Myocardial Gene Expression Profiling Research Articles

Abstract 18520: Impaired Ubiquitin-Proteasome Function in Right Ventricular Myocardium Correlates to Postoperative Outcomes in Tetralogy of Fallot

Introduction: At the time of initial repair, patients with Tetralogy of Fallot (TOF) undergo a sudden shift from a pressure to volume loaded right ventricle (RV). It is difficult to predict how TOF RVs will respond to this hemodynamic transition. Identifying mechanisms and targets may enable interventions to improve outcomes. Hypothesis: RV myocardial gene expression profiles at the time of TOF repair correlate to pre- and early postoperative clinical outcomes. Methods: RNAseq was performed from RV myocardium resected at the time of initial TOF repair (n=44). Gene expression profiling was performed using a weighted gene correlation network analysis (WGCNA) against pre- and post-op clinical variables. Mouse pulmonary artery band (PAB, n=9) stratified by degree of RV dilation was used to correlate pathways. Results: WGCNA identified a gene module that was associated with younger age at repair and worse TOF postop outcomes (prolonged milrinone, decreased right atrial and right ventricular strain) without a concomitant association with preop oxygen saturation. Biological process gene-set enrichment analysis using the 2023 Gene Ontology library revealed enrichment of regulators for ubiquitination, cell cycle/mitosis, DNA repair, microtubule polymerization, and Rho/GTPase. PAB mouse RV demonstrated a RV-dilation severity-dependent increase in bound ubiquitin (R 2 =0.61, p=0.01) and loss of free ubiquitin (R 2 =0.72, p=0.004; Figure). Conclusions: WGCNA reveals a RV myocardial gene expression profile that is associated with preoperative characteristics and early postoperative outcomes, and which is enriched for ubiquitination regulators. The PAB mouse recapitulates a severity-dependent increase in bound ubiquitin and loss of free ubiquitin which is consistent with literature suggesting proteostatic dysfunction and accumulation of misfolded proteins in RVF. Targeting proteostatic disruption prior to TOF repair may improve postoperative outcomes.

Myocardial Remodeling in Early Chronic Kidney Disease—Mineral and Bone Disorder Model with Low Bone Turnover

Chronic kidney disease—mineral and bone disorder (CKD-MBD) plays a significant role in causing cardiovascular morbidity and mortality related to CKD. CKD-MBD has been studied during advanced stages when changes in inorganic phosphate (Pi) and its hormonal regulation are obvious. The initial phases of myocardial remodeling (MR) in early CKD-MBD remain poorly understood. We induced mild CKD-MBD in spontaneously hypertensive rats using 3/4 nephrectomy. Animals were fed standard chow, containing 0.6% phosphate. In each animal, we analyzed indices of chronic kidney injury, bone turnover and Pi exchange, and assessed the myocardial histology and gene expression profile. Applied CKD-MBD models corresponded to human CKD S1-2 with low bone turnover and without an increase in systemic Pi-regulating factors (parathyroid hormone and fibroblast growth factor 23). In mild CKD-MBD models, we found MR features characterized by cardiomyocyte hypertrophy, interstitial and perivascular fibrosis, intramyocardial artery media thickening, along with alterations in Ppp3ca, Mapk1, Jag1, Hes1, Ptch1, Numb, Lgr4 and Bmp4 genes. Among other genes, the down-regulation of Jag1 was most tightly associated with either myocardial hypertrophy or fibrosis. Myocardial alterations concurrently occurred with mild CKD-MBD and comprised fibrosis preceding cardiomyocyte hypertrophy. The histological features of MR were associated with myocardial P accumulation in settings of low bone turnover, prior to a response of systemic Pi-regulating factors and with alterations in calcineurin, ERK1/2, Notch, BMP and Hedgehog genes.

Left ventricular assist device bioinformatics identify possible hubgenes and regulatory networks involved in the myocardium of patients with left ventricular assist device.

