RESUMO
The ocean serves as a repository for various types of artificial nanoparticles. Nanoplastics (NPs) and nano zinc oxide (nZnO), which are frequently employed in personal care products and food packaging materials, are likely simultaneously released and eventually into the ocean with surface runoff. Therefore, their mutual influence and shared destiny in marine environment cannot be ignored. This study examined how nanomaterials interacted and transported through sea sand in various salinity conditions. Results showed that NPs remained dispersed in brine, while nZnO formed homoaggregates. In seawater of 35 practical salinity units (PSU), nZnO formed heteroaggregates with NPs, inhibiting NPs mobility and decreasing the recovered mass percentage (Meff) from 24.52% to 12.65%. In 3.5 PSU brackish water, nZnO did not significantly aggregate with NPs, and thus barely affected their mobility. However, NPs greatly enhanced nZnO transport with Meff increasing from 14.20% to 25.08%, attributed to the carrier effect of higher mobility NPs. Cotransport from brackish water to seawater was simulated in salinity change experiments and revealed a critical salinity threshold of 10.4 PSU, below which the mobility of NPs was not affected by coexisting nZnO and above which nZnO strongly inhibited NP transport. This study highlights the importance of considering the mutual influence and shared destiny of artificial nanoparticles in the marine environment and how their interaction and cotransport are dependent on changes in seawater salinity.
Assuntos
Águas Salinas , Salinidade , Água do Mar , Poluentes Químicos da Água , Óxido de Zinco , Óxido de Zinco/química , Água do Mar/química , Águas Salinas/química , Poluentes Químicos da Água/química , Poluentes Químicos da Água/análise , Porosidade , Microplásticos , Modelos Químicos , Nanopartículas Metálicas/químicaRESUMO
Identifying the essential factors and underlying mechanisms regulating plant heat stress (HS) responses is crucial for mitigating the threat posed by HS on plant growth, development, distribution, and productivity. Here, we found that the Arabidopsis (Arabidopsis thaliana) super-killer2 (ski2) dicer-like4 (dcl4) mutant, characterized by RNA processing defects and accumulation of abundant 22-nt small interfering RNAs (siRNAs) derived from protein-coding transcripts, displayed significantly increased expression levels of HS-responsive genes and enhanced thermotolerance. These traits primarily resulted from the suppression of SMAX1-LIKE4 (SMXL4) and SMXL5, which encode two putative transcriptional regulators that belong to the SMXL protein family. While smxl4 and smxl5 single mutants were similar to wild type, the smxl4 smxl5 double mutant displayed substantially heightened seedling thermotolerance. Further investigation demonstrated that SMXL4 and SMXL5 repressed the transcription of HEAT SHOCK TRANSCRIPTION FACTOR A2 (HSFA2), encoding a master regulator of thermotolerance, independently of EAR motifs. Moreover, SMXL4 and SMXL5 interacted with HSFA1d and HSFA1e, central regulators sensing and transducing HS stimuli, and antagonistically affected their transactivation activity. In addition, HSFA2 directly bound to the SMXL4 and SMXL5 promoters, inducing their expression during recovery from HS. Collectively, our findings elucidate the role of the SMXL4/SMXL5-HSFA2 regulatory module in orchestrating plant thermotolerance under HS.
RESUMO
Polymer chain extenders, commonly used in plastic production, have garnered increasing attention due to their potential environmental impacts. However, a comprehensive understanding of their ecological risks remains largely unknown. In this study, we employed the model organism Caenorhabditis elegans to investigate toxicological profiles of ten commonly-used chain extenders. Exposure to environmentally relevant concentrations of these chain extenders (ranging from 0.1 µg L-1 to 10 mg L-1) caused significant variations in toxicity. Lethality assays demonstrated the LC50 values ranged from 92.42 µg L-1 to 1553.65 mg L-1, indicating marked differences in acute toxicity. Sublethal exposures could inhibit nematodes' growth, shorten lifespan, and induce locomotor deficits, neuronal damage, and reproductive toxicity. Molecular analyses further elucidated the involvement of the DAF-16 and SKN-1 signaling pathways, as evidenced by upregulated expression of genes including ctl-1,2,3, sod-3, gcs-1, and gst-4. It implicates these pathways in mediating oxidative stress and toxicities induced by chain extenders. Particularly, hexamethylene diisocyanate and diallyl maleate exhibited markedly high toxicity among the chain extenders, as revealed through a comparative analysis of multiple endpoints. These findings demonstrate the potential ecotoxicological risks of polymer chain extenders, and suggest the need for more rigorous environmental safety assessments.
Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Proteínas de Ligação a DNA , Fatores de Transcrição Forkhead , Transdução de Sinais , Fatores de Transcrição , Animais , Caenorhabditis elegans/efeitos dos fármacos , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Fatores de Transcrição Forkhead/metabolismo , Fatores de Transcrição Forkhead/genética , Transdução de Sinais/efeitos dos fármacos , Polímeros/toxicidade , Polímeros/química , Longevidade/efeitos dos fármacosRESUMO
This study examined the distinct effects of algae polysaccharides (AP), namely sodium alginate (SA), fucoidan (FU), and laminarin (LA), on the aggregation of nanoplastics (NP) in seawater, as well as their subsequent transport in seawater-saturated sea sand. The pristine 50 nm NP tended to form large aggregates, with an average size of approximately 934.5 ± 11 nm. Recovery of NP from the effluent (Meff) was low, at only 18.2 %, and a ripening effect was observed in the breakthrough curve (BTC). Upon the addition of SA, which contains carboxyl groups, the zeta (ζ)-potential of the NP increased by 2.8 mV. This modest enhancement of electrostatic interaction with NP colloids led to a reduction in the aggregation size of NP to 598.0 ± 27 nm and effectively mitigated the ripening effect observed in the BTC. Furthermore, SA's adherence to the sand surface and the resulting increase in electrostatic repulsion, caused a rise in Meff to 27.5 %. In contrast, the introduction of FU, which contains sulfate ester groups, resulted in a surge in ζ-potential of the NP to -27.7 ± 0.76 mV. The intensified electrostatic repulsion between NP and between NP and sand greatly increased Meff to 45.6 %. Unlike the effects of SA and FU, the addition of LA, a neutral compound, caused a near disappearance of ζ-potential of NP (-3.25 ± 0.68 mV). This change enhanced the steric hindrance effect, resulting in complete stabilization of particles and a blocking effect in the BTC of NP. Quantum chemical simulations supported the significant changes in the electrostatic potential of NP colloids induced by SA, FU and LA. In summary, the presence of AP can induce variability in the mobility of NP in seawater-saturated porous media, depending on the nature of the weak, strong, or non-electrostatic interactions between colloids, which are influenced by the structure and functionalization of the polysaccharides themselves. These findings provide valuable insights into the complex and variable behavior of NP transport in the marine environment.
Assuntos
Polissacarídeos , Água do Mar , Polissacarídeos/química , Água do Mar/química , Porosidade , Alginatos/química , Microplásticos/química , Eletricidade EstáticaRESUMO
Colloidal interactions between clay minerals and microplastics (MPs) in high salinity seawater are crucial for determining MP fate in marine environments. Montmorillonite (MMT) forms thin and pliable films that tightly cover MPs, while the thick and rigid lamellae of kaolinite (KLT) have limited contact with MPs, resulting in unstable bonding. However, a small quantity of small-sized KLT can create relatively stable heteroaggregates by embedding into the interstitial spaces of MPs. Both MMT and KLT colloids can decrease the mobility of MPs in seawater-saturated sea sand, but their breakthrough curves (BTCs) show distinct phenomena of "blocking" and "ripening", respectively. The "blocking" phenomenon occurs when flexible MMT adheres to the sand surface, depleting attachment sites quickly and inhibiting the retention of subsequent heteroaggregates of MMT-wrapped MPs. The transport of single MMT also experiences colloid competition for attachment sites, but pre-equilibration experiments reveal no competition between MMT and bare MPs for attachment sites. Instead, the attached MMT provides additional attachment sites for MPs. These results suggest that the wrapping of MPs by MMT plays a dominant role in the "blocking" of cotransport. In contrast, rigid KLT forms a three-dimensional stack on the sand surface, offering more attachment sites for subsequent MPs and heteroaggregates.
Assuntos
Bentonita , Argila , Microplásticos , Água do Mar , Poluentes Químicos da Água , Microplásticos/química , Argila/química , Porosidade , Água do Mar/química , Bentonita/química , Poluentes Químicos da Água/química , Caulim/química , Minerais/química , Coloides/químicaRESUMO
Degraded mulch pollution is of a great concern for agricultural soils. Although numerous studies have examined this issue from an environmental perspective, there is a lack of research focusing on crop-specific factors such as crop type. This study aimed to explore the correlation between meteorological and crop factors and mulch contamination. The first step was to estimate the amounts of mulch-derived microplastics (MPs) and phthalic acid esters (PAEs) during the rapid expansion period (1993-2012) of mulch usage in China. Subsequently, the Elastic Net (EN) and Random Forest (RF) models were employed to process a dataset that included meteorological, crop, and estimation data. At the national level, the RF model suggested that coldness in fall was crucial for MPs generation, while vegetables acted as a key factor for PAEs release. On a regional scale, the EN results showed that crops like vegetables, cotton, and peanuts remained significantly involved in PAEs contamination. As for MPs generation, coldness prevailed over all regions. Aridity became more critical for southern regions compared to northern regions due to solar radiation. Lastly, each region possessed specific crop types that could potentially influence its MPs contamination levels and provide guidance for developing sustainable ways to manage mulch contamination.
Assuntos
Ácidos Ftálicos , Poluentes do Solo , Ácidos Ftálicos/análise , Plásticos , Poluentes do Solo/análise , Agricultura , Solo , Verduras , Microplásticos , China , Ésteres/análiseRESUMO
Marine sedimentary environment serves as an important sink of terrigenous nanoplastics (NP) and graphene oxides (GO). In this study, we discovered that GO of varying sizes exhibited distinct binding modes with 200 nm NP in 35 practical salinity unit (PSU) seawater, resulting in varying impacts on the mobility of NP in porous media. GO-8, with a size of 8±2 nm, firmly adhered to the surface of NP and formed stable primary heterogeneous aggregates, which promoted NP mobility and increased the mass recovery of effluent (Meff) from 24.74% to 31.08%. GO-250 (246±10 nm) partly enveloped NP and only slightly increased the volume of heteroaggregates, which had minimal effect on NP transport. Conversely, GO-850 (855±55 nm) wrapped numerous NP particles to form large secondary heteroaggregates that clung to sand surfaces, providing additional attachment sites for NP, resulting in complete inhibition of NP mobility in porous media (Meff = 0%). In brackish water with 3.5 PSU, all GO-8, GO-250 and GO-850 achieved enhanced mobility of NP, with Meff increasing from 50.35% to 85.62%, 69.45% and 75.41%, respectively. The results indicate that GO size effects on NP mobility are also salinity-dependent.
