Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 432
Filtrar
1.
Chem Rev ; 2020 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-31967451

RESUMO

In this contribution, we provide a comprehensive overview of C-H activation methods promoted by NHC-transition metal complexes, covering the literature since 2002 (the year of the first report on metal-NHC-catalyzed C-H activation) through June 2019, focusing on both NHC ligands and C-H activation methods. This review covers C-H activation reactions catalyzed by group 8 to 11 NHC-metal complexes. Through discussing the role of NHC ligands in promoting challenging C-H activation methods, the reader is provided with an overview of this important area and its crucial role in forging carbon-carbon and carbon-heteroatom bonds by directly engaging ubiquitous C-H bonds.

2.
Anal Chem ; 92(1): 1097-1105, 2020 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-31814401

RESUMO

Chemical cross-linking combined with mass spectrometry (CXMS) has emerged as a powerful tool to study protein structure, conformation, and protein-protein interactions (PPIs). Until now, most cross-linked peptides were generated by using commercial cross-linkers, such as DSS, BS3, and DSSO, which react with the primary amino groups of the lysine residues of proteins. However, trypsin, the most commonly used proteolytic enzyme, cannot cleave the C-terminus of a linked lysine, making the obtained cross-linked peptides longer than common peptides and unfavorable for MS identification and data searching. Herein, we propose an in situ sequential digestion strategy using enzymes with distinct cleavage specificity, named as smart cutter, to generate cross-linked peptides with suitable length so that the identification coverage could improve. Through the application of such a strategy to DSS cross-linked E. coli lysates, additional cross-linked sites (1.3-fold increase) obtained in comparison with those obtained by trypsin-trypsin digestion (2879 vs 1255). Among the different digestion combinations, AspN-trypsin performed the best, with 64% (673/1059) of the cross-linked sites complementary to trypsin-trypsin digestion, which is beneficial to ensure the depth for studying protein structure and PPIs. Taking the 60 kDa chaperonin protein as an example, more than twice the cross-linked sites (30 vs 14) were identified to enrich the protein structure information. In addition, compared to the published protein interaction network for E. coli ( http://www.bacteriome.org ), 91 potential PPIs were discovered with our strategy, of which 65 have not covered by trypsin-trypsin digestion. Therefore, these results illustrate the great significance of smart-cutter-based CXMS for the revelation of protein structure as well as finding new PPIs.

3.
Biomed Pharmacother ; 121: 109663, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31751870

RESUMO

P-glycoprotein (P-gp) plays a significant role in multi-drug resistance (MDR) of cancer cells, resulting in the failure of cancer chemotherapy. Lathyrane diterpene was a class of promising MDR modulator. The phytochemical investigation on the seeds of Euphorbia lathyris L. aff ;orded four new lathyrol-type diterpenoids (1-4), together with seventeen known ones (5-23). The structures of these compounds were elucidated by using 1D and 2D NMR spectroscopy. All the compounds were evaluated reversing MDR activity in HepG2/ADR cells. Compounds 2-4, 7-9, 11, 13-14, 16, 18-19, and 2 1-2 3 at 20 µM was able to reverse MDR of HepG2/ADR cells to adriamycin (reversal fold: 10.05-448.39). In the investigation of reversing the MDR mechanism, the most potent compound 21 facilitated the accumulation of intracellular adriamycin in HepG2/ADR cells in the time-dependent model. Although 21 neither affected the P-gp distribution nor expression in HepG2/ADR cells, the amount of P-gp monomer was induced by 21 and verapamil. Compound 21 has also activated the P-gp coupled ATPase activity in a dose-dependent model. The molecular docking analysis implied that 21 had lower binding energy than verapamil and adriamycin. The present data demonstrated that lathyrane diterpenes may act as a class of high-affinity P-gp substrate and was effluxed by P-gp monomer to reverse the MDR.

4.
Toxicol Appl Pharmacol ; 386: 114813, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31715269

RESUMO

Pristimerin, a triterpenoid, has exhibited potential anti-inflammatory and anti-tumor activities. Nevertheless, the role and mechanism of pristimerin in intestinal inflammation and colon cancer require further investigation. Here, we found that pristimerin protected mice from dextran sulfate sodium (DSS)-induced colitis, restoring epithelial damage and reducing tissue inflammation and inflammatory cell infiltration. In addition, pristimerin dramatically reduced the number and size of the tumors in a azoxymethane (AOM)/DSS-induced colitis-associated colorectal cancer (CAC) model. Furthermore, we found that pristimerin suppressed Wnt/ß-catenin signaling by RNA-Seq. Pristimerin inhibited Wnt/ß-catenin signaling via activation of GSK3ß, thereby suppressing Wnt target gene expression in colon cancer HCT116 and HT-29 cells. In HCT116 colon cancer xenografts and APCmin/+ mice, which undergo spontaneous intestinal tumorigenesis, administration of pristimerin reduced the tumor progression and decreased the expression of phosphorylated GSK3ß Ser 9, ß-catenin, cyclin D1 and c-Myc. These results suggest that pristimerin is a potent agent for preventing colon inflammation and carcinogenesis.

5.
Planta Med ; 2019 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-31766070

RESUMO

The endophytic microbiome in medicinal plants is rich and diverse, but few studies have followed the endophytic microbiome of medicinal plants in different tissues with their growth. In this study, we examined the endophytic bacterial and fungal community structures associated with both the stem and root compartments of Dendrobium huoshanense at different growth years via high-throughput sequencing of 16S rRNA genes and nrDNA fragments of internal transcribed spacer regions. Results indicated that more diverse prokaryotic and fungal operational taxonomic units were detected in roots than in stems, and the alpha diversity of endophytic prokaryotic significantly differed among the 1-, 2-, and 3-year-old roots. The dominant bacterial phyla Proteobacteria Firmicutes, Actinobacteria, Bacteroidetes, and Acidobacteria, and fungal phyla Ascomycota, Basidiomycota, and Ascomycota were detected in the stems and roots with 3 growth years. Moreover, linear discriminant effect size analysis revealed 138 differentially abundant taxonomic clades in the bacterial level, and 197 in the fungal level in six groups. Our results provide evidence for endophytic microbiota communities depending on the tissues and growth years of D. huoshanense. The results from this study should be useful to better understand medicinal plant-microbe interactions.

6.
Pathol Res Pract ; : 152727, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31757661

RESUMO

The purpose of this study was to analyze the influencing factors of BVI in advanced gastric cancer and explore the factors affecting the prognosis of advanced gastric cancer, so as to accurately evaluate the disease status and enable patients to receive effective treatment. We retrospectively analyzed 622 cases with complete data and successful follow-up. BVI was found in 144 of the 622 patients with advanced gastric cancer, with a detection rate of 23.15%. BVI was closely related to the differentiation degree, infiltration depth and lymph node metastasis of advanced gastric cancer, (P <  0.05). Gender, age, tumor location, tumor size, Lauren classification, tumor M stage, and clinical TNM stage were not the influencing factors of BVI in patients with advanced gastric cancer (P >  0.05). The 5-year survival rate of patients in the positive group of BVI was 34.72%. The 5-year survival rate of patients with advanced gastric cancer was correlated with BVI, Lauren classification, depth of invasion, lymph node metastasis, and clinical TNM staging, (P <  0.05). The 5-year survival rate was independent of gender, age, tumor location, tumor size, tumor tissue differentiation, and M stage (P >  0.05). The results of multi-factor analysis showed that BVI, N stage and clinical TNM stage were independent predictors of prognosis in patients with advanced radical gastric cancer. By analyzing the stage and related prognostic factors of resectable advanced gastric cancer, we found that BVI was not only closely related to lymph node metastasis, but also an independent predictor of prognosis of advanced gastric cancer. As this study was only a single-center retrospective study, there may be a selective bias in clinical data. So large-scale and multi-center collaboration is needed to further explore the influencing factors of BVI in the progression of gastric cancer.

