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In eukaryotic cells, organelle biogenesis is pivotal for cellular function and cell survival. Chloroplasts are unique organelles with a complex internal membrane network. The mechanisms of the migration of imported nuclear-encoded chloroplast proteins across the crowded stroma to thylakoid membranes are less understood. Here, we identified two Arabidopsis ankyrin-repeat proteins, STT1 and STT2, that specifically mediate sorting of chloroplast twin arginine translocation (cpTat) pathway proteins to thylakoid membranes. STT1 and STT2 form a unique hetero-dimer through interaction of their C-terminal ankyrin domains. Binding of cpTat substrate by N-terminal intrinsically disordered regions of STT complex induces liquid-liquid phase separation. The multivalent nature of STT oligomer is critical for phase separation. STT-Hcf106 interactions reverse phase separation and facilitate cargo targeting and translocation across thylakoid membranes. Thus, the formation of phase-separated droplets emerges as a novel mechanism of intra-chloroplast cargo sorting. Our findings highlight a conserved mechanism of phase separation in regulating organelle biogenesis.
Assuntos
Arabidopsis/metabolismo , Transporte Proteico/fisiologia , Sistema de Translocação de Argininas Geminadas/metabolismo , Proteínas de Cloroplastos/metabolismo , Cloroplastos/metabolismo , Membranas Intracelulares/metabolismo , Proteínas de Membrana/metabolismo , Biogênese de Organelas , Organelas/metabolismo , Transição de Fase , Proteínas de Plantas/metabolismo , Tilacoides/metabolismo , Sistema de Translocação de Argininas Geminadas/fisiologiaRESUMO
The biogenesis of functional forms of chloroplast ribosomal RNAs (rRNAs) is crucial for the translation of chloroplast mRNAs into polypeptides. However, the molecular mechanisms underlying the proper processing and maturation of chloroplast rRNA species are poorly understood. Through a genetic approach, we isolated and characterized an Arabidopsis mutant, α1-4, harboring a missense mutation in the plastid chaperonin-60α1 gene. Using allelism tests and transgenic manipulation, we determined functional redundancy among ptCPN60 subunits. The ptCPN60α1S57F mutation caused specific defects in the formation of chloroplast rRNA species, including 23S, 5S, and 4.5S rRNAs, but not 16S rRNAs. Allelism tests suggested that the dysfunctional ptCPN60α1S57F competes with other members of the ptCPN60 family. Indeed, overexpression of the ptCPN60α1S57F protein in wild-type plants mimicked the phenotypes observed in the α1-4 mutant, while increasing the endogenous transcriptional levels of ptCPN60α2, ß1, ß2, and ß3 in the α1-4 mutant partially mitigated the abnormal fragmentation processing of chloroplast 23S, 5S, and 4.5S rRNAs. Furthermore, we demonstrated functional redundancy between ptCPN60ß1 and ptCPN60ß2 in chloroplast rRNA processing through double-mutant analysis. Collectively, our data reveal a novel physiological role of ptCPN60 subunits in generating the functional rRNA species of the large 50S ribosomal subunit in Arabidopsis chloroplasts.
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Fe-S clusters are ancient, ubiquitous and highly essential prosthetic groups for numerous fundamental processes of life. The biogenesis of Fe-S clusters is a multistep process including iron acquisition, sulfur mobilization, and cluster formation. Extensive studies have provided deep insights into the mechanism of the latter two assembly steps. However, the mechanism of iron utilization during chloroplast Fe-S cluster biogenesis is still unknown. Here we identified two Arabidopsis DnaJ proteins, DJA6 and DJA5, that can bind iron through their conserved cysteine residues and facilitate iron incorporation into Fe-S clusters by interactions with the SUF (sulfur utilization factor) apparatus through their J domain. Loss of these two proteins causes severe defects in the accumulation of chloroplast Fe-S proteins, a dysfunction of photosynthesis, and a significant intracellular iron overload. Evolutionary analyses revealed that DJA6 and DJA5 are highly conserved in photosynthetic organisms ranging from cyanobacteria to higher plants and share a strong evolutionary relationship with SUFE1, SUFC, and SUFD throughout the green lineage. Thus, our work uncovers a conserved mechanism of iron utilization for chloroplast Fe-S cluster biogenesis.
Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Cloroplastos/metabolismo , Proteínas Ferro-Enxofre/metabolismo , Ferro/metabolismo , Enxofre/metabolismo , Fotossíntese/fisiologiaRESUMO
The spreading of a liquid droplet on flat surfaces is a well-understood phenomenon, but little is known about how liquids spread on a rough surface. When the surface roughness is of the nanoscopic length scale, the capillary forces dominate and the liquid droplet spreads by wetting the nanoscale textures that act as capillaries. Here, using a combination of advanced nanofabrication and liquid-phase transmission electron microscopy, we image the wetting of a surface patterned with a dense array of nanopillars of varying heights. Our real-time, high-speed observations reveal that water wets the surface in two stages: 1) an ultrathin precursor water film forms on the surface, and then 2) the capillary action by nanopillars pulls the water, increasing the overall thickness of water film. These direct nanoscale observations capture the previously elusive precursor film, which is a critical intermediate step in wetting of rough surfaces.
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Lipid droplets (LDs) are intracellular organelles that dynamically regulate lipids and energy homeostasis in the cell. LDs can grow through either local lipid synthesis or LD fusion. However, how lipids involving in LD fusion for LD growth is largely unknown. Here, we show that genetic mutation of acox-3 (acyl-CoA oxidase), maoc-1 (enoyl-CoA hydratase), dhs-28 (3-hydroxylacyl-CoA dehydrogenase), and daf-22 (3-ketoacyl-CoA thiolase), all involved in the peroxisomal ß-oxidation pathway in Caenorhabditis elegans, led to rapid fusion of adjacent LDs to form giant LDs (gLDs). Mechanistically, we show that dysfunction of peroxisomal ß-oxidation results in the accumulation of long-chain fatty acid-CoA and phosphocholine, which may activate the sterol-binding protein 1/sterol regulatory element-binding protein to promote gLD formation. Furthermore, we found that inactivation of either FAT-2 (delta-12 desaturase) or FAT-3 and FAT-1 (delta-15 desaturase and delta-6 desaturase, respectively) to block the biosynthesis of polyunsaturated fatty acids (PUFAs) with three or more double bonds (n≥3-PUFAs) fully repressed the formation of gLDs; in contrast, dietary supplementation of n≥3-PUFAs or phosphocholine bearing these PUFAs led to recovery of the formation of gLDs in peroxisomal ß-oxidation-defective worms lacking PUFA biosynthesis. Thus, we conclude that n≥3-PUFAs, distinct from other well-known lipids and proteins, promote rapid LD fusion leading to LD growth.
Assuntos
Caenorhabditis elegans , Ácidos Graxos Ômega-3 , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Coenzima A/metabolismo , Ácidos Graxos Dessaturases/genética , Ácidos Graxos Dessaturases/metabolismo , Ácidos Graxos/metabolismo , Ácidos Graxos Ômega-3/metabolismo , Ácidos Graxos Insaturados/metabolismo , Gotículas Lipídicas/metabolismo , Fosforilcolina/metabolismo , Esteróis/metabolismoRESUMO
The comorbid mechanism of depression and chronic pain has been a research hotspot in recent years. Until now, the role of purinergic signals in the comorbid mechanism of depression and chronic pain has not been fully understood. This review mainly summarizes the research results published in PubMed during the past 5 years and concludes that purinergic signaling is a potential therapeutic target for comorbid depression and chronic pain, and the purinergic receptors A1, A2A, P2X3, P2X4, and P2X7and P2Y6, P2Y1, and P2Y12 may be important factors. The main potential pathways are as follows: A1 receptor-related G protein-dependent activation of introverted K+ channels (GIRKs), A2A receptor-related effects on the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) and MAPK/nuclear factor-κB (NF-κB) pathways, P2X3 receptor-related effects on dorsal root ganglia (DRG) excitability, P2X4 receptor-related effects on proinflammatory cytokines and inflammasome activation, P2X7 receptor-related effects on ion channels, the NLRP3 inflammasome and brain-derived neurotrophic factor (BDNF), and P2Y receptor-related effects on the phospholipase C (PLC)/inositol triphosphate (IP3)/Ca2+ signaling pathway. We hope that the conclusions of this review will provide key ideas for future research on the role of purinergic signaling in the comorbid mechanism of depression and chronic pain.
