RESUMO
Neonatal arrhythmias are significant contributors to infant mortality. Timely diagnosis and treatment are essential for neonates with non-benign arrhythmias to avoid severe complications, and ongoing treatment and follow-up are sometimes needed. The main objective of this study will be to understand the incidence and demographic characteristics of arrhythmias in hospitalized neonates in China and the related factors of outcomes. A secondary objective will be to establish the first follow-up system for neonatal arrhythmias in China. The medical burdens of neonatal arrhythmias in China will also be investigated. The data from the Futang Research Center of Pediatric Development (FRCPD) database between January 2016 and December 2021 were obtained. Newborns admitted to member hospitals with a discharge diagnosis of "neonatal arrhythmia" (ICD-10 code P29.151) or "arrhythmia" (ICD-10 code I49.904) were included. The medical record information was collected and classified into two groups: heart failure and non-heart failure. The differences between the two groups and independent risk factors for neonatal arrhythmias complicated with heart failure were analyzed. In addition, a follow-up study of patients discharged from Beijing Children's Hospital was conducted to evaluate their outcomes at the age of 3 years old. Factors influencing hospitalization costs were analyzed using rank-sum tests and multiple linear regression. It is anticipated that the study findings will provide new and comprehensive data on the health needs of neonatal arrhythmias in China. The study will establish the first follow-up system for neonatal arrhythmias in China. This study will help reduce the burden of patients and their families as well as the society.
Assuntos
Insuficiência Cardíaca , Hospitais , Lactente , Humanos , Recém-Nascido , Criança , Pré-Escolar , Seguimentos , Estudos Retrospectivos , China/epidemiologia , Arritmias Cardíacas/epidemiologia , Arritmias Cardíacas/terapiaRESUMO
Sulfur-driven autotrophic denitrification (S0dAD) was employed to remove residual nitrogen from the biological effluent of landfill leachate after partial nitrification and denitrification pretreatment. The performance of S0dAD were assessed with various NOx--N (NO2--N and NO3--N) loadings over a 185-day operational period. The results demonstrated that a notable NOx--N removal efficiency of 97.8 ± 2.0% was achieved under nitrogen removal rates of 0.12 ± 0.02 kg N/(m3· d), leading to total nitrogen concentrations of 8.6 ± 3.8 mg/L in the effluent. Batch experiments revealed competitive utilization of nitrogenous electron acceptors, with NO2--N demonstrating 2-4 times higher denitrification rates than NO3--N under coexistence conditions. Genus-level microbial community identified that Thiobacillus and Sulfurovum was highly enriched with as key denitrifying bacteria in the S0dAD system. These findings provide insights for advanced nitrogen removal coupling S0dAD with partial nitrification and denitrification process for landfill leachate treatment.
Assuntos
Desnitrificação , Nitrificação , Nitrogênio , Enxofre , Poluentes Químicos da Água , Nitrogênio/metabolismo , Enxofre/metabolismo , Poluentes Químicos da Água/metabolismo , Processos AutotróficosRESUMO
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel coronavirus that is currently causing a pandemic and has been termed coronavirus disease (COVID-19). The elderly or those with preexisting conditions like diabetes, hypertension, coronary heart disease, chronic obstructive pulmonary disease, cerebrovascular disease, or kidney dysfunction are more likely to develop severe cases when infected. Patients with COVID-19 admitted to the ICU have higher mortality than non-ICU patients. Critical illness has consistently posed a challenge not only in terms of mortality but also in regard to long-term outcomes of survivors. Patients who survive acute critical illness including, but not limited to, pulmonary and systemic insults associated with acute respiratory distress syndrome, pneumonia, systemic inflammation, and mechanical ventilation, will likely suffer from post-ICU syndrome, a phenomenon of cognitive, psychiatric, and/or physical disability after treatment in the ICU. Post-ICU morbidity and mortality continue to be a cause for concern when considering large-scale studies showing 12-month mortality risks of 11.8-21%. Previous studies have demonstrated that multiple mechanisms, including cytokine release, mitochondrial dysfunction, and even amyloids, may lead to end-organ dysfunction in patients. We hypothesize that COVID-19 infection will lead to post-ICU syndrome via potentially similar mechanisms as other chronic critical illnesses and cause long-term morbidity and mortality in patients. We consider a variety of mechanisms and questions that not only consider the short-term impact of the COVID-19 pandemic but its long-term effects that may not yet be imagined.
