RESUMO
Patients with paroxysmal nocturnal hemoglobinuria (PNH) are susceptible to complement-mediated intravascular hemolysis and thrombosis. Factor H (FH) is the main regulator of the complement alternative pathway, which protects cells from unwanted complement-mediated damage. Although FH is not a glycosylphosphatidylinositol-linked molecule, it may play a role in PNH. We sought to determine if rare germline variants in complement factor H (CFH) affect the PNH course, screening 84 patients with PNH treated with eculizumab for rare variants in CFH, CFI, and C3 genes. We compared the allelic frequencies with populational data and a geographically-matched control group, looking for an association between presence of the variants and treatment response (transfusion independence by 6 months). Sixteen patients presented rare variants, 9 in CFH (10.7%). Germline CFH variants were more frequent among patients with PNH than among controls (P = .02) or public data (P < .001) and were more likely to be transfusion-dependent at 6 months after eculizumab initiation (P = .015). With a median follow-up of 5.8 years, 8 of 9 patients with the CFH variant received transfusions, and 2 developed thromboses. None of the patients with the CFH variant had severe aplastic anemia from eculizumab initiation until 6 months. We demonstrated for the first time that rare CFH variants are over-represented among patients with PNH and that germline genetic background may affect the response to eculizumab.
Assuntos
Fator H do Complemento , Hemoglobinúria Paroxística , Trombose , Humanos , Anemia Aplástica , Fator H do Complemento/genética , Hemoglobinúria Paroxística/tratamento farmacológico , Hemoglobinúria Paroxística/genética , HemóliseRESUMO
Atypical hemolytic uremic syndrome (aHUS) is a rare kidney disease due to a dysregulation of the complement alternative pathway. Complement factor I (CFI) negatively regulates the alternative pathway and CFI gene rare variants have been associated to aHUS with a low disease penetrance. We report 10 unrelated cases of HUS associated to a rare CFI variant, p.Ile357Met (c.1071T>G). All patients with isolated p.Ile357Met CFI missense variant were retrospectively identified among patients included between January 2007 and January 2022 in the French HUS Registry. We identified 10 unrelated patients (70% women; median age at HUS diagnosis, 36.5 years) who carry the same rare variant p.Ile357Met in the CFI gene. Seven patients (cases 1-7) presented with aHUS in the native kidney associated with malignant hypertension in 5 patients. None received a C5 inhibitor. Two of these cases occurred in the peripartum period with complete recovery of kidney function, while 5 of these patients reached kidney failure requiring replacement therapy (KFRT). Four patients with KFRT subsequently underwent kidney transplantation. Three later developed C3 glomerulopathy in their kidney graft, but none had aHUS recurrence. Three other patients (cases 8-10) experienced de novo thrombotic microangiopathy after kidney transplantation, precipitated by various triggers. The rare CFI variant p.Ile357Met appears to be a facilitating genetic factor for HUS and for some forms of secondary HUS.
Assuntos
Síndrome Hemolítico-Urêmica Atípica , Fator I do Complemento , Adulto , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Síndrome Hemolítico-Urêmica Atípica/genética , Fator I do Complemento/genética , Mutação de Sentido Incorreto , Estudos RetrospectivosRESUMO
Coastal zones account for 75% of marine methane emissions, despite covering only 15% of the ocean surface area. In these ecosystems, the tight balance between methane production and oxidation in sediments prevents most methane from escaping into seawater. However, anthropogenic activities could disrupt this balance, leading to an increased methane escape from coastal sediments. To quantify and unravel potential mechanisms underlying this disruption, we used a suite of biogeochemical and microbiological analyses to investigate the impact of anthropogenically induced redox shifts on methane cycling in sediments from three sites with contrasting bottom water redox conditions (oxic-hypoxic-euxinic) in the eutrophic Stockholm Archipelago. Our results indicate that the methane production potential increased under hypoxia and euxinia, while anaerobic oxidation of methane was disrupted under euxinia. Experimental, genomic, and biogeochemical data suggest that the virtual disappearance of methane-oxidizing archaea at the euxinic site occurred due to sulfide toxicity. This could explain a near 7-fold increase in the extent of escape of benthic methane at the euxinic site relative to the hypoxic one. In conclusion, these insights reveal how the development of euxinia could disrupt the coastal methane biofilter, potentially leading to increased methane emissions from coastal zones.
