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Microglia are necessary for central nervous system (CNS) function during development and play roles in ageing, Alzheimer's disease and the response to demyelinating injury1-5. The mitochondrial respiratory chain (RC) is necessary for conventional T cell proliferation6 and macrophage-dependent immune responses7-10. However, whether mitochondrial RC is essential for microglia proliferation or function is not known. We conditionally deleted the mitochondrial complex III subunit Uqcrfs1 (Rieske iron-sulfur polypeptide 1) in the microglia of adult mice to assess the requirement of microglial RC for survival, proliferation and adult CNS function in vivo. Notably, mitochondrial RC function was not required for survival or proliferation of microglia in vivo. RNA sequencing analysis showed that loss of RC function in microglia caused changes in gene expression distinct from aged or disease-associated microglia. Microglia-specific loss of mitochondrial RC function is not sufficient to induce cognitive decline. Amyloid-ß plaque coverage decreased and microglial interaction with amyloid-ß plaques increased in the hippocampus of 5xFAD mice with mitochondrial RC-deficient microglia. Microglia-specific loss of mitochondrial RC function did impair remyelination following an acute, reversible demyelinating event. Thus, mitochondrial respiration in microglia is dispensable for proliferation but is essential to maintain a proper response to CNS demyelinating injury.
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Type I interferons (IFNs) are critical for the antiviral immune response, and fine-tuning type I IFN production is critical to effectively clearing viruses without causing harmful immunopathology. We showed that the transcription factor Miz1 epigenetically repressed the expression of genes encoding type I IFNs in mouse lung epithelial cells by recruiting histone deacetylase 1 (HDAC1) to the promoters of Ifna and Ifnb. Loss of function of Miz1 resulted in augmented production of these type I IFNs during influenza A virus (IAV) infection, leading to improved viral clearance in vitro and in vivo. IAV infection induced Miz1 accumulation by promoting the cullin-4B (CUL4B)-mediated ubiquitylation and degradation of the E3 ubiquitin ligase Mule (Mcl-1 ubiquitin ligase E3; also known as Huwe1 or Arf-BP1), which targets Miz1 for degradation. As a result, Miz1 accumulation limited type I IFN production and favored viral replication. This study reveals a previously unrecognized function of Miz1 in regulating antiviral defense and a potential mechanism for influenza viruses to evade host immune defense.
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Vírus da Influenza A , Influenza Humana , Interferon Tipo I , Camundongos , Animais , Humanos , Vírus da Influenza A/fisiologia , Ubiquitinação , Células Epiteliais/metabolismo , Regulação da Expressão Gênica , Replicação Viral , Interferon Tipo I/genética , Interferon Tipo I/metabolismo , Influenza Humana/genética , Interferons/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Proteínas Inibidoras de STAT Ativados/genética , Proteínas Inibidoras de STAT Ativados/metabolismoRESUMO
Keratins are epithelial intermediate filament proteins that play a crucial role in cellular stress protection, with K8 being the most abundant in the colon. The intestinal epithelial-specific K8-deficient mouse model (K8flox/flox;Villin-Cre) exhibits characteristics of inflammatory bowel disease, including diarrhea, crypt erosion, hyperproliferation, and decreased barrier function. Nevertheless, the order in which these events occur and whether they are a direct cause of K8 loss or a consequence of one event inducing another remains unexplored. Increased knowledge about early events in the disruption of colon epithelial integrity would help to understand the early pathology of inflammatory and functional colon disorders and develop preclinical models and diagnostics of colonic diseases. Here, we aimed to characterize the order of physiological events after Krt8 loss by utilizing K8flox/flox;Villin-CreERt2 mice with tamoxifen-inducible Krt8 deletion in intestinal epithelial cells, and assess stool analysis as a noninvasive method to monitor real-time gene expression changes following Krt8 loss. K8 protein was significantly decreased within a day after induction, followed by its binding partners, K18 and K19 from day 4 onward. The sequential colonic K8 downregulation in adult mice leads to immediate diarrhea and crypt elongation with activation of proliferation signaling, followed by crypt loss and increased neutrophil activity within 6-8 days, highlighting impaired water balance and crypt elongation as the earliest colonic changes upon Krt8 loss. Furthermore, epithelial gene expression patterns were comparable between colon tissue and stool samples, demonstrating the feasibility of noninvasive monitoring of gut epithelia in preclinical research utilizing Cre-LoxP-based intestinal disease models.NEW & NOTEWORTHY Understanding the order in which physiological and molecular events occur helps to recognize the onset of diseases and improve their preclinical models. We utilized Cre-Lox-based inducible keratin 8 deletion in mouse intestinal epithelium to characterize the earliest events after keratin 8 loss leading to colitis. These include diarrhea and crypt elongation, followed by erosion and neutrophil activity. Our results also support noninvasive methodology for monitoring colon diseases in preclinical models.
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Colite , Queratina-8 , Animais , Camundongos , Colite/genética , Diarreia , Queratina-18/genética , Queratina-8/genética , Queratina-8/metabolismo , Queratinas/química , Queratinas/genéticaRESUMO
Rationale: To identify barriers and opportunities for Ph.D., basic and translational scientists to be fully integrated into clinical units. Objectives: In 2022, an ad hoc committee of the American Thoracic Society developed a project proposal and workshop to identify opportunities and barriers for scientists who do not practice medicine to develop successful careers and achieve tenure-track faculty positions in clinical departments and divisions within academic medical centers (AMCs) in the United States. Methods: This document focuses on results from a survey of adult and pediatric pulmonary, critical care, and sleep medicine division chiefs as well as a survey of workshop participants, including faculty in departmental and school leadership roles in both basic science and clinical units within U.S. AMCs. Results: We conclude that full integration of non-clinically practicing basic and translational scientists into the clinical units, in addition to their traditional placements in basic science units, best serves the tripartite mission of AMCs to provide care, perform research, and educate the next generation. Evidence suggests clinical units do employ Ph.D. scientists in large numbers, but these faculty are often hired into non-tenure track positions, which do not provide the salary support, start-up funds, research independence, or space often associated with hiring in basic science units within the same institution. These barriers to success of Ph.D. faculty in clinical units are largely financial. Conclusions: Our recommendation is for AMCs to consider and explore some of our proposed strategies to accomplish the goal of integrating basic and translational scientists into clinical units in a meaningful way.
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Centros Médicos Acadêmicos , Médicos , Adulto , Estados Unidos , Humanos , Criança , Seleção de Pessoal , Liderança , Docentes de MedicinaRESUMO
Vimentin is highly expressed in metastatic cancers, and its expression correlates with poor patient prognoses. However, no causal in vivo studies linking vimentin and non-small cell lung cancer (NSCLC) progression existed until now. We use three complementary in vivo models to show that vimentin is required for the progression of NSCLC. First, we crossed LSL-KrasG12D; Tp53fl/fl mice (KPV+/+) with vimentin knockout mice (KPV-/-) to demonstrate that KPV-/- mice have attenuated tumor growth and improved survival compared with KPV+/+ mice. Next, we therapeutically treated KPV+/+ mice with withaferin A (WFA), an agent that disrupts vimentin intermediate filaments (IFs). We show that WFA suppresses tumor growth and reduces tumor burden in the lung. Finally, luciferase-expressing KPV+/+, KPV-/-, or KPVY117L cells were implanted into the flanks of athymic mice to track cancer metastasis to the lung. In KPVY117L cells, vimentin forms oligomers called unit-length filaments but cannot assemble into mature vimentin IFs. KPV-/- and KPVY117L cells fail to metastasize, suggesting that cell-autonomous metastasis requires mature vimentin IFs. Integrative metabolomic and transcriptomic analysis reveals that KPV-/- cells upregulate genes associated with ferroptosis, an iron-dependent form of regulated cell death. KPV-/- cells have reduced glutathione peroxidase 4 (GPX4) levels, resulting in the accumulation of toxic lipid peroxides and increased ferroptosis. Together, our results demonstrate that vimentin is required for rapid tumor growth, metastasis, and protection from ferroptosis in NSCLC.
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Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Camundongos , Animais , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Filamentos Intermediários/metabolismo , Vimentina/genética , Vimentina/metabolismo , Modelos Animais de Doenças , Camundongos KnockoutRESUMO
Gigaxonin is an adaptor protein for E3 ubiquitin ligase substrates. It is necessary for ubiquitination and degradation of intermediate filament (IF) proteins. Giant axonal neuropathy is a pathological condition caused by mutations in the GAN gene that encodes gigaxonin. This condition is characterized by abnormal accumulation of IFs in both neuronal and non-neuronal cells; however, it is unclear what causes IF aggregation. In this work, we studied the dynamics of IFs using their subunits tagged with a photoconvertible protein mEOS 3.2. We have demonstrated that the loss of gigaxonin dramatically inhibited transport of IFs along microtubules by the microtubule motor kinesin-1. This inhibition was specific for IFs, as other kinesin-1 cargoes, with the exception of mitochondria, were transported normally. Abnormal distribution of IFs in the cytoplasm can be rescued by direct binding of kinesin-1 to IFs, demonstrating that transport inhibition is the primary cause for the abnormal IF distribution. Another effect of gigaxonin loss was a more than 20-fold increase in the amount of soluble vimentin oligomers in the cytosol of gigaxonin knock-out cells. We speculate that these oligomers saturate a yet unidentified adapter that is required for kinesin-1 binding to IFs, which might inhibit IF transport along microtubules causing their abnormal accumulation.
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Proteínas do Citoesqueleto , Neuropatia Axonal Gigante , Humanos , Proteínas do Citoesqueleto/metabolismo , Filamentos Intermediários/metabolismo , Cinesinas/genética , Cinesinas/metabolismo , Proteínas de Filamentos Intermediários/metabolismo , Neuropatia Axonal Gigante/genética , Neuropatia Axonal Gigante/metabolismo , Neuropatia Axonal Gigante/patologia , Microtúbulos/metabolismoRESUMO
Targeting KRAS-mutated non-small-cell lung cancer (NSCLC) remains clinically challenging. Here we show that loss of function of Miz1 inhibits lung tumorigenesis in a mouse model of oncogenic KRAS-driven lung cancer. In vitro, knockout or silencing of Miz1 decreases cell proliferation, clonogenicity, migration, invasion, or anchorage-independent growth in mutant (MT) KRAS murine or human NSCLC cells but has unremarkable impact on non-tumorigenic cells or wild-type (WT) KRAS human NSCLC cells. RNA-sequencing reveals Protocadherin-10 (Pcdh10) as the top upregulated gene by Miz1 knockout in MT KRAS murine lung tumor cells. Chromatin immunoprecipitation shows Miz1 binding on the Pcdh10 promoter in MT KRAS lung tumor cells but not non-tumorigenic cells. Importantly, silencing of Pcdh10 rescues cell proliferation and clonogenicity in Miz1 knockout/knockdown MT KRAS murine or human tumor cells, and rescues allograft tumor growth of Miz1 knockout tumor cells in vivo. Miz1 is upregulated in MT KRAS lung tumor tissues compared with adjacent non-involved tissues in mice. Consistent with this, Miz1 is upregulated while Pcdh10 is downregulated in human lung adenocarcinomas (LUAD) compared with normal tissues, and high Miz1 levels or low Pcdh10 levels are associated with poor survival in lung cancer patients. Furthermore, the Miz1 signature is associated with worse survival in MT but not WT KRAS LUAD, and Pcdh10 is downregulated in MT compared to WT KRAS LUAD. Taken together, our studies implicate the Miz1/Pcdh10 axis in oncogenic KRAS-driven lung tumorigenesis.
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Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Animais , Humanos , Camundongos , Carcinogênese/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Pulmão/patologia , Neoplasias Pulmonares/metabolismo , Proteínas Inibidoras de STAT Ativados/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Protocaderinas , Ubiquitina-Proteína Ligases/metabolismoRESUMO
Keratin intermediate filaments convey mechanical stability and protection against stress to epithelial cells. Keratins are essential for colon health, as seen in keratin 8 knockout (K8-/-) mice exhibiting a colitis phenotype. We hypothesized that keratins support the nuclear envelope and lamina in colonocytes. K8-/- colonocytes in vivo exhibit significantly decreased levels of lamins A/C, B1, and B2 in a colon-specific and cell-intrinsic manner. CRISPR/Cas9- or siRNA-mediated K8 knockdown in Caco-2 cells similarly decreased lamin levels, which recovered after reexpression of K8 following siRNA treatment. Nuclear area was not decreased, and roundness was only marginally increased in cells without K8. Down-regulation of K8 in adult K8flox/flox;Villin-CreERt2 mice following tamoxifen administration significantly decreased lamin levels at day 4 when K8 levels had reduced to 40%. K8 loss also led to reduced levels of plectin, LINC complex, and lamin-associated proteins. While keratins were not seen in the nucleoplasm without or with leptomycin B treatment, keratins were found intimately located at the nuclear envelope and complexed with SUN2 and lamin A. Furthermore, K8 loss in Caco-2 cells compromised nuclear membrane integrity basally and after shear stress. In conclusion, colonocyte K8 helps maintain nuclear envelope and lamina composition and contributes to nuclear integrity.
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Queratina-8 , Queratinas , Animais , Células CACO-2 , Colo/metabolismo , Proteínas do Citoesqueleto/metabolismo , Células Epiteliais/metabolismo , Humanos , Queratina-8/genética , Queratinas/metabolismo , Lamina Tipo A/metabolismo , Camundongos , Membrana Nuclear/metabolismo , Plectina/metabolismo , RNA Interferente Pequeno/metabolismo , TamoxifenoRESUMO
OBJECTIVE: Failure to close the ductus arteriosus, patent ductus arteriosus, accounts for 10% of all congenital heart defects. Despite significant advances in patent ductus arteriosus management, including pharmacological treatment targeting the prostaglandin pathway, a proportion of patients fail to respond and must undergo surgical intervention. Thus, further refinement of the cellular and molecular mechanisms that govern vascular remodeling of this vessel is required. METHODS: We performed single-cell RNA-sequencing of the ductus arteriosus in mouse embryos at E18.5 (embryonic day 18.5), and P0.5 (postnatal day 0.5), and P5 to identify transcriptional alterations that might be associated with remodeling. We further confirmed our findings using transgenic mouse models coupled with immunohistochemistry analysis. RESULTS: The intermediate filament vimentin emerged as a candidate that might contribute to closure of the ductus arteriosus. Indeed, mice with genetic deletion of vimentin fail to complete vascular remodeling of the ductus arteriosus. To seek mechanisms, we turned to the RNA-sequencing data that indicated changes in Jagged1 with similar profile to vimentin and pointed to potential links with Notch. In fact, Notch3 signaling was impaired in vimentin null mice and vimentin null mice phenocopies patent ductus arteriosus in Jagged1 endothelial and smooth muscle deleted mice. CONCLUSIONS: Through single-cell RNA-sequencing and by tracking closure of the ductus arteriosus in mice, we uncovered the unexpected contribution of vimentin in driving complete closure of the ductus arteriosus through a mechanism that includes deregulation of the Notch signaling pathway.
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Permeabilidade do Canal Arterial , Canal Arterial , Animais , Canal Arterial/metabolismo , Permeabilidade do Canal Arterial/genética , Permeabilidade do Canal Arterial/metabolismo , Humanos , Filamentos Intermediários/metabolismo , Camundongos , RNA , Remodelação Vascular , Vimentina/genética , Vimentina/metabolismoRESUMO
More than 27 yr ago, the vimentin knockout (Vim-/- ) mouse was reported to develop and reproduce without an obvious phenotype, implying that this major cytoskeletal protein was nonessential. Subsequently, comprehensive and careful analyses have revealed numerous phenotypes in Vim-/- mice and their organs, tissues, and cells, frequently reflecting altered responses in the recovery of tissues following various insults or injuries. These findings have been supported by cell-based experiments demonstrating that vimentin intermediate filaments (IFs) play a critical role in regulating cell mechanics and are required to coordinate mechanosensing, transduction, signaling pathways, motility, and inflammatory responses. This review highlights the essential functions of vimentin IFs revealed from studies of Vim-/- mice and cells derived from them.
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Filamentos Intermediários , Vimentina/metabolismo , Animais , Fenômenos Fisiológicos Celulares , Filamentos Intermediários/genética , Filamentos Intermediários/metabolismo , Camundongos , Vimentina/genéticaRESUMO
Aging is among the most important risk factors for morbidity and mortality. To contribute toward a molecular understanding of aging, we analyzed age-resolved transcriptomic data from multiple studies. Here, we show that transcript length alone explains most transcriptional changes observed with aging in mice and humans. We present three lines of evidence supporting the biological importance of the uncovered transcriptome imbalance. First, in vertebrates the length association primarily displays a lower relative abundance of long transcripts in aging. Second, eight antiaging interventions of the Interventions Testing Program of the National Institute on Aging can counter this length association. Third, we find that in humans and mice the genes with the longest transcripts enrich for genes reported to extend lifespan, whereas those with the shortest transcripts enrich for genes reported to shorten lifespan. Our study opens fundamental questions on aging and the organization of transcriptomes.
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Envelhecimento , Transcriptoma , Humanos , Animais , Camundongos , Transcriptoma/genética , Envelhecimento/genética , Longevidade/genética , Perfilação da Expressão Gênica , Fatores de RiscoRESUMO
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has infected more than 180 million people since the onset of the pandemic. Despite similar viral load and infectivity rates between children and adults, children rarely develop severe illness. Differences in the host response to the virus at the primary infection site are among the mechanisms proposed to account for this disparity. Our objective was to investigate the host response to SARS-CoV-2 in the nasal mucosa in children and adults and compare it with the host response to respiratory syncytial virus (RSV) and influenza virus. We analyzed clinical outcomes and gene expression in the nasal mucosa of 36 children with SARS-CoV-2, 24 children with RSV, 9 children with influenza virus, 16 adults with SARS-CoV-2, and 7 healthy pediatric and 13 healthy adult controls. In both children and adults, infection with SARS-CoV-2 led to an IFN response in the nasal mucosa. The magnitude of the IFN response correlated with the abundance of viral reads, not the severity of illness, and was comparable between children and adults infected with SARS-CoV-2 and children with severe RSV infection. Expression of ACE2 and TMPRSS2 did not correlate with age or presence of viral infection. SARS-CoV-2-infected adults had increased expression of genes involved in neutrophil activation and T-cell receptor signaling pathways compared with SARS-CoV-2-infected children, despite similar severity of illness and viral reads. Age-related differences in the immune response to SARS-CoV-2 may place adults at increased risk of developing severe illness.
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Envelhecimento/imunologia , COVID-19/imunologia , Regulação da Expressão Gênica/imunologia , Imunidade nas Mucosas , Mucosa Nasal/imunologia , SARS-CoV-2/imunologia , Adolescente , Fatores Etários , Enzima de Conversão de Angiotensina 2/imunologia , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Mucosa Nasal/virologia , Infecções por Vírus Respiratório Sincicial/imunologia , Vírus Sinciciais Respiratórios/imunologia , Serina Endopeptidases/imunologiaRESUMO
Keratin 8 (K8) is the main intestinal epithelial intermediate filament protein with proposed roles for colonic epithelial cell integrity. Here, we used mice lacking K8 in intestinal epithelial cells (floxed K8 and Villin-Cre1000 and Villin-CreERt2) to investigate the cell-specific roles of intestinal epithelial K8 for colonocyte function and pathologies. Intestinal epithelial K8 deletion decreased K8 partner proteins, K18-K20, 75-95%, and the remaining keratin filaments were located at the colonocyte apical regions with type II K7, which decreased 30%. 2-Deoxy-2-[18F]-fluoroglucose positron emission tomography in vivo imaging identified a metabolic phenotype in the lower gut of the conditional K8 knockouts. These mice developed intestinal barrier leakiness, mild diarrhea, and epithelial damage, especially in the proximal colon. Mice exhibited shifted differentiation from enterocytes to goblet cells, displayed longer crypts and an increased number of Ki67 + transit-amplifying cells in the colon. Significant proproliferative and regenerative signaling occurred in the IL-22, STAT3, and pRb pathways, with minor effects on inflammatory parameters, which, however, increased in aging mice. Importantly, colonocyte K8 deletion induced a dramatically increased sensitivity to azoxymethane-induced tumorigenesis. In conclusion, intestinal epithelial K8 plays a significant role in colonocyte epithelial integrity maintenance, proliferation regulation and tumor suppression.
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Carcinogênese/metabolismo , Carcinogênese/patologia , Colo/patologia , Células Epiteliais/metabolismo , Deleção de Genes , Marcação de Genes , Intestinos/patologia , Queratina-8/genética , Envelhecimento/patologia , Animais , Diferenciação Celular , Proliferação de Células , Diarreia/complicações , Diarreia/patologia , Regulação para Baixo , Fluordesoxiglucose F18/metabolismo , Células Caliciformes/metabolismo , Inflamação/patologia , Integrases/metabolismo , Queratina-8/deficiência , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas dos Microfilamentos/metabolismo , Permeabilidade , Fenótipo , Tomografia por Emissão de PósitronsRESUMO
The coronavirus disease 2019 (COVID-19) pandemic is among the most important public health crises of our generation. Despite the promise of prevention offered by effective vaccines, patients with severe COVID-19 will continue to populate hospitals and intensive care units for the foreseeable future. The most common clinical presentation of severe COVID-19 is hypoxemia and respiratory failure, typical of the acute respiratory distress syndrome (ARDS). Whether the clinical features and pathobiology of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pneumonia differ from those of pneumonia secondary to other pathogens is unclear. This uncertainty has created variability in the application of historically proven therapies for ARDS to patients with COVID-19. We review the available literature and find many similarities between patients with ARDS from pneumonia attributable to SARS-CoV-2 versus other respiratory pathogens. A notable exception is the long duration of illness among patients with COVID-19, which could result from its unique pathobiology. Available data support the use of care pathways and therapies proven effective for patients with ARDS, while pointing to unique features that might be therapeutically targeted for patients with severe SARS-CoV-2 pneumonia.
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COVID-19/etiologia , Pneumonia Viral/etiologia , Síndrome do Desconforto Respiratório/etiologia , SARS-CoV-2 , Enzima de Conversão de Angiotensina 2/fisiologia , Autopsia , COVID-19/epidemiologia , COVID-19/patologia , Citocinas/biossíntese , Humanos , Pulmão/imunologia , Pulmão/patologia , Pulmão/virologia , Macrófagos Alveolares/imunologia , Macrófagos Alveolares/virologia , Modelos Biológicos , Pandemias , Pneumonia Viral/imunologia , Pneumonia Viral/patologia , Receptores Virais/fisiologia , Síndrome do Desconforto Respiratório/imunologia , Síndrome do Desconforto Respiratório/patologia , SARS-CoV-2/imunologia , SARS-CoV-2/patogenicidade , SARS-CoV-2/fisiologia , Índice de Gravidade de DoençaRESUMO
Alveolar macrophages orchestrate the response to viral infections. Age-related changes in these cells may underlie the differential severity of pneumonia in older patients. We performed an integrated analysis of single-cell RNA-Seq data that revealed homogenous age-related changes in the alveolar macrophage transcriptome in humans and mice. Using genetic lineage tracing with sequential injury, heterochronic adoptive transfer, and parabiosis, we found that the lung microenvironment drove an age-related resistance of alveolar macrophages to proliferation that persisted during influenza A viral infection. Ligand-receptor pair analysis localized these changes to the extracellular matrix, where hyaluronan was increased in aged animals and altered the proliferative response of bone marrow-derived macrophages to granulocyte macrophage colony-stimulating factor (GM-CSF). Our findings suggest that strategies targeting the aging lung microenvironment will be necessary to restore alveolar macrophage function in aging.
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Envelhecimento/imunologia , Microambiente Celular/imunologia , Pulmão/imunologia , Macrófagos Alveolares/imunologia , Envelhecimento/patologia , Animais , Humanos , Pulmão/patologia , Macrófagos Alveolares/patologia , Camundongos , Camundongos Transgênicos , RNA-SeqRESUMO
RATIONALE: Despite similar viral load and infectivity rates between children and adults infected with SARS-CoV-2, children rarely develop severe illness. Differences in the host response to the virus at the primary infection site are among the proposed mechanisms. OBJECTIVES: To investigate the host response to SARS-CoV-2, respiratory syncytial virus (RSV), and influenza virus (IV) in the nasal mucosa in children and adults. METHODS: Clinical outcomes and gene expression in the nasal mucosa were analyzed in 36 children hospitalized with SARS-CoV-2 infection, 24 children with RSV infection, 9 children with IV infection, 16 adults with mild to moderate SARS-CoV-2 infection, and 7 healthy pediatric and 13 healthy adult controls. RESULTS: In both children and adults, infection with SARS-CoV-2 leads to an interferon response in the nasal mucosa. The magnitude of the interferon response correlated with the abundance of viral reads and was comparable between symptomatic children and adults infected with SARS-CoV-2 and symptomatic children infected with RSV and IV. Cell type deconvolution identified an increased abundance of immune cells in the samples from children and adults with a viral infection. Expression of ACE2 and TMPRSS2 - key entry factors for SARS-CoV-2 - did not correlate with age or presence or absence of viral infection. CONCLUSIONS: Our findings support the hypothesis that differences in the immune response to SARS-CoV-2 determine disease severity, independent of viral load and interferon response at the primary infection primary site.
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Research experience garnered through summer student programs (SSPs) is critical for high school and college student retention in science, technology, engineering, and math (STEM) disciplines. However, the global coronavirus disease (COVID-19) pandemic prevented in-person SSPs in 2020, eliminating these essential experiences that students need to advance their STEM training. In response, we created a remote-learning model that can be broadly adapted for other SSPs. We aimed to uphold our traditional SSP's academic rigor by cultivating critical thinking skills, providing mentorship, and equipping students with tools to serve as public health ambassadors in their communities. We designed the remote SSP around an anchor topic to integrate didactic lectures with research-based independent projects. Program success was evaluated quantitatively and qualitatively via content assessments and written feedback. By comparing preassessments to postassessments, we show that students gained general scientific literacy and improved critical thinking skills. Based on qualitative measures, students were satisfied with their mentorship, reported that they would use what they learned through the SSP in the future, indicated that they had the tools to understand and communicate public health information, and, overall, rated the quality of the SSP positively. As the pandemic continues to necessitate remote learning, traditional in-person experiences will need to be adapted to best support students. We have developed a modular and adaptable SSP that upholds the same standards as the traditional SSP by continuing to provide essential experiences necessary to advance students' training in STEM.
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The presence of DNA in the cytosol is usually a sign of microbial infections, which alerts the host innate immune system to mount a defense response. Cyclic GMP-AMP synthase (cGAS) is a critical cytosolic DNA sensor that elicits robust innate immune responses through the production of the second messenger, cyclic GMP-AMP (cGAMP), which binds and activates stimulator of interferon genes (STING). However, cGAS binds to DNA irrespective of DNA sequence, therefore, self-DNA leaked from the nucleus or mitochondria can also serve as a cGAS ligand to activate this pathway and trigger extensive inflammatory responses. Dysregulation of the cGAS-STING pathway is responsible for a broad array of inflammatory and autoimmune diseases. Recently, evidence has shown that self-DNA release and cGAS-STING pathway over-activation can drive lung disease, making this pathway a promising therapeutic target for inflammatory lung disease. Here, we review recent advances on the cGAS-STING pathway governing self-DNA sensing, highlighting its role in pulmonary disease.
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DNA/metabolismo , Pneumopatias/metabolismo , Proteínas de Membrana/metabolismo , Nucleotidiltransferases/metabolismo , Transdução de Sinais , Animais , Humanos , Pneumopatias/genética , Proteínas de Membrana/genética , Nucleotidiltransferases/genéticaRESUMO
Cigarette smoking, the leading cause of chronic obstructive pulmonary disease (COPD), has been implicated as a risk factor for severe disease in patients infected with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Here we show that mice with lung epithelial cell-specific loss of function of Miz1, which we identified as a negative regulator of nuclear factor κB (NF-κB) signaling, spontaneously develop progressive age-related changes resembling COPD. Furthermore, loss of Miz1 up-regulates the expression of Ace2, the receptor for SARS-CoV-2. Concomitant partial loss of NF-κB/RelA prevented the development of COPD-like phenotype in Miz1-deficient mice. Miz1 protein levels are reduced in the lungs from patients with COPD, and in the lungs of mice exposed to chronic cigarette smoke. Our data suggest that Miz1 down-regulation-induced sustained activation of NF-κB-dependent inflammation in the lung epithelium is sufficient to induce progressive lung and airway destruction that recapitulates features of COPD, with implications for COVID-19.
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Células Epiteliais/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , Pulmão/metabolismo , Peptidil Dipeptidase A/metabolismo , Fenótipo , Proteínas Inibidoras de STAT Ativados/genética , Doença Pulmonar Obstrutiva Crônica/genética , Ubiquitina-Proteína Ligases/genética , Regulação para Cima/genética , Enzima de Conversão de Angiotensina 2 , Animais , Betacoronavirus , COVID-19 , Infecções por Coronavirus/metabolismo , Infecções por Coronavirus/virologia , Técnicas de Inativação de Genes , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pandemias , Pneumonia Viral/metabolismo , Pneumonia Viral/virologia , Proteínas Inibidoras de STAT Ativados/metabolismo , Doença Pulmonar Obstrutiva Crônica/etiologia , Doença Pulmonar Obstrutiva Crônica/metabolismo , SARS-CoV-2 , Transdução de Sinais/genética , Fumar/efeitos adversos , Fator de Transcrição RelA/metabolismo , Ubiquitina-Proteína Ligases/metabolismoRESUMO
Respiratory infections from influenza A virus (IAV) cause substantial morbidity and mortality in children relative to adults. T cells play a critical role in the host response to IAV by supporting the innate and humoral responses, mediating cytotoxic activity, and promoting recovery. There are age-dependent differences in the number, subsets, and localization of T cells, which impact the host response to pathogens. In this article, we first review how T cells recognize IAV and examine differences in the resting T-cell populations between juveniles and adults. Next, we describe how the juvenile CD4+, CD8+, and regulatory T-cell responses compare with those in adults and discuss the potential physiologic and clinical consequences of the differences. Finally, we explore the roles of two unconventional T-cell types in the juvenile response to influenza, natural-killer T cells and γδ T cells. A clear understanding of age-dependent differences in the T-cell response is essential to developing therapies to prevent or reverse the deleterious effects of IAV in children.