Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 786
Filtrar
1.
Cell ; 184(22): 5670-5685.e23, 2021 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-34637702

RESUMO

We describe an approach to study the conformation of individual proteins during single particle tracking (SPT) in living cells. "Binder/tag" is based on incorporation of a 7-mer peptide (the tag) into a protein where its solvent exposure is controlled by protein conformation. Only upon exposure can the peptide specifically interact with a reporter protein (the binder). Thus, simple fluorescence localization reflects protein conformation. Through direct excitation of bright dyes, the trajectory and conformation of individual proteins can be followed. Simple protein engineering provides highly specific biosensors suitable for SPT and FRET. We describe tagSrc, tagFyn, tagSyk, tagFAK, and an orthogonal binder/tag pair. SPT showed slowly diffusing islands of activated Src within Src clusters and dynamics of activation in adhesions. Quantitative analysis and stochastic modeling revealed in vivo Src kinetics. The simplicity of binder/tag can provide access to diverse proteins.


Assuntos
Técnicas Biossensoriais , Peptídeos/química , Imagem Individual de Molécula , Animais , Adesão Celular , Linhagem Celular , Sobrevivência Celular , Embrião de Mamíferos/citologia , Ativação Enzimática , Fibroblastos/metabolismo , Transferência Ressonante de Energia de Fluorescência , Humanos , Cinética , Camundongos , Nanopartículas/química , Conformação Proteica , Quinases da Família src/metabolismo
2.
Cell ; 169(2): 243-257.e25, 2017 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-28388409

RESUMO

Of all known cultured stem cell types, pluripotent stem cells (PSCs) sit atop the landscape of developmental potency and are characterized by their ability to generate all cell types of an adult organism. However, PSCs show limited contribution to the extraembryonic placental tissues in vivo. Here, we show that a chemical cocktail enables the derivation of stem cells with unique functional and molecular features from mice and humans, designated as extended pluripotent stem (EPS) cells, which are capable of chimerizing both embryonic and extraembryonic tissues. Notably, a single mouse EPS cell shows widespread chimeric contribution to both embryonic and extraembryonic lineages in vivo and permits generating single-EPS-cell-derived mice by tetraploid complementation. Furthermore, human EPS cells exhibit interspecies chimeric competency in mouse conceptuses. Our findings constitute a first step toward capturing pluripotent stem cells with extraembryonic developmental potentials in culture and open new avenues for basic and translational research. VIDEO ABSTRACT.


Assuntos
Técnicas de Cultura de Células/métodos , Células-Tronco Pluripotentes/citologia , Animais , Blastocisto/citologia , Linhagem Celular , Quimera/metabolismo , Dimetideno/farmacologia , Humanos , Indicadores e Reagentes/química , Camundongos , Minociclina/química , Minociclina/farmacologia , Células-Tronco Pluripotentes/efeitos dos fármacos , Poli(ADP-Ribose) Polimerase-1/metabolismo
3.
Nature ; 605(7909): 325-331, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35418683

RESUMO

Cellular reprogramming can manipulate the identity of cells to generate the desired cell types1-3. The use of cell intrinsic components, including oocyte cytoplasm and transcription factors, can enforce somatic cell reprogramming to pluripotent stem cells4-7. By contrast, chemical stimulation by exposure to small molecules offers an alternative approach that can manipulate cell fate in a simple and highly controllable manner8-10. However, human somatic cells are refractory to chemical stimulation owing to their stable epigenome2,11,12 and reduced plasticity13,14; it is therefore challenging to induce human pluripotent stem cells by chemical reprogramming. Here we demonstrate, by creating an intermediate plastic state, the chemical reprogramming of human somatic cells to human chemically induced pluripotent stem cells that exhibit key features of embryonic stem cells. The whole chemical reprogramming trajectory analysis delineated the induction of the intermediate plastic state at the early stage, during which chemical-induced dedifferentiation occurred, and this process was similar to the dedifferentiation process that occurs in axolotl limb regeneration. Moreover, we identified the JNK pathway as a major barrier to chemical reprogramming, the inhibition of which was indispensable for inducing cell plasticity and a regeneration-like program by suppressing pro-inflammatory pathways. Our chemical approach provides a platform for the generation and application of human pluripotent stem cells in biomedicine. This study lays foundations for developing regenerative therapeutic strategies that use well-defined chemicals to change cell fates in humans.


