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1.
Mol Cell ; 68(4): 698-714.e5, 2017 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-29149597

RESUMO

Telomere elongation through telomerase enables chromosome survival during cellular proliferation. The conserved multifunctional shelterin complex associates with telomeres to coordinate multiple telomere activities, including telomere elongation by telomerase. Similar to the human shelterin, fission yeast shelterin is composed of telomeric sequence-specific double- and single-stranded DNA-binding proteins, Taz1 and Pot1, respectively, bridged by Rap1, Poz1, and Tpz1. Here, we report the crystal structure of the fission yeast Tpz1475-508-Poz1-Rap1467-496 complex that provides the structural basis for shelterin bridge assembly. Biochemical analyses reveal that shelterin bridge assembly is a hierarchical process in which Tpz1 binding to Poz1 elicits structural changes in Poz1, allosterically promoting Rap1 binding to Poz1. Perturbation of the cooperative Tpz1-Poz1-Rap1 assembly through mutation of the "conformational trigger" in Poz1 leads to unregulated telomere lengthening. Furthermore, we find that the human shelterin counterparts TPP1-TIN2-TRF2 also assemble hierarchically, indicating cooperativity as a conserved driving force for shelterin assembly.


Assuntos
Proteínas de Transporte/química , Proteínas de Schizosaccharomyces pombe/química , Schizosaccharomyces/química , Proteínas de Ligação a Telômeros/química , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Cristalografia por Raios X , Proteínas de Ligação a DNA , Humanos , Estrutura Quaternária de Proteína , Schizosaccharomyces/genética , Schizosaccharomyces/metabolismo , Proteínas de Schizosaccharomyces pombe/genética , Proteínas de Schizosaccharomyces pombe/metabolismo , Complexo Shelterina , Proteínas de Ligação a Telômeros/genética , Proteínas de Ligação a Telômeros/metabolismo
2.
FASEB J ; 37(8): e23004, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37440279

RESUMO

The superficial zone cells in mandibular condylar cartilage are proliferative. The present purpose was to delineate the relation of calcium-sensing receptor (CaSR) and parathyroid hormone-related peptide nuclear localization sequence (PTHrP87-139 ), and their role in the proliferation behaviors of the superficial zone cells. A gain- and loss-of-function strategy were used in an in vitro fluid flow shear stress (FFSS) model and an in vivo bilateral elevation bite model which showed mandibular condylar cartilage thickening. CaSR and PTHrP87-139 were modulated through treating the isolated superficial zone cells with activator/SiRNA and via deleting CaSR or parathyroid hormone-related peptide (PTHrP) gene in mice with the promoter gene of proteoglycan 4 (Prg4-CreERT2 ) in the tamoxifen-inducible pattern with or without additional injection of Cinacalcet, the CaSR agonist, or PTHrP87-139 peptide. FFSS stimulated CaSR and PTHrP expression, and accelerated proliferation of the Prg4-expressing superficial zone cells, in which process CaSR acted as an up-streamer of PTHrP. Proteoglycan 4 specific knockout of CaSR or PTHrP reduced the cartilage thickness, suppressed the proliferation and early differentiation of the superficial zone cells, and inhibited cartilage thickening and matrix production promoted by bilateral elevation bite. Injections of CaSR agonist Cinacalcet could not improve the phenotype caused by PTHrP mutation. Injections of PTHrP87-139 peptide rescued the cartilage from knockout of CaSR gene. CaSR modulates proliferation of the superficial zone cells in mandibular condylar cartilage through activation of PTHrP nuclear localization sequence. Our data support the therapeutic target of CaSR in promoting PTHrP production in superficial zone cartilage.


Assuntos
Proteína Relacionada ao Hormônio Paratireóideo , Receptores de Detecção de Cálcio , Camundongos , Animais , Proteína Relacionada ao Hormônio Paratireóideo/genética , Proteína Relacionada ao Hormônio Paratireóideo/metabolismo , Receptores de Detecção de Cálcio/genética , Receptores de Detecção de Cálcio/metabolismo , Condrócitos/metabolismo , Cartilagem/metabolismo , Articulação Temporomandibular/metabolismo , Proteoglicanas/metabolismo , Proliferação de Células
3.
Fish Shellfish Immunol ; 145: 109330, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38159874

RESUMO

Thioester-containing proteins (TEPs) play a vital role in the innate immune response to biotic and abiotic stresses. In this study, the TEPs in C. gigas were identified, and their gene structure, phylogenetic relationships, collinearity relationships, expression profiles, sequence diversity, and alternative splicing were analyzed. Eight Tep genes were identified in C. gigas genome. Functional analysis and evolutionary relationships indicated a high level of homology to other mollusks TEPs. The transcriptome quantitative analysis results showed that the Tep genes in C. gigas respond to heat stress and Vibrio stress. Alternative splicing analysis revealed four Tep genes (designated A2M_1, CD109_3, CD109_5, complement C3) encode multiple alternative splice variants. Analysis of gene structure and multiple alignments revealed that seven CD109_5 variants are produced through the alternative splicing of the 19th exon, which encodes the highly variable central region. Sequence diversity analysis revealed thirteen missense variants within the 19th exon region of these seven CD109_5 alternative splice variants. Furthermore, the differential alternative splicing analysis showed significant induction of CD109_5, A2M_1 and A2M_2 variants after infection with V. parahaemolyticus. This study explores the Tep genes of C. gigas, providing insights into the molecular mechanisms underlying the involvement of C. gigas TEPs in innate immunity.


Assuntos
Crassostrea , Animais , Filogenia , Perfilação da Expressão Gênica , Imunidade Inata/genética , Estresse Fisiológico
4.
Genes Dev ; 30(7): 827-39, 2016 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-26988418

RESUMO

Telomeric regions contain prominent sites of heterochromatin, which is associated with unique histone modification profiles such as the methylation of histone H3 at Lys9 (H3K9me). In fission yeast, the conserved telomeric shelterin complex recruits the histone H3K9 methyltransferase complex CLRC to establish subtelomeric heterochromatin. Although many shelterin mutations affect subtelomeric heterochromatin assembly, the mechanism remains elusive due to the diverse functions of shelterin. Through affinity purification, we found that shelterin directly associates with CLRC through the Ccq1 subunit. Surprisingly, mutations that disrupt interactions between shelterin subunits compromise subtelomeric heterochromatin without affecting CLRC interaction with shelterin component Pot1, located at chromosome ends. We further discovered that telomeric repeats are refractory to heterochromatin spreading and that artificial restoration of shelterin connections or increased heterochromatin spreading rescued heterochromatin defects in these shelterin mutants. Thus, subtelomeric heterochromatin assembly requires both the recruitment of CLRC by shelterin to chromosome ends and the proper connection of shelterin components, which allows CLRC to skip telomeric repeats to internal regions.


Assuntos
Montagem e Desmontagem da Cromatina/fisiologia , Heterocromatina/metabolismo , Proteínas de Schizosaccharomyces pombe/metabolismo , Schizosaccharomyces/fisiologia , Proteínas de Ligação a Telômeros/metabolismo , Telômero/metabolismo , Montagem e Desmontagem da Cromatina/genética , Heterocromatina/genética , Histona Metiltransferases , Histona-Lisina N-Metiltransferase/genética , Histona-Lisina N-Metiltransferase/metabolismo , Mutação , Ligação Proteica , Schizosaccharomyces/enzimologia , Schizosaccharomyces/genética , Proteínas de Schizosaccharomyces pombe/genética , Complexo Shelterina , Telômero/genética , Proteínas de Ligação a Telômeros/genética
5.
BMC Cancer ; 23(1): 523, 2023 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-37291493

RESUMO

BACKGROUND: We conducted a systematic review and meta-analysis to summarize the predictive and prognostic ability of the log odds of positive lymph nodes (LODDS) staging system and compare it with pathological N (pN) classification and the ratio-based lymph node system (rN) for the overall survival (OS) of gastric cancer (GC). METHODS: Through a systematic review till March 7, 2022, we identified population-based studies that reported the prognostic effects of LODDS in patients with GC. We compare the predictive effectiveness of the LODDS staging system with that of the rN and pN classification systems for the OS of GC. RESULTS: Twelve studies comprising 20,312 patients were included in this systematic review and meta-analysis. The results showed that LODDS1, LODDS2, LODDS3, and LODDS4 in GC patients were correlated with poor OS compared with LODDS0 (LODDS1 vs. LODDS0: HR = 1.62, 95% CI (1.42, 1.85); LODDS2 vs. LODDS0: HR = 2.47, 95% CI (2.02, 3.03); LODDS3 vs. LODDS0: HR = 3.15, 95% CI (2.50, 3.97); LODDS4 vs. LODDS0: HR = 4.55, 95% CI (3.29, 6.29)). Additionally, significant differences in survival were observed among patients with different LODDS classifications (all P-values were < 0.001) with the same rN and pN classifications. Meanwhile, for patients with different pN or rN classifications with the same LODDS classification, prognosis was highly similar. CONCLUSION: The findings show that LODDS is correlated with the prognosis of GC patients and is superior to the pN and rN classifications for prognostic assessment.


