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1.
Plant Cell ; 36(6): 2393-2409, 2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38489602

RESUMO

Optimizing the root architecture of crops is an effective strategy for improving crop yields. Soil compaction is a serious global problem that limits crop productivity by restricting root growth, but the underlying molecular mechanisms are largely unclear. Here, we show that ethylene stimulates rice (Oryza sativa) crown root development in response to soil compaction. First, we demonstrate that compacted soil promotes ethylene production and the accumulation of ETHYLENE INSENSITIVE 3-LIKE 1 (OsEIL1) in rice roots, stimulating crown root primordia initiation and development, thereby increasing crown root number in lower stem nodes. Through transcriptome profiling and molecular analyses, we reveal that OsEIL1 directly activates the expression of WUSCHEL-RELATED HOMEOBOX 11 (OsWOX11), an activator of crown root emergence and growth, and that OsWOX11 mutations delay crown root development, thus impairing the plant's response to ethylene and soil compaction. Genetic analysis demonstrates that OsWOX11 functions downstream of OsEIL1. In summary, our results demonstrate that the OsEIL1-OsWOX11 module regulates ethylene action during crown root development in response to soil compaction, providing a strategy for the genetic modification of crop root architecture and grain agronomic traits.


Assuntos
Regulação da Expressão Gênica de Plantas , Oryza , Proteínas de Plantas , Raízes de Plantas , Fatores de Transcrição , Etilenos/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Oryza/genética , Oryza/crescimento & desenvolvimento , Oryza/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Solo/química , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética
2.
Proc Natl Acad Sci U S A ; 121(8): e2314561121, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38359295

RESUMO

Coordinated metabolic reprogramming and epigenetic remodeling are critical for modulating T cell function and differentiation. However, how the epigenetic modification controls Th17/Treg cell balance via metabolic reprogramming remains obscure. Here, we find that Setd2, a histone H3K36 trimethyltransferase, suppresses Th17 development but promotes iTreg cell polarization via phospholipid remodeling. Mechanistically, Setd2 up-regulates transcriptional expression of lysophosphatidylcholine acyltransferase 4 (Lpcat4) via directly catalyzing H3K36me3 of Lpcat4 gene promoter in T cells. Lpcat4-mediated phosphatidylcholine PC(16:0,18:2) generation in turn limits endoplasmic reticulum stress and oxidative stress. These changes decrease HIF-1α transcriptional activity and thus suppress Th17 but enhance Treg development. Consistent with this regulatory paradigm, T cell deficiency of Setd2 aggravates neuroinflammation and demyelination in experimental autoimmune encephalomyelitis due to imbalanced Th17/Treg cell differentiation. Overall, our data reveal that Setd2 acts as an epigenetic brake for T cell-mediated autoimmunity through phospholipid remodeling, suggesting potential targets for treating neuroinflammatory diseases.


Assuntos
Doenças Autoimunes , Fosfolipídeos , Humanos , Histonas/genética , Histonas/metabolismo , Diferenciação Celular , Linfócitos T/metabolismo
3.
Plant Cell ; 34(4): 1273-1288, 2022 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-35021223

RESUMO

Primary root growth in cereal crops is fundamental for early establishment of the seedling and grain yield. In young rice (Oryza sativa) seedlings, the primary root grows rapidly for 7-10 days after germination and then stops; however, the underlying mechanism determining primary root growth is unclear. Here, we report that the interplay of ethylene and gibberellin (GA) controls the orchestrated development of the primary root in young rice seedlings. Our analyses advance the knowledge that primary root growth is maintained by higher ethylene production, which lowers bioactive GA contents. Further investigations unraveled that ethylene signaling transcription factor ETHYLENE INSENSITIVE3-LIKE 1 (OsEIL1) activates the expression of the GA metabolism genes GIBBERELLIN 2-OXIDASE 1 (OsGA2ox1), OsGA2ox2, OsGA2ox3, and OsGA2ox5, thereby deactivating GA activity, inhibiting cell proliferation in the root meristem, and ultimately gradually inhibiting primary root growth. Mutation in OsGA2ox3 weakened ethylene-induced GA inactivation and reduced the ethylene sensitivity of the root. Genetic analysis revealed that OsGA2ox3 functions downstream of OsEIL1. Taken together, we identify a molecular pathway impacted by ethylene during primary root elongation in rice and provide insight into the coordination of ethylene and GA signals during root development and seedling establishment.


Assuntos
Giberelinas , Oryza , Etilenos/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Giberelinas/metabolismo , Giberelinas/farmacologia , Oryza/metabolismo , Plântula/metabolismo
4.
Proc Natl Acad Sci U S A ; 119(30): e2201072119, 2022 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-35858424

RESUMO

Soil compaction represents a major agronomic challenge, inhibiting root elongation and impacting crop yields. Roots use ethylene to sense soil compaction as the restricted air space causes this gaseous signal to accumulate around root tips. Ethylene inhibits root elongation and promotes radial expansion in compacted soil, but its mechanistic basis remains unclear. Here, we report that ethylene promotes abscisic acid (ABA) biosynthesis and cortical cell radial expansion. Rice mutants of ABA biosynthetic genes had attenuated cortical cell radial expansion in compacted soil, leading to better penetration. Soil compaction-induced ethylene also up-regulates the auxin biosynthesis gene OsYUC8. Mutants lacking OsYUC8 are better able to penetrate compacted soil. The auxin influx transporter OsAUX1 is also required to mobilize auxin from the root tip to the elongation zone during a root compaction response. Moreover, osaux1 mutants penetrate compacted soil better than the wild-type roots and do not exhibit cortical cell radial expansion. We conclude that ethylene uses auxin and ABA as downstream signals to modify rice root cell elongation and radial expansion, causing root tips to swell and reducing their ability to penetrate compacted soil.


Assuntos
Ácido Abscísico , Etilenos , Ácidos Indolacéticos , Oryza , Raízes de Plantas , Ácido Abscísico/metabolismo , Etilenos/metabolismo , Ácidos Indolacéticos/metabolismo , Oxigenases de Função Mista/genética , Oxigenases de Função Mista/metabolismo , Mutação , Oryza/genética , Oryza/crescimento & desenvolvimento , Oryza/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Solo
5.
Anal Chem ; 96(9): 3802-3809, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38381523

RESUMO

Fluoride anions (F-) play a crucial role in human physiological processes. However, excessive intake of F- would affect oxygen metabolism and promote the generation of oxygen-free radicals. Hence, it is essential to develop a precise and efficient fluorescent probe for visualizing F--induced oxidative stress. In this work, we developed the first bifunctional BODIPY-based fluorescent probe dfBDP with p-tert-butyldimethylsilanolate benzyl thioether as the sensing site for the detection of F- and HClO via two distinct reactions, the self-immolative removal and the thioether oxidation, which generate the sensing products with two nonoverlap fluorescence bands: 800-1200 and 500-750 nm, respectively. The probe dfBDP displays rapid response, high specificity, and sensitivity for the detection of F- (LOD, 316.2 nM) and HClO (LOD, 33.9 nM) in vitro. Cellular imaging reveals a correlation between F--induced oxidative stress and the upregulation of HClO. Finally, probe dfBDP was employed to detect F- and HClO in mice under the stimulation of F-. The experimental results display that the level of HClO elevates in the liver of mice.


Assuntos
Compostos de Boro , Corantes Fluorescentes , Ácido Hipocloroso , Camundongos , Humanos , Animais , Ácido Hipocloroso/metabolismo , Sulfetos , Oxigênio
6.
Plant Biotechnol J ; 22(7): 1881-1896, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38346083

RESUMO

Plants grow rapidly for maximal production under optimal conditions; however, they adopt a slower growth strategy to maintain survival when facing environmental stresses. As salt stress restricts crop architecture and grain yield, identifying genetic variations associated with growth and yield responses to salinity is critical for breeding optimal crop varieties. OsDSK2a is a pivotal modulator of plant growth and salt tolerance via the modulation of gibberellic acid (GA) metabolism; however, its regulation remains unclear. Here, we showed that OsDSK2a can be phosphorylated at the second amino acid (S2) to maintain its stability. The gene-edited mutant osdsk2aS2G showed decreased plant height and enhanced salt tolerance. SnRK1A modulated OsDSK2a-S2 phosphorylation and played a substantial role in GA metabolism. Genetic analysis indicated that SnRK1A functions upstream of OsDSK2a and affects plant growth and salt tolerance. Moreover, SnRK1A activity was suppressed under salt stress, resulting in decreased phosphorylation and abundance of OsDSK2a. Thus, SnRK1A preserves the stability of OsDSK2a to maintain plant growth under normal conditions, and reduces the abundance of OsDSK2a to limit growth under salt stress. Haplotype analysis using 3 K-RG data identified a natural variation in OsDSK2a-S2. The allele of OsDSK2a-G downregulates plant height and improves salt-inhibited grain yield. Thus, our findings revealed a new mechanism for OsDSK2a stability and provided a valuable target for crop breeding to overcome yield limitations under salinity stress.


Assuntos
Oryza , Proteínas de Plantas , Proteínas Serina-Treonina Quinases , Tolerância ao Sal , Tolerância ao Sal/genética , Oryza/genética , Oryza/crescimento & desenvolvimento , Oryza/metabolismo , Fosforilação , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Serina-Treonina Quinases/genética , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Giberelinas/metabolismo , Variação Genética , Plantas Geneticamente Modificadas/genética
7.
Plant Physiol ; 191(3): 1953-1967, 2023 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-36535001

RESUMO

Soil compaction is a global problem causing inadequate rooting and poor yield in crops. Accumulating evidence indicates that phytohormones coordinately regulate root growth via regulating specific growth processes in distinct tissues. However, how abscisic acid (ABA) signaling translates into auxin production to control root growth during adaptation to different soil environments is still unclear. In this study, we report that ABA has biphasic effects on primary root growth in rice (Oryza sativa) through an auxin biosynthesis-mediated process, causing suppression of root elongation and promotion of root swelling in response to soil compaction. We found that ABA treatment induced the expression of auxin biosynthesis genes and auxin accumulation in roots. Conversely, blocking auxin biosynthesis reduced ABA sensitivity in roots, showing longer and thinner primary roots with larger root meristem size and smaller root diameter. Further investigation revealed that the transcription factor basic region and leucine zipper 46 (OsbZIP46), involved in ABA signaling, can directly bind to the YUCCA8/rice ethylene-insensitive 7 (OsYUC8/REIN7) promoter to activate its expression, and genetic analysis revealed that OsYUC8/REIN7 is located downstream of OsbZIP46. Moreover, roots of mutants defective in ABA or auxin biosynthesis displayed the enhanced ability to penetrate compacted soil. Thus, our results disclose the mechanism in which ABA employs auxin as a downstream signal to modify root elongation and radial expansion, resulting in short and swollen roots impaired in their ability to penetrate compacted soil. These findings provide avenues for breeders to select crops resilient to soil compaction.


Assuntos
Ácido Abscísico , Oryza , Ácido Abscísico/farmacologia , Ácido Abscísico/metabolismo , Oryza/metabolismo , Raízes de Plantas/metabolismo , Ácidos Indolacéticos/metabolismo , Solo , Regulação da Expressão Gênica de Plantas
8.
Opt Lett ; 49(5): 1301-1304, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38426998

RESUMO

Bound state in the continuum (BIC) is a phenomenon that describes the perfect confinement of electromagnetic waves despite their resonant frequencies lying in the continuous radiative spectrum. BICs can be realized by introducing a destructive interference between distinct modes, referred to as Friedrich-Wintgen BICs (FW-BICs). Herein, we demonstrate that FW-BICs can be derived from coupled modes of individual split-ring resonators (SRR) in the terahertz band. The eigenmode results manifest that FW-BICs are in the center of the far-field polarization vortices. Quasi-BIC-I keeps an ultrahigh quality factor (Q factor) in a broad momentum range along the Γ-X direction, while the Q factor of the quasi-BIC-II drops rapidly. Our results can facilitate the design of devices with high-Q factors with extreme robustness against the incident angle.

9.
J Sleep Res ; 33(1): e14020, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37709966

RESUMO

Obstructive sleep apnea is a highly prevalent sleep-related breathing disorder, resulting in a disturbed breathing pattern, changes in blood gases, abnormal autonomic regulation, metabolic fluctuation, poor neurocognitive performance, and increased cardiovascular risk. With broad inter-individual differences recognised in risk factors, clinical symptoms, gene expression, physiological characteristics, and health outcomes, various obstructive sleep apnea subtypes have been identified. Therapeutic efficacy and its impact on outcomes, particularly for cardiovascular consequences, may also vary depending on these features in obstructive sleep apnea. A number of interventions such as positive airway pressure therapies, oral appliance, surgical treatment, and pharmaceutical options are available in clinical practice. Selecting an effective obstructive sleep apnea treatment and therapy is a challenging medical decision due to obstructive sleep apnea heterogeneity and numerous treatment modalities. Thus, an objective marker for clinical evaluation is warranted to estimate the treatment response in patients with obstructive sleep apnea. Currently, while the Apnea-Hypopnea Index is used for severity assessment of obstructive sleep apnea and still considered a major guide to diagnosis and managements of obstructive sleep apnea, the Apnea-Hypopnea Index is not a robust marker of symptoms, function, or outcome improvement. Abnormal cardiac autonomic modulation can provide additional insight to better understand obstructive sleep apnea phenotyping. Heart rate variability is a reliable neurocardiac tool to assess altered autonomic function and can also provide cardiovascular information in obstructive sleep apnea. Beyond the Apnea-Hypopnea Index, this review aims to discuss the role of heart rate variability as an indicator and predictor of therapeutic efficacy to different modalities in order to optimise tailored treatment for obstructive sleep apnea.


Assuntos
Sistema Nervoso Autônomo , Apneia Obstrutiva do Sono , Humanos , Frequência Cardíaca/fisiologia , Resultado do Tratamento , Fatores de Risco
10.
J Org Chem ; 89(5): 3618-3628, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38358945

RESUMO

A one-pot, sequential three-component reaction between salicylaldehyde, indole, and 2-bromoprop-2-ene-1-sulfonyl fluoride (BPESF) has been demonstrated for the synthesis of sulfonyl fluoride substituted 4H-chromene derivatives in moderate to excellent yields (45%-94%). This one-pot sequential method features easily available starting materials, wide substrate scope, mild conditions, and great efficiency.

11.
Org Biomol Chem ; 22(26): 5325-5332, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38874178

RESUMO

In this paper, the hydrogenation of aldehydes and ketones using the RANEY® nickel catalyst was successfully applied for the synthesis of alcohol compounds without additional column chromatographic purification. This synthetic strategy features a wide range of substrates, excellent atom economy, high chemical discrimination and the use of a ligand-free catalytic system. Reactions were performed at room temperature in water providing alcohols in high yields and purity.

12.
Org Biomol Chem ; 22(4): 805-810, 2024 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-38170477

RESUMO

A method involving a metal-free visible-light-promoted synthesis was developed for the construction of difluoroalkylated oxindoles with N-phenylacrylamides and bromodifluoroacetamides as starting materials in the presence of N,N,N',N'-tetramethylethylenediamine (TMEDA). Twenty-four examples of the photochemical reaction were successfully performed, with good yields (44-99%) and excellent substrate adaptability. Mechanistic studies showed that the visible-light-promoted reaction involved a radical addition to N-phenylacrylamide, intramolecular cyclization, dehydrogenation, and rearomatization. The difluoroacetamide radical was produced as a result of electron transfer to bromodifluoroacetamides from the electron donor TMEDA in their electron-donor-acceptor (EDA) complexes under visible light irradiation. This protocol is a promising photochemical method due to its advantages of mild conditions, simple operation, wide substrate scope and high yields. And the obtained products may have great potential in the field of medicine.

13.
Intern Med J ; 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38563467

RESUMO

BACKGROUND AND AIMS: Sleep-disordered breathing (SDB) and nocturnal hypoxemia were known to be present in patients with chronic thromboembolic pulmonary hypertension (CTEPH), but the difference between SDB and nocturnal hypoxemia in patients who have chronic thromboembolic pulmonary disease (CTEPD) with or without pulmonary hypertension (PH) at rest remains unknown. METHODS: Patients who had CTEPH (n = 80) or CTEPD without PH (n = 40) and who had undergone sleep studies from July 2020 to October 2022 at Shanghai Pulmonary Hospital were enrolled. Nocturnal mean SpO2 (Mean SpO2) <90% was defined as nocturnal hypoxemia, and the percentage of time with a saturation below 90% (T90%) exceeding 10% was used to evaluate the severity of nocturnal hypoxemia. Logistic and linear regression analyses were performed to investigate the difference and potential predictor of SDB or nocturnal hypoxemia between CTEPH and CTEPD without PH. RESULTS: SDB was similarly prevalent in CTEPH and CTEPD without PH (P = 0.104), both characterised by obstructive sleep apnoea (OSA). Twenty-two patients with CTEPH were diagnosed with nocturnal hypoxemia, whereas only three were diagnosed with CTEPD without PH (P = 0.021). T90% was positively associated with mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance in patients with CTEPH and CTEPD without PH (P < 0.001); T90% was also negatively related to cardiac output in these patients. Single-breath carbon monoxide diffusing capacity, sex and mPAP were all correlated with nocturnal hypoxemia in CTEPH and CTEPD without PH (all P < 0.05). CONCLUSION: Nocturnal hypoxemia was worse in CTEPD with PH; T90%, but not SDB, was independently correlated with the hemodynamics in CTEPD with or without PH.

14.
Proc Natl Acad Sci U S A ; 118(39)2021 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-34544866

RESUMO

Genome evolution is an essential and stringently regulated aspect of biological fitness. For bacteria, natural competence is one of the principal mechanisms of genome evolution and is frequently subject to multiple layers of regulation derived from a plethora of environmental and physiological stimuli. Here, we present a regulatory mechanism that illustrates how such disparate stimuli can be integrated into the Streptococcus mutans natural competence phenotype. S. mutans possesses an intriguing, but poorly understood ability to coordinately control its independently regulated natural competence and bacteriocin genetic pathways as a means to acquire DNA released from closely related, bacteriocin-susceptible streptococci. Our results reveal how the bacteriocin-specific transcription activator BrsR directly mediates this coordination by serving as an anti-adaptor protein responsible for antagonizing the proteolysis of the inherently unstable, natural competence-specific alternative sigma factor ComX. This BrsR ability functions entirely independent of its transcription regulator function and directly modulates the timing and severity of the natural competence phenotype. Additionally, many of the DNA uptake proteins produced by the competence system were surprisingly found to possess adaptor abilities, which are employed to terminate the BrsR regulatory circuit via negative feedback. BrsR-competence protein heteromeric complexes directly inhibit nascent brsR transcription as well as stimulate the Clp-dependent proteolysis of extant BrsR proteins. This study illustrates how critical genetic regulatory abilities can evolve in a potentially limitless variety of proteins without disrupting their conserved ancestral functions. These unrecognized regulatory abilities are likely fundamental for transducing information through complex genetic networks.


Assuntos
Proteínas de Bactérias/metabolismo , Bacteriocinas/metabolismo , Regulação Bacteriana da Expressão Gênica , Mapas de Interação de Proteínas , Streptococcus mutans/metabolismo , Fatores de Transcrição/metabolismo , Proteínas de Bactérias/genética , Streptococcus mutans/genética , Streptococcus mutans/crescimento & desenvolvimento , Fatores de Transcrição/genética
15.
Am J Physiol Cell Physiol ; 324(1): C183-C192, 2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-36468843

RESUMO

Arterial remodeling is a common pathological basis of cardiovascular diseases such as atherosclerosis, vascular restenosis, hypertension, pulmonary hypertension, aortic dissection, and aneurysm. Vascular smooth muscle cells (VSMCs) are not only the main cellular components in the middle layer of the arterial wall but also the main cells involved in arterial remodeling. Dedifferentiated VSMCs lose their contractile properties and are converted to a synthetic, secretory, proliferative, and migratory phenotype, playing key roles in the pathogenesis of arterial remodeling. As mitochondria are the main site of biological oxidation and energy transformation in eukaryotic cells, mitochondrial numbers and function are very important in maintaining the metabolic processes in VSMCs. Mitochondrial dysfunction and oxidative stress are novel triggers of the phenotypic transformation of VSMCs, leading to the onset and development of arterial remodeling. Therefore, pharmacological measures that alleviate mitochondrial dysfunction reverse arterial remodeling by ameliorating VSMCs metabolic dysfunction and phenotypic transformation, providing new options for the treatment of cardiovascular diseases related to arterial remodeling. This review summarizes the relationship between mitochondrial dysfunction and cardiovascular diseases associated with arterial remodeling and then discusses the potential mechanism by which mitochondrial dysfunction participates in pathological arterial remodeling. Furthermore, maintaining or improving mitochondrial function may be a new intervention strategy to prevent the progression of arterial remodeling.


Assuntos
Doenças Cardiovasculares , Hipertensão , Humanos , Músculo Liso Vascular/metabolismo , Doenças Cardiovasculares/metabolismo , Proliferação de Células , Hipertensão/metabolismo , Fenótipo , Mitocôndrias/metabolismo , Miócitos de Músculo Liso/metabolismo , Remodelação Vascular , Células Cultivadas
16.
Anal Chem ; 95(2): 1755-1763, 2023 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-36596643

RESUMO

Mustard gas [sulfur mustard (SM)] and phosgene are the most frequently used chemical warfare agents (CWAs), which pose a serious threat to human health and national security, and their rapid and accurate detection is essential to respond to terrorist attacks and industrial accidents. Herein, we developed a fluorescent probe with o-hydroxythioketone as two sensing sites, AQso, which can detect and distinguish mustard gas and phosgene. The dual-sensing-site probe AQso reacts with mustard gas to form a cyclic product with high sensitivity [limit of detection (LOD) = 70 nM] and is highly selective to SM over phosgene, SM analogues, active alkylhalides, acylhalides, and nerve agent mimics, in ethanol solutions. When encountering phosgene, AQso rapidly converts to cyclic carbonate, which is sensitive (LOD = 14 nM) and highly selective. Their sensing mechanisms of AQso to mustard gas and phosgene were well demonstrated by separation and characterization of the sensing products. Furthermore, a facile test strip with the probe was prepared to distinguish 2-chloroethyl ethyl sulfide (CEES) and phosgene in the gas phase by different fluorescence colors and response rates. Not using the complicated instrument, the qualitative and quantitative detection of CEES or phosgene can be achieved only by measuring the red-green-blue (RGB) channel intensity of the test strip after being exposed to CEES or phosgene gas by the smartphone with an RGB color application.


Assuntos
Substâncias para a Guerra Química , Gás de Mostarda , Fosgênio , Humanos , Fosgênio/química , Corantes Fluorescentes/química
17.
Eur J Immunol ; 52(2): 222-236, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34559883

RESUMO

Chronic airway inflammation mediated by CD8+ T lymphocytes contributes to the pathogenesis of Chronic obstructive pulmonary disease (COPD). Deciphering the fingerprint of the chronic inflammation orchestrated by CD8+ T cells may allow the development of novel approaches to COPD management. Here, the expression of IL-27 and IFN-γ+ CD8+ Tc1 cells were evaluated in patients with COPD and in cigarette smoke-exposed mice. The production of IL-27 by marrow-derived dendritic cells (mDCs) in response to cigarette smoke extract (CSE) was assessed. The role of IL-27 in IFN-γ+ CD8+ Tc1 cells was explored. We demonstrated that elevated IL-27 was accompanied by an exaggerated IFN-γ+ CD8+ Tc1 response in a smoking mouse model of emphysema. We noted that lung dendritic cells were one of the main sources of IL-27 during chronic cigarette smoke exposure. Moreover, CSE directly induced the production of IL-27 by mDCs in vitro. IL-27 negatively regulated the differentiation of IFN-γ+ CD8+ Tc1 cells isolated from cigarette smoke-exposed mice in a STAT1- and STAT3-independent manner. Systemic administration of recombinant IL-27 attenuated IFN-γ+ CD8+ Tc1 response in the late phase of cigarette smoke exposure. Our results uncovered that IL-27 negatively regulates IFN-γ+ CD8+ Tc1 response in the late stage of chronic cigarette smoke exposure, which may provide a new strategy for the anti-inflammatory treatment of smoking-related COPD/emphysema.


Assuntos
Diferenciação Celular , Fumar Cigarros , Interferon gama , Interleucinas , Enfisema Pulmonar , Linfócitos T Citotóxicos , Idoso , Animais , Feminino , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Diferenciação Celular/imunologia , Fumar Cigarros/efeitos adversos , Fumar Cigarros/imunologia , Modelos Animais de Doenças , Inflamação/etiologia , Inflamação/imunologia , Interferon gama/imunologia , Interleucinas/imunologia , Enfisema Pulmonar/etiologia , Enfisema Pulmonar/imunologia , Linfócitos T Citotóxicos/imunologia
18.
Plant Physiol ; 189(2): 1110-1127, 2022 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-35294556

RESUMO

Rice (Oryza sativa) germination and seedling establishment, particularly in increasingly saline soils, are critical to ensure successful crop yields. Seed vigor, which determines germination and seedling growth, is a complex trait affected by exogenous (environmental) and endogenous (hormonal) factors. Here, we used genetic and biochemical analyses to uncover the role of an APETALA2-type transcription factor, SALT AND ABA RESPONSE ERF1 (OsSAE1), as a positive regulator of seed germination and salt tolerance in rice by repressing the expression of ABSCISIC ACID-INSENSITIVE5 (OsABI5). ossae1 knockout lines exhibited delayed seed germination, enhanced sensitivity to abscisic acid (ABA) during germination and in early seedling growth, and reduced seedling salt tolerance. OsSAE1 overexpression lines exhibited the converse phenotype, with increased seed germination and salt tolerance. In vivo and in vitro assays indicated that OsSAE1 binds directly to the promoter of OsABI5, a major downstream component of the ABA signaling pathway and acts as a major regulator of seed germination and stress response. Genetic analyses revealed that OsABI5-mediated ABA signaling functions downstream of OsSAE1. This study provides important insights into OsSAE1 regulation of seed vigor and salt tolerance and facilitates the practical use of OsSAE1 in breeding salt-tolerant varieties suitable for direct seeding cultivation.


Assuntos
Ácido Abscísico , Oryza , Ácido Abscísico/metabolismo , Ácido Abscísico/farmacologia , Regulação da Expressão Gênica de Plantas , Germinação/genética , Oryza/metabolismo , Melhoramento Vegetal , Reguladores de Crescimento de Plantas/metabolismo , Tolerância ao Sal/genética , Plântula , Sementes
19.
Opt Express ; 31(12): 19754-19765, 2023 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-37381384

RESUMO

We report a sub-terahertz scattering-type scanning near-field microscope (sub-THz s-SNOM) which uses a 6 mm long metallic tip driven by a quartz tuning fork as the near-field probe. Under continuous-wave illumination by a 94 GHz Gunn diode oscillator, terahertz near-field images are obtained by demodulating the scattered wave at both the fundamental and the second harmonic of the tuning fork oscillation frequency together with the atomic-force-microscope (AFM) image. The terahertz near-field image of a gold grating with a period of 2.3 µm obtained at the fundamental modulation frequency agrees well with the AFM image. The experimental relationship between the signal demodulated at the fundamental frequency and the tip-sample distance is well fitted with the coupled dipole model indicating that the scattered signal from the long probe is mainly contributed by the near-field interaction between the tip and the sample. This near-filed probe scheme using quartz tuning fork can adjust the tip length flexibly to match the wavelength over the entire terahertz frequency range and allows for operation in cryogenic environment.

20.
Opt Express ; 31(6): 10720-10731, 2023 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-37157613

RESUMO

To satisfy the demand for broadband and high-sensitivity terahertz detectors, we designed and verified a broadband terahertz detector built with antenna-coupled AlGaN/GaN high-electron-mobility transistors (HEMTs). Eighteen pairs of dipole antennas with different center frequency from 0.24 to 7.4 THz are arrayed into a bow-tie pattern. The corresponding eighteen transistors have common a source and a drain but different gated channels coupled by the corresponding antennas. The photocurrents generated by each gated channel are combined in the drain as the output port. With incoherent terahertz radiation from a hot blackbody in a Fourier-transform spectrometer (FTS), the detector exhibits a continuous response spectrum from 0.2 to 2.0 THz at 298 K and from 0.2 to 4.0 THz at 77 K, respectively. The results agree well with simulations taking into account the silicon lens, antenna and blackbody radiation law. The sensitivity is characterized under coherent terahertz irradiation, the average noise-equivalent power (NEP) is about 188 p W/H z at 298 K and 19 p W/H z at 77 K from 0.2 to 1.1 THz, respectively. A maximum optical responsivity of 0.56 A/W and a minimum NEP of 7.0 p W/H z at 0.74 THz are achieved at 77 K. The blackbody response spectrum is divided by the blackbody radiation intensity to obtain a performance spectrum, which is calibrated by measuring coherence performance from 0.2 to 1.1 THz to evaluate detector performance at frequencies above 1.1 THz. At 298 K, the NEP is about 1.7 n W/H z at 2.0 THz. At 77 K, the NEP is about 3 n W/H z at 4.0 THz. For further improvements in sensitivity and bandwidth, high-bandwidth coupling components, smaller series resistance, smaller gate lengths and high-mobility materials need to be considered.

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