Assuntos
Diferenciação Celular , Reprogramação Celular , Células-Tronco Pluripotentes Induzidas , Linhagem da Célula , Humanos , Células-Tronco Pluripotentes Induzidas/citologia
4.
Nat Chem Biol ; 19(7): 900-910, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37095237

RESUMO

Replicative errors contribute to the genetic diversity needed for evolution but in high frequency can lead to genomic instability. Here, we show that DNA dynamics determine the frequency of misincorporating the A•G mismatch, and altered dynamics explain the high frequency of 8-oxoguanine (8OG) A•8OG misincorporation. NMR measurements revealed that Aanti•Ganti (population (pop.) of >91%) transiently forms sparsely populated and short-lived Aanti+•Gsyn (pop. of ~2% and kex = kforward + kreverse of ~137 s-1) and Asyn•Ganti (pop. of ~6% and kex of ~2,200 s-1) Hoogsteen conformations. 8OG redistributed the ensemble, rendering Aanti•8OGsyn the dominant state. A kinetic model in which Aanti+•Gsyn is misincorporated quantitatively predicted the dA•dGTP misincorporation kinetics by human polymerase ß, the pH dependence of misincorporation and the impact of the 8OG lesion. Thus, 8OG increases replicative errors relative to G because oxidation of guanine redistributes the ensemble in favor of the mutagenic Aanti•8OGsyn Hoogsteen state, which exists transiently and in low abundance in the A•G mismatch.


Assuntos
Dano ao DNA , DNA , Humanos , Pareamento de Bases , DNA/química , Mutagênese
5.
FASEB J ; 38(1): e23375, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-38102968

RESUMO

BACKGROUND: Elevated IL-21 expression which can effectively induce Th17 cell differentiation has been implicated in the pathogenesis of psoriasis, but its role in angiogenesis remains poorly understood. METHODS: PASI and PSI score assessment was applied to evaluate the severity of psoriatic lesions. The expression of IL-21, IL-21 receptor (IL-21R), CD31, VEGFA, MMP-9, and ICAM-1 in skin was determined by immunohistochemistry or quantitative real-time polymerase chain reaction. The serum level of IL-21 was measured by enzyme-linked immunosorbent assay (ELISA). Then, their correlation was analyzed statistically. Human umbilical vein endothelial cells (HUVECs) cocultured with conditional medium from normal human epidermal keratinocytes (NHEKs) were treated with IL-21 and/or M5 cocktail (mixture of IL-1α, IL-17A, IL-22, TNF-α, and oncostatin M). The migration and tube formation of HUVECs were detected, and the levels of VEGFA, MMP-9, and ICAM-1 in NHEKs were measured by Western blotting or ELISA. RESULTS: Increased IL-21 and IL-21R expression was observed in psoriatic sera or skin specimens, with IL-21R mainly locating in keratinocytes and IL-21 in immune cells. Pearson analysis showed significantly positive correlation between IL-21/IL-21R and erythema scores/microvessel density in psoriatic lesions. Moreover, the expression of proangiogenic genes, VEGFA, ICAM-1, and MMP-9 was upregulated in skins of psoriasis. Additionally, in M5 microenvironment, migration and tube formation could be magnified in HUVECs using IL-21 pre-treated NHEK medium. Mechanically, the co-stimulation of IL-21 and M5 to NEHKs increased the expression of ICAM-1. CONCLUSION: IL-21 could regulate keratinocytes to secrete ICAM-1, thereby promoting angiogenesis in psoriasis.


Assuntos
Interleucinas , Psoríase , Humanos , Angiogênese , Células Endoteliais/metabolismo , Molécula 1 de Adesão Intercelular/genética , Molécula 1 de Adesão Intercelular/metabolismo , Queratinócitos/metabolismo , Metaloproteinase 9 da Matriz/genética , Metaloproteinase 9 da Matriz/metabolismo , Psoríase/metabolismo , Pele/metabolismo , Interleucinas/metabolismo
6.
Proc Natl Acad Sci U S A ; 119(24): e2112496119, 2022 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-35671421

RESUMO

Thermodynamic preferences to form non-native conformations are crucial for understanding how nucleic acids fold and function. However, they are difficult to measure experimentally because this requires accurately determining the population of minor low-abundance (<10%) conformations in a sea of other conformations. Here, we show that melting experiments enable facile measurements of thermodynamic preferences to adopt nonnative conformations in DNA and RNA. The key to this "delta-melt" approach is to use chemical modifications to render specific minor non-native conformations the major state. The validity and robustness of delta-melt is established for four different non-native conformations under various physiological conditions and sequence contexts through independent measurements of thermodynamic preferences using NMR. Delta-melt is faster relative to NMR, simple, and cost-effective and enables thermodynamic preferences to be measured for exceptionally low-populated conformations. Using delta-melt, we obtained rare insights into conformational cooperativity, obtaining evidence for significant cooperativity (1.0 to 2.5 kcal/mol) when simultaneously forming two adjacent Hoogsteen base pairs. We also measured the thermodynamic preferences to form G-C+ and A-T Hoogsteen and A-T base open states for nearly all 16 trinucleotide sequence contexts and found distinct sequence-specific variations on the order of 2 to 3 kcal/mol. This rich landscape of sequence-specific non-native minor conformations in the DNA double helix may help shape the sequence specificity of DNA biochemistry. Thus, melting experiments can now be used to access thermodynamic information regarding regions of the free energy landscape of biomolecules beyond the native folded and unfolded conformations.


Assuntos
DNA , Conformação de Ácido Nucleico , RNA , Sequência de Bases , DNA/química , Congelamento , RNA/química , Termodinâmica , Raios Ultravioleta
7.
Hippocampus ; 34(2): 58-72, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38049972

RESUMO

Numerous epilepsy-related genes have been identified in recent decades by unbiased genome-wide screens. However, the available druggable targets for temporal lobe epilepsy (TLE) remain limited. Furthermore, a substantial pool of candidate genes potentially applicable to TLE therapy awaits further validation. In this study, we reveal the significant role of KCNQ2 and KCNQ3, two M-type potassium channel genes, in the onset of seizures in TLE. Our investigation began with a quantitative analysis of two publicly available TLE patient databases to establish a correlation between seizure onset and the downregulated expression of KCNQ2/3. We then replicated these pathological changes in a pilocarpine seizure mouse model and observed a decrease in spike frequency adaptation due to the affected M-currents in dentate gyrus granule neurons. In addition, we performed a small-scale simulation of the dentate gyrus network and confirmed that the impaired spike frequency adaptation of granule cells facilitated epileptiform activity throughout the network. This, in turn, resulted in prolonged seizure duration and reduced interictal intervals. Our findings shed light on an underlying mechanism contributing to ictogenesis in the TLE hippocampus and suggest a promising target for the development of antiepileptic drugs.


Assuntos
Epilepsia do Lobo Temporal , Camundongos , Animais , Humanos , Epilepsia do Lobo Temporal/patologia , Giro Denteado/metabolismo , Convulsões/induzido quimicamente , Convulsões/patologia , Hipocampo/metabolismo , Neurônios/fisiologia , Canal de Potássio KCNQ2/genética
8.
Mol Med ; 30(1): 100, 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-38992588

RESUMO

BACKGROUND: Diabetes mellitus (DM)-induced testicular damage is associated with sexual dysfunction and male infertility in DM patients. However, the pathogenesis of DM-induced testicular damage remains largely undefined. METHODS: A streptozotocin (STZ)-induced diabetic model and high glucose (HG)-treated in vitro diabetic model were established. The histological changes of testes were assessed by H&E staining. Serum testosterone, iron, MDA and GSH levels were detected using commercial kits. Cell viability and lipid peroxidation was monitored by MTT assay and BODIPY 581/591 C11 staining, respectively. qRT-PCR, immunohistochemistry (IHC) or Western blotting were employed to detect the levels of BRD7, Clusterin, EZH2 and AMPK signaling molecules. The associations among BRD7, EZH2 and DNMT3a were detected by co-IP, and the transcriptional regulation of Clusterin was monitored by methylation-specific PCR (MSP) and ChIP assay. RESULTS: Ferroptosis was associated with DM-induced testicular damage in STZ mice and HG-treated GC-1spg cells, and this was accompanied with the upregulation of BRD7. Knockdown of BRD7 suppressed HG-induced ferroptosis, as well as HG-induced Clusterin promoter methylation and HG-inactivated AMPK signaling in GC-1spg cells. Mechanistical studies revealed that BRD7 directly bound to EZH2 and regulated Clusterin promoter methylation via recruiting DNMT3a. Knockdown of Clusterin or inactivation of AMPK signaling reverses BRD7 silencing-suppressed ferroptosis in GC-1spg cells. In vivo findings showed that lack of BRD7 protected against diabetes-induced testicular damage and ferroptosis via increasing Clusterin expression and activating AMPK signaling. CONCLUSION: BRD7 suppressed Clusterin expression via modulating Clusterin promoter hypermethylation in an EZH2 dependent manner, thereby suppressing AMPK signaling to facilitate ferroptosis and induce diabetes-associated testicular damage.


Assuntos
Proteínas Quinases Ativadas por AMP , Clusterina , Metilação de DNA , Diabetes Mellitus Experimental , Ferroptose , Regiões Promotoras Genéticas , Transdução de Sinais , Testículo , Animais , Masculino , Camundongos , Proteínas Quinases Ativadas por AMP/metabolismo , Linhagem Celular , Clusterina/genética , Clusterina/metabolismo , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/complicações , DNA Metiltransferase 3A/metabolismo , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Ferroptose/genética , Camundongos Endogâmicos C57BL , Testículo/metabolismo , Testículo/patologia
9.
Small ; 20(8): e2306267, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37840405

RESUMO

Heteroatom-doped layered porous carbons are recently regarded as promising electrode materials for high energy density supercapacitors because they can integrate high-level heteroatom-doping and layered nano-space together to provide huge pseudocapacitive reaction areas and accelerate ion diffusion/transport. Herein, an innovative strategy is reported to prepare N/B/O co-doped layered porous carbons via ammonium folate-reinforced self-assembly of gelatin and boric acid followed by carbonization. Biomass-derived ammonium folate not only acts as an N-riched precursor but also can fasten in the process of self-assembly via boric acid-assisted electrostatic adsorption and hydrogen bonding to promote the formation of stable 3D cross-linked networks, resulting in the obtained N/B/O co-doped layered porous carbon (BNLC-850) has a large specific surface area (1822 m2 g-1 ), hierarchical porous structure and super-high heteroatom contents (N, 12.65; B, 5.67; and O, 13.84 at.%). The BNLC-850 achieves an ultrahigh specific capacitance of 525.2 F g-1 in the alkaline electrolyte at 0.5 A g-1 , meanwhile, DFT calculations reveal that the high-level N/B/O-doping can effectively weaken the adsorption barriers of K-ions. Moreover, the BNLC-850 assembles anti-freezing flexible solid-state supercapacitors in MPEI-TF-IL gel polymer electrolyte deliver a high energy density of 41.2 Wh kg-1 , excellent flexibility, and long cycle-life at -20 °C.

10.
Small ; : e2309893, 2024 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-38516960

RESUMO

Metal-free organic photocatalysts for photo-mediated reversible deactivation radical polymerization (photo-RDRP) are witnessed to make increasing advancement in the precise synthesis of polymers. However, challenges still exist in the development of high-efficiency and environmentally sustainable carbon dots (CDs)-based organocatalysts. Herein, N-doped CDs derived from phenanthroline derivative (Aphen) are prepared as metal-free photocatalysts for photoinduced electron transfer reversible addition-fragmentation chain transfer (PET-RAFT) polymerization. The introduction of phenanthroline structure enhances the excited state lifetime of CDs and expands the conjugated length of their internal structure to enable the light-absorption to reach green light region, thereby enhancing photocatalytic activity. The as-designed CDs exhibit unprecedented photocatalytic capacity in photopolymerization even in large-volume reaction (100 mL) with high monomer conversion and narrow polymer dispersity (Mw/Mn < 1.20) under green light. The photocatalytic system is compatible with PET-RAFT polymerization of numerous monomers and the production of high molecular weight polyacrylate (Mn >250 000) with exquisite spatiotemporal control. Above results confirm the potential of CDs as photocatalyst, which has not been achieved with other CDs catalysts used in photo-RDRP. In addition, the construction of fluorescent polymer nanoparticles using CDs as both photocatalyst and phosphor through photoinitiated polymerization-induced self-assembly (Photo-PISA) technology is successfully demonstrated for the first time.

11.
Small ; : e2310884, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38376170

RESUMO

Exploring covalent triazine frameworks (CTFs) with high capacitative activity is highly desirable and challenging. Herein, the S-rich CTFs cathode is pioneeringly introduced in Zn-ion hybrid supercapacitors (ZSC), achieving outstanding capacity and energy density, and satisfactory anti-freezing flexibility. Specifically, the S-bridged CTFs are synthesized by a bifunctional template-catalytic strategy, where ZnCl2 serves as both the catalyst/solvent and in situ template to construct triazine frameworks with interconnected pores and layered gaps. The resultant CTFs (CTFS-750) are employed as a reasonable pattern-like system to more deeply scrutinize the synergistic effect of S-bridged triazine and layered porous architecture for polymer-based cathodes in Zn-ion storage. The experimental results indicate that the adsorption barriers of Zn-ions on CTFS-750 are effectively weakened, and accessible Zn2+ -absorption sites provided by the C─S─C and C═N bonds have been confirmed via DFT calculations. Consequently, the CTFS-750 cathode-assembled ZSC displays an ultra-high capacity of 211.6 mAh g-1 at 1.0 A g-1 , an outstanding energy density of 202.7 Wh kg-1 , and attractive cycling performance. Moreover, the resulting flexible ZSC device shows superior capacity, good adaptability, and satisfactory anti-freezing behavior. This approach sheds new light on constructing advanced polymer-based cathodes at the atom level and paves the way for fabricating high-performance ZSC and beyond.

12.
Microb Pathog ; 187: 106513, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38147968

RESUMO

Since pseudorabies (PR) re-emerged and rapidly spread in China at the end of 2011, researchers have focused on effective vaccine strategies to prevent and control pseudorabies virus (PRV) infection in pig herds. Due to the extensive application of an attenuated vaccine based on the Bartha-K61 strain isolated in Hungary in 1961 and the variation of the PRV strain, it has been suggested that traditional vaccines based on the Bartha-K61 strain offer only partial protection against variant strains. It was therefore evaluated whether the Porcilis® Begonia vaccine, which is based on the NIA-3 strain with deletions in the gE and TK genes, is efficacious against experimental infection with the virulent, contemporary Chinese PRV strain ZJ01. In this study, piglets were vaccinated with Porcilis® Begonia through either the intradermal (ID) route or the intramuscular (IM) route and subsequently challenged intranasally with strain ZJ01 at 4 weeks post-vaccination. An unvaccinated challenge group and an unvaccinated/nonchallenged group were also included in the study. All animals were monitored for 14 days after challenge. Vaccinated and negative control pigs stayed healthy during the study, while the unvaccinated control animals developed lesions associated with PRV ZJ01 challenge, and 44% of these pigs died before the end of the experiment. This study demonstrated that ID or IM vaccination of pigs with a vaccine based on the NIA-3 strain Porcilis® Begonia clinically protects against fatal PRV challenge with the ZJ01 strain.


Assuntos
Begoniaceae , Herpesvirus Suídeo 1 , Doenças dos Suínos , Vacinas Virais , Suínos , Animais , Herpesvirus Suídeo 1/genética , Vacinas contra Pseudorraiva , Anticorpos Antivirais , Vacinação/veterinária , Vacinas Virais/genética
13.
Int J Behav Nutr Phys Act ; 21(1): 42, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38650004

RESUMO

BACKGROUND: Healthy lifestyle behaviors (LBs) have been widely recommended for the prevention and management of cardiovascular disease (CVD). Despite a large number of studies exploring the association between combined LBs and CVD, a notable gap exists in integration of relevant literatures. We conducted a systematic review and meta-analysis of prospective cohort studies to analyze the correlation between combined LBs and the occurrence of CVD, as well as to estimate the risk of various health complications in individuals already diagnosed with CVD. METHODS: Articles published up to February 10, 2023 were sourced through PubMed, EMBASE and Web of Science. Eligible prospective cohort studies that reported the relations of combined LBs with pre-determined outcomes were included. Summary relative risks (RRs) and 95% confidence intervals (CIs) were estimated using either a fixed or random-effects model. Subgroup analysis, meta-regression, publication bias, and sensitivity analysis were as well performed. RESULTS: In the general population, individuals with the healthiest combination of LBs exhibited a significant risk reduction of 58% for CVD and 55% for CVD mortality. For individuals diagnosed with CVD, adherence to the healthiest combination of LBs corresponded to a significant risk reduction of 62% for CVD recurrence and 67% for all-cause mortality, when compared to those with the least-healthy combination of LBs. In the analysis of dose-response relationship, for each increment of 1 healthy LB, there was a corresponding decrease in risk of 17% for CVD and 19% for CVD mortality within the general population. Similarly, among individuals diagnosed with CVD, each additional healthy LB was associated with a risk reduction of 27% for CVD recurrence and 27% for all-cause mortality. CONCLUSIONS: Adopting healthy LBs is associated with substantial risk reduction in CVD, CVD mortality, and adverse outcomes among individuals diagnosed with CVD. Rather than focusing solely on individual healthy LB, it is advisable to advocate for the adoption of multiple LBs for the prevention and management of CVD. TRIAL REGISTRATION: PROSPERO: CRD42023431731.


Assuntos
Doenças Cardiovasculares , Estilo de Vida , Humanos , Estudos Prospectivos , Prognóstico , Estilo de Vida Saudável , Comportamentos Relacionados com a Saúde , Exercício Físico , Fatores de Risco , Comportamento de Redução do Risco
14.
BMC Infect Dis ; 24(1): 371, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38566017

RESUMO

BACKGROUND: There is an urgent clinical need for developing novel immunoprophylaxis and immunotherapy strategies against Staphylococcus aureus (S. aureus). In our previous work, immunization with a tetra-branched multiple antigenic peptide, named MAP2-3 that mimics lipoteichoic acid, a cell wall component of S. aureus, successfully induced a humoral immune response and protected BALB/c mice against S. aureus systemic infection. In this study, we further investigated whether vaccination with MAP2-3 can elicit immunologic memory. METHODS: BALB/c mice were immunized with MAP2-3 five times. After one month of the last vaccination, mice were challenged with heat-killed S. aureus via intraperitoneal injection. After a 7-day inoculation, the percentage of plasma cells, memory B cells, effector memory T cells, and follicular helper T cells were detected by flow cytometry. The levels of IL-6, IL-21, IL-2, and IFN-γ were measured by real-time PCR and ELISA. Flow cytometry results were compared by using one-way ANOVA or Mann-Whitney test, real-time PCR results were compared by using one-way ANOVA, and ELISA results were compared by using one-way ANOVA or student's t-test. RESULTS: The percentage of plasma cells and memory B cells in the spleen and bone marrow from the MAP2-3 immunized mice was significantly higher than that from the control mice. The percentage of effector memory T cells in spleens and lymphoid nodes as well as follicular helper T cells in spleens from the MAP2-3 immunized mice were also higher. Moreover, the levels of IL-6 and IL-21, two critical cytokines for the development of memory B cells, were significantly higher in the isolated splenocytes from immunized mice after lipoteichoic acid stimulation. CONCLUSIONS: Immunization with MAP2-3 can efficiently induce memory B cells and memory T cells.


Assuntos
Interleucina-6 , Lipopolissacarídeos , Células B de Memória , Ácidos Teicoicos , Camundongos , Animais , Camundongos Endogâmicos BALB C , Staphylococcus aureus , Imunização , Vacinação , Peptídeos
15.
J Immunol ; 209(6): 1200-1211, 2022 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-35995508

RESUMO

Dendritic cells (DCs) are professional APCs equipped with MHC-restricted Ags, costimulations, and cytokines that effectively prime and differentiate naive T cells into distinct functional subsets. The immune signals that DCs carry reflect the route of Ag uptake and the innate stimuli they received. In the mucosal tissues, owing to the great variety of foreign Ags and inflammatory cues, DCs are predominantly activated and migratory. In the small intestine, CD4 Th17 cells are abundant and have been shown to be regulated by DCs and macrophages. Using a mouse commensal bacteria experimental model, we identified that the early priming step of commensal-driven Th17 cells is controlled by bona fide Zbtb46-expressing DCs. CCR7-dependent migration of type 2 DCs (DC2s) from the small intestine to the mesenteric lymph nodes (MLNs) is essential for the activation of naive CD4 T cells. The migratory DC2 population in the MLNs is almost exclusively Esam+ cells. Single-cell RNA sequencing highlighted the abundance of costimulatory markers (CD40 and OX40) and chemokines (Ccl22 and Cxcl16) on MLN migratory DCs. Further resolution of MLN migratory DC2s revealed that the Th17-polarizing cytokine IL-6 colocalizes with DC2s expressing CD40, Ccl17, and Ccl22. Thus, early Th17 cell differentiation is initiated by a small subset of migratory DC2s in the gut-draining lymph nodes.


Assuntos
Células Dendríticas , Células Th17 , Bactérias , Quimiocinas , Citocinas , Interleucina-6 , Intestino Delgado , Linfonodos , Mucosa , Receptores CCR7
16.
Phys Chem Chem Phys ; 26(26): 18302-18310, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38910568

RESUMO

This study introduces a new wide-bandgap graphene-like structure, denoted as C6BN, achieved by incorporating an eight-electron BN pair, substantially modifying its electronic properties. Utilizing extensive density functional calculations, we comprehensively analyzed the stability, electronic structure, mechanical properties, and optical-electrical characteristics of C6BN. Our investigations reveal the material's exceptional thermodynamic, mechanical, and dynamic stability. Notably, the calculated wide bandgap of 2.81 eV in C6BN, supported by analyses of energy levels, band structures, and density of states, positions it as a promising two-dimensional wide-bandgap semiconductor. Additionally, C6BN exhibits isotropic mechanical features, highlighting its inherent flexibility. Remarkably, our calculations indicate an ultra-low dielectric constant (k = 1.67) for C6BN, surpassing that of well-established third-generation semiconductors. Further exploration into the thermoelectric properties of C6BN demonstrates its promising performance, as evidenced by calculations of thermal conductivity (κ), power factor (P), and Seebeck coefficient (S). In summary, our findings underscore the significant potential of the proposed C6BN structure as a flexible two-dimensional material poised to drive future advancements in electronic and energy-related technologies.

17.
Environ Res ; 256: 119249, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-38810831

RESUMO

China has always adhered to the strategy of sustainable development. It is prevalent the public want a good living environment, which requires local governments and businesses to enhance their environmental governance capabilities. Using the panel data from Chinese cities from 2012 to 2019 and econometrics models, we examine the impact mechanisms of public environmental appeals (PEA) on efficiency of collaborative governance in pollution reduction and carbon mitigation (GPC). Results indicate that there is a positive spatial clustering of GPC across cities, with high-high clustering is notably concentrated in the southern regions of China and low-low clustering is prevalent in the northern regions. Spatial econometrics model results reveal that the stronger PEA, the higher GPC. The result of mechanism analysis shows the mediation of environmentally friendly technological innovation is crucial. Subsequent inquiry uncovers that the digital economy positively moderates the impact of PEA on GPC. The Belt and Road policy region exhibits heightened sensitivity to PEA, thereby enhancing the positive impact of PEA on GPC.


Assuntos
Cidades , China , Poluição Ambiental/prevenção & controle , Política Ambiental , Desenvolvimento Sustentável , Humanos
18.
Environ Res ; 251(Pt 2): 118639, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38508359

RESUMO

Frontier studies have neglected the impact of digital transformation (DT) on the synergy for pollution and carbon reduction (SPCR) from the perspective of micro enterprises. This paper explores the SPCR effect of DT, as well as its mechanism at micro-firm level. The study found that: (1) DT significantly facilitates corporate SPCR. For every 10% increase in the level of DT, the ranking of SPCR will rise by about 2.3 places. This effect is more obvious in high-tech firms and non-heavy polluters, firms in the eastern region in China, and non-SOE. (2) DT creates innovation-driven and structure-optimizing effects, which enhance the corporate green innovation ability, optimize the business structure and capital allocation structure of enterprises, and then drive the SPCR. (3) External public environmental concerns (PEC) and internal corporate ESG governance act as "accelerators" promoting the SPCR effect of DT. Based on these, policy implications are made to accelerate the pace of corporate DT, give full play to the first-mover advantage, and break the "pollution (carbon) lock-in" with a view to providing theoretical references for the listed enterprises' digitalized governance of SPCR, as well as the governmental departments' formulation of relevant guiding policies, and striving to achieve the high-quality development goal.


Assuntos
Poluição Ambiental , China , Poluição Ambiental/prevenção & controle , Carbono/química , Política Ambiental
19.
J Clin Periodontol ; 51(1): 24-32, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37872750

RESUMO

AIM: To compare the implant accuracy, safety and morbidity between robot-assisted and freehand dental implant placement. MATERIALS AND METHODS: Subjects requiring single-site dental implant placement were recruited. Patients were randomly allocated to freehand implant placement and robot-assisted implant placement. Differences in positional accuracy of the implant, surgical morbidity and complications were assessed. The significance of intergroup differences was tested with an intention-to-treat analysis and a per-protocol (PP) analysis (excluding one patient due to calibration error). RESULTS: Twenty patients (with a median age of 37, 13 female) were included. One subject assigned to the robotic arm was excluded from the PP analysis because of a large calibration error due to the dislodgement of the index. For robot-assisted and freehand implant placement, with the PP analysis, the median (25th-75th percentile) platform global deviation, apex global deviation and angular deviation were 1.23 (0.9-1.4) mm/1.9 (1.2-2.3) mm (p = .03, the Mann-Whitney U-test), 1.40 (1.1-1.6) mm/2.1 (1.7-3.9) mm (p < .01) and 3.0 (0.9-6.0)°/6.7 (2.2-13.9)° (p = .08), respectively. Both methods showed limited damage to the alveolar ridge and had similar peri- and post-operative morbidity and safety. CONCLUSIONS: Robot-assisted implant placement enabled greater positional accuracy of the implant compared to freehand placement in this pilot trial. The robotic system should be further developed to simplify surgical procedures and improve accuracy and be validated in properly sized trials assessing the full spectrum of relevant outcomes.


Assuntos
Implantes Dentários , Robótica , Cirurgia Assistida por Computador , Humanos , Feminino , Projetos Piloto , Tecnologia Háptica , Implantação Dentária Endóssea/métodos , Tomografia Computadorizada de Feixe Cônico , Desenho Assistido por Computador
20.
J Med Genet ; 60(10): 933-938, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37012053

RESUMO

BACKGROUND: Low-pass genome sequencing (LP GS) is an alternative to chromosomal microarray analysis (CMA). However, validations of LP GS as a prenatal diagnostic test for amniotic fluid are rare. Moreover, sequencing depth of LP GS in prenatal diagnosis has not been evaluated. OBJECTIVE: The diagnostic performance of LP GS was compared with CMA using 375 amniotic fluid samples. Then, sequencing depth was evaluated by downsampling. RESULTS: CMA and LP GS had the same diagnostic yield (8.3%, 31/375). LP GS showed all copy number variations (CNVs) detected by CMA and six additional variant of uncertain significance CNVs (>100 kb) in samples with negative CMA results; CNV size influenced LP GS detection sensitivity. CNV detection was greatly influenced by sequencing depth when the CNV size was small or the CNV was located in the azoospermia factor c (AZFc) region of the Y chromosome. Large CNVs were less affected by sequencing depth and more stably detected. There were 155 CNVs detected by LP GS with at least a 50% reciprocal overlap with CNVs detected by CMA. With 25 M uniquely aligned high-quality reads (UAHRs), the detection sensitivity for the 155 CNVs was 99.14%. LP GS using samples with 25 M UAHRs showed the same performance as LP GS using total UAHRs. Considering the detection sensitivity, cost and interpretation workload, 25 M UAHRs are optimal for detecting most aneuploidies and microdeletions/microduplications. CONCLUSION: LP GS is a promising, robust alternative to CMA in clinical settings. A total of 25 M UAHRs are sufficient for detecting aneuploidies and most microdeletions/microduplications.


Assuntos
Líquido Amniótico , Variações do Número de Cópias de DNA , Gravidez , Feminino , Humanos , Variações do Número de Cópias de DNA/genética , Diagnóstico Pré-Natal/métodos , Aneuploidia , Análise em Microsséries
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa