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1.
Mol Cell ; 83(2): 266-280.e6, 2023 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-36638783

RESUMEN

Tumor suppression by TP53 involves cell-autonomous and non-cell-autonomous mechanisms. TP53 can suppress tumor growth by modulating immune system functions; however, the mechanistic basis for this activity is not well understood. We report that p53 promotes the degradation of the DNA exonuclease TREX1, resulting in cytosolic dsDNA accumulation. We demonstrate that p53 requires the ubiquitin ligase TRIM24 to induce TREX1 degradation. The cytosolic DNA accumulation resulting from TREX1 degradation activates the cytosolic DNA-sensing cGAS/STING pathway, resulting in induction of type I interferons. TREX1 overexpression sufficed to block p53 activation of the cGAS/STING pathway. p53-mediated induction of type I interferon (IFNB1) is suppressed by cGAS/STING knockout, and p53's tumor suppressor activities are compromised by the loss of signaling through the cGAS/STING pathway. Thus, our study reveals that p53 utilizes the cGAS/STING innate immune system pathway for both cell-intrinsic and cell-extrinsic tumor suppressor activities.


Asunto(s)
Inmunidad Innata , Interferón Tipo I , ADN/metabolismo , Inmunidad Innata/genética , Interferón Tipo I/metabolismo , Nucleotidiltransferasas/genética , Nucleotidiltransferasas/metabolismo , Transducción de Señal/fisiología , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismo , Proteínas de la Membrana/metabolismo
2.
Nature ; 614(7947): 343-348, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36697821

RESUMEN

Transcriptional enhancer elements are responsible for orchestrating the temporal and spatial control over gene expression that is crucial for programming cell identity during development1-3. Here we describe a novel enhancer element that is important for regulating the expression of Prox1 in lymphatic endothelial cells. This evolutionarily conserved enhancer is bound by key lymphatic transcriptional regulators including GATA2, FOXC2, NFATC1 and PROX1. Genome editing of the enhancer to remove five nucleotides encompassing the GATA2-binding site resulted in perinatal death of homozygous mutant mice due to profound lymphatic vascular defects. Lymphatic endothelial cells in enhancer mutant mice exhibited reduced expression of genes characteristic of lymphatic endothelial cell identity and increased expression of genes characteristic of haemogenic endothelium, and acquired the capacity to generate haematopoietic cells. These data not only reveal a transcriptional enhancer element important for regulating Prox1 expression and lymphatic endothelial cell identity but also demonstrate that the lymphatic endothelium has haemogenic capacity, ordinarily repressed by Prox1.


Asunto(s)
Células Endoteliales , Elementos de Facilitación Genéticos , Hematopoyesis , Vasos Linfáticos , Animales , Ratones , Células Endoteliales/metabolismo , Elementos de Facilitación Genéticos/genética , Hematopoyesis/genética , Proteínas de Homeodominio/metabolismo , Vasos Linfáticos/citología , Vasos Linfáticos/metabolismo , Factores de Transcripción/metabolismo
3.
EMBO J ; 42(5): e109032, 2023 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-36715213

RESUMEN

Despite a growing catalog of secreted factors critical for lymphatic network assembly, little is known about the mechanisms that modulate the expression level of these molecular cues in blood vascular endothelial cells (BECs). Here, we show that a BEC-specific transcription factor, SOX7, plays a crucial role in a non-cell-autonomous manner by modulating the transcription of angiocrine signals to pattern lymphatic vessels. While SOX7 is not expressed in lymphatic endothelial cells (LECs), the conditional loss of SOX7 function in mouse embryos causes a dysmorphic dermal lymphatic phenotype. We identify novel distant regulatory regions in mice and humans that contribute to directly repressing the transcription of a major lymphangiogenic growth factor (Vegfc) in a SOX7-dependent manner. Further, we show that SOX7 directly binds HEY1, a canonical repressor of the Notch pathway, suggesting that transcriptional repression may also be modulated by the recruitment of this protein partner at Vegfc genomic regulatory regions. Our work unveils a role for SOX7 in modulating downstream signaling events crucial for lymphatic patterning, at least in part via the transcriptional repression of VEGFC levels in the blood vascular endothelium.


Asunto(s)
Células Endoteliales , Vasos Linfáticos , Humanos , Ratones , Animales , Células Endoteliales/metabolismo , Vasos Linfáticos/metabolismo , Regulación de la Expresión Génica , Endotelio Vascular , Factores de Transcripción/metabolismo , Linfangiogénesis/genética , Factores de Transcripción SOXF/genética , Factores de Transcripción SOXF/metabolismo
4.
Nature ; 585(7823): 91-95, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32788726

RESUMEN

Signalling between cells of the neurovascular unit, or neurovascular coupling, is essential to match local blood flow with neuronal activity. Pericytes interact with endothelial cells and extend processes that wrap capillaries, covering up to 90% of their surface area1,2. Pericytes are candidates to regulate microcirculatory blood flow because they are strategically positioned along capillaries, contain contractile proteins and respond rapidly to neuronal stimulation3,4, but whether they synchronize microvascular dynamics and neurovascular coupling within a capillary network was unknown. Here we identify nanotube-like processes that connect two bona fide pericytes on separate capillary systems, forming a functional network in the mouse retina, which we named interpericyte tunnelling nanotubes (IP-TNTs). We provide evidence that these (i) have an open-ended proximal side and a closed-ended terminal (end-foot) that connects with distal pericyte processes via gap junctions, (ii) carry organelles including mitochondria, which can travel along these processes, and (iii) serve as a conduit for intercellular Ca2+ waves, thus mediating communication between pericytes. Using two-photon microscope live imaging, we demonstrate that retinal pericytes rely on IP-TNTs to control local neurovascular coupling and coordinate light-evoked responses between adjacent capillaries. IP-TNT damage following ablation or ischaemia disrupts intercellular Ca2+ waves, impairing blood flow regulation and neurovascular coupling. Notably, pharmacological blockade of Ca2+ influx preserves IP-TNTs, rescues light-evoked capillary responses and restores blood flow after reperfusion. Our study thus defines IP-TNTs and characterizes their critical role in regulating neurovascular coupling in the living retina under both physiological and pathological conditions.


Asunto(s)
Nanotubos , Acoplamiento Neurovascular , Pericitos/metabolismo , Animales , Isquemia Encefálica/metabolismo , Isquemia Encefálica/patología , Calcio/metabolismo , Señalización del Calcio , Capilares/fisiopatología , Capilares/efectos de la radiación , Comunicación Celular , Femenino , Uniones Comunicantes/metabolismo , Hemodinámica , Masculino , Ratones , Mitocondrias/metabolismo , Acoplamiento Neurovascular/fisiología , Pericitos/citología , Pericitos/patología , Retina/citología , Retina/patología
5.
Mol Microbiol ; 121(2): 291-303, 2024 02.
Artículo en Inglés | MEDLINE | ID: mdl-38169053

RESUMEN

Pseudomonas aeruginosa is an important opportunistic pathogen. Several of its virulence-related processes, including the synthesis of pyocyanin (PYO) and biofilm formation, are controlled by quorum sensing (QS). It has been shown that the alternative sigma factor RpoS regulates QS through the reduction of lasR and rhlR transcription (encoding QS regulators). However, paradoxically, the absence of RpoS increases PYO production and biofilm development (that are RhlR dependent) by unknown mechanisms. Here, we show that RpoS represses pqsE transcription, which impacts the stability and activity of RhlR. In the absence of RpoS, rhlR transcript levels are reduced but not the RhlR protein concentration, presumably by its stabilization by PqsE, whose expression is increased. We also report that PYO synthesis and the expression of pqsE and phzA1B1C1D1E1F1G1 operon exhibit the same pattern at different RpoS concentrations, suggesting that the RpoS-dependent PYO production is due to its ability to modify PqsE concentration, which in turn modulates the activation of the phzA1 promoter by RhlR. Finally, we demonstrate that RpoS favors the expression of Vfr, which activates the transcription of lasR and rhlR. Our study contributes to the understanding of how RpoS modulates the QS response in P. aeruginosa, exerting both negative and positive regulation.


