Big tau aggregation disrupts microtubule tyrosination and causes myocardial diastolic dysfunction: from discovery to therapy

BACKGROUND

Amyloid plaques and neurofibrillary tangles, the molecular lesions that characterize Alzheimer's disease (AD) and other forms of dementia, are emerging as determinants of proteinopathies 'beyond the brain'. This study aims to establish tau's putative pathophysiological mechanistic roles and potential future therapeutic targeting of tau in heart failure (HF).

METHODS AND RESULTS

A mouse model of tauopathy and human myocardial and brain tissue from patients with HF, AD, and controls was employed in this study. Tau protein expression was examined together with its distribution, and in vitro tau-related pathophysiological mechanisms were identified using a variety of biochemical, imaging, and functional approaches. A novel tau-targeting immunotherapy was tested to explore tau-targeted therapeutic potential in HF. Tau is expressed in normal and diseased human hearts, in contradistinction to the current oft-cited observation that tau is expressed specifically in the brain. Notably, the main cardiac isoform is high-molecular-weight (HMW) tau (also known as big tau), and hyperphosphorylated tau segregates in aggregates in HF and AD hearts. As previously described for amyloid-beta, the tauopathy phenotype in human myocardium is of diastolic dysfunction. Perturbation in the tubulin code, specifically a loss of tyrosinated microtubules, emerged as a potential mechanism of myocardial tauopathy. Monoclonal anti-tau antibody therapy improved myocardial function and clearance of toxic aggregates in mice, supporting tau as a potential target for novel HF immunotherapy.

CONCLUSION

The study presents new mechanistic evidence and potential treatment for the brain-heart tauopathy axis in myocardial and brain degenerative diseases and ageing.

Trimethylamine-N-oxide is associated with cardiovascular mortality and vascular brain lesions in patients with atrial fibrillation

OBJECTIVE

Trimethylamine-N-oxide (TMAO) is a metabolite derived from the microbial processing of dietary phosphatidylcholine and carnitine and the subsequent hepatic oxidation. Due to its prothrombotic and inflammatory mechanisms, we aimed to assess its role in the prediction of adverse events in a susceptible population, namely patients with atrial fibrillation.

METHODS

Baseline TMAO plasma levels were measured by liquid chromatography-tandem mass spectrometry in 2379 subjects from the ongoing Swiss Atrial Fibrillation cohort. 1722 underwent brain MRI at baseline. Participants were prospectively followed for 4 years (Q1-Q3: 3.0-5.0) and stratified into baseline TMAO tertiles. Cox proportional hazards and linear and logistic mixed effect models were employed adjusting for risk factors.

RESULTS

Subjects in the highest TMAO tertile were older (75.4±8.1 vs 70.6±8.5 years, p<0.01), had poorer renal function (median glomerular filtration rate: 49.0 mL/min/1.73 m² (35.6-62.5) vs 67.3 mL/min/1.73 m² (57.8-78.9), p<0.01), were more likely to have diabetes (26.9% vs 9.1%, p<0.01) and had a higher prevalence of heart failure (37.9% vs 15.8%, p<0.01) compared with patients in the lowest tertile. Oral anticoagulants were taken by 89.1%, 94.0% and 88.2% of participants, respectively (from high to low tertiles). Cox models, adjusting for baseline covariates, showed increased total mortality (HR 1.65, 95% CI 1.17 to 2.32, p<0.01) as well as cardiovascular mortality (HR 1.86, 95% CI 1.21 to 2.88, p<0.01) in the highest compared with the lowest tertile. When present, subjects in the highest tertile had more voluminous, large, non-cortical and cortical infarcts on MRI (log-transformed volumes; exponentiated estimate 1.89, 95% CI 1.11 to 3.21, p=0.02) and a higher chance of small non-cortical infarcts (OR 1.61, 95% CI 1.16 to 2.22, p<0.01).

CONCLUSIONS

High levels of TMAO are associated with increased risk of cardiovascular mortality and cerebral infarction in patients with atrial fibrillation.

TRIAL REGISTRATION NUMBER

NCT02105844.

Trimethylamine N-oxide is associated with impaired cognitive function in patients with atrial fibrillation

Introduction

Since patients with atrial fibrillation (AF) are predisposed to suffer from major adverse cerebrovascular events (MACE), they are more likely to suffer MACE linked sequelae, such as cognitive impairment. We hypothesised that the gut microbiome derivate trimethylamine N-oxide (TMAO) may amplify this pathomechanism given its hypercoagulative, proinflammatory and proatherogenic effects.

Methods

Patients of the Swiss-AF cohort with determined TMAO plasma levels, cognitive scores (n=2'379) and cerebral magnetic resonance imaging (cMRI) (n=1'722) collected at baseline were included. TMAO levels were measured by liquid chromatography-mass spectrometry (HPLC). Overall cognitive performance was evaluated using the Cognitive Construct (CoCo) score reflecting different cognitive functions measured by four validated neuropsychological assessments, namely the Montreal Cognitive Assessment (MoCA), Trail Making Test (TMT parts A and B), Semantic Fluency Test (SFT) and Digital Symbol Substitution Test (DSST). The scores were compared with the quartiles of patients' TMAO plasma levels (Q1: 0.6–4, Q2: 4–5.8, Q3: 5.8–9.1, Q4: 9.1–164μmol/l) in linear effect models. All models were adjusted for multiple covariates correlating with this association: For TMAO (overall meat consumption &gt;3 times per week, physical activity, glomerular filtration rate, presence of diabetes mellitus), cognitive function (EQ-5D-5L score, geriatric depression scale, education level) and cerebral affects (white matter lesions volume and total brain volume in cMRI). The relevance of high TMAO plasma levels in different stroke groups in cMRI (i.e., clinically overt, silent, or no stroke) were analysed in a subgroup analysis. The subgroups were additionally adjusted for total brain volume to eliminate the effect of simultaneous decrease of cerebral white matter.

Results

After multivariable adjustment, AF patients in the highest quartile of TMAO levels performed significantly poorer in the global cognitive score (CoCo: estimate −0.11, 95% CI [−0.17, −0.05], p=0.002) compared to patients in the lowest quartile. This was observed also in the MoCA, SFT, DSST, TMT-A and TMT-B.