ObjectiveThe aim of this study was to clarify the changes of myocardial gene expression profile after left ventricular assist device (LVAD) implantation and the related molecular biological significance.MethodsA thorough bioinformatic analysis to evaluate the changes in gene expression profile in patients pre-LVAD and post-LVAD was conducted. Four relevant gene expression datasets—GSE430, GSE974, GSE21610, and GSE52601 from Gene Expression Omnibus (GEO) database were downloaded. Analysis of GEO2R, Gene Ontology (GO), protein-protein interaction (PPI) were used to determine differentially expressed genes (DEGs) and their function, respectively.ResultsA total of 37 DEGs were identified, including 26 down-regulated and 11 up-regulated genes. The molecular function of DEGs were enriched in “cytokine activity,” “neurotransmitter binding,” “receptor ligand activity.” The gene set enrichment analysis (GSEA) revealed an overall marked increase of neutrophil degranulation signaling, closely correlated with the G protein coupled receptor (GPCR)—ligand binding process after LVAD assistance. 16 hubgenes in these DEGs were further selected and the biological process involved is mainly related to positive regulation of leukocyte chemotaxis mediated by chemokines.ConclusionInflammatory signaling pathway is crucial for the pathophysiology after LVAD implantation. Chemokines mediate cardiac inflammatory response and tissue remodeling after LVAD implantation through GPCR—ligand binding.

Inhibition of GCN2 Alleviates Cardiomyopathy in Type 2 Diabetic Mice via Attenuating Lipotoxicity and Oxidative Stress.

Diabetic cardiomyopathy (DCM) is a kind of heart disease that affects diabetic patients and is one of the primary causes of death. We previously demonstrated that deletion of the general control nonderepressible 2 (GCN2) kinase ameliorates cardiac dysfunction in diabetic mice. The aim of this study was to investigate the protective effect of GCN2iB, a GCN2 inhibitor, in type 2 diabetic (T2D) mice induced by a high-fat diet (HFD) plus low-dose streptozotocin (STZ) treatments or deletion of the leptin receptor (db/db). GCN2iB (3 mg/kg/every other day) treatment for 6 weeks resulted in significant decreases in fasting blood glucose levels and body weight and increases in the left ventricular ejection fraction. GCN2iB treatment also attenuated myocardial fibrosis, lipid accumulation and oxidative stress in the hearts of T2D mice, which was associated with decreases in lipid metabolism-related genes and increases in antioxidative genes. Untargeted metabolomics and RNA sequencing analysis revealed that GCN2iB profoundly affected myocardial metabolomic profiles and gene expression profiles. In particular, GCN2iB increased myocardial phosphocreatine and taurine levels and upregulated genes involved in oxidative phosphorylation. In conclusion, the data provide evidence that GCN2iB effectively protects against cardiac dysfunction in T2D mice. Our findings suggest that GCN2iB might be a novel drug candidate for DCM therapy.

Abstract 10279: Altered Myocardial Gene Expression in H2-kbm1 Mice with Orexinergic Dysfunction and Heart Failure

Introduction: Mice carrying a homozygous frameshift mutation of the class I major histocompatibility antigen H2-K1 (H2-Kbm1) exhibit impaired development of hypothalamic orexinergic neurons. Similar to mice lacking the hypocretin (orexin) 2 receptor, H2-Kbm1 mice develop dilated cardiomyopathy and systolic heart failure (HF) from an early age. Previous studies suggest response to orexinergic signaling is predictive of patient response to current HF pharmacotherapeutic regimes. Our goal was to characterize the myocardial gene expression profiles of H2-Kbm1 mice. Methods: RNA was isolated from mice hearts (wild type n=5, mutant n=7) via the Qiagen RNeasy Mini Kit. DNase treatment was done to limit contamination of genomic DNA. Gene expression was measured using Illumina nexteq500 and 550 sequencing systems from a DNA library generated via the NuGene library kit (10 ng RNA). RNA-seq data analyses including comparisons, volcano and heatmap plots were completed. Results: H2-Kbm1 mice differentially express 398 myocardial genes compared to control mice. Ingenuity pathway analysis indicates that these genes are involved in necrosis of cardiac muscle (z-score -1.8), cell death (z-score 1.6), and cardiac contractility (z-score -4). Upstream signaling analysis suggest regulation by Mir-122 (z-score 2.4), DNMT3 A and B (z-score 3.3 and 2.5), VEGF (z-score 4.6) and rosiglitazone (z-score -6.8). Canonical pathway analysis is shown in Figure 1. Conclusion: H2-Kbm1 mice develop heart failure with marked myocardial transcriptional abnormalities that lead to impaired cardiac contraction and cell death. Differentially expressed genes are predominantly involved in mitochondrial function, oxidative phosphorylation, sirtuin signaling and the TCA cycle. Regulation of these genes is associated with miR-122, DNA methylations by DNMT3 A & B, VEGF and rosiglitazone signaling. The orexin pathway is a potential target for heart failure therapeutics.

