Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 522
Filtrar
1.
Cell ; 185(26): 4904-4920.e22, 2022 12 22.
Artigo em Inglês | MEDLINE | ID: mdl-36516854

RESUMO

Cells communicate with each other via receptor-ligand interactions. Here, we describe lentiviral-mediated cell entry by engineered receptor-ligand interaction (ENTER) to display ligand proteins, deliver payloads, and record receptor specificity. We optimize ENTER to decode interactions between T cell receptor (TCR)-MHC peptides, antibody-antigen, and other receptor-ligand pairs. A viral presentation strategy allows ENTER to capture interactions between B cell receptor and any antigen. We engineer ENTER to deliver genetic payloads to antigen-specific T or B cells to selectively modulate cellular behavior in mixed populations. Single-cell readout of ENTER by RNA sequencing (ENTER-seq) enables multiplexed enumeration of antigen specificities, TCR clonality, cell type, and states of individual T cells. ENTER-seq of CMV-seropositive patient blood samples reveals the viral epitopes that drive effector memory T cell differentiation and inter-clonal vs. intra-clonal phenotypic diversity targeting the same epitope. ENTER technology enables systematic discovery of receptor specificity, linkage to cell fates, and antigen-specific cargo delivery.


Assuntos
Receptores de Antígenos de Linfócitos T , Internalização do Vírus , Humanos , Biologia , Epitopos , Ligantes , Peptídeos , Receptores de Antígenos de Linfócitos T/metabolismo , Análise de Célula Única , Genômica
2.
Plant J ; 113(3): 546-561, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36534116

RESUMO

The jasmonic acid (JA) signaling pathway is involved in the plant response to drought stress. JA and other hormones synergistically regulate the drought response in plants. However, the molecular mechanism underlying this synergism remains poorly defined. In the present study, transcriptome analyses of guard cells and quantitative PCR experiments revealed that MYC2 negatively regulated the negative regulator of ABA signaling, SlPP2C1, and the type-B response regulator in the cytokinin pathway, SlRR26, and this negative regulation was direct. SlRR26 overexpression reduced drought tolerance in transgenic tomatoes, whereas slrr26cr lines were more tolerant to drought. SlRR26 negatively modulated reactive oxygen species levels in stomata and stomatal closure through RobhB. Moreover, SlRR26 overexpression counteracted JA-mediated stomatal closure, suggesting that SlRR26 played a negative role in the JA-mediated drought response. These findings suggest that MYC2 plays a key role in JA-regulated stomatal closure under drought stress by inhibiting SlPP2C1 and SlRR26.


Assuntos
Solanum lycopersicum , Fatores de Transcrição , Fatores de Transcrição/metabolismo , Ácido Abscísico/metabolismo , Solanum lycopersicum/genética , Osmorregulação , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Estresse Fisiológico , Estômatos de Plantas/fisiologia , Regulação da Expressão Gênica de Plantas , Plantas/metabolismo , Fosfoproteínas Fosfatases/metabolismo , Secas
3.
BMC Plant Biol ; 24(1): 451, 2024 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-38789940

RESUMO

Root-knot nematodes (RKNs) infect host plants and obtain nutrients such as sugars for their own development. Therefore, inhibiting the nutrient supply to RKNs may be an effective method for alleviating root-knot nematode disease. At present, the pathway by which sucrose is unloaded from the phloem cells to giant cells (GCs) in root galls and which genes related to sugar metabolism and transport play key roles in this process are unclear. In this study, we found that sugars could be unloaded into GCs only from neighboring phloem cells through the apoplastic pathway. With the development of galls, the contents of sucrose, fructose and glucose in the galls and adjacent tissue increased gradually. SUT1, SUT2, SWEET7a, STP10, SUS3 and SPS1 may provide sugar sources for GCs, while STP1, STP2 and STP12 may transport more sugar to phloem parenchyma cells. At the early stage of Meloidogyne incognita infestation, the sucrose content in tomato roots and leaves increased, while the glucose and fructose contents decreased. SWEET7a, SPS1, INV-INH1, INV-INH2, SUS1 and SUS3 likely play key roles in root sugar delivery. These results elucidated the pathway of sugar unloading in tomato galls and provided an important theoretical reference for eliminating the sugar source of RKNs and preventing root-knot nematode disease.


Assuntos
Raízes de Plantas , Tumores de Planta , Solanum lycopersicum , Tylenchoidea , Tylenchoidea/fisiologia , Animais , Solanum lycopersicum/parasitologia , Solanum lycopersicum/metabolismo , Raízes de Plantas/parasitologia , Raízes de Plantas/metabolismo , Tumores de Planta/parasitologia , Doenças das Plantas/parasitologia , Sacarose/metabolismo , Açúcares/metabolismo , Metabolismo dos Carboidratos
4.
J Virol ; 97(1): e0138122, 2023 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-36625579

RESUMO

Although segmented negative-sense RNA viruses (SNSRVs) have been frequently discovered in various fungi, most SNSRVs reported only the large segments. In this study, we investigated the diversity of the mycoviruses in the phytopathogenic fungus Fusarium asiaticum using the metatranscriptomic technique. We identified 17 fungal single-stranded RNA (ssRNA) viruses including nine viruses within Mitoviridae, one each in Narnaviridae, Botourmiaviridae, Hypoviridae, Fusariviridae, and Narliviridae, two in Mymonaviridae, and one trisegmented virus temporarily named Fusarium asiaticum mycobunyavirus 1 (FaMBV1). The FaMBV1 genome comprises three RNA segments, large (L), medium (M), and small (S) with 6,468, 2,639, and 1,420 nucleotides, respectively. These L, M, and S segments putatively encode the L protein, glycoprotein, and nucleocapsid, respectively. Phylogenetic analysis based on the L protein showed that FaMBV1 is phylogenetically clustered with Alternaria tenuissima negative-stranded RNA virus 2 (AtNSRV2) and Sclerotinia sclerotiorum negative-stranded RNA virus 5 (SsNSRV5) but distantly related to the members of the family Phenuiviridae. FaMBV1 could be vertically transmitted by asexual spores with lower efficiency (16.7%, 2/42). Comparison between FaMBV1-free and -infected fungal strains revealed that FaMBV1 has little effect on hyphal growth, pathogenicity, and conidium production, and its M segment is dispensable for viral replication and lost during subculture and asexual conidiation. The M and S segments of AtNSRV2 and SsNSRV5 were found using bioinformatics methods, indicating that the two fungal NSRVs harbor trisegmented genomes. Our results provide a new example of the existence and evolution of the segmented negative-sense RNA viruses in fungi. IMPORTANCE Fungal segmented negative-sense RNA viruses (SNSRVs) have been frequently found. Only the large segment encoding RNA-dependent RNA polymerase (RdRp) has been reported in most fungal SNSRVs, except for a few fungal SNSRVs reported to encode nucleocapsids, nonstructural proteins, or movement proteins. Virome analysis of the Fusarium spp. that cause Fusarium head blight discovered a novel virus, Fusarium asiaticum mycobunyavirus 1 (FaMBV1), representing a novel lineage of the family Phenuiviridae. FaMBV1 harbors a trisegmented genome that putatively encodes RdRp, glycoproteins, and nucleocapsids. The putative glycoprotein was first described in fungal SNSRVs and shared homology with glycoprotein of animal phenuivirus but was dispensable for its replication in F. asiaticum. Two other trisegmented fungal SNSRVs that also encode glycoproteins were discovered, implying that three-segment bunyavirus infections may be common in fungi. These findings provide new insights into the ecology and evolution of SNSRVs, particularly those infecting fungi.


Assuntos
Micovírus , Fusarium , Vírus de RNA , Micovírus/genética , Genoma Viral , Glicoproteínas/genética , Fases de Leitura Aberta , Filogenia , Vírus de RNA/genética , RNA Viral/genética , Fusarium/virologia
5.
Opt Express ; 32(9): 16523-16532, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38859277

RESUMO

The direction variation of the fundamental wave in the same nonlinear photonic crystal would cause different pattern of harmonics generation. In a 2D/3D crystal with dense reciprocal lattice vectors, there will be large numbers of conical harmonic beams evolving with direction change of the fundamental wave. By rearranging the Ewald sphere and superposing it into the Ewald shell, we have a hybrid Ewald construction. It becomes a simple but useful geometric method to comprehensively depict the distribution of these quasi-phase-matching second harmonics and their conical form evolution. It presents conical second harmonic beams by their related reciprocal lattice vectors and simplifies the beams' distribution according to spatial arrangement of those reciprocal lattice vectors. It finds that the conical beams will create, annihilate, or get enhanced in specific order when fundamental waves change incident directions. We applied the method on a periodically poled 2D LiTaO3 crystal and all observed phenomena, meet the method's predictions. In our experiment, we observed that the conical beams distorted along the optic axis of the sample due to anisotropy, which was generally overlooked by earlier researches. The eccentricities of their ring projections suggest a potential auxiliary approach for crystal dispersion measurement.

6.
J Gen Intern Med ; 39(8): 1360-1368, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38172410

RESUMO

BACKGROUND: Whether variation in Medicaid reimbursement fees influenced the impacts of the Medicaid expansions is not well understood. OBJECTIVE: We examine whether changes in health care access associated with Medicaid expansion are different in states with comparatively high Medicaid reimbursement rates compared against expanding in states with lower Medicaid reimbursement rates. DESIGN: Using a difference-in-difference-in-difference (DDD or triple-difference) regression approach, we compare relative differences in Medicaid expansion effects between lower and higher reimbursement states. PARTICIPANTS: 512,744 low-income adults aged 20-64 in the 2011-2019 Behavioral Risk Factor Surveillance System. MAIN MEASURES: Health insurance coverage status, unmet medical needs due to cost, regular source for health care, and a regular/scheduled checkup within the past year. KEY RESULTS: Medicaid expansion has significant and positive impacts on health coverage and access in both high- and low-fee states. In states with fee levels above the median Medicare-to-Medicaid ratios, expanding Medicaid eligibility reduced uninsurance rate by 15.2 percentage point (ppt, p < 0.01), shrank the cost-associated unmet medical need by 10.3 ppt (p < 0.01), improved access to usual source of care by 1.9 ppt (p < 0.1), and increased regular checkup by 14.4 ppt (p < 0.01), while such effects in low-fee states were 11.7 ppt (p < 0.01), 8.3 ppt (p < 0.01), 3.1 ppt (p < 0.1), and 12.3 ppt (p < 0.01), respectively. Our results suggest that Medicaid expansion effect on unmet medical need due to cost in higher-reimbursing states was 2.98 ppt (p < 0.05) larger than in lower-reimbursing states. Evidence suggests modest increases in health care access were more strongly associated with expansions in higher-fee states. CONCLUSIONS: Medicaid's fee structure should be considered as a factor influencing large-scale coverage expansions.


Assuntos
Acessibilidade aos Serviços de Saúde , Medicaid , Pobreza , Humanos , Medicaid/economia , Medicaid/estatística & dados numéricos , Estados Unidos , Acessibilidade aos Serviços de Saúde/economia , Acessibilidade aos Serviços de Saúde/estatística & dados numéricos , Adulto , Pessoa de Meia-Idade , Pobreza/economia , Feminino , Masculino , Adulto Jovem , Cobertura do Seguro/economia , Cobertura do Seguro/estatística & dados numéricos , Patient Protection and Affordable Care Act/economia , Reembolso de Seguro de Saúde/economia , Sistema de Vigilância de Fator de Risco Comportamental
7.
BMC Anesthesiol ; 24(1): 61, 2024 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-38336612

RESUMO

BACKGROUND: The pupillary response to tetanic electrical stimulation reflects the balance between nociceptive stimulation and analgesia. Although pupillary pain index (PPI) was utilized to predict postoperative pain, it depended on tetanic stimulation and was complex. We aim to describe the potential relationship between PD in the presence of surgical stimulation and pain levels after awakening. METHODS: According to the Verbal Rating Scale (VRS) score after extubation, the patients were divided into painless group (VRS = 0) and pain group (VRS ≥ 1). Pupillary diameter (PD) and pupillary light reflex velocity (PLRV) were compared between two groups when patients entered the operating room (T1), before incision (T2), 10 s after incision (T3), 30 s after incision (T4), 1 h after incision (T5), at the end of surgery (T6), shortly after extubation (T7), and when patients expressed pain clearly (T8). The magnitude of PD change (ΔPD) compared to the baseline value after anesthesia induction (T2) was calculated. The correlations between pupillary parameters and pain after awakening were calculated. RESULTS: Patients with VRS ≥ 1 had greater PD than painless patients at T3-7 (P = 0.04, 0.04, 0.003, <0.001, <0.001), and it was positively correlated with VRS score after awakening at T4-7 (r = 0.188, 0.217, 0.684, 0.721). The ability of T6ΔPD to predict VRS ≥ 1 was strong [threshold: 20.53%, area under the curve (AUC): 0.93, 95% confidence interval (CI): 0.89-0.97 ]. CONCLUSION: Our study indicates that PD is a useful index to direct the individualized analgesics used during operation, to better avoid the occurrence of pain during the postoperative emergence period. TRIAL REGISTRATION: This study was registered with the Chinese Clinical Trial Registry (registration number: ChiCTR2000040908, registration date: 15/12/2020).


