RESUMEN
The endosomal sorting complexes required for transport (ESCRTs) are responsible for membrane remodeling in many cellular processes, such as multivesicular body biogenesis, viral budding, and cytokinetic abscission. ESCRT-III, the most abundant ESCRT subunit, assembles into flat spirals as the primed state, essential to initiate membrane invagination. However, the three-dimensional architecture of ESCRT-III flat spirals remained vague for decades due to highly curved filaments with a small diameter and a single preferred orientation on the membrane. Here, we unveiled that yeast Snf7, a component of ESCRT-III, forms flat spirals on the lipid monolayers using cryogenic electron microscopy. We developed a geometry-constrained Euler angle-assigned reconstruction strategy and obtained moderate-resolution structures of Snf7 flat spirals with varying curvatures. Our analyses showed that Snf7 subunits recline on the membrane with N-terminal motifs α0 as anchors, adopt an open state with fused α2/3 helices, and bend α2/3 gradually from the outer to inner parts of flat spirals. In all, we provide the orientation and conformations of ESCRT-III flat spirals on the membrane and unveil the underlying assembly mechanism, which will serve as the initial step in understanding how ESCRTs drive membrane abscission.
Asunto(s)
Microscopía por Crioelectrón , Complejos de Clasificación Endosomal Requeridos para el Transporte , Proteínas de Saccharomyces cerevisiae , Membrana Celular/metabolismo , Complejos de Clasificación Endosomal Requeridos para el Transporte/metabolismo , Complejos de Clasificación Endosomal Requeridos para el Transporte/química , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/ultraestructuraRESUMEN
Researchers commonly anneal metals, alloys, and semiconductors to repair defects and improve microstructures via recrystallization. Theoretical studies indicate that simulated annealing on biological macromolecules helps predict the final structures with minimum free energy. Experimental validation of this homogenizing effect and further exploration of its applications are fascinating scientific questions that remain elusive. Here, we chose the apo-state 70S ribosome from Escherichia coli as a model, wherein the 30S subunit undergoes a thermally driven intersubunit rotation and exhibits substantial structural flexibility as well as distinct free energy. We experimentally demonstrate that annealing at a fast cooling rate enhances the 70S ribosome homogeneity and improves local resolution on the 30S subunit. After annealing, the 70S ribosome is in a nonrotated state with respect to corresponding intermediate structures in unannealed or heated ribosomes. Manifold-based analysis further indicates that the annealed 70S ribosome takes a narrow conformational distribution and exhibits a minimum-energy state in the free-energy landscape. Our experimental results offer a facile yet robust approach to enhance protein stability, which is ideal for high-resolution cryogenic electron microscopy. Beyond structure determination, annealing shows great potential for synchronizing proteins on a single-molecule level and can be extended to study protein folding and explore conformational and energy landscapes.
Asunto(s)
Conformación Proteica , Proteínas Ribosómicas/ultraestructura , Ribosomas/fisiología , Microscopía por Crioelectrón , Escherichia coli/metabolismo , Proteínas de Escherichia coli/metabolismo , Modelos Moleculares , ARN Ribosómico/metabolismo , ARN Ribosómico/ultraestructura , Proteínas Ribosómicas/metabolismo , Ribosomas/ultraestructuraRESUMEN
The tumor immune microenvironment plays essential roles in regulating inflammation, angiogenesis, immune modulation, and sensitivity to therapies. Here, we developed a powerful prognostic signature with immune-related lncRNAs (irlncRNAs) in lung adenocarcinoma (LUAD). We obtained differentially expressed irlncRNAs by intersecting the transcriptome dataset for The Cancer Genome Atlas (TCGA)-LUAD cohort and the ImmLnc database. A rank-based algorithm was applied to select top-ranking altered irlncRNA pairs for the model construction. We built a prognostic signature of 33 irlncRNA pairs comprising 40 unique irlncRNAs in the TCGA-LUAD cohort (training set). The immune signature significantly dichotomized LUAD patients into high- and low-risk groups regarding overall survival, which is likewise independently predictive of prognosis (hazard ratio = 3.580, 95% confidence interval = 2.451-5.229, P < 0.001). A nomogram with a C-index of 0.79 demonstrates the superior prognostic accuracy of the signature. The prognostic accuracy of the signature of 33 irlncRNA pairs was validated using the GSE31210 dataset (validation set) from the Gene Expression Omnibus database. Immune cell infiltration was calculated using ESTIMATE, CIBERSORT, and MCP-count methodologies. The low-risk group exhibited high immune cell infiltration, high mutation burden, high expression of CTLA4 and human leukocyte antigen genes, and low expression of mismatch repair genes, which predicted response to immunotherapy. Interestingly, pRRophetic analysis demonstrated that the high-risk group possessed reverse characteristics was sensitive to chemotherapy. The established immune signature shows marked clinical and translational potential for predicting prognosis, tumor immunogenicity, and therapeutic response in LUAD.
Asunto(s)
Adenocarcinoma , Neoplasias Pulmonares , ARN Largo no Codificante , Adenocarcinoma/metabolismo , Biomarcadores de Tumor/metabolismo , Humanos , Inmunoterapia , Pulmón/patología , Neoplasias Pulmonares/patología , Pronóstico , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Microambiente Tumoral/genéticaRESUMEN
BACKGROUND: Ubiquitin-conjugating enzyme E2T (UBE2T) acts as an oncogene in various types of cancer. However, the mechanisms behind its oncogenic role remain unclear in lung cancer. This study aims to explore the function and clinical relevance of UBE2T in lung cancer. METHODS: Lentiviral vectors were used to mediate UBE2T depletion or overexpress UBE2T in lung cancer cells. CCK8 analysis and western blotting were performed to investigate the effects of UBE2T on proliferation, autophagy, and relevant signaling pathways. To exploit the clinical significance of UBE2T, we performed immunohistochemistry staining with an anti-UBE2T antibody on 131 NSCLC samples. Moreover, we downloaded the human lung adenocarcinoma (LUAD) dataset from The Cancer Atlas Project (TCGA). Lasso Cox regression model was adopted to establish a prognostic model with UBE2T-correlated autophagy genes. RESULTS: We found that UBE2T stimulated proliferation and autophagy, and silencing this gene abolished autophagy in lung cancer cells. As suggested by Gene set enrichment analysis, we observed that UBE2T downregulated p53 levels in A549 cells and vice versa. Blockade of p53 counteracted the inhibitory effects of UBE2T depletion on autophagy. Meanwhile, the AMPK/mTOR signaling pathway was activated during UBE2T-mediated autophagy, suggesting that UBE2T promotes autophagy via the p53/AMPK/mTOR pathway. Interestingly, UBE2T overexpression increased cisplatin-trigged autophagy and led to cisplatin resistance of A549 cells, whereas inhibiting autophagy reversed drug resistance. However, no association was observed between UEB2T and overall survival in a population of 131 resectable NSCLC patients. Therefore, we developed and validated a multiple gene signature by considering UBE2T and its relevance in autophagy in lung cancer. The risk score derived from the prognostic signature significantly stratified LUAD patients into low- and high-risk groups with different overall survival. The risk score might independently predict prognosis. Interestingly, nomogram and decision curve analysis demonstrated that the signature's prognostic accuracy culminated while combined with clinical features. Finally, the risk score showed great potential in predicting clinical chemosensitivity. CONCLUSIONS: We found that UBE2T upregulates autophagy in NSCLC cells by activating the p53/AMPK/mTOR signaling pathway. The clinical predicting ability of UBE2T in LUAD can be improved by considering the autophagy-regulatory role of UBE2T.
Asunto(s)
Adenocarcinoma del Pulmón , Neoplasias Pulmonares , Serina-Treonina Quinasas TOR/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Enzimas Ubiquitina-Conjugadoras/metabolismo , Proteínas Quinasas Activadas por AMP , Adenocarcinoma del Pulmón/genética , Autofagia , Humanos , Neoplasias Pulmonares/genética , Transducción de Señal , Serina-Treonina Quinasas TOR/genética , Proteína p53 Supresora de Tumor/genética , Enzimas Ubiquitina-Conjugadoras/genéticaRESUMEN
Accumulating evidence indicates that a wide range of E3 ubiquitin ligases are involved in the development of many human diseases. Searching for small-molecule modulators of these E3 ubiquitin ligases is emerging as a promising drug discovery strategy. Here, we report the development of a cell-based high-throughput screening method to identify modulators of E3 ubiquitin ligases by integrating the ubiquitin-reference technique (URT), based on a fusion protein of ubiquitin located between a protein of interest and a reference protein moiety, with a Dual-Luciferase system. Using this method, we screened for small-molecule modulators of SMAD ubiquitin regulatory factor 1 (SMURF1), which belongs to the NEDD4 family of E3 ubiquitin ligases and is an attractive therapeutic target because of its roles in tumorigenesis. Using RAS homolog family member B (RHOB) as a SMURF1 substrate in this screen, we identified a potent SMURF1 inhibitor and confirmed that it also blocks SMURF1-dependent degradation of SMAD family member 1 (SMAD1) and RHOA. An in vitro auto-ubiquitination assay indicated that this compound inhibits both SMURF1 and SMURF2 activities, indicating that it may be an antagonist of the catalytic activity of the HECT domain in SMURF1/2. Moreover, cell functional assays revealed that this compound effectively inhibits protrusive activity in HEK293T cells and blocks transforming growth factor ß (TGFß)-induced epithelial-mesenchymal transition (EMT) in MDCK cells, similar to the effects on these processes caused by SMURF1 loss. In summary, the screening approach presented here may have great practical potential for identifying modulators of E3 ubiquitin ligases.
Asunto(s)
Inhibidores Enzimáticos/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Ensayos Analíticos de Alto Rendimiento/métodos , Ubiquitina-Proteína Ligasas/antagonistas & inhibidores , Ubiquitina/metabolismo , Animales , Perros , Células HEK293 , Humanos , Células de Riñón Canino Madin Darby , Transducción de Señal , Ubiquitina-Proteína Ligasas/metabolismo , UbiquitinaciónRESUMEN
N6-methyladenosine (m6 A) RNA modification can alter gene expression and function by regulating RNA splicing, stability, translocation, and translation. Deregulation of m6 A has been involved in various types of cancer. However, its implications in non-small-cell lung cancer (NSCLC) are mostly unknown. This posttranscriptional modification is dynamically and reversibly mediated by different regulators, including methyltransferase, demethylases, and m6 A binding proteins. In this study, we comprehensively investigated the contributions and prognostic values of 13 common m6 A RNA modification regulators using The Cancer Genome Atlas database. We found that the expression levels of most of the studied genes were significantly altered in lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC). Using consensus clustering, the gene-expression profiles of 13 m6 A regulators could classify patients with LUAD into two subgroups with significantly distinct clinical outcomes, but not the LUSC cohort or the combination of the two cohorts. Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, and gene set enrichment analysis were applied to explore differential signaling pathways and cellular processes between the two LUAD subgroups. Moreover, we found that this gene-expression signature could better predict prognosis in the late-stage (III + IV) than in the early-stage (I + II) LUAD. Finally, we developed an optimal prognostic gene signature by using the least absolute shrinkage and selection operator Cox regression algorithm and compute risk score. In conclusion, our study unveiled the implication of m6 A RNA modification regulators in NSCLC and identified the m6 A gene expression classifiers for predicting the prognosis of NSCLC.
Asunto(s)
Adenosina/análogos & derivados , Carcinoma de Pulmón de Células no Pequeñas/genética , Metilación de ADN/genética , ARN/genética , Adenosina/genética , Adenosina/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/genética , Carcinoma de Pulmón de Células no Pequeñas/epidemiología , Carcinoma de Pulmón de Células no Pequeñas/patología , Supervivencia sin Enfermedad , Femenino , Regulación Neoplásica de la Expresión Génica/genética , Humanos , Masculino , Metiltransferasas/genética , Persona de Mediana Edad , PronósticoRESUMEN
The aim of our study is to construct the competing endogenous RNA (ceRNA) network of head and neck squamous cell carcinoma (HNSCC) and identify key long noncoding RNAs (lncRNAs) to predict prognosis. The genes whose expression were differentially in HNSCC and normal tissues were explored by the Cancer Genome Atlas database. The ceRNA network was constructed by the Cytoscape software. The lncRNAs which could estimate the overall survival were explored from Cox proportional hazards regression. There are 1997, 589, and 82 mRNAs, lncRNAs, and miRNAs whose expression were statistically significant different, respectively. Then, the network between miRNA and mRNA or miRNA and lncRNA was constructed by miRcode, miRDB, TargetScan, and miRanda. Five mRNAs, 10 lncRNAs, and 3 miRNAs were associated with overall survival. Then, 11-lncRNAs were found to be prognostic factors. Therefore, our research analyzed the potential signature of novel 11-lncRNA as candidate prognostic biomarker from the ceRNA network for patients with HNSCC.
Asunto(s)
Biomarcadores de Tumor/genética , Carcinoma de Células Escamosas/genética , Perfilación de la Expresión Génica/métodos , Regulación Neoplásica de la Expresión Génica , Neoplasias de Cabeza y Cuello/genética , ARN Largo no Codificante/genética , Anciano , Carcinoma de Células Escamosas/diagnóstico , Biología Computacional/métodos , Femenino , Ontología de Genes , Redes Reguladoras de Genes , Neoplasias de Cabeza y Cuello/diagnóstico , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Curva ROC , Análisis de SupervivenciaRESUMEN
The regulation of inflammation is pivotal for preventing the development or reoccurrence of multiple sclerosis (MS). A biased ratio of high-M1 versus low-M2 polarized microglia is a major pathological feature of MS Here, using microarray screening, we identify the long noncoding RNA (lncRNA) GAS5 as an epigenetic regulator of microglial polarization. Gain- and loss-of-function studies reveal that GAS5 suppresses microglial M2 polarization. Interference with GAS5 in transplanted microglia attenuates the progression of experimental autoimmune encephalomyelitis (EAE) and promotes remyelination in a lysolecithin-induced demyelination model. In agreement, higher levels of GAS5 are found in amoeboid-shaped microglia in MS patients. Further, functional studies demonstrate that GAS5 suppresses transcription of TRF4, a key factor controlling M2 macrophage polarization, by recruiting the polycomb repressive complex 2 (PRC2), thereby inhibiting M2 polarization. Thus, GAS5 may be a promising target for the treatment of demyelinating diseases.
Asunto(s)
Microglía/fisiología , Esclerosis Múltiple/fisiopatología , ARN Largo no Codificante/genética , Diferenciación Celular , Enfermedades Desmielinizantes/fisiopatología , Encefalomielitis Autoinmune Experimental , Epigénesis Genética , Regulación de la Expresión Génica , Humanos , Inflamación , Macrófagos , Esclerosis Múltiple/genética , ARN Largo no Codificante/metabolismoRESUMEN
Aralia echinocaulis is used for the treatment of rheumatoid arthritis by Tujia Minority in China. A previous study demonstrated that A. echinocaulis had a significant anti-arthritic effect on adjuvant arthritis (AA) rats in vivo. However, it remains unclear whether A. echinocaulis can induce the apoptosis of fibroblast-like synoviocytes (FLS) from AA rats and the underlying mechanism is unknown. In this paper, CCK-8 assay, Hoechst staining and flow cytometry were used to evaluate the apoptotic effect of an A. echinocaulis ethanol extract (AEE) on AA FLS. Western blotting analysis was performed to measure the protein expression levels of Bcl-2, Bax, cleaved caspase-3, Akt, p-Akt, and Hif-1α. The results revealed that AEE could inhibit FLS proliferation in a dose and time-dependent manner. After treatment with AEE, AA FLS displayed the classical apoptotic morphology, and the apoptosis rates were significantly increased. Furthermore, we found that AEE increased the protein levels of Bax, cleaved caspase 3, and decreased the protein levels of Bcl-2, Hif-1α and p-Akt, without affecting total Akt levels. Collectively, these results suggested that the apoptosis inducing effect of AEE on AA FLS was related to the regulation of the expression of apoptosis-related proteins and the inhibition of the Akt/Hif-1α signaling pathway.
Asunto(s)
Apoptosis/efectos de los fármacos , Apoptosis/genética , Aralia/química , Artritis Experimental/genética , Artritis Experimental/patología , Regulación del Desarrollo de la Expresión Génica/efectos de los fármacos , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Extractos Vegetales/farmacología , Proteínas Proto-Oncogénicas c-akt/genética , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal/efectos de los fármacos , Transducción de Señal/genética , Sinoviocitos/patología , Animales , Caspasa 3/genética , Caspasa 3/metabolismo , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Masculino , Ratas Sprague-Dawley , Factores de TiempoRESUMEN
A surface plasmon resonance (SPR) biosensor-based active ingredients recognition system (SPR-AIRS) was developed, validated, and applied to screen signal transducer and activator of transcription 3 (STAT3) ligands. First, features of the screening system were investigated in four aspects: (1) specificity of the STAT3-immobilized chip, it shows that the chip could be applied to screen STAT3 ligands from complex mixture; (2) linearity and limit of detection (LOD) of the system, the minimum recovery cycle number was determined as 5 cycles; (3) saturability of the chip, the results indicate that it is necessary to select a proper concentration based on the compound's Kd value; (4) robustness of the system, it indicates that inactive compounds in the matrix could not interfere with active compounds in the process of screening. Next, SPR-AIRS was applied to screen STAT3 ligands from medicinal herbs. Nine candidate compounds were fished out. Then SPR assay and molecular docking were performed to verify the interplay between STAT3 and candidate compounds. Apoptosis assay and luciferase report assay were performed to investigate the drug effect of candidate compounds on STAT3 activity. Western blot results indicated that neobaicalein and polydatin could inhibit the phosphorylation of STAT3. As far as we know, this is the first time that neobaicalein and polydatin are reported as effective STAT3 ligands. In a conclusion, we have systemically demonstrated the feasibility of SPR biosensor-based screening method applying to complex drug systems, and our findings suggest that SPR-AIRS could be a sensitive and effective solution for the discovery of active compounds from a complex matrix.
Asunto(s)
Extractos Vegetales/química , Extractos Vegetales/farmacología , Plantas Medicinales/química , Factor de Transcripción STAT3/metabolismo , Resonancia por Plasmón de Superficie/métodos , Apoptosis/efectos de los fármacos , Descubrimiento de Drogas/métodos , Evaluación Preclínica de Medicamentos/métodos , Células Hep G2 , Humanos , Proteínas Inmovilizadas/metabolismo , Ligandos , Células MCF-7 , Simulación del Acoplamiento MolecularRESUMEN
UNLABELLED: T-helper 17 (Th17) cells play an important role in the pathogenesis of multiple sclerosis (MS), an autoimmune demyelinating disease that affects the CNS. In the present study, MicroRNA sequencing (miRNA-seq) was performed in mouse Th0 and Th17 cells to determine the critical miRNAs that are related to Th17 differentiation. We found that miR-30a was significantly downregulated during mouse Th17 differentiation. In addition, the level of miR-30a in CD4(+) T cells from peripheral blood of MS patients and experimental autoimmune encephalomyelitis (EAE) animal models was also decreased and inversely correlated with the expression of interleukin 17a, the canonical cytokine of Th17 cells. Moreover, overexpression of miR-30a inhibited Th17 differentiation and prevented the full development of EAE, whereas interference of miR-30a promoted Th17 differentiation. Mechanism studies showed that miR-30a reduced IRF4 expression by specifically binding with the 3'-untranslated region. Through screening of 640 different Food and Drug Administration (FDA)-approved drugs, we found that disulfiram and diphenhydramine hydrochloride were effective candidates for inhibiting Th17 differentiation and ameliorating EAE development through upregulating miR-30a. To our knowledge, the present work is not only the first miRNA-seq study focusing on Th17 differentiation, but also the first chemical screening for FDA-approved drugs that inhibit Th17 differentiation through regulating miRNA expression. SIGNIFICANCE STATEMENT: The present work is the first miRNA sequencing (miRNA-seq) study focusing on T-helper 17 (Th17) differentiation. By miRNA deep sequencing, we found that miR-30a was downregulated during Th17 differentiation. miR-30a was also decreased in CD4(+) T cells from multiple sclerosis patients and experimental autoimmune encephalomyelitis (EAE) mice. miR-30a reduced IRF4 expression by specific binding with the 3'-untranslated region and thus suppressed Th17 differentiation and prevented the full development of EAE. Interestingly, by performing a chemical screen with Food and Drug Administration-approved small-molecule drugs, we found that disulfiram and diphenhydramine upregulated miR-30a and suppressed Th17-associated autoimmune demyelination.
Asunto(s)
Difenhidramina/farmacología , Disulfiram/farmacología , Encefalomielitis Autoinmune Experimental/metabolismo , Interleucina-17/metabolismo , MicroARNs/metabolismo , Regulación hacia Arriba/efectos de los fármacos , Animales , Estudios de Casos y Controles , Diferenciación Celular/efectos de los fármacos , Células Cultivadas , Modelos Animales de Enfermedad , Encefalomielitis Autoinmune Experimental/prevención & control , Femenino , Células HEK293 , Humanos , Factores Reguladores del Interferón/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Proteína Proteolipídica de la Mielina/toxicidad , Glicoproteína Mielina-Oligodendrócito/toxicidad , Fragmentos de Péptidos/toxicidad , Estadísticas no Paramétricas , TransfecciónRESUMEN
BACKGROUND/OBJECTIVES: Pulmonary apoptosis is an important pathogenic mechanism of acute lung injury induced by many factors. This study aims to investigate whether the caspase inhibitor zVAD-fmk has a protective effect against lung injury in the severe acute pancreatitis model (SAP) in rats. METHODS: Seventy-two Sprague-Dawley rats were randomly divided into Sham, SAP, and SAP + zVAD-fmk groups. The SAP model was established by injection of 5% sodium taurocholate into the pancreatic duct. Animals were sacrificed at 3 h, 6 h, 12 h, and 24 h after operation and then HE staining analysis was performed to assess the lung injury. ELISA was used to detect the activity of myeloperoxidase (MPO) and the concentrations of tumor necrosis factor α (TNF-α) and interleukin 1ß (IL-1ß). Western blotting was used to detect the expression of cleaved caspase-3 in the lung tissues. RESULTS: Rats in SAP group showed obvious lung injury through pathologic examination. Pretreatment with zVAD-fmk significantly inhibited a post-SAP increase in the activation of MPO, TNF-α, IL-1ß, and caspase-3, and decreased lung injury induced by SAP as determined by the pathologic score. CONCLUSION: Our results suggest that apoptosis plays an important role in acute pancreatitis-associated lung injury (APALI), and inhibition of caspase activity may represent a new therapeutic approach for the treatment of APALI.
Asunto(s)
Lesión Pulmonar Aguda/etiología , Lesión Pulmonar Aguda/prevención & control , Clorometilcetonas de Aminoácidos/uso terapéutico , Apoptosis/efectos de los fármacos , Inhibidores de Caspasas/uso terapéutico , Inflamación/etiología , Inflamación/prevención & control , Pancreatitis/complicaciones , Lesión Pulmonar Aguda/patología , Amilasas/sangre , Animales , Caspasa 3/biosíntesis , Interleucina-1beta/antagonistas & inhibidores , Masculino , Conductos Pancreáticos/patología , Pancreatitis/inducido químicamente , Pancreatitis/patología , Ratas , Ratas Sprague-Dawley , Ácido Taurocólico , Factor de Necrosis Tumoral alfa/antagonistas & inhibidoresRESUMEN
Differentiation of oligodendrocyte precursor cells (OPCs) is a prerequisite for both developmental myelination and adult remyelination in the central nervous system. The molecular mechanisms underlying OPC differentiation remain largely unknown. Here, we show that the thirty-kDa HIV-1 Tat interacting protein (TIP30) is a negative regulator in oligodendrocyte development. The TIP30(-/-) mice displayed an increased myelin protein level at postnatal day 14 and 21. By using a primary OPC culture system, we demonstrated that overexpression of TIP30 dramatically inhibited the stage progression of differentiating OPCs, while knockdown of TIP30 enhanced the differentiation of oligodendroglial cells remarkably. Moreover, overexpression of TIP30 was found to sequester the transcription factor Olig1 in the cytoplasm and weaken its nuclear translocation due to the interaction between TIP30 and Olig1, whereas knockdown of TIP30 led to more Olig1 localized in the nucleus in the initiation stage during OPC differentiation. In the cuprizone-induced demyelination model, there was a dramatic increase in NG2-expressing cells with nuclear location of Olig1 in the corpus callosum during remyelination. In contrast, within chronic demyelinated lesions in multiple sclerosis, TIP30 was abnormally expressed in NG2-expressing cells, and few nuclear Olig1 was observed in these cells. Taken together, our findings suggest that TIP30 plays a negative regulatory role in oligodendroglial differentiation.
Asunto(s)
Diferenciación Celular/genética , Diferenciación Celular/fisiología , Citoplasma/metabolismo , Oligodendroglía/citología , Proteínas Represoras/metabolismo , Células Madre/citología , Proteínas Supresoras de Tumor/metabolismo , Animales , Animales Recién Nacidos , Antígenos/metabolismo , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Biomarcadores/metabolismo , Técnicas de Cultivo de Célula , Núcleo Celular/metabolismo , Cuerpo Calloso/citología , Ratones , Ratones de la Cepa 129 , Ratones Endogámicos C57BL , Ratones Noqueados , Vaina de Mielina/metabolismo , Fibras Nerviosas Mielínicas/metabolismo , Oligodendroglía/metabolismo , Oligodendroglía/fisiología , Proteoglicanos/metabolismo , Proteínas Represoras/deficiencia , Proteínas Represoras/genética , Proteínas Supresoras de Tumor/deficiencia , Proteínas Supresoras de Tumor/genéticaRESUMEN
Dedifferentiated liposarcoma represents a form of liposarcoma composed of a non-lipogenic sarcoma associated with well-differentiated liposarcoma. The prognostic significance of histological grading of the dedifferentiated component remains to be elucidated due to vague grading criteria employed in previous studies. Molecular markers of tumor behavior, including amplification levels of murine double minute-2 (MDM2) and cyclin-dependent kinase-4 (CDK4) genes, have been explored in a limited number of cases. Here we investigate whether 'Fédération Nationale des Centres de Lutte Contre le Cancer' (FNCLCC) grade and MDM2 gene amplification levels have prognostic value in dedifferentiated liposarcoma in terms of local recurrence and disease-specific survival. Fifty cases were retrieved, reviewed and FNCLCC grade was scored for the dedifferentiated component. Testing for MDM2 gene amplification was performed by fluorescence in situ hybridization. Amplification was categorized as high level (≥20 copies) and as low level (<20 copies). Follow-up data was obtained through chart review. Log-rank test and Cox proportional hazard models were used to determine the effect of grade and level of MDM2 amplification on outcomes. Our series includes 50 patients (male n=28, female n=22) with an average age of 63 years (range, 28-88) and a median follow-up of 28 months (range, 2-120). Tumors were graded as grade 1 (6%), grade 2 (58%), and grade 3 (36%). When adjusted for age, sex, site, tumor size, and margin status, grade 3 patients had a higher recurrence rate than grades 1 and 2 (HR=2.07, 95% CI: 1.24, 7.62; P=0.015). Patients with high-level MDM2 amplification had higher recurrence rate on univariate analysis (P=0.028), but not on multivariate analysis (HR=1.69, 95% CI: 0.73, 3.94; P=0.221). FNCLCC grade 3 dedifferentiation confers a worse prognosis in dedifferentiated liposarcoma in terms of local recurrence. MDM2 amplification level remains a useful diagnostic tool in dedifferentiated liposarcoma, but has no prognostic value in terms of local recurrence.
Asunto(s)
Liposarcoma/genética , Liposarcoma/patología , Recurrencia Local de Neoplasia/genética , Recurrencia Local de Neoplasia/patología , Proteínas Proto-Oncogénicas c-mdm2/genética , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Amplificación de Genes , Humanos , Inmunohistoquímica , Hibridación Fluorescente in Situ , Estimación de Kaplan-Meier , Liposarcoma/mortalidad , Masculino , Persona de Mediana Edad , Clasificación del Tumor , Pronóstico , Modelos de Riesgos Proporcionales , Estudios RetrospectivosRESUMEN
BACKGROUND: Gallic acid (GA) has been shown to inhibit demineralization and enhance remineralization of enamel; however, GA solution is highly acidic. This study was to investigate the stability of GA solutions at various pH and to examine the resultant effects on enamel demineralization. METHODS: The stability of GA in H2O or in phosphate buffer at pH 5.5, pH 7.0 and pH 10.0 was evaluated qualitatively by ultraviolet absorption spectra and quantified by high performance liquid chromatography with diode array detection (HPLC-DAD). Then, bovine enamel blocks were subjected to a pH-cycling regime of 12 cycles. Each cycle included 5 min applications with one of the following treatments: 1 g/L NaF (positive control), 4 g/L GA in H2O or buffered at pH 5.5, pH 7.0 and pH 10.0 and buffers without GA at the same pH (negative control), followed by a 60 min application with pH 5.0 acidic buffers and a 5 min application with neutral buffers. The acidic buffers were analysed for dissolved calcium. RESULTS: GA was stable in pure water and acidic condition, but was unstable in neutral and alkaline conditions, in which ultraviolet spectra changed and HPLC-DAD analysis revealed that most of the GA was degraded. All the GA groups significantly inhibited demineralization (p < 0.05) and there was no significant difference of the inhibition efficacy among different GA groups (p > 0.05). CONCLUSIONS: GA could inhibit enamel demineralization and the inhibition effect is not influenced by pH. GA could be a useful source as an anti-cariogenic agent for broad practical application.
Asunto(s)
Cariostáticos/uso terapéutico , Esmalte Dental/efectos de los fármacos , Ácido Gálico/uso terapéutico , Desmineralización Dental/prevención & control , Animales , Tampones (Química) , Calcio/análisis , Bovinos , Cromatografía Líquida de Alta Presión , Esmalte Dental/química , Concentración de Iones de Hidrógeno , Fosfatos/química , Fluoruro de Sodio/uso terapéutico , Espectrofotometría Ultravioleta , Remineralización Dental , Agua/químicaRESUMEN
OBJECTIVE: To explore the effect of Tanshinone II A on severe acute pancreatitis (SAP) lung injury (ALI) rats and its possible mechanism. METHODS: SD rats were injected with sodium taurocholate to induce SAP group, and then intervened with sodium tanshinone II A sulfonate ( STS group). Simultaneously a sham-operation group (SO group) was set up. There were 24 rats in each group. The survival state and wet-to-dry weight ratio of lung tissues were observed. Activities of myeloperoxidase (MPO) in lung were determined by MPO reagent kit. Pathologic changes of lung tissues were determined by Hofbuaer method. Expression levels of three cytokines, TNF-alpha, IL-1beta, and intercellular cell adhesion molecule-1 (ICAM-1) were detected by ELISA. RESULTS: The survival state of rats in the SAP group was deteriorated. The wet-to-dry weight ratio, MPO activities, pathologic changes in lung tissues, and expression levels of TNF-alpha, IL-1beta, and ICAM-1 increased significantly more in the SAP group than in the SO group (P < 0.05). Compared with those in the SAP group, the survival state of rats in the STS group was improved; the wet-to-dry weight ratio, MPO activities, pathologic changes in lung tissues, and expression levels of TNF-alpha, IL-1beta, and ICAM-1 obviously decreased in the STS group (P < 0.05). CONCLUSION: Tanshinone II A had remarkable effect on SPA LI rats, which might be associated with changing cytokines levels and attenuating infiltration of lung inflammatory cells.
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Abietanos/farmacología , Lesión Pulmonar Aguda/tratamiento farmacológico , Citocinas/metabolismo , Pancreatitis/tratamiento farmacológico , Abietanos/uso terapéutico , Animales , Molécula 1 de Adhesión Intercelular , Interleucina-1beta , Pulmón , Peroxidasa , Ratas , Ratas Sprague-Dawley , Ácido Taurocólico , Factor de Necrosis Tumoral alfaRESUMEN
PURPOSE: We sought to characterize the natural history of vascular Ehlers-Danlos syndrome in individuals with heterozygous COL3A1 mutations. METHODS: We reviewed clinical records for details of vascular, bowel, and organ complications in 1,231 individuals (630 index cases and 601 relatives). RESULTS: Missense and splice-site mutations accounted for more than 90% of the 572 alterations that we had identified in COL3A1. Median survival was 51 years but was influenced by gender (lower in men) and by the type of mutation. CONCLUSION: Although vascular Ehlers-Danlos syndrome appears to be genetically homogeneous, allelic heterogeneity is marked, and the natural history varies with gender and type of mutation in COL3A1. These findings indicate that when counseling families, confirmation of the presence of a COL3A1 mutation and its nature can help evaluate the risks of complications. These data are also important ingredients in both the selection and allocation of individuals to appropriate arms in clinical trials to assess the effects of interventions.
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Colágeno Tipo III/genética , Análisis Mutacional de ADN , Síndrome de Ehlers-Danlos/genética , Síndrome de Ehlers-Danlos/mortalidad , Mutación , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Alelos , Niño , Femenino , Variación Genética , Humanos , Masculino , Persona de Mediana Edad , Mutación Missense , Empalme del ARN , Resultado del Tratamiento , Adulto JovenRESUMEN
BACKGROUND AND AIMS: Refractory chronic pancreatitis has been proposed as a challenge for endoscopists following routine single plastic stenting. However, data on the efficacy and safety of further endoscopic stenting are still controversial. The current systematic review aimed to assess the efficacy and safety of placement of fully covered self-expandable metal stent (FCSEMS) and multiple plastic stents. METHODS: Databases including MEDLINE, EMBASE, the Cochrane Library, CBM, CNKI, VIP, and WANFANG Database were used to search relevant trials. Published studies were assessed by using well-defined inclusion and exclusion criteria. The process was independently performed by two investigators. RESULTS: A total of 5 studies provided data of 80 patients. Forest plots and publication bias were not carried out because few studies were relevant and screened studies were all case series. The technical success rate was 100% both in placement of FCSEMS and multiple plastic stents. The functional success rate after placement of FCSEMS was 100%, followed by multiple plastic stents (94.7%). Complications occurred 26.2% after FCSEMS placement, which was not described in detail in multiple plastic stents. The stent migration rate was 8.2% for FCSEMS and 10.5% for multiple plastic stents. Reintervention rate was 9.8% for FCSEMS and 15.8% for multiple plastic stents. Pain improvement rate was 85.2% for FCSEMS and 84.2% for multiple plastic stents. CONCLUSIONS: FCSEMS appeared to be no significant difference with multiple plastic stents in treatment of refractory chronic pancreatitis. We need to develop more investigations.
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Materiales Biocompatibles , Metales , Conductos Pancreáticos/cirugía , Pancreatitis/cirugía , Plásticos , Stents , Enfermedad Crónica , Constricción Patológica/terapia , Humanos , Complicaciones Posoperatorias/epidemiología , Diseño de Prótesis , Reoperación/estadística & datos numéricos , Stents/efectos adversosRESUMEN
T cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibitory motif (ITIM) domain (TIGIT) is an inhibitory receptor expressed by T and natural killer cells. Here, we used TIGIT knockout (KO) mice to demonstrate that mouse TIGIT directly interacts with Candida albicans. Reduced fungal growth and colonization were observed when TIGIT-KO splenocytes were co-cultured with C. albicans compared to the wild type (WT). In a systemic candidiasis model, TIGIT-KO mice exhibited improved survival and reduced body weight loss compared to WT mice. Organ-specific fungal burden assessment revealed significantly lower fungal loads in the kidneys, spleen, and lungs of TIGIT-KO mice. Finally, we show that the agglutinin-like sequence proteins ALS6, ALS7, and ALS9 of C. albicans are ligands for TIGIT and that the absence of these proteins abolishes the TIGIT effect in vivo. Our results identify the significance of TIGIT in modulating host defense against C. albicans and highlight the potential therapeutic implications for C. albicans infections. IMPORTANCE: Our results identify the significance of T cell immunoreceptor with immunoglobulin and ITIM domain in modulating host defense against Candida albicans and highlight the potential therapeutic implications for C. albicans infections.