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Antibiotic resistance genes (ARGs) as an emerging contaminant have attracted much attention for their transfer in agricultural ecosystems. Meanwhile, graphene oxide (GO), due to its high adsorption capacity and antibacterial properties, poses potential environmental ecological risks to the occurrence of ARGs, bacteria, and plant physiological ecology. However, the impact and mechanism of GO on the transfer of ARGs in host plants remain unclear. Therefore, this study selected rice as the research object and inoculated Bacillus subtilis carrying ARGs to investigate the influence of GO on the migration of ARGs into rice and its microbiological mechanism. The study found that GO had a certain inhibitory effect on the transfer of ARGs in rice. Although GO reduced the rhizosphere pH in rice, leading to a transition in endophytic bacteria from dominance by Burkholderia to dominance by Gordonia, this process did not directly affect the transfer of ARGs in rice. Further analysis of bacterial interactions revealed that GO could inhibit the transfer of ARGs in rice by reducing the network complexity of endophytic bacteria. Additionally, GO inhibited the formation of endophytic bacterial biofilms and mobile elements, which might affect ARGs' migration in rice. This study elucidated the key microbiological ecological processes of GO on the transfer of ARGs in rice, providing fundamental information for the ecological risk assessment of GO.
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INTRODUCTION: There is a correlation between molar incisor hypomineralization (MIH) and hypomineralized second primary molars (HSPM), but this relationship has not been definitively confirmed. The purpose of this systematic review and meta-analysis was to reevaluate whether children with HSPM are more affected by MIH than non-HSPM children. METHODS: A systematic search was conducted in four databases (PubMed, Embase, Web of Science and the Cochrane Library) for literature, published up to December 2022. Two independent reviewers conducted the study search and screening, quality assessment, and data extraction according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement. The risk of bias assessment of all included cohort studies and case-control studies were assessed by the Newcastle-Ottawa Scale (NOS), and cross-sectional studies were assessed using the Agency for Healthcare Research Quality (AHRQ) scale. RevMan 5.4 software was used for all data analyses, with odds ratios (ORs) and 95% confidence intervals (CIs) as the effect measures. Sensitivity and subgroup analyses were conducted to identify the potential sources of heterogeneity among the studies. Publication bias was tested and corrected by funnel plots and Egger's test. Trial sequential analysis (TSA) was performed using TSA 0.9.5.10 Beta software to control for type-1 and type-2 errors. RESULTS: A total of 12 studies involving 8,944 children were included in this meta-analysis. Compared with the non-HSPM group, the HSPM group had an increased likelihood of MIH (OR = 10.90, 95% CI = 4.59-25.89, P <0.05). All the included studies were of moderate-to-high quality. TSA and sensitivity analyses suggested the robustness of this outcome. CONCLUSION: This systematic review demonstrated a certain correlation between HSPM and MIH, suggesting that HSPM can play a predictive role in the occurrence of MIH. Further high-quality, multicenter and large-sample longitudinal studies are highly recommended.
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Biological nitrogen fixation catalyzed by nitrogenase contributes greatly to the global nitrogen cycle. Nitrogenase expression is subject to regulation in response to nitrogen availability. However, the mechanism through which the transcriptional activator NifA regulates nitrogenase expression by interacting with PII nitrogen regulatory proteins remains unclear in diazotrophic proteobacteria lacking NifL. Here, we demonstrate that in Rhodopseudomonas palustris grown with ammonium, NifA bound deuridylylated PII proteins to form an inactive NifA-PII complex, thereby inhibiting the expression of nitrogenase. Upon nitrogen limitation, the dissociation of uridylylated PII proteins from NifA resulted in the full restoration of NifA activity, and, simultaneously, uridylylation of the significantly up-regulated PII protein GlnK2 led to the increased expression of NifA in R. palustris. This insight into how NifA interacts with PII proteins and controls nitrogenase expression sets the stage for creating highly efficient diazotrophs, reducing the need for energy-intensive chemical fertilizers and helping to diminish carbon emissions.
Subject(s)
Ammonium Compounds , Bacterial Proteins , Nitrogen Fixation , PII Nitrogen Regulatory Proteins , Transcription Factors , Bacterial Proteins/metabolism , Bacterial Proteins/genetics , Ammonium Compounds/metabolism , PII Nitrogen Regulatory Proteins/metabolism , PII Nitrogen Regulatory Proteins/genetics , Transcription Factors/metabolism , Transcription Factors/genetics , Gene Expression Regulation, Bacterial , Nitrogenase/metabolism , Rhodopseudomonas/metabolism , Rhodopseudomonas/geneticsABSTRACT
Heavy metal contamination in soils poses a significant environmental threat to human health. This study examines the effects of the chiral herbicide napropamide (NAP) on Arabidopsis thaliana, focusing on growth metrics and cadmium (Cd) accumulation. R-NAP does not adversely affect plant growth compared to the control, whereas S-NAP significantly reduces root length and fresh weight. Notably, R-NAP markedly increases Cd accumulation in the shoots, exceeding levels observed in the control and S-NAP. This increase coincides with reduced photosynthetic efficiency. Noninvasive electrode techniques reveal a higher net Cd absorption flux in the root mature zone under R-NAP than S-NAP, although similar to the control. Transcriptomic analysis highlights significant stereoisomer differences in Cd transporters, predominantly under R-NAP treatment. SEM and molecular docking simulations support that R-NAP primarily upregulates transporters such as HMA4. The results suggest careful management of herbicides like R-NAP in contaminated fields to avoid excessive heavy metal buildup in crops.
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BACKGROUND: In the current context of ageing, the field of smart elderly care has gradually developed, contributing to the promotion of health among older adults. While the positive impact on health has been established, there is a scarcity of research examining its impact on the quality of life (QoL). This study aims to investigate the mediating role of social support in the relationship between smart elderly care and QoL among older adults. METHODS: A total of 1313 older adults from Zhejiang Province, China, participated in the study. Questionnaires were used to collect data on participants' basic demographic information, smart elderly care, social support, and QoL. The descriptive analyses of the demographic characteristics and correlation analyses of the three variables were calculated. Indirect effects were tested using bootstrapped confidence intervals (CI). RESULTS: The analysis revealed a positive association between smart elderly care and social support (ß = 0.42, p < 0.01), as well as a positive correlation between social support and QoL (ß = 0.65, p < 0.01). Notably, social support emerged as an important independent mediator (effect size = 0.28, 95% bootstrap CI 0.24 to 0.32) in the relationship between smart elderly care and QoL. CONCLUSIONS: The results of this study underscore the importance of promoting the utilization of smart elderly care and improving multi-faceted social support for older adults, as these factors positively contribute to the overall QoL.
Subject(s)
Quality of Life , Social Support , Humans , Aged , Quality of Life/psychology , Female , Male , Aged, 80 and over , China/epidemiology , Surveys and Questionnaires , Middle Aged , Cross-Sectional Studies , Health Services for the AgedABSTRACT
Pancreatic cancer (PC) is a lethal disease and associated with metabolism dysregulation. Nogo-B is related to multiple metabolic related diseases and types of cancers. However, the role of Nogo-B in PC remains unknown. In vitro, we showed that cell viability and migration was largely reduced in Nogo-B knockout or knockdown cells, while enhanced by Nogo-B overexpression. Consistently, orthotopic tumor and metastasis was reduced in global Nogo knockout mice. Furthermore, we indicated that glucose enhanced cell proliferation was associated to the elevation expression of Nogo-B and nuclear factor κB (NF-κB). While, NF-κB, glucose transporter type 1 (GLUT1) and sterol regulatory element-binding protein 1 (SREBP1) expression was reduced in Nogo-B deficiency cells. In addition, we showed that GLUT1 and SREBP1 was downstream target of NF-κB. Therefore, we demonstrated that Nogo deficiency inhibited PC progression is regulated by the NF-κB/GLUT1 and SREBP1 pathways, and suggested that Nogo-B may be a target for PC therapy.
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Benzotriazole ultraviolet (UV) stabilizers (BUVs) have emerged as significant environmental contaminants, frequently detected in various ecosystems. While the toxicity of BUVs to aquatic organisms is well-documented, studies on their impact on plant life are scarce. Plants are crucial as they provide the primary source of energy and organic matter in ecosystems through photosynthesis. This study investigated the effects of UV-328 (2-(2-hydroxy-4',6'-di-tert-amylphenyl) benzotriazole) on plant growth indices and photosynthesis processes, employing conventional physiological experiments, RNA sequencing (RNA-seq) analysis, and computational methods. Results demonstrated a biphasic response in plant biomass and the maximum quantum yield of PS II (Fv/Fm), showing improvement at a 50 µM UV-328 treatment but reduction under 150 µM UV-328 exposure. Additionally, disruption in thylakoid morphology was observed at the higher concentration. RNA-seq and qRT-PCR analysis identified key differentially expressed genes (light-harvesting chlorophyll-protein complex â subunit A4, light-harvesting chlorophyll b-binding protein 3, UVR8, and curvature thylakoid 1 A) related to photosynthetic light harvesting, UV-B sensing, and chloroplast structure pathways, suggesting they may contribute to the observed alterations in photosynthesis activity induced by UV-328 exposure. Molecular docking analyses further supported the binding affinity between these proteins and UV-328. Overall, this study provided comprehensive physiological and molecular insights, contributing valuable information to the evaluation of the potential risks posed by UV-328 to critical plant physiological processes.
Subject(s)
Photosynthesis , Triazoles , Ultraviolet Rays , Photosynthesis/drug effects , Photosynthesis/radiation effects , Triazoles/toxicity , Molecular Docking Simulation , Gene Expression Regulation, Plant/drug effects , Gene Expression Regulation, Plant/radiation effects , Arabidopsis/radiation effects , Arabidopsis/drug effects , Arabidopsis/metabolism , Arabidopsis/growth & developmentABSTRACT
PURPOSE: The aim of this study was to explore the association of cardiac CT-based left atrium (LA) structural and functional parameters and left atrial epicardial adipose tissue (LA-EAT) parameters with postablation atrial fibrillation (AF) recurrence within 2 years. MATERIALS AND METHODS: Contrast-enhanced cardiac CT images of 286 consecutive AF patients (median age: 65 y; 97 females) who underwent initial ablation between June 2018 and June 2020 were retrospectively analyzed. Structural and functional parameters of LA, including maximum and minimum volume and ejection fraction of LA and left atrial appendage (LAA), and LA-EAT volume, were measured. The body surface area indexed maximum and minimum volume of LA (LAVImax, LAVImin) and LAA (LAAVImax, LAAVImin), and LA-EAT volume index (LA-EATVI) were calculated. Independent predictors of AF recurrence were determined using Cox regression analysis. The clinical predictors were added to the imaging predictors to build a combined model (clinical+imaging). The predictive performance of the clinical, imaging, and combined models was assessed using the area under the receiver operating characteristics curve (AUC). RESULTS: A total of 108 (37.8%) patients recurred AF within 2 years after ablation at a median follow-up of 24 months (IQR=11, 32). LA and LAA size and LA-EAT volume were significantly increased in patients with AF recurrence (P<0.05). After the multivariable regression analysis, LA-EATVI, LAAVImax, female sex, AF duration, and stroke history were independent predictors for AF recurrence. The combined model exhibited superior predictive performance compare to the clinical model (AUC=0.712 vs. 0.641, P=0.023) and the imaging model (AUC=0.712 vs. 0.663, P=0.018). CONCLUSION: Cardiac CT-based LA-EATVI and LAAVImax are independent predictors for postablation AF recurrence within 2 years and may provide a complementary value for AF recurrence risk assessment.
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Exogenous abscisic acid (ABA) presents a novel approach to mitigate heavy metal (HM) accumulation in plants, yet its efficacy against multiple HMs and potential enhancement methods remain underexplored. In this study, we demonstrated that the exogenous ABA application simultaneously decreased Zn, Cd and Ni accumulation by 22-25 %, 27-39 % and 60-62 %, respectively, in wild-type (WT) Arabidopsis. Conversely, ABA reduced Pb in shoots but increased its root concentration. ABA application also modulated the expression of HM uptake genes, inhibiting IRT1, NRAMP1, NRAMP4, and HMA3, and increasing ZIP1 and ZIP4 expressions. Further analysis revealed that overexpressing the ABA-importing transporter (AIT1) in plants intensified the reduction of Cd, Zn, and Ni, compared to WT. However, the inhibitory effect of exogenous ABA on Pb accumulation was mitigated in shoots with higher AIT1 expression. Furthermore, HMs-induced growth inhibition and the damage to photosynthesis were also alleviated with ABA treatment. Conclusively, AIT1's synergistic effect with ABA effectively reduces Cd, Zn and Ni accumulation, offering a synergistic approach to mitigate HM stress in plants.
Subject(s)
Abscisic Acid , Arabidopsis Proteins , Arabidopsis , Metals, Heavy , Abscisic Acid/metabolism , Arabidopsis/drug effects , Arabidopsis/metabolism , Arabidopsis/genetics , Arabidopsis Proteins/metabolism , Arabidopsis Proteins/genetics , Gene Expression Regulation, Plant/drug effects , Metals, Heavy/metabolism , Metals, Heavy/toxicity , Plant Growth Regulators/pharmacology , Plant Growth Regulators/metabolism , Plant Roots/metabolism , Plant Roots/drug effects , Plant Shoots/metabolism , Plant Shoots/drug effects , Plants, Genetically Modified/metabolism , Plants, Genetically Modified/genetics , Soil Pollutants/toxicity , Soil Pollutants/metabolismABSTRACT
Infection and chronic inflammation caused by oxidative stress are major challenges in chronic wound healing. Preparing a simple, efficient hydrogel with reactive oxygen-scavenging properties for chronic wound repair is a promising strategy. Herein, we report an injectable, self-repairing hydrogel with antioxidant and antibacterial properties that can be used to regenerate diabetic wounds. Hydrogels are prepared by coordination crosslinking of gelatin (Gel), a natural biopolymer derived from collagen, with Zr4+. Because of the dynamic properties of metal ion coordination bonds and the bactericidal effect of Zr4+, the obtained coordination hydrogels exhibit self-healing, injectable, and antibacterial properties. The plant polyphenol "proanthocyanidins," which has reactive oxygen-scavenging and anti-inflammatory effects, was simultaneously loaded into the coordination hydrogel during cross-linking. We obtained a versatile hydrogel that is easy to prepare, resistant to mechanical irritation, and antioxidant, and antibacterial in vitro. We further demonstrated that the injectable self-healing hydrogels could effectively repair diabetic skin wounds and accelerate collagen deposition and wound healing. This study shows that the multifunctional antioxidant hydrogel has great potential in developing multifunctional biomaterials for chronic wound healing.
Subject(s)
Diabetes Mellitus , Proanthocyanidins , Prunella , Hydrogels/pharmacology , Antioxidants/pharmacology , Zirconium , Acceleration , Anti-Bacterial Agents/pharmacology , Oxygen , CollagenABSTRACT
OBJECTIVE: This study aimed to describe the association between empathy and residents' clinical performance and investigate whether work-related perception mediates this relationship. METHODS: A multi-center cross-sectional study was conducted, including 1160 residents from 10 cities in Liaoning Province between March and October 2020. The participants completed various self-reported questionnaires regarding demographic characteristics, work-related perceptions, self-perceived clinical performance, and empathy. The relationships among empathy, work-related perception, and self-perceived clinical performance were examined using a structural equation model (SEM). RESULTS: Of the 1160 residents, 961 (82.8 %) completed the questionnaires. The SEM path analysis showed that the direct effect of empathy on self-perceived clinical performance was significant and positive (ß = 0.34, P < 0.001). There existed significant effects of empathy on work-related perception (ß = 0.26, P < 0.001) and work-related perception on performance (ß = 0.31, P < 0.001). The path coefficients of empathy concerning self-perceived clinical performance decreased significantly (ß = 0.26, P < 0.001) when work-related perception was modeled as a mediator. The bias-corrected and accelerated bootstrap test revealed that work-related perception significantly mediated the relationship between empathy and self-perceived clinical performance (a*b = 0.08, BCa 95 % CI: 0.05-0.13). However, the correlation between the sub-scales of empathy and the items of self-perceived clinical performance was not substantial, even if most of them were statistically significant. The final SEM produced a good fit to the sample data, with CMIN/DF = 2.07 (P < 0.001), CFI = 0.99, GFI = 0.99, AGFI = 0.98, TLI = 0.98, NFI = 0.97, RMSEA (90 % CI) = 0.033 (0.017, 0.049), and SRMR = 0.024. CONCLUSION: Empathy might significantly affect self-perceived clinical performance both directly and indirectly through the mediating role of work-related perception. PRACTICE IMPLICATIONS: Efforts to improve clinical performance among residents might benefit from interventions for cultivating empathy and practices for improving work-related perceptions of residents.