Assuntos
Procedimentos Ortopédicos , Reflexo Pupilar , Humanos , Reflexo Pupilar/fisiologia , Medição da Dor , Anestesia Geral , Percepção da Dor , Dor Pós-Operatória/diagnóstico , Procedimentos Ortopédicos/efeitos adversos
8.
Proc Natl Acad Sci U S A ; 118(21)2021 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-34021082

RESUMO

Tumors are often infiltrated by T lymphocytes recognizing either self- or mutated antigens but are generally inactive, although they often show signs of prior clonal expansion. Hypothesizing that this may be due to peripheral tolerance, we formulated nanoparticles containing innate immune stimulants that we found were sufficient to activate self-specific CD8+ T cells and injected them into two different mouse tumor models, B16F10 and MC38. These nanoparticles robustly activated and/or expanded antigen-specific CD8+ tumor-infiltrating T cells, along with a decrease in regulatory CD4+ T cells and an increase in Interleukin-17 producers, resulting in significant tumor growth retardation or elimination and the establishment of immune memory in surviving mice. Furthermore, nanoparticles with modification of stimulating human T cells enabled the robust activation of endogenous T cells in patient-derived tumor organoids. These results indicate that breaking peripheral tolerance without regard to the antigen specificity creates a promising pathway for cancer immunotherapy.


Assuntos
Antígenos/imunologia , Imunidade Inata/efeitos dos fármacos , Linfócitos do Interstício Tumoral/efeitos dos fármacos , Melanoma Experimental/terapia , Animais , Antígenos/genética , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linhagem Celular Tumoral , Humanos , Melanoma Experimental/imunologia , Camundongos , Nanopartículas/uso terapêutico
9.
Plant Dis ; 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38568791

RESUMO

Chrysanthemum (Chrysanthemum morifolium cv. Fubaiju) is used as medicinal herb (Chen et al. 2020). In October 2021, a leaf spot disease was observed on leaves of C. morifolium in Huanggang, Hubei province. Disease incidence was approximately 40%. Leaf lesions manifested as necrotic spots, coalesced, and expanded to form brown-black spots, leading to wilting of the leaves. On stems, the lesions manifested as dark brown necrotic spots. To identify the pathogen, 29 pieces (5 × 5 mm) from lesion margins were surface sterilized in 1% NaOCl and rinsed three times with sterile water. The pieces were transferred onto potato dextrose agar (PDA) for incubation at 25℃ for 3 d in the dark. Fifteen fungal colonies were successfully isolated. The colony morphology with flat wavy edge, sparse aerial mycelia, and surface olivaceous black were observed at 7 days post incubation. Subglobular pycnidia were brown with a short beak, and pycnidia diameters were thick (212 to 265 × 189 to 363 µm, n = 20). Ovoid conidia were aseptate and hyaline, conidia diameters were thick (4.0 to 9.8 × 1.8 to 4.7 µm, n = 100). The morphological characters of these isolates were consistent with those of Stagonosporopsis chrysanthemi (Zhao et al. 2021). Pure culture of representative HGNU2021-18 isolated from the diseased leaves subjected to molecular identification. Sequences of the rDNA internal transcribed spacer (ITS) region, 28S large subunit ribosomal RNA (LSU), ß-tubulin (TUB2), actin (ACT), and partial RNA polymerase II largest subunit (RPB2) genes were amplified from genomic DNA of isolate HGNU2021-18 using the following primer pairs: ITS1/ITS4 (White et al. 1990), LR0R/LR5 (Rehner et al. 1994), Btub2Fd/Btub4Rd (Woudenberg et al. 2009), ACT512F/ACT783R (Carbone et al.1999), and RPB2-5F2 (Sung et al. 2007)/fRPB2-7cR (Liu et al. 1999), respectively. The PCR products were purified and then sequenced by Sangon Biotech (China). Nucleotide sequences of ITS (544 bp, OM346748), LSU (905 bp, OM758418), TUB2 (563 bp, OM945724), ACT (294 bp, OM793715), and RPB2 (957 bp, OM793716) amplified from the isolate HGNU2021-18 were subjected to BLASTn analysis. The results showed that ITS, LSU, TUB2, ACT, and RPB2 shared 100.00%, 99.45%, 99.20%, 100.00%, and 100.00% sequence identity to the five published sequences (MW810272.1, MH869953.1, MW815129.1, JN251973.1, and MT018012.1, respectively) of the S. chrysanthemi isolate CBS 500.63. Phylogenetic analysis of the multilocus sequences of ITS, LSU, RPB2, ACT, and TUB2 belonging to different Stagonosporopsis species was performed in MEGA 7.0 (Chen et al. 2015). Isolate HGNU2021-18 was placed in a clade with S. chrysanthemi with 99% bootstrap support. Thus, the results of morphological and molecular analyses indicated that the disease symptoms on chrysanthemum plants were caused by S. chrysanthemi. Under conditions of 25°C and 85% relative humidity, pathogenicity test was performed on 2-month-old healthy plants using isolate HGNU2021-18. The leaves were inoculated with 5 mm diameter mycelial plugs or with sterile agar plugs (control). Six plants were used in each treatment. Disease symptoms were observed on treated plants at 2 weeks post inoculation which were those previously observed in the field, while the control plants remained symptomless. The pathogen was re-isolated from the diseased plants, and S. chrysanthemi was confirmed as the causal pathogen. This is the first report of S. chrysanthemi causing stem and foliage blight of chrysanthemum in China.

10.
New Phytol ; 238(4): 1651-1670, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36829301

RESUMO

Jasmonic acid (JA) is involved in the modulation of defence and growth activities in plants. The best-characterized growth-defence trade-offs stem from antagonistic crosstalk among hormones. In this study, we first confirmed that JA negatively regulates root-knot nematode (RKN) susceptibility via the root exudates (REs) of tomato plants. Omics and toxicological analyses implied that kaempferol, a type of flavonol, from REs has a negative effect on RKN infection. We demonstrated that SlMYB57 negatively regulated kaempferol contents in tomato roots, whereas SlMYB108/112 had the opposite effect. We revealed that JA fine-tuned the homeostasis of kaempferol via SlMYB-mediated transcriptional regulation and the interaction between SlJAZs and SlMYBs, thus ensuring a balance between lateral root (LR) development and RKN susceptibility. Overall, this work provides novel insights into JA-modulated LR development and RKN susceptibility mechanisms and elucidates a trade-off model mediated by JA in plants encountering stress.


Assuntos
Solanum lycopersicum , Tylenchoidea , Animais , Doenças das Plantas , Tylenchoidea/fisiologia , Quempferóis/farmacologia , Raízes de Plantas
11.
Plant Physiol ; 190(1): 828-842, 2022 08 29.
Artigo em Inglês | MEDLINE | ID: mdl-35689622

RESUMO

Botrytis cinerea is one of the most widely distributed and harmful pathogens worldwide. Both the phytohormone jasmonate (JA) and the VQ motif-containing proteins play crucial roles in plant resistance to B. cinerea. However, their crosstalk in resistance to B. cinerea is unclear, especially in tomato (Solanum lycopersicum). In this study, we found that the tomato VQ15 was highly induced upon B. cinerea infection and localized in the nucleus. Silencing SlVQ15 using virus-induced gene silencing reduced resistance to B. cinerea. Overexpression of SlVQ15 enhanced resistance to B. cinerea, while disruption of SlVQ15 using clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein9 (Cas9) technology increased susceptibility to B. cinerea. Furthermore, SlVQ15 formed homodimers. Additionally, SlVQ15 interacted with JA-ZIM domain proteins, repressors of the JA signaling pathway, and SlWRKY31. SlJAZ11 interfered with the interaction between SlVQ15 and SlWRKY31 and repressed the SlVQ15-increased transcriptional activation activity of SlWRKY31. SlVQ15 and SlWRKY31 synergistically regulated tomato resistance to B. cinerea, as silencing SlVQ15 enhanced the sensitivity of slwrky31 to B. cinerea. Taken together, our findings showed that the SlJAZ-interacting protein SlVQ15 physically interacts with SlWRKY31 to cooperatively control JA-mediated plant defense against B. cinerea.


Assuntos
Solanum lycopersicum , Botrytis/fisiologia , Ciclopentanos/metabolismo , Resistência à Doença/genética , Regulação da Expressão Gênica de Plantas , Solanum lycopersicum/genética , Solanum lycopersicum/metabolismo , Oxilipinas/metabolismo , Doenças das Plantas/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
12.
Med Care ; 61(12): 872-881, 2023 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-37801548

RESUMO

BACKGROUND: Unemployment associated with the coronavirus disease 2019 (COVID-19) pandemic was linked to financial insecurity and disruptions in access to health care. OBJECTIVE: To explore whether expanded access to Medicaid mitigated the likelihood of health and non-health financial hardship associated with pandemic-linked job loss. DESIGN: We estimate linear regression models comparing differences in the levels of outcomes attributable to pandemic-linked joblessness in Medicaid expansion and nonexpansion states. OBSERVATIONS: A total of 20,281 adults aged 19-64 were in the 2021 National Financial Capability Study. MEASURES: Our key exposure was job loss, layoffs, and furloughs, attributable to the COVID-19 pandemic. Outcomes under evaluation include indicators of health care access and household financial health. RESULTS: Relative to persons reporting pandemic-linked unemployment in nonexpansion states, adults experiencing pandemic-linked job loss in expansion states were less likely to report as uninsured [-6.2 percentage points (PPs); 95% CI: -10.8, -1.6; P < 0.01], having unpaid medical bills (-4.3 PP; 95% CI: -8, -0.6; P < 0.05), having unmet medical needs due to cost (-5.3 PP; 95% CI: -10.1, -0.5; P < 0.05), and having calls from debt collection agencies (-6.9 PP; 95% CI: -10.6, -3.1; P < 0.01). Patterns consistent with Medicaid acting as a safety net for the adverse financial effects of job loss were more pronounced for middle-income households. CONCLUSIONS: In economic downturns, such as the COVID-19 crisis, Medicaid can help insulate households from diminished health care access and financial distress associated with job loss.


Assuntos
COVID-19 , Medicaid , Adulto , Estados Unidos/epidemiologia , Humanos , Pandemias , Patient Protection and Affordable Care Act , COVID-19/epidemiologia , Acessibilidade aos Serviços de Saúde
13.
J Exp Bot ; 74(4): 1186-1197, 2023 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-35670512

RESUMO

Flower development and fertility are coordinately regulated by endogenous developmental signals, including the phytohormones jasmonates (JAs), auxin, and gibberellin, and environmental cues. JAs regulate stamen development and fertility under basal conditions, affect root growth and trichome formation under stress conditions, and control defense responses against insect herbivores and pathogens. Since the 1990s, an increasing number of studies have revealed the essential roles of JA biosynthesis, signaling, and crosstalk in regulation of flower development and fertility. Here, we summarize and present an updated overview of the JA pathway and its crosstalk in modulating flower/sexual organ development and fertility in Arabidopsis, tomato, rice, maize, and sorghum.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Reguladores de Crescimento de Plantas/metabolismo , Giberelinas/metabolismo , Ciclopentanos/metabolismo , Oxilipinas/metabolismo , Fertilidade , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Flores , Regulação da Expressão Gênica de Plantas
14.
Environ Sci Technol ; 57(47): 18834-18845, 2023 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-37183372

RESUMO

Dichloroacetonitrile (DCAN) as one of the potentially prioritized regulated DBPs has drawn great attention; however, understanding its formation, especially the C-C bond cleavage mechanisms, is limited. In this study, DCAN formation mechanisms from long-chain primary amines, amino acids, and dipeptides during chlorination were investigated by a combined computational and experimental approach. The results indicate that nitriles initially generate for all of the above precursors, then they undergo ß-C-hydroxylation or/and α-C-chlorination processes, and finally, DCAN is produced through the Cα-Cß bond cleavage. For the first time, the underlying mechanism of the C-C bond cleavage was unraveled to be electron transfer from the O- anion into its attached C atom in the chlorinated nitriles, leading to the strongly polarized Cα-Cß bond heterocleavage and DCAN- formation. Moreover, DCAN molar yields of precursors studied in the present work were found to be determined by their groups at the γ-site of the amino group, where the carbonyl group including -CO2-, -COR, and -CONHR, the aromatic group, and the -OH group can all dramatically facilitate DCAN formation by skipping over or promoting the time-consuming ß-C-hydroxylation process and featuring relatively lower activation free energies in the C-C bond cleavage. Importantly, 4-amino-2-hydroxybutyric acid was revealed to possess the highest DCAN yield among all the known aliphatic long-chain precursors to date during chlorination. Additionally, enonitriles, (chloro-)isocyanates, and nitriles can be generated during DCAN formation and should be of concern due to their high toxicities.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Aminoácidos , Aminas , Halogenação , Dipeptídeos , Desinfecção , Purificação da Água/métodos , Acetonitrilas/química , Poluentes Químicos da Água/química
15.
J Immunol ; 207(8): 2077-2085, 2021 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-34551964

RESUMO

CMV infection is a significant complication after solid organ transplantation. We used single cell TCR αß sequencing to determine how memory inflation impacts clonality and diversity of the CMV-responsive CD8 and CD4 T cell repertoire in the first year after transplantation in human subjects. We observed CD8 T cell inflation but no changes in clonal diversity, indicating homeostatic stability in clones. In contrast, the CD4 repertoire was diverse and stable over time, with no evidence of CMV-responsive CD4 T cell expansion. We identified shared CDR3 TCR motifs among patients but no public CMV-specific TCRs. Temporal changes in clonality in response to transplantation and in the absence of detectable viral reactivation suggest changes in the repertoire immediately after transplantation followed by an expansion with stable clonal competition that may mediate protection.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Infecções por Citomegalovirus/imunologia , Citomegalovirus/fisiologia , Rejeição de Enxerto/imunologia , Transplante de Coração , Transplante de Rim , Adulto , Idoso , Antígenos Virais/imunologia , Proliferação de Células , Células Clonais , Feminino , Variação Genética , Humanos , Memória Imunológica , Masculino , Pessoa de Meia-Idade , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Transplante Homólogo , Ativação Viral/imunologia
16.
Phys Chem Chem Phys ; 25(14): 10155-10165, 2023 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-36975125

RESUMO

As one of the significant pollutants in indoor air, formaldehyde (HCHO) has attracted increasing attention due to its negative effects on human health. Thus, to reduce formaldehyde pollution, herein, an Ag-promoted Cr/MnO2 catalyst (Ag/Cr/MnO2) was obtained via a hydrothermal-calcination method, which was employed for the catalytic oxidation of low-concentration indoor HCHO (∼1 ppm) at room temperature. The Ag/Cr/MnO2 catalyst eliminated approximately 98.62% HCHO within 14 h and maintained a high removal efficiency continuously under the dynamic test conditions. Furthermore, the catalyst exhibited good recycling stability and outstanding activity in a humid environment. Different characterization techniques were utilized to determine the physicochemical properties that contribute to improving the catalytic performance. The Ag substance contained metallic Ag (Ag0) as the main component and some Ag2O, and the Ag0 particles provided ample active sites for the catalytic oxidation of HCHO. Besides, the incorporation of Ag increased the reducibility of the catalyst and the content of Mn4+, Cr6+ and oxygen vacancies. The abundant active sites, high reducibility, rich Mn4+, Cr6+, oxygen vacancies, and surface lattice oxygen species, and the powerful interaction between Cr/MnO2 and Ag were the reasons for the splendid catalytic capability for HCHO by the Ag/Cr/MnO2 catalyst. In conclusion, the Ag/Cr/MnO2 catalyst can be a promising catalyst to degrade HCHO with practical application significance.

17.
Phys Chem Chem Phys ; 25(36): 24495-24507, 2023 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-37655797

RESUMO

Formaldehyde (HCHO) is one of the major air pollutants, and its effective removal at room temperature has proven to be a great challenge. In this study, an Ag/Mn/CeO2 catalyst for the catalytic oxidation of low-concentration HCHO at room temperature was prepared by a hydrothermal-calcination method. The removal performance of the Ag/Mn/CeO2 catalyst for HCHO was systematically studied, and its surface chemical properties and microstructure were analyzed. The incorporation of Ag did not change the mesoporous structure of the Mn/CeO2 catalyst but reduced the pore size and specific surface area. The Ag species included metallic Ag as the main component and part of Ag+. The well-dispersed Ag species on the catalyst provided sufficient active sites for the catalytic oxidation of HCHO. The more the Ag active sites, the more the lattice defects and oxygen vacancies generated from the interaction of Ag with Mn/CeO2. Precisely because of this, the Ag/Mn/CeO2 catalyst exhibited high catalytic activity for HCHO at room temperature with a removal efficiency of 96.76% within 22 h, which is 22.91% higher than that of the Mn/CeO2 catalyst. Moreover, the Ag/Mn/CeO2 catalyst showed good cycling stability and the removal efficiency reached 85.77% after five cycles. Therefore, the as-prepared catalyst is an effective and sustainable material that can be used to remove HCHO from actual indoor polluted air. This paper provides ideas for the research and development of efficient catalysts.

18.
Nature ; 547(7661): 94-98, 2017 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-28636589

RESUMO

T cell receptor (TCR) sequences are very diverse, with many more possible sequence combinations than T cells in any one individual. Here we define the minimal requirements for TCR antigen specificity, through an analysis of TCR sequences using a panel of peptide and major histocompatibility complex (pMHC)-tetramer-sorted cells and structural data. From this analysis we developed an algorithm that we term GLIPH (grouping of lymphocyte interactions by paratope hotspots) to cluster TCRs with a high probability of sharing specificity owing to both conserved motifs and global similarity of complementarity-determining region 3 (CDR3) sequences. We show that GLIPH can reliably group TCRs of common specificity from different donors, and that conserved CDR3 motifs help to define the TCR clusters that are often contact points with the antigenic peptides. As an independent validation, we analysed 5,711 TCRß chain sequences from reactive CD4 T cells from 22 individuals with latent Mycobacterium tuberculosis infection. We found 141 TCR specificity groups, including 16 distinct groups containing TCRs from multiple individuals. These TCR groups typically shared HLA alleles, allowing prediction of the likely HLA restriction, and a large number of M. tuberculosis T cell epitopes enabled us to identify pMHC ligands for all five of the groups tested. Mutagenesis and de novo TCR design confirmed that the GLIPH-identified motifs were critical and sufficient for shared-antigen recognition. Thus the GLIPH algorithm can analyse large numbers of TCR sequences and define TCR specificity groups shared by TCRs and individuals, which should greatly accelerate the analysis of T cell responses and expedite the identification of specific ligands.


Assuntos
Algoritmos , Antígenos HLA/química , Antígenos HLA/imunologia , Receptores de Antígenos de Linfócitos T/química , Receptores de Antígenos de Linfócitos T/imunologia , Adolescente , Sequência de Aminoácidos , Cristalografia por Raios X , Epitopos de Linfócito T/química , Epitopos de Linfócito T/imunologia , Humanos , Ligantes , Modelos Moleculares , Mycobacterium tuberculosis/química , Mycobacterium tuberculosis/imunologia , Especificidade por Substrato
19.
Environ Res ; 222: 115364, 2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-36736757

RESUMO

The highly promising formaldehyde (HCHO)-removing materials are essential for eliminating interior pollution to safeguard the public's health with increasing indoor HCHO contamination situations being recorded on a global scale. In the paper, bamboo charcoal (BC) was activated with boric acid to prepare bamboo-based activated carbon (BAC), and then impregnated with ammonium acetate solution to successfully develop porous adsorbent with ammonium acetate particles (N/BAC), which was applied to remove low concentration of HCHO at room temperature. The adsorption performance for HCHO was systematically investigated while the surface chemical properties and microstructure of the as-prepared adsorbents were described and analyzed. The specific surface area, total pore volume and microporous volume of N/BAC sample were 240.09 m2/g, 0.27 cm3/g and 0.12 cm3/g, which increased by 42.40 m2/g, 0.15 cm3/g and 0.03 cm3/g compared with BAC sample, respectively. The specific surface area and the microporous volume, as well as the content of oxygen- and nitrogen-containing functional groups of N/BAC sample were augmented by contrast with other samples, and numerous ammonium acetate particles were present on the surface. Precisely because of this, the N/BAC sample exhibited a high removal rate of 98.89%, which was 18.38% greater than that of BAC sample. A superior correlation coefficient (0.9999) from the experimental values of the kinetics and the fitted values of the pseudo-second-order kinetic model demonstrated that the adsorption process of HCHO on N/BAC sample was physical-chemical combined adsorption. The adsorption of HCHO on N/BAC sample was investigated under different humidity, and the results showed that the adsorbent yet had excellent adsorption capacity (87.93%) under RH 75%. Moreover, the N/BAC sample was renewable, and the removal rate still reached 82.81% after five cycles of regeneration. Therefore, the as-prepared adsorbent is an effective, economical and sustainable material, and could be used to remove HCHO from real contaminated indoor air.


Assuntos
Gases , Poluentes Químicos da Água , Carvão Vegetal/química , Adsorção , Cinética , Formaldeído/química , Poluentes Químicos da Água/análise
20.
Cell Mol Life Sci ; 79(9): 507, 2022 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-36059036

RESUMO

Patients with autism spectrum disorder (ASD) typically experience substantial social isolation, which may cause secondary adverse effects on their brain development. miR-124 is the most abundant miRNA in the human brain, acting as a pivotal molecule regulating neuronal fate determination. Alterations of miR-124 maturation or expression are observed in various neurodevelopmental, neuropsychiatric, and neurodegenerative disorders. In the present study, we analyzed a panel of brain-enriched microRNAs in serums from 2 to 6 year old boys diagnosed with ASD. The hsa-miR-124 level was found significantly elevated in ASD boys than in age and sex-matched healthy controls. In an isolation-reared weanling mouse model, we evidenced elevated mmu-miR-124 level in the serum and the medial prefrontal cortex (mPFC). These mice displayed significant sociability deficits, as well as myelin abnormality in the mPFC, which was partially rescued by expressing the miR-124 sponge in the bilateral mPFC, ubiquitously or specifically in oligodendroglia. In cultured mouse oligodendrocyte precursor cells, introducing a synthetic mmu-miR-124 inhibited the differentiation process through suppressing expression of nuclear receptor subfamily 4 group A member 1 (Nr4a1). Overexpressing Nr4a1 in the bilateral mPFC also corrected the social behavioral deficits and myelin impairments in the isolation-reared mice. This study revealed an unanticipated role of the miR-124/Nr4a1 signaling in regulating early social experience-dependent mPFC myelination, which may serve as a potential therapy target for social neglect or social isolation-related neuropsychiatric disorders.


Assuntos
Transtorno do Espectro Autista , MicroRNAs , Animais , Transtorno do Espectro Autista/genética , Transtorno do Espectro Autista/metabolismo , Encéfalo/metabolismo , Criança , Pré-Escolar , Humanos , Masculino , Camundongos , MicroRNAs/metabolismo , Bainha de Mielina/genética , Bainha de Mielina/metabolismo , Córtex Pré-Frontal/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA