV/LV ratio IL-1R2 HF: 4.400 ± 1.359; MCS: 4.657 ± 0.655; IL-1RL1 HF: 3.697 ± 0.876; MCS: 4.529 ± 0.5839). In addition, IL1-RaP and IL-33 RV expression levels were significantly elevated in MCS. Furthermore, IL-33 expression correlates with C-reactive protein (CRP) plasma levels in HF, but not in MCS patients. Increased expression of IL-1B and altered correlation patterns of IL-1 receptors indicate enhanced IL-1β signaling in MCS patients. Correlation of IL-1 receptor expression with IL-33 may hint towards a link between both pathways. Moreover, diverging expression in LV and RV suggests specific regulation of local cytokine signaling.

A Neuroligin Isoform Translated by circNlgn Contributes to Cardiac Remodeling.

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MicroRNA-520d-3p alleviates hypoxia/reoxygenation-induced damage in human cardiomyocytes by targeting ATG-12.

Hypoxia/reoxygenation (H/R) induced injury results in extensive damages to myocardial tissue in patients with coronary heart disease, which leads to heart failure. MicroRNA (miRNA) is thought to be associated with myocardial H/R injury. The purpose of this study was to investigate the in vitro role of microRNA-520d-3p in human myocardial cell (HCM) myocardial H/R injury. MTT method and Annexin V-FITC flow cytometry were employed to measure the viability and apoptosis of H/R treated HCM. RT-qPCR was employed to determine miRNA and mRNA expression. MicroRNA-520d-3p mimic and microRNA-520d-3p inhibitor were used to overexpression and inhibit the expression of microRNA-520d-3p. In addition, pcDNA3.1-ATG12 was used to upregulate ATG12 expression. The protein levels of ATG12, Bcl-2 and autophagy related-genes were determined by western blotting. Hypoxia/reoxygenation (H/R) injury could inhibit cell viability, apoptosis and inhibited microRNA-520d-3p expression in HCM. The down-regulation of microRNA-520d-3p inhibited cell viability and induced apoptosis in HCM. The overexpression of microRNA-520d-3p attenuated the effects of H/R treatment on the viability and apoptosis of HCM cells. In addition, microRNA-520d-3p inhibited the expression of autophagy-associated 12 (ATG12). More importantly, H/R treatment could promote autophagy in HCM, and microRNA-520d-3p mimic transfection could significantly reverse this effect. Our result indicated that overexpression of microRNA-520d-3p attenuated the effect of H/R treatments on cell viability, apoptosis and autophagy, through partly regulating ATG12 expression in HCM.

Levels of phospholipids and triacylglycerol-containing omega 3 fatty acids in myocardial tissue of patients with myocardial infarction: analyzed by a lipidomics profiling method

Abstract Objective According to population-based studies, low omega 3 fatty acid (omega3FA) intake and high levels of serum triacylglycerol (TAG) are associated with cardiovascular diseases. Recent advances in mass spectrometry allow molecular lipid (lipidomics) profiling, which may enhance cardiovascular risk prediction. In this study, we assessed the levels of omega3FA-containing phospholipids (PL) and TAG in myocardial tissues of patients with and without myocardial infarction (MI) using a lipidomics profiling method. Methods We performed lipidomics profiling of human left atrial appendage (LAA) tissue of 29 consecutive patients receiving off-pump coronary bypass surgery with standard LAA resection. The patients were divided into the MI group (n=7) and an age- and gender-matched non-MI group (n=7). Results Lipidomics profiling revealed that the MI group tended to have low levels of phosphatidylcholines (PC), phosphatidylethanolamine (PE), lysophosphatidylethanolamine (LPE), and plasmalogen, and high levels of TAG species. Individual molecular species containing omega3FA, such as PC (18:0/20:5; 3,200±1,200 vs. 4,500±910 pmol/g tissue, p=0.04) and plasmalogen (18:1/20:5; 57,000±21,000 vs. 91,000±28,000 pmol/g tissue, p=0.02), were significantly lower in the MI group than in the non-MI group. Conclusions To our knowledge, this is the first study to determine the levels of omega3FA-containing PL and TAG in myocardial tissue using lipidomics profiling. We discovered that lower levels of omega3FA-containing PL and higher levels of TAG existed in myocardial tissues of patients with MI than in those of patients without MI. Accordingly, the lipidomics profiling method for human myocardial tissue may be useful for developing therapy targets for cardiovascular diseases. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): MEXT/JSPS KAKENHI Grant

