Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 184
Filtrar
1.
Front Pharmacol ; 15: 1361371, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38633608

RESUMO

The lymphoma incidence rate is on the rise, with invasive forms particularly prone to relapse following conventional treatment, posing a significant threat to human life and wellbeing. Numerous studies have shown that traditional Chinese botanical drug medicine offers promising therapeutic benefits for various malignancies, with previous experimental findings indicating that Celastrus orbiculatus extract effectively combats digestive tract tumors. However, its impact on lymphoma remains unexplored. This study aims to investigate the impact and underlying mechanisms of COE on the proliferation and apoptosis of Burkitt lymphoma cells. We diluted COE in RPMI-1640 medium to create various working concentrations and introduced it to human Burkitt lymphoma Raji and Ramos cells. To evaluate cell viability, we used the CCK-8 assay, and we observed morphological changes using HE staining. We also conducted Annexin V-PI and JC-1 staining experiments to assess apoptosis. By combining the cell cycle experiment with the EDU assay, we gained insights into the effects of COE on DNA replication in lymphoma cells. Using Western blotting, we detected alterations in apoptosis-related proteins. In vivo experiments revealed that following COE intervention, tumor volume decreased, survival time was prolonged, spleen size reduced, and the expression of tumor apoptosis-related proteins changed. Our findings indicate that COE effectively inhibits lymphoma cell proliferation and promotes apoptosis by regulating these apoptosis-related proteins.

2.
J Mater Chem B ; 12(15): 3710-3718, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38529668

RESUMO

Meeting the demand for efficient photosensitizers in photodynamic therapy (PDT), a series of iridium(III) complexes decorated with silicane-modified rhodamine (Si-rhodamine) was meticulously designed and synthesized. These complexes demonstrate exceptional PDT potential owing to their strong absorption in the near-infrared (NIR) spectrum, particularly responsive to 808 nm laser stimulation. This feature is pivotal, enabling deep-penetration laser excitation and overcoming depth-related challenges in clinical PDT applications. The molecular structures of these complexes allow for reliable tuning of singlet oxygen generation with NIR excitation, through modification of the cyclometalating ligand. Notably, one of the complexes (4) exhibits a remarkable ROS quantum yield of 0.69. In vivo results underscore the efficacy of 4, showcasing significant tumor regression at depths of up to 8.4 mm. This study introduces a promising paradigm for designing photosensitizers capable of harnessing NIR light effectively for deep PDT applications.


Assuntos
Fotoquimioterapia , Fármacos Fotossensibilizantes , Silanos , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/química , Fotoquimioterapia/métodos , Irídio/farmacologia , Irídio/química , Rodaminas , Linhagem Celular Tumoral , Raios Infravermelhos
3.
Commun Biol ; 7(1): 301, 2024 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-38461223

RESUMO

Hyalectan cleavage may play an important role in extracellular matrix remodeling. However, the proteolytic enzyme responsible for hyalectan degradation for fetal membrane rupture at parturition remains unknown. Here, we reveal that versican (VCAN) is the major hyalectan in the amnion, where its cleavage increases at parturition with spontaneous rupture of membrane. We further reveal that ADAMTS4 is a crucial proteolytic enzyme for VCAN cleavage in the amnion. Inflammatory factors may enhance VCAN cleavage by inducing ADAMTS4 expression and inhibiting ADAMTS4 endocytosis in amnion fibroblasts. In turn, versikine, the VCAN cleavage product, induces inflammatory factors in amnion fibroblasts, thereby forming a feedforward loop between inflammation and VCAN degradation. Mouse studies show that intra-amniotic injection of ADAMTS4 induces preterm birth along with increased VCAN degradation and proinflammatory factors abundance in the fetal membranes. Conclusively, there is enhanced VCAN cleavage by ADAMTS4 in the amnion at parturition, which can be reenforced by inflammation.


