scholarly journals Familial Arrhythmogenic Cardiomyopathy: Clinical Determinants of Phenotype Discordance and the Impact of Endurance Sports

2020 ◽  
Vol 9 (11) ◽  
pp. 3781
Author(s):  
Sarah Costa ◽  
Alessio Gasperetti ◽  
Argelia Medeiros-Domingo ◽  
Deniz Akdis ◽  
Corinna Brunckhorst ◽  
...  

Arrhythmogenic cardiomyopathy (ACM) is primarily a familial disease with autosomal dominant inheritance. Incomplete penetrance and variable expression are common, resulting in diverse clinical manifestations. Although recent studies on genotype–phenotype relationships have improved our understanding of the molecular mechanisms leading to the expression of the full-blown disease, the underlying genetic substrate and the clinical course of asymptomatic or oligo-symptomatic mutation carriers are still poorly understood. We aimed to analyze different phenotypic expression profiles of ACM in the context of the same familial genetic mutation by studying nine adult cases from four different families with four different familial variants (two plakophilin-2 and two desmoglein-2) from the Swiss Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) Registry. The affected individuals with the same genetic variants presented with highly variable phenotypes ranging from no disease or a classical, right-sided disease, to ACM with biventricular presentation. Moreover, some patients developed early-onset, electrically unstable disease whereas others with the same genetic variants presented with late-onset electrically stable disease. Despite differences in age, gender, underlying genotype, and other clinical characteristics, physical exercise has been observed as the common denominator in provoking an arrhythmic phenotype in these families.

2021 ◽  
Vol 23 (3) ◽  
Author(s):  
Ania M. Fiksinski ◽  
Maude Schneider ◽  
Janneke Zinkstok ◽  
Danielle Baribeau ◽  
Samuel J. R. A. Chawner ◽  
...  

AbstractPurpose of ReviewThe 22q11.2 deletion syndrome (22q11DS) is associated with a broad spectrum of neurodevelopmental phenotypes and is the strongest known single genetic risk factor for schizophrenia. Compared to other rare structural pathogenic genetic variants, 22q11DS is relatively common and one of the most extensively studied. This review provides a state-of-the-art overview of current insights regarding associated neurodevelopmental phenotypes and potential implications for 22q11DS and beyond.Recent FindingsWe will first discuss recent findings with respect to neurodevelopmental phenotypic expression associated with 22q11DS, including psychotic disorders, intellectual functioning, autism spectrum disorders, as well as their interactions. Second, we will address considerations that are important in interpreting these data and propose potential implications for both the clinical care for and the empirical study of individuals with 22q11DS. Third, we will highlight variable penetrance and pleiotropy with respect to neurodevelopmental phenotypes in 22q11DS. We will discuss how these phenomena are consistently observed in the context of virtually all rare pathogenic variants and that they pose substantial challenges from both a clinical and a research perspective.SummaryWe outline how 22q11DS could be viewed as a genetic model for studying neurodevelopmental phenotypes. In addition, we propose that 22q11DS research can help elucidate mechanisms underlying variable expression and pleiotropy of neurodevelopmental phenotypes, insights that are likely relevant for 22q11DS and beyond, including for individuals with other rare pathogenic genetic variants and for individuals with idiopathic neurodevelopmental conditions.


Author(s):  
Qiao Li ◽  
Manran Liu ◽  
Yan Sun ◽  
Ting Jin ◽  
Pengpeng Zhu ◽  
...  

Abstract Background Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer, with poor prognosis and limited treatment options. Hypoxia is a key hallmark of TNBC. Metabolic adaptation promotes progression of TNBC cells that are located within the hypoxic tumor regions. However, it is not well understood regarding the precise molecular mechanisms underlying the regulation of metabolic adaptions by hypoxia. Methods RNA sequencing was performed to analyze the gene expression profiles in MDA-MB-231 cell line (20% O2 and 1% O2). Expressions of Slc6a8, which encodes the creatine transporter protein, were detected in breast cancer cells and tissues by quantitative real-time PCR. Immunohistochemistry was performed to detect SLC6A8 protein abundances in tumor tissues. Clinicopathologic correlation and overall survival were evaluated by chi-square test and Kaplan-Meier analysis, respectively. Cell viability assay and flow cytometry analysis with Annexin V/PI double staining were performed to investigate the impact of SLC6A8-mediated uptake of creatine on viability of hypoxic TNBC cells. TNBC orthotopic mouse model was used to evaluate the effects of creatine in vivo. Results SLC6A8 was aberrantly upregulated in TNBC cells in hypoxia. SLC6A8 was drastically overexpressed in TNBC tissues and its level was tightly associated with advanced TNM stage, higher histological grade and worse overall survival of TNBC patients. We found that SLC6A8 was transcriptionally upregulated by p65/NF-κB and mediated accumulation of intracellular creatine in hypoxia. SLC6A8-mediated accumulation of creatine promoted survival and suppressed apoptosis via maintaining redox homeostasis in hypoxic TNBC cells. Furthermore, creatine was required to facilitate tumor growth in xenograft mouse models. Mechanistically, intracellular creatine bolstered cell antioxidant defense by reducing mitochondrial activity and oxygen consumption rates to reduce accumulation of intracellular reactive oxygen species, ultimately activating AKT-ERK signaling, the activation of which protected the viability of hypoxic TNBC cells via mediating the upregulation of Ki-67 and Bcl-2, and the downregulation of Bax and cleaved Caspase-3. Conclusions Our study indicates that SLC6A8-mediated creatine accumulation plays an important role in promoting TNBC progression, and may provide a potential therapeutic strategy option for treatment of SLC6A8 high expressed TNBC.


2016 ◽  
Vol 2016 ◽  
pp. 1-15 ◽  
Author(s):  
Ben Holmes ◽  
Seung Ho Jung ◽  
Jing Lu ◽  
Jessica A. Wagner ◽  
Liudmilla Rubbi ◽  
...  

Transcranial direct current stimulation (tDCS) has been shown to modulate neuroplasticity. Beneficial effects are observed in patients with psychiatric disorders and enhancement of brain performance in healthy individuals has been observed following tDCS. However, few studies have attempted to elucidate the underlying molecular mechanisms of tDCS in the brain. This study was conducted to assess the impact of tDCS on gene expression within the rat cerebral cortex. Anodal tDCS was applied at 3 different intensities followed by RNA-sequencing and analysis. In each current intensity, approximately 1,000 genes demonstrated statistically significant differences compared to the sham group. A variety of functional pathways, biological processes, and molecular categories were found to be modified by tDCS. The impact of tDCS on gene expression was dependent on current intensity. Results show that inflammatory pathways, antidepressant-related pathways (GTP signaling, calcium ion binding, and transmembrane/signal peptide pathways), and receptor signaling pathways (serotonergic, adrenergic, GABAergic, dopaminergic, and glutamate) were most affected. Of the gene expression profiles induced by tDCS, some changes were observed across multiple current intensities while other changes were unique to a single stimulation intensity. This study demonstrates that tDCS can modify the expression profile of various genes in the cerebral cortex and that these tDCS-induced alterations are dependent on the current intensity applied.


Author(s):  
Francisco Javier Falaguera-Vera ◽  
María Garcia-Escudero ◽  
Javier Bonastre-Férez ◽  
Mario Zacarés ◽  
Elisa Oltra

Current pharmacological treatments of Fibromyalgia (FM) are merely symptom palliative, as clinical trials have so far failed to provide overall benefits without associated harms. Polypharmacy often leads to patient’s health deterioration and chronic drug use to an eventual lack of patient’s response. Emerging evidence supports that physiotherapy treatments based on mechanical triggers improve FM symptoms and therefore could be used for therapeutic purposes by themselves or in combination with current pharmacological treatments, as part of integrative medicine programs. However, a paucity of studies rigorously and systematically evaluating this possibility exists. This study uses scores from validated standardized questionnaires, algometer pressure point threshold (PPT) readings and responses from a custom self-developed questionnaire to determine the impact of a pressure-controlled custom manual protocol on FM hyperalgesia/allodynia, fatigue and patient’s quality of life. The results show that patient’s baseline sensitivity to pain inversely correlates with treatment response in FM. Moreover, post-stratification analysis unexpectedly reveals that patients presenting comorbid ME/CFS do not seem to respond to the applied therapy as those presenting FM only. Therefore, pre-treatment PPTs and ME/CFS comorbidity may serve as indicators to predict patient’s response to physiotherapy programs based on mechanical triggers. Further exploration of these findings is granted. In addition, the study of gene expression profiles in the blood collection generated by this study should help unveil the molecular mechanisms behind patient’s differential response to manual therapy.


2021 ◽  
Author(s):  
Nathalia Beatriz Ramos de Sá ◽  
Milena Neira-Goulart ◽  
Marcelo Ribeiro-Alves ◽  
Kim Mattos Geraldo ◽  
Maria Pia Diniz Ribeiro ◽  
...  

Abstract Background COVID-19 has a broad spectrum of clinical manifestations, from asymptomatic to mild or moderate symptoms, reaching the most severe forms and death. The mechanisms underlying the SARS-CoV-2 infection and its clinical evolution are still unclear. Once SARS-CoV-2 infects individuals, host factors are activated by the presence of the virus inside the cells, such as the inflammasome system. The search of risk factors for COVID-19 is of relevance for clinical management. In this study, we investigated the impact of 11 single-base polymorphisms (SNPs) in the NLRP3, CARD8, AIM2, CASP-1, IFI16, and IL-1β inflammasome genes in SARS-CoV-2 infected individuals with distinct disease outcomes. Methods Patients were divided into two groups: (1) inpatients, with severe/critical disease (Hospitalized group, n=451), and (2) convalescent volunteers with prior SARS-CoV-2 infection and a history of asymptomatic to mild symptoms (Mild group, n=43). Patients hospitalized were followed up at a Hospital Center for COVID-19 Pandemic – National Institute of Infectology (INI)/FIOCRUZ, Rio de Janeiro, Brazil, from June 2020 to March 2021. The Mild group was recruited at Oswaldo Cruz Institute (IOC)/FIOCRUZ, Rio de Janeiro, Brazil, in 2020. Genotyping of the SNPs was determined by Real-Time PCR. Protection and risk estimations were performed by unconditional logistic regression models. Results Among the genotyped SNPs, significant differences in the NLRP3 rs1539019 and rs10754558 frequencies were observed between the groups. The C/C genotype (ORadj=6.31; Padj=0.026) or allele C (ORadj=1.05; Padj=0.002) in rs1539019 polymorphism were associated with the risk for hospitalization, while the C/G genotype (ORadj=0.16; Padj=0.016) or carrier-G (ORadj=0.2; Padj=0.028) in rs10754558 polymorphism were associated with protection for hospitalization. Regarding the NLRP3 genetic variants, the A-C-G-C-G haplotype (ORadj=0.14; Padj= 0.030) was associated with protection for hospitalization. No significant association was observed for the other polymorphisms. Conclusions As of our knowledge, this is the first study demonstrating the association of inflammasome NLRP3 variants with risk and/or protection for hospitalization in COVID-19. Studies linking the NLRP3 inflammasome and SARS-CoV-2 infection are still scarce due to the recent emergence of this pathogen. Our results contribute to the discussion of the impact of inflammasomes in the clinical evolution of COVID-19.


2016 ◽  
Vol 5 (2) ◽  
pp. 90 ◽  
Author(s):  
Deniz Akdis ◽  
Corinna Brunckhorst ◽  
Firat Duru ◽  
Ardan M Saguner ◽  
◽  
...  

This overview gives an update on the molecular mechanisms, clinical manifestations, diagnosis and therapy of arrhythmogenic cardiomyopathy (ACM). ACM is mostly hereditary and associated with mutations in genes encoding proteins of the intercalated disc. Three subtypes have been proposed: the classical right-dominant subtype generally referred to as ARVC/D, biventricular forms with early biventricular involvement and left-dominant subtypes with predominant LV involvement. Typical symptoms include palpitations, arrhythmic (pre)syncope and sudden cardiac arrest due to ventricular arrhythmias, which typically occur in athletes. At later stages, heart failure may occur. Diagnosis is established with the 2010 Task Force Criteria (TFC). Modern imaging tools are crucial for ACM diagnosis, including both echocardiography and cardiac magnetic resonance imaging for detecting functional and structural alternations. Of note, structural findings often become visible after electrical alterations, such as premature ventricular beats, ventricular fibrillation (VF) and ventricular tachycardia (VT). 12-lead ECG is important to assess for depolarisation and repolarisation abnormalities, including T-wave inversions as the most common ECG abnormality. Family history and the detection of causative mutations, mostly affecting the desmosome, have been incorporated in the TFC, and stress the importance of cascade family screening. Differential diagnoses include idiopathic right ventricular outflow tract (RVOT) VT, sarcoidosis, congenital heart disease, myocarditis, dilated cardiomyopathy, athlete’s heart, Brugada syndrome and RV infarction. Therapeutic strategies include restriction from endurance and competitive sports, β-blockers, antiarrhythmic drugs, heart failure medication, implantable cardioverter-defibrillators and endocardial/epicardial catheter ablation.


2021 ◽  
Author(s):  
Sandrine Lenglez ◽  
Ariane Sablon ◽  
Gilles Fénelon ◽  
Anne Boland ◽  
Jean-François Deleuze ◽  
...  

Abstract Platelet-derived growth factor receptor beta (PDGFRB) is one of the genes associated with primary familial brain calcification (PFBC), an inherited neurological disease (OMIM:173410). Genetic analysis of patients and families revealed at least 13 PDGFRB heterozygous missense variants, including two novel ones described in the present report. Limited experimental data published on five of these variants had suggested that they decrease the receptor activity. No functional information was available on the impact of variants located within the receptor extracellular domains. Here, we performed a comprehensive molecular analysis of PDGFRB variants linked to PFBC. Mutated receptors were transfected in various cell lines to monitor receptor expression, signaling, mitogenic activity, and ligand binding. Four mutants caused a complete loss of tyrosine kinase activity in multiple assays. One of the novel variants, p.Pro154Ser, decreased the receptor expression and abolished binding of platelet-derived growth factor (PDGF-BB). Others showed a partial loss of function related to reduced expression or signaling. Combining clinical, genetic and molecular data, we consider nine variants as pathogenic or likely pathogenic, three as benign or likely benign and one as a variant of unknown significance. We discuss the possible relationship between the variant residual activity, incomplete penetrance, brain calcification and neurological symptoms. In conclusion, we identified distinct molecular mechanisms whereby PDGFRB variants may result in a receptor loss of function. This work will facilitate genetic counselling in PFBC.


2013 ◽  
Vol 57 (4) ◽  
pp. 1617-1624 ◽  
Author(s):  
Julia Gödeke ◽  
Christian Pustelny ◽  
Susanne Häussler

ABSTRACTAcute and chronic infections caused by the opportunistic pathogenPseudomonas aeruginosapose a serious threat to human health worldwide, and its increasing resistance to antibiotics requires alternative treatments that are more effective than available strategies. Clinical studies have clearly demonstrated that cystic fibrosis (CF) patients with chronicP. aeruginosainfections benefit from long-term low-dose azithromycin (AZM) treatment. Immunomodulating activity, the impact of AZM on the expression of quorum-sensing-dependent virulence factors, type three secretion, and motility inP. aeruginosaseem to contribute to the therapeutic response. However, to date, the molecular mechanisms underlying these AZM effects have remained elusive. Our data indicate that the AZM-mediated phenotype is caused by a depletion of the intracellular pools of tRNAs available for protein synthesis. Overexpression of theP. aeruginosapeptidyl-tRNA hydrolase, which recycles the tRNA from peptidyl-tRNA drop-off during translation, counteracted the effects of AZM on stationary-phase cell killing, cytotoxicity, and the production of rhamnolipids and partially restored swarming motility. Intriguingly, the exchange of a rare for a frequent codon inrhlRalso explicitly diminished the AZM-mediated decreased production of rhamnolipids. These results indicate that depletion of the tRNA pools by AZM seems to affect the translation of genes that use rare aminoacyl-tRNA isoacceptors to a great extent and might explain the selective activity of AZM on theP. aeruginosaproteome and possibly also on the protein expression profiles of other bacterial pathogens.


2017 ◽  
Author(s):  
Rachel Larder ◽  
M. F. Michelle Sim ◽  
Pawan Gulati ◽  
Robin Antrobus ◽  
Y.C. Loraine Tung ◽  
...  

AbstractAn intergenic region of human Chromosome 2 (2p25.3) harbours genetic variants which are among those most strongly and reproducibly associated with obesity. The molecular mechanisms mediating these effects remain entirely unknown. The gene closest to these variants is TMEM18, encoding a transmembrane protein localised to the nuclear membrane. The expression of Tmem18 within the murine hypothalamic paraventricular nucleus was altered by changes in nutritional state, with no significant change seen in three other closest genes. Germline loss of Tmem18 in mice resulted in increased body weight, which was exacerbated by high fat diet and driven by increased food intake. Selective overexpression of Tmem18 in the PVN of wild-type mice reduced food intake and also increased energy expenditure. We confirmed the nuclear membrane localisation of TMEM18 but provide new evidence that it is has four, not three, transmembrane domains and that it physically interacts with key components of the nuclear pore complex. Our data support the hypothesis that TMEM18 itself, acting within the central nervous system, is a plausible mediator of the impact of adjacent genetic variation on human adiposity.


2014 ◽  
Vol 32 (3_suppl) ◽  
pp. 50-50
Author(s):  
Yu Sunakawa ◽  
Takeru Wakatsuki ◽  
Wu Zhang ◽  
Dongyun Yang ◽  
Mizutomo Azuma ◽  
...  

50 Background: Dysregulation of the c-MET signaling pathway occurs in a wide range of human cancers including GC. Such derangements result from various molecular mechanisms, including mutations, amplification and overexpression of c-MET. Overexpression and amplification of c-MET have been correlated with poor clinical outcomes in pts with GC. However, the association between c-MET polymorphisms and prognosis in GC is not well defined. We examined the prognostic impact of c-MET polymorphisms on clinical outcomes in pts with localized GC treated with surgery. Methods: One-hundred and sixty-one Japanese pts were included, with localized GC (stage Ib-IV) treated with surgery alone (n=58), or surgery plus adjuvant therapy (n=103) between 2002 and 2010. Median follow up was 4 years. Genomic DNA was extracted from the pts’ blood or tissue. Six functionally significant c-MET SNPs (rs1621, rs40239, rs41736, rs41739, rs184953, rs10234854) were analyzed by PCR-based direct sequencing. All candidate SNPs were analyzed for association with disease free survival (DFS) and overall survival (OS) by uni- and multivariate analyses, adjusting for age, sex, stage and type of adjuvant therapy. Results: The MET rs40239 variant was associated with favorable clinical outcomes. Univariate analysis showed pts with any G (AG/GG) allele had significantly longer DFS and OS compared to those with the AA genotype (HR: 0.43; 95% CI: 0.25-0.74; P=0.001, HR: 0.47; 95% CI: 0.27-0.81; P=0.006, log-rank test, respectively); this remained significant upon multivariate analysis (HR: 0.48; 95% CI: 0.27-0.83; P=0.009, HR: 0.50; 95% CI: 0.28-0.88; P=0.017, respectively). In the subgroup analysis by gender, men, but not women, with the AG/GG genotypes maintained a DFS and OS benefit. Conclusions: Our results show for the first time that the c-MET polymorphism, rs40239, may serve as a prognostic marker in pts with localized GC treated with surgery. There also appears to be a gender-related difference in the impact on clinical outcome by genetic variants of c-MET. Prospective validation of this study is warranted.


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