In the subgroup analysis, an association between the highest TMAO quartile (compared with the lowest quartile) and lower CoCo score was found in the group of patients with overt strokes (−0.18, 95% CI [−0.33, −0.04], p=0.012). Weak evidence of the same association was found in the group of patients with silent strokes (−0.13, 95% CI [−0.25, 0.002], p=0.053) and patients with no strokes (−0.08, 95% CI [−0.16, 0.01], p=0.07).

After adjustment for decreased brain volume, the association remained for silent strokes (−0.14, 95% CI [−0.28, −0.01], p=0.036) indicating the impact of TMAO in this subgroup.

Conclusion

TMAO plasma levels were associated with cognitive impairment in patients with AF. Longitudinal data will clarify dynamics and likely causality between TMAO and cognitive impairment.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Swiss National Science Foundation

DNA damage contributes to neurotoxic inflammation in Aicardi-Goutières syndrome astrocytes

Aberrant induction of type I IFN is a hallmark of the inherited encephalopathy Aicardi-Goutières syndrome (AGS), but the mechanisms triggering disease in the human central nervous system (CNS) remain elusive. Here, we generated human models of AGS using genetically modified and patient-derived pluripotent stem cells harboring TREX1 or RNASEH2B loss-of-function alleles. Genome-wide transcriptomic analysis reveals that spontaneous proinflammatory activation in AGS astrocytes initiates signaling cascades impacting multiple CNS cell subsets analyzed at the single-cell level. We identify accumulating DNA damage, with elevated R-loop and micronuclei formation, as a driver of STING- and NLRP3-related inflammatory responses leading to the secretion of neurotoxic mediators. Importantly, pharmacological inhibition of proapoptotic or inflammatory cascades in AGS astrocytes prevents neurotoxicity without apparent impact on their increased type I IFN responses. Together, our work identifies DNA damage as a major driver of neurotoxic inflammation in AGS astrocytes, suggests a role for AGS gene products in R-loop homeostasis, and identifies common denominators of disease that can be targeted to prevent astrocyte-mediated neurotoxicity in AGS.

Delivery Platforms for CRISPR/Cas9 Genome Editing of Glial Cells in the Central Nervous System

Glial cells (astrocytes, oligodendrocytes, and microglia) are emerging as key players in several physiological and pathological processes of the central nervous system (CNS). Astrocytes and oligodendrocytes are not only supportive cells that release trophic factors or regulate energy metabolism, but they also actively modulate critical neuronal processes and functions in the tripartite synapse. Microglia are defined as CNS-resident cells that provide immune surveillance; however, they also actively contribute to shaping the neuronal microenvironment by scavenging cell debris or regulating synaptogenesis and pruning. Given the many interconnected processes coordinated by glial cells, it is not surprising that both acute and chronic CNS insults not only cause neuronal damage but also trigger complex multifaceted responses, including neuroinflammation, which can critically contribute to the disease progression and worsening of symptoms in several neurodegenerative diseases. Overall, this makes glial cells excellent candidates for targeted therapies to treat CNS disorders. In recent years, the application of gene editing technologies has redefined therapeutic strategies to treat genetic and age-related neurological diseases. In this review, we discuss the advantages and limitations of clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9-based gene editing in the treatment of neurodegenerative disorders, focusing on the development of viral- and nanoparticle-based delivery methods for in vivo glial cell targeting.

A proteomic approach of the different environmental conditions of Listeria monocytogenes

 

Listeria monocytogenes is the ubiquitous food-borne pathogen which causes listeriosis, a disease with a high mortality rate, mostly transmitted through contaminated ready-to-eat foods. To better understand the systemic response of L. monocytogenes exposed at 3 environmental factors (T, pH and NaCl), the proteome of L. monocytogenes strain NRG 1749-2016, isolated from a meat product, was investigated to identify differences in the protein patterns of such pathogen. Four different conditions were carried out as follows: A) T 37 °C, pH 7.0, NaCl 0.5%; B) T 37 °C, pH 5.5, NaCl 7%; C) T 12° pH 7, NaCl 0.5%; D) T 12 °C, pH 5.5, NaCl 7%. The proteins belonging to cytosol (C1) and vesicles (C2) were isolated and purified by CelLytic B Cell Lysis Reagent and CelLytic IB Inclusion Body Solubilization Reagent according manufacturer's instructions. The analysis were conducted by SDS PAGE and Immunoblotting techniques. The protein concentrations were evaluated by Pierce BCA Protein Assay Kit. From preliminary results, the protein banding patterns generated by 1D SDS PAGE were found to be different at visual observation for C1 and C2, in A, B, C and D conditions. The presence of specific antigen-antibody immunocomplexes (Ag-Ab ICs) was identified by Immunoblotting, in C1 at 100, 60, 55, 35 and 25 kDa for all incubated conditions with a positive serum to L. monocytogenes. As regards C2, Ag-Ab ICs at 110 kDa were observed in A and B, Ag-Ab ICs at 80 kDa in C and D, Ag-Ab ICs at 60 kDa in A and D, while Ag-Ab ICs at 40 and 30 kDa in all conditions. The analysis of the proteome profiles shows an intra-strain variation in the protein patterns produced by L. monocytogenes during the adaptation at different environmental conditions. Further analysis will be carried out to better understand the systemic response of L. monocytogenes, in particular in order to characterize the immunogenic proteins highlighted by Immunoblotting and their role in the virulence expression of such pathogen.

Key messages

Understand how L. monocytogenes adapts physiologically to different environmental factors. Development of new detection method of L. monocytogenes and prevention strategies for listeriosis outbreaks.

Trimethylamine-N-oxide (TMAO) is associated with cardiovascular mortality and vascular brain lesions in patients with atrial fibrillation

Introduction

Trimethylamine-N-oxide (TMAO) is a well characterized pro-atherogenic metabolite derived from the microbial processing of phosphatidylcholine and carnitine (usually present in red meat) and subsequent hepatic oxydation, which promotes endothelial dysfunction, platelet activation and thrombosis initiation. Its role concerning cerebral and cardiovascular adverse events has been assessed in various patient subpopulations but not for long term in patients with atrial fibrillation.

Methods

Baseline TMAO plasma levels were measured by high-performance liquid chromatography/mass spectrometry in plasmas of 2,379 subjects from our multicentric study. Among them, 1,722 participants at time of recruitment underwent brain MRI. Participants were stratified into TMAO tertiles and Cox PH models, linear mixed effect models or logistic mixed effect models were employed adjusting for several risk factors (age, sex, BMI, active and past smoke habit, cystatin c levels, heart failure, diabetes mellitus, hypertension, coronary artery disease and history of TIA/stroke). Subjects were prospectively followed with a median observation time of 4 years.

Results

Subjects in the highest tertile of TMAO were older (75.4 vs. 70.6 years in low tertile p&lt;0.001) and had significantly more often comorbidities, (26.9% of subjects were diabetic vs. 9.1% in low tertile p&lt;0.001), with higher BMI (28.1 vs 27.0, p&lt;0.001) and worse renal function as assessed by serum cystatin C (1.46 vs 1.07, mg/dl; p&lt;0.001). Heart failure was present in 37.9% participants in the upper compared to 15.8% in the lower tertile. (p&lt;0.001). As shown in Figure 1, Kaplan Meier estimates showed increased cardiovascular mortality with increasing TMAO tertiles (p&lt;0.0001). After adjustment for the abovementioned factors the upper tertile (T3) had an increased hazard ratio (HR) compared to the lowest one (HR 2.36 95% CI 1.56–3.58 p&lt;0.01). Similar trends for global and ischemic stroke occurrences were not found although TMAO levels positively weakly correlated with NIHSS severity (Spearman's coefficient 0.31 p=0.02). Concerning brain MRI findings, TMAO tertiles identified individuals with different prevalence of small non-cortical infarcts (30.5%, 18.1% and 17.4% in high, middle and low tertiles respectively; p&lt;0.001) and when present, larger white matter lesions volumes (5061 mm3, 4158 mm3 and 2970 mm3; p&lt;0.001). After adjustment, the association with small non-cortical infarcts with TMAO levels remained significant in the highest tertile (T3) (OR 1.48 95% CI 1.07–2.05; p=0.02) and a trend towards larger white matter lesions volumes was observed (estimate 1307 95% CI −90–2705; p=0.07).

Conclusions

TMAO represents a robust prognostic independent biomarker identifying multimorbid, high risk patients for cardiovascular mortality and brain damage.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Swiss National Science Foundation (SNSF) and Theodor und Ida Herzog-Egli Foundation Figure 1. CV mortality according to TMAOFigure 2. Brain lesions assessment

Long-COVID Headache

The so-called long COVID-19 is a set of symptoms that accompanies the patient even for months after discharge from the hospital. These symptoms include easy muscle fatigue, moderate breathlessness, persistent headache, the feeling of a foggy head, and the development of psychiatric disorders. In general, the quality of life of at least half of the patients who come out of the COVID-19 syndrome, both mild and severe, shows a markedly worsening despite having passed a difficult physical and psychological test. Among all the neurological disorders that can most frequently be found in the long COVID-19, it is important to consider the persistent headache symptomatology as a possible chronic sequela of the infection. Since there is not a definition in the International Headache Society classification of this type of headache, we must focus our attention on this long-COVID-19 headache especially because clinical studies are being planned to collect big data for the International Headache Society Classification Committee.

The long and winding road to target protein misfolding in cardiovascular diseases

BACKGROUND

In the last decades, cardiovascular diseases (CVD) have remained the first leading cause of mortality and morbidity in the world. Although several therapeutic approaches have been introduced in the past, the development of novel treatments remains an important research goal, which is hampered by the lack of understanding of key mechanisms and targets. Emerging evidences in recent years indicate the involvement of misfolded proteins aggregation and the derailment of protein quality control in the pathogenesis of cardiovascular diseases. Several potential interventions targeting protein quality control have been translated from the bench to the bedside to effectively employ the misfolded proteins as promising therapeutic targets for cardiac diseases, but with trivial results.

DESIGN

In this review, we describe the recent progresses in preclinical and clinical studies of protein misfolding and compromised protein quality control by selecting and reporting studies focusing on cardiovascular diseases including cardiomyopathies, cardiac amyloidosis, atherosclerosis, atrial fibrillation and thrombosis.

RESULTS

In preclinical models, modulators of several molecular targets (eg heat shock proteins, unfolded protein response, ubiquitin protein system, autophagy and histone deacetylases) have been tested in various conditions with promising results although lacking an adequate transition towards clinical setting.

CONCLUSIONS

At present, no therapeutic strategies have been reported to attenuate proteotoxicity in patients with CVD due to a lack of specific biomarkers for pinpointing upstream events in protein folding defects at a subclinical stage of the diseases requiring an intensive collaboration between basic scientists and clinicians.

The epilepsy specialist nurse: A mixed-methods case study on the role and activities

PURPOSE

To describe the role and activities of epilepsy specialist nurses (ESNs) operating as a team in the setting of a hospital specialising in the diagnosis and management of seizure disorders.

METHODS

We conducted a descriptive mixed-methods embedded single case study. We recruited 9 ESNs, 14 of their professional colleagues and 9 'key informants' to analyse their perceptions of the role and activities of ESNs. We collected data through interviews, questionnaires, observations, and documentation. The study was conducted at the Filadelfia Epilepsy Hospital, Denmark.

RESULTS

The team of ESNs offers holistic care to patients and their caregivers regarding the clinical, social, and emotional aspects of epilepsy. The ESNs are integrated in a multidisciplinary team and promote collaboration among the team members. ESNs also contribute to organisational aspects and perform research activities.

CONCLUSION

A structured group of ESNs can operate effectively and extensively in a specialised hospital setting. Our findings contribute to clarifying the description of the ESN's role, and provide an example of how ESNs can be incorporated into a hospital's organisational structure.

Human iPSC-Based Models for the Development of Therapeutics Targeting Neurodegenerative Lysosomal Storage Diseases

Lysosomal storage diseases (LSDs) are a group of rare genetic conditions. The absence or deficiency of lysosomal proteins leads to excessive storage of undigested materials and drives secondary pathological mechanisms including autophagy, calcium homeostasis, ER stress, and mitochondrial abnormalities. A large number of LSDs display mild to severe central nervous system (CNS) involvement. Animal disease models and post-mortem tissues partially recapitulate the disease or represent the final stage of CNS pathology, respectively. In the last decades, human models based on induced pluripotent stem cells (hiPSCs) have been extensively applied to investigate LSD pathology in several tissues and organs, including the CNS. Neural stem/progenitor cells (NSCs) derived from patient-specific hiPSCs (hiPS-NSCs) are a promising tool to define the effects of the pathological storage on neurodevelopment, survival and function of neurons and glial cells in neurodegenerative LSDs. Additionally, the development of novel 2D co-culture systems and 3D hiPSC-based models is fostering the investigation of neuron-glia functional and dysfunctional interactions, also contributing to define the role of neurodevelopment and neuroinflammation in the onset and progression of the disease, with important implications in terms of timing and efficacy of treatments. Here, we discuss the advantages and limits of the application of hiPS-NSC-based models in the study and treatment of CNS pathology in different LSDs. Additionally, we review the state-of-the-art and the prospective applications of NSC-based therapy, highlighting the potential exploitation of hiPS-NSCs for gene and cell therapy approaches in the treatment of neurodegenerative LSDs.

Extremely Severe Case of COVID-19 Pneumonia Recovered Despite Bad Prognostic Indicators: a Didactic Report

COVID-19 is a highly infectious respiratory disease caused by severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). Starting from Wuhan (China) where it was firstly reported, it rapidly spread to the rest of the world, causing a pandemic with more than 300,000 deaths to date. We report an extremely severe case of coronavirus pneumonia in an over 80-year-old patient with hypertension, coronary heart disease, chronic heart failure, and chronic obstructive pulmonary disease. Despite a clearly poor anamnestic and clinical prognostic forecast, she was successfully discharged thanks to a careful evaluation of the case and of the complications that have arisen. Although a higher vulnerability of geriatric patients has been observed, the literature on elderly COVID-19 patients has remained very scarce, especially in those over 80. The article aims to explore factors that may allow the successful outcome and provides important elements to better understand this disease.

Natural History of Perianal Fistulising Lesions in Patients With Elderly-onset Crohn's Disease: A Population-based Study

INTRODUCTION

Most studies of elderly-onset Crohn's disease [CD; diagnosed in patients aged 60 or over] have described a mild course. However, data on the natural history of perianal fistulising CD [pfCD] in this population are scarce. In a population-based cohort study, we described the prevalence, natural history, and treatment of pfCD in patients with elderly-onset CD vs patients with paediatric-onset CD.

METHOD

All patients diagnosed with CD at or after the age of 60 between 1988 and 2006, were included [n = 372]. Logistic regression, Cox models, and a nested case-control method were used to identify factors associated with pfCD.

RESULTS

A total of 34 elderly patients [9% of the 372] had pfCD at diagnosis. After a median follow-up of 6 years (interquartile range [IQR]: 3; 10), 59 patients [16%] had pfCD; the same prevalence [16%] was observed in paediatric-onset patients. At last follow-up, anal incontinence was more frequent in elderly patients with pfCD than in elderly patients without pfCD [22% vs 4%, respectively; p < 10-4]. Rectal CD at diagnosis was associated with pfCD: hazard ratio (95% confidence interval [CI] = 2.8 [1.6-5.0]). Although 37% of the patients received immunosuppressants and 17% received anti-tumour necrosis factor agents, 24% [14 out of 59] had a definitive stoma at last follow-up.

CONCLUSION

During the first 6 years of disease, the prevalence of pfCD was similar in elderly and paediatric patients. Rectal involvement was associated with the appearance of pfCD in elderly-onset patients. Around a quarter of patients with elderly-onset CD will have a stoma. Our results suggest that treatment with biologics should be evaluated in these patients.

Reintroducing Heart Sounds for Early Detection of Acute Myocardial Ischemia in a Porcine Model - Correlation of Acoustic Cardiography With Gold Standard of Pressure-Volume Analysis

Background

Acoustic cardiography is a hybrid technique that couples heart sounds recording with ECG providing insights into electrical-mechanical activity of the heart in an unsupervised, non-invasive and inexpensive manner. During myocardial ischemia hemodynamic abnormalities appear in the first minutes and we hypothesize a putative diagnostic role of acoustic cardiography for prompt detection of cardiac dysfunction for future patient management improvement.

Methods and Results

Ten female Swiss large white pigs underwent permanent distal coronary occlusion as a model of acute myocardial ischemia. Acoustic cardiography analyses were performed prior, during and after coronary occlusion. Pressure-volume analysis was conducted in parallel as an invasive method of hemodynamic assessment for comparison. Similar systolic and diastolic intervals obtained with the two techniques were significantly correlated [Q to min dP/dt vs. Q to second heart sound (r² = 0.9583, p < 0.0001), PV diastolic filling time vs. AC perfusion time (r² = 0.9686, p < 0.0001)]. Indexes of systolic and diastolic impairment correlated with quantifiable features of heart sounds [Tau vs. fourth heart sound Display Value (r² = 0.2721, p < 0.0001) cardiac output vs. third heart sound Display Value (r² = 0.0791 p = 0.0023)]. Additionally, acoustic cardiography diastolic time (AUC 0.675, p = 0.008), perfusion time (AUC 0.649, p = 0.024) and third heart sound Display Value (AUC 0.654, p = 0.019) emerged as possible indicators of coronary occlusion. Finally, these three parameters, when joined with heart rate into a composite joint-index, represent the best model in our experience for ischemia detection (AUC 0.770, p < 0.001).

Conclusion

In the rapidly evolving setting of acute myocardial ischemia, acoustic cardiography provided meaningful insights of mechanical dysfunction in a prompt and non-invasive manner. These findings should propel interest in resurrecting this technique for future translational studies as well as reconsidering its reintroduction in the clinical setting.

Prosthetic valve endocarditis: predictors of early outcome of surgical therapy. A multicentric study

OBJECTIVES

Prosthetic valve endocarditis (PVE) is an uncommon yet dreadful complication in patients with prosthetic valves that requires a distinct analysis from native valve endocarditis. The present study aims to investigate independent risk factors for early surgical outcomes in patients with PVE.

METHODS

A retrospective cohort study was conducted in 8 Italian Cardiac Surgery Units from January 2000 to December 2013 by enrolling all PVE patients undergoing surgical treatment.

RESULTS

A total of 209 consecutive patients were included in the study. During the study period, the global rate of surgical procedures for PVE among all operations for isolated or associated valvular disease was 0.45%. Despite its rarity this percentage increased significantly during the second time frame (2007-2013) in comparison with the previous one (2000-2006): 0.58% vs 0.31% (P < 0.001). Intraoperative and in-hospital mortality rates were 4.3% and 21.5%, respectively. Logistic regression analysis identified the following factors associated with in-hospital mortality: female gender [odds ratio (OR) = 4.62; P < 0.001], shock status (OR = 3.29; P = 0.02), previous surgical procedures within 3 months from the treatment (OR = 3.57; P = 0.009), multivalvular involvement (OR = 8.04; P = 0.003), abscess (OR = 2.48; P = 0.03) and urgent surgery (OR = 6.63; P < 0.001).

CONCLUSIONS

Despite its rarity, PVE showed a significant increase over time. Up to now, in-hospital mortality after surgical treatment still remains high (>20%). Critical clinical presentation and extension of anatomical lesions are strong preoperative predictors for poor early outcome.

Current and future circulating biomarkers for cardiac amyloidosis

Cardiac amyloidosis (CA) comprises a heterogeneous group of medical conditions affecting the myocardium. It presents with proteinaceous infiltration with variable degrees of severity, prevalence and evolution. Despite this heterogeneity, erroneous protein folding is the common pathophysiologic process, yielding the formation of a single misfolded protein (monomer) that progressively evolves and ultimately forms amyloid fibers. Additionally, by seeding out from the organs of origin, intermediates called oligomers metastasize and restart the process. Such self-echoing behavior makes the secondary affected organs as important as the primary ones. Unfortunately, CA can be clinically challenging and only suggestive in a late stage of its natural history, leaving a narrow therapeutic time window available. In light of the evolutionary nature of amyloidosis, here, we propose a new classification of the currently used biomarkers based on time stages with different specificity and applicability across CA subtypes. Early markers (free light chains, serum amyloid A, β2-microglobulin, osteopontin and osteoprotegerin) can be employed for disease detection. Intermediate markers [soluble suppression of tumorigenicity 2 (sST-2), midregional proadrenomedullin (MR-proADM), von Willebrand factor (vWF), hepatocyte growth factor (HGF), matrix metalloproteinases (MMPs) and tissue inhibitor metalloproteinases (TIMPs)] can provide information on the biological mechanisms of myocardial damage. As in heart failure, late-stage biomarkers (troponins and natriuretic peptides) can help clinicians with prognosis and therapeutic response evaluation in CA. Such findings have generated a remarkable foundation for our current knowledge on CA. Nevertheless, we envision a future class of biomarkers targeted at upstream events capable of detecting folding defects, which will ultimately expand the therapeutic window.

Cardioband system as a treatment for functional mitral regurgitation

INTRODUCTION

Are the current data on the Cardioband in the clinical area enough to consider it a tool for mitral regurgitation treatment? Severe secondary mitral valve insufficiency frequently affects high-risk surgical patients. The Cardioband system is a novel percutaneous surgical-like device for direct annuloplasty. It is implanted into the beating heart by transvenous femoral access, with minimal impact on hemodynamic and cardiac function during implantation. So far, it has demonstrated safety and feasibility in high-risk patients with functional mitral regurgitation; it has imparted significant annular reduction and regurgitation improvements. In well-selected patients, it could be an option for mitral valve repair.

AREAS COVERED

This is a bibliographic review based on scientific publications and medical congress reports. It includes the most current information related to Cardioband in mitral regurgitation.

EXPERT COMMENTARY

This novel, less-invasive and effective tool is an option for the open repair or replacement of the mitral valve in high-risk surgical patients. Although the current results of Cardioband are promising, more data and longer follow-up times are necessary to confirm its safety and efficacy and to evaluate the durability of the results.

Human iPSC-based models highlight defective glial and neuronal differentiation from neural progenitor cells in metachromatic leukodystrophy

The pathological cascade leading from primary storage to neural cell dysfunction and death in metachromatic leukodystrophy (MLD) has been poorly elucidated in human-derived neural cell systems. In the present study, we have modeled the progression of pathological events during the differentiation of patient-specific iPSCs to neuroepithelial progenitor cells (iPSC-NPCs) and mature neurons, astrocytes, and oligodendrocytes at the morphological, molecular, and biochemical level. We showed significant sulfatide accumulation and altered sulfatide composition during the differentiation of MLD iPSC-NPCs into neuronal and glial cells. Changes in sulfatide levels and composition were accompanied by the expansion of the lysosomal compartment, oxidative stress, and apoptosis. The neuronal and glial differentiation capacity of MLD iPSC-NPCs was significantly impaired. We showed delayed appearance and/or reduced levels of oligodendroglial and astroglial markers as well as reduced number of neurons and disorganized neuronal network. Restoration of a functional Arylsulfatase A (ARSA) enzyme in MLD cells using lentiviral-mediated gene transfer normalized sulfatide levels and composition, globally rescuing the pathological phenotype. Our study points to MLD iPSC-derived neural progeny as a useful in vitro model to assess the impact of ARSA deficiency along NPC differentiation into neurons and glial cells. In addition, iPSC-derived neural cultures allowed testing the impact of ARSA reconstitution/overexpression on disease correction and, importantly, on the biology and functional features of human NPCs, with important therapeutic implications.

Dramatic Increase in Incidence of Ulcerative Colitis and Crohn's Disease (1988-2011): A Population-Based Study of French Adolescents

OBJECTIVES

Few data are available to describe the changes in incidence of pediatric-onset inflammatory bowel disease (IBD). The aim of this study was to describe changes in incidence and phenotypic presentation of pediatric-onset IBD in northern France during a 24-year period.

METHODS

Pediatric-onset IBD (<17 years) was issued from a population-based IBD study in France between 1988 and 2011. Age groups and digestive location were defined according to the Paris classification.

RESULTS

1,350 incident cases were recorded (8.3% of all IBD) including 990 Crohn's disease (CD), 326 ulcerative colitis (UC) and 34 IBD unclassified (IBDU). Median age at diagnosis was similar in CD (14.4 years (Q1=11.8-Q3=16.0)) and UC (14.0 years (11.0-16.0)) and did not change over time. There were significantly more males with CD (females/males=0.82) than UC (females/males=1.25) (P=0.0042). Median time between onset of symptoms and IBD diagnosis was consistently 3 months (1-6). Mean incidence was 4.4/10⁵ for IBD overall (3.2 for CD, 1.1 for UC and 0.1 for IBDU). From 1988-1990 to 2009-2011, a dramatic increase in incidences of both CD and UC were observed in adolescents (10-16 years): for CD from 4.2 to 9.5/10⁵ (+126%; P<0.001) and for UC, from 1.6 to 4.1/10⁵ (+156%; P<0.001). No modification in age or location at diagnosis was observed in either CD or UC.

CONCLUSIONS

In this population-based study, CD and UC incidences increased dramatically in adolescents across a 24-year span, suggesting that one or more strong environmental factors may predispose this population to IBD.

Phase IIa study of dabigatran etexilate in children with venous thrombosis: pharmacokinetics, safety, and tolerability

Essentials Dabigatran etexilate may provide a new treatment option for pediatric venous thromboembolism. Children aged 1 to < 12 years were given dabigatran etexilate in an open-label, single-arm study. The pharmacokinetic-pharmacodynamic relationship was similar to that seen in adult patients. There were no serious adverse events, bleeding events or recurrent venous thromboembolism.

SUMMARY

Background The current standard-of-care treatments for pediatric venous thromboembolism (VTE) have limitations. Dabigatran etexilate (DE), a direct thrombin inhibitor, may offer an alternative therapeutic option. Objectives To assess the pharmacokinetics, pharmacodynamics, safety, and tolerability of a DE oral liquid formulation (OLF) in pediatric patients with VTE. Patients/Methods Patients who had completed planned treatment with low molecular weight heparin or oral anticoagulants for VTE were enrolled in two age groups (2 to < 12 years and 1 to < 2 years), and received a DE OLF based on an age-adjusted and weight-adjusted nomogram. Originally, patients were to receive a DE OLF twice daily for 3 days, but the protocol was amended to a single dose on day 1. The primary endpoints were pharmacokinetics/pharmacodynamics-related: plasma concentrations of DE and its metabolites; activated partial thromboplastin time (APTT), ecarin clotting time (ECT), and dilute thrombin time (dTT); and pharmacokinetic (PK)-pharmacodynamic (PD) correlation. Safety endpoints included incidence rates of bleeding events and all other adverse events (AEs). Results Eighteen patients entered the study and received the DE OLF (an exposure equivalent to a dose of 150 mg twice daily in adults). The projected steady-state dabigatran trough concentrations were largely comparable between pediatric patients and adults. The PK/PD relationship was linear for ECT and dTT, and non-linear for APTT. No serious or severe AEs, bleeding events, or recurrent VTEs were reported. Mild AEs were reported in three patients in the single-dose group (screening period) and in one patient in the multiple-dose group (on-treatment period). Conclusion The current study supports the further evaluation of DE OLFs in pediatric patients with VTE.

Extra-intestinal Manifestations at Diagnosis in Paediatric- and Elderly-onset Ulcerative Colitis are Associated With a More Severe Disease Outcome: A Population-based Study

BACKGROUND AND AIMS

Data on extra-intestinal manifestations [EIM] and their impact on the disease course of ulcerative colitis [UC] in population-based cohorts are scarce, particularly in paediatric- and elderly-onset UC patients. The aims of this population-based study were to assess: 1] the occurrence of EIM in paediatric- and elderly-onset UC; 2] the factors associated with EIM; and 3] their impact on long-term disease outcome.

METHODS

Paediatric-onset [< 17 years at diagnosis] and elderly-onset UC patients [> 60 years at diagnosis] from a French prospective population-based registry [EPIMAD] were included. Data on EIM and other clinical factors at diagnosis and at maximal follow-up were collected.

RESULTS

In all, 158 paediatric- and 470 elderly-onset patients were included [median age at diagnosis 14.5 and 68.8 years, median follow-up 11.2 and 6.2 years, respectively]. EIM occurred in 8.9% of childhood- and 3% of elderly-onset patients at diagnosis and in 16.7% and 2.2% of individuals during follow-up [p < 0.01], respectively. The most frequent EIM was joint involvement [15.8% of paediatric onset and 2.6% of elderly-onset]. Presence of EIM at diagnosis was associated with more severe disease course [need for immunosuppressants or biologic therapy or colectomy] in both paediatric- and elderly-onset UC (hazard ratio [HR] = 2.0, 95% confidence interval [CI]: 1.0-4.2; and HR = 2.8, 0.9-7.9, respectively). Extensive colitis was another independent risk factor in both age groups.

CONCLUSIONS

Elderly-onset UC patients had lower risk of EIM either at diagnosis or during follow-up than paediatric-onset individuals. EIM at diagnosis predicted more severe disease outcome, including need for immunosuppressive or biologic therapy or surgery, in both paediatric- and elderly-onset UC.

Insights from Second-Line Treatments for Idiopathic Dilated Cardiomyopathy

Background: Dilated cardiomyopathy (DCM) is an independent nosographic entity characterized by left ventricular dilatation and contractile dysfunction leading to heart failure (HF). The idiopathic form of DCM (iDCM) occurs in the absence of coronaropathy or other known causes of DCM. Despite being different from other forms of HF for demographic, clinical, and prognostic features, its current pharmacological treatment does not significantly diverge. Methods: In this study we performed a Pubmed library search for placebo-controlled clinical investigations and a post-hoc analysis recruiting iDCM from 1985 to 2016. We searched for second-line pharmacologic treatments to reconsider drugs for iDCM management and pinpoint pathological mechanisms. Results: We found 33 clinical studies recruiting a total of 3392 patients of various durations and sizes, as well as studies that tested different drug classes (statins, pentoxifylline, inotropes). A metanalysis was unfeasible, although a statistical significance for changes upon treatment for molecular results, morphofunctional parameters, and clinical endpoints was reported. Statins appeared to be beneficial in light of their pleiotropic effects; inotropes might be tolerated more for longer times in iDCM compared to ischemic patients. General anti-inflammatory therapies do not significantly improve outcomes. Metabolic and growth modulation remain appealing fields to be investigated. Conclusions: The evaluation of drug effectiveness based on direct clinical benefit is an inductive method providing evidence-based insights. This backward approach sheds light on putative and underestimated pathologic mechanisms and thus therapeutic targets for iDCM management.