Effect of Donor Simvastatin Treatment on Gene Expression Profiles in Human Cardiac Allografts during Reperfusion

Purpose Statin therapy initiated early after heart transplantation has beneficial effects on the development of cardiac allograft vasculopathy. Recently, we showed in a randomized clinical trial that simvastatin treatment of brain-dead donors conditions the heart transplant to endure ischemia-reperfusion injury and to reduce the need for rejection-related treatments early after transplantation (Nykanen et al, 2019). In this study, we analyzed the effect of simvastatin treatment on myocardial gene expression profiles of cardiac allografts before and after reperfusion. Methods In a prospective, randomized, controlled double-blinded trial, 42 of 84 heart transplant donors received 80 mg of simvastatin via nasogastric tube, whereas the other 42 donors received no treatment. Transmural Tru-Cut biopsies were taken from the apex of the donor heart's left ventricle immediately before reperfusion and 1 hour after reperfusion. After quality control, the RNA of 40 heart biopsies from donors with simvastatin treatment and of 37 heart biopsies from donors without treatment was analyzed with RNA sequencing. Results The analysis of RNA sequencing data from myocardial biopsies of 40 + 37 patients revealed altogether 314 significantly differentially expressed genes due to simvastatin effects. Gene ontology analysis showed these genes to be related to biological functions such as leukocyte migration, regulation of complement cascade, platelet activation, chemokine receptor binding, and epithelial cell proliferation. Conclusion We have shown in previous studies that donor simvastatin treatment has protective effects against IRI in heart transplant recipients. In this study, we were able to detect significantly differentially expressed genes related to effects of simvastatin treatment. In order to single out genes that show beneficial effects of simvastatin treatment, further analysis will be conducted by exploring gene expression changes in specific biological functional categories. The complete analysis will be presented at the ISHLT 2021 congress.

Evaluation of Myocardial Gene Expression Profiling for Superior Diagnosis of Idiopathic Giant-Cell Myocarditis and Clinical Feasibility in a Large Cohort of Patients with Acute Cardiac Decompensation

Aims: The diagnostic approach to idiopathic giant-cell myocarditis (IGCM) is based on identifying various patterns of inflammatory cell infiltration and multinucleated giant cells (GCs) in histologic sections taken from endomyocardial biopsies (EMBs). The sampling error for detecting focally located GCs by histopathology is high, however. The aim of this study was to demonstrate the feasibility of gene profiling as a new diagnostic method in clinical practice, namely in a large cohort of patients suffering from acute cardiac decompensation. Methods and Results: In this retrospective multicenter study, EMBs taken from n = 427 patients with clinically acute cardiac decompensation and suspected acute myocarditis were screened (mean age: 47.03 ± 15.69 years). In each patient, the EMBs were analyzed on the basis of histology, immunohistology, molecular virology, and gene-expression profiling. Out of the total of n = 427 patient samples examined, GCs could be detected in 26 cases (6.1%) by histology. An established myocardial gene profile consisting of 27 genes was revealed; this was narrowed down to a specified profile of five genes (CPT1, CCL20, CCR5, CCR6, TLR8) which serve to identify histologically proven IGCM with high specificity in 25 of the 26 patients (96.2%). Once this newly established profiling approach was applied to the remaining patient samples, an additional n = 31 patients (7.3%) could be identified as having IGCM without any histologic proof of myocardial GCs. In a subgroup analysis, patients diagnosed with IGCM using this gene profiling respond in a similar fashion to immunosuppressive therapy as patients diagnosed with IGCM by conventional histology alone. Conclusions: Myocardial gene-expression profiling is a promising new method in clinical practice, one which can predict IGCM even in the absence of any direct histologic proof of GCs in EMB sections. Gene profiling is of great clinical relevance in terms of (a) overcoming the sampling error associated with purely histologic examinations and (b) monitoring the effectiveness of therapy.