Assuntos
Grafite , Pontos Quânticos , Areia , Microplásticos , Água do Mar , PorosidadeRESUMO
Trivalent chromium is generally assumed to form insoluble species, resulting in low mobility of Cr(III) in soils. Here, we report continuous distributions (0-19 m) of a high concentration of Cr(III) in the alkaline soils of a historically industrial site for producing Na2Cr2O7, CrO3, and Cr2O3, which challenges this abovementioned conventional wisdom. The thermodynamic equilibrium model showed the low possibility of Cr(III) originating from Cr(VI) reduction under the redox conditions of this study. The AF4-MALLS-ICP-MS and µ-XRF-XANES were used to identify the particle size distribution of Cr(III)-containing colloids and Cr(III) species in mobile colloids. In any soil layer, Cr(III) accounts for 71.1-94.3% of the total Cr in submicron soil colloids and is composed of submicron intrinsic Cr2O3 (55.2%-63.8%), Cr(OH)3 (0-33.0%), and Cr(III) adsorbed by ferrihydrite (0-19.0%) and clay montmorillonite (11.1%-21.1%) colloid. On the contrary, Cr(VI) was mainly distributed in bulk soil (> 2 µm) except for the topsoil, accounting for 62.6-90.0% of total Cr(VI). Organic matter content and soil texture are the most critical factors driving the mobilization of submicron colloids in soils by principal component analysis. Humic acid (HA) formed HA-corona on Cr2O3 surface and enhanced colloidal dispersion, thereby accelerating the long-distance mobilization of submicron Cr2O3 colloids in alkaline soil layers, whereas the heteroaggregation of clay colloid with Cr2O3 was only favorable for short-distance mobilization. Our findings help to re-recognize the potential migration risks of insoluble heavy metals in soils.
Assuntos
Poluentes do Solo , Solo , Argila , Cromo/análise , Substâncias Húmicas/análise , Oxirredução , Poluentes do Solo/análise , ColoidesRESUMO
We used the Illumina MiSeq platform to sequence the complete mitochondrial genome of Triplophysa jianchuanensis (Cypriniformes: Cobitidae). The mitochondrial genome of T. jianchuanensis is 16,569 bp in length, and its genetic constitution and arrangement are consistent with those of the teleost taxon, containing 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes, an origin of light-strand replication, and a control region. The overall nucleotide base composition was 28.33% A, 27.25% T, 17.77% G, and 26.65% C. Phylogenetic analysis showed that T. jianchuanensis was grouped with T. venusta. These findings are valuable for further studies on the evolution, genetic diversity, and taxonomy of Triplophysa.
RESUMO
Iron in the form of (oxyhydr)oxides plays a profound role in the (im)mobilization of heavy metals in environmental geochemical processes occurring in the soil-groundwater system. Here, the influence of saltwater intrusion on Fe-(oxyhydr)oxide-mediated (im)mobilization of Ni(II) and Zn(II) in redox-fluctuating shallow aquifers was evaluated by chemical extraction, µ-XRF-XANES analysis, and 16S rRNA high-throughput sequencing. In phreatic water, the ferrihydrite-bound Ni/Zn (Fh-Ni/Zn) in soils contributed to a 12%-17% increase in carbonate-bound Ni/Zn (Cb-Ni/Zn) due to its own reductive dissolution, whereas the illite-adsorbed Ni/Zn (illite-Ni/Zn) only contributed 6%, 7%. The relative abundance of non-salt tolerant anaerobic Herbaspirillum and iron-reducing associated Ralstonia in soils accounted for nearly 50%. During the oxidation stage, the dissolved ferrihydrite reprecipitated to bind free Ni/Zn. However, saltwater invasion strongly weakened the dissolution-precipitation of ferrihydrite by inhibiting the growth of non-salt tolerant anaerobes and iron-reducing bacteria, and highlighted the contribution of illite-Ni/Zn. Under brackish water intrusion, illite-Zn contributed to a 12% increase in Cb-Zn, thereby surpassing the contribution of Fh-Zn (8%). Under seawater invasion, the dissolution-precipitation of ferrihydrite hardly occurred and the anaerobic salt-tolerant Bacillus (> 95%) prevailed. Therefore, the increase of Cb-Ni/Zn (7%-15%) in the reduction stages was contributed by illite-Ni/Zn. However, in the oxidation stages, the carbonate replaced the original role of reprecipitated ferrihydrite to bind the free Ni/Zn in solutions. These newly recognized mechanisms may be the key to predicting the mobility of toxic elements and developing appropriate remediation techniques of permeable reactive barriers under salinity stress.
Assuntos
Água Subterrânea , Solo , Ferro/análise , Oxirredução , Óxidos , RNA Ribossômico 16S , Zinco/análiseRESUMO
The transport of microplastics (MP) or nanoplastics (NP) in porous media has been widely reported. However, their mutual interaction and effect on cotransport remain unclear. Here, we investigated the colloidal interaction between NP (50â¯nm), submicroplastics (SP, 300â¯nm), and MP (1000â¯nm) in seawater and their cotransport in saturated natural sea sands. In the single-component suspension, the recovered mass percentage (Meff) of colloids was as follows: MP (47.81%) > NP (24.18%) > SP (21.66%). SP and MP remained monodispersed. MP had the highest mobility due to the strongest electrostatic repulsion with sand surface, whereas NP formed homoaggregates and was characterized by ripening phenomena. In the SP-MP mixture, SP and MP kept independent mobility without mutual effect. In the NP-SP-MP mixture, the Meff of MP was reduced by 10% because unstable NP induced MP to form heteroaggregates with SP, which could not pass through the pores. In addition, NP attached to the sand surface could form additional retention sites to retain MP. By contrast, SP showed a 13% increase in Meff because MP became an indirect carrier of SP through the bridging of NP. Overall, this study demonstrates the dominant role of unstable NP in the cotransport of NP-SP-MP in the marine sedimentary environment.
Assuntos
Microplásticos , Plásticos , Porosidade , Areia , Água do MarRESUMO
Although the role of ethylene in tomato (Solanum lycopersicum) fruit ripening has been intensively studied, its role in tomato fruit growth remains poorly understood. In addition, the relationship between ethylene and the developmental factors NON-RIPENING (NOR) and RIPENING INHIBITOR (RIN) during ripening is under debate. Here, we carried out comprehensive genetic analyses of genome-edited mutants of tomato ETHYLENE INSENSITIVE 2 (SlEIN2), four EIN3-like genes (SlEIL1-4), and three EIN3 BINDING F-box protein genes (SlEBF1-3). Both slein2-1 and the high-order sleil mutant (sleil1 sleil2 sleil3/SlEIL3 sleil4) showed reduced fruit size, mainly due to decreased auxin biosynthesis. During fruit maturation, slein2 mutants displayed the complete cessation of ripening, which was partially rescued by slebf1 but not slebf2 or slebf3. We also discovered that ethylene directly activates the expression of the developmental genes NOR, RIN, and FRUITFULL1 (FUL1) via SlEIL proteins. Indeed, overexpressing these genes partially rescued the ripening defects of slein2-1. Finally, the signal intensity of the ethylene burst during fruit maturation was intimately connected with the progression of full ripeness. Collectively, our work uncovers a critical role of ethylene in fruit growth and supports a molecular framework of ripening control in which the developmental factors NOR, RIN, and FUL1 act downstream of ethylene signaling.
Assuntos
Solanum lycopersicum , Etilenos , Frutas , Regulação da Expressão Gênica de Plantas , Proteínas de PlantasRESUMO
This study explored the influence of fibrous and filmy polyethylene terephthalate (PET) on the transportation of nanoplastics (NPs) in saturated porous media. With the strong electrostatic repulsion, the negatively charged PET fibers (-57.5 mV) improved the transport of NPs, and the mass percentage of NPs recovered from the effluent (Meff) increased from 69.3% to 86.7%. However, PET films (-49.7 mV) showed the opposite result, that is, Meff decreased from 69.3% to 57.0%. X-ray micro-computed tomography quantitatively revealed the change in effective porosity of porous media before and after adding various PET MPs. The addition of 10 mm fiber increased the porosity from 0.39 to 0.43, whereas the addition of 10 × 10 mm2 film reduced the porosity from 0.39 to 0.29. The fiber-facilitated transport of NPs is presumably due to the formation of new connected pores between fibers and sand grains, whereas the film-inhibited transport of NPs may be due to the partial truncation of transport path of NPs. Overall, the effect of coexisting MPs on the mobility of NPs strongly relies on the shape and size of MPs.
Assuntos
Microplásticos , Plásticos , Porosidade , Areia , Microtomografia por Raio-XRESUMO
BACKGROUND: Long non-coding RNAs (lncRNAs) have been discovered to participate in various cancer developments. However, the biological function of lncRNAs associated with gastric cancer (GC) has not been fully elucidated. METHODS: Quantitative RT-PCR (qRT-PCR) assay was performed to measure lncRNAs, microRNAs (miRNAs) and message RNA (mRNA) expression. Cell Counter Kit-8 (CCK-8), clone formation, wound healing, and transwell assays were performed to investigate cell proliferation, migration, invasion, and apoptosis. Fluorescence in situ hybridization (FISH) assay was used to analyze LINC00922 in either the cytoplasm or nucleus. The potential binding among lncRNA, miRNA, and mRNA was evidenced by bioinformatics, luciferase reporter assay. Mouse-xenograft experiments were used to explore the tumorigenesis in vivo. RESULTS: LINC00922 was upregulated in GC, and high LINC00922 expression was associated with poor prognosis. Inhibition of LINC00922 suppressed GC cell proliferation, migration, invasion, and activated cell apoptosis in vitro and inhibited tumorigenesis in vivo. Besides, LINC00922 was markedly located in the cytoplasm. The mechanistic analysis demonstrated that LINC00922 acted as a sponge of miR-204-5p, thereby inhibiting the expression of the target gene-High Mobility Group AT-hook 2 (HMGA2). CONCLUSION: LINC00922 accelerated the progression of GC by miR-204-5p/HMGA2 axis. These findings support LINC00922 may be a promising option for the diagnosis and therapy of GC.
Assuntos
MicroRNAs , RNA Longo não Codificante , Neoplasias Gástricas , Animais , Carcinogênese/genética , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Hibridização in Situ Fluorescente , Camundongos , MicroRNAs/genética , MicroRNAs/metabolismo , Oncogenes , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , RNA Mensageiro/genética , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismoRESUMO
The application of nanomaterials for the removal of heavy metals has received a great deal of attention because of their high efficiencies in the environment. But it is difficult to remove multiple heavy metals simultaneously with high efficiency and stability. Herein, the core-shell structured nanoscale zero-valent iron (nZVI) encapsulated with mesoporous hydrated silica (nZVI@mSiO2) were prepared for efficient removal of heavy metals including Pb(II), Cd(II), and metalloid As(V). The material prepared uniformly with a high surface area (147.7 m2 g-1) has a nZVI core with the particle size of 20-60 nm and a modified dendritic mesoporous shell of 19 nm. 0.15 g L-1 of the optimal material exhibited an extraordinary performance on removing Cd(II) and the maximum adsorption capacity for Pb(II), Cd(II), and As(V) reached 372.2 mg g-1, 105.2 mg g-1, and 115.2 mg g-1 with a pH value at 5.0, respectively. The dissolved iron during the reaction showed that the mesoporous silica (mSiO2) played an important role in enhancing the stability of nZVI. In addition, the competitive relationship between the coexistence of two heavy metals was discussed and it was found that the removal efficiency of the material for both was improved when Cd(II) and As(V) were removed synergistically.
Assuntos
Metais Pesados , Poluentes Químicos da Água , Adsorção , Cádmio , Ferro/análise , Chumbo , Ácido Silícico , Dióxido de Silício , Poluentes Químicos da Água/análiseRESUMO
Supported alloy catalysts play a pivotal role in many heterogeneous catalytic processes of socioeconomic and environmental importance. But the controlled synthesis of supported alloy nanoparticles with consistent composition and tight size distribution remains a challenging issue. Herein, a simple yet effective method for preparation of highly dispersed, homogeneously alloyed bimetallic nanoparticles on oxide supports is reported. This method is based on solid solution of metal cations in parent oxide and strong electrostatic adsorption of a secondary metal species onto the oxide surface. In the reductive annealing process, hydrogen spillover occurs from the surface metal with a higher reduction potential to the solute metal in solid solution, leading to metal exsolution and homogenous alloying of the metals on the oxide surface. The ceria-supported Ni-Pt alloy is chosen as a model catalyst and hydrazine monohydrate decomposition is chosen as a probe reaction to demonstrate this method, and particularly its advantages over the conventional impregnation and galvanic replacement methods. A systematic application of this method using different oxides and base-noble metal pairs further elucidates its applicability and generality.
Assuntos
Nanopartículas , Óxidos , Ligas , Oxirredução , Metais , HidrogênioRESUMO
Liver fibrosis is a hallmark feature of many chronic liver diseases, which is the leading cause of morbidity and mortality worldwide. Bone marrow mesenchymal stem cells (BMSCs)-derived extracellular vesicles have been applied in many diseases. In this study, we aimed to explore the specific mechanism of extracellular vesicles from BMSCs in liver fibrosis. Bioinformatics analysis was employed to screen miRNA and its target mRNA. Sirius Red staining was carried out to examine fibrosis in liver tissues. Extracellular vesicle morphology was assessed using Transmission Electron Microscopy. Quantitative real-time PCR (qRT-PCR) and western blotting analysis were performed to detect the expressions of miR-148a-5p, Smad4, transforming growth factor-ß1 (TGF-ß1), tissue inhibitor of metalloproteinase 1 (TIMP-1), Collagen I, α-smooth muscle actin (α-SMA), and extracellular vesicle markers CD9, TSG101, CD63, and calnexin. Dual-luciferase report gene assay was used for the luciferase activity analysis. Bioinformatics analysis revealed miR-148a-5p as a regulator in liver fibrosis. QRT-PCR results indicated that miR-148a-5p was lowly expressed in both thioacetamide (TAA)-induced mice and TGF-ß1-activated hepatic stellate cells. Extracellular vesicles from miR-148a-5p enriched BMSCs downregulated the mRNA and protein levels of TGF-ß1, TIMP-1, Collagen I, and α-SMA. Further bioinformatics analysis indicated that Smad4 was related to liver fibrosis. Furthermore, the dual-luciferase report gene assay confirmed the binding relationship between miR-148a-5p and Smad4. Extracellular vesicles from miR-148a-5p enriched BMSCs attenuated hepatic fibrosis in liver fibrosis by targeting Smad4.