Subject(s)
Clinical Competence , Empathy , Internship and Residency , Humans , China , Cross-Sectional Studies , Self Report , Surveys and QuestionnairesABSTRACT
Previously, a novel Corynebacterium glutamicum strain for the de novo biosynthesis of tailored poly-γ-glutamic acid (γ-PGA) has been constructed by our group. The strain was based on the γ-PGA synthetase complex, PgsBCA, which is the only polyprotein complex responsible for γ-PGA synthesis in Bacillus spp. In the present study, PgsBCA was reconstituted and overexpressed in C. glutamicum to further enhance γ-PGA synthesis. First, we confirmed that all the components (PgsB, PgsC, and PgsA) of γ-PGA synthetase derived from B. licheniformis are necessary for γ-PGA synthesis, and γ-PGA was detected only when PgsB, PgsC, and PgsA were expressed in combination in C. glutamicum. Next, the expression level of each pgsB, pgsC, and pgsA was tuned in order to explore the effect of expression of each of the γ-PGA synthetase subunits on γ-PGA production. Results showed that increasing the transcription levels of pgsB or pgsC and maintaining a medium-level transcription level of pgsA led to 35.44% and 76.53% increase in γ-PGA yield (γ-PGA yield-to-biomass), respectively. Notably, the expression level of pgsC had the greatest influence (accounting for 68.24%) on γ-PGA synthesis, followed by pgsB. Next, genes encoding for PgsC from four different sources (Bacillus subtilis, Bacillus anthracis, Bacillus methylotrophicus, and Bacillus amyloliquefaciens) were tested in order to identify the influence of PgsC-encoding orthologues on γ-PGA production, but results showed that in all cases the synthesis of γ-PGA was significantly inhibited. Similarly, we also explored the influence of gene orthologues encoding for PgsB on γ-PGA production, and found that the titer increased to 17.14 ± 0.62 g/L from 8.24 ± 0.10 g/L when PgsB derived from B. methylotrophicus replaced PgsB alone in PgsBCA from B. licheniformis. The resulting strain was chosen for further optimization, and we achieved a γ-PGA titer of 38.26 g/L in a 5 L fermentor by optimizing dissolved oxygen level. Subsequently, by supplementing glucose, γ-PGA titer increased to 50.2 g/L at 48 h. To the best of our knowledge, this study achieved the highest titer for de novo production of γ-PGA from glucose, without addition of L-glutamic acid, resulting in a novel strategy for enhancing γ-PGA production.
Subject(s)
Corynebacterium glutamicum , Fermentation , Corynebacterium glutamicum/genetics , Corynebacterium glutamicum/metabolism , Glutamic Acid , Polyglutamic Acid/genetics , Ligases/metabolism , Glucose/metabolismABSTRACT
Treating the most widespread complication of diabetes: diabetic wounds poses a significant clinical obstacle due to the intricate nature of wound healing in individuals with diabetes. Here a novel approach is proposed using easily applicable injectable gelatin/metal/tea polyphenol double nanonetworks, which effectively remodel the wound microenvironment and accelerates the healing process. The gelatin(Gel) crosslink with metal ions (Zr4+ ) through the amino acids, imparting advantageous mechanical properties like self-healing, injectability, and adhesion. The nanonetwork's biological functions are further enhanced by incorporating the tea polyphenol metal nanonetwork through in situ doping of the epigallocatechin gallate (EGCG) with great antibacterial, self-healing, antioxidant, and anticancer capabilities. The in vitro and in vivo tests show that this double nanonetworks hydrogel exhibits faster cell migration and favorable anti-inflammatory and antioxidant properties and can greatly reshape the microenvironment of diabetic wounds and accelerate the wound healing rate. In addition, this hydrogel is completely degraded after subcutaneous injection for 7 days, with nondetectable cytotoxicity in H&E staining of major mice organs and the serum level of liver function indicators. Considering the above-mentioned merits of this hydrogel, it is believed that the injectable gelatin/metal/tea polyphenol double nanonetworks have broad biomedical potential, especially in diabetic wound repair and tissue engineering.
Subject(s)
Diabetes Mellitus , Gelatin , Animals , Mice , Antioxidants , Hydrogels , Metals , Polyphenols , Wound Healing , TeaABSTRACT
Soil heavy metal contamination and its enrichment in the edible parts of crops have gained global concern. In this study, a compound bacterial agent possessing the ability to produce the plant hormone, abscisic acid (ABA), was applied to contaminated farmland in Hunan province. Its application reduced the concentration of Cd in radish, cabbage, mustard, and lettuce by 15-144%. Accordingly, the Cd contents in these vegetables were found to be below the maximum limits set by GB 2762-2017. Meanwhile, bacteria agents also led to a significant increase in crops yield by 45-82%. Furthermore, the nutritional indices, including soluble sugar and soluble protein increased by 18-66%, as well as the antioxidant indices, including total phenolic, ascorbate content, and DPPH capacity, enhanced by 12-76%, 10-49% and 50-140%, respectively. In conclusion, the use of ABA-producing bacteria is anticipated to be a novel approach for the safe use of soil with moderate and low pollution.
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Cadmium (Cd) causes severe toxicity in plants. However, the molecular mechanisms underlying plant resistance to Cd in relation to nitrogen (N) supply remain unclear. The non-symbiotic hemoglobin gene Hb1 plays an important role in scavenging nitric oxide (NO) in plants. In this study, there was no differential effect of Cd on the biomass of wild-type (WT) and AHb1-overexpressing (H7) plants when NH4+-N was used as a nitrogen source. However, under NO3--N conditions, Cd exerted less biomass stress on AHb1-silenced (L3) plants and more stress on H7 plants than on WT plants. The Cd tolerance index followed the order: L3 > WT > H7. However, there was no difference in Cd concentrations in the roots or shoots of the WT, L3, and H7 plants, indicating that differences in AHb1 expression were unrelated to Cd uptake. Further investigation showed that Cd exposure enhanced H2O2 accumulation and aggravated oxidative damage in H7 plants. The application of an NO donor effectively reversed growth inhibition, H2O2 burst, and oxidative stress induced by Cd in H7 plants. Thus, we suggest that NO3--induced AHb1 expression suppresses Cd-induced NO production in plants, increasing the ROS burst and exacerbating Cd toxicity.
Subject(s)
Cadmium , Nitrates , Cadmium/toxicity , Hydrogen Peroxide , Plant Physiological Phenomena/drug effectsABSTRACT
Microbial-assisted phytoremediation has great potential to improve the efficiency of phytoremediation in heavy metal (HM)-contaminated soils. In this study, the synergistic effects of rhamnolipids and the abscisic acid (ABA)-metabolizing bacterium Rhodococcus qingshengii on the phytoremediation efficiency of Indian mustard (Brassica juncea) in HM-contaminated soils were investigated. The Cd, Zn, and Pb contents in plants treated with a combination of rhamnolipids and R. qingshengii were 48.4-77.1 %, 14.6-40.4 %, and 16.1-20.0 % higher, respectively, than in those treated with R. qingshengii alone, and 42.8-59.2 %, 13.1-48.2 %, and 7.3-67.5 % higher, respectively, than in those treated with rhamnolipids alone. In addition, the bioconcentration factors of each metal were improved, and the biomass further increased by 36.6-65.7 % compared to that of single treatments. Pearson's correlation analysis showed that rhamnolipids and R. qingshengii enhanced the accumulation of HMs in B. juncea by activating the available forms of HMs in the soil and regulating the ABA and indole-3-acetic acid in plants, respectively. The structural equation model indicated that R. qingshengii had a larger path coefficient than rhamnolipids in terms of HM content and plant biomass, suggesting that R. qingshengii may have a greater contribution to promoting the extraction of HMs from the soil under synergistic conditions. In conclusion, the combination of rhamnolipids and R. qingshengii has great potential to enhance the phytoremediation efficiency of hyperaccumulating plants in HM-contaminated soils.
Subject(s)
Metals, Heavy , Soil Pollutants , Biodegradation, Environmental , Abscisic Acid/analysis , Metals, Heavy/analysis , Bacteria , Soil/chemistry , Soil Pollutants/analysis , Cadmium/analysisABSTRACT
Long-term inhalation of silica nanoparticles (SiNPs) can induce pulmonary fibrosis (PF), nevertheless, the potential mechanisms remain elusive. Herein, we constructed a three-dimensional (3D) co-culture model by using Matrigel to investigate the interaction among different cells and potential regulatory mechanisms after SiNPs exposure. Methodologically, we dynamically observed the changes in cell morphology and migration after exposure to SiNPs by co-culturing mouse monocytic macrophages (RAW264.7), human non-small cell lung cancer cells (A549), and medical research council cell strain-5 (MRC-5) in Matrigel for 24 h. Subsequently, we detected the expression of nuclear factor kappa B (NF-κB), inflammatory factor and epithelial-mesenchymal transition (EMT) markers. The results showed that SiNPs produced toxic effects on cells. In the 3D co-culture state, the cell's movement velocity and displacement increased, and the cell migration ability was enhanced. Meanwhile, the expression of inflammatory factor tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) were upregulated, the epithelial marker E-cadherin (E-cad) was downregulated, the mesenchymal marker N-cadherin (N-cad) and myofibroblast marker alpha-smooth muscle actin (α-SMA) expression were upregulated, while NF-κB expression was also upregulated after SiNPs exposure. We further found that cells were more prone to transdifferentiate into myofibroblasts in the 3D co-culture state. Conversely, utilizing the NF-κB-specific inhibitor BAY 11-7082 effectively downregulated the expression of TNF-α, IL-6, interleukin-1ß (IL-1ß), N-cad, α-SMA, collagen-I (COL I), and fibronectin (FN), the expression of E-cad was upregulated. These findings suggest that NF-κB is involved in regulating SiNPs-induced inflammatory, EMT, and fibrosis in the 3D co-culture state.
