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1.
Nat Commun ; 12(1): 5074, 2021 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-34417463

RESUMO

ß cells may participate and contribute to their own demise during Type 1 diabetes (T1D). Here we report a role of their expression of Tet2 in regulating immune killing. Tet2 is induced in murine and human ß cells with inflammation but its expression is reduced in surviving ß cells. Tet2-KO mice that receive WT bone marrow transplants develop insulitis but not diabetes and islet infiltrates do not eliminate ß cells even though immune cells from the mice can transfer diabetes to NOD/scid recipients. Tet2-KO recipients are protected from transfer of disease by diabetogenic immune cells.Tet2-KO ß cells show reduced expression of IFNγ-induced inflammatory genes that are needed to activate diabetogenic T cells. Here we show that Tet2 regulates pathologic interactions between ß cells and immune cells and controls damaging inflammatory pathways. Our data suggests that eliminating TET2 in ß cells may reduce activating pathologic immune cells and killing of ß cells.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Diabetes Mellitus Tipo 1/patologia , Inflamação/patologia , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/patologia , Proteínas Proto-Oncogênicas/metabolismo , Animais , Sequência de Bases , Citotoxicidade Imunológica , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/imunologia , Progressão da Doença , Feminino , Humanos , Imunidade , Inflamação/genética , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Linfócitos T/imunologia , Transcrição Genética
2.
Commun Biol ; 4(1): 629, 2021 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-34040149

RESUMO

The increasing availability of single-cell data revolutionizes the understanding of biological mechanisms at cellular resolution. For differential expression analysis in multi-subject single-cell data, negative binomial mixed models account for both subject-level and cell-level overdispersions, but are computationally demanding. Here, we propose an efficient NEgative Binomial mixed model Using a Large-sample Approximation (NEBULA). The speed gain is achieved by analytically solving high-dimensional integrals instead of using the Laplace approximation. We demonstrate that NEBULA is orders of magnitude faster than existing tools and controls false-positive errors in marker gene identification and co-expression analysis. Using NEBULA in Alzheimer's disease cohort data sets, we found that the cell-level expression of APOE correlated with that of other genetic risk factors (including CLU, CST3, TREM2, C1q, and ITM2B) in a cell-type-specific pattern and an isoform-dependent manner in microglia. NEBULA opens up a new avenue for the broad application of mixed models to large-scale multi-subject single-cell data.


Assuntos
Biologia Computacional/métodos , Perfilação da Expressão Gênica/métodos , Análise de Célula Única/métodos , Doença de Alzheimer/genética , Apolipoproteínas E/genética , Distribuição Binomial , Expressão Gênica/genética , Humanos , Microglia/metabolismo , Modelos Estatísticos
3.
J Immunol ; 2021 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-34049971

RESUMO

Protective immunity against COVID-19 likely depends on the production of SARS-CoV-2-specific plasma cells and memory B cells postinfection or postvaccination. Previous work has found that germinal center reactions are disrupted in severe COVID-19. This may adversely affect long-term immunity against reinfection. Consistent with an extrafollicular B cell response, patients with severe COVID-19 have elevated frequencies of clonally expanded, class-switched, unmutated plasmablasts. However, it is unclear whether B cell populations in individuals with mild COVID-19 are similarly skewed. In this study, we use single-cell RNA sequencing of B cells to show that in contrast to patients with severe COVID-19, subjects with mildly symptomatic COVID-19 have B cell repertoires enriched for clonally diverse, somatically hypermutated memory B cells ∼30 d after the onset of symptoms. This provides evidence that B cell responses are less disrupted in mild COVID-19 and result in the production of memory B cells.

4.
Immunity ; 54(5): 1083-1095.e7, 2021 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-33891889

RESUMO

Multisystem inflammatory syndrome in children (MIS-C) is a life-threatening post-infectious complication occurring unpredictably weeks after mild or asymptomatic SARS-CoV-2 infection. We profiled MIS-C, adult COVID-19, and healthy pediatric and adult individuals using single-cell RNA sequencing, flow cytometry, antigen receptor repertoire analysis, and unbiased serum proteomics, which collectively identified a signature in MIS-C patients that correlated with disease severity. Despite having no evidence of active infection, MIS-C patients had elevated S100A-family alarmins and decreased antigen presentation signatures, indicative of myeloid dysfunction. MIS-C patients showed elevated expression of cytotoxicity genes in NK and CD8+ T cells and expansion of specific IgG-expressing plasmablasts. Clinically severe MIS-C patients displayed skewed memory T cell TCR repertoires and autoimmunity characterized by endothelium-reactive IgG. The alarmin, cytotoxicity, TCR repertoire, and plasmablast signatures we defined have potential for application in the clinic to better diagnose and potentially predict disease severity early in the course of MIS-C.


