Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 36
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Environ Sci Technol ; 2024 Jul 04.
Artículo en Inglés | MEDLINE | ID: mdl-38963915

RESUMEN

Investigating the ternary relationship among nanoparticles (NPs), their immediate molecular environment, and test organisms rather than the direct interaction between pristine NPs and test organisms has been thrust into the mainstream of nanotoxicological research. Diverging from previous work that predominantly centered on surrounding molecules affecting the toxicity of NPs by modulating their nanoproperties, this study has unveiled a novel dimension: surrounding molecules altering bacterial susceptibility to NPs, consequently impacting the outcomes of nanobio interaction. The study found that adding nitrate as the surrounding molecules could alter bacterial respiratory pathways, resulting in an enhanced reduction of ceria NPs (nanoceria) on the bacterial surfaces. This, in turn, increased the ion-specific toxicity originating from the release of Ce3+ ions at the nanobio interface. Further transcriptome analysis revealed more mechanistic details underlying the nitrate-induced changes in the bacterial energy metabolism and subsequent toxicity patterns. These findings offer a new perspective for the deconstruction of nanobio interactions and contribute to a more comprehensive understanding of NPs' environmental fate and ecotoxicity.

2.
Dev Cell ; 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38636517

RESUMEN

During enteric nervous system (ENS) development, pioneering wavefront enteric neural crest cells (ENCCs) initiate gut colonization. However, the molecular mechanisms guiding their specification and niche interaction are not fully understood. We used single-cell RNA sequencing and spatial transcriptomics to map the spatiotemporal dynamics and molecular landscape of wavefront ENCCs in mouse embryos. Our analysis shows a progressive decline in wavefront ENCC potency during migration and identifies transcription factors governing their specification and differentiation. We further delineate key signaling pathways (ephrin-Eph, Wnt-Frizzled, and Sema3a-Nrp1) utilized by wavefront ENCCs to interact with their surrounding cells. Disruptions in these pathways are observed in human Hirschsprung's disease gut tissue, linking them to ENS malformations. Additionally, we observed region-specific and cell-type-specific transcriptional changes in surrounding gut tissues upon wavefront ENCC arrival, suggesting their role in shaping the gut microenvironment. This work offers a roadmap of ENS development, with implications for understanding ENS disorders.

3.
Sci Total Environ ; 903: 166608, 2023 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-37640070

RESUMEN

The accumulation, mobilization, and distribution of toxic metal(loid)s in rice are key factors that affect food security and determine bio-utilization patterns. In this study, five soil amendments with different components were used in paddy fields to study the key factors: organic amendments: (1) polyaspartic acid (OA1) and (2) organic fertilizer (OA2); inorganic amendments: (3) kaolinite (IA1) and (4) magnesium slag (IA2); and organic-inorganic composite amendments: (5) modified biochar/quicklime (OIA). Although the Cd and As exhibited opposite chemical dissolution behaviors, IA1/OIA, can simultaneously reduce their accumulation and transfer coefficients in rice tissues, while other amendments only work for one of them. The in situ distribution in grains showed that IA1/OIA changed the original Cd distribution in the lemma and palea, whereas all amendments reduced Cd accumulation in the germ. In contrast, OA1/IA2 amendments led to more As accumulation in the rice husks and bran than in the endosperm center, and the germ had higher As signals. Because of their similar transport pathways and interactions, the concentrations of Cd and As in the grains were correlated with a variety of mineral elements (Fe, Mo, Zn, etc.). Changes in the Cd/As concentration and distribution in rice were achieved through the improvement of soil properties and plant growth behavior through amendments. The application of OIA resulted in the highest immobilization indices, at 82.17 % and 35.34 % for Cd and As, respectively. The Cd/As concentrations in the rice grains were highly positively correlated with extractable-Cd/As in the soil (Cd: R2 = 0.95, As: R2 = 0.93). These findings reveal the migration and distribution mechanisms of Cd and As in the soil-rice system, and thus provide fundamental information for minimizing food safety risk.

4.
Anal Chem ; 95(15): 6391-6398, 2023 04 18.
Artículo en Inglés | MEDLINE | ID: mdl-37019686

RESUMEN

The development of nanotechnology has transformed many cutting-edge studies related to single-molecule analysis into nanoparticle (NP) detection with a single-NP sensitivity and ultrahigh resolution. While laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has been successful in quantifying and tracking NPs, its quantitative calibration remains a major challenge due to the lack of suitable standards and the uncertain matrix effects. Herein, we frame a new approach to prepare quantitative standards via precise synthesis of NPs, nanoscale characterization, on-demand NP distribution, and deep learning-assisted NP counting. Gold NP standards were prepared to cover the mass range from sub-femtogram to picogram levels with sufficient accuracy and precision, thus establishing an unambiguous relationship between the sampled NP number in each ablation and the corresponding mass spectral signal. Our strategy facilitated for the first time the study of the factors affecting particulate sample capture and signal transductions in LA-ICP-MS analysis and culminated in the development of an LA-ICP-MS-based method for absolute NP quantification with single-NP sensitivity and single-cell quantification capability. The achievements would herald the emergence of new frontiers cut across a spectrum of toxicological and diagnostic issues related to NP quantification.


Asunto(s)
Terapia por Láser , Nanopartículas , Espectrometría de Masas/métodos , Análisis Espectral , Rayos Láser
5.
Molecules ; 28(4)2023 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-36838784

RESUMEN

With the widespread applications of manufactured nanoparticles (NPs), there are increasing concerns about their potential adverse effects on the environment and living systems. Many studies demonstrated that NPs could significantly affect the growth and development of crop plants. However, knowledge regarding the impacts of NPs on crop quality is rather limited. In this study, the effects of CeO2 NPs (25, 75, and 225 mg Ce/kg) and CeCl3 (25 mg Ce/kg) on the nutritional components of soil-cultivated corn and soybean plants were evaluated. Both treatments tended to decrease the dry weight of grain per plant, while only 225 mg/kg CeO2 NPs on soybean and CeCl3 on corn showed statistical significance compared with the respective control. CeO2 NPs at 225 mg/kg significantly decreased the content of starch in the corn kernels by 18.2% but increased total phenols in soybean seeds by 18.4%. Neither CeO2 NPs nor CeCl3 significantly affected the contents of minerals in corn kernels except for Zn. However, in the case of soybean, the two treatments tended to decrease the contents of P, Zn, Mn, and Mo but increase the content of S. Overall, the results suggest that CeO2 NPs and Ce3+ ions showed similar but not identical effects on corn and soybean plants. CeO2 NPs affect the nutritional quality of crop plants in a species-dependent manner.


Asunto(s)
Cerio , Nanopartículas del Metal , Nanopartículas , Glycine max , Zea mays , Cerio/farmacología , Valor Nutritivo
6.
Nat Biotechnol ; 41(8): 1107-1116, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-36604543

RESUMEN

Capturing an individual cell's transcriptional history is a challenge exacerbated by the functional heterogeneity of cellular communities. Here, we leverage reprogrammed tracrRNAs (Rptrs) to record selected cellular transcripts as stored DNA edits in single living bacterial cells. Rptrs are designed to base pair with sensed transcripts, converting them into guide RNAs. The guide RNAs then direct a Cas9 base editor to target an introduced DNA target. The extent of base editing can then be read in the future by sequencing. We use this approach, called TIGER (transcribed RNAs inferred by genetically encoded records), to record heterologous and endogenous transcripts in individual bacterial cells. TIGER can quantify relative expression, distinguish single-nucleotide differences, record multiple transcripts simultaneously and read out single-cell phenomena. We further apply TIGER to record metabolic bet hedging and antibiotic resistance mobilization in Escherichia coli as well as host cell invasion by Salmonella. Through RNA recording, TIGER connects current cellular states with past transcriptional states to decipher complex cellular responses in single cells.


