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1.
Environ Sci Technol ; 2024 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-39259849

RESUMO

Drought induces dry hazards, including wildfire, and increased air pollution from wildfire may be a mechanism by which drought increases health risks. We examined whether the drought-wildfire pathway increases the risk of childhood stunting. We analyzed all geocoded children under five across 44 low- and middle-income countries (LMICs). We first conducted mixed-effect regressions to examine the three pairwise associations between standardized precipitation evapotranspiration index (SPEI), fire-sourced PM2.5, and childhood stunting. We then employed a causal mediation analysis to determine whether compounding drought-wildfire (cascading or co-occurring) events significantly impact the drought-stunting pathway. We found that each 1-unit decrease in SPEI exposure was associated with a 2.16% [95% confidence interval (CI): 0.79, 3.49%] increase in stunting risk and 0.57 (95% CI 0.55, 0.59%) µg/m3 increase in fire-sourced PM2.5. Additionally, each 1 µg/m3 increase in 24 month average fire-sourced PM2.5 was associated with an increased risk of 2.46% (95% CI: 2.16, 2.76%) in stunting. Drought-mediated fires accounted for 26.7% (95% CI: 14.5, 36.6%) of the linkage between SPEI and stunting. Our study revealed fire-sourced PM2.5 is a mediator in the drought-stunting pathway in LMICs. To protect child health under increasing drought conditions, personal interventions against wildfire should be considered to enhance climate resilience.

4.
Environ Int ; 191: 109002, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39265323

RESUMO

Beijing, with the highest number of motor vehicles in China, significantly contributes to O3 pollution through substantial NOx and VOC emissions in the on-road transportation sector. Understanding the unique impact of emissions from different vehicle types on O3 levels is crucial for developing targeted strategies for O3 pollution. This study applied the Community Multiscale Air Quality Modeling System (CMAQ) to comprehensively investigate the impacts of emissions from different vehicle types on O3 levels in various regions of Beijing and to provide valuable insights into source contributions and formation processes. The results revealed that various vehicle types exhibited different spatial-temporal emission patterns, with medium-heavy duty trucks (HDT) and mini-light passenger vehicles (LDPV) identified as the primary contributors to NOx (36.1 %) and VOC (57.6 %) emissions. Using the Integrated Source Apportionment Method (ISAM) coupled in CMAQ, we found the total vehicle emissions contributed to over 20 % of daily maximum 8-h average O3 (MDA8 O3) concentration, ranked as the second largest contributor after regional transport. Contributions to O3 formation from LDPV and medium-large passenger vehicles (MDPV) were 2.6-4.0 and 4.2-6.8 ppb and mainly concentrated in urban areas, while the contributions from mini-light duty trucks (LDT) and HDT were 3.5-4.8 and 3.7-6.2 ppb and mainly concentrated in suburban areas. Through scenario analysis that removed emissions from specific types of vehicles, we found removing LDPV emissions led to decreases in daytime O3 concentration by 0.3-3.8 ppb. In contrast, removing MDPV emissions led to notable O3 increases by 4.0-11.8 ppb at rush hours. Removing LDT and HDT emissions resulted in 0.6-8.0 ppb increases in nocturnal O3 concentrations while 0.8-2.0 ppb decreases during the afternoon. This research highlights the necessity of tailoring control strategies for different vehicle types to effectively reduce O3 levels in Beijing and provides useful information for decision-makers to formulate effective measures of vehicle management in the future.