Assuntos
COVID-19/imunologia , COVID-19/patologia , SARS-CoV-2/imunologia , Síndrome de Resposta Inflamatória Sistêmica/imunologia , Síndrome de Resposta Inflamatória Sistêmica/patologia , Adolescente , Alarminas/imunologia , Autoanticorpos/imunologia , Linfócitos T CD8-Positivos/imunologia , Criança , Pré-Escolar , Citotoxicidade Imunológica/genética , Endotélio/imunologia , Endotélio/patologia , Humanos , Células Matadoras Naturais/imunologia , Células Mieloides/imunologia , Plasmócitos/imunologia , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/imunologia , Índice de Gravidade de Doença
5.
medRxiv ; 2020 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-33300011

RESUMO

Multisystem inflammatory syndrome in children (MIS-C) is a life-threatening post-infectious complication occurring unpredictably weeks after mild or asymptomatic SARS-CoV2 infection in otherwise healthy children. Here, we define immune abnormalities in MIS-C compared to adult COVID-19 and pediatric/adult healthy controls using single-cell RNA sequencing, antigen receptor repertoire analysis, unbiased serum proteomics, and in vitro assays. Despite no evidence of active infection, we uncover elevated S100A-family alarmins in myeloid cells and marked enrichment of serum proteins that map to myeloid cells and pathways including cytokines, complement/coagulation, and fluid shear stress in MIS-C patients. Moreover, NK and CD8 T cell cytotoxicity genes are elevated, and plasmablasts harboring IgG1 and IgG3 are expanded. Consistently, we detect elevated binding of serum IgG from severe MIS-C patients to activated human cardiac microvascular endothelial cells in culture. Thus, we define immunopathology features of MIS-C with implications for predicting and managing this SARS-CoV2-induced critical illness in children.

6.
bioRxiv ; 2020 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-33140047

RESUMO

While inhibition of T cell co-inhibitory receptors has revolutionized cancer therapy, the mechanisms governing their expression on human T cells have not been elucidated. Type 1 interferon (IFN-I) modulates T cell immunity in viral infection, autoimmunity, and cancer, and may facilitate induction of T cell exhaustion in chronic viral infection 1,2 . Here we show that IFN-I regulates co-inhibitory receptors expression on human T cells, inducing PD-1/TIM-3/LAG-3 while surprisingly inhibiting TIGIT expression. High-temporal-resolution mRNA profiling of IFN-I responses enabled the construction of dynamic transcriptional regulatory networks uncovering three temporal transcriptional waves. Perturbation of key transcription factors on human primary T cells revealed both canonical and non-canonical IFN-I transcriptional regulators, and identified unique regulators that control expression of co-inhibitory receptors. To provide direct in vivo evidence for the role of IFN-I on co-inhibitory receptors, we then performed single cell RNA-sequencing in subjects infected with SARS-CoV-2, where viral load was strongly associated with T cell IFN-I signatures. We found that the dynamic IFN-I response in vitro closely mirrored T cell features with acute IFN-I linked viral infection, with high LAG3 and decreased TIGIT expression. Finally, our gene regulatory network identified SP140 as a key regulator for differential LAG3 and TIGIT expression. The construction of co-inhibitory regulatory networks induced by IFN-I with identification of unique transcription factors controlling their expression may provide targets for enhancement of immunotherapy in cancer, infectious diseases, and autoimmunity.

7.
Nat Commun ; 11(1): 4364, 2020 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-32868781

RESUMO

Pathophysiological roles of cardiac dopamine system remain unknown. Here, we show the role of dopamine D1 receptor (D1R)-expressing cardiomyocytes (CMs) in triggering heart failure-associated ventricular arrhythmia. Comprehensive single-cell resolution analysis identifies the presence of D1R-expressing CMs in both heart failure model mice and in heart failure patients with sustained ventricular tachycardia. Overexpression of D1R in CMs disturbs normal calcium handling while CM-specific deletion of D1R ameliorates heart failure-associated ventricular arrhythmia. Thus, cardiac D1R has the potential to become a therapeutic target for preventing heart failure-associated ventricular arrhythmia.


Assuntos
Arritmias Cardíacas/etiologia , Insuficiência Cardíaca , Miócitos Cardíacos/metabolismo , Receptores de Dopamina D1/metabolismo , Animais , Arritmias Cardíacas/prevenção & controle , Perfilação da Expressão Gênica/métodos , Humanos , Camundongos , Camundongos Transgênicos , Ratos , Receptores de Dopamina D1/genética , Análise de Sequência de RNA/métodos , Análise de Célula Única/métodos , Taquicardia Ventricular/etiologia , Taquicardia Ventricular/prevenção & controle
8.
Int Heart J ; 60(4): 944-957, 2019 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-31257341

RESUMO

Cardiac fibrosis plays an important role in cardiac remodeling after myocardial infarction (MI). The molecular mechanisms that promote cardiac fibrosis after MI are well studied; however, the mechanisms by which the progression of cardiac fibrosis becomes attenuated after MI remain poorly understood. Recent reports show the role of cellular senescence in limiting tissue fibrosis. In the present study, we tested whether cellular senescence of cardiac fibroblasts (CFs) plays a role in attenuating the progression of cardiac fibrosis after MI. We found that the number of γH2AX-positive CFs increased up to day 7, whereas the number of proliferating CFs peaked at day 4 after MI. Senescent CFs were also observed at day 7, suggesting that attenuation of CF proliferation occurred simultaneously with the activation of the DNA damage response (DDR) system and the appearance of senescent CFs. We next cultured senescent CFs with non-senescent CFs and showed that senescent CFs suppressed proliferation of the surrounding non-senescent CFs in a juxtacrine manner. We also found that the blockade of DDR by Atm gene deletion sustained the proliferation of CFs and exacerbated the cardiac fibrosis at the early stage after MI. Our results indicate the role of DDR activation and cellular senescence in limiting cardiac fibrosis after MI. Regulation of cellular senescence in CFs may become one of the therapeutic strategies for preventing cardiac remodeling after MI.


Assuntos
Senescência Celular/genética , Dano ao DNA/genética , Infarto do Miocárdio/patologia , Miócitos Cardíacos/metabolismo , Remodelação Ventricular/genética , Animais , Modelos Animais de Doenças , Fibroblastos/metabolismo , Fibroblastos/patologia , Fibrose/genética , Fibrose/metabolismo , Fibrose/patologia , Citometria de Fluxo , Marcação In Situ das Extremidades Cortadas , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Infarto do Miocárdio/genética , Infarto do Miocárdio/metabolismo , Miócitos Cardíacos/patologia
10.
Nat Microbiol ; 4(6): 948-955, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30858571

RESUMO

A recent epidemic of Zika virus in the Americas, affecting well over a million people, caused substantial mortality and morbidity, including Guillain-Barre syndrome, microcephaly and other fetal developmental defects1,2. Preventive and therapeutic measures that specifically target the virus are not readily available. The transmission of Zika virus is predominantly mosquito-borne, and Aedes aegypti mosquitoes serve as a key vector for Zika virus3. Here, to identify salivary factors that modulate mosquito-borne Zika virus infection, we focused on antigenic proteins in mice that were repeatedly bitten by mosquitoes and developed antibodies against salivary proteins. Using a yeast surface display screen, we identified five antigenic A. aegypti salivary proteins in mice. Antiserum against one of these five proteins-A. aegypti bacteria-responsive protein 1 (AgBR1)-suppressed early inflammatory responses in the skin of mice bitten by Zika-virus-infected mosquitoes. AgBR1 antiserum also partially protected mice from lethal mosquito-borne-but not needle-injected-Zika virus infection. These data suggest that AgBR1 is a target for the prevention of mosquito-transmitted Zika virus infection.


Assuntos
Aedes/imunologia , Mosquitos Vetores/imunologia , Proteínas e Peptídeos Salivares/imunologia , Infecção por Zika virus/imunologia , Zika virus/patogenicidade , Aedes/virologia , Animais , Bactérias , Modelos Animais de Doenças , Feminino , Inativação Gênica , Mordeduras e Picadas de Insetos/prevenção & controle , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mosquitos Vetores/virologia , Proteínas Recombinantes/imunologia , Saliva/imunologia , Glândulas Salivares , Proteínas e Peptídeos Salivares/genética , Pele/imunologia , Pele/patologia , Infecção por Zika virus/prevenção & controle , Infecção por Zika virus/transmissão
11.
J Mol Cell Cardiol ; 128: 77-89, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30611794

RESUMO

BACKGROUND: The heart responds to hemodynamic overload through cardiac hypertrophy and activation of the fetal gene program. However, these changes have not been thoroughly examined in individual cardiomyocytes, and the relation between cardiomyocyte size and fetal gene expression remains elusive. We established a method of high-throughput single-molecule RNA imaging analysis of in vivo cardiomyocytes and determined spatial and temporal changes during the development of heart failure. METHODS AND RESULTS: We applied three novel single-cell analysis methods, namely, single-cell quantitative PCR (sc-qPCR), single-cell RNA sequencing (scRNA-seq), and single-molecule fluorescence in situ hybridization (smFISH). Isolated cardiomyocytes and cross sections from pressure overloaded murine hearts after transverse aortic constriction (TAC) were analyzed at an early hypertrophy stage (2 weeks, TAC2W) and at a late heart failure stage (8 weeks, TAC8W). Expression of myosin heavy chain ß (Myh7), a representative fetal gene, was induced in some cardiomyocytes in TAC2W hearts and in more cardiomyocytes in TAC8W hearts. Expression levels of Myh7 varied considerably among cardiomyocytes. Myh7-expressing cardiomyocytes were significantly more abundant in the middle layer, compared with the inner or outer layers of TAC2W hearts, while such spatial differences were not observed in TAC8W hearts. Expression levels of Myh7 were inversely correlated with cardiomyocyte size and expression levels of mitochondria-related genes. CONCLUSIONS: We developed a new image-analysis pipeline to allow automated and unbiased quantification of gene expression at the single-cell level and determined the spatial and temporal regulation of heterogenous Myh7 expression in cardiomyocytes after pressure overload.


Assuntos
Aorta/diagnóstico por imagem , Cardiomegalia/genética , Insuficiência Cardíaca/diagnóstico por imagem , Imagem Molecular/métodos , Cadeias Pesadas de Miosina/genética , Animais , Aorta/metabolismo , Aorta/patologia , Cardiomegalia/diagnóstico , Cardiomegalia/diagnóstico por imagem , Regulação da Expressão Gênica/genética , Coração/diagnóstico por imagem , Coração/fisiopatologia , Insuficiência Cardíaca/patologia , Hemodinâmica , Hibridização in Situ Fluorescente , Camundongos , Mitocôndrias/genética , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Cadeias Pesadas de Miosina/isolamento & purificação , RNA/genética , RNA/isolamento & purificação , Análise de Sequência de RNA , Imagem Individual de Molécula , Análise de Célula Única
12.
Nat Commun ; 9(1): 5337, 2018 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-30559390

RESUMO

Epigenetic annotation studies of genetic risk variants for multiple sclerosis (MS) implicate dysfunctional lymphocytes in MS susceptibility; however, the role of central nervous system (CNS) cells remains unclear. We investigated the effect of the risk variant, rs7665090G, located near NFKB1, on astrocytes. We demonstrated that chromatin is accessible at the risk locus, a prerequisite for its impact on astroglial function. The risk variant was associated with increased NF-κB signaling and target gene expression, driving lymphocyte recruitment, in cultured human astrocytes and astrocytes within MS lesions, and with increased lesional lymphocytic infiltrates and lesion sizes. Thus, our study establishes a link between genetic risk for MS (rs7665090G) and dysfunctional astrocyte responses associated with increased CNS access for peripheral immune cells. MS may therefore result from variant-driven dysregulation of the peripheral immune system and of the CNS, where perturbed CNS cell function aids in establishing local autoimmune inflammation.


Assuntos
Astrócitos/metabolismo , Sistema Nervoso Central/citologia , Esclerose Múltipla/genética , Subunidade p50 de NF-kappa B/genética , Células Cultivadas , Sistema Nervoso Central/patologia , Predisposição Genética para Doença/genética , Humanos , Esclerose Múltipla/patologia , Subunidade p50 de NF-kappa B/metabolismo , Polimorfismo de Nucleotídeo Único/genética , Fatores de Risco , Fator de Transcrição RelA/genética , Fator de Transcrição RelA/metabolismo
13.
Sci Rep ; 8(1): 15858, 2018 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-30374020

RESUMO

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

14.
Nat Immunol ; 19(12): 1391-1402, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30374130

RESUMO

Foxp3+ regulatory T cells (Treg cells) are the central component of peripheral immune tolerance. Whereas a dysregulated Treg cytokine signature has been observed in autoimmune diseases, the regulatory mechanisms underlying pro- and anti-inflammatory cytokine production are elusive. Here, we identify an imbalance between the cytokines IFN-γ and IL-10 as a shared Treg signature present in patients with multiple sclerosis and under high-salt conditions. RNA-sequencing analysis on human Treg subpopulations revealed ß-catenin as a key regulator of IFN-γ and IL-10 expression. The activated ß-catenin signature was enriched in human IFN-γ+ Treg cells, as confirmed in vivo with Treg-specific ß-catenin-stabilized mice exhibiting lethal autoimmunity with a dysfunctional Treg phenotype. Moreover, we identified prostaglandin E receptor 2 (PTGER2) as a regulator of IFN-γ and IL-10 production under a high-salt environment, with skewed activation of the ß-catenin-SGK1-Foxo axis. Our findings reveal a novel PTGER2-ß-catenin loop in Treg cells linking environmental high-salt conditions to autoimmunity.


Assuntos
Autoimunidade/imunologia , Inflamação/imunologia , Esclerose Múltipla Recidivante-Remitente/imunologia , Linfócitos T Reguladores/imunologia , beta Catenina/imunologia , Animais , Regulação da Expressão Gênica/imunologia , Humanos , Interferon gama/biossíntese , Interferon gama/imunologia , Interleucina-10/biossíntese , Interleucina-10/imunologia , Camundongos Endogâmicos C57BL , Receptores de Prostaglandina E Subtipo EP2/imunologia , Linfócitos T Reguladores/metabolismo
15.
Nat Commun ; 9(1): 4435, 2018 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-30375404

RESUMO

Pressure overload induces a transition from cardiac hypertrophy to heart failure, but its underlying mechanisms remain elusive. Here we reconstruct a trajectory of cardiomyocyte remodeling and clarify distinct cardiomyocyte gene programs encoding morphological and functional signatures in cardiac hypertrophy and failure, by integrating single-cardiomyocyte transcriptome with cell morphology, epigenomic state and heart function. During early hypertrophy, cardiomyocytes activate mitochondrial translation/metabolism genes, whose expression is correlated with cell size and linked to ERK1/2 and NRF1/2 transcriptional networks. Persistent overload leads to a bifurcation into adaptive and failing cardiomyocytes, and p53 signaling is specifically activated in late hypertrophy. Cardiomyocyte-specific p53 deletion shows that cardiomyocyte remodeling is initiated by p53-independent mitochondrial activation and morphological hypertrophy, followed by p53-dependent mitochondrial inhibition, morphological elongation, and heart failure gene program activation. Human single-cardiomyocyte analysis validates the conservation of the pathogenic transcriptional signatures. Collectively, cardiomyocyte identity is encoded in transcriptional programs that orchestrate morphological and functional phenotypes.


Assuntos
Cardiomegalia/genética , Cardiomegalia/patologia , Insuficiência Cardíaca/genética , Insuficiência Cardíaca/patologia , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Transcriptoma/genética , Animais , Perfilação da Expressão Gênica , Redes Reguladoras de Genes/genética , Humanos , Masculino , Camundongos Endogâmicos C57BL , Transdução de Sinais , Análise de Célula Única , Proteína Supressora de Tumor p53/metabolismo
16.
Int Heart J ; 59(5): 1096-1105, 2018 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-30101858

