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1.
FASEB J ; 38(1): e23355, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-38071609

RESUMEN

Drosophila melanogaster (fruit fly) insulin receptor (D-IR) is highly homologous to the human counterpart. Like the human pathway, D-IR responds to numerous insulin-like peptides to activate cellular signals that regulate growth, development, and lipid metabolism in fruit flies. Allelic mutations in the D-IR kinase domain elevate life expectancy in fruit flies. We developed a robust heterologous expression system to express and purify wild-type and longevity-associated mutant D-IR kinase domains to investigate enzyme kinetics and substrate specificities. D-IR exhibits remarkable similarities to the human insulin receptor kinase domain but diverges in substrate preferences. We show that longevity-associated mutations reduce D-IR catalytic activity. Deletion of the unique kinase insert domain portion or mutations proximal to activating tyrosines do not influence kinase activity, suggesting their potential role in substrate recruitment and downstream signaling. Through biochemical investigations, this study enhances our comprehension of D-IR's role in Drosophila physiology, complementing genetic studies and expanding our knowledge on the catalytic functions of this conserved signaling pathway.


Asunto(s)
Proteínas de Drosophila , Drosophila , Humanos , Animales , Drosophila/metabolismo , Receptor de Insulina/genética , Receptor de Insulina/metabolismo , Drosophila melanogaster/metabolismo , Longevidad/genética , Transducción de Señal/fisiología , Insulina/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo
2.
J Biol Chem ; 299(9): 105115, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37527777

RESUMEN

Erythropoietin-producing hepatoma (Eph) receptor tyrosine kinases regulate the migration and adhesion of cells that are required for many developmental processes and adult tissue homeostasis. In the intestinal epithelium, Eph signaling controls the positioning of cell types along the crypt-villus axis. Eph activity can suppress the progression of colorectal cancer (CRC). The most frequently mutated Eph receptor in metastatic CRC is EphB1. However, the functional effects of EphB1 mutations are mostly unknown. We expressed and purified the kinase domains of WT and five cancer-associated mutant EphB1 and developed assays to assess the functional effects of the mutations. Using purified proteins, we determined that CRC-associated mutations reduce the activity and stability of the folded structure of EphB1. By mammalian cell expression, we determined that CRC-associated mutant EphB1 receptors inhibit signal transducer and activator of transcription 3 and extracellular signal-regulated kinases 1 and 2 signaling. In contrast to the WT, the mutant EphB1 receptors are unable to suppress the migration of human CRC cells. The CRC-associated mutations also impair cell compartmentalization in an assay in which EphB1-expressing cells are cocultured with ligand (ephrin B1)-expressing cells. These results suggest that somatic mutations impair the kinase-dependent tumor suppressor function of EphB1 in CRC.


Asunto(s)
Neoplasias Colorrectales , Receptor EphB1 , Animales , Humanos , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/fisiopatología , Mutación , Receptor EphB1/genética , Receptor EphB1/metabolismo , Transducción de Señal/fisiología , Línea Celular , Activación Enzimática/genética , Estabilidad Proteica , Sistema de Señalización de MAP Quinasas/genética , Movimiento Celular/genética
3.
Conserv Biol ; 38(4): e14257, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38545678

RESUMEN

The expanding use of community science platforms has led to an exponential increase in biodiversity data in global repositories. Yet, understanding of species distributions remains patchy. Biodiversity data from social media can potentially reduce the global biodiversity knowledge gap. However, practical guidelines and standardized methods for harvesting such data are nonexistent. Following data privacy and protection safeguards, we devised a standardized method for extracting species distribution records from Facebook groups that allow access to their data. It involves 3 steps: group selection, data extraction, and georeferencing the record location. We present how to structure keywords, search for species photographs, and georeference localities for such records. We further highlight some challenges users might face when extracting species distribution data from Facebook and suggest solutions. Following our proposed framework, we present a case study on Bangladesh's biodiversity-a tropical megadiverse South Asian country. We scraped nearly 45,000 unique georeferenced records across 967 species and found a median of 27 records per species. About 12% of the distribution data were for threatened species, representing 27% of all species. We also obtained data for 56 DataDeficient species for Bangladesh. If carefully harvested, social media data can significantly reduce global biodiversity knowledge gaps. Consequently, developing an automated tool to extract and interpret social media biodiversity data is a research priority.


Un protocolo para recolectar datos sobre biodiversidad en Facebook Resumen El uso creciente de plataformas de ciencia comunitaria ha causado un incremento exponencial de los datos sobre biodiversidad en los repositorios mundiales. Sin embargo, el conocimiento sobre la distribución de las especies todavía está incompleto. Los datos sobre biodiversidad obtenidos de las redes sociales tienen el potencial para disminuir el vacío de conocimiento sobre la biodiversidad mundial. No obstante, no existe una guía práctica o un método estandarizado para recolectar dichos datos. Seguimos los protocolos de privacidad y protección de datos para diseñar un método estandarizado para extraer registros de la distribución de especies de grupos en Facebook que permiten el acceso a sus datos. El método consta de tres pasos: selección del grupo, extracción de datos y georreferenciación de la localidad registrada. También planteamos cómo estructurar las palabras clave, buscar fotografías de especies y georreferenciar las localidades de dichos registros. Además, resaltamos algunos retos que los usuarios pueden enfrentar al extraer los datos de distribución de Facebook y sugerimos algunas soluciones. Aplicamos nuestro marco de trabajo propuesto a un estudio de caso de la biodiversidad en Bangladesh, un país tropical megadiverso en el sureste de Asia. Reunimos casi 45,000 registros georreferenciados únicos para 967 especies y encontramos una media de 27 registros por especie. Casi el 12% de los datos de distribución correspondió a especies amenazadas, que representaban el 27% de todas las especies. También obtuvimos datos para 56 especies deficientes de datos en Bangladesh. Si los datos de las redes sociales se recolectan con cuidado, éstos pueden reducir de forma significativa el vacío de conocimiento para la biodiversidad mundial. Como consecuencia, es una prioridad para la investigación el desarrollo de una herramienta automatizada para extraer e interpretar los datos sobre biodiversidad de las redes sociales.


Asunto(s)
Biodiversidad , Conservación de los Recursos Naturales , Medios de Comunicación Sociales , Conservación de los Recursos Naturales/métodos , Bangladesh , Especies en Peligro de Extinción
4.
Conserv Biol ; 38(1): e14161, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37551776

RESUMEN

Citizen science plays a crucial role in helping monitor biodiversity and inform conservation. With the widespread use of smartphones, many people share biodiversity information on social media, but this information is still not widely used in conservation. Focusing on Bangladesh, a tropical megadiverse and mega-populated country, we examined the importance of social media records in conservation decision-making. We collated species distribution records for birds and butterflies from Facebook and Global Biodiversity Information Facility (GBIF), grouped them into GBIF-only and combined GBIF and Facebook data, and investigated the differences in identifying critical conservation areas. Adding Facebook data to GBIF data improved the accuracy of systematic conservation planning assessments by identifying additional important conservation areas in the northwest, southeast, and central parts of Bangladesh, extending priority conservation areas by 4,000-10,000 km2 . Community efforts are needed to drive the implementation of the ambitious Kunming-Montreal Global Biodiversity Framework targets, especially in megadiverse tropical countries with a lack of reliable and up-to-date species distribution data. We highlight that conservation planning can be enhanced by including available data gathered from social media platforms.


Registros de las redes sociales para guiar la planeación de la conservación Resumen La ciencia ciudadana es importante para monitorear la biodiversidad e informar la conservación. Con el creciente uso de los teléfonos inteligentes, muchas personas comparten información de la biodiversidad en redes sociales, pero todavía no se usa ampliamente en la conservación. Analizamos la importancia de los registros de las redes sociales para las decisiones de conservación enfocados en Bangladesh, un país tropical megadiverso y mega poblado. Cotejamos los registros de distribución de especies de aves y mariposas en Facebook y Global Biodiversity Information Facility (GBIF), las agrupamos en datos sólo de GBIF o datos combinados de Facebook y GBIF e investigamos las diferencias en la identificación de las áreas de conservación críticas. La combinación de los datos de Facebook con los de GBIF mejoró la precisión de las evaluaciones de la planeación de la conservación sistemática al identificar otras áreas importantes de conservación en el noroeste, sureste y centro de Bangladesh, extendiendo así las áreas prioritarias de conservación en unos 4,000-10,000 km2 . Se requieren esfuerzos comunitarios para impulsar la implementación de los objetivos ambiciosos del Marco Global de Biodiversidad Kunming-Montreal, especialmente en países tropicales que carecen de datos confiables y actuales sobre la distribución de las especies. Destacamos que la planeación de la conservación puede mejorarse si se incluye información tomada de las redes sociales.


Asunto(s)
Mariposas Diurnas , Medios de Comunicación Sociales , Humanos , Animales , Conservación de los Recursos Naturales , Biodiversidad , Aves
5.
J Biol Chem ; 298(12): 102664, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36334623

RESUMEN

Human Tnk1 (thirty-eight negative kinase 1) is a member of the Ack family of nonreceptor tyrosine kinases. Tnk1 contains a sterile alpha motif, a tyrosine kinase catalytic domain, an SH3 (Src homology 3) domain, and a large C-terminal region that contains a ubiquitin association domain. However, specific physiological roles for Tnk1 have not been characterized in depth. Here, we expressed and purified Tnk1 from Sf9 insect cells and established an in vitro assay system using a peptide substrate derived from the Wiskott-Aldrich Syndrome Protein (WASP). By Tnk1 expression in mammalian cells, we found that the N-terminal SAM domain is important for self-association and kinase activity. We also studied a fusion protein, originally discovered in a Hodgkin's Lymphoma cell line, that contains an unrelated sequence from the C17ORF61 gene fused to the C-terminus of Tnk1. Cells expressing the fusion protein showed increased tyrosine phosphorylation of cellular substrates relative to cells expressing WT Tnk1. A truncated Tnk1 construct (residues 1-465) also showed enhanced phosphorylation, indicating that the C17ORF61 sequence was dispensable for the effect. Additionally, in vitro kinase assays with the WASP peptide substrate showed no increase in intrinsic Tnk1 activity in C-terminally truncated constructs, suggesting that the truncations did not simply remove an autoinhibitory element. Fluorescence microscopy experiments demonstrated that the C-terminus of Tnk1 plays an important role in the subcellular localization of the kinase. Taken together, our data suggest that the noncatalytic regions of Tnk1 play important roles in governing activity and substrate phosphorylation.


Asunto(s)
Proteínas Tirosina Quinasas , Dominios Homologos src , Humanos , Proteínas Fetales/metabolismo , Mamíferos/metabolismo , Péptidos/metabolismo , Fosforilación , Proteínas Tirosina Quinasas/metabolismo , Especificidad por Sustrato , Tirosina/metabolismo
6.
Bioscience ; 73(6): 453-459, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37397834

RESUMEN

Citizen science programs are becoming increasingly popular among naturalists but remain heavily biased taxonomically and geographically. However, with the explosive popularity of social media and the near-ubiquitous availability of smartphones, many post wildlife photographs on social media. Here, we illustrate the potential of harvesting these data to enhance our biodiversity understanding using Bangladesh, a tropical biodiverse country, as a case study. We compared biodiversity records extracted from Facebook with those from the Global Biodiversity Information Facility (GBIF), collating geospatial records for 1013 unique species, including 970 species from Facebook and 712 species from GBIF. Although most observation records were biased toward major cities, the Facebook records were more evenly spatially distributed. About 86% of the Threatened species records were from Facebook, whereas the GBIF records were almost entirely Of Least Concern species. To reduce the global biodiversity data shortfall, a key research priority now is the development of mechanisms for extracting and interpreting social media biodiversity data.

7.
Mem Cognit ; 50(8): 1694-1705, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-35426069

RESUMEN

How do we form opinions about typical and morally acceptable behavior in other social groups despite variability in behavior? Similar learning problems arise during language acquisition, where learners need to infer grammatical rules (e.g., the walk/walk-ed past-tense) despite frequent exceptions (e.g., the go/went alternation). Such rules need to occur with many different words to be learned (i.e., they need a high type frequency). In contrast, frequent individual words do not lead to learning. Here, we ask whether similar principles govern social learning. Participants read a travel journal where a traveler observed behaviors in different imaginary cities. The behaviors were performed once by many distinct actors (high type frequency) or frequently by a single actor (low type frequency), and could be good, neutral or bad. We then asked participants how morally acceptable the behavior was (in general or for the visited city), and how widespread it was in that city. We show that an ideal observer model estimating the prevalence of behaviors is only sensitive to the behaviors' type frequency, but not to how often they are performed. Empirically, participants rated high type frequency behaviors as more morally acceptable more prevalent than low type frequency behaviors. They also rated good behaviors as more acceptable and prevalent than neutral or bad behaviors. These results suggest that generic learning mechanisms and epistemic biases constrain social learning, and that type frequency can drive inferences about groups. To combat stereotypes, high type frequency behaviors might thus be more effective than frequently appearing individual role models.


Asunto(s)
Desarrollo del Lenguaje , Aprendizaje , Humanos , Lenguaje , Actitud
8.
J Infect Dis ; 224(2): 332-344, 2021 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-33606878

RESUMEN

BACKGROUND: Multidrug-resistant (MDR) tuberculosis has low treatment success rates, and new treatment strategies are needed. We explored whether treatment with active vitamin D3 (vitD) and phenylbutyrate (PBA) could improve conventional chemotherapy by enhancing immune-mediated eradication of Mycobacterium tuberculosis. METHODS: A clinically relevant model was used consisting of human macrophages infected with M. tuberculosis isolates (n = 15) with different antibiotic resistance profiles. The antimicrobial effect of vitD+PBA, was tested together with rifampicin or isoniazid. Methods included colony-forming units (intracellular bacterial growth), messenger RNA expression analyses (LL-37, ß-defensin, nitric oxide synthase, and dual oxidase 2), RNA interference (LL-37-silencing in primary macrophages), and Western blot analysis and confocal microscopy (LL-37 and LC3 protein expression). RESULTS: VitD+PBA inhibited growth of clinical MDR tuberculosis strains in human macrophages and strengthened intracellular growth inhibition of rifampicin and isoniazid via induction of the antimicrobial peptide LL-37 and LC3-dependent autophagy. Gene silencing of LL-37 expression enhanced MDR tuberculosis growth in vitD+PBA-treated macrophages. The combination of vitD+PBA and isoniazid were as effective in reducing intracellular MDR tuberculosis growth as a >125-fold higher dose of isoniazid alone, suggesting potent additive effects of vitD+PBA with isoniazid. CONCLUSIONS: Immunomodulatory agents that trigger multiple immune pathways can strengthen standard MDR tuberculosis treatment and contribute to next-generation individualized treatment options for patients with difficult-to-treat pulmonary tuberculosis.


Asunto(s)
Péptidos Antimicrobianos/inmunología , Colecalciferol/farmacología , Agentes Inmunomoduladores/farmacología , Tuberculosis Resistente a Múltiples Medicamentos , Antibióticos Antituberculosos/farmacología , Células Cultivadas , Humanos , Isoniazida/farmacología , Macrófagos/inmunología , Macrófagos/microbiología , Mycobacterium tuberculosis , Rifampin/farmacología , Tuberculosis Resistente a Múltiples Medicamentos/tratamiento farmacológico , Tuberculosis Resistente a Múltiples Medicamentos/inmunología
9.
Public Health Nutr ; 24(5): 1009-1020, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-32327006

RESUMEN

OBJECTIVE: Chronic undernutrition is a common phenomenon in Bangladesh. However, information is grossly lacking to report the correlation between chronic undernutrition trajectory and lung function in children. The aim of the current study was to understand the association between early-childhood chronic undernutrition trajectory and lung function at preadolescence. DESIGN: The current study is a part of the 9-year follow-up of a large-scale cohort study called the Maternal and Infant Nutrition Interventions in Matlab. SETTINGS: The current study was conducted in Matlab, a sub-district area of Bangladesh that is located 53 km south of the capital, Dhaka. PARTICIPANTS: A total of 517 children participated in lung function measured with a spirometer at the age of 9 years. Weight and height were measured at five intervals from birth till the age of 9 years. RESULTS: Over half of the cohort have experienced a stunting undernutrition phenomenon up to 9 years of age. Children who were persistently or intermittently stunted showed lower forced expiratory volume (ml/s) than normal-stature children (P < 0·05). Children who exhibited catch-up growth throughout 4·5 years from the stunted group showed similar lung function with normal counterparts, and a better lung function than in children with the same growth velocity or who had faltering growth. In the multivariable models, similar associations were observed in children who experienced catch-up growth than their counterparts after adjusting for covariates. CONCLUSION: Our data suggest that catch-up growth in height during early childhood is associated with a better lung function at preadolescence.


Asunto(s)
Desnutrición , Bangladesh/epidemiología , Niño , Preescolar , Estudios de Cohortes , Trastornos del Crecimiento/epidemiología , Trastornos del Crecimiento/etiología , Humanos , Lactante , Pulmón , Desnutrición/complicaciones , Desnutrición/epidemiología
10.
Infect Immun ; 88(8)2020 07 21.
Artículo en Inglés | MEDLINE | ID: mdl-32513857

RESUMEN

Infections caused by multidrug-resistant (MDR) Klebsiella pneumoniae are difficult to treat with conventional antibiotics. Thus, alternative strategies to control the growth of MDR Klebsiella are warranted. We hypothesized that activation of innate effector systems could sensitize MDR K. pneumoniae to conventional antibiotics. Thus, human primary macrophages were stimulated with compounds known to activate innate immunity (vitamin D3, phenylbutyrate [PBA], and the aroylated phenylenediamine HO53) and then infected with MDR Klebsiella in the presence or absence of antibiotics. Antibiotics alone were ineffective against MDR Klebsiella in the cellular model, whereas vitamin D3, PBA, and HO53 reduced intracellular growth by up to 70%. The effect was further improved when the innate activators were combined with antibiotics. Vitamin D3- and PBA-induced bacterial killing was dependent on CAMP gene expression, whereas HO53 needed the production of reactive oxygen species (ROS), as shown in cells where the CYBB gene was silenced and in cells from a patient with reduced ROS production due to a deletion in the CYBB gene and skewed lyonization. The combination of innate effector activation by vitamin D3, PBA, and HO53 was effective in sensitizing MDR Klebsiella to conventional antibiotics in a primary human macrophage model. This study provides new evidence for future treatment options for K. pneumoniae.


Asunto(s)
Antibacterianos/farmacología , Colecalciferol/farmacología , Farmacorresistencia Bacteriana Múltiple/efectos de los fármacos , Klebsiella pneumoniae/efectos de los fármacos , Macrófagos/efectos de los fármacos , Fenilbutiratos/farmacología , Fenilendiaminas/farmacología , Péptidos Catiónicos Antimicrobianos/deficiencia , Péptidos Catiónicos Antimicrobianos/genética , Péptidos Catiónicos Antimicrobianos/inmunología , Sinergismo Farmacológico , Regulación de la Expresión Génica , Interacciones Huésped-Patógeno , Humanos , Inmunidad Innata , Klebsiella pneumoniae/crecimiento & desarrollo , Klebsiella pneumoniae/inmunología , Activación de Macrófagos/efectos de los fármacos , Macrófagos/inmunología , Macrófagos/microbiología , Pruebas de Sensibilidad Microbiana , NADPH Oxidasa 2/deficiencia , NADPH Oxidasa 2/genética , NADPH Oxidasa 2/inmunología , Fagocitosis/efectos de los fármacos , Cultivo Primario de Células , Especies Reactivas de Oxígeno/agonistas , Especies Reactivas de Oxígeno/metabolismo , Catelicidinas
11.
J Muscle Res Cell Motil ; 40(2): 185-196, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-31254136

RESUMEN

Vascular smooth muscle cells (VSMCs) are the predominant cell type in the blood vessel wall and normally adopt a quiescent, contractile phenotype. VSMC migration is tightly controlled, however, disease associated changes in the soluble and insoluble environment promote VSMC migration. Classically, studies investigating VSMC migration have described the influence of soluble factors. Emerging data has highlighted the importance of insoluble factors, including extracellular matrix stiffness and porosity. In this review, we will recap on the important signalling pathways that regulate VSMC migration and reflect on the potential importance of emerging regulators of VSMC function.


Asunto(s)
Movimiento Celular , Matriz Extracelular/metabolismo , Músculo Liso Vascular/metabolismo , Miocitos del Músculo Liso/metabolismo , Animales , Humanos
12.
BMC Public Health ; 19(1): 1631, 2019 Dec 04.
Artículo en Inglés | MEDLINE | ID: mdl-31801496

RESUMEN

BACKGROUND: Human Immunodeficiency Virus (HIV), Hepatitis, and Tuberculosis (TB) are three primary communicable infections have the likely potential to cause severe morbidity in prison settings. The prison has the most favorable environment for the transmission of infections. We conducted this survey to determine the prevalence and feasibility of rapid diagnostic tests in an active screening of these infectious diseases in prison. METHODS: This cross-sectional survey conducted in central Jail Gaddani, one of the largest prisons in the Balochistan province of Pakistan. All prisoners, jail staffs, and staff's family members participated. Informed consent obtained from each participant before the screening. Van equipped with digital X-ray linked with Computer-Aided Detection for TB (CAD4TB) software used for testing. Sputum samples tested on Xpert for MTB/RIF assay and blood specimens collected for HIV and hepatitis serology. Diagnosed TB patients enrolled for treatment at Basic Management Unit (BMU), reactive on hepatitis Rapid Diagnostic Tools (RDTs) were referred for further testing and management, while HIV reactive referred to Anti Retro Viral (ARV) center for Anti Retro Viral Treatment (ART). RESULTS: A total of 567 participants offered screening, 63% (356) prisoners, 23% (129) staff's family members, and 14% (82) jail staffs. Among tested 10.3% (58/562) were hepatitis seropositive (Hepatitis-C 41 [7.29%] Hepatitis-B, 16 [2.84%] Hepatitis B&C both, 01 [0.17%]). In reactive participants, 49 were prisoners, 08 were jail staffs, and 01 was the staff's family member. HIV seropositive was 4% (24/566), and all were prisoners. Almost 99% (565/567) screened by digital X-ray, 172 (30%) were with abnormal CAD4TB suggestion (score > 50), out of them sputum of 26% (148) tested on Xpert, and 2% (03) found Mycobacterium tuberculosis Positive (MTB+). A total of five TB patients were detected; out of two were diagnosed clinically. Co-morbidities observed in 15 patients, (01 TB/HIV co-infected, 12 HIV/HCV, 01 HIV/HBV, and 01 HBV/HCV). CONCLUSION: The high frequency of infectious diseases in prison is alarming. For limiting the transmission of infections among prison and community, immediate steps are needed to be taken for improvement of prisons condition by application of recommended screening protocols at the time of the first entry of prisoners in prisons.


Asunto(s)
Infecciones por VIH/epidemiología , Hepatitis B/epidemiología , Hepatitis C/epidemiología , Prisiones/estadística & datos numéricos , Tuberculosis/epidemiología , Síndrome de Inmunodeficiencia Adquirida/epidemiología , Adulto , Comorbilidad , Estudios Transversales , Femenino , Anticuerpos contra la Hepatitis C/sangre , Humanos , Masculino , Tamizaje Masivo/organización & administración , Tamizaje Masivo/estadística & datos numéricos , Persona de Mediana Edad , Pakistán/epidemiología , Prevalencia , Prisioneros/estadística & datos numéricos , Esputo/microbiología , Adulto Joven
13.
Mol Pharm ; 15(9): 3962-3968, 2018 09 04.
Artículo en Inglés | MEDLINE | ID: mdl-30036484

RESUMEN

Angiopoietin-1 (Ang1) is a vascular protective ligand that acts through the receptor tyrosine kinase Tie2 to enhance endothelial survival and quiescence. In sepsis, diabetic retinopathy, and a range of other diseases, Ang2, an antagonist of Tie2, increases markedly. This antagonist suppresses Ang1 protective effects leading to vascular destabilization, inflammation, and endothelial death. Administration of recombinant Ang1 can counter Ang2 antagonism and restore vascular function. However, recombinant Ang1 is needed at sufficiently high concentrations to block Ang2, and the protein is difficult to produce, requires mammalian expression systems, and is prone to aggregation. Here we present an engineered synthetic Tie2 ligand that is not antagonized by Ang2 but is easy to produce and more robust than Ang1. Using a peptide phage display, we isolated a heptameric sequence that binds Tie2-ectodomain and fused this to the coiled:coil domain of cartilage oligomeric matrix protein. This pentameric protein is 60 kDa in size, expressed in E. coli, and facile to purify. The protein, designated TSL1, binds to Tie2-ectodomain in vitro and on the cell surface. TSL1 inhibits endothelial apoptosis. Crucially, TSL1 binds at a site on Tie2 distinct from the angiopoietin-binding site and is resistant to antagonism by Ang2. This engineered ligand has several advantages over recombinant Ang1 for potential therapeutic applications. The study also highlights the value of orthogonal ligands for regulating cellular receptors without being subject to antagonism or modulation by endogenous ligands.


Asunto(s)
Angiopoyetina 2/metabolismo , Biblioteca de Péptidos , Receptor TIE-2/metabolismo , Angiopoyetina 2/genética , Apoptosis/genética , Apoptosis/fisiología , Células Endoteliales/citología , Células Endoteliales/metabolismo , Ensayo de Inmunoadsorción Enzimática , Escherichia coli/genética , Escherichia coli/metabolismo , Citometría de Flujo , Células Endoteliales de la Vena Umbilical Humana , Humanos , Inmunoprecipitación , Receptor TIE-2/genética
14.
Nanotechnology ; 29(39): 395401, 2018 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-29968570

RESUMEN

Research and development on all-solid-state, flexible supercapacitors is the prime concern of the scientific community these days due to their various advantages including their easy transportability, miniaturization, and compactness in different appliances. We report the novel configuration of all-solid symmetrical supercapacitors employing free-standing, flexible films of poly(3,4-ethylenedioxythiophene) poly(styrene sulfonate) (PEDOT:PSS) and its nanocomposite electrodes with graphene nanoplatelets (GNPs), separated by ionic liquid (IL) (1-ethyl 3-methylimidazolium trifluoromethanesulfonate (EMITf))-based gel polymer electrolyte (GPE) films. The free-standing and flexible form of PEDOT:PSS/GNP nanocomposite films have been prepared via simple mixing of the two counterparts. Scanning electron microscopy, x-ray diffraction, Raman analysis, and thermal and mechanical characterizations have been performed to ascertain the suitability of pristine and nanocomposite PEDOT:PSS films as potential supercapacitor electrodes. The GPE film, comprising of a solution of NH4CF3SO3 (NH4-triflate or NH4Tf) in IL, entrapped in poly(vinylidine fluoride-co-hexafluoropropylene) (PVdF-HFP), is a promising electrolyte due to its high ionic conductivity and sufficient electrochemical stability window. The supercapacitor with a PEDOT:PSS nanocomposite containing ∼3.8 wt.% of GNP has been found to give an optimum specific capacitance of ∼106 F g-1 (evaluated from electrochemical impedance spectroscopy), and specific energy and power of ∼6.95 Wh kg-1 and 2.58 kW kg-1, respectively (evaluated from galvanostatic charge-discharge). More importantly, the capacitors demonstrate stable performance for more than 2000 charge-discharge cycles, with only ∼10% initial fading in capacitance. Interestingly, the PEDOT:PSS/GNP nanocomposite-based solid-state supercapacitors with the IL-incorporated GPE have shown comparable (even better) performance than other reported PEDOT:PSS-based supercapacitors.

15.
BMC Infect Dis ; 18(1): 303, 2018 07 04.
Artículo en Inglés | MEDLINE | ID: mdl-29973153

RESUMEN

BACKGROUND: We have previously shown that 8 weeks' treatment with phenylbutyrate (PBA) (500mgx2/day) with or without vitamin D3 (vitD3) (5000 IU/day) as host-directed therapy (HDT) accelerated clinical recovery, sputum culture conversion and increased expression of cathelicidin LL-37 by immune cells in a randomized, placebo-controlled trial in adults with pulmonary tuberculosis (TB). In this study we further aimed to examine whether HDT with PBA and vitD3 promoted clinically beneficial immunomodulation to improve treatment outcomes in TB patients. METHODS: Cytokine concentration was measured in supernatants of peripheral blood mononuclear cells (PBMC) from patients (n = 31/group). Endoplasmic reticulum stress-related genes (GADD34 and XBP1spl) and human beta-defensin-1 (HBD1) gene expression were studied in monocyte-derived-macrophages (MDM) (n = 18/group) from PBMC of patients. Autophagy in MDM (n = 6/group) was evaluated using LC3 expression by confocal microscopy. RESULTS: A significant decline in the concentration of cytokines/chemokines was noted from week 0 to 8 in the PBA-group [TNF-α (ß = - 0.34, 95% CI = - 0.68, - 0.003; p = 0.04), CCL11 (ß = - 0.19, 95% CI = - 0.36, - 0.03; p = 0.02) and CCL5 (ß = - 0.08, 95% CI = - 0.16, 0.002; p = 0.05)] and vitD3-group [(CCL11 (ß = - 0.17, 95% CI = - 0.34, - 0.001; p = 0.04), CXCL10 (ß = - 0.38, 95% CI = - 0.77, 0.003; p = 0.05) and PDGF-ß (ß = - 0.16, 95% CI = - 0.31, 0.002; p = 0.05)] compared to placebo. Both PBA- and vitD3-groups showed a decline in XBP1spl mRNA on week 8 (p < 0.03). All treatment groups demonstrated increased LC3 expression in MDM compared to placebo over time (p < 0.037). CONCLUSION: The use of PBA and vitD3 as adjunct therapy to standard TB treatment promoted favorable immunomodulation to improve treatment outcomes. TRIALS REGISTRATION: This trial was retrospectively registered in clinicaltrials.gov, under identifier NCT01580007 .


Asunto(s)
Tuberculosis Pulmonar/inmunología , Vitamina D/uso terapéutico , Vitaminas/uso terapéutico , Adulto , Péptidos Catiónicos Antimicrobianos/metabolismo , Colecalciferol , Citocinas/sangre , Estrés del Retículo Endoplásmico , Femenino , Humanos , Leucocitos Mononucleares , Macrófagos/inmunología , Masculino , Persona de Mediana Edad , Fenilbutiratos , ARN Mensajero , Estudios Retrospectivos , Resultado del Tratamiento , Tuberculosis Pulmonar/tratamiento farmacológico , Adulto Joven , beta-Defensinas , Catelicidinas
16.
Arch Toxicol ; 92(8): 2487-2500, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-29947889

RESUMEN

Exposure to inorganic arsenic (As), a carcinogen and epigenetic toxicant, has been associated with lower circulating levels of insulin-like growth factor 1 (IGF1) and impaired growth in children of pre-school age. The aim of this study was to assess the potential impact of exposure to As on IGF1 and insulin-like growth factor-binding protein 3 (IGFBP3) as well as DNA methylation changes in 9-year-old children. To this end, we studied 9-year-old children from a longitudinal mother-child cohort in rural Bangladesh (n = 551). Prenatal and concurrent exposure to As was assessed via concentrations in maternal urine at gestational week 8 and in child urine at 9 years, measured by HPLC-HG-ICPMS. Plasma IGF1 and IGFBP3 concentrations were quantified with immunoassays. DNA methylation was measured in blood mononuclear cells at 9 years in a sub-sample (n = 113) using the Infinium HumanMethylation450K BeadChip. In multivariable-adjusted linear regression models, prenatal As (natural log-transformed), but not children's concurrent urinary As, was positively associated with IGFBP3 concentrations (ß = 76, 95% CI 19, 133). As concentrations were not associated with IGF1. DNA methylation analysis revealed CpGs associated with both prenatal As and IGFBP3. Mediation analysis suggested that methylation of 12 CpG sites for all children was mediator of effect for the association between prenatal As and IGFBP3. We also found differentially methylated regions, generally hypermethylated, that were associated with both prenatal As and IGFBP3. In all, our study revealed that prenatal exposure to As was positively associated with IGFBP3 concentrations in children at 9 years, independent of IGF1, and this association may, at least in part, be epigenetically mediated.


Asunto(s)
Arsénico/toxicidad , Metilación de ADN/efectos de los fármacos , Proteína 3 de Unión a Factor de Crecimiento Similar a la Insulina/sangre , Efectos Tardíos de la Exposición Prenatal/sangre , Arsénico/orina , Bangladesh , Niño , Femenino , Humanos , Proteína 3 de Unión a Factor de Crecimiento Similar a la Insulina/genética , Factor I del Crecimiento Similar a la Insulina/análisis , Estudios Longitudinales , Masculino , Embarazo , Regiones Promotoras Genéticas , Población Rural
17.
Med Princ Pract ; 27(6): 501-507, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30173215

RESUMEN

Rheumatoid arthritis (RA) is a chronic, inflammatory, systemic autoimmune disease, affecting the joints with varying severity among patients. The risk factors include age, gender, genetics, and environmental exposure (cigarette smoking, air pollutants, and occupational). Many complications can follow, such as permanent joint damage requiring arthroplasty, rheumatoid vasculitis, and Felty syndrome requiring splenectomy if it remains unaddressed. As there is no cure for RA, the treatment goals are to reduce the pain and stop/slow further damage. Here, we present a brief summary of various past and present treatment modalities to address the complications associated with RA.


Asunto(s)
Artritis Reumatoide/tratamiento farmacológico , Corticoesteroides/efectos adversos , Corticoesteroides/uso terapéutico , Analgésicos Opioides/uso terapéutico , Antiinflamatorios no Esteroideos/efectos adversos , Antiinflamatorios no Esteroideos/uso terapéutico , Anticuerpos Monoclonales Humanizados/uso terapéutico , Antirreumáticos/efectos adversos , Antirreumáticos/uso terapéutico , Artritis Reumatoide/complicaciones , Artritis Reumatoide/cirugía , Humanos , Inmunosupresores/uso terapéutico , Proteína Antagonista del Receptor de Interleucina 1/uso terapéutico , Leflunamida/uso terapéutico , Modalidades de Fisioterapia , Factores de Riesgo , Factor de Necrosis Tumoral alfa/uso terapéutico
18.
Pak J Med Sci ; 32(2): 329-32, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27182233

RESUMEN

OBJECTIVE: To confirm that either Fibrinolytic therapy or open decortication which of the two is an effective First line treatment of pleural empyema. METHODS: This prospective comparative study was conducted in the department of surgery Sheikh Zayed Medical College and Hospital, Rahim Yaar Khan. Seventy eight (78) patients were included in this study. There were two groups of patients; Group I (n=35) patients treated with fibrinolytic therapy, Group II (n=43) patients treated with open decortication. Data was entered and analyzed in SPSS v16. Student's t-test was used for comparison of quantitative variables. Chi-square and Fisher's Exact test were used for comparison of qualitative variables. P-value ≤ 0.05 was taken as significant difference. RESULTS: There was no significant difference in base baseline characteristics of patients of Group I and II. Incidence of comorbidities was also same between the groups. Most of the patients in Group I and II were in empyema stage III. Fluid cultures was positive in 33 (94.3%) patients in group I and 39 (90.7%) patients in group II. 30 (85.7%) was successfully treated using fibrinolytic therapy but this therapy failed in five (14.3%) patients, two of these patients expired within the hospital. There was only one (2.3%) treatment failure in open decortication Group that patient expired within the hospital (p-value 0.04). Overall duration of hospitalization was significantly high in fibrinolytic group, this was 17.6± 1.95 days versus 12.09± 2.18 days in open decortication group (p-value<0.0001). There was no significant difference regarding operative mortality within the two groups. CONCLUSION: Open Drainage is associated with better outcomes as compared to fibrinolytic therapy when used as a First line treatment of empyema.

19.
Cureus ; 16(7): e64806, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-39156475

RESUMEN

Meningitis due to Staphylococcus aureus is extremely rare, with an annual incidence of 1-3%. In this report, we present a rare case involving meningitis, an infected graft, and an infected fluid collection with two forms of S. aureus in a patient who received a bovine brain graft status post-decompression and suboccipital craniectomy with C1 laminectomy and duraplasty for Chiari malformation. The treatment approach included surgical debridement and graft retention, followed by an extended course of antibiotic treatment with oxacillin and rifampin. The patient successfully completed 12 weeks of total antibiotic therapy and was transitioned to suppressive therapy indefinitely with cefadroxil. This case highlights the importance of prompt identification and treatment of S. aureus meningitis due to the high mortality associated with this disease.

20.
FEBS J ; 2024 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-39428852

RESUMEN

DAF-2, the Caenorhabditis elegans insulin-like receptor homolog, regulates larval development, metabolism, stress response, and lifespan. The availability of numerous daf-2 mutant alleles has made it possible to elucidate the genetic mechanisms underlying these physiological processes. The DAF-2 pathway is significantly conserved with the human insulin/IGF-1 signaling pathway; it includes proteins homologous to human IRS, GRB-2, and PI3K, making it an important model to investigate human pathological conditions. We expressed and purified the kinase domain of wild-type DAF-2 to examine the catalytic activity and substrate specificity of the enzyme. Like the human insulin receptor kinase, DAF-2 kinase phosphorylates tyrosines within specific YxN or YxxM motifs, which are important for recruiting downstream effectors. DAF-2 kinase phosphorylated peptides derived from the YxxM and YxN motifs located in the C-terminal extension of the receptor tyrosine kinase, consistent with the idea that the DAF-2 receptor may possess independent signaling capacity. Unlike the human insulin or IGF-1 receptor kinases, DAF-2 kinase was poorly inhibited by the small-molecule inhibitor linsitinib. We also expressed and purified mutant kinases corresponding to daf-2 alleles that result in partial loss-of-function phenotypes in C. elegans. These mutations caused a complete loss of kinase function in vitro. Our biochemical investigations provide new insights into DAF-2 kinase function, and the approach should be useful for studying other mutations to shed light on DAF-2 signaling in C. elegans physiology.

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