RESUMO
During metazoan development, how cell division and metabolic programs are coordinated with nutrient availability remains unclear. Here, we show that nutrient availability signaled by the neuronal cytokine, ILC-17.1, switches Caenorhabditis elegans development between reproductive growth and dormancy by controlling the activity of the tumor suppressor p53 ortholog, CEP-1. Specifically, upon food availability, ILC-17.1 signaling by amphid neurons promotes glucose utilization and suppresses CEP-1/p53 to allow growth. In the absence of ILC-17.1, CEP-1/p53 is activated, up-regulates cell-cycle inhibitors, decreases phosphofructokinase and cytochrome C expression, and causes larvae to arrest as stress-resistant, quiescent dauers. We propose a model whereby ILC-17.1 signaling links nutrient availability and energy metabolism to cell cycle progression through CEP-1/p53. These studies describe ancestral functions of IL-17 s and the p53 family of proteins and are relevant to our understanding of neuroimmune mechanisms in cancer. They also reveal a DNA damage-independent function of CEP-1/p53 in invertebrate development and support the existence of a previously undescribed C. elegans dauer pathway.
Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Animais , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Interleucina-17/metabolismo , Dano ao DNARESUMO
OBJECTIVE: Establish a baseline of informatics professionals' perspectives on climate change and health. MATERIALS AND METHODS: Anonymized survey sent to 9 informatics listservs March 31, 2022 to April 15, 2022. RESULTS: N = 85 participants completed part or all of survey. Majority of participants worked at hospitals with 1000+ employees (73%) in urban areas (60%) in the United States. Respondents broadly reported general understanding of climate change and health (51%), but 71% reported unfamiliarity with technologies that could help clinicians and informaticians address the impacts of climate change. Seventy-one percent of surveyed wanted climate-driven environmental health information included in EHRs. Seventy-six percent of respondents reported that informaticians should be involved in institutional decarbonization. Seventy-eight percent of respondents felt that it was extremely, very, or moderately important to receive education on climate change. DISCUSSION: General consensus on need to engage informaticians in climate change response, but gaps identified in knowledge dissemination and tools for adaptation and mitigation. CONCLUSION: Informaticians broadly concerned about climate change and want to be engaged in efforts to combat it, but further education and tool development needed.
Assuntos
Mudança Climática , Informática Médica , Humanos , Estados Unidos , Inquéritos e Questionários , Informática Médica/educação , EscolaridadeRESUMO
BACKGROUND: Multimorbidity clinical risk scores allow clinicians to quickly assess their patients' health for decision making, often for recommendation to care management programs. However, these scores are limited by several issues: existing multimorbidity scores (1) are generally limited to one data group (eg, diagnoses, labs) and may be missing vital information, (2) are usually limited to specific demographic groups (eg, age), and (3) do not formally provide any granularity in the form of more nuanced multimorbidity risk scores to direct clinician attention. OBJECTIVE: Using diagnosis, lab, prescription, procedure, and demographic data from electronic health records (EHRs), we developed a physiologically diverse and generalizable set of multimorbidity risk scores. METHODS: Using EHR data from a nationwide cohort of patients, we developed the total health profile, a set of six integrated risk scores reflecting five distinct organ systems and overall health. We selected the occurrence of an inpatient hospital visitation over a 2-year follow-up window, attributable to specific organ systems, as our risk endpoint. Using a physician-curated set of features, we trained six machine learning models on 794,294 patients to predict the calibrated probability of the aforementioned endpoint, producing risk scores for heart, lung, neuro, kidney, and digestive functions and a sixth score for combined risk. We evaluated the scores using a held-out test cohort of 198,574 patients. RESULTS: Study patients closely matched national census averages, with a median age of 41 years, a median income of $66,829, and racial averages by zip code of 73.8% White, 5.9% Asian, and 11.9% African American. All models were well calibrated and demonstrated strong performance with areas under the receiver operating curve (AUROCs) of 0.83 for the total health score (THS), 0.89 for heart, 0.86 for lung, 0.84 for neuro, 0.90 for kidney, and 0.83 for digestive functions. There was consistent performance of this scoring system across sexes, diverse patient ages, and zip code income levels. Each model learned to generate predictions by focusing on appropriate clinically relevant patient features, such as heart-related hospitalizations and chronic hypertension diagnosis for the heart model. The THS outperformed the other commonly used multimorbidity scoring systems, specifically the Charlson Comorbidity Index (CCI) and the Elixhauser Comorbidity Index (ECI) overall (AUROCs: THS=0.823, CCI=0.735, ECI=0.649) as well as for every age, sex, and income bracket. Performance improvements were most pronounced for middle-aged and lower-income subgroups. Ablation tests using only diagnosis, prescription, social determinants of health, and lab feature groups, while retaining procedure-related features, showed that the combination of feature groups has the best predictive performance, though only marginally better than the diagnosis-only model on at-risk groups. CONCLUSIONS: Massive retrospective EHR data sets have made it possible to use machine learning to build practical multimorbidity risk scores that are highly predictive, personalizable, intuitive to explain, and generalizable across diverse patient populations.
Assuntos
Aprendizado de Máquina , Multimorbidade , Adulto , Estudos de Coortes , Registros Eletrônicos de Saúde , Humanos , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de RiscoRESUMO
BACKGROUND: Although it is well-known that older individuals with certain comorbidities are at the highest risk for complications related to COVID-19 including hospitalization and death, we lack tools to identify communities at the highest risk with fine-grained spatial resolution. Information collected at a county level obscures local risk and complex interactions between clinical comorbidities, the built environment, population factors, and other social determinants of health. OBJECTIVE: This study aims to develop a COVID-19 community risk score that summarizes complex disease prevalence together with age and sex, and compares the score to different social determinants of health indicators and built environment measures derived from satellite images using deep learning. METHODS: We developed a robust COVID-19 community risk score (COVID-19 risk score) that summarizes the complex disease co-occurrences (using data for 2019) for individual census tracts with unsupervised learning, selected on the basis of their association with risk for COVID-19 complications such as death. We mapped the COVID-19 risk score to corresponding zip codes in New York City and associated the score with COVID-19-related death. We further modeled the variance of the COVID-19 risk score using satellite imagery and social determinants of health. RESULTS: Using 2019 chronic disease data, the COVID-19 risk score described 85% of the variation in the co-occurrence of 15 diseases and health behaviors that are risk factors for COVID-19 complications among ~28,000 census tract neighborhoods (median population size of tracts 4091). The COVID-19 risk score was associated with a 40% greater risk for COVID-19-related death across New York City (April and September 2020) for a 1 SD change in the score (risk ratio for 1 SD change in COVID-19 risk score 1.4; P<.001) at the zip code level. Satellite imagery coupled with social determinants of health explain nearly 90% of the variance in the COVID-19 risk score in the United States in census tracts (r2=0.87). CONCLUSIONS: The COVID-19 risk score localizes risk at the census tract level and was able to predict COVID-19-related mortality in New York City. The built environment explained significant variations in the score, suggesting risk models could be enhanced with satellite imagery.
Assuntos
COVID-19/epidemiologia , Efeitos Psicossociais da Doença , Características de Residência/estatística & dados numéricos , COVID-19/mortalidade , Cidades/epidemiologia , Indicadores Básicos de Saúde , Humanos , Cidade de Nova Iorque/epidemiologia , Medição de Risco/métodos , Fatores de Risco , Determinantes Sociais da Saúde , Estados Unidos/epidemiologia , Aprendizado de Máquina não SupervisionadoRESUMO
The transcription factor heat shock factor-1 (HSF-1) regulates the heat shock response (HSR), a cytoprotective response induced by proteotoxic stresses. Data from model organisms has shown that HSF-1 also has non-stress biological roles, including roles in the regulation of development and longevity. To better study HSF-1 function, we created a C. elegans strain containing HSF-1 tagged with GFP at its endogenous locus utilizing CRISPR/Cas9-guided transgenesis. We show that the HSF-1::GFP CRISPR worm strain behaves similarly to wildtype worms in response to heat and other stresses, and in other physiological processes. HSF-1 was expressed in all tissues assayed. Immediately following the initiation of reproduction, HSF-1 formed nuclear stress bodies, a hallmark of activation, throughout the germline. Upon the transition to adulthood, of HSF-1 nuclear stress bodies appeared in most somatic cells. Genetic loss of the germline suppressed nuclear stress body formation with age, suggesting that the germline influences HSF-1 activity. Interestingly, we found that various neurons did not form nuclear stress bodies after transitioning to adulthood. Therefore, the formation of HSF-1 nuclear stress bodies upon the transition to adulthood does not occur in a synchronous manner in all cell types. In sum, these studies enhance our knowledge of the expression and activity of the aging and proteostasis factor HSF-1 in a tissue-specific manner with age.
Assuntos
Envelhecimento/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , Resposta ao Choque Térmico , Fatores de Transcrição/fisiologia , Animais , Proteínas de Caenorhabditis elegans/fisiologia , Expressão GênicaRESUMO
OBJECTIVE: Prior studies examining diabetes prevalence in India have found that nearly 50% of the diabetes population remains undiagnosed; however, the specific populations at risk are unclear. RESEARCH DESIGN AND METHODS: First, we estimated the prevalence of undiagnosed diabetes in India for 750 924 persons between the ages of 15 years and 50 years who participated in the National Family Health Survey (NFHS-4)/Demographic Health Survey (2015-2016), a cross-sectional survey of all 29 states and 7 union territories of India. We defined 'undiagnosed diabetes' as individuals who did not know about their diabetes status but had high random (≥200 mg/dL) or fasting (≥126 mg/dL) blood glucose levels. Second, using Poisson regression, we associated 10 different factors, including the role of healthcare access, and undiagnosed diabetes. Third, we examined the association of undiagnosed diabetes with other potential comorbid conditions. RESULTS: The crude prevalence of diabetes for women and men aged 15-50 years was 2.9%, 95% CI 2.9% to 3.1%, with self-reported diabetes prevalence at 1.7%, 95% CI 1.6 to 1.8. The overall prevalence of undiagnosed diabetes for 15-50 year olds was at 1.2%, 95% CI 1.2% to 1.3%. Forty-two per cent, 95% CI 40.7% to 43.4% of the individuals with high glucose levels were unaware of their diabetes status. Approximately 45%, 95% CI 42.9% to 46.4% of undiagnosed diabetes population had access to healthcare. Men, younger individuals, and those with lower levels of education were most at risk of being undiagnosed. Geographically, the Southern states in India had a significantly higher prevalence of undiagnosed diabetes despite having nearly universal access to healthcare. Risk factors combined with random glucose could predict undiagnosed diabetes (area under the curve of 97.8%, 95% CI 97.7% to 97.8%), Nagelkerke R2 of 66%). CONCLUSION: Close to half (42%) of the people with diabetes in India are not aware of their disease status, and a large subset of these people are at risk of poor detection, despite having health insurance and/or having access to healthcare. Younger age groups and men are the most vulnerable.
Assuntos
Diabetes Mellitus/diagnóstico , Diabetes Mellitus/epidemiologia , Doenças não Diagnosticadas/diagnóstico , Doenças não Diagnosticadas/epidemiologia , Adolescente , Adulto , Fatores Etários , Glicemia/análise , Estudos de Coortes , Estudos Transversais , Diabetes Mellitus/sangue , Jejum/sangue , Feminino , Inquéritos Epidemiológicos , Humanos , Índia/epidemiologia , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de Risco , Autorrelato , Fatores Sexuais , Doenças não Diagnosticadas/sangue , Adulto JovemRESUMO
Metallic structures can be used for the localized heating of fluid and the controlled generation of microfluidic currents. Carefully designed currents can move and trap small particles and cells. Here we demonstrate a new bi-metallic substrate that allows much more powerful micro-scale manipulation. We show that there are multiple regimes of opto-fluidic manipulation that can be controlled by an external laser power. While the lowest power does not affect even small objects, medium power can be used for efficiently capturing and trapping particles and cells. Finally, the high-power regime can be used for 3D levitation that, for the first time, has been demonstrated in this paper. Additionally, we demonstrate opto-fluidic manipulation for an extraordinarily dynamic range of masses extending eight orders of magnitude: from 80 fg nano-wires to 5.4 µg live worms.
RESUMO
Defects in protein quality control during aging are central to many human diseases, and strategies are needed to better understand mechanisms of controlling the quality of the proteome. The heat-shock response (HSR) is a conserved survival mechanism mediated by the transcription factor HSF1 which functions to maintain proteostasis. In mammalian cells, HSF1 is regulated by a variety of factors including the prolongevity factor SIRT1. SIRT1 promotes the DNA-bound state of HSF1 through deacetylation of the DNA-binding domain of HSF1, thereby enhancing the HSR. SIRT1 is also regulated by various factors, including negative regulation by the cell-cycle and apoptosis regulator CCAR2. CCAR2 negatively regulates the HSR, possibly through its inhibitory interaction with SIRT1. We were interested in studying conservation of the SIRT1/CCAR2 regulatory interaction in Caenorhabditis elegans, and in utilizing this model organism to observe the effects of modulating sirtuin activity on the HSR, longevity, and proteostasis. The HSR is highly conserved in C. elegans and is mediated by the HSF1 homolog, HSF-1. We have uncovered that negative regulation of the HSR by CCAR2 is conserved in C. elegans and is mediated by the CCAR2 ortholog, CCAR-1. This negative regulation requires the SIRT1 homolog SIR-2.1. In addition, knockdown of CCAR-1 via ccar-1 RNAi works through SIR-2.1 to enhance stress resistance, motility, longevity, and proteostasis. This work therefore highlights the benefits of enhancing sirtuin activity to promote the HSR at the level of the whole organism.
Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , Resposta ao Choque Térmico , Acetilação , Animais , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Modelos Animais de Doenças , Resposta ao Choque Térmico/genética , Doença de Huntington/patologia , Longevidade , Peptídeos/metabolismo , Regiões Promotoras Genéticas/genética , Ligação Proteica , Interferência de RNA , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Sirtuínas/metabolismo , Estresse Fisiológico , Temperatura , Fatores de Transcrição/metabolismoRESUMO
Although multiple CHCHD10 mutations are associated with the spectrum of familial and sporadic frontotemporal dementia-amyotrophic lateral sclerosis (FTD-ALS) diseases, neither the normal function of endogenous CHCHD10 nor its role in the pathological milieu (that is, TDP-43 pathology) of FTD/ALS have been investigated. In this study, we made a series of observations utilizing Caenorhabditis elegans models, mammalian cell lines, primary neurons and mouse brains, demonstrating that CHCHD10 normally exerts a protective role in mitochondrial and synaptic integrity as well as in the retention of nuclear TDP-43, whereas FTD/ALS-associated mutations (R15L and S59L) exhibit loss of function phenotypes in C. elegans genetic complementation assays and dominant negative activities in mammalian systems, resulting in mitochondrial/synaptic damage and cytoplasmic TDP-43 accumulation. As such, our results provide a pathological link between CHCHD10-associated mitochondrial/synaptic dysfunction and cytoplasmic TDP-43 inclusions.
Assuntos
Esclerose Lateral Amiotrófica/genética , Caenorhabditis elegans/genética , Proteínas de Ligação a DNA/metabolismo , Demência Frontotemporal/genética , Proteínas Mitocondriais/genética , Sinapses/metabolismo , Animais , Linhagem Celular , Citoplasma/metabolismo , Teste de Complementação Genética , Células HEK293 , Humanos , Camundongos , Microscopia de Fluorescência , Mitocôndrias/metabolismo , Mutação , Células NIH 3T3 , Neurônios/metabolismo , Fenótipo , Ligação Proteica , Domínios Proteicos , RNA Interferente Pequeno/metabolismo , TransgenesRESUMO
SKN-1/Nrf are the primary antioxidant/detoxification response transcription factors in animals and they promote health and longevity in many contexts. SKN-1/Nrf are activated by a remarkably broad-range of natural and synthetic compounds and physiological conditions. Defining the signaling mechanisms that regulate SKN-1/Nrf activation provides insights into how cells coordinate responses to stress. Nrf2 in mammals is regulated in part by the redox sensor repressor protein named Keap1. In C. elegans, the p38 MAPK cascade in the intestine activates SKN-1 during oxidative stress by promoting its nuclear accumulation. Interestingly, we find variation in the kinetics of p38 MAPK activation and tissues with SKN-1 nuclear accumulation among different pro-oxidants that all trigger strong induction of SKN-1 target genes. Using genome-wide RNAi screening, we identify new genes that are required for activation of the core SKN-1 target gene gst-4 during exposure to the natural pro-oxidant juglone. Among 10 putative activators identified in this screen was skr-1/2, highly conserved homologs of yeast and mammalian Skp1, which function to assemble protein complexes. Silencing of skr-1/2 inhibits induction of SKN-1 dependent detoxification genes and reduces resistance to pro-oxidants without decreasing p38 MAPK activation. Global transcriptomics revealed strong correlation between genes that are regulated by SKR-1/2 and SKN-1 indicating a high degree of specificity. We also show that SKR-1/2 functions upstream of the WD40 repeat protein WDR-23, which binds to and inhibits SKN-1. Together, these results identify a novel p38 MAPK independent signaling mechanism that activates SKN-1 via SKR-1/2 and involves WDR-23.
Assuntos
Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/genética , Inativação Metabólica/genética , Longevidade/genética , Proteínas Ligases SKP Culina F-Box/genética , Receptores de Ativinas Tipo I/genética , Animais , Antioxidantes/metabolismo , Caenorhabditis elegans/crescimento & desenvolvimento , Proteínas de Caenorhabditis elegans/antagonistas & inibidores , Proteínas de Caenorhabditis elegans/biossíntese , Trato Gastrointestinal/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Proteína 1 Associada a ECH Semelhante a Kelch/biossíntese , Proteína 1 Associada a ECH Semelhante a Kelch/genética , Fosforilação , Interferência de RNA , Espécies Reativas de Oxigênio/metabolismo , Proteínas Quinases Associadas a Fase S/genética , Proteínas Ligases SKP Culina F-Box/antagonistas & inibidores , Proteínas Quinases p38 Ativadas por Mitógeno/genética , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
Analysis of individual cells at the subcellular level is important for understanding diseases and accelerating drug discovery. Nanoscale endoscopes allow minimally invasive probing of individual cell interiors. Several such instruments have been presented previously, but they are either too complex to fabricate or require sophisticated external detectors because of low signal collection efficiency. Here we present a nanoendoscope that can locally excite fluorescence in labelled cell organelles and collect the emitted signal for spectral analysis. Finite Difference Time Domain (FDTD) simulations have shown that with an optimized nanoendoscope taper profile, the light emission and collection was localized within ~100 nm. This allows signal detection to be used for nano-photonic sensing of the proximity of fluorophores. Upon insertion into the individual organelles of living cells, the nanoendoscope was fabricated and resultant fluorescent signals collected. This included the signal collection from the nucleus of Acridine orange labelled human fibroblast cells, the nucleus of Hoechst stained live liver cells and the mitochondria of MitoTracker Red labelled MDA-MB-231 cells. The endoscope was also inserted into a live organism, the yellow fluorescent protein producing nematode Caenorhabditis elegans, and a fluorescent signal was collected. To our knowledge this is the first demonstration of in vivo, local fluorescence signal collection on the sub-organelle level.
Assuntos
Caenorhabditis elegans/metabolismo , Mitocôndrias Hepáticas/metabolismo , Imagem Molecular/métodos , Nanotecnologia/métodos , Imagem Óptica/métodos , Animais , Linhagem Celular Tumoral , Endoscopia , HumanosRESUMO
Chart reviews of 350 randomly sampled syphilis cases of men who had sex with men in British Columbia from 2010 to 2013 revealed no change in the median number of partners per case, and an increasing proportion of partners notified by cases but fewer partners were known to be tested for syphilis.
Assuntos
Busca de Comunicante , Sífilis/epidemiologia , Adulto , Idoso , Colúmbia Britânica/epidemiologia , Homossexualidade Masculina , Humanos , Masculino , Pessoa de Meia-Idade , Parceiros Sexuais , Minorias Sexuais e de GêneroRESUMO
BACKGROUND: The British Columbia take-home naloxone (BCTHN) program has been in operation since 2012 and has resulted in the successful reversal of over 581 opioid overdoses. The study aims to explore BCTHN program participant perspectives about the program, barriers to participants contacting emergency services (calling "911") during an overdose, and perspectives of law enforcement officials on naloxone administration by police officers. METHODS: Two focus groups and four individual interviews were conducted with BCTHN program participants; interviews with two law enforcement officials were also conducted. Qualitative analysis of all transcripts was performed. RESULTS: Positive themes about the BCTHN program from participants included easy to understand training, correcting misperceptions in the community, and positive interactions with emergency services. Potential barriers to contacting emergency services during an overdose include concerns about being arrested for outstanding warrants or for other illegal activities (such as drug possession) and confiscation of kits. Law enforcement officials noted that warrants were complex situational issues, kits would normally not be confiscated, and admitted arrests for drug possession or other activities may not serve the public good in an overdose situation. Law enforcement officials were concerned about legal liability and jurisdictional/authorization issues if naloxone administration privileges were expanded to police. CONCLUSIONS: Program participants and law enforcement officials expressed differing perspectives about warrants, kit confiscation, and arrests. Facilitating communication between BCTHN program participants and other stakeholders may address some of the confusion and remove potential barriers to further improving program outcomes. Naloxone administration by law enforcement would require policies to address jurisdiction/authorization and liability issues.
Assuntos
Aplicação da Lei , Naloxona/uso terapêutico , Antagonistas de Entorpecentes/uso terapêutico , Transtornos Relacionados ao Uso de Opioides/reabilitação , Atitude Frente a Saúde , Colúmbia Britânica , Crime/estatística & dados numéricos , Feminino , Serviços de Assistência Domiciliar/legislação & jurisprudência , Serviços de Assistência Domiciliar/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Tratamento de Substituição de Opiáceos/estatística & dados numéricos , PolíciaRESUMO
BACKGROUND: CD4(+) T cells are key regulators of the adaptive immune system and can be divided into T helper (Th) cells and regulatory T (Treg) cells. During an immune response Th cells mature from a naive state into one of several effector subtypes that exhibit distinct functions. The transcriptional mechanisms that underlie the specific functional identity of CD4(+) T cells are not fully understood. RESULTS: To assist investigations into the transcriptional identity and regulatory processes of these cells we performed mRNA-sequencing on three murine T helper subtypes (Th1, Th2 and Th17) as well as on splenic Treg cells and induced Treg (iTreg) cells. Our integrated analysis of this dataset revealed the gene expression changes associated with these related but distinct cellular identities. Each cell subtype differentially expresses a wealth of 'subtype upregulated' genes, some of which are well known whilst others promise new insights into signalling processes and transcriptional regulation. We show that hundreds of genes are regulated purely by alternative splicing to extend our knowledge of the role of post-transcriptional regulation in cell differentiation. CONCLUSIONS: This CD4(+) transcriptome atlas provides a valuable resource for the study of CD4(+) T cell populations. To facilitate its use by others, we have made the data available in an easily accessible online resource at www.th-express.org.
Assuntos
Regulação da Expressão Gênica , Linfócitos T Auxiliares-Indutores/citologia , Linfócitos T Reguladores/citologia , Células Th17/citologia , Transcriptoma , Processamento Alternativo , Animais , Diferenciação Celular , Análise por Conglomerados , Citometria de Fluxo , Perfilação da Expressão Gênica , Sistema Imunitário , Camundongos , Camundongos Endogâmicos C57BL , Análise de Componente Principal , Isoformas de Proteínas/genética , RNA Mensageiro/metabolismo , Análise de Sequência de RNA , Transdução de Sinais , Regulação para CimaRESUMO
SKN-1/Nrf transcription factors activate cytoprotective genes in response to reactive small molecules and strongly influence stress resistance, longevity, and development. The molecular mechanisms of SKN-1/Nrf regulation are poorly defined. We previously identified the WD40 repeat protein WDR-23 as a repressor of Caenorhabditis elegans SKN-1 that functions with a ubiquitin ligase to presumably target the factor for degradation. However, SKN-1 activity and nuclear accumulation are not always correlated, suggesting that there could be additional regulatory mechanisms. Here, we integrate forward genetics and biochemistry to gain insights into how WDR-23 interacts with and regulates SKN-1. We provide evidence that WDR-23 preferentially regulates one of three SKN-1 variants through a direct interaction that is required for normal stress resistance and development. Homology modeling predicts that WDR-23 folds into a ß-propeller, and we identify the top of this structure and four motifs at the termini of SKN-1c as essential for the interaction. Two of these SKN-1 motifs are highly conserved in human Nrf1 and Nrf2 and two directly interact with target DNA. Lastly, we demonstrate that WDR-23 can block the ability of SKN-1c to interact with DNA sequences of target promoters identifying a new mechanism of regulation that is independent of the ubiquitin proteasome system, which can become occupied with damaged proteins during stress.
Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , Proteínas de Ligação a DNA/metabolismo , Proteínas Repressoras/metabolismo , Fatores de Transcrição/metabolismo , Animais , Animais Geneticamente Modificados , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/antagonistas & inibidores , Proteínas de Caenorhabditis elegans/genética , DNA de Protozoário/genética , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica/genética , Larva/metabolismo , Longevidade/genética , Ligação Proteica , Dobramento de Proteína , Proteínas Repressoras/genética , Estresse Fisiológico/genética , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/genéticaRESUMO
An autochthonous model of pancreatic ductal adenocarcinoma (PDA) permitted the analysis of why immunotherapy is ineffective in this human disease. Despite finding that PDA-bearing mice had cancer cell-specific CD8(+) T cells, the mice, like human patients with PDA, did not respond to two immunological checkpoint antagonists that promote the function of T cells: anti-cytotoxic T-lymphocyte-associated protein 4 (α-CTLA-4) and α-programmed cell death 1 ligand 1 (α-PD-L1). Immune control of PDA growth was achieved, however, by depleting carcinoma-associated fibroblasts (CAFs) that express fibroblast activation protein (FAP). The depletion of the FAP(+) stromal cell also uncovered the antitumor effects of α-CTLA-4 and α-PD-L1, indicating that its immune suppressive activity accounts for the failure of these T-cell checkpoint antagonists. Three findings suggested that chemokine (C-X-C motif) ligand 12 (CXCL12) explained the overriding immunosuppression by the FAP(+) cell: T cells were absent from regions of the tumor containing cancer cells, cancer cells were coated with the chemokine, CXCL12, and the FAP(+) CAF was the principal source of CXCL12 in the tumor. Administering AMD3100, a CXCL12 receptor chemokine (C-X-C motif) receptor 4 inhibitor, induced rapid T-cell accumulation among cancer cells and acted synergistically with α-PD-L1 to greatly diminish cancer cells, which were identified by their loss of heterozygosity of Trp53 gene. The residual tumor was composed only of premalignant epithelial cells and inflammatory cells. Thus, a single protein, CXCL12, from a single stromal cell type, the FAP(+) CAF, may direct tumor immune evasion in a model of human PDA.
Assuntos
Carcinoma Ductal Pancreático/terapia , Quimiocina CXCL12/metabolismo , Gelatinases/metabolismo , Imunoterapia/métodos , Proteínas de Membrana/metabolismo , Neoplasias Pancreáticas/terapia , Serina Endopeptidases/metabolismo , Evasão Tumoral/genética , Análise de Variância , Animais , Sequência de Bases , Benzilaminas , Carcinoma Ductal Pancreático/imunologia , Ciclamos , Endopeptidases , ELISPOT , Fibroblastos/metabolismo , Citometria de Fluxo , Imunofluorescência , Compostos Heterocíclicos , Imuno-Histoquímica , Camundongos , Dados de Sequência Molecular , Neoplasias Pancreáticas/imunologia , Análise de Sequência de RNARESUMO
Negative-feedback loops between transcription factors and repressors in responses to xenobiotics, oxidants, heat, hypoxia, DNA damage, and infection have been described. Although common, the function of feedback is largely unstudied. Here, we define a negative-feedback loop between the Caenorhabditis elegans detoxification/antioxidant response factor SKN-1/Nrf and its repressor wdr-23 and investigate its function in vivo. Although SKN-1 promotes stress resistance and longevity, we find that tight regulation by WDR-23 is essential for growth and reproduction. By disabling SKN-1 transactivation of wdr-23, we reveal that feedback is required to set the balance between growth/reproduction and stress resistance/longevity. We also find that feedback is required to set the sensitivity of a core SKN-1 target gene to an electrophile. Interestingly, the effect of feedback on target gene induction is greatly reduced when the stress response is strongly activated, presumably to ensure maximum activation of cytoprotective genes during potentially fatal conditions. Our work provides a framework for understanding the function of negative feedback in inducible stress responses and demonstrates that manipulation of feedback alone can shift the balance of competing animal processes toward cell protection, health, and longevity.
Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/fisiologia , Proteínas de Ligação a DNA/metabolismo , Proteínas Repressoras/metabolismo , Fatores de Transcrição/metabolismo , Animais , Caenorhabditis elegans/crescimento & desenvolvimento , Proteínas de Caenorhabditis elegans/genética , Citoproteção , Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica , Longevidade , Proteínas Repressoras/genética , Reprodução , Estresse Fisiológico , Fatores de Transcrição/genéticaRESUMO
High-throughput screening (HTS) is a powerful approach to drug discovery, but many lead compounds are found to be unsuitable for use in vivo after initial screening. Screening in small animals like C. elegans can help avoid these problems, but this system has been limited to screens with low-throughput or no specific molecular target. We report the first in vivo 1536-well plate assay for a specific genetic pathway in C. elegans. Our assay measures induction of a gene regulated by SKN-1, a master regulator of detoxification genes. SKN-1 inhibitors will be used to study and potentially reverse multidrug resistance in parasitic nematodes. Screens of two small commercial libraries and the full Molecular Libraries Small Molecule Repository (MLSMR) of â¼364,000 compounds validate our platform for ultra HTS. Our platform overcomes current limitations of many whole-animal screens and can be widely adopted for other inducible genetic pathways in nematodes and humans.
Assuntos
Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/genética , Avaliação Pré-Clínica de Medicamentos/métodos , Ensaios de Triagem em Larga Escala/métodos , Bibliotecas de Moléculas Pequenas/farmacologia , Acrilamida/farmacologia , Animais , Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/fisiologia , Proteínas de Caenorhabditis elegans/genética , Relação Dose-Resposta a Droga , Estabilidade de Medicamentos , Regulação da Expressão Gênica/efeitos dos fármacos , Resposta ao Choque Térmico/efeitos dos fármacos , Resposta ao Choque Térmico/genética , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/genética , Acetato de Tetradecanoilforbol/farmacologiaRESUMO
Fibroblast activation protein-α (FAP) identifies stromal cells of mesenchymal origin in human cancers and chronic inflammatory lesions. In mouse models of cancer, they have been shown to be immune suppressive, but studies of their occurrence and function in normal tissues have been limited. With a transgenic mouse line permitting the bioluminescent imaging of FAP(+) cells, we find that they reside in most tissues of the adult mouse. FAP(+) cells from three sites, skeletal muscle, adipose tissue, and pancreas, have highly similar transcriptomes, suggesting a shared lineage. FAP(+) cells of skeletal muscle are the major local source of follistatin, and in bone marrow they express Cxcl12 and KitL. Experimental ablation of these cells causes loss of muscle mass and a reduction of B-lymphopoiesis and erythropoiesis, revealing their essential functions in maintaining normal muscle mass and hematopoiesis, respectively. Remarkably, these cells are altered at these sites in transplantable and spontaneous mouse models of cancer-induced cachexia and anemia. Thus, the FAP(+) stromal cell may have roles in two adverse consequences of cancer: their acquisition by tumors may cause failure of immunosurveillance, and their alteration in normal tissues contributes to the paraneoplastic syndromes of cachexia and anemia.
Assuntos
Anemia/metabolismo , Medula Óssea/metabolismo , Caquexia/metabolismo , Gelatinases/genética , Gelatinases/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Músculo Esquelético/metabolismo , Serina Endopeptidases/genética , Serina Endopeptidases/metabolismo , Células Estromais/metabolismo , Tecido Adiposo/metabolismo , Anemia/genética , Anemia/patologia , Animais , Caquexia/genética , Caquexia/patologia , Linhagem da Célula/genética , Quimiocina CXCL12/genética , Quimiocina CXCL12/metabolismo , Endopeptidases , Eritropoese/genética , Folistatina/genética , Folistatina/metabolismo , Hematopoese/genética , Linfopoese/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos/genética , Camundongos Transgênicos/metabolismo , Músculo Esquelético/citologia , Transtornos Musculares Atróficos/genética , Transtornos Musculares Atróficos/metabolismo , Neoplasias/genética , Neoplasias/metabolismo , Pâncreas/metabolismo , Células Estromais/citologia , Transcriptoma/genéticaRESUMO
BACKGROUND: The R project includes a large variety of packages designed for spatial statistics. Google dynamic maps provide web based access to global maps and satellite imagery. We describe a method for displaying directly the spatial output from an R script on to a Google dynamic map. METHODS: This is achieved by creating a Java based web application which runs the R script and then displays the results on the dynamic map. In order to make this method easy to implement by those unfamiliar with programming Java based web applications, we have added the method to the options available in the R Web User Interface (Rwui) application. Rwui is an established web application for creating web applications for running R scripts. A feature of Rwui is that all the code for the web application being created is generated automatically so that someone with no knowledge of web programming can make a fully functional web application for running an R script in a matter of minutes. RESULTS: Rwui can now be used to create web applications that will display the results from an R script on a Google dynamic map. Results may be displayed as discrete markers and/or as continuous overlays. In addition, users of the web application may select regions of interest on the dynamic map with mouse clicks and the coordinates of the region of interest will automatically be made available for use by the R script. CONCLUSIONS: This method of displaying R output on dynamic maps is designed to be of use in a number of areas. Firstly it allows statisticians, working in R and developing methods in spatial statistics, to easily visualise the results of applying their methods to real world data. Secondly, it allows researchers who are using R to study health geographics data, to display their results directly onto dynamic maps. Thirdly, by creating a web application for running an R script, a statistician can enable users entirely unfamiliar with R to run R coded statistical analyses of health geographics data. Fourthly, we envisage an educational role for such applications.