Assuntos
Proteína ADAMTS4 , Âmnio , Versicanas , Feminino , Humanos , Recém-Nascido , Gravidez , Proteína ADAMTS4/metabolismo , Âmnio/metabolismo , Inflamação/metabolismo , Parto/metabolismo , Peptídeo Hidrolases/metabolismo , Nascimento Prematuro/metabolismo , Versicanas/metabolismo , Animais , Camundongos
4.
Environ Sci Technol ; 58(10): 4824-4836, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38408018

RESUMO

Electrochemically converting nitrate, a widely distributed nitrogen contaminant, into harmless N2 is a feasible and environmentally friendly route to close the anthropogenic nitrogen-based cycle. However, it is currently hindered by sluggish kinetics and low N2 selectivity, as well as scarce attention to reactor configuration. Here, we report a flow-through zero-gap electrochemical reactor that shows a high performance of nitrate reduction with 100% conversion and 80.36% selectivity of desired N2 in the chlorine-free system at 100 mg-N·L-1 NO3- while maintaining a rapid reduction kinetics of 0.07676 min-1. More importantly, the mass transport and current utilization efficiency are significantly improved by shortening the inter-electrode distance, especially in the zero-gap electrocatalytic system where the current efficiency reached 50.15% at 5 mA·cm-2. Detailed characterizations demonstrated that during the electroreduction process, partial Cu(OH)2 on the cathode surface was reconstructed into stable Cu/Cu2O as the active phase for efficient nitrate reduction. In situ characterizations revealed that the highly selective *NO to *N conversion and the N-N coupling step played crucial roles during the selective reduction of NO3- to N2 in the zero-gap electrochemical system. In addition, theoretical calculations demonstrated that improving the key intermediate *N coverage could effectively facilitate the N-N coupling step, thereby promoting N2 selectivity. Moreover, the environmental and economic benefits and long-term stability shown by the treatment of real nitrate-containing wastewater make our proposed electrocatalytic system more attractive for practical applications.


Assuntos
Nitratos , Águas Residuárias , Nitratos/química , Eletrodos , Nitrogênio/análise , Nitrogênio/química , Cinética
5.
Front Immunol ; 15: 1274474, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38361941

RESUMO

Metastatic disease, a leading and lethal indication of deaths associated with tumors, results from the dissemination of metastatic tumor cells from the site of primary origin to a distant organ. Dispersion of metastatic cells during the development of tumors at distant organs leads to failure to comply with conventional treatments, ultimately instigating abrupt tissue homeostasis and organ failure. Increasing evidence indicates that the tumor microenvironment (TME) is a crucial factor in cancer progression and the process of metastatic tumor development at secondary sites. TME comprises several factors contributing to the initiation and progression of the metastatic cascade. Among these, various cell types in TME, such as mesenchymal stem cells (MSCs), lymphatic endothelial cells (LECs), cancer-associated fibroblasts (CAFs), myeloid-derived suppressor cells (MDSCs), T cells, and tumor-associated macrophages (TAMs), are significant players participating in cancer metastasis. Besides, various other factors, such as extracellular matrix (ECM), gut microbiota, circadian rhythm, and hypoxia, also shape the TME and impact the metastatic cascade. A thorough understanding of the functions of TME components in tumor progression and metastasis is necessary to discover new therapeutic strategies targeting the metastatic tumor cells and TME. Therefore, we reviewed these pivotal TME components and highlighted the background knowledge on how these cell types and disrupted components of TME influence the metastatic cascade and establish the premetastatic niche. This review will help researchers identify these altered components' molecular patterns and design an optimized, targeted therapy to treat solid tumors and restrict metastatic cascade.


Assuntos
Células Supressoras Mieloides , Neoplasias , Humanos , Células Endoteliais/patologia , Neoplasias/patologia , Microambiente Tumoral , Células Supressoras Mieloides/patologia
6.
J Viral Hepat ; 31(3): 143-150, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38235846

RESUMO

Previous studies did not provide substantial evidence for long-term immune persistence after the hepatitis B vaccine (HepB) in preterm birth (PTB) children. Consequently, there is ongoing controversy surrounding the booster immunization strategy for these children. Therefore, we conducted a retrospective cohort study to evaluate the disparities in immune persistence between PTB children and full-term children. A total of 1027 participants were enrolled in this study, including 505 PTB children in the exposure group and 522 full-term children in the control group. The negative rate of hepatitis B surface antibody (HBsAb) in the PTB group was significantly lower than that in the control group (47.9% vs. 41.4%, p = .035). The risk of HBsAb-negative in the exposure group was 1.5 times higher than that in the control group (adjusted odds ratio [aOR] = 1.5, 95% confidence interval [CI]: 1.1-2.0). The geometric mean concentration (GMC) of HBsAb was much lower for participants in the exposure group compared to participants in the control group (9.3 vs. 12.4 mIU/mL, p = .029). Subgroup analysis showed that the very preterm infants (gestational age <32 weeks) and the preterm low birth weight infants (birth weight <2000 g) had relatively low GMC levels of 3.2 mIU/mL (95% CI: 0.9-11.1) and 7.9 mIU/mL (95% CI: 4.2-14.8), respectively. Our findings demonstrated that PTB had a significant impact on the long-term persistence of HBsAb after HepB vaccination. The very preterm infants (gestational age <32 weeks) and the preterm low birth weight infants (birth weight <2000 g) may be special populations that should be given priority for HepB booster vaccination.


Assuntos
Hepatite B , Fenilbutiratos , Nascimento Prematuro , Criança , Feminino , Humanos , Lactente , Recém-Nascido , Peso ao Nascer , Seguimentos , Hepatite B/epidemiologia , Hepatite B/prevenção & controle , Anticorpos Anti-Hepatite B , Antígenos de Superfície da Hepatite B , Vacinas contra Hepatite B , Recém-Nascido Prematuro , Nascimento Prematuro/epidemiologia , Estudos Retrospectivos , Vacinação
7.
Nat Commun ; 15(1): 122, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38167862

RESUMO

Targeting tumor-infiltrating regulatory T cells (Tregs) is an efficient way to evoke an anti-tumor immune response. However, how Tregs maintain their fragility and stability remains largely unknown. IFITM3 and STAT1 are interferon-induced genes that play a positive role in the progression of tumors. Here, we showed that IFITM3-deficient Tregs blunted tumor growth by strengthening the tumor-killing response and displayed the Th1-like Treg phenotype with higher secretion of IFNγ. Mechanistically, depletion of IFITM3 enhances the translation and phosphorylation of STAT1. On the contrary, the decreased IFITM3 expression in STAT1-deficient Tregs indicates that STAT1 conversely regulates the expression of IFITM3 to form a feedback loop. Blocking the inflammatory cytokine IFNγ or directly depleting STAT1-IFITM3 axis phenocopies the restored suppressive function of tumor-infiltrating Tregs in the tumor model. Overall, our study demonstrates that the perturbation of tumor-infiltrating Tregs through the IFNγ-IFITM3-STAT1 feedback loop is essential for anti-tumor immunity and constitutes a targetable vulnerability of cancer immunotherapy.


Assuntos
Neoplasias , Linfócitos T Reguladores , Humanos , Retroalimentação , Neoplasias/genética , Neoplasias/terapia , Citocinas/metabolismo , Fatores de Transcrição Forkhead/metabolismo , Proteínas de Membrana/metabolismo , Proteínas de Ligação a RNA/metabolismo , Fator de Transcrição STAT1/genética , Fator de Transcrição STAT1/metabolismo
8.
Biochem Biophys Res Commun ; 690: 149247, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38000292

RESUMO

Hepatocellular carcinoma (HCC) is a highly malignant tumor with a global prevalence. In addition to the existing clinical guidelines, the effectiveness of anlotinib and Aurora-A inhibitors in treating HCC has also been demonstrated. However, Anlotinib, as an anti-angiogenesis therapy, has shown significant benefits in clinical trials but is limited by its single-agent treatment and the development of drug resistance. Aurora-A inhibitors are currently being tested in clinical trials but have limited efficacy. Combination therapy may offer clear advantages over monotherapy in this context. METHODS: In this study, we used HCC cell lines to investigate whether the combination of the two drugs could enhance their individual strengths and mitigate their weaknesses, thereby providing greater clinical benefits both in vitro and in vivo. RESULTS: Our findings confirmed that the Aurora-A inhibitor alisertib and anlotinib exhibited a time-dose-dependent inhibitory effect on HCC cells. In vitro cytological experiments demonstrated that the combination of the two drugs synergistically inhibited cell proliferation, invasion, and metastasis, while promoting cell apoptosis. Furthermore, we identified the underlying molecular mechanism by which the combination of the Aurora-A inhibitor alisertib and anlotinib inhibited HCC through the inhibition of the NF-ĸB signaling pathway. CONCLUSIONS: In summary, we have demonstrated the effectiveness of combining anlotinib with an Aurora-A inhibitor, which expands the potential applications of anlotinib in the clinical treatment of HCC in the future.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Quinolinas , Humanos , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Indóis/farmacologia , Indóis/uso terapêutico , Quinolinas/farmacologia , Quinolinas/uso terapêutico , Apoptose , Proliferação de Células , Linhagem Celular Tumoral
10.
Front Microbiol ; 14: 1260181, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38075930

RESUMO

Salmonella including drug-resistant strains are major foodborne pathogens causing serious illness and pose a great threat to the prevention and control for food safety. Phages can naturally defect the bacterium, is considered as a new and promising biological antimicrobial agent in the post-antibiotic era. A poultry facility in Wuhan, China provided wastewater samples from which a collection of 29 phages were isolated and purified. A broad host spectrum phage ISTP3, which capable of infecting all tested Salmonella, including drug-resistant Salmonella enterica, were examined. Additionally, the effectiveness of this phage ISTP3 in reducing drug-resistant S. enterica was assessed in diverse food samples. Transmission electron microscopy (TEM) and whole genome sequencing demonstrated that ISTP3 was found to belong to family Ackermannviridae. The one-step growth experiment and assays of stability demonstrated that ISTP3 exhibited short periods of inactivity before replicating, produced a significant number of viral progeny during infection, and remained high stable under varying pH and temperature conditions. We evaluated the efficacy of phage ISTP3 against drug-resistant Salmonella on chicken breast and lettuce samples at different temperatures. When applying phage ISTP3 in food matrices, the drug resistant Salmonella count significantly reduced at 4°C and 25°C at an MOI of 100 or 1,000 within a timescale of 12 h. Overall, the results, such as broad host ranges, strictly lytic lifestyles, absence of lysogenic related genes, toxin genes, or virulence genes in the genome, demonstrate that the application of phage ISTP3 as a biocontrol agent has promising potential for preventing and controlling drug-resistant S. typhimurium in the context of food safety, processing, and production.

11.
Endocrinology ; 165(2)2023 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-38146648

RESUMO

Progesterone synthesized in the placenta is essential for pregnancy maintenance. CYP11A1 is a key enzyme in progesterone synthesis, and its expression increases greatly during trophoblast syncytialization. However, the underlying mechanism remains elusive. Here, we demonstrated that passive demethylation of CYP11A1 promoter accounted for the upregulation of CYP11A1 expression during syncytialization with the participation of the transcription factor C/EBPα. We found that the methylation rate of a CpG locus in the CYP11A1 promoter was significantly reduced along with decreased DNA methyltransferase 1 (DNMT1) expression and its enrichment at the CYP11A1 promoter during syncytialization. DNMT1 overexpression not only increased the methylation of this CpG locus in the CYP11A1 promoter, but also decreased CYP11A1 expression and progesterone production. In silico analysis disclosed multiple C/EBPα binding sites in both CYP11A1 and DNMT1 promoters. C/EBPα expression and its enrichments at both the DNMT1 and CYP11A1 promoters were significantly increased during syncytialization. Knocking-down C/EBPα expression increased DNMT1 while it decreased CYP11A1 expression during syncytialization. Conclusively, C/EBPα plays a dual role in the regulation of CYP11A1 during syncytialization. C/EBPα not only drives CYP11A1 expression directly, but also indirectly through downregulation of DNMT1, which leads to decreased methylation in the CpG locus of the CYP11A1 promoter, resulting in increased progesterone production during syncytialization.


Assuntos
Proteína alfa Estimuladora de Ligação a CCAAT , Enzima de Clivagem da Cadeia Lateral do Colesterol , DNA (Citosina-5-)-Metiltransferase 1 , Placenta , Feminino , Humanos , Gravidez , Proteína alfa Estimuladora de Ligação a CCAAT/genética , Proteína alfa Estimuladora de Ligação a CCAAT/metabolismo , Enzima de Clivagem da Cadeia Lateral do Colesterol/genética , Enzima de Clivagem da Cadeia Lateral do Colesterol/metabolismo , Metilação de DNA , Placenta/metabolismo , Progesterona/metabolismo , Trofoblastos/metabolismo , DNA (Citosina-5-)-Metiltransferase 1/genética , DNA (Citosina-5-)-Metiltransferase 1/metabolismo
12.
Front Immunol ; 14: 1280741, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37936703

RESUMO

A healthy immune system is pivotal for the hosts to resist external pathogens and maintain homeostasis; however, the immunosuppressive tumor microenvironment (TME) damages the anti-tumor immunity and promotes tumor progression, invasion, and metastasis. Recently, many studies have found that Foxp3+ regulatory T (Treg) cells are the major immunosuppressive cells that facilitate the formation of TME by promoting the development of various tumor-associated cells and suppressing the activity of effector immune cells. Considering the role of Tregs in tumor progression, it is pivotal to identify new therapeutic drugs to target and deplete Tregs in tumors. Although several studies have developed strategies for targeted deletion of Treg to reduce the TME and support the accumulation of effector T cells in tumors, Treg-targeted therapy systematically affects the Treg population and may lead to the progression of autoimmune diseases. It has been understood that, nevertheless, in disease conditions, Foxp3 undergoes several definite post-translational modifications (PTMs), including acetylation, glycosylation, phosphorylation, ubiquitylation, and methylation. These PTMs not only elevate or mitigate the transcriptional activity of Foxp3 but also affect the stability and immunosuppressive function of Tregs. Various studies have shown that pharmacological targeting of enzymes involved in PTMs can significantly influence the PTMs of Foxp3; thus, it may influence the progression of cancers and/or autoimmune diseases. Overall, this review will help researchers to understand the advances in the immune-suppressive mechanisms of Tregs, the post-translational regulations of Foxp3, and the potential therapeutic targets and strategies to target the Tregs in TME to improve anti-tumor immunity.


Assuntos
Doenças Autoimunes , Neoplasias , Humanos , Linfócitos T Reguladores , Terapia de Imunossupressão , Processamento de Proteína Pós-Traducional , Doenças Autoimunes/patologia , Microambiente Tumoral
13.
Front Oncol ; 13: 1290296, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38033486

RESUMO

Cancer is a devastating disease with a high global mortality rate and is projected to increase further in the coming years. Current treatment options, such as chemotherapy and radiation therapy, have limitations including side effects, variable effectiveness, high costs, and limited availability. There is a growing need for alternative treatments that can target cancer cells specifically with fewer side effects. Phages, that infect bacteria but not eukaryotic cells, have emerged as promising cancer therapeutics due to their unique properties, including specificity and ease of genetic modification. Engineered phages can transform cancer treatment by targeting cancer cells while sparing healthy ones. Phages exhibit versatility as nanocarriers, capable of delivering therapeutic agents like gene therapy, immunotherapy, and vaccines. Phages are extensively used in vaccine development, with filamentous, tailed, and icosahedral phages explored for different antigen expression possibilities. Engineered filamentous phages bring benefits such as built in adjuvant properties, cost-effectiveness, versatility in multivalent formulations, feasibility of oral administration, and stability. Phage-based vaccines stimulate the innate immune system by engaging pattern recognition receptors on antigen-presenting cells, enhancing phage peptide antigen presentation to B-cells and T-cells. This review presents recent phage therapy advances and challenges in cancer therapy, exploring its versatile tools and vaccine potential.

14.
Front Immunol ; 14: 1292238, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37928539

RESUMO

T-cell-mediated autoimmune type 1 diabetes (T1D) is characterized by the immune-mediated destruction of pancreatic beta cells (ß-cells). The increasing prevalence of T1D poses significant challenges to the healthcare system, particularly in countries with struggling economies. This review paper highlights the multifaceted roles of Peroxisome Proliferator-Activated Receptors (PPARs) in the context of T1D, shedding light on their potential as regulators of immune responses and ß-cell biology. Recent research has elucidated the intricate interplay between CD4+ T cell subsets, such as Tregs and Th17, in developing autoimmune diseases like T1D. Th17 cells drive inflammation, while Tregs exert immunosuppressive functions, highlighting the delicate balance crucial for immune homeostasis. Immunotherapy has shown promise in reinstating self-tolerance and restricting the destruction of autoimmune responses, but further investigations are required to refine these therapeutic strategies. Intriguingly, PPARs, initially recognized for their role in lipid metabolism, have emerged as potent modulators of inflammation in autoimmune diseases, particularly in T1D. Although evidence suggests that PPARs affect the ß-cell function, their influence on T-cell responses and their potential impact on T1D remains largely unexplored. It was noted that PPARα is involved in restricting the transcription of IL17A and enhancing the expression of Foxp3 by minimizing its proteasomal degradation. Thus, antagonizing PPARs may exert beneficial effects in regulating the differentiation of CD4+ T cells and preventing T1D. Therefore, this review advocates for comprehensive investigations to delineate the precise roles of PPARs in T1D pathogenesis, offering innovative therapeutic avenues that target both the immune system and pancreatic function. This review paper seeks to bridge the knowledge gap between PPARs, immune responses, and T1D, providing insights that may revolutionize the treatment landscape for this autoimmune disorder. Moreover, further studies involving PPAR agonists in non-obese diabetic (NOD) mice hold promise for developing novel T1D therapies.


Assuntos
Doenças Autoimunes , Diabetes Mellitus Tipo 1 , Camundongos , Animais , Camundongos Endogâmicos NOD , Diferenciação Celular , Inflamação/metabolismo , PPAR alfa
15.
Sensors (Basel) ; 23(19)2023 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-37836929

RESUMO

Birds play a vital role in the study of ecosystems and biodiversity. Accurate bird identification helps monitor biodiversity, understand the functions of ecosystems, and develop effective conservation strategies. However, previous bird sound recognition methods often relied on single features and overlooked the spatial information associated with these features, leading to low accuracy. Recognizing this gap, the present study proposed a bird sound recognition method that employs multiple convolutional neural-based networks and a transformer encoder to provide a reliable solution for identifying and classifying birds based on their unique sounds. We manually extracted various acoustic features as model inputs, and feature fusion was applied to obtain the final set of feature vectors. Feature fusion combines the deep features extracted by various networks, resulting in a more comprehensive feature set, thereby improving recognition accuracy. The multiple integrated acoustic features, such as mel frequency cepstral coefficients (MFCC), chroma features (Chroma) and Tonnetz features, were encoded by a transformer encoder. The transformer encoder effectively extracted the positional relationships between bird sound features, resulting in enhanced recognition accuracy. The experimental results demonstrated the exceptional performance of our method with an accuracy of 97.99%, a recall of 96.14%, an F1 score of 96.88% and a precision of 97.97% on the Birdsdata dataset. Furthermore, our method achieved an accuracy of 93.18%, a recall of 92.43%, an F1 score of 93.14% and a precision of 93.25% on the Cornell Bird Challenge 2020 (CBC) dataset.


Assuntos
Ecossistema , Reconhecimento Psicológico , Animais , Som , Acústica , Aves
16.
Biomolecules ; 13(9)2023 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-37759759

RESUMO

The self-assembly of lipid molecules in aqueous solution under shear flows was investigated using the dissipative particle dynamics simulation method. Three cases were considered: zero shear flow, weak shear flow and strong shear flow. Various self-assembled structures, such as double layers, perforated double layers, hierarchical discs, micelles, and vesicles, were observed. The self-assembly behavior was investigated in equilibrium by constructing phase diagrams based on chain lengths. Results showed the remarkable influence of chain length, shear flow and solution concentration on the self-assembly process. Furthermore, the self-assembly behavior of lipid molecules was analyzed using the system energy, particle number and shape factor during the dynamic processes, where the self-assembly pathways were observed and analyzed for the typical structures. The results enhance our understanding of biomacromolecule self-assembly in a solution and hold the potential for applications in biomedicine.


Assuntos
Lipídeos , Micelas
17.
Molecules ; 28(15)2023 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-37570760

RESUMO

The interaction between macromolecular chains and phospholipid membranes in aqueous solution was investigated using dissipative particle dynamics simulations. Two cases were considered, one in which the macromolecular chains were pulled along parallel to the membrane surfaces and another in which they were pulled vertical to the membrane surfaces. Several parameters, including the radius of gyration, shape factor, particle number, and order parameter, were used to investigate the interaction mechanisms during the dynamics processes by adjusting the pulling force strength of the chains. In both cases, the results showed that the macromolecular chains undergo conformational transitions from a coiled to a rod-like structure. Furthermore, the simulations revealed that the membranes can be damaged and repaired during the dynamic processes. The role of the pulling forces and the adsorption interactions between the chains and membranes differed in the parallel and perpendicular pulling cases. These findings contribute to our understanding of the interaction mechanisms between macromolecules and membranes, and they may have potential applications in biology and medicine.


Assuntos
Fenômenos Mecânicos , Fosfolipídeos , Substâncias Macromoleculares , Membranas , Conformação Molecular
18.
Eur J Immunol ; 53(12): e2250182, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37615189

RESUMO

Hypoxia-inducible factor 1 alpha (HIF1α), under hypoxic conditions, is known to play an oxygen sensor stabilizing role by exerting context- and cell-dependent stimulatory and inhibitory functions in immune cells. Nevertheless, how HIF1α regulates T cell differentiation and functions in tumor settings has not been elucidated. Herein, we demonstrated that T-cell-specific deletion of HIF1α improves the inflammatory potential and memory phenotype of CD8+ T cells. We validated that T cell-specific HIF1α ablation reduced the B16 melanomas development with the indication of ameliorated antitumor immune response with enhanced IFN-γ+ CD8+ T cells despite the increase in the Foxp3+ regulatory T-cell population. This was further verified by treating tumor-bearing mice with a HIF1α inhibitor. Results indicated that HIF1α inhibitor also recapitulates HIF1α ablation effects by declining tumor growth and enhancing the memory and inflammatory potential of CD8+ T cells. Furthermore, a combination of Treg inhibitor with HIF1α inhibitor can substantially reduce tumor size. Collectively, these findings highlight the notable roles of HIF1α in distinct CD8+ T-cell subsets. This study suggests the significant implications for enhancing the potential of T cell-based antitumor immunity by combining HIF1α and Tregs inhibitors.


Assuntos
Melanoma Experimental , Linfócitos T Reguladores , Camundongos , Animais , Linfócitos T CD8-Positivos , Subpopulações de Linfócitos T , Melanoma Experimental/terapia , Imunidade
19.
Cell Death Dis ; 14(7): 430, 2023 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-37452072

RESUMO

Tumor progression and evolution are frequently associated with chromosomal instability (CIN). Tumor cells often express high levels of the mitotic checkpoint protein MAD2, leading to mitotic arrest and cell death. However, some tumor cells are capable of exiting mitosis and consequently increasing CIN. How cells escape the mitotic arrest induced by MAD2 and proliferate with CIN is not well understood. Here, we explored loss-of-function screens and drug sensitivity tests associated with MAD2 levels in aneuploid cells and identified that aneuploid cells with high MAD2 levels are more sensitive to FOXM1 depletion. Inhibition of FOXM1 promotes MAD2-mediated mitotic arrest and exacerbates CIN. Conversely, elevating FOXM1 expression in MAD2-overexpressing human cell lines reverts prolonged mitosis and rescues mitotic errors, cell death and proliferative disadvantages. Mechanistically, we found that FOXM1 facilitates mitotic exit by inhibiting the spindle assembly checkpoint (SAC) and the expression of Cyclin B. Notably, we observed that FOXM1 is upregulated upon aneuploid induction in cells with dysfunctional SAC and error-prone mitosis, and these cells are sensitive to FOXM1 knockdown, indicating a novel vulnerability of aneuploid cells.


Assuntos
Proteínas de Ciclo Celular , Mitose , Humanos , Proteínas de Ciclo Celular/metabolismo , Proteínas Mad2/genética , Proteínas Mad2/metabolismo , Mitose/genética , Linhagem Celular Tumoral , Fuso Acromático/metabolismo , Aneuploidia , Proteína Forkhead Box M1/genética , Proteína Forkhead Box M1/metabolismo
20.
Commun Biol ; 6(1): 721, 2023 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-37452099

RESUMO

The helper CD4+ T cell-type 17 (Th17) cells and regulatory CD4+ T cells (Tregs) are balanced through numerous molecular regulators, particularly metabolic factors, and their alteration causes immune dysregulation. Herein, we report that peroxisome proliferator of activated receptor-alpha (Pparα), a lipid metabolism regulator, suppresses Th17 differentiation. We demonstrated that Pparα ablation improves Th17 and pro-Th17 factor HIF-1α by enhancing the expression and nuclear localization of NFκB-activator IκB kinase-alpha (IKKα). Unexpectedly, we found that IKKα directly interacts with RORγt and enhances the expression of Il17a gene. Meanwhile, IKKα also interacts with Foxp3, leading to the post-translational regulation of Foxp3 by elevating its proteasomal degradation, and influencing Th17 development. Pparα deficiency leads to enhanced Th17 development in vivo and is associated with enhanced pathology in a murine experimental autoimmune encephalomyelitis (EAE) model. Overall, our data indicate that Pparα may serve as a potential therapeutic target for autoimmune and inflammatory diseases.


Assuntos
Encefalomielite Autoimune Experimental , Quinase I-kappa B , Camundongos , Animais , Quinase I-kappa B/genética , PPAR alfa/genética , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/genética , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo , Células Th17 , Diferenciação Celular , Fatores de Transcrição Forkhead/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...