RESUMO
Altered ankyrin-R (AnkR; encoded by ANK1) expression is associated with diastolic function, left ventricular remodeling, and heart failure with preserved ejection fraction (HFpEF). First identified in erythrocytes, the role of AnkR in other tissues, particularly the heart, is less studied. Here, we identified the expression of both canonical and small isoforms of AnkR in the mouse myocardium. We demonstrate that cardiac myocytes primarily express small AnkR (sAnkR), whereas cardiac fibroblasts predominantly express canonical AnkR. As canonical AnkR expression in cardiac fibroblasts is unstudied, we focused on expression and localization in these cells. AnkR is expressed in both the perinuclear and cytoplasmic regions of fibroblasts with considerable overlap with the trans-Golgi network protein 38, TGN38, suggesting a potential role in trafficking. To study the role of AnkR in fibroblasts, we generated mice lacking AnkR in activated fibroblasts (Ank1-ifKO mice). Notably, Ank1-ifKO mice fibroblasts displayed reduced collagen compaction, supportive of a novel role of AnkR in normal fibroblast function. At the whole animal level, in response to a heart failure model, Ank1-ifKO mice displayed an increase in fibrosis and T-wave inversion compared with littermate controls, while preserving cardiac ejection fraction. Collagen type I fibers were decreased in the Ank1-ifKO mice, suggesting a novel function of AnkR in the maturation of collagen fibers. In summary, our findings illustrate the novel expression of AnkR in cardiac fibroblasts and a potential role in cardiac function in response to stress.
Assuntos
Anquirinas , Fibroblastos , Insuficiência Cardíaca , Camundongos Knockout , Animais , Insuficiência Cardíaca/metabolismo , Insuficiência Cardíaca/patologia , Insuficiência Cardíaca/genética , Anquirinas/metabolismo , Anquirinas/genética , Camundongos , Fibroblastos/metabolismo , Miocárdio/metabolismo , Miocárdio/patologia , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Masculino , Fibrose , Camundongos Endogâmicos C57BLRESUMO
Acute severe mitral regurgitation (MR) is rare, but often leads to cardiogenic shock, pulmonary edema, or both. Most common causes of acute severe MR are chordae tendineae (CT) rupture, papillary muscle (PM) rupture, and infective endocarditis (IE). Mild to moderate MR is often seen in patients with acute myocardial infarction (AMI). CT rupture in patients with floppy mitral valve/mitral valve prolapse is the most common etiology of acute severe MR today. In IE, native or prosthetic valve damage can occur (leaflet perforation, ring detachment, other), as well as CT or PM rupture. Since the introduction of percutaneous revascularization in AMI, the incidence of PM rupture has substantially declined. In acute severe MR, the hemodynamic effects of the large regurgitant volume into the left atrium (LA) during left ventricular (LV) systole, and in turn back into the LV during diastole, are profound as the LV and LA have not had time to adapt to this additional volume. A rapid, but comprehensive evaluation of the patient with acute severe MR is essential in order to define the underline cause and apply appropriate management. Echocardiography with Doppler provides vital information related to the underlying pathology. Coronary arteriography should be performed in patients with an AMI to define coronary anatomy and need for revascularization. In acute severe MR, medical therapy should be used to stabilize the patient before intervention (surgery, transcatheter); mechanical support is often required. Diagnostic and therapeutic steps should be individualized, and a multi-disciplinary team approach should be utilized.
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Insuficiência Cardíaca , Doenças das Valvas Cardíacas , Insuficiência da Valva Mitral , Prolapso da Valva Mitral , Infarto do Miocárdio , Humanos , Insuficiência da Valva Mitral/complicações , Valva Mitral/patologia , Valva Mitral/cirurgia , Prolapso da Valva Mitral/complicações , Prolapso da Valva Mitral/diagnóstico , Prolapso da Valva Mitral/cirurgia , Doenças das Valvas Cardíacas/complicações , Insuficiência Cardíaca/complicações , Insuficiência Cardíaca/terapia , Insuficiência Cardíaca/patologia , Infarto do Miocárdio/complicaçõesRESUMO
[Figure: see text].