Assuntos
Neoplasias Gástricas , Humanos , Prognóstico , Estadiamento de Neoplasias , Neoplasias Gástricas/patologia , Estudos Retrospectivos , Linfonodos/patologia
6.
Future Oncol ; 19(36): 2395-2403, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37990937

RESUMO

At present, preoperative chemotherapy is the standard of care for the neoadjuvant treatment of potentially resectable gastric cancer (GC). However, because the efficacy and prognosis are not ideal, curative effects for this population are unsatisfactory. With the development of immune checkpoint inhibitors, the results of a few encouraging early trials of immunotherapeutic agents as neoadjuvant therapies for resectable GC have been reported. However, markers of the efficacy of immune checkpoint inhibitors remain unclear. This prospective single-center, single-arm observational study was designed to evaluate the efficacy of sintilimab plus the fluorouracil, leucovorin, oxaliplatin and docetaxel regimen as a neoadjuvant treatment for localized GC. More importantly, this work assesses multiple dimensions and include ctDNA, the immune microenvironment and intestinal microbiome to explore correlations between biomarkers and neoadjuvant therapeutic efficacy. Clinical trial registration: ChiCTR2200061629 (www.chictr.org.cn/index.aspx).


Assuntos
Neoplasias Gástricas , Humanos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Biomarcadores , Docetaxel/uso terapêutico , Fluoruracila/uso terapêutico , Inibidores de Checkpoint Imunológico/uso terapêutico , Leucovorina/uso terapêutico , Terapia Neoadjuvante/métodos , Oxaliplatina/uso terapêutico , Estudos Prospectivos , Neoplasias Gástricas/diagnóstico , Neoplasias Gástricas/tratamento farmacológico , Microambiente Tumoral
7.
Nucleic Acids Res ; 49(14): 8110-8119, 2021 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-34255844

RESUMO

Shelterin is a six-protein complex that coats chromosome ends to ensure their proper protection and maintenance. Similar to the human shelterin, fission yeast shelterin is composed of telomeric double- and single-stranded DNA-binding proteins, Taz1 and Pot1, respectively, bridged by Rap1, Poz1 and Tpz1. The assembly of the proteinaceous Tpz1-Poz1-Rap1 complex occurs cooperatively and disruption of this shelterin bridge leads to unregulated telomere elongation. However, how this biophysical property of bridge assembly is integrated into shelterin function is not known. Here, utilizing synthetic bridges with a range of binding properties, we find that synthetic shelterin bridge lacking cooperativity requires a linker pair that matches the native bridge in complex lifespan but has dramatically higher affinity. We find that cooperative assembly confers kinetic properties on the shelterin bridge allowing disassembly to function as a molecular timer, regulating the duration of the telomere open state, and consequently telomere lengthening to achieve a defined species-specific length range.


Assuntos
Proteínas de Ligação a DNA/genética , Proteínas de Schizosaccharomyces pombe/genética , Homeostase do Telômero/genética , Proteínas de Ligação a Telômeros/genética , Cromossomos/genética , DNA/genética , DNA de Cadeia Simples/genética , Humanos , Cinética , Complexos Multiproteicos/genética , Complexos Multiproteicos/ultraestrutura , Mutação , Schizosaccharomyces/genética , Complexo Shelterina , Telômero/genética , Proteínas de Ligação a Telômeros/ultraestrutura
8.
Hereditas ; 160(1): 10, 2023 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-36895014

RESUMO

BACKGROUND: RNA binding proteins (RBPs) have been implicated in oncogenesis and progression in various cancers. However, the potential value of RBPs as prognostic indicators and therapeutic targets in colorectal cancer (CRC) requires further investigation. METHODS: Four thousand eighty two RBPs were collected from literature. The weighted gene co-expression network analysis (WGCNA) was performed to identify prognosis-related RBP gene modules based on the data attained from the TCGA cohorts. LASSO algorithm was conducted to establish a prognostic risk model, and the validity of the proposed model was confirmed by an independent GEO dataset. Functional enrichment analysis was performed to reveal the potential biological functions and pathways of the signature and to estimate tumor immune infiltration. Potential therapeutic compounds were inferred utilizing CMap database. Expressions of hub genes were further verified through the Human Protein Atlas (HPA) database and RT-qPCR. RESULTS: One thousand seven hundred thirty four RBPs were differently expressed in CRC samples and 4 gene modules remarkably linked to the prognosis were identified, based on which a 12-gene signature was established for prognosis prediction. Multivariate Cox analysis suggested this signature was an independent predicting factor of overall survival (P < 0.001; HR:3.682; CI:2.377-5.705) and ROC curves indicated it has an effective predictive performance (1-year AUC: 0.653; 3-year AUC:0.673; 5-year AUC: 0.777). GSEA indicated that high risk score was correlated with several cancer-related pathways, including cytokine-cytokine receptor cross talk, ECM receptor cross talk, HEDGEHOG signaling cascade and JAK/STAT signaling cascade. ssGSEA analysis exhibited a significant correlation between immune status and the risk signature. Noscapine and clofazimine were screened as potential drugs for CRC patients with high-risk scores. TDRD5 and GPC1 were identified as hub genes and their expression were validated in 15 pairs of surgically resected CRC tissues. CONCLUSION: Our research provides a depth insight of RBPs' role in CRC and the proposed signature are helpful to the personalized treatment and prognostic judgement.


Assuntos
Neoplasias Colorretais , Proteínas Hedgehog , Humanos , Algoritmos , Neoplasias Colorretais/genética , Citocinas , Prognóstico , Redes Reguladoras de Genes , Proteínas de Ligação a RNA/genética
9.
Sensors (Basel) ; 23(17)2023 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-37688070

RESUMO

Knowledge distillation (KD) is a well-established technique for compressing neural networks and has gained increasing attention in object detection tasks. However, typical object detection distillation methods use fixed-level semantic features for distillation, which might not be best for all training stages and samples. In this paper, a multilayer semantic feature adaptive distillation (MSFAD) method is proposed that uses a routing network composed of a teacher and a student detector, along with an agent network for decision making. Specifically, the inputs to the proxy network consist of the features output by the neck structures of the teacher and student detectors, and the output is a decision on which features to choose for distillation. The MSFAD method improves the distillation training process by enabling the student detector to automatically select valuable semantic-level features from the teacher detector. Experimental results demonstrated that the proposed method increased the mAP50 of YOLOv5s by 3.4% and the mAP50-90 by 3.3%. Additionally, YOLOv5n with only 1.9 M parameters achieved detection performance comparable to that of YOLOv5s.

10.
Plant Physiol ; 186(1): 361-372, 2021 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-33764473

RESUMO

Maintaining the activity and function of the shallow root system of plants is essential for withstanding drought stress, but the associated mechanism is poorly understood. By investigating sap flow in 14 lateral roots (LRs) randomly selected from trees of a Chinese white poplar (Populus tomentosa) plantation receiving three levels of irrigation, an unknown root water transport mode of simultaneous daytime bi-directional water flow was discovered. This mode existed in five LRs confined to the surface soil without attached sinker roots. In the longer term, the bi-directional water flow was correlated with the soil water content. However, within the day, it was associated with transpiration. Our data demonstrated that bi-directional root sap flow occurred during the day, and was driven by evaporative demand, further suggesting the existence of circumferential water movement in the LR xylem. We named this phenomenon evaporation-driven hydraulic redistribution (EDHR). A soil-root water transport model was proposed to encapsulate this water movement mode. EDHR may be a crucial drought-tolerance mechanism that allows plants to maintain shallow root survival and activity by promoting root water recharge under extremely dry conditions.


Assuntos
Transpiração Vegetal , Populus/fisiologia , Árvores/fisiologia , Água/metabolismo , Xilema/fisiologia , Modelos Biológicos
11.
BMC Cancer ; 22(1): 290, 2022 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-35303818

RESUMO

BACKGROUND: Colorectal cancer (CRC) is the third most prevalent cancer in the world, which remains one of the leading causes of cancer-related deaths. Accurate prognosis prediction of CRC is pivotal to reduce the mortality and disease burden. Lymph node (LN) metastasis is one of the most commonly used criteria to predict prognosis in CRC patients. However, inaccurate surgical dissection and pathological evaluation may lead to inaccurate nodal staging, affecting the effectiveness of pathological N (pN) classification in survival prediction among patients with CRC. In this meta-analysis, we aimed to estimate the prognostic value of the log odds of positive lymph nodes (LODDS) in patients with CRC. METHODS: PubMed, Medline, Embase, Web of Science and the Cochrane Library were systematically searched for relevant studies from inception to July 3, 2021. Statistical analyses were performed on Stata statistical software Version 16.0 software. To statistically assess the prognostic effects of LODDS, we extracted the hazard ratio (HR) and 95% confidence interval (CI) of overall survival (OS) and disease-free survival (DFS) from the included studies. RESULTS: Ten eligible articles published in English involving 3523 cases were analyzed in this study. The results showed that LODDS1 and LODDS2 in CRC patients was correlated with poor OS compared with LODDS0 (LODDS1 vs. LODDS0: HR = 1.77, 95% CI (1.38, 2.28); LODDS2 vs. LODDS0: HR = 3.49, 95% CI (2.88, 4.23)). Meanwhile, LODDS1 and LODDS2 in CRC patients was correlated with poor DFS compared with LODDS0 (LODDS1 vs. LODDS0: HR = 1.82, 95% CI (1.23, 2.68); LODDS2 vs. LODDS0: HR =3.30, 95% CI (1.74, 6.27)). CONCLUSIONS: The results demonstrated that the LODDS stage was associated with prognosis of CRC patients and could accurately predict the prognosis of patients with CRC.


Assuntos
Neoplasias Colorretais/patologia , Linfonodos/patologia , Metástase Linfática/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Colorretais/terapia , Intervalo Livre de Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Intervalo Livre de Progressão , Modelos de Riscos Proporcionais
12.
Future Oncol ; 18(6): 701-717, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35048740

RESUMO

Aim: To identify a potential prognostic signature of esophageal carcinoma based on autophagy-related genes (ARGs). Methods: RNA sequencing and clinical data were downloaded from the Cancer Genome Atlas. Significantly different ARGs were identified by Wilcoxon signed-rank test. A prognostic model was established employing Cox regression analysis. The model was evaluated by receiver operating characteristic and Kaplan-Meier curve. Results: A total of 28 significantly different ARGs were identified. Seven ARGs were screened to construct the prognostic model. The efficacy of the model was verified. A nomogram also validated the role of risk score in predicting prognosis. Enrichment analyses showed the possible underlying mechanisms. Conclusion: The seven-ARGs prognostic model was validated to be promising for predicting the prognosis of patients with esophageal carcinoma.


Plain language summary Autophagy is an important metabolic process in cells. Also known as type II cell death, it is a process in which cells degrade their damaged organelles and macromolecular substances by lysosomes. Autophagy is reported to be involved in the development of multiple tumor types, including esophageal carcinoma (ESCA). Autophagy-related genes (ARGs) are those genes proved to be closely related to, or in control of, autophagy. We aimed to identify a model for predicting prognosis based on ARGs, using gene expression profiles and clinical data of ESCA patients from an online database. We identified 28 ARGs as having significantly different activity in ESCA cells compared with normal cells. Among them, four genes were less active, and 24 genes were more active in cancer. Seven ARGs were screened to construct the prognostic model. The effectiveness of the model in predicting the prognosis of ESCA patients was confirmed by standard statistical methods. This study is valuable for finding possible therapeutic targets and predicting prognosis in ESCA patients based on ARGs.


Assuntos
Autofagia/genética , Biomarcadores Tumorais/genética , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/patologia , Perfilação da Expressão Gênica , Medição de Risco/métodos , Idoso , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Nomogramas , Modelos de Riscos Proporcionais , Fatores de Risco
13.
World J Surg Oncol ; 20(1): 52, 2022 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-35216598

RESUMO

BACKGROUND: Oesophagectomy, the gold standard for oesophageal cancer treatment, causes significantly high morbidity and mortality. McKeown minimally invasive oesophagectomy (MIE) is preferred for treating oesophageal malignancies; however, limited studies with large sample sizes focusing on the surgical and oncological outcomes of this procedure have been reported. We aimed to compare the clinical safety and efficacy of McKeown MIE with those of open oesophagectomy (OE). PATIENTS AND METHODS: Overall, 338 oesophageal cancer patients matched by gender, age, location, size, and T and N stages (McKeown MIE: 169 vs OE: 169) were analysed. The clinicopathologic features, operational factors, postoperative complications, and prognoses were compared between the groups. RESULTS: McKeown MIE resulted in less bleeding (200 mL vs 300 mL, p<0.01), longer operation time (335.0 h vs 240.0 h, p<0.01), and higher number of harvested lymph nodes (22 vs 9, p<0.01) than OE did. Although the rate of recurrent laryngeal nerve injury in the two groups was not significantly different, incidence of anastomotic leakage (8 vs 24, p=0.003) was significantly lower in the McKeown MIE group. In addition, patients who underwent McKeown MIE had higher 5-year overall survival than those who underwent OE (69.9% vs 40.4%, p<0.001). CONCLUSION: McKeown MIE is proved to be feasible and safe to achieve better surgical and oncological outcomes for oesophageal cancer compared with OE.


Assuntos
Neoplasias Esofágicas , Esofagectomia , Neoplasias Esofágicas/complicações , Neoplasias Esofágicas/cirurgia , Esofagectomia/métodos , Humanos , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Complicações Pós-Operatórias/etiologia , Pontuação de Propensão , Estudos Retrospectivos , Resultado do Tratamento
14.
Genes Dev ; 27(17): 1917-31, 2013 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-24013504

RESUMO

Telomeres are nucleoprotein complexes comprising telomeric DNA repeats bound by the multiprotein shelterin complex. A dynamic binary switch between telomerase-extendible and telomerase-nonextendible telomeric states determines telomere length homeostasis. However, the molecular nature of the nonextendible state is largely unknown. Here, we show that, in fission yeast, Tpz1 (the ortholog of human TPP1)-mediated complete linkage within the shelterin complex, bridging telomeric dsDNA to ssDNA, controls the telomerase-nonextendible state. Disruption of this linkage leads to unregulated telomere elongation while still retaining the shelterin components on telomeres. Therefore, the linkage within the shelterin components, rather than the individual shelterin components per se, defines the telomerase-nonextendible state. Furthermore, epistasis analyses reveal that Tpz1 also participates in the activation of telomeres to the extendible state via its interaction with Ccq1. Our results suggest critical regulatory roles of Tpz1 in the telomere binary switch.


Assuntos
Proteínas de Transporte/metabolismo , Proteínas de Schizosaccharomyces pombe/metabolismo , Schizosaccharomyces/genética , Schizosaccharomyces/metabolismo , Telomerase/metabolismo , Proteínas de Transporte/química , Proteínas de Transporte/genética , Proteínas de Ligação a DNA , Regulação Enzimológica da Expressão Gênica , Modelos Moleculares , Mutação , Ligação Proteica , Estrutura Quaternária de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Schizosaccharomyces/enzimologia , Proteínas de Schizosaccharomyces pombe/química , Proteínas de Schizosaccharomyces pombe/genética , Complexo Shelterina , Telômero/genética , Telômero/metabolismo , Proteínas de Ligação a Telômeros/química , Proteínas de Ligação a Telômeros/metabolismo
15.
Genes Dev ; 27(22): 2489-99, 2013 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-24240238

RESUMO

The RNAi pathway is required for heterochromatin assembly at repetitive DNA elements in diverse organisms. In fission yeast, loss of RNAi causes pericentric heterochromatin defects, compromising gene silencing and chromosome segregation. Here we show that deletion of telomere shelterin components restores pericentric heterochromatin and its functions in RNAi mutants. We further isolated a separation-of-function mutant of Poz1 and revealed that defective telomere silencing, but not telomere length control, is critical for bypassing RNAi. Further analyses demonstrated that compromising shelterin-mediated heterochromatin assembly in RNAi mutants releases heterochromatin protein Swi6, which is redistributed to pericentric regions through RNAi-independent heterochromatin assembly pathways. Given the high mobility of Swi6 protein and that increased levels of Swi6 facilitates heterochromatin spreading as well as ectopic heterochromatin assembly, our results suggest that constitutive heterochromatin domains use multiple pathways to form high-affinity platforms to restrain Swi6, thus limiting its availability and avoiding promiscuous heterochromatin formation.


Assuntos
Montagem e Desmontagem da Cromatina/genética , Heterocromatina/metabolismo , Interferência de RNA , Schizosaccharomyces/genética , Schizosaccharomyces/metabolismo , Proteínas de Ligação a Telômeros/genética , Proteínas Cromossômicas não Histona/metabolismo , Mutação , Proteínas de Schizosaccharomyces pombe/genética , Proteínas de Schizosaccharomyces pombe/metabolismo , Proteínas de Ligação a Telômeros/metabolismo
16.
BMC Cancer ; 20(1): 149, 2020 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-32093683

RESUMO

BACKGROUND: It remains controversial whether prophylactic No.10 lymph node clearance is necessary for gastric cancer. Thus, the present study aims to investigate the impact of prophylactic No.10 lymph node clearance on the perioperative complications and prognosis of upper and middle third gastric cancer. METHODS: A network meta-analysis to identify both direct and indirect evidence with respect to the comparison of gastrectomy alone (G-A), gastrectomy combination with splenectomy (G + S) and gastrectomy combination with spleen-preserving splenic hilar dissection (G + SPSHD) was conducted. We searched Medline, Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL) for studies published before September 2018. Perioperative complications and overall survival were analyzed. Hazard ratios (HR) were extracted from the publications on the basis of reported values or were extracted from survival curves by established methods. RESULTS: Ten retrospective studies involving 2565 patients were included. In the direct comparison analyses, G-A showed comparable 5-year overall survival rate (HR: 1.1, 95%CI: 0.97-1.3) but lower total complication rate (OR: 0.37, 95%CI: 0.17-0.77) compared with G + S. Similarly, the 5-year overall survival rate between G + SPSHD and G + S was comparable (HR: 1.1, 95%CI: 0.92-1.4), while the total complication rate of G + SPSHD was lower than that of G + S (OR: 0.50, 95%CI: 0.28-0.88). In the indirect comparison analyses, both the 5-year overall survival rate (HR: 1.0, 95%CI: 0.78-1.3) and total complication rate (OR: 0.75, 95%CI: 0.29-1.9) were comparable between G-A and G + SPSHD. CONCLUSIONS: Prophylactic No.10 lymph node clearance was not recommended for treatment of upper and middle third gastric cancer.


Assuntos
Gastrectomia/métodos , Excisão de Linfonodo/métodos , Linfonodos/cirurgia , Procedimentos Cirúrgicos Profiláticos/métodos , Baço/cirurgia , Neoplasias Gástricas/cirurgia , Humanos , Linfonodos/patologia , Metástase Linfática , Metanálise em Rede , Prognóstico , Estudos Retrospectivos , Baço/patologia , Neoplasias Gástricas/patologia , Taxa de Sobrevida
17.
BMC Cancer ; 20(1): 581, 2020 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-32571299

RESUMO

BACKGROUND: Esophageal carcinoma (EC) is the seventh-most prevalent tumor in the world, which is still one of the primary causes of tumor-related death. Identifying noteworthy biomarkers for EC is particularly significant in guiding effective treatment. Recently, circulating tumor cells (CTCs) in peripheral blood (PB) were intensively discussed as prognostic markers in patients with EC. However, an ongoing controversy still exists regarding the prognostic significance of CTCs determined by the CellSearch system in EC sufferers. This meta-analysis was designed to approach this topic. METHODS: We systematically conducted searches using PubMed, Medline, Web of Science and the Cochrane Library for relevant studies, which were published through February 20, 2020. Using the random-effects model, our study was performed in Review Manager software, with odds ratios (ORs), risk ratios (RRs), hazard ratios (HRs) and 95% confidence intervals (CIs) as the effect values. RESULTS: Totally 7 articles were finally included in this study. For clinicopathological characteristics, the pooled results on TNM stage indicated that the III/IV group had higher rate of CTCs compared with the I/II group (OR = 1.36, 95% CI: 0.68-2.71, I2 = 0%). Incidence of CTCs was higher in patients with T3/T4 stage (OR = 2.92, 95% CI: 1.31-6.51, I2 = 0%) and distant metastasis group (OR = 5.18, 95% CI: 2.38-11.25, I2 = 0%) compared to patients with T1/T2 stage or non-metastatic group. The pooled analysis revealed that CTC positivity detected in EC patients was correlated with poor overall survival (OS) (HR = 2.83, 95% CI:1.99-4.03, I2 = 0%) and relapse-free survival (RFS) (HR = 4.71, 95% CI:2.73-8.13, I2 = 0%). When pooling the estimated RR, a poor therapeutic response to chemoradiotherapy was discovered in patients with CTC positivity (RR = 1.99, 95% CI:1.73-2.29, I2 = 60%). CONCLUSIONS: In summary, our meta-analysis demonstrated that CTCs positivity determined by the CellSearch system are correlated with the prognosis of EC patients and might indicate a poor therapeutic response to chemotherapy in EC patients.


Assuntos
Neoplasias Esofágicas/patologia , Células Neoplásicas Circulantes , Neoplasias Esofágicas/tratamento farmacológico , Neoplasias Esofágicas/mortalidade , Humanos , Estadiamento de Neoplasias , Prognóstico , Viés de Publicação
18.
Fish Shellfish Immunol ; 97: 390-402, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31866450

RESUMO

Lipopolysaccharide-induced TNF-alpha factor (LITAF), as a transcription factor, activates the transcription of TNF and other cytokines in inflammatory response upon lipopolysaccharide (LPS) stimulation. In the present study, we cloned and identified the full-length cDNA of LITAF homolog from blood clam Tegillarca granosa for the first time. The full-length cDNA of TgLITAF was 1801 bp encoding a polypeptide of 147 amino acids with an estimated molecular mass of 16.13 kDa. TgLITAF contained a zf-LITAF-like zinc ribbon domain at the C-terminal of the protein and the TgLITAF domain showed 48-74% amino acid sequence identity with other known LITAFs from other species. Subcellular localization study showed that TgLITAF was mainly expressed in the nucleus. qRT-PCR analysis showed that the TgLITAF transcription expressed constitutively in all the examined tissues with the highest expression level in the gills. After LPS or V. alginolyticus treatment, expression of TgLITAF in hemocytes was both up-regulated significantly at 3-6 h. Furthermore, in vitro study indicated that overexpression of TgLITAF in HeLa cells resulted in the activation of TNFα, p53, and influenced the expression levels of apoptotic-related genes Bax, Bcl-2, Caspase-3, Caspase-6, and Caspase-7. The proliferation of HeLa cells was inhibited by overexpression of TgLITAF. Apoptotic fluorescence assay further revealed that TgLITAF participated in the apoptotic process of HeLa cells. Western blotting analysis showed that overexpression of TgLITAF increased endogenous level of cleaved Caspase-7. Taken together, these results revealed that TgLITAF participates in the innate immune response to the pathogen invasion in blood clams and induces apoptosis in HeLa cells.


Assuntos
Arcidae/genética , Arcidae/imunologia , Regulação da Expressão Gênica/imunologia , Imunidade Inata/genética , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/imunologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Perfilação da Expressão Gênica , Células HeLa , Hemócitos/imunologia , Humanos , Lipopolissacarídeos/farmacologia , Filogenia , Alinhamento de Sequência , Fator de Necrose Tumoral alfa/química
19.
Oral Dis ; 26(3): 597-608, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31901146

RESUMO

OBJECTIVE: The temporomandibular joint (TMJ) displays a high remodelling capability in response to occlusion changes. The purpose of the current study was to investigate the responses of TMJ condyles of growing mice to the installation of a unilateral anterior crossbite (UAC) prosthesis and the replacement of the UAC prothesis with a bilateral anterior elevation (BAE) prosthesis. MATERIALS AND METHODS: C57BL/6J mice were randomly assigned to the blank control and experimental groups. In mice in the experimental groups, UAC was created, while in others, BAE was created after the creation of UAC or removal of UAC. Changes in TMJ condylar cartilage and subchondral bone were assessed. RESULTS: The degradation of condylar cartilage induced by UAC was reversed by BAE, as evaluated by cartilage histochemical changes, collagen II-positive area, collagen X-positive chondrocytes and expression levels of Adamts-5, Mmp13, Tnf-α and Il-1ß. Subchondral bone was assessed based on the subchondral bone volume, the number of TRAP-positive cells and the Opg/Rankl ratio. CONCLUSION: The growing mouse TMJ condyle displays a high remodelling capability, which can be degenerative or rehabilitative in response to the creation of UAC and the replacement of UAC with BAE. Early correction of occlusion is beneficial for the recovery of degenerative condyles.


Assuntos
Remodelação Óssea , Oclusão Dentária , Prótese Dentária , Côndilo Mandibular/crescimento & desenvolvimento , Animais , Cartilagem Articular/crescimento & desenvolvimento , Condrócitos , Camundongos , Camundongos Endogâmicos C57BL , Distribuição Aleatória , Articulação Temporomandibular/crescimento & desenvolvimento
20.
Entropy (Basel) ; 22(6)2020 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-33286467

RESUMO

Biological recognition methods often use biological characteristics such as the human face, iris, fingerprint, and palm print; however, such images often become blurred under the limitation of the complex environment of the underground, which leads to low identification rates of underground coal mine personnel. A gait recognition method via similarity learning named Two-Stream neural network (TS-Net) is proposed based on a densely connected convolution network (DenseNet) and stacked convolutional autoencoder (SCAE). The mainstream network based on DenseNet is mainly used to learn the similarity of dynamic deep features containing spatiotemporal information in the gait pattern. The auxiliary stream network based on SCAE is used to learn the similarity of static invariant features containing physiological information. Moreover, a novel feature fusion method is adopted to achieve the fusion and representation of dynamic and static features. The extracted features are robust to angle, clothing, miner hats, waterproof shoes, and carrying conditions. The method was evaluated on the challenging CASIA-B gait dataset and the collected gait dataset of underground coal mine personnel (UCMP-GAIT). Experimental results show that the method is effective and feasible for the gait recognition of underground coal mine personnel. Besides, compared with other gait recognition methods, the recognition accuracy has been significantly improved.

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