Assuntos
COVID-19 , Pandemias , Idoso , Cuidados Críticos , Estado Terminal , Humanos , SARS-CoV-2RESUMO
Pulmonary microvascular endothelial cells (PMVECs) uniquely express an α1G-subtype of voltage-gated T-type Ca2+ channel. We have previously revealed that the α1G channel functions as a background Ca2+ entry pathway that is critical for the cell proliferation, migration, and angiogenic potential of PMVECs, a novel function attributed to the coupling between α1G-mediated Ca2+ entry and constitutive Akt phosphorylation and activation. Despite this significance, mechanism(s) that link the α1G-mediated Ca2+ entry to Akt phosphorylation remain incompletely understood. In this study, we demonstrate that Ca2+/calmodulin-dependent protein kinase (CaMK) 4 serves as a downstream effector of the α1G-mediated Ca2+ entry to promote the angiogenic potential of PMVECs. Notably, CaMK2 and CaMK4 are both expressed in PMVECs. Pharmacological blockade or genetic knockdown of the α1G channel led to a significant reduction in the phosphorylation level of CaMK4 but not the phosphorylation level of CaMK2. Pharmacological inhibition as well as genetic knockdown of CaMK4 significantly decreased cell proliferation, migration, and network formation capacity in PMVECs. However, CaMK4 inhibition or knockdown did not alter Akt phosphorylation status in PMVECs, indicating that α1G/Ca2+/CaMK4 is independent of the α1G/Ca2+/Akt pathway in sustaining the cells' angiogenic potential. Altogether, these findings suggest a novel α1G-CaMK4 signaling complex that regulates the Ca2+-dominated angiogenic potential in PMVECs.
Assuntos
Canais de Cálcio Tipo T/metabolismo , Sinalização do Cálcio , Proteína Quinase Tipo 4 Dependente de Cálcio-Calmodulina/metabolismo , Cálcio/metabolismo , Células Endoteliais/enzimologia , Pulmão/irrigação sanguínea , Microvasos/enzimologia , Neovascularização Fisiológica , Inibidores da Angiogênese/farmacologia , Animais , Sinalização do Cálcio/efeitos dos fármacos , Proteína Quinase Tipo 4 Dependente de Cálcio-Calmodulina/antagonistas & inibidores , Proteína Quinase Tipo 4 Dependente de Cálcio-Calmodulina/genética , Movimento Celular , Proliferação de Células , Células Cultivadas , Células Endoteliais/efeitos dos fármacos , Masculino , Microvasos/efeitos dos fármacos , Neovascularização Fisiológica/efeitos dos fármacos , Fosforilação , Inibidores de Proteínas Quinases/farmacologia , Ratos Sprague-DawleyRESUMO
Cadmium (Cd) is present in many soils and, when enter a food chain, represents a major health threat to humans. The existent large variation in grain Cd content amongst wheat genotypes opens prospects for genetic improvement for reduced Cd uptake in this species. However, selecting low-Cd-accumulating varieties comes with a possible caveat of affecting uptake other essential nutrients. In this work, we screened 134 wheat varieties in 3 various field studies and selected 15 high- and 15 low-Cd accumulating varieties in grains for ionomics analysis. Our results showed that high-Cd accumulating varieties also possessed an ability to accumulate mineral elements of calcium, magnesium, manganese, iron and zinc, while varieties with low Cd content were deficient in many essential nutrients and, especially, zinc (Zn). The above data was confirmed in an independent trail involving another 97 wheat varieties. Thus, selecting plants for high Zn accumulation (as a part of biofortification programs) resulted in an inadvertent increase in accumulation of the toxic Cd in wheat. Vice versa, selecting low Cd-accumulating varieties comes with a danger of reducing their Zn content, with major consequences to food quality and human health. We suggest that the above conundrum can be resolved by understanding the structure-function relations of various transporters isoforms involved in Zn and Cd transport and issue-specific mode of their operation, via cell-based phenotyping followed by molecular breeding.
Assuntos
Cádmio , Poluentes do Solo , Cádmio/análise , Grão Comestível/química , Humanos , Solo , Poluentes do Solo/análise , Triticum/genética , Zinco/análiseRESUMO
Molybdenum (Mo), which is an essential microelement for plant growth, plays important roles in multiple metabolic and physiological processes, including responses to drought and cold stress in wheat. Lipids also have crucial roles in plant adaptions to abiotic stresses. The aim of this study was to use glycerolipidomic and transcriptomic analyses to determine the changes in lipids induced by Mo that are associated with Mo-enhanced drought tolerance in wheat. Mo treatments increased the transcript levels of genes involved in fatty acid and glycerolipid biosynthesis and desaturation, but suppressed the expression of genes involved in oxylipin production. Wheat plants supplemented with Mo displayed higher contents of monogalactosyldiacyglycerol (MGDG), digalactosyldoacylglycerol (DGDG), phosphatidylglycerol (PG), phosphatidylethanolamine (PE), and phosphatidylcholine (PC) with increased levels of unsaturation. The levels of MGDG, DGDG, PG, and PC increased under PEG-simulated drought (PSD), and the magnitude of the responses varied in the presence and absence of Mo. Mo increased the accumulation of the most abundant glycerolipid species of C36:6, C34:4, and C34:3 by increasing the expression of genes related to desaturation under PSD, and this contributed to maintaining the fluidity of membranes. In addition, Mo attenuated the decreases in the ratios of DGDG/MGDG and PC/PE that were observed under PSD. These changes in lipids in Mo-treated wheat would contribute to maintaining the integrity of membranes and to protecting the photosynthetic apparatus, thus acting together to enhance drought tolerance.
