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1.
Proc Natl Acad Sci U S A ; 121(2): e2219352120, 2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38165927

RESUMO

High levels of mitochondrial reactive oxygen species (mROS) are linked to cancer development, which is tightly controlled by the electron transport chain (ETC). However, the epigenetic mechanisms governing ETC gene transcription to drive mROS production and cancer cell growth remain to be fully characterized. Here, we report that protein demethylase PHF8 is overexpressed in many types of cancers, including colon and lung cancer, and is negatively correlated with ETC gene expression. While it is well known to demethylate histones to activate transcription, PHF8 demethylates transcription factor YY1, functioning as a co-repressor for a large set of nuclear-coded ETC genes to drive mROS production and cancer development. In addition to genetically ablating PHF8, pharmacologically targeting PHF8 with a specific chemical inhibitor, iPHF8, is potent in regulating YY1 methylation, ETC gene transcription, mROS production, and cell growth in colon and lung cancer cells. iPHF8 exhibits potency and safety in suppressing tumor growth in cell-line- and patient-derived xenografts in vivo. Our data uncover a key epigenetic mechanism underlying ETC gene transcriptional regulation, demonstrating that targeting the PHF8/YY1 axis has great potential to treat cancers.


Assuntos
Neoplasias Pulmonares , Fatores de Transcrição , Humanos , Fatores de Transcrição/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Histona Desmetilases/metabolismo , Histonas/metabolismo , Transformação Celular Neoplásica , Neoplasias Pulmonares/genética , Fator de Transcrição YY1/genética , Fator de Transcrição YY1/metabolismo
2.
Mol Carcinog ; 63(4): 785-796, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38289126

RESUMO

Triple-negative breast cancer (TNBC) is an exceptionally aggressive breast cancer subtype associated with neuropathic pain. This study explores the effects of 5'-nucleotidase domain-containing protein 2 (NT5DC2) on the progression of TNBC and neuropathic pain. Microarray analysis was conducted to identify differentially expressed genes in TNBC and the pathways involved. Gain- and loss-of-function assays of NT5DC2 were performed in TNBC cells, followed by detection of the extracellular acidification rate, adenosine triphosphate (ATP) levels, lactic acid production, glucose uptake, proliferation, migration, and invasion in TNBC cells. Macrophages were co-cultured with TNBC cells to examine the release of polarization-related factors and cytokines. A xenograft tumor model was established for in vivo validation. In addition, a mouse model of neuropathic pain was established through subepineural injection of TNBC cells, followed by measurement of the sciatic functional index and behavioral analysis to assess neuropathic pain. NT5DC2 was upregulated in TNBC and was positively correlated with epidermal growth factor receptor (EGFR). NT5DC2 interacted with EGFR to promote downstream signal transduction in TNBC cells. NT5DC2 knockdown diminished proliferation, migration, invasion, the extracellular acidification rate, ATP levels, lactic acid production, and glucose uptake in TNBC cells. Co-culture with NT5DC2-knockdown TNBC cells alleviated the M2 polarization of macrophages. Furthermore, NT5DC2 knockdown reduced tumor growth and neuropathic pain in mice. Importantly, activation of the EGFR pathway counteracted the effects of NT5DC2 knockdown. NT5DC2 knockdown protected against TNBC progression and neuropathic pain by inactivating the EGFR pathway.


Assuntos
Neuralgia , Neoplasias de Mama Triplo Negativas , Humanos , Animais , Camundongos , Neoplasias de Mama Triplo Negativas/patologia , Proliferação de Células , Receptores ErbB/genética , Receptores ErbB/metabolismo , Glicólise , Neuralgia/genética , Trifosfato de Adenosina/metabolismo , Ácido Láctico , Glucose/farmacologia , Linhagem Celular Tumoral
3.
Ecotoxicol Environ Saf ; 275: 116278, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38564860

RESUMO

Due to the rise in temperature and sea level caused by climate change, the detection rate of aflatoxin B1 (AFB1) in food crops has increased dramatically, and the frequency and severity of aflatoxicosis in humans and animals are also increasing. AFB1 has strong hepatotoxicity, causing severe liver damage and even cancer. However, the mechanism of AFB1 hepatotoxicity remains unclear. By integrating network toxicology, molecular docking and in vivo experiments, this research was designed to explore the potential hepatotoxicity mechanisms of AFB1. Thirty-three intersection targets for AFB1-induced liver damage were identified using online databases. PI3K/AKT1, MAPK, FOXO1 signaling pathways, and apoptosis were significantly enriched. In addition, the proteins of ALB, AKT1, PIK3CG, MAPK8, HSP90AA1, PPARA, MAPK1, EGFR, FOXO1, and IGF1 exhibited good affinity with AFB1. In vivo experiments, significant pathological changes occurred in the liver of mice. AFB1 induction increased the expression levels of EGFR, ERK, and FOXO1, and decreased the expression levsls of PI3K and AKT1. Moreover, AFB1 treatment caused an increase in Caspase3 expression, and a decrease in Bcl2/Bax ratio. By combining network toxicology with in vivo experiments, this study confirms for the first time that AFB1 promotes the FOXO1 signaling pathway by inactivating PI3K/AKT1 and activating EGFR/ERK signaling pathways, hence aggravating hepatocyte apoptosis. This research provides new strategies for studying the toxicity of environmental pollutants and new possible targets for the development of hepatoprotective drugs.


Assuntos
Aflatoxina B1 , Doença Hepática Induzida por Substâncias e Drogas , Humanos , Camundongos , Animais , Simulação de Acoplamento Molecular , Aflatoxina B1/toxicidade , Fígado/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Receptores ErbB/metabolismo
4.
Int J Mol Sci ; 25(11)2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38892017

RESUMO

The impact of age on mesenchymal stromal cell (MSC) characteristics has been well researched. However, increased age is concomitant with increased prevalence of polypharmacy. This adjustable factor may have further implications for the functionality of MSCs and the effectiveness of autologous MSC procedures. We applied hyperspectral microscopy of cell autofluorescence-a non-invasive imaging technique used to characterise cytometabolic heterogeneity-to identify changes in the autofluorescence signals of MSCs from (1) young mice, (2) old mice, (3) young mice randomised to receive polypharmacy (9-10 weeks of oral therapeutic doses of simvastatin, metoprolol, oxycodone, oxybutynin and citalopram), and (4) old mice randomised to receive polypharmacy. Principal Component Analysis and Logistic Regression Analysis were used to assess alterations in spectral and associated metabolic characteristics. Modelling demonstrated that cells from young mice receiving polypharmacy had less NAD(P)H and increased porphyrin relative to cells from old control mice, allowing for effective separation of the two groups (AUC of ROC curve > 0.94). Similarly, cells from old polypharmacy mice were accurately separated from those from young controls due to lower levels of NAD(P)H (p < 0.001) and higher porphyrin (p < 0.001), allowing for an extremely accurate logistic regression (AUC of ROC curve = 0.99). This polypharmacy regimen may have a more profound impact on MSCs than ageing, and can simultaneously reduce optical redox ratio (ORR) and increase porphyrin levels. This has implications for the use of autologous MSCs for older patients with chronic disease.


Assuntos
Envelhecimento , Células-Tronco Mesenquimais , Polimedicação , Animais , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Mesenquimais/citologia , Camundongos , Envelhecimento/metabolismo , Masculino , Imagem Óptica/métodos , NADP/metabolismo
5.
Brain Behav Immun ; 109: 308-320, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36754246

RESUMO

Pain is one of the most severe complications affecting the quality of life of cancer patients. Although substantial progress has been made in the diagnosis and treatment of cancer, the neurobiological mechanism of cancer pain is still unclear. In the present study, we identified the critical role of CXC chemokine 2 (CXCL2), released by Schwann cells after being activated by cancer cells, in maintaining cancer-induced macrophage infiltration and the resulting mechanical hypersensitivity and persistent spontaneous nociception. In vitro, Schwann cells cocultured with breast cancer cells exhibited a significant increase in CXCL2 expression; in addition, conditioned medium from Schwann cells activated by breast cancer cells had a similar effect to recombinant CXCL2 in terms of inducing macrophage migration. Targeting CXCL2 signaling by both CXC chemokine receptor 2 (CXCR2) antagonist pharmacological blockade and anti-CXCL2 mAb immunological blockade robustly prevented conditioned medium-induced macrophage migration. In vivo, both application of recombinant CXCL2 and perineural breast cancer cell implantation resulted in mechanical hypersensitivity and persistent spontaneous nociception in mice, along with increased macrophage infiltration into the sciatic nerves. Similar to the in vitro results, inhibition of CXCL2/CXCR2 signaling or conditional knockdown of CXCL2 in sciatic nerve Schwann cells effectively attenuated breast cancer cell-induced mechanical hypersensitivity, persistent spontaneous nociception, and macrophage recruitment in the sciatic nerve. Mechanistically, we found that redox effector factor-1 (Ref-1) secreted by breast cancer cells activated hypoxia inducible factor-1α (HIF-1α) expression and inhibited reactive oxygen species (ROS) production in Schwann cells, ultimately inducing CXCL2 expression in Schwann cells. In brief, the present study expands new insights into cancer pain mechanisms from promising animal models to provide new strategies for the control of cancer pain.


Assuntos
Dor do Câncer , Neoplasias , Camundongos , Animais , Quimiocinas CXC/metabolismo , Dor do Câncer/metabolismo , Meios de Cultivo Condicionados/farmacologia , Meios de Cultivo Condicionados/metabolismo , Qualidade de Vida , Macrófagos/metabolismo , Fatores Imunológicos , Células de Schwann/metabolismo , Neoplasias/metabolismo
6.
Ecotoxicol Environ Saf ; 251: 114546, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36646010

RESUMO

Aflatoxin B1 (AFB1) is the most dangerous and abundant mycotoxin, which is toxic to almost all animals, and poultry is more sensitive to AFB1 toxicity. Ingesting AFB1-contaminated feed can cause significant liver damage and brings serious harm to poultry, which greatly restricts the development of the poultry industry. The present research was implemented to explore the intervention effect and its mechanism of taraxasterol on liver damage induced by AFB1 in broiler chickens. The liver damage model in broiler chickens was established by feeding 0.5 mg/kg AFB1 feed, and taraxasterol (25, 50 and 100 mg/kg BW, respectively) was given in the drinking water for 21 days. The growth performance, liver function, oxidative stress, apoptosis and autophagy were evaluated. The results showed that taraxasterol increased BW and reduced feed-to-gain ratio of broiler chickens induced by AFB1. Taraxasterol improved the levels of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyltransferase (GGT), total bilirubin (TBIL) and alkaline phosphatase (ALP), and attenuated hepatic histopathological changes induced by AFB1. Meantime, taraxasterol down-regulated cytochrome P450 (CYP450) enzyme system CYP1A1 and CYP2A6 mRNA expression, inhibited the overproduction of reactive oxygen species (ROS) and malondialdehyde (MDA), and enhanced the activities of antioxidant enzymes glutathione (GSH) and catalase (CAT) and the content of antioxidant superoxide dismutase (SOD) of the liver in broiler chickens induced by AFB1. Furthermore, taraxasterol up-regulated the mRNA and protein expression of hepatic nuclear factor E2 related factor 2 (Nrf2), heme oxygenase 1 (HO-1) and NAD(P)H: quinone oxidoreductase 1 (NQO1), and down-regulated the expression of hepatic kelch like ECH associated protein 1 (Keap1) induced by AFB1 in Keap1/Nrf2 signaling pathway. The ultrastructural observation and RT-qPCR results found that taraxasterol inhibited apoptosis of hepatocytes, up-regulated the expression of B-cell lymphoma-2 (Bcl-2) mRNA and down-regulated the expression of Bax and caspase3 mRNA. Further, taraxasterol restored the autophagy of hepatocytes and down-regulated the mRNA expression of phosphatidylinositol 3-kinase K (PI3K), protein kinase B (AKT) and mammalian target of rapamycin (mTOR) in AFB1-induced liver of broiler chickens. The above results indicate that taraxasterol alleviates liver damage induced by AFB1 in broiler chickens through regulation of Keap1/Nrf2 signaling pathway to exert its antioxidant effect, mitochondrial apoptosis pathway to improve anti-apoptotic ability and PI3K/AKT/mTOR pathway to restore autophagy.


Assuntos
Antioxidantes , Proteínas Proto-Oncogênicas c-akt , Animais , Antioxidantes/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Galinhas/metabolismo , Aflatoxina B1/toxicidade , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Estresse Oxidativo , Fígado , Apoptose , Glutationa/metabolismo , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , RNA Mensageiro/metabolismo , Autofagia , Mamíferos/metabolismo
7.
Angew Chem Int Ed Engl ; 62(6): e202214706, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36468459

RESUMO

Diesters are of fundamental importance in the chemical industry and are used for many applications, e.g. as plasticizers, surfactants, emulsifiers, and lubricants. Herein, we present a straightforward and efficient method for the selective synthesis of diesters via palladium-catalyzed direct carbonylation of di- or polyols with readily available alkenes. Key-to-success is the use of a specific palladium catalyst with the "built-in-base" ligand L16 providing esterification of all alcohols and a high n/iso ratio. The synthesized diesters were evaluated as potential plasticizers in PVC films by measuring the glass transition temperature (Tg ) via differential scanning calorimetry (DSC).

8.
Angew Chem Int Ed Engl ; 62(43): e202313099, 2023 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-37694769

RESUMO

The development of practical materials for (de)hydrogenation reactions is a prerequisite for the launch of a sustainable hydrogen economy. Herein, we present the design and construction of an atomically dispersed dual-metal site Co/Cu-N-C catalyst allowing significantly improved dehydrogenation of formic acid, which is available from carbon dioxide and green hydrogen. The active catalyst centers consist of specific CoCuN6 moieties with double-N-bridged adjacent metal-N4 clusters decorated on a nitrogen-doped carbon support. At optimal conditions the dehydrogenation performance of the nanostructured material (mass activity 77.7 L ⋅ gmetal -1 ⋅ h-1 ) is up to 40 times higher compared to commercial 5 % Pd/C. In situ spectroscopic and kinetic isotope effect experiments indicate that Co/Cu-N-C promoted formic acid dehydrogenation follows the so-called formate pathway with the C-H dissociation of HCOO* as the rate-determining step. Theoretical calculations reveal that Cu in the CoCuN6 moiety synergistically contributes to the adsorption of intermediate HCOO* and raises the d-band center of Co to favor HCOO* activation and thereby lower the reaction energy barrier.

9.
Immunopharmacol Immunotoxicol ; 44(1): 129-138, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34918603

RESUMO

CONTEXT: As a medicinal and edible fungus, Inonotus obliquus has been traditionally used to prevent and treat various ailments. Inonotus obliquus polysaccharide (IOP) isolated from I. obliquus processes many biological activities, our series of in vivo studies have shown that IOP protects against Toxoplasma gondii infection. OBJECTIVE: This study aimed to investigate the in vitro immunomodulatory effects and its mechanisms of IOP on mouse splenic lymphocytes infected with T. gondii. MATERIALS AND METHODS: Mouse splenic lymphocytes were infected with T. gondii tachyzoites, and treated with different concentrations of IOP. The levels of cytokines and chemokines were measured by enzyme-linked immunosorbent assay (ELISA) and reverse transcription-polymerase chain reaction (RT-PCR). The expression of toll-like receptor 2 (TLR2) and TLR4, and the modulation of nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinases (MAPKs) signaling pathways were determined by Western blot. RESULTS: IOP significantly decreased the over-release of cytokine interleukin-1 beta (IL-1ß), IL-4, IL-6, interferon-gamma (IFN-γ), and tumor necrosis factor-alpha (TNF-α) in supernatant from T. gondii-infected splenic lymphocytes. IOP also effectively inhibited the overexpression of cytokines and chemokine macrophage inflammatory protein-1 (MIP-1) and monocyte chemoattractant protein-1 (MCP-1) mRNA. Furthermore, IOP down-regulated TLR2 and TLR4 expressions and inhibited the over-phosphorylation of NF-κB p65 and inhibitor κBα (IκBα) in NF-κB signaling pathway and p38, c-Jun N-terminal kinase (JNK) in MAPKs signaling pathway. By observing the effect of IOP on TNF-α secretion after pretreatment with specific inhibitors, it was further confirmed that IOP was involved in the regulation of NF-κB, p38, and JNK signaling pathways. CONCLUSIONS: These data indicate that IOP can inhibit the excessive inflammatory response caused by T. gondii infection through modulating NF-κB, p38, and JNK signaling pathways, and thus plays the in vitro anti-T. gondii role.


Assuntos
NF-kappa B , Toxoplasma , Animais , Inonotus , Linfócitos/metabolismo , Camundongos , Proteínas Quinases Ativadas por Mitógeno , NF-kappa B/metabolismo , Polissacarídeos/farmacologia , Toxoplasma/metabolismo
10.
Angew Chem Int Ed Engl ; 58(40): 14365-14373, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31390131

RESUMO

The synthesis of carboxylic acids is of fundamental importance in the chemical industry and the corresponding products find numerous applications for polymers, cosmetics, pharmaceuticals, agrochemicals, and other manufactured chemicals. Although hydroxycarbonylations of olefins have been known for more than 60 years, currently known catalyst systems for this transformation do not fulfill industrial requirements, for example, stability. Presented herein for the first time is an aqueous-phase protocol that allows conversion of various olefins, including sterically hindered and demanding tetra-, tri-, and 1,1-disubstituted systems, as well as terminal alkenes, into the corresponding carboxylic acids in excellent yields. The outstanding stability of the catalyst system (26 recycling runs in 32 days without measurable loss of activity), is showcased in the preparation of an industrially relevant fatty acid. Key-to-success is the use of a built-in-base ligand under acidic aqueous conditions. This catalytic system is expected to provide a basis for new cost-competitive processes for the industrial production of carboxylic acids.

11.
J Am Chem Soc ; 140(15): 5217-5223, 2018 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-29528637

RESUMO

A general and selective palladium-catalyzed alkoxycarbonylation of all kinds of alkenes with formic acid (HCOOH, FA) is described. Terminal, di-, tri-, and tetra-substituted including functionalized olefins are converted into linear esters with high yields and regioselectivity. Key-to-success is the use of specific palladium catalysts containing ligands with built-in base, e.g., L5. Comparison experiments demonstrate that the active catalyst system not only facilitates isomerization and carbonylation of alkenes but also promotes the selective decomposition of HCOOH to CO under mild conditions.

12.
Pharmazie ; 73(10): 589-593, 2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30223923

RESUMO

Astragalus membranaceus Bunge has long been used to improve immune function in traditional Chinese medicine. The total flavonoids of Astragalus (TFA) are the main active components isolated from Astragalus membranaceus Bunge. Our recent study has shown that TFA has in vivo and in vitro immunomodulatory and anti-inflammatory effects; however, its potential mechanisms have not yet been elucidated. The present study aims to confirm the immunomodulatory and anti-inflammatory mechanisms of the action involved. Murine RAW 264.7 macrophages were treated with 10, 25 and 100 µg/ml of TFA. The mRNA expression levels of the tumour necrosis factor (TNF)-α, interleukin (IL)-6, IL-1ß, IL-10, inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 were examined by RT-PCR in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. The protein expression levels of iNOS and COX-2, in addition to the phosphorylations of proteins in the mitogen activated protein kinase (MAPK) and nuclear factor (NF)-κB signalling pathways were measured by Western blot in LPS-stimulated RAW 264.7 macrophages. The results showed that TFA significantly inhibited TNF-α, IL-1ß, IL-6, iNOS and COX-2 mRNA levels and increased IL-10 mRNA level in LPS-stimulated RAW 264.7 cells in a dose-dependent manner. Further studies revealed that TFA significantly inhibited iNOS and COX-2 protein levels, the phosphorylations of p38 and JNK in MAPKs pathway and IKKα/ß, IκBα and the expression of nuclear NF-κB p65 in NF-κB pathway in LPS-stimulated RAW 264.7 cells. It suggests that TFA possesses immunomodulatory and anti-inflammatory effects by regulating MAPK and NF-ΚB signalling pathways in RAW 264.7 macrophages.


Assuntos
Flavonoides/farmacologia , Fatores Imunológicos/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , NF-kappa B/metabolismo , Animais , Astrágalo/química , Ciclo-Oxigenase 2/metabolismo , Quinase I-kappa B/metabolismo , Interleucinas/genética , Interleucinas/metabolismo , Lipopolissacarídeos/farmacologia , MAP Quinase Quinase 4/metabolismo , Macrófagos/metabolismo , Camundongos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Células RAW 264.7 , RNA Mensageiro/genética , Fator de Transcrição RelA/metabolismo , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
13.
Angew Chem Int Ed Engl ; 56(22): 6203-6207, 2017 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-28429424

RESUMO

A general palladium-catalyzed synthesis of linear esters directly from sec- and tert-alcohols is described. Compared to the classic Koch-Haaf reaction, which leads to branched products, this new transformation gives the corresponding linear esters in high yields and selectivity. Key for this protocol is the use of an advanced palladium catalyst system with L2 (pyt bpx) as the ligand. A variety of aliphatic and benzylic alcohols can be directly used and the catalyst efficiency for the benchmark reaction is outstanding (turnover number up to 89 000).

14.
Angew Chem Int Ed Engl ; 56(19): 5267-5271, 2017 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-28371002

RESUMO

The development of ligands plays a key role and provides important innovations in homogeneous catalysis. In this context, we report a novel class of ferrocenyl phosphines for the alkoxycarbonylation of industrially important alkenes. A basic feature of our ligands is the combination of sterically hindered and amphoteric moieties on the P atoms, which leads to improved activity and productivity for alkoxycarbonylation reactions compared to the current industrial state-of-the-art ligand 1,2-bis((di-tert-butylphosphino)methyl)benzene). Advantageously, palladium catalysts with these novel ligands also enable such transformations without additional acid under milder reaction conditions. The practicability of the optimized ligand was demonstrated by preparation on >10 g scale and its use in palladium-catalyzed carbonylations on kilogram scale.

15.
Chemistry ; 21(50): 18033-7, 2015 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-26503672

RESUMO

An improved domino hydroformylation/benzoin condensation to give α-hydroxy ketones has been developed. Easily available olefins are smoothly converted into the corresponding α-hydroxy ketones in high yields with excellent regioselectivities. Key to success is the use of a specific catalytic system consisting of a rhodium/phosphine complex and the CO2 adduct of an N-heterocyclic carbene.

16.
J Org Chem ; 79(8): 3519-28, 2014 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-24670223

RESUMO

The first example for the preparation of enantioenriched azo compounds from hydrazones and Morita-Baylis-Hillman adducts has been developed, affording azo compounds incorporating an oxindole scaffold in up to 91% yield along with a 93% ee value under the catalysis of (DHQ)2AQN.


Assuntos
Antraquinonas/química , Compostos Azo/síntese química , Éteres/química , Hidrazonas/química , Indóis/química , Isatina/química , Compostos Azo/química , Catálise , Estrutura Molecular , Oxindóis , Estereoisomerismo
17.
J Mater Chem B ; 12(15): 3764-3773, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38533806

RESUMO

In this study, we utilized X-ray-induced photodynamic therapy (X-PDT) against triple-negative breast cancer (TNBC) cells. To achieve this, we developed a liposome delivery system that co-loaded protoporphyrin IX (PPIX) and perfluorooctyl bromide (PFOB) in a rational manner. Low-dose X-ray at 2 Gy was employed to activate PPIX for the generation of reactive oxygen species (ROS), and the co-loading of PFOB provided additional oxygen to enhance ROS production. The resulting highly toxic ROS effectively induced cell death in TNBC. In vitro X-PDT effects, including intracellular ROS generation, cell viability, and apoptosis/necrosis assays in TNBC cells, were thoroughly investigated. Our results indicate that the nanocarriers effectively induced X-PDT effects with very low-dose radiation, making it feasible to damage cancer cells. This suggests the potential for the effective utilization of X-PDT in treating hypoxic cancers, including TNBC, with only a fraction of conventional radiotherapy.


Assuntos
Fluorocarbonos , Hidrocarbonetos Bromados , Fotoquimioterapia , Protoporfirinas , Neoplasias de Mama Triplo Negativas , Humanos , Fotoquimioterapia/métodos , Lipossomos/uso terapêutico , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Espécies Reativas de Oxigênio/metabolismo
18.
Nat Commun ; 15(1): 1818, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38443394

RESUMO

Control of CRISPR/Cas12a trans-cleavage is crucial for biosensor development. Here, we show that small circular DNA nanostructures which partially match guide RNA sequences only minimally activate Cas12a ribonucleoproteins. However, linearizing these structures restores activation. Building on this finding, an Autocatalytic Cas12a Circular DNA Amplification Reaction (AutoCAR) system is established which allows a single nucleic acid target to activate multiple ribonucleoproteins, and greatly increases the achievable reporter cleavage rates per target. A rate-equation-based model explains the observed near-exponential rate trends. Autocatalysis is also sustained with DNA nanostructures modified with fluorophore-quencher pairs achieving 1 aM level (<1 copy/µL) DNA detection (106 times improvement), without additional amplification, within 15 min, at room temperature. The detection range is tuneable, spanning 3 to 11 orders of magnitude. We demonstrate 1 aM level detection of SNP mutations in circulating tumor DNA from blood plasma, genomic DNA (H. Pylori) and RNA (SARS-CoV-2) without reverse transcription as well as colorimetric lateral flow tests of cancer mutations with ~100 aM sensitivity.


Assuntos
Helicobacter pylori , Nanoestruturas , DNA Circular/genética , RNA/genética , Sistemas CRISPR-Cas , RNA Guia de Sistemas CRISPR-Cas , DNA/genética , Ribonucleoproteínas
19.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi ; 39(1): 34-40, 2023 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-36631013

RESUMO

Objective To examine the effects of Coxsackie virus B3 (CVB3) on the NLR family, pyrin domain containing protein 3 (NLPR3) of mouse macrophages and its mechanisms. Methods RAW264.7 cells, primary mouse macrophages (bone marrow-derived macrophages or peritoneal macrophages), and short hairpin RNA (shRNA)-NLRP3 lentivirus infected RAW264.7 cells were stimulated by different dosages of CVB3. The transcript levels of NLRP3 and IL-1ß were measured by quantitative real-time PCR. IL-1ß in the supernatants of cell cultures was determined by ELISA. The protein level of NLRP3 was tested by Western blot analysis and the interacting proteins of NLRP3 were detected by co-immunoprecipitation (Co-IP). Results The transcript levels of NLRP3 and IL-1ß were significantly up-regulated in the CVB3 stimulated RAW264.7 cells and primary mouse macrophages (bone marrow-derived macrophages or peritoneal macrophages). The expression level of NLRP3 presented CVB3-dose dependence and demonstrated the highest expression level at 6 hours after CVB3 treatment. The transcript level of IL-1ß significantly increased the most at 6 hours after CVB3 treatment, while the protein level of IL-1ß peaked at 24 hours after CVB3 treatment. In the GFP-shRNA-NLRP3 lentivirus infected RAW264.7 cells, NLRP3 was obviously inhibited, and with CVB3 stimulation, IL-1ß in the supernatants of cell cultures decreased significantly. Moreover, NLRP3 antibody was used for Co-IP experiment, in which the resultant protein complex was then stained with silver nitrate. The differential protein band between different groups was identified as nicotinamide adenine dinucleotide kinase 2 (NADK2) by mass spectrometry. This result demonstrated that CVB3 induced the interaction between NADK2 and NLRP3. Conclusion CVB3 stimulation promotes the activation of NLRP3 in macrophages, thereby enhancing the expression and secretion of pro-inflammatory cytokine IL-1ß by activating NADK2.


Assuntos
Enterovirus , Macrófagos , NAD , Proteína 3 que Contém Domínio de Pirina da Família NLR , Fosfotransferases (Aceptor do Grupo Álcool) , Animais , Camundongos , Enterovirus/metabolismo , Infecções por Enterovirus/metabolismo , Inflamassomos/metabolismo , Interleucina-1beta/metabolismo , Macrófagos/metabolismo , NAD/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , RNA Interferente Pequeno/metabolismo
20.
Poult Sci ; 102(1): 102286, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36436372

RESUMO

Aflatoxin B1 (AFB1) is the most toxic subtype of aflatoxin in feed. Poultry is sensitive to AFB1, and the liver is the main target organ of AFB1. Our previous studies have shown that taraxasterol isolated from the traditional Chinese medicinal herb Taraxacum has protective effects against immune-mediated and alcoholic-induced liver injuries. This study aimed to investigate whether taraxasterol has the protective effect and its mechanism against AFB1-induced injury in chicken primary hepatocytes in vitro. The chicken primary hepatocytes were induced with AFB1 (0.05 µg/mL), and treated with taraxasterol (5, 10, and 20 µg/mL). The results showed that taraxasterol increased superoxide dismutase (SOD) and glutathione (GSH) activity and decreased malondialdehyde (MDA) and reactive oxygen species (ROS) production in AFB1-induced hepatocytes. Moreover, taraxasterol up-regulated the mRNA and protein expression of antioxidant-related factors heme oxygenase-1 (HO-1), NADPH quinone oxidoreductase 1 (NQO1) and nuclear factor erythroid E2-related factor 2 (Nrf2), while down-regulated the expression of oxidant-related factor Kelch-like ECH-associated protein 1 (Keap1) in Nrf2/Keap1 signaling pathway. In addition, taraxasterol effectively reduced AFB1-induced hepatocyte autophagy and inhibited the mRNA expression of autophagy-related genes Beclin-2, LC3-I, LC3-II, and ATG-5. Taraxasterol also inhibited AFB1-induced hepatocyte apoptosis and decreased the mRNA expression of apoptosis-related genes Caspase3 and Caspase9. These findings indicates taraxasterol alleviates oxidative stress in AFB1-induced chicken hepatocytes by activating Nrf2/Keap1 signaling pathway, and regulating the cell autophagy and apoptosis.


Assuntos
Aflatoxina B1 , Galinhas , Animais , Aflatoxina B1/toxicidade , Aflatoxina B1/metabolismo , Galinhas/genética , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Hepatócitos , Estresse Oxidativo , Apoptose , Glutationa/metabolismo , RNA Mensageiro/metabolismo
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