RESUMO
N2-Alkyl-2'-deoxyguanosine (N2-alkyl-dG) is a major type of minor-groove DNA lesions arising from endogenous metabolic processes and exogenous exposure to environmental contaminants. The N2-alkyl-dG lesions, if left unrepaired, can block DNA replication and transcription and induce mutations in these processes. Nevertheless, the repair pathways for N2-alkyl-dG lesions remain incompletely elucidated. By utilizing a photo-cross-linking coupled with mass spectrometry-based quantitative proteomic analysis, we identified a series of candidate N2-alkyl-dG-binding proteins. We found that two of these proteins, i.e., high-mobility group protein B3 (HMGB3) and SUB1, could bind directly to N2-nBu-dG-containing duplex DNA in vitro and promote the repair of this lesion in cultured human cells. In addition, HMGB3 and SUB1 protected cells against benzo[a]pyrene-7,8-diol-9,10-epoxide (BPDE). SUB1 exhibits preferential binding to both the cis and trans diastereomers of N2-BPDE-dG over unmodified dG. On the other hand, HMGB3 binds favorably to trans-N2-BPDE-dG; the protein, however, does not distinguish cis-N2-BPDE-dG from unmodified dG. Consistently, genetic ablation of HMGB3 conferred diminished repair of trans-N2-BPDE-dG, but not its cis counterpart, whereas loss of SUB1 conferred attenuated repair of both diastereomers. Together, we identified proteins involved in the cellular sensing and repair of minor-groove N2-alkyl-dG lesions and documented a unique role of HMGB3 in the stereospecific recognition and repair of N2-BPDE-dG.
Assuntos
Reparo do DNA , DNA , Proteína HMGB3 , Humanos , DNA/química , DNA/metabolismo , Dano ao DNA , Enzimas Reparadoras do DNA , Proteínas de Ligação a DNA/metabolismo , Proteínas de Ligação a DNA/química , Guanina/química , Guanina/metabolismo , Proteína HMGB3/metabolismo , Proteína HMGB3/química , Ligação ProteicaRESUMO
BACKGROUND: Premature ovarian failure (POF), also known as primary ovarian insufficiency, is a common endocrine disease in young women. The emergence of regenerative medicine using stem cells may improve ovarian function and structure, and represents a promising prospect for POF treatment. In his study, we explored the therapeutic effects of human umbilical cord mesenchymal stem cell (HUCMSC) transplantation in a Tibetan miniature pig model of cyclophosphamide (CTX)-induced POF. METHODS: We cultured and identified HUCMSCs, labeled them with DiR iodide red dye, and implanted them into a CTX-induced model of POF in Tibetan miniature pigs. The daily weight changes were recorded, and the levels of estradiol (E2) and follicle-stimulating hormone (FSH) were measured on days 0, 7, and 14. At the end of the 21-day observation period, in vivo imaging of the bilateral ovaries was performed, and the ovarian index was measured. Ovarian tissue morphology and follicles were examined by hematoxylin-eosin staining. The terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay was employed to assess cell apoptosis, and immunohistochemistry was used to determine the levels of p-AKT, p-ERK1/2, BAX, and BCL2 expression. RESULTS: Our analysis indicated successful delivery of HUCMSCs to the ovaries of the POF pig model. Significant increases were observed in body weight, E2 levels, ovarian index, and number of normal follicles (all p < 0.05). Moreover, FSH levels reduced and ovarian tissue morphology improved following HUCMSCs transplantation (all p < 0.05). Importantly, upregulated p-AKT, p-ERK1/2, and BCL2 expression were observed, whereas the expression of BAX was suppressed (all p < 0.05), suggesting the inhibition of ovarian cell apoptosis. CONCLUSION: Our study highlights the significant therapeutic effects of HUCMSC transplantation on CTX-induced POF in a Tibetan miniature pig model.
Assuntos
Apoptose , Ciclofosfamida , Modelos Animais de Doenças , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais , Insuficiência Ovariana Primária , Porco Miniatura , Animais , Feminino , Insuficiência Ovariana Primária/terapia , Insuficiência Ovariana Primária/induzido quimicamente , Suínos , Transplante de Células-Tronco Mesenquimais/métodos , Humanos , Apoptose/efeitos dos fármacos , Cordão Umbilical/citologia , Células Cultivadas , Estradiol/sangue , Ovário/patologiaRESUMO
Ferroptosis is a form of non-apoptotic cell death, regulated by phospholipid hydroperoxide glutathione peroxidase 4 (GPX4), a selenoprotein with a selenocysteine residue (sec) in the active site. GPX4 is a promising target for cancer cells in therapy-resistant conditions via ferroptosis, which can reduce the level of lipid reactive oxygen species (ROS). So far, all existing GPX4 inhibitors covalently bind to GPX4 via a reactive alkyl chloride moiety or masked nitrile-oxide electrophiles with poor selectivity and pharmacokinetic properties and most were obtained by cell phenotype-based screening. Lacking of effective high-throughput screening methods for GPX4 protein limits the discovery of GPX4 inhibitors. Here, we report a fluorescence polarization (FP)-based high throughput screening (HTS) assay for GPX4-U46C-C10A-C66A in vitro, and found Metamizole sodium from our in-house compound library inhibits GPX4-U46C-C10A-C66A enzyme activity. Structure-activity relationships (SAR) demonstrated the importance of sulfonyl group on interaction between Metamizole sodium and GPX4-U46C-C10A-C66A. Our FP assay could be an effective tool for discovery of GPX4 inhibitors and Metamizole sodium was a potential inhibitor for GPX4 in vitro.
Assuntos
Dipirona , Ensaios de Triagem em Larga Escala , Fosfolipídeo Hidroperóxido Glutationa Peroxidase , Selenocisteína/metabolismo , Relação Estrutura-Atividade , Glutationa Peroxidase/metabolismoRESUMO
The nutritional quality of three edible parts (gonads, hepatopancreas and muscles) of Chinese mitten crabs (CMCs) from rice field culture and pond culture was firstly compared in our current study. It was found that the contents of mineral elements and volatile compounds in rice CMCs were superior to those in pond CMCs, and the antioxidant enzyme activities of rice CMCs were markedly higher than those of pond CMCs. Besides, the total free amino acid levels in the edible parts of pond CMCs were higher than those of rice CMCs. Compared with other tissues, the nucleotide and equivalent umami concentrations of the gonads in female rice CMCs were the maximum. Overall, both types of crabs demonstrated good nutritional quality, which met human nutrition and dietary needs. In comparison, the quality of rice CMCs was better than that of pond CMCs.
RESUMO
The lethality and chemotherapy resistance of pancreatic cancer necessitates the urgent development of innovative strategies to improve patient outcomes. To address this issue, we designed a novel drug delivery system named GDMCN2,which uses iron-based metal organic framework (Fe-MOF) nanocages encased in a covalent organic framework (COF) and modified with the pancreatic cancer-specific antibody, NRP2. After being targeted into tumor cells, GDMCN2 gradually release the sonosensitizer sinoporphyrin sodium (DVDMS) and chemotherapeutic gemcitabine (GEM) and simultaneously generated reactive oxygen species (ROS) under ultrasound (US) irradiation. This system can overcome gemcitabine resistance in pancreatic cancer and reduce its toxicity to non-targeted cells and tissues. In a mechanistic cascade, the release of ROS activates the mitochondrial transition pore (MPTP), leading to the release of Ca2+ and induction of endoplasmic reticulum (ER) stress. Therefore, microtubule-associated protein 1A/1B-light chain 3 (LC3) is activated, promoting lysosomal autophagy. This process also induces autophagy-dependent ferroptosis, aided by the upregulation of Nuclear Receptor Coactivator 4 (NCOA4). This mechanism increases the sensitivity of pancreatic cancer cells to chemotherapeutic drugs and increases mitochondrial and DNA damage. The findings demonstrate the potential of GDMCN2 nanocages as a new avenue for the development of cancer therapeutics.
Assuntos
Ferroptose , Estruturas Metalorgânicas , Neoplasias Pancreáticas , Humanos , Estruturas Metalorgânicas/metabolismo , Linhagem Celular Tumoral , Espécies Reativas de Oxigênio/metabolismo , Apoptose , Anticorpos Monoclonais/uso terapêutico , Autofagia , Gencitabina , Neoplasias Pancreáticas/tratamento farmacológico , Retículo Endoplasmático/metabolismo , Neoplasias PancreáticasRESUMO
Background: Uterine corpus endometrial carcinoma (UCEC) belongs to a group of epithelial malignant tumors. Icaritin is the main active compound of Epimedii Folium. Icaritin has been utilized to induce UCEC cells to death. Methods: We wished to identify potential targets for icaritin in the treatment of UCEC, as well as to provide a groundwork for future studies into its pharmacologic mechanism of action. Network pharmacology was employed to conduct investigations on icaritin. Target proteins were chosen from the components of icaritin for UCEC treatment. A protein-protein interaction (PPI) network was established using overlapping genes. Analyses of enrichment of function and signaling pathways were undertaken using the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases, respectively, to select "hub genes". Finally, experiments were carried out to ascertain the effect of icaritin on endometrial cancer (HEC-1-A) cells. Results: We demonstrated that icaritin has bioactive components and putative targets that are therapeutically important. Icaritin treatment induced sustained activation of the phosphoinositide 3-kinase/protein kinase B (PI3K/Akt pathway) and inhibited growth of HEC-1-A cells. Conclusion: Our data provide a rationale for preclinical and clinical evaluations of icaritin for UCEC therapy.
RESUMO
Chromatin remodeling regulates many basic cellular processes, such as gene transcription, DNA repair, and programmed cell death. As the largest member of nucleosome remodeling factor (NURF), BPTF plays a vital role in the occurrence and development of cancer. Currently, BPTF bromodomain inhibitors are still in development. In this study, by conducting homogenous time-resolved fluorescence resonance energy transfer (HTRF) assay, we identified a potential, novel BPTF inhibitor scaffold Sanguinarine chloride with the IC50 value of 344.2 ± 25.1 nM. Biochemical analysis revealed that compound Sanguinarine chloride exhibited high binding affinity to the BPTF bromodomain. Molecular docking predicted the binding mode of Sanguinarine chloride and elucidated the activities of its derivatives. Moreover, Sanguinarine chloride showed a potent anti-proliferative effect in MIAPaCa-2 cells and inhibited the expression of BPTF target gene c-Myc. Taken together, Sanguinarine chloride provides a qualified chemical tool for developing potent BPTF bromodomain inhibitors.
Assuntos
Neoplasias , Fatores de Transcrição , Humanos , Fatores de Transcrição/metabolismo , Simulação de Acoplamento Molecular , Montagem e Desmontagem da CromatinaRESUMO
A simple, sensitive method for pesticide distinguishment based on a colorimetric sensor array using diverse gold nanoparticles (AuNPs) at room temperature is presented in this study. Acetylcholinesterase (AChE) hydrolysis ability was influenced by different pesticides and produced different concentrations of thiocholine by hydrolyzing acetylthiocholine iodide (ATCh). Thiocholine could be easily linked to the AuNPs through an Au - S covalent bond, and AuNPs underwent aggregation, resulting in a visible color change due to alteration of surface plasmon resonance properties. Based on these results, we successfully distinguished eight pesticides (glyphosate, thiram, imidacloprid, tribenuron methyl, nicosulfuron, thifensulfuron methyl, dichlorprop, and fenoprop) utilizing five different AuNPs by colorimetric assay. The limit of detection (LOD) of this visual method for all pesticides was less than 1.5 × 10-7 M, which was more sensitive than the U.S. Environmental Protection Agency regulations specify (1.18 â¼ 3.91 × 10-6 M). This method was further improved by combining a portable smartphone device with a color picking application using (color name AR) and RGB (red, green, blue) values. The method was successfully applied to pesticide residue distinguishment in real samples by linear discriminant analysis (LDA).
Assuntos
Nanopartículas Metálicas , Praguicidas , Estados Unidos , Colorimetria , Ouro , Smartphone , Acetilcolinesterase , TiocolinaRESUMO
This study contributes to the marriage trafficking literature by highlighting its demand, unique forms of exploitation, and conducive context through a qualitative study in China-Vietnam border areas. The findings indicate: (a) local demand for marriage constitutes a premise for the emergence and development of a marriage trafficking market, (b) three forms of exploitation distinguish marriage trafficking from other trafficking forms; (c) the local contexts conducive to the formation and facilitation of marriage trafficking also impede trafficked women's agency. In-depth interviews were conducted with marriage trafficked women who have not exited the trafficking situations, and with key local social network actors in the trafficking areas.
Assuntos
Casamento , Humanos , Feminino , Vietnã , Pesquisa Qualitativa , ChinaRESUMO
Speedy, point-of-need detection and monitoring of small-molecule metabolites are vital across diverse applications ranging from biomedicine to agri-food and environmental surveillance. Nanomaterial-based sensor (nanosensor) platforms are rapidly emerging as excellent candidates for versatile and ultrasensitive detection owing to their highly configurable optical, electrical and electrochemical properties, fast readout, as well as portability and ease of use. To translate nanosensor technologies for real-world applications, key challenges to overcome include ultralow analyte concentration down to ppb or nM levels, complex sample matrices with numerous interfering species, difficulty in differentiating isomers and structural analogues, as well as complex, multidimensional datasets of high sample variability. In this Perspective, we focus on contemporary and emerging strategies to address the aforementioned challenges and enhance nanosensor detection performance in terms of sensitivity, selectivity and multiplexing capability. We outline 3 main concepts: (1) customization of designer nanosensor platform configurations via chemical- and physical-based modification strategies, (2) development of hybrid techniques including multimodal and hyphenated techniques, and (3) synergistic use of machine learning such as clustering, classification and regression algorithms for data exploration and predictions. These concepts can be further integrated as multifaceted strategies to further boost nanosensor performances. Finally, we present a critical outlook that explores future opportunities toward the design of next-generation nanosensor platforms for rapid, point-of-need detection of various small-molecule metabolites.
RESUMO
Brominated compounds are important, but they are usually prepared in organic solvents. Here, efficient amphiphilic indole-based phase-transfer organocatalysts were developed for environmentally benign bromination reactions in water. As test reactions, hydroxybromination of olefins and aromatic bromination could be conducted in a greener and more sustainable manner compared with methods using organic solvents, producing the corresponding bromides in good yields. Some pure products could be obtained without column chromatography.
Assuntos
Halogenação , Água , Catálise , Indóis/química , Solventes/químicaRESUMO
Palmatine is a protoberberine alkaloid separated from several plants and application as an anti-inflammatory and antibacterial agent in the therapy of gastrointestinal and genitourinary disorder. Thus, the fast quantification of palmatine is important in clinic medical assays. Herein, we report simple, fast and sensitive colorimetric visualization and surface-enhanced Raman spectroscopy (SERS) dual-mode detection of palmatine basing on bimetallic size tunable silver shell capped gold nanoparticles (Au@Ag NPs). Interesting, the best signals output for dual-mode sensing of palmatine were both 5â¯nm Ag shell thickness of Au@Ag NPs. Meanwhile, we found that the addition of NaHSO4 significantly improves the aggregating sensitivity of Au@Ag NPs to trace palmatine. Upon exposure to 0.1⯵M level palmatine, NaHSO4-optimized Au@Ag NPs solution exhibits a highly sensitive color change from orange to green and rapid aggregation kinetics within the initial 5â¯min, which can directly be seen with the naked eye and monitored by UV-vis absorbance spectra. In addition, we measured palmatine by SERS with the excellent enhancement effect of Au@Ag NPs for further increase the sensitivity and selectivity. More importantly, other protoberberine alkaloids do not interfere with this dual-mode sensor due to the different interaction force between Au@Ag NPs and these alkaloids, and the applicability of the sensor is well demonstrated in real samples with satisfactory results. This provide a fast and simple assay for the rapid detection of palmatine in traditional Chinese medicine, the limit of detection (LOD) is 0.13⯵M by the naked eye and 0.10⯵M by UV-vis spectroscopy. Therefore, the size-tunable of NaHSO4-optimized Au@Ag NPs can be used not only as a naked-eye sensor of palmatine, but also as a highly selective SERS probe.
Assuntos
Alcaloides de Berberina/análise , Medicamentos de Ervas Chinesas/análise , Ouro/química , Nanopartículas Metálicas/química , Prata/química , Coloides , Colorimetria , Cinética , Ligantes , Limite de Detecção , Medicina Tradicional Chinesa , Tamanho da Partícula , Reprodutibilidade dos Testes , Espectrofotometria Ultravioleta , Análise Espectral Raman , Eletricidade Estática , Propriedades de SuperfícieRESUMO
A ratiometric probe is described for the fluorometric determination of Cu(II) ions based on their quenching effect on the luminescence of dually-emitting quantum dots (QDs). ZnS QDs were doped with Mn(II) and subsequently modified with mercaptopropionic acid to give the QD probe which consists of a sole fluorophore but has two emission peaks (at 430 and 590 nm under 310 nm excitation, respectively). On addition of Cu(II) ions, the 590 nm band is quenched while the 430 nm band exhibits a little change. The changes in the intensity ratios of the yellow and the purple bands increases linearly in the 0 to 3.0 µM Cu(II) concentration range, and the detection limit reached 14 nM. The QD probe was validated and successfully applied to the determination of Cu(II) in spiked real water samples. Graphical abstract Mn-doped ZnS (ZnS:Mn(II)) quantum dots were synthesized with yellow fluorescence. After the modification of 3-mercaptopropionic acid (MPA), ZnS:Mn(II) was transferred to aqueous phase and became MPA modified Mn-doped ZnS (MPA- ZnS:Mn(II)). The fluorescence was changed to purple upon the addition of copper ions because the yellow band was largely quenched while the purple band only changed a little.