Assuntos
Dor Crônica , Humanos , Inflamassomos , Depressão , Transdução de Sinais , Receptores Purinérgicos , Trifosfato de Adenosina/metabolismoRESUMO
The mechano-bactericidal activity of nanostructured surfaces has become the focus of intensive research toward the development of a new generation of antibacterial surfaces, particularly in the current era of emerging antibiotic resistance. This work demonstrates the effects of an incremental increase of nanopillar height on nanostructure-induced bacterial cell death. We propose that the mechanical lysis of bacterial cells can be influenced by the degree of elasticity and clustering of highly ordered silicon nanopillar arrays. Herein, silicon nanopillar arrays with diameter 35 nm, periodicity 90 nm and increasing heights of 220, 360, and 420 nm were fabricated using deep UV immersion lithography. Nanoarrays of 360-nm-height pillars exhibited the highest degree of bactericidal activity toward both Gram stain-negative Pseudomonas aeruginosa and Gram stain-positive Staphylococcus aureus bacteria, inducing 95 ± 5% and 83 ± 12% cell death, respectively. At heights of 360 nm, increased nanopillar elasticity contributes to the onset of pillar deformation in response to bacterial adhesion to the surface. Theoretical analyses of pillar elasticity confirm that deflection, deformation force, and mechanical energies are more significant for the substrata possessing more flexible pillars. Increased storage and release of mechanical energy may explain the enhanced bactericidal action of these nanopillar arrays toward bacterial cells contacting the surface; however, with further increase of nanopillar height (420 nm), the forces (and tensions) can be partially compensated by irreversible interpillar adhesion that reduces their bactericidal effect. These findings can be used to inform the design of next-generation mechano-responsive surfaces with tuneable bactericidal characteristics for antimicrobial surface technologies.
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Antibacterianos/farmacologia , Nanoestruturas/química , Estresse Mecânico , Antibacterianos/química , Aderência Bacteriana , Elasticidade , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/fisiologia , Silício/química , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/fisiologiaRESUMO
Ampelopsis grossedentata, commonly known as "Vine Tea" and well-recognized for its rich flavonoid content, is mainly distributed in the southern regions of the Yangtze River basin in China. These regions include Hunan, Hubei, Jiangxi, and Guizhou provinces. Vine Tea is mainly consumed as an herbal tea and has garnered attention for its reported health benefits, including antioxidant, anti-inflammatory, anti-tumor, anti-diabetic, and neuroprotective properties. It has been used to alleviate coughs and sore throats (Zhang et al., 2021; Wang et al., 2017; Gao et al., 2009). In the Zhangjiajie region of Hunan province alone, the Vine Tea planting area reached 7,670.5 hectares and produced commercial goods worth 1.417 billion RMB in 2022. In May 2021, leaf margins and veins fading to yellowing mottling, and crumpling of leaf blades in the shape of a boat symptoms were found in ~16% of Vine Tea plants in the Sanjiakuan Township, Yongding District, Zhangjiajie region (29°15'E, 110°30' N) (Figure 1a, b, c). (Figure 1a, b, c). Phytoplasma-like microbial cells (small oval shaped bacterial cells, around 1000 nm in size) were observed in sieve tube cells in the phloem of diseased leaves using transmission electron microscopy. No such cell was observed in the phloem of healthy leaves (Figure 2a, b). To investigate the potential association between phytoplasma and the observed symptoms of the diseased plants, total DNA was isolated from ten diseasedeaves and compared with ten healthy leaves from the same field using SteadyPure Plant Genomic DNA Extraction Kit. The isolated DNAs were analyzed first in a direct PCR using universal phytoplasma primer pair R16mF2/R16mR1 targeting the 16S rRNA gene (Gundersen and Lee 1996) and specific pair rpF1/rpR1 (Lee et al. 1998) targeting the DNA fragment