Asunto(s)
Percepción de Quorum , Factor sigma , Percepción de Quorum/genética , Factor sigma/genética , Factor sigma/metabolismo , Pseudomonas aeruginosa/metabolismo , Biopelículas , Piocianina , Operón , Proteínas Bacterianas/metabolismo , Regulación Bacteriana de la Expresión Génica
6.
PLoS Pathog ; 19(4): e1010941, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-37115795

RESUMEN

The encapsulated fungus Cryptococcus neoformans is the most common cause of fungal meningitis, with the highest rate of disease in patients with AIDS or immunosuppression. This microbe enters the human body via inhalation of infectious particles. C. neoformans capsular polysaccharide, in which the major component is glucuronoxylomannan (GXM), extensively accumulates in tissues and compromises host immune responses. C. neoformans travels from the lungs to the bloodstream and crosses to the brain via transcytosis, paracytosis, or inside of phagocytes using a "Trojan horse" mechanism. The fungus causes life-threatening meningoencephalitis with high mortality rates. Hence, we investigated the impact of intranasal exogenous GXM administration on C. neoformans infection in C57BL/6 mice. GXM enhances cryptococcal pulmonary infection and facilitates fungal systemic dissemination and brain invasion. Pre-challenge of GXM results in detection of the polysaccharide in lungs, serum, and surprisingly brain, the latter likely reached through the nasal cavity. GXM significantly alters endothelial cell tight junction protein expression in vivo, suggesting significant implications for the C. neoformans mechanisms of brain invasion. Using a microtiter transwell system, we showed that GXM disrupts the trans-endothelial electrical resistance, weakening human brain endothelial cell monolayers co-cultured with pericytes, supportive cells of blood vessels/capillaries found in the blood-brain barrier (BBB) to promote C. neoformans BBB penetration. Our findings should be considered in the development of therapeutics to combat the devastating complications of cryptococcosis that results in an estimated ~200,000 deaths worldwide each year.


Asunto(s)
Criptococosis , Cryptococcus neoformans , Meningitis Criptocócica , Animales , Ratones , Humanos , Cryptococcus neoformans/metabolismo , Roedores , Ratones Endogámicos C57BL , Criptococosis/microbiología , Polisacáridos/metabolismo , Pulmón/metabolismo
7.
PLoS Pathog ; 19(7): e1011522, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37498954

RESUMEN

ATP hydrolysis is required for the synthesis, transport and polymerization of monomers for macromolecules as well as for the assembly of the latter into cellular structures. Other cellular processes not directly related to synthesis of biomass, such as maintenance of membrane potential and cellular shape, also require ATP. The unicellular flagellated parasite Trypanosoma brucei has a complex digenetic life cycle. The primary energy source for this parasite in its bloodstream form (BSF) is glucose, which is abundant in the host's bloodstream. Here, we made a detailed estimation of the energy budget during the BSF cell cycle. As glycolysis is the source of most produced ATP, we calculated that a single parasite produces 6.0 x 1011 molecules of ATP/cell cycle. Total biomass production (which involves biomass maintenance and duplication) accounts for ~63% of the total energy budget, while the total biomass duplication accounts for the remaining ~37% of the ATP consumption, with in both cases translation being the most expensive process. These values allowed us to estimate a theoretical YATP of 10.1 (g biomass)/mole ATP and a theoretical [Formula: see text] of 28.6 (g biomass)/mole ATP. Flagellar motility, variant surface glycoprotein recycling, transport and maintenance of transmembrane potential account for less than 30% of the consumed ATP. Finally, there is still ~5.5% available in the budget that is being used for other cellular processes of as yet unknown cost. These data put a new perspective on the assumptions about the relative energetic weight of the processes a BSF trypanosome undergoes during its cell cycle.


Asunto(s)
Parásitos , Trypanosoma brucei brucei , Animales , Trypanosoma brucei brucei/metabolismo , Glucólisis , Parásitos/metabolismo , Adenosina Trifosfato/metabolismo , Modelos Teóricos , Proteínas Protozoarias/metabolismo
9.
Proc Natl Acad Sci U S A ; 119(7)2022 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-35135877

RESUMEN

Reduced blood flow and impaired neurovascular coupling are recognized features of glaucoma, the leading cause of irreversible blindness worldwide, but the mechanisms underlying these defects are unknown. Retinal pericytes regulate microcirculatory blood flow and coordinate neurovascular coupling through interpericyte tunneling nanotubes (IP-TNTs). Using two-photon microscope live imaging of the mouse retina, we found reduced capillary diameter and impaired blood flow at pericyte locations in eyes with high intraocular pressure, the most important risk factor to develop glaucoma. We show that IP-TNTs are structurally and functionally damaged by ocular hypertension, a response that disrupted light-evoked neurovascular coupling. Pericyte-specific inhibition of excessive Ca2+ influx rescued hemodynamic responses, protected IP-TNTs and neurovascular coupling, and enhanced retinal neuronal function as well as survival in glaucomatous retinas. Our study identifies pericytes and IP-TNTs as potential therapeutic targets to counter ocular pressure-related microvascular deficits, and provides preclinical proof of concept that strategies aimed to restore intrapericyte calcium homeostasis rescue autoregulatory blood flow and prevent neuronal dysfunction.


Asunto(s)
Estructuras de la Membrana Celular/fisiología , Glaucoma/patología , Pericitos/fisiología , Retina/citología , Retina/patología , Animales , Antígenos , Calcio/metabolismo , Femenino , Eliminación de Gen , Regulación de la Expresión Génica , Glaucoma/etiología , Fenómenos Magnéticos , Masculino , Ratones , Microesferas , Nanotubos , Regiones Promotoras Genéticas , Proteoglicanos , Vasos Retinianos/patología , Técnicas de Cultivo de Tejidos
10.
J Infect Dis ; 2024 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-38622836

RESUMEN

Cryptococcus neoformans (Cn) is an opportunistic fungus that causes severe central nervous system (CNS) disease in immunocompromised individuals. Brain parenchyma invasion requires fungal traversal of the blood-brain barrier. In this study, we describe that Cn alters the brain endothelium by activating small GTPase RhoA, causing reorganization of the actin cytoskeleton and tight junction modulation to regulate endothelial barrier permeability. We confirm that the main fungal capsule polysaccharide glucuronoxylomannan is responsible for these alterations. We reveal a therapeutic benefit of RhoA inhibition by CCG-1423 in vivo. RhoA inhibition prolonged survival and reduced fungal burden in a murine model of disseminated cryptococcosis, supporting the therapeutic potential targeting RhoA in the context of cryptococcal infection. We examine the complex virulence of Cn in establishing CNS disease, describing cellular components of the brain endothelium that may serve as molecular targets for future antifungal therapies to alleviate the burden of life-threatening cryptococcal CNS infection.

11.
PLoS Pathog ; 18(1): e1010210, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-35085375

RESUMEN

In the course of experiments aimed at deciphering the inhibition mechanism of mycophenolic acid and ribavirin in hepatitis C virus (HCV) infection, we observed an inhibitory effect of the nucleoside guanosine (Gua). Here, we report that Gua, and not the other standard nucleosides, inhibits HCV replication in human hepatoma cells. Gua did not directly inhibit the in vitro polymerase activity of NS5B, but it modified the intracellular levels of nucleoside di- and tri-phosphates (NDPs and NTPs), leading to deficient HCV RNA replication and reduction of infectious progeny virus production. Changes in the concentrations of NTPs or NDPs modified NS5B RNA polymerase activity in vitro, in particular de novo RNA synthesis and template switching. Furthermore, the Gua-mediated changes were associated with a significant increase in the number of indels in viral RNA, which may account for the reduction of the specific infectivity of the viral progeny, suggesting the presence of defective genomes. Thus, a proper NTP:NDP balance appears to be critical to ensure HCV polymerase fidelity and minimal production of defective genomes.