Assuntos
Secas , Triticum , Adaptação Fisiológica , Molibdênio , Estresse Fisiológico , Triticum/genéticaRESUMO
Pulmonary microvascular endothelial cells (PMVECs) display a rapid angioproliferative phenotype, essential for maintaining homeostasis in steady-state and promoting vascular repair after injury. Although it has long been established that endothelial cytosolic Ca2+ ([Ca2+]i) transients are required for proliferation and angiogenesis, mechanisms underlying such regulation and the transmembrane channels mediating the relevant [Ca2+]i transients remain incompletely understood. In the present study, the functional role of the microvascular endothelial site-specific α1G T-type Ca2+ channel in angiogenesis was examined. PMVECs intrinsically possess an in vitro angiogenic "network formation" capacity. Depleting extracellular Ca2+ abolishes network formation, whereas blockade of vascular endothelial growth factor receptor or nitric oxide synthase has little or no effect, suggesting that the network formation is a [Ca2+]i-dependent process. Blockade of the T-type Ca2+ channel or silencing of α1G, the only voltage-gated Ca2+ channel subtype expressed in PMVECs, disrupts network formation. In contrast, blockade of canonical transient receptor potential (TRP) isoform 4 or TRP vanilloid 4, two other Ca2+ permeable channels expressed in PMVECs, has no effect on network formation. T-type Ca2+ channel blockade also reduces proliferation, cell-matrix adhesion, and migration, three major components of angiogenesis in PMVECs. An in vivo study demonstrated that the mice lacking α1G exhibited a profoundly impaired postinjury cell proliferation in the lungs following lipopolysaccharide challenge. Mechanistically, T-type Ca2+ channel blockade reduces Akt phosphorylation in a dose-dependent manner. Blockade of Akt or its upstream activator, phosphatidylinositol-3-kinase (PI3K), also impairs network formation. Altogether, these findings suggest a novel functional role for the α1G T-type Ca2+ channel to promote the cell's angiogenic potential via a PI3K-Akt signaling pathway.
Assuntos
Canais de Cálcio Tipo T/metabolismo , Células Endoteliais/metabolismo , Pulmão/metabolismo , Neovascularização Patológica/metabolismo , Animais , Cálcio/metabolismo , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Células Endoteliais/efeitos dos fármacos , Feminino , Lipopolissacarídeos/farmacologia , Pulmão/efeitos dos fármacos , Masculino , Camundongos , Fosfatidilinositol 3-Quinase/metabolismo , Ratos , Transdução de Sinais/efeitos dos fármacos , Canais de Cátion TRPC/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
The present study sought to determine the pharmacological effects of penehyclidine, an anticholinergic agent, on the angiogenic capacity of pulmonary microvascular endothelial cells (PMVECs). In vitro Matrigel network formation assay, cell proliferation assay, cell-matrix adhesion assay, and wound-healing assay were performed in PMVECs with or without exposure to penehyclidine or, in some cases, glycopyrrolate or acetylcholine, over a concentration range. In addition, the phosphorylation state of Akt and ERK, as well as the endogenous level of mTOR and RICTOR were examined in PMVECs by Western blot following the cells exposure to penehyclidine or, for some proteins, glycopyrrolate or acetylcholine. Finally, Western blot for Akt phosphorylation and in vitro Matrigel network formation assay were performed in PMVECs following their exposure to penehyclidine with or without phosphoinositide 3-kinase (PI3K) inhibitor LY294002 or mTOR inhibitor torin-1. We found that, in PMVECs, penehyclidine affected the network formation and cell migration, but not proliferation or cell-matrix adhesion, in a concentration-specific manner, i.e., penehyclidine increased the network formation and cell migration at lower concentrations but increased these processes at higher concentrations. Coincidentally, we observed that penehyclidine concentration-specifically affected the phosphorylation state of Akt in PMVECs, i.e., increased Akt phosphorylation at lower concentrations and decreased it at higher concentrations. In contrast, glycopyrrolate was found straightly to decrease network formation and Akt phosphorylation in a concentration-dependent manner. Further, we demonstrated that PI3K or mTOR blockade abolished both the enhanced network formation and the increased Akt phosphorylation by penehyclidine. Hence, penehyclidine may differentially alter the angiogenic capacity of PMVECs through affecting the Akt signaling pathway downstream of PI3K and mTOR. Findings from this study suggest a unique pharmacological feature of penehyclidine, which may imply its clinical and therapeutic value in modulating angiogenesis.
Assuntos
Antagonistas Colinérgicos/farmacologia , Células Endoteliais/efeitos dos fármacos , Neovascularização Fisiológica/efeitos dos fármacos , Quinuclidinas/farmacologia , Animais , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Cromonas/farmacologia , Células Endoteliais/citologia , Endotélio Vascular/citologia , Endotélio Vascular/efeitos dos fármacos , Pulmão/irrigação sanguínea , Pulmão/citologia , Pulmão/efeitos dos fármacos , Morfolinas/farmacologia , Fosfatidilinositol 3-Quinase/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Serina-Treonina Quinases TOR/metabolismoRESUMO
Zinc (Zn) possesses similar properties to cadmium (Cd) and inhibits Cd uptake in plants. To get more detailed mechanisms of Zn-inhibited Cd uptake in pakchoi, a hydroponic experiment was conducted to investigate the effects of various Zn levels on Cd concentrations, real time flux of Cd, expressions of genes related to Cd uptake under Cd exposure. The results showed that the Cd concentrations and Cd accumulations in pakchoi root decreased with increasing Zn levels, which were coincident with that real time Cd influx and net Cd influx of pakchoi root decreased with increasing Zn levels by non-invasive micro-test technology (NMT). Additionally, the expressions of Cd-related transporters including BcNRAMP5, BcIRT1 and BcMGT1 decreased with the increase of Zn levels under Cd exposure, especially BcIRT1 with the highest decreased rates. Furthermore, the expressions of these genes decreased gradually with the prolongation of Zn treated time under Cd toxicity. The results indicate that Zn inhibits Cd uptake by inhibition of the expressions of Cd-related transporters, especially BcIRT1 in pakchoi root.
Assuntos
Brassica/metabolismo , Cádmio/análise , Microeletrodos , Zinco/análise , Transporte Biológico , Cádmio/farmacocinética , Proteínas de Transporte de Cátions/genética , Proteínas de Transporte de Cátions/metabolismo , Regulação da Expressão Gênica de Plantas , Hidroponia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , Zinco/farmacocinéticaRESUMO
KEY MESSAGE: Our study first reveals that Mo mediates oxidative tolerance through ABA signaling. Moreover, NO acts downstream of ABA signaling in Mo-induced oxidative tolerance in wheat under drought stress. Nitric oxide (NO) is related to the improvement of molybdenum (Mo)-induced oxidative tolerance. While the function of Mo in abscisic acid (ABA) synthesis and in mediating oxidative tolerance by the interaction of ABA and NO remain to be studied. The -Mo and +Mo treatment-cultivated wheat was separated and subsequently was pretreated with AO inhibitor, ABA synthesis inhibitor, exogenous ABA, NO scavenger, NO donor or their combinations under polyethylene glycol 6000 (PEG)-stimulated drought stress (PSD). The AO activity and ABA content were increased by Mo in wheat under PSD, however, AO inhibitor decreased AO activity, correspondingly reduced ABA accumulation, suggesting that AO involves in the regulation of Mo-induced ABA synthesis. Mo enhanced activities and expressions of antioxidant enzyme, while these effects of Mo were reversed by AO inhibitor and ABA synthesis inhibitor due to the decrease of ABA content, but regained by exogenous ABA, indicating that Mo induces oxidative tolerance through ABA. Moreover, NO scavenger inhibited activities of antioxidant enzyme caused by Mo and exogenous ABA, but the inhibitions were eliminated by NO donor, indicating that NO is involved in ABA pathway in the regulation of Mo-induced oxidative tolerance in wheat under PSD. Finally, we proposed a scheme for the mechanism of Mo-induced oxidative tolerance.
Assuntos
Ácido Abscísico/metabolismo , Molibdênio/metabolismo , Óxido Nítrico/metabolismo , Estresse Oxidativo/fisiologia , Triticum/fisiologia , Ácido Abscísico/farmacologia , Adaptação Fisiológica/efeitos dos fármacos , Adaptação Fisiológica/fisiologia , Aldeído Oxidase/metabolismo , Antioxidantes/metabolismo , Secas , Modelos Biológicos , Molibdênio/farmacologia , Doadores de Óxido Nítrico/farmacologia , Nitroprussiato/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Reguladores de Crescimento de Plantas/metabolismo , Reguladores de Crescimento de Plantas/farmacologia , Estresse Fisiológico , Triticum/metabolismoRESUMO
Most plants exhibit strong tolerance to excess molybdenum (Mo). However, the metabolic profile and tolerance mechanisms of plants in response to excess Mo remain unknown. We comprehensively analyzed changes in the metabolic profiles of leaves and roots in soybean (Glycine max L.) seedlings cultured under normal-Mo and excess-Mo conditions by using ultra performance liquid chromatography (UPLC) combined with MS/MS (mass spectrometry). There were 42 differential metabolites in the roots and 19 differential metabolites in the leaves in response to excess Mo stress. In roots, the organic acids, levels of gluconic acid, D-glucarate and citric acid increased by 107.63-, 4.42- and 2.87-folds after excess Mo exposure. Several hormones (salicylic acid, jasmonic acid) and lipids (PG, MG, DG etc) also increased significantly under excess Mo condition. Metabolites related to ascorbate-glutathione metabolism and flavonoid and isoflavone biosynthesis notably accumulated in roots. Only lipid metabolism and salicylic acid accumulation were induced in leaves under excess Mo stress. It is speculated that organic compounds such as 2-oxoarginine, L-nicotine, gluconic acid, D-glucurate, and citric acid played important roles to chelate Mo and reduce its toxicity. Signaling molecules (JA, SA, and some lipids) and non-enzyme antioxidants such as flavonoids/isoflavones act synergistically to detoxify ROS and contribute to Mo tolerance in soybean seedlings. More metabolic pathways were induced by Mo excess in roots than in leaves, suggesting that roots play more implant role in Mo tolerance.
Assuntos
Glycine max/metabolismo , Metabolômica , Molibdênio/metabolismo , Ciclopentanos/metabolismo , Exposição Ambiental , Metaboloma , Oxilipinas/metabolismo , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Ácido Salicílico/metabolismo , Plântula/metabolismoRESUMO
The low-voltage-activated T-type Ca(2+) channels play an important role in mediating the cellular responses to altered oxygen tension. Among three T-type channel isoforms, α1G, α1H, and α1I, only α1H was found to be upregulated under hypoxia. However, mechanisms underlying such hypoxia-dependent isoform-specific gene regulation remain incompletely understood. We, therefore, studied the hypoxia-dependent transcriptional regulation of α1G and α1H gene promoters with the aim to identify the functional hypoxia-response elements (HREs). In rat pulmonary artery smooth muscle cells (PASMCs) and pheochromocytoma (PC12) cells after hypoxia (3% O2) exposure, we observed a prominent increase in α1H mRNA at 12 h along with a significant rise in α1H-mediated T-type current at 24 and 48 h. We then cloned two promoter fragments from the 5'-flanking regions of rat α1G and α1H gene, 2,000 and 3,076 bp, respectively, and inserted these fragments into a luciferase reporter vector. Transient transfection of PASMCs and PC12 cells with these recombinant constructs and subsequent luciferase assay revealed a significant increase in luciferase activity from the reporter containing the α1H, but not α1G, promoter fragment under hypoxia. Using serial deletion and point mutation analysis strategies, we identified a functional HRE at site -1,173cacgc-1,169 within the α1H promoter region. Furthermore, an electrophoretic mobility shift assay using this site as a DNA probe demonstrated an increased binding activity to nuclear protein extracts from the cells after hypoxia exposure. Taken together, these findings indicate that hypoxia-induced α1H upregulation involves binding of hypoxia-inducible factor to an HRE within the α1H promoter region.
Assuntos
Canais de Cálcio Tipo T/genética , Transcrição Gênica , Animais , Sítios de Ligação , Canais de Cálcio Tipo T/metabolismo , Hipóxia Celular , Potenciais da Membrana , Músculo Liso Vascular/metabolismo , Mutação , Miócitos de Músculo Liso/metabolismo , Células PC12 , Artéria Pulmonar/metabolismo , Veias Pulmonares/metabolismo , RNA Mensageiro/metabolismo , Ratos , Elementos de Resposta , Fatores de Tempo , Transfecção , Regulação para CimaRESUMO
RATIONALE: Canonical transient receptor potential 4 (TRPC4) contributes to the molecular composition of a channel encoding for a calcium selective store-operated current, I(SOC), whereas Orai1 critically comprises a channel encoding for the highly selective calcium release activated calcium current, I(CRAC). However, Orai1 may interact with TRPC proteins and influence their activation and permeation characteristics. Endothelium expresses both TRPC4 and Orai1, and it remains unclear as to whether Orai1 interacts with TRPC4 and contributes to calcium permeation through the TPRC4 channel. OBJECTIVE: We tested the hypothesis that Orai1 interacts with TRPC4 and contributes to the channel's selective calcium permeation important for endothelial barrier function. METHODS AND RESULTS: A novel method to purify the endogenous TRPC4 channel and probe for functional interactions was developed, using TRPC4 binding to protein 4.1 as bait. Isolated channel complexes were conjugated to anti-TRPC protein antibodies labeled with cy3-cy5 pairs. Förster Resonance Energy Transfer among labeled subunits revealed the endogenous protein alignment. One TRPC1 and at least 2 TRPC4 subunits constituted the endogenous channel (TRPC1/4). Orai1 interacted with TRPC4. Conditional Orai1 knockdown reduced the probability for TRPC1/4 channel activation and converted it from a calcium-selective to a nonselective channel, an effect that was rescued on Orai1 reexpression. Loss of Orai1 improved endothelial cell barrier function. CONCLUSION: Orai1 interacts with TRPC4 in the endogenous channel complex, where it controls TRPC1/4 activation and channel permeation characteristics, including calcium selectivity, important for control of endothelial cell barrier function.
Assuntos
Canais de Cálcio/metabolismo , Cálcio/metabolismo , Células Endoteliais/metabolismo , Canais de Cátion TRPC/metabolismo , Animais , Canais de Cálcio/genética , Permeabilidade Capilar , Transferência Ressonante de Energia de Fluorescência , Células HEK293 , Humanos , Imunoprecipitação , Ativação do Canal Iônico , Potenciais da Membrana , Proteína ORAI1 , Técnicas de Patch-Clamp , Ligação Proteica , Multimerização Proteica , Interferência de RNA , Ratos , Canais de Cátion TRPC/genética , Fatores de Tempo , TransfecçãoRESUMO
Symbiotic nitrogen fixation can reduce the impact of agriculture on the environment by reducing fertilizer input. The rapid development of nanomaterials in agriculture provides a new prospect for us to improve the biological nitrogen fixation ability of leguminous crops. Molybdenum is an important component of nitrogenase, and the potential application of MoO3NPs in agriculture is largely unexplored. In this study, on the basis of verifying that MoO3NPs can improve the nitrogen fixation ability of soybean, the effects of MoO3NPs on the symbiotic nitrogen fixation process of soybean were investigated by using dynamic transcriptome and targeted metabolome techniques. Here we showed that compared with conventional molybdenum fertilizer, minute concentrations of MoO3NPs (0.01-0.1 mg kg-1) could promote soybean growth and nitrogen fixation efficiency. The nodules number, fresh nodule weight and nitrogenase activity of 0.1 mg kg-1 were increased by 17 %, 14 % and 27 %, and plant nitrogen accumulation increased by 17 %. Compared with conventional molybdenum fertilizer, MoO3NPs had a greater effect on apigenin, kaempferol and other flavonoid, and the expression of nodulation related genes such as ENOD93, F3'H. Based on WGCNA analysis, we identified a core gene GmCHS9 that was positively responsive to molybdenum and was highly expressed during MoO3NPs induced nodulation. MoO3NPs could improve the nitrogen fixation ability of soybean by promoting the secretion of flavonoids and the expression of key genes. This study provided a new perspective for the nano-strengthening strategy of nodules development and flavonoid biosynthesis by molybdenum.
Assuntos
Flavonoides , Glycine max , Metaboloma , Molibdênio , Fixação de Nitrogênio , Transcriptoma , Glycine max/efeitos dos fármacos , Fixação de Nitrogênio/efeitos dos fármacos , Fertilizantes , Nodulação/efeitos dos fármacos , Nanopartículas/toxicidade , Nanopartículas Metálicas/toxicidadeRESUMO
The transcriptional activator ß-catenin is a key mediator of the canonical Wnt signaling pathway. ß-catenin itself does not bind DNA but functions via interaction with T-cell factor (TCF)/lymphoid-enhancing factor (LEF) transcription factors. Thus, in the case of active Wnt signaling, ß-catenin, in cooperation with TCF/LEF proteins family, activates the expression of a wide variety of genes. To date, the list of established ß-catenin interacting targets is far from complete. In this study, we aimed to establish the interaction between ß-catenin and transcription factors that might affect TCF activity. We took advantage of EMSA, using TCF as a probe, to screen oligonucleotides known to bind specific transcription factors that might dislodge or antagonize ß-catenin/TCF binding. We found that Sox9 and KLF4 antagonize ß-catenin/TCF binding in HEK293, A549, SW480, and T47D cells. This inhibition of TCF binding was concentration-dependent and correlated to the in vitro TCF-luciferase functional assays. Overexpression of Sox9 and KLF4 transcription factors in cancer cells shows a concentration-dependent reduction of TCF-luciferase as well as the TCF-binding activities. In addition, we demonstrated that both Sox9 and KLF4 interact with ß-catenin in an immunoprecipitation assay and reduce its binding to TCF4. Together, these results demonstrate that Sox9 and KLF4 transcription factors antagonize ß-catenin/TCF in cancer cells.
Assuntos
Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , Fatores de Transcrição SOX9/metabolismo , Fatores de Transcrição/metabolismo , beta Catenina/antagonistas & inibidores , Ligação Competitiva/efeitos dos fármacos , Linhagem Celular Tumoral , Células HEK293 , Humanos , Fator 4 Semelhante a Kruppel , Luciferases/metabolismo , Oligonucleotídeos/farmacologia , Ligação Proteica/efeitos dos fármacos , Fator de Transcrição 4 , beta Catenina/metabolismoRESUMO
RATIONALE: Platelet-activating factor (PAF) increases lung vascular permeability within minutes by activation of acid sphingomyelinase (ASM) and a subsequent nitric oxide (NO)-inhibitable and Ca(2+)-dependent loss in barrier function. OBJECTIVES: To elucidate the molecular mechanisms underlying this response. METHODS: In isolated perfused rat and mouse lungs, endothelial Ca(2+) concentration ([Ca(2+)](i)) was quantified by real-time fluorescence imaging, and caveolae of endothelial cells were isolated and probed for Ca(2+) entry channels. Regulation of transient receptor potential classical (TRPC) 6-mediated currents in lung endothelial cells was assessed by patch clamp technique. MEASUREMENTS AND MAIN RESULTS: PAF increased lung weight gain and endothelial [Ca(2+)](i). This response was abrogated by inhibitors of ASM or in ASM-deficient mice, and replicated by lung perfusion with exogenous ASM or C2-ceramide. PAF increased the caveolar abundance of TRPC6 channels, which was similarly blocked by ASM inhibition. PAF-induced increases in lung endothelial [Ca(2+)](i), vascular filtration coefficient, and edema formation were attenuated by the TRPC inhibitor SKF96365 and in TRPC6-deficient mice, whereas direct activation of TRPC6 replicated the [Ca(2+)](i) and edema response to PAF. The exogenous NO donor PapaNONOate or the cyclic guanosine 3',5'-monophosphate analog 8Br-cGMP blocked the endothelial [Ca(2+)](i) and permeability response to PAF, in that they directly blocked TRPC6 channels without interfering with their PAF-induced recruitment to caveolae. CONCLUSIONS: The present findings outline a new signaling cascade in the induction of PAF-induced lung edema, in that stimulation of ASM causes recruitment of TRPC6 channels to caveolae, thus allowing for Ca(2+) influx and subsequent increases in endothelial permeability that are amplified in the absence of endothelial NO synthesis.
Assuntos
Cálcio/metabolismo , Permeabilidade Capilar , Endotélio Vascular/metabolismo , Pulmão/metabolismo , Fator de Ativação de Plaquetas/metabolismo , Esfingomielina Fosfodiesterase/metabolismo , Canais de Cátion TRPC/metabolismo , Animais , Endotélio Vascular/enzimologia , Técnicas In Vitro , Pulmão/enzimologia , Camundongos , Óxido Nítrico/metabolismo , RatosRESUMO
Estimating a sequence of dynamic undirected graphical models, in which adjacent graphs share similar structures, is of paramount importance in various social, financial, biological, and engineering systems, since the evolution of such networks can be utilized for example to spot trends, detect anomalies, predict vulnerability, and evaluate the impact of interventions. Existing methods for learning dynamic graphical models require the tuning parameters that control the graph sparsity and the temporal smoothness to be selected via brute-force grid search. Furthermore, these methods are computationally burdensome with time complexity O(NP3) for P variables and N time points. As a remedy, we propose a low-complexity tuning-free Bayesian approach, named BASS. Specifically, we impose temporally dependent spike and slab priors on the graphs such that they are sparse and varying smoothly across time. An efficient variational inference algorithm based on natural gradients is then derived to learn the graph structures from the data in an automatic manner. Owing to the pseudo-likelihood and the mean-field approximation, the time complexity of BASS is only O(NP2). To cope with the local maxima problem of variational inference, we resort to simulated annealing and propose a method based on bootstrapping of the observations to generate the annealing noise. We provide numerical evidence that BASS outperforms existing methods on synthetic data in terms of structure estimation, while being more efficient especially when the dimension P becomes high. We further apply the approach to the stock return data of 78 banks from 2005 to 2013 and find that the number of edges in the financial network as a function of time contains three peaks, in coincidence with the 2008 global financial crisis and the two subsequent European debt crisis. On the other hand, by identifying the frequency-domain resemblance to the time-varying graphical models, we show that BASS can be extended to learning frequency-varying inverse spectral density matrices, and further yields graphical models for multivariate stationary time series. As an illustration, we analyze scalp EEG signals of patients at the early stages of Alzheimer's disease (AD) and show that the brain networks extracted by BASS can better distinguish between the patients and the healthy controls.
RESUMO
Exploration of the mechanisms of cadmium (Cd) activation mediated by the rhizosphere process is important to advance our understanding of Cd accumulation in plants. In this study, two oilseed rape cultivars (L338, L351) with varied Cd accumulation traits were applied and the responses of their rhizosphere ecology to Cd stress were investigated by metabolome and microbiome. The results showed that shoot Cd accumulations in L338 accounted for 54.16% and 64.76% of those in L351 under low and high Cd contamination, respectively. Moreover, the cultivars response of rhizosphere process reflected that the lower pH and higher Cd mobility were assigned to the characters of L351, which were induced by the secretion of carboxylic acid (e.g. Acetaminophen cysteine, N-Fructosyl alliin) and the enrichment of bacterial taxa with the capacities of Cd resistant and activation (e.g. Sphingomonas, Flavobacterium, Neorhizobium, Altererythrobacter). Conclusively, the varied Cd accumulation traits of two oilseed rape cultivars were not only derived from the Cd transfer ability, it would be ascribed to Cd mobility regulated by rhizosphere processes as well. The results provide baseline data and a new perspective on the cultivar response of Cd accumulation, thus maintaining cleaner production of oilseed rape.
Assuntos
Brassica napus , Poluentes do Solo , Cádmio/análise , Biodegradação Ambiental , Exsudatos e Transudatos/química , Ácidos Carboxílicos , Raízes de Plantas/químicaRESUMO
This study aims to further examine the effect of Magnesium (Mg) application on fruit quality and carotenoid metabolism in Satsuma mandarin pulp. For this, a field experiment was using 20-year-old Satsuma mandarin (C. unshiu Marc.) for two treatment; (1) CK treatment (without Mg), (2) Mg fertilizer treatment (200 g MgO plant-1). Compared with CK, Mg treatment substantially raised the Mg content in pulp at 90 to 150 DAF (the fruit expansion period), increasing by 15.69%-21.74%. Mg treatment also increased fruit TSS content by 15.84% and 9.88%, decreased fruit TA content in by 34.25% and 33.26% at 195 DAF and 210 DAF (the fruit ripening period). Moreover, at 120 to 195 DAF, Mg treatment significantly increased the levels of lutein, ß-cryptoxanthin, zeaxanthin and violaxanthin in the pulp. This can be explained by the increased expression of important biosynthetic genes, including CitPSY, CitPDS, CitLCYb1, CitLCYb2, CitLCYe, CitHYb, and CitZEP, that played a role in altering the carotenoid composition. The findings of this research offer a novel approach for augmenting both the economic and nutritional worth of citrus fruits.
Assuntos
Citrus , Frutas , Frutas/metabolismo , Magnésio/metabolismo , Carotenoides/metabolismo , Citrus/genética , Regulação da Expressão Gênica de PlantasRESUMO
Nutritional enhancement has been reported to effectively relieve infected symptoms of Huanglongbing, one of the most destructive diseases of citrus. However, few studies focused on the role of plant nutrition in citrus plant-vector (Asian citrus psyllid; Diaphorina citri Kuwayama) interactions, which is regarded as an important part to develop an effective management strategy. METHOD: In the present study, a hydroponic culture was carried out to evaluate the effects of boron deficiency on psyllid feeding process to decode the molecular/biochemical basis of host-psyllid interaction. RESULTS: Boron deficiency was observed to play a major role in accelerating the release of volatile organic compounds, especially methyl salicylate, affecting the shikimic acid pathway through an elevated synthesis of shikimic acid, l-phenylalanine, 3-phenylpyruvic acid and salicylic acid. These changes made citrus leaf more attractive to psyllid adults. Meanwhile, boron deficiency evidently decreased the boron concentration of leaf cell wall fractions, thereby, weakened the structural stability by affecting pectin and cellulose formations. A significant decrease of cell wall mechanical strength was observed in boron-deficiency leaf, which could be the critical reasons to reduce piercing and to increase phloem ingestion during psyllid feeding. CONCLUSION: Our study demonstrated that boron deficiency facilitated the feeding behavior of psyllid adults through elevated release of methyl salicylate, coupled with weakened mechanical properties of cell wall.