Effect of Donor Simvastatin Treatment on Gene Expression Profiles in Human Cardiac Allografts during Ischemia-Reperfusion Injury

Numerous studies have shown that statin therapy initiated early after heart transplantation has beneficial effects on the development of cardiac allograft vasculopathy. Recently, we were able to show in a randomized clinical trial that simvastatin treatment of brain-dead donors conditions the heart transplant to withstand ischemia-reperfusion injury and to reduce the need for rejection treatments early after transplantation. In this study, we analyzed myocardial gene expression profiles in cardiac allografts after donor simvastatin treatment. 84 heart transplant donors received 80 mg of simvastatin via nasogastric tube (n=42), or no treatment (n=42) in a prospective, double-blinded randomized controlled trial. Transmural Tru-Cut biopsies were taken from the apex of the donor heart's left ventricle immediately before reperfusion and 1 hour after reperfusion. The transcriptome of the biopsies will be analyzed with RNA sequencing. The preliminary analysis of RNA sequencing data from myocardial biopsies of 20 + 20 patients revealed altogether 137 significantly differentially expressed genes in all pairwise comparisons. The overall biological functions of these genes were related to gene ontology terms such as response to toxic substance, leukocyte migration, neutrophil mediated immunity, response to lipopolysaccharide, and response to oxidative stress. Enrichment pathway analysis indicated alterations in Th17, TGF-β, and muscle repair signaling pathways. At time of abstract submission, data of the remaining samples is about to enter the sequencing data analysis pipeline. We have shown in previous studies that donor simvastatin treatment induces protective effects against IRI in heart transplant recipients. In this study, we were able to detect significantly differentially expressed genes related to effects of simvastatin treatment. In order to single out genes that show beneficial effects of simvastatin treatment, further analysis will be conducted by exploring gene expression changes in specific biological functional categories, such as interleukin signaling and neutrophil degranulation. The complete analysis will be presented at the ISHLT 2020 congress.

2425Evaluation of myocardial gene expression profiling for superior diagnosis of idiopathic giant cell myocarditis in a large cohort of patients with acute cardiac decompensation

Abstract Background Idiopathic giant cell myocarditis (IGCM) diagnostics is based on differential patterns of inflammatory cell infiltration, and multinucleated giant cells (GCs) in histological sections of endomyocardial biopsies (EMBs). However, the sampling error is high for the detection of focally GCs by histopathology. We report on a clinical evaluation of a recently published method for improved differential diagnosis of this frequently fatal disease by myocardial gene expression profiling. Objective This is to improve the diagnostics of IGCM by gene expression profiling, and to demonstrate the feasibility of this method in clinical practice in a large cohort of patients. Methods In this multicenter study, EMBs of n=427 patients with clinically acute cardiac decompensation and suspected acute myocarditis were screened (mean age 47.03±15.69 years). In each patient, EMBs were analyzed by histology, immunohistology, molecular virology, and gene expression profiling. Results Out of the total of n=427 patient samples examined, GCs could be detected in 26 cases (6.0%) by histology. An established myocardial gene profile – consisting of 27 genes – was revealed resulting in a specified profile of 5 genes (chemokine receptor 5 (CCR5), chemokine receptor 6 (CCR6); carnitine palmitoyltransferase I (CPT1), toll-like receptor 8 (TLR8), and chemokine (C-C motif) ligand 20 (CCL20)) which identified histologically proven IGCM with high specificity in 25 of the 26 patients (96.2%). Applying this newly established profiling on the remaining patient samples, additional n=31 (7.3%) patients were identified for IGCM without any histological proof of myocardial GCs. Conclusions Myocardial gene expression profiling is a reliable method in clinical practice to predict IGCM even without direct histological proof of GCs in EMB section. The gene profiling is of high clinical relevance to overcome the sampling error of purely histological examination, and to control the effectiveness of the therapy. The data clearly show the importance to take EMB in unexplained acute decompensation to get a diagnosis and improve the prognosis.

Donor Simvastatin Treatment in Heart Transplantation.

Ischemia-reperfusion injury may compromise the short-term and long-term prognosis after heart transplantation. Experimental studies show that simvastatin administered to the organ donor is vasculoprotective and inhibits cardiac allograft ischemia-reperfusion injury. Eighty-four multiorgan donors were randomly assigned to receive 80 mg of simvastatin (42 donors) via nasogastric tube after declaration of brain death and upon acceptance as a cardiac donor, or to receive no simvastatin (42 donors). The primary efficacy end point was postoperative plasma troponin T and I levels during the first 24 hours after heart transplantation. Secondary end points included postoperative hemodynamics, inflammation, allograft function, rejections and rejection treatments, and mortality. Results: Organ donor simvastatin treatment significantly reduced the heart recipient plasma levels of troponin T by 34% (14 900 ± 12 100 ng/L to 9800 ± 7900 ng/L, P=0.047), and troponin I by 40% (171 000 ± 151 000 ng/L to 103 000 ± 109 000 ng/L, P=0.023) at 6 hours after reperfusion, the levels of NT-proBNP (N-terminal pro-B-type natriuretic peptide) by 36% (32 800 ± 24 300 ng/L to 20 900 ± 15 900 ng/L; P=0.011) at 1 week, and the number of rejection treatments with hemodynamic compromise by 53% within the first 30 days (P=0.046). Donor simvastatin treatment did not affect donor lipid levels but was associated with a specific transplant myocardial biopsy gene expression profile, and a decrease in recipient postoperative plasma levels of CXCL10 (C-X-C motif chemokine 10), interleukin-1α, placental growth factor, and platelet-derived growth factor-BB. Postoperative hemodynamics, biopsy-proven acute rejections, and mortality were similar. No adverse effects were seen in recipients receiving noncardiac solid organ transplants from simvastatin-treated donors. Donor simvastatin treatment reduces biomarkers of myocardial injury after heart transplantation, and-also considering its documented general safety profile-may be used as a novel, safe, and inexpensive adjunct therapy in multiorgan donation. URL: https://www.clinicaltrials.gov. Unique identifier: NCT01160978.

Effect of Donor Simvastatin Treatment on Gene Expression Profiles in Human Cardiac Allografts during Ischemia-Reperfusion Injury

Purpose Numerous studies have shown that statin therapy initiated early after heart transplantation has beneficial effects on the development of cardiac allograft vasculopathy. Recently, we were able to show in a randomized clinical trial that simvastatin treatment of brain-dead donors conditions the heart transplant to withstand ischemia-reperfusion injury and to reduce the need for rejection treatments early after transplantation. In this study, we analyzed myocardial gene expression profiles in cardiac allografts after donor simvastatin treatment. Methods 84 heart transplant donors received 80 mg of simvastatin via nasogastric tube (n=42), or no treatment (n=42) in a prospective, double-blinded randomized controlled trial. Transmural Tru-Cut biopsies were taken from the apex of left ventricle of the donor heart immediately before reperfusion and 1 hour after reperfusion. 20 heart biopsies from donors without treatment and 20 heart biopsies from donors with simvastatin treatment will be analyzed with RNA sequencing. Results The preliminary analysis of RNA sequencing data from myocardial biopsies revealed altogether 137 significantly differentially expressed genes in all pairwise comparisons. The overall biological functions of these genes were related to gene ontology terms such as response to toxic substance, leukocyte migration, neutrophil mediated immunity, response to lipopolysaccharide, and response to oxidative stress. At the KEGG pathway level, our results indicated alterations in IL-17, TNF, MAPK and the AGE-RAGE signaling pathways. Conclusion We have shown in previous studies that donor simvastatin treatment induces protective effects against IRI in heart transplant recipients. In this study, we were able to detect significantly differentially expressed genes related to effects of simvastatin treatment. In order to single out genes that show beneficial effects of simvastatin treatment, further analysis will be conducted by exploring gene expression changes in specific biological functional categories, such as interleukin signaling and neutrophil degranulation. The complete analysis will be presented at the ISHLT 2019 congress.

Altered myocardial gene expression profiling in the ischemic tissues at different time points after cardiac ischemia/reperfusion in rats

// Zhi-Xiao Li 1, * , Qiong Lin 2, * , Zhi-Gang He 1 , Quan Wang 1 , Ying-Le Chen 3 , Mao-Hui Feng 4 , Shun-Yuan Li 3 and Hong-Bing Xiang 1 1 Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China 2 Department of Anesthesiology, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou 510120, China 3 Department of Anesthesiology, The First Affiliated Quanzhou Hospital of Fujian Medical University, Quanzhou 362000, China 4 Department of Oncology, Wuhan Peritoneal Cancer Clinical Medical Research Center, Zhongnan Hospital of Wuhan University, Hubei Key Laboratory of Tumor Biological Behaviors and Hubei Cancer Clinical Study Center, Wuhan 430071, China * These authors contributed equally to this work Correspondence to: Shun-Yuan Li, email: cylfj@126.com Hong-Bing Xiang, email: xhbtj2004@163.com Keywords: cardiac ischemia/reperfusion injury; differentially expressed genes; lncRNAs; real-time quantitative PCR Received: October 07, 2017      Accepted: November 13, 2017      Published: January 03, 2018 ABSTRACT We used Agilent Gene Expression microarray to analyze differential gene and lncRNA expression patterns in the myocardial ischemia regions during ischemia/reperfusion (I/R)-induced cardiac injury in rats. Male SD rats were assigned into control group, 2 h group (30 min ischemia followed by 2 h reperfusion), 0.5 h (30 min ischemia followed by 0.5h reperfusion) group. We observed that of 18090 lncRNAs, an average of 233 lncRNAs was up-regulated in ischemic tissues of 2 h group, compared with those in control group, while an average of 6115 lncRNAs was down-regulated (with a > 2.0 fold-change and p < 0.05). Further, a total of 3135 mRNAs were differentially expressed between control group and 2h group, in which 542 mRNAs were up-regulated and 2593 mRNAs were down-regulated. Some differentially expressed genes were validated by qRT-PCR analyses of select lncRNAs in different time points after cardiac I/R injury. We unveiled that the expressions of lncRNA XR_345533.2, NONRATT025386, NONRATT024318, XR_599241.1, and NONRATT025509 were significantly up-regulated in 2h group compared with control group and 0.5h group, whereas the expression of lncRNA NR_130708.1 was down-regulated after cardiac I/R injury and had no statistically different between 0.5h group and 2h group. Otherwise, the expressions of lncRNA NONRATT028627, NONRATT021959, XR_590005.1 and NONRATT023191 were significantly up-regulated in 2h group compared with 0.5h group. These findings provide evidence for differential expression patterns of mRNAs and lncRNAs in the ischemic tissues after cardiac I/R injury in rats.

128 Genomic insights of ecg strain patten in aortic stenosis: t wave inversion and st-segment depression are underlined by different molecular pathways

BackgroundECG strain pattern is frequently presented in AS patients as a marker of LV hypertrophy and is emerging as one of the predictors for AVR. Our previous study had demonstrated...

Functional Genomics of Cardioprotection by Ischemic Conditioning and the Influence of Comorbid Conditions: Implications in Target Identification.

Ischemic heart disease including myocardial infarction develops on the basis of several risk-factors and comorbidities such as obesity, diabetes, hypertension, and hypercholesterolemia. Ischemic heart disease is the leading cause of mortality worldwide, therefore, identification of novel drug targets for cardioprotection is of great importance. Ischemic preconditioning, postconditioning, and remote conditioning trigger endogenous cardioprotective mechanisms that render the heart more resistant to lethal ischemic-reperfusion injury. However, major cardiovascular co-morbidities such as hyperlipidemia, diabetes, and their co-medications interfere with these cardioprotective mechanisms thereby limiting the efficacy of cardioprotective ischemic conditioning maneuvers. Ischemia reperfusion injury and cardioprotection by conditioning have been shown to affect global myocardial gene expression profile at the transcript level. Further understanding and the comprehensive analysis of the cardioprotective gene expression fingerprint in normal, protected, and in comorbid conditions may lead to identification of novel molecular targets for cardioprotection.

Improved diagnosis of idiopathic giant cell myocarditis and cardiac sarcoidosis by myocardial gene expression profiling

Improvement of clinical diagnostics of idiopathic giant cell myocarditis (IGCM) and cardiac sarcoidosis (CS), two frequently fatal human myocardial diseases. Currently, IGCM and CS are diagnosed based on differential patterns of inflammatory cell infiltration and non-caseating granulomas in histological sections of endomyocardial biopsies (EMBs), after heart explantation or postmortem. We report on a method for improved differential diagnosis by myocardial gene expression profiling in EMBs. We examined gene expression profiles in EMBs from 10 patients with histopathologically proven IGCM, 10 with CS, 18 with active myocarditis (MCA), and 80 inflammation-free control subjects by quantitative RT-QPCR. We identified distinct differential profiles that allowed a clear discrimination of tissues harbouring giant cells (IGCS, CS) from those with MCA or inflammation-free controls. The expression levels of genes coding for cytokines or chemokines (CCL20, IFNB1, IL6, IL17D; P < 0.05), cellular receptors (ADIPOR2, CCR5, CCR6, TLR4, TLR8; P < 0.05), and proteins involved in the mitochondrial energy metabolism (CPT1, CYB, DHODH; P < 0.05) were deregulated in 2- to 300-fold, respectively. Bioinformatic analyses and correlation of the gene expression data with immunohistochemical findings provided novel information regarding the differential cellular and molecular pathomechanisms in IGCM, CS, and MCA. Myocardial gene expression profiling is a reliable method to predict the presence of multinuclear giant cells in the myocardium, even without a direct histological proof, in single small EMB sections, and thus to reduce the risk of sampling errors. This profiling also facilitates the discrimination between IGCM and CS, as two different clinical entities that require immediate and tailored differential therapy.

(193) - Targeted Myocardial Gene Expression Profiling By RNA Sequencing

Myocardial recovery with LVAD therapy is highly variable and difficult to predict. Next generation RNA sequencing is an innovative, rapid, and quantitative approach to gene expression profiling. Our goal was to identify baseline patterns of gene expression in non-ischemic cardiomyopathies that predict myocardial recovery in response to LVAD therapy.

Pathogenesis of Chagas Cardiomyopathy: Role of Inflammation and Oxidative Stress

Described by the Brazilian scientist Carlos Chagas more than a century ago, Chagas disease (ChD) currently affects 8 to 10 million persons and causes more than 10 000 deaths each year.[1][1] Originally confined to Latin American countries, ChD had been considered an exotic disease and received less

DNA Microarray and Quantitative Analysis Reveal Enhanced Myocardial VEGF Expression with Stunted Angiogenesis in Human Tetralogy of Fallot

Tetralogy of Fallot (ToF) is a cyanotic congenital heart disease with prominent right ventricular hypertrophy (RVH) associated with impaired myocardial oxygen and nutrient supply. Consequently, the right ventricle may manifest in altered molecular phenotype with a number of adaptive and inherited gene profiles which are largely unknown. The aim of the present study was to investigate the myocardial differential gene expression profile and to assess myocardial vascularisation in patients with ToF. DNA microarray analysis on right ventricular biopsies from ToF-patients operated for primary corrective surgery (referred as ToF-1; n=12, mean age 0.5year) and age matched controls (n=6) was validated by Northern hybridisation and RT-PCR. Employing immunohistochemistry and video image analysis expression of vascular endothelial growth factor (VEGF), vascular density (by α-SMA and CD31 staining) and myocyte cross sectional area (Gomori's reticuline staining) were assessed in ToF-1 and adult patients (referred as ToF-2, n=12, mean age 30years) who underwent surgery for pulmonary regurgitation and compared the data with respective age matched controls (n=6/12). DNA microarray analysis revealed altered expression pattern for 236 genes including enhanced (1.5-2.2-fold) expression of angiogenic factors and their receptors including; VEGF, flt-1, flk-1 angiopoietin-2, FGF-2, FGF-R1, PDGF-A, whereas, flt-4, Tie, TGF-β, TGF-β3R showed decreased (1.6-3.4-fold) expression in ToF-patients. Northern blot analysis verified the expression patterns of VEGF and flk-1 in both ToF-1 and ToF-2 patients. VEGF staining in cardiomyocytes was increased in ToF-1 (1.5-fold, p<0.05) as compared to ToF-2. Video image analysis revealed enhanced vascular density (p<0.01) with enlarged myocyte cross sectional area (p<0.01), but vascular wall thickness remained unchanged in ToF-1 patients as compared to age matched controls. Our data suggest that RVH is associated with profound changes in gene profile for a number of genes, where VEGF/VEGF-R system contributes to enhance, but stunted myocardial angiogenesis in patients with ToF.

