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1.
Antiviral Res ; 188: 105046, 2021 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-33588012

RESUMO

This study aimed at understanding the impact of different substitutions at codon 715 localized in the region II of the palm domain of herpes simplex virus 1 (HSV-1) and human cytomegalovirus (HCMV) DNA polymerases (pol). Here, we report a new theoretical mutation V715S that confers resistance of HSV-1 to foscarnet/acyclovir (5.6- and 9.2-fold increases EC50 values compared to wild type, respectively) and of HCMV to foscarnet/ganciclovir (2.8- and 2.9-fold increases in EC50 values compared to wild type, respectively). To further analyze the importance of this amino acid, we investigated the impact of the already known mutations V715M and V715G on the replicative capacities and drug susceptibilities of both viruses as well as on the activity and drug inhibition of the DNA pol. The V715G recombinant HSV-1 mutant was resistant to foscarnet and acyclovir (3.4- and 4.6-fold EC50 increase, respectively) whereas the V715M mutant was susceptible to foscarnet and resistant to acyclovir (3.4-fold EC50 increase). The V715G recombinant HCMV mutant did not grow and the V715M mutant was resistant to foscarnet (3.7-fold EC50 increase) and susceptible to ganciclovir. Finally, we showed by three-dimensional modeling that the differential impact of these mutations on the viral replicative capacity and drug resistance profile was related to different hydrophobic local environments for V715 in the DNA pol of the two viruses. Furthermore, we hypothesize that the DNA pol of HSV-1 is more tolerant to changes at this residue compared to that of HCMV because of a more hydrophobic environment stabilizing the region.

2.
Med Sci Monit ; 27: e927474, 2021 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-33397840

RESUMO

BACKGROUND This study aimed to assess the utility of magnetic resonance imaging (MRI) in the diagnosis of prenatal non-visualization of the fetal gallbladder (PNVGB). MATERIAL AND METHODS The clinical data of 32 pregnant women with PNVGB who underwent MRI examination during the second and third trimester of pregnancy were collected and their outcomes were analyzed. RESULTS MRI showed that 26 patients (81.3%) had isolated PNVGB and 6 (18.8%) had additional malformations. In 26 patients with isolated PNVGB, 7 were found in the gallbladder on MRI and 4 were found on subsequent ultrasonography. One patient had termination of pregnancy (TOP) and 1 patient was lost to follow-up; the remaining 24 patients were known to deliver a healthy child. Among the 6 patients with additional malformations, 3 terminated their pregnancies due to combined severe abnormalities: 1 patient with horseshoe kidney and 1 with fetal echogenic bowel both had a healthy child, while 1 with fetal growth restriction (FGR) delivered a child who walked on tiptoe. CONCLUSIONS MRI contributes to identifying PNVGB detected or suspected by ultrasonography.

3.
Spine (Phila Pa 1976) ; 46(1): 62-68, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32925689

RESUMO

STUDY DESIGN: A retrospective study was conducted. OBJECTIVE: This study aims to compare the perioperative outcomes of minimal invasive spine surgery (MISS) and traditional open surgery (TOS) for thoracolumbar spine metastasis. SUMMARY OF BACKGROUND DATA: TOS for metastatic spinal tumors has many disadvantages, such as significant blood loss and high complication rate. MISS may change the treatment modality, but its safety and efficacy for spinal metastasis are lacking. METHODS: We retrospectively reviewed clinical data from 154 consecutive patients registered in our institute who underwent separation surgery for spinal metastases from January 2017 to December 2019. Forty-nine patients received MISS and 105 patients had TOS. The demographic and perioperative data were collected and compared between two approaches. RESULTS: There were no significant differences in baseline characteristics between the MISS and TOS group, except the sex (P = 0.04). The mean intraoperative blood loss in MISS group was lower than that in TOS group (748.57 vs. 950.48 mL, P = 0.039). The operative time was comparable between both groups (mean 213.45 vs. 221.03 minutes, P = 0.78). The postoperative drainage before discharge in MISS group was remarkably less than that in TOS group (mean 494.02 vs. 1099.10 mL, P = 0.0004). As compared to TOS group, patients in MISS group had lower complication rate, although the difference is not significant (9.52% vs. 6.12%, P = 0.55). The infection rate of MISS group was two-fold lower than that in the TOS group, although the difference is not significant (P = 0.43). The mean hospital stay of MISS group is 7.35 days, which is significantly shorter than TOS group (9.94 days, P = 0.0007). Patients in both groups exhibited similar postoperative neurological outcomes. CONCLUSION: MISS is a safe and effective technique that could be considered the optimal treatment for patients with spinal metastasis and myelopathy and thus is an excellent alternative in managing thoracolumbar spine metastasis. LEVEL OF EVIDENCE: 3.

4.
Nat Microbiol ; 6(3): 327-338, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33349664

RESUMO

Bloodstream infections caused by nontyphoidal Salmonella are a major public health concern in Africa, causing ~49,600 deaths every year. The most common Salmonella enterica pathovariant associated with invasive nontyphoidal Salmonella disease is Salmonella Typhimurium sequence type (ST)313. It has been proposed that antimicrobial resistance and genome degradation has contributed to the success of ST313 lineages in Africa, but the evolutionary trajectory of such changes was unclear. Here, to define the evolutionary dynamics of ST313, we sub-sampled from two comprehensive collections of Salmonella isolates from African patients with bloodstream infections, spanning 1966 to 2018. The resulting 680 genome sequences led to the discovery of a pan-susceptible ST313 lineage (ST313 L3), which emerged in Malawi in 2016 and is closely related to ST313 variants that cause gastrointestinal disease in the United Kingdom and Brazil. Genomic analysis revealed degradation events in important virulence genes in ST313 L3, which had not occurred in other ST313 lineages. Despite arising only recently in the clinic, ST313 L3 is a phylogenetic intermediate between ST313 L1 and L2, with a characteristic accessory genome. Our in-depth genotypic and phenotypic characterization identifies the crucial loss-of-function genetic events that occurred during the stepwise evolution of invasive S. Typhimurium across Africa.

5.
Aging (Albany NY) ; 13(2): 2168-2183, 2020 12 09.
Artigo em Inglês | MEDLINE | ID: mdl-33316779

RESUMO

Tumor microenvironments are strongly related to tumor development, and immune-infiltrating cells and immune-related molecules are potential prognostic markers. However, the shortcomings of traditional measurement methods limit the accurate evaluation of various components in tumor microenvironments. With the rapid advancement of Next-Generation RNA Sequencing technology, dedicated and in-depth analyses of immune filtration within the tumor microenvironment has been achieved. In this study, we combined the bioinformatics analysis methods ESTIMATE, CIBERSORT, and ssGSEA to characterize the immune infiltration of sarcomas and to identify specific immunomodulators of different pathological subtypes. We further extracted a functional enrichment of significant immune-related genes related to improved prognosis, including NR1H3, VAMP5, GIMAP2, GBP2, HLA-E and CRIP1. Overall, the immune microenvironment is an important prognostic determinant of sarcomas and may be a potential resource for developing effective immunotherapy.

7.
Cell Discov ; 6: 74, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33133634

RESUMO

It remains challenging to construct a complete cell lineage map of the origin of vascular endothelial cells in any vertebrate embryo. Here, we report the application of in toto light-sheet fluorescence imaging of embryos to trace the origin of vascular endothelial cells (ECs) at single-cell resolution in zebrafish. We first adapted a previously reported method to embryo mounting and light-sheet imaging, created an alignment, fusion, and extraction all-in-one software (AFEIO) for processing big data, and performed quantitative analysis of cell lineage relationships using commercially available Imaris software. Our data revealed that vascular ECs originated from broad regions of the gastrula along the dorsal-ventral and anterior-posterior axes, of which the dorsal-anterior cells contributed to cerebral ECs, the dorsal-lateral cells to anterior trunk ECs, and the ventral-lateral cells to posterior trunk and tail ECs. Therefore, this work, to our knowledge, charts the first comprehensive map of the gastrula origin of vascular ECs in zebrafish, and has potential applications for studying the origin of any embryonic organs in zebrafish and other model organisms.

8.
J Appl Toxicol ; 2020 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-33079441

RESUMO

Refractory ceramic fibers (RCFs) are increasingly used as heating-insulated materials in various industries. However, toxicological and epidemiological studies focusing on the adverse effects of RCFs were still insufficient, particularly in China. We conducted a cross-sectional study to evaluate comprehensively the associations between occupational exposure to RCFs and respiratory health effects among Chinese workers. We measured and calculated cumulative RCFexposure levels of RCFs workers from the biggest RCFs factory in China. In total, 430 RCF-exposed workers and 121 controls were enrolled in this study. Physical examinations of the respiratory system were performed and serum levels of biomarkers including Clara cell protein 16 (CC16), surfactant protein D (SP-D), transforming growth factor ß1 (TGF-ß1), and 8-hydroxy-2'-deoxyguanosine (8-OHdG) were determined among all subjects. RCF exposure workers showed a higher prevalence rate of respiratory symptoms (cough: 11.9%) and lower levels of small airways function indices (V50 %: 82.71 ± 20.01, maximal mid expiratory flow (MMEF)%: 81.08 ± 19.56) compared with the control group (cough: 5.0%, V50 %: 90.64 ± 24.36, MMEF%: 88.83 ± 24.22). RCFs workers showed higher levels of TGF-ß1 (31.04 ng/mL) and 8-OHdG (130.72 ng/mL) and lower levels of CC16 (3.68 ng/mL) compared with the controls (TGF-ß1: 26.63 ng/mL, 8-OHdG: 106.86 ng/mL, CC16: 5.65 ng/mL). After adjusting for covariates, cumulative RCF exposure levels showed significant positive associations with the levels of TGF-ß1 and 8-OHdG and negative association with the level of CC16. Occupational RCF exposure could induce adverse respiratory health effects, including cough and small airways damage, which may correlate to the altered levels of lung damage markers (CC16 and TGF-ß1) and oxidative markers (8-OHdG).

9.
Antiviral Res ; 184: 104953, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33065138

RESUMO

BACKGROUND & AIMS: Normal/mildly elevated ALT (<2 × ULN) CHB patients are potentially at risk of progression to cirrhosis and/or hepatocellular carcinoma (HCC). We aimed to assess the outcomes of anti-viral therapy for normal/mild elevation of ALT CHB patients. METHODS: CHB patients (n = 432) who have had liver biopsied were determined. It was determined that the outcomes of anti-viral therapy in CHB patients with normal/mild elevation of ALT, in response to nucleoside/nucleotide analogues (NAs) (n = 190) and pegylated interferon (PEG-IFN) (n = 30) treatment for up to 72 weeks. Non-anti-viral treated patients were used as control (n = 40). RESULTS: There was about 50% of the CHB patients showed hepatic inflammatory necrosis ≥ G2 and/or fibrosis ≥ S2 among >30-years-old. The rate of undetectable HBV DNA in NAs and PEG-IFN groups was ~50%, ~80% or ~90% at week 24, 48 or 72, respectively. HBeAg clearance rate was lower in NAs treated than that in PEG-IFN group at week 48 (6% vs 20%, P < 0.05). ALT normalization rate was increased by 1.18-fold at week 72. HBsAg decline in HBeAg+ patients treated with NAs or PEG-IFN was 0.418 or 1.217 log IU/mL (P < 0.0001) at week 48; whereas HBsAg decline was 0.176 or 0.816 log IU/mL (P < 0.001) in HBeAg- patients. HBsAg at baseline and week 24 were strong predictors of "low HBsAg at week 48". CONCLUSION: Long term anti-viral therapy inhibits HBV replication effectively in ALT<2 × ULN CHB patients. PEG-IFN therapy is recommended for HBeAg+ patients with baseline HBsAg<4.37 log IU/ml and HBeAg- patients with baseline HBsAg<2.66 log IU/ml to achieve "low HBsAg at week 48".