encoding partial ribosomal proteins (rp) L22 (complete) and S3 and S19 (partial). The initial amplified products were used as templates and further amplified by nested PCR respectively with primer pair R16F2n/R16R2 for the 16S rRNA gene (Lee et al. 1998) and the rpF2/rpR2 primer pair for the rp gene (Martini et al. 2007). No amplification was obtained with DNA from healthy leaf samples using any of the four primer pairs. The amplified fragments from diseased leaves by nested PCR were cloned and sequenced (Qingke Biotech, China). The obtained sequences have been deposited in GenBank with accession numbers OR282806 for the 16S rRNA gene and GenBank OR353012 for the rp gene. BLASTn analysis revealed that the partial 16S rRNA gene sequence in our sample shared 99.4% nucleotide sequence identity with 'Candidatus Phytoplasma sp.' (MW364378) and 'Peony yellows phytoplasma' (KY814723) of the 16SrI group. Similarly, our rp gene sequence shared 99.6% nucleotide identity with the rpI group of phytoplasma such as the 'Balsamine virescence phytoplasma' (JN572890) and 'Paulownia witches'-broom phytoplasma' (HM146079). Phylogenetic analysis of the 16S rRNA and rp sequences using MEGA version 7.0 revealed that the phytoplasma strain associated with A. grossedentata yellow leaf syndrome in our study site belonged to the 16SrI (Candidatus Phytoplasma asteris) group of phytoplasma (Figure 3a, b). Using the interactive online phytoplasma classification tool iPhyClassifier (Zhao et al., 2009), virtual restriction fragment length polymorphism (RFLP) analysis of the 16S rRNA gene sequences showed our strain having a distinct RFLP map but was closest to that of the onion yellow phytoplasma 16SrI-B subgroup (GenBank accession number: AP006628), with a similarity coefficient of 0.94 (Figure 4a, b). To confirm phytoplasma transmission, healthy plants were inoculated with three scions of infected plants of A. grossedentata. After 16 days, the new leaves of the inoculated A. grossedentata showed yellow leaf symptoms (Figure 5a, b, c), akin to the symptoms originally observed in the field, and the outer contour of the leaf margin appeared chlorotic. After 26 days, primer pairs R16mF2/R16R1 and R16F2n/R16R2 were used for nested PCR detection of phytoplasma in symptomatic A. grossedentata leaves. Phytoplasma was detected in the first and second leaves of symptomatic branches and leaves while negative control showed no amplification. Sequencing of the amplified fragments showed 100% nucleotide identity to the strain from the grafting source. Our results indicated that the pathogen and the disease can be transmitted by tissue grafting, consistent with the biological characteristics of phytoplasma, and further confirmed that the phytoplasma was the pathogen of yellow leaf syndrome of A. grossedentata. Toour knowledge, this is the first report of phytoplasma of group 16SrI affecting A. grossedentata.
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This paper discusses the compensation standard for exhaust pollution and devises a compensation mechanism for Macao's tourism-related transport sector based on an integration of chemical exergy and universal exergy, using data on gasoline consumption by automobile sector retrieved from the transportation industry. The results reveal that: (1) the exergy values of air pollutant emissions increased from 1.53 × 1012 kJ in 2010 to 2.03 × 1012 kJ in 2019 (an increase of 1.33 times), and the exergy of CO, NOx, and SO2 emissions accounted for 77.5%, 20.4% and 2.1% of total exhaust emissions in Macao respectively. (2) In 2019, the monetary value of emission exergy, and the environmental costs of air pollution, were 1.7 times greater than in 2010. (3) If Light Rail Transit is compensated for, then the mean interval's values of the upper and lower limits of the compensation standard are 0.55 USD and 0.05 USD, respectively. When gasoline tax is used as a means of compensation it is necessary to raise its rate by about 8% based on the tax rate. A three-stage bargaining game model is used to provide evidence that this compensation standard is practical and acceptable.