Asunto(s)
Sistemas CRISPR-Cas , ARN , ARN/genética , ARN Guía de Sistemas CRISPR-Cas , Bacterias/genética , Bacterias/metabolismo , ADN/genética , Edición Génica , ARN Bacteriano/genética
7.
Front Pediatr ; 10: 979149, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36204664

RESUMEN

Background: Preoperative evaluation of the dysganglionic bowel segment is critical for establishing the optimal resection strategy for Hirschsprung's disease (HSCR), which facilitates patient outcomes. Objective: We set out to determine the utility of the 24-h delayed film of barium retention in predicting the length of dysganglionic bowel segment in HSCR. Materials and methods: A retrospective study of patients with clinically suspicious HSCR who underwent a preoperative 24-h delayed film of barium enema and were surgically treated from January 2015 to December 2019 was conducted. Results: Two hundred and 58 patients were enrolled in this study. The sensitivity, specificity, positive and negative predictive values (NPVs) of the 24-h delayed film of barium enema to predict the neuropathological segment were 89.1, 91.5, 91.3, and 89.4%, respectively. The Youden index was 80.6%, with a kappa value of 0.806 (P < 0.001). The correlation rate between barium retention level and pathological results was 72.7% (16/22) when aganglionosis was restricted within the mid-distal rectum (short-segment type), increasing to 92.0% (46/50) and 93.5% (174/186) for patients that had aganglionosis extended beyond the mid-distal rectum (classical type) and sigmoid colon (long-segment type), respectively. Lastly, patients younger than 3 months showed a lower correlation rate (72.2%) compared to patients aged 3-12 months (91.0%) and > 12 months (92.6%). Conclusions: Our investigation of the 24-h delayed film of barium enema performed for patients suspected of having HSCR indicated that the barium retention level remains crucial in predicting dysganglionic bowel segment, which contributes to the decision-making for surgical physicians.

8.
Pediatr Surg Int ; 38(9): 1263-1271, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35852594

RESUMEN

BACKGROUND: Anastomotic leakage (AL) is one of the most perplexing complications that can occur following a radical operation to treat Hirschsprung disease (HSCR). The purpose of this study was to document our experience with anastomotic leakage following radical HSCR surgery to enhance therapeutic effect and prognosis. METHODS: Between January 2007 and April 2021, a retrospective study was conducted on 12 children who developed anastomotic leakage following radical surgery for HSCR. Medical records were analyzed to determine the clinical manifestations, primary surgical procedures, evaluation methods, surgical plans, and outcomes of the patients. To assess postoperative bowel function, the Rintala score was used. RESULTS: The Soave procedure was used as the primary surgical method in seven cases (58.3%), the Swenson procedure was used in four cases (33.3%), and the Rehbein procedure was used in one case (8.3%). Enterostomy (10, 83.3%) and conservative treatment (2, 16.7%) were performed when anastomotic leakage was diagnosed. Two patients who directly closed stoma without redoing pull-through both accepted enterostomy within 48 h. One female with anastomotic fistula who was closed leakage or fistula in situ had to endure lifelong stoma. Other patients who underwent redo pull-through procedures had normal bowel function. Seven patients underwent a redo pull-through procedure. Three of them preferred the transanal full-thickness pull-through (FTPT) approach, while four preferred the Soave technique. Three children had mild postoperative soiling, which improved with conservative treatment. Bowel function score was 17.5 ± 1.1. CONCLUSION: Enterostomy should be performed immediately if anastomotic leakage occurs. After leakage, it is necessary to redo the pull-through procedure in an anastomotic fistula or anastomotic stricture. Transanal FTPT reconstruction is an effective method for repairing anastomoses and leakage.


Asunto(s)
Procedimientos Quirúrgicos del Sistema Digestivo , Enfermedad de Hirschsprung , Fuga Anastomótica/etiología , Fuga Anastomótica/cirugía , Niño , Procedimientos Quirúrgicos del Sistema Digestivo/métodos , Femenino , Enfermedad de Hirschsprung/complicaciones , Enfermedad de Hirschsprung/cirugía , Humanos , Lactante , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/cirugía , Estudios Retrospectivos , Resultado del Tratamiento
9.
Methods Mol Biol ; 2518: 217-235, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35666448

RESUMEN

CRISPR-based detection and recording technologies are gaining increasing attention in disease surveillance and prevention. In this chapter, we describe how our recent discovery of noncanonical crRNAs inspired the engineering of reprogrammed tracrRNAs and led to a powerful platform for multiplexed RNA detection. We provide detailed protocols regarding how to design reprogrammed tracrRNA and carry out assays in vitro and in vivo.


Asunto(s)
ARN Guía de Kinetoplastida , ARN , Sistemas CRISPR-Cas/genética , ARN/genética , ARN Guía de Kinetoplastida/genética
10.
Nanomaterials (Basel) ; 12(5)2022 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-35269237

RESUMEN

Nanoparticles (NPs) suspension is thermodynamically unstable, agglomeration and sedimentation may occur after introducing NPs into a physiological solution, which in turn affects their recognition and uptake by cells. In this work, rod-like gold NPs (AuNRs) with uniform morphology and size were synthesized to study the impact of bovine serum albumin (BSA) pre-coating on the cellular uptake of AuNRs. A comparison study using horizontal and vertical cell culture configurations was performed to reveal the effect of NPs sedimentation on AuNRs uptake at the single-cell level. Our results demonstrate that the well-dispersed AuNRs-BSA complexes were more stable in culture medium than the pristine AuNRs, and therefore were less taken up by cells. The settled AuNRs agglomerates, although only a small fraction of the total AuNRs, weighed heavily in determining the average AuNRs uptake at the population level. These findings highlight the necessity of applying single-cell quantification analysis in the study of the mechanisms underlying the cellular uptake of NPs.

11.
Environ Sci Technol ; 55(21): 14649-14657, 2021 11 02.
Artículo en Inglés | MEDLINE | ID: mdl-34652129

RESUMEN

The time-course association of soil physicochemical properties and fate of CeO2 nanoparticles (NPs) is not well understood. This study for the first time investigated the dissolution and retention of CeO2 NPs (<25 nm) during soil short-term (6 h) and long-term (30 d) aging processes with dynamic redox conditions. Under the additional reductant-induced initial reductive condition, theoretically, up to 220‰ of Ce(IV) was temporarily reductively dissolved within 10 min, accompanied by a slow retention process (180 min) of Ce species in soil solutions. Conversely, the dissolution and slow retention of Ce species were not significant in soil solutions without added reductant. X-ray absorption near edge spectroscopy (XANES) shows that most of Ce species were present as Ce(IV) (94.0%-97.8%) in all soils after a long-term aging process. These results indicate that the soil dynamic redox conditions induced by oxidant/reductant intrinsically determined the different time-course dissolution and retention of CeO2 NPs, highlighting the occasional reductive condition in soil solution that may contribute to the migration and diffusion of Ce species. The time-course study should be also adopted to develop a comprehensive understanding of the nano-soil interactions.


Asunto(s)
Cerio , Nanopartículas del Metal , Nanopartículas , Oxidación-Reducción , Suelo , Solubilidad
12.
Front Genet ; 12: 684905, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34484289

RESUMEN

Background: Diaphyseal and metaphyseal modeling defects lead to severe changes in bone mass and shape, which are common features in osteoporosis that linked to non-vertebral fractures. Original mechanism of diaphyseal and metaphyseal modeling defects has proved elusive. Studying rare syndromes can elucidate mechanisms of common disorders and identify potential therapeutic targets. Methods: We evaluated a family pedigree with craniometadiaphyseal dysplasia (CRMDD, OMIM 269300), a genetic disorder that is characterized by cortical-bone thinning, limb deformity, and absent of normal metaphyseal flaring and diaphyseal constriction. Systemic radiographic examination and serum hormone test were made for this rare disease. One patient and her two normal parents were examined by means of whole-exome sequencing (WES) to identify the candidate pathogenic gene and rule out mucopolysaccharidosis and Prader-Willi Syndrome by means of Sanger sequencing. Results: There are several conspicuous radiographic characteristics: (1) bullet-shaped phalanges, (2) long and narrow pelvic inlet, absent of supra-acetabular constriction, (3) round rod-shaped long tubular bones, (4) prominent aiploic mastoid, (5) bending-shaped limb, genua varus and genu varum, and (6) congenital dislocation of elbow. Here, we did not find any wormian bones, and there are several typical clinical characteristics: (1) macrocephaly and wide jaw, (2) Avatar elf-shaped ears, pointed and protruding ears, (3) hypertrophy of limbs, (4) flat feet and giant hand phenomenon, (5) nail dystrophy, (6) limb deformity, (7) high-arched palate, (8) superficial hemangiomas, (9) tall stature, and intellectual disability. In this patient, we found biallelic frameshift deletion mutations in WRAP53, and those two mutations were transmitted from her parents respectively. Conclusions: We describe her clinical and radiological findings and presented a new subtype without wormian bones and with a tall stature. Our study showed that craniometadiaphyseal dysplasia was caused by a deficiency of WRAP53 with autosomal recessive inheritance.

13.
Metallomics ; 13(7)2021 07 02.
Artículo en Inglés | MEDLINE | ID: mdl-34100933

RESUMEN

The influence of morphology on the biological effects of nanomaterials (NMs) has not been well understood. In the present study, we compared the phytotoxicity of rod-shaped nano-cerium dioxide (R-CeO2) and nano-cerium phosphate (R-CePO4) to lettuce plants. The results showed that R-CeO2 significantly inhibited the root elongation of lettuce, induced oxidative damages, and caused cell death, while R-CePO4 was nontoxic to lettuce. The different distribution and speciation of Ce in plant tissues were determined by transmission electron microscopy (TEM) and X-ray absorption near edge spectroscopy (XANES) combined with linear combination fitting (LCF). The results showed that in the R-CeO2 group, part of Ce was transformed from Ce(IV) to Ce(III), while only Ce(III) was present in the R-CePO4 group. When interacting with plants, R-CeO2 is easier to be dissolved and transformed than R-CePO4, which might be the reason for their different phytotoxicity. Although both are Ce-based NMs and have the same morphology, the toxicity of R-CeO2 seems to come from the released Ce3+ ions rather than its shape. This research emphasizes the importance of chemical composition and reactivity of NMs to their toxicological effects.


Asunto(s)
Cerio/toxicidad , Lactuca/crecimiento & desarrollo , Nanopartículas del Metal/toxicidad , Estrés Oxidativo , Fosfatos/toxicidad , Raíces de Plantas/crecimiento & desarrollo , Lactuca/efectos de los fármacos , Raíces de Plantas/efectos de los fármacos
14.
J Nanosci Nanotechnol ; 21(11): 5436-5442, 2021 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-33980353

RESUMEN

Quantitatively studying the biodistribution and transformation of nanomaterials is of great importance for nanotoxicological evaluation. Recently, laser ablation inductively coupled plasma mass spectrometry has been employed to distinguish nanoparticles (NPs) with their dissolved ions in biological samples. The principle of the proposal is based on a hypothesis that the intact NPs sampled by laser ablation will generate discrete sharp pulses of signals in ICP-MS measurement, being totally different from the continuous, relatively lower signals generated by ions. However, it is still a controversy whether NPs could maintain their intactness during the laser ablation. This work found a way to exactly determine the number of NPs sampled for each LA-ICP-MS measurement. It made possible to reveal the signal profile of a single NP in LA-ICP-MS analysis. The results suggest that AuNR, AgNP and TIO2 NP were broken into much smaller secondary NPs during the laser ablation, therefore generating continuous signals in the analyzer. There was a certain probability that the fragmentation of large-sized NP or multiple NPs by laser ablation was not sufficient, leaving some NPs unbroken or some secondary NPs with relatively large sizes to generate discrete pulses of signals in the analyzer. When the intactness of NPs during laser ablation cannot be assured, it is impossible to determine the attribution of mass spectrum signals. These findings compromise the reliability of distinguishing NPs from their dissolved ions by LA-ICP-MS.


Asunto(s)
Terapia por Láser , Nanopartículas , Espectrometría de Masas , Reproducibilidad de los Resultados , Distribución Tisular
15.
Science ; 372(6545): 941-948, 2021 05 28.
Artículo en Inglés | MEDLINE | ID: mdl-33906967

RESUMEN

CRISPR-Cas systems recognize foreign genetic material using CRISPR RNAs (crRNAs). In type II systems, a trans-activating crRNA (tracrRNA) hybridizes to crRNAs to drive their processing and utilization by Cas9. While analyzing Cas9-RNA complexes from Campylobacter jejuni, we discovered tracrRNA hybridizing to cellular RNAs, leading to formation of "noncanonical" crRNAs capable of guiding DNA targeting by Cas9. Our discovery inspired the engineering of reprogrammed tracrRNAs that link the presence of any RNA of interest to DNA targeting with different Cas9 orthologs. This capability became the basis for a multiplexable diagnostic platform termed LEOPARD (leveraging engineered tracrRNAs and on-target DNAs for parallel RNA detection). LEOPARD allowed simultaneous detection of RNAs from different viruses in one test and distinguished severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its D614G (Asp614→Gly) variant with single-base resolution in patient samples.


Asunto(s)
Proteína 9 Asociada a CRISPR/metabolismo , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas , ARN Guía de Kinetoplastida/genética , ARN Viral/análisis , ARN/análisis , ARN/genética , SARS-CoV-2/genética , Secuencia de Bases , COVID-19/diagnóstico , COVID-19/virología , Prueba de Ácido Nucleico para COVID-19 , Sistemas CRISPR-Cas , Campylobacter jejuni , Humanos , Hibridación de Ácido Nucleico , ARN Bacteriano/genética , ARN Mensajero/genética , ARN Viral/genética , Glicoproteína de la Espiga del Coronavirus/genética
16.
Inflamm Res ; 70(3): 343-358, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33564933

RESUMEN

BACKGROUND: Activation of intestinal macrophages is implicated in the pathogenesis of neonatal necrotizing enterocolitis (NEC), yet its precise mechanisms remain unclear. OBJECTIVE: The purpose of this study is to investigate the role of macrophages and TNF-α via an inflammatory MicroRNA in NEC. MATERIALS AND METHODS: Immunofluorescence (IF) staining of CD68, iNOS, and Arg-1 was employed to identify phenotypes of macrophage in the intestines of NEC infants and NEC mice. Expression of TNF-α, c-kit, and miR-222 was evaluated by qRT-PCR, Western blot, and immunochemical staining from the tissue samples. RESULTS: Large number of M1 macrophage infiltration was found in the NEC intestines. Expression of CD68, iNOS, and TNF-α were significantly increased, while c-kit was decreased distinctly in the NEC group. In the early phase of NEC mouse model, inhibition of M1 macrophages reduced the incidence of NEC and intestinal inflammation. We found that TNF-α upregulated the expression of miRNA-222 and inhibited the expression of c-kit. Conversely, such decrease of c-kit expression could be reversed by miR-222 antagonists. Furtherly, dual-luciferase assay confirmed that c-kit can be inhibited by miR-222 directly. CONCLUSION: Macrophages activation in NEC intestine results in an increased inflammatory response and TNF-α production, accompanied with miR-222 upregulation and c-kit suppression. Modulations of M1 macrophages, TNF-α or miR-222 may be potential therapeutic targets for NEC treatment.


Asunto(s)
Enterocolitis Necrotizante/inmunología , Macrófagos/inmunología , MicroARNs , Proteínas Proto-Oncogénicas c-kit/inmunología , Factor de Necrosis Tumoral alfa/inmunología , Animales , Enterocolitis Necrotizante/patología , Femenino , Humanos , Recién Nacido , Intestino Delgado/inmunología , Intestino Delgado/patología , Activación de Macrófagos , Masculino , Ratones Endogámicos C57BL , Regulación hacia Arriba
17.
NanoImpact ; 24: 100364, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-35559823

RESUMEN

Phytotoxicity of nanoceria (nCeO2) has been reported, but there are few studies on how to reduce its phytotoxicity. In the present study, we modified nCeO2 with two organophosphates (nCeO2@ATMP and nCeO2@EDTMP) and compared their toxicity to lettuce with that of uncoated nCeO2. The results showed that bare nCeO2 significantly inhibited the root growth of lettuce, leading to oxidative damages and root cell death. In contrast, after surface modification, the toxicity of nCeO2@ATMP to lettuce was weakened, while nCeO2@EDTMP was nontoxic to lettuce. It was found that the surface properties of the modified materials have been changed, resulting in sharp decreases in their bioavailability. Although nCeO2 with and without surface coatings were all transformed when interacting with plants, the absolute contents of Ce(III) in roots treated with modified nCeO2 decreased significantly, which may be the main reason for the reduction of toxicity. This study indicates that it is feasible to reduce the phytotoxicity of nanomaterials through surface coating.


