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1.
Ann Palliat Med ; 10(10): 10756-10767, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34763437

RESUMO

BACKGROUND: Myocardial infarction (MI) is one of the most common cardiovascular diseases, inducing severe myocardial injury and leading to high mortality. Bromodomain-containing protein 7 (BRD7), a member of bromodomain-containing protein family, is involved in multiple cellular processes, such as cell cycle, transcriptional regulation, and chromatin remodeling, but the functions of BRD7 in regulating MI-associated myocardial injury are still obscure. In this work, we investigated the effect of BRD7 on MI-induced myocardial injury in vitro and in vivo. METHODS: The MI model was established by ligating the left anterior descending coronary artery (LAD) of rats which were then injected with BRD7 short hairpin RNA (shRNA). The rat H9C2 cardiomyocytes were treated with hypoxia and injected with BRD7 shRNA. The expression of BRD7 in MI rat model, and hypoxia-treated H9C2 cells was detected by quantitative polymerase chain reaction (qPCR), western blot, and immunohistochemical staining. The effect of BRD7 was analyzed using western blot, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, echocardiography, and flow cytometry analysis. The expressions of Wnt/ß-catenin signaling relative proteins were determined by western blot. RESULTS: Significantly, BRD7 was highly expressed in MI patients, MI rat models, and hypoxia treated rat H9C2 cardiomyocytes. Echocardiography analysis demonstrated that the left ventricular ejection fraction (LVEF) and left ventricular fraction shortening (LVFS) were repressed in the MI rats relative to sham group rats, while the silencing of BRD7 rescued the dysfunction in the model. We also found that BRD7 silencing reduced cardiomyocyte apoptosis in both MI rats and H9C2 cells under the treatment of hypoxia. BRD7 silencing inhibited the activation of Wnt/ß-catenin signaling in H9C2 cells under the treatment of hypoxia. Moreover, Wnt agonist BML294 reversed the anti-apoptosis effect of BRD7 silencing in hypoxia-induced H9C2 cells. CONCLUSIONS: Collectively, we concluded that BRD7 contributed to MI-induced myocardial injury through activating Wnt/ß-catenin signaling. Targeting BRD7 may become a promising therapeutic strategy for the treatment of MI-induced myocardial injury.


Assuntos
MicroRNAs , Infarto do Miocárdio , Animais , Proteínas Cromossômicas não Histona , Humanos , Infarto do Miocárdio/genética , Ratos , Ratos Sprague-Dawley , Volume Sistólico , Função Ventricular Esquerda , Via de Sinalização Wnt , beta Catenina/genética , beta Catenina/metabolismo
2.
Front Pharmacol ; 12: 714628, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34737698

RESUMO

Xihuang pill, an approved Chinese medicine formula (state medical permit number. Z11020073), is a commonly used adjuvant drug for cancer patients in China. Xihuang pill has a satisfactory effect in treating breast cancer in clinics, especially triple-negative breast cancer (TNBC), which is the most aggressive type of breast cancer, and finite effective therapies. However, the mechanism of Xihuang pill in treating TNBC remains unclear. The present study aims to explore the pharmacological mechanism of Xihuang pill in treating advanced TNBC. We identified the main chemical components of Xihuang pill by using HPLC-Q-TOF-MS/MS. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) analysis shows that serum containing Xihuang pill (XS) had no obvious killing effect on any subtype of breast cancer cells, but it inhibited mammosphere colony formation of two TNBC cell lines (4T1 and HCC1806 cells) and could enhance the inhibitory effect of paclitaxel (PTX) on the proliferation of 4T1 and HCC1806 cells when combined with PTX. Seventy-six active compounds in Xihuang pill, their 300 protein targets, and 16667 TNBC stem cell-related genes were identified. The drug-herb-active compound-target gene-disease network and enrichment analyses were constructed with 190 overlapping candidate targets. Through text mining and molecular docking, the target gene NR3C2 and its active compound naringenin were selected for further validation. According to the TCGA database, we observed that a high expression of NR3C2 promoted a higher survival probability regarding overall survival (OS). In vitro experiments indicated that naringenin presented an identical effect to XS, possibly by regulating the NR3C2 expression. Overall, this study explored the effect of Xihuang pill in treating advanced TNBC cells and showed that naringenin, which is the key active compound of Xihuang pill, could lessen the stemness of TNBC cells to produce a synergistic effect on PTX by regulating the NR3C2 gene.

3.
Psychol Res Behav Manag ; 14: 1675-1689, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34675707

RESUMO

Purpose: Given that extensive studies have documented the wide-ranging benefits of living a calling, determining whether and how living a calling can be improved is of great importance. Although recent research implies that a growth mindset about work may link to self-regulatory processes and living a calling, little research to date has directly examined the relationships between these variables. Building on Burnette's SOMA model, this study was designed to examine the premise that a growth mindset about work was a predictor of living a calling and to explore the mediating role of self-regulation in the growth mindset about work-living a calling link. Methods: This cross-sectional study was conducted among educational professionals in China. Data were collected from 608 primary and secondary school teachers on growth mindsets about work, self-regulation and living a calling. A structural equation model was used to test the hypothesis that self-regulation would mediate the relationship between a growth mindset about work and living a calling. Results: Consistent with our premise, a growth mindset about work was positively associated with living a calling. Also, a growth mindset about work was significantly associated with self-regulation strategies in terms of goal setting, perseverance, decision making, and learning from mistakes. As hypothesized, a growth mindset about work was related to higher levels of living a calling via goal setting, perseverance, and learning from mistakes. Conclusion: The findings contribute to the increasing breadth of the growth mindset literature across various contexts and its consequences for one's living a calling, which expand the nomological web of correlates of growth mindset about work. Furthermore, these findings suggest that fostering a growth mindset about work may facilitate adaptive behaviors and, thereby, serve as a calling intervention.

4.
Sensors (Basel) ; 21(17)2021 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-34502876

RESUMO

Mining activities under the circumstances of huge-thick stratum occurrence commonly result in dynamic response of the working face. It is crucial to understand the rock failure and movement of the huge-thick stratum in order to prevent dynamic hazards. This paper introduces distributed optical fiber sensor (DOFS) monitoring into a large-scale model test to investigate the deformation pattern and movement law of the huge-thick conglomerate (HTC); the monitoring results are verified by numerical simulation. The results indicate that DOFS monitoring captures the spatiotemporal evolution of zoning development in the overburden deformation. The deformation field of HTC is illustrated, and there exists a strain basin that can be used to estimate the movement law of HTC. The average strain variability Ex, a new homogenization index for characterizing the overburden deformation, is proposed to describe the broken rules of the HTC. The numerical simulation proves the feasibility of the DOFS monitoring method and the correctness of the deformation pattern and movement law. This study provides efficient methods for DOFS monitoring utilization to investigate mining engineering problems and could be beneficial for unearthing the mechanisms of deep ground rock deformation.

5.
Front Psychol ; 12: 643708, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34456781

RESUMO

Previous studies have indicated that obese people face many forms of severe prejudice and discrimination in various settings, such as education, employment, and interpersonal relationships. However, research aimed at reducing obesity stereotyping is relatively rare, and prior studies have focused primarily on negative stereotypes. Based on the empathy-altruism hypothesis and self-other overlap hypothesis, this study investigates the impact of perspective taking (PT) on both positive and negative obesity stereotypes and examines the mediating effects of empathy and self-other overlap. A sample of 687 students (191 males and 496 females) at Chinese universities participated by completing self-report questionnaires on trait tendency and evaluation toward obese people. Structural equation modeling and the bootstrap method revealed that self-other overlap (but not empathy) mediated the relationship between PT and negative obesity stereotypes. While self-other overlap and empathy both mediated the relationship between PT and positive obesity stereotypes. These findings address the importance of PT for improving positive and negative obesity stereotypes: specifically, PT promotes psychological merging, and produces empathic concern (EC).

6.
Ann Transl Med ; 9(12): 999, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34277799

RESUMO

Background: Neuroinflammation involving the central nervous system (CNS), such as depression, is associated with a significantly increased risk of cancer and cancer-specific mortality due to breast cancer. It is of great significance to learn about the regulatory process of CNS in breast cancer progression. Methods: We established a depressive MMTV-PyVT mouse model. The expression levels of neurotransmitters in the serum of depression animal models were assessed by enzyme-linked immunosorbent assay (ELISA). Changes of the microglia cells in the mice's brains were evaluated by immunofluorescence and reverse transcription-polymerase chain reaction (RT-PCR). Breast cancer progression was assessed by immunohistochemistry (IHC) analysis. To further investigate the mechanism by which ant-depressant drugs disrupt breast cancer progression, protein sequencing and network pharmacology were applied to identify related targets. Furthermore, we used conditioned medium from BV-2 microglia to culture breast cancer cells and treated the cells with quercetin at different concentrations; cell viability was assessed by the MTT assay. Results: Our results show a possible regulatory target between neuroinflammation in the CNS and development of breast cancer, along with the reversal effect of quercetin on breast cancer progression. Conclusions: Chronic stress may be an indicator of breast cancer and that quercetin could be an effective treatment for breast cancer patients with chronic stress.

7.
Aging (Albany NY) ; 13(14): 18191-18222, 2021 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-34289449

RESUMO

This investigation attempted to discern whether formononetin restrained progression of triple-negative breast cancer (TNBC) by blocking lncRNA AFAP1-AS1-miR-195/miR-545 axis. We prepared TNBC cell lines (i.e. MDA-MB-231 and BT-549) and normal human mammary epithelial cell line (i.e. MCF-10A) in advance, and the TNBC cell lines were, respectively, transfected by pcDNA3.1-lncRNA AFAP1-AS1, si-lncRNA AFAP1-AS1, pcDNA6.2/GW/EmGFP-miR-545 or pcDNA6.2/GW/EmGFP-miR-195. Resistance of TNBC cells in response to 5-Fu, adriamycin, paclitaxel and cisplatin was evaluated through MTT assay, while potentials of TNBC cells in proliferation, migration and invasion were assessed via CCK8 assay and Transwell assay. Consequently, silencing of lncRNA AFAP1-AS1 impaired chemo-resistance, proliferation, migration and invasion of TNBC cells (P<0.05), and over-expression of miR-195 and miR-545, which were sponged and down-regulated by lncRNA AFAP1-AS1 (P<0.05), significantly reversed the promoting effect of pcDNA3.1-lncRNA AFAP1-AS1 on proliferation, migration, invasion and chemo-resistance of TNBC cells (P<0.05). Furthermore, CDK4 and Raf-1, essential biomarkers of TNBC progression, were, respectively, subjected to target and down-regulation of miR-545 and miR-195 (P<0.05), and they were promoted by pcDNA3.1-lncRNA AFAP1-AS1 at protein and mRNA levels (P<0.05). Additionally, formononetin significantly decreased expressions of lncRNA AFAP1-AS1, CDK4 and Raf-1, while raised miR-195 and miR-545 expressions in TNBC cells (P<0.05), and exposure to it dramatically contained malignant behaviors of TNBC cells (P<0.05). In conclusion, formononetin alleviated TNBC malignancy by suppressing lncRNA AFAP1-AS1-miR-195/miR-545 axis, suggesting that molecular targets combined with traditional Chinese medicine could yield significant clinical benefits in TNBC.

8.
Front Oncol ; 11: 646315, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34178633

RESUMO

Abstract: The present systematic review and meta-analysis was undertaken to evaluate the effects of acupuncture in women with breast cancer (BC), focusing on patient-reported outcomes (PROs). Methods: A comprehensive literature search was carried out for randomized controlled trials (RCTs) reporting PROs in BC patients with treatment-related symptoms after undergoing acupuncture for at least four weeks. Literature screening, data extraction, and risk bias assessment were independently carried out by two researchers. Results: Out of the 2, 524 identified studies, 29 studies representing 33 articles were included in this meta-analysis. At the end of treatment (EOT), the acupuncture patients' quality of life (QoL) was measured by the QLQ-C30 QoL subscale, the Functional Assessment of Cancer Therapy-Endocrine Symptoms (FACT-ES), the Functional Assessment of Cancer Therapy-General/Breast (FACT-G/B), and the Menopause-Specific Quality of Life Questionnaire (MENQOL), which depicted a significant improvement. The use of acupuncture in BC patients lead to a considerable reduction in the scores of all subscales of the Brief Pain Inventory-Short Form (BPI-SF) and Visual Analog Scale (VAS) measuring pain. Moreover, patients treated with acupuncture were more likely to experience improvements in hot flashes scores, fatigue, sleep disturbance, and anxiety compared to those in the control group, while the improvements in depression were comparable across both groups. Long-term follow-up results were similar to the EOT results. Conclusions: Current evidence suggests that acupuncture might improve BC treatment-related symptoms measured with PROs including QoL, pain, fatigue, hot flashes, sleep disturbance and anxiety. However, a number of included studies report limited amounts of certain subgroup settings, thus more rigorous, well-designed and larger RCTs are needed to confirm our results.

9.
Cell Rep ; 35(12): 109281, 2021 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-34161765

RESUMO

Obesity has become a global pandemic. Identification of key factors in adipogenesis helps to tackle obesity and related metabolic diseases. Here, we show that DDB1 binds the histone reader BRWD3 to promote adipogenesis and diet-induced obesity. Although typically recognized as a component of the CUL4-RING E3 ubiquitin ligase complex, DDB1 stimulates adipogenesis independently of CUL4. A DDB1 mutant that does not bind CUL4A or CUL4B fully restores adipogenesis in DDB1-deficient cells. Ddb1+/- mice show delayed postnatal development of white adipose tissues and are protected from diet-induced obesity. Mechanistically, by interacting with BRWD3, DDB1 is recruited to acetylated histones in the proximal promoters of ELK1 downstream immediate early response genes and facilitates the release of paused RNA polymerase II, thereby activating the transcriptional cascade in adipogenesis. Our findings have uncovered a CUL4-independent function of DDB1 in promoting the transcriptional cascade of adipogenesis, development of adipose tissues, and onset of obesity.

10.
J Agric Food Chem ; 69(45): 13315-13322, 2021 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-34076413

RESUMO

Buckwheat is one of the five main allergenic foods (eggs, milk, wheat, buckwheat, and peanuts). Oleosin is an important type of allergen in some allergic foods. However, although most diagnostic nut and seed extracts are defatted, some patients with food allergies may have false negative diagnostic results of oleosin in vitro. Recently, we found that the serum of buckwheat allergic patients responded strongly to an 18 kDa protein. Mass spectrometry analysis showed it is the oleosin protein family. We further purified and evaluated the allergenicity of this buckwheat oleosin-type allergen, which is involved in the formation of buckwheat oil bodies. The tartary buckwheat oleosin allergen was named Fag t 6, according to the WHO/IUIS Allergen Nomenclature Subcommittee criteria. The DNA sequence of tartary buckwheat oleosin was cloned. Dot blot and enzyme-linked immunosorbent assay (ELISA) showed half of the 20 buckwheat allergic patients' serum had strong reactivity with purified buckwheat Fag t 6. Circular dichroism experiment analysis of its thermal stability showed a Tm of 64.65 ± 0.65 °C. A buckwheat allergy showed possible cross-reaction with a wheat allergy. In summary, this study not only increases our understanding of buckwheat allergies and oil-soluble allergens in general, it may also be used to improve diagnostic tests for buckwheat allergies in the future.


Assuntos
Fagopyrum , Hipersensibilidade Alimentar , Hipersensibilidade a Trigo , Alérgenos , Humanos , Proteínas de Plantas/genética , Sementes
11.
J BUON ; 26(2): 641, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34077025

RESUMO

Retraction of: 'Anticancer activity of Fisetin against the human osteosarcoma cell lines involves G2/M cell cycle arrest, mitochondrial apoptosis and inhibition of cell migration and invasion', by Chunyang Xing, Yuzhu Zhang, Rong Su, Ronghuan Wu JBUON 2019;25(2):1022-1027; PMID:32521901. Following the publication of the above article, readers drew to our attention that part of the data was unreliable. The authors were requested to provide the raw data to prove the originality, but were unable to do so. After an investigation, the Editors of JBUON decided to retract this article. We thank the readers for bringing this matter to our attention. We apologize for any inconvenience it may cause.

12.
Sensors (Basel) ; 21(7)2021 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-33918354

RESUMO

The blast-induced damage of a high rock slope is directly related to construction safety and the operation performance of the slope. Approaches currently used to measure and predict the blast-induced damage are time-consuming and costly. A Bayesian approach was proposed to predict the blast-induced damage of high rock slopes using vibration and sonic data. The relationship between the blast-induced damage and the natural frequency of the rock mass was firstly developed. Based on the developed relationship, specific procedures of the Bayesian approach were then illustrated. Finally, the proposed approach was used to predict the blast-induced damage of the rock slope at the Baihetan Hydropower Station. The results showed that the damage depth representing the blast-induced damage is proportional to the change in the natural frequency. The first step of the approach is establishing a predictive model by undertaking Bayesian linear regression, and the second step is predicting the damage depth for the next bench blasting by inputting the change rate in the natural frequency into the predictive model. Probabilities of predicted results being below corresponding observations are all above 0.85. The approach can make the best of observations and includes uncertainty in predicted results.

14.
J Microbiol Biotechnol ; 31(4): 510-519, 2021 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-33746186

RESUMO

The pathological impact of haze upon the phyllosphere microbiota awaits investigation. A moderate degree of haze environment and a clean control were selected in Chengdu, China. Artemisia argyi, a ubiquitously distributed and extensively applied Chinese herb, was also chosen for experiment. Total genome DNA was extracted from leaf samples, and for metagenome sequencing, an Illumina HiSeq 2500 platform was applied. The results showed that the gene numbers of phyllosphere microbiota derived from haze leaves were lower than those of the clean control. The phyllosphere microbiota derived from both haze and clean groups shared the same top ten phyla; the abundances of Proteobacteria, Actinomycetes and Anorthococcuso of the haze group were substantially increased, while Ascomycetes and Basidiomycetes decreased. At the genus level, the abundances of Nocardia, Paracoccus, Marmoricola and Knoelia from haze leaves were markedly increased, while the yeasts were statistically decreased. KEGG retrieval demonstrated that the functional genes were most annotated to metabolism. An interesting find of this work is that the phyllosphere microbiota responsible for the synthesis of primary and secondary metabolites in A. argyi were significantly increased under a haze environment. Relatively enriched genes annotated by eggNOG belong to replication, recombination and repair, and genes classified into the glycoside hydrolase and glycosyltransferase enzymes were significantly increased. In summary, we found that both structure and function of phyllosphere microbiota are globally impacted by haze, while primary and secondary metabolites responsible for haze tolerance were considerably increased. These results suggest an adaptive strategy of plants for tolerating and confronting haze damage.


Assuntos
Poluição do Ar/efeitos adversos , Artemisia/microbiologia , Bactérias/classificação , Fungos/classificação , Microbiota , Bactérias/efeitos dos fármacos , China , Fungos/efeitos dos fármacos , Metagenoma , Folhas de Planta/microbiologia , Metabolismo Secundário
16.
J Struct Biol ; 213(2): 107704, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33571640

RESUMO

Human RNase MRP ribonucleoprotein complex is an essential endoribonuclease involved in the processing of ribosomal RNAs, mitochondrial RNAs and certain messenger RNAs. Its RNA subunit RMRP catalyzes the cleavage of substrate RNAs, and the protein components of RNase MRP are required for activity. RMRP mutations are associated with several types of inherited developmental disorders, but the pathogenic mechanism is largely unknown. Recent structural studies shed lights on the catalytic mechanism of yeast RNase MRP and the closely related RNase P; however, the structural and catalytic mechanism of RMRP in human RNase MRP complex remains unclear. Here we report the crystal structure of the P3 domain of RMRP in complex with the RPP20 and RPP25 proteins of human RNase MRP, which shows that the P3 RNA binds to a conserved positively-charged surface of the RPP20-RPP25 heterodimer through its distal stem and internal loop regions. The disease-related mutations of RMRPP3 are mostly located at the protein-RNA interface and are likely to weaken the binding of P3 to RPP20-RPP25. Moreover, the structure reveals a homodimeric organization of the entire RPP20-RPP25-RMRPP3 complex, which might mediate the dimerization of human RNase MRP complex in cells. These findings provide structural clues to the assembly and pathogenesis of human RNase MRP complex and also reveal a tetrameric feature of RPP20-RPP25 evolutionarily conserved with that of the archaeal Alba proteins.

17.
Int J Biol Macromol ; 175: 254-261, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33561459

RESUMO

The efficiency of enzymatic cyclodextrin production using cyclodextrin glycosyltransferases (CGTases) is limited by product inhibition. In this study, maltose binding site 2 (MBS2) of the ß-CGTase from Bacillus circulans STB01 was modified to decrease product inhibition. First, two point mutants were prepared at position 599 (A599V and A599N). Then, two double mutants incorporating alanine at position 633 (A599N/Y633A and A599V/Y633A) were prepared. Finally, the entire MBS2 region was replaced by that of the α-CGTase from Paenibacillus macerans JFB05-01 to form multipoint mutant MBS2 ߠ→ α. All five mutants exhibited mixed-type product inhibition, although both the competitive and uncompetitive components of this inhibition were decreased. The total cyclization activities of A599N, A599V and A599V/Y633A were 15.6%, 76.8% and 70.9% lower than that of the wild-type, respectively, while that of A599N/Y633A was 22.4% higher. Among the mutants, only MBS2 ߠ→ α showed catalytic efficiency (kcat/Km) comparable with that of the wild-type. Moreover, A599N, A599N/Y633A and MBS2 ߠ→ α produced cyclodextrin yields 13.1%, 15.8% and 19.7% greater than that of the wild-type, respectively. These results suggest that A599N, A599N/Y633A and MBS2 ߠ→ α may be more suitable than the wild-type for cyclodextrin production.


Assuntos
Bacillus/metabolismo , Glucosiltransferases/genética , Glucosiltransferases/metabolismo , Maltose/metabolismo , Bacillus/genética , Proteínas de Bactérias/química , Sítios de Ligação/genética , Ciclização/genética , Ciclodextrinas/metabolismo , Cinética , Proteínas Ligantes de Maltose/genética , Proteínas Ligantes de Maltose/metabolismo , Modelos Moleculares , Mutagênese Sítio-Dirigida/métodos , Mutação/genética , Paenibacillus/genética , Especificidade por Substrato/genética , beta-Ciclodextrinas/química
18.
Ann Palliat Med ; 10(5): 5870-5874, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33040540

RESUMO

Aggressive angiomyxoma (AAM) is rare. AAM is characterized by invasion and recurrence. Improving the detection rate of AAM through ultrasonic inspection technology. There is very little literature reported on AAM. And the literature on the ultrasonic performance of AAM is rare. Therefore, this article describes the ultrasound manifestation of a 54-year-old woman whose pathology is confirmed to be AAM, and summarizes the common ultrasound manifestations of AAM. The unique feature is that the ultrasound performance does not explore the typical "vortex". So we need to diagnose this case through other ultrasound findings. The patient initially had no obvious cause of pain in the right hip. Transvaginal ultrasound examination of the pelvic was performed on the patient, and pathological sections were examined. The result suggested mesenchymal tumor. After surgical resection of the tumor, the pathology was again confirmed as AAM. The tumor is composed of well-differentiated spindle-shaped stellate cells with interstitial mucus degeneration, and vascular proliferation can be seen, which is consistent with deep AAM. Through this case we found that pathology is the gold standard for AAM, but early screening of AAM by ultrasound is feasible.


Assuntos
Mixoma , Diagnóstico Diferencial , Feminino , Humanos , Pessoa de Meia-Idade , Mixoma/diagnóstico por imagem , Ultrassonografia
19.
Front Microbiol ; 11: 542961, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33133029

RESUMO

The emergence of new physiological races of Puccinia striiformis f. sp. tritici (Pst) causing wheat stripe rust can lead to the loss of resistance of wheat cultivars to stripe rust, thus resulting in severe losses in wheat yield. In this study, after the germination of urediospores of three Pst strains including the original strain (CYR32, a dominant physiological race of Pst in China) and two virulence-mutant strains (CYR32-5 and CYR32-61) acquired from CYR32 via UV-B radiation, proteomic analysis based on isobaric tags for relative and absolute quantification (iTRAQ) technology was performed on the strains. A total of 2,271 proteins were identified, and 59, 74, and 64 differentially expressed proteins (DEPs) were acquired in CYR32-5 vs. CYR32, CYR32-61 vs. CYR32, and CYR32-61 vs. CYR32-5, respectively. The acquired DEPs were mainly involved in energy metabolism, carbon metabolism, and cellular substance synthesis. Furthermore, quantitative reverse transcription PCR assays were used to determine the relative expression of the 6, 7, and 1 DEPs of CYR32-5 vs. CYR32, CYR32-61 vs. CYR32, and CYR32-61 vs. CYR32-5, respectively, at the transcriptional level. The relative expression levels of one, five, and one gene, respectively, encoding the DEPs, were consistent with the corresponding protein abundance determined by iTRAQ technology. Compared with CYR32, the DEPs associated with energy metabolism and stress-including E3JWK6, F4S0Z3, and A8N2Q4-were up-regulated in the mutant strains. The results indicated that the virulence-mutant strains CYR32-5 and CYR32-61 had more tolerance to stress than the original strain CYR32. The results obtained in this study are of great significance for exploring the virulence variation mechanisms of Pst, monitoring the changes in Pst populations, breeding new disease-resistant wheat cultivars, and managing wheat stripe rust sustainably.

20.
Acta Crystallogr D Struct Biol ; 76(Pt 11): 1104-1113, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-33135681

RESUMO

Cellobiose 2-epimerase (CE) is commonly recognized as an epimerase as most CEs mainly exhibit an epimerization activity towards disaccharides. In recent years, several CEs have been found to possess bifunctional epimerization and isomerization activities. They can convert lactose into lactulose, a high-value disaccharide that is widely used in the food and pharmaceutical industries. However, the factors that determine the catalytic direction in CEs are still not clear. In this study, the crystal structures of three newly discovered CEs, CsCE (a bifunctional CE from Caldicellulosiruptor saccharolyticus), StCE (a bifunctional CE from Spirochaeta thermophila DSM 6578) and BtCE (a monofunctional CE from Bacillus thermoamylovorans B4166), were determined at 1.54, 2.05 and 1.80 Šresolution, respectively, in order to search for structural clues to their monofunctional/bifunctional properties. A comparative analysis of the hydrogen-bond networks in the active pockets of diverse CEs, YihS and mannose isomerase suggested that the histidine corresponding to His188 in CsCE is uniquely required to catalyse isomerization. By alignment of the apo and ligand-bound structures of diverse CEs, it was found that bifunctional CEs tend to have more flexible loops and a larger entrance around the active site, and that the flexible loop 148-181 in CsCE displays obvious conformational changes during ligand binding. It was speculated that the reconstructed molecular interactions of the flexible loop during ligand binding helped to motivate the ligands to stretch in a manner beneficial for isomerization. Further site-directed mutagenesis analysis of the flexible loop in CsCE indicated that the residue composition of the flexible loop did not greatly impact epimerization but affects isomerization. In particular, V177D and I178D mutants showed a 50% and 80% increase in isomerization activity over the wild type. This study provides new information about the structural characteristics involved in the catalytic properties of CEs, which can be used to guide future molecular modifications.


Assuntos
Bacillus/enzimologia , Proteínas de Bactérias/química , Caldicellulosiruptor/enzimologia , Carboidratos Epimerases/química , Spirochaeta/enzimologia , Proteínas de Bactérias/genética , Biocatálise , Carboidratos Epimerases/genética , Domínio Catalítico , Isomerismo , Mutagênese Sítio-Dirigida , Especificidade por Substrato
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