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1.
J Nanobiotechnology ; 21(1): 265, 2023 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-37563614

RESUMO

BACKGROUND: Emerging ferroptosis-driven therapies based on nanotechnology function either by increasing intracellular iron level or suppressing glutathione peroxidase 4 (GPX4) activity. Nevertheless, the therapeutic strategy of simultaneous iron delivery and GPX4 inhibition remains challenging and has significant scope for improvement. Moreover, current nanomedicine studies mainly use disulfide-thiol exchange to deplete glutathione (GSH) for GPX4 inactivation, which is unsatisfactory because of the compensatory effect of continuous GSH synthesis. METHODS: In this study, we design a two-in-one ferroptosis-inducing nanoplatform using iron-based metal-organic framework (MOF) that combines iron supply and GPX4 deactivation by loading the small molecule buthionine sulfoxide amine (BSO) to block de novo GSH biosynthesis, which can achieve sustainable GSH elimination and dual ferroptosis amplification. A coated lipid bilayer (L) can increase the stability of the nanoparticles and a modified tumor-homing peptide comprising arginine-glycine-aspartic acid (RGD/R) can achieve tumor-specific therapies. Moreover, as a decrease in GSH can alleviate resistance of cancer cells to chemotherapy drugs, oxaliplatin (OXA) was also loaded to obtain BSO&OXA@MOF-LR for enhanced cancer chemo-ferrotherapy in vivo. RESULTS: BSO&OXA@MOF-LR shows a robust tumor suppression effect and significantly improved the survival rate in 4T1 tumor xenograft mice, indicating a combined effect of dual amplified ferroptosis and GSH elimination sensitized apoptosis. CONCLUSION: BSO&OXA@MOF-LR is proven to be an efficient ferroptosis/apoptosis hybrid anti-cancer agent. This study is of great significance for the clinical development of novel drugs based on ferroptosis and apoptosis for enhanced cancer chemo-ferrotherapy.


Assuntos
Estruturas Metalorgânicas , Neoplasias , Humanos , Camundongos , Animais , Butionina Sulfoximina/farmacologia , Oxaliplatina/farmacologia , Glutationa
2.
Nano Lett ; 22(20): 8250-8257, 2022 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-36218311

RESUMO

Photodynamic therapy (PDT) holds great promise in tumor therapy due to high safety, efficacy, and specificity. However, the risk of increased metastasis in hypoxic tumors after oxygen-dependent PDT remains underestimated. Here, we propose a post-PDT oxygen supply (POS) strategy to reduce the risk of metastasis. Herein, biocompatible and tumor-targeting Ce6@BSA and PFC@BSA nanoparticles were constructed for PDT and POS in a 4T1-orthotropic breast cancer model. PDT with Ce6@BSA nanoparticles increased tumor metastasis via the HIF-1α signaling pathway, whereas POS significantly reduced the PDT-triggered metastasis by blocking this pathway. Furthermore, POS, with clinical protocols and an FDA-approved photosensitizer (hypericin), and oxygen inhalation reduced PDT-induced metastasis. Our study findings indicate that PDT may increase the risk of tumor metastasis and that POS may solve this problem. POS can reduce the metastasis resulting not only from PDT but also from other oxygen-dependent treatments such as radiotherapy and sonodynamic therapy.


Assuntos
Nanopartículas , Fotoquimioterapia , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Linhagem Celular Tumoral , Nanopartículas/uso terapêutico , Oxigênio
3.
J Diabetes ; 16(2): e13479, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37751894

RESUMO

BACKGROUND: The association between adrenal size and metabolic profiles in patients with diabetes mellitus (DM) is unclear. This study was conducted to determine whether the adrenal thickness measured by computed tomography (CT) is correlated with the metabolic profiles of patients with DM. METHODS: This was a cross-sectional study including 588 Chinese hospitalized patients with DM without comorbidities or medications known to affect adrenal morphology or hormone secretion. Adrenal limb thickness was measured on unenhanced chest CT. Participants were stratified into tertiles according to their total adrenal limb thickness. Linear and logistic regression models were used to estimate the correlations. RESULTS: After adjustment for sex and age, the adrenal thickness was positively associated with body mass index (BMI), waist circumference (WC), urinary albumin/creatinine ratio, and 24-h urinary free cortisol (UFC) and negatively correlated with high-density lipoprotein cholesterol. The sequential equation model (SEM) suggested UFC partially mediated the effect of adrenal limb thickness on WC by 12%. Adrenal thickness, but not UFC, was associated with a higher risk of existing hypertension (odds ratio [OR] = 3.78, 95% confidence interval [CI] 1.58, 9.02) and hyperlipidemia (OR = 2.76, 95% CI 1.03, 7.38), independent of age, gender, BMI, and WC. CONCLUSIONS: The adrenal thickness is independently associated with BMI, WC, cortisol levels, urinary albumin/creatinine ratio, hypertension, and dyslipidemia but not glycemic parameters in patients with diabetes. Our study encourages further studies to investigate the role of adrenal physiology in patients with diabetes.


Assuntos
Diabetes Mellitus , Hipertensão , Humanos , Fatores de Risco , Estudos Transversais , Hidrocortisona , Creatinina , Circunferência da Cintura/fisiologia , Albuminas , Índice de Massa Corporal
4.
Nat Commun ; 14(1): 4776, 2023 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-37553334

RESUMO

Chitin is one of the most abundant natural biopolymers and serves as a critical structural component of extracellular matrices, including fungal cell walls and insect exoskeletons. As a linear polymer of ß-(1,4)-linked N-acetylglucosamine, chitin is synthesized by chitin synthases, which are recognized as targets for antifungal and anti-insect drugs. In this study, we determine seven different cryo-electron microscopy structures of a Saccharomyces cerevisiae chitin synthase in the absence and presence of glycosyl donor, acceptor, product, or peptidyl nucleoside inhibitors. Combined with functional analyses, these structures show how the donor and acceptor substrates bind in the active site, how substrate hydrolysis drives self-priming, how a chitin-conducting transmembrane channel opens, and how peptidyl nucleoside inhibitors inhibit chitin synthase. Our work provides a structural basis for understanding the function and inhibition of chitin synthase.


Assuntos
Quitina Sintase , Quitina , Quitina Sintase/química , Quitina Sintase/metabolismo , Quitina/metabolismo , Microscopia Crioeletrônica , Nucleosídeos/metabolismo , Saccharomyces cerevisiae/metabolismo , Catálise
5.
Sci Adv ; 9(37): eadh7820, 2023 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-37703377

RESUMO

1,3-ß-Glucan serves as the primary component of the fungal cell wall and is produced by 1,3-ß-glucan synthase located in the plasma membrane. This synthase is a molecular target for antifungal drugs such as echinocandins and the triterpenoid ibrexafungerp. In this study, we present the cryo-electron microscopy structure of Saccharomyces cerevisiae 1,3-ß-glucan synthase (Fks1) at 2.47-Å resolution. The structure reveals a central catalytic region adopting a cellulose synthase fold with a cytosolic conserved GT-A-type glycosyltransferase domain and a closed transmembrane channel responsible for glucan transportation. Two extracellular disulfide bonds are found to be crucial for Fks1 enzymatic activity. Through structural comparative analysis with cellulose synthases and structure-guided mutagenesis studies, we gain previously unknown insights into the molecular mechanisms of fungal 1,3-ß-glucan synthase.


Assuntos
beta-Glucanas , Microscopia Crioeletrônica , Antifúngicos , Catálise
6.
J Phys Chem Lett ; 13(25): 5860-5866, 2022 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-35727229

RESUMO

Most high-performance non-fullerene acceptors are of the acceptor-donor-acceptor (A-D-A)-type structure. Under photoexcitation, the intramolecular charge transfer effect on the A-D-A framework results in a large dipole moment change, facilitating the efficient generation of charge carriers. Achieving more efficient intramolecular charge transfer by adjusting the molecular structure is one of the current research ideas. Recently, we found that the power conversion efficiency can be improved from 4.41 to 13.13% by tuning the planarity of the non-fused ring electron acceptor backbone through steric hindrance of lateral substituents. We found that the planar backbone can effectively improve the intramolecular charge transfer, which has a great influence on the power conversion efficiency of the device. Our results demonstrate that charge transfer dynamics can be controlled by optimizing steric hindrance, which plays a crucial role in the photovoltaic performance of organic solar cells.

7.
Materials (Basel) ; 14(13)2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34209180

RESUMO

In this paper, a high-speed train-CRTS III slab track-subgrade coupled dynamic model is established. With the model, the influence of vehicle number on the dynamic characteristics of a train-CRTS III slab track-subgrade coupled system with smooth and random track irregularity conditions for conventional and vibration-reduction CRTS III slab tracks are theoretically studied and analyzed. Some conclusions are drawn from the results: (1) the largest dynamic responses of the coupled system for all items and cases are no longer changed when the vehicle number exceeds three, and three vehicles are adequate to guarantee the simulation precision to investigate the dynamic responses of the coupled system. (2) The acceleration of the car body has almost no relation with the vehicle number, and only one vehicle is needed to study the vehicle dynamics using the train-CRTS III slab track-subgrade coupled dynamic model. (3) For the conventional CRTS III slab track on a subgrade, the vehicle number has a negligible influence on the accelerations of the rail, slab, and concrete base, the positive and negative bending moments of the rail, the compressive force of the fastener, and the positive bending stress of slab, but it has a large influence on the tension force of the fastener, and the negative bending stresses of the slab and concrete base. Only one vehicle is needed to study track dynamics without considering the tension force of the fastener, the negative bending stresses of the slab and concrete base, otherwise, two or more vehicles are required. (4) For vibration reduction of the CRTS III slab track on a subgrade, the number of vehicles has some influence on the dynamic responses of all track components, and at least two vehicles are required to investigate the track dynamics.

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