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1.
Int J Mol Sci ; 25(7)2024 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-38612570

RESUMO

Plants are exposed to various stressors, including pathogens, requiring specific environmental conditions to provoke/induce plant disease. This phenomenon is called the "disease triangle" and is directly connected with a particular plant-pathogen interaction. Only a virulent pathogen interacting with a susceptible plant cultivar will lead to disease under specific environmental conditions. This may seem difficult to accomplish, but soft rot Pectobacteriaceae (SRPs) is a group virulent of pathogenic bacteria with a broad host range. Additionally, waterlogging (and, resulting from it, hypoxia), which is becoming a frequent problem in farming, is a favoring condition for this group of pathogens. Waterlogging by itself is an important source of abiotic stress for plants due to lowered gas exchange. Therefore, plants have evolved an ethylene-based system for hypoxia sensing. Plant response is coordinated by hormonal changes which induce metabolic and physiological adjustment to the environmental conditions. Wetland species such as rice (Oryza sativa L.), and bittersweet nightshade (Solanum dulcamara L.) have developed adaptations enabling them to withstand prolonged periods of decreased oxygen availability. On the other hand, potato (Solanum tuberosum L.), although able to sense and response to hypoxia, is sensitive to this environmental stress. This situation is exploited by SRPs which in response to hypoxia induce the production of virulence factors with the use of cyclic diguanylate (c-di-GMP). Potato tubers in turn reduce their defenses to preserve energy to prevent the negative effects of reactive oxygen species and acidification, making them prone to soft rot disease. To reduce the losses caused by the soft rot disease we need sensitive and reliable methods for the detection of the pathogens, to isolate infected plant material. However, due to the high prevalence of SRPs in the environment, we also need to create new potato varieties more resistant to the disease. To reach that goal, we can look to wild potatoes and other Solanum species for mechanisms of resistance to waterlogging. Potato resistance can also be aided by beneficial microorganisms which can induce the plant's natural defenses to bacterial infections but also waterlogging. However, most of the known plant-beneficial microorganisms suffer from hypoxia and can be outcompeted by plant pathogens. Therefore, it is important to look for microorganisms that can withstand hypoxia or alleviate its effects on the plant, e.g., by improving soil structure. Therefore, this review aims to present crucial elements of potato response to hypoxia and SRP infection and future outlooks for the prevention of soft rot disease considering the influence of environmental conditions.


Assuntos
Gammaproteobacteria , Solanum tuberosum , Solanum , Hipóxia , Oxigênio , Agricultura
2.
Int J Mol Sci ; 25(7)2024 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-38612680

RESUMO

The central exacerbating factor in the pathophysiology of ischemic-reperfusion acute kidney injury (AKI) is oxidative stress. Lipid peroxidation and DNA damage in ischemia are accompanied by the formation of 3-nitrotyrosine, a biomarker for oxidative damage. DNA double-strand breaks (DSBs) may also be a result of postischemic AKI. γH2AX(S139) histone has been identified as a potentially useful biomarker of DNA DSBs. On the other hand, hypoxia-inducible factor (HIF) is the "master switch" for hypoxic adaptation in cells and tissues. The aim of this research was to evaluate the influence of hyperbaric oxygen (HBO) preconditioning on antioxidant capacity estimated by FRAP (ferric reducing antioxidant power) and ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) assay, as well as on oxidative stress parameter 3-nitrotyrosine, and to assess its effects on γH2AX(S139), HIF-1α, and nuclear factor-κB (NF-κB) expression, in an experimental model of postischemic AKI induced in spontaneously hypertensive rats. The animals were divided randomly into three experimental groups: sham-operated rats (SHAM, n = 6), rats with induced postischemic AKI (AKI, n = 6), and group exposed to HBO preconditioning before AKI induction (AKI + HBO, n = 6). A significant improvement in the estimated glomerular filtration rate, eGFR, in AKI + HBO group (p < 0.05 vs. AKI group) was accompanied with a significant increase in plasma antioxidant capacity estimated by FRAP (p < 0.05 vs. SHAM group) and a reduced immunohistochemical expression of 3-nitrotyrosine and γH2AX(S139). Also, HBO pretreatment significantly increased HIF-1α expression (p < 0.001 vs. AKI group), estimated by Western blot and immunohistochemical analysis in kidney tissue, and decreased immunohistochemical NF-κB renal expression (p < 0.01). Taking all of these results together, we may conclude that HBO preconditioning has beneficial effects on acute kidney injury induced in spontaneously hypertensive rats.


Assuntos
Injúria Renal Aguda , Oxigenoterapia Hiperbárica , Traumatismo por Reperfusão , Animais , Ratos , Antioxidantes , NF-kappa B , Ratos Endogâmicos SHR , Injúria Renal Aguda/etiologia , Injúria Renal Aguda/terapia , Rim , Isquemia , Reperfusão , Estresse Oxidativo , Oxigênio , Dano ao DNA , Biomarcadores , DNA
3.
Int J Mol Sci ; 25(7)2024 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-38612734

RESUMO

Being the green gold of the future, cyanobacteria have recently attracted considerable interest worldwide. This study investigates the adaptability and biocompatibility of the cyanobacterial strain Synechococcus sp. PCC 7002 with human dermal cells, focusing on its potential application in biomedical contexts. First, we investigated the adaptability of Synechococcus PCC 7002 bacteria to human cell culture conditions. Next, we evaluated the biocompatibility of cyanobacteria with common dermal cells, like 3T3 fibroblasts and HaCaT keratinocytes. Therefore, cells were directly and indirectly cocultured with the corresponding cells, and we measured metabolic activity (AlamarBlue assay) and proliferation (cell count and PicoGreen assay). The lactate dehydrogenase (LDH) assay was performed to determine the cytotoxic effect of cyanobacteria and their nutrition medium on human dermal cells. The cyanobacteria exhibited exponential growth under conventional human cell culture conditions, with the temperature and medium composition not affecting their viability. In addition, the effect of illumination on the proliferation capacity was investigated, showing a significant impact of light exposure on bacterial growth. The measured oxygen production under hypoxic conditions demonstrated a sufficient oxygen supply for further tissue engineering approaches depending on the number of bacteria. There were no significant adverse effects on human cell viability and growth under coculture conditions, whereas the LDH assay assessed signs of cytotoxicity regarding 3T3 fibroblasts after 2 days of coculturing. These negative effects were dismissed after 4 days. The findings highlight the potential of Synechococcus sp. PCC 7002 for integration into biomedical approaches. We found no cytotoxicity of cyanobacteria on 3T3 fibroblasts and HaCaT keratinocytes, thus paving the way for further in vivo studies to assess long-term effects and systemic reactions.


Assuntos
Synechococcus , Humanos , Bioensaio , Contagem de Células , Técnicas de Cultura de Células , Oxigênio
4.
Int J Mol Sci ; 25(7)2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38612759

RESUMO

As a regulator of alveolo-capillary barrier integrity, Transient Receptor Potential Vanilloid 4 (TRPV4) antagonism represents a promising strategy for reducing pulmonary edema secondary to chemical inhalation. In an experimental model of acute lung injury induced by exposure of anesthetized swine to chlorine gas by mechanical ventilation, the dose-dependent effects of TRPV4 inhibitor GSK2798745 were evaluated. Pulmonary function and oxygenation were measured hourly; airway responsiveness, wet-to-dry lung weight ratios, airway inflammation, and histopathology were assessed 24 h post-exposure. Exposure to 240 parts per million (ppm) chlorine gas for ≥50 min resulted in acute lung injury characterized by sustained changes in the ratio of partial pressure of oxygen in arterial blood to the fraction of inspiratory oxygen concentration (PaO2/FiO2), oxygenation index, peak inspiratory pressure, dynamic lung compliance, and respiratory system resistance over 24 h. Chlorine exposure also heightened airway response to methacholine and increased wet-to-dry lung weight ratios at 24 h. Following 55-min chlorine gas exposure, GSK2798745 marginally improved PaO2/FiO2, but did not impact lung function, airway responsiveness, wet-to-dry lung weight ratios, airway inflammation, or histopathology. In summary, in this swine model of chlorine gas-induced acute lung injury, GSK2798745 did not demonstrate a clinically relevant improvement of key disease endpoints.


Assuntos
Lesão Pulmonar Aguda , Antineoplásicos , Benzimidazóis , Compostos de Espiro , Animais , Suínos , Cloro/toxicidade , Canais de Cátion TRPV , Lesão Pulmonar Aguda/induzido quimicamente , Lesão Pulmonar Aguda/tratamento farmacológico , Inflamação , Oxigênio
5.
Clin Transl Sci ; 17(4): e13780, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38618722

RESUMO

Despite a rapid increase in pediatric mortality rate from prescription and illicit opioids, there is limited research on the dose-dependent impact of opioids on respiratory depression in children, the leading cause of opioid-associated death. In this article, we extend a previously developed translational model to cover pediatric populations by incorporating age-dependent pharmacokinetic, pharmacodynamic, and physiological changes compared to adults. Our model reproduced previous perioperative clinical findings that adults and children have similar risk of respiratory depression at the same plasma fentanyl concentration when specific endpoints (minute ventilation, CO2 tension in the blood) were used. However, our model points to a potential caveat that, in a perioperative setting, routine use of mechanical ventilation and supplemental oxygen maintained the blood and tissue oxygen partial pressures in patients and prevented the use of oxygen-related endpoints to evaluate the consequences of respiratory depression. In a community setting when such oxygenation procedures are not immediately available, our model suggests that the higher oxygen demand and reduced cerebrovascular reactivity could make children more susceptible to severe hypoxemia and brain hypoxia, even with the same plasma fentanyl concentration as adults. Our work indicates that when developing intervention strategies to protect children from opioid overdose in a community setting, these pediatric-specific factors may need to be considered.


Assuntos
Overdose de Opiáceos , Insuficiência Respiratória , Adulto , Humanos , Criança , Insuficiência Respiratória/induzido quimicamente , Oxigênio , Analgésicos Opioides/efeitos adversos , Fentanila/efeitos adversos
6.
Mol Biol Rep ; 51(1): 505, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38619680

RESUMO

Recent and continuing advances in gut microbiome research have pointed out the role of the gut microbiota as an unexplored source of potentially beneficial probiotic microbes. Along the lines of these advances, both public awareness and acceptance of probiotics are increasing. That's why; academic and industrial research is dedicated to identifying and investigating new microbial strains for the development of next-generation probiotics (NGPs). At this time, there is a growing interest in NGPs as biotherapeutics that alter the gut microbiome and affect various diseases development. In this work, we have focused on some emergent and promising NGPs, specifically Eubacterium hallii, Faecalibacterium prausnitzii, Roseburia spp., Akkermansia muciniphila, and Bacteroides fragilis, as their presence in the gut can have an impact on the development of various diseases. Emerging studies point out the beneficial roles of these NGPs and open up novel promising therapeutic options. Interestingly, these NGPs were found to enhance gastrointestinal immunity, enhance immunotherapy efficacy in cancer patients, retain the intestinal barrier integrity, generate valuable metabolites, especially short-chain fatty acids, and decrease complications of chemotherapy and radiotherapy. Although many of these NGPs are considered promising for the prevention and treatment of several chronic diseases, research on humans is still lacking. Therefore, approval of these microbes from regulatory agencies is rare. Besides, some issues limit their wide use in the market, such as suitable methods for the culture and storage of these oxygen-sensitive microbes. The present review goes over the main points related to NGPs and gives a viewpoint on the key issues that still hinder their wide application. Furthermore, we have focused on the advancement in NGPs and human healthiness investigations by clarifying the limitations of traditional probiotic microorganisms, discussing the characteristics of emerging NGPs and defining their role in the management of certain ailments. Future research should emphasize the isolation, mechanisms of action of these probiotics, safety, and clinical efficacy in humans.


Assuntos
Microbioma Gastrointestinal , Probióticos , Humanos , Imunoterapia , Oxigênio , Probióticos/uso terapêutico
8.
J Nanobiotechnology ; 22(1): 180, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38622591

RESUMO

To address the limitations of traditional photothermal therapy (PTT)/ photodynamic therapy (PDT) and real-time cancer metastasis detection, a pH-responsive nanoplatform (NP) with dual-modality imaging capability was rationally designed. Herein, 1 H,1 H-undecafluorohexylamine (PFC), served as both an oxygen carrier and a 19F magnetic resonance imaging (MRI) probe, and photosensitizer indocyanine green (ICG) were grafted onto the pH-responsive peptide hexahistidine (H6) to form H6-PFC-ICG (HPI). Subsequently, the heat shock protein 90 inhibitor, gambogic acid (GA), was incorporated into hyaluronic acid (HA) modified HPI (HHPI), yielding the ultimate HHPI@GA NPs. Upon self-assembly, HHPI@GA NPs passively accumulated in tumor tissues, facilitating oxygen release and HA-mediated cell uptake. Once phagocytosed by lysosomes, protonation of H6 was triggered due to the low pH, resulting in the release of GA. With near-infrared laser irradiation, GA-mediated decreased HSP90 expression and PFC-mediated increased ROS generation amplified the PTT/PDT effect of HHPI@GA, leading to excellent in vitro and in vivo anticancer efficacies. Additionally, the fluorescence and 19F MRI dual-imaging capabilities of HHPI@GA NPs enabled effective real-time primary cancer and lung metastasis monitoring. This work offers a novel approach for enhanced cancer phototherapy, as well as precise cancer diagnosis.


Assuntos
Neoplasias Pulmonares , Nanopartículas , Fotoquimioterapia , Humanos , Fototerapia/métodos , Verde de Indocianina , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/terapia , Oxigênio , Concentração de Íons de Hidrogênio , Linhagem Celular Tumoral
9.
Clin Lab ; 70(4)2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38623665

RESUMO

BACKGROUND: This study aims to ascertain the predictive value of platelet and inflammation markers in severe cases of COVID-19. METHODS: A retrospective real-world cohort study was conducted using propensity score matching (PSM). Patients were classified into severe and non-severe COVID-19 groups based on the severity of the disease, and the correlation between severe COVID-19 and laboratory parameters at admission was analyzed. RESULTS: The study included 397 adult patients, comprising 212 (53%) males and 185 (47%) females. Among these, 309 were non-severe and 88 were severe cases. The severe group had a higher median age than the non-severe group (60 vs. 42 years, p < 0.001). Independent risk factors for severe COVID-19 included age, diabetes comorbidity, fever, respiratory symptoms, platelet count, high-sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6), and the ratio of arterial oxygen partial pressure (PaO2) to the fraction of inspired oxygen (FiO2) (P/F ratio). After one-to-one PSM, adjusted for age, diabetes comorbidities, fever, and respiratory symptoms, significant differences in laboratory parameters at admission were observed. Compared to the non-severe group (n = 71), in the severe group (n = 71), elevated levels of hsCRP (median: 27.1 mg/L vs. 14.6 mg/L, p = 0.005) and IL-6 (median: 16.2 pg/mL vs. 15.3 pg/mL, p = 0.005) were observed, while platelet count (164 ± 36 × 109 vs. 180 ± 50 × 109, p = 0.02) and P/F ratio (median: 351 vs. 397, p = 0.001) were reduced. CONCLUSIONS: Elevated levels of hsCRP and IL-6, along with reduced platelet count and P/F ratio at admission, were significantly associated with severe COVID-19 and may serve as predictive indicators.


Assuntos
COVID-19 , Diabetes Mellitus , Masculino , Adulto , Feminino , Humanos , Estudos Retrospectivos , Proteína C-Reativa , Interleucina-6 , Estudos de Coortes , Pontuação de Propensão , Inflamação , Oxigênio , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/epidemiologia
10.
J Colloid Interface Sci ; 665: 825-837, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38564946

RESUMO

Photocatalytic peroxymonosulfate (PMS) oxidation systems demonstrate significant potential and promising prospects through the interconnection of photocatalytic and PMS oxidation for simultaneously achieving efficient pollutant removal and reduction of PMS dosage, which prevents resource wastage and secondary pollution. In this study, a Z-scheme Bi25FeO40/BiOCl (BOFC) heterojunction was constructed to carry out the photocatalytic PMS oxidation process for tetracyclines (TCs) pollutants at low PMS concentrations (0.08 mM). The photocatalytic PMS oxidation rate of Bi25FeO40/BiOCl composites for tetracycline hydrochloride (TCH), chlortetracycline (CTC), oxytetracycline (OTC) and doxycycline (DXC) reaches 86.6%, 83.6%, 86.7%, and 88.0% within 120 min. Simultaneously, the BOFC/PMS system under visible light (Vis) equally displayed the practical application prospects for the solo and mixed simulated TCs antibiotics wastewater. Based on the electron spin resonance (ESR) and X-ray photoelectron spectroscopy (XPS) valence band spectrum, a Z-scheme electron migration pathway was proposed to elucidate the mechanism underlying the performance enhancement of BOFC composites. Bi25FeO40 in BOFC composites can serve as active site for activating PMS by the formation of Fe3+/Fe2+ cycle. Toxicity estimation software tool (T.E.S.T.) and mung beans planting experiment demonstrates that BOFC/PMS/Vis system can reduce toxicity of TCs wastewater. Therefore, BOFC/PMS/Vis system achieves efficient examination in different water environments and efficient utilization of PMS, which displays a scientific reference for achieving environmentally-friendly and resource-saving handling processes.


Assuntos
Poluentes Ambientais , Peróxidos , Águas Residuárias , Espécies Reativas de Oxigênio , Antibacterianos , Tetraciclina , Luz , Tetraciclinas , Oxigênio
11.
S Afr J Commun Disord ; 71(1): e1-e7, 2024 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-38572899

RESUMO

BACKGROUND:  Oral feeding practices of young patients on high-flow oxygen (HFO2) have been controversial. Limited literature exists on this topic, but new studies suggest introducing oral feeds. OBJECTIVE:  This study aims to describe the changes in swallowing and feeding of a group of young children on HFO2. METHOD:  Twelve participants (mean age 34.17 months [s.d. = 3.97]) on HFO2 were assessed clinically at the bedside using the Schedule of Oral Motor Assessment. Assessments were conducted twice to determine the change in characteristics: upon approval from the managing doctor when respiratory stability on HFO2 was achieved and for a second time on the last day of receiving HFO2 (mean 2.6 days apart). Patients received standard in-patient care and speech therapy intervention. RESULTS:  Most participants displayed typical oral motor function at initial and final assessments for liquid, puree and semi-solid consistencies. Purees and soft solid consistencies were introduced to most participants (n = 11, 91.7%). Solids and chewables were challenging for all participants during both assessments. Half of the participants displayed gagging and a wet vocal quality with thin liquids at the initial assessment only. CONCLUSION:  This small-scale study found that HFO2 should not preclude oral diets, but in this sample, small amounts of oral feeding could be introduced with caution, in an individualised manner, and with a collaborative multidisciplinary approach. Further research is essential.Contribution: Partial oral feeding of specific consistencies was possible during the assessment of young paediatric in-patients on HFO2. Monitoring of individual patient characteristics and risk factors by a specialist feeding team is essential.


Assuntos
Transtornos de Deglutição , Deglutição , Humanos , Criança , Pré-Escolar , Transtornos de Deglutição/etiologia , Oxigênio , Fatores de Risco
12.
Environ Sci Technol ; 58(15): 6704-6715, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38574268

RESUMO

The transformation of toxic arsine (AsH3) gas into valuable elemental arsenic (As0) from industrial exhaust gases is important for achieving sustainable development goals. Although advanced arsenic removal catalysts can improve the removal efficiency of AsH3, toxic arsenic oxides generated during this process have not received adequate attention. In light of this, a novel approach for obtaining stable As0 products was proposed by performing controlled moderate oxidation. We designed a tailored Ni-based catalyst through an acid etching approach to alter interactions between Ni and NaY. As a result, the 1Ni/NaY-H catalyst yielded an unprecedented proportion of As0 as the major product (65%), which is superior to those of other reported catalysts that only produced arsenic oxides. Density functional theory calculations clarified that Ni species changed the electronic structure of oxygen atoms, and the formed [NiIII-OH (µ-O)] active centers facilitated the adsorption of AsH2*, AsH*, and As* reaction intermediates for As-H bond cleavage, thereby decreasing the direct reactivity of oxygen with the arsenic intermediates. This work presents pioneering insights into inhibiting excessive oxidation during AsH3 removal, demonstrating potential environmental applications for recovery of As0 from toxic AsH3.


Assuntos
Arsênio , Zeolitas , Níquel/química , Elétrons , Oxigênio , Gases
13.
Environ Sci Technol ; 58(15): 6637-6646, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38580315

RESUMO

Methanogenesis is a critical process in the carbon cycle that is applied industrially in anaerobic digestion and biogas production. While naturally occurring in diverse environments, methanogenesis requires anaerobic and reduced conditions, although varying degrees of oxygen tolerance have been described. Microaeration is suggested as the next step to increase methane production and improve hydrolysis in digestion processes; therefore, a deeper understanding of the methanogenic response to oxygen stress is needed. To explore the drivers of oxygen tolerance in methanogenesis, two parallel enrichments were performed under the addition of H2/CO2 in an environment without reducing agents and in a redox-buffered environment by adding redox mediator 9,10-anthraquinone-2,7-disulfonate disodium. The cellular response to oxidative conditions is mapped using proteomic analysis. The resulting community showed remarkable tolerance to high-redox environments and was unperturbed in its methane production. Next to the expression of pathways to mitigate reactive oxygen species, the higher redox potential environment showed an increased presence of selenocysteine and selenium-associated pathways. By including sulfur-to-selenium mass shifts in a proteomic database search, we provide the first evidence of the dynamic and large-scale incorporation of selenocysteine as a response to oxidative stress in hydrogenotrophic methanogenesis and the presence of a dynamic selenoproteome.


Assuntos
Euryarchaeota , Selênio , Metano , Proteômica , Selenocisteína/metabolismo , Euryarchaeota/metabolismo , Estresse Oxidativo , Oxigênio , Anaerobiose , Reatores Biológicos
14.
Life Sci ; 345: 122610, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38580194

RESUMO

Brain Organiods (BOs) are a promising technique for researching disease progression in the human brain. These organoids, which are produced from human induced pluripotent stem cells (HiPSCs), can construct themselves into structured frameworks. In the context of Parkinson's disease (PD), recent advancements have been made in the development of Midbrain organoids (MBOs) models that consider key pathophysiological mechanisms such as alpha-synuclein (α-Syn), Lewy bodies, dopamine loss, and microglia activation. However, there are limitations to the current use of BOs in disease modelling and drug discovery, such as the lack of vascularization, long-term differentiation, and absence of glial cells. To address these limitations, researchers have proposed the use of spinning bioreactors to improve oxygen and nutrient perfusion. Modelling PD utilising modern experimental in vitro models is a valuable tool for studying disease mechanisms and elucidating previously unknown features of PD. In this paper, we exclusively review the unique methods available for cultivating MBOs using a pumping system that mimics the circulatory system. This mechanism may aid in delivering the required amount of oxygen and nutrients to all areas of the organoids, preventing cell death, and allowing for long-term culture and using co-culturing techniques for developing glial cell in BOs. Furthermore, we emphasise some of the significant discoveries about the BOs and the potential challenges of using BOs will be discussed.


Assuntos
Células-Tronco Pluripotentes Induzidas , Doença de Parkinson , Humanos , Doença de Parkinson/metabolismo , alfa-Sinucleína/metabolismo , Mesencéfalo/metabolismo , Mesencéfalo/patologia , Organoides/metabolismo , Oxigênio/metabolismo , Neurônios Dopaminérgicos/metabolismo
15.
J Vis Exp ; (205)2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38619265

RESUMO

Reactive oxygen species (ROS) are highly unstable oxygen-containing molecules. Their chemical instability makes them extremely reactive and gives them the ability to react with important biological molecules such as proteins, nucleic acids, and lipids. Superoxide anions are important ROS generated by the reduction of molecular oxygen reduction (i.e., acquisition of one electron). Despite their initial implication exclusively in aging, degenerative, and pathogenic processes, their participation in important physiological responses has recently become apparent. In the vascular system, superoxide anions have been shown to modulate the differentiation and function of vascular smooth muscle cells, the proliferation and migration of vascular endothelial cells in angiogenesis, the immune response, and the activation of platelets in hemostasis. The role of superoxide anions is particularly important in the dysregulation of platelets and the cardiovascular complications associated with a plethora of conditions, including cancer, infection, inflammation, diabetes, and obesity. It has, therefore, become extremely relevant in cardiovascular research to be able to effectively measure the generation of superoxide anions by human platelets, understand the redox-dependent mechanisms regulating the balance between hemostasis and thrombosis and, eventually, identify novel pharmacological tools for the modulation of platelet responses leading to thrombosis and cardiovascular complications. This study presents three experimental protocols successfully adopted for the detection of superoxide anions in platelets and the study of the redox-dependent mechanisms regulating hemostasis and thrombosis: 1) dihydroethidium (DHE)-based superoxide anion detection by flow cytometry; 2) DHE-based superoxide anion visualization and analysis by single platelet imaging; and 3) spin probe-based quantification of superoxide anion output in platelets by electron paramagnetic resonance (EPR).


Assuntos
Superóxidos , Trombose , Humanos , Espécies Reativas de Oxigênio , Células Endoteliais , Oxigênio
16.
Neurotox Res ; 42(2): 25, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38619632

RESUMO

Oxygen (O2) supplementation is commonly used to treat hypoxia in patients with respiratory failure. However, indiscriminate use can lead to hyperoxia, a condition detrimental to living tissues, particularly the brain. The brain is sensitive to reactive oxygen species (ROS) and inflammation caused by high concentrations of O2, which can result in brain damage and mitochondrial dysfunction, common features of neurodegenerative disorders. Hyperoxia leads to increased production of ROS, causing oxidative stress, an imbalance between oxidants and antioxidants, which can damage tissues. The brain is particularly vulnerable to oxidative stress due to its lipid composition, high O2 consumption rate, and low levels of antioxidant enzymes. Moreover, hyperoxia can cause vasoconstriction and decreased O2 supply to the brain, posing a challenge to redox balance and neurodegenerative processes. Studies have shown that the severity of hyperoxia-induced brain damage varies with inspired O2 concentration and duration of exposure. Therefore, careful evaluation of the balance between benefits and risks of O2 supplementation, especially in clinical settings, is crucial.


Assuntos
Lesões Encefálicas , Hiperóxia , Humanos , Espécies Reativas de Oxigênio , Encéfalo , Oxigênio , Antioxidantes
17.
Sci Rep ; 14(1): 8395, 2024 04 10.
Artigo em Inglês | MEDLINE | ID: mdl-38600099

RESUMO

The aim of the present study was to investigate retinal microcirculatory and functional metabolic changes in patients after they had recovered from a moderate to severe acute COVID-19 infection. Retinal perfusion was quantified using laser speckle flowgraphy. Oxygen saturation and retinal calibers were assessed with a dynamic vessel analyzer. Arterio-venous ratio (AVR) was calculated based on retinal vessel diameter data. Blood plasma samples underwent mass spectrometry-based multi-omics profiling, including proteomics, metabolomics and eicosadomics. A total of 40 subjects were included in the present study, of which 29 had recovered from moderate to severe COVID-19 within 2 to 23 weeks before inclusion and 11 had never had COVID-19, as confirmed by antibody testing. Perfusion in retinal vessels was significantly lower in patients (60.6 ± 16.0 a.u.) than in control subjects (76.2 ± 12.1 a.u., p = 0.006). Arterio-venous (AV) difference in oxygen saturation and AVR was significantly lower in patients compared to healthy controls (p = 0.021 for AVR and p = 0.023 for AV difference in oxygen saturation). Molecular profiles demonstrated down-regulation of cell adhesion molecules, NOTCH3 and fatty acids, and suggested a bisphasic dysregulation of nitric oxide synthesis after COVID-19 infection. The results of this study imply that retinal perfusion and oxygen metabolism is still significantly altered in patients well beyond the acute phase of COVID-19. This is also reflected in the molecular profiling analysis of blood plasma, indicating a down-regulation of nitric oxide-related endothelial and immunological cell functions.Trial Registration: ClinicalTrials.gov ( https://clinicaltrials.gov ) NCT05650905.


Assuntos
COVID-19 , Oxigênio , Humanos , Oxigênio/metabolismo , Microcirculação , Óxido Nítrico , Oximetria/métodos , Vasos Retinianos , Perfusão , Proteínas Sanguíneas , Lipídeos
19.
Plant Mol Biol ; 114(3): 37, 2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38602592

RESUMO

Reactive oxygen species (ROS) is a chemically reactive chemical substance containing oxygen and a natural by-product of normal oxygen metabolism. Excessive ROS affect the growth process of crops, which will lead to the decrease of yield. Nitrogen, as a critical nutrient element in plants and plays a vital role in plant growth and crop production. Nitrate is the primary nitrogen source available to plants in agricultural soil and various natural environments. However, the molecular mechanism of ROS-nitrate crosstalk is still unclear. In this study, we used the foxtail millet (Setaria italica L.) as the material to figure it out. Here, we show that excessive NaCl inhibits nitrate-promoted plant growth and nitrogen use efficiency (NUE). NaCl induces ROS accumulation in roots, and ROS inhibits nitrate-induced gene expression in a short time. Surprisingly, low concentration ROS slight promotes and high concentration of ROS inhibits foxtail millet growth under long-term H2O2 treatment. These results may open a new perspective for further exploration of ROS-nitrate signaling pathway in plants.


Assuntos
Nitratos , Setaria (Planta) , Espécies Reativas de Oxigênio , Nitratos/farmacologia , Setaria (Planta)/genética , Peróxido de Hidrogênio , Cloreto de Sódio , Oxigênio , Transdução de Sinais , Perfilação da Expressão Gênica , Nitrogênio
20.
Cells ; 13(7)2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38607059

RESUMO

Embryonic neurogenesis can be defined as a period of prenatal development during which divisions of neural stem and progenitor cells give rise to neurons. In the central nervous system of most mammals, including humans, the majority of neocortical neurogenesis occurs before birth. It is a highly spatiotemporally organized process whose perturbations lead to cortical malformations and dysfunctions underlying neurological and psychiatric pathologies, and in which oxygen availability plays a critical role. In case of deprived oxygen conditions, known as hypoxia, the hypoxia-inducible factor (HIF) signaling pathway is activated, resulting in the selective expression of a group of genes that regulate homeostatic adaptations, including cell differentiation and survival, metabolism and angiogenesis. While a physiological degree of hypoxia is essential for proper brain development, imbalanced oxygen levels can adversely affect this process, as observed in common obstetrical pathologies such as prematurity. This review comprehensively explores and discusses the current body of knowledge regarding the role of hypoxia and the HIF pathway in embryonic neurogenesis of the mammalian cortex. Additionally, it highlights existing gaps in our understanding, presents unanswered questions, and provides avenues for future research.


Assuntos
Células-Tronco Neurais , Humanos , Animais , Gravidez , Feminino , Células-Tronco Neurais/metabolismo , Neurônios/metabolismo , Neurogênese/genética , Hipóxia/metabolismo , Oxigênio/metabolismo , Mamíferos
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