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1.
Planta ; 259(5): 100, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38536457

RESUMO

MAIN CONCLUSION: SbYS1 and its upstream transcription factor SbWRKY72 were involved in Cd tolerance and accumulation and are valuable for developing sweet sorghum germplasm with high-Cd tolerance or accumulation ability through genetic manipulation. Cadmium (Cd) is highly toxic and can severely affect human health. Sweet sorghum, as an energy crop, shows great potential in extracting cadmium from Cd-contaminated soils. However, its molecular mechanisms of Cd-tolerance and -accumulation remain largely unknown. Here, we isolated a YSL family gene SbYS1 from the sweet sorghum genotype with high Cd accumulation ability and the expression of SbYS1 in roots was induced by cadmium. GUS staining experiment exhibited that SbYS1 was expressed in the epidermis and parenchyma tissues of roots. Further subcellular localization analysis suggested that SbYS1 was localized in the endoplasmic reticulum and plasma membrane. Yeast transformed with SbYS1 exhibited a sensitive phenotype compared to the control when exposed to Cd-NA (chelates of cadmium and nicotianamine), indicating that SbYS1 may absorb cadmium in the form of Cd-NA. Arabidopsis overexpressing SbYS1 had a longer root length and accumulated less Cd in roots and shoots. SbWRKY72 bound to the promoter of SbYS1 and negatively regulated the expression of SbYS1. Transgenic Arabidopsis of SbWRKY72 showed higher sensitivity to cadmium and increased cadmium accumulation in roots. Our results provide references for improving the phytoremediation efficiency of sweet sorghum by genetic manipulation in the future.


Assuntos
Arabidopsis , Poluentes do Solo , Sorghum , Humanos , Cádmio/toxicidade , Cádmio/metabolismo , Sorghum/genética , Sorghum/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Biodegradação Ambiental , Grão Comestível/metabolismo , Raízes de Plantas/metabolismo , Poluentes do Solo/toxicidade , Poluentes do Solo/metabolismo
2.
Environ Res ; 249: 118383, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38331152

RESUMO

Zonation is a typical pattern of soil distribution and species assembly across riparian habitats. Microorganisms are essential members of riparian ecosystems and whether soil microbial communities demonstrate similar zonation patterns and how bulk and rhizosphere soil microorganisms interact along the elevation (submergence stress) gradient remain largely unknown. In this study, bulk and rhizosphere (dominant plant) soil samples were collected and investigated across riparian zones where the submergence stress intensity increased as the elevation decreased. Results showed that the richness of bacterial communities in bulk and rhizosphere soil samples was significantly different and presented a zonation pattern along with the submergence stress gradient. Bulk soil at medium elevation that underwent moderate submergence stress had the most abundant bacterial communities, while the species richness of rhizobacteria at low elevation that experienced serious submergence stress was the highest. Additionally, principal coordinate analysis (PCoA) and significance tests showed that bulk and rhizosphere soil samples were distinguished according to the structure of bacterial communities, and so were bulk or rhizosphere soil samples from different elevations. Redundancy analysis (RDA) and Mantel test suggested that bacterial communities of bulk soil mainly relied on the contents of soil organic matter, total carbon (TC), total nitrogen (TN), sodium (Na), calcium (Ca) and magnesium (Mg). Contrastingly, the contents of Na and Mg were the main factors explaining the variation in rhizobacterial community composition. Correlation and microbial source tracking analyses showed thatthe relationship of bulk and rhizosphere soil bacteria became much stronger, and the rhizosphere soil may get more bacterial communities from bulk soil with the increase in submergence severity. Our results suggest that the abiotic and biotic components of the riparian ecosystem are closely covariant along the submergence stress gradient and imply that the bacterial community may be a key node linking soil physiochemical properties and vegetation communities.


Assuntos
Bactérias , Rizosfera , Microbiologia do Solo , China , Bactérias/classificação , Rios/microbiologia , Rios/química , Altitude , Microbiota , Solo/química
3.
Drug Resist Updat ; 67: 100917, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36608472

RESUMO

Bacterial biofilm-associated infection is a life-threatening emergency contributing from drug resistance and immune escape. Herein, a novel non-antibiotic strategy based on the synergy of bionanocatalysts-driven heat-amplified chemodynamic therapy (CDT) and innate immunomodulation is proposed for specific biofilm elimination by the smart design of a biofilm microenvironment (BME)-responsive double-layered metal-organic framework (MOF) bionanocatalysts (MACG) composed of MIL-100 and CuBTC. Once reaching the acidic BME, the acidity-triggered degradation of CuBTC allows the sequential release of glucose oxidase (GOx) and an activable photothermal agent, 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). GOx converts glucose into H2O2 and gluconic acid, which can further acidify the BME to accelerate the CuBTC degradation and GOx/ABTS release. The in vitro and in vivo results show that horseradish peroxidase (HRP)-mimicking MIL-100 in the presence of self-supplied H2O2 can catalyze the oxidation of ABTS into oxABTS to yield a photothermal effect that breaks the biofilm structure via eDNA damage. Simultaneously, the Cu ion released from the degraded CuBTC can deplete glutathione and catalyze the splitting of H2O2 into •OH, which can effectively penetrate the heat-induced loose biofilms and kill sessile bacteria (up to 98.64%), such as E. coli and MRSA. Particularly, MACG-stimulated M1-macrophage polarization suppresses the biofilm regeneration by secreting pro-inflammatory cytokines (e.g., IL-6, TNF-α, etc.) and forming a continuous pro-inflammatory microenvironment in peri-implant biofilm infection animals for at least 14 days. Such BME-responsive strategy has the promise to precisely eliminate refractory peri-implant biofilm infections with extremely few adverse effects.


