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1.
PLoS Pathog ; 19(12): e1011814, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38039338

RESUMEN

Single amino acid changes in the parasite protein Kelch13 (K13) result in reduced susceptibility of P. falciparum parasites to artemisinin and its derivatives (ART). Recent work indicated that K13 and other proteins co-localising with K13 (K13 compartment proteins) are involved in the endocytic uptake of host cell cytosol (HCCU) and that a reduction in HCCU results in reduced susceptibility to ART. HCCU is critical for parasite survival but is poorly understood, with the K13 compartment proteins among the few proteins so far functionally linked to this process. Here we further defined the composition of the K13 compartment by analysing more hits from a previous BioID, showing that MyoF and MCA2 as well as Kelch13 interaction candidate (KIC) 11 and 12 are found at this site. Functional analyses, tests for ART susceptibility as well as comparisons of structural similarities using AlphaFold2 predictions of these and previously identified proteins showed that vesicle trafficking and endocytosis domains were frequent in proteins involved in resistance or endocytosis (or both), comprising one group of K13 compartment proteins. While this strengthened the link of the K13 compartment to endocytosis, many proteins of this group showed unusual domain combinations and large parasite-specific regions, indicating a high level of taxon-specific adaptation of this process. Another group of K13 compartment proteins did not influence endocytosis or ART susceptibility and lacked detectable vesicle trafficking domains. We here identified the first protein of this group that is important for asexual blood stage development and showed that it likely is involved in invasion. Overall, this work identified novel proteins functioning in endocytosis and at the K13 compartment. Together with comparisons of structural predictions it provides a repertoire of functional domains at the K13 compartment that indicate a high level of adaption of endocytosis in malaria parasites.


Asunto(s)
Antimaláricos , Malaria Falciparum , Parásitos , Animales , Antimaláricos/farmacología , Plasmodium falciparum/metabolismo , Parásitos/metabolismo , Proteínas Protozoarias/genética , Proteínas Protozoarias/metabolismo , Resistencia a Medicamentos , Malaria Falciparum/parasitología , Mutación
2.
J Cell Sci ; 133(2)2020 01 23.
Artículo en Inglés | MEDLINE | ID: mdl-31932504

RESUMEN

Mesenchymal stem cells (MSCs) are essential for the regenerative process; however, biological aging and environmental stress can induce senescence - an irreversible state of growth arrest - that not only affects the behavior of cells but also disrupts their ability to restore tissue integrity. While abnormal tissue properties, including increased extracellular matrix stiffness, are linked with the risk of developing breast cancer, the role and contribution of senescent MSCs to the disease progression to malignancy are not well understood. Here, we investigated senescence-associated biophysical changes in MSCs and how this influences cancer cell behavior in a 3D matrix interface model. Although senescent MSCs were far less motile than pre-senescent MSCs, they induced an invasive breast cancer phenotype, characterized by increased spheroid growth and cell invasion in collagen gels. Further analysis of collagen gels using second-harmonic generation showed increased collagen density when senescent MSCs were present, suggesting that senescent MSCs actively remodel the surrounding matrix. This study provides direct evidence of the pro-malignant effects of senescent MSCs in tumors.


Asunto(s)
Neoplasias de la Mama/genética , Matriz Extracelular/metabolismo , Células Madre Mesenquimatosas/metabolismo , Proliferación Celular , Femenino , Humanos , Fenotipo , Microambiente Tumoral
3.
Anaerobe ; 62: 102151, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31945474

RESUMEN

C. difficile induces antibiotic-associated diarrhea due to the action of two secreted toxins, TcdA and TcdB. A considerable range of virulence among C. difficile strains has been widely reported. During a hospital outbreak, 46 isolates were collected that belonged to different genotypes. Of those, the majority corresponded to two virulent strains, the globally distributed Sequence Type 1 (ST1)_North American Pulsotype 1 (NAP1) and the endemic ST54_NAPCR1 genotypes, respectively. Whereas the virulence of the latter has been attributed to increased secretion of toxins and production of a highly cytotoxic TcdB, these characteristics do not explain the increased lethality of the former. We undertook a proteomic comparative approach of the isolates participating in the outbreak to look for proteins present in the exoproteome of the ST1_NAP1and ST54_NAPCR1 strains. We used a low virulent ST2_NAP4 strain isolated also in the outbreak as control. Dendrograms constructed using the exoproteomes of the strains were very similar to those created using genomic information, suggesting an association between secreted proteins and relative virulence of the strains. By 2D electrophoresis and mass spectrometry it was found that approximately half of the proteins are shared among strains of different genotypes. From the identified proteins, the surface-located SlpA draw our attention due to its detection in ST54_NAPCR1 exoproteomes. Biochemical analysis indicated that the processing of SlpA is different in the ST54_NAPCR1 strain and confirmed that this strain secretes more SlpA than its counterparts. Furthermore, SlpA from the ST54_NAPCR1 strain exerted an increased proinflammatory activity. Altogether, these results indicate that the exoproteome composition correlates with the C. difficile genotype and suggest that particular proteins secreted by some strains could synergize with the effects of TcdA and TcdB increasing their virulence.