Assuntos
Vesículas Extracelulares , Células-Tronco Mesenquimais , MicroRNAs , Animais , Colágeno/metabolismo , Vesículas Extracelulares/genética , Vesículas Extracelulares/metabolismo , Cirrose Hepática/genética , Camundongos , MicroRNAs/genética , MicroRNAs/metabolismo , RNA Mensageiro/metabolismo , Inibidor Tecidual de Metaloproteinase-1/genética , Inibidor Tecidual de Metaloproteinase-1/metabolismo , Fator de Crescimento Transformador beta1/genética , Fator de Crescimento Transformador beta1/farmacologiaRESUMO
The emerging animal-derived biochar (AB) has shown potential for mitigating the contamination of cationic heavy metals, but has no affinity to oxyanionic metals. In this study, we developed an AB/ferrihydrite composite with a AB/Fe mass ratio of 4.0 (ABF-4) for the simultaneous adsorption of cationic Pb(II)/Cd(II) and anionic As(III). ABF-4 is a type of hydroxyapatite-rich biochar coated with nanoscale iron hydroxide aggregates. The adsorption of Pb(II), Cd(II), and As(III) on ABF-4 were 2.64, 1.55, and 0.48 mmol/g, and were 135%, 150%, and 4500% higher than those of pure AB, respectively. The enhanced adsorption of Pb(II) and Cd(II) by ABF-4 is partially due to the increase in surface area and micropores. The nano-sized ferrihydrite on ABF might help form surface complexation with As(III) and oxidize As(III) to As(V). In multimetal systems, Pb(II) and Cd(II) can promote As(III) adsorption due to the formation of NaPb4(AsO4)3 precipitate and the ternary complex of arsenite and cadmium with ABF-4, whereas Cd(II) adsorption might be inhibited because of the surface coverage of Pb5(PO4)3Cl precipitate on ABF-4. However, the coexistence of Pb in soils does not influence the immobilization of Cd. The amendment of ABF-4 can considerably decrease the availability of Pb, Cd, and As in soils from Pb-Zn smelting sites. Hence, ABF-4 is a promising multifunctional material for the potential immobilization of multicomponent heavy metals.
Assuntos
Cádmio , Poluentes do Solo , Adsorção , Animais , Carvão Vegetal , Compostos Férricos , Chumbo , Solo , Poluentes do Solo/análiseRESUMO
The development of a hook-like structure at the apical part of the soil-emerging organs has fascinated botanists for centuries, but how it is initiated remains unclear. Here, we demonstrate with high-throughput infrared imaging and 2-D clinostat treatment that, when gravity-induced root bending is absent, apical hook formation still takes place. In such scenarios, hook formation begins with a de novo growth asymmetry at the apical part of a straightly elongating hypocotyl. Remarkably, such de novo asymmetric growth, but not the following hook enlargement, precedes the establishment of a detectable auxin response asymmetry, and is largely independent of auxin biosynthesis, transport and signaling. Moreover, we found that functional cortical microtubule array is essential for the following enlargement of hook curvature. When microtubule array was disrupted by oryzalin, the polar localization of PIN proteins and the formation of an auxin maximum became impaired at the to-be-hook region. Taken together, we propose a more comprehensive model for apical hook initiation, in which the microtubule-dependent polar localization of PINs may mediate the instruction of growth asymmetry that is either stochastically taking place, induced by gravitropic response, or both, to generate a significant auxin gradient that drives the full development of the apical hook.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Hipocótilo/metabolismo , Ácidos Indolacéticos/metabolismoRESUMO
In this work, the mechanism of Pb(II)-mediated precipitation transformation to improve the removal of Cr(VI)-oxyanion on biogenic hydroxyapatite (BHAp) were investigated. The Pb(II)-preloading formed pyromorphite [Pb5(PO4)3Cl] precipitate on the BHAp surface (Pb@BHAp), thus causing an increase of 2.2 times in the uptake of Cr(VI) by Pb@BHAp at pH of 2.4. It was primarily due to the dissolution of Pb5(PO4)3Cl accompanied with the release of Pb(II), resulting in the rapid formation of crocoite (PbCrO4). Although the Ksp of Pb5(PO4)3Cl was approximately 23 orders of magnitude lower than that of PbCrO4, Pb(II)-mediated precipitation transformation could still occur. XRD and SEM-EDX analyses demonstrated that the process was a time-dependent that included rapid crystal precipitation in the initial 10 min and subsequent precipitate accumulation for several hours. The Pb(II) released from the dissolution of Pb5(PO4)3Cl was immediately immobilized by Cr(VI); therefore, it did not cause any retention risk of Pb(II) in the solution. Furthermore, a small quantity of Cr(VI) could be reduced to Cr(III) by BHAp, and Cr(III) could enter into the BHAp lattice for the exchange of Ca(II). This study provides a new insight into the resource utilization of Pb-bearing BHAp and a potential method for the successive removal of Pb(II) and Cr(VI).