Assuntos
Temperatura Alta , Neoplasias , Animais , Escherichia coli , Peróxido de Hidrogênio/farmacologia , Biofilmes , Linhagem Celular Tumoral , Microambiente Tumoral
4.
Artigo em Inglês | MEDLINE | ID: mdl-38662919

RESUMO

BACKGROUND: Treatment of femoral neck fractures in patients who are nongeriatric (≤ 60 years) is challenging because of high failure rates. Anatomic parameters influence the biomechanical environment for fracture healing, but their associations with clinical prognosis remains unclear. QUESTIONS/PURPOSES: (1) Which anatomic parameter that is identifiable on pelvic radiographs shows a statistical correlation with a higher risk of clinical failure defined as nonunion, avascular necrosis (AVN), reoperation, and functional failure (decrease in Harris hip score reaching the minimum clinically important difference) in the screw fixation of femoral neck fractures among nongeriatric patients? (2) How does the influence of anatomic parameters on clinical prognosis manifest: directly or mediated by additional mechanisms? METHODS: This retrospective, multicenter study used a nationwide database in China. Between January 2014 and December 2020, we evaluated 1066 patients with femoral neck fractures with a median age of 53 years (interquartile range 46 to 56) and median follow-up period of 62 months. Anatomic parameters including femoral neck-shaft angle (NSA), femoral head radius, femoral neck width, femoral offset, acetabular center-edge angle, and acetabular sharp angle were variables of interest. The primary outcome was clinical failure including nonunion, AVN, reoperation, and functional failure (decrease in Harris hip score reaching the minimum clinically important difference). Risk factors for failure were first filtered using the Bayesian information criterion and then assessed with multiple regression adjusting for confounders. The mediation effect was further explored using model-based causal mediation analysis with a quasi-Bayesian Monte Carlo method. RESULTS: Of all anatomic parameters we assessed, the contralateral NSA was associated with clinical failure, after adjusting for all potential covariates and confounding variables (adjusted odds ratio 0.92 [95% confidence interval 0.89 to 0.95]; p < 0.001). The optimal threshold for the NSA was 130°, with the highest Youden index of 0.27. Patients with an NSA < 130° (41% [441 of 1066]) demonstrated an increased occurrence of nonunion (15% [68 of 441] versus 5% [33 of 625]; p < 0.001), AVN (32% [141 of 441] versus 22% [136 of 625]; p < 0.001), functional failure (25% [110 of 441] versus 15% [93 of 625]), and reoperations (28% [122 of 441] versus 13% [79 of 625]). The impact of an NSA less than 130° on clinical failure was direct and substantially mediated by the type of displaced fracture (mediation proportion: 18.7%). CONCLUSION: In our study of screw fixations for femoral neck fractures among nongeriatric patients, we identified that a contralateral NSA < 130° correlates with an increased risk of clinical failure including nonunion, AVN, functional failure, and reoperation. The effect is either direct or mediated through displaced fracture types. This is important for surgeons in order to recognize the elevated rate of clinical failure and nature of the challenging biomechanical environment, which should guide them in refining surgical details and selecting appropriate fixation and rehabilitation plans. Approaches to managing these fractures require further validation with large-scale clinical trials. LEVEL OF EVIDENCE: Level III, prognostic study.

5.
J Nanobiotechnology ; 20(1): 68, 2022 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-35123501

RESUMO

BACKGROUND: Femoral stem of titanium alloy has been widely used for hip arthroplasty with considerable efficacy; however, the application of this implant in patients with osteoporosis is limited due to excessive bone resorption. Macrophages participate in the regulation of inflammatory response and have been a topic of increasing research interest in implant field. However, few study has explored the link between macrophage polarization and osteogenic-osteoclastic differentiation. The present study aims to develop a novel hierarchical biofunctionalized 3D-printed porous Ti6Al4V scaffold with enhanced osteoporotic osseointegration through immunotherapy. METHOD: To improve the osteointegration under osteoporosis, we developed a hierarchical biofunctionalized 3D-printed porous Ti6Al4V scaffold (PT). Biomimetic extracellular matrix (ECM) was constructed inside the interconnected pores of PT in micro-scale. And in nano-scale, a drug cargo icariin@Mg-MOF-74 (ICA@MOF) was wrapped in ECM-like structure that can control release of icariin and Mg2+. RESULTS: In this novel hierarchical biofunctionalized 3D-printed porous Ti6Al4V scaffold, the macroporous structure provides mechanical support, the microporous structure facilitates cell adhesion and enhances biocompatibility, and the nanostructure plays a biological effect. We also demonstrate the formation of abundant new bone at peripheral and internal sites after intramedullary implantation of the biofunctionalized PT into the distal femur in osteoporotic rats. We further find that the controlled-release of icariin and Mg2+ from the biofunctionalized PT can significantly improve the polarization of M0 macrophages to M2-type by inhibiting notch1 signaling pathway and induce the secretion of anti-inflammatory cytokines; thus, it significantly ameliorates bone metabolism, which contributes to improving the osseointegration between the PT and osteoporotic bone. CONCLUSION: The therapeutic potential of hierarchical PT implants containing controlled release system are effective in geriatric orthopaedic osseointegration.


Assuntos
Osseointegração , Titânio , Idoso , Ligas , Animais , Humanos , Osteogênese , Porosidade , Impressão Tridimensional , Ratos , Titânio/química , Titânio/farmacologia
6.
Planta ; 254(1): 16, 2021 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-34185181

RESUMO

MAIN CONCLUSION: Key miRNAs including sbi-miR169p/q, sbi-miR171g/j, sbi-miR172a/c/d, sbi-miR172e, sbi-miR319a/b, sbi-miR396a/b, miR408, sbi-miR5384, sbi-miR5565e and nov_23 were identified to function in the regulation of Cd accumulation and tolerance. As an energy plant, sweet sorghum shows great potential in the phytoremediation of Cd-contaminated soils. However, few studies have focused on the regulatory roles of miRNAs and their targets under Cd stress. In this study, comparative analysis of sRNAs, degradome and transcriptomics was conducted in high-Cd accumulation (H18) and low-Cd accumulation (L69) genotypes of sweet sorghum. A total of 38 conserved and 23 novel miRNAs with differential expressions were identified under Cd stress or between H18 and L69, and 114 target genes of 41 miRNAs were validated. Furthermore, 25 miRNA-mRNA pairs exhibited negatively correlated expression profiles and sbi-miR172e together with its target might participate in the distinct Cd tolerance between H18 and L69 as well as sbi-miR172a/c/d. Additionally, two groups of them: miR169p/q-nov_23 and miR408 were focused through the co-expression analysis, which might be involved in Cd uptake and tolerance by regulating their targets associated with transmembrane transportation, cytoskeleton activity, cell wall construction and ROS (reactive oxygen species) homeostasis. Further experiments exhibited that cell wall components of H18 and L69 were different when exposed to cadmium, which might be regulated by miR169p/q, miR171g/j, miR319a/b, miR396a/b, miR5384 and miR5565e through their targets. Through this study, we aim to reveal the potential miRNAs involved in sweet sorghum in response to Cd stress and provide references for developing high-Cd accumulation or high Cd-resistant germplasm of sweet sorghum that can be used in phytoremediation.


Assuntos
MicroRNAs , Sorghum , Biodegradação Ambiental , Cádmio/metabolismo , Cádmio/toxicidade , Regulação da Expressão Gênica de Plantas , MicroRNAs/genética , Sorghum/genética , Sorghum/metabolismo , Transcriptoma/genética
7.
Plant Cell Environ ; 44(5): 1549-1564, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33560528

RESUMO

Salt cress (Eutrema salsugineum) presents relatively high phosphate (Pi) use efficiency cy in its natural habitat. Phosphate Transporters (PHTs) play critical roles in Pi acquisition and homeostasis. Here, a comparative study of PHT families between salt cress and Arabidopsis was performed. A total of 27 putative PHT genes were identified in E. salsugineum genome. Notably, seven tandem genes encoding PHT1;3 were found, and function analysis in Arabidopsis indicated at least six EsPHT1;3s participated in Pi uptake. Meanwhile, different expression profiles of PHT genes between the two species under Pi limitation and salt stress were documented. Most PHT1 genes were down-regulated in Arabidopsis while up-regulated in salt cress under salinity, among which EsPHT1;9 was further characterized. EsPHT1;9 was involved in root-to-shoot Pi translocation. Particularly, the promoter of EsPHT1;9 outperformed that of AtPHT1;9 in promoting Pi translocation, K+ /Na+ ratio, thereby salt tolerance. Through cis-element analysis, we identified a bZIP transcription factor EsABF5 negatively regulating EsPHT1;9 and plant tolerance to low-Pi and salt stress. Altogether, more copies and divergent transcriptional regulation of PHT genes contribute to salt cress adaptation to the co-occurrence of salinity and Pi limitation, which add our knowledge on the evolutionary and molecular component of multistress- tolerance of this species.