7.
PLoS One ; 14(11): e0225045, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31703104

RESUMO

Deperetellidae is a clade of peculiar, Asian endemic tapiroids from the early and middle Eocene. The previously published material mainly comprises maxillae, mandibles, and some postcranial elements. However, the absence of cranial materials and primitive representatives of the deperetellids obscures their phylogenetic relationships within Tapiroidea. Furthermore, derived deperetellids have completely molarized premolars, but the pattern of their evolution remains unclear. Here, we report a nearly complete skull and some carpals of a new basal deperetellid tapiroid, Irenolophus qii gen. et sp. nov., from the late early Eocene of the Erlian Basin, Inner Mongolia, China. We suggest that deperetellids (along with Tapiridae) probably also arose from some basal 'helaletids', based on the reduced, flat, lingually depressed metacones on the upper molars, the trend towards the bilophodonty on the lower molars, and a shallow narial notch with the premaxilla in contact with the nasal. The molarization of the premolars in Deperetellidae from Irenolophus through Teleolophus to Deperetella was initiated and gradually enhanced by the separation between the paraconule and the protocone. That pattern differs from the protocone-hypocone separation in helaletids, tapirids, and most rhinoceroses, and the metaconule-derived pseudohypocone in amynodontids. However, the specific relationship of deperetellids within Tapiroidea and the roles of different patterns of premolar molarization in perissodactyl evolution need further and comprehensive study.

8.
Front Physiol ; 10: 1087, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31507450

RESUMO

The Pacific white shrimp (Litopenaeus vannamei), a euryhaline penaeid species, can tolerate a wide range of salinities, but little is known on its strategies to cope with low salinity fluctuations from the aspect of lipidomics. Thus, in this study, L. vannamei were grown in two different salinities [3 and 30‰ (control)] for 8 weeks, and then an liquid chromatography (LC)-mass spectrometry (MS)-based lipidomics analysis was performed to reveal the lipid profile differences in gill and muscle. L. vannamei under low salinity had lower weight gain and condition factor than the control shrimp at 30‰, but no differences were found in survival and hepatopancreas index. A higher number of differential lipid metabolites were identified in gill than in muscle in L. vannamei at salinity 3‰ relative to the control shrimp at salinity of 30‰ (159 versus 37), which belonged to 11 and 6 lipids classes, respectively. Of these lipids, phosphatidylcholine (PC), phosphatidylinositol (PI), phosphatidic acid (PA), phosphatidylethanolamine (PE), and triglyceride (TG) were the main lipids in both shrimp gill and muscle, regardless of salinities. Compared with the control shrimp at salinity 30‰, the percentage of PC significantly reduced, but TG and PA significantly increased in gill of shrimp at salinity 3‰. Moreover, the relative fatty acid abundances showed significant changes in L. vannamei between the two salinity groups, but the patterns of the changes were complex and were fatty acid dependent. Neither lipid nor fatty acid composition in muscle was affected by salinity. Further pathway analysis showed that these metabolites were closely related to lipid and fatty acid metabolic pathways. All the findings in this study reveal that the lipid variations are closely related to bio-membrane structure, mitochondrial function, energy supply, or organic osmolyte contents in hemolymph for improving osmoregulatory capacity of L. vannamei under low salinity.

9.
BMC Cancer ; 19(1): 930, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31533653

RESUMO

BACKGROUND: The Foxo3 gene, belonging to the forkhead family, is one of the classes of transcription factors characterized by a forkhead DNA-binding domain, which usually considered being a cancer suppressor gene. Circ-Foxo3 is a circular structure which connects the 3'end to the 5'end. Scholars detected that circ-Foxo3 could compete with Foxo3 for binding to some miRNAs. METHODS: In this study, we will test the expression of Foxo3 and circ-Foxo3 in de novo acute myeloid leukemia (AML) patients to explore the relationship between Foxo3 gene and circ-Foxo3. All the de novo AML samples and normal control samples was measured by real-time quantitative PCR. A receiver operating characteristic curve was conducted to differentiate AML patients from control people. Association of Foxo3 expression and overall survival was conducted by Kaplan-Meier survival analysis. RESULTS: We found that the expression of Foxo3 gene in de novo patients was significantly lower than control samples (P = 0.009). Meanwhile, circ-Foxo3 also expressed lower in de novo AML patients than in control samples (P = 0.040). In different classifications, this trend could be observed more remarkably. In non-M3 patients, the Foxo3 high patients' survival time was longer than Foxo3 low patients (P = 0.002). Besides, in non-favorable risk groups, patients with low expression of Foxo3 had longer survival time than Foxo3 high patients (P = 0.004). Furthermore, in normal Karyotypic patients, the overall survival time of patients with high-expressed Foxo3 was significantly longer than those with low expression (P = 0.034). Besides, Pearson analysis was also conducted between these two genes in AML patients. Results revealed that they were positively correlated (R = 0.63, P < 0.001). CONCLUSION: In conclusion, we found that low expression of circ-Foxo3 and Foxo3 were frequent in AML patients, and patients with high expression of Foxo3 often had a trend of better prognosis.

10.
AIDS ; 33 Suppl 1: S63-S70, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-31397724

RESUMO

OBJECTIVES: The current study aims to examine associations between psychosocial factors and health-related quality of life (HRQoL) and the role of psychological resilience in mediating the relationship between perceived social support (PSS) and HRQoL. DESIGN: A cross-sectional study was conducted among people living with HIV (PLHIV) in Guangxi, China. A sample of 2987 PLHIV (1876 men and 1111 women) was included in the current analysis. METHODS: Hierarchical multiple regression models were employed to assess the association of HRQoL with stigma, three types of PSS (informational, emotional and tangible), and resilience as well as to identify the possible role of resilience in mediating the effect of PSS on HRQoL RESULTS:: HRQoL was negatively associated with stigma (ß = -0.27, P < 0.001), but positively associated with emotional PSS (ß = 0.13, P < 0.001). After resilience was added to the model, HRQoL remained negatively associated with stigma (ß = -0.20, P < 0.001), but positively associated with resilience (ß = 0.38, P < 0.001). A mediating effect of resilience was found between emotional PSS and HRQoL (Sobel's Z = 16.87, P < 0.001). CONCLUSION: Interventions that consider enhancing resilience through building social support, especially emotional social support, will likely improve HRQoL among PLHIV.

11.
FASEB J ; 33(11): 11973-11992, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31398290

RESUMO

Invasive spread of glioblastoma (GBM) is linked to changes in chondroitin sulfate (CS) proteoglycan (CSPG)-associated sulfated glycosaminoglycans (GAGs) that are selectively up-regulated in the tumor microenvironment (TME). We hypothesized that inhibiting CS-GAG signaling in the TME would stem GBM invasion. Rat F98 GBM cells demonstrated enhanced preferential cell invasion into oversulfated 3-dimensional composite of CS-A and CS-E [4- and 4,6-sulfated CS-GAG (COMP)] matrices compared with monosulfated (4-sulfated) and unsulfated hyaluronic acid matrices in microfluidics-based choice assays, which is likely influenced by differential GAG receptor binding specificities. Both F98 and human patient-derived glioma stem cells (GSCs) demonstrated a high degree of colocalization of the GSC marker CD133 and CSPGs. The small molecule sulfated GAG antagonist bis-2-methyl-4-amino-quinolyl-6-carbamide (surfen) reduced invasion and focal adhesions in F98 cells encapsulated in COMP matrices and blocked CD133 and antichondroitin sulfate antibody (CS-56) detection of respective antigens in F98 cells and human GSCs. Surfen-treated F98 cells down-regulated CSPG-binding receptor transcripts and protein, as well as total and activated ERK and protein kinase B. Lastly, rats induced with frontal lobe tumors and treated with a single intratumoral dose of surfen demonstrated reduced tumor burden and spread compared with untreated controls. These results present a first demonstration of surfen as an inhibitor of sulfated GAG signaling to stem GBM invasion.-Logun, M. T., Wynens, K. E., Simchick, G., Zhao, W., Mao, L., Zhao, Q., Mukherjee, S., Brat, D. J., Karumbaiah, L. Surfen-mediated blockade of extratumoral chondroitin sulfate glycosaminoglycans inhibits glioblastoma invasion.

12.
Cell Death Discov ; 5: 125, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31396402

RESUMO

Breast cancer is the most common malignant tumor in women, and progress toward long-term survival has stagnated. Pristimerin, a natural quinonemethide triterpenoid, exhibits potential anti-tumor effects on various cancers. However, the underlying mechanism remains poorly understood. In this study, we found that pristimerin reduced the viability of breast cancer cells in vitro and the growth of xenografts in vivo, and these reductions were accompanied by thioredoxin-1 (Trx-1) inhibition and ASK1 and JNK activation. The results showed that pristimerin inhibited cell cycle progression and triggered cell apoptosis and autophagy. Furthermore, we found that the generation of reactive oxygen species (ROS) was a critical mediator in pristimerin-induced cell death. Enhanced ROS generation by pristimerin activated the ASK1/JNK signaling pathway. Inhibition of ROS with N-acetyl cysteine (NAC) significantly decreased pristimerin-induced cell death by inhibiting the phosphorylation of ASK1 and JNK. Taken together, these results suggest a critical role for the ROS/ASK1/JNK pathway in the anticancer activity of pristimerin.

14.
Med Sci Monit ; 25: 4952-4959, 2019 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-31271156

RESUMO

BACKGROUND The transcription factor Oct-4 is necessary for maintaining pluripotency and self-renewal of embryonic stem cells, and POU5F1B is a processed pseudogene of Oct-4 with coding capacity. The purpose of this study is to evaluate the expression and clinical implication of POU5F1B in AML. MATERIAL AND METHODS The expression of the POU5F1B transcript was evaluated in 175 newly diagnosed AML patients and 39 healthy controls by use of real-time quantitative PCR (RQ-PCR). RESULTS POU5F1B was underexpressed in AML compared with controls (P<0.001). The receiver operating characteristic (ROC) curve revealed that the POU5F1B transcript level was able to differentiate AML patients from healthy individuals (AUC=0.682). In non-APL AML patients, the POU5F1Blow group had significantly higher WBC than the POU5F1Bhigh group (20.2×109 vs. 4.6×109 L⁻¹, P=0.021). Among whole-cohort AML, non-APL AML, and intermediate-risk AML, POU5F1Bhigh patients had obviously higher complete remission (CR) rates than POU5F1Blow patients (P=0.012, P=0.012 and P=0.027). In addition, Kaplan-Meier analysis demonstrated better overall survival (OS, P=0.019, P=0.007 and P=0.046, respectively) in POU5F1Bhigh patients compared with POU5F1Blow patients. Furthermore, in multivariate survival analysis, POU5F1B was independently associated with OS in non-APL AML patients and intermediate-risk AML as a favorable prognostic factor. CONCLUSIONS POU5F1B was frequently underexpressed in AML, and might contribute to the diagnosis and prognosis of AML.


Assuntos
Leucemia Mieloide Aguda/genética , Fator 3 de Transcrição de Octâmero/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Área Sob a Curva , Biomarcadores Tumorais/metabolismo , Feminino , Genes Homeobox , Humanos , Estimativa de Kaplan-Meier , Leucemia Mieloide Aguda/diagnóstico , Masculino , Pessoa de Meia-Idade , Fator 3 de Transcrição de Octâmero/metabolismo , Prognóstico , Pseudogenes , Curva ROC , Indução de Remissão , Transcriptoma
15.
Chem Biodivers ; 16(8): e1900325, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31290253

RESUMO

Chronic myeloid leukemia (CML) is a lethal malignancy, and the progress toward long-term survival has stagnated in recent decades. Pristimerin, a quinone methide triterpenoid isolated from the Celastraceae and Hippocrateaceae families, is well-known to exert potential anticancer activities. In this study, we investigated the effects and the mechanisms of action on CML. We found that pristimerin inhibited cell proliferation of K562 CML cells by causing G1 phase arrest. Furthermore, we demonstrated that pristimerin triggered autophagy and apoptosis. Intriguingly, pristimerin-induced cell death was restored by an autophagy inhibitor, suggesting that autophagy is cross-linked with pristimerin-induced apoptosis. Further studies revealed that pristimerin could produce excessive reactive oxygen species (ROS), which then induce JNK activation. These findings provide clear evidence that pristimerin might be clinical benefit to patients with CML.


Assuntos
Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Triterpenos/farmacologia , Pontos de Checagem da Fase G1 do Ciclo Celular/efeitos dos fármacos , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Células K562 , Espécies Reativas de Oxigênio/metabolismo , Triterpenos/química
16.
Chem Commun (Camb) ; 55(61): 9003-9006, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31290865

RESUMO

We report sequential ruthenium(0)-catalysis for the synthesis of sterically-hindered amines via direct C-H arylation of simple imines and imine hydrosilylation. The method involves direct C-H arylation under neutral conditions with organoboranes enabled by ruthenium(0) catalysis. The catalytic hydrosilylation was performed in a one-pot fashion using Et3SiH. The reaction is compatible with a broad range of electronically- and sterically-varied imines, enabling rapid production of valuable biaryl amines in good to excellent yields. The method constitutes a two-step, one-pot procedure to synthesize sterically-hindered amines from aldehydes. The utility of this atom-economic strategy is demonstrated in one-pot, three-component coupling, direct in situ aldehyde arylation and the use of transfer hydrogenation.

17.
Fish Shellfish Immunol ; 92: 629-636, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31265910

RESUMO

Imbalance of intestinal microbiota has been recognized in aquatic animals infected with various diseases. However, the signature of intestinal bacteria of the "cotton shrimp-like" disease in the Pacific white shrimp Litopenaeus vannamei remains unknown. This study investigates the composition, diversity, microbial-mediated function and interspecies interaction of intestinal microbiota on shrimp with different health status using 16S rRNA gene high-throughput sequencing. Meanwhile, the growth performance and the mRNA expression of innate immune gene in hepatopancreas were also investigated. The growth performance and the mRNA expression of innate immune genes (e.g., crustin, toll, and immune deficiency genes) in the hepatopancreas were significantly decreased in diseased shrimp compared with healthy shrimp. Bacteria of the family Rickettsiaceae and genus Tenacibaculum were exclusively enriched and significantly increased in diseased shrimp, respectively, whereas, the Actinobacteria class dramatically deceased. The diseased shrimp exhibited higher ACE and Chao1 indices and lower complexity of intestinal interspecies interaction than healthy shrimp. Microbial-mediated functions predicted by PICRUSt showed that 83% KEGG pathway including nutrient absorption and digestion significantly increased in diseased shrimp. This study provides an overview on the interplay among the "cotton shrimp-like" disease, intestinal microbiota, growth performance and host immune responses from an ecological perspective.


Assuntos
Microbioma Gastrointestinal/fisiologia , Imunidade Inata/genética , Penaeidae/genética , Penaeidae/imunologia , Animais , Bactérias/classificação , Fenômenos Fisiológicos Bacterianos , Penaeidae/crescimento & desenvolvimento , Penaeidae/microbiologia , RNA Bacteriano/análise , RNA Ribossômico 16S/análise
18.
Water Res ; 160: 209-216, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31152946

RESUMO

Although photochemical transformation is a major degradation pathway for antibiotics in surface freshwaters, the photodegradation of antibiotics from freshwaters downstream into seawater is largely unknown. Herein, sulfadiazine was adopted as a representative antibiotic to probe the alteration of photolytic kinetics along freshwater to seawater sampled from Qinzhou Bay, China. The results showed that the photodegradation rate constants of sulfadiazine significantly increased in estuarine waters along freshwaters to seawaters. Experiments in synthetic water samples with isolated local dissolved organic matter (IL-DOM) indicated that the increased photodegradation of sulfadiazine is attributed to the integrative effect of both IL-DOM and halide ions. Radical quenching experiments with tert-butanol (quenching of ·OH) and isopropanol (quenching of both ·OH and reactive halogen species, RHS) demonstrated that RHS are largely responsible for the halide-specific enhancement in the photodegradation of sulfadiazine, rather than other reactive species, such as triplet-excited IL-DOM and ·OH. However, triplet-excited IL-DOM was involved in the production of RHS by the oxidation of halide ions by the triplet-excited states. Experiments conducted with DOM analogues verified DOM-sensitized RHS formation, and the degradation induced by RHS is positively correlated with the triplet-excited reduction potentials of DOM analogues. These findings are helpful in deeply understanding the transformation of antibiotics, and demonstrate the importance of RHS-induced degradation in antibiotics fate models in estuarine water systems.


Assuntos
Sulfadiazina , Poluentes Químicos da Água , China , Halogênios , Fotólise
19.
Endocrine ; 65(2): 440-450, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31168749

RESUMO

INTRODUCTION: Developmental dysplasia of the hip (DDH) is a major cause of disability in children, and the genetic mechanism of this disease remains unclear. In our previous study, we found that pregnancy-associated plasma protein-A2 (PAPP-A2) was associated with DDH significantly. OBJECTIVES: The aim of this study was to investigate the insulin-like growth factor (IGF) expression and collagen synthesis as well as cartilage proliferation-related proteins in the case of abnormal expression of Pappa2 in mice to research the relationship between PAPP-A2 and the pathological changes of DDH. METHODS: In vivo animal experiments, the mice were directly injected with 50 µl of Cas9/PAPP-A2 sgRNA lentiviruses around the hip to downregulate the Pappa2 gene expression and injected with control lentiviruses on the other side, then to observe the expression and localization of related proteins. And in an in vitro experiment, mice fibroblasts and primary chondrocytes were cultured with insulin-like growth factor binding protein-5 (IGFBP-5) protein, PAPP-A2 protein and Cas9/PAPP-A2 sgRNA lentiviruses to detect of related proteins and mRNA expression. RESULTS: Cartilage proliferation-related proteins demonstrated a significant decrease in the PAPP-A2 knockdown hips acetabulum and femoral head cartilage, meanwhile the IGF expression was also downregulated in the soft tissue around the acetabulum compared with the control hips. Furthermore, the role PAPP-A2 played in chondrocytes and fibroblasts was the same as in the in vivo experiments, downregulation of PAPP-A2 expression or upregulation of IGFBP-5 expression can reduce collagen synthesis and cartilage proliferation. CONCLUSIONS: PAPP-A2 may be involved in the development of the mouse hip joint by interfering the fibrous and cartilaginous metabolism via IGF pathway-associated proteins pathway.

20.
Cancer Lett ; 459: 100-111, 2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31158430

RESUMO

The mixed lineage kinase domain-like protein (MLKL) has emerged as a critical mediator of necroptosis, which results in the release of cellular damage-associated molecular patterns (DAMPs). However, its physiological role in regulating inflammation is not fully understood. We herein showed that Mlkl-/- mice were highly susceptible to colitis and colitis-associated tumorigenesis (CAT), which was associated with massive leukocyte infiltration and increased inflammatory responses. Moreover, we used bone marrow transplantation to reveal that MLKL in inflammatory cells is crucial for its role on colitis. Intestinal mucosal tissue and polyps isolated from Mlkl-/- mice exhibited increased ERK activation and elevated expression of genes associated with inflammation and cancer. Mechanistically, enhanced inflammation in Mlkl-/- mice was due to MEK/ERK activation particularly in dendritic cells (DCs). Our results demonstrate the role of MLKL in maintaining intestinal homeostasis and protecting against colitis and tumorigenesis.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA