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1.
Small Methods ; : e2400273, 2024 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-38733258

RESUMO

Chronic wounds pose a significant clinical challenge worldwide, which is characterized by impaired tissue regeneration and excessive scar formation due to over-repair. Most studies have focused on developing wound repair materials that either facilitate the healing process or control hyperplastic scars caused by over-repair, respectively. However, there are limited reports on wound materials that can both promote wound healing and prevent scar hyperplasia at the same time. In this study, VR23-loaded dendritic mesoporous bioglass nanoparticles (dMBG) are synthesized and electrospun in poly(ester-curcumin-urethane)urea (PECUU) random composite nanofibers (PCVM) through the synergistic effects of physical adsorption, hydrogen bond, and electrospinning. The physicochemical characterization reveals that PCVM presented matched mechanical properties, suitable porosity, and wettability, and enabled sustained and temporal release of VR23 and BDC with the degradation of PCVM. In vitro experiments demonstrated that PCVM can modulate the functions and polarization of macrophages under an inflammatory environment, and possess effective anti-scarring potential and reliable cytocompatibility. Animal studies further confirmed that PCVM can efficiently promote re-epithelialization and angiogenesis and reduce excessive inflammation, thereby remarkably accelerating wound healing while preventing potential scarring. These findings suggest that the prepared PCVM holds promise as a bidirectional regulatory dressing for effectively promoting scar-free healing of chronic wounds.

2.
Clin Exp Pharmacol Physiol ; 51(6): e13869, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38725222

RESUMO

Treatment with erythropoietin (EPO) can correct anaemia in chronic kidney disease (CKD) patients; however, up to 10% exhibit resistance or hyporesponsiveness to EPO. Non-alcoholic fatty liver disease (NAFLD), prevalent liver disease in CKD patients, may limit EPO response because of thrombopoietin deficiency, iron homeostasis disorder and inflammation. Therefore, we hypothesized NAFLD is a risk factor for EPO responsiveness. To test our hypothesis, we evaluated the effect of EPO in healthy rats and rats with NAFLD induced by a high-fat, high-carbohydrate (HFHC) diet. After 12 weeks on the HFHC diet, NAFLD rats showed lower erythroid response to EPO treatment than healthy rats. We, then, determined that the primary cause of EPO hyporesponsiveness could be iron deficiency associated with inflammation, which reduces erythroid cell production. Specifically, the concentrations of hepcidin, ferritin, transferrin and white blood cells in NAFLD rats were 12.8-, 16.4-, 2.51- and 1.40-fold higher than those in healthy rats, respectively. However, erythroid cell types in the bone marrow of NAFLD rats were significantly reduced. In conclusion, our data suggest that NAFLD could be a risk factor for EPO responsiveness, which is attributed to functional iron deficiency associated with inflammation.


Assuntos
Eritropoetina , Hepatopatia Gordurosa não Alcoólica , Animais , Hepatopatia Gordurosa não Alcoólica/metabolismo , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/patologia , Ratos , Masculino , Ratos Sprague-Dawley , Dieta Hiperlipídica/efeitos adversos , Hepcidinas/metabolismo
3.
Bioact Mater ; 37: 477-492, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38698919

RESUMO

Degradable rotator cuff patches, followed over five years, have been observed to exhibit high re-tear rates exceeding 50%, which is attributed to the inability of degradable polymers alone to restore the post-rotator cuff tear (RCT) inflammatory niche. Herein, poly(ester-ferulic acid-urethane)urea (PEFUU) was developed, featuring prolonged anti-inflammatory functionality, achieved by the integration of ferulic acid (FA) into the polyurethane repeating units. PEFUU stably releases FA in vitro, reversing the inflammatory niche produced by M1 macrophages and restoring the directed differentiation of stem cells. Utilizing PEFUU, hierarchical composite nanofiber patch (HCNP) was fabricated, simulating the natural microstructure of the tendon-to-bone interface with an aligned-random alignment. The incorporation of enzymatic hydrolysate derived from decellularized Wharton jelly tissue into the random layer could further enhance cartilage regeneration at the tendon-to-bone interface. Via rat RCT repairing model, HCNP possessing prolonged anti-inflammatory properties uniquely facilitated physiological healing at the tendon-to-bone interface's microstructure. The alignment of fibers was restored, and histologically, the characteristic tripartite distribution of collagen I - collagen II - collagen I was achieved. This study offers a universal approach to the functionalization of degradable polymers and provides a foundational reference for their future applications in promoting the in vivo regeneration of musculoskeletal tissues.

4.
Bioresour Technol ; 401: 130760, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38692376

RESUMO

This study aims to apply the Absorbing oxygen carriers (AOCs) to induce the migration and transformation of phosphorus compounds during the microwave thermal conversion of sludge so the hard-to-extract organic phosphorus (OP) can be converted to easy-to-extract inorganic phosphorus (IP) and be enriched onto the sludge char. The AOCs were recycled by screen separation from the IP-rich sludge char, with the latter being a renewable phosphorus source from sludge. The AOCs in this novel process enhanced the conversion efficiency of OP into non-apatite inorganic phosphorus (NAlP), which was further converted to apatite inorganic phosphorus (AP). Most phosphorus in the sludge char is presented in the form of orthophosphate.


Assuntos
Micro-Ondas , Oxigênio , Fósforo , Esgotos , Esgotos/química , Oxigênio/química , Temperatura
5.
Br J Pharmacol ; 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38653449

RESUMO

BACKGROUND AND PURPOSE: Our previous study reported that erythroferrone (ERFE), a newly identified hormone produced by erythroblasts, responded to recombinant human erythropoietin (rHuEPO) sensitively but its dynamics was complicated by double peaks and circadian rhythm. This study intends to elucidate the underlying mechanisms for the double peaks of ERFE dynamics and further determine whether early ERFE measurements can predict haemoglobin responses to rHuEPO. EXPERIMENTAL APPROACH: By using the purified recombinant rat ERFE protein and investigating its deposition in rats, the production of ERFE was deconvoluted. To explore the role of iron in ERFE production, we monitored short-term changes of iron status after injection of rHuEPO or deferiprone. Pharmacokinetic/pharmacodynamic (PK/PD) modelling was used to confirm the mechanisms and examine the predictive ability of ERFE for long-term haemoglobin responses. KEY RESULTS: The rRatERFE protein was successfully purified. The production of ERFE was deconvoluted and showed two independent peaks (2 and 8 h). Transient iron decrease was observed at 4 h after rHuEPO injection and deferiprone induced significant increases of ERFE. Based on this mechanism, the PK/PD model could characterize the complex dynamics of ERFE. In addition, the model predictions further revealed a stronger correlation between ERFE and haemoglobin peak values than that for observed values. CONCLUSIONS AND IMPLICATIONS: The complex dynamics of ERFE should be composited by an immediate release and transient iron deficiency-mediated secondary production of ERFE. The early peak values of ERFE, which occur within a few hours, can predict haemoglobin responses several weeks after ESA treatment.

6.
ACS Omega ; 9(14): 16147-16159, 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38617641

RESUMO

In low-permeability coal reservoirs, utilizing the organic solvent N-methyl-2-pyrrolidone (NMP) has emerged as an effective approach to improving the coal pore structure and enhancing coalbed methane productivity. However, the exact mechanisms of how solvent erosion alters functional groups and develops pores remain incompletely understood. This study utilized Fourier transform infrared spectroscopy and low-field nuclear magnetic resonance to assess the impact of NMP on the functional groups and pore structures of lignite, bituminous coal, and anthracite. The results indicate that a 6 h treatment with NMP led to an increased proportion of oxygen-containing functional groups in all coal samples, accompanied by a decrease in hydroxyls and aliphatic hydrocarbons. The aromaticity of the coal samples was enhanced to varying degrees, most notably for lignite. In terms of pore modification, the porosity of lignite and bituminous coal increased by 84.82 and 43.56%, while anthracite experienced a porosity increase of 3.04%, indicating a diminished effectiveness of NMP as the coal rank increased. These findings suggest that NMP selectively dissolves specific organic molecules in coals, thereby enhancing pore connectivity and promoting a transition from micro- to meso- and macropores. These findings highlight the potential of NMP in enhancing coalbed methane production and advance our understanding of the mechanisms behind solvent erosion.

7.
Environ Geochem Health ; 46(4): 112, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38472659

RESUMO

N-nitrosamines in reservoir water have drawn significant attention because of their carcinogenic properties. Karst reservoirs containing dissolved organic matter (DOM) are important drinking water sources and are susceptible to contamination because of the fast flow of various contaminants. However, it remains unclear whether N-nitrosamines and their precursor, DOM, spread in karst reservoirs. Therefore, this study quantitatively investigated the occurrence and sources of N-nitrosamines based on DOM properties in three typical karst reservoirs and their corresponding tap water. The results showed that N-nitrosamines were widely spread, with detection frequencies > 85%. Similar dominant compounds, including N-nitrosodimethylamine, N-nitrosomethylethylamine, N-nitrosopyrrolidine, and N-nitrosodibutylamine, were observed in reservoirs and tap water, with average concentrations of 4.7-8.9 and 2.8-6.7 ng/L, respectively. The average carcinogenic risks caused by these N-nitrosamines were higher than the risk level of 10-6. Three-dimensional fluorescence excitation-emission matrix modeling revealed that DOM was composed of humus-like component 1 (C1) and protein-like component 2 (C2). Fluorescence indicators showed that DOM in reservoir water was mainly affected by exogenous pollution and algal growth, whereas in tap water, DOM was mainly affected by microbial growth with strong autopoietic properties. In the reservoir water, N-nitrosodiethylamine and N-nitrosopiperidine were significantly correlated with C2 and biological indicators, indicating their endogenously generated sources. Based on the principal component analysis and multiple linear regression methods, five sources of N-nitrosamines were identified: agricultural pollution, microbial sources, humus sources, degradation processes, and other factors, accounting for 46.8%, 36.1%, 7.82%, 8.26%, and 0.96%, respectively. For tap water, two sources, biological reaction processes, and water distribution systems, were identified, accounting for 75.7% and 24.3%, respectively. Overall, this study presents quantitative information on N-nitrosamines' sources based on DOM properties in typical karst reservoirs and tap water, providing a basis for the safety of drinking water for consumers.


Assuntos
Água Potável , Nitrosaminas , Poluentes Químicos da Água , Humanos , Água Potável/análise , Poluentes Químicos da Água/análise , Nitrosaminas/análise , Carcinógenos/análise , Solo , China , Carcinogênese
8.
Waste Manag ; 178: 168-175, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38401430

RESUMO

With the rapid development of the global new energy vehicle industry, how to minimize the environmental impact of the recovery has become a common concern and urgent concern. China is a major production and consumption market for electric vehicles, there are no specific and extensive resource and environmental assessment system for batteries. In this paper, the retired Electric vehicles lithium-ion batteries (LIBs) was the research object, and a specific analysis of the recycling treatment and gradual use stages of power batteries were based on life cycle assessment. Different battery assessment scenarios were established according to the development of battery recycling in China. The results showed that the secondary use has the optimal performance compared to the full-component physical, pyrometallurgical and hydrometallurgy recycling. The results showed that direct recycling has a GWP of 0.037 kg-CO2 eq·kg LIB-1, which is lower than others. Secondary use of LIB accounts for the most emission reductions with Global warming (GWP) as 12.134 kg-CO2 eq·kg LIB-1. The secondary use has the greatest impact on the assessment results, especially in dynamic scenarios. Through a comprehensive comparison of different recycling technologies, the secondary use, increasing the recycling rate, reducing resource, energy consumption and pollution emissions.


Assuntos
Dióxido de Carbono , Lítio , Animais , Reciclagem , Íons , Fontes de Energia Elétrica , China , Estágios do Ciclo de Vida
9.
Int J Mol Sci ; 25(3)2024 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-38338855

RESUMO

Systemic chronic inflammation (SCI) due to intrinsic immune over-activation is an important factor in the development of many noninfectious chronic diseases, such as neurodegenerative diseases and diabetes mellitus. Among these immune responses, macrophages are extensively involved in the regulation of inflammatory responses by virtue of their polarization plasticity; thus, dysregulation of macrophage polarization direction is one of the potential causes of the generation and maintenance of SCI. High-temperature demand protein A2 (HtrA2/Omi) is an important regulator of mitochondrial quality control, not only participating in the degradation of mis-accumulated proteins in the mitochondrial unfolded protein response (UPRmt) to maintain normal mitochondrial function through its enzymatic activity, but also participating in the regulation of mitochondrial dynamics-related protein interactions to maintain mitochondrial morphology. Recent studies have also reported the involvement of HtrA2/Omi as a novel inflammatory mediator in the regulation of the inflammatory response. HtrA2/Omi regulates the inflammatory response in BMDM by controlling TRAF2 stabilization in a collagen-induced arthritis mouse model; the lack of HtrA2 ameliorates pro-inflammatory cytokine expression in macrophages. In this review, we summarize the mechanisms by which HtrA2/Omi proteins are involved in macrophage polarization remodeling by influencing macrophage energy metabolism reprogramming through the regulation of inflammatory signaling pathways and mitochondrial quality control, elucidating the roles played by HtrA2/Omi proteins in inflammatory responses. In conclusion, interfering with HtrA2/Omi may become an important entry point for regulating macrophage polarization, providing new research space for developing HtrA2/Omi-based therapies for SCI.


Assuntos
Serina Peptidase 2 de Requerimento de Alta Temperatura A , Inflamação , Macrófagos , Mitocôndrias , Animais , Camundongos , Apoptose , Serina Peptidase 2 de Requerimento de Alta Temperatura A/metabolismo , Inflamação/metabolismo , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Macrófagos/metabolismo
10.
Sci Total Environ ; 921: 170731, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38325488

RESUMO

In recent years, the frequent occurrence of nocturnal background ozone enhancement (A gradually increasing trend in the long-term change of nocturnal ozone concentration, [NBOE]) and nocturnal ozone enhancement (the presence of a nocturnal ozone peak and high nocturnal ozone value, [NOE]) have attracted extensive attention in the academic community. NBOE and NOE impact atmospheric chemical processes, and higher nocturnal ozone concentrations adversely affect human health and biological growth. Therefore, we reviewed the research history of NBOE and NOE, provided an overview of research on NBOE, and summarized the spatiotemporal distribution characteristics of NOE. According to the available observations, the frequency of NOE in a long-time series (i.e., more than one year) from 2005 to 2020 generally ranges between 15 % and 50 %. Compared to other nations, China has a higher nocturnal ozone peak. In most NOE events, the magnitude of ozone increase (ΔO3/Δt) ranges from 5 to 20 ppb, and NOE events occur more frequently during midnight. In addition, we described the current international-level understanding of the causes of NOE and the impact of NOE on nighttime and next-day atmospheric chemical processes. Future research should not only enhance the quantitative analysis of the causal factors of NBOE and NOE, but also prioritize exploring how NBOE and NOE influence secondary pollutant production, human health, and biological growth. Finally, attention should be paid to the influence of NBOE and NOE on the formulation of synergistic control policies for PM2.5 and ozone.

11.
Proc Natl Acad Sci U S A ; 121(10): e2319366121, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38422020

RESUMO

Acute myeloid leukemia (AML) is an aging-related and heterogeneous hematopoietic malignancy. In this study, a total of 1,474 newly diagnosed AML patients with RNA sequencing data were enrolled, and targeted or whole exome sequencing data were obtained in 94% cases. The correlation of aging-related factors including age and clonal hematopoiesis (CH), gender, and genomic/transcriptomic profiles (gene fusions, genetic mutations, and gene expression networks or pathways) was systematically analyzed. Overall, AML patients aged 60 y and older showed an apparently dismal prognosis. Alongside age, the frequency of gene fusions defined in the World Health Organization classification decreased, while the positive rate of gene mutations, especially CH-related ones, increased. Additionally, the number of genetic mutations was higher in gene fusion-negative (GF-) patients than those with GF. Based on the status of CH- and myelodysplastic syndromes (MDS)-related mutations, three mutant subgroups were identified among the GF- AML cohort, namely, CH-AML, CH-MDS-AML, and other GF- AML. Notably, CH-MDS-AML demonstrated a predominance of elderly and male cases, cytopenia, and significantly adverse clinical outcomes. Besides, gene expression networks including HOXA/B, platelet factors, and inflammatory responses were most striking features associated with aging and poor prognosis in AML. Our work has thus unraveled the intricate regulatory circuitry of interactions among different age, gender, and molecular groups of AML.


Assuntos
Leucemia Mieloide Aguda , Síndromes Mielodisplásicas , Idoso , Humanos , Masculino , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patologia , Envelhecimento/genética , Mutação , Síndromes Mielodisplásicas/genética , Síndromes Mielodisplásicas/patologia , Prognóstico
12.
Nat Commun ; 15(1): 1427, 2024 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-38365776

RESUMO

Electrochemical carbon dioxide reduction reaction using sustainable energy is a promising approach of synthesizing chemicals and fuels, yet is highly energy intensive. The oxygen evolution reaction is particularly problematic, which is kinetically sluggish and causes anodic carbon loss. In this context, we couple CO2 electrolysis with hydrogen oxidation reaction in a single electrochemical cell. A Ni(OH)2/NiOOH mediator is used to fully suppress the anodic carbon loss and hydrogen oxidation catalyst poisoning by migrated reaction products. This cell is highly flexible in producing either gaseous (CO) or soluble (formate) products with high selectivity (up to 95.3%) and stability (>100 h) at voltages below 0.9 V (50 mA cm-2). Importantly, thanks to the "transferred" oxygen evolution reaction to a water electrolyzer with thermodynamically and kinetically favored reaction conditions, the total polarization loss and energy consumption of our H2-integrated CO2 reduction reaction, including those for hydrogen generation, are reduced up to 22% and 42%, respectively. This work demonstrates the opportunity of combining CO2 electrolysis with the hydrogen economy, paving the way to the possible integration of various emerging energy conversion and storage approaches for improved energy/cost effectiveness.

13.
Molecules ; 29(3)2024 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-38338456

RESUMO

Diabetic muscle atrophy is an inflammation-related complication of type-2 diabetes mellitus (T2DM). Even though regular exercise prevents further deterioration of atrophic status, there is no effective mediator available for treatment and the underlying cellular mechanisms are less explored. In this study, we investigated the therapeutic potential of MCC950, a specific, small-molecule inhibitor of NLRP3, to treat pyroptosis and diabetic muscle atrophy in mice. Furthermore, we used MCC950 to intervene in the protective effects of aerobic exercise against muscle atrophy in diabetic mice. Blood and gastrocnemius muscle (GAS) samples were collected after 12 weeks of intervention and the atrophic state was assessed. We initially corroborated a diabetic muscle atrophy phenotype in db/db mice (D) by comparison with control m/m mice (W) by examining parameters such as fasting blood glucose (D vs. W: 24.47 ± 0.45 mmol L-1 vs. 4.26 ± 0.6 mmol L-1, p < 0.05), grip strength (D vs. W: 166.87 ± 15.19 g vs. 191.76 ± 14.13 g, p < 0.05), exercise time (D vs. W: 1082.38 ± 104.67 s vs. 1716 ± 168.55 s, p < 0.05) and exercise speed to exhaustion (D vs. W: 24.25 ± 2.12 m min-1 vs. 34.75 ± 2.66 m min-1, p < 0.05), GAS wet weight (D vs. W: 0.07 ± 0.01 g vs. 0.13 ± 0.01 g, p < 0.05), the ratio of GAS wet weight to body weight (D vs. W: 0.18 ± 0.01% vs. 0.54 ± 0.02%, p < 0.05), and muscle fiber cross-sectional area (FCSA) (D vs. W: 1875 ± 368.19 µm2 vs. 2747.83 ± 406.44 µm2, p < 0.05). We found that both MCC950 (10 mg kg-1) treatment and exercise improved the atrophic parameters that had deteriorated in the db/db mice, inhibited serum inflammatory markers and significantly attenuated pyroptosis in atrophic GAS. In addition, a combined MCC950 treatment with exercise (DEI) exhibited a further improvement in glucose uptake capacity and muscle performance. This combined treatment also improved the FCSA of GAS muscle indicated by Laminin immunofluorescence compared to the group with the inhibitor treatment alone (DI) (DEI vs. DI: 2597 ± 310.97 vs. 1974.67 ± 326.15 µm2, p < 0.05) or exercise only (DE) (DEI vs. DE: 2597 ± 310.97 vs. 2006.33 ± 263.468 µm2, p < 0.05). Intriguingly, the combination of MCC950 treatment and exercise significantly reduced NLRP3-mediated inflammatory factors such as cleaved-Caspase-1, GSDMD-N and prevented apoptosis and pyroptosis in atrophic GAS. These findings for the first time demonstrate that targeting NLRP3-mediated pyroptosis with MCC950 improves diabetic muscle homeostasis and muscle function. We also report that inhibiting pyroptosis by MCC950 can enhance the beneficial effects of aerobic exercise on diabetic muscle atrophy. Since T2DM and muscle atrophy are age-related diseases, the young mice used in the current study do not seem to fully reflect the characteristics of diabetic muscle atrophy. Considering the fragile nature of db/db mice and for the complete implementation of the exercise intervention, we used relatively young db/db mice and the atrophic state in the mice was thoroughly confirmed. Taken together, the current study comprehensively investigated the therapeutic effect of NLRP3-mediated pyroptosis inhibited by MCC950 on diabetic muscle mass, strength and exercise performance, as well as the synergistic effects of MCC950 and exercise intervention, therefore providing a novel strategy for the treatment of the disease.


Assuntos
Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 2 , Neuropatias Diabéticas , Camundongos , Animais , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Inflamassomos , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/terapia , Piroptose , Sulfonamidas/farmacologia , Camundongos Endogâmicos , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/terapia , Exercício Físico , Atrofia Muscular/tratamento farmacológico , Atrofia Muscular/etiologia
14.
Int J Mol Sci ; 25(2)2024 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-38256070

RESUMO

Hepatocellular carcinoma (HCC) is the most common primary liver cancer, and, with increasing research on the tumor immune microenvironment (TIME), the immunosuppressive micro-environment of HCC hampers further application of immunotherapy, even though immunotherapy can provide survival benefits to patients with advanced liver cancer. Current studies suggest that polyamine metabolism is not only a key metabolic pathway for the formation of immunosuppressive phenotypes in tumor-associated macrophages (TAMs), but it is also profoundly involved in mitochondrial quality control signaling and the energy metabolism regulation process, so it is particularly important to further investigate the role of polyamine metabolism in the tumor microenvironment (TME). In this review, by summarizing the current research progress of key enzymes and substrates of the polyamine metabolic pathway in regulating TAMs and T cells, we propose that polyamine biosynthesis can intervene in the process of mitochondrial energy metabolism by affecting mitochondrial autophagy, which, in turn, regulates macrophage polarization and T cell differentiation. Polyamine metabolism may be a key target for the interactive dialog between HCC cells and immune cells such as TAMs, so interfering with polyamine metabolism may become an important entry point to break intercellular communication, providing new research space for developing polyamine metabolism-based therapy for HCC.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Macrófagos Associados a Tumor , Mitocôndrias , Preservação Biológica , Imunossupressores , Microambiente Tumoral
15.
J Am Chem Soc ; 146(5): 2933-2938, 2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38253007

RESUMO

Most of the known single-electron reductants are either metal based reagents, used in a stoichiometric amount, or a combination of an organic species and a photocatalyst. Here we report that 1H-1,2,3-triazol-5-ylidenes act not only as stoichiometric one-electron donors but also as catalytic organic reducing agents, without the need of a photocatalyst. As a proof of concept, we studied the reduction of quinones, which are well-known electron conveyors that are involved in various biological and industrial processes. This work also provides experimental evidence for the formation of a bis(triazolium)carbonate adduct, which acts as the resting state of the catalytic cycle and as the carbene reservoir.

16.
J Am Chem Soc ; 146(4): 2748-2756, 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38214454

RESUMO

Controlling the enantioselectivity of hydrogen atom transfer (HAT) reactions has been a long-standing synthetic challenge. While recent advances on photoenzymatic catalysis have demonstrated the great potential of non-natural photoenzymes, all of the transformations are initiated by single-electron reduction of the substrate, with only one notable exception. Herein, we report an oxidation-initiated photoenzymatic enantioselective hydrosulfonylation of olefins using a novel mutant of gluconobacter ene-reductase (GluER-W100F-W342F). Compared to known photoenzymatic systems, our approach does not rely on the formation of an electron donor-acceptor complex between the substrates and enzyme cofactor and simplifies the reaction system by obviating the addition of a cofactor regeneration mixture. More importantly, the GluER variant exhibits high reactivity and enantioselectivity and a broad substrate scope. Mechanistic studies support the proposed oxidation-initiated mechanism and reveal that a tyrosine-mediated HAT process is involved.


Assuntos
Alcenos , Elétrons , Estereoisomerismo , Oxirredução , Hidrogênio , Catálise
17.
J Org Chem ; 89(1): 681-686, 2024 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-38065576

RESUMO

Herein, we report the introduction of a silole unit into cycloparaphenylenes (CPPs), and two compounds [12]Si3CPP and [16]Si4CPP are obtained by a platinum- and gold-mediated cyclooligomerization strategy. Their optical and electronic properties are studied by UV-vis absorption and fluorescence spectra, which show red shifts and higher photoluminescence quantum yields (PLQYs) compared with the corresponding CPPs.

18.
J Ethnopharmacol ; 321: 117390, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-37956911

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Pyrrolizidine alkaloids (PAs) are a group of phytotoxins present in about 3% of flowering plants worldwide. Ingestion of PA-containing herbal products may lead to hepatotoxicity. Notably, the toxicokinetic (TK) behaviors, especially pyrrole-protein adducts (PPAs) having the same structure but generated from metabolic activation of different PAs, significantly affect the toxicity of structurally diverse PAs, therefore studying them in their pure form is preferable to extracts to stratify toxic potency of different PAs co-existing in herbal extracts. However, previous studies mainly focus on the establishment of TK profiles of the intact PAs, revealing less or no kinetic information on the main PA metabolites (PA N-oxides) and PPAs which mediate PA-induced hepatotoxicity. In this study, PPA was measured as the biomarker of PA exposure and PA-induced toxicity. AIM OF STUDY: This study aims to investigate the TK difference between structurally diverse PAs of retronecine-type PAs: retrorsine (RTS) and monocrotaline (MCT), and otonecine-type PA: clivorine (CLI), and their toxicity-related metabolite PPAs and PA N-oxides, the main metabolite of retronecine-type PAs, for the establishment of a more accurate risk assessment of PAs exposure. MATERIALS AND METHODS: The TK studies were conducted using rats through intravenous (i.v.) or oral (p.o.) administration of PAs at 20 mg/kg. The main TK parameters of PAs and PA N-oxides were determined from plasma concentration-time profiles, and the kinetic profiles of PPAs were assessed from both plasma and erythrocyte concentration-time profiles. RESULTS: MCT demonstrated the slowest but the highest extent of absorption among the three PAs, while RTS demonstrated a similar absorption rate with a lower extent than CLI. For elimination, MCT demonstrated a similar elimination rate as RTS but the lowest extent of elimination among the three PAs, and CLI exhibited significantly faster elimination than MCT and RTS. Moreover, the formation of PA N-oxide, which only occurs in retronecine-type PAs, was remarkably less in MCT-treated rats compared to RTS-treated ones. Of note, the retronecine-type RTS and MCT induced more PPAs via p.o. than i.v. administration route, whereas the otonecine-type CLI showed the opposite trend. CONCLUSION: Dramatic TK differences, including not only PAs but also PA N-oxides and the derived protein adduct PPAs, were found among structurally diverse PAs in rats, laying the basis for varied hepatotoxic potencies induced by different PA-containing herbal products. Notably, our findings for the first time uncovered that oral administration of retronecine-type PAs might cause severer toxicity compared with the intravenous route, which warrants further in-depth exploration.


Assuntos
Alcaloides , Doença Hepática Induzida por Substâncias e Drogas , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Alcaloides de Pirrolizidina , Ratos , Animais , Toxicocinética , Alcaloides de Pirrolizidina/química , Óxidos/química
19.
Cancer Causes Control ; 35(1): 55-62, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37540479

RESUMO

BACKGROUND: The use of antidepressants has increased over the years, but the relationship between antidepressant use and the risk of breast cancer is not uniform because of confounding factors. We aimed to assess the effect of antidepressants on breast cancer risk using a two-sample Mendelian randomization (MR) approach.stet METHODS: Secondary data analysis was performed on pooled data from genome-wide association studies based on single-nucleotide polymorphisms that were highly correlated with antidepressants, SSRI drugs, and serotonin and prolactin levels were selected as instrumental variables to evaluate the association between antidepressants and SSRI drugs and prolactin levels with breast cancer and ER+/ER- breast cancer. We then performed a test of the hypothesis that SSRI drugs elevate prolactin concentrations. We performed two-sample Mendelian randomization analyses using inverse variance weighting, MR-Egger regression, and weighted median methods, respectively. RESULTS: There was no significant risk association between antidepressant and SSRI use and the development of breast cancer, ER-positive or ER-negative breast cancer (P > 0.05), and serotonin concentration was not associated with breast cancer risk (P > 0.05). There was a positive causal relationship between prolactin levels and breast cancer (IVW, P = 0.02, OR = 1.058) and ER-positive breast cancer (Weighted median, P = 0.043, OR = 1.141; IVW, P = 0.009, OR = 1.125). Results in SSRI medication and prolactin levels showed no association between SSRI analogs and prolactin levels (P > 0.05). CONCLUSION: Large MR analysis showed that antidepressants as well as SSRI drugs were not associated with breast cancer risk and the SSRI-prolactin-breast cancer hypothesis did not hold in our analysis.


Assuntos
Neoplasias da Mama , Humanos , Feminino , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/genética , Análise da Randomização Mendeliana , Estudo de Associação Genômica Ampla , Prolactina , Serotonina , Polimorfismo de Nucleotídeo Único , Antidepressivos/efeitos adversos
20.
J Pharm Sci ; 113(1): 246-256, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37913904

RESUMO

Erythropoiesis-stimulating agents (ESAs) have been a common treatment for anemia associated with chronic kidney disease (CKD), while 10-20 % of patients continue to suffer from persistent anemia despite receiving ESA treatments. Our previous findings suggested that intensive ESA usage can cause resistance by depleting the erythroid precursor cells. Here, we used a mechanism-based pharmacokinetic/pharmacodynamic (PK/PD) model of ESAs and conducted simulations to evaluate the influence of dose regimens and other factors (such as administration route, individual PK/PD parameters, types of ESAs, and disease status) on ESA resistance with instantaneous dose adaptations in healthy populations and anemic patients. The simulated results show that instantaneous dose-adaptation can reduce ESA resistance, but up to 30 % of subjects still ended up developing ESA resistance in healthy populations. The Smax is markedly higher in hypo-responders than in normal-responders, while hypo-responders possess fewer precursors and experience a faster decline compared to normal-responders. There is a ceiling effect of increasing ESA dosage to improve HGB responses and reduce ESA resistance, and the limit is lower in anemic patients compared to healthy populations. Subcutaneous administrations and ESAs with longer half-lives lead to stronger HGB responses and less resistance at equivalent doses. Taken together, this study indicates that precursor depletion contributes to ESA resistance and dose regimens can greatly influence the occurrence of ESA resistance. Furthermore, ESA treatment for patients showing ESA resistance should avoid continuously increasing doses and instead consider stimulating the renewal of precursors.


Assuntos
Anemia , Hematínicos , Insuficiência Renal Crônica , Humanos , Hematínicos/farmacologia , Hematínicos/uso terapêutico , Eritropoese , Hemoglobinas/uso terapêutico , Anemia/tratamento farmacológico , Anemia/complicações , Insuficiência Renal Crônica/complicações , Insuficiência Renal Crônica/tratamento farmacológico
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