Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 163
Filtrar
1.
Vaccine ; 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38777696

RESUMO

PURPOSE: To evaluate the impact of momentary intervention on the willingness and actual uptake of influenza vaccination among the elderly in China. METHODS: A cross-sectional study assessed the willingness of the elderly to receive influenza vaccination, and an momentary intervention aimed to increase vaccination willingness among those initially unwilling. The elderly reporting a willingness were offered free influenza vaccination through a community intervention program. RESULTS: A total of 3138 participants were recruited in this study, and 61.3 % (95 % CI 59.6 %-63.0 %) were willing to receive influenza vaccination at baseline. The willingness rate of influenza vaccination increased to 79.8 % (95 % CI 78.4 %-81.2 %), with an increase of 18.5 % (95 % CI 16.3 %-20.7 %) after momentary intervention. The influenza vaccination rate was 40.4 % (95 % CI 38.5 %-42.3 %) before and 53.9 % (95 % CI 52.0 %-55.8 %) after momentary intervention with an increase of 13.5 % (95 % CI 10.9 %-16.2 %). There was no significant difference in influenza vaccination rates between the initially willing people and those who changed to be willing to receive influenza vaccination after momentary intervention (vaccination rates: 78.0 % vs. 81.3 %). CONCLUSION: Momentary intervention has been shown to effectively enhance the willingness of the elderly to receive influenza vaccination, thereby facilitating the translation of this intention into actual behavior.

2.
ACS Biomater Sci Eng ; 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38748565

RESUMO

The silicon nitride (Si3N4) coating exhibits promising potential in oral applications due to its excellent osteogenic and antibacterial properties. However, a comprehensive investigation of Si3N4 coatings in the context of dental implants is still lacking, especially regarding their corrosion resistance and in vivo performance. In this study, Si3N4 coatings were prepared on a titanium surface using the nonequilibrium magnetron sputtering method. A systematic comparison among the titanium group (Ti), Si3N4 coating group (Si3N4-Ti), and sandblasted and acid-etched-treated titanium group (SLA-Ti) has been conducted in vitro and in vivo. The results showed that the Si3N4-Ti group had the best corrosion resistance and antibacterial properties, which were mainly attributed to the dense structure and chemical activity of Si-O and Si-N bonds on the surface. Furthermore, the Si3N4-Ti group exhibited superior cellular responses in vitro and new bone regeneration and osseointegration in vivo, respectively. In this sense, silicon nitride coating shows promising prospects in the field of dental implantology.

3.
BMC Genomics ; 25(1): 458, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38730432

RESUMO

BACKGROUND: While rabbits are used as models in skin irritation tests, the presence of irregular patches and thickening on the dorsal skin can affect precise evaluation. In this study, genes associated with patchiness or non-patchiness on the dorsal skin of New Zealand rabbits were investigated to identify potential regulators of the patchiness phenotype. RESULTS: The results showed that parameters associated with hair follicles (HFs), such as HF density, skin thickness, and HF depth, were augmented in rabbits with the patchiness phenotype relative to the non-patchiness phenotype. A total of 592 differentially expressed genes (DEGs) were identified between the two groups using RNA-sequencing. These included KRT72, KRT82, KRT85, FUT8, SOX9, and WNT5B. The functions of the DEGs were investigated by GO and KEGG enrichment analyses. A candidate gene, KRT82, was selected for further molecular function verification. There was a significant positive correlation between KRT82 expression and HF-related parameters, and KRT82 overexpression and knockdown experiments with rabbit dermal papilla cells (DPCs) showed that it regulated genes related to skin and HF growth and development. Investigation of single nucleotide polymorphisms (SNPs) in the exons and promoter region of KRT82 identified four SNPs in the promoter region but none in the exons. The G.-631G > T, T.-696T > C, G.-770G > T and A.-873 A > C alleles conformed to the Hardy - Weinberg equilibrium, and three identified haplotypes showed linkage disequilibrium. Luciferase reporter assays showed that the core promoter region of KRT82 was located in the - 600 to - 1200 segment, in which the four SNPs were located. CONCLUSIONS: The morphological characteristics of the patchiness phenotype were analyzed in New Zealand rabbits and DEGs associated with this phenotype were identified by RNA-sequencing. The biological functions of the gene KRT82 associated with this phenotype were analyzed, and four SNPs were identified in the promoter region of the gene. These findings suggest that KRT82 may be a potential biomarker for the breeding of experimental New Zealand rabbits.


Assuntos
Polimorfismo de Nucleotídeo Único , Regiões Promotoras Genéticas , Pele , Animais , Coelhos , Pele/metabolismo , Fenótipo , Folículo Piloso/metabolismo
4.
Neoplasia ; 53: 101005, 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38761506

RESUMO

Colorectal cancer (CRC) stands as a prevalent malignancy globally. A pivotal event in CRC pathogenesis involves the loss-of-function mutation in the APC gene, leading to the formation of benign polyps. Despite the well-established role of APC, the contribution of CUL4B to CRC initiation in the pre-tumorous stage remains poorly understood. In this investigation, we generated a murine model by crossing ApcMin/+ mice with Cul4bΔIEC mice to achieve specific deletion of Cul4b in the gut epithelium against an ApcMin/+ background. By employing histological methods, RNA-sequencing (RNA-seq), and flow cytometry, we assessed alterations and characterized the immune microenvironment. Our results unveiled that CUL4B deficiency in gut epithelium expedited ApcMin/+ adenoma formation. Notably, CUL4B in adenomas restrained the accumulation of tumor-infiltrating myeloid-derived suppressor cells (MDSCs). In vivo inhibition of MDSCs significantly delayed the growth of CUL4B deleted ApcMin/+ adenomas. Furthermore, the addition of MDSCs to in vitro cultured ApcMin/+; Cul4bΔIEC adenoma organoids mitigated their alterations. Mechanistically, CUL4B directly interacted with the promoter of Csf3, the gene encoding granulocyte-colony stimulating factor (G-CSF) by coordinating with PRC2. Inhibiting CUL4B epigenetically activated the expression of G-CSF, promoting the recruitment of MDSCs. These findings offer novel insights into the tumor suppressor-like roles of CUL4B in regulating ApcMin/+ adenomas, suggesting a potential therapeutic strategy for CRC initiation and progression in the context of activated Wnt signaling.

5.
Genes (Basel) ; 15(4)2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38674344

RESUMO

This study investigated the regulatory effect of alternative spliceosomes of the fibroblast growth factor 5 (FGF5) gene on hair follicle (HF) growth and development in rabbits. The FGF5 alternative spliceosomes (called FGF5-X1, FGF5-X2, FGF5-X3) were cloned. The overexpression vector and siRNA of spliceosomes were transfected into dermal papilla cells (DPCs) to analyze the regulatory effect on DPCs. The results revealed that FGF5-X2 and FGF5-X3 overexpression significantly decreased LEF1 mRNA expression (p < 0.01). FGF5-X1 overexpression significantly reduced CCND1 expression (p < 0.01). FGF5-X1 and FGF5-X2 possibly downregulated the expression level of FGF2 mRNA (p < 0.05), and FGF5-X3 significantly downregulated the expression level of FGF2 mRNA (p < 0.01). The FGF5 alternative spliceosomes significantly downregulated the BCL2 mRNA expression level in both cases (p < 0.01). FGF5-X1 and FGF5-X2 significantly increased TGFß mRNA expression (p < 0.01). All three FGF5 alternative spliceosomes inhibited DPC proliferation. In conclusion, the expression profile of HF growth and development-related genes can be regulated by FGF5 alternative spliceosomes, inhibiting the proliferation of DPCs and has an influence on the regulation of HF growth in rabbits. This study provides insights to further investigate the mechanism of HF development in rabbits via FGF5 regulation.


Assuntos
Fator 5 de Crescimento de Fibroblastos , Folículo Piloso , Animais , Coelhos , Folículo Piloso/crescimento & desenvolvimento , Folículo Piloso/metabolismo , Fator 5 de Crescimento de Fibroblastos/genética , Fator 5 de Crescimento de Fibroblastos/metabolismo , Proliferação de Células/genética , Processamento Alternativo
6.
Sci Rep ; 14(1): 9906, 2024 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-38689033

RESUMO

CUL4B, a crucial scaffolding protein in the largest E3 ubiquitin ligase complex CRL4B, is involved in a broad range of physiological and pathological processes. While previous research has shown that CUL4B participates in maintaining intestinal homeostasis and function, its involvement in facilitating intestinal recovery following ionizing radiation (IR) damage has not been fully elucidated. Here, we utilized in vivo and in vitro models to decipher the role of CUL4B in intestinal repair after IR-injury. Our findings demonstrated that prior to radiation exposure, CUL4B inhibited the ubiquitination modification of PSME3, which led to the accumulation of PSME3 and subsequent negative regulation of p53-mediated apoptosis. In contrast, after radiation, CUL4B dissociated from PSME3 and translocated into the nucleus at phosphorylated histones H2A (γH2AX) foci, thereby impeding DNA damage repair and augmenting p53-mediated apoptosis through inhibition of BRCA1 phosphorylation and RAD51. Our study elucidated the dynamic role of CUL4B in the repair of radiation-induced intestinal damage and uncovered novel molecular mechanisms underlying the repair process, suggesting a potential therapeutic strategy of intestinal damage after radiation therapy for cancers.


Assuntos
Apoptose , Proteínas Culina , Intestinos , Regeneração , Proteína Supressora de Tumor p53 , Animais , Humanos , Camundongos , Apoptose/efeitos da radiação , Proteína BRCA1/metabolismo , Proteína BRCA1/genética , Proteínas Culina/metabolismo , Proteínas Culina/genética , Dano ao DNA , Reparo do DNA , Histonas/metabolismo , Intestinos/efeitos da radiação , Intestinos/patologia , Camundongos Endogâmicos C57BL , Fosforilação/efeitos da radiação , Rad51 Recombinase/metabolismo , Radiação Ionizante , Regeneração/efeitos da radiação , Proteína Supressora de Tumor p53/metabolismo , Ubiquitinação
7.
Hepatology ; 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38466833

RESUMO

BACKGROUND AND AIMS: RAD51 recombinase (RAD51) is a highly conserved DNA repair protein and is indispensable for embryonic viability. As a result, the role of RAD51 in liver development and function is unknown. Our aim was to characterize the function of RAD51 in postnatal liver development. APPROACH AND RESULTS: RAD51 is highly expressed during liver development and during regeneration following hepatectomy and hepatic injury, and is also elevated in chronic liver diseases. We generated a hepatocyte-specific Rad51 deletion mouse model using Alb -Cre ( Rad51 -conditional knockout (CKO)) and Adeno-associated virus 8-thyroxine-binding globulin-cyclization recombination enzyme to evaluate the function of RAD51 in liver development and regeneration. The phenotype in Rad51 -CKO mice is dependent on CRE dosage, with Rad51fl/fl ; Alb -Cre +/+ manifesting a more severe phenotype than the Rad51fl/fl ; Alb -Cre +/- mice. RAD51 deletion in postnatal hepatocytes results in aborted mitosis and early onset of pathological polyploidization that is associated with oxidative stress and cellular senescence. Remarkable liver fibrosis occurs spontaneously as early as in 3-month-old Rad51fl/fl ; Alb -Cre +/+ mice. While liver regeneration is compromised in Rad51 -CKO mice, they are more tolerant of carbon tetrachloride-induced hepatic injury and resistant to diethylnitrosamine/carbon tetrachloride-induced HCC. A chronic inflammatory microenvironment created by the senescent hepatocytes appears to activate ductular reaction the transdifferentiation of cholangiocytes to hepatocytes. The newly derived RAD51 functional immature hepatocytes proliferate vigorously, acquire increased malignancy, and eventually give rise to HCC. CONCLUSIONS: Our results demonstrate a novel function of RAD51 in liver development, homeostasis, and tumorigenesis. The Rad51 -CKO mice represent a unique genetic model for premature liver senescence, fibrosis, and hepatocellular carcinogenesis.

8.
PLoS One ; 19(3): e0300049, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38466737

RESUMO

In order to assess the electromagnetic exposure safety of passengers under the civil communication system of the subway, the radio-frequency (RF) electromagnetic environment of subway carriage is established by using COMSOL Multiphysics software, it includes a 1-1/4 " leaky coaxial cable (LCX1) and a 1-5/8" leaky coaxial cable (LCX2), which are designed to be the exposure sources, and twelve passengers at different position. The electromagnetic environment model has been verified through field measurement. The exposure dose distribution of twelve passengers is compared and analyzed, when LCX1 and LCX2 works respectively. The simulated results show that, to compare with LCX2, the electromagnetic dose absorbed by the passengers is reduced by 9.19% and 22.50% at 2100 MHz and 2600 MHz respectively. The specific absorption rate (SAR) of passengers obtains the maximum value of 1.91×10-4 W/Kg and the temperature rise to 0.214 K when the LCX1 works at 3400 MHz. By comparing with the public exposure limitation of the International Commission of Non-Ionizing Radiation Protection (ICNIRP), it demonstrates the electromagnetic exposure safety of the passengers under the civil communication system. More importantly, the proposed LCX1 not only could add the 5G signal cover but also lower the SAR absorbed by the passengers, which indicates that the public electromagnetic exposure dose could be reduced by adjusting the radiation performances of exposure source, which provide a new way for electromagnetic protecting.


Assuntos
Campos Eletromagnéticos , Ferrovias , Campos Eletromagnéticos/efeitos adversos , Ondas de Rádio/efeitos adversos , Temperatura , Comunicação
9.
Cell Rep Med ; 5(4): 101484, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38554704

RESUMO

The use of Bruton tyrosine kinase (BTK) inhibitors such as ibrutinib achieves a remarkable clinical response in mantle cell lymphoma (MCL). Acquired drug resistance, however, is significant and affects long-term survival of MCL patients. Here, we demonstrate that DNA methyltransferase 3A (DNMT3A) is involved in ibrutinib resistance. We find that DNMT3A expression is upregulated upon ibrutinib treatment in ibrutinib-resistant MCL cells. Genetic and pharmacological analyses reveal that DNMT3A mediates ibrutinib resistance independent of its DNA-methylation function. Mechanistically, DNMT3A induces the expression of MYC target genes through interaction with the transcription factors MEF2B and MYC, thus mediating metabolic reprogramming to oxidative phosphorylation (OXPHOS). Targeting DNMT3A with low-dose decitabine inhibits the growth of ibrutinib-resistant lymphoma cells both in vitro and in a patient-derived xenograft mouse model. These findings suggest that targeting DNMT3A-mediated metabolic reprogramming to OXPHOS with decitabine provides a potential therapeutic strategy to overcome ibrutinib resistance in relapsed/refractory MCL.


Assuntos
Adenina/análogos & derivados , Linfoma de Célula do Manto , Piperidinas , Proteínas Tirosina Quinases , Humanos , Animais , Camundongos , Adulto , Tirosina Quinase da Agamaglobulinemia/metabolismo , Resistencia a Medicamentos Antineoplásicos/genética , DNA Metiltransferase 3A , Fosforilação Oxidativa , Linfoma de Célula do Manto/tratamento farmacológico , Linfoma de Célula do Manto/genética , Linfoma de Célula do Manto/patologia , Decitabina/metabolismo , Decitabina/uso terapêutico
10.
J Mol Neurosci ; 74(1): 19, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38358571

RESUMO

The sympathetic nervous system (SNS) is a crucial branch of the autonomic nervous system (ANS) that is responsible for regulating visceral function and various physiological processes. Dysfunction of the SNS can lead to various diseases, such as hypertension and metabolic disorders. However, obtaining sympathetic neurons from human tissues for research is challenging. The current research aimed at recapitulating the process of human sympathetic neuron development and achieved the successful establishment of a stepwise, highly efficient in vitro differentiation protocol. This protocol facilitated the generation of functional and mature sympathetic neurons from human pluripotent stem cells (hPSCs) using a chemical-defined induction medium. Initially, each differentiation stage was refined to derive sympathoadrenal progenitors (SAPs) from hPSCs through neural epithelial cells (NECs) and trunk neural crest stem cells (NCSCs). hPSC-derived SAPs could be expanded in vitro for at least 12 passages while maintaining the expression of SAP-specific transcription factors and neuronal differentiation potency. SAPs readily generated functional sympathetic neurons (SymNs) when cultured in the neuronal maturation medium for 3-4 weeks. These SymNs expressed sympathetic markers, exhibited electrophysiological properties, and secreted sympathetic neurotransmitters. More importantly, we further demonstrated that hPSC-derived SymNs can efficiently regulate the adipogenesis of human adipose-derived stem cells (ADSCs) and lipid metabolism in vitro. In conclusion, our study provided a simple and robust protocol for generating functional sympathetic neurons from hPSCs, which may be an invaluable tool in unraveling the mechanisms of SNS-related diseases.


Assuntos
Neurônios , Células-Tronco Pluripotentes , Humanos , Adipócitos , Diferenciação Celular , Células Epiteliais
11.
Chem Soc Rev ; 53(5): 2326-2349, 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38259195

RESUMO

As a class of multifunctional reagents, organic peroxides play vital roles in the chemical industry, pharmaceutical synthesis and polymerization reactions. Metal-catalyzed asymmetric catalysis has emerged as one of the most straightforward and efficient strategies to construct enantioenriched molecules, and an increasing number of metal-catalyzed asymmetric reactions enabled by organic peroxides have been disclosed by researchers in recent years. Despite remarkable progress, the types of asymmetric reactions facilitated by organic peroxides remain limited and the catalysis systems need to be further broadened. To the best of our knowledge, there is still no review devoted to summarizing the reactions from this perspective. In this review, we will endeavor to highlight the advances in metal-catalyzed asymmetric reactions enabled by organic peroxides. We hope that this survey will summarize the functions of organic peroxides in catalytic reactions, improve the understanding of these compounds and inspire future developments in this area.

12.
RSC Adv ; 14(1): 700-706, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38173585

RESUMO

Selectively producing a variety of valuable compounds using controlled chemical reactions starting from a common material is an appealing yet complex concept. Herein, a photocatalytic approach for the selective synthesis of (E)-ß-aminovinyl sulfones and (E)-ß-amidovinyl sulfones from allenamides and sodium sulfinates was established. This reaction exhibits the traits of an eco-friendly solvent and adjustable amide cleavage, and can accommodate a diverse range of substrates with exceptional functional group tolerance. Based on control experiments and deuterium labeling experiments, a plausible radical reaction pathway is proposed.

13.
Small ; 20(14): e2306308, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37990392

RESUMO

Stable plating/stripping of Zn metal anode remains a great challenge owing to uncontrollable dendrite growth and side reactions. Ion-sieving separators is a unique and promising solution, that possess Zn2+ permeability and promote Zn2+ transport, can effectively alleviate the abovementioned problems. Ion-sieving on glass fiber separator by deposition of oxygen-deficient SiOx layer via active screen plasma technology is achieved. While having chemical composition similar to the glass fiber, the SiOx nanoparticles contain oxygen-rich vacancies that promoted dissociation of the adsorbed water and generation of the hydroxyl groups. The negatively-charged hydroxylated SiOx layer can repel SO4 2- and attract Zn2+, which can alleviate the side reactions. The strong interplay between hydroxyl groups and Zn2+ can boost Zn affinity and yield fast Zn2+ transport. Consequently, the SiOx-deposited GF separator enabled dendrite-free Zn deposition morphology, which displays lower overpotential of 18 mV and longer cycling life over 2000 h for Zn symmetric cell. Such a separator can also be easily scaled up to prepare the high-performance large-area (4 × 6 cm2) pouch Zn-based devices, showing remarkable flexibility and practicality.

14.
Vaccines (Basel) ; 11(12)2023 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-38140167

RESUMO

The meningococcal meningitis (MM) vaccine reduces the incidence of MM significantly; however, outbreaks still occur in communities with high vaccine coverage. We aimed to analyze the driving factors of infection from a community outbreak. A total of 266 children aged 9 to 15 years old from the three junior high schools of Tongzi county were identified. We documented infection cases using laboratory tests and analyzed attack rates, infection rates and risk factors for transmission. The index case in School A was identified, and the attack rate in School A was 0.03%. Children showed a significantly low infection rate of MenC in School A (13.2% vs. 19.5% in total children, p = 0.002), while exhibiting significantly high infection rates of MenA in School B (44.1% vs. 24.8% in total children, p < 0.001) and MenB in School C (11.1% vs. 4.1% in total children, p = 0.015). The infection rate of MenA for females (30.0%) was higher (p = 0.055) than for males (19.9%). In School A, 63.19% of children were vaccinated against MenC, while in School B the rate was 42.65% and in School C, it was 59.26%. Three male MenC infection cases were detected as breakthrough infection cases in addition to the index case. The findings suggest that the current full-course immunization has limited long-term effectiveness and is inefficient in preventing the transmission of MM among older children.

15.
Nat Commun ; 14(1): 7032, 2023 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-37923718

RESUMO

Regulation of alternative splicing (AS) enables a single transcript to yield multiple isoforms that increase transcriptome and proteome diversity. Here, we report that spliceosome component Usp39 plays a role in the regulation of hepatocyte lipid homeostasis. We demonstrate that Usp39 expression is downregulated in hepatic tissues of non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) subjects. Hepatocyte-specific Usp39 deletion in mice leads to increased lipid accumulation, spontaneous steatosis and impaired autophagy. Combined analysis of RNA immunoprecipitation (RIP-seq) and bulk RNA sequencing (RNA-seq) data reveals that Usp39 regulates AS of several autophagy-related genes. In particular, deletion of Usp39 results in alternative 5' splice site selection of exon 6 in Heat shock transcription factor 1 (Hsf1) and consequently its reduced expression. Importantly, overexpression of Hsf1 could attenuate lipid accumulation caused by Usp39 deficiency. Taken together, our findings indicate that Usp39-mediated AS is required for sustaining autophagy and lipid homeostasis in the liver.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Spliceossomos , Animais , Humanos , Camundongos , Autofagia/genética , Homeostase , Lipídeos , Fígado/metabolismo , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/metabolismo , Spliceossomos/genética , Spliceossomos/metabolismo
16.
Int Immunopharmacol ; 125(Pt A): 111074, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37879229

RESUMO

Sepsis-induced myocardial dysfunction (SIMD) is the main cause of mortality in sepsis. In this study, we identified Polo-like kinase 1 (Plk-1) is a promoter of SIMD. Plk-1 expression was increased in lipopolysaccharide (LPS)-treated mouse hearts and neonatal rat cardiomyocytes (NRCMs). Inhibition of Plk-1 either by heterozygous deletion of Plk-1 or Plk-1 inhibitor BI 6727 alleviated LPS-induced myocardial injury, inflammation, cardiac dysfunction, and thereby improved the survival of LPS-treated mice. Plk-1 was identified as a kinase of inhibitor of kappa B kinase alpha (IKKα). Plk-1 inhibition impeded NF-κB signal pathway activation in LPS-treated mouse hearts and NRCMs. Augmented Plk-1 is thus essential for the development of SIMD and is a druggable target for SIMD.


Assuntos
Cardiomiopatias , Sepse , Ratos , Camundongos , Animais , Miocárdio/metabolismo , NF-kappa B/metabolismo , Lipopolissacarídeos/farmacologia , Cardiomiopatias/etiologia , Cardiomiopatias/metabolismo , Sepse/metabolismo , Quinase 1 Polo-Like
17.
Opt Lett ; 48(19): 5133-5136, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37773403

RESUMO

The Stern-Volmer constant (KSV) is an important parameter to describe the capability of energy transfer to oxygen for porphyrin and its derivatives. By fitting Stern-Volmer equation, IP0/IP = 1 + KSV[O2], the KSV is generally determined through phosphorescence intensities (IP) under aerobic and oxygen-free conditions. In this work, the effect of excitation power density on the KSV measurement is theoretically analyzed and experimentally studied, using palladium octaethylporphyrin (PdOEP) as an example. The IP of PdOEP increased nonlinearly with excitation power density, and the power dependent slope of IP0/IP could be obtained. By way of the functional relationship between the slope of IP0/IP and power density, the real KSV of PdOEP was fitted to be 58 ± 2 kPa-1. The oxygen-dependent phosphorescence lifetimes (τP) and IP under a weak excitation power are also measured to calculate the real KSV, which verifies our analysis.

