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1.
Mol Cell ; 81(7): 1469-1483.e8, 2021 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-33609448

RESUMEN

We demonstrate that DNA hypomethylating agent (HMA) treatment can directly modulate the anti-tumor response and effector function of CD8+ T cells. In vivo HMA treatment promotes CD8+ T cell tumor infiltration and suppresses tumor growth via CD8+ T cell-dependent activity. Ex vivo, HMAs enhance primary human CD8+ T cell activation markers, effector cytokine production, and anti-tumor cytolytic activity. Epigenomic and transcriptomic profiling shows that HMAs vastly regulate T cell activation-related transcriptional networks, culminating with over-activation of NFATc1 short isoforms. Mechanistically, demethylation of an intragenic CpG island immediately downstream to the 3' UTR of the short isoform was associated with antisense transcription and alternative polyadenylation of NFATc1 short isoforms. High-dimensional single-cell mass cytometry analyses reveal a selective effect of HMAs on a subset of human CD8+ T cell subpopulations, increasing both the number and abundance of a granzyme Bhigh, perforinhigh effector subpopulation. Overall, our findings support the use of HMAs as a therapeutic strategy to boost anti-tumor immune response.


Asunto(s)
Linfocitos T CD8-positivos/inmunología , Islas de CpG/inmunología , Metilación de ADN/efectos de los fármacos , Decitabina/farmacología , Granzimas/inmunología , Activación de Linfocitos/efectos de los fármacos , Metilación de ADN/inmunología , Humanos , Factores de Transcripción NFATC/inmunología , Perforina/inmunología
2.
Environ Microbiol ; 24(11): 5534-5545, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36100999

RESUMEN

Cold surface sediments host a seedbank of functionally diverse thermophilic bacteria. These thermophiles are present as endospores, which are widely dispersed in aquatic environments. Here, we investigated the functional potential of endospore populations in cold surface sediments heated to 80°C. Microbial production of acetate was observed at 80°C and could be enhanced by supplying additional organic carbon substrates. Comparison of 16S rRNA gene amplicon libraries from 80°C enrichments to sediments heated to lower temperatures (50-70°C) showed that temperature selects for distinct populations of endospore-forming bacteria. Whereas sulfate-reducing thermophiles were enriched in 50-70°C incubations, 80°C exceeds their thermal tolerance and selects for hyperthermophilic organotrophic bacteria that are similarly detected in amplicon libraries from sediments heated to 90°C. Genome-resolved metagenomics revealed novel carbon cycling members of Symbiobacteriales, Thermosediminibacteraceae, Thermanaeromonas and Calditerricola with the genomic potential for the degradation of carbohydrates, sugars, amino acids and nucleotides. Endospores of thermophilic bacteria are deposited on seabed sediments worldwide where they remain dormant as they are buried in the accumulating sediments. Our results suggest that endospore populations could be activated by temperature increases encountered during burial and show the potential for organotrophic metabolic activity contributing to acetate generation in deep hot sediments.


Asunto(s)
Carbono , Sedimentos Geológicos , ARN Ribosómico 16S/genética , Sedimentos Geológicos/microbiología , Archaea/genética , Esporas Bacterianas/genética , Bacterias Anaerobias/genética , Firmicutes/genética
3.
Nature ; 526(7575): 700-4, 2015 Oct 29.
Artículo en Inglés | MEDLINE | ID: mdl-26466568

RESUMEN

Neuroblastoma is a malignant paediatric tumour of the sympathetic nervous system. Roughly half of these tumours regress spontaneously or are cured by limited therapy. By contrast, high-risk neuroblastomas have an unfavourable clinical course despite intensive multimodal treatment, and their molecular basis has remained largely elusive. Here we have performed whole-genome sequencing of 56 neuroblastomas (high-risk, n = 39; low-risk, n = 17) and discovered recurrent genomic rearrangements affecting a chromosomal region at 5p15.33 proximal of the telomerase reverse transcriptase gene (TERT). These rearrangements occurred only in high-risk neuroblastomas (12/39, 31%) in a mutually exclusive fashion with MYCN amplifications and ATRX mutations, which are known genetic events in this tumour type. In an extended case series (n = 217), TERT rearrangements defined a subgroup of high-risk tumours with particularly poor outcome. Despite a large structural diversity of these rearrangements, they all induced massive transcriptional upregulation of TERT. In the remaining high-risk tumours, TERT expression was also elevated in MYCN-amplified tumours, whereas alternative lengthening of telomeres was present in neuroblastomas without TERT or MYCN alterations, suggesting that telomere lengthening represents a central mechanism defining this subtype. The 5p15.33 rearrangements juxtapose the TERT coding sequence to strong enhancer elements, resulting in massive chromatin remodelling and DNA methylation of the affected region. Supporting a functional role of TERT, neuroblastoma cell lines bearing rearrangements or amplified MYCN exhibited both upregulated TERT expression and enzymatic telomerase activity. In summary, our findings show that remodelling of the genomic context abrogates transcriptional silencing of TERT in high-risk neuroblastoma and places telomerase activation in the centre of transformation in a large fraction of these tumours.


Asunto(s)
Regulación Neoplásica de la Expresión Génica/genética , Genoma Humano/genética , Neuroblastoma/genética , Neuroblastoma/patología , Recombinación Genética/genética , Telomerasa/genética , Telomerasa/metabolismo , Línea Celular Tumoral , Transformación Celular Neoplásica/genética , Cromatina/genética , Cromatina/metabolismo , Cromosomas Humanos Par 5/genética , ADN Helicasas/genética , Metilación de ADN , Elementos de Facilitación Genéticos/genética , Activación Enzimática/genética , Amplificación de Genes/genética , Silenciador del Gen , Humanos , Lactante , Proteína Proto-Oncogénica N-Myc , Neuroblastoma/clasificación , Neuroblastoma/enzimología , Proteínas Nucleares/genética , Proteínas Oncogénicas/genética , Pronóstico , ARN Mensajero/análisis , ARN Mensajero/genética , Riesgo , Translocación Genética/genética , Regulación hacia Arriba/genética , Proteína Nuclear Ligada al Cromosoma X
4.
Environ Microbiol ; 22(1): 456-465, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31742859

RESUMEN

Thermophilic endospores are widespread in cold marine sediments where the temperature is too low to support growth and activity of thermophiles in situ. These endospores are likely expelled from warm subsurface environments and subsequently dispersed by ocean currents. The endospore upper temperature limit for survival is 140°C, which can be tolerated in repeated short exposures, potentially enabling transit through hot crustal fluids. Longer-term thermal tolerance of endospores, and how long they could persist in an environment hotter than their maximum growth temperature, is less understood. To test whether thermophilic endospores can survive prolonged exposure to high temperatures, sediments were incubated at 80-90°C for 6, 12 or 463 days. Sediments were then cooled by 10-40°C, mimicking the cooling in subsurface oil reservoirs subjected to seawater injection. Cooling the sediments induced sulfate reduction, coinciding with an enrichment of endospore-forming Clostridia. Different Desulfofundulus, Desulfohalotomaculum, Desulfallas, Desulfotomaculum and Desulfofarcimen demonstrated different thermal tolerances, with some Desulfofundulus strains surviving for >1 year at 80°C. In an oil reservoir context, heat-resistant endospore-forming sulfate-reducing bacteria have a survival advantage if they are introduced to, or are resident in, an oil reservoir normally too hot for germination and growth, explaining observations of reservoir souring following cold seawater injection.


Asunto(s)
Clostridiaceae/metabolismo , Sedimentos Geológicos/microbiología , Peptococcaceae/metabolismo , Agua de Mar/microbiología , Sulfatos/metabolismo , Archaea , Clostridiaceae/clasificación , Clostridiaceae/genética , Frío , Calor , Oxidación-Reducción , Peptococcaceae/clasificación , Peptococcaceae/genética , Filogenia , Esporas Bacterianas/genética , Esporas Bacterianas/crecimiento & desarrollo
5.
Development ; 144(4): 567-579, 2017 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-28087629

RESUMEN

Jmjd2 H3K9 demethylases cooperate in promoting mouse embryonic stem cell (ESC) identity. However, little is known about their importance at the exit of ESC pluripotency. Here, we reveal that Jmjd2c facilitates this process by stabilising the assembly of mediator-cohesin complexes at lineage-specific enhancers. Functionally, we show that Jmjd2c is required in ESCs to initiate appropriate gene expression programs upon somatic multi-lineage differentiation. In the absence of Jmjd2c, differentiation is stalled at an early post-implantation epiblast-like stage, while Jmjd2c-knockout ESCs remain capable of forming extra-embryonic endoderm derivatives. Dissection of the underlying molecular basis revealed that Jmjd2c is re-distributed to lineage-specific enhancers during ESC priming for differentiation. Interestingly, Jmjd2c-bound enhancers are co-occupied by the H3K9-methyltransferase G9a (also known as Ehmt2), independently of its H3K9-modifying activity. Loss of Jmjd2c abrogates G9a recruitment and further destabilises loading of the mediator and cohesin components Med1 and Smc1a at newly activated and poised enhancers in ESC-derived epiblast-like cells. These findings unveil Jmjd2c and G9a as novel enhancer-associated factors, and implicate Jmjd2c as a molecular scaffold for the assembly of essential enhancer-protein complexes with an impact on timely gene activation.


Asunto(s)
Células Madre Embrionarias/citología , Elementos de Facilitación Genéticos , N-Metiltransferasa de Histona-Lisina/fisiología , Histona Demetilasas con Dominio de Jumonji/fisiología , Animales , Proteínas de Ciclo Celular/fisiología , Diferenciación Celular , Linaje de la Célula , Proteínas Cromosómicas no Histona/fisiología , Perfilación de la Expresión Génica , Regulación del Desarrollo de la Expresión Génica , Estratos Germinativos/citología , Histonas/metabolismo , Ratones , Ratones Noqueados , Células Madre Pluripotentes/citología , Unión Proteica , Análisis de Secuencia de ARN , Cohesinas
6.
Environ Microbiol ; 20(3): 1134-1147, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29393553

RESUMEN

Endospores of thermophilic bacteria are found in cold and temperate sediments where they persist in a dormant state. As inactive endospores that cannot grow at the low ambient temperatures, they are akin to tracer particles in cold sediments, unaffected by factors normally governing microbial biogeography (e.g., selection, drift, mutation). This makes thermophilic endospores ideal model organisms for studying microbial biogeography since their spatial distribution can be directly related to their dispersal history. To assess dispersal histories of estuarine bacteria, thermophilic endospores were enriched from sediments along a freshwater-to-marine transect of the River Tyne in high temperature incubations (50°C). Dispersal histories for 75 different taxa indicated that the majority of estuarine endospores were of terrestrial origin; most closely related to bacteria from warm habitats associated with industrial activity. A subset of the taxa detected were marine derived, with close relatives from hot deep marine biosphere habitats. These patterns are consistent with the sources of sediment in the River Tyne being predominantly terrestrial in origin. The results point to microbial communities in estuarine and marine sediments being structured by bi-directional currents, terrestrial run-off and industrial effluent as vectors of passive dispersal and immigration.


Asunto(s)
Bacterias/aislamiento & purificación , Sedimentos Geológicos/microbiología , Ríos/microbiología , Esporas Bacterianas/aislamiento & purificación , Bacterias/clasificación , Bacterias/genética , Frío , Estuarios , Calor , Microbiota
7.
Br J Cancer ; 114(2): 151-62, 2016 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-26671749

RESUMEN

BACKGROUND: The current biomarkers alpha-fetoprotein and human chorionic gonadotropin have limited sensitivity and specificity for diagnosing malignant germ-cell tumours (GCTs). MicroRNAs (miRNAs) from the miR-371-373 and miR-302/367 clusters are overexpressed in all malignant GCTs, and some of these miRNAs show elevated serum levels at diagnosis. Here, we developed a robust technical pipeline to quantify these miRNAs in the serum and cerebrospinal fluid (CSF). The pipeline was used in samples from a cohort of exclusively paediatric patients with gonadal and extragonadal malignant GCTs, compared with appropriate tumour and non-tumour control groups. METHODS: We developed a method for miRNA quantification that enabled sample adequacy assessment and reliable data normalisation. We performed qRT-PCR profiling for miR-371-373 and miR-302/367 cluster miRNAs in a total of 45 serum and CSF samples, obtained from 25 paediatric patients. RESULTS: The exogenous non-human spike-in cel-miR-39-3p and the endogenous housekeeper miR-30b-5p were optimal for obtaining robust serum and CSF qRT-PCR quantification. A four-serum miRNA panel (miR-371a-3p, miR-372-3p, miR-373-3p and miR-367-3p): (i) showed high sensitivity/specificity for diagnosing paediatric extracranial malignant GCT; (ii) allowed early detection of relapse of a testicular mixed malignant GCT; and (iii) distinguished intracranial malignant GCT from intracranial non-GCT tumours at diagnosis, using CSF and serum samples. CONCLUSIONS: The pipeline we have developed is robust, scalable and transferable. It potentially promises to improve clinical management of paediatric (and adult) malignant GCTs.


Asunto(s)
Biomarcadores de Tumor/sangre , Neoplasias del Sistema Nervioso Central/diagnóstico , MicroARNs/sangre , Recurrencia Local de Neoplasia/diagnóstico , Neoplasias de Células Germinales y Embrionarias/diagnóstico , Neoplasias Ováricas/diagnóstico , Neoplasias Testiculares/diagnóstico , Adolescente , Biomarcadores de Tumor/líquido cefalorraquídeo , Carcinoma Embrionario/sangre , Carcinoma Embrionario/líquido cefalorraquídeo , Carcinoma Embrionario/diagnóstico , Neoplasias del Sistema Nervioso Central/sangre , Neoplasias del Sistema Nervioso Central/líquido cefalorraquídeo , Niño , Preescolar , Coriocarcinoma no Gestacional/sangre , Coriocarcinoma no Gestacional/líquido cefalorraquídeo , Coriocarcinoma no Gestacional/diagnóstico , Gonadotropina Coriónica/sangre , Gonadotropina Coriónica/líquido cefalorraquídeo , Tumor del Seno Endodérmico/sangre , Tumor del Seno Endodérmico/líquido cefalorraquídeo , Tumor del Seno Endodérmico/diagnóstico , Femenino , Germinoma/sangre , Germinoma/líquido cefalorraquídeo , Germinoma/diagnóstico , Humanos , Lactante , Recién Nacido , Masculino , MicroARNs/líquido cefalorraquídeo , Recurrencia Local de Neoplasia/sangre , Recurrencia Local de Neoplasia/líquido cefalorraquídeo , Neoplasias de Células Germinales y Embrionarias/sangre , Neoplasias de Células Germinales y Embrionarias/líquido cefalorraquídeo , Neoplasias Ováricas/sangre , Neoplasias Ováricas/líquido cefalorraquídeo , Reacción en Cadena de la Polimerasa , Región Sacrococcígea , Sensibilidad y Especificidad , Neoplasias Testiculares/sangre , Neoplasias Testiculares/líquido cefalorraquídeo , alfa-Fetoproteínas/líquido cefalorraquídeo , alfa-Fetoproteínas/metabolismo
8.
BMC Cancer ; 15: 337, 2015 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-25927974

RESUMEN

BACKGROUND: DNA methylation variability regions (MVRs) across the oestrogen receptor alpha (ESR1) gene have been identified in peripheral blood cells from breast cancer patients and healthy individuals. In contrast to promoter methylation, gene body methylation may be important in maintaining active transcription. This study aimed to assess MVRs in ESR1 in breast cancer cell lines, tumour biopsies and exfoliated epithelial cells from expressed breast milk (EBM), to determine their significance for ESR1 transcription. METHODS: DNA methylation levels in eight MVRs across ESR1 were assessed by pyrosequencing bisulphite-converted DNA from three oestrogen receptor (ER)-positive and three ER-negative breast cancer cell lines. DNA methylation and expression were assessed following treatment with DAC (1 µM), or DMSO (controls). ESR1 methylation levels were also assayed in DNA from 155 invasive ductal carcinoma biopsies provided by the Breast Cancer Campaign Tissue Bank, and validated with DNA methylation profiles from the TCGA breast tumours (n = 356 ER-pos, n = 109 ER-neg). DNA methylation was profiled in exfoliated breast epithelial cells from EBM using the Illumina 450 K (n = 36) and pyrosequencing in a further 53 donor samples. ESR1 mRNA levels were measured by qRT-PCR. RESULTS: We show that ER-positive cell lines had unmethylated ESR1 promoter regions and highly methylated intragenic regions (median, 80.45%) while ER-negative cells had methylated promoters and lower intragenic methylation levels (median, 38.62%). DAC treatment increased ESR1 expression in ER-negative cells, but significantly reduced methylation and expression of ESR1 in ER-positive cells. The ESR1 promoter was unmethylated in breast tumour biopsies with high levels of intragenic methylation, independent of ER status. However, ESR1 methylation in the strongly ER-positive EBM DNA samples were very similar to ER-positive tumour cell lines. CONCLUSION: DAC treatment inhibited ESR1 transcription in cells with an unmethylated ESR1 promoter and reduced intragenic DNA methylation. Intragenic methylation levels correlated with ESR1 expression in homogenous cell populations (cell lines and exfoliated primary breast epithelial cells), but not in heterogeneous tumour biopsies, highlighting the significant differences between the in vivo tumour microenvironment and individual homogenous cell types. These findings emphasise the need for care when choosing material for epigenetic research and highlights the presence of aberrant intragenic methylation levels in tumour tissue.


Asunto(s)
Neoplasias de la Mama/genética , Carcinoma Ductal de Mama/genética , Receptor alfa de Estrógeno/genética , Regiones Promotoras Genéticas , Neoplasias de la Mama/metabolismo , Carcinoma Ductal de Mama/metabolismo , Línea Celular Tumoral , Metilación de ADN , Epigénesis Genética , Receptor alfa de Estrógeno/metabolismo , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Glándulas Mamarias Humanas/metabolismo , Leche Humana/citología , Análisis de Secuencia de ADN , Transcripción Genética
9.
Pediatr Blood Cancer ; 61(9): 1711-3, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24803179

RESUMEN

Neuroblastoma is an embryonal malignancy of the developing neural crest. Despite improvements in treatment, prognoses remain dire for patients with high-risk disease. Interest in this enigmatic cancer has led to a rapidly changing research landscape and we report on the recent advances in four themes that were discussed at the 3rd Neuroblastoma Research Symposium: (1) The epigenetic signature of neuroblastoma and the epigenetic control of tumour development, (2) novel approaches to targeting MYCN, (3) valuable in vivo modelling and (4) improving differentiation therapies based on a knowledge of normal sympathetic neuron development. Through lively discussion, the development of combined therapies with synergistic effects for which we have a good mechanistic understanding emerged as offering greatest promise. Drug synergies enhance efficacy but also specificity, the latter crucial for reducing long-term side effects in young children.


Asunto(s)
Investigación Biomédica , Congresos como Asunto , Neuroblastoma/terapia , Epigénesis Genética , Humanos , Neuroblastoma/diagnóstico , Neuroblastoma/genética
10.
J Bacteriol ; 195(21): 4924-35, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23995638

RESUMEN

The genome sequences of eight Streptomyces phages are presented, four of which were isolated for this study. Phages R4, TG1, Hau3, and SV1 were isolated previously and have been exploited as tools for understanding and genetically manipulating Streptomyces spp. We also extracted five apparently intact prophages from recent Streptomyces spp. genome projects and, together with six phage genomes in the database, we analyzed all 19 Streptomyces phage genomes with a view to understanding their relationships to each other and to other actinophages, particularly the mycobacteriophages. Fifteen of the Streptomyces phages group into four clusters of related genomes. Although the R4-like phages do not share nucleotide sequence similarity with other phages, they clearly have common ancestry with cluster A mycobacteriophages, sharing many protein homologues, common gene syntenies, and similar repressor-stoperator regulatory systems. The R4-like phage Hau3 and the prophage StrepC.1 (from Streptomyces sp. strain C) appear to have hijacked a unique adaptation of the streptomycetes, i.e., use of the rare UUA codon, to control translation of the essential phage protein, the terminase. The Streptomyces venezuelae generalized transducing phage SV1 was used to predict the presence of other generalized transducing phages for different Streptomyces species.


Asunto(s)
Bacteriófagos/genética , Bacteriófagos/fisiología , Evolución Biológica , Streptomyces/virología , Adaptación Fisiológica , Secuencia de Aminoácidos , Secuencia de Bases , Regulación Viral de la Expresión Génica/fisiología , Genoma Viral , Datos de Secuencia Molecular , Profagos/genética , Profagos/metabolismo , Especificidad de la Especie , Streptomyces/clasificación , Proteínas Virales/genética , Proteínas Virales/metabolismo
11.
Am J Chin Med ; 51(6): 1577-1594, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37465963

RESUMEN

Colorectal cancer (CRC) is a leading cause of cancer-related death in the United States, and chronic gut inflammation is a risk factor for CRC initiation and development. Curcuma longa L., or turmeric, has become one of the most studied herbal medicines in recent years due to its anticancer potentials. It is generally accepted that the major component in turmeric is curcuminoids, and the active constituent in curcuminoids is curcumin. However, unprocessed curcumin is characterized by poor water solubility, which means low bioavailability in humans. To increase the bioavailability of curcumin, in this study, we utilized a novel surfactant-formulated curcumin (CuminUP60[Formula: see text]) and evaluated its CRC chemopreventive activities. Compared with the chemo-sensitive CRC cell line HCT-116, the management of the CRC SW-480 cell line is a challenge, since the latter is chemo-resistant. In other words, these cancer cells resist the effects of the chemotherapy. Using the newly formulated CuminUP60[Formula: see text] water solution, this study demonstrated its strong antiproliferative effects on the SW-480 cells in a dose- and time-dependent manner. This new formulation induced early apoptosis and arrested the cell cycle in the G2/M phase via the upregulation of cyclin B1. We also observed that this new formulation possessed inhibitory effects on Th17 cell differentiation, which regulates the body's immune response against gut malignancies. In summary, our results exhibited a potential clinical utility of the surfactant-formulated curcumin in chemo-resistant colorectal cancer management.


Asunto(s)
Neoplasias Colorrectales , Curcumina , Humanos , Curcumina/farmacología , Diarilheptanoides , Tensoactivos , Curcuma , Neoplasias Colorrectales/tratamiento farmacológico , Agua
12.
J Bus Ethics ; 178(3): 597-608, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-33840869

RESUMEN

Posthuman affirmative ethics relies upon a fluid, nomadic conception of the ethical subject who develops affective, material and immaterial connections to multiple others. Our purpose in this paper is to consider what posthuman affirmative business ethics would look like, and to reflect on the shift in thinking and practice this would involve. The need for a revised understanding of human-animal relations in business ethics is amplified by crises such as climate change and pandemics that are related to ecologically destructive business practices such as factory farming. In this analysis, we use feminist speculative fiction as a resource for reimagination and posthuman ethical thinking. By focusing on three ethical movements experienced by a central character named Toby in Margaret Atwood's MaddAddam trilogy, we show how she is continually becoming through affective, embodied encounters with human and nonhuman others. In the discussion, we consider the vulnerability that arises from openness to affect which engenders heightened response-ability to and with, rather than for, multiple others. This expanded concept of subjectivity enables a more relational understanding of equality that is urgently needed in order to respond affirmatively to posthuman futures.

13.
ISME J ; 16(6): 1583-1593, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35173296

RESUMEN

Microbial life is widespread in the terrestrial subsurface and present down to several kilometers depth, but the energy sources that fuel metabolism in deep oligotrophic and anoxic environments remain unclear. In the deep crystalline bedrock of the Fennoscandian Shield at Olkiluoto, Finland, opposing gradients of abiotic methane and ancient seawater-derived sulfate create a terrestrial sulfate-methane transition zone (SMTZ). We used chemical and isotopic data coupled to genome-resolved metaproteogenomics to demonstrate active life and, for the first time, provide direct evidence of active anaerobic oxidation of methane (AOM) in a deep terrestrial bedrock. Proteins from Methanoperedens (formerly ANME-2d) are readily identifiable despite the low abundance (≤1%) of this genus and confirm the occurrence of AOM. This finding is supported by 13C-depleted dissolved inorganic carbon. Proteins from Desulfocapsaceae and Desulfurivibrionaceae, in addition to 34S-enriched sulfate, suggest that these organisms use inorganic sulfur compounds as both electron donor and acceptor. Zerovalent sulfur in the groundwater may derive from abiotic rock interactions, or from a non-obligate syntrophy with Methanoperedens, potentially linking methane and sulfur cycles in Olkiluoto groundwater. Finally, putative episymbionts from the candidate phyla radiation (CPR) and DPANN archaea represented a significant diversity in the groundwater (26/84 genomes) with roles in sulfur and carbon cycling. Our results highlight AOM and sulfur disproportionation as active metabolisms and show that methane and sulfur fuel microbial activity in the deep terrestrial subsurface.


Asunto(s)
Archaea , Metano , Anaerobiosis , Archaea/metabolismo , Carbono/metabolismo , Sedimentos Geológicos , Metano/metabolismo , Methanosarcinales/metabolismo , Oxidación-Reducción , Filogenia , Sulfatos/metabolismo , Azufre/metabolismo
14.
Nat Cancer ; 3(4): 471-485, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35484422

RESUMEN

Aberrant expression of MYC transcription factor family members predicts poor clinical outcome in many human cancers. Oncogenic MYC profoundly alters metabolism and mediates an antioxidant response to maintain redox balance. Here we show that MYCN induces massive lipid peroxidation on depletion of cysteine, the rate-limiting amino acid for glutathione (GSH) biosynthesis, and sensitizes cells to ferroptosis, an oxidative, non-apoptotic and iron-dependent type of cell death. The high cysteine demand of MYCN-amplified childhood neuroblastoma is met by uptake and transsulfuration. When uptake is limited, cysteine usage for protein synthesis is maintained at the expense of GSH triggering ferroptosis and potentially contributing to spontaneous tumor regression in low-risk neuroblastomas. Pharmacological inhibition of both cystine uptake and transsulfuration combined with GPX4 inactivation resulted in tumor remission in an orthotopic MYCN-amplified neuroblastoma model. These findings provide a proof of concept of combining multiple ferroptosis targets as a promising therapeutic strategy for aggressive MYCN-amplified tumors.


Asunto(s)
Ferroptosis , Neuroblastoma , Muerte Celular , Niño , Cisteína/uso terapéutico , Ferroptosis/genética , Glutatión/uso terapéutico , Humanos , Proteína Proto-Oncogénica N-Myc/genética , Neuroblastoma/genética
15.
Nat Commun ; 12(1): 4253, 2021 07 12.
Artículo en Inglés | MEDLINE | ID: mdl-34253732

RESUMEN

While oligotrophic deep groundwaters host active microbes attuned to the low-end of the bioenergetics spectrum, the ecological constraints on microbial niches in these ecosystems and their consequences for microbiome convergence are unknown. Here, we provide a genome-resolved, integrated omics analysis comparing archaeal and bacterial communities in disconnected fracture fluids of the Fennoscandian Shield in Europe. Leveraging a dataset that combines metagenomes, single cell genomes, and metatranscriptomes, we show that groundwaters flowing in similar lithologies offer fixed niches that are occupied by a common core microbiome. Functional expression analysis highlights that these deep groundwater ecosystems foster diverse, yet cooperative communities adapted to this setting. We suggest that these communities stimulate cooperation by expression of functions related to ecological traits, such as aggregate or biofilm formation, while alleviating the burden on microorganisms producing compounds or functions that provide a collective benefit by facilitating reciprocal promiscuous metabolic partnerships with other members of the community. We hypothesize that an episodic lifestyle enabled by reversible bacteriostatic functions ensures the subsistence of the oligotrophic deep groundwater microbiome.


Asunto(s)
Metabolismo Energético , Agua Subterránea/microbiología , Microbiota , Biodiversidad , Bases de Datos Genéticas , Regulación de la Expresión Génica , Punto Isoeléctrico , Metagenoma , Microbiota/genética , Filogenia , Transcripción Genética , Transcriptoma/genética
16.
Front Microbiol ; 12: 764058, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-35069469

RESUMEN

Many pathways for hydrocarbon degradation have been discovered, yet there are no dedicated tools to identify and predict the hydrocarbon degradation potential of microbial genomes and metagenomes. Here we present the Calgary approach to ANnoTating HYDrocarbon degradation genes (CANT-HYD), a database of 37 HMMs of marker genes involved in anaerobic and aerobic degradation pathways of aliphatic and aromatic hydrocarbons. Using this database, we identify understudied or overlooked hydrocarbon degradation potential in many phyla. We also demonstrate its application in analyzing high-throughput sequence data by predicting hydrocarbon utilization in large metagenomic datasets from diverse environments. CANT-HYD is available at https://github.com/dgittins/CANT-HYD-HydrocarbonBiodegradation.

17.
ISME J ; 14(5): 1260-1272, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32047278

RESUMEN

The deep terrestrial subsurface remains an environment where there is limited understanding of the extant microbial metabolisms. At Olkiluoto, Finland, a deep geological repository is under construction for the final storage of spent nuclear fuel. It is therefore critical to evaluate the potential impact microbial metabolism, including sulfide generation, could have upon the safety of the repository. We investigated a deep groundwater where sulfate is present, but groundwater geochemistry suggests limited microbial sulfate-reducing activity. Examination of the microbial community at the genome-level revealed microorganisms with the metabolic capacity for both oxidative and reductive sulfur transformations. Deltaproteobacteria are shown to have the genetic capacity for sulfate reduction and possibly sulfur disproportionation, while Rhizobiaceae, Rhodocyclaceae, Sideroxydans, and Sulfurimonas oxidize reduced sulfur compounds. Further examination of the proteome confirmed an active sulfur cycle, serving for microbial energy generation and growth. Our results reveal that this sulfide-poor groundwater harbors an active microbial community of sulfate-reducing and sulfide-oxidizing bacteria, together mediating a sulfur cycle that remained undetected by geochemical monitoring alone. The ability of sulfide-oxidizing bacteria to limit the accumulation of sulfide was further demonstrated in groundwater incubations and highlights a potential sink for sulfide that could be beneficial for geological repository safety.


Asunto(s)
Agua Subterránea/microbiología , Azufre/metabolismo , Bacterias/metabolismo , Finlandia , Microbiota , Oxidación-Reducción , Sulfatos/metabolismo , Sulfuros/metabolismo
18.
Nat Commun ; 11(1): 1112, 2020 02 28.
Artículo en Inglés | MEDLINE | ID: mdl-32111830

RESUMEN

Clusters of enhancers, referred as to super-enhancers (SEs), control the expression of cell identity genes. The organisation of these clusters, and how they are remodelled upon developmental transitions remain poorly understood. Here, we report the existence of two types of enhancer units within SEs typified by distinctive CpG methylation dynamics in embryonic stem cells (ESCs). We find that these units are either prone for decommissioning or remain constitutively active in epiblast stem cells (EpiSCs), as further established in the peri-implantation epiblast in vivo. Mechanistically, we show a pivotal role for ESRRB in regulating the activity of ESC-specific enhancer units and propose that the developmentally regulated silencing of ESRRB triggers the selective inactivation of these units within SEs. Our study provides insights into the molecular events that follow the loss of ESRRB binding, and offers a mechanism by which the naive pluripotency transcriptional programme can be partially reset upon embryo implantation.


Asunto(s)
Islas de CpG , Metilación de ADN , Elementos de Facilitación Genéticos/genética , Células Madre Pluripotentes/metabolismo , Receptores de Estrógenos/metabolismo , Animales , Regulación del Desarrollo de la Expresión Génica , Estratos Germinativos/citología , Complejo Mediador/metabolismo , Ratones , Células Madre Embrionarias de Ratones/metabolismo , Unión Proteica , ARN Polimerasa II/metabolismo , Transcripción Genética
19.
J Antimicrob Chemother ; 64(1): 181-7, 2009 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-19411678

RESUMEN

OBJECTIVES: The long elimination half-life of teicoplanin facilitates outpatient parenteral antibiotic therapy (OPAT) with thrice-weekly dosing. This study aimed to develop teicoplanin dosage guidelines for OPAT use from routine clinical data. METHODS: Patients received 15-25 mg/kg/day for 3 days, then 15-25 mg/kg thrice weekly. Trough concentrations were measured weekly and doses adjusted to maintain 20-30 or 10-20 mg/L according to clinical condition. Concentration-time data were analysed using the pharmacokinetic package NONMEM and the final model was used to develop new dosage guidelines. RESULTS: Data from 94 and 36 patients were used for model development and validation, respectively. Patient ages ranged from 15 to 94 years, weights from 43 to 146 kg and estimated CL(CR) from 9 to 195 mL/min. Teicoplanin concentrations (n = 670) ranged from 6.7 to 66.9 mg/L and a one-compartment model adequately described the data. The typical estimate of CL was 0.542 L/h and changed by 10.6% for every 10 mL/min difference from a CL(CR) of 66 mL/min. V was 1.62 L/kg. Dosage guidelines based on body weight and CL(CR) can be expected to lead to a significant improvement in the proportion of concentrations in the range 20-30 mg/L. Alternative doses aimed at lower target concentrations have also been developed. CONCLUSIONS: New dosage guidelines have been developed to support thrice-weekly administration of teicoplanin in an OPAT setting.


Asunto(s)
Antibacterianos/administración & dosificación , Antibacterianos/farmacocinética , Infecciones Bacterianas/tratamiento farmacológico , Teicoplanina/administración & dosificación , Teicoplanina/farmacocinética , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Monitoreo de Drogas , Femenino , Humanos , Inyecciones Intravenosas , Masculino , Persona de Mediana Edad , Pacientes Ambulatorios , Plasma/química , Adulto Joven
20.
Stem Cell Res Ther ; 10(1): 122, 2019 04 18.
Artículo en Inglés | MEDLINE | ID: mdl-30999923

RESUMEN

BACKGROUND: Sox2 is a well-established pluripotent transcription factor that plays an essential role in establishing and maintaining pluripotent stem cells (PSCs). It is also thought to be a linage specifier that governs PSC neural lineage specification upon their exiting the pluripotent state. However, the exact role of SOX2 in human PSCs was still not fully understood. In this study, we studied the role of SOX2 in human embryonic stem cells (hESCs) by gain- and loss-of-function approaches and explored the possible underlying mechanisms. RESULTS: We demonstrate that knockdown of SOX2 induced hESC differentiation to endoderm-like cells, whereas overexpression of SOX2 in hESCs enhanced their pluripotency under self-renewing culture conditions but promoted their neural differentiation upon replacing the culture to non-self-renewal conditions. We show that this culture-dependent dual function of SOX2 was probably attributed to its interaction with different transcription factors predisposed by the culture environments. Whilst SOX2 interacts with OCT4 under self-renewal conditions, we found that, upon neural differentiation, PAX6, a key neural transcription factor, is upregulated and shows interaction with SOX2. The SOX2-PAX6 complex has different gene regulation pattern from that of SOX2-OCT4 complex. CONCLUSIONS: Our work provides direct evidence that SOX2 is necessarily required for hESC pluripotency; however, it can also function as a neural factor, depending on the environmental input. OCT4 and PAX6 might function as key SOX2-interacting partners that determine the function of SOX2 in hESCs.


Asunto(s)
Diferenciación Celular , Células Madre Embrionarias Humanas/metabolismo , Factor 3 de Transcripción de Unión a Octámeros/metabolismo , Factor de Transcripción PAX6/metabolismo , Factores de Transcripción SOXB1/metabolismo , Línea Celular , Células Madre Embrionarias Humanas/citología , Humanos , Células-Madre Neurales/citología
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