Assuntos
Sedimentos Geológicos , Metano , Oxirredução , Sulfetos , Metano/metabolismo , Sedimentos Geológicos/química , Anaerobiose , Água do Mar/química , Eutrofização , Archaea/metabolismoRESUMO
While it is experimentally supported that impaired myocardial vascularization contributes to a mismatch between myocardial oxygen demand and supply, a mechanistic basis for disruption of coordinated tissue growth and angiogenesis in heart failure remains poorly understood. Silencing strategies that impair microRNA biogenesis have firmly implicated microRNAs in the regulation of angiogenesis, and individual microRNAs prove to be crucial in developmental or tumor angiogenesis. A high-throughput functional screening for the analysis of a whole-genome microRNA silencing library with regard to their phenotypic effect on endothelial cell proliferation as a key parameter, revealed several anti- and pro-proliferative microRNAs. Among those was miR-216a, a pro-angiogenic microRNA which is enriched in cardiac microvascular endothelial cells and reduced in expression under cardiac stress conditions. miR-216a null mice display dramatic cardiac phenotypes related to impaired myocardial vascularization and unbalanced autophagy and inflammation, supporting a model where microRNA regulation of microvascularization impacts the cardiac response to stress.
Assuntos
Insuficiência Cardíaca , MicroRNAs , Animais , Camundongos , Células Endoteliais/metabolismo , Insuficiência Cardíaca/metabolismo , MicroRNAs/metabolismo , Miocárdio/metabolismo , Neovascularização Patológica/genética , Neovascularização Patológica/metabolismo , Neovascularização Fisiológica/genéticaRESUMO
The potential and drivers of microbial methane removal in the water column of seasonally stratified coastal ecosystems and the importance of the methanotrophic community composition for ecosystem functioning are not well explored. Here, we combined depth profiles of oxygen and methane with 16S rRNA gene amplicon sequencing, metagenomics and methane oxidation rates at discrete depths in a stratified coastal marine system (Lake Grevelingen, The Netherlands). Three amplicon sequence variants (ASVs) belonging to different genera of aerobic Methylomonadaceae and the corresponding three methanotrophic metagenome-assembled genomes (MOB-MAGs) were retrieved by 16S rRNA sequencing and metagenomic analysis, respectively. The abundances of the different methanotrophic ASVs and MOB-MAGs peaked at different depths along the methane oxygen counter-gradient and the MOB-MAGs show a quite diverse genomic potential regarding oxygen metabolism, partial denitrification and sulphur metabolism. Moreover, potential aerobic methane oxidation rates indicated high methanotrophic activity throughout the methane oxygen counter-gradient, even at depths with low in situ methane or oxygen concentration. This suggests that niche-partitioning with high genomic versatility of the present Methylomonadaceae might contribute to the functional resilience of the methanotrophic community and ultimately the efficiency of methane removal in the stratified water column of a marine basin.