Assuntos
Brassicaceae/enzimologia , Brassicaceae/genética , Família Multigênica , Proteínas de Transporte de Fosfato/genética , Fosfatos/deficiência , Salinidade , Arabidopsis/genética , Arsênio/metabolismo , Análise por Conglomerados , Regulação para Baixo/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Especificidade de Órgãos/genética , Fosfatos/metabolismo , Filogenia , Raízes de Plantas/metabolismo , Brotos de Planta/metabolismo , Potássio/metabolismo , Regiões Promotoras Genéticas/genética , Estresse Salino/genética , Sódio/metabolismo
8.
BMC Musculoskelet Disord ; 22(1): 951, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34781964

RESUMO

BACKGROUND: A variety of bone graft substitutes have been introduced into the treatment of bone non-unions. However, clinical outcomes from current evidences are various and conflicting. This study aimed to present the preliminary outcomes of a treatment protocol in which the combination of demineralized bone matrix (DBM) and platelet rich plasma (PRP) was used as a bone graft substitute for long bone non-unions. METHODS: Data of this retrospective study were reviewed and collected from a consecutive case series involving 43 patients who presented with a long bone non-union and were treated in our department from October 2018 to May 2019. The combination of DMB and PRP was applied as a bone defect filler in 16 patients, whilst the other 27 patients were treated with iliac bone autografting. Patients' demographics, postoperative complications and the result of bone union were compared and evaluated. RESULTS: The demographic data between the two groups were comparable. No significant difference was found with regard to the incidence of postoperative complications. No graft rejection, heterotopic ossification or other complications were noted. The distribution of bony healing time was rather scattered but did not differ significantly between the groups (7.533 ± 3.357 months vs. 6.625 ± 2.516 months; P=0.341). Union was identified radiographically in 15 of 16 patients in the DBM+PRP group and in 24 of 27 patients in autograft group. CONCLUSIONS: The present study identified that low incidence of postoperative complications and satisfactory bony healing rate could be achieved in the treatment of long bone non-unions augmented with the combination of DBM and PRP. Although these findings might indicate the promising future of this treatment protocol, larger and higher quality studies should also be executed to assess its routine use.


Assuntos
Substitutos Ósseos , Plasma Rico em Plaquetas , Matriz Óssea , Transplante Ósseo , Humanos , Estudos Retrospectivos , Transplante Autólogo
9.
Int J Mol Sci ; 22(3)2021 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-33499312

RESUMO

Globally, flooding is a major threat causing substantial yield decline of cereal crops, and is expected to be even more serious in many parts of the world due to climatic anomaly in the future. Understanding the mechanisms of plants coping with unanticipated flooding will be crucial for developing new flooding-tolerance crop varieties. Here we describe survival strategies of plants adaptation to flooding stress at the morphological, physiological and anatomical scale systemically, such as the formation of adventitious roots (ARs), aerenchyma and radial O2 loss (ROL) barriers. Then molecular mechanisms underlying the adaptive strategies are summarized, and more than thirty identified functional genes or proteins associated with flooding-tolerance are searched out and expounded. Moreover, we elaborated the regulatory roles of phytohormones in plant against flooding stress, especially ethylene and its relevant transcription factors from the group VII Ethylene Response Factor (ERF-VII) family. ERF-VIIs of main crops and several reported ERF-VIIs involving plant tolerance to flooding stress were collected and analyzed according to sequence similarity, which can provide references for screening flooding-tolerant genes more precisely. Finally, the potential research directions in the future were summarized and discussed. Through this review, we aim to provide references for the studies of plant acclimation to flooding stress and breeding new flooding-resistant crops in the future.


Assuntos
Adaptação Fisiológica , Produtos Agrícolas/fisiologia , Inundações , Melhoramento Vegetal , Etilenos/química , Regulação da Expressão Gênica de Plantas , Giberelinas/química , Ácidos Indolacéticos/química , Oxigênio/fisiologia , Filogenia , Reguladores de Crescimento de Plantas/fisiologia , Proteínas de Plantas/fisiologia , Raízes de Plantas/fisiologia , Espécies Reativas de Oxigênio/química , Estresse Fisiológico , Fatores de Transcrição/fisiologia
10.
BMC Musculoskelet Disord ; 21(1): 842, 2020 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-33308185

RESUMO

BACKGROUND: The treatment of vertical femoral neck fractures (vFNFs) in young patients remains challenging, with a high complication rate by using traditional techniques. The use of cannulated screws (CSs) combined with a buttress plate represents an alternative approach for treating vFNFs. However, the biomechanical influence of the use or non-use of the proximal screws of buttress plates on vFNFs stability remains unclear. This study aims to analyse the biomechanics of buttress plate fixation with or without the use of proximal screws through finite element analysis (FEA) to further understand this approach. METHODS: We built five vFNFs (Pauwels angle 70°) finite element models treated using three cannulated screws (CS group) or three cannulated screws plus a locking buttress plate (buttress group). In the buttress group, use or non-use of proximal screws was carried out on two types of plates (4-hole & 6-hole). The following seven parameters were analysed to compare biomechanical properties of the five models: the stiffness; the maximal stress of the plate system (plate and screws), CSs and bone (MPS, MCS, MBS); the maximal displacement of internal fixations (plate system & CSs) and bone (MIFD, MBD); and the maximal relative displacement of interfragments (MID). RESULTS: Compared with CS model, the buttress models exhibited improved biomechanical properties, with increased stiffness and decreased MCS, MBS, MIFD, MBD and MID. The models fixed using buttress plates combined with a proximal screw showed greater stiffness (+ 3.75% & + 8.31% vs + 0.98% & + 4.57%) and MPS (795.6 & 947.2 MPa vs 294.9 & 556.2 MPa) values, and smaller MCS, MBS, MIFD, MBD and MID (- 3.41% to - 15.35% vs - 0.07% to - 4.32%) values than those using the same length plates without a proximal screw. CONCLUSIONS: Based on the FEA results, buttress plates can improve construct mechanics, help to resist shear force and prevent varus collapse; under the modelling conditions, the use of a proximal screw on buttress plate may be a key technical feature in improving anti-shearing ability; additionally, this screw may be essential to reduce stress and prevent re-displacement of cannulated screws and fracture fragments.


