A methylation-dependent checkpoint by SETD7 promotes myocardial ischemic injury in mice and men

Background

Despite appropriate revascularization strategies, a significant number of patients with myocardial infarction (MI) develop ischemic heart failure suggesting that breakthrough therapies are yet to be approved in this setting. Methylation of non-histone proteins is emerging as a central regulatory mechanism in health and disease. The methyltransferase SETD7 has been shown to methylate and alter the function of a variety of proteins in vitro, however, its function in the heart is poorly understood.

Purpose

To determine the role of SETD7 in myocardial ischemic injury.

Methods

Neonatal rat ventricular myocytes (NRVM) were exposed to normal glucose levels or glucose deprivation (GD) for 15 h, in the presence of the selective SETD7 inhibitor (R)-PFI-2 or its inactive enantiomer (S)-PFI-2. Western blot and real-time PCR were employed to investigate the effects of energy stress on SETD7 and the Hippo pathway, while apoptosis and oxidative stress were assessed by Caspase-3 activity assay and mitoSOX staining. YAP transcriptional activity was assessed by chromatin immunoprecipitation assay (ChIP) while its localization and methylation were examined by confocal microscopy and immunoblotting, respectively. SETD7 knockout (SETD7−/−) mice and wild-type (WT) littermates underwent myocardial ischemia-reperfusion (I/R) injury (1h coronary ligation /24 h of reperfusion) followed by assessment of cardiac function by echocardiography. Left ventricular (LV) myocardial samples were collected from I/R mice and patients with ischemic cardiomyopathy (ICM), and isolated cardiomyocytes were treated with (R)-PFI-2. Finally, SETD7 expression was also assessed in peripheral blood mononuclear cells (PBMCs) from patients with ST-elevation MI (STEMI).

Results

SETD7 was activated upon energy deprivation in cultured NRVMs and methylated YAP, leading to its cytosolic retention and impaired transcription of antioxidant genes MnSOD and CAT. Pharmacological inhibition of SETD7 by (R)-PFI-2 restored YAP nuclear localization thus preventing mitochondrial reactive oxygen species (mtROS) and apoptosis. SETD7 deletion in mice attenuated I/R injury, mtROS and LV dysfunction by restoring YAP-dependent transcriptional programs. SETD7/YAP dysregulation was also observed in LV specimens from ICM patients. Moreover, in cardiomyocytes isolated from I/R mice and ICM patients, (R)-PFI-2 restored YAP nuclear localization, prevented mtROS accumulation while improving myofibrillar protein contractility and Ca2+ sensitivity. Finally, SETD7 was upregulated in PBMCs from STEMI patients and negatively correlated with the expression of MnSOD and CAT.

Conclusions

SETD7-dependent methylation of YAP is an important mechanism underpinning myocardial oxidative stress and apoptosis during ischemia. Pharmacological modulation of SETD7 by (R)-PFI-2 may represent a potential therapeutic approach to prevent myocardial ischemic damage through modulation of the Hippo pathway.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): University of Zurich

Left atrial strain analysis improves non-invasive estimation of left ventricular filling pressures in takotsubo syndrome

Background

Takotsubo syndrome (TTS) is associated with a non-negligible risk of in-hospital (IH) complications. Elevated left ventricular filling pressures (LVFP), measured invasively as LV end-diastolic pressure (LVEDP), showed to predict adverse IH outcomes in this population.

Recently, novel indexes of left atrial (LA) function, including LA reservoir and LA pump strain, demonstrated a close correlation with increased LVFP in unselected patients.

Purpose

To assess the ability of LA reservoir and LA pump strain to improve non-invasive estimation of LVFP and to predict IH complications in TTS patients.

Methods

We retrospectively enrolled patients with confirmed TTS diagnosis at invasive left heart catheterization and coronary angiography. LVEDP was assessed invasively at the time of catheterization. Transthoracic echocardiography was performed with 48 hours from hospital admission. IH complications were collected, including occurrence of acute heart failure (pulmonary oedema/cardiogenic shock; Killip class III/IV), death from any cause and life-threatening arrhythmias.

Results

A total of 62 patients were analysed (72.2±10.1 years, female 80%). IH complications occurred in 25 (40.3%). Patients who experienced IH complications had higher LVEDP and lower LVEF, LA reservoir strain and LA pump strain values compared to patients without IH complications (all P≤0.001). At multivariate analysis, EF and LVEDP were independent predictors of worse IH outcomes (P≤0.001 and P=0.004 respectively). Correlation analysis proved that lower values of both LA reservoir and pump strain were associated with increasingly higher LVEDP (r −0.859, P≤0.001 and r −0.848, P≤0.001 respectively). Receiving operating characteristic (ROC) curve analysis showed that the AUC for LVEDP to predict IH complications was 0.814 (95% CI 0.679–0.949, P≤0.001) with an optimal cut-off value of 24.5 mmHg (sensitivity 77%, specificity 53%).

Therefore, we performed ROC curve analysis to compare the ability of LA strain values and standard echocardiographic parameters currently used for non-invasive LVFP assessment to predict LVEDP ≥24.5 mmHg. As a result, we obtained higher AUC for LA reservoir and pump strain [0.909 (95% CI 0.818–0.999, P≤0.001) and 0.889 (95% CI 0.789–0.988, P≤0.001), respectively] vs E/e' 0.800 (95% CI 0.663–0.937, P≤0.001), LAVi 0.666 (P=0.092) and tricuspid regurgitation (TR) peak velocity 0.582 (P=0.596). The incorporation of LA strain values in a multivariable model including E/e' ratio, LAVi and TR peak velocity to predict a LVEDP ≥24.5 mmHg led to a significant incremental predictive value (changes in χ2=11.99; P=0.002).

Conclusion

In patients with TTS, lower LA reservoir and pump strain values correlate with increased LVEDP and improve non-invasive estimation of LVFP. LA strain analysis may be an easy tool to individuate subjects at higher risk of IH complications.

Funding Acknowledgement

Type of funding sources: None.

Incessant pericarditis following the second dose of SARS-CoV-2 mRNA vaccine successfully treated with anakinra: a case report

Background

The SARS-CoV-2 pandemic has led to the development of the first mRNA vaccines used in humans. These vaccines are well tolerated, safe, and highly effective; however, post-marketing surveillance is revealing potential rare adverse effects. We report a case of incessant pericarditis following administration of the second dose of mRNA-1273 SARS-CoV-2 vaccine, unresponsive to conventional therapy, and successfully treated with anakinra.

Case summary

A 30-year-old man presented to the Emergency Department for incessant pericarditis unresponsive to evacuative pericardiocentesis and conventional first-line anti-inflammatory therapy. Given the typical ‘inflammatory phenotype’ clinically characterized by fever, C-reactive protein (CRP) elevation, and leucocytosis, we decided, in agreement with the rheumatologist team, to avoid glucocorticoid and to administer anakinra. A sudden clinical and echocardiographic improvement was observed, with complete resolution of the symptoms and of the pericardial effusion; similarly, CRP values progressively decreased. The patient was discharged at home; no recurrences of pericarditis were described at clinical and instrumental follow-up made 3 months later.

Discussion

Several cases of pericarditis have been described in patients who received the COVID-19 vaccination, especially with the mRNA vaccine that can induce a non-adaptive immunity response against the viral spike protein, triggering cardiac damage for a molecular mimicry mechanism; however, defined pathogenesis of pericarditis associated with mRNA vaccine is still missing. The clinical scenario described is characterized by the typical ‘inflammatory phenotype’, triggered by a disproportionate and uncontrolled activation of the inflammasome based on an interleukin-1 (IL-1) overproduction. We administered anakinra, an IL-1 blocking drug, with a sharp clinical, echocardiographic and laboratoristic improvement. The complete response observed in this case suggests that vaccine-related pericarditis could be triggered by an auto-inflammatory pathway based on IL-1 overproduction. Further research is, therefore, warranted to determine the mechanisms by which the mRNA vaccine may cause pericarditis in order to choose the most targeted therapy.

Levosimendan for acute right heart failure in COVID-19: another arrow in our quiver?

OBJECTIVE

SARS-CoV-2 infection is associated with a higher risk of acute right heart failure (RHF) due to primary right ventricle (RV) dilation and systemic inflammatory response, which in turn lead to microvascular and cardiomyocytes dysfunction, local hypoxia and multi-organ failure. In this clinical setting, levosimendan could be a viable therapy thanks to its right-heart tropism and its additional pleiotropic properties.

CASE REPORT

We present the case of a 72 years-old man with positive nasopharyngeal swab for SARS-CoV-2 infection, mild pulmonary involvement and clinical signs of new-onset RHF. We started a 12-hour levosimendan cycle to improve RV performance and reduce cardiac filling pressures.

RESULTS

We obtained a net clinical benefit in terms of acute RHF-related signs and symptoms, progressive renal and liver function improvement and concomitant reduction of high-sensitivity C-Reactive Protein and Interleukin-6 (IL-6) levels.

CONCLUSIONS

Acute RHF during SARS-CoV-2 infection could be related to a convergent widespread systemic inflammatory response. Thanks to its anti-inflammatory and anti-remodeling properties, levosimendan might represent a viable therapy in this clinical setting, contributing to the dampening of the inflammatory response.

Transcatheter versus surgical aortic valve replacement in patients with aortic stenosis: characterization of molecular pathways before and after treatment

Funding Acknowledgements

Type of funding sources: None.

Background/Introduction

Recently, the transcatheter aortic valve replacement (TAVR) has reformed the management of Aortic Stenosis (AS), providing a valid therapeutic alternative to surgical aortic valve replacement (SAVR). Although optimizing the timing of surgery is a crucial aspiration, the introduction of innovative pharmacological therapies able to modify disease evolution might help clinicians to treat patients in a non-invasive way. Several evidences pointed out the role of inflammation, oxidative stress, and pathological remodelling in AS natural history.

Purpose

The aim of this study is to assess biological pathways modifications after aortic valve replacement, comparing the transcatheter and the surgical approach.

Methods

We enrolled a total of 35 consecutive patients with severe symptomatic aortic stenosis undergoing aortic valve replacement with transcatheter (n = 19) or surgical (n = 16) approach. Biological samples were collected and stored before (T0) and 72 hours after the procedure (T1). We firstly performed gene expression arrays for a total of 132 genes, on two groups of pooled cDNA from peripheral blood mononuclear cells of TAVR (n = 10) and SAVR (n = 10) patients. Then, taking into account the most relevant result of the arrays, we selected 15 genes for validation.

Results

Our preliminary data showed several differences in the gene expression levels of the two groups under examination for a large number of molecules, mostly associated with the oxidative balance. More in detail, after procedure, TAVR patients showed higher levels of glutathione peroxidase 1 (GPX1, TAVR p = 0.029; SAVR p = 0.031) and glutathione reductase (GSR, p = 0.029), while SAVR patients showed higher expression of GPX1, catalase (CAT, p = 0.019) and NADPH oxidase 2 (NOX2, p = 0.008), thus confirming an intense post-operative oxidative stress particularly for patients undergoing surgery. Moreover, Caspase 3 (CASP3, p = 0.013), involved in apoptotic pathway and myocyte enhancer factor 2C (MEF2C, p = 0.036), implicated in overload induced hypertrophy genes showed a significantly reduction in their expression after TAVR.

Conclusions

In our study, we describe different gene expression signatures in patients with an AS diagnosis and their recalibration after AV replacement with two kinds of procedure, TAVR and SAVR. Our data describe for the first time an altered oxidative balance in patient undergoing aortic valve replacement, that is particularly evident for patients undergoing SAVR. A clearer understanding of biological processes taking place in the first hours post AV replacement lays the ground to a more efficient management of post-operative status and, in the incessant research for a tailored therapy, the results of our study add a little piece of information to assist clinicians in selecting the optimal procedure for each patient.

Left ventricular end-diastolic pressure predicts in-hospital outcomes in Takotsubo syndrome

Background

Takotsubo syndrome (TTS) is an acute and reversible form of myocardial injury often preceded by an emotional or physical stressful event. Of importance, TTS may be associated to serious adverse in-hospital complications. Coronary angiography and left ventricle angiography remain a cornerstone for TTS diagnosis. However, the prognostic role of invasively assessed left ventricular end-diastolic pressure (LVEDP) at the time of cardiac catheterization has never been investigated.

Purpose

We evaluated the role of invasively assessed LVEDP for predicting in-hospital complications in TTS patients compared to the most widely used echocardiographic parameters of ventricular function.

Methods

We prospectively enrolled 130 patients (mean age 71.2±11.3 years, 114 [87.7%] female) with TTS. Invasive measurement of LVEDP was performed at the time of cardiac catheterization. The rate of in-hospital complications (composite of acute heart failure, cardiogenic shock, life-threatening arrhythmias and all-cause death) was examined.

Results

In-hospital complications occurred in 37 (28.5%) patients. Patients who experienced in-hospital complications had a higher prevalence of neurological trigger and lower prevalence of emotional trigger, higher LVEDP and mean E/e' ratio and lower LV ejection fraction (LVEF) values compared to those who did not experience in-hospital complications. At multivariable Cox regression, higher LVEDP (hazard ratio [HR] 1.12, 95% confidence interval [CI] [1.05–1.20], p<0.001) and lower LVEF (HR 0.95, 95% CI [0.91–0.99], p=0.011) remained independently predictors of in-hospital complications, while emotional trigger was associated to a lower risk (HR 0.24, 95% CI [0.06–0.96], p=0.044). The area under the curve (AUC) for LEVDP in the prediction of in-hospital events was 0.776 (95% CI [0.69–0.86], p<0.001, with a sensitivity and specificity of 95% and 58% using a LVEDP cut-off value of 22.5 mmHg). The AUC was significantly higher for LVEDP than for E/e' ratio (p=0.045).

Conclusions

LVEDP measured at the time of cardiac catheterization may help in identifying TTS patients at higher risk of cardiovascular events during the hospitalization with relevant therapeutic implications. Of note, in the prediction of in-hospital events the LEVDP performed better than non-invasive indexes commonly used for the assessment of diastolic function.

Funding Acknowledgement

Type of funding sources: None.

Takotsubo syndrome: a way to reach a straightforward diagnosis

Background/Introduction

Acute stress-induced cardiomyopathy, also known as Takotsubo Syndrome (TTS), was originally classified as a benign disease. Nowadays, this assumption has changed, especially in its long-term outcome, due to TTS clinical presentation, that often mirrors the acute myocardial infarction (MI) phenotype. Current knowledge already delineate clinical features distinctive of TTS and MI patients, however, diagnosis requires multiple, expansive, and invasive medical examinations. Moreover, concerning the biological panorama, very slight is known and the lack of a tailored therapy is resented. Therefore, a biological profile for this clinical category could provide easier and less invasive diagnostic tools, leading edge towards novel therapeutic pathways.

Purpose

The aim of the study is to perform a biological profile of the TTS group compared to the ST Segment Elevation Myocardial Infarction (STEMI) in order to explore the molecular peculiarities attendant the pathophysiologic mechanisms.

Methods

We performed a gene expression array on two groups of pooled cDNA from peripheral blood mononuclear cells, from TTS (n=11) and STEMI (n=19) patients. We conducted gene expression validations for each enrolled patient through qPCR.

Results

Our preliminary data displayed several differences in gene expression levels of a grand number of cell adhesion signaling molecule between the two groups. As shown in figure 1, three gene were more expressed in TTS group: Nitric Oxide Synthase 3, also known as endothelial NOS (NOS3; p=0.002), Superoxide dismutase 1 (SOD1; p=0.03) and transferrin receptor (TFRC; p=0.005). Meanwhile, five gene displayed a higher expression in STEMI patients compared to TTS: phospholipase A2 Group 7 (PLA2G7; p=0.04), Galectin 8 (LGALS8; p=0.02), Intercellular Adhesion Molecule 1 (ICAM1; p=0.002), Hyaluronidase 2 (HYAL2; p=0.01) and Hyaluronan Receptor (CD44; p=0.0002).

Conclusions

The earliest results of this study led us to focus on fewer genes related to endothelial and oxidative stress pathways. TTS is habitually triggered by intense emotional or physical stress. Indeed, our results showed how TTS patients present higher expression of NOS3, SOD1 and TFRC, all components involved in the oxidative stress pathways. In STEMI patients, top expressed genes, such as HYAL2, CD44 and ICAM1, are all associated with extracellular matrix turnover, likely due to the presence of a stenotic plaque and the consequent endothelial derangement. The uncovering of diagnostic biomarkers in TTS might improve the early, non-invasive, stratification of this group of patients, thus facilitating novel and personalized therapeutics design.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The present study was supported by the Italian National Project Grant PRIN 2017.

Targeting the methyltransferase setd7 prevents myocardial ischemic injury: a translational study

Background

Despite appropriate revascularization strategies, a significant number of patients with myocardial infarction (MI) develop ischemic heart failure suggesting that breakthrough therapies are yet to be approved in this setting. Methylation of non-histone proteins is emerging as a central regulatory mechanism in health and disease. The methyltransferase SETD7 has shown to methylate and alter the function of a variety of proteins in vitro, however its function in the heart is poorly understood.

Purpose

In the present study we sought to determine the role of SETD7 in myocardial ischemic injury.

Methods

Neonatal rat ventricular myocytes (NRVM) were exposed to glucose deprivation (GD) for 15 h, in the presence of the selective SETD7 inhibitor [(R)-PFI-2] or its inactive enantiomer [(S)-PFI-2]. Western blot and real time PCR were employed to investigate the effects of energy stress on SETD7 and the Hippo pathway, while apoptosis and oxidative stress were assessed by Caspase-3 activity assay and mitochondrial swelling. YAP activity was assessed through chromatin immunoprecipitation assay (ChIP), its localization was examined by confocal microscopy while mono-methylation was assessed by immunoblotting. Expression of YAP-dependent antioxidant genes was assessed by western blot. SETD7 knockout (SETD7−/−) mice and wild-type (WT) littermates underwent ischemia/reperfusion (I/R) injury. Rats underwent permanent ligation of left anterior descending coronary artery (MI). Left ventricular (LV) myocardial samples were collected from mice undergoing I/R injury and patients with ischemic cardiomyopathy (ICM) and treated ex-vivo with (R)-PFI-2. SETD7 and antioxidant genes expression was assessed in peripheral blood mononuclear cells (PBMCs) from patients with ST-elevation MI (STEMI).

Results

We show that SETD7 is activated upon energy deprivation in cultured NRVMs and methylates the Hippo pathway effector YAP, leading to its cytosolic retention and impaired transcription of antioxidant genes. Pharmacological inhibition of SETD7 by (R)-PFI-2 restored YAP nuclear localization thus preventing mitochondrial reactive oxygen species (mtROS) and apoptosis. SETD7 deletion in mice attenuated I/R injury, mtROS and LV dysfunction by restoring YAP-dependent transcriptional programs. SETD7/YAP dysregulation was also observed in rats with MI and LV specimens from ICM patients. Of note, (R)-PFI-2 treatment prevented titin oxidation and myofilament stiffness in cardiomyocytes isolated from I/R mice and patients with ICM. Finally, SETD7 was upregulated in STEMI patients and its expression negatively correlated with antioxidant genes.

Conclusions

Targeting SETD7 may represent a valid therapeutic strategy to protect the heart during ischemia.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): University of Zurich

From angiotensin-converting enzyme 2 disruption to thromboinflammatory microvascular disease: A paradigm drawn from COVID-19

We concisely review clinical, autopsy, experimental and molecular data of 2019 coronavirus disease (COVID-19). Angiotensin-converting enzyme 2 disruption and thromboinflammatory microangiopathy emerge as distinctive features. Briefly, entry of the virus into microvessels can profoundly disrupt the local renin-angiotensin system, cause endothelial injury, activate the complement cascade and induce powerful thromboinflammatory reactions, involving, in particular, von Willebrand factor, that, if widespread, may lead to microvascular plugging, ischemia and, ultimately, organ failure. We believe the current COVID-19 data consolidate a widely unrecognised paradigm of potentially fatal thromboinflammatory microvascular disease.

Non invasive ventilation and right ventricle function in cardiogenic pulmonary edema: an echocardiographic perspective to select the "right" ventilatory support

Funding Acknowledgements

Type of funding sources: None.

Background

High-flow nasal cannulae oxygen therapy (HFNCOT) represents a better tolerated alternative to non-invasive pressure support ventilation (NIPSV) for acute cardiogenic pulmonary edema (ACPE) treatment. However, there are still few data on the effect of HFNCOT on cardiac function and hemodynamic.

Purpose

To assess and compare the effects of NIPSV and HFNCOT in ACPE setting on right ventricular (RV) systolic function and on indices of cardiac filling and output, as measured by echocardiography. 

Methods

 This is a cross-over controlled study, enrolling 15 consecutive patients admitted to our Cardiovascular Intensive Care Unit for ACPE and hypoxaemic, normo/hypocapnic acute respiratory failure, with P/F ratio < 200. Each patient received NIPSV, followed by HFNCOT. Full echocardiographic assessment and blood gas analysis (BGA) were performed 40 minutes from onset of each ventilation modality, respectively before NIPSV to HFNCOT switch and before HFNCOT interruption. In particular, RV function parameters, together with RV and atrial strain, were prospectively collected.

Results

 In spite of not significant changes in BGA, RV function was significantly improved under HFNCOT, as compared to NIPSV, as assessed by the following parameters: tricuspid annular plane excursion (TAPSE) (P = 0.001), RV S’ wave (P = 0.007), RV fractional area change (RVFAC) (P = 0.006). Strain analysis confirmed the significant improvement in RV function, with free wall global longitudinal strain (GLS) and free wall and septum GLS significantly higher under HFNCOT, as compared to NIPSV (-21% vs -18% P < 0.001, and -15% vs -19% P = 0.008, respectively,), and a significant increase in right atrial positive longitudinal strain (P < 0.001). 

Conclusions

NIPSV significantly affect RV function making more complex the management of patients presenting with ACPE. In this setting, HFNCOT represents a valuable alternative, providing similar respiratory outcomes while preserving good right ventricle performance.

Fluid-dynamics and biological features of unstable plaques: different shear stress for different plaques

Background

The use of Optical Coherence Tomography (OCT) in acute coronary syndromes (ACS) allows recognizing ruptured fibrous cap (RFC) and intact fibrous cap (IFC) culprit lesions. The biological differences between them, as recently pointed out in translation studies, highlight different mechanisms for a similar clinical manifestation that might deserve different therapeutic approaches. The relationship between endothelial wall shear stress (WSS) and ACS has been demonstrated, however the differences in WSS features between RFC and IFC have not been elucidated.

Purpose

The aim of this study is to provide a fluid-dynamic and biological description of unstable and stable (SA) plaques, according to OCT analysis.

Methods

We enrolled 10 SA and 20 Non-ST Elevation Myocardial Infarction (NSTEMI)-ACS patients, with IFC (n=10) and RFC (n=10) culprit lesions according to OCT analysis. We performed Real-time PCR primer array on pooled Peripheral Blood Mononuclear Cell (PBMC) for 30 different molecules whose expression is strictly dependent on WSS. High-fidelity 3D-coronary artery models were created for 3 patients per group, applying previously validated methodologies.

Results

Among the groups we found a broad difference in molecular expression (Fig. 1A), with RFC displaying higher levels of molecules involved in vasoconstriction/dilatation (EDN1, NOS3), cellular adhesion (ICAM1), and peptidase inhibition (PI16). A significantly higher WSS was observed in RFC group (p<0.001, Fig 1B and C), with larger variability and larger areas exposed to both low and high WSS (Fig. 1D). Interestingly, the molecules overexpressed in RFC are known to be upregulated by high WSS.

Conclusions

Our data demonstrated that IFC and RFC unstable plaques are associated with different WSS conditions, alongside with the expression of different molecular patterns specifically related to altered WSS. In the era of precision medicine these findings may have relevant therapeutical implications.

Funding Acknowledgement

Type of funding source: None

Plaque instability in acute coronary syndromes: a possible pathogenic role of gut microbial communities

Background

The imbalance between protective and harmful bacteria in the microbial communities leads to a non-physiological condition, known as “dysbiosis”. In the last decade, several studies have suggested that gut microbiota can contribute to the development and progression of various disease including cardiovascular disease through metabolism-mediated pathways. The production and the release of bacterial metabolites, including Trimethylamine N-oxide (TMAO), can affect host health acting to distant organs.

Purpose

The aim of the present study was to explore the gut microbiota and the levels of TMAO in patients with stable angina (SA) and acute coronary syndrome (ACS) with or without elevation of the ST segment, respectively STEMI and NSTEMI, and in control subjects.

Methods

Feces were obtained from ACS (n=31) and SA (n=23) patients and controls (n=24). Genomic DNA was isolated using the QIamp DNA Stool Mini Kit. Samples were subjected to 16S rRNA gene V3–V4 region sequencing by an Illumina MiSeq TM platform. A combination of software packages QIIME and VSEARCH was used to generate a biological observation matrix (BIOM) at different taxonomic levels (from phylum to genus). The BIOM was analysed using the Web-based program MicrobiomeAnalyst. β-diversity between groups was obtained by weighted UniFrac distance metric analysis. Serum TMAO levels were measured with a UPLC-MS/MS mass spectrometry in SA and ACS patients.

Results

β-diversity analysis showed a different bacterial composition in SA and ACS patients and controls ([PERMANOVA] F-value: 1.9706; R-squared: 0.050567; p-value <0.018) (Figure 1A). In particular, analysis between the three groups revealed a significant enrichment of Streptococcus genus in ACS patients (Kruskas Wallis test; p=0.0085) (Figure 1B). Controls and ACS revealed a similar gut microbial composition ([PERMANOVA] F-value: 0.7591; R-squared: 0.014388; p-value <0.61) (Figure 2A); in contrast, controls and SA showed separate clusters according to relative differences in taxonomic composition ([PERMANOVA] F-value: 3.0498; R-squared: 0.064821 p-value <0.006) (Figure 2B). Finally, β-diversity analysis in SA and ACS revealed different microbial communities in the two groups [PERMANOVA] F-value: 2.5103; R-squared: 0.046051; p-value <0.025) (Figure 2C) that could partially explain the severity progression of cardiovascular disease. Serum TMAO levels were higher in STEMI (n=14) as compared to SA and to NSTEMI (n=16) (respectively p=0.016 and p=0.028) (Figure 3).

Conclusion

These results, taken together, suggest that gut microbiota and its derived metabolites might play an essential role in the progression of atherosclerosis and in coronary plaque instability.

Funding Acknowledgement

Type of funding source: Other. Main funding source(s): Linea D1 Università Cattolica del Sacro Cuore

Meta-inflammation in monocytes of patients with Acute Coronary Syndrome

Background

Several studies suggest that an alteration of monocyte metabolism might be implicated in inflammatory diseases. Enhanced glycolysis might be a hallmark of pro-inflammatory monocyte subsets. Improved glycolysis enables the immune cells to generate sufficient ATP and biosynthetic intermediates to carry out its particular effector functions. For macrophages this includes phagocytosis and inflammatory cytokine production. Pyruvate Kinase isozyme M2 (PKM-2) catalyzes the final step of glycolysis producing pyruvate and ATP. Latest studies have shown that a member of Jumonji family (JMJD8) acts as a positive regulator in TNF-induced NF-kB signaling leading to pro-inflammatory pathways in macrophages and is involved in angiogenesis and cellular metabolism through interacting with PKM-2 in endothelial cells.

Purpose

The aims of the study are to assess the expression of the glycolytic key enzyme PKM-2 in CD14+ monocytes obtained from patients with non-ST-elevation myocardial infarction (NSTEMI) or with stable angina (SA). Furthermore, the expression of JMJD8 was evaluated.

Methods

30 patients with NSTEMI and 30 patients with SA were enrolled. Peripheral blood mononuclear cells were obtained from whole blood samples. For cytoplasmatic protein identification, cells were fixed and permeabilized and then incubated with fluorochrome-conjugated mAbs anti-CD14, anti-PKM-2 and anti-JMJD8. For analysis we used Two-tailed Mann-Whitney non parametric Comparison test.

Results

CD14+ monocytes from NSTEMI patients showed reduced expression of the key glycolytic enzyme PKM-2 as compared to CD14+ monocytes from SA patients (p=0.02) (Figure 1). JMJD8 expression in NSTEMI patients is increased compared with SA patients (p=0.02) (Figure 2).

Conclusion

This study introduces a role for immune-metabolism in the immunity dysregulation described in ACS patients and provides novel insights into the mechanisms responsible for coronary instability. Taking their potential interaction into account, our data suggest that in acute setting glycolysis key enzyme PKM2 expression is downregulated. Besides, JMJD8 protein levels increase in NSTEMI patients acting as potential limiting factor of PKM2 function. Moreover, our data propose the potential roles of immune-metabolism to detect novel therapeutic targets, associated with an accurate patient stratification based on immune-metabolic profiles, for prevention and treatment of atherosclerosis, in the perspective of a personalized medicine approach.

Funding Acknowledgement

Type of funding source: Private hospital(s). Main funding source(s): Fondazione Policlinico A. Gemelli

Combined atherogenic effects of celiac disease and type 1 diabetes mellitus

OBJECTIVE

Previous studies have shown a high cardiovascular risk in patients with autoimmune diseases, such as type 1 diabetes mellitus (T1DM). Conversely, few data are available about patients with celiac disease (CD). The aim of our study was to assess carotid intima-media thickness (c-IMT), in patients with T1DM, CD or both (T1DM+CD) as compared with age- and sex-matched healthy individuals (H).

METHODS

We enrolled 120 patients, 30 with T1DM, 30 with CD, 30 with T1DM+CD and 30 H. Clinical, metabolic and anthropometric data were collected. All T1DM patients were on insulin while all CD patients were on a gluten-free diet. c-IMT was evaluated by high frequency linear digital ultrasound.

RESULTS

c-IMT was significantly greater in patients with T1DM+CD than in patients with T1DM or CD (P<0.001 for both), while no difference was found between T1DM and CD. Moreover, c-IMT was greater in CD than in H (P<0.001). Glycemic control and disease duration were similar between T1DM+CD and T1DM. Lipid and anthropometric parameters were similar among groups. Furthermore, in a pooled multivariate analysis, only age and disease type were significantly correlated with c-IMT (P<0.001 for both).

CONCLUSION

Our study demonstrates that celiac patients have greater c-IMT as compared with healthy individuals. Thus, non-invasive monitoring of c-IMT in CD might be useful in preventing cardiovascular disease. Moreover, patients with T1DM+CD show more severe subclinical atherosclerosis as compared with those presenting T1DM or CD only, suggesting that the association of these autoimmune diseases might accelerate the atherosclerotic process.