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1.
Proc Natl Acad Sci U S A ; 120(3): e2207832120, 2023 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-36626561

RESUMO

Microorganisms play essential roles in soil ecosystem functioning and maintenance, but methods are currently lacking for quantitative assessments of the mechanisms underlying microbial diversity patterns observed across disparate systems and scales. Here we established a quantitative model to incorporate pH into metabolic theory to capture and explain some of the unexplained variation in the relationship between temperature and soil bacterial diversity. We then tested and validated our newly developed models across multiple scales of ecological organization. At the species level, we modeled the diversification rate of the model bacterium Pseudomonas fluorescens evolving under laboratory media gradients varying in temperature and pH. At the community level, we modeled patterns of bacterial communities in paddy soils across a continental scale, which included natural gradients of pH and temperature. Last, we further extended our model at a global scale by integrating a meta-analysis comprising 870 soils collected worldwide from a wide range of ecosystems. Our results were robust in consistently predicting the distributional patterns of bacterial diversity across soil temperature and pH gradients-with model variation explaining from 7 to 66% of the variation in bacterial diversity, depending on the scale and system complexity. Together, our study represents a nexus point for the integration of soil bacterial diversity and quantitative models with the potential to be used at distinct spatiotemporal scales. By mechanistically representing pH into metabolic theory, our study enhances our capacity to explain and predict the patterns of bacterial diversity and functioning under current or future climate change scenarios.


Assuntos
Ecossistema , Solo , Solo/química , Microbiologia do Solo , Bactérias/genética , Bactérias/metabolismo , Concentração de Íons de Hidrogênio , Biodiversidade
2.
J Am Chem Soc ; 146(23): 16213-16221, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38814730

RESUMO

Combining metal-organic frameworks (MOFs) with liquid crystals to construct liquid crystalline MOFs (LCMOF) offers the advantage of endowing and enhancing their functionality, yet it remains a challenging task. Herein, we report chiral liquid crystalline MOF (CLCMOF) thin films by cross-linking the chiral liquid crystals (CLC) with MOF thin films to realize highly circular polarization luminescence (CPL) performance with photo and thermal switching. By layer by layer cross-linking stilbene-containing CLC with stilbene-based MOF (CLC/MOF) thin film, the CLCMOF thin films were successfully obtained after UV irradiation due to the abundant [2 + 2] photocycloaddition. The resulted CLCMOF thin films have strong chirality, obvious photochromic fluorescent, and strong CPL performance (the asymmetry factor reaches to 0.4). Furthermore, due to the photochromic fluorescent MOF and thermotropic CLC, the CPL can be reversed and red-shifted after heating and UV irradiation treatment, showing photo- and thermal CPL switching. Such MOF-based CPL thin films with photo/thermal CPL switching were prepared to patterns and codes for the demonstration of potential application in advanced information anticounterfeit and encryption. This study not only opens a strategy for developing chiral thin films combining MOFs and liquid crystals but also offers a new route to achieve CPL switching in optical applications.

3.
Chemistry ; 30(24): e202400350, 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38407517

RESUMO

The development of new metal-organic frameworks (MOFs) thin films is important for expanding their functions and applications. Herein, we first report a new kind of MOF thin film by using aggregation-induced emission (AIE) dicarboxyl ligand through a liquid-phase epitaxial (LPE) layer-by-layer (LBL) spraying method (named AIE surface-coordinated metal-organic frameworks thin film, AIE-SURMOF). The obtained AIE-SURMOF Zn4O(TPE)3 (ZnTPE) has highly growth orientation and homogeneous thin film, showing strong fluorescent property. Furthermore, by loading chiral guest in the MOF pore, the formed chiral encapsulated AIE-SURMOF can clearly indicate obvious circularly polarized luminescence performance with glum of 0.01. This study provides new MOF thin film and new strategy for expanding function and application of MOF materials.