10.
Artigo em Inglês | MEDLINE | ID: mdl-32831863

RESUMO

Objective: To evaluate the impact of long-term Traditional Chinese Medicine (TCM) syndrome differentiation combined with antiviral therapy with Nucleos (t) ide analogues (NAs) on the incidence of cirrhosis in patients with chronic hepatitis B. Methods: This retrospective cohort study included 521 patients with chronic hepatitis B who underwent a treatment course of ≥3 years from 1998-2019. Of the 521 patients, 261 were defined as TCM users while 260 were TCM nonusers (control group). All the enrolled subjects were followed up until February 2019 to measure the incidence and hazard ratio (HR) of cirrhosis, and the Cox proportional hazards regression model was used to analyze the independent factors affecting the occurrence of cirrhosis. Results: The cumulative incidence of TCM users and nonusers was 6.9% and 13.5%, respectively (P=0.013). Results of the Kaplan-Meier analysis demonstrated that TCM users had a significantly lower cumulative incidence of cirrhosis than TCM nonusers (P=0.011), and TCM users had a significantly lower liver cirrhosis risk than TCM nonusers (adjusted HR = 0.416, 95% CI, 0.231-0.749). The histological evaluation revealed improved fibrosis in 45.0% of TCM users and 11.1% of TCM nonusers (P=0.033). The analysation of the prescriptions including total 119 single Chinese herbs medicinal demonstrated that "replenish qi and fortify the spleen," "clear heat and dispel dampness," and "soothe the liver and regulate qi" are the main treatment methods of TCM for CHB. Conclusions: Our study demonstrated that long-term TCM use may attenuate liver cirrhosis risk in patients with chronic hepatitis B (CHB).

11.
Front Oncol ; 10: 1198, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32850346

RESUMO

Background: Osteosarcoma (OSA), the most common primary bone malignancy in children and adolescents, is prone to metastases and unfavorable prognosis. Owing to its strong genomic heterogeneity, traditional chemotherapy, or targeted immunotherapy has not effectively improved the related overall survival for decades. Since the landscape of the OSA tumor immune microenvironment is scarcely known, despite it playing a crucial role in predicting clinical outcomes and therapeutic efficacies, we aimed to elucidate its molecular characteristics. Methods: The immune signature of 101 OSA samples was explored using transcriptome profiling and clinical characteristics retrieved from the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) program. Correlations between the prognostic immune markers and their clinical chemotherapy responses were assessed and verified based on 45 OSA primary tumors. Findings: We identified the heterogeneity underlying tumor immune signature in OSA, and found CD4+ T cells and macrophage markers CD4/IFNGR2/CD68 to be feasible prognostic factors, exerting significantly positive correlation with each other. Specifically, CSF1R, which plays an essential role in the regulation of proliferation and differentiation of macrophages, was found to be a specific signature associated with CD4/CD68, with improved OSA clinical outcomes. Interpretation: The immune landscape based on CD4/CD68/CSF1R gene signatures showed considerable promise for prognostic and therapeutic stratification in OSA patients. A specific immune signature for OSA, abundantly consisting of Th1-polarized CD4+ T cells and CSF1R-related CD68+ macrophages, may improve the predictive efficacy of chemotherapy and improve prognosis in patients with OSA.

12.
Arch Gynecol Obstet ; 302(6): 1389-1399, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32856138

RESUMO

PURPOSE: The mechanisms underlying HBV intrauterine transmission remain unknown. In this study, we explored the mechanism of HBV intrauterine transmission by iTRAQ proteomics analysis. METHODS: iTRAQ technology was applied to perform comparative proteomics studies on six HBV+/+ neonates and six HBV+/- neonates whose mothers and fathers were HBsAg positive and paternal HBsAg negative, respectively. The data obtained from the mass spectrometer were analyzed using MASCOT ( https://matrixscience.com ) to qualitatively and quantitatively compare the differentially expressed proteins in the two groups. Gene Ontology and KEGG pathway analyses were performed to analyze the differentially expressed proteins. The expressions of HBV intrauterine transmission-related proteins in serum samples and corresponding placental tissues were further verified by immunohistochemistry and Western Blot. Then, the human trophoblast cell line (Swan71) infected with HBV was used to analyze the potential mechanisms of HBV intrauterine transmission under the mediation of differential proteins. RESULTS: A total of 35 differentially expressed proteins, including 17 up-regulated proteins and 18 down-regulated proteins, were identified by comparing serum protein expression levels in HBV+/+ and HBV+/- neonates. The differentially expressed proteins were mainly related to RAGE receptor binding, NF-kappa B transcription factor activity, innate immune response, defense response to bacterium, and the signaling pathway in pathogenic microorganism infection. The expressions of S100A8/9/12 in HBV+/+ maternal placenta tissue were significantly increased. The expressions of S100A8/9/12 proteins in Swan71 cells were significantly increased after HBV infection. CONCLUSION: High expression of S100 proteins may be associated with the intrauterine-transplacental transmission of HBV.

13.
Proc Natl Acad Sci U S A ; 117(34): 20717-20728, 2020 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-32788367

RESUMO

Mucosal-associated invariant T (MAIT) cells are innate T lymphocytes activated by bacteria that produce vitamin B2 metabolites. Mouse models of infection have demonstrated a role for MAIT cells in antimicrobial defense. However, proposed protective roles of MAIT cells in human infections remain unproven and clinical conditions associated with selective absence of MAIT cells have not been identified. We report that typhoidal and nontyphoidal Salmonella enterica strains activate MAIT cells. However, S. Typhimurium sequence type 313 (ST313) lineage 2 strains, which are responsible for the burden of multidrug-resistant nontyphoidal invasive disease in Africa, escape MAIT cell recognition through overexpression of ribB This bacterial gene encodes the 4-dihydroxy-2-butanone-4-phosphate synthase enzyme of the riboflavin biosynthetic pathway. The MAIT cell-specific phenotype did not extend to other innate lymphocytes. We propose that ribB overexpression is an evolved trait that facilitates evasion from immune recognition by MAIT cells and contributes to the invasive pathogenesis of S. Typhimurium ST313 lineage 2.


Assuntos
Células T Invariáveis Associadas à Mucosa/imunologia , Salmonella typhimurium/genética , Salmonella typhimurium/metabolismo , África ao Sul do Saara , Antibacterianos , Diarreia/microbiologia , Diarreia/mortalidade , Humanos , Evasão da Resposta Imune/genética , Evasão da Resposta Imune/fisiologia , Células T Invariáveis Associadas à Mucosa/metabolismo , Infecções por Salmonella/imunologia , Salmonella typhimurium/patogenicidade
14.
J Immunol Res ; 2020: 1826587, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32766317

RESUMO

Helping B cells and antibody responses is a major function of CD4+T helper cells. Follicular helper T (Tfh) cells are identified as a subset of CD4+T helper cells, which is specialized in helping B cells in the germinal center reaction. Tfh cells express high levels of CXCR5, PD-1, IL-21, and other characteristic markers. Accumulating evidence has demonstrated that the dysregulation of Tfh cells is involved in infectious, inflammatory, and autoimmune diseases, including lymphocytic choriomeningitis virus (LCMV) infection, inflammatory bowel disease (IBD), systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), IgG4-related disease (IgG4-RD), Sjögren syndrome (SS), and type 1 diabetes (T1D). Activation of subset-specific transcription factors is the essential step for Tfh cell differentiation. The differentiation of Tfh cells is regulated by a complicated network of transcription factors, including positive factors (Bcl6, ATF-3, Batf, IRF4, c-Maf, and so on) and negative factors (Blimp-1, STAT5, IRF8, Bach2, and so on). The current knowledge underlying the molecular mechanisms of Tfh cell differentiation at the transcriptional level is summarized in this paper, which will provide many perspectives to explore the pathogenesis and treatment of the relevant immune diseases.

15.
Cell Oncol (Dordr) ; 43(6): 1129-1145, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32623699

RESUMO

PURPOSE: Hepatitis B virus (HBV)-associated hepatocellular carcinoma (HCC), which has a male predominance, lacks effective therapeutic options. Previously, the cardiac glycoside analogue bufalin has been found to inhibit HBV infection and HCC development. As yet, however, its molecular role in HBV-associated HCC has remained obscure. METHODS: Colony formation and soft agar assays, xenograft and orthotopic mouse models and HBV X protein (HBx) transgenic mice with exposure to diethylnitrosamine were used to evaluate the effect of bufalin on HBV-associated HCC growth and tumorigenicity. HBx-induced oncogenic signaling regulated by bufalin was assessed using PCR array, chromatin immunoprecipitation, site-directed mutagenesis, luciferase reporter, transcription and protein expression assays. Synergistic HCC therapeutic effects were examined using combinations of bufalin and sorafenib. RESULTS: We found that bufalin exerted a more profound effect on inhibiting the proliferation of HBV-associated HCC cells than of non HBV-associated HCC cells. Bufalin significantly inhibited HBx-induced malignant transfromation in vitro and tumorigenicity in vivo. Androgen receptor (AR) signaling was found to be a target of bufalin resistance to HBV-associated hepatocarcinogenesis. We also found that bufalin induced both AR dephosphorylation and cell cycle-related kinase (CCRK) degradation to inhibit ß-catenin/TCF signaling, which subsequently led to cell cycle arrest via cyclin D1 down-regulation and p21 up-regulation, resulting in HCC regression. Furthermore, we found that bufalin reduced > 60% diethylnitrosamine-induced hepatocarcinogenesis in HBx transgenic mice, and improved the sensitivity of refractory HBV-associated HCC cells to sorafenib treatment. CONCLUSION: Our results indicate that bufalin acts as a potential anti-HCC therapeutic candidate to block HBx-induced AR/CCRK/ß-catenin signaling by targeting AR and CCRK, which may provide a novel strategy for the treatment of HBV-associated HCC.

16.
Nanoscale ; 12(31): 16403-16408, 2020 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-32525164

RESUMO

To date, plasmonic nanowire lasers mostly adopt hybrid plasmonic waveguides, while there is a lack of study in terms of the confinement effect and the corresponding ultrafast dynamics of non-hybridized plasmonic lasers. Here, we report ultrafast plasmonic nanowire lasers composed of a single CH3NH3PbBr3 nanowire on a silver film without any insulating layer at room temperature. The non-hybridized plasmonic nanowire lasers exhibit ultrafast lasing dynamics with around 1.9 ps decay rate and 1 ps peak response time. Such values are among the best ones ever reported. Interestingly, the threshold of the non-hybridized plasmonic nanowire lasers is in the same order as that of their hybrid counterparts. The low threshold is due to the ultra-flat single-crystal silver films and high-quality single-crystal perovskite nanowires. The non-hybridized plasmonic lasing in CH3NH3PbBr3 nanowires originates from the stimulated emission of an electron-hole plasma based on our experiments. This work deepens the understanding of non-hybridized plasmonic lasers and paves the way to design electric pump plasmonic lasers by getting rid of insulating layers.

17.
Diagn Pathol ; 15(1): 67, 2020 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-32493336

RESUMO

BACKGROUND: High Programmed death ligand 1 (PD-L1) expression are thought to be necessary to PD-1/PD-L1 axis blockades in many tumors. The aim of the study was to explore the variation of PD-L1 expression after neoadjuvant chemotherapy (NAC) in cervical squamous cell carcinoma (SCC) and its clinical implications. METHODS: A total of 142 paired SCC specimens before and after platinum-based NAC were obtained from cervical cancer patients. The expression of PD-L1 and CD3+, CD4+, CD8+ tumor infiltrating lymphocytes (TILs) was detected by immunohistochemistry and the association between TILs, chemotherapy response, clinical outcome and PD-L1 expression was evaluated. RESULTS: The fraction of patients with high PD-L1 expression was significantly increased from 32.4 to 46.5% after NAC (χ2 = 5.897, p = 0.015), while the increase of CD3+, CD4+, CD8+ TILs was not significant. High PD-L1 expression was not associated with CD3+, CD4+, CD8+ TILs before NAC, however CD8+ TILs infiltration was positively associated with high PD-L1 expression after NAC (r = 0.205, p = 0.014). The decreased PD-L1 expression was more observed in patients with clinical response to NAC (χ2 = 6.890, p = 0.009). A longer DFS was seen in patients with decreased PD-L1 expression than those with elevated or stable PD-L1 expression (p = 0.048, 95% CI: 0.091-0.987), while the difference was not significant in multivariate analysis (p = 0.113, 95% CI: 0.108-1.266). CONCLUSIONS: Cisplatin based chemotherapy can increase PD-L1 expression in cervical cancer. The increased PD-L1 expression and a lymphocyte predominant microenvironment after chemotherapy provide a rational for use of PD-1/PD-L1 axis-inhibitor in the neoadjuvant setting.

18.
J Biol Chem ; 295(26): 8708-8724, 2020 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-32371400

RESUMO

Mammalian acetylcholinesterase (AChE) is well-studied, being important in both cholinergic brain synapses and the peripheral nervous systems and also a key drug target for many diseases. In contrast, little is known about the structures and molecular mechanism of prokaryotic acetylcholinesterases. We report here the structural and biochemical characterization of ChoE, a putative bacterial acetylcholinesterase from Pseudomonas aeruginosa Analysis of WT and mutant strains indicated that ChoE is indispensable for P. aeruginosa growth with acetylcholine as the sole carbon and nitrogen source. The crystal structure of ChoE at 1.35 Å resolution revealed that this enzyme adopts a typical fold of the SGNH hydrolase family. Although ChoE and eukaryotic AChEs catalyze the same reaction, their overall structures bear no similarities constituting an interesting example of convergent evolution. Among Ser-38, Asp-285, and His-288 of the catalytic triad residues, only Asp-285 was not essential for ChoE activity. Combined with kinetic analyses of WT and mutant proteins, multiple crystal structures of ChoE complexed with substrates, products, or reaction intermediate revealed the structural determinants for substrate recognition, snapshots of the various catalytic steps, and the molecular basis of substrate inhibition at high substrate concentrations. Our results indicate that substrate inhibition in ChoE is due to acetate release being blocked by the binding of a substrate molecule in a nonproductive mode. Because of the distinct overall folds and significant differences of the active site between ChoE and eukaryotic AChEs, these structures will serve as a prototype for other prokaryotic acetylcholinesterases.

19.
Cancer Sci ; 111(6): 1899-1909, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32232912

RESUMO

Tumor-infiltrating immune cells play a crucial role in tumor progression and response to treatment. However, the limited studies on infiltrating immune cells have shown inconsistent and even controversial results for osteosarcoma (OS). In addition, the dynamic changes of infiltrating immune cells after neoadjuvant chemotherapy are largely unknown. We downloaded the RNA expression matrix and clinical information of 80 OS patients from the TARGET database. CIBERSORT was used to evaluate the proportion of 22 immune cell types in patients based on gene expression data. M2 macrophages were found to be the most abundant immune cell type and were associated with improved survival in OS. Another cohort of pretreated OS samples was evaluated by immunohistochemistry to validate the results from CIBERSORT analysis. Matched biopsy and surgical samples from 27 patients were collected to investigate the dynamic change of immune cells and factors before and after neoadjuvant chemotherapy. Neoadjuvant chemotherapy was associated with increased densities of CD3+ T cells, CD8+ T cells, Ki67 + CD8+ T cells and PD-L1+ immune cells. Moreover, HLA-DR-CD33+ myeloid-derived suppressive cells (MDSC) were decreased after treatment. We determined that the application of chemotherapy may activate the local immune status and convert OS into an immune "hot" tumor. These findings provide rationale for investigating the schedule of immunotherapy treatment in OS patients in future clinical trials.


Assuntos
Neoplasias Ósseas/imunologia , Linfócitos do Interstício Tumoral/imunologia , Osteossarcoma/imunologia , Microambiente Tumoral/efeitos dos fármacos , Microambiente Tumoral/imunologia , Adolescente , Adulto , Antineoplásicos Imunológicos/uso terapêutico , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/patologia , Quimioterapia Adjuvante/métodos , Criança , Feminino , Humanos , Linfócitos do Interstício Tumoral/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Masculino , Células Supressoras Mieloides/efeitos dos fármacos , Células Supressoras Mieloides/imunologia , Terapia Neoadjuvante/métodos , Osteossarcoma/tratamento farmacológico , Osteossarcoma/patologia
20.
J Biol Chem ; 295(14): 4709-4722, 2020 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-32111738

RESUMO

Group A flavin-dependent monooxygenases catalyze the cleavage of the oxygen-oxygen bond of dioxygen, followed by the incorporation of one oxygen atom into the substrate molecule with the aid of NADPH and FAD. These flavoenzymes play an important role in many biological processes, and their most distinct structural feature is the choreographed motions of flavin, which typically adopts two distinct conformations (OUT and IN) to fulfill its function. Notably, these enzymes seem to have evolved a delicate control system to avoid the futile cycle of NADPH oxidation and FAD reduction in the absence of substrate, but the molecular basis of this system remains elusive. Using protein crystallography, size-exclusion chromatography coupled to multi-angle light scattering (SEC-MALS), and small-angle X-ray scattering (SEC-SAXS) and activity assay, we report here a structural and biochemical characterization of PieE, a member of the Group A flavin-dependent monooxygenases involved in the biosynthesis of the antibiotic piericidin A1. This analysis revealed that PieE forms a unique hexamer. Moreover, we found, to the best of our knowledge for the first time, that in addition to the classical OUT and IN conformations, FAD possesses a "sliding" conformation that exists in between the OUT and IN conformations. This observation sheds light on the underlying mechanism of how the signal of substrate binding is transmitted to the FAD-binding site to efficiently initiate NADPH binding and FAD reduction. Our findings bridge a gap currently missing in the orchestrated order of chemical events catalyzed by this important class of enzymes.

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