Asunto(s)
Lactuca , Nanopartículas , Nanopartículas/toxicidad , Estrés Oxidativo
18.
NanoImpact ; 22: 100311, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-35559968

RESUMEN

The release of toxic ions from metal-based nanoparticles (NPs) may play an important role in biological effects of NPs. In this life cycle study, physiological and biochemical responses of soil-grown corn (Zea mays) plants exposed to ceria NPs and its ionic counterparts Ce3+ ions at 0, 25, 75 and 225 mg Ce/kg were investigated. Both treatments tended to reduce the fresh weight and height of the plants at 28 days after sowing (DAS), and delay silk appearance and finally decrease fruit weight at harvest. Uptake and distribution of some mineral nutrients, Ca, P, Fe, B, Zn and Mn in the plants were disturbed. None of the treatments significantly affected activities of antioxidant enzymes and MDA contents in the roots and leaves at 28 DAS. At 90 DAS, ceria NPs and Ce3+ ions disturbed the homeostasis of antioxidative systems in the plants, Ce3+ ions at all concentrations provoked significant oxidative damage in the roots and significantly increased MDA levels as compare to the control. The results indicate that the effects of ceria NPs and Ce3+ ions on corn plants varied with different growth stages and ceria NPs had similar but less severe impacts than Ce3+ ions. Speciation analysis revealed there was mutual transformation between CeO2 and Ce3+ in the soil-plant system. It is speculated that Ce3+ ions play a key role in toxicity. To the authors' knowledge, this is the first report of a life cycle study on comparative toxicity of CeO2 NPs and Ce3+ ions on corn plants.


Asunto(s)
Cerio , Nanopartículas del Metal , Antioxidantes/farmacología , Cerio/farmacología , Iones/farmacología , Nanopartículas del Metal/toxicidad , Suelo/química , Zea mays
19.
Front Toxicol ; 3: 753316, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-35295152

RESUMEN

Quantifying the distribution of nanomaterials in complex samples is of great significance to the toxicological research of nanomaterials as well as their clinical applications. Radiotracer technology is a powerful tool for biological and environmental tracing of nanomaterials because it has the advantages of high sensitivity and high reliability, and can be matched with some spatially resolved technologies for non-invasive, real-time detection. However, the radiolabeling operation of nanomaterials is relatively complicated, and fundamental studies on how to optimize the experimental procedures for the best radiolabeling of nanomaterials are still needed. This minireview looks back into the methods of radiolabeling of nanomaterials in previous work, and highlights the superiority of the "last-step" labeling strategy. At the same time, the problems existing in the stability test of radiolabeling and the suggestions for further improvement are also addressed.

20.
J Clin Invest ; 130(12): 6443-6456, 2020 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-32809970

RESUMEN

Interstitial cells of Cajal (ICCs) are pacemaker cells in the intestine, and their function can be compromised by loss of C-KIT expression. Macrophage activation has been identified in intestine affected by Hirschsprung disease-associated enterocolitis (HAEC). In this study, we examined proinflammatory macrophage activation and explored the mechanisms by which it downregulates C-KIT expression in ICCs in colon affected by HAEC. We found that macrophage activation and TNF-α production were dramatically increased in the proximal dilated colon of HAEC patients and 3-week-old Ednrb-/- mice. Moreover, ICCs lost their C-KIT+ phenotype in the dilated colon, resulting in damaged pacemaker function and intestinal dysmotility. However, macrophage depletion or TNF-α neutralization led to recovery of ICC phenotype and restored their pacemaker function. In isolated ICCs, TNF-α-mediated phosphorylation of p65 induced overexpression of microRNA-221 (miR-221), resulting in suppression of C-KIT expression and pacemaker currents. We also identified a TNF-α/NF-κB/miR-221 pathway that downregulated C-KIT expression in ICCs in the colon affected by HAEC. These findings suggest the important roles of proinflammatory macrophage activation in a phenotypic switch of ICCs, representing a promising therapeutic target for HAEC.


Asunto(s)
Colon/metabolismo , Enterocolitis/metabolismo , Enfermedad de Hirschsprung/metabolismo , Células Intersticiales de Cajal/metabolismo , Activación de Macrófagos , Transducción de Señal , Animales , Colon/patología , Enterocolitis/genética , Enterocolitis/patología , Femenino , Enfermedad de Hirschsprung/patología , Humanos , Células Intersticiales de Cajal/patología , Macrófagos , Masculino , Ratones , Ratones Noqueados , MicroARNs/genética , MicroARNs/metabolismo , FN-kappa B/genética , FN-kappa B/metabolismo , Receptor de Endotelina B/genética , Receptor de Endotelina B/metabolismo , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/metabolismo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...