Subject(s)
Epithelial-Mesenchymal Transition , Fibrosis , Lung Diseases , Nanoparticles , Silicon Dioxide , Animals , Humans , Mice , Carcinoma, Non-Small-Cell Lung , Coculture Techniques , Epithelial-Mesenchymal Transition/immunology , Fibrosis/etiology , Fibrosis/immunology , Interleukin-6 , Lung Neoplasms , Nanoparticles/toxicity , NF-kappa B/metabolism , Silicon Dioxide/toxicity , Tumor Necrosis Factor-alpha/metabolism , Lung Diseases/etiology , Lung Diseases/immunologyABSTRACT
Phytoremediation is an environment-friendly approach regarded as a potential candidate for remediating heavy metal (HM)-contaminated soils. However, the low efficacy of phytoremediation is a major limitation that hampers its large-scale application. Therefore, developing strategies to enhance phytoremediation efficacy for contaminated soils is crucial. Plant growth-promoting rhizobacteria (PGPR) considerably contribute to phytoremediation intensification. To improve the efficiency of plant-microbe symbiosis for remediation, the mechanisms underlying PGPR-stimulated HM accumulation and tolerance in plants should be comprehensively understood. This review focuses on hyperaccumulators, PGPR, and the mechanisms by which PGPR enhance phytoremediation from four aspects: providing nutrients to plants, secreting plant hormones and specific enzymes, inducing systemic resistance, and altering the bioavailability of HMs in soils. It also provides a theoretical and technical basis for future research on PGPR synergism in promoting the phytoextraction efficiency in HM-contaminated soils.
Subject(s)
Metals, Heavy , Soil Pollutants , Biodegradation, Environmental , Soil Pollutants/analysis , Plant Development , Soil , PlantsABSTRACT
[This corrects the article DOI: 10.3389/fendo.2022.1041555.].
ABSTRACT
Bacterial-assisted phytoextraction is an attractive strategy to enhance the phytoremediation efficiency of heavy metal (HM)-contaminated soils. In the present study, we investigated the synergistic effects of N fertilizers and abscisic acid (ABA)-catabolizing bacteria on the HM (Cd, Zn, and Pb) phytoremediation efficiency of Brassica juncea L. (B. juncea). Compared with Rhodococcus qingshengii (R. qingshengii) alone, urea, ammoniumnitrogen (NH4+-N), and nitratenitrogen (NO3--N) fertilizers combined with R. qingshengii increased HM concentrations in B. juncea by 13.8 %-48.2 %, 44.2 %-54.4 %, and 59.4 %-113.6 %, respectively, and enhanced the biomass of B. juncea by 7.7 %-38.8 %, 10.9 %-29.5 %, and 19.9 %-46.8 %, respectively. Consequently, the bioconcentration factor increased by 3.4 %-30.9 % and the phytoextraction rate increased by 18.5 %-98.7 %. Treatment with NO3--N showed the most significant effect. In structural equation modeling, R. qingshengii inoculation showed greater path coefficients with soil pH and ABA and indoleacetic acid concentrations of B. juncea than N fertilization, indicating that R. qingshengii contributed more to HM extraction efficiency than N fertilizers. Additionally, differences in the extraction rates of Cd, Zn, and Pb from B. juncea were reduced following N fertilization. In summary, synergistic R. qingshengii inoculation and N fertilization have substantial potential to enhance phytoremediation efficiency. Combined application of R. qingshengii and NO3--N fertilizers is recommended.