Aβ Amyloid Pathology Affects the Hearts of Patients With Alzheimer's Disease: Mind the Heart

BACKGROUND

Individually, heart failure (HF) and Alzheimer's disease (AD) are severe threats to population health, and their potential coexistence is an alarming prospect. In addition to sharing analogous epidemiological and genetic profiles, biochemical characteristics, and common triggers, the authors recently recognized common molecular and pathological features between the 2 conditions. Whereas cognitive impairment has been linked to HF through perfusion defects, angiopathy, and inflammation, whether patients with AD present with myocardial dysfunction, and if the 2 conditions bear a common pathogenesis as neglected siblings are unknown.

OBJECTIVES

Here, the authors investigated whether amyloid beta (Aβ) protein aggregates are present in the hearts of patients with a primary diagnosis of AD, affecting myocardial function.

METHODS

The authors examined myocardial function in a retrospective cross-sectional study from a cohort of AD patients and age-matched controls. Imaging and proteomics approaches were used to identify and quantify Aβ deposits in AD heart and brain specimens compared with controls. Cell shortening and calcium transients were measured on isolated adult cardiomyocytes.

RESULTS

Echocardiographic measurements of myocardial function suggest that patients with AD present with an anticipated diastolic dysfunction. As in the brain, Aβ₄₀ and Aβ₄₂ are present in the heart, and their expression is increased in AD.

CONCLUSIONS

Here, the authors provide the first report of the presence of compromised myocardial function and intramyocardial deposits of Aβ in AD patients. The findings depict a novel biological framework in which AD may be viewed either as a systemic disease or as a metastatic disorder leading to heart, and possibly multiorgan failure. AD and HF are both debilitating and life-threatening conditions, affecting enormous patient populations. Our findings underline a previously dismissed problem of a magnitude that will require new diagnostic approaches and treatments for brain and heart disease, and their combination.

Fungal Endocarditis Due to Aspergillus oryzae: The First Case Reported in the Literature

Infective endocarditis (IE) is a severe disease with high mortality and morbidity. Prosthetic valve endocarditis is a life-threatening complication which can occur in less than 10% of patients with valve prosthesis. A fungal etiology of IE is rare and accounts for only 2-4% of all case of endocarditis, but is associated with a higher mortality and morbidity. Herein is reported the first case of fungal endocarditis of aortic valve prosthesis due to Aspergillus oryzae in a 67-year-old caucasian man who nine years previously underwent mitral and aortic valve replacement with mechanical prostheses, and tricuspid annuloplasty for acute IE due to Enterococcus spp. Seven months previously, the patient also underwent a redo cardiac procedure to replace a mitral valve prosthesis with a new mechanical device due to a leakage. Aspergillus oryzae showed impressive growth with strong and unexpected virulence in both local and systemic settings.

Human cardiac progenitor cells with regenerative potential can be isolated and characterized from 3D-electro-anatomic guided endomyocardial biopsies

AIMS

In the present study, we aimed to develop a percutaneous approach and a reproducible methodology for the isolation and expansion of Cardiac Progenitor Cells (CPCs) from EndoMyocardial Biopsies (EMB) in vivo. Moreover, in an animal model of non-ischemic heart failure (HF), we would like to test whether CPCs obtained by this methodology may engraft the myocardium and differentiate.

METHODS AND RESULTS

EMB were obtained using a preformed sheath and a disposable bioptome, advanced via right femoral vein in 12 healthy mini pigs, to the right ventricle. EMB were enzymatically dissociated, cells were expanded and sorted for c-kit. We used 3D-Electro-Anatomic Mapping (3D-EAM) to obtain CPCs from 32 patients affected by non-ischemic cardiomyopathy. The in vivo regenerative potential of CPCs was tested in a rodent model of drug-induced non-ischemic cardiomyopathy. c-kit positive CPCs replicative capacity was assessed in 30 patients. Telomere length averaged 7.4±0.4kbp and telomerase activity was present in all preparations (1.7×10⁵ copies). The in situ hybridization experiments showed that injected human CPCs may acquire a neonatal myocyte phenotype given the expression of the alpha-sarcomeric actin together with the presence of the Alu probe, suggesting a beneficial impact on LV performance.

CONCLUSIONS

The success in obtaining CPCs characterized by high regenerative potential, in vitro and in vivo, from EMB indicates that harvesting without thoracotomy in patients affected by either ischemic or non-ischemic cardiomyopathy is feasible. These initial results may potentially expand the future application of CPCs to all patients affected by HF not undergoing surgical procedures.

Generation of Human Induced Pluripotent Stem Cell-Derived Bona Fide Neural Stem Cells for Ex Vivo Gene Therapy of Metachromatic Leukodystrophy

Allogeneic fetal‐derived human neural stem cells (hfNSCs) that are under clinical evaluation for several neurodegenerative diseases display a favorable safety profile, but require immunosuppression upon transplantation in patients. Neural progenitors derived from patient‐specific induced pluripotent stem cells (iPSCs) may be relevant for autologous ex vivo gene‐therapy applications to treat genetic diseases with unmet medical need. In this scenario, obtaining iPSC‐derived neural stem cells (NSCs) showing a reliable “NSC signature” is mandatory. Here, we generated human iPSC (hiPSC) clones via reprogramming of skin fibroblasts derived from normal donors and patients affected by metachromatic leukodystrophy (MLD), a fatal neurodegenerative lysosomal storage disease caused by genetic defects of the arylsulfatase A (ARSA) enzyme. We differentiated hiPSCs into NSCs (hiPS‐NSCs) sharing molecular, phenotypic, and functional identity with hfNSCs, which we used as a “gold standard” in a side‐by‐side comparison when validating the phenotype of hiPS‐NSCs and predicting their performance after intracerebral transplantation. Using lentiviral vectors, we efficiently transduced MLD hiPSCs, achieving supraphysiological ARSA activity that further increased upon neural differentiation. Intracerebral transplantation of hiPS‐NSCs into neonatal and adult immunodeficient MLD mice stably restored ARSA activity in the whole central nervous system. Importantly, we observed a significant decrease of sulfatide storage when ARSA‐overexpressing cells were used, with a clear advantage in those mice receiving neonatal as compared with adult intervention. Thus, we generated a renewable source of ARSA‐overexpressing iPSC‐derived bona fide hNSCs with improved features compared with clinically approved hfNSCs. Patient‐specific ARSA‐overexpressing hiPS‐NSCs may be used in autologous ex vivo gene therapy protocols to provide long‐lasting enzymatic supply in MLD‐affected brains. Stem Cells Translational Medicine2017;6:352–368

Reduction in Kv Current Enhances the Temporal Dispersion of the Action Potential in Diabetic Myocytes: Insights From a Novel Repolarization Algorithm

BACKGROUND

Diabetes is associated with prolongation of the QT interval of the electrocardiogram and enhanced dispersion of ventricular repolarization, factors that, together with atherosclerosis and myocardial ischemia, may promote the occurrence of electrical disorders. Thus, we tested the possibility that alterations in transmembrane ionic currents reduce the repolarization reserve of myocytes, leading to action potential (AP) prolongation and enhanced beat-to-beat variability of repolarization.

METHODS AND RESULTS

Diabetes was induced in mice with streptozotocin (STZ), and effects of hyperglycemia on electrical properties of whole heart and myocytes were studied with respect to an untreated control group (Ctrl) using electrocardiographic recordings in vivo, ex vivo perfused hearts, and single-cell patch-clamp analysis. Additionally, a newly developed algorithm was introduced to obtain detailed information of the impact of high glucose on AP profile. Compared to Ctrl, hyperglycemia in STZ-treated animals was coupled with prolongation of the QT interval, enhanced temporal dispersion of electrical recovery, and susceptibility to ventricular arrhythmias, defects observed, in part, in the Akita mutant mouse model of type I diabetes. AP was prolonged and beat-to-beat variability of repolarization was enhanced in diabetic myocytes, with respect to Ctrl cells. Density of Kv K(+) and L-type Ca(2+) currents were decreased in STZ myocytes, in comparison to cells from normoglycemic mice. Pharmacological reduction of Kv currents in Ctrl cells lengthened AP duration and increased temporal dispersion of repolarization, reiterating features identified in diabetic myocytes.

CONCLUSIONS

Reductions in the repolarizing K(+) currents may contribute to electrical disturbances of the diabetic heart.

Myocyte repolarization modulates myocardial function in aging dogs

Studies of myocardial aging are complex and the mechanisms involved in the deterioration of ventricular performance and decreased functional reserve of the old heart remain to be properly defined. We have studied a colony of beagle dogs from 3 to 14 yr of age kept under a highly regulated environment to define the effects of aging on the myocardium. Ventricular, myocardial, and myocyte function, together with anatomical and structural properties of the organ and cardiomyocytes, were evaluated. Ventricular hypertrophy was not observed with aging and the structural composition of the myocardium was modestly affected. Alterations in the myocyte compartment were identified in aged dogs, and these factors negatively interfere with the contractile reserve typical of the young heart. The duration of the action potential is prolonged in old cardiomyocytes contributing to the slower electrical recovery of the myocardium. Also, the remodeled repolarization of cardiomyocytes with aging provides inotropic support to the senescent muscle but compromises its contractile reserve, rendering the old heart ineffective under conditions of high hemodynamic demand. The defects in the electrical and mechanical properties of cardiomyocytes with aging suggest that this cell population is an important determinant of the cardiac senescent phenotype. Collectively, the delayed electrical repolarization of aging cardiomyocytes may be viewed as a critical variable of the aging myopathy and its propensity to evolve into ventricular decompensation under stressful conditions.

IgG antibodies from dourine infected horses identify a distinctive Trypanosoma equiperdum antigenic pattern of low molecular weight molecules

Diagnosis and control of dourine is strongly based on serological evidence, but knowledge of the humoral response of horses during infection is limited. In this study we developed a chemiluminescent immunoblotting (cIB) assay to characterise the Trypanosoma equiperdum antigen pattern recognised by IgGs from naturally or experimentally dourine-infected horses and analyse the kinetics of IgG humoral response following the infection. One compounding factor is that sera from uninfected animals often cross-react with T. equiperdum antigens. Development of the cIB assay was based on the hypothesis that serum IgGs from healthy and infected animals recognise different T. equiperdum antigen patterns. We used sera from 8 naturally infected horses which had recovered from Italian outbreaks and 2 experimentally infected mares. In addition, sera from 10 healthy control animals, eight of which were CFT positive but IFA negative for dourine, were collected from disease free regions. Sera were compared by the complement fixation test (CFT), indirect immune fluorescence (IFA) and the cIB assay. cIB analysis revealed that IgGs from infected horses, in contrast to IgGs from healthy horses, specifically recognise a T. equiperdum antigenic profile with low molecular weight bands ranging between 16 and 35 kDa. A time course experiment indicated that IgGs specific for the 16-35 kDa parasite protein fraction appear 17 days post-infection. The cIB assay confirmed all ten infected animals as positive and all controls as negative. This study demonstrated that analysis of IgGs by cIB can provide clear confirmation of trypanosome infection in horses, suggesting that this technique can be applied as a confirmatory serological test for dourine infection.

Adrenergic effects on force-frequency relationship: a pivotal role for the cardiac intrinsic systems

AIM

The force-frequency relationship (F-FR) is an important intrinsic regulatory mechanism of cardiac contractility. The involvement of autonomic nervous system in this physiological aspect of cardiac control remains unclear. The aim of the study was to evaluate the role of extrinsic and intrinsic cardiac adrenergic innervations on the heart rate (HR)-related positive inotropic response.

METHODS

Twenty-four dogs were anesthetized and acutely instrumented to monitor and record ECG, systemic and left ventricular pressures and derivatives, and to pace the heart at 130, 150, 170, 190 and 210 bpm, in order to construct the F-FR curve. Animals were randomly assigned to four groups (n = 6 each): vehicle (V), ganglion-blocked (G-B), β-blocked (β-B) and ganglion-blocked plus β-blocked (G-B + β-B).

RESULTS

Vehicle treated animals presented the classical F-FR. In the β-B group F-FR was blunted, but never fully suppressed. The G-B treated animals showed a bell-shape response curve of the induced inotropic effect with the zenith at 170 bpm: the first part of the curve resembling the control one, followed by a rapid decline toward baseline value. The co-administration of G-B and β-B agents reversed the contractile response to HR rise with a curve resembling the negative F-FR curve observed in the failing heart.

CONCLUSION

The F-FR appeared to be constituted by two consecutive mechanisms: first depolarization-rate dependent, and a second catecholamine-dependent. The natural consequence of these observations is that the full expression of F-FR needs an intact adrenergic system.