Asunto(s)
Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Clostridioides difficile/genética , Clostridioides difficile/metabolismo , Infecciones por Clostridium/microbiología , Filogenia , Proteómica , Clostridioides difficile/clasificación , Enterotoxinas/genética , Genoma Bacteriano , Genómica/métodos , Genotipo , Humanos , Tipificación de Secuencias Multilocus , Proteómica/métodos , Virulencia
4.
Rev Med Chil ; 146(1): 116-121, 2018 Jan.
Artículo en Español | MEDLINE | ID: mdl-29806686

RESUMEN

Pseudohypoparathyroidism (PHP) is a group of rare genetic disorders that share organ targeted resistance to the action of parathyroid hormone (PTH) as a common feature. Biochemically, they may present with hypocalcemia, hyperphosphatemia and elevated PTH. Some forms present with a specific phenotype: short stature, round facies, short neck, obesity, brachydactyly and subcutaneous calcifications, called Albrigth's Hereditary Osteodystrophy (AHO). This spectrum of disorders are caused by several alterations in the gene coding for the alpha subunit of the G protein (GNAS): an ubiquitous signaling protein that mediates the action of numerous hormones such as PTH, TSH, gonadotropins, and ACTH, among others. According to their inheritance with maternal or paternal imprinting, they may manifest in a diversity of clinical forms. Although most commonly diagnosed during childhood, PHP may manifest clinically during adolescence or early adulthood. We report two late presenting cases of pseudohypoparathyroidism. A 21-year-old female with biochemical abnormalities characteristic of pseudohypoparathyroidism who was misdiagnosed as epilepsy and a 13-year-old boy with the classic AHO phenotype but without alterations in phospho-calcium metabolism, compatible with pseudopseudohypoparathyrodism.


Asunto(s)
Seudohipoparatiroidismo/diagnóstico por imagen , Adolescente , Femenino , Humanos , Masculino , Factores de Tiempo , Tomografía Computarizada por Rayos X , Adulto Joven
5.
Infect Immun ; 84(3): 856-65, 2016 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-26755157

RESUMEN

Clostridium difficile strains within the hypervirulent clade 2 are responsible for nosocomial outbreaks worldwide. The increased pathogenic potential of these strains has been attributed to several factors but is still poorly understood. During a C. difficile outbreak, a strain from this clade was found to induce a variant cytopathic effect (CPE), different from the canonical arborizing CPE. This strain (NAP1V) belongs to the NAP1 genotype but to a ribotype different from the epidemic NAP1/RT027 strain. NAP1V and NAP1 share some properties, including the overproduction of toxins, the binary toxin, and mutations in tcdC. NAP1V is not resistant to fluoroquinolones, however. A comparative analysis of TcdB proteins from NAP1/RT027 and NAP1V strains indicated that both target Rac, Cdc42, Rap, and R-Ras but only the former glucosylates RhoA. Thus, TcdB from hypervirulent clade 2 strains possesses an extended substrate profile, and RhoA is crucial for the type of CPE induced. Sequence comparison and structural modeling revealed that TcdBNAP1 and TcdBNAP1V share the receptor-binding and autoprocessing activities but vary in the glucosyltransferase domain, consistent with the different substrate profile. Whereas the two toxins displayed identical cytotoxic potencies, TcdBNAP1 induced a stronger proinflammatory response than TcdBNAP1V as determined in ex vivo experiments and animal models. Since immune activation at the level of intestinal mucosa is a hallmark of C. difficile-induced infections, we propose that the panel of substrates targeted by TcdB is a determining factor in the pathogenesis of this pathogen and in the differential virulence potential seen among C. difficile strains.


Asunto(s)
Proteínas Bacterianas/metabolismo , Toxinas Bacterianas/metabolismo , Clostridioides difficile/metabolismo , Clostridioides difficile/patogenicidad , Enterocolitis Seudomembranosa/enzimología , Enterocolitis Seudomembranosa/microbiología , Proteína de Unión al GTP rhoA/metabolismo , Animales , Proteínas Bacterianas/genética , Toxinas Bacterianas/genética , Clostridioides difficile/clasificación , Clostridioides difficile/genética , Enterocolitis Seudomembranosa/genética , Genotipo , Glicosilación , Interacciones Huésped-Patógeno , Humanos , Masculino , Ratones , Virulencia , Proteína de Unión al GTP rhoA/genética
6.
Eur Respir J ; 47(3): 947-53, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26699724

RESUMEN

Our aim was to describe the characteristics of a case-series of never-smoker small cell lung cancer (SCLC) cases.Cases of SCLC were selected from a prospective, multicenter, hospital-based case-control study performed in Spain. Participants were never-smokers older than 30 years with an anatomo-pathological confirmation of primary lung cancer. We collected clinical and epidemiological variables according to the study's protocol.We included 19 SCLC cases, 18 females (94.7%), median age 75 years (interquartile range (IQR) 70-80 years). Median residential radon concentration was 195 Bq·m(-3) (IQR 130-229 Bq·m(-3)). 10 patients had limited disease and nine had extended disease. Median survival was 242 days (IQR 94-496 days); 1- and 2-year survival were 36.8% and 17.6%, respectively. Survival was much higher for individuals with limited disease than for those with extended disease (median 336 versus 235 days; 1-year survival 50% versus 22.2% and 2-year survival 27% versus 0%, respectively). Performance status at diagnosis was closely related to survival.SCLC is an infrequent, highly aggressive disease in never-smokers. Survival is poor, even for limited disease. Age at diagnosis in SCLC is higher than that observed for never-smokers with adenocarcinoma. Residential radon exposure is higher than the action levels recommended by the World Health Organization.


Asunto(s)
Adenocarcinoma/epidemiología , Exposición a Riesgos Ambientales/efectos adversos , Neoplasias Pulmonares/epidemiología , Radón/efectos adversos , Carcinoma Pulmonar de Células Pequeñas/epidemiología , Adenocarcinoma/diagnóstico , Adenocarcinoma del Pulmón , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Femenino , Vivienda , Humanos , Neoplasias Pulmonares/diagnóstico , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Factores de Riesgo , Carcinoma Pulmonar de Células Pequeñas/diagnóstico , Fumar , España
7.
Arch Bronconeumol ; 60(7): 417-422, 2024 Jul.
Artículo en Inglés, Español | MEDLINE | ID: mdl-38729884

RESUMEN

INTRODUCTION: Treatment with LABA/LAMA is recommended in GOLD B patients. We hypothesized that triple therapy (LABA/LAMA/ICS) will be superior to LABA/LAMA in achieving and maintaining clinical control (CC), a composite outcome that considers both impact and disease stability in a subgroup of GOLD B patients (here termed GOLD B+ patients) characterized by: (1) remaining symptomatic (CAT≥10) despite regular LABA/LAMA therapy; (2) having suffered one moderate exacerbation in the previous year; and (3) having blood eosinophil counts (BEC) ≥150cells/µL. METHODS: The ANTES B+ study is a prospective, multicenter, open label, randomized, pragmatic, controlled trial designed to test this hypothesis. It will randomize 1028 B+ patients to continue with their usual LABA/LAMA combination prescribed by their attending physician or to begin fluticasone furoate (FF) 92µg/umeclidinium (UMEC) 55µg/vilanterol (VI) 22µg in a single inhaler q.d. for 12 months. The primary efficacy outcome will be the level of CC achieved. Secondary outcomes include the clinical important deterioration index (CID), annual rate of exacerbations, and FEV1. Exploratory objectives include the interaction of BEC and smoking status, all-cause mortality and proportion of patients on LABA/LAMA arm that switch therapy arms. Safety analysis include adverse events and incidence of pneumonia. RESULTS: The first patient was recruited on February 29, 2024; results are expected in the first quarter of 2026. CONCLUSIONS: The ANTES B+ study is the first to: (1) explore the efficacy and safety of triple therapy in a population of B+ COPD patients and (2) use a composite index (CC) as the primary result of a COPD trial.


Asunto(s)
Alcoholes Bencílicos , Combinación de Medicamentos , Enfermedad Pulmonar Obstructiva Crónica , Humanos , Enfermedad Pulmonar Obstructiva Crónica/tratamiento farmacológico , Estudios Prospectivos , Alcoholes Bencílicos/uso terapéutico , Alcoholes Bencílicos/administración & dosificación , Clorobencenos/uso terapéutico , Clorobencenos/administración & dosificación , Quinuclidinas/uso terapéutico , Quinuclidinas/administración & dosificación , Quimioterapia Combinada , Antagonistas Muscarínicos/uso terapéutico , Antagonistas Muscarínicos/administración & dosificación , Androstadienos/uso terapéutico , Androstadienos/administración & dosificación , Resultado del Tratamiento , Corticoesteroides/uso terapéutico , Broncodilatadores/uso terapéutico , Broncodilatadores/administración & dosificación , Administración por Inhalación , Masculino , Femenino , Agonistas de Receptores Adrenérgicos beta 2/uso terapéutico , Agonistas de Receptores Adrenérgicos beta 2/administración & dosificación , Eosinófilos , Persona de Mediana Edad
8.
Front Plant Sci ; 14: 1273235, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38023851

RESUMEN

In Arabidopsis seedlings, inhibition of aspartate transcarbamoylase (ATC) and de novo pyrimidine synthesis resulted in pyrimidine starvation and developmental arrest a few days after germination. Synthesis of pyrimidine nucleotides by salvaging of exogenous uridine (Urd) restored normal seedling growth and development. We used this experimental system and transcriptional profiling to investigate genome-wide responses to changes in pyrimidine availability. Gene expression changes at different times after Urd supplementation of pyrimidine-starved seedlings were mapped to major pathways of nucleotide metabolism, in order to better understand potential coordination of pathway activities, at the level of transcription. Repression of de novo synthesis genes and induction of intracellular and extracellular salvaging genes were early and sustained responses to pyrimidine limitation. Since de novo synthesis is energetically more costly than salvaging, this may reflect a reduced energy status of the seedlings, as has been shown in recent studies for seedlings growing under pyrimidine limitation. The unexpected induction of pyrimidine catabolism genes under pyrimidine starvation may result from induction of nucleoside hydrolase NSH1 and repression of genes in the plastid salvaging pathway, diverting uracil (Ura) to catabolism. Identification of pyrimidine-responsive transcription factors with enriched binding sites in highly coexpressed genes of nucleotide metabolism and modeling of potential transcription regulatory networks provided new insights into possible transcriptional control of key enzymes and transporters that regulate nucleotide homeostasis in plants.

9.
Sci Rep ; 13(1): 19232, 2023 11 06.
Artículo en Inglés | MEDLINE | ID: mdl-37932310

RESUMEN

More than 75% of epithelial ovarian cancer (EOC) patients experience disease recurrence after initial treatment, highlighting our incomplete understanding of how chemoresistant populations evolve over the course of EOC progression post chemotherapy treatment. Here, we show how two paclitaxel (PTX) treatment methods- a single high dose and a weekly metronomic dose for four weeks, generate unique chemoresistant populations. Using mechanically relevant alginate microspheres and a combination of transcript profiling and heterogeneity analyses, we found that these PTX-treatment regimens produce distinct and resilient subpopulations that differ in metabolic reprogramming signatures, acquisition of resistance to PTX and anoikis, and the enrichment for cancer stem cells (CSCs) and polyploid giant cancer cells (PGCCs) with the ability to replenish bulk populations. We investigated the longevity of these metabolic reprogramming events using untargeted metabolomics and found that metabolites associated with stemness and therapy-induced senescence were uniquely abundant in populations enriched for CSCs and PGCCs. Predictive network analysis revealed that antioxidative mechanisms were likely to be differentially active dependent on both time and exposure to PTX. Our results illustrate how current standard chemotherapies contribute to the development of chemoresistant EOC subpopulations by either selecting for intrinsically resistant subpopulations or promoting the evolution of resistance mechanisms. Additionally, our work describes the unique phenotypic signatures in each of these distinct resistant subpopulations and thus highlights potential vulnerabilities that can be exploited for more effective treatment.


Asunto(s)
Neoplasias Ováricas , Paclitaxel , Femenino , Humanos , Paclitaxel/farmacología , Neoplasias Ováricas/metabolismo , Resistencia a Antineoplásicos , Recurrencia Local de Neoplasia , Carcinoma Epitelial de Ovario , Línea Celular Tumoral
10.
Cancers (Basel) ; 15(12)2023 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-37370796

RESUMEN

Metastatic progression of epithelial ovarian cancer (EOC) involves the partial epithelial-to-mesenchymal transition (EMT) of cancer cells in the primary tumor and dissemination into peritoneal fluid. In part to the high degree of heterogeneity in EOC cells, the identification of EMT in highly epithelial cells in response to differences in matrix mechanics, growth factor signaling, and tissue hypoxia is very difficult. We analyzed different degrees of EMT by tracking changes in cell and nuclear morphology, along with the organization of cytoskeletal proteins. In our analysis, we see a small percentage of individual cells that show dramatic response to TGF-ß1 and hypoxia treatment. We demonstrate that EOC cells are spatially aware of their surroundings, with a subpopulation of EOC cells at the periphery of a cell cluster in 2D environments exhibited a greater degree of EMT. These peripheral cancer cells underwent partial EMT, displaying a hybrid of mesenchymal and epithelial characteristics, which often included less cortical actin and more perinuclear cytokeratin expression. Collectively, these data show that tumor-promoting microenvironment conditions can mediate invasive cell behavior in a spatially regulated context in a small subpopulation of highly epithelial clustered cancer cells that maintain epithelial characteristics while also acquiring some mesenchymal traits through partial EMT.

11.
Genes (Basel) ; 14(4)2023 03 29.
Artículo en Inglés | MEDLINE | ID: mdl-37107578

RESUMEN

Autism spectrum disorders (ASD) comprise a group of neurodevelopmental disorders (NDD) characterized by deficits in communication and social interaction, as well as repetitive and restrictive behaviors, etc. The genetic implications of ASD have been widely documented, and numerous genes have been associated with it. The use of chromosomal microarray analysis (CMA) has proven to be a rapid and effective method for detecting both small and large deletions and duplications associated with ASD. In this article, we present the implementation of CMA as a first-tier test in our clinical laboratory for patients with primary ASD over a prospective period of four years. The cohort was composed of 212 individuals over 3 years of age, who met DSM-5 diagnostic criteria for ASD. The use of a customized array-CGH (comparative genomic hybridization) design (KaryoArray®) found 99 individuals (45.20%) with copy number variants (CNVs); 34 of them carried deletions (34.34%) and 65 duplications (65.65%). A total of 28 of 212 patients had pathogenic or likely pathogenic CNVs, representing approximately 13% of the cohort. In turn, 28 out of 212 (approximately 12%) had variants of uncertain clinical significance (VUS). Our findings involve clinically significant CNVs, known to cause ASD (syndromic and non-syndromic), and other CNVs previously related to other comorbidities such as epilepsy or intellectual disability (ID). Lastly, we observed new rearrangements that will enhance the information available and the collection of genes associated with this disorder. Our data also highlight that CMA could be very useful in diagnosing patients with essential/primary autism, and demonstrate the existence of substantial genetic and clinical heterogeneity in non-syndromic ASD individuals, underscoring the continued challenge for genetic laboratories in terms of its molecular diagnosis.


Asunto(s)
Trastorno del Espectro Autista , Humanos , Trastorno del Espectro Autista/diagnóstico , Trastorno del Espectro Autista/genética , Centros de Atención Terciaria , Estudios Prospectivos , Hibridación Genómica Comparativa/métodos , Análisis por Micromatrices
12.
Cancer Diagn Progn ; 3(2): 264-271, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36875311

RESUMEN

BACKGROUND/AIM: Prior immune-checkpoint inhibitors, weekly paclitaxel-cetuximab was one of the few options for platinum-ineligible patients with recurrent/ metastatic squamous cell carcinoma of the head and neck (R/M-SCCHN). This real-world study analyzed the long-term outcomes of this regimen. PATIENTS AND METHODS: A multicenter, retrospective, observational, cross-sectional, chart review study was realized in nine hospitals of the Galician Group of Head and Neck Cancer. Eligible population was adult platinum-ineligible patients with R/M SCCHN (unfit to, or after progressing following EXTREME or other platinum-based regimens) that received weekly paclitaxel plus cetuximab regimen as first- or second-line (1L or 2L) between January 2009 and December 2014. The efficacy was evaluated (1L-2L) in regards to overall survival (OS) and progression-free survival (PFS), and safety was assessed as the incidence of adverse events (AEs). RESULTS: Seventy-five R/M-SCCHN patients received the scheme (1L, n=50; 2L: n=25). The mean age of the patients was 59 years (1L, 59.5 years; 2L, 59.2 years), 90% were male (1L, 96%; 2L, 79%), 55% were smokers (1L, 60.4%; 2L, 45.8%), and 61% presented ECOG performance status (PS) 1 (1L, 54%; 2L, 62.5%). Median OS [interquartile range (IQR)] was 8.85 (4.22-40.96) months. Median PFS (IQR) was 8.5 (3.93-12.55) (1L) and 8.8 (5.62-16.91) (2L) months. Disease control rate was 60% (1L) and 85% (2L). Weekly paclitaxel-cetuximab was well tolerated in 1L/2L (cutaneous-toxicity, mucositis, neuropathy; mainly Grade 1-2). No grade 4 AEs were notified in 2L. CONCLUSION: Weekly paclitaxel-cetuximab is an active and well tolerated therapeutical option in platinum-ineligible or after platinum regimens in R/M-SCCHN patients.

13.
Viruses ; 15(12)2023 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-38140614

RESUMEN

West Nile Virus (WNV) is a mosquito vector-borne zoonosis with an increasing incidence in Europe that has become a public health concern. In Spain, although local circulation has been known for decades, until 2020, when a large outbreak occurred, West Nile Virus cases were scarce and mostly occurred in southern Spain. Since then, there have been new cases every year and the pathogen has spread to new regions. Thus, monitoring of circulating variants and lineages plays a fundamental role in understanding WNV evolution, spread and dynamics. In this study, we sequenced WNV consensus genomes from mosquito pools captured in 2022 as part of a newly implemented surveillance program in southern Spain and compared it to other European, African and Spanish sequences. Characterization of WNV genomes in mosquitoes captured in 2022 reveals the co-circulation of two WNV lineage 1 variants, the one that caused the outbreak in 2020 and another variant that is closely related to variants reported in Spain in 2012, France in 2015, Italy in 2021-2022 and Senegal in 2012-2018. The geographic distribution of these variants indicates that WNV L1 dynamics in southern Europe include an alternating dominance of variants in some territories.


Asunto(s)
Culicidae , Fiebre del Nilo Occidental , Virus del Nilo Occidental , Animales , Humanos , Virus del Nilo Occidental/genética , Fiebre del Nilo Occidental/epidemiología , España/epidemiología , Europa (Continente)/epidemiología
14.
Cancers (Basel) ; 14(6)2022 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-35326569

RESUMEN

High-grade serous ovarian cancer (HGSOC) constitutes the majority of all ovarian cancer cases and has staggering rates of both refractory and recurrent disease. While most patients respond to the initial treatment with paclitaxel and platinum-based drugs, up to 25% do not, and of the remaining that do, 75% experience disease recurrence within the subsequent two years. Intrinsic resistance in refractory cases is driven by environmental stressors like tumor hypoxia which alter the tumor microenvironment to promote cancer progression and resistance to anticancer drugs. Recurrent disease describes the acquisition of chemoresistance whereby cancer cells survive the initial exposure to chemotherapy and develop adaptations to enhance their chances of surviving subsequent treatments. Of the environmental stressors cancer cells endure, exposure to hypoxia has been identified as a potent trigger and priming agent for the development of chemoresistance. Both in the presence of the stress of hypoxia or the therapeutic stress of chemotherapy, cancer cells manage to cope and develop adaptations which prime populations to survive in future stress. One adaptation is the modification in the secretome. Chemoresistance is associated with translational reprogramming for increased protein synthesis, ribosome biogenesis, and vesicle trafficking. This leads to increased production of soluble proteins and extracellular vesicles (EVs) involved in autocrine and paracrine signaling processes. Numerous studies have demonstrated that these factors are largely altered between the secretomes of chemosensitive and chemoresistant patients. Such factors include cytokines, growth factors, EVs, and EV-encapsulated microRNAs (miRNAs), which serve to induce invasive molecular, biophysical, and chemoresistant phenotypes in neighboring normal and cancer cells. This review examines the modifications in the secretome of distinct chemoresistant ovarian cancer cell populations and specific secreted factors, which may serve as candidate biomarkers for aggressive and chemoresistant cancers.

15.
Protein Sci ; 31(5): e4306, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35481648

RESUMEN

The essential bacterial division protein in Escherichia coli, FtsZ, assembles into the FtsZ-ring at midcell and recruits other proteins to the division site to promote septation. A region of the FtsZ amino acid sequence that links the conserved polymerization domain to a C-terminal protein interaction site was predicted to be intrinsically disordered and has been implicated in modulating spacing and architectural arrangements of FtsZ filaments. While the majority of cell division proteins that directly bind to FtsZ engage either the polymerization domain or the C-terminal interaction site, ClpX, the recognition and unfolding component of the bacterial ClpXP proteasome, has a secondary interaction with the predicted intrinsically disordered region (IDR) of FtsZ when FtsZ is polymerized. Here, we use NMR spectroscopy and reconstituted degradation reactions in vitro to demonstrate that this linker region is indeed disordered in solution and, further, that amino acids in the IDR of FtsZ enhance the degradation in polymer-guided interactions.


Asunto(s)
Proteínas de Escherichia coli , Péptido Hidrolasas , Proteínas Bacterianas/química , Proteínas del Citoesqueleto/metabolismo , Endopeptidasa Clp/genética , Endopeptidasa Clp/metabolismo , Elementos de Facilitación Genéticos , Escherichia coli/metabolismo , Proteínas de Escherichia coli/química , Péptido Hidrolasas/metabolismo , Polímeros/metabolismo
16.
Cell Host Microbe ; 29(12): 1774-1787.e9, 2021 12 08.
Artículo en Inglés | MEDLINE | ID: mdl-34863371

RESUMEN

Intraerythrocytic malaria parasites proliferate bounded by a parasitophorous vacuolar membrane (PVM). The PVM contains nutrient permeable channels (NPCs) conductive to small molecules, but their relevance for parasite growth for individual metabolites is largely untested. Here we show that growth-relevant levels of major carbon and energy sources pass through the NPCs. Moreover, we find that NPCs are a gate for several antimalarial drugs, highlighting their permeability properties as a critical factor for drug design. Looking into NPC-dependent amino acid transport, we find that amino acid shortage is a reason for the fitness cost in artemisinin-resistant (ARTR) parasites and provide evidence that NPC upregulation to increase amino acids acquisition is a mechanism of ARTR parasites in vitro and in human infections to compensate this fitness cost. Hence, the NPCs are important for nutrient and drug access and reveal amino acid deprivation as a critical constraint in ARTR parasites.


Asunto(s)
Antimaláricos/farmacología , Artemisininas/farmacología , Malaria , Nutrientes , Parásitos , Vacuolas , Aminoácidos , Animales , Diseño de Fármacos , Ejercicio Físico , Humanos , Regulación hacia Arriba
17.
Sci Rep ; 10(1): 5454, 2020 03 25.
Artículo en Inglés | MEDLINE | ID: mdl-32214134

RESUMEN

Today, we face difficulty in generating new hypotheses and understanding oral lichen planus due to the large amount of biomedical information available. In this research, we have used an integrated bioinformatics approach assimilating information from data mining, gene ontologies, protein-protein interaction and network analysis to predict candidate genes related to oral lichen planus. A detailed pathway analysis led us to propose two promising therapeutic targets: the stromal cell derived factor 1 (CXCL12) and the C-X-C type 4 chemokine receptor (CXCR4). We further validated our predictions and found that CXCR4 was upregulated in all oral lichen planus tissue samples. Our bioinformatics data cumulatively support the pathological role of chemokines and chemokine receptors in oral lichen planus. From a clinical perspective, we suggest a drug (plerixafor) and two therapeutic targets for future research.


Asunto(s)
Quimiocina CXCL12/genética , Quimiocina CXCL12/metabolismo , Estudios de Asociación Genética , Liquen Plano Oral/tratamiento farmacológico , Liquen Plano Oral/genética , Terapia Molecular Dirigida , Mucosa Bucal/metabolismo , Receptores CXCR4/genética , Receptores CXCR4/metabolismo , Bencilaminas , Biología Computacional , Ciclamas , Femenino , Compuestos Heterocíclicos/uso terapéutico , Humanos , Masculino , Regulación hacia Arriba
18.
Medicine (Baltimore) ; 99(49): e23373, 2020 Dec 04.
Artículo en Inglés | MEDLINE | ID: mdl-33285719

RESUMEN

Two-dimensional gel electrophoresis (2D-GE) is an indispensable technique for the study of proteomes of biological systems, providing an assessment of changes in protein abundance under various experimental conditions. However, due to the complexity of 2D-GE gels, there is no systematic, automatic, and reproducible protocol for image analysis and specific implementations are required for each context. In addition, practically all available solutions are commercial, which implies high cost and little flexibility to modulate the parameters of the algorithms. Using the bacterial strain, Pseudomonas aeruginosaAG1 as a model, we obtained images from 2D-GE of periplasmic protein profiles when the strain was exposed to multiple conditions, including antibiotics. Then, we proceeded to implement and evaluate an image analysis protocol with open-source software, CellProfiler. First, a preprocessing step included a bUnwarpJ-Image pipeline for aligning 2D-GE images. Then, using CellProfiler, we standardized two pipelines for spots identification. Total spots recognition was achieved using segmentation by intensity, whose performance was evaluated when compared with a reference protocol. In a second pipeline with the same program, differential identification of spots was addressed when comparing pairs of protein profiles. Due to the characteristics of the programs used, our workflow can automatically analyze a large number of images and it is parallelizable, which is an advantage with respect to other implementations. Finally, we compared six experimental conditions of bacterial strain in the presence or absence of antibiotics, determining protein profiles relationships by applying clustering algorithms PCA (Principal Components Analysis) and HC (Hierarchical Clustering).


