Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 693
Filtrar
1.
Opt Express ; 29(24): 39016-39026, 2021 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-34809273

RESUMO

The decoherence effect of a laser caused by a speckle field seriously restricts the development of heterodyne lidar. To address this problem, we proposed a spatial decoherence compensation algorithm, whose feasibility was proved by experiments with a system featuring simple structure and convenient operation. The results demonstrated that the speed of the proposed algorithm was several orders higher than that of other algorithms and the system SNR was increased by a maximum of 1464 times after the algorithm processing. The proposed algorithm can process the signal in real time and effectively, having great application potential in long-distance weak target detection.

2.
mSystems ; : e0091121, 2021 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-34726491

RESUMO

Multidrug resistance (MDR) efflux pumps are involved in bacterial intrinsic resistance to multiple antimicrobials. Expression of MDR efflux pumps can be either constitutive or transiently induced by various environmental signals, which are typically perceived by bacterial two-component systems (TCSs) and relayed to the bacterial nucleoid, where gene expression is modulated for niche adaptation. Here, we demonstrate that RstA/RstB, a TCS previously shown to control acid-induced and biofilm-related genes in Escherichia coli, confers resistance to multiple antibiotics in Pseudomonas fluorescens by directly regulating the MDR efflux pumps EmhABC and MexCD-OprJ. Moreover, we show that phosphorylation of the conserved Asp52 residue in RstA greatly enhances RstA-DNA interaction, and regulation of the multidrug resistance by RstA/RstB is dependent on the phosphorylation of the RstA Asp52 residue by RstB. Proteome analysis reveals RstA/RstB also positively regulates the efflux pump MexEF-OprN and enzymes involved in anaerobic nitrate respiration and pyoverdine biosynthesis. Our results suggest that, by coupling the expression of multiple efflux pumps and anaerobic nitrate respiration, RstA/RstB could play a role in defense against nitrosative stress caused by anaerobic nitrate respiration. IMPORTANCE Microenvironmental hypoxia typically increases bacterial multidrug resistance by elevating expression of multidrug efflux pumps, but the precise mechanism is currently not well understood. Here, we showed that the two-component system RstA/RstB not only positively regulated expression of several efflux pumps involved in multidrug resistance, but also promoted expression of enzymes involved in anaerobic nitrate respiration and pyoverdine biosynthesis. These results suggested that, by upregulating expression of efflux pumps and pyoverdine biosynthesis-related enzymes, RstA/RstB could play a role in promoting bacterial tolerance to hypoxia by providing protection against nitrosative stress.

3.
J Alzheimers Dis ; 2021 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-34806605

RESUMO

BACKGROUND: Cognitive deficit is mainly clinical characteristic of Alzheimer's disease (AD). Recent reports showed adiponectin and its analogues could reverse cognitive impairments, lower amyloid-ß protein (Aß) deposition, and exert anti-inflammatory effects in different APP/PS1 AD model mice mainly exhibiting amyloid plaque pathology. However, the potential in vivo electrophysiological mechanism of adiponectin protecting against cognitive deficits in AD and the neuroprotective effects of adiponectin on 3xTg-AD mice including both plaque and tangle pathology are still unclear. OBJECTIVE: To observe the effects of adiponectin treatment on cognitive deficits in 3xTg-AD mice, investigate its potential in vivo electrophysiological mechanism, and testify its anti-inflammatory effects. METHODS: Barnes maze test, Morris water maze test, and fear conditioning test were used to evaluate the memory-ameliorating effects of adiponectin on 3xTg-AD mice. In vivo hippocampal electrophysiological recording was used to observe the change of basic synaptic transmission, long-term potentiation, and long-term depression. Immunohistochemistry staining and western blot were used to observe the activation of microglia and astroglia, and the expression levels of proinflammatory factors and anti-inflammtory factor IL-10. RESULTS: Adiponectin treatment could alleviate spatial memory and conditioned fear memory deficits observed in 3xTg-AD mice, improve in vivo LTP depression and LTD facilitation, inhibit overactivation of microglia and astroglia, decrease the expression of proinflammatory factors NF- κB and IL-1ß, and increase the expression level of IL-10 in the hippocampus of 3xTg-AD mice. CONCLUSION: Adiponectin could ameliorate cognitive deficits in 3xTg-AD mice through improving in vivo synaptic plasticity impairments and alleviating neuroinflammation in the hippocampus of 3xTg-AD mice.

4.
Front Biosci (Landmark Ed) ; 26(10): 740-751, 2021 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-34719202

RESUMO

Objectives: To quantify the integrated levels of ACE2 and TMPRSS2, the two well-recognized severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) entry-related genes, and to further identify key factors contributing to SARS-CoV-2 susceptibility in head and neck squamous cell carcinoma (HNSC). Methods: We developed a metric of the potential for tissue infected with SARS-CoV-2 ("TPSI") based on ACE2 and TMPRSS2 transcript levels and compared TPSI levels between tumor and matched normal tissues across 11 tumor types. For further analysis of HNSC, weighted gene co-expression network analysis (WGCNA), functional analysis, and single sample gene set enrichment analysis (ssGSEA) were conducted to investigate TPSI-relevant biological processes and their relationship with the immune landscape. TPSI-related factors were identified from clinical and mutational domains, followed by lasso regression to determine their relative effects on TPSI levels. Results: TPSI levels in tumors were generally lower than in the normal tissues. In HNSC, the genes highly associated with TPSI were enriched in viral entry-related processes, and TPSI levels were positively correlated with both eosinophils and T helper 17 (Th17) cell infiltration. Furthermore, the site of onset, human papillomaviruses (HPV) status, and nuclear receptor binding SET domain protein 1 (NSD1) mutations were identified as the most important factors shaping TPSI levels. Conclusions: This study identified the infection risk of SARS-CoV-2 between tumor and normal tissues, and provided evidence for the risk stratification of HNSC.


Assuntos
Enzima de Conversão de Angiotensina 2/genética , COVID-19/genética , Carcinoma de Células Escamosas/genética , Neoplasias de Cabeça e Pescoço/genética , Serina Endopeptidases/genética , Enzima de Conversão de Angiotensina 2/metabolismo , COVID-19/metabolismo , COVID-19/virologia , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/virologia , Perfilação da Expressão Gênica/métodos , Regulação Neoplásica da Expressão Gênica , Redes Reguladoras de Genes , Neoplasias de Cabeça e Pescoço/metabolismo , Neoplasias de Cabeça e Pescoço/virologia , Humanos , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , SARS-CoV-2/metabolismo , SARS-CoV-2/fisiologia , Serina Endopeptidases/metabolismo , Internalização do Vírus
5.
Nature ; 2021 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-34789875

RESUMO

In the clades of animals that diverged from the bony fish, a group of Mas-related G-protein-coupled receptors (MRGPRs) evolved that have an active role in itch and allergic signals1,2. As an MRGPR, MRGPRX2 is known to sense basic secretagogues (agents that promote secretion) and is involved in itch signals and eliciting pseudoallergic reactions3-6. MRGPRX2 has been targeted by drug development efforts to prevent the side effects induced by certain drugs or to treat allergic diseases. Here we report a set of cryo-electron microscopy structures of the MRGPRX2-Gi1 trimer in complex with polycationic compound 48/80 or with inflammatory peptides. The structures of the MRGPRX2-Gi1 complex exhibited shallow, solvent-exposed ligand-binding pockets. We identified key common structural features of MRGPRX2 and describe a consensus motif for peptidic allergens. Beneath the ligand-binding pocket, the unusual kink formation at transmembrane domain 6 (TM6) and the replacement of the general toggle switch from Trp6.48 to Gly6.48 (superscript annotations as per Ballesteros-Weinstein nomenclature) suggest a distinct activation process. We characterized the interfaces of MRGPRX2 and the Gi trimer, and mapped the residues associated with key single-nucleotide polymorphisms on both the ligand and G-protein interfaces of MRGPRX2. Collectively, our results provide a structural basis for the sensing of cationic allergens by MRGPRX2, potentially facilitating the rational design of therapies to prevent unwanted pseudoallergic reactions.

6.
Adv Ther ; 2021 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-34797505

RESUMO

INTRODUCTION: Brentuximab vedotin (BV) showed high overall remission rates in refractory/relapsed classical Hodgkin's lymphoma (HL) and systemic anaplastic large cell lymphoma (sALCL). Although the efficacy of BV has been reported in clinical trials, its efficacy as a frontline therapy in real world for patients with CD30 positive subtypes of non-Hodgkin's lymphoma (NHL) such as peripheral T-cell lymphoma with T-follicular helper cell (TFH) phenotype (PTCL, TFH), anaplastic large-cell lymphoma (ALCL) and angioimmunoblastic T-cell lymphoma (AITL) in China has not been well documented. METHODS: Analysis of a real-world, observational, retrospective case series in patients suffering from AITL, sALCL and peripheral T-cell lymphoma with T-follicular helper phenotype (PTCL-TFH) and other types of PTCL treated with BV in frontline treatment was conducted. The patients were given treatment from May 2020 till June 28, 2021. All patients were pathologically diagnosed to have PTCL before treatment and expressed CD30. Patients received BV (1.8 mg/kg) combined with CEP (cyclophosphamide, epirubicin, prednisone acetate every 3 weeks). The primary endpoint was objective response rates (ORR), and secondary endpoints were duration of response and incidence of adverse events (AEs). Exploratory endpoints such as progression-free survival (PFS) are discussed even though after such a short period. RESULTS: Nineteen patients completed ≥ 1 cycles of BV-CEP treatment (16 cases completed ≥ 4 cycles, 3 cases only completed 1 cycle). Among them, the ORR reached 89.5% [CR 52.7%; partial response (PR) 36.8%]. In the ALCL group, CR reached 100% with the median duration of response of up to 8 months, while in the AITL group, the ORR was 75% and 2 patients had disease progression after treatment with BV + CEP. We also observed that BV-CEP may extend the PFS compared to traditional chemotherapy such as the CHOEP regimen (BV-CEP: not evaluable, CHOEP: 6.5 months), although the median follow-up was only 6.7 months. Adverse events (AEs), including incidence and severity of febrile neutropenia (26% patients in the BV-CEP group and 30% in the CHOEP group), were similar between groups. There was no incidence of AEs leading to treatment withdrawal or death under BV-CEP treatment. CONCLUSION: BV is a promising treatment in patients with ALCL, AITL and PTCL-TFH in frontline treatment settings.

7.
Org Lett ; 23(22): 8905-8909, 2021 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-34756037

RESUMO

A novel strategy based on Cu-catalyzed (4+1) cascade annulation of terminal alkynes as one-carbon synthons with 2-(tosylmethyl)anilines has been developed for the expeditious synthesis of 2,3-disubstituted indoles, in which in situ generations of aza-o-quinone methides and alkynyl-copper(I) species are involved. This annulation provides an effective method for the assembly of synthetically and structurally interesting 2,3-disubstituted indoles.

8.
J Proteomics ; 251: 104411, 2021 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-34728423

RESUMO

The functions of proteins at the onset of puberty in goats remain largely unexplored. To identify the proteins regulating puberty in goats, we analysed protein abundance and pathways in the hypothalamus of female goats. We applied tandem mass tag (TMT) labelling, liquid chromatography-tandem mass spectrometry (LC-MS/MS), and parallel reaction monitoring (PRM) to examine hypothalamus of pubertal (cases; n = 3) and prepubertal (controls; n = 3) goats. We identified 5119 proteins, including 69 differentially abundant proteins (DAPs), of which 35 were upregulated and 34 were downregulated. Fourteen DAPs were randomly selected to verify these results using PRM, and the results were consistent with the TMT quantitative results. DAPs were enriched in MAPK signalling pathway, Ras signalling pathway, Autophagy-animal, Endocytosis, and PI3K/Akt/mTOR signalling pathway categories. These pathways are related to embryogenesis, cell proliferation, cell differentiation, and promoting the release of gonadotropin-releasing hormone (GnRH) in the hypothalamus. In particular, PDGFRß and MAP3K7 occupied important locations in the protein-protein interaction network. The results demonstrate that DAPs and their related signalling pathways are crucial in regulating puberty in goats. However, further research is needed to explore the functions of DAPs and their pathways to provide new insights into the mechanism of puberty onset. SIGNIFICANCE: In domestic animals, reaching the age of puberty is an event that contributes significantly to lifetime reproductive potential. And the hypothalamus functions directly in the complex systemic changes that control puberty. Our study was the first TMT proteomics analysis on hypothalamus tissues of pubertal goats, which revealed the changes of protein and pathways that are related to the onset of puberty. We identified 69 DAPs, which were enriched in the MAPK signaling pathway, the Ras signaling pathway, and the IGF-1/PI3K/Akt/mTOR pathway, suggesting that these processes were probably involved in the onset of puberty.

9.
Front Microbiol ; 12: 735767, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34690975

RESUMO

As unconventional forage source, mulberry (Morus alba L.) has been cultivated to alleviate animal feed shortages. This study aimed to investigate the effects of N fertilization during cultivation and Lactobacillus plantarum inoculation at ensiling on the chemical composition and bacterial community of mulberry silage. Mulberry was separately cultivated under two N fertilization rates (N1, 390 kg/ha/year; N2, 485 kg/ha/year) in 2016-2019, harvested on 30 April (the first-cut) and 15 June (the second-cut) in 2019, and then chopped for producing small bag silage. The silage was treated without (control) or with L. plantarum (LP, a recommended application rate of 105 cfu/g on fresh matter basis). After storage of 60 days in dark room at ambient temperature, silage was sampled for analysis of chemical and microbial compositions. Higher (P < 0.05) final pH value and acetic acid content and lower (P < 0.05) lactic acid content were found in silage of mulberry under N2 fertilization, resulting in more dry matter loss than that under N1 fertilization. Compared with control, inoculation of LP at ensiling increased (P < 0.05) lactic acid content and decreased (P < 0.05) final pH value, acetic acid and propionic acid contents of silage, by advancing the dominance of Lactobacillus and reducing the abundance of Enterococcus and Enterobacter. In particular, inoculation of LP at ensiling decreased (P < 0.05) dry matter loss and butyric acid content of first-cut silage. In conclusion, inoculation of LP at ensiling could reduce the undesirable effects from high N fertilization rate during cultivation on silage quality of mulberry harvested at different growing seasons.

10.
J Transl Med ; 19(1): 443, 2021 10 24.
Artigo em Inglês | MEDLINE | ID: mdl-34689804

RESUMO

BACKGROUND: This study aimed to evaluate the utility of radiomics-based machine learning analysis with multiparametric DWI and to compare the diagnostic performance of radiomics features and mean diffusion metrics in the characterization of breast lesions. METHODS: This retrospective study included 542 lesions from February 2018 to November 2018. One hundred radiomics features were computed from mono-exponential (ME), biexponential (BE), stretched exponential (SE), and diffusion-kurtosis imaging (DKI). Radiomics-based analysis was performed by comparing four classifiers, including random forest (RF), principal component analysis (PCA), L1 regularization (L1R), and support vector machine (SVM). These four classifiers were trained on a training set with 271 patients via ten-fold cross-validation and tested on an independent testing set with 271 patients. The diagnostic performance of the mean diffusion metrics of ME (mADCall b, mADC0-1000), BE (mD, mD*, mf), SE (mDDC, mα), and DKI (mK, mD) were also calculated for comparison. The area under the receiver operating characteristic curve (AUC) was used to compare the diagnostic performance. RESULTS: RF attained higher AUCs than L1R, PCA and SVM. The AUCs of radiomics features for the differential diagnosis of breast lesions ranged from 0.80 (BE_D*) to 0.85 (BE_D). The AUCs of the mean diffusion metrics ranged from 0.54 (BE_mf) to 0.79 (ME_mADC0-1000). There were significant differences in the AUCs between the mean values of all diffusion metrics and radiomics features of AUCs (all P < 0.001) for the differentiation of benign and malignant breast lesions. Of the radiomics features computed, the most important sequence was BE_D (AUC: 0.85), and the most important feature was FO-10 percentile (Feature Importance: 0.04). CONCLUSIONS: The radiomics-based analysis of multiparametric DWI by RF enables better differentiation of benign and malignant breast lesions than the mean diffusion metrics.


Assuntos
Mama , Aprendizado de Máquina , Área Sob a Curva , Mama/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética , Humanos , Curva ROC , Estudos Retrospectivos
11.
Front Oncol ; 11: 738330, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34631572

RESUMO

Purpose: We aimed to assess the additional value of a radiomics-based signature for distinguishing between benign and malignant non-mass enhancement lesions (NMEs) on dynamic contrast-enhanced breast magnetic resonance imaging (breast DCE-MRI). Methods: In this retrospective study, 232 patients with 247 histopathologically confirmed NMEs (malignant: 191; benign: 56) were enrolled from December 2017 to October 2020 as a primary cohort to develop the discriminative models. Radiomic features were extracted from one post-contrast phase (around 90s after contrast injection) of breast DCE-MRI images. The least absolute shrinkage and selection operator (LASSO) regression model was adapted to select features and construct the radiomics-based signature. Based on clinical and routine MR features, radiomics features, and combined information, three discriminative models were built using multivariable logistic regression analyses. In addition, an independent cohort of 72 patients with 72 NMEs (malignant: 50; benign: 22) was collected from November 2020 to April 2021 for the validation of the three discriminative models. Finally, the combined model was assessed using nomogram and decision curve analyses. Results: The routine MR model with two selected features of the time-intensity curve (TIC) type and MR-reported axillary lymph node (ALN) status showed a high sensitivity of 0.942 (95%CI, 0.906 - 0.974) and low specificity of 0.589 (95%CI, 0.464 - 0.714). The radiomics model with six selected features was significantly correlated with malignancy (P<0.001 for both primary and validation cohorts). Finally, the individual combined model, which contained factors including TIC types and radiomics signatures, showed good discrimination, with an acceptable sensitivity of 0.869 (95%CI, 0.816 to 0.916), improved specificity of 0.839 (95%CI, 0.750 to 0.929). The nomogram was applied to the validation cohort, reaching good discrimination, with a sensitivity of 0.820 (95%CI, 0.700 to 0.920), specificity of 0.864 (95%CI,0.682 to 1.000). The combined model was clinically helpful, as demonstrated by decision curve analysis. Conclusions: Our study added radiomics signatures into a conventional clinical model and developed a radiomics nomogram including radiomics signatures and TIC types. This radiomics model could be used to differentiate benign from malignant NMEs in patients with suspicious lesions on breast MRI.

12.
World J Clin Cases ; 9(26): 7930-7936, 2021 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-34621848

RESUMO

BACKGROUND: Malignant fibrous histiocytoma (MFH) is one of the most common soft tissue sarcomas among adults. It is characterized by large size, high grade, and biological aggressiveness. There are many reports of MFH after local stimulation, such as bone fracture, implants, and chronic osteomyelitis. In this paper, we report a patient who developed MFH 6 years after amputation, suggesting that wound healing and mechanical force play a role in the local stimulation of this disease. CASE SUMMARY: A 66-year-old man complained of persistent pain in his residual mid-thigh. He had undergone amputation surgery due to a traffic accident 6 years prior. Physical examination showed tenderness but no abnormalities in appearance. X-ray radiographs and magnetic resonance imaging supported the diagnosis of a tumor, and a biopsy confirmed that the lesion was MFH. The patient received neoadjuvant chemotherapy and left hip disarticulation. During the 6-mo follow-up, there were no symptoms of recurrence. CONCLUSION: Postsurgery MFH has been reported before, and many studies have attributed it to the biological effects of implants. Our case report shows that this disease can develop without an implant and thus highlights the importance of local stimulation. The wound-healing process and mechanical force can both promote this tumor, but whether they directly cause MFH needs further investigation.

13.
J Ethnopharmacol ; 284: 114748, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34662666

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: The dried roots and rhizomes of Cynanchum atratum Bunge is named 'Baiwei' according to traditional Chinese medicine theory. It is also named Cynanchi atrati Radix in Chinese Pharmacopoeia. Cynanchi atrati Radix is famous for its medicinal value of clearing away heat, relieving drenching, detoxifying and treating abscesses. It was commonly used in some Asian countries for the treatment of fever, vasoconstrictive syncope, lymphangitis and other diseases, obviously due to the effect of C21 steroidal glycosides. THE AIM OF THE REVIEW: The review concentrates on the botany, ethnopharmacology, phytochemistry, pharmacology and toxicology of Cynanchum atratum. We also discuss expectations for prospective research and implementation of this herb. MATERIALS AND METHODS: Relevant information about C. atratum was gained from ancient books and records, Doctoral and master's Theses, Science Direct, Pubmed, Wiley, CNKI, WanFang DATA, Google Scholar and other domestic and foreign literature. Some electronic databases have been included. RESULTS: As a member of the Apocynaceae family, C. atratum possesses its up-and-coming biological characteristics. It is widely reported for treating of postpartum fatigue, vomiting, urine drops, nephritis, urinary tract infection, edema, bronchitis and rheumatic low back pain. By now, over 100 compounds have been identified from C. atratum, including C21 steroidal glycosides, acetophenones, alkaloids, volatile oil and other ingredients. Activities such as anti-inflammatory, anti-tumor, anti-virus, antibacterial, anti-forgetful and others have been corroborated in vivo and in vitro. In addition, many of the active ingredients, such as Cynatratoside A, Cynanversicoside A, B, D, G, p-hydroxyacetophenone, 2,4-dihydroxyacetophenone and some volatile oils have been used as quality markers. CONCLUSION: All kinds of research conducted on C.atratum, especially in field of ethnopharmacological use, phytochemicals and pharmacology have been reviewed. The herb has been used over the years in treating nephritis, urinary tract infection, bronchitis and rheumatic lumbocrural pain. Many studies have been carried out to identify compounds that play a leading role in drug activity. However, the mechanism of drug therapy remains unclear. The evidence used to prove the quality standard of medicinal materials is obviously inadequate. Besides, safety evaluation is necessary for clinical medication. Similarly, the separation of steroidal saponins and the development of new drugs will also need further discussion.

14.
Anal Chem ; 93(44): 14784-14791, 2021 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-34704744

RESUMO

Lipid droplets (LDs) are spherical organelles that participate in numerous biological processes. In order to visualize LDs on the nanoscale, nanoscopy fluorescence imaging is considered as the most attractive technique but is substantially limited by the characteristics of fluorescent probes. Thus, the development of a superior fluorescent probe that is capable of nanoscopy fluorescence imaging has attracted enormous attention. Herein, a benzodithiophene-tetraoxide-based molecule Lipi-BDTO has been developed that can easily undergo the stimulated emission depletion (STED) process and displays high photostability. These two characteristics of fluorescent probes finely satisfy the requirements of STED nanoscopy imaging. Indeed, applying the probe for STED imaging achieves a high resolution of 65 nm, belonging to one of the leading results of LDs fluorescence imaging. Furthermore, the high photostability of this fluorescent probe enables it to monitor the dynamics of LDs by time-lapse STED imaging as well as to visualize the three-dimensional (3D) spatial distribution of LDs by 3D STED imaging. Notably, the resolution of the 3D STED image represents one of the best LDs fluorescence imaging results so far. Besides STED nanoscopy imaging, the superior utility of this fluorescent probe has been also demonstrated in two-color 3D confocal imaging and four-color confocal imaging.


Assuntos
Corantes Fluorescentes , Gotículas Lipídicas , Células HeLa , Humanos , Microscopia de Fluorescência , Imagem Óptica
15.
Gene ; 809: 146017, 2021 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-34655725

RESUMO

Flavonoids and lignin consist of a large number of secondarymetabolites which are derived from the phenylpropanoid pathway, and they act as a significant role in plant growth, development, and stress response. However, few reports have documented that how different subbranches of phenylpropanoid metablolic pathway mutually interact. In Arabidopsis, AtCPC (AtCAPRICE) is known to play a negative role in anthocyanin accumulation. Nonetheless, whether AtCPC could control the biosynthesis of lignin is largely unknown. Additionally, whether the RrFLS and RrANR, flavonol synthase and anthocyanidin reductase, from Rosa rugosa regulate different branches of phenylpropanoid pathway is unclear. Here, we performed a series of transgenic experiments with short life cycle tobacco and RNA-Seq analysis. Finally, a series of assays related to biological, physiological, and phenotypic characteristics were undertaken. Our results indicated that ectopic expression of AtCPC in tobacco not only decreased the flavonoid compound accumulation, but also up-regulated several lignin biosynthetic genes, and significantly increased the accumulation of lignin. Our results also revealed that although they respectively improved the flavonol and proanthocyanidin contents, the overexpression of RrFLS and RrANR plays positive roles in lignin biosynthesis in transgenic tobacco plants. Our findings provide a novel insight into the mechanism underlying homeostatic regulation of flavonoid and lignin biosynthesis in phenylpropanoid pathway of plants.

16.
Biosens Bioelectron ; 194: 113598, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34507097

RESUMO

On-site monitoring of carbamate pesticide in complex matrix remians as a challenge in terms of the real-time control of food safety and supervision of environmental quality. Herein, we fabricated robust upconversion nanoparticles (UCNPS)/polydopamine (PDA)-based hydrogel portable suit that precisely quantified carbaryl in complex tea samples with smartphone detector. UCNPS/PDA nanoprobe was developed by polymerization of dopamine monomers on the surface of NaErF4: 0.5% Tm3+@NaYF4 through electrostatic interaction, leading to efficient red luminescence quenching of UCNPS under near-infrared excitation, which circumvented autofluorescence and background interference in complicated environment. Such a luminescence quenching could be suppressed by thiocholine that was produced by acetylcholinesterase-mediated catalytic reaction, thus enabling carbaryl bioassay by inhibiting the activity of enzyme. Bestowed with the feasibility analysis of fluorescent output, portable platform was designed by integrating UCNPS-embedded sodium alginate hydrogel with 3D-printed smartphone device for quantitatively on-site monitoring of carbaryl in the range of 0.5-200 ng mL-1 in tea sample, accompanied by a detection limit of 0.5 ng mL-1. Owing to specific UCNPS signatures and hydrogel immobilization, this modular platform displayed sensitive response, portability and anti-interference capability in complex matrix analysis, thus holding great potential in point-of-care application.


Assuntos
Técnicas Biossensoriais , Nanopartículas , Praguicidas , Acetilcolinesterase , Carbamatos , Hidrogéis
17.
Environ Pollut ; 290: 118000, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34482244

RESUMO

During three sampling periods in 2014, systematic investigations were conducted into contamination profiles of ten organophosphate flame retardants (OPFRs) in both suspended particulate phase and water phase in the Yellow River (Henan Area). This research shows that OPFRs exist at lower concentrations in the suspended phase than in the water phase. The median concentration of 10 OPFRs (∑10OPFRs) in the suspended particulate phase was 62.5 ng/g (fluctuating from ND to 6.17 × 103 ng/g, dw), while their median concentration in the water phase was 109 ng/L (fluctuating from 35.6 to 469 ng/L). Among the selected 10 OPFRs, triethylphosphate (TEP), tris(1-chloro-2-propyl) phosphate (TCPP), and tris(2-chloroethyl) phosphate (TCEP) were the predominant compounds in the water phase (occupying 91.6% of the ∑10OPFRs), while TCPP, TCEP, and tri-o-tolyl phosphate (o-TCP) were the most common in the suspended particulate phase, accounting for 90.1% of the ∑10OPFRs. Across the three sampling periods, there was no significant seasonable variation for OPFRs either in the water phase or in the suspended particulate phase, except for TCEP and TCPP in the water phase. Compared with research findings relating to concentrations of OPFRs around China and abroad, the OPFRs of the Yellow River (Henan Area) in the water phase were at a moderate level. Suspended particles (SS) had a very important impact on the transportation of OPFRs in the studied area, with about 83.9% of ∑10OPFRs inflow attributed to SS inflow and about 81.7% of ∑10OPFRs outflow attributed to SS outflow. The total annual inflow and outflow of OPFRs were 7.72 × 104 kg and 6.62 × 104 kg in the studied area, respectively.


Assuntos
Retardadores de Chama , China , Poeira , Retardadores de Chama/análise , Organofosfatos/análise , Compostos Organofosforados/análise , Rios
18.
Cell Mol Immunol ; 18(10): 2344-2357, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34480146

RESUMO

Colitis is a common disease of the colon that is very difficult to treat. Probiotic bacteria could be an effective treatment. The probiotic Escherichia coli Nissle 1917 (EcN) was engineered to synthesize the ketone body (R)-3-hydroxybutyrate (3HB) for sustainable production in the gut lumen of mice suffering from colitis. Components of heterologous 3HB synthesis routes were constructed, expressed, optimized, and inserted into the EcN genome, combined with deletions in competitive branch pathways. The genome-engineered EcN produced the highest 3HB level of 0.6 g/L under microaerobic conditions. The live therapeutic was found to colonize the mouse gastrointestinal tract over 14 days, elevating gut 3HB and short-chain-length fatty acid (SCFA) levels 8.7- and 3.1-fold compared to those of wild-type EcN, respectively. The sustainable presence of 3HB in mouse guts promoted the growth of probiotic bacteria, especially Akkermansia spp., to over 31% from the initial 2% of all the microbiome. As a result, the engineered EcN termed EcNL4 ameliorated colitis induced via dextran sulfate sodium (DSS) in mice. Compared to wild-type EcN or oral administration of 3HB, oral EcNL4 uptake demonstrated better effects on mouse weights, colon lengths, occult blood levels, gut tissue myeloperoxidase activity and proinflammatory cytokine concentrations. Thus, a promising live bacterium was developed to improve colonic microenvironments and further treat colitis. This proof-of-concept design can be employed to treat other diseases of the colon.

19.
Talanta ; 235: 122784, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34517642

RESUMO

Acetylcholinesterase (AChE), as an important neurotransmitter, is widely present in the peripheral and central nervous systems. The aberrant expression of AChE could cause diverse neurodegenerative diseases. Herein, we developed a facile and interference-free fluorimetric biosensing platform for highly sensitive AChE activity determination based on a NaErF4: 0.5 % Ho3+@NaYF4 nano-probe. This nano-probe exhibits a unique property of emitting bright monochromic red (650 nm) upconversion (UC) emission under multiband (~808, ~980, and ~1530 nm) near-infrared (NIR) excitations. The principle of this detection relies on the quenching of the strong monochromic red UC emission by oxidization products of 3,3',5,5'-tetramethylbenzidine generated through AChE-modulated cascade reactions. This system shows a great sensing performance with a detection limit (LOD) of 0.0019 mU mL- 1 for AChE, as well as good specificity and stability. Furthermore, we validated the potential of the nano-probe in biological samples by determination of AChE in whole blood with a LOD of 0.0027 mU mL-1, indicating the potential application of our proposed platform for monitoring the progression of AChE-related disease.


Assuntos
Acetilcolinesterase , Técnicas Biossensoriais , Raios Infravermelhos
20.
Medicine (Baltimore) ; 100(38): e27224, 2021 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-34559115

RESUMO

BACKGROUNG: Tumor microenvironment (TME) has gradually emerged as an important research topic in the fight against cancer. The immune system is a major contributing factor in TME, and investigations have revealed that tumors are partially infiltrated with numerous immune cell subsets. METHOD: We obtained transcriptome RNA-seq data from the the Cancer Genome Atlas databases for 521 patients with colon adenocarcinoma (COAD). ESTIMATE algorithms are then used to estimate the fraction of stromal and immune cells in COAD samples. RESULT: A total of 1109 stromal-immune score-related differentially expressed genes were identified and used to generate a high-confidence protein-protein interaction network and univariate COX regression analysis. C-X-C motif chemokine 10 (CXCL10) was identified as the core gene by intersection analysis of data from protein-protein interaction network and univariate COX regression analysis. Then, for CXCL10, we performed gene set enrichment analysis, survival analysis and clinical analysis, and we used CIBERSORT algorithms to estimate the proportion of tumor-infiltrating immune cells in COAD samples. CONCLUSION: We discovered that CXCL10 levels could be effective for predicting the prognosis of COAD patients as well as a clue that the status of TME is transitioning from immunological to metabolic activity, which provided additional information for COAD therapies.


Assuntos
Quimiocina CXCL10/análise , Quimiocina CXCL10/farmacologia , Neoplasias do Colo/complicações , Microambiente Tumoral , Idoso , Biomarcadores Tumorais/análise , Biomarcadores Tumorais/sangue , Quimiocina CXCL10/sangue , Neoplasias do Colo/mortalidade , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Prognóstico
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...