Assuntos
Fraturas do Colo Femoral , Fixação Interna de Fraturas , Fenômenos Biomecânicos , Placas Ósseas , Parafusos Ósseos , Fraturas do Colo Femoral/diagnóstico por imagem , Fraturas do Colo Femoral/cirurgia , Análise de Elementos Finitos , Humanos
11.
J Foot Ankle Surg ; 58(6): 1138-1144, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31562067

RESUMO

As the commonly used fixation strategy of medial malleolar fractures, cancellous screws (CS) have been challenged for instability, bone destruction, and metal prominence. It is still unclear whether a locking compression plate (LCP) is a better choice in such fractures. Our purpose is to compare the mechanical efficacy of LCP with traditional 4.0-mm CS for transverse, oblique, and vertical medial malleolar fractures by using finite element analysis. In this study, 3-dimensional models of the distal tibia were reconstructed from a computed tomography scan of a young healthy male adult. Conditions included 3 fracture lines at 30°, 60°, and 90°; 2 groups of fixation (LCP and CS); and 3 adduction loads of 300, 500, and 700 N applied to the medial malleolar joint surface. The proximal part of the tibia was fixed for all degrees of freedom. The fracture displacements of the LCP were smaller than those of CS (p < .05). The stiffness of the LCP constructs was much higher than that of the CS constructs, especially in the 90° fractures (490.3 versus 163.6 N/mm). The mean stress around the CS was higher than that in LCP for 60° and 90° fractures, but there was no difference for 30°. Maximal bone stress increased (19.84 to 50.86 MPa) and concentrated on cortical bone in LCP, whereas it concentrated on cancellous bone in CS. The results showed that LCP could improve stability, preventing bone destruction in oblique and vertical medial malleolar fractures. However, in transverse fractures, CS provides sufficient stability, with no need to use LCP.


Assuntos
Fraturas do Tornozelo/cirurgia , Articulação do Tornozelo/fisiopatologia , Placas Ósseas , Parafusos Ósseos , Fixação Interna de Fraturas/métodos , Imageamento Tridimensional , Tomografia Computadorizada por Raios X/métodos , Adulto , Fraturas do Tornozelo/diagnóstico , Fraturas do Tornozelo/fisiopatologia , Articulação do Tornozelo/diagnóstico por imagem , Articulação do Tornozelo/cirurgia , Fenômenos Biomecânicos , Análise de Elementos Finitos , Voluntários Saudáveis , Humanos , Masculino
12.
J Biol Chem ; 292(9): 3827-3840, 2017 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-28100770

RESUMO

Intercellular amino acid transport is essential for the growth of all multicellular organisms, and its dysregulation is implicated in developmental disorders. By an unknown mechanism, amino acid efflux is stimulated in plants by overexpression of a membrane-localized protein (GLUTAMINE DUMPER 1 (GDU1)) that requires a ubiquitin ligase (LOSS OF GDU 2 (LOG2). Here we further explore the physiological consequences of the interaction between these two proteins. LOG2 ubiquitin ligase activity is necessary for GDU1-dependent tolerance to exogenous amino acids, and LOG2 self-ubiquitination was markedly stimulated by the GDU1 cytosolic domain, suggesting that GDU1 functions as an adaptor or coactivator of amino acid exporter(s). However, other consequences more typical of a ligase-substrate relationship are observed: disruption of the LOG2 gene increased the in vivo half-life of GDU1, mass spectrometry confirmed that LOG2 ubiquitinates GDU1 at cytosolic lysines, and GDU1 protein levels decreased upon co-expression with active, but not enzymatically inactive LOG2. Altogether these data indicate LOG2 negatively regulates GDU1 protein accumulation by a mechanism dependent upon cytosolic GDU1 lysines. Although GDU1-lysine substituted protein exhibited diminished in vivo ubiquitination, overexpression of GDU1 lysine mutants still conferred amino acid tolerance in a LOG2-dependent manner, consistent with GDU1 being both a substrate and facilitator of LOG2 function. From these data, we offer a model in which GDU1 activates LOG2 to stimulate amino acid export, a process that could be negatively regulated by GDU1 ubiquitination and LOG2 self-ubiquitination.