4.
J Nanobiotechnology ; 22(1): 268, 2024 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-38764056

RESUMO

The development of cost-effective and eco-friendly fertilizers is crucial for enhancing iron (Fe) uptake in crops and can help alleviate dietary Fe deficiencies, especially in populations with limited access to meat. This study focused on the application of MgFe-layered double hydroxide nanoparticles (MgFe-LDHs) as a potential solution. We successfully synthesized and characterized MgFe-LDHs and observed that 1-10 mg/L MgFe-LDHs improved cucumber seed germination and water uptake. Notably, the application of 10 mg/L MgFe-LDHs to roots significantly increased the seedling emergence rate and growth under low-temperature stress. The application of 10 mg/L MgFe-LDHs during sowing increased the root length, lateral root number, root fresh weight, aboveground fresh weight, and hypocotyl length under low-temperature stress. A comprehensive analysis integrating plant physiology, nutrition, and transcriptomics suggested that MgFe-LDHs improve cold tolerance by upregulating SA to stimulate CsFAD3 expression, elevating GA3 levels for enhanced nitrogen metabolism and protein synthesis, and reducing levels of ABA and JA to support seedling emergence rate and growth, along with increasing the expression and activity of peroxidase genes. SEM and FTIR further confirmed the adsorption of MgFe-LDHs onto the root hairs in the mature zone of the root apex. Remarkably, MgFe-LDHs application led to a 46% increase (p < 0.05) in the Fe content within cucumber seedlings, a phenomenon not observed with comparable iron salt solutions, suggesting that the nanocrystalline nature of MgFe-LDHs enhances their absorption efficiency in plants. Additionally, MgFe-LDHs significantly increased the nitrogen (N) content of the seedlings by 12% (p < 0.05), promoting nitrogen fixation in the cucumber seedlings. These results pave the way for the development and use of LDH-based Fe fertilizers.


Assuntos
Temperatura Baixa , Cucumis sativus , Ferro , Plântula , Cucumis sativus/crescimento & desenvolvimento , Cucumis sativus/metabolismo , Cucumis sativus/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Plântula/efeitos dos fármacos , Ferro/metabolismo , Raízes de Plantas/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Germinação/efeitos dos fármacos , Hidróxidos/farmacologia , Hidróxidos/metabolismo , Fertilizantes , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Nanopartículas/química , Estresse Fisiológico , Magnésio/metabolismo
5.
J Appl Clin Med Phys ; 25(7): e14371, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38682540

RESUMO

PURPOSE: To create and evaluate a three-dimensional (3D) Prompt-nnUnet module that utilizes the prompts-based model combined with 3D nnUnet for producing the rapid and consistent autosegmentation of high-risk clinical target volume (HR CTV) and organ at risk (OAR) in high-dose-rate brachytherapy (HDR BT) for patients with postoperative endometrial carcinoma (EC). METHODS AND MATERIALS: On two experimental batches, a total of 321 computed tomography (CT) scans were obtained for HR CTV segmentation from 321 patients with EC, and 125 CT scans for OARs segmentation from 125 patients. The numbers of training/validation/test were 257/32/32 and 87/13/25 for HR CTV and OARs respectively. A novel comparison of the deep learning neural network 3D Prompt-nnUnet and 3D nnUnet was applied for HR CTV and OARs segmentation. Three-fold cross validation and several quantitative metrics were employed, including Dice similarity coefficient (DSC), Hausdorff distance (HD), 95th percentile of Hausdorff distance (HD95%), and intersection over union (IoU). RESULTS: The Prompt-nnUnet included two forms of parameters Predict-Prompt (PP) and Label-Prompt (LP), with the LP performing most similarly to the experienced radiation oncologist and outperforming the less experienced ones. During the testing phase, the mean DSC values for the LP were 0.96 ± 0.02, 0.91 ± 0.02, and 0.83 ± 0.07 for HR CTV, rectum and urethra, respectively. The mean HD values (mm) were 2.73 ± 0.95, 8.18 ± 4.84, and 2.11 ± 0.50, respectively. The mean HD95% values (mm) were 1.66 ± 1.11, 3.07 ± 0.94, and 1.35 ± 0.55, respectively. The mean IoUs were 0.92 ± 0.04, 0.84 ± 0.03, and 0.71 ± 0.09, respectively. A delineation time < 2.35 s per structure in the new model was observed, which was available to save clinician time. CONCLUSION: The Prompt-nnUnet architecture, particularly the LP, was highly consistent with ground truth (GT) in HR CTV or OAR autosegmentation, reducing interobserver variability and shortening treatment time.


Assuntos
Braquiterapia , Aprendizado Profundo , Neoplasias do Endométrio , Órgãos em Risco , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador , Tomografia Computadorizada por Raios X , Humanos , Feminino , Neoplasias do Endométrio/radioterapia , Neoplasias do Endométrio/cirurgia , Neoplasias do Endométrio/diagnóstico por imagem , Neoplasias do Endométrio/patologia , Braquiterapia/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Órgãos em Risco/efeitos da radiação , Tomografia Computadorizada por Raios X/métodos , Imageamento Tridimensional/métodos , Radioterapia de Intensidade Modulada/métodos , Processamento de Imagem Assistida por Computador/métodos , Algoritmos , Prognóstico
6.
Crit Care ; 27(1): 493, 2023 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-38102705

RESUMO

BACKGROUND: Intensive care unit-acquired weakness (ICU-AW) is a prevalent and severe issue among ICU patients. Resistance training and beta-hydroxy-beta-methylbutyrate (HMB) intervention have demonstrated the potential to enhance muscle function in patients with sarcopenia and in older adults. The purpose of this study was to determine whether resistance training and/or HMB administration would improve physical function, muscle strength, and quality of life in medical ICU patients. METHODS: In this multicentre, four-arm, single-blind randomised control trial, a total of 112 adult patients with internal medical diagnoses admitted to the ICU were enrolled. These participants were then randomly assigned to one of four treatment groups: the resistance training group received protocol-based multilevel resistance exercise, the HMB group received 3 g/day of HMBCa, combination group and control groups received standard care, from the ICU to the general ward until discharge. The primary outcomes assessed at discharge included six-minute walking distance (6MWD) and short physical performance battery (SPPB). Secondary outcomes measured included muscle mass, MRC score, grip strength, and health reports quality of life at different time points. Data analysis was performed using a generalised linear mixed model, adhering to the principles of intention-to-treat analysis. RESULTS: Resistance training and combination treatment groups exhibited significant increases in SPPB scores (3.848 and 2.832 points, respectively) compared to the control group and substantial improvements in 6WMD (99.768 and 88.577 m, respectively) (all with P < 0.01). However, no significant changes were observed in the HMB group. Muscle strength, as indicated by MRC and grip strength tests conducted at both ICU and hospital discharge, showed statistically significant improvements in the resistance training and combination groups (P < 0.05). Nevertheless, no significant differences were found between the treatment groups and usual care in terms of 60-day mortality, prevalence of ICU-AW, muscle mass, quality of life, or other functional aspects. CONCLUSIONS: Resistance training with or without beta-hydroxy-beta-methylbutyrate during the entire hospitalisation intervention improves physical function and muscle strength in medical ICU patients, but muscle mass, quality of life, and 60-day mortality were unaffected. TRIAL REGISTRATION: ChiCTR2200057685 was registered on March 15th, 2022.


Assuntos
Treinamento Resistido , Humanos , Suplementos Nutricionais , Unidades de Terapia Intensiva , Força Muscular , Músculo Esquelético/fisiologia , Alta do Paciente , Qualidade de Vida , Método Simples-Cego , Adulto
7.
J Nanobiotechnology ; 21(1): 417, 2023 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-37950234

RESUMO

Layered double hydroxides (LDHs) have been widely used in the field of plant engineering, such as DNA/RNA transformation and enhancing plant disease resistance. However, few studies have examined the direct effects of LDHs on plants and their potential utility as nanofertilizers. In this study, the retention capacity of Cu/Fe-layered double hydroxide nanoparticles (CuFe-LDHs) was assessed by comparative experiments on vegetables. The results showed that the retention of CuFe-LDHs in leafy vegetables was high, such as lettuce. Phenotypic analysis revealed that the fresh and dry weights of lettuce leaves were both increased by spraying 10-100 µg/mL CuFe-LDHs. Using the optimal concentration of 10 µg/mL, we conducted further experiments to elucidate the mechanism of CuFe-LDHs promoting lettuce growth. It was found that the application of CuFe-LDHs had a significant effect on growth and induced physiological, transcriptomic, and metabolomic changes, including an increase in the chlorophyll b content, net photosynthetic rate, and intercellular carbon dioxide concentration, as well as modifications in gene expression patterns and metabolite profiles. This work provides compelling evidence that CuFe-LDHs can efficiently adsorb on the surface of lettuce leaves through hydrogen bonding, promote lettuce growth, mitigate the toxicity of heavy metal ions compared to their raw materials at the same concentration and offer a molecular-scale insight into the response of leafy vegetables to CuFe-LDHs.


Assuntos
Metais Pesados , Nanopartículas , Lactuca , Hidróxidos
8.
Nucleic Acids Res ; 49(6): 3204-3216, 2021 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-33675669

RESUMO

Autoactivation of two-component systems (TCSs) can increase the sensitivity to signals but inherently cause a delayed response. Here, we describe a unique negative feedback mechanism enabling the global NtrB/NtrC regulator to rapidly respond to nitrogen starvation over the course of histidine utilization (hut) in Pseudomonas fluorescens. NtrBC directly activates transcription of hut genes, but overexpression will produce excess ammonium leading to NtrBC inactivation. To prevent this from occurring, the histidine-responsive repressor HutC fine-tunes ntrBC autoactivation: HutC and NtrC bind to the same operator site in the ntrBC promoter. This newly discovered low-affinity binding site shows little sequence similarity with the consensus sequence that HutC recognizes for substrate-specific induction of hut operons. A combination of genetic and transcriptomic analysis indicated that both ntrBC and hut promoter activities cannot be stably maintained in the ΔhutC background when histidine fluctuates at high concentrations. Moreover, the global carbon regulator CbrA/CbrB is involved in directly activating hut transcription while de-repressing hut translation via the CbrAB-CrcYZ-Crc/Hfq regulatory cascade. Together, our data reveal that the local transcription factor HutC plays a crucial role in governing NtrBC to maintain carbon/nitrogen homeostasis through the complex interactions between two TCSs (NtrBC and CbrAB) at the hut promoter.


Assuntos
Proteínas de Bactérias/metabolismo , Carbono/metabolismo , Regulação Bacteriana da Expressão Gênica , Nitrogênio/metabolismo , Pseudomonas fluorescens/genética , Proteínas Repressoras/metabolismo , Fatores de Transcrição/metabolismo , Proteínas de Bactérias/genética , Sítios de Ligação , Retroalimentação Fisiológica , Histidina/metabolismo , Homeostase , Regiões Promotoras Genéticas , Pseudomonas fluorescens/metabolismo , Proteínas Repressoras/genética , Fatores de Transcrição/genética , Ativação Transcricional
9.
J Environ Manage ; 325(Pt A): 116499, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36257227

RESUMO

Over-compensatory growth of plants after disturbance is generally preferred by grassland users and managers because of more forage. How the grassland productivity and the plant growth condition before disturbance affect the compensatory growth are important for grazing management and the understanding of grassland degradation, yet they are not well understood. A clipping experiment was conducted on the Qinghai-Tibetan Plateau to understand the compensatory growth and conditions for the occurrence of over-compensatory at alpine meadows with different degradation status. Results showed the competition for light constrains the plant growth post-clipping at non-degraded and slightly degraded alpine meadows, while the reduction of soil nitrogen limits it at heavily degraded alpine meadow. The biomass accumulated post-clipping was positively correlated with the growing season biomass in unclipped plots and the biomass at clipping in clipped plots. When the aboveground biomass at clipping was less than 40.10 g m-2 and the growing season biomass was between 38 and 97 g m-2, the over-compensatory growth of alpine meadow could occur. Higher clipping rate is required for the alpine meadow with high productivity but the maximum clipping rate should be less than 0.71 to induce the over-compensatory growth. Equal-compensatory occurred at non-degraded and slightly degraded, while over-compensatory growth was observed at moderately degraded and a marginally significant over-compensatory growth at heavily degraded alpine meadow. The over-compensatory growth occurred at moderately degraded alpine meadow is mainly due to the performance of forbs. Our results suggest that grazing at moderately degraded alpine meadow may induce the over-compensatory growth at the community level, but the over-compensatory growth of forbs at moderately degraded alpine meadow may aggravate the alpine meadow degradation.


Assuntos
Pradaria , Solo , Tibet , Biomassa , Nitrogênio/análise , Plantas/metabolismo
10.
Mol Plant Microbe Interact ; 35(10): 893-905, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35762679

RESUMO

Legumes in the inverted repeat-lacking clade (IRLC) each produce a unique set of nodule-specific cysteine-rich (NCR) peptides, which act in concert to determine the terminal differentiation of nitrogen-fixing bacteroid. IRLC legumes differ greatly in their numbers of NCR and sequence diversity. This raises the significant question how bacteroid differentiation is collectively controlled by the specific NCR repertoire of an IRLC legume. Astragalus sinicus is an IRLC legume that forms indeterminate nodules with its microsymbiont Mesorhizobium huakuii 7653R. Here, we performed transcriptome analysis of root and nodule samples at 3, 7, 14, 28 days postinoculation with M. huakuii 7653R and its isogenic ∆bacA mutant. BacA is a broad-specificity peptide transporter required for the host-derived NCRs to target rhizobial cells. A total of 167 NCRs were identified in the RNA transcripts. Comparative sequence and electrochemical analysis revealed that A. sinicus NCRs (AsNCRs) are dominated by a unique cationic group (termed subgroup C), whose mature portion is relatively long (>60 amino acids) and phylogenetically distinct and possessing six highly conserved cysteine residues. Subsequent functional characterization showed that a 7653R variant harboring AsNCR083 (a representative of subgroup C AsNCR) displayed significant growth inhibition in laboratory media and formed ineffective white nodules on A. sinicus with irregular symbiosomes. Finally, bacterial two-hybrid analysis led to the identification of GroEL1 and GroEL3 as the molecular targets of AsNCR067 and AsNCR076. Together, our data contribute to a systematic understanding of the NCR repertoire associated with the A. sinicus and M. huakuii symbiosis. [Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.


Assuntos
Cisteína , Fabaceae , Cisteína/química , Cisteína/genética , Cisteína/metabolismo , Fabaceae/microbiologia , Nitrogênio/metabolismo , Fixação de Nitrogênio/genética , Peptídeos/metabolismo , RNA/metabolismo , Nódulos Radiculares de Plantas/microbiologia , Simbiose/genética , Transcriptoma/genética
11.
Kidney Int ; 102(2): 321-336, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35483524

RESUMO

Energy metabolism is crucial in maintaining cellular homeostasis and adapting to stimuli for tubular cells. However, the underlying mechanisms remain largely unknown. Here, we report that PP2Acα was upregulated in damaged tubular cells from patients and animal models with acute or chronic kidney injury. Using in vitro and in vivo model, we demonstrated that PP2Acα induction in damaged tubular cells suppresses fatty acid oxidation and promotes glycolysis, leading to cell death and fibrosis. Mechanistically, we revealed that PP2Acα dephosphorylates ACC through interaction with B56δ, leading to the regulation of fatty acid oxidation. Furthermore, PP2Acα also dephosphorylates p-Glut1 (Thr478) and suppresses Trim21-mediated Glut1 ubiquitination and degradation, leading to the promotion of glucose intake and glycolysis. Thus, this study adds new insight into the tubular cell metabolic alterations in kidney diseases. PP2Acα may be a promising therapeutic target for kidney injury.


Assuntos
Glicólise , Rim , Animais , Ácidos Graxos , Transportador de Glucose Tipo 1 , Fosfoproteínas Fosfatases
12.
Environ Microbiol ; 24(3): 1150-1165, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34499799

RESUMO

Pseudomonas aeruginosa rugose small-colony variants (RSCVs) are frequently isolated from chronic infections, yet, they are rarely reported in environmental isolates. Here, during the comparative genomic analysis of two P. aeruginosa strains isolated from crude oil, we discovered a spontaneous in-frame deletion, wspAΔ280-307 , which led to hyper-biofilm and RSCV phenotypes. WspA is a homologue of methyl-accepting chemotaxis proteins (MCPs) that senses surfaces to regulate biofilm formation by stimulating cyclic-di-guanosine monophosphate (c-di-GMP) synthesis through the Wsp system. However, the methylation sites of WspA have never been identified. In this study, we identified E280 and E294 of WspA as methylation sites. The wspAΔ280-307 mutation enabled the Wsp system to lock into a constitutively active state that is independent of regulation by methylation. The result is an enhanced production of c-di-GMP. Sequence alignment revealed three conserved repeat sequences within the amino acid residues 280-313 (aa280-313) region of WspA homologues, suggesting that a spontaneous deletion within this DNA encoding region was likely a result of intragenic recombination and that similar mutations might occur in several related bacterial genera. Our results provide a plausible explanation for the selection of RSCVs and a mechanism to confer a competitive advantage for P. aeruginosa in a crude-oil environment.


Assuntos
Proteínas de Bactérias , Pseudomonas aeruginosa , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Biofilmes , GMP Cíclico/metabolismo , Regulação Bacteriana da Expressão Gênica , Mutação , Pseudomonas aeruginosa/metabolismo , Transdução de Sinais/genética
13.
Inorg Chem ; 61(43): 16981-16985, 2022 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-36251482

RESUMO

Metal-organic framework (MOF) glass is a new type of glass material, but it usually lacks sufficient porosity. Thus, regulating the pore structure of MOF glass to improve its adsorption performance is very important. Herein, we found that the porosity of MOF glasses agZIF-62 and agZIF-76 can be regulated via an ammonia-immersion approach. After ammonia immersion, the resulting agZIF-62-NH3 and agZIF-76-NH3 could be maintained in their glass states or converted to their amorphous states, respectively. Their porosity changed according to the gas adsorption experiments. Notably, compared with agZIF-62 and agZIF-76, the iodine uptake capacities for agZIF-62-NH3 and agZIF-76NH3 increased by 12 and 21 times, respectively. This work shows that the subsequent treatment of MOF glass can regulate their adsorption performance.

14.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 44(6): 1102-1106, 2022 Dec.
Artigo em Zh | MEDLINE | ID: mdl-36373637

RESUMO

Most of the neuroendocrine tumors(NETs) overexpress the somatostatin receptor(SSTR),which provides a reliable target for SSTR-targeted peptide receptor radionuclide therapy(PRRT).Compared with drug therapy,PRRT has high objective response rate and significantly prolongs patients' survival.Moreover,the patients have good tolerance to this therapy.Considering that PRRT is in clinical trial phase in China,this article elaborates on the selection and preparation of patients,pre-treatment medications,administration methods,treatment cycles,side effects,follow-up plan,and the combination of PRRT with other drugs based on the published international guidelines in this field and our experience from clinical practice.Hoping that relevant professionals can well understand the principle of PRRT and apply it in clinical practice,we write this article to provide a basis for serving real-world patients and carrying out clinical trials.


Assuntos
Tumores Neuroendócrinos , Compostos Organometálicos , Humanos , Tumores Neuroendócrinos/radioterapia , Octreotida/uso terapêutico , Compostos Organometálicos/uso terapêutico , China
15.
Mol Plant Microbe Interact ; 34(5): 547-559, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33596109

RESUMO

Rhizobia are rod-shaped bacteria that form nitrogen-fixing root nodules on leguminous plants; however, they don't carry MreB, a key determinant of rod-like cell shape. Here, we introduced an actin-like mreB homolog from a pseudomonad into Mesorhizobium huakuii 7653R (a microsymbiont of Astragalus sinicus L.) and examined the molecular, cellular, and symbiotic phenotypes of the resultant mutant. Exogenous mreB caused an enlarged cell size and slower growth in laboratory medium. However, the mutant formed small, ineffective nodules on A. sinicus (Nod+ Fix-), and rhizobial cells in the infection zone were unable to differentiate into bacteroids. RNA sequencing analysis also revealed minor effects of mreB on global gene expression in free-living cells but larger effects for cells grown in planta. Differentially expressed nodule-specific genes include cell cycle regulators such as the tubulin-like ftsZ1 and ftsZ2. Unlike the ubiquitous FtsZ1, an FtsZ2 homolog was commonly found in Rhizobium, Sinorhizobium, and Mesorhizobium spp. but not in closely related nonsymbiotic species. Bacterial two-hybrid analysis revealed that MreB interacts with FtsZ1 and FtsZ2, which are targeted by the host-derived nodule-specific cysteine-rich peptides. Significantly, MreB mutation D283A disrupted the protein-protein interactions and restored the aforementioned phenotypic defects caused by MreB in M. huakuii. Together, our data indicate that MreB is detrimental for modern rhizobia and its interaction with FtsZ1 and FtsZ2 causes the symbiotic process to cease at the late stage of bacteroid differentiation. These findings led to a hypothesis that loss of mreB in the common ancestor of members of Rhizobiales and subsequent acquisition of ftsZ2 are critical evolutionary steps leading to legume-rhizobial symbiosis.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.


Assuntos
Fabaceae , Rhizobium , Proteínas do Citoesqueleto , Mesorhizobium , Fixação de Nitrogênio , Nódulos Radiculares de Plantas , Simbiose
16.
Chembiochem ; 22(6): 1042-1048, 2021 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-33140570

RESUMO

The development of small molecules that can selectively target G-quadruplex (G4) DNAs has drawn considerable attention due to their unique physiological and pathological functions. However, only a few molecules have been found to selectively bind a particular G4 DNA structure. We have developed a fluorescence ligand Q1, a molecular scaffold with a carbazole-pyridine core bridged by a phenylboronic acid side chain, that acts as a selective ascaris telomere antiparallel G4 DNA ASC20 ligand with about 18 nm blue-shifted and enhanced fluorescence intensity. Photophysical properties revealed that Q1 was sensitive to the microenvironment and gave the best selectivity to ASC20 with an equilibrium binding constant Ka =6.04×105  M-1 . Time-resolved fluorescence studies also demonstrated that Q1 showed a longer fluorescence lifetime in the presence of ASC20. The binding characteristics of Q1 with ASC20 were shown in detail in a fluorescent intercalator displacement (FID) assay, a 2-Ap titration experiment and by molecular docking. Ligand Q1 could adopt an appropriate pose at terminal G-quartets of ASC20 through multiple interactions including π-π stacking between aromatic rings; this led to strong fluorescence enhancement. In addition, a co-staining image showed that Q1 is mainly distributed in the cytoplasm. Accordingly, this work provides insights for the development of ligands that selectively targeting a specific G4 DNA structure.


Assuntos
Ascaris/genética , Corantes Fluorescentes/química , Quadruplex G , Telômero/química , Animais , Sítios de Ligação , Carbazóis/química , Dicroísmo Circular , Células HeLa , Humanos , Concentração de Íons de Hidrogênio , Ligantes , Metais/química , Simulação de Acoplamento Molecular , Conformação de Ácido Nucleico , Espectrometria de Fluorescência
17.
Glob Chang Biol ; 27(24): 6578-6591, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34606141

RESUMO

Phosphorus (P) is essential for productivity of alpine grassland ecosystems, which are sensitive to global warming. We tested the hypotheses that (1) mobilized 'calcium-bound inorganic P' (Ca-Pi ) is a major source of plant-available P in alpine meadows with alkaline soils after long-term warming, (2) mobilization of Ca-Pi is linked to effective plant carboxylate-releasing P-acquisition strategies under warming, and (3) the mobilization is also related to plant nitrogen (N)-acquisition. We conducted an 8-year warming experiment in an alpine meadow (4635 m above sea level) on the Qinghai-Tibetan Plateau. A significant increase in P concentration in both aboveground and belowground biomass indicates an increased mobilization and assimilation of P by plants under warming. We observed a significant decrease in Ca-Pi , no change in moderately-labile organic P, and an increase in highly resistant organic P after warming. There was no increase in phosphatase activities. Our results indicate that Ca-Pi , rather than organic P was the major source of plant-available P for alpine meadows under warming. Higher leaf manganese concentrations of sedges and forbs after warming indicate that carboxylates released by these plants are a key mechanism of Ca-Pi mobilization. The insignificant increase in Rhizobiales after warming and the very small cover of legumes show a minor role of N-acquisition strategies in solubilizing phosphate. The insignificant change in relative abundance of mycorrhizal fungi and bacteria related to P cycling after warming shows a small contribution of microorganisms to Ca-Pi mobilization. The significant increase in leaf N and P concentrations and N:P ratio of grasses and no change in sedge leaf N:P ratio reflect distinct responses of plant nutrient status to warming due to differences in P-acquisition strategies. We highlight the important effects of belowground P-acquisition strategies, especially plant carboxylate-releasing P-acquisition strategies on responses of plants to global changes in alpine meadows.


Assuntos
Fósforo , Solo , Ecossistema , Pradaria , Fosfatos , Tibet
18.
BMC Cancer ; 21(1): 988, 2021 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-34479538

RESUMO

BACKGROUND: In clinical studies, it has been observed that esophageal cancer (EC) patient prognosis can be very different even for those patients with tumors of the same TNM stage. Tumor length has been analysed as a possible independent prognostic factor in many studies, but no unanimous conclusion has been reached. Therefore, this review used a meta-analysis to evaluate the association between tumor length and prognosis in EC patients. METHODS: A systematic search for relevant articles was performed in PubMed, Web of Science, and Embase. Hazard ratios (HRs) and 95% confidence intervals (CIs) were used as effective measures to estimate the correlation between tumor length and prognosis, including overall survival, disease-free survival, progression-free survival, disease-specific survival, and cancer-specific survival. STATA 15.0 software was used to perform the meta-analysis and the data synthesis. RESULTS: Finally, 41 articles with 28,973 patients were included in our study. The comprehensive statistical results showed that long tumors are an independent prognostic parameter associated with poor overall survival (OS) (HR = 1.30; 95% CI: 1.21-1.40, p < .001) and disease-free survival (DFS) (HR = 1.38; 95% CI: 1.18-1.61, p < .001) in EC patients. Subgroup analyses also suggested a significant correlation between long tumors and poor OS. Sensitivity analysis and publication bias evaluation confirmed the reliability and stability of the results. Similar results were obtained in the analyses of progression-free survival (PFS), disease-specific survival (DSS), and cancer-specific survival (CSS). CONCLUSION: The results of this meta-analysis showed that long tumors were related to poor OS, DFS, PFS, DSS and CSS in EC patients. Tumor length might be an important predictor of prognosis in EC patients, and it can be used as an independent staging index. Further well-designed and large-scale prospective clinical studies are needed to confirm these findings.


Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias Esofágicas/mortalidade , Neoplasias Esofágicas/patologia , Neoplasias Esofágicas/metabolismo , Humanos , Prognóstico , Taxa de Sobrevida
19.
Bioorg Med Chem Lett ; 53: 128438, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34740774

RESUMO

Human serum albumin (HSA) in blood serves as an important biomarker for clinical diagnosis, and fluorescence sensing method has attracted extensive attention. In this work, a small organic molecule probe, YS8, involving twisted intramolecular charge transfer (TICT) characteristic, was designed and investigated to detect HSA. YS8 kept silent state in fluorescence under physiological conditions, but the encapsulation of YS8 in the hydrophobic subdomain IB region of HSA inhibited the TICT state and produced a clear light-up fluorescent signal. Especially, YS8 was demonstrated to be an efficient fluorogenic probe to discriminate HSA from other proteins including the bovine serum albumin (BSA). Moreover, YS8/HSA complex could be applied in fluorescence imaging in living cells and is also useful in the study of artificial fluorescent protein (AFP).


Assuntos
Desenho de Fármacos , Corantes Fluorescentes/química , Imagem Óptica , Albumina Sérica Humana/análise , Animais , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Corantes Fluorescentes/síntese química , Camundongos , Estrutura Molecular , Relação Estrutura-Atividade
20.
Biosci Biotechnol Biochem ; 85(2): 233-241, 2021 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-33604631

RESUMO

Eucommia ulmoides is an economic tree that can biosynthesize secondary metabolites with pharmacological functions. Genetic basis of biosynthesis of these compounds is almost unknown. Therefore, genomic-wide association study was performed to exploit the genetic loci maybe involved in biosynthetic pathways of 5 leaf inclusions (aucubin, chlorogenic acid, gutta-percha, polyphenols, total flavonoids). It was shown that contents of the 5 leaf metabolites have a wide variation following normal distribution. A total of 2 013 102 single nucleotide polymorphism (SNP) markers were identified in a population containing 62 individual clones. Through genome-wide association study analysis, many SNP loci were identified perhaps associated with phenotypes of the leaf inclusions. Higher transcriptional levels of the candidate genes denoted by significant SNPs in leaves suggested they may be involved in biosynthesis of the leaf inclusions. These genetic loci provide with invaluable information for further studies on the gene functions in biosynthesis of the leaf inclusions and selective breeding of the plus trees.


Assuntos
Eucommiaceae/genética , Genes de Plantas/genética , Estudo de Associação Genômica Ampla , Folhas de Planta/metabolismo , Eucommiaceae/metabolismo , Perfilação da Expressão Gênica , Fenótipo , Polimorfismo de Nucleotídeo Único
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