RESUMEN

In this work, a horseradish peroxidase (HRP)-encapsulated metal organic framework (MOF)@MOF nanocomposite is developed for detecting H2O2 converted by dismutation of superoxide anions released from live HeLa mitochondria. Initially, an HRP-polyacrylic acid cluster is incorporated on a mesoporous, peroxidase-like Cu/Co-1,4-benzenedicarboxylate (BDC) MOF platform to avoid structural change and deactivation of HRP through its interactions with MOF metal ions. Additionally, a Cu/Co-BDC(HRP)@1,3,5-benzenetricarboxyate (BTC) core-shell MOF/MOF structure, also with peroxide-like properties, serves as a protective matrix for HRP. Then, ultrathin porous carbon shells (UPCS) are adopted to improve the electrical conductivity of the MOF@MOF. The Cu/Co-BDC(HRP)@BTC|UPCS sensing platform exhibits two linear ranges of 0.05-1 µM and 1-1000 µM with a sensitivity of 172 mA mM-1 cm-2 and 1.63 mA mM-1 cm-2, respectively. A limit of detection of 0.057 µM, good selectivity and stability over 35 days for H2O2 detection are also achieved. After treating the mitochondrial complex with specific inhibitors, amperometric results at the sensing platform confirmed complex I and III within mitochondria as the main electron leakage sites in the electron transfer chains. Therefore, this sensing platform provides a tool that may aid in predicting and even developing treatments for some oxidative stress diseases caused by mitochondrial abnormalities.

RESUMEN

This review summarises the data from long-term experimental studies and literature data on the role of oxidatively modified low-density lipoproteins (LDL) in atherogenesis and diabetogenesis. It was shown that not "oxidized" (lipoperoxide-containing) LDL, but dicarbonyl-modified LDL are atherogenic (actively captured by cultured macrophages with the help of scavenger receptors), and also cause expression of lectin like oxidized low density lipoprotein receptor 1 (LOX-1) and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 1 (NOX-1) genes in endotheliocytes, which stimulate apoptosis and endothelial dysfunction. The obtained data allowed us to justify new approaches to pharmacotherapy of atherosclerosis and diabetes mellitus.

RESUMEN

Human space activities have been continuously increasing. Astronauts experiencing spaceflight are faced with health problems caused by special space environments such as microgravity, and the investigation of cell injury is fundamental. The development of a platform capable of cell culture and injury detection is the prerequisite for the investigation. Constructing a platform suitable for special conditions in space life science research is the key issue. The ground-based investigation is an indispensable part of the research. Accordingly, a simulated microgravity (SMG)-oriented integrated chip platform capable of 3D cell culture and in situ visual detection of superoxide anion radical (O2•-) is developed. SMG can cause oxidative stress in human cells, and O2•- is one of the signaling molecules. Thus, a O2•--responsive aggregation-induced emission (AIE) probe is designed, which shows high selectivity and sensitivity to O2•-. Moreover, the probe exhibits abilities of long-term and wash-free staining to cells due to the AIE behavior, which is precious for space cell imaging. Meanwhile, a chip with a high-aspect-ratio chamber for adequate medium storage for the lack of the perfusion system during the SMG experiment and a cell culture chamber which can integrate the extracellular matrix (ECM) hydrogel for the bioinspired 3D cell culture is fabricated. In addition, a porous membrane is introduced between the chambers to prevent the hydrogel from separating during the SMG experiment. The afforded AIE probe-ECM hydrogel-integrated chip can achieve 3D culturing of U87-MG cells and in situ fluorescent detection of endogenous O2•- in the cells after long-term staining under SMG. The chip provides a powerful and potential platform for ground-based investigation in space life science and biomedical research.

Asunto(s)

Técnicas Biosensibles , Hidrogeles , Superóxidos , Humanos , Superóxidos/análisis , Técnicas Biosensibles/instrumentación , Técnicas Biosensibles/métodos , Hidrogeles/química , Matriz Extracelular/química , Técnicas de Cultivo de Célula/instrumentación , Simulación de Ingravidez , Diseño de Equipo , Colorantes Fluorescentes/química , Dispositivos Laboratorio en un Chip , Ingravidez , Estrés Oxidativo

RESUMEN

Opuntia plants are abundant but still underexplored edible resources of the Algerian region. This work chemically characterizes extracts of different parts of the fruit of the commercial Opuntia ficus-indica (L.) Mill. and the wild Opuntia stricta (Haw.) Haw. growing in Bejaia, and evaluates their anti-inflammatory potential through different cell and cell-free bioassays. The LC-ESI-UHR-QqTOF-MS/MS analysis enabled the identification of 18 compounds, with azelaic acid and 1-O-vanilloyl-ß-d-glucose reported here for the first time. Aqueous extracts of seeds were the most effective in scavenging superoxide anion radical (IC50 = 111.08 µg/mL) and presented the best anti-inflammatory potential in LPS-stimulated macrophages (IC50 = 206.30 µg/mL). The pulp of O. stricta suggested potential for addressing post-inflammatory hyperpigmentation, with piscidic and eucomic acids predicted with the strongest binding affinity towards tyrosinase, exhibiting higher scoring values than the reference inhibitor kojic acid. This pioneer study brings valuable perspectives for the pharmacological, nutritional and economic valorization of the wild O. stricta for functional foods.

Asunto(s)

Antiinflamatorios , Frutas , Opuntia , Extractos Vegetales , Espectrometría de Masas en Tándem , Opuntia/química , Frutas/química , Antiinflamatorios/farmacología , Antiinflamatorios/química , Extractos Vegetales/química , Extractos Vegetales/farmacología , Argelia , Animales , Ratones , Macrófagos/efectos de los fármacos , Macrófagos/inmunología , Células RAW 264.7 , Humanos , Cromatografía Líquida de Alta Presión , Espectrometría de Masa por Ionización de Electrospray

RESUMEN

Drug-induced liver injury (DILI) poses a significant risk to human health. Increasing evidence indicates that the superoxide anion (O2•-), as the precursor of the other reactive oxygen species, is key in the pathological processes associated with DILI. Nonetheless, understanding of the mechanisms of DILI is difficult due to the lack of an imaging tool for monitoring the fluctuation of O2•- levels during the progression of DILI. Herein, we developed an upconversion nanoprobe (Rbh-UCNs) for in vivo ratiometric tracking of endogenous O2•- in DILI. In this design, the addition of O2•- triggers the luminescent resonance energy transfer between Rbh and UCNs, which significantly enhances absorption centered at 534 nm and translates into a distinct decrease of the UCL emission at 543 nm, while the UCL emission peak at 654 nm and 800 nm are not significantly affected, offering a ratiometric UCL signal for the quantitative detection of O2•-. In addition, Rbh-UCNs could effectively visualize endogenous O2•- in living cells, zebrafish, and liver tissues upon stimulation with PMA or cisplatin. More importantly, tissue imaging of the liver region of mice revealed that the fluctuation of O2•- levels is associated with DILI and the protective effect of L-carnitine against DILI. Altogether, this study provides an available method for a deeper comprehension of the mechanisms underlying DILI and accelerating the development process of hepatoprotective medicines.

Asunto(s)

Enfermedad Hepática Inducida por Sustancias y Drogas , Superóxidos , Pez Cebra , Enfermedad Hepática Inducida por Sustancias y Drogas/diagnóstico por imagen , Animales , Superóxidos/análisis , Superóxidos/metabolismo , Ratones , Humanos , Nanopartículas/química , Nanopartículas/toxicidad , Rayos Infrarrojos , Imagen Óptica , Hígado/diagnóstico por imagen , Hígado/metabolismo , Luminiscencia

RESUMEN

Nitric oxide (NO) is a multifunctional signalling molecule involved in the regulation of plant ontogenesis and adaptation to different adverse environmental factors, in particular to osmotic stress. Understanding NO-induced plant protection is important for the improvement of plant stress tolerance and crop productivity under global climate changes. The root system is crucial for plant survival in a changeable environment. Damages that it experiences under water deficit conditions during the initial developmental periods seriously affect the viability of the plants. This work was devoted to the comparative analysis of the pretreatment of wheat seedlings through the root system with NO donor sodium nitroprusside (SNP) for 24 h on various parameters of redox homeostasis under exposure to osmotic stress (PEG 6000, 12%) over 0.5-24 h. The active and exhausted solutions of SNP, termed as (SNP/+NO) and (SNP/-NO), respectively, were used in this work at a concentration of 2 × 10-4 M. Using biochemistry and light microscopy methods, it has been revealed that osmotic stress caused oxidative damages and the disruption of membrane cell structures in wheat roots. PEG exposure increased the production of superoxide (O2•-), hydrogen peroxide (H2O2), malondialdehyde (MDA), and the levels of electrolyte leakage (EL) and lipid peroxidation (LPO). Stress treatment enhanced the activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT), the excretion of proline, and the rate of cell death and inhibited their division. Pretreatment with (SNP/+NO) decreased PEG-induced root damages by differently regulating the antioxidant enzymes under stress conditions. Thus, (SNP/+NO) pretreatment led to SOD, APX, and CAT inhibition during the first 4 h of stress and stimulated their activity after 24 h of PEG exposure when compared to SNP-untreated or (SNP/-NO)-pretreated and stress-subjected plants. Osmotic stress triggered the intense excretion of proline by roots into the external medium. Pretreatment with (SNP/+NO) in contrast with (SNP/-NO) additionally increased stress-induced proline excretion. Our results indicate that NO is able to mitigate the destructive effects of osmotic stress on the roots of wheat seedlings. However, the mechanisms of NO protective action may be different at certain periods of stress exposure.

RESUMEN

Introduction Oxidative stress, an imbalance between reactive oxygen species (ROS) production and antioxidant defenses, plays an important role in various dental diseases. Local anesthetics are frequently used in dentistry. The potential antioxidant activity of dental local anesthetics can contribute to dental practice. Therefore, this study aimed to investigate the ROS-scavenging activities of three commonly used dental local anesthetics, lidocaine, prilocaine, and articaine, focusing on their effects on hydroxyl radicals (HO•) and superoxide anions (O2 •-). Materials and methods The electron spin resonance (ESR) spin-trapping technique was employed to specifically measure the ROS-scavenging activities of these local anesthetics at varying concentrations. Results Lidocaine, prilocaine, and articaine exhibited concentration-dependent HO•-scavenging activities, with IC50 values of 0.029%, 0.019%, and 0.014%, respectively. Lidocaine and prilocaine showed concentration-dependent O2 •--scavenging activity, with IC50 values of 0.033% and 0.057%, respectively. However, articaine did not scavenge O2 •-. Conclusions The proactive use of dental local anesthetics may mitigate oxidative injury and inflammatory damage through direct ROS scavenging. However, further research is needed to elucidate the specific mechanisms underlying the antioxidant effects of these dental local anesthetics and their potential impact on the dental diseases associated with oxidative stress.

RESUMEN

Reactive oxygen species (ROS) including the superoxide anion (O2•-) are typically studied in cell cultures using fluorescent dyes, which provide only discrete single-point measurements. These methods lack the capabilities for assessing O2•- kinetics and release in a quantitative manner over long monitoring times. Herein, we present the fabrication and application of an electrochemical biosensor that enables real-time continuous monitoring of O2•- release in cell cultures for extended periods (> 8 h) using an O2•- specific microelectrode. To achieve the sensitivity and selectivity requirements for cellular sensing, we developed a biohybrid system consisting of superoxide dismutase (SOD) and Ti3C2Tx MXenes, deposited on a gold microwire electrode (AuME) as O2•- specific materials with catalytic amplification through the synergistic action of the enzyme and the biomimetic MXenes-based structure. The biosensor demonstrated a sensitivity of 18.35 nA/µM with a linear range from 147 to 930 nM in a cell culture medium. To demonstrate its robustness and practicality, we applied the biosensor to monitor O2•- levels in human leukemia monocytic THP-1 cells upon stimulation with lipopolysaccharide (LPS). Using this strategy, we successfully monitored LPS-induced O2•- in THP-1 cells, as well as the quenching effect induced by the ROS scavenger N-acetyl-L-cysteine (NAC). The biosensor is generally useful for exploring the role of oxidative stress and longitudinally monitoring O2•- release in cell cultures, enabling studies of biochemical processes and associated oxidative stress mechanisms in cellular and other biological environments.

Asunto(s)

Técnicas Biosensibles , Superóxido Dismutasa , Superóxidos , Humanos , Superóxidos/metabolismo , Superóxidos/análisis , Técnicas Biosensibles/métodos , Superóxido Dismutasa/metabolismo , Células THP-1 , Técnicas Electroquímicas/métodos , Técnicas Electroquímicas/instrumentación , Lipopolisacáridos/farmacología , Límite de Detección

RESUMEN

The pressing need for highly efficient antibacterial strategies arises from the prevalence of microbial biofilm infections and the emergence of rapidly evolving antibiotic-resistant strains of pathogenic bacteria. Photodynamic therapy represents a highly efficient and compelling antibacterial approach, offering promising prospects for effective control of the development of bacterial resistance. However, the effectiveness of many photosensitizers is limited due to the reduced generation of reactive oxygen species (ROS) in hypoxic microenvironment, which commonly occur in pathological conditions such as inflammatory and bacteria-infected wounds. Herein, we designed and prepared two phenothiazine-derived photosensitizers (NB-1 and NB-2), which can effectively generate superoxide anion radicals (O2●-) through the type I process. Both photosensitizers demonstrate significant efficacy in vitro for the eradication of broad-spectrum bacteria. Moreover, NB-2 possesses distinct advantages including strong membrane binding and strong generation of O2●-, rendering it an exceptionally efficient antibacterial agent against mature biofilms. In addition, laser activated NB-2 could be applied to treat MRSA-infected wound in vivo, which offers new opportunities for potential practical applications.

Asunto(s)

Antibacterianos , Biopelículas , Fotoquimioterapia , Fármacos Fotosensibilizantes , Superóxidos , Infección de Heridas , Superóxidos/metabolismo , Fármacos Fotosensibilizantes/farmacología , Fármacos Fotosensibilizantes/química , Infección de Heridas/tratamiento farmacológico , Infección de Heridas/microbiología , Antibacterianos/farmacología , Antibacterianos/química , Animales , Biopelículas/efectos de los fármacos , Ratones , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Fenotiazinas/química , Fenotiazinas/farmacología , Humanos , Especies Reactivas de Oxígeno/metabolismo

RESUMEN

Chromium (Cr) contamination in soils reduces crop yields and poses a remarkable risk to human and plant system. The main objective of this study was to observe the protective mechanisms of exogenously applied melatonin (Mel- 0.05, 0.1, and 0.15 µM) in seedlings of Brassica juncea L. under Cr (0.2 mM) stress. This was accomplished by analysing the plant's morpho-physiological, biochemical, nuclear, membrane, and cellular characteristics, as well as electrolyte leakage. Superoxide, malondialdehyde, and hydrogen peroxide increased with Cr toxicity. Cr also increased electrolyte leakage. Seedlings under Cr stress had 86.4% more superoxide anion and 27.4% more hydrogen peroxide. Electrolyte leakage increased 35.7% owing to Cr toxicity. B. juncea L. cells with high radical levels had membrane and nuclear damage and decreased viability. Besides this, the activities of the antioxidative enzymes, as POD, APOX, SOD, GST, DHAR, GPOX and GR also elevated in the samples subjected to Cr toxicity. Conversely, the activity of catalase was downregulated due to Cr toxicity. In contrast, Mel reduced oxidative damage and conserved membrane integrity in B. juncea seedlings under Cr stress by suppressing ROS generation. Moreover, the activity of antioxidative enzymes that scavenge reactive oxygen species was substantially upregulated by the exogenous application of Mel. The highest concentration of Mel (Mel c- 0.15 µM) applied showed maximum ameliorative effect on the toxicity caused by Cr. It causes alleviation in the activity of SOD, CAT, POD, GPOX, APOX, DHAR, GST and GR by 51.32%, 114%, 26.44%, 48.91%, 87.51%, 149%, 42.30% and 40.24% respectively. Histochemical investigations showed that Mel increased cell survival and reduced ROS-induced membrane and nuclear damage. The findings showed that Mel treatment upregulated several genes, promoting plant development. Its supplementation decreased RBOH1 gene expression in seedling sunder stress. The results supported the hypothesis that Mel concentrations reduce Cr-induced oxidative burst in B. juncea.

Asunto(s)

Antioxidantes , Cromo , Melatonina , Planta de la Mostaza , Estrés Oxidativo , Contaminantes del Suelo , Planta de la Mostaza/efectos de los fármacos , Planta de la Mostaza/genética , Cromo/toxicidad , Melatonina/farmacología , Antioxidantes/metabolismo , Estrés Oxidativo/efectos de los fármacos , Contaminantes del Suelo/toxicidad , Plantones/efectos de los fármacos , Plantones/genética , Especies Reactivas de Oxígeno/metabolismo , Catalasa/metabolismo , Malondialdehído/metabolismo , Peróxido de Hidrógeno , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos

RESUMEN

Ovarian tissue vitrification is associated with multiple events that promote accumulation of ROS (reactive oxygen species) which culminate in follicular apoptosis. Thus, this study was aimed at evaluating the role of melatonin in vitrification and culture of feline (Felis catus) ovarian tissue. In phase 1, domestic cat ovaries were fragmented into equal circular pieces of 1.5 mm diameter by 1 mm thickness and divided into four groups (fresh control and 3 treatments). The treatments were exposed to vitrification solutions supplemented with melatonin at 0 M, 10-9 M, and 10-7 M, then vitrified-warmed, histologically evaluated and assayed for ROS. Consequently, phase 2 experiment was designed wherein ovarian fragments were divided into two groups. One group was exposed to vitrification solution without melatonin and the other with 10-7 M melatonin supplementation, then vitrified-warmed and cultured for ten days with fresh ovarian fragments as control prior to assessment for histology, immunohistochemistry (Ki-67, MCM-7 and caspase-3) and ROS. Concentration of ROS was lower (p = 0.0009) in 10-7 M supplemented group in addition to higher proportion of grade 1 follicles. After culture, proportions of intact and activated follicles were higher (p < 0.05) in melatonin supplemented group evidenced by higher expression of Ki-67 and MCM-7. Follicular apoptosis was lower in melatonin supplemented group. In conclusion, melatonin at 10-7 M concentration preserved follicular morphological integrity while reducing ROS concentration in vitrified-warmed feline ovarian tissue. It has also promoted the follicular viability and activation with reduced apoptosis during in vitro culture of vitrified-warmed feline ovarian tissue.

Asunto(s)

Melatonina , Folículo Ovárico , Estrés Oxidativo , Vitrificación , Animales , Femenino , Gatos , Melatonina/farmacología , Estrés Oxidativo/efectos de los fármacos , Folículo Ovárico/efectos de los fármacos , Criopreservación/veterinaria , Criopreservación/métodos , Ovario/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo , Antioxidantes/farmacología , Técnicas de Cultivo de Tejidos/veterinaria , Apoptosis/efectos de los fármacos

RESUMEN

Breast cancer, the predominant malignancy afflicting women, continues to pose formidable challenges despite advancements in therapeutic interventions. This study elucidates the potential of phototherapy, comprising both photothermal and photodynamic therapy (PTT/PDT), as a novel and promising modality. To achieve this goal, we devised liposomes coated with macrophage cell membranes including macrophage-associated membrane proteins, which have demonstrated promise in biomimetic delivery systems for targeting tumors while preserving their inherent tumor-homing capabilities. This integrated biomimetic delivery system comprised IR780, NONOate, and perfluorocarbon. This strategic encapsulation aims to achieve a synergistic combination of photodynamic therapy (PDT) and reactive nitrogen species (RNS) therapy. Under near-infrared laser irradiation at 808 nm, IR780 demonstrates its ability to prolifically generate reactive oxygen species (ROS), including superoxide anion (O2•-), singlet oxygen, and hydroxyl radical (·OH). Simultaneously, NONOate releases nitric oxide (NO) gas upon the same laser irradiation, thereby engaging with IR780-induced ROS to facilitate the formation of peroxynitrite anion (ONOO-), ultimately inducing programmed cell death in cancer cells. Additionally, the perfluorocarbon component of our delivery system exhibits a notable affinity for oxygen and demonstrates efficient oxygen-carrying capabilities. Our results demonstrate that IR780-NO-PFH-Lip@M significantly enhances breast cancer cell toxicity, reducing proliferation and in vivo tumor growth through simultaneous heat, ROS, and RNS production. This study contributes valuable insights to the ongoing discourse on innovative strategies for advancing cancer therapeutics.

Asunto(s)

Neoplasias de la Mama , Liposomas , Macrófagos , Fotoquimioterapia , Especies de Nitrógeno Reactivo , Liposomas/química , Femenino , Animales , Especies de Nitrógeno Reactivo/metabolismo , Ratones , Neoplasias de la Mama/terapia , Neoplasias de la Mama/patología , Neoplasias de la Mama/tratamiento farmacológico , Humanos , Macrófagos/metabolismo , Macrófagos/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo , Membrana Celular/metabolismo , Membrana Celular/química , Proliferación Celular/efectos de los fármacos , Fluorocarburos/química , Fluorocarburos/farmacología , Indoles/química , Indoles/farmacología , Supervivencia Celular/efectos de los fármacos , Fármacos Fotosensibilizantes/química , Fármacos Fotosensibilizantes/farmacología , Ratones Endogámicos BALB C , Fototerapia/métodos , Antineoplásicos/farmacología , Antineoplásicos/química , Línea Celular Tumoral , Propiedades de Superficie , Células RAW 264.7 , Tamaño de la Partícula

RESUMEN

Antimicrobial photoinactivation (API) has shown some promise in potentially treating different nosocomial bacterial infections, however, its application on staphylococci, especially other than Staphylococcus aureus or methicillin-resistant S. aureus (MRSA) species is still limited. Although S. aureus is a well-known and important nosocomial pathogen, several other species of the genus, particularly coagulase-negative Staphylococcus (CNS) species such as Staphylococcus epidermidis and Staphylococcus saprophyticus, can also cause healthcare-associated infections and foodborne intoxications. CNS are often involved in resilient biofilm formation on medical devices and can cause infections in patients with compromised immune systems or those undergoing invasive procedures. In this study, the effects of chlorophyllin and riboflavin-mediated API on S. epidermidis and S. saprophyticus planktonic cells and biofilm are demonstrated for the first time. Based on the residual growth determination and metabolic reduction ability changes, higher inactivating efficiency of chlorophyllin-mediated API was determined against the planktonic cells of both tested species of bacteria and against S. saprophyticus biofilm. Some insights on whether aqueous solutions of riboflavin and chlorophyllin, when illuminated with optimal exciting wavelength (440 nm and 402 nm, respectively) generate O2-•, are also provided in this work.

RESUMEN

Reactive oxygen species (ROS) are produced by energy transfer and electron transport in plant chloroplast thylakoids at non-toxic levels under normal growth conditions, but at threatening levels under adverse or fluctuating environmental conditions. Among chloroplast ROS, singlet oxygen and superoxide anion radical, respectively, produced by photosystem II (PSII) and PSI, are known to be the major ROS under several stress conditions. Both are very unlikely to diffuse out of chloroplasts, but they are instead capable of triggering ROS-mediated chloroplast operational retrograde signalling to activate defence gene expression in concert with hormones and other molecular compounds. Therefore, their detection, identification and localization in vivo or in biological preparations is a priority for a deeper understanding of their role in (concurrent) regulation of plant growth and defence responses. Here, we present two EPR spin traps, abbreviated as TEMPD-HCl and DEPMPO, to detect and identify ROS in complex systems, such as isolated thylakoids, together with some hints and cautions to perform reliable spin trapping experiments.

Asunto(s)

Superóxidos , Tilacoides , Oxígeno Singlete , Especies Reactivas de Oxígeno , Detección de Spin , Aniones

RESUMEN

Photocatalytic oxygen reduction reactions and water oxidation reactions are extremely promising green approaches for massive H2O2 production. Nonetheless, constructing effective photocatalysts for H2O2 generation is critical and still challenging. Since the network topology has significant impacts on the electronic properties of two dimensional (2D) polymers, herein, for the first time, we regulated the H2O2 photosynthetic activity of 2D covalent organic frameworks (COFs) by topology. Through designing the linking sites of the monomers, we synthesized a pair of novel COFs with similar chemical components on the backbones but distinct topologies. Without sacrificial agents, TBD-COF with cpt topology exhibited superior H2O2 photoproduction performance (6085 and 5448 µmol g-1 h-1 in O2 and air) than TBC-COF with hcb topology through the O2-O2⋅--H2O2, O2-O2⋅--O2 1-H2O2, and H2O-H2O2 three paths. Further experimental and theoretical investigations confirmed that during the H2O2 photosynthetic process, the charge carrier separation efficiency, O2⋅- generation and conversion, and the energy barrier of the rate determination steps in the three channels, related to the formation of *OOH, *O2 1, and *OH, can be well tuned by the topology of COFs. The current study enlightens the fabrication of high-performance photocatalysts for H2O2 production by topological structure modulation.

RESUMEN

Superoxide anion (O2•-), a significant reactive oxygen species (ROS) within biological systems, plays a widespread role in cellular function regulation and is closely linked to the onset and progression of numerous diseases. To unveil the pathological implications of O2•- in these diseases, the development of effective monitoring techniques within biological systems is imperative. Small molecule fluorescent probes have garnered considerable attention due to their advantages: simplicity in operation, heightened sensitivity, exceptional selectivity, and direct applicability in monitoring living cells, tissues, and animals. In the past few years, few reports have focused on small molecule fluorescence probes for the detection of O2•-. In this small review, we systematically summarize the design and application of O2•- responsive small molecule fluorescent probes. In addition, we present the limitations of the current detection of O2•- and suggest the construction of new fluorescent imaging probes to indicate O2•- in living cells and in vivo.

RESUMEN

Cyanobacteria are among the oldest organisms colonizing Earth. Their great biodiversity and ability to biosynthesize secondary metabolites through a variety of routes makes them attractive resources for biotechnological applications and drug discovery. In this pioneer study, four filamentous cyanobacteria (Cephalothrix lacustris LEGE 15493, Leptolyngbya boryana LEGE 15486, Nodosilinea nodulosa LEGE 06104 and Leptothoe sp. LEGE 11479) were explored for their anti-inflammatory potential in cell and cell-free in vitro bioassays, involving different inflammatory mediators and enzymes. Extracts of different polarities were sequentially prepared and chemically characterized for their content of phycobiliproteins (PBPs) and carotenoids. HPLC-PDA analysis of the acetone extracts revealed ß-carotene to be the dominant carotenoid (18.4-44.3 mg/g) and zeaxanthin as the dominant xanthophyll (52.7-192.9 mg/g), with Leptothoe sp. LEGE 11479 and Nodosilinea nodulosa LEGE 06104, respectively, being the richest strains. The PBP profile was in accordance with the color presented by the aqueous extracts, with Leptolyngbya boryana LEGE 15486 being the richest in phycocyanin (204.5 µg/mg) and Leptothoe sp. LEGE 11479 the richest in phycoerythrin (78.5 µg/mg). Aqueous extracts were more effective in superoxide anion radical scavenging, while acetone ones were more effective in scavenging nitric oxide radical (●NO) and in inhibiting lipoxygenase. Acetone extracts also reduced ●NO production in lipopolysaccharide-stimulated RAW 264.7 macrophages, with the mechanistic study suggesting a downregulation of the inducible nitric oxide synthase expression. Nodosilinea nodulosa LEGE 06104 and Leptothoe sp. LEGE 11479 acetone extracts presented the lowest IC50 values for the mentioned assays, pointing them out as promising resources for the development of new multi-target anti-inflammatory therapies.

Asunto(s)

Acetona , Cianobacterias , Óxido Nítrico Sintasa de Tipo II , Antiinflamatorios , Carotenoides , Radicales Libres

RESUMEN

Detection of superoxide anion (O2·-) levels holds significant importance for the diagnosis and even clinical treatments of oxidative stress-related diseases. Herein, we prepared a composite electrode material to encapsulate copper-zinc superoxide dismutase (SOD1) for biosensing of O2·-. The sensing material consists of gold nanowires (AuNWs), reduced graphene oxide (rGO), carboxymethyl cellulose (CMC) and PEDOT:PSS. CMC provides abundant -COOH to bind SOD1, with a high adsorption coverage of 1.499 × 10-9 mol cm-2 on the sensor surface. rGO and PEDOT endow the composite with significant conductivity, whereas PSS has antifouling capability. Moreover, AuNWs exhibit excellent electrical conductivity and a high aspect ratio, which promotes electron transfer, and ultimately enhances the catalytic performance of the enzyme. Meanwhile, SOD1(Cu2+) catalyzes the dismutation of O2·- to O2 and H2O2, and H2O2 is then electrochemically oxidized to generate amperometric signals for determination of O2·-. The sensor demonstrates outstanding detection performance for O2·- with a low detection limit of 2.52 nM, and two dynamic ranges (14.30 nM-1.34 µM and 1.34 µM-42.97 µM) with corresponding sensitivity of 0.479 and 0.052 µA µM-1cm-2, respectively. Additionally, the calculated apparent Michaelis constant (Kmapp) of 1.804 µM for SOD1 demonstrates the outstanding catalytic activity and the surface-immobilized enzyme's substrate affinity. Furthermore, the sensor shows the capability to dynamically detect the level of O2·- released from living HepG2 cells. This study provides an inovative design to obtain a biocompatible electrochemical sensing platform with plenty of immobilization sites for biomolecules, large surface area, high conductivity and flexibility.

Asunto(s)

Técnicas Biosensibles , Grafito , Superóxidos/química , Carboximetilcelulosa de Sodio , Peróxido de Hidrógeno , Superóxido Dismutasa-1 , Técnicas Biosensibles/métodos , Grafito/química , Superóxido Dismutasa/química , Técnicas Electroquímicas

RESUMEN

Ferroptosis is an emerging iron-dependent oxidative cell death type, and recently has been demonstrated to show close relation with Golgi apparatus (GA). Exploring the fluctuation of superoxide anion (O2•-) level in GA during ferroptosis is of great significance to profoundly study the biological functions of GA in ferroptosis. Here, we present a GA-targeting probe (N-GA) to monitor cellular O2•- during ferroptosis. N-GA employed a triflate group and a tetradecanoic amide unit as the recognition site for O2•- and GA-targeting unit, respectively. After the response of N-GA to O2•-, the triflate unit of N-GA converted into hydroxyl group with strong electron-donating ability, generating bright green fluorescence under UV light. N-GA exhibited excellent sensitivity and selectivity towards O2•-. Fluorescence imaging results showed that N-GA could be applied as a GA-targeting probe to monitor cellular O2•-. The stimulation of cells with PMA and rotenone could result in the massive generation of endogenous O2•- in GA. Erastin-induced ferroptosis can markedly induce the increase of O2•- level in GA. Similar to Fer-1 and DFO, dihydrolipoic acid (DHLA) and rutin were demonstrated to inhibit the enormous production of O2•- in GA of the living cells during ferroptosis.

Asunto(s)

Ferroptosis , Superóxidos , Colorantes Fluorescentes/toxicidad , Hierro , Aparato de Golgi/metabolismo

RESUMEN

Nanoplastics (NPs) is a novel plastic contaminant that could be taken up by cells and lead to severe biotoxicity toxicity, NPs in cells can cause oxidant damage by inducing reactive oxygen species (ROS) production and lead to acute inflammation. As a major ROS which related to many kinds of physiological and pathological processes, superoxide anion radical (O2•-) could be utilized as a signal of oxidant damage effected by NPs exposure in vivo. To detect the toxic damage mechanism of NPs, a fluorescence probe Bcy-OTf has been developed to monitor O2•- fluctuations content in cells and aquatic organisms after exposure to NPs. The probe has a high sensitivity (LOD = 20 nM) and a rapid responsive time (within 6 min), and it has high selectivity and low cytotoxicity to analysis the levels of the endogenous O2•-. Endogenous O2•- induced by NPs in living cells, Daphnia magna and larval zebrafish were analyzed. Moreover, the results confirmed the key role of MAPK and NF-κB pathway in NPs stimulation mechanisms in cells. This study indicated that Bcy-OTf can precisely assess the fluctuations of endogenous O2•-, which has potential for applying in further analysis mechanisms of NPs biological risks.

Asunto(s)

Daphnia magna , Microplásticos , Especies Reactivas de Oxígeno , Superóxidos , Contaminantes Químicos del Agua , Pez Cebra , Animales , Daphnia magna/efectos de los fármacos , Colorantes Fluorescentes/química , Larva/efectos de los fármacos , Larva/metabolismo , Microplásticos/toxicidad , Nanopartículas/toxicidad , FN-kappa B/metabolismo , Oxidación-Reducción , Especies Reactivas de Oxígeno/metabolismo , Superóxidos/metabolismo , Contaminantes Químicos del Agua/toxicidad