Assuntos
Poluentes Atmosféricos , Poluição do Ar , Poluentes Atmosféricos/análise , Gasolina , Macau , Turismo , Poluição do Ar/análise , Emissões de Veículos/análiseRESUMO
This paper uses the tourism heat footprint (THF) and a structural vector autoregressive model to investigate how tourism has affected the urban heat island effect in Macao, a typical urban tourism destination. The dynamic relationships between the THF, heat island intensity (HII), and quarterly average temperature (QAT) are investigated. The impulse response function and variance decomposition analysis are used to assess if a long-term causal relationship exists between the three indicators. The results show the following. (1) The hotel industry in Macao is the source of energy consumption and heat release. (2) A Granger causality relationship exists between the THF and QAT but not between the THF and HII. (3) The interaction effect between the growth rate of the THF and QAT is manifested as shocks with the same frequency and regular periodic fluctuations. (4) The heat island effect of this tourism destination is reflected in an increase in local temperature due to the energy consumption and heat release by tourists. Based on the results, policy implications for a sustainable tourism city are provided.
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Objectiveï¼ This study aimed to assess the impact of urogenital ureaplasma urealyticum (Uu), Mycoplasma hominis (Mh), and Chlamydia trachomatis (Ct) infections on semen quality in men.Methodsï¼ In this study, 1022 males were enrolled at the Department of Reproductive Medicine, Rizhao People's Hospital, Shandong Province from October 2014 to January 2023. The participants included 393 in the infertility group, 139 in the recurrent miscarriage group, and 490 in the control group. Based on age, 852 cases were < 36 years old, and 170 cases were ≥ 36 years old. All patients underwent routine semen analysis and tests for Uu, Mh, and Ct, with results statistically analyzed for their impact on semen quality and compared among different age groups. Results: Among the 1022 patients, 344 (33.6%) were Uu-positive, 49 (4.7%) were Mh-positive, and 31 (3.0%) were Ct positive. The sperm concentration, total sperm count, forward sperm motility rate (PR), sperm motility rate (PR+NP) and normal sperm morphology rate of Uu Mh and/or Ct-positive patients were significantly lower than those of the negative group, and the overall difference between the two groups was statistically significant (P<0.05). The positive rate of Uu infection was 41.7% in the infertility group, 30.2% in the recurrent miscarriage group and 28.2% in the control group, and the overall positive rate of the three groups was statistically significant(P<0.05). The positive rate of Mh infection was 6.9% in the infertility group, 8.6% in the recurrent miscarriage group and 2.0% in the control group, and the overall positive rate of the three groups was statistically significant (P<0.001). The positive rate of Ct infection was 6.1% in the infertility group, 2.9% in the recurrent miscarriage group and 0.6% in the control group, and the overall positive rate of the three groups was statistically significant (P<0.001). The positivity rate of Uu infection was 35.8% at the age of <36 years and 22.9% at the age ≥ 36 years, and there was a statistically significant difference in the positivity rate between the two groups (P<0.05). Conclusion: The prevalence of Uu infection in the male urogenital tract is significantly higher than that of Mh and Ct, which is the main pathogen of urogenital tract infection in men. Uu, Mh and Ct infections have adverse effects on sperm concentration, total sperm count, sperm forward motility rate (PR), sperm motility rate (PR+NP) and normal sperm morphology rate, which will lead to a decrease in semen quality and affect male fertility. Genital tract infections are closely related to age, and the prevalence of Uu infection is higher in the younger age group.
Assuntos
Aborto Habitual , Infecções por Chlamydia , Infertilidade , Mycoplasma , Masculino , Humanos , Feminino , Adulto , Análise do Sêmen , Sêmen , Motilidade dos Espermatozoides , Mycoplasma hominis , Infecções por Chlamydia/complicações , FertilidadeRESUMO
In response to changing light quantity and quality, photosynthetic organisms perform state transitions, a process which optimizes photosynthetic yield and mitigates photo-damage. The serine/threonine-protein kinase STN7 phosphorylates the light-harvesting complex of photosystem II (PSII; light-harvesting complex II), which then migrates from PSII to photosystem I (PSI), thereby rebalancing the light excitation energy between the photosystems and restoring the redox poise of the photosynthetic electron transport chain. Two conserved cysteines forming intra- or intermolecular disulfide bonds in the lumenal domain (LD) of STN7 are essential for the kinase activity although it is still unknown how activation of the kinase is regulated. In this study, we show lumen thiol oxidoreductase 1 (LTO1) is co-expressed with STN7 in Arabidopsis (Arabidopsis thaliana) and interacts with the LD of STN7 in vitro and in vivo. LTO1 contains thioredoxin (TRX)-like and vitamin K epoxide reductase domains which are related to the disulfide-bond formation system in bacteria. We further show that the TRX-like domain of LTO1 is able to oxidize the conserved lumenal cysteines of STN7 in vitro. In addition, loss of LTO1 affects the kinase activity of STN7 in Arabidopsis. Based on these results, we propose that LTO1 helps to maintain STN7 in an oxidized active state in state 2 through redox interactions between the lumenal cysteines of STN7 and LTO1.
Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Proteínas Serina-Treonina Quinases/metabolismo , Vitamina K Epóxido Redutases/metabolismo , Arabidopsis/enzimologia , Arabidopsis/fisiologia , Proteínas de Arabidopsis/genética , Oxirredução , Fosforilação , Fotossíntese , Complexo de Proteína do Fotossistema I/metabolismo , Complexo de Proteína do Fotossistema II/metabolismo , Proteínas Serina-Treonina Quinases/genética , Compostos de Sulfidrila/metabolismo , Vitamina K Epóxido Redutases/genéticaRESUMO
Plant organs often grow into a genetically determined size and shape. How organ growth is finely regulated to achieve a well defined pattern is a fascinating, but largely unresolved, question in plant research. We utilised the Arabidopsis petal to study the genetic control of plant organ growth, and identify two closely related U-box E3 ligases PUB25 and PUB26 as important growth regulators by screening the targets of the petal-specific growth-promoting transcription factor RABBIT EARS (RBE). We showed that PUB25 is directly controlled by RBE in petal development in a spatial- and temporal-specific manner and acts as a major target to mediate RBE's function in petal growth. We also showed that PUB25 and PUB26 repress petal growth by restricting the period of cell proliferation, and their regulation appears to be independent of other plant E3 ligase genes implicated in growth control. PUB25 and PUB26 are among the first U-box E3 ligases shown to function in plant growth control. Furthermore, as they were also found to play a vital role in plant stress responses, PUB25 and PUB26 may act as a key hub to integrate developmental and environmental signals for balancing growth and defence in plants.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Fatores de Transcrição/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismoRESUMO
Trichome initiation and leaf growth are two critical developmental processes in the plant life cycle, which need to be optimized in accordance with developmental stage and immediate surroundings. To a large extent, this optimization is achieved by fine-tuning of hormonal pathways, including the gibberellin (GA) pathway. However, the mechanism by which plants control GA homeostasis to optimize these two developmental processes is unknown. Here, we report that HAT1, a HD-ZIP II transcription factor, negatively regulates GA-mediated trichome initiation and cotyledon expansion. Both protein and transcript levels indicated that HAT1 was induced by GA, while an increased abundance of HAT1, in turn, was found to suppress GA biosynthesis and signaling, thus forming a regulatory negative feedback loop that controls GA homeostasis to fine-tune trichome development and cotyledon expansion. We also found that HAT1 interacts with DELLAs, including GAI and RGA. GAI inhibits both protein stability and the binding activity of HAT1 to its target genes. Overexpression of HAT1 in della5 can completely suppress the enhanced trichome initiation and enlarged cotyledon of della5. Our findings demonstrate that HAT1 functions as a critical repressor to regulate GA-mediated trichome initiation and cotyledon growth; in addition, we describe a novel mechanism by which the plant regulates trichome initiation and cotyledon expansion through a HAT1-DELLA regulatory module under various GA concentrations.
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Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Giberelinas , Histona Acetiltransferases , Homeostase , Folhas de Planta/metabolismo , Fatores de Transcrição , Tricomas/metabolismoRESUMO
Here, Tb3+ ions are incorporated into Cs2Ag0.6Na0.4InCl6:Bi double perovskite microcrystals via a re-crystallization method. Tb3+ ions doping not only makes the white light spectrum adjustable, but also maintains the high photoluminescence quantum yield (PLQY). The optimal value of PLQY is 95%. These are comparable to the current highest values. Noteworthy is that, intrinsic emission of Tb3+ ions is attributed to the effective energy transfer from the trapped exciton state of the double perovskite host to Tb3+ ions. Finally, mixing 30% Tb3+ alloyed Cs2Ag0.6Na0.4InCl6:Bi and Cs2NaInCl6:10%Sb phosphors, a series of double-perovskite-based white light-emitting diodes (WLEDs) are prepared. The color coordinates of the best WLEDs are (0.34, 0.32), the lumen efficiency is 42 lm/W, and the color rendering index is 94.3. It is worth mentioning here that there is no blue light loss caused by energy reabsorption between the two phosphors, because the excitation wavelengths of the two phosphors are concentrated in the ultraviolet band. This work provides a new strategy for preparing high-performance WLED.
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Here, composites including highly efficient inert shell-modified NaYF4:Yb/Tm@NaYF4 upconversion nanoparticles (UCNPs) and CsPbI3 perovskite quantum dots (PQDs) have been successfully synthesized by the assistance of (3-aminopropyl)triethoxysilane (APTES) as a precursor for a SiO2 matrix. UCNPs and CsPbI3 PQDs in this composite structure show excellent stability in ambient conditions. Importantly, the efficient UC emission of CsPbI3 PQDs was realized, which means that the single red emission of inert shell-modified UCNPs can be easily obtained by depending on these composite structures. Furthermore, the single red emission wavelength can be easily regulated from 705 to 625 nm by introducing appropriate proportion of Br- ions, which is very difficult to achieve for traditional UCNPs. Moreover, benefiting from the efficient downshifting (DS) red emission of CsPbI3 PQDs, the composites possess the dual-wavelength excitation characteristics. So, the excellent dual-mode anticounterfeiting application has been demonstrated. This work will provide a new idea for the development of perovskite-based multifunctional materials.
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The aim of the present study was to investigate the potential predictive significance of pretreatment prognostic nutritional index (PNI) in intravenous immunoglobulin (IVIG) resistant Kawasaki disease (KD). The PNI, neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR) were analyzed in 1257 eligible patients with KD. Receiver operating curve analysis was used to explore the prediction accuracy for IVIG-resistant KD. The optimal cut-off values were identified as 49.5 for PNI, 3.58 for NLR and 164.00 for PLR, respectively. Lower pretreatment PNI (< 49.5) was demonstrated to be associated with lower age, serum sodium levels and platelet counts, and with a higher incidence of IVIG resistance and higher C-reactive protein levels. There was a significantly negative association between the PNI and NLR, and PLR. Univariate and multivariate analyses revealed that PNI, NLR and PLR were independent predictive factors for IVIG resistance. The discriminatory ability of PNI was not inferior to NLR, PLR and their combination (NLR > 3.58 and PLR > 164) for predicting IVIG resistance, respectively. Pretreatment PNI may serve as a novel surrogate independent predictor for IVIG-resistant KD.
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Síndrome de Linfonodos Mucocutâneos , Humanos , Imunoglobulinas Intravenosas , Síndrome de Linfonodos Mucocutâneos/diagnóstico , Síndrome de Linfonodos Mucocutâneos/tratamento farmacológico , Neutrófilos , Avaliação Nutricional , Prognóstico , Estudos RetrospectivosRESUMO
A fundamental challenge for cells is how to coordinate various biochemical reactions in space and time. To achieve spatiotemporal control, cells have developed organelles that are surrounded by lipid bilayer membranes. Further, membraneless compartmentalization, a process induced by dynamic physical association of biomolecules through phase transition offers another efficient mechanism for intracellular organization. While our understanding of phase separation was predominantly dependent on yeast and animal models, recent findings have provided compelling evidence for emerging roles of phase separation in plants. In this review, we first provide an overview of the current knowledge of phase separation, including its definition, biophysical principles, molecular features and regulatory mechanisms. Then we summarize plant-specific phase separation phenomena and describe their functions in plant biological processes in great detail. Moreover, we propose that phase separation is an evolutionarily conserved and efficient mechanism for cellular compartmentalization which allows for distinct metabolic processes and signaling pathways, and is especially beneficial for the sessile lifestyle of plants to quickly and efficiently respond to the changing environment.
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Compartimento Celular , Células Vegetais , Plantas/metabolismoRESUMO
Diabetes is the largest global epidemic of the 21st century, and the cost of diabetes and its complications comprise about 12% of global health expenditure. Diabetic neuropathy is the most common complication of diabetes, affecting up to 50% of patients over the course of their disease. Among them, 30%-50% develop neuropathic pain, which has typical symptoms that originate from the toes and progress to foot ulcers and seriously influence quality of life. The pathogenesis of diabetic neuropathic pain (DNP) is complicated and incompletely understood and there is no effective treatment except supportive treatment. Long noncoding RNAs (lncRNAs), a class of noncoding RNAs exceeding 200 nucleotides in length, have been shown to play key roles in fundamental cellular processes, and are considered to be potential targets for treatment. Recent research indicates that lncRNA is involved in the pathogenesis of DNP. Certain overexpressed lncRNAs can enhance the purinergic receptor-mediated neuropathic pain in peripheral ganglia and inflammatory cytokines are released due to receptors activated by adenosine triphosphate. In recent years, our laboratory also has been exploring the relationship and pathogenesis between lncRNAs and DNP. In this review, we focus on the recent progress in functional lncRNAs associated with DNP and investigate their roles related to respective receptors.
Assuntos
Neuropatias Diabéticas/genética , Proteínas Quinases Ativadas por Mitógeno/metabolismo , RNA Longo não Codificante/genética , Citocinas/metabolismo , Neuropatias Diabéticas/metabolismo , Neuropatias Diabéticas/patologia , Humanos , Sistema de Sinalização das MAP Quinases/genética , Sistema de Sinalização das MAP Quinases/fisiologia , Proteínas Quinases Ativadas por Mitógeno/genética , Neuralgia/metabolismo , Neuralgia/fisiopatologia , RNA Longo não Codificante/metabolismo , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/metabolismoRESUMO
Pyroptosis is a type of programmed cell death, displaying caspase-1-dependent and pro-inflammatory features. Purinergic 2X4 (P2X4 ) receptor activation in response to high-adenosine triphosphate release can induce inflammation. Envelope glycoprotein 120 (gp120) of human immunodeficiency virus type 1 is considered one of the primary pathogens leading to neuronal injury. In this study, we investigated the possible role of P2X4 receptor activation in gp120-triggered pyroptosis in cultured satellite glial cells (SGCs) of rat dorsal root ganglia (DRG). MTS assay, TdT-mediated dUTP Nick-end labeling assay, real-time RT-PCR, and western blotting et al. methods were used. The results indicated that the expression of P2X4 receptor in SGCs of DRG was up-regulated upon cultured with gp120 for 24 h. The highest decrease in viability of SGCs due to gp120 treatment was accompanied by marked increases of positive pyroptosis cells and cellular lactate dehydrogenase release, elevated levels of interleukin-1ß, interleukin-18, active caspase-1 and NOD-like receptor family, pyrin domain containing 1, and enhanced phosphorylation of p38MAPK. These abnormal changes because of gp120 were significantly inhibited and cell viability was markedly improved when SGCs of DRG were treated with short hairpin RNAs targeting P2X4 receptor. Our data suggest that silencing of P2X4 receptor may act effectively against gp120-induced pyroptosis mediated by the activation of NOD-like receptor family, pyrin domain containing 1 inflammasome and caspase-1 signaling in SGCs of DRG.