RESUMO

Hypertrophic cardiomyopathy (HCM) is a genetic disorder that is characterized by hypertrophy of the myocardium. Some of the patients are diagnosed for HCM during infancy, and the prognosis of infantile HCM is worse than general HCM. Nevertheless, pathophysiology of infantile HCM is less investigated and remains largely unknown. In the present study, we generated induced pluripotent stem cells (iPSCs) from two patients with infantile HCM: one with Noonan syndrome and the other with idiopathic HCM. We found that iPSC-derived cardiomyocytes (iPSC-CMs) from idiopathic HCM patient were significantly larger and showed higher diastolic intracellular calcium concentration compared with the iPSC-CMs from healthy subject. Unlike iPSC-CMs from the adult/adolescent HCM patient, arrhythmia was not observed as a disease-related phenotype in iPSC-CMs from idiopathic infantile HCM patient. Phenotypic screening revealed that Pyr3, a transient receptor potential channel 3 channel inhibitor, decreased both the cell size and diastolic intracellular calcium concentration in iPSC-CMs from both Noonan syndrome and idiopathic infantile HCM patients, suggesting that the target of Pyr3 may play a role in the pathogenesis of infantile HCM, regardless of the etiology. Further research may unveil the possibility of Pyr3 or its derivatives in the treatment of infantile HCM.


Assuntos
Cardiomiopatia Hipertrófica/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Programas de Rastreamento/métodos , Síndrome de Noonan/metabolismo , Canais de Potencial de Receptor Transitório/antagonistas & inibidores , Adulto , Cálcio/metabolismo , Cardiomiopatia Hipertrófica/diagnóstico , Cardiomiopatia Hipertrófica/tratamento farmacológico , Cardiomiopatia Hipertrófica/patologia , Pré-Escolar , Humanos , Masculino , Mutação , Miocárdio/patologia , Miócitos Cardíacos/patologia , Síndrome de Noonan/diagnóstico , Síndrome de Noonan/tratamento farmacológico , Síndrome de Noonan/patologia , Fenótipo , Prevalência , Canais de Potencial de Receptor Transitório/uso terapêutico
17.
Nat Commun ; 8: 15104, 2017 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-28436431

RESUMO

The DNA damage response (DDR) plays a pivotal role in maintaining genome integrity. DNA damage and DDR activation are observed in the failing heart, however, the type of DNA damage and its role in the pathogenesis of heart failure remain elusive. Here we show the critical role of DNA single-strand break (SSB) in the pathogenesis of pressure overload-induced heart failure. Accumulation of unrepaired SSB is observed in cardiomyocytes of the failing heart. Unrepaired SSB activates DDR and increases the expression of inflammatory cytokines through NF-κB signalling. Pressure overload-induced heart failure is more severe in the mice lacking XRCC1, an essential protein for SSB repair, which is rescued by blocking DDR activation through genetic deletion of ATM, suggesting the causative role of SSB accumulation and DDR activation in the pathogenesis of heart failure. Prevention of SSB accumulation or persistent DDR activation may become a new therapeutic strategy against heart failure.


Assuntos
Quebras de DNA de Cadeia Simples , Dano ao DNA/genética , DNA/metabolismo , Insuficiência Cardíaca/genética , Miócitos Cardíacos/metabolismo , Proteína 1 Complementadora Cruzada de Reparo de Raio-X/genética , Animais , Proteínas Mutadas de Ataxia Telangiectasia/genética , Citocinas/imunologia , Dano ao DNA/imunologia , Reparo do DNA/genética , Técnicas de Inativação de Genes , Insuficiência Cardíaca/imunologia , Inflamação , Camundongos , Miócitos Cardíacos/imunologia , NF-kappa B/imunologia
18.
Sci Rep ; 6: 25009, 2016 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-27146149

RESUMO

Activation of ß-catenin-dependent canonical Wnt signaling in endothelial cells plays a key role in angiogenesis during development and ischemic diseases, however, other roles of Wnt/ß-catenin signaling in endothelial cells remain poorly understood. Here, we report that sustained activation of ß-catenin signaling in endothelial cells causes cardiac dysfunction through suppressing neuregulin-ErbB pathway in the heart. Conditional gain-of-function mutation of ß-catenin, which activates Wnt/ß-catenin signaling in Bmx-positive arterial endothelial cells (Bmx/CA mice) led to progressive cardiac dysfunction and 100% mortality at 40 weeks after tamoxifen treatment. Electron microscopic analysis revealed dilatation of T-tubules and degeneration of mitochondria in cardiomyocytes of Bmx/CA mice, which are similar to the changes observed in mice with decreased neuregulin-ErbB signaling. Endothelial expression of Nrg1 and cardiac ErbB signaling were suppressed in Bmx/CA mice. The cardiac dysfunction of Bmx/CA mice was ameliorated by administration of recombinant neuregulin protein. These results collectively suggest that sustained activation of Wnt/ß-catenin signaling in endothelial cells might be a cause of heart failure through suppressing neuregulin-ErbB signaling, and that the Wnt/ß-catenin/NRG axis in cardiac endothelial cells might become a therapeutic target for heart failure.


Assuntos
Células Endoteliais/fisiologia , Receptores ErbB/antagonistas & inibidores , Insuficiência Cardíaca/fisiopatologia , Neuregulina-1/antagonistas & inibidores , Via de Sinalização Wnt , beta Catenina/metabolismo , Animais , Modelos Animais de Doenças , Camundongos , Análise de Sobrevida
19.
Int Heart J ; 57(1): 112-7, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26673445

RESUMO

Duchenne muscular dystrophy (DMD) is caused by mutations in the DMD gene which encodes dystrophin protein. Dystrophin defect affects cardiac muscle as well as skeletal muscle. Cardiac dysfunction is observed in all patients with DMD over 18 years of age, but there is no curative treatment for DMD cardiomyopathy. To establish novel experimental platforms which reproduce the cardiac phenotype of DMD patients, here we established iPS cell lines from T lymphocytes donated from two DMD patients, with a protocol using Sendai virus vectors. We successfully conducted the differentiation of the DMD patient-specific iPS cells into beating cardiomyocytes. DMD patient-specific iPS cells and iPS cell-derived cardiomyocytes would be a useful in vitro experimental system with which to investigate DMD cardiomyopathy.


Assuntos
Células-Tronco Pluripotentes Induzidas/fisiologia , Distrofia Muscular de Duchenne/metabolismo , Miócitos Cardíacos/citologia , Adolescente , Adulto , Diferenciação Celular , Células Cultivadas , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Distrofia Muscular de Duchenne/genética , Distrofia Muscular de Duchenne/patologia , Miócitos Cardíacos/metabolismo , RNA/genética , Reação em Cadeia da Polimerase em Tempo Real
20.
Sci Rep ; 5: 14453, 2015 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-26571361

RESUMO

Disruption of angiotensin II type 1 (AT1) receptor prolonged life span in mice. Since aging-related decline in skeletal muscle function was retarded in Atgr1a(-/-) mice, we examined the role of AT1 receptor in muscle regeneration after injury. Administration of AT1 receptor blocker irbesartan increased the size of regenerating myofibers, decreased fibrosis, and enhanced functional muscle recovery after cryoinjury. We recently reported that complement C1q, secreted by macrophages, activated Wnt/ß-catenin signaling and promoted aging-related decline in regenerative capacity of skeletal muscle. Notably, irbesartan induced M2 polarization of macrophages, but reduced C1q expression in cryoinjured muscles and in cultured macrophage cells. Irbesartan inhibited up-regulation of Axin2, a downstream gene of Wnt/ß-catenin pathway, in cryoinjured muscles. In addition, topical administration of C1q reversed beneficial effects of irbesartan on skeletal muscle regeneration after injury. These results suggest that AT1 receptor blockade improves muscle repair and regeneration through down-regulation of the aging-promoting C1q-Wnt/ß-catenin signaling pathway.


Assuntos
Bloqueadores do Receptor Tipo 1 de Angiotensina II/farmacologia , Complemento C1q/genética , Regulação para Baixo/efeitos dos fármacos , Músculo Esquelético/metabolismo , Receptor Tipo 1 de Angiotensina/metabolismo , Administração Tópica , Envelhecimento/genética , Animais , Proteína Axina/metabolismo , Compostos de Bifenilo/farmacologia , Linhagem Celular , Complemento C1q/metabolismo , Imuno-Histoquímica , Irbesartana , Macrófagos/citologia , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Músculo Esquelético/patologia , Fator de Transcrição PAX7/metabolismo , Receptor Tipo 1 de Angiotensina/química , Receptor Tipo 1 de Angiotensina/genética , Regeneração/fisiologia , Tetrazóis/farmacologia , Via de Sinalização Wnt/efeitos dos fármacos
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