Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 450
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Immunity ; 53(3): 685-696.e3, 2020 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-32783921

RESUMO

The coronavirus disease 2019 (COVID-19) pandemic poses a current world-wide public health threat. However, little is known about its hallmarks compared to other infectious diseases. Here, we report the single-cell transcriptional landscape of longitudinally collected peripheral blood mononuclear cells (PBMCs) in both COVID-19- and influenza A virus (IAV)-infected patients. We observed increase of plasma cells in both COVID-19 and IAV patients and XIAP associated factor 1 (XAF1)-, tumor necrosis factor (TNF)-, and FAS-induced T cell apoptosis in COVID-19 patients. Further analyses revealed distinct signaling pathways activated in COVID-19 (STAT1 and IRF3) versus IAV (STAT3 and NFκB) patients and substantial differences in the expression of key factors. These factors include relatively increase of interleukin (IL)6R and IL6ST expression in COVID-19 patients but similarly increased IL-6 concentrations compared to IAV patients, supporting the clinical observations of increased proinflammatory cytokines in COVID-19 patients. Thus, we provide the landscape of PBMCs and unveil distinct immune response pathways in COVID-19 and IAV patients.


Assuntos
Infecções por Coronavirus/imunologia , Citocinas/imunologia , Influenza Humana/imunologia , Leucócitos Mononucleares/imunologia , Pneumonia Viral/imunologia , Transdução de Sinais/imunologia , Betacoronavirus/imunologia , COVID-19 , Humanos , Vírus da Influenza A Subtipo H1N1/imunologia , Pandemias , SARS-CoV-2
2.
Immunity ; 49(4): 725-739.e6, 2018 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-30314758

RESUMO

Systemic Lupus Erythematosus (SLE) is characterized by B cells lacking IgD and CD27 (double negative; DN). We show that DN cell expansions reflected a subset of CXCR5- CD11c+ cells (DN2) representing pre-plasma cells (PC). DN2 cells predominated in African-American patients with active disease and nephritis, anti-Smith and anti-RNA autoantibodies. They expressed a T-bet transcriptional network; increased Toll-like receptor-7 (TLR7); lacked the negative TLR regulator TRAF5; and were hyper-responsive to TLR7. DN2 cells shared with activated naive cells (aNAV), phenotypic and functional features, and similar transcriptomes. Their PC differentiation and autoantibody production was driven by TLR7 in an interleukin-21 (IL-21)-mediated fashion. An in vivo developmental link between aNAV, DN2 cells, and PC was demonstrated by clonal sharing. This study defines a distinct differentiation fate of autoreactive naive B cells into PC precursors with hyper-responsiveness to innate stimuli, as well as establishes prominence of extra-follicular B cell activation in SLE, and identifies therapeutic targets.


Assuntos
Subpopulações de Linfócitos B/imunologia , Linfócitos B/imunologia , Lúpus Eritematoso Sistêmico/imunologia , Receptor 7 Toll-Like/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Subpopulações de Linfócitos B/metabolismo , Linfócitos B/metabolismo , Feminino , Redes Reguladoras de Genes/genética , Redes Reguladoras de Genes/imunologia , Humanos , Lúpus Eritematoso Sistêmico/genética , Lúpus Eritematoso Sistêmico/metabolismo , Masculino , Pessoa de Meia-Idade , Plasmócitos/imunologia , Plasmócitos/metabolismo , Receptor 7 Toll-Like/genética , Receptor 7 Toll-Like/metabolismo , Transcriptoma/genética , Transcriptoma/imunologia , Adulto Jovem
3.
Proc Natl Acad Sci U S A ; 121(11): e2318320121, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38457518