Assuntos
Metano , Methylococcaceae , Metano/metabolismo , Ecossistema , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/metabolismo , Oxirredução , Methylococcaceae/genética , Methylococcaceae/metabolismo , Água/metabolismo , Oxigênio/metabolismo , FilogeniaRESUMO
RATIONALE & OBJECTIVE: C3 glomerulopathy (C3GN) and atypical hemolytic uremic syndrome (aHUS) are 2 distinct rare kidney diseases caused by dysregulation of the alternative complement pathway. Patients with C3GN and concurrent kidney lesions of thrombotic microangiopathy (TMA) have been rarely reported. We characterized the clinical features and underlying immunological abnormalities in these patients. STUDY DESIGN: Case series. SETTING & PARTICIPANTS: Patients with C3GN and concomitant TMA lesions on biopsy registered from 2009 to 2019 in the French National Registry of C3GN. FINDINGS: Among 278 registered patients with C3GN, 16 (6%) had biopsy-proven glomerular and/or vascular TMA lesions. Their median age at diagnosis was 39 years (range, 7-76), and 59% were female. Fourteen of the 16 patients (88%) had an estimated glomerular filtration rate of<30mL/min/1.73m2 and 3 of 16 (19%) required dialysis. Twelve of the 14 evaluated patients (86%) showed evidence of mechanical hemolysis. Fifty percent of the patients had low C3 levels. Six of the 14 evaluated patients had a rare variant in complement genes, and 4 of the 16 patients (25%) had monoclonal gammopathy. Among the 16 patients, 10 (63%) received eculizumab, 5 (31%) received immunosuppressive therapy, and 4 (25%) received clone-targeted chemotherapy. Median kidney survival was 49 months. LIMITATIONS: Small retrospective case series with a limited number of biopsies including electron microscopy. CONCLUSIONS: Concomitant C3GN and TMA is extremely rare and is associated with poor kidney outcomes. Genetic or acquired abnormalities of the alternative complement pathway are common as is the presence of monoclonal gammopathy, which may inform the selection of treatment approaches.
Assuntos
Síndrome Hemolítico-Urêmica Atípica , Paraproteinemias , Microangiopatias Trombóticas , Humanos , Feminino , Criança , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Idoso , Masculino , Estudos Retrospectivos , Rim , Síndrome Hemolítico-Urêmica Atípica/tratamento farmacológico , Microangiopatias Trombóticas/terapia , Microangiopatias Trombóticas/complicações , Paraproteinemias/complicaçõesRESUMO
[Figure: see text].
Assuntos
Potenciais de Ação , Bloqueio Atrioventricular/metabolismo , Nó Atrioventricular/metabolismo , Canais de Cálcio Tipo L/metabolismo , Frequência Cardíaca , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização/metabolismo , Miócitos Cardíacos/metabolismo , Resistência Física , Animais , Bloqueio Atrioventricular/induzido quimicamente , Bloqueio Atrioventricular/diagnóstico , Bloqueio Atrioventricular/fisiopatologia , Nó Atrioventricular/fisiopatologia , Atropina , Biópsia , Canais de Cálcio Tipo L/genética , Modelos Animais de Doenças , Eletrocardiografia , Cavalos , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização/genética , Masculino , Camundongos Endogâmicos C57BL , MicroRNAs/genética , MicroRNAs/metabolismo , Condicionamento Físico Animal , Propranolol , Natação , Transcrição GênicaRESUMO
Methane is a powerful greenhouse gas that is produced in large quantities in marine sediments. Microbially mediated oxidation of methane in sediments, when in balance with methane production, prevents the release of methane to the overlying water. Here, we present a gene-based reactive transport model that includes both microbial and geochemical dynamics and use it to investigate whether the rate of growth of methane oxidizers in sediments impacts the efficiency of the microbial methane filter. We focus on iron- and methane-rich coastal sediments and, with the model, show that at our site, up to 10% of all methane removed is oxidized by iron and manganese oxides, with the remainder accounted for by oxygen and sulfate. We demonstrate that the slow growth rate of anaerobic methane-oxidizing microbes limits their ability to respond to transient perturbations, resulting in periodic benthic release of methane. Eutrophication and deoxygenation decrease the efficiency of the microbial methane filter further, thereby enhancing the role of coastal environments as a source of methane to the atmosphere.
Assuntos
Sedimentos Geológicos , Metano , Anaerobiose , Oxirredução , Ferro , SulfatosRESUMO
As mediators of intercellular communication, extracellular vesicles containing molecular cargo, such as microRNAs, are secreted by cells and taken up by recipient cells to influence their cellular phenotype and function. Here we report that cardiac stress-induced differential microRNA content, with miR-200c-3p being one of the most enriched, in cardiomyocyte-derived extracellular vesicles mediates functional cross-talk with endothelial cells. Silencing of miR-200c-3p in mice subjected to chronic increased cardiac pressure overload resulted in attenuated hypertrophy, smaller fibrotic areas, higher capillary density, and preserved cardiac ejection fraction. We were able to maximally rescue microvascular and cardiac function with very low doses of antagomir, which specifically silences miR-200c-3p expression in non-myocyte cells. Our results reveal vesicle transfer of miR-200c-3p from cardiomyocytes to cardiac endothelial cells, underlining the importance of cardiac intercellular communication in the pathophysiology of heart failure.