New technologies, new therapies: toward personalized medicine in heart failure patients?

This editorial refers to ‘Myocardial gene expression profiles and cardiodepressant autoantibodies predict response of patients with dilated cardiomyopathy to immunoadsorption therapy’, by S. Ameling et al., doi:10.1093/eurheartj/ehs330 During the last decade, the therapeutic management of patients with left ventricular systolic dysfunction has improved. The major goals of the treatment are to reduce the mortality and the morbidity, to improve symptoms, and, if possible, to induce a reverse remodelling of the left ventricle.1 There is indeed a direct link between survival and left ventricular ejection fraction (LVEF). Drugs such as beta-blockers2,3 or, more recently, ivabradine,4 or interventions such as resynchronization therapy5 have been associated with a significant reverse remodelling in heart failure patients. However, the responses to these different treatments are highly variable. Some patients may undergo major reverse remodelling with a dramatic increase in LVEF (i.e. responders), while in others the LEVF remains unchanged (i.e. non-responders). Early identification of responders/non-responders may be associated with a better therapeutic management. In patients with dilated cardiomyopathy (DCM), a possible physio-pathological role for circulating autoantibodies against cardiac proteins has been suggested. Immunoadsorption (IA), by removing these …

Myocardial gene expression profiles and cardiodepressant autoantibodies predict response of patients with dilated cardiomyopathy to immunoadsorption therapy

AimsImmunoadsorption with subsequent immunoglobulin G substitution (IA/IgG) represents a novel therapeutic approach in the treatment of dilated cardiomyopathy (DCM) which leads to the improvement of left ventricular ejection fraction (LVEF). However, response to this therapeutic intervention shows wide inter-individual variability. In this pilot study, we tested the value of clinical, biochemical, and molecular parameters for the prediction of the response of patients with DCM to IA/IgG.Methods and resultsForty DCM patients underwent endomyocardial biopsies (EMBs) before IA/IgG. In eight patients with normal LVEF (controls), EMBs were obtained for clinical reasons. Clinical parameters, negative inotropic activity (NIA) of antibodies on isolated rat cardiomyocytes, and gene expression profiles of EMBs were analysed. Dilated cardiomyopathy patients displaying improvement of LVEF (≥20 relative and ≥5% absolute) 6 months after IA/IgG were considered responders. Compared with non-responders (n = 16), responders (n = 24) displayed shorter disease duration (P = 0.006), smaller LV internal diameter in diastole (P = 0.019), and stronger NIA of antibodies. Antibodies obtained from controls were devoid of NIA. Myocardial gene expression patterns were different in responders and non-responders for genes of oxidative phosphorylation, mitochondrial dysfunction, hypertrophy, and ubiquitin–proteasome pathway. The integration of scores of NIA and expression levels of four genes allowed robust discrimination of responders from non-responders at baseline (BL) [sensitivity of 100% (95% CI 85.8–100%); specificity up to 100% (95% CI 79.4–100%); cut-off value: −0.28] and was superior to scores derived from antibodies, gene expression, or clinical parameters only.ConclusionCombined assessment of NIA of antibodies and gene expression patterns of DCM patients at BL predicts response to IA/IgG therapy and may enable appropriate selection of patients who benefit from this therapeutic intervention.