Correlation between Serum Markers of Adverse Left Ventricular Remodelling and Gene Expression Levels Measured in the Myocardial Tissue of Patients with Chronic Primary Mitral Regurgitation

Abstract Background: Chronic primary mitral regurgitation (CPMR) is characterized by progressive myocardial hypertrophy, fibrosis and dilatation. Although molecular markers of adverse left ventricular (LV) remodelling have been identified in the progression from compensated to decompensated heart failure in these patients, serum markers that could guide the optimal timing of intervention in these patients are still needed. Here we describe the correlation between the levels of expression of several genes important in adverse LV remodelling in CPMR and the serum levels of these markers. Methods: We performed echocardiography, cardiac catheterization, endomyocardial biopsy (EMB) and serum analysis in patients with severe CPMR during the preoperative workup for mitral valve surgery. Serum levels of N-terminal-pro hormone B-type natriuretic peptide, suppression of tumourigenicity 2, tumour necrosis factor α, Interleukin 6, FS-7-associated surface antigen (FAS), FAS ligand, matrix metalloproteinase (MMP)-1, MMP-2, MMP-9, tissue inhibitor of matrix metalloproteinases (TIMP)-1 and TIMP-4 were determined using commercially available enzyme-linked immunosorbent assays. Myocardial levels of expression of the genes encoding these proteins were determined by multiplex gene expression analysis. Results: Serum and EMBs were obtained from 12 patients with CPMR at the time of preoperative cardiac catheterization. Overall, there was no significant correlation between the serum levels and gene expression levels for the markers evaluated in this study. A non-significant inverse correlation between serum MMP-2 and myocardial MMP-2 was noted (r = −0.343, P = 0.263). Conclusion: We found a poor correlation between the myocardial gene expression levels of several markers of adverse LV remodelling in patients with CPMR and the serum levels of these markers sampled at the same time.

Autologous CXCR4+ Hematopoietic Stem Cells Injected into the Scar Tissue of Chronic Myocardial Infarction Patients Normalizes Tissue Contractility and Perfusion

Chronic myocardial infarction (CMI), represents a public health and a financial burden. Since stem cell transplant is used to regenerate cardiac tissue after acute myocardial infarction. To determine if autologous CXCR4 stem cells could restore damaged myocardial tissue in patients with CMI lesions. 20 NYHA grade III male patients with CMI defined by clinical, biochemical, ECG and echocardiographic parameters were included. Patients were treated with G-CSF for 6d before isolating their autologous stem cells from PBMCs. Cell phenotyping was done by cytofluorometry using monoclonal antibodies (anti-CXCR4, -CD34, -48, -117, -133, -Ki67, -SDF1 and CXCR4); CXCR4 cell subpopulations isolated by sorting were adjusted to 1×108cells by subpopulation and injected in a circular pattern into the cicatrix previously defined by echocardiography. Patients were followed for 6 and 12months. Six months after cell implant improvements in left ventricle ejection fraction (from 33-50%), stress rate values (from -3/-9% to -18/-22%), stress tests (from 4-12 METS), and the quantity of left ventricle affected segments (3-9) disappeared according to the G-SPECT images. 12months evaluations did not show significant differences. Interestingly, 3months after cell implant the ECG showed normal electrical activity in 9 patients whereas after 6months it was normal in all the patients. These results ratify that locally injected autologous CXCR4+ bone marrow-derived stem cells have a physiological and a clinical impact in patients with CMI.

P5992Why aortic valve disease may persist after surgery? A joint basic science - Clinical effort

Abstract Background Diseases of the aortic valve are a common reason for heart surgery. Aortic stenosis (AS) is associated with pressure and aortic regurgitation (AR) with a volume overload of the left ventricle (LV). Over time both pathologies lead to systolic and diastolic heart failure, while progressive downregulation of β-adrenoceptors occurs. While LV re-remodeling occurs in the majority of patients after aortic valve surgery, LV dysfunction persists in one fourth of such patients and leads to a terminal heart failure. We aimed to investigate whether differential remodeling in the protein kinase A (PKA) dependent inotropic response in myocytes and myocardial tissue obtained from patients undergoing aortic valve surgery is associated with the LV re-remodeling after surgery. Methods Preoperatively, pro BNP levels were measured and left ventricular strain analysis via echocardiography was performed. Interventricular septal biopsy was obtained intraoperatively in 10 patients who underwent aortic valve surgery. In-vitro contractility was analyzed in myocardial tissue paced with 4 Hz at 37 °C. Freshly isolated cells were transduced with an adenovirus expressing a cytosolic Förster resonance energy transfer (FRET) based cAMP biosensor (Epac1-camps). After 48 hours of culture, Föster-resonance energy transfer (FRET) was used for the first time to measure cAMP in 60 isolated human ventricular myocytes. Isoprenaline (10 nM – 10 μM) was used for β-adrenoceptor activation and forskolin (10 μmol) to activate adenylyl cyclase directly. Results We found a significantly downregulated β-adrenergic sensitivity in cardiomyocytes of patients with aortic valve disease, although contractile response to forskolin was maintained. Furthermore, we found a clear association between reduced sensitivity to isoprenaline (i.e., high EC50 values) and low maximum effect size to isoprenaline in myocardial tissue of patients with aortic valve disease, pointing out relevant β-adrenoceptor dysfunction. There were no significant differences in basal myocardial force between tissue samples of patients with AR and AS. Conclusion Collectively, our data show a profound remodelling in the cAMP/PKA pathway in patients with aortic valve disease. These disturbances may have an impact on the postoperative ventricular function and possibly on the long-term LV re-remodelling after aortic valve surgery.

The usefulness of cardiovascular magnetic resonance imaging in children with myocardial diseases.

Cardiovascular magnetic resonance (CMR) imaging is a clinically proven and reliable diagnostic method for the assessment of morphology, function, and characteristics of myocardial tissue in patients with myocardial diseases. The use of gadolinium contrast agents has created new diagnostic possibilities for tissue characterisation in patients with suspected or known cardiomyopathy, myocarditis, and cardiac tumours. To evaluate the usefulness of CMR in the diagnostic process in children with myocardial diseases and to compare the results of CMR and other non-invasive cardiovascular methods, including echocardiography. The study included 112 children, with an average age of 12 ± 4.64 years, with various forms of myocardial disease: 63 children with hypertrophic cardiomyopathy (HCM), 9 with suspected myocarditis, 5 with history of myocarditis, 4 with dilated cardiomyopathy (DCM), 9 with suspected arrhythmogenic right ventricular cardiomyopathy (ARVC), 6 with left ventricular non-compaction cardiomyopathy (LVNC), 9 with suspected restrictive cardiomyopathy (RCM) to be differentiated with constrictive pericarditis (CP), and 7 with cardiac tumours. CMR confirmed the echocardiographic diagnosis of HCM in 92% of children and ruled it out in 8%, and in three children apical hypertrophy was found. CMR revealed the presence of myocardial fibrosis in 60% of patients with HCM. In 33% of children with clinically suspected myocarditis CMR confirmed this diagnosis, while in 44% of them DCM was recognised. Of the five children with a history of myocarditis, in one patient CMR performed 13 years after myocarditis revealed features of post-inflammatory DCM. In 75% of patients with the echocardiographic diagnosis of post-inflammatory DCM the result of CMR was consistent. CMR ruled out the presence of ARVC in 89% of children. Echocardiographic and CMR diagnosis of LVNC was consistent in 67% of children. CMR confirmed the clinical diagnosis of RCM in 63% of patients, and in one patient CP was recognised. CMR confirmed the presence of cardiac tumour in 57% of children and excluded it in 43% of patients. CMR is increasingly recognised as an important tool in the investigation of myocardial disease and should be part of routine clinical work-up. CMR provides an additional diagnostic technique to assess the presence or exclusion of an active myocarditis. In children with clinical and echocardiographic suspicion of LVNC, ARVC, RCM, CP, and cardiac tumours CMR can conclusively confirm the presence of the disease.

Interaction between expression of angiogenic factors and pathology of the microvasculature and cardiomyocytes in myocardial tissue of patients with diabetes mellitus

Sudden death with myocardial infarction has always been a challenging issue for the investigators and forensic pathologists. When a person suffering from angina or myocardial infarction is simultaneously suffering from diabetes mellitus issue becomes even more complex for the investigators as usual signs and symptoms of MI may not manifest so as to rouse a suspicion of MI. This study will help the pathologists to understand the microscopic changes of diabetic cardiomyopathy better in a case having MI with diabetes. This study was done in 47 cases to know the pathology of microvasculature and cardiomyocytes in myocardial tissue of diabetic patients and expression of angiogenic factors.

Truncating Plakophilin-2 Mutations in Arrhythmogenic Cardiomyopathy Are Associated With Protein Haploinsufficiency in Both Myocardium and Epidermis

Arrhythmogenic cardiomyopathy (AC) is a hereditary cardiac condition associated with ventricular arrhythmias, heart failure, and sudden death. The disease is most often caused by mutations in the desmosomal gene for plakophilin-2 (PKP2), which is expressed in both myocardial and epidermal tissue. This study aimed to investigate protein expression in myocardial tissue of patients with AC carrying PKP2 mutations and elucidate whether keratinocytes of the same individuals exhibited a similar pattern of protein expression. Direct sequencing of 5 AC genes in 71 unrelated patients with AC identified 10 different PKP2 mutations in 12 index patients. One patient, heterozygous for a PKP2 nonsense mutation, developed severe heart failure and underwent cardiac transplantation. Western blotting and immunohistochemistry of the explanted heart showed a significant decrease in PKP2 protein expression without detectable amounts of truncated PKP2 protein. Cultured keratinocytes of the patient showed a similar reduction in PKP2 protein expression. Nine additional PKP2 mutations were investigated in both cultured keratinocytes and endomyocardial biopsies from affected individuals. It was evident that PKP2 mutations introducing a premature termination codon in the reading frame were associated with PKP2 transcript and protein levels reduced to ≈50%, whereas a missense variant did not seem to affect the amount of PKP2 protein. The results of this study showed that truncating PKP2 mutations in AC are associated with low expression of the mutant allele and that the myocardial protein expression of PKP2 is mirrored in keratinocytes. These findings indicate that PKP2 haploinsufficiency contributes to pathogenesis in AC.

MicroRNA-150 inhibits expression of adiponectin receptor 2 and is a potential therapeutic target in patients with chronic heart failure

Adiponectin is an anti-inflammatory adipocytokine believed to be involved in the pathogenesis of chronic heart failure (CHF). We aimed to characterize the expression of adiponectin and its receptors in CHF and to assess the impact of microRNAs on the cardiac adiponectin system. Expression of adiponectin and adiponectin receptors (ADIPOR1 and ADIPOR2) was studied by qPCR and immunohistochemistry in myocardial tissues of patients with end-stage CHF and control subjects. MicroRNA binding was evaluated by cloning of an ADIPOR2 3´-untranslated-region reporter construct and subsequent transfection experiments. Effects of miRNA transfection were analyzed in cardiomyocyte cell cultures by qPCR and Western blotting. Gene silencing of ADIPOR2 was performed by siRNA transfection, and the effects of hypoxia/serum starvation were analyzed by flow cytometry. Although CHF patients displayed elevated plasma adiponectin levels, myocardial adiponectin expression generally was very low. In CHF, cardiac ADIPOR1 expression increased by >4-fold, whereas the increase in ADIPOR2 was less than 2-fold. Reporter gene assays on constructs containing the ADIPOR2-3'-untranslated region suggest that microRNA-150 specifically repressed ADIPOR2 expression. Transfection of cardiomyocytes with premiR-150 precursor molecules resulted in 60% down-regulation of ADIPOR2 mRNA and a significant reduction of ADIPOR2 protein expression. MicroRNA-150 was substantially expressed in both normal and CHF myocardium, with a 1.7-fold higher expression in CHF. Finally, knock-down experiments elucidated a stress-protective role of ADIPOR2 in cardiomyocytes. MicroRNA-150 counteracts ADIPOR2 up-regulation in CHF and thus may contribute to adiponectin resistance. Targeting microRNA-150 may be a future strategy to restore cardioprotective adiponectin effects.

Radiometry of water-containing myocardial tissue in patients with arterial hypertension

Radiometry of water-containing myocardial tissue in patients with arterial hypertension

Presence of the viral genome in the myocardial tissue of patients without clinical suspicion of myocarditis

Presence of the viral genome in the myocardial tissue of patients without clinical suspicion of myocarditis