Assuntos
Poluentes Atmosféricos , Monitoramento Ambiental , Ozônio , Emissões de Veículos , Emissões de Veículos/análise , Ozônio/análise , Poluentes Atmosféricos/análise , Pequim , Poluição do Ar/estatística & dados numéricos , Veículos Automotores
5.
ACS Nano ; 2024 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-39238258

RESUMO

Rescuing or compensating mitochondrial function represents a promising therapeutic avenue for radiation-induced chronic wounds. Adult stem cell efficacies are primarily dependent on the paracrine secretion of mitochondria-containing extracellular vesicles (EVs). However, effective therapeutic strategies addressing the quantity of mitochondria and mitochondria-delivery system are lacking. Thus, in this study, we aimed to design an effective hydrogel microneedle patch (MNP) loaded with stem cell-derived mitochondria-rich EVs to gradually release and deliver mitochondria into the wound tissues and boost wound healing. We, first, used metformin to enhance mitochondrial biogenesis and thereby increasing the secretion of mitochondria-containing EVs (termed "Met-EVs") in adipose-derived stem cells. To verify the therapeutic effects of Met-EVs, we established an in vitro and an in vivo model of X-ray-induced mitochondrial dysfunction. The Met-EVs ameliorated the mitochondrial dysfunction by rescuing mitochondrial membrane potential, increasing adenosine 5'-triphosphate levels, and decreasing reactive oxygen species production by transferring active mitochondria. To sustain the release of EVs into damaged tissues, we constructed a Met-EVs@Decellularized Adipose Matrix (DAM)/Hyaluronic Acid Methacrylic Acid (HAMA)-MNP. Met-EVs@DAM/HAMA-MNP can load and gradually release Met-EVs and their contained mitochondria into wound tissues to alleviate mitochondrial dysfunction. Moreover, we found Met-EVs@DAM/HAMA-MNP can markedly promote macrophage polarization toward the M2 subtype with anti-inflammatory and regenerative functions, which can, in turn, enhance the healing process in mice with skin wounds combined radiation injuries. Collectively, we successfully fabricated a delivery system for EVs, Met-EVs@DAM/HAMA-MNP, to effectively deliver stem cell-derived mitochondria-rich EVs. The effectiveness of this system has been demonstrated, holding great potential for chronic wound treatments in clinic.

6.
Environ Sci Ecotechnol ; 20: 100447, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39105071

RESUMO

•Health benefits from China's pollution-carbon co-control actions have already been seen.•Co-control of air pollution and greenhouse gases can avoid premature deaths.•More comparative evaluations of the health impacts of specific policies are needed.

7.
Mar Biotechnol (NY) ; 2024 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-39207652

RESUMO

In this study, we examined the effect of Laminaria japonica polysaccharide (fucoidan) on the regulation of lipid metabolism. A rat model of diabetes mellitus (DM) was established by a high-sugar and high-fat diet combined with streptozotocin. Changes in the rats' body weight and blood glucose level during the experiment were recorded. Before the end of the experiment, an automatic biochemical analyzer was used to detect the fasting blood glucose (FBG), lipid content in serum, and insulin content, and calculate the insulin resistance index. Oil red O staining was used to detect lipid deposition in the liver. H&E staining, Masson staining, and PASM staining were used to observe the pathological structural changes in the liver. 16 s RNA sequencing and targeted metabolomics were used to detect intestinal microbiota and bile acid content. The results showed that fucoidan was able to inhibit weight loss in the DM rats and reduce the content of triglycerides (TG), cholesterol (TC), and low-density lipoprotein (LDL-C) in serum. Oil red O staining showed a decrease in liver fat accumulation after fucoidan treatment. 16 s RNA sequencing demonstrated that fucoidan increased the abundance of Bacteroidia, Campylobacteria, Clostridia, Gammaproteobacteria, Negativicutes, and Verrucomicrobi. Fucoidan also increased the secretion of secondary bile acids (Nor-DCA, TLCA, ß-UDCA) and alleviated lipid metabolism disorders. The expression of α-SMA was inhibited by fucoidan, whereas the expression of FXR and TGR5 was promoted. Fucoidan shows good activity in regulating lipid metabolism by regulating the expression of FXR and TGR5 and acting on the intestinal flora-bile acid axis.

8.
Biomed Mater ; 19(6)2024 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-39208838

RESUMO

The invasion and metastasis of tumors pose significant challenges in the treatment of ovarian cancer (OC), making it difficult to cure. One potential treatment approach that has gained attention is the use of matrix metalloproteinase reactive controlled release micelle preparations. In this study, we developed a novel PEG5000-PVGLIG-hyaluronic acid docetaxel/bakuchiol (PP-HA-DTX/BAK) micelles formulation with desirable characteristics such as particle size, narrow polydispersity index, and a ZETA potential of approximately -5 mV. The surface modification with HA facilitates tumor penetration into the tumor interior, while the incorporation of DSPE-PEG2000-PVGLIG-PEG5000helps conceal DSPE-PEG2000-HA, reducing off-target effects and prolonging drug circulation timein vivo. Bothin vitroandin vivoexperiments demonstrated that these micelles effectively inhibit proliferation, invasion, and metastasis of OC cells while promoting apoptosis. Therefore, our findings suggest that PP-HA-DTX/BAK micelles represent a safe and effective therapeutic strategy for treating OC.


Assuntos
Docetaxel , Micelas , Invasividade Neoplásica , Neoplasias Ovarianas , Fenóis , Polietilenoglicóis , Docetaxel/química , Docetaxel/farmacologia , Docetaxel/administração & dosagem , Feminino , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/patologia , Humanos , Animais , Linhagem Celular Tumoral , Polietilenoglicóis/química , Fenóis/química , Fenóis/farmacologia , Camundongos , Apoptose/efeitos dos fármacos , Ácido Hialurônico/química , Taxoides/química , Taxoides/farmacologia , Taxoides/administração & dosagem , Proliferação de Células/efeitos dos fármacos , Antineoplásicos/química , Antineoplásicos/farmacologia , Antineoplásicos/administração & dosagem , Camundongos Nus , Tamanho da Partícula , Camundongos Endogâmicos BALB C , Metástase Neoplásica , Portadores de Fármacos/química
9.
Environ Sci Technol ; 58(36): 15971-15983, 2024 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-39190587

RESUMO

Whether maternal exposure to dust-sourced particulate matter (hereafter, dust PM2.5) is associated with stillbirth remains unknown. We adopted a sibling-matched case-control design to analyze 9332 stillbirths and 17,421 live births. We associated the risk of stillbirth simultaneously with dust and nondust components of PM2.5 and developed a nonlinear joint exposure-response function. Next, we estimated the burden of stillbirths attributable to the PM2.5 mixture. The concentration index was used to evaluate whether the burden of PM2.5-related stillbirths was disproportionally distributed among pregnancies exposed to dust-rich particles. Each 10 µg/m3 increase in dust PM2.5 was associated with a 14.5% (95% confidence interval: 5.5, 24.2%) increase in the odds of stillbirth. Based on the risk assessment across 137 countries, sand dust contributed to about 15% of the PM2.5 exposure but to about 45% of the PM2.5-related stillbirths during 2003-2019. In 2015, 30% of the PM2.5-related stillbirths were concentrated within 15% of pregnancies exposed to the dust-richest PM2.5. The index increased in subregions, such as South Asia, suggesting the growth of health inequality due to exposure to dust PM2.5. Based on our findings, land management, such as halting desertification, will help prevent stillbirths and reduce global maternal health inequality.


Assuntos
Poeira , Material Particulado , Natimorto , Natimorto/epidemiologia , Humanos , Feminino , Gravidez , Poluentes Atmosféricos , Areia , Exposição Materna , Poluição do Ar , Países em Desenvolvimento , Estudos de Casos e Controles
10.
Inorg Chem ; 63(34): 15906-15914, 2024 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-39119932

RESUMO

The host effect of the supramolecular [Ga4L6]12- tetrahedral metallocage on Prins cyclization reaction of the substrate by encapsulated citronellal has been investigated by means of molecular dynamics and quantum mechanics. The encapsulation process of the substrate into the [Ga4L6]12- cavity was simulated via attach-pull-release (APR) methods. Thermodynamic calculations and classical molecular dynamics simulations assessed the substrate's microenvironment inside the cavity, guiding DFT-level modeling of the reaction. DFT calculations show diol product predominance in acidic solution but high enol selectivity inside [Ga4L6]12-, consistent with experimental findings. [Ga4L6]12- alters the selectivity of the Prins cyclization reaction by inhibiting diol formation. The activation strain model-based decomposition analysis (ASM-DA) of the barrier difference among distortion and interaction terms indicates that the more positive interaction between a host and guest in the diol transition state than enol determines the product selectivity, particularly the fewer C-H···O and O-H···O hydrogen-bonding interactions. These theoretical insights could contribute to a deeper understanding of the nature of supramolecular catalysis and to further develop new supramolecular catalysts.

11.
Oncol Lett ; 28(3): 435, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39049982

RESUMO

[This retracts the article DOI: 10.3892/ol.2020.12030.].

12.
Int J Biol Macromol ; 276(Pt 1): 133489, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38964679

RESUMO

Indole-based bis-acylhydrazone compounds can inhibit the activity of α-glucosidase and control the concentration of blood glucose. In this paper, the characteristics of three indole-based bis-acylhydrazone compounds with different inhibitory activities of α-glucosidase as well as the interaction with α-glucosidase were studied by experiments and computational simulation techniques. Enzyme kinetic and spectral experiments showed that the indole-based bis-acylhydrazone compounds were able to inhibit enzyme activity through mixed inhibition dominated by competitive inhibition, and during the binding reaction, indole-based bis-acylhydrazone compounds can quench the intrinsic fluorescence of α-glucosidase through static quenching and an aggregation of the indole-based bis-acylhydrazone with α-glucosidase produces a stable complex with a molar ratio of 1:1, and the combination of indole-based bis-acylhydrazone compounds could lead to slight change in the conformation of α-glucosidase. The theoretical simulation demonstrated that the stability of the complex systems was positively correlated with the inhibitory activity of indole-based bis-acylhydrazone compounds, and the indole-based bis-acylhydrazone compounds occupied the active site in the multi-ligand system, resulting in a significant decrease in the binding ability of starch to active amino acids. These results suggested that indole-based bis-acylhydrazone compound was expected to be a new type of α-glucosidase inhibitor.


Assuntos
Inibidores de Glicosídeo Hidrolases , Hidrazonas , Indóis , alfa-Glucosidases , alfa-Glucosidases/metabolismo , alfa-Glucosidases/química , Inibidores de Glicosídeo Hidrolases/química , Inibidores de Glicosídeo Hidrolases/farmacologia , Indóis/química , Indóis/farmacologia , Hidrazonas/química , Hidrazonas/farmacologia , Cinética , Simulação de Acoplamento Molecular , Análise Espectral
14.
Environ Sci Technol ; 58(29): 12954-12965, 2024 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-38995993

RESUMO

Addressing environmental factors has recently been recommended to curb the growing trend of anemia in low- and middle-income countries (LMICs). Fine particulate matter (PM2.5) generated by dust storms were concentrated in place with a high prevalence of anemia. In a multicounty, multicenter study, we analyzed the association between anemia and life-course averaged exposure to dust PM2.5 among children aged <5 years based on 0.65 million records from 47 LMICs. In the fully adjusted mixed effects model, each 10 µg/m3 increase in life-course averaged exposure to dust PM2.5 was associated with a 9.3% increase in the odds of anemia. The estimated exposure-response association was nonlinear, with a greater effect of dust PM2.5 exposure seen at low concentrations. Applying this association, we found that, in 2017, among all children aged <5 years in the 125 LMICs, dust PM2.5 contributed to 37.98 million cases of anemia. Results indicated that dust PM2.5 contributed a heavier burden than all of the well-identified risk factors did, except for iron deficiency. Our study revealed that long-term exposure to dust PM2.5 can be a novel risk factor, pronouncedly contributed to the burden of child anemia in LMICs, affected by land degradations or arid climate.


