Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 24
Filtrar
1.
Mod Pathol ; 37(2): 100398, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38043788

RESUMO

Immunohistochemistry (IHC) is a well-established and commonly used staining method for clinical diagnosis and biomedical research. In most IHC images, the target protein is conjugated with a specific antibody and stained using diaminobenzidine (DAB), resulting in a brown coloration, whereas hematoxylin serves as a blue counterstain for cell nuclei. The protein expression level is quantified through the H-score, calculated from DAB staining intensity within the target cell region. Traditionally, this process requires evaluation by 2 expert pathologists, which is both time consuming and subjective. To enhance the efficiency and accuracy of this process, we have developed an automatic algorithm for quantifying the H-score of IHC images. To characterize protein expression in specific cell regions, a deep learning model for region recognition was trained based on hematoxylin staining only, achieving pixel accuracy for each class ranging from 0.92 to 0.99. Within the desired area, the algorithm categorizes DAB intensity of each pixel as negative, weak, moderate, or strong staining and calculates the final H-score based on the percentage of each intensity category. Overall, this algorithm takes an IHC image as input and directly outputs the H-score within a few seconds, significantly enhancing the speed of IHC image analysis. This automated tool provides H-score quantification with precision and consistency comparable to experienced pathologists but at a significantly reduced cost during IHC diagnostic workups. It holds significant potential to advance biomedical research reliant on IHC staining for protein expression quantification.


Assuntos
Aprendizado Profundo , Humanos , Imuno-Histoquímica , Hematoxilina/metabolismo , Algoritmos , Núcleo Celular/metabolismo
2.
bioRxiv ; 2023 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-38106214

RESUMO

Spatially resolved transcriptomics (SRT) techniques have revolutionized the characterization of molecular profiles while preserving spatial and morphological context. However, most next-generation sequencing-based SRT techniques are limited to measuring gene expression in a confined array of spots, capturing only a fraction of the spatial domain. Typically, these spots encompass gene expression from a few to hundreds of cells, underscoring a critical need for more detailed, single-cell resolution SRT data to enhance our understanding of biological functions within the tissue context. Addressing this challenge, we introduce BayesDeep, a novel Bayesian hierarchical model that leverages cellular morphological data from histology images, commonly paired with SRT data, to reconstruct SRT data at the single-cell resolution. BayesDeep effectively model count data from SRT studies via a negative binomial regression model. This model incorporates explanatory variables such as cell types and nuclei-shape information for each cell extracted from the paired histology image. A feature selection scheme is integrated to examine the association between the morphological and molecular profiles, thereby improving the model robustness. We applied BayesDeep to two real SRT datasets, successfully demonstrating its capability to reconstruct SRT data at the single-cell resolution. This advancement not only yields new biological insights but also significantly enhances various downstream analyses, such as pseudotime and cell-cell communication.

3.
ACS Omega ; 8(26): 24042-24052, 2023 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-37426247

RESUMO

Direct CO2 methylation with toluene, as one of the CO2 hydrogenation technologies, exhibits great potential for the CO2 utilization to produce the valuable para-xylene (PX), but the tandem catalysis remains a challenge for low conversion and selectivity due to the competitive side reactions. The thermodynamic analyses and the comparation with two series of catalytic results of direct CO2 methylation are conducted to investigate the product distribution and possible mechanism in adjusting the feasibility of higher conversion and selectivity. Based on the Gibbs energy minimization method, the optimal thermodynamic conditions for direct CO2 methylation are 360-420 °C, 3 MPa with middle CO2/C7H8 ratio (1:1 to 1:4) and high H2 feed (CO2/H2 = 1:3 to 1:6). As a tandem process, the toluene feed would break the thermodynamic limit and has the higher potential of >60% CO2 conversion than that of CO2 hydrogenation without toluene. The direct CO2 methylation route also has advantages over the methanol route with a good prospect for >90% PX selectivity in its isomers due to the dynamic effect of selective catalysis. These thermodynamic and mechanistic analyses would promote the optimal design of bifunctional catalysts for CO2 conversion and product selectivity from the view of reaction pathways of the complex system.