Asunto(s)
Electroforesis en Gel Bidimensional/métodos , Procesamiento de Imagen Asistido por Computador/métodos , Proteómica/métodos , Pseudomonas aeruginosa/citología , Humanos , Proteómica/instrumentación
19.
PLoS One ; 13(2): e0191600, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29389996

RESUMEN

In a typical questionnaire testing situation, examinees are not allowed to choose which items they answer because of a technical issue in obtaining satisfactory statistical estimates of examinee ability and item difficulty. This paper introduces a new item response theory (IRT) model that incorporates information from a novel representation of questionnaire data using network analysis. Three scenarios in which examinees select a subset of items were simulated. In the first scenario, the assumptions required to apply the standard Rasch model are met, thus establishing a reference for parameter accuracy. The second and third scenarios include five increasing levels of violating those assumptions. The results show substantial improvements over the standard model in item parameter recovery. Furthermore, the accuracy was closer to the reference in almost every evaluated scenario. To the best of our knowledge, this is the first proposal to obtain satisfactory IRT statistical estimates in the last two scenarios.


Asunto(s)
Conducta de Elección , Modelos Teóricos , Humanos , Encuestas y Cuestionarios
20.
Horiz. sanitario (en linea) ; 22(1): 117-123, Jan.-Apr. 2023. tab
Artículo en Español | LILACS-Express | LILACS | ID: biblio-1528695

RESUMEN

Resumen Objetivo: En el tercero de los Objetivos del Desarrollo Sostenible: Salud y Bienestar, se encuentra la meta destinada a fortalecer la prevención y el tratamiento del abuso de sustancias. Se proponen tres objetivos: (1) identificar bibliografía referente al uso de vaporizadores en adolescentes y jóvenes para constatar variables importantes como factores asociados, (2) realizar una recopilación comunitaria mediante entrevistas y foros para reconocer la percepción social del uso de vaporizadores, y (3) determinar, en la población de jóvenes y adolescentes puertorriqueños, la prevalencia del uso de vaporizadores. Materiales y Métodos: Un estudio mixto: cualitativo observacional y transversal analítico fue realizado basado en el modelo conceptual de la Promoción de la Salud (comunitario, individual y científico) con una recopilación de datos consistente en: revisión de 13 artículos, entrevistas a informantes claves que trabajan con la salud y seguridad de jóvenes puertorriqueños, y análisis, utilizando el programado SPSS, de prevalencias del cuestionario puertorriqueño autoadministrado Consulta Juvenil (n=8,603), base de datos secundaria. Resultados: La literatura establece factores asociados como: mercadeo, relación familiar y socialización. Se encontró que las organizaciones visualizan a la promoción de la salud comunitaria como un método preventivo. El 21.9% de estudiantes de escuela superior hacen uso de vaporizadores. 22.1% no saben la sustancia que contiene su vaporizador. Conclusión: La promoción de la salud se basa en políticas públicas favorables, educación en salud, movilización social-comunitaria y trabajo multidisciplinario. Recomendamos que, se practiquen evaluaciones y prevenciones del uso de vaporizadores basados en una salud pública promotora de la salud. De esta manera, se trabajará el Objetivo del Desarrollo Sostenible: Salud y Bienestar, para la protección de generaciones jóvenes y disminuir las prevalencias del uso de sustancias.


Abstract Objective: In the third of the Sustainable Development Goals: Health and Well-being, there is a goal aimed at strengthening the prevention and treatment of substance abuse. Three objectives are proposed: (1) identify a bibliography regarding the use of vaporizers in adolescents and young people to verify important variables as associated factors, and (2) carry out a community compilation through interviews and forums to recognize the social perception of the use of vaporizers, and (3) determine, in the population of Puerto Rican youth and adolescents, the prevalence of the use of vaporizers. Materials and methods: A mixed study: qualitative observational and cross-sectional analytical was carried out with data collection consisting of a review of 13 articles, interviews with key informants who work with the health and safety of young Puerto Ricans, and analysis, using the SPSS program, of the prevalence of the Puerto Rican self-administered questionnaire Consulta Juvenil as a secondary database (n=8,603). Results: The literature establishes associated factors such as marketing, family relationship, and socialization. It was found that organizations view community health promotion as a preventive method. 21.9% of high school students use vaporizers. 22.1% do not know the substance contained in their vaporizer. Conclusion: Health promotion is based on favorable public policies, health education, social- community mobilization, and multidisciplinary work. We recommend that evaluations and prevention of the use of vaporizers be practiced based on health-promoting public health. In this way, the Sustainable Development Goal will be worked on: Health and Well-being for the protection of young generations and to reduce the prevalence of substance use.

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