Assuntos
Anemia , Poeira , Material Particulado , Humanos , Anemia/epidemiologia , Pré-Escolar , Feminino , Masculino , Países em Desenvolvimento , Exposição Ambiental , Lactente , Fatores de Risco
15.
World J Clin Cases ; 12(21): 4691-4702, 2024 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-39070844

RESUMO

BACKGROUND: Numerous studies have assessed the efficacy and safety of fecal microbiota transplantation (FMT) as a therapy for ulcerative colitis (UC). However, the treatment processes and outcomes of these studies vary. AIM: To evaluate the efficacy and safety of FMT for treating UC by conducting a systematic meta-analysis. METHODS: The inclusion criteria involved reports of adult patients with UC treated with FMT, while studies that did not report clinical outcomes or that included patients with infection were excluded. Clinical remission (CR) and endoscopic remission (ER) were the primary and secondary outcomes, respectively. RESULTS: We included nine studies retrieved from five electronic databases. The FMT group had better CR than the control group [relative risk (RR) = 1.53; 95% confidence interval (CI): 1.19-1.94; P < 0.0008]. ER was statistically significantly different between the two groups (RR = 2.80; 95%CI: 1.93-4.05; P < 0.00001). Adverse events did not differ significantly between the two groups. CONCLUSION: FMT demonstrates favorable performance and safety; however, well-designed randomized clinical trials are still needed before the widespread use of FMT can be recommended. Furthermore, standardizing the FMT process is urgently needed for improved safety and efficacy.

16.
J Ethnopharmacol ; 333: 118487, 2024 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-38925322

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Nonalcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease worldwide. Nonalcoholic steatohepatitis (NASH) is a crucial component of this disease spectrum. The Yanxiao Di'naer formula (YXDNE) is an Uyghur medical extract that has been used in folk medicine to treat hepatitis for a long time. However, the role and mechanism of action of YXDNE in NASH treatment remains unclear. OBJECTIVE: The objective of this study was to assess the effectiveness of YXDNE in treating NASH induced by injections of carbon tetrachloride combined with a high-fat high-cholesterol diet (HFHCD), and to clarify the underlying mechanisms. METHODS: The compounds in the YXDNE extract were analysed for classification and proportions using ultra-performance liquid chromatography-mass spectrometry. The efficacy of YXDNE in treating abnormal lipid metabolism was evaluated in L02 cells in vitro. In addition, a C57BL/6 mouse model of NASH was established to evaluate the therapeutic efficacy of YXDNE in vivo. Metabolomics and RNA sequencing were used to analyse the therapeutic effects of YXDNE on the liver. The corresponding signalling pathways were found to target AMPKα1, PPARα, and NF-κB. The efficacy of YXDNE was validated using inhibitors or silencing RNA (siRNA) against AMPKα1 and PPARα. RESULTS: This study confirmed that YXDNE treatment ameliorated NASH in a murine model of this disease. Metabolomics analysis suggested that YXDNE efficacy was associated with fatty acid catabolism and AMPK signalling pathways. RNA sequencing results showed that YXDNE efficacy in treating NASH was highly correlated with the AMPK, PPARα and NF-κB pathways. Both in vitro and in vivo experimental data demonstrated that YXDNE affected the expression of p-AMPKα1, PPARα, p-NF-κB, IκB, and p-IκB. The efficacy of YXDNE in treating NASH in vitro was cancelled when AMPK was inhibited with Compound C or PPARα was modulated via siRNA. CONCLUSIONS: YXDNE may have a therapeutic effect on abnormal lipid metabolism in L02 cells and in a murine model of NASH by affecting the AMPKα1/PPARα/NF-κB signalling pathway. Therefore, YXDNE has the potential for clinical application in the prevention and treatment of NASH.


Assuntos
Medicamentos de Ervas Chinesas , Metabolômica , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica , Animais , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/metabolismo , Masculino , Camundongos , Medicamentos de Ervas Chinesas/farmacologia , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/uso terapêutico , Humanos , Metabolismo dos Lipídeos/efeitos dos fármacos , PPAR alfa/metabolismo , PPAR alfa/genética , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Análise de Sequência de RNA , Linhagem Celular , Fígado/efeitos dos fármacos , Fígado/metabolismo , Proteínas Quinases Ativadas por AMP/metabolismo
17.
Org Lett ; 26(27): 5670-5675, 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-38923904

RESUMO

Axially chiral carboxylic acids are important motifs in chiral catalysts and ligands. We herein reported the synthesis of axially chiral carboxylic acids via Pd(II)-catalyzed atroposelective C-H olefination using carboxylic acid as the native directing group. A broad range of axial chiral biaryl-2-carboxylic acids were synthesized in good yields with high enantioselectivities (up to 84% yield with 99% ee). Gram-scale reaction and further transformation reactions also provide a platform for synthetic applications of this method.

18.
Int J Nanomedicine ; 19: 5193-5211, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38859958

RESUMO

Purpose: Ovarian cancer is a fatal gynecologic malignancy with a high rate of abdominal metastasis. Chemotherapy still has a poor clinical prognosis for ovarian cancer patients, with cell proliferation and angiogenesis leading to invasion, migration, and recurrence. To overcome these obstacles, we constructed a novel HA-modified paclitaxel and diosgenin liposome (PEG-TK-HA-PDLPs) using two novel functional materials, DSPE-PEG2000-HA and DSPE-PEG2000-TK-PEG5000, to specifically deliver the drugs to the tumor site in order to reduce OC cell proliferation and anti-angiogenic generation, thereby inhibiting invasion and migration. Methods and Results: PEG-TK-HA-PDLPs were prepared by film dispersion, with ideal physicochemical properties and exhibits active targeting for enhanced cellular uptake. The ZIP synergy score for PTX and Dios was calculated using the online SynergyFinder software to be 3.15, indicating synergy. In vitro results showed that PEG-TK-HA-PDLPs were highly cytotoxic to ID8 cells, induced ID8 cell apoptosis, and inhibited ID8 cell migration and invasion. In vivo studies showed that PEG-TK-HA-PDLPs could prolong the circulation time in the blood, accumulate significantly in the tumor site, and effectively fight against angiogenesis with significant anti-tumor effects. Conclusion: The production of PEG-TK-HA-PDLPs is an effective strategy for the treatment of OC.


Assuntos
Apoptose , Diosgenina , Ácido Hialurônico , Lipossomos , Neoplasias Ovarianas , Paclitaxel , Polietilenoglicóis , Espécies Reativas de Oxigênio , Feminino , Lipossomos/química , Lipossomos/farmacocinética , Paclitaxel/farmacologia , Paclitaxel/química , Paclitaxel/farmacocinética , Paclitaxel/administração & dosagem , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/patologia , Diosgenina/farmacologia , Diosgenina/química , Diosgenina/farmacocinética , Diosgenina/administração & dosagem , Ácido Hialurônico/química , Ácido Hialurônico/farmacologia , Linhagem Celular Tumoral , Polietilenoglicóis/química , Animais , Espécies Reativas de Oxigênio/metabolismo , Humanos , Apoptose/efeitos dos fármacos , Sinergismo Farmacológico , Proliferação de Células/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Fosfatidiletanolaminas
19.
ACS Appl Mater Interfaces ; 16(24): 31586-31596, 2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38837344

RESUMO

We leveraged the potential of high χ-low N block copolymer (BCP), namely, poly[2-(perfluorobutyl) ethyl methacrylate]-block-poly(2-vinylpyridine) (P2PFBEMA-b-P2VP), and demonstrated its utility in next-generation nanomanufacturing. By combining molecular dynamics simulations with experiments, the χ value was calculated to be as high as 0.4 (at 150 °C), surpassing similar structures. Highly ordered features suitable for application were observed, ranging in periods from 19.0 nm down to 12.1 nm, with feature sizes as small as 6 nm. Transmission electron microscopy images of the BCP solutions indicated that preformed micelles in the solution facilitated the self-assembly process of the thin film. In addition, the vertical or parallel orientation of the cylindrical structure was determined by manipulating the solvent, substrate, and annealing conditions. Finally, guided by a wide topographical template, nearly defect-free directed self-assembly (DSA) lines with a resolution of 8 nm were achieved, highlighting its potential practical application in DSA lithography technology.

20.
J Virol ; 98(7): e0040524, 2024 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-38874362

RESUMO

Human T-cell leukemia virus type 1 (HTLV-I) is the etiological agent of adult T-cell leukemia (ATL). Mutational analysis has demonstrated that the tumor suppressor, F-box and WD repeat domain containing 7 (FBXW7/FBW7/CDC4), is mutated in primary ATL patients. However, even in the absence of genetic mutations, FBXW7 substrates are stabilized in ATL cells, suggesting additional mechanisms can prevent FBXW7 functions. Here, we report that the viral oncoprotein Tax represses FBXW7 activity, resulting in the stabilization of activated Notch intracellular domain, c-MYC, Cyclin E, and myeloid cell leukemia sequence 1 (BCL2-related) (Mcl-1). Mechanistically, we demonstrate that Tax directly binds to FBXW7 in the nucleus, effectively outcompeting other targets for binding to FBXW7, resulting in decreased ubiquitination and degradation of FBXW7 substrates. In support of the nuclear role of Tax, a non-degradable form of the nuclear factor kappa B subunit 2 (NFκB2/p100) was found to delocalize Tax to the cytoplasm, thereby preventing Tax interactions with FBXW7 and Tax-mediated inhibition of FBXW7. Finally, we characterize a Tax mutant that is unable to interact with FBXW7, unable to block FBXW7 tumor suppressor functions, and unable to effectively transform fibroblasts. These results demonstrate that HTLV-I Tax can inhibit FBXW7 functions without genetic mutations to promote an oncogenic state. These results suggest that Tax-mediated inhibition of FBXW7 is likely critical during the early stages of the cellular transformation process. IMPORTANCE: F-box and WD repeat domain containing 7 (FBXW7), a critical tumor suppressor of human cancers, is frequently mutated or epigenetically suppressed. Loss of FBXW7 functions is associated with stabilization and increased expression of oncogenic factors such as Cyclin E, c-Myc, Mcl-1, mTOR, Jun, and Notch. In this study, we demonstrate that the human retrovirus human T-cell leukemia virus type 1 oncoprotein Tax directly interacts with FBXW7, effectively outcompeting other targets for binding to FBXW7, resulting in decreased ubiquitination and degradation of FBXW7 cellular substrates. We further demonstrate that a Tax mutant unable to interact with and inactivate FBXW7 loses its ability to transform primary fibroblasts. Collectively, our results describe a novel mechanism used by a human tumor virus to promote cellular transformation.


Assuntos
Proteínas de Ciclo Celular , Proteínas F-Box , Proteína 7 com Repetições F-Box-WD , Produtos do Gene tax , Vírus Linfotrópico T Tipo 1 Humano , Ubiquitina-Proteína Ligases , Proteína 7 com Repetições F-Box-WD/metabolismo , Proteína 7 com Repetições F-Box-WD/genética , Humanos , Vírus Linfotrópico T Tipo 1 Humano/genética , Vírus Linfotrópico T Tipo 1 Humano/metabolismo , Produtos do Gene tax/metabolismo , Produtos do Gene tax/genética , Proteínas F-Box/metabolismo , Proteínas F-Box/genética , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/genética , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina-Proteína Ligases/genética , Ligação Proteica
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