4.
Waste Manag ; 168: 45-53, 2023 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-37276633

RESUMO

Dioxins in municipal solid waste incineration fly ash (MSWIFA) can cause significant risks to the environment and human health. In this study, the low-temperature thermal treatment of MSWIFA under industrial conditions was simulated in the laboratory to investigate the process parameters for dioxin degradation and ash discharge stages. Correlation analysis and dioxin fingerprint characterization were used to analyze the degradation and ash discharge processes. The degradation efficiency of low-temperature thermal treatment was influenced by multiple factors. At 400℃ for 90 min and 1% O2, the dioxin removal rate was 95.80%, the detoxification rate was 91.73%, and the residual dioxin toxicity in MSWIFA was 22.7 ± 17.8 ng I-TEQ/kg, which was in line with the limit value of 50 ng I-TEQ/kg in the "Technical specification for pollution control of fly-ash from municipal solid waste incineration" (HJ1134-2020). The increase in dioxins during ash discharge did not follow a linear relationship with the process parameters. This was assumed to be related to the MSWIFA composition, as some components containing P, Si, and Al at 150 °C may inhibit dioxin formation. The dioxin increased only by 0.79 ± 2.65 ng/kg, an increase in toxicity of 0.42 ± 0.10 ng I-TEQ/kg, when treated at 150 °C for 30 min and 10% O2.


Assuntos
Dioxinas , Dibenzodioxinas Policloradas , Humanos , Incineração , Resíduos Sólidos , Cinza de Carvão , Temperatura , Dibenzodioxinas Policloradas/análise
5.
Genes (Basel) ; 14(4)2023 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-37107679

RESUMO

Polyploidy, the duplication of the entire genome within a single cell, is a significant characteristic of cells in many tissues, including the liver. The quantification of hepatic ploidy typically relies on flow cytometry and immunofluorescence (IF) imaging, which are not widely available in clinical settings due to high financial and time costs. To improve accessibility for clinical samples, we developed a computational algorithm to quantify hepatic ploidy using hematoxylin-eosin (H&E) histopathology images, which are commonly obtained during routine clinical practice. Our algorithm uses a deep learning model to first segment and classify different types of cell nuclei in H&E images. It then determines cellular ploidy based on the relative distance between identified hepatocyte nuclei and determines nuclear ploidy using a fitted Gaussian mixture model. The algorithm can establish the total number of hepatocytes and their detailed ploidy information in a region of interest (ROI) on H&E images. This is the first successful attempt to automate ploidy analysis on H&E images. Our algorithm is expected to serve as an important tool for studying the role of polyploidy in human liver disease.


Assuntos
Aprendizado Profundo , Humanos , Amarelo de Eosina-(YS) , Hematoxilina , Fígado , Ploidias , Poliploidia
6.
Mod Pathol ; 36(8): 100196, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37100227

RESUMO

Microscopic examination of pathology slides is essential to disease diagnosis and biomedical research. However, traditional manual examination of tissue slides is laborious and subjective. Tumor whole-slide image (WSI) scanning is becoming part of routine clinical procedures and produces massive data that capture tumor histologic details at high resolution. Furthermore, the rapid development of deep learning algorithms has significantly increased the efficiency and accuracy of pathology image analysis. In light of this progress, digital pathology is fast becoming a powerful tool to assist pathologists. Studying tumor tissue and its surrounding microenvironment provides critical insight into tumor initiation, progression, metastasis, and potential therapeutic targets. Nucleus segmentation and classification are critical to pathology image analysis, especially in characterizing and quantifying the tumor microenvironment (TME). Computational algorithms have been developed for nucleus segmentation and TME quantification within image patches. However, existing algorithms are computationally intensive and time consuming for WSI analysis. This study presents Histology-based Detection using Yolo (HD-Yolo), a new method that significantly accelerates nucleus segmentation and TME quantification. We demonstrate that HD-Yolo outperforms existing WSI analysis methods in nucleus detection, classification accuracy, and computation time. We validated the advantages of the system on 3 different tissue types: lung cancer, liver cancer, and breast cancer. For breast cancer, nucleus features by HD-Yolo were more prognostically significant than both the estrogen receptor status by immunohistochemistry and the progesterone receptor status by immunohistochemistry. The WSI analysis pipeline and a real-time nucleus segmentation viewer are available at https://github.com/impromptuRong/hd_wsi.


Assuntos
Neoplasias da Mama , Aprendizado Profundo , Humanos , Feminino , Microambiente Tumoral , Algoritmos , Processamento de Imagem Assistida por Computador/métodos , Neoplasias da Mama/patologia
7.
Semin Diagn Pathol ; 40(2): 109-119, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36890029

RESUMO

Over the past decade, many new cancer treatments have been developed and made available to patients. However, in most cases, these treatments only benefit a specific subgroup of patients, making the selection of treatment for a specific patient an essential but challenging task for oncologists. Although some biomarkers were found to associate with treatment response, manual assessment is time-consuming and subjective. With the rapid developments and expanded implementation of artificial intelligence (AI) in digital pathology, many biomarkers can be quantified automatically from histopathology images. This approach allows for a more efficient and objective assessment of biomarkers, aiding oncologists in formulating personalized treatment plans for cancer patients. This review presents an overview and summary of the recent studies on biomarker quantification and treatment response prediction using hematoxylin-eosin (H&E) stained pathology images. These studies have shown that an AI-based digital pathology approach can be practical and will become increasingly important in improving the selection of cancer treatments for patients.


Assuntos
Aprendizado Profundo , Neoplasias , Humanos , Inteligência Artificial , Medicina de Precisão/métodos , Neoplasias/terapia , Neoplasias/patologia
8.
Sci Total Environ ; 875: 162565, 2023 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-36889396

RESUMO

Dioxin degradation is considered essential for the environmentally sound management of municipal solid waste incineration fly ash (MSWIFA). Among the many degradation techniques, thermal treatment has shown good prospects owing to its high efficiency and wide range of applications. Thermal treatment is divided into high-temperature thermal, microwave thermal, hydrothermal, and low-temperature thermal treatments. High-temperature sintering and melting not only have dioxin degradation rates higher than 95 % but also remove volatile heavy metals, although energy consumption is high. High-temperature industrial co-processing effectively solves the problem of energy consumption, but with a low fly ash (FA) mixture, and the process is limited by location. Microwave thermal treatment and hydrothermal treatment are still in the experimental stage and cannot be used for large-scale processing. The dioxin degradation rate of low-temperature thermal treatment can also be stabilized at higher than 95 %. Compared to other methods, low-temperature thermal treatment is less costly and energy consumption with no restriction on location. This review comprehensively compares the current status of the above-mentioned thermal treatment methods and their ability to dispose of MSWIFA, especially the potential for large-scale processing. Then, the respective characteristics, challenges, and application prospects of different thermal treatment methods were discussed. Finally, based on the goal of low carbon and emission reduction, three possible approaches for improvement were proposed to address the challenges of large-scale processing of low-temperature thermal treatment, namely, adding a catalyst, changing the FA fraction, or supplementing with blockers, providing a reasonable development direction for the degradation of dioxins in MSWIFA.

9.
Am J Pathol ; 193(4): 404-416, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36669682

RESUMO

Whole slide imaging is becoming a routine procedure in clinical diagnosis. Advanced image analysis techniques have been developed to assist pathologists in disease diagnosis, staging, subtype classification, and risk stratification. Recently, deep learning algorithms have achieved state-of-the-art performances in various imaging analysis tasks, including tumor region segmentation, nuclei detection, and disease classification. However, widespread clinical use of these algorithms is hampered by their performances often degrading due to image quality issues commonly seen in real-world pathology imaging data such as low resolution, blurring regions, and staining variation. Restore-Generative Adversarial Network (GAN), a deep learning model, was developed to improve the imaging qualities by restoring blurred regions, enhancing low resolution, and normalizing staining colors. The results demonstrate that Restore-GAN can significantly improve image quality, which leads to improved model robustness and performance for existing deep learning algorithms in pathology image analysis. Restore-GAN has the potential to be used to facilitate the applications of deep learning models in digital pathology analyses.


Assuntos
Algoritmos , Patologistas , Humanos , Núcleo Celular , Processamento de Imagem Assistida por Computador , Coloração e Rotulagem
10.
J Pers Med ; 12(7)2022 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-35887522

RESUMO

Objectives-To investigate the clinical characteristics, managements, outcome, and evaluate the risk factors of Multisystem (MS) Langerhans Cell Histiocytosis (LCH) with diverse skin lesions as the first sign in four young infants. Methods-Their clinical features, disease progression, therapy, and outcomes were reviewed and analyzed retrospectively. Results-The average onset age of skin lesions was about 2 months. Cases 1 and 2 had risk organs involved (RO+) and a lack of bone lesions, and progression could not be reversed by systemic chemotherapy. They both died eventually. Cases 3 and 4 (RO-) had bone involvement and were given systemic chemotherapy for a prolonged duration. Unluckily, Case 3 had a recurrence 2 years later, while Case 4's recurrence happened nearly one year later, and diabetes insipidus one and a half years later. They both survived and are still in remission. Conclusion-MS-LCH infants with a low age of the first presentation in the skin are prone to dissemination, while RO+ is associated with high mortality. In addition, bone involvement may be a protective factor. Immunohistochemical examination of skin tissue facilitates correct early diagnosis, and adequate follow-up is necessary.

11.
Cell ; 184(5): 1262-1280.e22, 2021 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-33636129

RESUMO

Improving effector activity of antigen-specific T cells is a major goal in cancer immunotherapy. Despite the identification of several effector T cell (TEFF)-driving transcription factors (TFs), the transcriptional coordination of TEFF biology remains poorly understood. We developed an in vivo T cell CRISPR screening platform and identified a key mechanism restraining TEFF biology through the ETS family TF, Fli1. Genetic deletion of Fli1 enhanced TEFF responses without compromising memory or exhaustion precursors. Fli1 restrained TEFF lineage differentiation by binding to cis-regulatory elements of effector-associated genes. Loss of Fli1 increased chromatin accessibility at ETS:RUNX motifs, allowing more efficient Runx3-driven TEFF biology. CD8+ T cells lacking Fli1 provided substantially better protection against multiple infections and tumors. These data indicate that Fli1 safeguards the developing CD8+ T cell transcriptional landscape from excessive ETS:RUNX-driven TEFF cell differentiation. Moreover, genetic deletion of Fli1 improves TEFF differentiation and protective immunity in infections and cancer.


Assuntos
Linfócitos T CD8-Positivos/citologia , Proteína Proto-Oncogênica c-fli-1/metabolismo , Animais , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Sistemas CRISPR-Cas , Diferenciação Celular , Doença Crônica , Subunidade alfa 3 de Fator de Ligação ao Core/metabolismo , Epigênese Genética , Redes Reguladoras de Genes , Infecções/imunologia , Camundongos , Neoplasias/imunologia
12.
Transl Pediatr ; 9(5): 677-685, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33209731

RESUMO

BACKGROUND: To analyze the expression and clinical significance of murine double minute 2 (MDM2), lysosome-associated membrane protein (LAMP1) and P-glycoprotein (P-gp) in children with acute lymphoblastic leukemia (ALL). METHODS: Thirty-three children with ALL who were admitted to our hospital between January 2017 and January 2018 were enrolled as the ALL group. The expression of MDM2, LAMP1 and P-gp was compared between the two groups, as well as between ALL patients with different clinical characteristics. Logistic regression was used to analyze the risk factors that affect the prognosis and survival of ALL patients. Kaplan-Meier survival curves were used to analyze the correlations of MDM2, LAMP1 and P-gp on the prognosis and survival of ALL patients. RESULTS: The expression levels of MDM2, LAMP1 and P-gp in the ALL group were higher than those in the control group (P<0.05). The average survival time of the group with low expression of MDM2 was (34.92±0.56) months, the average survival time of the group with high expression of MDM2 was (31.32±0.42) months, and the difference was statistically significant (P<0.05). The average survival time of the group with low expression of LAMP1 was (36.71±0.55) months, the average survival time of the group with high expression of LAMP1 was (29.87±0.40) months, the difference was statistically significant (P<0.05). The average survival time of the group with low expression of P-gp was (36.29±0.41) months, the average survival time of the group with high expression of P-gp was (26.46±0.37) months, and the difference was statistically significant (P<0.05). CONCLUSIONS: Abnormal expression levels of MDM2, LAMP1 and P-gp protein are related to the occurrence and development of ALL, and are closely related to patient prognosis and survival. Therefore, MDM2, LAMP1and P-gp can serve as molecular markers for predicting the prognosis of children with ALL.