RESUMO

Coordinated carbon and nitrogen metabolism is crucial for bacteria living in the fluctuating environments. Intracellular carbon and nitrogen homeostasis is maintained by a sophisticated network, in which the widespread signaling protein PII acts as a major regulatory hub. In cyanobacteria, PII was proposed to regulate the nitrate uptake by an ABC (ATP-binding cassette)-type nitrate transporter NrtABCD, in which the nucleotide-binding domain of NrtC is fused with a C-terminal regulatory domain (CRD). Here, we solved three cryoelectron microscopy structures of NrtBCD, bound to nitrate, ATP, and PII, respectively. Structural and biochemical analyses enable us to identify the key residues that form a hydrophobic and a hydrophilic cavity along the substrate translocation channel. The core structure of PII, but not the canonical T-loop, binds to NrtC and stabilizes the CRD, making it visible in the complex structure, narrows the substrate translocation channel in NrtB, and ultimately locks NrtBCD at an inhibited inward-facing conformation. Based on these results and previous reports, we propose a putative transport cycle driven by NrtABCD, which is allosterically inhibited by PII in response to the cellular level of 2-oxoglutarate. Our findings provide a distinct regulatory mechanism of ABC transporter via asymmetrically binding to a signaling protein.


Assuntos
Cianobactérias , Transportadores de Nitrato , Nitratos/metabolismo , Proteínas de Bactérias/metabolismo , Regulação Alostérica , Microscopia Crioeletrônica , Cianobactérias/metabolismo , Trifosfato de Adenosina/metabolismo , Nitrogênio/metabolismo , Carbono/metabolismo , Proteínas PII Reguladoras de Nitrogênio/genética , Proteínas PII Reguladoras de Nitrogênio/metabolismo
4.
Plant Physiol ; 194(3): 1498-1511, 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-37956105

RESUMO

Drought and heat stresses usually occur concomitantly in nature, with increasing frequency and intensity of both stresses expected due to climate change. The synergistic agricultural impacts of these compound climate extremes are much greater than those of the individual stresses. However, the mechanisms by which drought and heat stresses separately and concomitantly affect dynamic photosynthesis have not been thoroughly assessed. To elucidate this, we used tomato (Solanum lycopersicum) seedlings to measure dynamic photosynthesis under individual and compound stresses of drought and heat. Individual drought and heat stresses limited dynamic photosynthesis at the stages of diffusional conductance to CO2 and biochemistry, respectively. However, the primary limiting factor for photosynthesis shifted to mesophyll conductance under the compound stresses. Compared with the control, photosynthetic carbon gain in fluctuating light decreased by 38%, 73%, and 114% under the individual drought, heat, and compound stresses, respectively. Therefore, compound stresses caused a greater reduction in photosynthetic carbon gain in fluctuating light conditions than individual stress. These findings highlight the importance of mitigating the effects of compound climate extremes on crop productivity by targeting mesophyll conductance and improving dynamic photosynthesis.


Assuntos
Secas , Solanum lycopersicum , Agricultura , Carbono , Mudança Climática , Fotossíntese
5.
Antimicrob Agents Chemother ; 68(1): e0077823, 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38095426

RESUMO

Vulvovaginal candidiasis (VVC) is a common condition among women. Fluconazole remains the dominant treatment option for VVC. Oteseconazole is a highly selective inhibitor of fungal CYP51. This randomized, double-blinded, phase 3 trial was conducted to evaluate the efficacy and safety of oteseconazole compared with fluconazole in treating severe VVC. Female subjects presenting with vulvovaginal signs and symptoms score of ≥7 and positive Candida infection determined by potassium hydroxide test or Gram staining were randomly assigned to receive oteseconazole (600 mg on D1 and 450 mg on D2) or fluconazole (150 mg on D1 and D4) in a 1:1 ratio. The primary endpoint was the proportion of subjects achieving therapeutic cure [defined as achieving both clinical cure (absence of signs and symptoms of VVC) and mycological cure (negative culture of Candida species)] at D28. A total of 322 subjects were randomized and 321 subjects were treated. At D28, a statistically significantly higher proportion of subjects achieved therapeutic cure in the oteseconazole group than in the fluconazole group (66.88% vs 45.91%; P = 0.0002). Oteseconazole treatment resulted in an increased proportion of subjects achieving mycological cure (82.50% vs 59.12%; P < 0.0001) and clinical cure (71.25% vs 55.97%; P = 0.0046) compared with fluconazole. The incidence of treatment-emergent adverse events was similar between the two groups. No subjects discontinued study treatment or withdrew study due to adverse events. Oteseconazole showed statistically significant and clinically meaningful superiority over fluconazole for the treatment of severe VVC and was generally tolerated.


Assuntos
Candidíase Vulvovaginal , Fluconazol , Feminino , Humanos , Fluconazol/farmacologia , Candidíase Vulvovaginal/tratamento farmacológico , Candidíase Vulvovaginal/microbiologia , Antifúngicos/efeitos adversos , Candida , Administração Oral , Candida albicans
6.
Mol Carcinog ; 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-39016636

RESUMO

LAIR1, a receptor found on immune cells, is capable of binding to collagen and is involved in immune-related diseases. However, the precise contribution of LAIR1 expressed on hepatocellular carcinoma (HCC) cells to tumor microenvironment is still unclear. In our study, bioinformatics analysis and immunofluorescence were employed to study the correlation between LAIR1 levels and clinical indicators. Transwell and scratch tests were used to evaluate how LAIR1 affected the migration and invasion of HCC cells. The chemotactic capacity and alternative activation of macrophages were investigated using RT-qPCR, transwell, and immunofluorescence. To investigate the molecular mechanisms, transcriptome sequencing analysis, Western blot, nucleus/cytoplasm fractionation, ELISA, and cytokine microarray were employed. We revealed a significant correlation between the presence of LAIR1 and an unfavorable outcome in HCC. We indicated that LAIR1 promoted migration and invasion of HCC cells through the AKT-IKKß-p65 axis. Additionally, the alternative activation and infiltration of tumor-associated macrophages induced by LAIR1 were reliant on the upregulation of IL6 and CCL5 within this axis, respectively. In conclusion, blocking LAIR1 was found to be an effective approach in combating the cancerous advancement of HCC.

7.
PLoS Pathog ; 18(4): e1010504, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35482828

RESUMO

RSK1, an essential cellular kinase for Kaposi's sarcoma-associated herpesvirus (KSHV) replication, is highly phosphorylated and SUMOylated during KSHV lytic cycle, which determine the substrate phosphorylation and specificity of RSK1, respectively. However, the SUMO E3 ligase responsible for attaching SUMO to RSK1 has not yet been identified. By genome-wide screening, we found that KSHV ORF45 is necessary and sufficient to enhance RSK1 SUMOylation. Mechanistically, KSHV ORF45 binds to SUMOs via two classic SUMO-interacting motifs (SIMs) and functions as a SIM-dependent SUMO E3 ligase for RSK1. Mutations on these ORF45 SIMs resulted in much lower lytic gene expressions, viral DNA replication, and mature progeny virus production. Interestingly, KSHV ORF45 controls RSK1 SUMOylation and phosphorylation via two separated functional regions: SIMs and amino acid 17-90, respectively, which do not affect each other. Similar to KSHV ORF45, ORF45 of Rhesus Macaque Rhadinovirus has only one SIM and also increases RSK1 SUMOylation in a SIM-dependent manner, while other ORF45 homologues do not have this function. Our work characterized ORF45 as a novel virus encoded SUMO E3 ligase, which is required for ORF45-RSK1 axis-mediated KSHV lytic gene expression.


Assuntos
Herpesvirus Humano 8 , Proteínas Imediatamente Precoces , Animais , Linhagem Celular , Replicação do DNA , DNA Viral , Herpesvirus Humano 8/genética , Herpesvirus Humano 8/metabolismo , Proteínas Imediatamente Precoces/genética , Proteínas Imediatamente Precoces/metabolismo , Macaca mulatta/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Replicação Viral
8.
Psychosom Med ; 86(3): 202-209, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38588496

RESUMO

OBJECTIVE: Major depressive disorder (MDD) is a severe psychiatric symptom worldwide, and the coexistence of MDD with metabolic syndrome (MetS) is common in clinical practice. However, gender differences in comorbid MetS in first-episode and drug-naïve (FEDN) MDD patients have not been reported. Here, we explored potential gender differences in the prevalence and clinical correlates of comorbid MetS in FEDN MDD patients. METHODS: A cross-sectional study of 1718 FEDN MDD patients was conducted. Demographic and clinical data were collected. The Hamilton Depression Scale (HAMD), Hamilton Anxiety Scale, and Positive and Negative Syndrome Scale positive subscale were used to evaluate depression, anxiety, and psychotic symptoms, respectively. RESULTS: The prevalence of MetS was 1.645-fold higher in female MDD patients (38.50%) than in male patients (26.53%). Patients with MetS had higher HAMD score, Hamilton Anxiety Scale score, and Positive and Negative Syndrome Scale positive subscale score than patients without MetS (p values < .001). Furthermore, suicide attempts (male: odds ratio [OR] = 1.706, p = .034; female: OR = 1.639, p = .004) and HAMD score (male: OR = 1.251, p < .001; female: OR = 1.148, p < .001) were independently associated with MetS in male and female patients, whereas age of onset was independently associated with MetS only in female patients (OR = 1.744, p = .047). CONCLUSIONS: Our findings suggest significant gender differences in the prevalence and clinical correlates of comorbid MetS in FEDN MDD patients. Clinical variables (suicide attempts and HAMD scores) may be independently associated with MetS in MDD patients.


Assuntos
Transtorno Depressivo Maior , Síndrome Metabólica , Humanos , Masculino , Feminino , Transtorno Depressivo Maior/epidemiologia , Transtorno Depressivo Maior/diagnóstico , Síndrome Metabólica/epidemiologia , Prevalência , Estudos Transversais , Fatores Sexuais
9.
Opt Lett ; 49(10): 2805-2808, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38748166

RESUMO

The advancement demands of high-speed wireless data link ask for higher requirements on visible light communication (VLC), where wide coverage stands as a critical criterion. Here, we present the design and implementation of a transmitter structure capable of emitting a high-power wide-coverage white light laser. This laser source exhibits excellent stability, with an irradiation range extending to a half-angle of 20°. Its high brightness satisfies the needs of indoor illumination while maintaining excellent communication performance. Utilizing bit-loading discrete multi-tone modulation, a peak data transmission rate of 3.24 Gbps has been achieved, spanning 1 to 5 m. Remarkably, the data rates exceed 2.5 Gbps within a 40° range at a distance of 5 m, enabling a long-distance, wide coverage, high-speed VLC link for future mobile network applications.

11.
Infection ; 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38568411

RESUMO

PURPOSE: To evaluate the efficacy and safety of oral ibrexafungerp (HS-10366) versus placebo in Chinese patients with vulvovaginal candidiasis (VVC). METHODS: A double-blind, placebo-controlled, randomized, multicenter phase III study was conducted in symptomatic VVC patients. Patients received (2:1) twice-daily oral ibrexafungerp 300 mg or matching placebo for 1 day. The primary endpoint was clinical cure (vulvovaginal signs and symptoms [VSS] score = 0) at test-of-cure (TOC) on day 11 ± 3. The secondary endpoints included mycological eradication, overall response, and clinical improvement (VSS score ≤ 1) at TOC, and vulvovaginal symptom resolution at follow-up on day 25 ± 4. RESULTS: In total, 360 patients were included in the modified intention-to-treat set (defined as positive Candida cultured and receiving at least one study drug; 239 for ibrexafungerp, 121 for placebo). Compared with placebo, patients receiving ibrexafungerp had a significantly higher proportion of clinical cure (51.0% vs. 25.6%), mycological eradication (55.6% vs. 18.2%), overall response (33.9%, vs. 8.3%) at TOC and complete symptom resolution (74.5% vs. 39.7%, all P < 0.001) at follow-up. Subgroup analysis of clinical cure indicated that patients with C. albicans could benefit from ibrexafungerp over placebo. A similar benefit trend was also observed in those with non-albicans Candida by post-hoc analysis. Further analyses revealed similar efficacy of ibrexafungerp between patients with fluconazole non-susceptible C. albicans and fluconazole susceptible C. albicans regarding clinical cure and mycological eradication. Ibrexafungerp was generally well tolerated. Adverse events were primarily gastrointestinal and were mainly mild in severity. CONCLUSIONS: As a first-in-class antifungal agent, ibrexafungerp demonstrated promising efficacy and favorable safety for VVC treatment in Chinese patients. CHINADRUGTRIALS.ORG. CN REGISTRY NUMBER: CTR20220918.

12.
BMC Geriatr ; 24(1): 15, 2024 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-38177993

RESUMO

BACKGROUND: Subclinical hypothyroidism (SCH) is highly correlated with major depressive disorder (MDD). However, the prevalence and risk factors for SCH in older patients with MDD have rarely been reported in China. METHODS: This cross-sectional study included 266 older MDD patients with SCH was performed. Clinical and anthropometric, biochemical, and thyroid function data were collected. Depression, anxiety, and psychotic symptoms were assessed using the Hamilton Depression Scale, the Hamilton Anxiety Scale, and the Positive and Negative Syndrome Scale positive subscale, respectively. RESULTS: Among older patients with MDD, the prevalence of SCH was 64.7% (172/266). Compared to patients without SCH, older MDD patients with SCH had a longer disease course and higher TSH, A-TG, A-TPO, HDL-C, LDL-C, TC, FPG, and systolic pressure levels (all P ≤ 0.002). Furthermore, disease progression (OR 1.082, 95% CI 1.020-1.147, P = 0.009), A-TG (OR 1.005, 95% CI 1.001-1.009, P = 0.017), TC (OR 2.024, 95% CI 1.213-3.377, P = 0.007), FPG (OR 2.916, 95% CI 1.637-5.194, P < 0.001), systolic pressure (OR 1.053, 95% CI 1.008-1.100, P = 0.022) were independently associated with SCH, in older patients with MDD. CONCLUSIONS: Our findings suggest a high prevalence of SCH in older patients with MDD. Several demographic and clinical variables were independently associated with SCH in older patients with MDD.


Assuntos
Transtorno Depressivo Maior , Hipotireoidismo , Humanos , Idoso , Transtorno Depressivo Maior/diagnóstico , Transtorno Depressivo Maior/epidemiologia , Prevalência , Estudos Transversais , Hipotireoidismo/diagnóstico , Hipotireoidismo/epidemiologia , Fatores de Risco
13.
Clin Rehabil ; 38(4): 510-519, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38092741

RESUMO

OBJECTIVE: To investigate the effectiveness of Baduanjin exercise on executive function in community-dwelling older adults with cognitive frailty. DESIGN: Randomized controlled trial. SETTING: Community residential centers. SUBJECTS: 120 eligible older adults. INTERVENTIONS: Baduanjin training group received supervised Baduanjin training, 60 min sessions three times per week for 24 weeks. The control group did not receive any exercise intervention. MAIN MEASURES: Primary outcome was executive function, assessed using Clock Drawing Test. Secondary outcomes included the subcomponents of executive function (working memory, inhibitory control and cognitive flexibility), attention and cognitive frailty (global cognitive function, physical frailty) assessed using Verbal Fluency Test, Trail Making Test-A/B, Stroop Test, Montreal Cognitive Assessment and Edmonton Frailty Scale, respectively, at baseline and 24 weeks after intervention. RESULTS: After the 24-week intervention, the scores of Clock Drawing Test and Verbal Fluency Test, the Trail Making Test-B time and the Card correct numbers of Stroop Test in Baduanjin training group showed significant improvement compared with control group (all P < 0.05) with small to moderate effect sizes and the significant interaction effect of group by time in the Clock Drawing Test and Trail Making Test-B test (P = 0.003 and P = 0.043); cognitive frailty variables, including Montreal Cognitive Assessment and Edmonton Frail Scale scores, also showed significant improvement (P = 0.002 and P = 0.004) with a moderate effect sizes and a significant interaction effect (P < 0.001, P = 0.013). No adverse events were reported. CONCLUSION: Regular Baduanjin training may be an effective and safe intervention to improve cognitive frailty and executive function in community-dwelling older adults with cognitive frailty. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR2100050857. Data of registration: 8/5/2020, https://www.chictr.org.cn/showproj.html?proj = 133037.


Assuntos
Função Executiva , Fragilidade , Humanos , Idoso , Terapia por Exercício , Exercício Físico , Cognição
14.
Sensors (Basel) ; 24(13)2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-39000976

RESUMO

We developed a novel method based on self-supervised learning to improve the ghost imaging of occluded objects. In particular, we introduced a W-shaped neural network to preprocess the input image and enhance the overall quality and efficiency of the reconstruction method. We verified the superiority of our W-shaped self-supervised computational ghost imaging (WSCGI) method through numerical simulations and experimental validations. Our results underscore the potential of self-supervised learning in advancing ghost imaging.

15.
Sensors (Basel) ; 24(10)2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38793940

RESUMO

Mobile visible light communication (VLC) is key for integrating lighting and communication applications in the 6G era, yet there exists a notable gap in experimental research on mobile VLC. In this study, we introduce a mobile VLC system and investigate the impact of mobility speed on communication performance. Leveraging a laser-based light transmitter with a wide coverage, we enable a light fidelity (LiFi) system with a mobile receiving end. The system is capable of supporting distances from 1 m to 4 m without a lens and could maintain a transmission rate of 500 Mbps. The transmission is stable at distances of 1 m and 2 m, but an increase in distance and speed introduces interference to the system, leading to a rise in the Bit Error Rate (BER). The mobile VLC experimental system provides a viable solution to the issue of mobile access in the integration of lighting and communication applications, establishing a solid practical foundation for future research.

16.
Cancer Immunol Immunother ; 72(12): 4103-4119, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37755466

RESUMO

Immunotherapy, which aims to enhance the function of T cells, has emerged as a novel therapeutic approach for hepatocellular carcinoma (HCC). Nevertheless, the clinical utility of using flow cytometry to assess immune cell infiltration (ICI) is hindered by its cumbersome procedures, prompting the need for more accessible methods. Here, we acquired gene expression profiles and survival data of HCC from TCGA and GSE10186 datasets. The patients were categorized into two clusters of ICI, and a set of 11 characteristic genes responsible for the differentiation performance of these ICI clusters were identified. Subsequently, we successfully developed a modified ICI score (mICIS) by utilizing the expression levels of these genes. The efficacy of our mICIS was confirmed via mass cytometry, flow cytometry, and immunohistochemistry. Our research indicated that the favorable overall survival (OS) rate could be attributed to the improved function of anti-tumor leukocytes rather than their infiltration. Furthermore, we observed that the low score group exhibited lower expression levels of T-cell exhaustion-associated genes, which was confirmed in both HCC tissues from patients and mice, which demonstrated that the benefits of the low scores were due to enhanced active/cytotoxic CD8+ T cells and reduced exhausted CD8+ T cells. Additionally, our mICIS stratified the benefits derived from immunotherapies. Lastly, we observed a misalignment between CD8+ T-cell infiltration and function in HCC. In summary, our mICIS demonstrated proficiency in assessing the OS rate of HCC and offering significant stratified data pertaining to distinct responses to immunotherapy.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Animais , Camundongos , Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , Linfócitos T CD8-Positivos , Imuno-Histoquímica , Imunoterapia , Microambiente Tumoral
17.
BMC Plant Biol ; 23(1): 73, 2023 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-36732696

RESUMO

BACKGROUND: Cadmium (Cd) is a highly toxic element for plant growth. In plants, hydrogen sulfide (H2S) and methylglyoxal (MG) have emerged as vital signaling molecules that regulate plant growth processes under Cd stress. However, the effects of sodium hydrosulfide (NaHS, a donor of H2S) and MG on Cd uptake, physiological responses, and gene expression patterns of Salix to Cd toxicity have been poorly understood. Here, Salix matsudana Koidz. seedlings were planted in plastic pot with applications of MG (108 mg kg- 1) and NaHS (50 mg kg- 1) under Cd (150 mg kg- 1) stress. RESULTS: Cd treatment significantly increased the reactive oxygen species (ROS) levels and malondialdehyde (MDA) content, but decreased the growth parameters in S. matsudana. However, NaHS and MG supplementation significantly decreased Cd concentration, ROS levels, and MDA content, and finally enhanced the growth parameters. Cd stress accelerated the activities of antioxidative enzymes and the relative expression levels of stress-related genes, which were further improved by NaHS and MG supplementation. However, the activities of monodehydroascorbate reductase (MDHAR), and dehydroascorbate reductase (DHAR) were sharply decreased under Cd stress. Conversely, NaHS and MG applications restored the MDHAR and DHAR activities compared with Cd-treated seedlings. Furthermore, Cd stress decreased the ratios of GSH/GSSG and AsA/DHA but considerably increased the H2S and MG levels and glyoxalase I-II system in S. matsudana, while the applications of MG and NaHS restored the redox status of AsA and GSH and further improved glyoxalase II activity. In addition, compared with AsA, GSH showed a more sensitive response to exogenous applications of MG and NaHS and plays more important role in the detoxification of Cd. CONCLUSIONS: The present study illustrated the crucial roles of H2S and MG in reducing ROS-mediated oxidative damage to S. matsudana and revealed the vital role of GSH metabolism in regulating Cd-induced stress.


Assuntos
Sulfeto de Hidrogênio , Salix , Cádmio/metabolismo , Sulfeto de Hidrogênio/farmacologia , Sulfeto de Hidrogênio/metabolismo , Aldeído Pirúvico/metabolismo , Salix/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Antioxidantes/metabolismo , Estresse Oxidativo , Glutationa/metabolismo , Plântula/metabolismo
18.
BMC Plant Biol ; 23(1): 176, 2023 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-37016323

RESUMO

BACKGROUND: Alfalfa (Medicago sativa L.) as an important legume plant can quickly produce adventitious roots (ARs) to form new plants by cutting. But the regulatory mechanism of AR formation in alfalfa remains unclear. RESULTS: To better understand the rooting process of alfalfa cuttings, plant materials from four stages, including initial separation stage (C stage), induction stage (Y stage), AR primordium formation stage (P stage) and AR maturation stage (S stage) were collected and used for RNA-Seq. Meanwhile, three candidate genes (SAUR, VAN3 and EGLC) were selected to explore their roles in AR formation. The numbers of differentially expressed genes (DEGs) of Y-vs-C (9,724) and P-vs-Y groups (6,836) were larger than that of S-vs-P group (150), indicating highly active in the early AR formation during the complicated development process. Pathways related to cell wall and sugar metabolism, root development, cell cycle, stem cell, and protease were identified, indicating that these genes were involved in AR production. A large number of hormone-related genes associated with the formation of alfalfa ARs have also been identified, in which auxin, ABA and brassinosteroids are thought to play key regulatory roles. Comparing with TF database, it was found that AP2/ERF-ERF, bHLH, WRKY, NAC, MYB, C2H2, bZIP, GRAS played a major regulatory role in the production of ARs of alfalfa. Furthermore, three identified genes showed significant promotion effect on AR formation. CONCLUSIONS: Stimulation of stem basal cells in alfalfa by cutting induced AR production through the regulation of various hormones, transcription factors and kinases. This study provides new insights of AR formation in alfalfa and enriches gene resources in crop planting and cultivation.


Assuntos
Regulação da Expressão Gênica de Plantas , Medicago sativa , Medicago sativa/genética , Medicago sativa/metabolismo , Ácidos Indolacéticos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
19.
Opt Express ; 31(4): 5736-5746, 2023 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-36823846

RESUMO

We disclose a transporting/collecting optical sling generated by a liquid crystal geometric phase optical element with spatial variant topological charge, which shows the intriguing repelling/indrawing effect on the micro-particle along the spiral orbit. Two proof-of-concept prototypes, i.e., an optical conveyor and a particle collector, are demonstrated. Based on the distinct dynamic characteristics of the micro-particles in different sizes, we conceptually propose a design for particle sorting. Thus, our proposed method to generate a spiral optical sling with spatial variant orbital angular momentum for on-demand collecting, transporting and sorting micro-particles is substantiated, which can find extensive applications in bio-medicine, micro-biology, etc.

20.
Opt Lett ; 48(15): 4085-4088, 2023 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-37527124

RESUMO

A simple and compact polarimeter comprising two electrically controlled liquid-crystal variable retarders (LCVRs) and a linear polarizer is demonstrated, which is enabled by analyzing the intensity variation of the modulated output light based on a computational algorithm. A proof-of-concept prototype is presented, which is mounted onto a power meter or a CMOS camera for the intensity data collection. The polarimetric measurement for the spatial variant polarization states of light is also verified, indicating the possibility of achieving a resolution-lossless polarimeter. Thus, our proposed method shows a cost-effective way to realize a compact polarimeter in polarization optics.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA