The Impact of Acute Heart Failure on Frailty Degree and Outcomes in Elderly Patients with Severe Aortic Stenosis and Chronic Heart Failure with Preserved Ejection Fraction

Frailty degree plays a critical role in the decision-making and outcomes of elderly patients with severe aortic stenosis (AS). Acute heart failure (AHF) results in a severely worse clinical hemodynamic status in this population. This study aimed to evaluate the impact of AHF on frailty degree and outcomes in older patients referred for tailored interventional treatment due to AS. A total of 109 patients (68% female; mean age 83.3 ± 5.4), evaluated by a multidisciplinary path for "frailty-based management" of valve disease, were divided into two groups, one with (AHF+) and one without AHF (AHF-) and preserved ejection fraction (mean value EF: 57.4 ± 8.6). AHF occurred a mean value of 55 days before geriatric, clinical, and surgical assessment. A follow-up for all-cause mortality and readmission was conducted at 20 months. AHF+ patients showed a higher frequency of advanced frailty (53.3% vs. 46.7%, respectively), rehospitalization (35.5% vs. 12.8; p = 0.007), and death (41.9% vs. 12.8%; p < 0.001). In stepwise logistic regression analysis, AHF emerged as an independent risk factor for advanced frailty (OR: 3.8 CI 1.3-10.7; p = 0.01) and hospital readmission (OR: 3.6 CI 1.1-11.6; p = 0.03). In addition, preceding AHF was an independent determinant associated with a higher risk of mortality (HR 2.65; CI 95% 1.04-6.74; p-value 0.04). AHF is independently associated with advanced frailty and poor outcomes in elderly patients with severe AS. So, this population needs careful clinical and geriatric monitoring and the implementation of interventional therapy for AS in the early stages of frailty to avoid the occurrence of AHF and poor outcomes.

A novel TGFβR2 splice variant in patient with aortic aneurysm and family history for aortic dissection: a case report

We report the clinical presentation and genetic screening of a 31-year-old man with dilatation of the aortic root and ascending aorta and a positive family history for aortic dissection and sudden death. A novel heterozygous variant in a splice acceptor site (c.1600-1G>T) of TGFβR2 gene was identified by using a targeted multi-gene panel analysis. Bioinformatics tools predicted that the c.1600-1G>T variant is pathogenic by altering acceptor splice site at - 1 position affecting pre-mRNA splicing. These data confirm that the diverging splicing in the TGF-β pathway genes may be an important process in aneurismal disease and emphasize the utility of genetic sequencing in the identification of high-risk patients for a more patient's management able to improve outcomes and minimize costs for the care of patients with heritable thoracic aortic aneurysm and dissection.

Low HDL cholesterol and the eNOS Glu298Asp polymorphism are associated with inducible myocardial ischemia in patients with suspected stable coronary artery disease

BACKGROUND

The endothelial nitric oxide synthase (eNOS) gene deficiency is known to cause impaired coronary vasodilating capability in animal models. In the general clinical population, the eNOS gene polymorphisms, able to affect eNOS activity, were associated with cardiometabolic risk features and prevalence of coronary artery disease (CAD).

AIM

To investigate the association of eNOS Glu298Asp gene polymorphism, cardiometabolic profile, obstructive CAD and inducible myocardial ischemia in patients with suspected stable CAD.

METHODS

A total of 506 patients (314 males; mean age 62 ± 9 years) referred for suspected CAD was enrolled. Among these, 325 patients underwent stress ECG or cardiac imaging to assess the presence of inducible myocardial ischemia and 436 patients underwent non-invasive computerized tomography or invasive coronary angiography to assess the presence of obstructive CAD. Clinical characteristics and blood samples were collected for each patient.

RESULTS

In the whole population, 49.6% of patients were homozygous for the Glu298 genotype (Glu/Glu), 40.9% heterozygotes (Glu/Asp) and 9.5% homozygous for the 298Asp genotype (Asp/Asp). Obstructive CAD was documented in 178/436 (40.8%) patients undergoing coronary angiography while myocardial ischemia in 160/325 (49.2%) patients undergoing stress testing. Patients with eNOS Asp genotype (Glu/Asp + Asp/Asp) had no significant differences in clinical risk factors and in circulating markers. Independent predictors of obstructive CAD were age, gender, obesity, and low HDL-C. Independent predictors of myocardial ischemia were gender, obesity, low HDL-C and Asp genotype. In the subpopulation in which both stress tests and coronary angiography were performed, the Asp genotype remained associated with increased myocardial ischemia risk after adjustment for obstructive CAD.

CONCLUSION

In this population, low-HDL cholesterol was the only cardiometabolic risk determinant of obstructive CAD. The eNOS Glu298Asp gene polymorphism was significantly associated with inducible myocardial ischemia independently of other risk factors and presence of obstructive CAD.

A Comprehensive Review of COVID-19-Related Olfactory Deficiency: Unraveling Associations with Neurocognitive Disorders and Magnetic Resonance Imaging Findings

Olfactory dysfunction (OD) is one of the most common symptoms in COVID-19 patients and can impact patients' lives significantly. The aim of this review was to investigate the multifaceted impact of COVID-19 on the olfactory system and to provide an overview of magnetic resonance (MRI) findings and neurocognitive disorders in patients with COVID-19-related OD. Extensive searches were conducted across PubMed, Scopus, and Google Scholar until 5 December 2023. The included articles were 12 observational studies and 1 case report that assess structural changes in olfactory structures, highlighted through MRI, and 10 studies correlating the loss of smell with neurocognitive disorders or mood disorders in COVID-19 patients. MRI findings consistently indicate volumetric abnormalities, altered signal intensity of olfactory bulbs (OBs), and anomalies in the olfactory cortex among COVID-19 patients with persistent OD. The correlation between OD and neurocognitive deficits reveals associations with cognitive impairment, memory deficits, and persistent depressive symptoms. Treatment approaches, including olfactory training and pharmacological interventions, are discussed, emphasizing the need for sustained therapeutic interventions. This review points out several limitations in the current literature while exploring the intricate effects of COVID-19 on OD and its connection to cognitive deficits and mood disorders. The lack of objective olfactory measurements in some studies and potential validity issues in self-reports emphasize the need for cautious interpretation. Our research highlights the critical need for extensive studies with larger samples, proper controls, and objective measurements to deepen our understanding of COVID-19's long-term effects on neurological and olfactory dysfunctions.

Psychological Impact of a Prenatal Diagnosis of Congenital Heart Disease on Parents: Is It Time for Tailored Psychological Support?

The prenatal diagnosis of congenital heart disease (CHD) represents, for both parents, a particularly stressful and traumatic life event from a psychological point of view. The present review sought to summarize the findings of the most relevant literature on the psychological impact of prenatal diagnosis of CHD on parents, describing the most common mechanisms employed in order to face this unexpected finding. We also highlight the importance of counseling and the current gaps in the effects of psychological support on this population.

A Novel Frailty Score Based on Laboratory Parameters (FIMS Score) for the Management of Older Patients with Severe Aortic Stenosis

This study aimed to develop a novel score based on common laboratory parameters able to identify frail and sarcopenic patients as well as predict mortality in elderly patients with severe aortic stenosis (AS) for tailored clinical decision-making. A total of 109 patients (83 ± 5 years; females, 68%) with AS underwent a multidisciplinary pre-operative assessment and finalized a "frailty-based management" for the AS interventional treatment. Laboratory parameters of statistically significant differences between sarcopenic and non-sarcopenic individuals were tested in the structural equation model (SEM) to build a Frailty Inflammation Malnutrition and Sarcopenia score (FIMS score). Mortality at 20 months of follow-up was considered an outcome. FIMS score, in particular, the cut-off value ≥ 1.28 was able to identify "frail" and "early frail" patients and predict mortality with a sensitivity of 83.3% and 82.6%, respectively (p = 0.001) and was an independent determinant associated with a higher risk of mortality (HR 5.382; p-value = 0.002). The FIMS score, easily achievable and usable in clinical practice, was able to identify frail and sarcopenic patients as well as predict their adverse clinical outcomes. This score could provide appropriate guidance during decision-making regarding elderly patients with severe AS.

Marine Collagen-Based Bioink for 3D Bioprinting of a Bilayered Skin Model

Marine organisms (i.e., fish, jellyfish, sponges or seaweeds) represent an abundant and eco-friendly source of collagen. Marine collagen, compared to mammalian collagen, can be easily extracted, is water-soluble, avoids transmissible diseases and owns anti-microbial activities. Recent studies have reported marine collagen as a suitable biomaterial for skin tissue regeneration. The aim of this work was to investigate, for the first time, marine collagen from basa fish skin for the development of a bioink for extrusion 3D bioprinting of a bilayered skin model. The bioinks were obtained by mixing semi-crosslinked alginate with 10 and 20 mg/mL of collagen. The bioinks were characterised by evaluating the printability in terms of homogeneity, spreading ratio, shape fidelity and rheological properties. Morphology, degradation rate, swelling properties and antibacterial activity were also evaluated. The alginate-based bioink containing 20 mg/mL of marine collagen was selected for 3D bioprinting of skin-like constructs with human fibroblasts and keratinocytes. The bioprinted constructs showed a homogeneous distribution of viable and proliferating cells at days 1, 7 and 14 of culture evaluated by qualitative (live/dead) and qualitative (XTT) assays, and histological (H&E) and gene expression analysis. In conclusion, marine collagen can be successfully used to formulate a bioink for 3D bioprinting. In particular, the obtained bioink can be printed in 3D structures and is able to support fibroblasts and keratinocytes viability and proliferation.

Association of eNOS Glu298Asp polymorphism with cardiometabolic risk and inducible myocardial ischemia in patients with stable coronary artery disease

Background

The endothelial nitric oxide synthase (eNOS) gene deficiency is known to cause insulin resistance, hypertension, hypertriglyceridemia and impaired coronary vasodilating capability in animal models. In the general clinical population, the eNOS gene polymorphism (Glu298Asp, G894T), able to reduce eNOS activity, was associated either with features of the metabolic syndrome or prevalence of coronary artery disease (CAD).

Purpose

To investigate the possible association of Glu298Asp polymorphism with cardiometabolic risk [insulin resistance, increased triglycerides (TG) and low HDL-cholesterol (HDL-C)], obstructive CAD and inducible myocardial ischemia in stable patients with suspected coronary disease.

Methods

Six cardiology units enrolled a total of 506 consecutive patients (314 males; mean age 62±9 years) referred for suspected CAD within the BIOGEN-CARE Tuscan Region Italian Study. Among these, 325 patients underwent stress ECG or cardiac imaging to assess the presence of inducible ischemia and 436 patients underwent non invasive computerized tomography or invasive coronary angiography to assess the presence of obstructive CAD (&gt;50% stenosis in at least one major coronary vessel). Blood samples were collected from each patient for genotyping and measurements of lipid and glucose parameters. The TG/HDL-C ratio and the TyG-index [ln(TG × Fasting plasma glucose/2)] were used as synthetic markers of atherogenic dyslipidemia and insulin resistance, main components of the cardiometabolic risk.

Results

In the whole population, 49.6% of patients were homozygous for the G894allele, 40.9% heterozygotes, and 9.5% homozygous for T894. Myocardial ischemia was documented in 160/325 (49.2%) patients undergoing stress testing and obstructive CAD in 178/436 (40.8%) patients undergoing coronary angiography. Patients carrying the T allele (dominant model TT+GT vs GG) had higher TG/HDL ratio (2.7±1.8 vs 2.5±1.9, P=0.03) (Figure) without differences in other lipid and glucose markers. Independent predictors of obstructive CAD were age, gender, obesity, diabetes and TG/HDL-C ratio but not the the T allele (OR 0.80; CI 0.51–1.25; ns). Independent predictors of inducible ischemia were age, gender, obesity and the T allele (OR 1.91; CI 01.19–3.08; P=0.007). Stratifying the population for both obstructive CAD and ischemia, the T allele was associated with increased risk of ischemia (OR 1.96; CI 1.11–3.44; P=0.02) even after adjustment for the presence of obstructive CAD (OR 3.09; CI 1.85–5.78; P&lt;0.001) (Figure 1).

Conclusions

In stable patients with suspected CAD, the eNOS Glu298Asp gene polymorphism is an independent risk factor for inducible myocardial ischemia and is significantly associated with the specific cardiometabolic risk expressed by high TG and low HDL-C which independently predicts obstructive CAD.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): “BIOhumoral and GENetic predictors of CARdiac Evolving phenotype in Ischemic Heart Disease (BIOGENCARE-IHD)”; funded by Toscan Region-Programma per la ricerca regionale in materia di Salute 2009

Dysregulated insulin secretion is associated with pancreatic β-cell hyperplasia and direct acinar-β-cell trans-differentiation in partially eNOS-deficient mice

eNOS-deficient mice were previously shown to develop hypertension and metabolic alterations associated with insulin resistance either in standard dietary conditions (eNOS-/- homozygotes) or upon high-fat diet (HFD) (eNOS+/- heterozygotes). In the latter heterozygote model, the present study investigated the pancreatic morphological changes underlying the abnormal glycometabolic phenotype. C57BL6 wild type (WT) and eNOS+/- mice were fed with either chow or HFD for 16 weeks. After being longitudinally monitored for their metabolic state after 8 and 16 weeks of diet, mice were euthanized and fragments of pancreas were processed for histological, immuno-histochemical and ultrastructural analyses. HFD-fed WT and eNOS+/- mice developed progressive glucose intolerance and insulin resistance. Differently from WT animals, eNOS+/- mice showed a blunted insulin response to a glucose load, regardless of the diet regimen. Such dysregulation of insulin secretion was associated with pancreatic β-cell hyperplasia, as shown by larger islet fractional area and β-cell mass, and higher number of extra-islet β-cell clusters than in chow-fed WT animals. In addition, only in the pancreas of HFD-fed eNOS+/- mice, there was ultrastructural evidence of a number of hybrid acinar-β-cells, simultaneously containing zymogen and insulin granules, suggesting the occurrence of a direct exocrine-endocrine transdifferentiation process, plausibly triggered by metabolic stress associated to deficient endothelial NO production. As suggested by confocal immunofluorescence analysis of pancreatic histological sections, inhibition of Notch-1 signaling, likely due to a reduced NO availability, is proposed as a novel mechanism that could favor both β-cell hyperplasia and acinar-β-cell transdifferentiation in eNOS-deficient mice with impaired insulin response to a glucose load.

Advanced glycation end products, leukocyte telomere length, and mitochondrial DNA copy number in patients with coronary artery disease and alterations of glucose homeostasis: From the GENOCOR study

BACKGROUND AND AIM

Alterations of glucose homeostasis can increase advanced glycation end products (AGEs) that exacerbate vascular inflammatory disease and may increase vascular senescence and aging. This study examined the relationships between carboxymethyl-lysine (CML) and soluble receptor for AGEs (sRAGE) with leukocyte telomere length (LTL) and mitochondrial DNA copy number (mtDNAcn), as cell aging biomarkers, in patients with established coronary artery disease (CAD).

METHODS AND RESULTS

We studied 459 patients with CAD further categorized as having normal glucose homeostasis (NG, n = 253), pre-diabetes (preT2D, n = 85), or diabetes (T2D, n = 121). All patients were followed up for the occurrence of major adverse cardiovascular events (MACEs). Plasma concentrations of sRAGE and CML were measured by ELISA. mtDNAcn and LTL were measured by qRT-PCR. CML levels were significantly higher in patients with preT2D (p < 0.007) or T2D (p < 0.003) compared with those with NG. mtDNAcn resulted lower in T2D vs preT2D (p = 0.04). At multivariate Cox proportional hazard analysis, short LTL (HR: 2.89; 95% CI: 1.11-10.1; p = 0.04) and high levels of sRAGE (HR: 2.20; 95% CI: 1.01-5.14; p = 0.04) were associated with an increased risk for MACEs in patients with preT2D and T2D, respectively. T2D patients with both short LTL and high sRAGE levels had the highest risk of MACEs (HR: 3.11; 95% CI: 1.11-9.92; p = 0.04).

CONCLUSIONS

High levels of sRAGE and short LTL were associated with an increased risk of MACEs, especially in patients with diabetes, supporting the usefulness of both biomarkers of glycemic impairment and aging in predicting cardiovascular outcomes in patients with CAD.

FLASH ultra-high dose rates in radiotherapy: preclinical and radiobiological evidence

PURPOSE

Flash radiotherapy (FLASH-RT) is currently being regarded as the next breakthrough in radiation treatment of cancer, delivering ultrahigh radiation doses in a very short time, and sparing normal tissues from detrimental injury. Here we review the current evidence on the preclinical findings as well as the radiobiological mechanisms underlying the FLASH effect. We also briefly examine the scenario of available technologies for delivering FLASH dose-rates for research and their implications for future clinical use.

CONCLUSIONS

Preclinical studies report that the FLASH-RT reduces radiation-induced toxicity whilst maintaining an equivalent tumor response across different animal models. However, the molecular radiobiology underlying FLASH effect is not fully understood and further experiments are necessary to understand the biological response. Future studies also includes the design of a FLASH delivery system able to produce beams appropriate for treatment of tumors with ultra-high dose rates. All these research activities will greatly benefit from a multidisciplinary collaboration across biology, physics and clinical oncology, increasing the potential of a rapid clinical translation of FLASH-RT.

Micronucleus assay for predicting coronary artery disease: A systematic review and meta-analysis

Coronary artery disease (CAD) is the leading cause of morbidity and mortality worldwide. Coronary angiography allows an accurate assessment of the extent and severity of atherosclerotic coronary narrowing, but it provides little characterization of early detection of potentially asymptomatic vulnerable plaque. The identification of the coronary "vulnerable patient" or high-risk plaques remains a major challenge in the treatment of CAD. Recently, growing evidence shows that DNA damage plays a role in the initiation and progression of atherosclerotic plaque. Cytokinesis-block micronucleus (CBMN) assay is one of the most frequently used and validated method for assessing chromosomal damage and genetic instability. Accordingly, the purpose of this systematic review was to retrieve and discuss existing literature on the studies assessing the association between MN and angiographically-proven CAD. A total of 8 studies published between 2001 and 2017 were included in the meta-analysis. Despite a large heterogeneity between studies (I²= 99.7 %, p < 0.0001), an overall increase of MN frequencies was found in patients with CAD compared with control group (meta-MR = 1.96; 95 % CI, 1.5-3.2, p = 0.009). A subgroup analysis showed an increase in the frequency of MN formation for both two- vessel (MR = 2.13, 95 % CI: 0.9-6.9, p = 0.08) and three-vessel disease (MR = 2.89, 95 % CI: 1.84-4.55, P = 0.06). Overall, the results of this meta-analysis provide evidence of an association between CBMN and presence, extent and severity of angiographically-assessed CAD. However, the small number of papers analyzed requires further large and more rigorously designed studies, carefully considering a series of clinical confounding factors, such as the quality of the metabolic control, the influence of drugs and radiation imaging treatments.

Genetic polymorphisms of miRNA machinery genes in bicuspid aortic valve and associated aortopathy

Aim: SNPs in miRNA machinery genes may affect miRNA function by impacting their biogenesis. Here, we investigated the association between three SNPs in miRNA machinery genes (DICER rs1057035, DROSHA rs10719 and XPO5 rs11077) and bicuspid aortic valve (BAV). Materials & methods: Three polymorphisms were analyzed in 177 BAV patients and 414 healthy subjects by using a TaqMan^®SNP assay. Results: The frequencies of XPO5 rs11077 genotype were significantly different between BAV patients and controls (p = 0.022). On multivariate logistic regression analysis, the XPO5 rs11077 C allele resulted a significant predictor of BAV (odds ratio_adjusted = 0.65; CI: 0.42-0.98; p = 0.047). Conclusion: The XPO5 rs11077 SNP was associated with a decreased BAV risk supporting the causative role of miRNAs in aortic valve development.

The molecular biomarkers of vascular aging and atherosclerosis: telomere length and mitochondrial DNA4977 common deletion

Age is the dominant risk factor for the most prevalent atherosclerotic vascular diseases, including coronary artery disease, myocardial infarction, cerebrovascular disease and stroke. In human, telomere erosion and mitochondrial DNA (mtDNA) damage play a central role in the mechanisms leading to cellular aging decline. This review summarizes the most relevant findings on the role of telomere shortening and the common mtDNA⁴⁹⁷⁷ deletion in the progression and evolution of atherosclerosis by combining insight from experimental models and human clinical studies. The current evidence shows a link between telomere erosion and compromised mitochondrial function and provides a new perspective regarding their potential role as clinical biomarkers and therapeutic targets.

Functional characterization and circulating expression profile of dysregulated microRNAs in BAV-associated aortopathy

Compelling evidence has shown that microRNAs (miRs) are involved in the pathophysiology of BAV-associated aortopathy. The purpose of this study was to assess the biological role as well as the circulating expression of two miRs (miR-424-3p and miR-3688-3p) that have been previously identified as significantly dysregulated in thoracic aortic aneurysm specimens of BAV patients. Bioinformatic tools were used to predict miR gene targets followed by functional validation transfecting synthetic miR mimics and negative controls into human aortic smooth muscle cells (HASMCs). Levels of miRs and target genes were evaluated by qRT-PCR. The circulating miR expression profile analysis was assessed on plasma samples collected from a cohort of 72 patients with aortopathy including 39 BAV (33 males; 58 ± 13 years) and 33 TAV patients (26 males; 67 ± 9 years). Computational analysis revealed that SMAD7 and YAP1 were potential targets of miR-424-3p and miR-3688-3p, respectively. Transfection with mimics confirmed a significantly decreased gene expression of SMAD7 and YAP1 compared to mimic negative control (p = 0.04 and p = 0.0005, respectively) or blank control (p = 0.01 and p = 0.0007, respectively). Overexpression of miR-3688-3p also significantly upregulated pro-apoptotic caspase-3 gene expression compared to mimic negative control (p = 0.02) or blank control (p = 0.01). Furthermore, a significant down-regulation of the circulating miR-424-3p was observed in BAV compared to TAV patients (p = 0.001). In multiple linear regression analysis, the aortic valve morphology (β = - 0.29, p = 0.04) and the presence of aortic stenosis (β = - 0.28, p = 0.03) had a significant effect on the miR-424-3p expression. In conclusion, our study demonstrated that miR-424-3p and miR-3688-3p directly targeted SMAD7 and YAP1 in HASMCs, pivotal genes of the TGF-β and Hippo-signaling pathways. Circulating miR-424-3p was also found to be significantly decreased in BAV patients when compared to TAV patients, especially in patients with aortic stenosis. Further large studies of well-characterized BAV patient cohorts are needed to define the clinical significance of the miR-424-3p.

Reproductive outcomes and Y chromosome instability in radiation-exposed male workers in cardiac catheterization laboratory

Occupational radiation exposure may impact the reproductive outcome of male workers in the cardiac catheterization laboratory (cath Lab) who receive a dose of ~1-10 mSv/year. An increased copy number variation (CNV) in azoospermia factor region c (AZFc) of the Y chromosome is a marker of spermatogenic failure, previously associated with radiation exposure. This study sought to investigate the association between paternal exposure in the Cath Lab and adverse reproductive outcomes as well as to assess the induction of CNV in the AZFc region. In a case-control study, we enrolled 193 catheterization lab workers (Group I) and 164 age-matched unexposed controls (Group II). Reproductive outcomes were assessed through a structured questionnaire. Two sequence-tagged sites (SY1197 and SY579) in AZFc region were evaluated by qRT-PCR in 83 exposed and 47 unexposed subjects. Exposed workers had a higher prevalence of low birth weight in offspring (Group I = 13% vs. II = 5.3%, P = 0.02; OR_adjusted = 2.7; 95% CI: 1.1-6.3; P = 0.02). The mean of CNV (microdeletion and microduplication) for SY1197 was significantly higher in the exposed workers (Group I = 1.53 ± 0.85 vs. Group II = 1.02 ± 0.41; P = 0.0005). Despite the study design limitations, our findings show that chronic occupational radiation exposure of male workers is correlated with higher prevalence of low birth weight in offspring and instability in the Y chromosome AZFc region. Environ. Mol. Mutagen. 61:361-368, 2020. © 2019 Wiley Periodicals, Inc.

Independent and Combined Effects of Telomere Shortening and mtDNA4977 Deletion on Long-term Outcomes of Patients with Coronary Artery Disease

Aging is one of the main risk factors for cardiovascular disease, resulting in a progressive organ and cell decline. This study evaluated a possible joint impact of two emerging hallmarks of aging, leucocyte telomere length (LTL) and common mitochondrial DNA deletion (mtDNA⁴⁹⁷⁷), on major adverse cardiovascular events (MACEs) and all-cause mortality in patients with coronary artery disease (CAD). We studied 770 patients (673 males, 64.8 ± 8.3 years) with known or suspected stable CAD. LTL and mtDNA⁴⁹⁷⁷ deletion were assessed in peripheral blood using qRT-PCR. During a median follow-up of 5.4 ± 1.2 years, MACEs were 140 while 86 deaths were recorded. After adjustments for confounding risk factors, short LTLs and high mtDNA⁴⁹⁷⁷ deletion levels acted independently as predictors of MACEs (HR: 2.2, 95% CI: 1.2-3.9, p = 0.01 and HR: 1.7, 95% CI: 1.1-2.9, p = 0.04; respectively) and all-cause mortality events (HR: 2.1, 95% CI: 1.1-4.6, p = 0.04 and HR: 2.3, 95% CI: 1.1-4.9, p = 0.02; respectively). Patients with both short LTLs and high mtDNA⁴⁹⁷⁷ deletion levels had an increased risk for MACEs (HR: 4.3; 95% CI: 1.9-9.6; p = 0.0006) and all-cause mortality (HR: 6.0; 95% CI: 2.0-18.4; p = 0.001). The addition of mtDNA⁴⁹⁷⁷ deletion to a clinical reference model was associated with a significant net reclassification improvement (NRI = 0.18, p = 0.01). Short LTL and high mtDNA⁴⁹⁷⁷ deletion showed independent and joint predictive value on adverse cardiovascular outcomes and all-cause mortality in patients with CAD. These findings strongly support the importance of evaluating biomarkers of physiological/biological age, which can predict disease risk and mortality more accurately than chronological age.

Increased mitochondrial DNA4977-bp deletion in catheterization laboratory workers with long-term low-dose exposure to ionizing radiation

AIMS

Ionizing radiation may lead to mitochondrial DNA (mtDNA) mutations and changes in mtDNA content in cells, major driving mechanisms for carcinogenesis, vascular aging and neurodegeneration. The aim of this study was to investigate the possible induction of common mitochondrial deletion (mtDNA4977) and mtDNA copy number (mtDNA-CN) changes in peripheral blood of personnel working in high-volume cardiac catheterization laboratories (Cath Labs).

METHODS

A group of 147 Cath Lab workers (median individual effective dose = 16.8 mSv, for the 41 with lifetime dosimetric record) and 74 unexposed individuals were evaluated. The occupational radiological risk score was computed for each subject on the basis of the length of employment, individual caseload and proximity to the radiation source. mtDNA4977 deletion and mtDNA-CN were assessed by using quantitative real-time polymerase chain reaction.

RESULTS

Increased levels of mtDNA4977 deletion were observed in high-exposure Cath Lab workers compared with unexposed individuals ( p < 0.0001). Conversely, mtDNA-CN was significantly greater in the low-exposure workers ( p = 0.003). Occupational radiological risk score was positively correlated with mtDNA4977 deletion (Spearman's r = 0.172, p = 0.03) and inversely correlated with mtDNA-CN (Spearman's r = -0.202, p = 0.01). In multiple regression model, occupational radiological risk score emerged as significant predictor of high levels of mtDNA4977 deletion (ß coefficient = 0.236, p = 0.04).

CONCLUSION

mtDNA4977 deletion is significantly high in Cath Lab personnel. Beyond the well-recognized nuclear DNA, mtDNA damage might deserve attention as a pathogenetic molecular pathway and a potential therapeutic target of ionizing radiation damage.

A Functional Aryl Hydrocarbon Receptor Genetic Variant, Alone and in Combination with Parental Exposure, is a Risk Factor for Congenital Heart Disease

Recent experimental studies showed that ablation of the aryl hydrocarbon receptor (AhR) as well as its activation by exogenous ligands disrupt the molecular networks involved in heart formation and function, leading to congenital heart disease (CHD). However, no evidence is available about the role of AhR in humans. We assessed the prevalence of a functional AhR genetic variant (p.Arg554Lys) in CHD patients as well as its joint effects with parental exposure. A total of 128 CHD patients (76 males; age 6.2 ± 6.7 years) and 274 controls (160 males; age at birth) were genotyped for the AhR polymorphism by using the TaqMan^® Drug Metabolism Genotyping assay. Both case and control parents completed a structured questionnaire on demographic, lifestyle and preconception exposures. Genotype (p = 0.001) and allele (p < 0.0001) distributions of AhR p.Arg554Lys differed significantly between patients and controls. A significant elevated CHD risk was found under dominant (OR = 2.9, 95% CI 1.9-4.6, p < 0.0001) and additive genetic models (OR = 6.2, 95% CI 2-19, p = 0.001). There was a significant interaction between 554-Lys allele and paternal smoking exposure (OR_smoking = 1.6, 95% CI = 0.9-2.9; OR_allele = 2.6, 95% CI = 1.3-5; OR_interaction = 4.9, 95% CI = 2.4-9.9, p _interaction < 0.0001). Additionally, 554-Lys allele exacerbated the effect of maternal periconceptional exposure (OR_exposure = 1.6, 95% CI = 0.8-3; OR_allele = 2.6, 95% CI = 1.5-4.5; OR_interaction = 5.7; 95% CI = 2.6-12, p _interaction < 0.0001). Our findings showed that the AhR p.Arg554Lys polymorphism, alone and in combination with parental exposures, is associated with the CHD risk, highlighting the significant role of AhR in the cardiovascular development.

Prognostic value of mitochondrial DNA4977 deletion and mitochondrial DNA copy number in patients with stable coronary artery disease

BACKGROUND AND AIMS

Mitochondrial DNA copy number (mtDNA-CN) depletion has been recently associated with an increased cardiovascular risk. However, the integrity of mtDNA is another key aspect of the energy metabolism and mitochondrial function. We investigated the prognostic role of peripheral blood common mitochondrial deletion (mtDNA⁴⁹⁷⁷) and mtDNA-CN on long-term major adverse cardiac events (MACEs) and all-cause mortality in a cohort of patients with coronary artery disease (CAD).

METHODS

Within the Italian GENOCOR (Genetic Mapping for Assessment of Cardiovascular Risk) cohort, we studied 515 patients (450 males, 65 ± 8 years) with known or suspected stable CAD. mtDNA⁴⁹⁷⁷ deletion and mtDNA-CN were assessed in peripheral blood using qRT-PCR.

RESULTS

During a mean follow-up of 4.5 ± 1.1 years, 78 (15%) patients had MACEs (15 cardiac deaths, 17 nonfatal myocardial infarction and 46 coronary revascularizations) and 28 patients died for non-cardiac causes. Patients with high levels of mtDNA⁴⁹⁷⁷ deletion (>75th) had increased risk of MACEs (log rank = 7.2, p=0.007) and all-cause mortality (log rank = 5.7, p=0.01) compared with patients with low mtDNA⁴⁹⁷⁷ deletion (≤75th). Multivariate Cox regression analysis showed that log mtDNA⁴⁹⁷⁷ was a significant predictor of MACEs (HR = 2.17; 95% CI, 1.31-3.59; p=0.003) and all-cause mortality (HR = 2.03; 95% CI: 1.13-3.65, p=0.02). Log mtDNA-CN was not significantly associated with MACEs or all-cause mortality. However, patients with high mtDNA⁴⁹⁷⁷ deletion (>75th) and low mtDNA-CN (<25th) had significantly increased risk for MACEs (HR: 3.73; 95% CI: 1.79-7.79; p=0.0005).

CONCLUSIONS

Mitochondria DNA damage was associated with an increased risk of MACEs and all-cause mortality in patients with stable CAD, confirming the critical role of mitochondrial dysfunction in atherosclerosis.

Targeted Next-Generation Sequencing in Patients with Non-syndromic Congenital Heart Disease

Congenital heart disease (CHD) is a genetically heterogeneous disease. Targeted next-generation sequencing (NGS) offers a unique opportunity to sequence multiple genes at lower cost and effort compared to Sanger sequencing. We tested a targeted NGS of a specific gene panel in a relatively large population of non-syndromic CHD patients. The patient cohort comprised 68 CHD patients (45 males; 8.3 ± 1.7 years). Amplicon libraries for 16 CHD-strictly related genes were generated using a TruSeq^® Custom Amplicon kit (Illumina, CA) and sequenced using the Illumina MiSeq platform. Sequence data were processed through the MiSeq Reporter and wANNOVAR softwares. After applying stringent filtering criteria, 20 missense variants in 9 genes were predicted to be damaging and were validated by Sanger sequencing with 100% concordance. Fourteen variants were present in public databases with very rare allele frequency, of which four variants (p.Arg25Cys in NKX2-5, p.Val763Ile in ZFPM2, p.Arg1398Gln and Gly1826Asp in MYH6) have been previously linked to CHD or cardiomyopathy. The remaining six variants in four genes (GATA4, NKX2-5, NOTCH1, TBX1) were novel mutations, currently not found in public databases, and absent in 200 control alleles of healthy subjects. Four patients (5.8%) carried two missense variants (1 compound heterozygote in the same gene and 3 double heterozygotes in different genes), with possibly synergistic deleterious effects. Targeted NGS is a powerful and efficient tool to detect DNA sequence variants in multiple genes, providing the opportunity for discovery of the co-occurrence of two or more missense rare variants.

Environmental pollutants: genetic damage and epigenetic changes in male germ cells

About a quarter of the human diseases occurs for exposure to air pollution. The male reproductive system, and especially spermatogenesis, seems to be particularly sensitive. As result, male infertility is increasing in industrial countries becoming a top priority for public health. In addition to psychological distress and economic constraints, poorer semen quality may have trans-generational effects including congenital malformations in the offspring and predispose to later onset adult diseases. Genetic and epigenetic alterations are involved in the failure of spermatogenesis. In this paper, we reviewed the major evidences of the effects of air pollutants on male infertility as well as the role of sperm DNA damage and epigenetic changes in affecting spermatogenesis. A better knowledge on the effects of air contaminants on the molecular mechanisms leading to infertility is of huge importance to help clinicians in identifying the cause of infertility but above all, in defining preventive and therapeutic protocols.

Genetic and Epigenetic Mechanisms Linking Air Pollution and Congenital Heart Disease

Epidemiological studies strongly suggest that parental air pollutants exposure during the periconceptional period may play a major role in causing fetal/newborn malformations, including a frequent heterogeneity in the methods applied and a difficulty in estimating the clear effect of environmental toxicants. Moreover, only some couples exposed to toxicants during the pre-conception period give birth to a child with congenital anomalies. The reasons for such phenomena remain elusive but they can be explained by the individual, innate ability to metabolize these contaminants that eventually defines the ultimate dose of a biological active toxicant. In this paper, we reviewed the major evidence regarding the role of parental air pollutant exposure on congenital heart disease (CHD) risk as well as the modulating effect on detoxification systems. Finally, major epigenetic alterations induced by adverse environment contaminants have been revised as possible mechanisms altering a correct heart morphogenesis.

Radiobiological Effectiveness of Ultrashort Laser-Driven Electron Bunches: Micronucleus Frequency, Telomere Shortening and Cell Viability

Laser-driven electron accelerators are capable of producing high-energy electron bunches in shorter distances than conventional radiofrequency accelerators. To date, our knowledge of the radiobiological effects in cells exposed to electrons using a laser-plasma accelerator is still very limited. In this study, we compared the dose-response curves for micronucleus (MN) frequency and telomere length in peripheral blood lymphocytes exposed to laser-driven electron pulse and X-ray radiations. Additionally, we evaluated the effects on cell survival of in vitro tumor cells after exposure to laser-driven electron pulse compared to electron beams produced by a conventional radiofrequency accelerator used for intraoperative radiation therapy. Blood samples from two different donors were exposed to six radiation doses ranging from 0 to 2 Gy. Relative biological effectiveness (RBE) for micronucleus induction was calculated from the alpha coefficients for electrons compared to X rays (RBE = alpha laser/alpha X rays). Cell viability was monitored in the OVCAR-3 ovarian cancer cell line using trypan blue exclusion assay at day 3, 5 and 7 postirradiation (2, 4, 6, 8 and 10 Gy). The RBE values obtained by comparing the alpha values were 1.3 and 1.2 for the two donors. Mean telomere length was also found to be reduced in a significant dose-dependent manner after irradiation with both electrons and X rays in both donors studied. Our findings showed a radiobiological response as mirrored by the induction of micronuclei and shortening of telomere as well as by the reduction of cell survival in blood samples and cancer cells exposed in vitro to laser-generated electron bunches. Additional studies are needed to improve preclinical validation of the radiobiological characteristics and efficacy of laser-driven electron accelerators in the future.

3'UTR SNPs and Haplotypes in the GATA4 Gene Contribute to the Genetic Risk of Congenital Heart Disease

INTRODUCTION AND OBJECTIVES

Single-nucleotide polymorphisms within a microRNA binding site can have different effects on gene expression, influencing the risk of disease. This study aimed to evaluate the association between single-nucleotide polymorphisms and haplotypes in the 3'UTR of the GATA4 gene and congenital heart disease risk.

METHODS

Bioinformatics algorithms were used to analyze single-nucleotide polymorphisms in putative microRNA-binding sites of GATA4 3'UTR and to calculate the difference in free energy of hybridization (ΔFE, kcal/mol) for each wild-type vs the variant allele.

RESULTS

The study population comprised 146 Caucasian patients (73 males; 6.68 ± 7.79 years) and a 265 healthy newborn participants (147 males). The sum of all |ΔFE| was considered to predict the biological importance of single-nucleotide polymorphisms binding more microRNAs. Next, the 4 polymorphisms (+1158C > T, +1256 A > T, +1355 G > A, +1521C > G) with the highest predicted |ΔFEtot| (9.91, 14.85, 11.03, 21.66kcal/mol, respectively) were genotyped in a case-control study (146 patients and 250 controls). Applying a correction for multiple testing only the +1158 T allele was found to be associated with a reduced risk showing significant difference between patients and controls. Haplotype analysis showed that the T-T-G-C haplotype (more uncommon in congenital heart diseases than in controls) was associated with a significantly decreased risk (P = .03), while the rare C-A-A-C haplotype, which was very uncommon in controls (0.3%) compared with the disease (2.4%), was associated with a 4-fold increased risk of disease (P = .04).

CONCLUSIONS

Common variants in 3'UTR of the GATA4 gene jointly interact, affecting the congenital heart disease susceptibility, probably by altering microRNA posttranscriptional regulation.

Next-generation sequencing technology in the genetics of cardiovascular disease

In recent years, next-generation sequencing (NGS) technologies have revolutionized approaches to genetic studies, making whole-genome sequencing a possible way for obtaining global genomic information. At present, three most NGS platforms are used in genetics for clonally amplified templates. These technologies share general processing steps but differing in specific technical details that determine their limits or advantages. NGS has been recently shown to have great potential for identifying novel causative mutations in different disorders. It is expected that the NGS will be increasingly important in the study of inherited and complex traits such as cardiovascular diseases (CVDs). Indeed, the identification and characterization of genes that enhance prediction of CVDs risk remain an important challenge for improving prevention and treatment.

Analysis of miRNAs Targeting 3'UTR of H2AFX Gene: a General in Silico Approach

MiRNAs are gene (post-transcriptional) regulators that bind the 3'UTR of target genes. Single-nucleotide polymorphisms (SNPs) located within a miRNA binding site can impact miRNAdependent gene regulation by weakening or reinforcing the microRNA:mRNA bond. We present a general in silico approach enabling researchers to "predict" which of the several SNPs of 3'UTR of H2AFX gene can mainly affect its regulation. H2AFX gene encodes a member of the H2A histone family which is central in the detection of and response to DNA double-strand breaks. All the 17 common SNPs located within the 3'UTR of H2AFX gene were analyzed for putative miRNA-binding sites by using different databases (such as dbSNP and miRBase) and pre-existing algorithms (such as MicroSNiPer and RNAcofold) in order to calculate the minimum free energies of hybridization of the microRNA:mRNA duplex, for both the wild-type and mutant alleles. The difference in these energies was also calculated. Since in each tissue one target sequence can bind only one miRNA at a time, the sum of all the difference of energies can be considered a relevant parameter for predicting the importance of a SNP with respect to miRNA regulation. We used tertiles to classify the SNPs and provide a priority list based on their theoretically strongest impact on miRNA binding. By using the described approach, we provided the basis for a reasoned, user-friendly algorithm-driven selection of SNPs impacting miRNA biology. The proposed method is helpful for selecting SNPs having a more powerful (putative) biological function, minimizing workflow and costs for experimental and clinical investigations.

Congenital heart disease: the crossroads of genetics, epigenetics and environment

Congenital heart diseases (CHDs) are recognized as the most common type of birth malformations. Although recent advances in pre- and neonatal diagnosis as well as in surgical procedures have reduced the morbidity and mortality for many CHD, the etiology for CHD remains undefined. In non-syndromic and isolated (without a familial history or a Mendelian inheritance) forms of CHDs, a multifactorial pathogenesis with interplay between inherited and non-inherited causes is recognized. In this paper, we discuss the current knowledge of the potential molecular mechanisms, mediating abnormal cardiac development in non-syndromic and isolated CHD, including mutations in cardiac transcription factors, the role of somatic mutations and epigenetic alterations as well as the influence of gene-environment interactions. In the near future, the advent of high-throughput genomic technologies with the integration of system biology will expand our understanding of isolated, non-syndromic CHDs for their prevention, early diagnosis and therapy.

Genetic risk score and acute skin toxicity after breast radiation therapy

Genetic predisposition has been shown to affect the severity of skin complications in breast cancer patients after radiotherapy. Limited data exist regarding the use of a genetic risk score (GRS) for predicting risk of tissue radiosensitivity. We evaluated the impact of different single-nucleotide polymorphisms (SNPs) in genes related to DNA repair mechanisms and oxidative stress response combined in a GRS on acute adverse effects induced by breast radiation therapy (RT). Skin toxicity was scored according to the Radiation Therapy Oncology Group (RTOG) criteria in 59 breast cancer patients who received RT. After genotyping, a multilocus GRS was constructed by summing the number of risk alleles. The hazard ratio (HR) for GSTM1 was 2.4 (95% confidence intervals [CI]=1.1-5.3, p=0.04). The other polymorphisms were associated to an increased adverse radiosensitivity, although they did not reach statistical significance. GRS predicted roughly 40% risk for acute skin toxicity per risk allele (HR 1.37, 95% CI=1.1-1.76, p<0.01). Patients in the top tertile had a fivefold higher risk of skin reaction (HR 5.1, 95% CI=1.2-22.8, p=0.03). Our findings demonstrate that the joint effect of SNPs from oxidative stress and DNA damage repair genes may be a promising approach to identify patients with a high risk of skin reaction after breast RT.

Partial deletion of eNOS gene causes hyperinsulinemic state, unbalance of cardiac insulin signaling pathways and coronary dysfunction independently of high fat diet

Abnormalities in eNOS gene, possibly interacting with high fat diet (HFD), affect peripheral vascular function and glucose metabolism. The relative role of eNOS gene, HFD and metabolic derangement on coronary function has not been fully elucidated. We test whether eNOS gene deficiency per se or in association with HFD modulates coronary function through mechanisms involving molecular pathways related to insulin signaling. Wild type (WT), eNOS^−/− and eNOS^+/− mice were studied. WT and eNOS^+/− mice were fed with either standard or HF diet for 16 weeks and compared with standard diet fed eNOS^−/−. Glucose and insulin tolerance tests were performed during the last week of diet. Coronary resistance (CR) was measured at baseline and during infusions of acetylcholine (Ach) or sodium-nitroprusside (SNP) to evaluate endothelium-dependent or independent vasodilation, in the Langendorff isolated hearts. Cardiac expression of Akt and ERK genes as evaluation of two major insulin-regulated signaling pathways involved in the control of vascular tone were assessed by western blot. HFD-fed mice developed an overt diabetic state. Conversely, chow-fed genetically modified mice (in particular eNOS^−/−) showed a metabolic pattern characterized by normoglycemia and hyperinsulinemia with a limited degree of insulin resistance. CR was significantly higher in animals with eNOS gene deletions than in WT, independently of diet. Percent decrease in CR, during Ach infusion, was significantly lower in both eNOS^−/− and eNOS^+/− mice than in WT, independently of diet. SNP reduced CR in all groups except eNOS^−/−. The cardiac ERK1-2/Akt ratio, increased in animals with eNOS gene deletions compared with WT, independently of diet. These results suggest that the eNOS genetic deficiency, associated or not with HFD, has a relevant effect on coronary vascular function, possibly mediated by increase in blood insulin levels and unbalance in insulin-dependent signaling in coronary vessels, consistent with a shift towards a vasoconstrictive pattern.

Anti-diabetic properties of a non-conventional radical scavenger, as compared to pioglitazone and exendin-4, in streptozotocin-nicotinamide diabetic mice

We previously showed that the innovative radical scavenger bis(1-hydroxy-2,2,6,6-tetramethyl-4-piperidinyl)-decandioate (IAC) improves metabolic dysfunctions in a diabetic mouse model. Here, we compared the in vivo effects of IAC with those of the anti-diabetic drugs pioglitazone (PIO) and exendin-4 (EX-4). Diabetes was induced in C57Bl/6J mice by streptozotocin and nicotinamide administration. Paralleled by healthy controls, diabetic animals (D) were randomly assigned to four groups and treated daily for 7 consecutive weeks: D+saline, ip; D+IAC 30mg/kgb.w., ip; D+PIO 10mg/kgb.w. per os; and D+EX-4, 50μg/kgb.w., ip. Our results show that IAC reduced basal hyperglycemia and improved glucose tolerance better than PIO or EX-4. Interestingly, in the heart of diabetic mice, IAC treatment normalized the increased levels of GSSG/GSH ratio and thiobarbituric acid reactive substances, indexes of oxidative stress and damage, while PIO and EX-4 were less effective. As supported by immunohistochemical data, IAC markedly prevented diabetic islet β-cell reduced density, differently from PIO and EX-4 that had only a moderate effect. Interestingly, in diabetic animals, IAC treatment enhanced the activity of pancreatic-duodenal homeobox 1 (PDX-1), an oxidative stress-sensitive transcription factor essential for maintenance of β-cell function, as evaluated by quantification of its nuclear immunostaining, whereas PIO or EX-4 treatments did not. Altogether, these observations support the improvement of the general redox balance and β-cell function induced by IAC treatment in streptozotocin-nicotinamide diabetic mice. Furthermore, in this model, the correction of diabetic alterations was better obtained by treatment with the radical scavenger IAC than with pioglitazone or exendin-4.

Insulin resistance is a major determinant of myocardial blood flow impairment in anginal patients

PURPOSE

In patients with chest pain, stress-induced myocardial perfusion abnormalities are often the result of depressed myocardial blood flow (MBF) reserve. We investigated the relative contribution of cardiovascular risk factors and coronary atherosclerosis to MBF abnormalities in anginal patients.

METHODS

We studied 167 patients with typical (n = 100) or atypical (n = 67) chest pain who underwent quantitative evaluation of MBF by PET at rest and after dipyridamole infusion, and quantitative coronary angiography (invasive or by 64-slice CT). Patients with left ventricular (LV) dysfunction (ejection fraction <45 %) were excluded. Coronary atherosclerosis of ≥50 % was defined as obstructive.

RESULTS

At rest median MBF was 0.60 ml min-1 g-1, and after dipyridamole infusion median MBF was 1.22 ml min-1 g-1. MBF reserve was <2 in 77 of 167 patients (46 %). Coronary atherosclerosis was present in 67 patients (40 %), 26 with obstructive disease. In a univariate analysis several variables were associated with reduced MBF at rest, including male gender, coronary atherosclerosis and elevated LV end-diastolic diameter, and during hyperaemia, including male gender, insulin resistance (IR), smoking habit, LV ejection fraction and end-diastolic diameter. In a multivariate analysis, after adjustment for LV function and for pharmacological treatments, male gender was the only independent predictor of reduced MBF at rest (P < 0.001), while male gender (P = 0.003), IR (P = 0.033) and coronary atherosclerosis (P < 0.001) remained the only independent predictors of reduced hyperaemic MBF. IR (P = 0.043) and coronary atherosclerosis (P = 0.005) were the only predictors of depressed MBF reserve. Coronary atherosclerosis, male gender and IR showed additive effects on hyperaemic MBF.

CONCLUSION

In patients with chest pain and normal LV systolic function, IR, male gender and coronary atherosclerosis are independent and additive determinants of impaired hyperaemic MBF.

Sequencing of NOTCH1, GATA5, TGFBR1 and TGFBR2 genes in familial cases of bicuspid aortic valve

BACKGROUND

The purpose of our study was to investigate the potential contribution of germline mutations in NOTCH1, GATA5 and TGFBR1 and TGFBR2 genes in a cohort of Italian patients with familial Bicuspid Aortic Valve (BAV).

METHODS

All the coding exons including adjacent intronic as well as 5' and 3' untranslated (UTR) sequences of NOTCH1, GATA5, TGFBR1 and TGFBR2 genes were screened by direct gene sequencing in 11 index patients (8 males; age = 42 ± 19 years) with familial BAV defined as two or more affected members.

RESULTS

Two novel mutations, a missense and a nonsense mutation (Exon 5, p.P284L; Exon 26, p.Y1619X), were found in the NOTCH1 gene in two unrelated families. The mutations segregated with the disease in these families, and they were not found on 200 unrelated chromosomes from ethnically matched controls. No pathogenetic mutation was identified in GATA5, TGFBR1 and TGFBR2 genes.

CONCLUSIONS

Two novel NOTCH1 mutations were identified in two Italian families with BAV, highlighting the role of a NOTCH1 signaling pathway in BAV and its aortic complications. These findings are of relevance for genetic counseling and clinical care of families presenting with BAV. Future studies are needed in order to unravel the still largely unknown genetics of BAV.

Germline hereditary, somatic mutations and microRNAs targeting-SNPs in congenital heart defects

Somatic mutations and dysregulation by microRNAs (miRNAs) may have a pivotal role in the Congenital Heart Defects (CHDs). The purpose of the study was to assess both somatic and germline mutations in the GATA4 and NKX2.5 genes as well as to identify 3'UTR single nucleotide polymorphisms (SNPs) in the miRNA target sites. We enrolled 30 patients (13 males; 13.4±8.3 years) with non-syndromic CHD. GATA4 and NKX2.5 genes were screened in cardiac tissue of sporadic and in blood samples of familial cases. Computational methods were used to detect putative miRNAs in the 3'UTR region and to assess the Minimum Free Energy of hybridization (MFE, kcal/mol). Difference of MFEs (ΔMFE) ≥4 kcal/mol between alleles was considered biologically relevant on miRNA binding. The sum of all ΔMFEs (|ΔMFEtot|=∑|ΔMFE|) was calculated in order to predict the biological importance of SNPs binding more miRNAs. No evidence of novel GATA4 and NKX2.5 mutations was found both in sporadic and familial patients. Bioinformatic analysis revealed 27 putative miRNAs binding to identified SNPs in the 3'UTR of GATA4. ΔMFE ≥4 kcal/mol between alleles was obtained for the +354A>C (miR-4299), +587A>G (miR-604), +1355G>A (miR-548v, miR-139-5p) and +1521C>G (miR-583, miR-3125, miR-3928) SNPs. The +1521C>G SNP showed the highest ΔMFEtot (21.66 kcal/mol). Luciferase reporter assays indicated that miR-583 was dose-dependently effective in regulating +1521 C allele compared with +1521 G allele. Based on the analysis of 100 CHD cases and 204 healthy newborns, the +1521 G allele was also associated with a lower risk of CHD (OR=0.5, 95% CI 0.3-0.9, p=0.03), likely due to the relatively low binding of the miRNA and high levels of protein. These results suggest that common SNPs in the 3'UTR of GATA4 alter miRNA gene regulation contributing to the pathogenesis of CHDs.

Lack of association of the 3'-UTR polymorphism (rs1017) in the ISL1 gene and risk of congenital heart disease in the white population

Congenital heart defects (CHDs) are the most prevalent of all birth defects and the leading cause of death in the first year of life. The molecular causes of most CHDs remain largely unknown. The LIM homeodomain transcriptor factor ISL1 is a marker for undifferentiated cardiac progenitor cells that give rise to both the right ventricle and the inflow and outflow tracts, which are affected by several cardiovascular malformations. Contradictory findings about the role of the ISL1 rs1017 single-nucleotide polymorphism in increasing the risk of CHD have been reported. In this study, we aimed to investigate whether the ISL1 rs1017 genetic polymorphism conferred susceptibility to CHD in the white population. In a case-control study design, 309 patients with CHD (197 men [age 21.3 ± 25.2]) and 500 healthy controls (272 men [age 15.7 ± 21.3]) were genotyped for the ISL1 rs1017 polymorphism. No significant difference in the genotype and variant allele distributions was found between patients and controls. In addition, the ISL1 rs1017 polymorphism was not associated with the risk of CHD neither overall (p = 0.7) nor stratifying the population by sex and CHD classification. In conclusion, ISL1 common variant rs1017 is not associated with increased genetic risk of CHD in the white population.

Abnormal glucose and lipid control in non-ischemic left ventricular dysfunction

BACKGROUND

Cardiovascular risk factors are classically associated with coronary atherosclerosis. We sought to investigate whether risk factors are also associated with left ventricular (LV) dilatation, contractile impairment and reduced myocardial blood flow (MBF) in patients with non-ischemic LV dysfunction.

METHODS

We studied 81 patients (59 males, age 60 ± 9 years) with mild-to-severe LV dysfunction (mean ejection fraction 37%, range 19%-50%), no history of diabetes and normal coronary arteries. Absolute MBF was measured by positron emission tomography and (13)N-ammonia at rest and after dipyridamole (0.56 mg/kg I.V. over 4 min).

RESULTS

Overt LV dysfunction (LV end-diastolic diameter >60 mm associated with LV ejection fraction <45%) was present in 42 patients (52%); severely depressed hyperemic MBF (<1.09 mL · min(-1) · g(-1)) was present in 41 patients (51%). Using multivariate logistic regression analysis, low high-density lipoprotein cholesterol (HDL-C, P < .036), newly diagnosed non-insulin-dependent diabetes or insulin-resistance (NIDD/IR, P < .019) and the use of diuretics (P = .001) were independently associated with overt LV dysfunction. Low HDL-C (P = .015) and NIDD/IR (P = .048) were also independently associated with severely depressed hyperemic MBF.

CONCLUSIONS

Low HDL-C and NIDD/IR are associated with more severe LV impairment and reduced hyperemic MBF in non-ischemic LV dysfunction.

Next generation sequencing in cardiovascular diseases

In the last few years, the advent of next generation sequencing (NGS) has revolutionized the approach to genetic studies, making whole-genome sequencing a possible way of obtaining global genomic information. NGS has very recently been shown to be successful in identifying novel causative mutations of rare or common Mendelian disorders. At the present time, it is expected that NGS will be increasingly important in the study of inherited and complex cardiovascular diseases (CVDs). However, the NGS approach to the genetics of CVDs represents a territory which has not been widely investigated. The identification of rare and frequent genetic variants can be very important in clinical practice to detect pathogenic mutations or to establish a profile of risk for the development of pathology. The purpose of this paper is to discuss the recent application of NGS in the study of several CVDs such as inherited cardiomyopathies, channelopathies, coronary artery disease and aortic aneurysm. We also discuss the future utility and challenges related to NGS in studying the genetic basis of CVDs in order to improve diagnosis, prevention, and treatment.

T(-786)→C polymorphism of the endothelial nitric oxide synthase gene is associated with insulin resistance in patients with ischemic or non ischemic cardiomyopathy

BACKGROUND

Insulin resistance (IR) and endothelial dysfunction are frequently associated in cardiac disease. The T(-786)→C variant in the promoter region of the endothelial nitric oxide synthase (eNOS) gene has been associated with IR in both non-diabetic and diabetic subjects. Aim of the study was to assess the reciprocal relationships between T(-786)→C eNOS polymorphism and IR in ischemic and non-ischemic cardiomyopathy.

METHOD

A group of 132 patients (108 males, median age 65 years) with global left ventricular (LV) dysfunction secondary to ischemic or non-ischemic heart disease was enrolled. Genotyping of T(-786)→C eNOS gene promoter, fasting glucose, insulin, and insulin resistance (defined as HOMA-IR index > 2.5) were determined in all patients.

RESULTS

Genotyping analysis yielded 37 patients homozygous for the T allele (TT), 70 heterozygotes (TC) and 25 homozygous for C (CC). Patients with CC genotype had significantly higher systemic arterial pressure, blood glucose, plasma insulin and HOMA index levels than TT. At multivariate logistic analysis, the history of hypertension and the genotype were the only predictors of IR. In particular, CC genotype increased the risk of IR (CI% 1.4-15.0, p < 0.01) 4.5-fold. The only parameter independently associated with the extent of LV dysfunction and the presence of heart failure (HF) was the HOMA index (2.4 CI% 1.1-5.6, p < 0.04).

CONCLUSIONS

T(-786)→C eNOS polymorphism was the major independent determinant of IR in a population of patients with ischemic and non-ischemic cardiomyopathy. The results suggest that a condition of primitive eNOS lower expression can predispose to an impairment of glucose homeostasis, which in turn is able to affect the severity of heart disease.

[Coronary microvascular disease: from experimental models to clinical practice]

Coronary vascular microcirculation plays a major role in the pathogenesis of left ventricular dysfunction as well as in the development of heart failure. Coronary microcirculation includes all the vessels which contribute to provide resistance to coronary flow. It represents the district where coronary circulation blood flow is regulated to ensure that each structural and functional cardiac component receives the proper amount of oxygen and metabolic substrates through the capillary network. Coronary microcirculation is fundamental for myocardial function which largely depends on the ratio between energetic metabolites received from coronary circulation and their utilization by the myocytes. Alterations in coronary microvascular circulation which limit myocardial perfusion can cause repetitive ischemic events leading to left ventricular dysfunction in several ischemic and non ischemic cardiomyopathies as the idiopathic dilated cardiomyopathy. To date, mechanisms underlying microvascular dysfunction are not completely understood and experimental animal models are employed to study alterations which may cause microcirculation impairment. These animals models are unique tools to identify new therapeutic targets, to test new drug therapies for the treatment of left ventricular dysfunction as well as its progression towards overt heart failure.

Cobalt-Protoporphyrin Improves Heart Function by Blunting Oxidative Stress and Restoring NO Synthase Equilibrium in an Animal Model of Experimental Diabetes

Myocardial dysfunction and coronary macro/microvascular alterations are the hallmarks of diabetic cardiomyopathy and are ascribed to increased oxidative stress and altered nitric oxide synthase (NOS) activity. We hypothesize that pre-treatment by cobalt-protoporphyrin IX (CoPP) ameliorates both myocardial function and coronary circulation in streptozotocin (STZ)-induced diabetic rats. Isolated hearts from diabetic rats in Langendorff configuration displayed lower left ventricular function and higher coronary resistance (CR) compared to hearts from control animals. CoPP treatment of diabetic animals (0.3 mg/100 g body weight i.p., once a week for 3 weeks) significantly increased all the contractile/relaxation indexes (p < 0.01), while decreasing CR (p < 0.01). CoPP enhanced HO-1 protein levels and reduced oxidative stress in diabetic animals, as indicated by the significant (p < 0.05) decrease in heart % GSSG, [Formula: see text] and malondialdehyde (MDA) levels. CoPP increased adiponectin levels and phosphorylation of AKT and AMPK and reversed the eNOS/iNOS expression imbalance observed in the untreated diabetic heart. Furthermore, after CoPP treatment, a rise in malonyl-CoA as well as a decrease in acetyl-CoA was observed in diabetic hearts. In this experimental model of diabetic cardiomyopathy, CoPP treatment improved both cardiac function and coronary flow by blunting oxidative stress, restoring eNOS/iNOS expression balance and increasing HO-1 levels, thereby favoring improvement in both endothelial function and insulin sensitivity.