Assuntos
Aminoácidos/química , Proteínas de Arabidopsis/metabolismo , Proteínas de Membrana/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Cromatografia Líquida , Cruzamentos Genéticos , Citosol/metabolismo , Retroalimentação Fisiológica , Homeostase , Lisina/química , Fenótipo , Domínios Proteicos , Espectrometria de Massas em Tandem , Nicotiana/genética , Ubiquitinação
13.
Plant Biotechnol J ; 16(2): 558-571, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28703450

RESUMO

Cadmium (Cd) is a widespread soil contaminant threatening human health. As an ideal energy plant, sweet sorghum (Sorghum bicolor (L.) Moench) has great potential in phytoremediation of Cd-polluted soils, although the molecular mechanisms are largely unknown. In this study, key factors responsible for differential Cd accumulation between two contrasting sweet sorghum genotypes (high-Cd accumulation one H18, and low-Cd accumulation one L69) were investigated. H18 exhibited a much higher ability of Cd uptake and translocation than L69. Furthermore, Cd uptake through symplasmic pathway and Cd concentrations in xylem sap were both higher in H18 than those in L69. Root anatomy observation found the endodermal apoplasmic barriers were much stronger in L69, which may restrict the Cd loading into xylem. The molecular mechanisms underlying these morpho-physiological traits were further dissected by comparative transcriptome analysis. Many genes involved in cell wall modification and heavy metal transport were found to be Cd-responsive DEGs and/or DEGs between these two genotypes. KEGG pathway analysis found phenylpropanoid biosynthesis pathway was over-represented, indicating this pathway may play important roles in differential Cd accumulation between two genotypes. Based on these results, a schematic representation of main processes involved in differential Cd uptake and translocation in H18 and L69 is proposed, which suggests that higher Cd accumulation in H18 depends on a multilevel coordination of efficient Cd uptake and transport, including efficient root uptake and xylem loading, less root cell wall binding, and weaker endodermal apoplasmic barriers.


Assuntos
Cádmio/metabolismo , Sorghum/metabolismo , Parede Celular/genética , Parede Celular/metabolismo , Sorghum/genética , Transcriptoma/genética
14.
Arch Biochem Biophys ; 613: 1-11, 2017 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-27983948

RESUMO

Soluble epoxide hydrolase (sEH) is an important therapeutic target of many diseases, such as chronic obstructive pulmonary disease (COPD) and diabetic neuropathic pain. It acts by hydrolyzing and thus regulating specific bioactive long chain polyunsaturated fatty acid epoxides (lcPUFA), like epoxyeicosatrienoic acids (EETs). To better predict which epoxides could be hydrolyzed by sEH, one needs to dissect the important factors and structural requirements that govern the binding of the substrates to sEH. This knowledge allows further exploration of the physiological role played by sEH. Unfortunately, a crystal structure of sEH with a substrate bound has not yet been reported. In this report, new photoaffinity mimics of a sEH inhibitor and EET regioisomers were prepared and used in combination with peptide sequencing and computational modeling, to identify the binding orientation of different regioisomers and enantiomers of EETs into the catalytic cavity of sEH. Results indicate that the stereochemistry of the epoxide plays a crucial role in dictating the binding orientation of the substrate.


Assuntos
Ácidos Araquidônicos/química , Epóxido Hidrolases/química , Ácidos Carboxílicos/química , Catálise , Domínio Catalítico , Simulação por Computador , Cristalização , Sistema Enzimático do Citocromo P-450/química , Compostos de Epóxi/química , Escherichia coli/metabolismo , Humanos , Hidrólise , Concentração Inibidora 50 , Luz , Espectrometria de Massas , Simulação de Dinâmica Molecular , Peptídeos/química , Proteínas Recombinantes/química , Solventes/química , Estereoisomerismo , Especificidade por Substrato , Tripsina/química
15.
Ecotoxicol Environ Saf ; 145: 391-397, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28759768

RESUMO

Cadmium (Cd) pollution is a worldwide environmental problem which heavily threatens human health and food security. Sorghum, as one of the most promising energy crop, has been considered to be the source of high-quality feedstock for ethanol fuel. Ninety-six sorghum genotypes were investigated under hydroponic conditions to compare their capabilities of Cd-tolerance, accumulation and translocation for their potential in remediation of Cd contamination. Different genotypes varied largely in the tolerance to Cd stress with tolerance indexes ranked from 0.107 to 0.933. Great difference was also found in Cd uptake and accumulation with concentrations ranging from 19.0 to 202.4mg/kg in shoots and 277.0-898.3mg/kg in roots. The total amounts of Cd ranked from 6.1 to 25.8µg per plant and the highest translocation factor was over 4 times higher than the lowest one. The correlation analysis demonstrated that Cd concentration in shoot reflected the ability of Cd translocation and tolerance of sorghum, and the path coefficient analysis indicated that root biomass could be taken as a biomarker to evaluate Cd extraction ability of sorghum. The results in this study can facilitate the restoring of Cd contaminated areas by sorghum.


Assuntos
Adaptação Fisiológica , Cádmio/análise , Poluentes do Solo/análise , Sorghum/metabolismo , Biodegradação Ambiental , Biocombustíveis , Biomassa , Cádmio/metabolismo , Cádmio/toxicidade , Genótipo , Humanos , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Poluentes do Solo/metabolismo , Poluentes do Solo/toxicidade , Sorghum/genética , Sorghum/crescimento & desenvolvimento , Especificidade da Espécie
16.
Surg Innov ; 24(5): 446-454, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28639848

RESUMO

The intraoperatively rotational control of femoral shaft fractures treated with a closed intramedullary interlocking nailing is a challenging problem. A novel surgical technique that includes respective insertions of guidewires into the proximal and distal femur under the guidance of a 2-dimensional fluoroscopy-based navigation system and the measurements of the intersection angle subtended by the proximal and distal guidewires with the smartphone positional software has been designed to provide intraoperatively quantitative parameters of femoral rotation deformation. The comparison of these parameters with preoperative measurement values of the contralateral intact femur on computed tomography images was used to align the proximal and distal femur fragments based on periaxial rotation. The purpose of this study was to evaluate its clinical suitability. Ten adult patients with femoral shaft fractures were attempted to correct intraoperatively femoral rotational deformity using this novel technique. The additional operation time was 20.04 ± 3.27 minutes. The angle of femoral anteversion was 20.85° ± 4.22°, 38.14° ± 19.07°, and 22.77° ± 3.38° in the contralateral intact and preoperatively and postoperatively injured femur, respectively. The mean absolute difference between both limbs was preoperatively 21.55° ± 10.14° with a statistically significant difference ( P = .005) and postoperatively 3.24° ± 1.69° with no statistically significant difference ( P = .092). Our results showed this novel technique could become an effective tool to correct intraoperatively rotational malalignment of femoral fractures.


Assuntos
Fraturas do Fêmur/cirurgia , Fêmur/cirurgia , Procedimentos Ortopédicos/métodos , Smartphone , Cirurgia Assistida por Computador/métodos , Adulto , Feminino , Fraturas do Fêmur/diagnóstico por imagem , Fraturas do Fêmur/fisiopatologia , Fêmur/diagnóstico por imagem , Fêmur/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Tomografia Computadorizada por Raios X , Adulto Jovem
17.
Plant J ; 80(4): 683-94, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25227635

RESUMO

In plants, the vascular system, specifically the phloem, functions in delivery of small RNA (sRNA) to exert epigenetic control over developmental and defense-related processes. Although the importance of systemic sRNA delivery has been established, information is currently lacking concerning the nature of the protein machinery involved in this process. Here, we show that a PHLOEM SMALL-RNA BINDING PROTEIN 1 (PSRP1) serves as the basis for formation of an sRNA ribonucleoprotein complex (sRNPC) that delivers sRNA (primarily 24 nt) to sink organs. Assembly of this complex is facilitated through PSRP1 phosphorylation by a phloem-localized protein kinase, PSRPK1. During long-distance transport, PSRP1-sRNPC is stable against phloem phosphatase activity. Within target tissues, phosphatase activity results in disassembly of PSRP1-sRNPC, a process that is probably required for unloading cargo sRNA into surrounding cells. These findings provide an insight into the mechanism involved in delivery of sRNA associated with systemic gene silencing in plants.


Assuntos
Cucurbita/genética , Proteínas de Plantas/metabolismo , RNA Interferente Pequeno , Sequência de Aminoácidos , Dados de Sequência Molecular , Floema/metabolismo , Fosforilação , Proteínas de Plantas/genética , RNA Interferente Pequeno/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Ribonucleoproteínas/metabolismo
18.
Antimicrob Agents Chemother ; 59(12): 7571-80, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26416858

RESUMO

There is growing interest in biomaterials that can cure bone infection and also regenerate bone. In this study, two groups of implants composed of 10% (wt/wt) teicoplanin (TEC)-loaded borate bioactive glass (designated TBG) or calcium sulfate (TCS) were created and evaluated for their ability to release TEC in vitro and to cure methicillin-resistant Staphylococcus aureus (MRSA)-induced osteomyelitis in a rabbit model. When immersed in phosphate-buffered saline (PBS), both groups of implants provided a sustained release of TEC at a therapeutic level for up to 3 to 4 weeks while they were gradually degraded and converted to hydroxyapatite. The TBG implants showed a longer duration of TEC release and better retention of strength as a function of immersion time in PBS. Infected rabbit tibiae were treated by debridement, followed by implantation of TBG or TCS pellets or intravenous injection with TEC, or were left untreated. Evaluation at 6 weeks postimplantation showed that the animals implanted with TBG or TCS pellets had significantly lower radiological and histological scores, lower rates of MRSA-positive cultures, and lower bacterial loads than those preoperatively and those of animals treated intravenously. The level of bone regeneration was also higher in the defects treated with the TBG pellets. The results showed that local TEC delivery was more effective than intravenous administration for the treatment of MRSA-induced osteomyelitis. Borate glass has the advantages of better mechanical strength, more desirable kinetics of release of TEC, and a higher osteogenic capacity and thus could be an effective alternative to calcium sulfate for local delivery of TEC.


Assuntos
Compostos de Boro/farmacologia , Sulfato de Cálcio/farmacologia , Portadores de Fármacos/farmacologia , Implantes de Medicamento/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Osteomielite/tratamento farmacológico , Infecções Estafilocócicas/tratamento farmacológico , Animais , Antibacterianos/farmacologia , Compostos de Boro/química , Sulfato de Cálcio/química , Modelos Animais de Doenças , Portadores de Fármacos/síntese química , Implantes de Medicamento/síntese química , Durapatita/química , Feminino , Vidro/química , Injeções Intralesionais , Staphylococcus aureus Resistente à Meticilina/crescimento & desenvolvimento , Osteomielite/microbiologia , Osteomielite/patologia , Coelhos , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/patologia , Teicoplanina/farmacologia , Tíbia/efeitos dos fármacos , Tíbia/microbiologia , Tíbia/patologia , Resultado do Tratamento
19.
BMC Plant Biol ; 15: 63, 2015 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-25848810

RESUMO

BACKGROUND: microRNAs (miRNAs) are implicated in plant development processes and play pivotal roles in plant adaptation to environmental stresses. Salicornia europaea, a salt mash euhalophyte, is a suitable model plant to study salt adaptation mechanisms. S. europaea is also a vegetable, forage, and oilseed that can be used for saline land reclamation and biofuel precursor production on marginal lands. Despite its importance, no miRNA has been identified from S. europaea thus far. RESULTS: Deep sequencing was performed to investigate small RNA transcriptome of S. europaea. Two hundred and ten conserved miRNAs comprising 51 families and 31 novel miRNAs (including seven miRNA star sequences) belonging to 30 families were identified. About half (13 out of 31) of the novel miRNAs were only detected in salt-treated samples. The expression of 43 conserved and 13 novel miRNAs significantly changed in response to salinity. In addition, 53 conserved and 13 novel miRNAs were differentially expressed between the shoots and roots. Furthermore, 306 and 195 S. europaea unigenes were predicted to be targets of 41 conserved and 29 novel miRNA families, respectively. These targets encoded a wide range of proteins, and genes involved in transcription regulation constituted the largest category. Four of these genes encoding laccase, F-box family protein, SAC3/GANP family protein, and NADPH cytochrome P-450 reductase were validated using 5'-RACE. CONCLUSIONS: Our results indicate that specific miRNAs are tightly regulated by salinity in the shoots and/or roots of S. europaea, which may play important roles in salt tolerance of this euhalophyte. The S. europaea salt-responsive miRNAs and miRNAs that target transcription factors, nucleotide binding site-leucine-rich repeat proteins and enzymes involved in lignin biosynthesis as well as carbon and nitrogen metabolism may be applied in genetic engineering of crops with high stress tolerance, and genetic modification of biofuel crops with high biomass and regulatable lignin biosynthesis.


Assuntos
Chenopodiaceae/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , MicroRNAs/genética , RNA de Plantas/genética , Tolerância ao Sal/genética , Sequência de Bases , Chenopodiaceae/efeitos dos fármacos , Sequência Conservada/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Biblioteca Gênica , Redes Reguladoras de Genes/efeitos dos fármacos , MicroRNAs/metabolismo , Anotação de Sequência Molecular , Dados de Sequência Molecular , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA de Plantas/metabolismo , Reprodutibilidade dos Testes , Tolerância ao Sal/efeitos dos fármacos , Cloreto de Sódio/farmacologia , Estatística como Assunto , Transcriptoma/genética
20.
J Exp Bot ; 66(15): 4497-510, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25956883

RESUMO

Improving crop nitrogen (N) use efficiency under salinity is essential for the development of sustainable agriculture in marginal lands. Salicornia europaea is a succulent euhalophyte that can survive under high salinity and N-deficient habitat conditions, implying that a special N assimilation mechanism may exist in this plant. In this study, phenotypic and physiological changes of S. europaea were investigated under different nitrate and NaCl levels. The results showed that NaCl had a synergetic effect with nitrate on the growth of S. europaea. In addition, the shoot nitrate concentration and nitrate uptake rate of S. europaea were increased by NaCl treatment under both low N and high N conditions, suggesting that nitrate uptake in S. europaea was NaCl facilitated. Comparative proteomic analysis of root plasma membrane (PM) proteins revealed 81 proteins, whose abundance changed significantly in response to NaCl and nitrate. These proteins are involved in metabolism, cell signalling, transport, protein folding, membrane trafficking, and cell structure. Among them, eight proteins were calcium signalling components, and the accumulation of seven of the above-mentioned proteins was significantly elevated by NaCl treatment. Furthermore, cytosolic Ca(2+) concentration ([Ca(2+)]cyt) was significantly elevated in S. europaea under NaCl treatment. The application of the Ca(2+) channel blocker LaCl3 not only caused a decrease in nitrate uptake rate, but also attenuated the promoting effects of NaCl on nitrate uptake rates. Based on these results, a possible regulatory network of NaCl-facilitated nitrate uptake in S. europaea focusing on the involvement of Ca(2+) signalling was proposed.


Assuntos
Sinalização do Cálcio/efeitos dos fármacos , Chenopodiaceae/metabolismo , Proteínas de Membrana/metabolismo , Nitratos/metabolismo , Proteínas de Plantas/metabolismo , Proteômica , Cloreto de Sódio/farmacologia , Membrana Celular/metabolismo , Raízes de Plantas/metabolismo , Plantas Tolerantes a Sal/metabolismo
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