Asunto(s)
Guanosina/metabolismo , Hepacivirus/metabolismo , Mutación INDEL/fisiología , Nucleótidos/metabolismo , Replicación Viral/fisiología , Línea Celular Tumoral , Guanosina/farmacología , Hepatitis C/metabolismo , Humanos , ARN Viral/genética , Replicación Viral/efectos de los fármacos
12.
Glob Chang Biol ; 30(5): e17298, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38712640

RESUMEN

Diversified crop rotations have been suggested to reduce grain yield losses from the adverse climatic conditions increasingly common under climate change. Nevertheless, the potential for climate change adaptation of different crop rotational diversity (CRD) remains undetermined. We quantified how climatic conditions affect small grain and maize yields under different CRDs in 32 long-term (10-63 years) field experiments across Europe and North America. Species-diverse and functionally rich rotations more than compensated yield losses from anomalous warm conditions, long and warm dry spells, as well as from anomalous wet (for small grains) or dry (for maize) conditions. Adding a single functional group or crop species to monocultures counteracted yield losses from substantial changes in climatic conditions. The benefits of a further increase in CRD are comparable with those of improved climatic conditions. For instance, the maize yield benefits of adding three crop species to monocultures under detrimental climatic conditions exceeded the average yield of monocultures by up to 553 kg/ha under non-detrimental climatic conditions. Increased crop functional richness improved yields under high temperature, irrespective of precipitation. Conversely, yield benefits peaked at between two and four crop species in the rotation, depending on climatic conditions and crop, and declined at higher species diversity. Thus, crop species diversity could be adjusted to maximize yield benefits. Diversifying rotations with functionally distinct crops is an adaptation of cropping systems to global warming and changes in precipitation.


Asunto(s)
Cambio Climático , Productos Agrícolas , Zea mays , Productos Agrícolas/crecimiento & desarrollo , Zea mays/crecimiento & desarrollo , América del Norte , Europa (Continente) , Grano Comestible/crecimiento & desarrollo , Agricultura/métodos , Biodiversidad , Producción de Cultivos/métodos
13.
Reprod Biomed Online ; 48(4): 103730, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38368763

RESUMEN

Assisted human reproduction has undergone rapid advances since its inception 45 years ago. To keep pace with these advances, assisted reproduction laboratories should adhere to a quality management system that addresses staffing and training, physical space and air quality, equipment maintenance and other operational matters, and ensures gamete and embryo handling in accordance with the latest quality and safety standards. Accordingly, this review aims to provide a reference document that highlights the critical aspects to consider when establishing and operating an ART laboratory. The review collates and expands upon published national and international guidelines and consensus documents, providing easier access to this large body of important information.


Asunto(s)
Opinión Pública , Técnicas Reproductivas Asistidas , Humanos , Laboratorios , Reproducción , Tecnología
14.
Infection ; 2024 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-38703288

RESUMEN

BACKGROUND: Community-acquired (CA) and healthcare-associated (HCA) infections caused by carbapenemase-producing Enterobacterales (CPE) are not well characterized. The objective was to provide detailed information about the clinical and molecular epidemiological features of nosocomial, HCA and CA infections caused by carbapenemase-producing Klebsiella pneumoniae (CP-Kp) and Escherichia coli (CP-Ec). METHODS: A prospective cohort study was performed in 59 Spanish hospitals from February to March 2019, including the first 10 consecutive patients from whom CP-Kp or CP-Ec were isolated. Patients were stratified according to acquisition type. A multivariate analysis was performed to identify the impact of acquisition type in 30-day mortality. RESULTS: Overall, 386 patients were included (363 [94%] with CP-Kp and 23 [6%] CP-Ec); in 296 patients (76.3%), the CPE was causing an infection. Acquisition was CA in 31 (8.0%) patients, HCA in 183 (47.4%) and nosocomial in 172 (48.3%). Among patients with a HCA acquisition, 100 (54.6%) had been previously admitted to hospital and 71 (38.8%) were nursing home residents. Urinary tract infections accounted for 19/23 (82.6%), 89/130 (68.5%) and 42/143 (29.4%) of CA, HCA and nosocomial infections, respectively. Overall, 68 infections (23%) were bacteremia (8.7%, 17.7% and 30.1% of CA, HCA and nosocomial, respectively). Mortality in infections was 28% (13%, 14.6% and 42.7% of CA, HCA and nosocomial, respectively). Nosocomial bloodstream infections were associated with increased odds for mortality (adjusted OR, 4.00; 95%CI 1.21-13.19). CONCLUSIONS: HCA and CA infections caused by CPE are frequent and clinically significant. This information may be useful for a better understanding of the epidemiology of CPE.

15.
J Appl Microbiol ; 2024 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-38955378

RESUMEN

AIMS: This study was conducted to evaluate the in vitro activity of clinically relevant aminoglycosides and to determine the prevalence of genes encoding aminoglycoside modifying enzymes (AMEs) and 16S ribosomal RNA (rRNA) methyltransferases among aminoglycoside-resistant E. coli (n=61) and K. pneumoniae (n=44) clinical isolates. Associated resistances to beta-lactams and their bla genes as well as the genetic relatedness of isolates were also investigated. MATERIALS AND METHODS: A total of 105 aminoglycoside-resistant E. coli (n=61) and K. pneumoniae (n=44) isolates recovered between March and May 2017 from 100 patients hospitalized in different wards of Charles Nicolle Hospital of Tunis, Tunisia, were studied. Minimal inhibitory concentrations of aminoglycosides compounds were determined by broth microdilution method. Aminoglycosides resistance encoding genes (aph(3´)-Ia, aph(3') IIa, aph(3´)-VIa, ant(2")-Ia, aac(3) IIa, aac(3)-IVa, aac(6')-Ib, rmtA, rmtB, rmtC, armA and npmA) and bla genes were investigated by PCR and sequencing. Genetic relatedness was examined by Multilocus Sequence Typing (MLST) for representative isolates. RESULTS: High rates of aminoglycoside resistance were found: gentamicin (85.7%), tobramycin (87.6%), kanamycin (78.0%), netilmincin (74.3%) and amikcin (18.0%). Most common AME gene was aac(3)-IIa (42%) followed by aac(6')-Ib (36.2%) and aph(3')-VIa (32.4%). The majority of isolates were resistant to beta-lactams and the blaCTX-M-15 was the most common ESBL. The blaNDM-1 and blaOXA-48 were also produced by one and 23 isolates, respectively. Novel sequence types have been reported among our isolates and high-risk clonal lineages have been detected, such as E. coli ST43 (ST131 in Achtman MLST scheme) and K. pneumoniae ST11/ST13). CONCLUSION: The high prevalence of aminoglycoside resistance rates and the diversity of corresponding genes, with diverse ß-lactamase enzymes among genetically heterogeneous clinical isolates present a matter of concern.

16.
Appl Microbiol Biotechnol ; 108(1): 109, 2024 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38204130

RESUMEN

RNA polymerase III (RNAP III) synthetizes small essential non-coding RNA molecules such as tRNAs and 5S rRNA. In yeast and vertebrates, RNAP III needs general transcription factors TFIIIA, TFIIIB, and TFIIIC to initiate transcription. TFIIIC, composed of six subunits, binds to internal promoter elements in RNAP III-dependent genes. Limited information is available about RNAP III transcription in the trypanosomatid protozoa Trypanosoma brucei and Leishmania major, which diverged early from the eukaryotic lineage. Analyses of the first published draft of the trypanosomatid genome sequences failed to recognize orthologs of any of the TFIIIC subunits, suggesting that this transcription factor is absent in these parasites. However, a putative TFIIIC subunit was recently annotated in the databases. Here we characterize this subunit in T. brucei and L. major and demonstrate that it corresponds to Tau95. In silico analyses showed that both proteins possess the typical Tau95 sequences: the DNA binding region and the dimerization domain. As anticipated for a transcription factor, Tau95 localized to the nucleus in insect forms of both parasites. Chromatin immunoprecipitation (ChIP) assays demonstrated that Tau95 binds to tRNA and U2 snRNA genes in T. brucei. Remarkably, by performing tandem affinity purifications we identified orthologs of TFIIIC subunits Tau55, Tau131, and Tau138 in T. brucei and L. major. Thus, contrary to what was assumed, trypanosomatid parasites do possess a TFIIIC complex. Other putative interacting partners of Tau95 were identified in T. brucei and L. major. KEY POINTS: • A four-subunit TFIIIC complex is present in T. brucei and L. major • TbTau95 associates with tRNA and U2 snRNA genes • Putative interacting partners of Tau95 might include some RNAP II regulators.


Asunto(s)
Parásitos , Factores de Transcripción TFIII , Animales , Bioensayo , ARN de Transferencia/genética
17.
Alzheimers Dement ; 20(2): 1298-1308, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37985413

RESUMEN

INTRODUCTION: Genome-wide association studies (GWAS) are fundamental for identifying loci associated with diseases. However, they require replication in other ethnicities. METHODS: We performed GWAS on sporadic Alzheimer's disease (AD) including 539 patients and 854 controls from Argentina and Chile. We combined our results with those from the European Alzheimer and Dementia Biobank (EADB) in a meta-analysis and tested their genetic risk score (GRS) performance in this admixed population. RESULTS: We detected apolipoprotein E ε4 as the single genome-wide significant signal (odds ratio  = 2.93 [2.37-3.63], P = 2.6 × 10-23 ). The meta-analysis with EADB summary statistics revealed four new loci reaching GWAS significance. Functional annotations of these loci implicated endosome/lysosomal function. Finally, the AD-GRS presented a similar performance in these populations, despite the score diminished when the Native American ancestry rose. DISCUSSION: We report the first GWAS on AD in a population from South America. It shows shared genetics modulating AD risk between the European and these admixed populations. HIGHLIGHTS: This is the first genome-wide association study on Alzheimer's disease (AD) in a population sample from Argentina and Chile. Trans-ethnic meta-analysis reveals four new loci involving lysosomal function in AD. This is the first independent replication for TREM2L, IGH-gene-cluster, and ADAM17 loci. A genetic risk score (GRS) developed in Europeans performed well in this population. The higher the Native American ancestry the lower the GRS values.


Asunto(s)
Enfermedad de Alzheimer , Azidas , Estudio de Asociación del Genoma Completo , Humanos , Chile , Enfermedad de Alzheimer/genética , Predisposición Genética a la Enfermedad/genética , Polimorfismo de Nucleótido Simple/genética
18.
Int J Mol Sci ; 25(7)2024 Mar 23.
Artículo en Inglés | MEDLINE | ID: mdl-38612435

RESUMEN

This study presents the synthesis of four series of novel hybrid chalcones (20,21)a-g and (23,24)a-g and six series of 1,3,5-triazine-based pyrimido[4,5-b][1,4]diazepines (28-33)a-g and the evaluation of their anticancer, antibacterial, antifungal, and cytotoxic properties. Chalcones 20b,d, 21a,b,d, 23a,d-g, 24a-g and the pyrimido[4,5-b][1,4]diazepines 29e,g, 30g, 31a,b,e-g, 33a,b,e-g exhibited outstanding anticancer activity against a panel of 60 cancer cell lines with GI50 values between 0.01 and 100 µM and LC50 values in the range of 4.09 µM to >100 µM, several of such derivatives showing higher activity than the standard drug 5-fluorouracil (5-FU). On the other hand, among the synthesized compounds, the best antibacterial properties against N. gonorrhoeae, S. aureus (ATCC 43300), and M. tuberculosis were exhibited by the pyrimido[4,5-b][1,4]diazepines (MICs: 0.25-62.5 µg/mL). The antifungal activity studies showed that triazinylamino-chalcone 29e and triazinyloxy-chalcone 31g were the most active compounds against T. rubrum and T. mentagrophytes and A. fumigatus, respectively (MICs = 62.5 µg/mL). Hemolytic activity studies and in silico toxicity analysis demonstrated that most of the compounds are safe.


Asunto(s)
Chalconas , Isocianatos , Mycobacterium tuberculosis , Chalconas/farmacología , Antifúngicos/farmacología , Staphylococcus aureus , Antibacterianos/farmacología , Azepinas/farmacología , Fluorouracilo , Neisseria gonorrhoeae , Triazinas/farmacología
19.
Artículo en Inglés | MEDLINE | ID: mdl-38195840

RESUMEN

BACKGROUND: Ocular trauma is one of the most important causes of ocular morbidity and inadequate visual acuity in developed and developing countries. In some countries, eye trauma is the leading cause of monocular blindness. Studies conducted in developing countries like Colombia suggest that there is a lack of awareness of preventive measures. In Colombia, there is no countrywide ocular trauma registry. The purpose of the present study is to describe and analyse characteristics of ocular trauma at a tertiary ophthalmology emergency department in Colombia. PATIENTS/METHODS AND MATERIAL: Patients who consulted or were referred to the ophthalmologic emergency department of FOSCAL due to eye injuries between March 1, 2022, and January 10, 2023, were included in this cross-sectional study. RESULTS: Of 1 957 patients, 2 088 eyes were included. Men comprised 78.5% of the patients, the median age was 36 years, and 75.0% lived in urban areas. The median latency between trauma and ophthalmology consultation was 21.8 hours. Of the eyes, 1 805 (88.4%) had suffered mechanical or mixed (mechanical plus burn) trauma. Of the injuries, 87.5% were unilateral. In terms of the circumstances, 45.9% of injuries occurred during working or educational activities (in 85.6% of these cases, without eye protection), 28.2% in home accidents, and 14.0% in transportation situations. According to the Birmingham Eye Trauma Terminology System (BETT), 1 735 eyes (91.1%) were closed globe injuries, and 49 eyes (2.7%) were open globe injuries. Fifty eyes (2.8%) could not be categorised according to BETT at the initial consultation and were classified as "still to be determined". In the Ocular Trauma Score (OTS), 85.8% were category 5. Of the ocular burn cases, 93.0% were categorised as grade I according to the Roper Hall classification. CONCLUSIONS: In line with global literature, a much higher proportion of men than women sought consultation for ocular trauma. The findings suggest a need for improvement in the referral process from institutions with the lowest level of care. Lack of awareness about eye protection is an issue. Surgical exploration or additional tests may be necessary for precise injury classification. We therefore propose adding a "still to be determined" category to the BETT initial classification. These cases may be reclassified later, thus improving the accuracy of OTS calculation.

20.
BMC Genomics ; 24(1): 431, 2023 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-37533008

RESUMEN

The H9c2 myoblast cell line, isolated from the left ventricular tissue of rat, is currently used in vitro as a mimetic for skeletal and cardiac muscle due to its biochemical, morphological, and electrical/hormonal signaling properties. During culture, H9c2 cells acquire a myotube phenotype, where a critical component is the inclusion of retinoic acid (RA). The results from some authors on H9c2 suggested that thousands of genes respond to RA stimuli, while others report hundreds of genes responding to RA over different cell types. In this article, using a more appropriate experimental design, we first confirm the H9c2 cardiac phenotype with and without RA and report transcriptomic and physiological changes regarding calcium handling, bioenergetics, and other biological concepts. Interestingly, of the 2360 genes showing a transcriptional change, 622 genes were statistically associated with the RA response. Of these genes, only 305 were RA-specific, and the rest also showed a culture-time component. Thus, the major expression changes (from 74 to 87%) were indeed due to culture conditions over time. Unexpectedly, only a few components of the retinol pathway in KEGG responded to RA. Our results show the role of RA in the H9c2 cultures impacting the interpretation using H9c2 as an in vitro model.


Asunto(s)
Miocardio , Tretinoina , Ratas , Animales , Tretinoina/farmacología , Tretinoina/metabolismo , Diferenciación Celular/genética , Miocardio/metabolismo , Mioblastos , Fenotipo
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