Assuntos
Doença da Artéria Coronariana/genética , Variação Genética , Receptores Depuradores Classe B/genética , Adulto , Idade de Início , Animais , Doença da Artéria Coronariana/diagnóstico , Doença da Artéria Coronariana/epidemiologia , Feminino , Estudos de Associação Genética , Predisposição Genética para Doença , Células HEK293 , Células Hep G2 , Hepatócitos/metabolismo , Hereditariedade , Heterozigoto , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Linhagem , Fenótipo , Medição de Risco , Fatores de Risco , Receptores Depuradores Classe B/metabolismo , Índice de Gravidade de Doença , Sequenciamento do ExomaRESUMO
Cardiovascular disease (CVD) remains the most common cause of adult morbidity and mortality in developed nations. As a result, predisposition for CVD is increasingly important to understand. Ankyrins are intracellular proteins required for the maintenance of membrane domains. Canonical ankyrin-G (AnkG) has been shown to be vital for normal cardiac function, specifically cardiac excitability, via targeting and regulation of the cardiac voltage-gated sodium channel. Noncanonical (giant) AnkG isoforms play a key role in neuronal membrane biogenesis and excitability, with evidence for human neurologic disease when aberrant. However, the role of giant AnkG in cardiovascular tissue has yet to be explored. Here, we identify giant AnkG in the myocardium and identify that it is enriched in 1-week-old mice. Using a new mouse model lacking giant AnkG expression in myocytes, we identify that young mice displayed a dilated cardiomyopathy phenotype with aberrant electrical conduction and enhanced arrhythmogenicity. Structural and electrical dysfunction occurred at 1 week of age, when giant AnkG was highly expressed and did not appreciably change in adulthood until advanced age. At a cellular level, loss of giant AnkG results in delayed and early afterdepolarizations. However, surprisingly, giant AnkG cKO myocytes display normal INa, but abnormal myocyte contractility, suggesting unique roles of the large isoform in the heart. Finally, transcript analysis provided evidence for unique pathways that may contribute to the structural and electrical findings shown in giant AnkG cKO animals. In summary, we identify a critical role for giant AnkG that adds to the diversity of ankyrin function in the heart.
Assuntos
Coração/fisiologia , Miócitos Cardíacos/fisiologia , Neurônios/fisiologia , Proteínas de Transporte de Fosfato/fisiologia , Animais , Animais Recém-Nascidos , Feminino , Masculino , Camundongos , Camundongos Knockout , Miócitos Cardíacos/citologia , Neurônios/citologiaRESUMO
We isolated 20 SARS-CoV-2 strains from positive clinical samples collected in Columbus, Ohio, and investigated the replication of one pair of isolates: a clade 20G strain and a variant of this strain carrying a Q677H mutation in the spike protein and six other amino acid mutations. The OSU.20G variant replicated to a higher peak infectious titer than the 20G base strain in Vero-E6 cells, but the titers were similar when both strains were grown in Calu-3 cells. These results suggest that the OSU.20G variant has increased replication fitness compared to the 20G base strain. This may have contributed to its emergence in December 2020-January 2021.
Assuntos
COVID-19 , Humanos , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/genética , MutaçãoRESUMO
RATIONALE: Voltage-gated Na+ channel ( INa) function is critical for normal cardiac excitability. However, the Na+ channel late component ( INa,L) is directly associated with potentially fatal forms of congenital and acquired human arrhythmia. CaMKII (Ca2+/calmodulin-dependent kinase II) enhances INa,L in response to increased adrenergic tone. However, the pathways that negatively regulate the CaMKII/Nav1.5 axis are unknown and essential for the design of new therapies to regulate the pathogenic INa,L. OBJECTIVE: To define phosphatase pathways that regulate INa,L in vivo. METHODS AND RESULTS: A mouse model lacking a key regulatory subunit (B56α) of the PP (protein phosphatase) 2A holoenzyme displayed aberrant action potentials after adrenergic stimulation. Unbiased computational modeling of B56α KO (knockout) mouse myocyte action potentials revealed an unexpected role of PP2A in INa,L regulation that was confirmed by direct INa,L recordings from B56α KO myocytes. Further, B56α KO myocytes display decreased sensitivity to isoproterenol-induced induction of arrhythmogenic INa,L, and reduced CaMKII-dependent phosphorylation of Nav1.5. At the molecular level, PP2A/B56α complex was found to localize and coimmunoprecipitate with the primary cardiac Nav channel, Nav1.5. CONCLUSIONS: PP2A regulates Nav1.5 activity in mouse cardiomyocytes. This regulation is critical for pathogenic Nav1.5 late current and requires PP2A-B56α. Our study supports B56α as a novel target for the treatment of arrhythmia.
Assuntos
Arritmias Cardíacas/enzimologia , Frequência Cardíaca , Ativação do Canal Iônico , Miócitos Cardíacos/enzimologia , Canal de Sódio Disparado por Voltagem NAV1.5/metabolismo , Proteína Fosfatase 2/metabolismo , Potenciais de Ação , Agonistas Adrenérgicos beta/farmacologia , Animais , Arritmias Cardíacas/genética , Arritmias Cardíacas/fisiopatologia , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Feminino , Predisposição Genética para Doença , Humanos , Ativação do Canal Iônico/efeitos dos fármacos , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Miócitos Cardíacos/efeitos dos fármacos , Fenótipo , Fosforilação , Proteína Fosfatase 2/deficiência , Proteína Fosfatase 2/genética , Fatores de TempoRESUMO
Spectrins are cytoskeletal proteins essential for membrane biogenesis and regulation and serve critical roles in protein targeting and cellular signaling. αII spectrin (SPTAN1) is one of two α spectrin genes and αII spectrin dysfunction is linked to alterations in axon initial segment formation, cortical lamination, and neuronal excitability. Furthermore, human αII spectrin loss-of-function variants cause neurological disease. As global αII spectrin knockout mice are embryonic lethal, the in vivo roles of αII spectrin in adult heart are unknown and untested. Here, based on pronounced alterations in αII spectrin regulation in human heart failure we tested the in vivo roles of αII spectrin in the vertebrate heart. We created a mouse model of cardiomyocyte-selective αII spectrin-deficiency (cKO) and used this model to define the roles of αII spectrin in cardiac function. αII spectrin cKO mice displayed significant structural, cellular, and electrical phenotypes that resulted in accelerated structural remodeling, fibrosis, arrhythmia, and mortality in response to stress. At the molecular level, we demonstrate that αII spectrin plays a nodal role for global cardiac spectrin regulation, as αII spectrin cKO hearts exhibited remodeling of αI spectrin and altered ß-spectrin expression and localization. At the cellular level, αII spectrin deficiency resulted in altered expression, targeting, and regulation of cardiac ion channels NaV1.5 and KV4.3. In summary, our findings define critical and unexpected roles for the multifunctional αII spectrin protein in the heart. Furthermore, our work provides a new in vivo animal model to study the roles of αII spectrin in the cardiomyocyte.
Assuntos
Arritmias Cardíacas/patologia , Modelos Animais de Doenças , Insuficiência Cardíaca/patologia , Isquemia/patologia , Miócitos Cardíacos/patologia , Espectrina/fisiologia , Animais , Arritmias Cardíacas/etiologia , Células Cultivadas , Feminino , Insuficiência Cardíaca/etiologia , Humanos , Isquemia/etiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , FenótipoRESUMO
PURPOSE OF REVIEW: Aortic valve disease is relatively common and encompasses both congenital and acquired forms. Bicuspid aortic valve (BAV) is the most common type of cardiac malformation and predisposes to the development of calcific aortic valve disease (CAVD). Since the description of the link between NOTCH1, BAV and CAVD approximately a decade ago, there have been significant advances in the genetic and molecular understanding of these diseases. RECENT FINDINGS: Recent work has defined the congenital cardiac phenotypes linked to mutations in NOTCH1, and in addition, novel etiologic genes for BAV have been discovered using new genetic technologies in humans. Furthermore, several mouse models of BAV have been described defining the role of endothelial Notch1 in aortic valve morphogenesis, whereas others have implicated new genes. These murine models along with other cell-based studies have led to molecular insights in the pathogenesis of CAVD. SUMMARY: These findings provide important insights into the molecular and genetic basis of aortic valve malformations, including BAV, specifically highlighting the etiologic role of endothelial cells. In addition, numerous investigations in to the mechanisms of CAVD demonstrate the importance of developmental origins and signaling pathways as well as communication between valve endothelial cells and the underlying interstitial cells in valve disease onset and progression.
RESUMO
RATIONALE: MicroRNA miR145 has been implicated in vascular smooth muscle cell differentiation, but its mechanisms of action and downstream targets have not been fully defined. OBJECTIVE: Here, we sought to explore and define the mechanisms of miR145 function in smooth muscle cells. METHODS AND RESULTS: Using a combination of cell culture assays and in vivo mouse models to modulate miR145, we characterized its downstream actions on smooth muscle phenotypes. Our results show that the miR-143/145 gene cluster is induced in smooth muscle cells by coculture with endothelial cells. Endothelial cell-induced expression of miR-143/145 is augmented by Notch signaling and accordingly expression is reduced in Notch receptor-deficient cells. Screens to identify miR145-regulated genes revealed that the transforming growth factor (TGF)-ß pathway has a significantly high number of putative target genes, and we show that TGFß receptor II is a direct target of miR145. Extracellular matrix genes that are regulated by TGFß receptor II were attenuated by miR145 overexpression, and miR145 mutant mice exhibit an increase in extracellular matrix synthesis. Furthermore, activation of TGFß signaling via angiotensin II infusion revealed a pronounced fibrotic response in the absence of miR145. CONCLUSIONS: These data demonstrate a specific role for miR145 in the regulation of matrix gene expression in smooth muscle cells and suggest that miR145 acts to suppress TGFß-dependent extracellular matrix accumulation and fibrosis, while promoting TGFß-induced smooth muscle cell differentiation. Our findings offer evidence to explain how TGFß signaling exhibits distinct downstream actions via its regulation by a specific microRNA.
Assuntos
Matriz Extracelular/metabolismo , MicroRNAs/fisiologia , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , Proteínas Serina-Treonina Quinases/biossíntese , Receptores de Fatores de Crescimento Transformadores beta/biossíntese , Animais , Células Cultivadas , Regulação da Expressão Gênica , Células HEK293 , Células Endoteliais da Veia Umbilical Humana , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptor do Fator de Crescimento Transformador beta Tipo IIRESUMO
Defects of atrial and ventricular septation are the most frequent form of congenital heart disease, accounting for almost 50% of all cases. We previously reported that a heterozygous G296S missense mutation of GATA4 caused atrial and ventricular septal defects and pulmonary valve stenosis in humans. GATA4 encodes a cardiac transcription factor, and when deleted in mice it results in cardiac bifida and lethality by embryonic day (E)9.5. In vitro, the mutant GATA4 protein has a reduced DNA binding affinity and transcriptional activity and abolishes a physical interaction with TBX5, a transcription factor critical for normal heart formation. To characterize the mutation in vivo, we generated mice harboring the same mutation, Gata4 G295S. Mice homozygous for the Gata4 G295S mutant allele have normal ventral body patterning and heart looping, but have a thin ventricular myocardium, single ventricular chamber, and lethality by E11.5. While heterozygous Gata4 G295S mutant mice are viable, a subset of these mice have semilunar valve stenosis and small defects of the atrial septum. Gene expression studies of homozygous mutant mice suggest the G295S protein can sufficiently activate downstream targets of Gata4 in the endoderm but not in the developing heart. Cardiomyocyte proliferation deficits and decreased cardiac expression of CCND2, a member of the cyclin family and a direct target of Gata4, were found in embryos both homozygous and heterozygous for the Gata4 G295S allele. To further define functions of the Gata4 G295S mutation in vivo, compound mutant mice were generated in which specific cell lineages harbored both the Gata4 G295S mutant and Gata4 null alleles. Examination of these mice demonstrated that the Gata4 G295S protein has functional deficits in early myocardial development. In summary, the Gata4 G295S mutation functions as a hypomorph in vivo and leads to defects in cardiomyocyte proliferation during embryogenesis, which may contribute to the development of congenital heart defects in humans.
Assuntos
Septo Interatrial , Proliferação de Células , Fator de Transcrição GATA4 , Cardiopatias Congênitas , Ventrículos do Coração , Miócitos Cardíacos , Animais , Septo Interatrial/metabolismo , Septo Interatrial/fisiopatologia , Ciclina D2/metabolismo , Desenvolvimento Embrionário/genética , Fator de Transcrição GATA4/genética , Fator de Transcrição GATA4/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Cardiopatias Congênitas/genética , Cardiopatias Congênitas/metabolismo , Cardiopatias Congênitas/fisiopatologia , Ventrículos do Coração/crescimento & desenvolvimento , Ventrículos do Coração/metabolismo , Humanos , Camundongos , Camundongos Mutantes , Mutação , Miócitos Cardíacos/citologia , Miócitos Cardíacos/metabolismo , Proteínas com Domínio T/genética , Proteínas com Domínio T/metabolismoRESUMO
The means by which vaginal microbiomes help prevent urogenital diseases in women and maintain health are poorly understood. To gain insight into this, the vaginal bacterial communities of 396 asymptomatic North American women who represented four ethnic groups (white, black, Hispanic, and Asian) were sampled and the species composition characterized by pyrosequencing of barcoded 16S rRNA genes. The communities clustered into five groups: four were dominated by Lactobacillus iners, L. crispatus, L. gasseri, or L. jensenii, whereas the fifth had lower proportions of lactic acid bacteria and higher proportions of strictly anaerobic organisms, indicating that a potential key ecological function, the production of lactic acid, seems to be conserved in all communities. The proportions of each community group varied among the four ethnic groups, and these differences were statistically significant [χ(2)(10) = 36.8, P < 0.0001]. Moreover, the vaginal pH of women in different ethnic groups also differed and was higher in Hispanic (pH 5.0 ± 0.59) and black (pH 4.7 ± 1.04) women as compared with Asian (pH 4.4 ± 0.59) and white (pH 4.2 ± 0.3) women. Phylotypes with correlated relative abundances were found in all communities, and these patterns were associated with either high or low Nugent scores, which are used as a factor for the diagnosis of bacterial vaginosis. The inherent differences within and between women in different ethnic groups strongly argues for a more refined definition of the kinds of bacterial communities normally found in healthy women and the need to appreciate differences between individuals so they can be taken into account in risk assessment and disease diagnosis.
Assuntos
Metagenoma/genética , Vagina/microbiologia , Adolescente , Adulto , Negro ou Afro-Americano , Asiático , Sequência de Bases , Código de Barras de DNA Taxonômico , Primers do DNA/genética , Feminino , Hispânico ou Latino , Humanos , Concentração de Íons de Hidrogênio , Maryland , Dados de Sequência Molecular , Análise de Componente Principal , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Especificidade da Espécie , População BrancaRESUMO
Shiga toxin-producing Escherichia coli are zoonotic pathogens that cause food-borne human disease. Among these, the O157:H7 serotype has evolved from an enteropathogenic O55:H7 ancestor through the displacement of the somatic gene cluster and recurrent toxigenic conversion by Shiga toxin-converting bacteriophages. However, atypical strains that lack the Shiga toxin, the characteristic virulence hallmark, are circulating in this lineage. For this study, we analyzed the pathogenome and virulence inventories of the stx+ strain, TT12A, isolated from a patient with hemorrhagic colitis, and its respective co-isolated stx- strain, TT12B. Sequencing the genomes to closure proved critical to the cataloguing of subtle strain differentiating sequence and structural polymorphisms at a high-level of phylogenetic accuracy and resolution. Phylogenomic profiling revealed SNP and MLST profiles similar to the near clonal outbreak isolates. Their prophage inventories, however, were notably different. The attenuated atypical non-shigatoxigenic status of TT12B is explained by the absence of both the ΦStx1a- and ΦStx2a-prophages carried by TT12A, and we also recorded further alterations in the non-Stx prophage complement. Phenotypic characterization indicated that culture growth was directly impacted by the strains' distinct lytic phage complement. Altogether, our phylogenomic and phenotypic analyses show that these intimately related isogenic strains are on divergent Stx(+/stx-) evolutionary paths.
RESUMO
Shiga toxin (Stx)-producing Escherichia coli (STEC) of non-O157:H7 serotypes are responsible for global and widespread human food-borne disease. Among these serogroups, O26, O45, O103, O111, O121, and O145 account for the majority of clinical infections and are colloquially referred to as the "Big Six." The "Big Six" strain panel we sequenced and analyzed in this study are reference type cultures comprised of six strains representing each of the non-O157 STEC serogroups curated and distributed by the American Type Culture Collection (ATCC) as a resource to the research community under panel number ATCC MP-9. The application of long- and short-read hybrid sequencing yielded closed chromosomes and a total of 14 plasmids of diverse functions. Through high-resolution comparative phylogenomics, we cataloged the shared and strain-specific virulence and resistance gene content and established the close relationship of serogroup O26 and O103 strains featuring flagellar H-type 11. Virulence phenotyping revealed statistically significant differences in the Stx-production capabilities that we found to be correlated to the strain's individual stx-status. Among the carried Stx1a, Stx2a, and Stx2d phages, the Stx2a phage is by far the most responsive upon RecA-mediated phage mobilization, and in consequence, stx2a + isolates produced the highest-level of toxin in this panel. The availability of high-quality closed genomes for this "Big Six" reference set, including carried plasmids, along with the recorded genomic virulence profiles and Stx-production phenotypes will provide a valuable foundation to further explore the plasticity in evolutionary trajectories in these emerging non-O157 STEC lineages, which are major culprits of human food-borne disease.
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The mature aortic valve is composed of a structured trilaminar extracellular matrix that is interspersed with aortic valve interstitial cells (AVICs) and covered by endothelium. Dysfunction of the valvular endothelium initiates calcification of neighboring AVICs leading to calcific aortic valve disease (CAVD). The molecular mechanism by which endothelial cells communicate with AVICs and cause disease is not well understood. Using a co-culture assay, we show that endothelial cells secrete a signal to inhibit calcification of AVICs. Gain or loss of nitric oxide (NO) prevents or accelerates calcification of AVICs, respectively, suggesting that the endothelial cell-derived signal is NO. Overexpression of Notch1, which is genetically linked to human CAVD, retards the calcification of AVICs that occurs with NO inhibition. In AVICs, NO regulates the expression of Hey1, a downstream target of Notch1, and alters nuclear localization of Notch1 intracellular domain. Finally, Notch1 and NOS3 (endothelial NO synthase) display an in vivo genetic interaction critical for proper valve morphogenesis and the development of aortic valve disease. Our data suggests that endothelial cell-derived NO is a regulator of Notch1 signaling in AVICs in the development of the aortic valve and adult aortic valve disease.
Assuntos
Valva Aórtica/metabolismo , Cardiopatias Congênitas/metabolismo , Doenças das Valvas Cardíacas/metabolismo , Óxido Nítrico/metabolismo , Receptor Notch1/metabolismo , Transdução de Sinais , Transporte Ativo do Núcleo Celular/genética , Animais , Valva Aórtica/patologia , Fatores de Transcrição Hélice-Alça-Hélice Básicos/biossíntese , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Doença da Válvula Aórtica Bicúspide , Calcinose/genética , Calcinose/metabolismo , Calcinose/patologia , Proteínas de Ciclo Celular/biossíntese , Proteínas de Ciclo Celular/genética , Núcleo Celular/genética , Núcleo Celular/metabolismo , Núcleo Celular/patologia , Cardiopatias Congênitas/genética , Cardiopatias Congênitas/patologia , Doenças das Valvas Cardíacas/genética , Doenças das Valvas Cardíacas/patologia , Células Endoteliais da Veia Umbilical Humana , Humanos , Camundongos , Óxido Nítrico/genética , Receptor Notch1/genética , Proteínas Repressoras/biossíntese , Proteínas Repressoras/genética , SuínosRESUMO
OBJECTIVE: Activation of inflammatory pathways plays a critical role in the development of abdominal aortic aneurysms (AAA). Notch1 signaling is a significant regulator of the inflammatory response; however, its role in AAA is unknown. METHODS AND RESULTS: In an angiotensin II-induced mouse model of AAA, activation of Notch1 signaling was observed in the aortic aneurysmal tissue of Apoe(-/-) mice, and a similar activation of Notch1 was observed in aneurysms of humans undergoing AAA repair. Notch1 haploinsufficiency significantly reduced the incidence of AAA in Apoe(-/-) mice in response to angiotensin II. Reconstitution of bone marrow-derived cells from Notch1(+/-);Apoe(-/-) mice (donor) in lethally irradiated Apoe(-/-) mice (recipient) decreased the occurrence of aneurysm. Flow cytometry and immunohistochemistry demonstrated that Notch1 haploinsufficiency prevented the influx of inflammatory macrophages at the aneurysmal site by causing defects in macrophage migration and proliferation. In addition, there was an overall reduction in the inflammatory burden in the aorta of the Notch1(+/-);Apoe(-/-) mice compared with the Apoe(-/-) mice. Last, pharmacological inhibition of Notch1 signaling also prevented AAA formation and progression in Apoe(-/-) mice. CONCLUSIONS: Our data suggest that decreased levels of Notch1 protect against the formation of AAA by preventing macrophage recruitment and attenuating the inflammatory response in the aorta.
Assuntos
Aneurisma da Aorta Abdominal/prevenção & controle , Arterite/prevenção & controle , Macrófagos/fisiologia , Receptor Notch1/deficiência , Receptor Notch1/genética , Transdução de Sinais/fisiologia , Angiotensina II/efeitos adversos , Animais , Aneurisma da Aorta Abdominal/induzido quimicamente , Aneurisma da Aorta Abdominal/fisiopatologia , Apolipoproteínas E/deficiência , Apolipoproteínas E/genética , Apolipoproteínas E/fisiologia , Arterite/fisiopatologia , Dipeptídeos/farmacologia , Modelos Animais de Doenças , Haploinsuficiência/genética , Humanos , Macrófagos/patologia , Masculino , Camundongos , Camundongos Knockout , Receptor Notch1/fisiologia , Transdução de Sinais/efeitos dos fármacosRESUMO
Fetal and neonatal hemolytic anemia can be caused by (γδß)(0)-thalassemia deletions of the ß-globin gene cluster. Many of these deletions have not been well characterized, and diagnostic tests are not readily available, thus hampering carrier detection, family counseling, and antenatal diagnosis. We report and define a 198 kb deletion removing the entire ß-globin gene cluster, which was found in members of a multigeneration family of Irish/Scottish descent. The proband had life-threatening fetal and neonatal hemolytic anemia which subsided by 1 year of age.
Assuntos
Anemia Hemolítica Congênita/genética , Doenças Fetais/genética , Deleção de Genes , Família Multigênica , Globinas beta/genética , Adulto , Anemia Hemolítica Congênita/terapia , Feminino , Doenças Fetais/terapia , Humanos , Lactente , Recém-Nascido , GravidezRESUMO
Hypoplastic left heart syndrome (HLHS), one of the most severe types of congenital heart disease (CHD), results in significant morbidity and mortality despite surgical palliation. The etiology of HLHS is unknown, but evidence supports genetic contributors. The authors hypothesized that submicroscopic chromosomal abnormalities exist in individuals with HLHS and are more frequent in those with additional birth defects. This study sought to determine the incidence and genomic location of submicroscopic chromosomal abnormalities in HLHS and potentially to identify novel genetic loci that may contribute to the disease. For this study, 43 children with HLHS were recruited and screened together with a control population of 16 subjects using array comparative genomic hybridization, also called chromosomal microarray, for chromosomal copy number variations (CNVs). A statistically greater number of CNVs were found in the HLHS group than in the control group (p < 0.03). The CNVs were predominantly small autosomal deletions and duplications (≤ 60,000 bp). The frequency of unique CNVs, those not previously reported in public databases, did not differ statistically between the HLHS subjects and the control subjects. No difference in the frequency of CNVs was noted between the patients with HLHS and additional anomalies and those with isolated HLHS. The identified CNVs did not harbor potential candidate genes for HLHS, but one microdeletion was located on chromosome 14q23, a genetic locus linked to left-sided CHD. The study data demonstrate that CNVs, specifically those relatively small in size, are more common in subjects with HLHS, but the frequency of large potentially disease-causing CNVs (>480,000 bp) did not differ between the HLHS and control populations.
Assuntos
Variações do Número de Cópias de DNA , Síndrome do Coração Esquerdo Hipoplásico/genética , Estudos de Casos e Controles , Criança , Pré-Escolar , Aberrações Cromossômicas , Hibridização Genômica Comparativa , Ecocardiografia , Feminino , Humanos , Síndrome do Coração Esquerdo Hipoplásico/diagnóstico por imagem , Lactente , Cariótipo , MasculinoRESUMO
Escherichia coli ST1485 strains belong to the clinically important phylogroup F and have disseminated worldwide in humans, animals, and the environment. Here, we elucidated the pathogenome of a global collection of E. coli ST1485 isolates from diverse sources retrieved from public databases and a high-quality sequenced complete genome of colistin-resistant E. coli strain CFSAN061771 isolated from raw milk cheese which designated as a reference strain. CFSAN061771 belongs to O83:H42-ST1485 pathotype and carries a conjugative ColV plasmid, pCFSAN061771_01, combining extraintestinal virulence genes (ompt, sitA, iroN, etsC, traT, cvaC, hylF, iss, tsh, mchf, iucC, iutA) with a multidrug resistance island (blaTEM-1, aph(6)-Id, aph(3â³)-Ib, sul2, dfrA14). Comparative genomic analysis revealed a high frequency of pCFSAN061771_01-like plasmids in E. coli ST1485. A notable evolutionary genetic event in E. coli ST1485 strains is the acquisition of a pCFSAN061771_02-like plasmid, which confers resistance to several antimicrobials, tellurium, and quaternary ammonium compounds. The identical virulence and antibiotic resistance profiles identified in some human and animal strains are worrisome. This is the first study to emphasize the significance of E. coli ST1485 as a global high-risk virulent and multidrug-resistant clone with zoonotic potential.