A novel mtDNA point mutation in tRNAVal is associated with hypertrophic cardiomyopathy and MELAS

Background. Pathological mutations of mitochondrial (mt) DNA may cause specific diseases such as cardiomyopathies or hearing loss, or syndromes such as mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episode (MELAS) syndrome. We describe a novel mtDNA mutation in a patient with severe hypertrophic cardiomyopathy associated with MELAS. The familial phenotype included 1) hypertrophic cardiomyopathy and MELAS, 2) clinically mild cardiac hypertrophy, and 3) deafness. Methods. The proband and her first degree relatives underwent echo and electrocardiograms, and biochemical tests. Magnetic resonance imaging of the brain was performed in the proband. mtDNA was fully analyzed by sequencing. DNA purification, polymerase chain reaction and direct automated sequencing were performed following standard procedures. Heteroplasmy of the novel mutation was quantified by densitometric analysis. Results. A novel G1644A transition affecting the tRNAVal was identified in the proband and maternal relatives. The mutation has been interpreted as pathological because the G at the 1644 position is a highly conserved base, is heteroplasmic with higher levels of mutant DNA in the proband than in the relatives, is located in the unique tRNAVal, is very close to a mutation described as causative of MELAS, and finally has not been found in 100 healthy controls. Conclusions. Although it is rare for patients with MELAS to be referred to cardiological evaluation because of coexisting cardiomyopathy, cardiologists should be aware of this association as well as of the non cardiac signs that may address the diagnosis to mtDNA defect-related disease in families with a variable phenotype. © 2004 CEPI Srl

Restrictive Cardiomyopathy, Atrioventricular Block and Mild to Subclinical Myopathy in Patients With Desmin-Immunoreactive Material Deposits

AbstractObjectives. We present clinical data and heart and skeletal muscle biopsy findings from a series of patients with ultrastructural accumulations of granulofilamentous material identified as desmin.Background. Desmin cardiomyopathy is a poorly understood disease characterized by abnormal desmin deposits in cardiac and skeletal muscle.Methods. Clinical evaluation, endomyocardial and skeletal muscle biopsy, light and electron microscopy and immunohistochemistry were used to establish the presence of desmin cardiomyopathy.Results. Six hundred thirty-one patients with primary cardiomyopathy underwent endomyocardial biopsy (EMB). Ultrastructural accumulations of granulofilamentous material were found in 5 of 12 biopsy samples from patients with idiopathic restrictive cardiomyopathy and demonstrated specific immunoreactivity with anti-desmin antibodies by immunoelectron microscopy. Immunohistochemical findings on light microscopy were nonspecific because of a diffuse intracellular distribution of desmin. All five patients had atrioventricular (AV) block and mild or subclinical myopathy. Granulofilamentous material was present in skeletal muscle biopsy samples in all five patients, and unlike the heart biopsy samples, light microscopic immunohistochemical analysis demonstrated characteristic subsarcolemmal desmin deposits. Two patients were first-degree relatives (mother and son); another son with first-degree AV block but without myopathy or cardiomyopathy demonstrated similar light and ultrastructural findings in skeletal muscle. Electrophoretic studies demonstrated two isoforms of desmin—one of normal and another of lower molecular weight—in cardiac and skeletal muscle of the familial cases.Conclusions. Desmin cardiomyopathy must be considered in the differential diagnosis of restrictive cardiomyopathy, especially in patients with AV block and myopathy. Diagnosis depends on ultrastructural examination of EMB samples or light microscopic immunohistochemical studies of skeletal muscle biopsy samples. Familial desminopathy may manifest as subclinical disease and may be associated with abnormal isoforms of desmin

Identification of two regions in the p140Cap adaptor protein that retain the ability to suppress tumor cell properties

p140Cap is an adaptor protein that negatively controls tumor cell properties, by inhibiting in vivo tumor growth and metastasis formation. Our previous data demonstrated that p140Cap interferes with tumor growth and impairs invasive properties of cancer cells inactivating signaling pathways, such as the tyrosine kinase Src or E-cadherin/EGFR cross-talk. In breast cancer p140Cap expression inversely correlates with tumor malignancy. p140Cap is composed of several conserved domains that mediate association with specific partners. Here we focus our attention on two domains of p140Cap, the TER (Tyrosine Enriched Region) which includes several tyrosine residues, and the CT (Carboxy Terminal) which contains a proline rich sequence, involved in binding to SH2 and SH3 domains, respectively. By generating stable cell lines expressing these two proteins, we demonstrate that both TER and CT domains maintain the ability to associate the C-terminal Src kinase (Csk) and Src, to inhibit Src activation and Focal adhesion kinase (Fak) phosphorylation, and to impair in vitro and in vivo tumor cell features. In particular expression of TER and CT proteins in cancer cells inhibits in vitro and in vivo growth and directional migration at a similar extent of the full length p140Cap protein. Moreover, by selective point mutations and deletion we show that the ability of the modules to act as negative regulators of cell migration and proliferation mainly resides on the two tyrosines (Y) inserted in the EPLYA and EGLYA sequences in the TER module and in the second proline-rich stretch contained in the CT protein. Gene signature of cells expressing p140Cap, TER or CT lead to the identification of a common pattern of 105 down-regulated and 128 up-regulated genes, suggesting that the three proteins can act through shared pathways. Overall, this work highlights that the TER and CT regions of p140Cap can efficiently suppress tumor cell properties, opening the perspective that short, defined p140Cap regions can have therapeutic effects

Long-Term Outcome and Risk Stratification in Dilated Cardiolaminopathies

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Atlas of the clinical genetics of human dilated cardiomyopathy

[Abstract] Aim. Numerous genes are known to cause dilated cardiomyopathy (DCM). However, until now technological limitations have hindered elucidation of the contribution of all clinically relevant disease genes to DCM phenotypes in larger cohorts. We now utilized next-generation sequencing to overcome these limitations and screened all DCM disease genes in a large cohort. Methods and results. In this multi-centre, multi-national study, we have enrolled 639 patients with sporadic or familial DCM. To all samples, we applied a standardized protocol for ultra-high coverage next-generation sequencing of 84 genes, leading to 99.1% coverage of the target region with at least 50-fold and a mean read depth of 2415. In this well characterized cohort, we find the highest number of known cardiomyopathy mutations in plakophilin-2, myosin-binding protein C-3, and desmoplakin. When we include yet unknown but predicted disease variants, we find titin, plakophilin-2, myosin-binding protein-C 3, desmoplakin, ryanodine receptor 2, desmocollin-2, desmoglein-2, and SCN5A variants among the most commonly mutated genes. The overlap between DCM, hypertrophic cardiomyopathy (HCM), and channelopathy causing mutations is considerably high. Of note, we find that >38% of patients have compound or combined mutations and 12.8% have three or even more mutations. When comparing patients recruited in the eight participating European countries we find remarkably little differences in mutation frequencies and affected genes. Conclusion. This is to our knowledge, the first study that comprehensively investigated the genetics of DCM in a large-scale cohort and across a broad gene panel of the known DCM genes. Our results underline the high analytical quality and feasibility of Next-Generation Sequencing in clinical genetic diagnostics and provide a sound database of the genetic causes of DCM.Hôpitaux de Paris; PHRC AOM0414

Peri-operative red blood cell transfusion in neonates and infants: NEonate and Children audiT of Anaesthesia pRactice IN Europe: A prospective European multicentre observational study

BACKGROUND: Little is known about current clinical practice concerning peri-operative red blood cell transfusion in neonates and small infants. Guidelines suggest transfusions based on haemoglobin thresholds ranging from 8.5 to 12 g dl-1, distinguishing between children from birth to day 7 (week 1), from day 8 to day 14 (week 2) or from day 15 (≥week 3) onwards. OBJECTIVE: To observe peri-operative red blood cell transfusion practice according to guidelines in relation to patient outcome. DESIGN: A multicentre observational study. SETTING: The NEonate-Children sTudy of Anaesthesia pRactice IN Europe (NECTARINE) trial recruited patients up to 60 weeks' postmenstrual age undergoing anaesthesia for surgical or diagnostic procedures from 165 centres in 31 European countries between March 2016 and January 2017. PATIENTS: The data included 5609 patients undergoing 6542 procedures. Inclusion criteria was a peri-operative red blood cell transfusion. MAIN OUTCOME MEASURES: The primary endpoint was the haemoglobin level triggering a transfusion for neonates in week 1, week 2 and week 3. Secondary endpoints were transfusion volumes, 'delta haemoglobin' (preprocedure - transfusion-triggering) and 30-day and 90-day morbidity and mortality. RESULTS: Peri-operative red blood cell transfusions were recorded during 447 procedures (6.9%). The median haemoglobin levels triggering a transfusion were 9.6 [IQR 8.7 to 10.9] g dl-1 for neonates in week 1, 9.6 [7.7 to 10.4] g dl-1 in week 2 and 8.0 [7.3 to 9.0] g dl-1 in week 3. The median transfusion volume was 17.1 [11.1 to 26.4] ml kg-1 with a median delta haemoglobin of 1.8 [0.0 to 3.6] g dl-1. Thirty-day morbidity was 47.8% with an overall mortality of 11.3%. CONCLUSIONS: Results indicate lower transfusion-triggering haemoglobin thresholds in clinical practice than suggested by current guidelines. The high morbidity and mortality of this NECTARINE sub-cohort calls for investigative action and evidence-based guidelines addressing peri-operative red blood cell transfusions strategies. TRIAL REGISTRATION: ClinicalTrials.gov, identifier: NCT02350348

Autosomal recessive paediatric sick sinus syndrome associated with novel compound mutations in SCN5A

We report the case of a boy who was first addressed to medical attention when he was 2-years-old because of an episode of Salmonellosis. His cardiologic evaluation was normal. There were no clinical signs of myocarditis. Three years later he was admitted to the hospital due to a prolonged episode of flu with persistent fever. At that time, his electrocardiogram (ECG) showed junctional rhythm (JR) at 35 bpm. Further ECGs revealed sinus rhythm (SR) with first degree atrio-ventricular block, episodes of sinoatrial (SA) exit blocks, sinus arrests and phases of JR, supporting the diagnosis of sick sinus syndrome (SSS) [1]. Although the boy did not complain of symptoms, Holter monitoring showed frequent pauses of sinus arrest (max interval = 5.4 s) and chronotropic incompetence. At the age of 8 years, he underwent permanent pacemaker (PM) implantation. Although ventricular pacing is less indicated in SSS [2], the patient was treated with VVIR modality because an attempt at right atrial catheter positioning failed, due to inexcitability of the atrium. Since then, the boy has been asymptomatic. Further Holter monitoring showed episodes of paroxysmal atrial fibrillation (Fig. 1) and showed rate responsive pacing with an acceptable mean heart rate of 66 bp

Coexpression of aspartic proteinases and human leukocyte antigen-DR in human transplanted lung.

Aspartic proteinases have recently been shown to be implicated in antigen processing. We explored the expression of two aspartic proteinases, cathepsins B and D, and of human leukocyte antigen-DR (NLA-DR) molecules in a consecutive series of 80 transbronchial biopsies from transplanted lungs. For controls, we studied five normal donor lungs (not suitable for transplantation on account of thoracic trauma) and macroscopically normal areas of three cancer-affected lungs. Two of the five unsuitable donor lungs showed minimal inflammatory changes. Macroscopically normal samples from the three cancerous lungs showed mild and focal inflammatory infiltrates, In histologically normal lungs, HLA-DR expression was limited to professional antigen-presenting cells. Macroscopically normal lung samples with minimal inflammatory changes from both donor and cancer lungs showed variable HLA-DR expression by alveolar and bronchial epithelial cells and by endothelial cells. All transplanted lung biopsies showed HLA-DR expression by epithelial (alveolar and bronchial) and endothelial cells, with a trend for increased positivity in acute rejection. Cathepsin E was restricted to Clara and to rare bronchus-associated lymphoid tissue-related epithelial cells in histologically normal lung samples, whereas minimal de novo cathepsin E expression by rare alveolar pneumocytes was noted in control lung samples exhibiting minimal inflammatory changes. In all transplanted lung biopsies, cathepsin E was diffusely expressed de novo by hyperplastic alveolar epithelial cells, regardless of the presence or degree of rejection, Cathepsin D was expressed only by alveolar macrophages and by ciliated bronchial cells of normal, minimally inflamed and transplanted lungs. In transplanted lung, Clara cells and several hyperplastic alveolar pneumocytes coexpressed HLA-DR and cathepsin E, whereas all alveolar macrophages and a few ciliated cells coexpressed cathepsin D and HLA-DR The present investigation suggests that the de novo expression of cathepsin E and HLA-DR by hyperplastic alveolar pneumocytes of transplanted lung may be crucial for antigen processing and presentation to recipient competent T cells, and thus for the triggering of the immune-inflammatory cascade that leads to rejection