Assuntos
Vesículas Extracelulares , MicroRNAs , Animais , Comunicação Celular , Células Endoteliais/metabolismo , Vesículas Extracelulares/metabolismo , Camundongos , MicroRNAs/genética , MicroRNAs/metabolismo , Miócitos Cardíacos/metabolismoRESUMO
C3 glomerulopathy (C3G) is a rare complement-mediated disease. Specific treatments are not yet available and factors predictive of kidney survival such as age, kidney function and proteinuria are not specific to C3G. The prognostic value of biomarkers of complement activation, which are pathognomonic of the diseases, remains unknown. In a large cohort of 165 patients from the French National registry, we retrospectively assess the prognostic value of C3, soluble C5b-9 (sC5b-9), C3 nephritic factor, and rare disease-predicting variants in complement genes in predicting clinical outcome of patients. By multivariate analysis age (adult onset), reduced kidney function (defined by estimated glomerular filtration rate under 60ml/min) and presence of rare disease-predicting variants in complement genes predicted risk of progression to kidney failure. Moreover, by multivariate analysis, normal C3/high sC5b-9 levels or low C3/normal sC5b-9 levels remained independently associated with a worse kidney prognosis, with the relative risk 3.7- and 8-times higher, respectively. Subgroup analysis indicated that the complement biomarker profiles independently correlated to kidney prognosis in patients with adult but not pediatric onset. In this subgroup, we showed that profiles of biomarkers C3 and/or sC5b-9 correlated with intra glomerular inflammation and may explain kidney outcomes. In children, only the presence of rare disease-predicting variants correlated with kidney survival. Thus, in an adult population, we propose a three-point C3G prognostic score based on biomarker profiles at risk, estimated glomerular filtration rate at presentation and genetic findings, which may help stratify adult patients into subgroups that require close monitoring and more aggressive therapy.
Assuntos
Glomerulonefrite Membranoproliferativa , Nefropatias , Adulto , Biomarcadores , Criança , Complemento C3/genética , Fator Nefrítico do Complemento 3/genética , Complexo de Ataque à Membrana do Sistema Complemento , Glomerulonefrite Membranoproliferativa/tratamento farmacológico , Glomerulonefrite Membranoproliferativa/genética , Humanos , Nefropatias/diagnóstico , Nefropatias/genética , Glomérulos Renais , Doenças Raras , Estudos RetrospectivosRESUMO
Bacteria in the order 'Candidatus Brocadiales' within the phylum Planctomycetes (Planctomycetota) have the remarkable ability to perform anaerobic ammonium oxidation (anammox). Two families of anammox bacteria with different biogeographical distributions have been reported, marine Ca. Scalinduaceae and freshwater Ca. Brocadiaceae. Here we report evidence of three new species within a novel genus and family of anammox bacteria, which were discovered in biofilms of a subsea road tunnel under a fjord in Norway. In this particular ecosystem, the nitrogen cycle is likely fuelled by ammonia from organic matter degradation in the fjord sediments and the rock mass above the tunnel, resulting in the growth of biofilms where anammox bacteria can thrive under oxygen limitation. We resolved several metagenome-assembled genomes (MAGs) of anammox bacteria, including three Ca. Brocadiales MAGs that could not be classified at the family level. MAGs of this novel family had all the diagnostic genes for a full anaerobic ammonium oxidation pathway in which nitrite was probably reduced by a NirK-like reductase. A survey of published molecular data indicated that this new family of anammox bacteria occurs in many marine sediments, where its members presumably would contribute to nitrogen loss.
Assuntos
Compostos de Amônio , Metagenoma , Compostos de Amônio/metabolismo , Oxidação Anaeróbia da Amônia , Anaerobiose , Bactérias , Bactérias Anaeróbias/metabolismo , Ecossistema , OxirreduçãoRESUMO
Cardiovascular diseases remain the leading cause of death, largely due to the limited regenerative capacity of the adult mammalian heart. Yet, neonatal mammals were shown to regenerate the myocardium after injury by increasing the proliferation of pre-existing cardiomyocytes. Re-activation of cardiomyocyte proliferation in adulthood has been considered a promising strategy to improve cardiac response to injury. Notwithstanding, quantification of cardiomyocyte proliferation, which occurs at a very low rate, is hampered by inefficient or unreliable techniques. Herein, we propose an optimized protocol to unequivocally assess cardiomyocyte proliferation and/or cardiomyocyte number in the myocardium. Resorting to a stereological approach we estimate the number of cardiomyocytes using representative thick sections of left ventricle fragments. This protocol overcomes the need for spatial-temporal capture of cardiomyocyte proliferation events by focusing instead on the quantification of the outcome of this process. In addition, assessment of cardiomyocyte nucleation avoids overestimation of cardiomyocyte proliferation due to increased binucleation. By applying this protocol, we were able to previously show that apical resection triggers proliferation of pre-existing cardiomyocytes generating hearts with more cardiomyocytes. Likewise, the protocol will be useful for any study aiming at evaluating the impact of neomyogenic therapies.
Assuntos
Coração , Miócitos Cardíacos , Animais , Proliferação de Células , Ventrículos do Coração , Miocárdio , RegeneraçãoRESUMO
Methoxylated aromatic compounds (MACs) are important components of lignin found in significant amounts in the subsurface. Recently, the methanogenic archaeon Methermicoccus shengliensis was shown to be able to use a variety of MACs during methoxydotrophic growth. After a molecular survey, we found that the hyperthermophilic non-methanogenic archaeon Archaeoglobus fulgidus also encodes genes for a bacterial-like demethoxylation system. In this study, we performed growth and metabolite analysis, and used transcriptomics to investigate the response of A. fulgidus during growth on MACs in comparison to growth on lactate. We observed that A. fulgidus converts MACs to their hydroxylated derivatives with CO2 as the main product and sulfate as electron acceptor. Furthermore, we could show that MACs improve the growth of A. fulgidus in the presence of organic substrates such as lactate. We also found evidence that other archaea such as Bathyarchaeota, Lokiarchaeota, Verstraetearchaeota, Korarchaeota, Helarchaeota and Nezhaarchaeota encode a demethoxylation system. In summary, we here describe the first non-methanogenic archaeon with the ability to grow on MACs indicating that methoxydotrophic archaea might play a so far underestimated role in the global carbon cycle.
Assuntos
Archaea , Archaeoglobus fulgidus , Methanosarcinales , Oxirredução , SulfatosRESUMO
BACKGROUND: The pathophysiology of the leading cause of pediatric acute nephritis, acute postinfectious GN, including mechanisms of the pathognomonic transient complement activation, remains uncertain. It shares clinicopathologic features with C3 glomerulopathy, a complement-mediated glomerulopathy that, unlike acute postinfectious GN, has a poor prognosis. METHODS: This retrospective study investigated mechanisms of complement activation in 34 children with acute postinfectious GN and low C3 level at onset. We screened a panel of anticomplement protein autoantibodies, carried out related functional characterization, and compared results with those of 60 children from the National French Registry who had C3 glomerulopathy and persistent hypocomplementemia. RESULTS: All children with acute postinfectious GN had activation of the alternative pathway of the complement system. At onset, autoantibodies targeting factor B (a component of the alternative pathway C3 convertase) were found in a significantly higher proportion of children with the disorder versus children with hypocomplementemic C3 glomerulopathy (31 of 34 [91%] versus 4 of 28 [14%], respectively). In acute postinfectious GN, anti-factor B autoantibodies were transient and correlated with plasma C3 and soluble C5b-9 levels. We demonstrated that anti-factor B antibodies enhance alternative pathway convertase activity in vitro, confirming their pathogenic effect. We also identified crucial antibody binding sites on factor B, including one correlated to disease severity. CONCLUSIONS: These findings elucidate the pathophysiologic mechanisms underlying acute postinfectious GN by identifying anti-factor B autoantibodies as contributing factors in alternative complement pathway activation. At onset of a nephritic syndrome with low C3 level, screening for anti-factor B antibodies might help guide indications for kidney biopsy to avoid misdiagnosed chronic glomerulopathy, such as C3 glomerulopathy, and to help determine therapy.
Assuntos
Autoanticorpos/sangue , Ativação do Complemento/fisiologia , Complemento C3/metabolismo , Fator B do Complemento/imunologia , Glomerulonefrite/sangue , Glomerulonefrite/diagnóstico , Criança , Pré-Escolar , Fator Nefrítico do Complemento 3/metabolismo , Feminino , França , Humanos , Masculino , Estudos RetrospectivosRESUMO
OBJECTIVES: To evaluate pain, disruptive behavior, and anxiety in children undergoing different local dental anesthetic techniques. METHODS: This randomized/parallel clinical trial analyzed three groups of patients (9-12 years old) (n = 35) who received infiltrative anesthesia using conventional (CA), vibrational (VBA), and computer-controlled techniques (CCLAD). The outcomes were pain self-perception (Wong-Baker Faces Pain Rating Scale (WBF); Numerical Ranting Scale (NRS)), disruptive behavior (Face, Legg, Activity, Crying, Consolability Scale (FLACC)), anxiety (Corah's Dental Anxiety Scale; modified Venham Picture test (VPTm)), and physiological parameters (systolic (SBP)/diastolic pressure (DBP); heart rate (HR); oxygen saturation (SpO2); respiratory rate (RR)). Statistical analysis was accomplished using Kruskall-Wallis test and ANOVA for repeated measures (α = 0.05). RESULTS: Dental anxiety levels at the baseline were similar for all patients. CA promoted less pain than VBA in WBF (p = 0.018) and NRS (p = 0.006) and CCLAD in WBF (p = 0.029). There were no differences in disruptive behavior (FLACC p = 0.573), anxiety (VPTm p = 0.474), blood pressure (SBP p = 0.954; DBP p = 0.899), heart rate (p = 0.726), oxygen saturation (p = 0.477), and respiratory rate (p = 0.930) between anesthetic techniques. CONCLUSION: Conventional technique resulted in less pain perception for dental local anesthesia. CLINICAL RELEVANCE: Conventional technique reduces the self-reported pain in children 9-12 years old, and therefore, the use of additional devices or different anesthetic techniques is not justified.
Assuntos
Anestesia Dentária , Anestesia Local , Anestésicos Locais , Ansiedade , Criança , Ansiedade ao Tratamento Odontológico/prevenção & controle , Humanos , DorRESUMO
The complement system is an innate immune defense cascade that can cause tissue damage when inappropriately activated. Evidence for complement over activation has been reported in small cohorts of patients with sickle cell disease (SCD). However, the mechanism governing complement activation in SCD has not been elucidated. Here, we observe that the plasma concentration of sC5b-9, a reliable marker for terminal complement activation, is increased at steady state in 61% of untreated SCD patients. We show that greater complement activation in vitro is promoted by SCD erythrocytes compared to normal ones, although no significant differences were observed in the regulatory proteins CD35, CD55, and CD59 in whole blood. Complement activation is positively correlated with the percentage of dense sickle cells (DRBCs). The expression levels of CD35, CD55, and CD59 are reduced in DRBCs, suggesting inefficient regulation when cell density increases. Moreover, the surface expression of the complement regulator CD46 on granulocytes was inversely correlated with the plasma sC5b-9. We also show increased complement deposition in cultured human endothelial cells incubated with SCD serum, which is diminished by the addition of the heme scavenger hemopexin. Treatment of SCD patients with hydroxyurea produces substantial reductions in complement activation, measured by sC5b-9 concentration and upregulation of CD46, as well as decreased complement activation on RBCs in vitro. In conclusion, complement over activation is a common pathogenic event in SCD that is associated with formation of DRBCs and hemolysis. And, it affects red cells, leukocytes and endothelial cells. This complement over activation is partly alleviated by hydroxyurea therapy.
Assuntos
Anemia Falciforme/terapia , Contagem de Células/métodos , Ativação do Complemento/genética , Hemólise/fisiologia , Hidroxiureia/uso terapêutico , Adolescente , Adulto , Feminino , Humanos , Hidroxiureia/farmacologia , Pessoa de Meia-Idade , Adulto JovemRESUMO
Atypical hemolytic uremic syndrome (aHUS) and C3 glomerulopathy (C3G) are associated with dysregulation and overactivation of the complement alternative pathway. Typically, gene analysis for aHUS and C3G is undertaken in small patient numbers, yet it is unclear which genes most frequently predispose to aHUS or C3G. Accordingly, we performed a six-center analysis of 610 rare genetic variants in 13 mostly complement genes (CFH, CFI, CD46, C3, CFB, CFHR1, CFHR3, CFHR4, CFHR5, CFP, PLG, DGKE, and THBD) from >3500 patients with aHUS and C3G. We report 371 novel rare variants (RVs) for aHUS and 82 for C3G. Our new interactive Database of Complement Gene Variants was used to extract allele frequency data for these 13 genes using the Exome Aggregation Consortium server as the reference genome. For aHUS, significantly more protein-altering rare variation was found in five genes CFH, CFI, CD46, C3, and DGKE than in the Exome Aggregation Consortium (allele frequency < 0.01%), thus correlating these with aHUS. For C3G, an association was only found for RVs in C3 and the N-terminal C3b-binding or C-terminal nonsurface-associated regions of CFH In conclusion, the RV analyses showed nonrandom distributions over the affected proteins, and different distributions were observed between aHUS and C3G that clarify their phenotypes.
Assuntos
Síndrome Hemolítico-Urêmica Atípica/genética , Complemento C3/genética , Fator H do Complemento/genética , Via Alternativa do Complemento/genética , Glomerulonefrite Membranoproliferativa/genética , Síndrome Hemolítico-Urêmica Atípica/patologia , Complemento C3/metabolismo , Via Alternativa do Complemento/fisiologia , Feminino , Frequência do Gene/genética , Predisposição Genética para Doença/genética , Glomerulonefrite Membranoproliferativa/patologia , Humanos , Masculino , Mutação de Sentido Incorreto/genéticaRESUMO
Heart failure is preceded by ventricular remodeling, changes in left ventricular mass, and myocardial volume after alterations in loading conditions. Concentric hypertrophy arises after pressure overload, involves wall thickening, and forms a substrate for diastolic dysfunction. Eccentric hypertrophy develops in volume overload conditions and leads wall thinning, chamber dilation, and reduced ejection fraction. The molecular events underlying these distinct forms of cardiac remodeling are poorly understood. Here, we demonstrate that miR-148a expression changes dynamically in distinct subtypes of heart failure: while it is elevated in concentric hypertrophy, it decreased in dilated cardiomyopathy. In line, antagomir-mediated silencing of miR-148a caused wall thinning, chamber dilation, increased left ventricle volume, and reduced ejection fraction. Additionally, adeno-associated viral delivery of miR-148a protected the mouse heart from pressure-overload-induced systolic dysfunction by preventing the transition of concentric hypertrophic remodeling toward dilation. Mechanistically, miR-148a targets the cytokine co-receptor glycoprotein 130 (gp130) and connects cardiomyocyte responsiveness to extracellular cytokines by modulating the Stat3 signaling. These findings show the ability of miR-148a to prevent the transition of pressure-overload induced concentric hypertrophic remodeling toward eccentric hypertrophy and dilated cardiomyopathy and provide evidence for the existence of separate molecular programs inducing distinct forms of myocardial remodeling.
Assuntos
Cardiomiopatias/metabolismo , Insuficiência Cardíaca/metabolismo , Transplante de Coração/métodos , MicroRNAs/metabolismo , Miocárdio/metabolismo , Animais , Cardiomiopatias/genética , Proliferação de Células/fisiologia , Insuficiência Cardíaca/genética , Humanos , Camundongos , MicroRNAs/genética , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais/fisiologia , Remodelação Ventricular/genética , Remodelação Ventricular/fisiologiaRESUMO
HIV-uninfected children exposed prenatally to the virus and to prophylactic antiretroviral therapy are at an uncertain risk of long-term myocardial dysfunction. This study aimed to analyse the structure and function of their ventricles and to identify potential screening tools for this at-risk population. One hundred and fifteen children (77 exposed vs 38 controls) aged between 2.7 and 16.2 years were included. An echocardiographic study was performed where both ventricles' dimensions and systolic functions were evaluated. In the left ventricle, parameters related to diastolic function were also analysed. Tissue Doppler values were determined in the basal state and after passive leg raising. Serologic analysis of amino-terminal pro-B-type natriuretic peptide (NT-proBNP) was carried out. The two groups had identical ventricular sizes and left ventricular diastolic functions. However, contractility assessed by myocardial peak systolic velocity was significantly inferior in the exposed group. These systolic echocardiographic differences were present despite similar values of NT-proBNP in both groups.Conclusion: HIV-exposed uninfected children may be vulnerable to ventricular systolic dysfunction at long term. Cardiovascular surveillance and periodic monitoring of biventricular function are therefore recommended. Myocardial peak systolic velocity may be a useful screening tool for this purpose.What is Known:⢠Previous studies on HIV-exposed uninfected children subjected prenatally to antiretroviral therapy have alerted to potential long-term cardiovascular toxicity effects on the left ventricle.What is New:⢠The study gives new insights on ventricular function and morphology in HIV-exposed uninfected children.⢠Myocardial peak systolic velocities are significantly inferior in this paediatric sub-group, therefore long-term cardiac surveillance is recommended.
Assuntos
Ventrículos do Coração/diagnóstico por imagem , Sístole , Função Ventricular Esquerda , Adolescente , Antirretrovirais/efeitos adversos , Biomarcadores/sangue , Velocidade do Fluxo Sanguíneo , Estudos de Casos e Controles , Criança , Pré-Escolar , Ecocardiografia , Feminino , Soronegatividade para HIV , Humanos , Masculino , Peptídeo Natriurético Encefálico/sangue , Fragmentos de Peptídeos/sangue , Gravidez , Efeitos Tardios da Exposição Pré-Natal/diagnósticoRESUMO
BACKGROUND: The use of statins in children, although not frequent, is recommended in specific clinical contexts, namely, familial hypercholesterolaemia, conditions carrying a moderate-high cardiovascular risk and sub-optimal cholesterol levels after implementation of lifestyle modifications. The aim of this study is to characterise children with dyslipidaemia managed with statins, followed at a tertiary referral centre in central Portugal. METHODS AND RESULTS: The authors carried out a retrospective and descriptive study made up of 66 patients (50% males, mean age of therapy onset 11.9 years) followed up at the Cardiovascular Clinic of a tertiary referral centre between January, 2012, and May, 2018. Clinical, analytical, and echocardiographic parameters were analysed. About 60.6% had clinical and/or molecular diagnosis of familial hypercholesterolaemia. On average, each patient had three cardiovascular risk factors, obesity (31%) being most prevalent, followed by arterial hypertension (14%). Statin therapy showed a statistically significant reduction in the lipid profile, particularly in the total cholesterol (23%) and low-density lipoprotein cholesterol (30%) levels, as well as in the carotid intima-media thickness (p = 0.015). Hepatic and muscle integrity markers were within normal range. CONCLUSIONS: Statins are safe and efficient in the management of children with hypercholesterolaemia. Our study showed that apart from its lipid-lowering properties, it also reduced significantly the carotid intima-media thickness and, implicitly, the cardiovascular risk of these patients.