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Surface plasmonics with its unique confinement of light1,2 is expected to be a cornerstone for future compact radiation sources and integrated photonics devices. The energy transfer between light and matter is a defining aspect that underlies recent studies on optical surface-wave-mediated spontaneous emissions3-5. However, coherent stimulated emission of free electrons, which is essential for free-electron light sources, and its dynamical amplification process remain to be disclosed in a clear, unambiguous and calibrated manner. Here we present the coherent amplification of terahertz surface plasmon polaritons via free-electron-stimulated emission: a femtosecond optical pulse creates an in-phase free-electron pulse with an initial terahertz surface wave, and their ensuing interactions intensify the terahertz surface wave coherently. The underlying dynamics of the amplification, including a twofold redshift in the radiation frequency over a one-millimetre interaction length, are resolved as electromagnetic-field-profile evolutions using an optical pump-probe method. By extending the approach to a properly phase-matched electron bunch, our theoretical analysis predicts a super-radiant surface-wave growth, which lays the ground for a stimulated surface-wave light source and may facilitate capable means for matter manipulation, especially in the terahertz band.
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Plasmodesmata connect adjoining plant cells, allowing molecules to move between the connected cells for communication and sharing resources. It has been well established that the plant polysaccharide callose is deposited at plasmodesmata, regulating their aperture and function. Among proteins involved in maintaining callose homeostasis, PLASMODESMATA-LOCATED PROTEINSs (PDLPs) promote callose deposition at plasmodesmata. This study explored the function of PDLP5 and PDLP6 in different cell types. We discovered that PDLP5 and PDLP6 are expressed in non-overlapping cell types in Arabidopsis (Arabidopsis thaliana). The overexpression of PDLP5 and PDLP6 results in the overaccumulation of plasmodesmal callose at different cell interfaces, indicating that PDLP5 and PDLP6 are active in different cell types. We also observed two distinct patterns of starch accumulation in mature leaves of PDLP5 and PDLP6 overexpressors. An enzyme-catalyzed proximity labeling approach was used to identify putative functional partners of the PDLPs. We identified SUCROSE SYNTHASE6 (SUS6) as a functional partner of PDLP6 in the vasculature. We further demonstrated that PDLP6 physically and genetically interacts with SUS6. In addition, CALLOSE SYNTHASE7 (CALS7) physically interacts with SUS6 and PDLP6. Genetic interaction studies showed that CALS7 is required for PDLP6 function. We propose that PDLP6 functions with SUS6 and CALS7 in the vasculature to regulate plasmodesmal function.
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As sessile organisms, plants must adapt to variations in the environment. Environmental stress triggers various responses, including growth inhibition, mediated by the plant hormone abscisic acid (ABA). The mechanisms that integrate stress responses with growth are poorly understood. Here, we discovered that the Target of Rapamycin (TOR) kinase phosphorylates PYL ABA receptors at a conserved serine residue to prevent activation of the stress response in unstressed plants. This phosphorylation disrupts PYL association with ABA and with PP2C phosphatase effectors, leading to inactivation of SnRK2 kinases. Under stress, ABA-activated SnRK2s phosphorylate Raptor, a component of the TOR complex, triggering TOR complex dissociation and inhibition. Thus, TOR signaling represses ABA signaling and stress responses in unstressed conditions, whereas ABA signaling represses TOR signaling and growth during times of stress. Plants utilize this conserved phospho-regulatory feedback mechanism to optimize the balance of growth and stress responses.
Asunto(s)
Ácido Abscísico/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/crecimiento & desarrollo , Regulación de la Expresión Génica de las Plantas/fisiología , Fosfatidilinositol 3-Quinasas/metabolismo , Reguladores del Crecimiento de las Plantas/metabolismo , Receptores de Superficie Celular/metabolismo , Fosforilación , Proteínas Serina-Treonina Quinasas/metabolismo , Proteína Reguladora Asociada a mTOR/metabolismo , Transducción de Señal , Estrés FisiológicoRESUMEN
Fine particulate matter (PM2.5) can damage airway epithelial barriers. The anion transport system plays a crucial role in airway epithelial barriers. However, the detrimental effect and mechanism of PM2.5 on the anion transport system are still unclear. In this study, airway epithelial cells and ovalbumin (OVA)-induced asthmatic mice were used. In transwell model, the adenosine triphosphate (ATP)-induced transepithelial anion short-circuit current (Isc) and airway surface liquid (ASL) significantly decreased after PM2.5 exposure. In addition, PM2.5 exposure decreased the expression levels of P2Y2R, CFTR and cytoplasmic free-calcium, but ATP can increase the expressions of these proteins. PM2.5 exposure increased the levels of Th2-related cytokines of bronchoalveolar lavage fluid, lung inflammation, collagen deposition and hyperplasisa of goblet cells. Interestingly, the administration of ATP showed an inhibitory effect on lung inflammation induced by PM2.5. Together, our study reveals that PM2.5 impairs the ATP-induced transepithelial anion Isc through downregulating P2Y2R/CFTR pathway, and this process may participate in aggravating airway hyperresponsiveness and airway inflammation. These findings may provide important insights on PM2.5-mediated airway epithelial injury.
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Asma , Regulador de Conductancia de Transmembrana de Fibrosis Quística , Material Particulado , Receptores Purinérgicos P2Y2 , Animales , Ratones , Receptores Purinérgicos P2Y2/metabolismo , Receptores Purinérgicos P2Y2/genética , Asma/metabolismo , Asma/patología , Asma/tratamiento farmacológico , Asma/inducido químicamente , Asma/inmunología , Material Particulado/efectos adversos , Material Particulado/toxicidad , Regulador de Conductancia de Transmembrana de Fibrosis Quística/metabolismo , Regulador de Conductancia de Transmembrana de Fibrosis Quística/genética , Humanos , Adenosina Trifosfato/metabolismo , Ovalbúmina/inmunología , Transducción de Señal/efectos de los fármacos , Células Epiteliales/efectos de los fármacos , Células Epiteliales/metabolismo , Regulación hacia Abajo/efectos de los fármacos , Mucosa Respiratoria/metabolismo , Mucosa Respiratoria/efectos de los fármacos , Mucosa Respiratoria/patología , Líquido del Lavado Bronquioalveolar/citología , Líquido del Lavado Bronquioalveolar/química , Líquido del Lavado Bronquioalveolar/inmunologíaRESUMEN
A hallmark of multicellular organisms is their ability to maintain physiological homeostasis by communicating among cells, tissues, and organs. In plants, intercellular communication is largely dependent on plasmodesmata (PD), which are membrane-lined channels connecting adjacent plant cells. Upon immune stimulation, plants close PD as part of their immune responses. Here, we show that the bacterial pathogen Pseudomonas syringae deploys an effector protein, HopO1-1, that modulates PD function. HopO1-1 is required for P. syringae to spread locally to neighboring tissues during infection. Expression of HopO1-1 in Arabidopsis (Arabidopsis thaliana) increases the distance of PD-dependent molecular flux between neighboring plant cells. Being a putative ribosyltransferase, the catalytic activity of HopO1-1 is required for regulation of PD. HopO1-1 physically interacts with and destabilizes the plant PD-located protein PDLP7 and possibly PDLP5. Both PDLPs are involved in bacterial immunity. Our findings reveal that a pathogenic bacterium utilizes an effector to manipulate PD-mediated host intercellular communication for maximizing the spread of bacterial infection.
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Arabidopsis/microbiología , Plasmodesmos/microbiología , Pseudomonas syringae/crecimiento & desarrollo , Pseudomonas syringae/patogenicidad , Adenosina Difosfato Ribosa/metabolismo , Arabidopsis/inmunología , Arabidopsis/metabolismo , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/metabolismo , Proteínas Bacterianas/metabolismo , Membrana Celular/metabolismo , Inmunidad de la Planta , Unión Proteica , Dominios Proteicos , Estabilidad Proteica , Transporte de Proteínas , Pseudomonas syringae/inmunología , VirulenciaRESUMEN
We put forward a novel method for producing ultrarelativistic high-density high-polarization positrons through a single-shot interaction of a strong laser with a tilted solid foil. In our method, the driving laser ionizes the target, and the emitted electrons are accelerated and subsequently generate abundant γ photons via the nonlinear Compton scattering, dominated by the laser. These γ photons then generate polarized positrons via the nonlinear Breit-Wheeler process, dominated by a strong self-generated quasistatic magnetic field B^{S}. We find that placing the foil at an appropriate angle can result in a directional orientation of B^{S}, thereby polarizing positrons. Manipulating the laser polarization direction can control the angle between the γ photon polarization and B^{S}, significantly enhancing the positron polarization degree. Our spin-resolved quantum electrodynamics particle-in-cell simulations demonstrate that employing a laser with a peak intensity of about 10^{23} W/cm^{2} can obtain dense (â³10^{18} cm^{-3}) polarized positrons with an average polarization degree of about 70% and a yield of above 0.1 nC per shot. Moreover, our method is feasible using currently available or upcoming laser facilities and robust with respect to the laser and target parameters. Such high-density high-polarization positrons hold great significance in laboratory astrophysics, high-energy physics, and new physics beyond the standard model.
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Vancomycin (VAN) has a narrow therapeutic window and variable pharmacokinetic properties, which require timely monitoring of plasma concentration to adjust the dosage for better effectiveness. A sensitive and quantitative immunochromatographic method was developed to detect VAN in plasma. The linear response range of the method to detect plasma VAN was 1.25-50 µg/mL. The intra- and inter-assay coefficients were 4.68% and 8.81%, respectively, while the recovery was 89.10%-98.32%. The clinical comparative experiment results demonstrated a good correlation (r > 0.90) between the fluorescent immunochromatographic strip test and the mass spectrum. In this study, a simple, rapid, and high-sensitivity immunochromatographic method was established for detecting VAN, which helped establish the basis for further application of monitoring plasma concentration.
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Vancomicina , Cromatografía de Afinidad/métodosRESUMEN
The optical vortex has been widely studied owing to its specific characteristics such as the orbital angular momentum, hollow intensity distribution, and topological charge. We report the generation of electromagnetic solitons with angular momentum and the conversion of angular momentum via a circularly polarized (CP) laser and underdense plasma interactions on the basis of three-dimensional particle-in-cell simulations. We find that when a CP laser is incident into the underdense plasma, a longitudinal current will be induced off the laser axis, which is critical for the angular momentum conversion. This novel, to the best of our knowledge, regime will allow potential applications such as optical control and electron manipulation.
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The intron-lariat spliceosome (ILS) complex is highly conserved among eukaryotes, and its disassembly marks the end of a canonical splicing cycle. In this study, we show that two conserved disassembly factors of the ILS complex, Increased Level of Polyploidy1-1D (ILP1) and NTC-Related protein 1 (NTR1), positively regulate microRNA (miRNA) biogenesis by facilitating transcriptional elongation of MIRNA (MIR) genes in Arabidopsis thaliana. ILP1 and NTR1 formed a stable complex and co-regulated alternative splicing of more than a hundred genes across the Arabidopsis genome, including some primary transcripts of miRNAs (pri-miRNAs). Intriguingly, pri-miRNAs, regardless of having introns or not, were globally down-regulated when the ILP1 or NTR1 function was compromised. ILP1 and NTR1 interacted with core miRNA processing proteins Dicer-like 1 and Serrate, and were required for proper RNA polymerase II occupancy at elongated regions of MIR chromatin, without affecting either MIR promoter activity or pri-miRNA decay. Our results provide further insights into the regulatory role of spliceosomal machineries in the biogenesis of miRNAs.
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Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Genoma de Planta , MicroARNs/genética , Proteínas de Unión Periplasmáticas/genética , Empalme del ARN , Proteínas Represoras/metabolismo , Empalmosomas/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Exones , Regulación de la Expresión Génica de las Plantas , Intrones , MicroARNs/biosíntesis , Proteínas de Unión Periplasmáticas/metabolismo , ARN Polimerasa II/genética , ARN Polimerasa II/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Proteínas de Unión al ARN/genética , Proteínas de Unión al ARN/metabolismo , Ribonucleasa III/genética , Ribonucleasa III/metabolismo , Empalmosomas/metabolismoRESUMEN
Leaf senescence is an integral part of plant development, during which, nutrients are remobilized from senescent leaves to fast-growing organs. The initiation and progression dynamics of leaf senescence is therefore vital not only to the maximal accumulation of assimilates but also to the efficient remobilization of nutrients. Senescence is a finely tuned process that involves the action of a large number of transcription factors (TFs). The NAC TFs play critical roles in regulating leaf senescence in Arabidopsis, wheat, rice and tomato. Here, we identified a NAC TF, ZmNAC126 that is responsive to leaf senescence in maize. Ectopic overexpression of ZmNAC126 in Arabidopsis and maize enhanced chlorophyll degradation and promoted leaf senescence. Electrophoretic mobility shift and chromatin immunoprecipitation assays revealed that ZmNAC126 could directly bind to the promoters of major chlorophyll catabolic genes in maize. Dual-luciferase assay in maize protoplasts indicated that ZmNAC126 positively regulates these chlorophyll catabolic genes in maize. Moreover, ZmNAC126 could be induced by ethylene, and ZmEIN3, a major TF of ethylene signalling, could bind to its promoter to transactivate its expression. Taken together, ZmNAC126 may play a pivotal role in regulating natural and ethylene-triggered leaf senescence in maize.
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Etilenos/metabolismo , Hojas de la Planta/fisiología , Proteínas de Plantas/metabolismo , Factores de Transcripción/metabolismo , Zea mays/fisiología , Arabidopsis/genética , Clorofila/genética , Clorofila/metabolismo , Regulación de la Expresión Génica de las Plantas , Proteínas de Plantas/genética , Plantas Modificadas Genéticamente , Regiones Promotoras Genéticas , Transducción de Señal/fisiología , Factores de Transcripción/genéticaRESUMEN
The miscellaneous applications of terahertz have called for an urgent demand of a super intense terahertz source. Here, we demonstrate the capability of femtosecond laser-driven wires as an efficient ultra-intense terahertz source using 700 mJ laser pulses. When focused onto a wire target, coherent THz generation took place in the miniaturized gyrotron-like undulator where emitted electrons move in the radial electric field spontaneously created on wire surface. The single-cycle terahertz pulse generated from the target is measured to be radially polarized with a pulse energy of a few milijoule. By further applying this scheme to a wire-tip target, we show the near field of the 500â nm radius apex could reach up to 90 GV/m. This efficient THz energy generation and intense THz electric field mark a substantial improvement toward ultra-intense terahertz sources.
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The H3K27 methyltransferase CLF inhibits lateral root (LR) formation through depositing the repressive H3K27me3 mark to the chromatin of PIN1, a key polar auxin transporter gene. Here, we show that the H3K27me3 demethylase REF6 promotes lateral root primordium initiation and LR emergence. REF6 directly binds to the chromatin of PIN1/3/7. Dysfunction in REF6 results in increased levels of H3K27me3 on PIN1/3/7 and suppressed expression of PIN genes. Genetic analysis of the clf ref6 double mutant revealed an antagonistic action between CLF and REF6, in terms of LR formation. Our findings indicate that H3K27 methylation and demethylation activities are likely coordinated to ensure proper LR organogenesis.
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Proteínas de Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Arabidopsis/genética , Regulación de la Expresión Génica de las Plantas , Genes de Plantas , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/genética , Factores de Transcripción/metabolismo , Proteínas de Arabidopsis/metabolismo , Cromatina/metabolismo , Histonas/metabolismo , Metilación , Unión ProteicaRESUMEN
In the seed industry, chlorophyll (Chl) fluorescence is often used as a major non-invasive reporter of seed maturation and quality. Breakdown of Chl is a proactive process during the late stage of seed maturation, as well as during leaf senescence and fruit ripening. However, the biological significance of this process is still unclear. NYE1 and NYE2 are Mg-dechelatases, catalyzing the first rate-limiting step of Chl a degradation. Loss-of-function of both NYE1 and NYE2 not only results in a nearly complete retention of Chl during leaf senescence, but also produces green seeds in Arabidopsis. In this study, we showed that Chl retention in the nye1 nye2 double-mutant caused severe photo-damage to maturing seeds. Upon prolonged light exposure, green seeds of nye1 nye2 gradually bleached out and eventually lost their germination capacity. This organ-specific photosensitive phenotype is likely due to an over-accumulation of free Chl, which possesses photosensitizing properties and causes a burst of reactive oxygen species upon light exposure. As expected, a similar, albeit much milder, photosensitive phenotype was observed in the seeds of d1 d2, a green-seed mutant defective in NYE/SGR orthologous genes in soybean. Taken together, our data suggest that efficient NYEs-mediated Chl degradation is critical for detoxification during seed maturation.
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Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimología , Proteínas de Cloroplastos/metabolismo , Enzimas/metabolismo , Arabidopsis/genética , Arabidopsis/fisiología , Arabidopsis/efectos de la radiación , Proteínas de Arabidopsis/genética , Clorofila/análisis , Clorofila/metabolismo , Proteínas de Cloroplastos/genética , Enzimas/genética , Germinación/efectos de la radiación , Peróxido de Hidrógeno/metabolismo , Luz , Especificidad de Órganos , Fenotipo , Especies Reactivas de Oxígeno/metabolismo , Plantones/enzimología , Plantones/genética , Plantones/fisiología , Plantones/efectos de la radiación , Semillas/enzimología , Semillas/genética , Semillas/fisiología , Semillas/efectos de la radiación , Glycine max/enzimología , Glycine max/genética , Glycine max/fisiología , Glycine max/efectos de la radiaciónRESUMEN
Although the biochemical pathway of chlorophyll (Chl) degradation has been largely elucidated, how Chl is rapidly yet coordinately degraded during leaf senescence remains elusive. Pheophytinase (PPH) is the enzyme for catalyzing the removal of the phytol group from pheophytin a, and PPH expression is significantly induced during leaf senescence. To elucidate the transcriptional regulation of PPH, we used a yeast (Saccharomyces cerevisiae) one-hybrid system to screen for its trans-regulators. SUPPRESSOR OF OVEREXPRESSION OF CO 1 (SOC1), a key flowering pathway integrator, was initially identified as one of the putative trans-regulators of PPH After dark treatment, leaves of an SOC1 knockdown mutant (soc1-6) showed an accelerated yellowing phenotype, whereas those of SOC1-overexpressing lines exhibited a partial stay-green phenotype. SOC1 and PPH expression showed a negative correlation during leaf senescence. Substantially, SOC1 protein could bind specifically to the CArG box of the PPH promoter in vitro and in vivo, and overexpression of SOC1 significantly inhibited the transcriptional activity of the PPH promoter in Arabidopsis (Arabidopsis thaliana) protoplasts. Importantly, soc1-6 pph-1 (a PPH knockout mutant) double mutant displayed a stay-green phenotype similar to that of pph-1 during dark treatment. These results demonstrated that SOC1 inhibits Chl degradation via negatively regulating PPH expression. In addition, measurement of the Chl content and the maximum photochemical efficiency of photosystem II of soc1-6 and SOC1-OE leaves after dark treatment suggested that SOC1 also negatively regulates the general senescence process. Seven SENESCENCE-ASSOCIATED GENES (SAGs) were thereafter identified as its potential target genes, and NONYELLOWING1 and SAG113 were experimentally confirmed. Together, we reveal that SOC1 represses dark-induced leaf Chl degradation and senescence in general in Arabidopsis.
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Proteínas de Arabidopsis/genética , Arabidopsis/genética , Regulación de la Expresión Génica de las Plantas/genética , Hidrolasas/genética , Proteínas de Dominio MADS/genética , Hojas de la Planta/genética , Arabidopsis/metabolismo , Arabidopsis/fisiología , Proteínas de Arabidopsis/metabolismo , Clorofila/metabolismo , Oscuridad , Regulación de la Expresión Génica de las Plantas/efectos de la radiación , Hidrolasas/metabolismo , Proteínas de Dominio MADS/metabolismo , Mutación , Fenotipo , Feofitinas/metabolismo , Fosfoproteínas Fosfatasas/genética , Fosfoproteínas Fosfatasas/metabolismo , Hojas de la Planta/metabolismo , Hojas de la Planta/fisiología , Regiones Promotoras Genéticas/genética , Unión Proteica , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
Degreening, caused by chlorophyll degradation, is the most obvious symptom of senescing leaves. Chlorophyll degradation can be triggered by endogenous and environmental cues, and ethylene is one of the major inducers. ETHYLENE INSENSITIVE3 (EIN3) is a key transcription factor in the ethylene signaling pathway. It was previously reported that EIN3, miR164, and a NAC (NAM, ATAF, and CUC) transcription factor ORE1/NAC2 constitute a regulatory network mediating leaf senescence. However, how this network regulates chlorophyll degradation at molecular level is not yet elucidated. Here we report a feed-forward regulation of chlorophyll degradation that involves EIN3, ORE1, and chlorophyll catabolic genes (CCGs). Gene expression analysis showed that the induction of three major CCGs, NYE1, NYC1 and PAO, by ethylene was largely repressed in ein3 eil1 double mutant. Dual-luciferase assay revealed that EIN3 significantly enhanced the promoter activity of NYE1, NYC1 and PAO in Arabidopsis protoplasts. Furthermore, Electrophoretic mobility shift assay (EMSA) indicated that EIN3 could directly bind to NYE1, NYC1 and PAO promoters. These results reveal that EIN3 functions as a positive regulator of CCG expression during ethylene-mediated chlorophyll degradation. Interestingly, ORE1, a senescence regulator which is a downstream target of EIN3, could also activate the expression of NYE1, NYC1 and PAO by directly binding to their promoters in EMSA and chromatin immunoprecipitation (ChIP) assays. In addition, EIN3 and ORE1 promoted NYE1 and NYC1 transcriptions in an additive manner. These results suggest that ORE1 is also involved in the direct regulation of CCG transcription. Moreover, ORE1 activated the expression of ACS2, a major ethylene biosynthesis gene, and subsequently promoted ethylene production. Collectively, our work reveals that EIN3, ORE1 and CCGs constitute a coherent feed-forward loop involving in the robust regulation of ethylene-mediated chlorophyll degradation during leaf senescence in Arabidopsis.
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Envejecimiento/genética , Proteínas de Arabidopsis/genética , Arabidopsis/fisiología , Etilenos/metabolismo , Proteínas Nucleares/genética , Factores de Transcripción/genética , Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Clorofila/metabolismo , Inmunoprecipitación de Cromatina , Proteínas de Unión al ADN/genética , Ensayo de Cambio de Movilidad Electroforética , Regulación de la Expresión Génica de las Plantas/genética , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Oxidorreductasas/genética , Oxidorreductasas/metabolismo , Oxigenasas/genética , Oxigenasas/metabolismo , Hojas de la Planta/crecimiento & desarrollo , Hojas de la Planta/fisiología , Regiones Promotoras Genéticas/genética , Unión Proteica/genética , Proteínas Represoras/genética , Transducción de Señal/genéticaRESUMEN
The major developmental significance of leaf senescence is the massive recycling of nutrients from senescing leaves to nascent organs, including seeds, to meet the requirement of their rapid development, so-called nutrient remobilization. The efficiency of nutrient remobilization is associated with the activity of diverse transporters. A large number of transporters are up-regulated during leaf senescence in Arabidopsis, many of which participate in regulating leaf senescence via different signaling pathways. Here, we report that a member of the cation/Ca2+ exchanger family, CCX1, is highly induced during leaf senescence in Arabidopsis. Although single mutation of CCX1 did not change the senescence phenotype, double mutation of CCX1 and CCX4 resulted in a subtle but significant stay-green phenotype during natural and dark-induced leaf senescence, suggesting that some members of the cation/Ca2+ exchanger family act redundantly in mediating leaf senescence. Consistently, overexpression of CCX1 accelerated leaf senescence. Moreover, the ccx1ccx4 double mutant was more tolerant to H2O2, whereas CCX1-overexpressing lines showed an elevated response to H2O2 treatment, presumably due to an overaccumulation of reactive oxygen species (ROS), indicating that CCX1 may promote leaf senescence via modulating ROS homeostasis. Notably, both ccx1-1 and ccx1ccx4 were sensitive to Ca2+ deprivation, implying that CCX1 may also be involved in modulating Ca2+ signaling and consequently affecting the initiation of leaf senescence.
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Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Calcio/metabolismo , Cationes/metabolismo , Regulación de la Expresión Génica de las Plantas , Especies Reactivas de Oxígeno/metabolismo , Antiportadores , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Canales de Calcio , Senescencia Celular , Oscuridad , Expresión Génica , Homeostasis , Peróxido de Hidrógeno/metabolismo , Bombas Iónicas/genética , Bombas Iónicas/metabolismo , Mutación , Fenotipo , Hojas de la Planta/genética , Hojas de la Planta/metabolismo , Plantas Modificadas Genéticamente , Semillas/genética , Semillas/metabolismo , Transducción de SeñalRESUMEN
BACKGROUND: Tracheal fistulas (TF) can be dangerous and even fatal in patients. The current treatment is really challenging. Previous studies reported that mesenchymal stem cells (MSCs) could be used to treat respiratory tract fistulas. Stem cells from human exfoliated deciduous teeth (SHED) are considered to be MSC-like cells that may also have the potential to treat the tracheal fistulas. In this study, we investigated the therapeutic effects of SHED in rat tracheal fistula models. METHODS: A total of 80 SD rats were randomly divided into five groups: a sham-operated group, a local PBS group (L-PBS), an intravenous PBS group (I-PBS), a local SHED treatment group (L-SHED), and an intravenous SHED treatment group (I-SHED). The L-SHED and I-SHED groups were given a topical application around the fistula or an intravenous injection of 1*107 SHED via the tail vein, respectively, while the L-PBS and I-PBS groups were given an equivalent volume of PBS through local or intravenous administration. A stereomicroscope was used to observe fistula healing on the 2nd, 3rd, and 5th days following transplantation. On the 7th day, the survival of SHED was observed by immunofluorescence. The pathology of the lungs and fistulas was observed by hematoxylin and eosin (H&E) and Masson staining. The expression levels of the Toll-like receptor 4 (TLR4), interleukin (IL)-1ß, IL-33, and IL-4 were measured using immunohistochemistry. The expression levels of TLR4, high mobility group box 1 (HMGB1), and myeloid differentiation factor 88 (MYD88) were studied using western blotting. On day 14, airway responsiveness of rats was detected and analyzed. RESULTS: Fistula healing in the L-SHED and I-SHED groups was faster than that in their respective PBS groups after transplantation. The fistula diameters in the L-SHED and I-SHED groups were significantly smaller than those in the L-PBS and I-PBS groups on the 3rd day. Moreover, the phenomenon of fibroblast proliferation and new blood vessel growth around the fistula seemed more pronounced in the L-SHED and I-SHED groups. Although no discernible difference was found in airway responsiveness after SHED treatment, the degree of inflammation in the lungs was reduced by intravenous SHED treatment. However, there was no significant reduction in lung inflammation by local SHED treatment. The expression levels of IL-1ß and IL-33 were decreased in the I-SHED group, while IL-4 was elevated compared with the I-PBS group. Interestingly, intravenous SHED treatment inhibited the activation of HMGB1/TLR4/MYD88 in the lung tissues of TF rats. CONCLUSIONS: SHED transplantation accelerated the rate of fistula healing in rats. Intravenous SHED treatment reduced lung inflammation. Thus, SHED may have potential in the treatment of tracheal fistula, providing hope for future therapeutic development for TF.
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Proteína HMGB1 , Fístula del Sistema Respiratorio , Animales , Proteína HMGB1/metabolismo , Humanos , Interleucina-33/metabolismo , Interleucina-4/metabolismo , Factor 88 de Diferenciación Mieloide/metabolismo , Ratas , Ratas Sprague-Dawley , Células Madre/metabolismo , Receptor Toll-Like 4/genética , Receptor Toll-Like 4/metabolismo , Diente PrimarioRESUMEN
Pathogenic microorganisms deliver protein effectors into host cells to suppress host immune responses. Recent findings reveal that phytopathogens manipulate the function of plant cell-to-cell communication channels known as plasmodesmata (PD) to promote diseases. Several bacterial and filamentous pathogen effectors have been shown to regulate PD in their host cells. A few effectors of filamentous pathogens have been reported to move from the infected cells to neighboring plant cells through PD; however, it is unclear whether bacterial effectors can traffic through PD in plants. In this study, we determined the intercellular movement of Pseudomonas syringae pv. tomato (Pst) DC3000 effectors between adjoining plant cells in Nicotiana benthamiana. We observed that at least 16 Pst DC3000 effectors have the capacity to move from transformed cells to the surrounding plant cells. The movement of the effectors is largely dependent on their molecular weights. The expression of PD regulators, Arabidopsis PD-located protein PDLP5 and PDLP7, leads to PD closure and inhibits the PD-dependent movement of a bacterial effector in N. benthamiana. Similarly, a 22-amino acid peptide of bacterial flagellin (flg22) treatment induces PD closure and suppresses the movement of a bacterial effector in N. benthamiana. Among the mobile effectors, HopAF1 and HopA1 are localized to the plasma membrane (PM) in plant cells. Interestingly, the PM association of HopAF1 does not negatively affect the PD-dependent movement. Together, our findings demonstrate that bacterial effectors are able to move intercellularly through PD in plants.
RESUMEN
To explore mechanism of intestinal flora dysregulation promoting constipation, 60 specific pathogen-free (SPF) mice were used as research objects and were treated with constipation population fecal fluid gavage and distilled water gavage. Then, relationship between intestinal dysregulation and constipation in mice with biofilm-mediated intestinal flora was investigated in vitro. The results showed that recombinant serotonin transporter (SERT) messenger ribonucleic acid (mRNA) level of the constipation population fecal fluid gavage group and the relative expression level of SERT mRNA were 1.61 ± 0.08 and 1.49 ± 0.06, which were higher markedly than those of distilled water group (P < 0.05). The level of 5-hydroxytryptamine (5-HT) in colonic tissue of the constipation population fecal fluid gavage group was 145.36 ± 14.12 ng/mL, and the expression level of 5-HT on the surface of epithelial cells of biofilm-positive colonic tissue was 20.11 ± 2.03, which were significantly lower than those of the distilled water group, with statistical significance (P < 0.05). Besides, the microbial sequencing of fecal flora indicated that The Akk and bacteroidetes ofconstipation population fecal fluid gavage group were higher hugely than those of distilled water group (P < 0.05).In conclusion, after the occurrence of constipation, the diversity of intestinal microflora decreased, and the probiotics reduced. Iintestinal microflora dysregulation would lead to increase of SERT expression level in defecation function and intestinal motility in mice, and the decrease of 5-HT, thereby changing the intestinal movement resulting in mucosal protective barrier damage,thereby causing changes in intestinal movement and the destruction of the intestinal mucosal protective barrier, which eventually resulted in constipation. The occurrence of constipation could be improved by regulating balance of intestinal flora, increasing the diversity of flora, and reducing the genus of opportunistic pathogens.
Asunto(s)
Estreñimiento , Disbiosis , Microbioma Gastrointestinal/fisiología , Animales , Biopelículas , Estreñimiento/microbiología , Estreñimiento/fisiopatología , Disbiosis/microbiología , Disbiosis/fisiopatología , Heces/microbiología , Femenino , Mucosa Intestinal/fisiopatología , Masculino , Ratones , Proteínas de Transporte de Serotonina en la Membrana Plasmática/metabolismoRESUMEN
GammadeltaT cells are considered as linkage between innate and adaptive immune response, which recognize specific antigen without MHC-restriction. Vgamma9Vdelta2T cells, isolated from peripheral blood and tumor tissue, can be activated by non-peptide phosphoantigen through binding to its gammadeltaTCR and proliferate under IL-2 stimulation. It has been shown that Vgamma9Vdelta2T cells possess anticancer activity against several types of tumor in vitro, as well as inhibit the growth of lymphoma, breast cancer and malignant melanoma in vivo. The phase I clinical trial of the application of Vgamma9Vdelta2T cells in treatment of lung cancer, renal cancer and prostate cancer demonstrated promising results. This review summarizes the recent advances in antigen recognition and activation of gammadeltaT cells, and the gammadeltaT cell-based immunotherapy for cancer treatment.