13.
Nat Cancer ; 1(5): 533-545, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32984844

RESUMO

Cancer cells express high levels of PD-L1, a ligand of the PD-1 receptor on T cells, allowing tumors to suppress T cell activity. Clinical trials utilizing antibodies that disrupt the PD-1/PD-L1 checkpoint have yielded remarkable results, with anti-PD-1 immunotherapy approved as first-line therapy for lung cancer patients. We used CRISPR-based screening to identify regulators of PD-L1 in human lung cancer cells, revealing potent induction of PD-L1 upon disruption of heme biosynthesis. Impairment of heme production activates the integrated stress response (ISR), allowing bypass of inhibitory upstream open reading frames in the PD-L1 5' UTR, resulting in enhanced PD-L1 translation and suppression of anti-tumor immunity. We demonstrated that ISR-dependent PD-L1 translation requires the translation initiation factor eIF5B. eIF5B overexpression, which is frequent in lung adenocarcinomas and associated with poor prognosis, is sufficient to induce PD-L1. These findings illuminate mechanisms of immune checkpoint activation and identify targets for therapeutic intervention.


Assuntos
Antígeno B7-H1 , Fatores de Iniciação em Eucariotos , Neoplasias Pulmonares , Antígeno B7-H1/genética , Fatores de Iniciação em Eucariotos/genética , Heme/biossíntese , Humanos , Neoplasias Pulmonares/genética
14.
Gastroenterology ; 158(6): 1698-1712.e14, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31972235

RESUMO

BACKGROUND & AIMS: Thirty to 90% of hepatocytes contain whole-genome duplications, but little is known about the fates or functions of these polyploid cells or how they affect development of liver disease. We investigated the effects of continuous proliferative pressure, observed in chronically damaged liver tissues, on polyploid cells. METHODS: We studied Rosa-rtTa mice (controls) and Rosa-rtTa;TRE-short hairpin RNA mice, which have reversible knockdown of anillin, actin binding protein (ANLN). Transient administration of doxycycline increases the frequency and degree of hepatocyte polyploidy without permanently altering levels of ANLN. Mice were then given diethylnitrosamine and carbon tetrachloride (CCl4) to induce mutations, chronic liver damage, and carcinogenesis. We performed partial hepatectomies to test liver regeneration and then RNA-sequencing to identify changes in gene expression. Lineage tracing was used to rule out repopulation from non-hepatocyte sources. We imaged dividing hepatocytes to estimate the frequency of mitotic errors during regeneration. We also performed whole-exome sequencing of 54 liver nodules from patients with cirrhosis to quantify aneuploidy, a possible outcome of polyploid cell divisions. RESULTS: Liver tissues from control mice given CCl4 had significant increases in ploidy compared with livers from uninjured mice. Mice with knockdown of ANLN had hepatocyte ploidy above physiologic levels and developed significantly fewer liver tumors after administration of diethylnitrosamine and CCl4 compared with control mice. Increased hepatocyte polyploidy was not associated with altered regenerative capacity or tissue fitness, changes in gene expression, or more mitotic errors. Based on lineage-tracing experiments, non-hepatocytes did not contribute to liver regeneration in mice with increased polyploidy. Despite an equivalent rate of mitosis in hepatocytes of differing ploidies, we found no lagging chromosomes or micronuclei in mitotic polyploid cells. In nodules of human cirrhotic liver tissue, there was no evidence of chromosome-level copy number variations. CONCLUSIONS: Mice with increased polyploid hepatocytes develop fewer liver tumors following chronic liver damage. Remarkably, polyploid hepatocytes maintain the ability to regenerate liver tissues during chronic damage without generating mitotic errors, and aneuploidy is not commonly observed in cirrhotic livers. Strategies to increase numbers of polypoid hepatocytes might be effective in preventing liver cancer.


Assuntos
Carcinoma Hepatocelular/genética , Hepatócitos/fisiologia , Neoplasias Hepáticas/genética , Regeneração Hepática/genética , Poliploidia , Animais , Tetracloreto de Carbono/toxicidade , Carcinoma Hepatocelular/induzido quimicamente , Carcinoma Hepatocelular/patologia , Células Cultivadas , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Doença Hepática Induzida por Substâncias e Drogas/patologia , Dietilnitrosamina/toxicidade , Feminino , Técnicas de Silenciamento de Genes , Hepatectomia , Hepatócitos/efeitos dos fármacos , Humanos , Fígado/citologia , Fígado/efeitos dos fármacos , Fígado/patologia , Cirrose Hepática/genética , Cirrose Hepática/patologia , Neoplasias Hepáticas/induzido quimicamente , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas Experimentais/induzido quimicamente , Neoplasias Hepáticas Experimentais/genética , Neoplasias Hepáticas Experimentais/patologia , Regeneração Hepática/efeitos dos fármacos , Masculino , Camundongos , Camundongos Transgênicos , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Cultura Primária de Células , Fatores de Proteção , RNA-Seq , Sequenciamento do Exoma
15.
Brain Res ; 1724: 146440, 2019 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-31513789

RESUMO

BACKGROUND: Previous studies have estimated that the risk of recurrent stroke was nearly 20% shortly after a transient ischemic attack (TIA) or minor stroke. A missing or hypoplastic (<0.5 mm) anterior communicating artery can have deleterious effects on the brain. Our study aimed to investigate the effect of anterior communicating artery flow on neurovascular injury and neurobehavioral outcomes in mice with recurrent stroke and to identify its underlying mechanisms. METHODS: A recurrent stroke model was established by an initial cortical infarction followed by a corticostriatal infarction 3 days later. The vascular structure was visualized using synchrotron radiation angiography & magnetic resonance angiography in vivo and transparent endovascular perfusion imaging in vitro. Microvessel perfusion was assessed via fluorescein isothiocyanate perfusion. The infarct volume was measured by magnetic resonance imaging. RESULTS: The finding that anterior communicating artery flow facilitates pial artery patency in the ipsilateral hemisphere in mice with recurrent stroke suggests that compensatory collateral patency contributes to increased regional cerebral blood flow, enhanced microcirculatory perfusion, improved neurological function and reduced infarct volume. CONCLUSIONS: The results of this study demonstrate that anterior communicating artery flow alleviates recurrent stroke-induced neurovascular injury and improves neurobehavioral outcomes by promoting the establishment of collateral circulation.


Assuntos
Isquemia Encefálica/patologia , Circulação Cerebrovascular/fisiologia , Ataque Isquêmico Transitório/patologia , Animais , Artéria Cerebral Anterior , Encéfalo/fisiopatologia , Estenose das Carótidas/patologia , Infarto Cerebral/patologia , China , Círculo Arterial do Cérebro/patologia , Circulação Colateral/fisiologia , Feminino , Imageamento por Ressonância Magnética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microcirculação , Acidente Vascular Cerebral/fisiopatologia
16.
J Neuroinflammation ; 16(1): 168, 2019 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-31426811

RESUMO

BACKGROUND: Functions of astrocytes in the rehabilitation after ischemic stroke, especially their impacts on inflammatory processes, remain controversial. This study uncovered two phenotypes of astrocytes, of which one was helpful, and the other harmful to anoxic neurons after brain ischemia. METHODS: We tested the levels of inflammatory factors including TNF-a, IL-6, IL-10, iNOS, IL-1beta, and CXCL10 in primary astrocytes at 0 h, 6 h, 12 h, 24 h, and 48 h after OGD, grouped the hypoxia astrocytes into iNOS-positive (iNOS(+)) and iNOS-negative (iNOS(-)) by magnetic bead sorting, and then co-cultured the two groups of cells with OGD-treated neurons for 24 h. We further verified the polarization of astrocytes in vivo by detecting the co-localization of iNOS, GFAP, and Iba-1 on MCAO brain sections. Lentivirus overexpressing LCN2 and LCN2 knockout mice (#024630. JAX, USA) were used to explore the role of LCN2 in the functional polarization of astrocytes. 7.0-T MRI scanning and the modified Neurological Severity Score (mNSS) were used to evaluate the neurological outcomes of the mice. RESULTS: After oxygen-glucose deprivation (OGD), iNOS mRNA expression increased to the peak at 6 h in primary astrocytes, but keep baseline expression in LCN2-knockout astrocytes. In mice with transient middle cerebral artery occlusion (tMCAO), LCN2 was proved necessary for astrocyte classical activation. In LCN2 knockout mice with MCAO, no classically activated astrocytes were detected, and smaller infarct volumes and better neurological functions were observed. CONCLUSIONS: The results indicated a novel pattern of astrocyte activation after ischemic stroke and lipocalin-2 (LCN2) plays a key role in polarizing and activating astrocytes.


Assuntos
Astrócitos/metabolismo , Astrócitos/patologia , Isquemia Encefálica/metabolismo , Isquemia Encefálica/patologia , Lipocalina-2/deficiência , Animais , Isquemia Encefálica/genética , Células Cultivadas , Feminino , Lipocalina-2/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
17.
Proc Natl Acad Sci U S A ; 116(3): 982-987, 2019 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-30593560

RESUMO

Phosphatase PP2A expression levels are positively correlated to the clinical severity of systemic lupus erythematosus (SLE) and IL17A cytokine overproduction, indicating a potential role of PP2A in controlling TH17 differentiation and inflammation. By generating a mouse strain with ablation of the catalytic subunit α of PP2A in peripheral mature T cells (PP2A cKO), we demonstrate that the PP2A complex is essential for TH17 differentiation. These PP2A cKO mice had reduced TH17 cell numbers and less severe disease in an experimental autoimmune encephalomyelitis (EAE) model. PP2A deficiency also ablated C-terminal phosphorylation of SMAD2 but increased C-terminal phosphorylation of SMAD3. By regulating the activity of RORγt via binding, the changes in the phosphorylation status of these R-SMADs reduced Il17a gene transcription. Finally, PP2A inhibitors showed similar effects on TH17 cells as were observed in PP2A cKO mice, i.e., decreased TH17 differentiation and relative protection of mice from EAE. Taken together, these data demonstrate that phosphatase PP2A is essential for TH17 differentiation and that inhibition of PP2A could be a possible therapeutic approach to controlling TH17-driven autoimmune diseases.


Assuntos
Diferenciação Celular , Encefalomielite Autoimune Experimental , Proteína Fosfatase 2 , Células Th17/imunologia , Transcrição Gênica/imunologia , Animais , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Encefalomielite Autoimune Experimental/genética , Encefalomielite Autoimune Experimental/imunologia , Encefalomielite Autoimune Experimental/patologia , Interleucina-17/genética , Interleucina-17/imunologia , Camundongos , Camundongos Knockout , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/genética , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/imunologia , Fosforilação/genética , Fosforilação/imunologia , Proteína Fosfatase 2/genética , Proteína Fosfatase 2/imunologia , Proteína Smad2/genética , Proteína Smad2/imunologia , Células Th17/patologia
18.
J Neurosci ; 37(43): 10498-10515, 2017 10 25.
Artigo em Inglês | MEDLINE | ID: mdl-28924010

RESUMO

Toll-like receptor 4 (TLR4) is a proinflammatory cascade initiator in poststroke inflammation. In this study, miR-1906, a novel regulator of TLR4, was identified via in silico analysis and microRNA profiling in male adult mice and its expression was then quantitated in the ischemic hemisphere. We found miR-1906 to be significantly brain enriched in the ischemic hemisphere and even more drastically enriched in the peri-infarct regions. Furthermore, in vitro experiments demonstrated that, during oxygen-glucose deprivation, miR-1906 expression was increased in glial cells but decreased in neurons. Surprisingly, despite the augmentation of intracellular abundance, miR-1906 expression in extracellular vesicles was decreased in astrocyte cell culture supernatants, suggesting reduced sources of miR-1906 from glia to neurons. When exogenous miR-1906 was administered, decreased TLR4 protein expression was observed both in vitro and in vivo Using Cy3 labeling, exogenous miR-1906 uptake by astrocytes, microglia, and neurons was visualized directly in vivo Reduced infarct volumes and improved functional outcomes were observed in middle cerebral artery occlusion mice receiving miR-1906. However, the protective effects of miR-1906 disappeared with the genetic knock-out of TLR4, suggesting that TLR4 is a major target of miR-1906 through which the microRNA exerts its therapeutic effects.SIGNIFICANCE STATEMENT The current study identified miR-1906 as a novel specific regulator of Toll-like receptor 4 (TLR4) and depicted its distinct expression patterns in different cerebral regions and cell types during ischemic attack. Therefore, the therapeutic supplementation of miR-1906 can be beneficial in the modulation of poststroke inflammation. Using Cy3 labeling, exogenous miR-1906 expression was visualized and shown to enter astrocytes, microglia, and neurons successfully in vivo Supplemental therapeutic miR-1906 resulted in reduced TLR4 expression and improved outcomes after middle cerebral artery occlusion in a mouse model, but its neuroprotective function was TLR4 dependent, suggesting that TLR4 is a major target of miR-1906.


Assuntos
Isquemia Encefálica/metabolismo , MicroRNAs/farmacologia , MicroRNAs/fisiologia , Acidente Vascular Cerebral/metabolismo , Receptor 4 Toll-Like/biossíntese , Animais , Isquemia Encefálica/tratamento farmacológico , Células Cultivadas , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , MicroRNAs/uso terapêutico , Gravidez , Acidente Vascular Cerebral/tratamento farmacológico , Receptor 4 Toll-Like/antagonistas & inibidores
19.
Brain Res ; 1665: 88-94, 2017 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-28435084

RESUMO

Intraluminal middle cerebral artery occlusion (MCAO) is the most widely used model of stroke. We aimed to predict the outcome of MCAO using a combination of fine behavioural tests for the prediction of unsuccessful surgery in mice leading to no infarction, haemorrhage and unexpected death. MCAO was performed on adult mice under the guidance of laser-Doppler flowmetry (LDF) to warrant a decrease in regional cerebral blood flow (rCBF) in the MCA territory. Four outcomes of MCAO were defined according to histological analysis: infarction, no infarction, haemorrhage and unexpected death (death within 24h post-surgery). Fine behavioural tests including the rotarod, modified neurological severity score (mNSS), Clark general and Clark focal tests were performed separately at 6h, 12h and 24h post-stroke. A total of 94 mice were included in the analysis. The infarction rate associated with MCAO was 58.5% (55/94). After optimization of the timing and behavioural tests, we found that higher Clark focal (>17.5) or higher mNSS scores (>10) were markedly related to early death, whereas a lower mNSS score (<3.5) was indicative of a tendency to show no infarction at 6h post-stroke. After 24h post-stroke, there was a positive correlation between the infarct volume and Clark focal results. Behavioural tests could help to predict the outcomes in the MCAO mouse model.


Assuntos
Comportamento Animal/fisiologia , Infarto da Artéria Cerebral Média/fisiopatologia , Artéria Cerebral Média/patologia , Animais , Escala de Avaliação Comportamental , Circulação Cerebrovascular/fisiologia , Modelos Animais de Doenças , Infarto da Artéria Cerebral Média/patologia , Fluxometria por Laser-Doppler/métodos , Masculino , Camundongos Endogâmicos C57BL , Valor Preditivo dos Testes , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/fisiopatologia
20.
Pediatr Pulmonol ; 52(6): 844-854, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28152280

RESUMO

To systematically review the clinical outcomes of surfactant administration via a thin endotracheal catheter during spontaneous breathing compared with conventional administration involving tracheal intubation, mechanical ventilation (MV), and tracheal extubation, in preterm infants. PubMed, EMBASE, and the Cochrane Library were searched to identify relevant clinical trials. Data were analyzed using the Cochrane Collaboration methods. Primary outcome measures included the incidence of MV and bronchopulmonary dysplasia (BPD). Finally, four RCTs, two prospective cohort trials, and six historical controlled trials involving 5,261 preterm infants were analyzed. In RCTs, surfactant administration though a thin catheter reduced the incidence of MV (risk ratio [RR]: 0.74; 95% confidence interval [CI]: 0.66, 0.81) in 72 hr and BPD (RR: 0.69, 95%CI: 0.50, 0.97) compared with conventional administration and in non-RCTs, there was also significant reduction in the incidence of MV (RR: 0.55, 95%CI: 0.45, 0.68) and BPD (RR: 0.70, 95%CI: 0.60, 0.82) in favor of the thin catheter group. There were no significant differences between the two procedures in terms of short-term pulmonary complications, intracranial pathology, necrotizing enterocolitis, retinopathy of prematurity, and mortality. Thus, surfactant administration via a thin endotracheal catheter to preterm infants has promising benefits, including reducing the incidences of MV and BPD, while providing comparable breathing support to conventional administration in MV. Pediatr Pulmonol. 2017; 52:844-854. © 2017 Wiley Periodicals, Inc.


Assuntos
Catéteres , Surfactantes Pulmonares/administração & dosagem , Extubação , Displasia Broncopulmonar/etiologia , Catéteres/efeitos adversos , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Intubação Intratraqueal , Surfactantes Pulmonares/uso terapêutico , Respiração , Respiração Artificial
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA