The role of cytomegalovirus infection in ischemic heart failure progression

Objective To study an association between cytomegalovirus infection (CMV) and molecular biomarkers (NT-proBNP, tumor necrosis factor (TNF-α), Interleukin-1β) and evaluate prognostic role of CMV infection in ischemic heart failure (HF) progression during the 12-month follow-up period. Methods A total of 104 patients (61.5% men, median age of 59 [53; 62.5] years) with stable coronary artery disease and baseline left ventricular ejection fraction (LVEF) of 43% [36; 57]% were enrolled in the study. At baseline evaluation HF patients were of New York Heart Association (NYHA) class I (7.7%), class II (61.0%), and class III (31.3%). Sixty five percent of patients had prior myocardial infarction and 70.2% received prior myocardial revascularization (coronary artery bypass graft/stent). Cytomegalovirus DNA concentrations in EDTA whole-blood samples were measured using a polymerase chain reaction baseline and at 12 months of follow-up period. Serum levels of NT-proBNP, Interleukin-1β, TNF-α were measured baseline using an enzyme immunoassay. Two-dimensional transthoracic echocardiography was performed at baseline and at the 12 months. Results At baseline, all patients were divided into 2 groups: group A comprised CMV seropositive patients (n=52); group B comprised CMV seronegative patients (n=52). Plasma concentration of cytomegalovirus DNA was 1709.4 [615; 3176] copies/mL. The values of cytomegalovirus DNA significantly correlated with NT-proBNP (r=0.781), TNF-α (r=0.799) and Interleukin-1β (r=0.756). Levels of NT-proBNP were higher (p=0.0001) in group A by 36.6% than in group 2 (559 [364; 756] vs. 354.5 [279; 545.5] pg/mL, respectively). Levels of TNF-α were also higher (p<0,001) by 35.3% (8.5 [6.5; 10.9] vs. 5.5 [4.1; 7.3] ng/mL, respectively) and levels of Interleukin-1β (p<0,001) by 17.6% (19.3 [15.8; 23.75] vs. 15.9 [13.15; 18.7] ng/mL, respectively) in group A than in group B. During the 12-month follow-up period in group A the rate of HF progression was 51.6% cases, and in group B 26.9% (p=0.009). Based on ROC-analysis, baseline plasma concentration of cytomegalovirus DNA ≥2020 copies/mL (AUC=0.798; specificity 67%, sensitivity 82%; p<0.001) were identified as a cut-off values predicting development of HF progression during the 12-month follow-up period. 12-month levels of cytomegalovirus DNA did not differ (p=0,678) in comparison to baseline ones and were 1737.9 [321; 3384] copies /mL. In group A LVEF significantly increased by 18.8% from 50.5 [36.5; 56.0] to 41.0 [35.0; 50.0]%, end-systolic dimension significantly increased by 7.3%, end-diastolic dimension by 9.6% (p<0,0001), while in group B these parameters did not change. Conclusion Our data suggest that values of cytomegalovirus DNA are associated with NT-proBNP, TNF-α, Interleukin-1β levels, and may be considered as non-invasive biomarker for prediction of ischemic heart failure progression during the 12-month follow-up period. FUNDunding Acknowledgement Type of funding sources: None.

Abstract MP217: Nuclease-deficient Cas9 Transcription Factors Restore Krueppel-like Factor 15 Expression In Stressed Mouse And Human Cardiomyocytes

Transcriptional changes in cardiomyocytes drive heart failure progression, however, precise control over endogenous gene expression remains challenging. The expression of Krueppel-like factor 15 ( KLF15 ), an evolutionary conserved nuclear and cardiomyocyte specific inhibitor of WNT/CTNNB1 signalling in the heart, is lost upon cardiac remodelling, and accompanied by aberrantly active WNT/CTNNB1 resulting in heart failure progression. We investigated KLF15 expression dynamics employing CRISPR/Cas9-based tools in mouse cardiomyocytes in vivo and in human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CM) under the hypothesis that re-establishment of KLF15 levels in myocardial stress conditions prevents heart failure progression. Using a mouse model expressing enzymatically inactive Cas9 (dCas9) fused to transcriptional activators (VPR) under Myh6 -promoter control, we activated Klf15 in a murine pressure overload model by transverse aortic constriction. Delivery of Klf15 gRNAs targeted to the Klf15 promoter region via AAV9 induced Klf15 expression sufficiently to re-normalize Klf15 expression to transcript levels comparable to sham surgery hearts. This was accompanied by reduced decrease of fractional shortening as well as reduced cardiomyocyte hypertrophy in stressed Klf15 re-activated hearts compared to non-trageted (NT) gRNA hearts (n=3-8 per group, echo data from 4 and 8 weeks post-surgery). We achieved titratable KLF15 activation in dCas9VPR transgenic hiPSC-CM by selection of single and multiple gRNAs (n=3-4 replicates) and used these cells to generate human engineered myocardium by combining hiPSC-CM and fibroblasts which we subjected to isometric contractions in order to induce mechanical stress, which resulted in KLF15 expressional decrease in line with our in vivo data. This transcriptional loss was rescued in CRISPR/dCas9VPR hiPSC-CM targeted to the KLF15 locus compared to controls (n=6-9/2/4 tissues per group/casting sessions/differentiations). Additionally, TGFB1 induced cardiomyocyte stress resulted in decreased KLF15 expression levels in 2D hiPSC-CM cultures which were rescued by dCas9VPR- KLF15 targeting (n=3 experiments). In conclusion, we report controllable gene activity by CRISPR/dCas9VPR to restore the loss of KLF15 in stressed mouse and human cardiomyocytes. We furthermore evaluate the potential to gain full control over gene dose titratability with these models to validate and define novel therapeutic targets for the prevention of heart failure progression.

Molecular Imaging Using Cardiac PET/CT: Opportunities to Harmonize Diagnosis and Therapy

Purpose of Review Current therapeutic strategies to mitigate heart failure progression after myocardial infarction involve support of endogenous repair through molecular targets. The capacity for repair varies greatly between individuals. In this review, we will assess how cardiac PET/CT enables precise characterization of early pathogenetic processes which govern ventricle remodeling and progression to heart failure. Recent Findings Inflammation in the first days after myocardial infarction predicts subsequent functional decline and can influence therapy decisions. The expansion of anti-inflammatory approaches to improve outcomes after myocardial infarction may benefit from noninvasive characterization using imaging. Novel probes also allow visualization of fibroblast transdifferentiation and activation, as a precursor to ventricle remodeling. Summary The expanding arsenal of molecular imaging agents in parallel with new treatment options provides opportunity to harmonize diagnostic imaging with precision therapy.

Exosomes' function in cardiovascular protection and neovascularization implies that they might be used to treat ischemia and atherosclerotic cardiovascular diseases

Myocardial hypertrophy, injury and infarction, ventricular remodeling, angiogenesis, and atherosclerosis are all influenced by cardiac exosome proteins and miRNAs, which mediate cell-to-cell communication, stimulate or inhibit target cell activities, and have an impact on myocardial hypertrophy, injury and infarction, ventricular remodeling, angiogenesis, and atherosclerosis. Circulating cardiac-specific exosome microRNAs show potential as biomarkers for early identification of acute myocardial infarction and as prognostic indicators for ischemic cardiomyopathy and congestive heart failure progression. Exosomes' function in cardiovascular protection and neovascularization implies that they might be used to treat ischemia and atherosclerotic cardiovascular diseases. Because of their biocompatibility, circulatory stability, biological barrier penetration, limited immunogenicity, and low toxicity, exosomes have the potential to deliver therapeutic pharmacologic compounds.A greater understanding of exosome composition and activity will facilitate the development of novel therapeutic alternatives for the treatment of patients with atherosclerotic cardiovascular diseases.

Insulin Signaling In the Heart

Insulin receptors are highly expressed in the heart and vasculature. Insulin signaling regulates cardiac growth, survival, substrate uptake, utilization and mitochondrial metabolism. Insulin signaling modulates the cardiac responses to physiological and pathological stressors. Altered insulin signaling in the heart may contribute to the pathophysiology of ventricular remodeling and heart failure progression. Myocardial insulin signaling adapts rapidly to changes in the systemic metabolic milieu. What may initially represent an adaptation to protect the heart from carbo-toxicity, may contribute to amplifying the risk of heart failure in obesity and diabetes. This review article presents the multiple roles of insulin signaling in cardiac physiology and pathology and discusses the potential therapeutic consequences of modulating myocardial insulin signaling.

Whether inflammatory disorders matter for long-term prognosis after myocardial infarction?

Funding Acknowledgements Type of funding sources: None. Introduction In the acute period of myocardial infarction (MI) inflammatory disorders of blood are registered, but data of prognostic significance of these disorders is multiple-valued. Purpose Research of manifestation of the inflammatory response in patients who suffered MI, and estimation of its prognostic significance. Materials and methods 772 patients with myocardial infarction were examined. Prospective follow-up from 1 to 7 years was performed. Results The death rate during all years of follow-up was 14,2 % of all included in the study. 61% of patients died suddenly, but 26% of them died as a consequence of the progression of chronic cardiac insufficiency. In patients died suddenly lower level of lymphocytes in the first 24 hours: 1,30 ± 0,47 * 109/l vs 1,80 ± 0,73*109/l, (p = 0,03) was registered. In patients who died due to heart failure progression, authentically registered higher leukocytosis in the first 24 hours, in comparison to survived ones, reached 13,83 ± 6,00*109/l (vs 11,9 ± 3,12*109/l; p = 0,005), but to 5th day in the compared groups leukocytes levels had practically the same values (7,36 ± 1,89*109/l vs 7,47 ± 1,99*109/l; accordingly p = 0,8). In the compared groups the number of lymphocytes, expressing CD 95 did not differ authentically, but in died abruptly patients this index was rather lower. There were not authentic differences detected among groups of dead and survived patients, in terms of interleukins 1β,2, and 6, whereas TNF-α was almost twice as high in patients who died due to CHF progression. Studying inflammatory markers were not included in the number of independent indexes, connected with the risk of death when conducting multivariate regressive Cox-analysis. Conclusion In our opinion, inflammatory factors were displaced from the prognostic model for assessing the risk of death, both sudden and due to heart progression, by more powerful structural-functional predictors.