18.
Blood ; 142(22): 1879-1894, 2023 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-37738652

RESUMO

The use of Bruton tyrosine kinase inhibitors, such as ibrutinib, to block B-cell receptor signaling has achieved a remarkable clinical response in several B-cell malignancies, including mantle cell lymphoma (MCL) and diffuse large B-cell lymphoma (DLBCL). Acquired drug resistance, however, is significant and affects the long-term survival of these patients. Here, we demonstrate that the transcription factor early growth response gene 1 (EGR1) is involved in ibrutinib resistance. We found that EGR1 expression is elevated in ibrutinib-resistant activated B-cell-like subtype DLBCL and MCL cells and can be further upregulated upon ibrutinib treatment. Genetic and pharmacological analyses revealed that overexpressed EGR1 mediates ibrutinib resistance. Mechanistically, TCF4 and EGR1 self-regulation induce EGR1 overexpression that mediates metabolic reprogramming to oxidative phosphorylation (OXPHOS) through the transcriptional activation of PDP1, a phosphatase that dephosphorylates and activates the E1 component of the large pyruvate dehydrogenase complex. Therefore, EGR1-mediated PDP1 activation increases intracellular adenosine triphosphate production, leading to sufficient energy to enhance the proliferation and survival of ibrutinib-resistant lymphoma cells. Finally, we demonstrate that targeting OXPHOS with metformin or IM156, a newly developed OXPHOS inhibitor, inhibits the growth of ibrutinib-resistant lymphoma cells both in vitro and in a patient-derived xenograft mouse model. These findings suggest that targeting EGR1-mediated metabolic reprogramming to OXPHOS with metformin or IM156 provides a potential therapeutic strategy to overcome ibrutinib resistance in relapsed/refractory DLBCL or MCL.


Assuntos
Antineoplásicos , Linfoma Difuso de Grandes Células B , Linfoma de Célula do Manto , Metformina , Humanos , Adulto , Animais , Camundongos , Tirosina Quinase da Agamaglobulinemia/metabolismo , Fosforilação Oxidativa , Resistencia a Medicamentos Antineoplásicos , Linhagem Celular Tumoral , Antineoplásicos/uso terapêutico , Linfoma de Célula do Manto/tratamento farmacológico , Linfoma de Célula do Manto/genética , Linfoma de Célula do Manto/patologia , Linfoma Difuso de Grandes Células B/patologia , Metformina/farmacologia , Proteína 1 de Resposta de Crescimento Precoce/metabolismo
19.
Front Neurosci ; 17: 1213720, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37564366

RESUMO

Brain-inspired deep spiking neural network (DSNN) which emulates the function of the biological brain provides an effective approach for event-stream spatiotemporal perception (STP), especially for dynamic vision sensor (DVS) signals. However, there is a lack of generalized learning frameworks that can handle various spatiotemporal modalities beyond event-stream, such as video clips and 3D imaging data. To provide a unified design flow for generalized spatiotemporal processing (STP) and to investigate the capability of lightweight STP processing via brain-inspired neural dynamics, this study introduces a training platform called brain-inspired deep learning (BIDL). This framework constructs deep neural networks, which leverage neural dynamics for processing temporal information and ensures high-accuracy spatial processing via artificial neural network layers. We conducted experiments involving various types of data, including video information processing, DVS information processing, 3D medical imaging classification, and natural language processing. These experiments demonstrate the efficiency of the proposed method. Moreover, as a research framework for researchers in the fields of neuroscience and machine learning, BIDL facilitates the exploration of different neural models and enables global-local co-learning. For easily fitting to neuromorphic chips and GPUs, the framework incorporates several optimizations, including iteration representation, state-aware computational graph, and built-in neural functions. This study presents a user-friendly and efficient DSNN builder for lightweight STP applications and has the potential to drive future advancements in bio-inspired research.

20.
J Phys Chem Lett ; 14(32): 7193-7197, 2023 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-37549221

RESUMO

Because of the absence of phosphorescence, the Stern-Volmer constant (KSV) of the photosensitizer is hard to determine accurately. Although the delayed fluorescence and correlated fluorescence methods have been proposed to determine KSV, the weak signal detection and non-uniform excitation enlarged the measurement error. In this work, a method was proposed to accurately determine KSV by oxygen-dependent consumption of 1,3-diphenylisobenzofuran. The consumption time (δ), as a measurable quantity, is introduced and could be obtained by the absorption spectrum with a high signal-to-noise ratio. Analytically, δ is linearly related to the inverse of oxygen content, and the ratio of the intercept to the slope equals KSV. Experimentally, rose Bengal was selected to perform this determination; the KSV is measured to be 43(1) kPa-1, and the error is reduced by 1 order of magnitude. In addition, metalloporphyrin was used to verify this method.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...