RESUMO
FUS is a nuclear RNA-binding protein, and its cytoplasmic aggregation is a pathogenic signature of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). It remains unknown how the FUS-RNA interactions contribute to phase separation and whether its phase behavior is affected by ALS-linked mutations. Here we demonstrate that wild-type FUS binds single-stranded RNA stoichiometrically in a length-dependent manner and that multimers induce highly dynamic interactions with RNA, giving rise to small and fluid condensates. In contrast, mutations in arginine display a severely altered conformation, static binding to RNA, and formation of large condensates, signifying the role of arginine in driving proper RNA interaction. Glycine mutations undergo rapid loss of fluidity, emphasizing the role of glycine in promoting fluidity. Strikingly, the nuclear import receptor Karyopherin-ß2 reverses the mutant defects and recovers the wild-type FUS behavior. We reveal two distinct mechanisms underpinning potentially disparate pathogenic pathways of ALS-linked FUS mutants.
Assuntos
Esclerose Lateral Amiotrófica/genética , Demência Frontotemporal/genética , Mutação/genética , Proteína FUS de Ligação a RNA/genética , RNA/genética , Transporte Ativo do Núcleo Celular/genética , Glicina/genética , HumanosRESUMO
RNA-binding proteins (RBPs) bind to RNAs and are crucial for regulating RNA splicing, stability, translation, and transport. Among these proteins, the CUGBP Elav-like family (CELF) is a highly conserved group crucial for posttranscriptional regulation by binding to CUG repeats. Comprising CELF1-6, this family exhibits diverse expression patterns and functions. Dysregulation of CELF has been implicated in various neural disorders, encompassing both neurodegenerative and neurodevelopmental conditions, such as Alzheimer's disease and autism. This article aims to provide a comprehensive summary of the CELF family's role in neurodevelopment and neurodevelopmental disorders. Understanding CELF's mechanisms may offer clues for potential therapeutic strategies by regulating their targets in neurodevelopmental disorders.
Assuntos
Proteínas CELF , Transtornos do Neurodesenvolvimento , Humanos , Transtornos do Neurodesenvolvimento/genética , Animais , Proteínas CELF/metabolismo , Proteínas CELF/genéticaRESUMO
Hydrogen sulfide (H2S), a critical gas signaling molecule, and N-acetyltransferase 2 (NAT2), a key enzyme in drug metabolism, are both known active biomarkers for liver function. However, the interactions and effects of H2S and NAT2 in living cells or lesion sites remain unknown due to the lack of imaging tools to achieve simultaneous detection of these two substances, making it challenging to implement real-time imaging and precise tracking. Herein, we report an activity-based two-photon fluorescent probe, TPSP-1, for the cascade detection of H2S and NAT2 in living liver cells. Continuous conversion from TPSP-1 to TPSP-3 was achieved in liver cells and tissues. Significantly, leveraging the outstanding optical properties of this two-photon fluorescent probe, TPSP-1, has been effectively used to identify pathological tissue samples directly from clinical liver cancer patients. This work provides us with this novel sensing and two-photon imaging probe, which can be used as a powerful tool to study the physiological functions of H2S and NAT2 and will help facilitate rapid and accurate diagnosis and therapeutic evaluation of hepatocellular carcinoma.
Assuntos
Arilamina N-Acetiltransferase , Carcinoma Hepatocelular , Corantes Fluorescentes , Sulfeto de Hidrogênio , Neoplasias Hepáticas , Fótons , Sulfeto de Hidrogênio/análise , Sulfeto de Hidrogênio/metabolismo , Corantes Fluorescentes/química , Corantes Fluorescentes/síntese química , Humanos , Arilamina N-Acetiltransferase/metabolismo , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/patologia , Animais , Camundongos , Células Hep G2 , Imagem ÓpticaRESUMO
INTRODUCTION: To explore the association between net vertebral artery flow volume (NVAFV), calculated through color duplex ultrasonography (CDU), and posterior circulation infarction (PCI) in patients with severe intracranial vertebral artery (VA) stenosis. METHODS: 234 patients with severe intracranial VA stenosis (≥70%) were categorized into the PCI group (n=139) and the non-PCI group (n=95) based on cranial MRI diagnosis, The correlation between NVAFV and CT perfusion (CTP) data was analyzed, and the occurrence of PCI under diverse PCI mechanisms was also investigated; Multifactorial logistic regression and Stratified analysis was performed to analyze the association between NVAFV and PCI. Lastly, generalized additive models and smooth curve fitting was utilized to outline relationship between NVAFV and PCI. RESULTS: NVAFV showed a significant correlation with cerebral blood flow (CBF), mean transmit Time (MTT) and time to peak (TTP); In the large artery atherosclerosis mechanism, a reduction in NVAFV correlated with a gradual rise in PCI cases (p = 0.002), while this trend lacked significance in the branch artery occlusive disease mechanism (p = 0.993); In the fully adjusted model, each 10 ml/min increase in NVAFV reduced PCI incidence by 11% (OR 0.890, 95%CI 0.840 to 0.943, p < 0.001), Sensitivity analysis showed similar results; NVAFV presented different PCI risks among various glucose level subgroups, the OR (95%CI) for PCI was 0.788 (0.684, 0.906) in low-glucose group(T1), 0.968 (0.878, 1.066) in moderate-glucose group(T2) and 0.886 (0.801, 0.979) in high-glucose group(T3). Smooth curve fitting demonstrated a linear negative association between NVAFV and PCI. CONCLUSION: NVAFV demonstrated an association with PCI in patients with severe intracranial VA stenosis, it can serve as a reference for identifying high-risk populations of PCI, however, it must be considered in combination with glucose.
RESUMO
Plant lead (Pb) tolerance and accumulation are key characteristics affecting phytoremediation efficiency. Bermudagrass is an excellent candidate for the remediation of Pb-polluted soil, and it needs to be mowed regularly. Here, we explored the effect of different mowing frequencies on the remediation of Pb-contaminated soil using bermudagrass. Mowing was found to decrease the biomass and photosynthetic efficiency of bermudagrass under Pb stress, thereby inhibiting its growth. Although mowing exacerbated membrane peroxidation, successive mowing treatments alleviated peroxidation damage by regulating enzymatic and nonenzymatic systems. A comprehensive evaluation of Pb tolerance revealed that all the mowing treatments reduced the Pb tolerance of bermudagrass, and a once-per-month mowing frequency had a less negative effect on Pb tolerance than did more frequent mowing. In terms of Pb enrichment, mowing significantly increased the Pb concentration, total Pb accumulation, translocation factor (TF), and bioenrichment factor (BCF) of bermudagrass. The total Pb accumulation was greatest under the once-a-month treatment, while the TF and BCF values were greatest under the three-times-a-month mowing treatment. Additionally, the decrease in soil pH and DOC were significantly correlated with the soil available Pb content and plant Pb accumulation parameters. The results showed that changes in the rhizosphere are crucial factors regulating Pb uptake in bermudagrass during mowing. Overall, once-a-month mowing minimally affects Pb tolerance and maximizes Pb accumulation, making it the optimal mowing frequency for soil Pb remediation by bermudagrass. This study provides a novel approach for the remediation of Pb-contaminated soil with bermudagrass based on mowing.
RESUMO
INTRODUCTION: The apolipoprotein E (APOE) ε4 allele exerts a significant influence on peripheral inflammation and neuroinflammation, yet the underlying mechanisms remain elusive. METHODS: The present study enrolled 54 patients diagnosed with late-onset Alzheimer's disease (AD; including 28 APOE ε4 carriers and 26 non-carriers). Plasma inflammatory cytokine concentration was assessed, alongside bulk RNA sequencing (RNA-seq) and single-cell RNA sequencing (scRNA-seq) analysis of peripheral blood mononuclear cells (PBMCs). RESULTS: Plasma tumor necrosis factor α, interferon γ, and interleukin (IL)-33 levels increased in the APOE ε4 carriers but IL-7 expression notably decreased. A negative correlation was observed between plasma IL-7 level and the hippocampal atrophy degree. Additionally, the expression of IL-7R and CD28 also decreased in PBMCs of APOE ε4 carriers. ScRNA-seq data results indicated that the changes were mainly related to the CD4+ Tem (effector memory) and CD8+ Tem T cells. DISCUSSION: These findings shed light on the role of the downregulated IL-7/IL-7R pathway associated with the APOE ε4 allele in modulating neuroinflammation and hippocampal atrophy. HIGHLIGHTS: The apolipoprotein E (APOE) ε4 allele decreases plasma interleukin (IL)-7 and aggravates hippocampal atrophy in Alzheimer's disease. Plasma IL-7 level is negatively associated with the degree of hippocampal atrophy. The expression of IL-7R signaling decreased in peripheral blood mononuclear cells of APOE ε4 carriers Dysregulation of the IL-7/IL-7R signal pathways enriches T cells.
RESUMO
Amyloid fibrils are large and insoluble protein assemblies composed of a rigid core associated with a cross-ß arrangement rich in ß-sheet structural elements. It has been widely observed in solid-state NMR experiments that semi-rigid protein segments or side chains do not yield easily observable NMR signals at room temperature. The reasons for the missing peaks may be due to the presence of unfavorable dynamics that interfere with NMR experiments, which result in very weak or unobservable NMR signals. Therefore, for amyloid fibrils, semi-rigid and dynamically disordered segments flanking the amyloid core are very challenging to study. Here, we show that high-field dynamic nuclear polarization (DNP), an NMR hyperpolarization technique typically performed at low temperatures, can circumvent this issue because (i) the low-temperature environment (~ 100 K) slows down the protein dynamics to escape unfavorable detection regime, (ii) DNP improves the overall NMR sensitivity including those of flexible side chains, and (iii) efficient cross-effect DNP biradicals (SNAPol-1) optimized for high-field DNP (≥ 18.8 T) are employed to offer high sensitivity and resolution suitable for biomolecular NMR applications. By combining these factors, we have successfully established an impressive enhancement factor of ε ~ 50 on amyloid fibrils using an 18.8 T/ 800 MHz magnet. We have compared the DNP efficiencies of M-TinyPol, NATriPol-3, and SNAPol-1 biradicals on amyloid fibrils. We found that SNAPol-1 (with ε ~ 50) outperformed the other two radicals. The MAS DNP experiments revealed signals of flexible side chains previously inaccessible at conventional room-temperature experiments. These results demonstrate the potential of MAS-DNP NMR as a valuable tool for structural investigations of amyloid fibrils, particularly for side chains and dynamically disordered segments otherwise hidden at room temperature.
Assuntos
Amiloide , Imageamento por Ressonância Magnética , Amiloide/química , Ressonância Magnética Nuclear Biomolecular/métodos , Espectroscopia de Ressonância Magnética/métodos , Proteínas AmiloidogênicasRESUMO
BACKGROUND: The objective response rate of microsatellite instability-high (MSI-H) metastatic colorectal cancer (mCRC) patients with first-line anti-programmed cell death protein-1 (PD-1) monotherapy is only 40-45%. Single-cell RNA sequencing (scRNA-seq) enables unbiased analysis of the full variety of cells comprising the tumor microenvironment. Thus, we used scRNA-seq to assess differences among microenvironment components between therapy-resistant and therapy-sensitive groups in MSI-H/mismatch repair-deficient (dMMR) mCRC. Resistance-related cell types and genes identified by this analysis were subsequently verified in clinical samples and mouse models to further reveal the molecular mechanism of anti-PD-1 resistance in MSI-H or dMMR mCRC. METHODS: The response of primary and metastatic lesions to first-line anti-PD-1 monotherapy was evaluated by radiology. Cells from primary lesions of patients with MSI-H/dMMR mCRC were analyzed using scRNA-seq. To identify the marker genes in each cluster, distinct cell clusters were identified and subjected to subcluster analysis. Then, a proteinâprotein interaction network was constructed to identify key genes. Immunohistochemistry and immunofluorescence were applied to verify key genes and cell marker molecules in clinical samples. Immunohistochemistry, quantitative real-time PCR, and western blotting were performed to examine the expression of IL-1ß and MMP9. Moreover, quantitative analysis and sorting of myeloid-derived suppressor cells (MDSCs) and CD8+ T cells were performed using flow cytometry. RESULTS: Tumor responses in 23 patients with MSI-H/dMMR mCRC were evaluated by radiology. The objective response rate was 43.48%, and the disease control rate was 69.57%. ScRNA-seq analysis showed that, compared with the treatment-resistant group, the treatment-sensitive group accumulated more CD8+ T cells. Experiments with both clinical samples and mice indicated that infiltration of IL-1ß-driven MDSCs and inactivation of CD8+ T cells contribute to anti-PD-1 resistance in MSI-H/dMMR CRC. CONCLUSIONS: CD8+ T cells and IL-1ß were identified as the cell type and gene, respectively, with the highest correlation with anti-PD-1 resistance. Infiltration of IL-1ß-driven MDSCs was a significant factor in anti-PD-1 resistance in CRC. IL-1ß antagonists are expected to be developed as a new treatment for anti-PD-1 inhibitor resistance.
Assuntos
Neoplasias Colorretais , Instabilidade de Microssatélites , Animais , Camundongos , Linfócitos T CD8-Positivos/patologia , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Imuno-Histoquímica , Microambiente TumoralRESUMO
Human telomeres are protected by shelterin proteins, but how telomeres maintain a dynamic structure remains elusive. Here, we report an unexpected activity of POT1 in imparting conformational dynamics of the telomere overhang, even at a monomer level. Strikingly, such POT1-induced overhang dynamics is greatly enhanced when TRF2 engages with the telomere duplex. Interestingly, TRF2, but not TRF2ΔB, recruits POT1-bound overhangs to the telomere ds/ss junction and induces a discrete stepwise movement up and down the axis of telomere duplex. The same steps are observed regardless of the length of the POT1-bound overhang, suggesting a tightly regulated conformational dynamic coordinated by TRF2 and POT1. TPP1 and TIN2 which physically connect POT1 and TRF2 act to generate a smooth movement along the axis of the telomere duplex. Our results suggest a plausible mechanism wherein telomeres maintain a dynamic structure orchestrated by shelterin.
Assuntos
Proteínas Recombinantes/metabolismo , Complexo Shelterina/metabolismo , Proteínas de Ligação a Telômeros/metabolismo , Telômero/metabolismo , Proteína 2 de Ligação a Repetições Teloméricas/metabolismo , Transferência Ressonante de Energia de Fluorescência/métodos , Corantes Fluorescentes/química , Corantes Fluorescentes/metabolismo , Humanos , Microscopia de Fluorescência/métodos , Ligação Proteica , Complexo Shelterina/genética , Telômero/genética , Proteínas de Ligação a Telômeros/genética , Proteína 2 de Ligação a Repetições Teloméricas/genética , Tripeptidil-Peptidase 1/genética , Tripeptidil-Peptidase 1/metabolismoRESUMO
BACKGROUND: Patients with lumbar degenerative spine diseases (LDSDs) commonly report sensory symptoms before and after lumbar spine surgery. AIM: To explore the changing patterns of sensory symptoms-namely pain, numbness, stinging, itching, and burning-and investigate the influences of sensory symptom changes on the health-related quality of life (HRQoL) of patients who experienced lumbar spine surgery. METHODS: All sensory symptoms (i.e., pain, numbness, paresthesia) were measured using a visual analog scale. The Chinese versions of the Oswestry Disability Index, Pittsburgh Sleep Quality Index, Clinically Useful Depression Outcome Scale, and EuroQol-five dimensions (EQ-5D) Scale were used to assess patients 1 week prior to surgery and 6 weeks and 6 months after surgery. A generalized estimating equation was used for data analysis. RESULTS: A total of 101 patients with mean age of 58.38 years were included. All sensory symptoms declined significantly over time (all p < .05) with the exception of itching (feeling on toes and thighs). Patients experiencing moderate-to-severe pain had poorer QoL over time, even after controlling for other sensory symptoms and potential confounders. CONCLUSIONS: Sensory symptoms gradually declined after surgery, but itching symptom did not. Moderate-to-severe pain was the only sensory symptom that influenced HRQoL over time in patients with LDSDs.
Assuntos
Hipestesia , Qualidade de Vida , Humanos , Pessoa de Meia-Idade , Dor , Vértebras Lombares/cirurgia , Resultado do TratamentoRESUMO
Herein, a novel direct Z-scheme photocatalyst was accomplished by hybridization of 0D MoS2 quantum dots (MSQDs) and 3D honeycomb-like conjugated triazine polymers (CTP) (namely, CTP-MSQD). The unique 0D/3D hierarchical structure significantly enhanced the exposure of active sites and light harvesting property, while the formed p-n junction enabled the direct strong interface coupling without the necessity of any mediators. The optimized CTP-MSQD3 exhibited continuously increased visible-light-driven photocatalytic activity and strong durability both in Cr(VI) reduction and H2 evolution, featured a rate of 0.069 min-1 and 1070 µmol/(hrâg), respectively, which were 8 times than those of pure 3D-CTP (0.009 min-1 and 129 µmol/(hrâg)). We believe that this work provides a promising photocatalyst system that combines a 0D/3D hierarchical structure and a Z-scheme charge flow for efficient and stable photocatalytic conversion.
RESUMO
BACKGROUND: Oblique lumbar interbody fusion (OLIF) is an important surgical modality for the treatment of degenerative lumbar spine disease. Various supplemental fixations can be co-applied with OLIF, increasing OLIF stability and reducing complications. However, it is unclear whether osteoporosis affects the success of supplemental fixations; therefore, this study analyzed the effects of osteoporosis on various supplemental fixations co-applied with OLIF. METHODS: We developed and validated an L3-S1 finite element (FE) model; we assigned different material properties to each component and established models of the osteoporotic and normal bone lumbar spine. We explored the outcomes of OLIF combined with each of five supplemental fixations: standalone OLIF; OLIF with lateral plate fixation (OLIF + LPF); OLIF with translaminar facet joint fixation and unilateral pedicle screw fixation (OLIF + TFJF + UPSF); OLIF with unilateral pedicle screw fixation (OLIF + UPSF); and OLIF with bilateral pedicle screw fixation (OLIF + BPSF). Under the various working conditions, we calculated the ranges of motion (ROMs) of the normal bone and osteoporosis models, the maximum Mises stresses of the fixation instruments (MMSFIs), and the average Mises stresses on cancellous bone (AMSCBs). RESULTS: Compared with the normal bone OLIF model, no demonstrable change in any segmental ROM was apparent. The MMSFIs increased in all five osteoporotic OLIF models. In the OLIF + TFJF + UPSF model, the MMSFIs increased sharply in forward flexion and extension. The stress changes of the OLIF + UPSF, OLIF + BPSF, and OLIF + TFJF + UPSF models were similar; all stresses trended upward. The AMSCBs decreased in all five osteoporotic OLIF models during flexion, extension, lateral bending, and axial rotation. The average stress change of cancellous bone was most obvious under extension. The AMSCBs of the five OLIF models decreased by 14%, 23.44%, 21.97%, 40.56%, and 22.44% respectively. CONCLUSIONS: For some supplemental fixations, the AMSCBs were all reduced and the MMSFIs were all increased in the osteoporotic model, compared with the OLIF model of normal bone. Therefore, the biomechanical performance of an osteoporotic model may be inferior to the biomechanical performance of a normal model for the same fixation method; in some instances, it may increase the risks of fracture and internal fixation failure.
Assuntos
Osteoporose , Parafusos Pediculares , Fusão Vertebral , Fenômenos Biomecânicos , Análise de Elementos Finitos , Humanos , Vértebras Lombares/cirurgia , Osteoporose/complicações , Osteoporose/cirurgia , Amplitude de Movimento Articular , Fusão Vertebral/métodosRESUMO
China is the largest producer and consumer of plastics worldwide. Microplastic (MP) pollution has been a recent research hotspot in environmental science and ecology. This study collects and analyzes the statistical data for microplastics (MPs) 86 lakes in entire China's lake ecosystems in past five years (2016-2020), their range in area is 0.056-4543.000 km2 (average: 566.045 km2), and the water storage varies from 0.162 × 108 to 1050.000 × 108 m3 (average: 77.884 ×108 m3). The results showed (1) The MP abundance in lake surface water is significantly correlated with lake area (ρ = -0.562, p ï¼0.01), provincial GDP (Gross Domestic Product, GDP) (ρ = 0.377, p = 0.002), GDP per capita (ρ = 0.346, p = 0.006), urban waste water discharge and ratio of agricultural land area (ρ = 0.369, p = 0.003). (2) The MP abundance in lake sediment is significantly correlated with per capita domestic volume of garbage disposal (ρ = -0.536, p ï¼0.001), per capita urban waste water discharge (ρ = -0.544, p ï¼0.001) and ratio of agricultural land area (ρ = 0.635, p ï¼0.001). (3) Irrespective of whether the samples were from surface water or sediment, MPs were primarily transparent, and the dominant types were fragments, films, and fibers. In addition, the size of MPs samples was mostly less than 2 mm, and the major polymers were polyethylene (PE), polypropylene (PP), and polystyrene (PS). (4) The degree of MP pollution in organisms was related to the degree of environmental pollution. These findings could provide a theoretical basis for the control and management of MP pollution in China's lake ecosystems.
Assuntos
Microplásticos , Poluentes Químicos da Água , China , Ecossistema , Monitoramento Ambiental/métodos , Poluição Ambiental/análise , Plásticos , Poluentes Químicos da Água/análiseRESUMO
Lead (Pb) is one of the most harmful, toxic pollutants to the ecological environment and humans. Centipedegrass, a fast-growing warm-season turfgrass, is excellent for Pb pollution remediation. Exogenous low-molecular-weight organic acid (LMWOA) treatment is a promising approach for assisted phytoremediation. However, the effects of this treatment on the tolerance and Pb accumulation of centipedegrass are unclear. This study investigated these effects on the physiological growth response and Pb accumulation distribution characteristics of centipedegrass. Applications of 400 µM citric acid (CA), malic acid (MA) and tartaric acid (TA) significantly reduced membrane lipid peroxidation levels of leaves and improved biomass production of Pb-stressed plants. These treatments mainly increased peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) activities and enhanced free protein (Pro), ascorbic acid (AsA) and phytochelatins (PCs) contents, ultimately improving the Pb tolerance of centipedegrass. Their promoting effects decreased as follows: TA>CA>MA. All the treatments decreased root Pb concentrations and increased stem and leaf Pb concentrations, thus increasing total Pb accumulation and TF values. MA had the best and worst effects on Pb accumulation and Pb transportation, respectively. CA had the best and worst effects on Pb transportation and Pb accumulation, respectively. TA exhibited strong effects on both Pb accumulation and transport. Furthermore, all treatments changed the subcellular Pb distribution patterns and distribution models of the chemical forms of Pb in each tissue. The root Pb concentration was more highly correlated with the Pb subcellular fraction distribution pattern, while the stem and leaf Pb concentrations were more highly correlated with the distribution models of the chemical forms of Pb. Overall, TA improved plant Pb tolerance best and promoted both Pb absorption and transportation well and is considered the best candidate for Pb-contaminated soil remediation with centipedegrass. This study provides a new idea for Pb-contaminated soil remediation with centipedegrass combined with LMWOAs.
Assuntos
Chumbo , Poluentes do Solo , Antioxidantes/metabolismo , Biodegradação Ambiental , Ácido Cítrico/metabolismo , Humanos , Chumbo/metabolismo , Fitoquelatinas/metabolismo , Raízes de Plantas/metabolismo , Plantas/metabolismo , Solo , Poluentes do Solo/metabolismo , Estresse FisiológicoRESUMO
Echinochloa crus-galli L., a notorious weed in rice paddy fields, is usually kept under control by mefenacet application at the pre-emergence or early post-emergence stage. Due to continuous and repeated usage, E. crus-galli is developing resistance to mefenacet in China. Two putative resistant and one susceptible E. crus-galli populations were collected from paddy fields in Jiangsu Province to characterize their herbicide resistance. Compared with the susceptible population, the two mefenacet-resistant populations had 2.8- and 4.1-times greater pre-emergence resistance, and 10- and 6.8-times greater early post-emergence resistance to mefenacet. These mefenacet-resistant E. crus-galli populations also exhibited cross- or multiple-resistance to acetochlor, pyraclonil, imazamox, and quinclorac. However, when the glutathione S-transferase (GST) inhibitor 4-chloro-7-nitrobenzoxadiazole (NBD-Cl) was applied prior to post-emergence treatment, mefenacet resistance levels were reduced in both populations. Additionally, GST activity in vivo in one resistant population was much higher than the susceptible population after mefenacet application. The very long chain fatty acid elongases (VLCFAEs) from both mefenacet-resistant populations required much higher mefenacet concentration to inhibit their activity. The reduced sensitivity of VLCFAEs to mefenacet indicates the presence of a target-site resistance mechanism and induction of high GST activity may provide additional contribution to E. crus-galli mefenacet resistance through a non-target-site mechanism.
Assuntos
Echinochloa , Herbicidas , Acetanilidas , Benzotiazóis , Resistência a Herbicidas , Herbicidas/farmacologiaRESUMO
Highly efficient organic thermally activated delayed fluorescence (TADF) and room-temperature phosphorescence (RTP) emitters for organic light-emitting diodes (OLEDs) generally consist of a twisted donor-acceptor skeleton with aromatic amine donors. Herein, through introducing sulfur atoms into isomeric pentaphene and pentacene frameworks, we demonstrate a set of polycyclic luminophores exhibiting efficient TADF and RTP characters. The incorporation of sulfur atoms confirms a folded molecular plane, while intensifies singlet-triplet spin-orbit coupling. Further, the isomeric effect has a significant effect on the electronic structure of excited state, giving rise to the investigated compounds tunable luminescence mechanisms of TADF and RTP. With efficient triplet harvesting ability, maximum external quantum efficiencies up to 25.1 % and 8.7 % are achieved for the corresponding TADF and RTP OLEDs, verifying the great potential of sulfur-bridged frameworks for highly efficient devices.
RESUMO
Dynamic nuclear polarization (DNP) is a powerful method to enhance the sensitivity of solid-state magnetic nuclear resonance (ssNMR) spectroscopy. However, its biomolecular applications at high magnetic fields (preferably>14â T) have so far been limited by the intrinsically low efficiency of polarizing agents and sample preparation aspects. Herein, we report a new class of trityl-nitroxide biradicals, dubbed SNAPols that combine high DNP efficiency with greatly enhanced hydrophilicity. SNAPol-1, the best compound in the series, shows DNP enhancement factors at 18.8 T of more than 100 in small molecules and globular proteins and also exhibits strong DNP enhancements in membrane proteins and cellular preparations. By integrating optimal sensitivity and high resolution, we expect widespread applications of this new polarizing agent in high-field DNP/ssNMR spectroscopy, especially for complex biomolecules.
Assuntos
Campos Magnéticos , Óxidos de Nitrogênio , Espectroscopia de Ressonância Magnética , Proteínas de MembranaRESUMO
Dwarf bamboos are clonal plants with potential applications in the remediation of heavy metal-polluted soils, although their pollution adaptation strategies are unknown. This study examined the biomass allocation strategies and lead (Pb) enrichment characteristics of various dwarf bamboo tissues by the end of the growing season and explored their potential for phytoremediation of Pb stress in the soils. Six dwarf bamboo genotypes were treated with three levels (0, 300, and 1500 mg kg-1) of soil Pb stress. The majority of the bamboos adopted two biomass allocation strategies to adapt to Pb stress, namely, "reducing biomass allocation into new bamboo growth" and "increasing/stabilizing biomass allocation into rhizomes". Pb accumulation was highest in the roots, rhizomes, and old stems and showed the following trend: rhizomes/old stems> new roots/old roots> old leaves> new leaves> new stems among various tissues. Moreover, the six bamboos used three different Pb-enrichment strategies, as follows: (i) "rhizome domination and old stem synergy" (Sasaella glabra (Nakai) f. albo-striata Muroi, Sasa auricoma (Mitford) E.G. Camus, Sasa fortunei (Van Houtte) Fiori, and Shibataea lanceifolia C.H. Hu); (ii) "old stem domination and rhizome synergy" (Indocalamus decorus Q.H. Dai); and (iii) "old stem domination and new root synergy" (Sasa argenteostriata (Regel) E.G. Camus). In Pb-contaminated soils, genotypes with TFs greater than 1 were Sasa fortunei (Van Houtte) Fiori, Sasa argenteostriata (Regel) E.G. Camus, and Indocalamus decorus Q.H. Dai; in addition, only S. argenteostriata had BCF values greater than 1. Furthermore, this study provides the ï¬rst evidence that S. argenteostriata can extract 0.22 and 0.58 mgplant-1 of Pb ions in soil polluted with 300 and 1500 mg kg-1 Pb, respectively. S. argenteostriata showed the greatest potential for phytoremediation among the bamboo genotypes in both Pb-contaminated urban and mining sites.
Assuntos
Chumbo/toxicidade , Sasa/toxicidade , Poluentes do Solo/toxicidade , Biodegradação Ambiental , Biomassa , Poluentes Ambientais , Chumbo/metabolismo , Metais Pesados/análise , Mineração , Folhas de Planta/química , Raízes de Plantas/química , Plantas , Poaceae/metabolismo , Poaceae/toxicidade , Sasa/metabolismo , Solo , Poluentes do Solo/análise , Poluentes do Solo/metabolismoRESUMO
Whitespotted bamboo shark (Chiloscyllium plagiosum) is a demersal cartilaginous fish with an adaptive immune system founded upon immunoglobulins. In this manuscript, we characterize the IgNAR of the whitespotted bamboo shark. A newly discovered alternative splicing form of IgNAR Sec (IgNARshort (ΔC2-C3) Sec) was identified, in which the C1 domain was spliced directly to the C4 domain, the process resulted in a molecule containing three constant domains. However, a single unpaired cysteine remains in the highly flexible hinge region, contributing in the formation of an interchain disulfide bond. Two types of C1 domain were found, and the one lacking a short α-helix showed lower proportion. This finding suggests that short α-helices might be important to the stability of IgNAR. High-throughput sequencing revealed that the percentage of VNAR types significantly vary between the diverse species of sharks. The variable region of IgNAR (the VNAR) with small size and stabilization is a potential candidate for immunotherapeutic agents. The structure and stability analysis in this manuscript may be useful in future biomedical applications.
Assuntos
Regulação da Expressão Gênica/imunologia , Receptores de Antígenos/genética , Receptores de Antígenos/imunologia , Tubarões/genética , Tubarões/imunologia , Sequência de Aminoácidos , Animais , Proteínas de Peixes/química , Proteínas de Peixes/genética , Proteínas de Peixes/imunologia , Imunoglobulinas/química , Filogenia , Receptores de Antígenos/químicaRESUMO
Dwarf bamboo Sasa argenteostriata (Regel) E.G. Camus is considered as potential plants for metal phytoremediation in previous filed observations. However, the mechanisms of lead (Pb) detoxification has not been described. The objective of this study was to explore the difference strategies or mechanisms of Pb detoxification in plant tissues. In this regard, four Pb treatments with hydroponics including 0 (control), 300, 600, and 900 mg L-1 were conducted to examine subcellular compartmentalization, Pb accumulation/species and antioxidant-assisted chelation. Our findings showed the retention of Pb by the whip-root system is one of its detoxification mechanisms to avoid damage the shoots. In addition, the cell wall retention is the dominant detoxification strategy of whips, new roots, old roots and new/old stems, while vacuolar compartmentalization is for new/old leaves. Interestingly, four low-mobility/-toxicity Pb species (i.e., FNaCl, FHAc, FHCl and FR) are distributed in roots, whips and stems, while two high-mobility/-toxicity Pb species (FE and FW) in leaves. The conversion of Pb to low-toxicity/-migration is a Pb-detoxification strategy in roots, whips and stems but not in leaves. Besides, the new/old roots and leaves can alleviate Pb damage through the synthesis of non-protein thiol, glutathione and phytochelatins. Among these, phytochelatins play a leading role in the detoxification in new/old roots, while glutathione is in new/old leaves. This study provides the first comprehensive evidence regarding the different strategies for Pb detoxification in dwarf bamboo tissues from physiological to cellular level, supporting that this plant could be rehabilitated for phytoremediation in Pb-contaminated media.