Oxygen Species Production Research Articles

Protective role of glycine and kolaviron on lipopolysaccharide-induced alterations of raw U937 cells and U937-derived macrophages

The effect of glycine and kolaviron on lipopolysaccharide-induced U937 cell damage and activation of U937-derived macrophages was studied. U937 cells were incubated with either glycine or kolaviron or both for 24 h before exposure to lipopolysaccharide. Cell viability and production of reactive oxygen species (ROS) were later assessed. In the other experiment, the U937 cells were transformed to the macrophage form using phorbol 12-myristate 13-acetate and incubated with or without glycine or kolaviron or both before exposure to lipopolysaccharide. Production of TNF-α, IL-1, IL-6 and NO were later assessed. The expression of the antioxidant enzymes- superoxide dismutase (SOD) and catalase (CAT) was also evaluated via reverse transcription polymerase chain reaction (RT PCR). It revealed that lipopolysaccharide caused significant cell death and production of reactive oxygen species that was reduced by glycine and kolaviron. Glycine and kolaviron also reduced lipopolysaccharide-mediated secretion of TNF-α, IL-1, IL-6 and NO in U937-derived macrophages. In some cases, pre-incubation of cells with both glycine and kolaviron was better than the individual responses. Glycine and kolaviron also reduced lipopolysaccharide-induced alterations in the expression of SOD and CAT (p<0.05). The study shows that both glycine and kolaviron (either separately or in combination) reduced lipopolysaccharide-mediated alterations in U937 cells and U937-derived macrophages.

A Pilot Single Cell Analysis of the Zebrafish Embryo Cellular Responses to Uropathogenic Escherichia coli Infection.

Uropathogenic Escherichia coli (UPEC) infections are common and when they disseminate can be of high morbidity. We studied the effects of UPEC infection using single cell RNA sequencing (scRNAseq) in zebrafish. Bulk RNA sequencing has historically been used to evaluate gene expression patterns, but scRNAseq allows gene expression to be evaluated at the single cell level and is optimal for evaluating heterogeneity within cell types and rare cell types. Zebrafish cohorts were injected with either saline or UPEC, and scRNAseq and canonical pathway analyses were performed. Canonical pathway analysis of scRNAseq data provided key information regarding innate immune pathways in the cells determined to be thymus cells, ionocytes, macrophages/monocytes, and pronephros cells. Pathways activated in thymus cells included interleukin 6 (IL-6) signaling and production of reactive oxygen species. Fc receptor-mediated phagocytosis was a leading canonical pathway in the pronephros and macrophages. Genes that were downregulated in UPEC vs saline exposed embryos involved the cellular response to the Gram-negative endotoxin lipopolysaccharide (LPS) and included Forkhead Box O1a (Foxo1a), Tribbles Pseudokinase 3 (Trib3), Arginase 2 (Arg2) and Polo Like Kinase 3 (Plk3). Because 4-day post fertilization zebrafish embryos only have innate immune systems, the scRNAseq provides insights into pathways and genes that cell types utilize in the bacterial response. Based on our analysis, we have identified genes and pathways that might serve as genetic targets for treatment and further investigation in UPEC infections at the single cell level.

Inflammation Promotes Oxidative and Nitrosative Stress in Chronic Myelogenous Leukemia

Chronic inflammation is characterized by the production of reactive oxygen species (ROS), reactive nitrogen species, and inflammatory cytokines in myeloproliferative neoplasms (MPNs). In addition to these parameters, the aim of this study was to analyze the influence of ROS on the proliferation-related AKT/mTOR signaling pathway and the relationship with inflammatory factors in chronic myelogenous leukemia (CML). The activity of the antioxidant enzymes superoxide dismutase, glutathione peroxidase, and catalase is reduced in erythrocytes while levels of the oxidative stress markers malondialdehyde and protein carbonyl are elevated in the plasma of patients with CML. In addition, nitrogen species (nitrotyrosine, iNOS, eNOS) and inflammation markers (IL-6, NFkB, and S100 protein) were increased in granulocytes of CML while anti-inflammatory levels of IL-10 were decreased in plasma. CML granulocytes exhibited greater resistance to cytotoxic H2O2 activity compared to healthy subjects. Moreover, phosphorylation of the apoptotic p53 protein was reduced while the activity of the AKT/mTOR signaling pathway was increased, which was further enhanced by oxidative stress (H2O2) in granulocytes and erythroleukemic K562 cells. IL-6 caused oxidative stress and DNA damage that was mitigated using antioxidant or inhibition of inflammatory NFkB transcription factor in K562 cells. We demonstrated the presence of oxidative and nitrosative stress in CML, with the former mediated by AKT/mTOR signaling and stimulated by inflammation.

PPARγ/SOD2 Protects Against Mitochondrial ROS-Dependent Apoptosis via Inhibiting ATG4D-Mediated Mitophagy to Promote Pancreatic Cancer Proliferation.

Pancreatic ductal adenocarcinoma (PDAC) is an extremely aggressive disease with poor prognosis. Our previous study found that peroxisome proliferator activated receptor gamma (PPARγ) was capable of enhancing glycolysis in PDAC cells. However, whether PPARγ could promote PDAC progression remains unclear. In our present study, PPARγ was positively associated with tumor size and poor prognosis in PDAC patients. Functional assays demonstrated that PPARγ could promote the proliferation of pancreatic cancer cells in vitro and in vivo. Additionally, flow cytometry results showed that PPARγ decreased mitochondrial reactive oxygen species (mitochondrial ROS) production, stabilized mitochondrial membrane potential (MMP) and inhibited cell apoptosis via up-regulating superoxide dismutase 2 (SOD2), followed by the inhibition of ATG4D-mediated mitophagy. Meanwhile, the activation of PPARγ might reduce pancreatic cancer cell stemness to improve PDAC chemosensitivity via down-regulating ATG4D. Thus, these results revealed that PPARγ/SOD2 might protect against mitochondrial ROS-dependent apoptosis via inhibiting ATG4D-mediated mitophagy to promote pancreatic cancer proliferation, further improving PDAC chemosensitivity.

Lifespan Increase of Podospora anserina by Oleic Acid Is Linked to Alterations in Energy Metabolism, Membrane Trafficking and Autophagy.

The maintenance of cellular homeostasis over time is essential to avoid the degeneration of biological systems leading to aging and disease. Several interconnected pathways are active in this kind of quality control. One of them is autophagy, the vacuolar degradation of cellular components. The absence of the sorting nexin PaATG24 (SNX4 in other organisms) has been demonstrated to result in impairments in different types of autophagy and lead to a shortened lifespan. In addition, the growth rate and the size of vacuoles are strongly reduced. Here, we report how an oleic acid diet leads to longevity of the wild type and a PaAtg24 deletion mutant (ΔPaAtg24). The lifespan extension is linked to altered membrane trafficking, which abrogates the observed autophagy defects in ΔPaAtg24 by restoring vacuole size and the proper localization of SNARE protein PaSNC1. In addition, an oleic acid diet leads to an altered use of the mitochondrial respiratory chain: complex I and II are bypassed, leading to reduced reactive oxygen species (ROS) production. Overall, our study uncovers multiple effects of an oleic acid diet, which extends the lifespan of P. anserina and provides perspectives to explain the positive nutritional effects on human aging.

Increased MCL-1 synthesis promotes irradiation-induced nasopharyngeal carcinoma radioresistance via regulation of the ROS/AKT loop

Worldwide, nasopharyngeal carcinoma (NPC) is a rare head and neck cancer; however, it is a common malignancy in southern China. Radiotherapy is the most important treatment strategy for NPC. However, although radiotherapy is a strong tool to kill cancer cells, paradoxically it also promotes aggressive phenotypes. Therefore, we mimicked the treatment process in NPC cells in vitro. Upon exposure to radiation, a subpopulation of NPC cells gradually developed resistance to radiation and displayed cancer stem-cell characteristics. Radiation-induced stemness largely depends on the accumulation of the antiapoptotic myeloid cell leukemia 1 (MCL-1) protein. Upregulated MCL-1 levels were caused by increased stability and more importantly, enhanced protein synthesis. We showed that repeated ionizing radiation resulted in persistently enhanced reactive oxygen species (ROS) production at a higher basal level, further promoting protein kinase B (AKT) signaling activation. Intracellular ROS and AKT activation form a positive feedback loop in the process of MCL-1 protein synthesis, which in turn induces stemness and radioresistance. AKT/MCL-1 axis inhibition attenuated radiation-induced resistance, providing a potential target to reverse radiation therapy-induced radioresistance.

SIGNALING ROLE OF REACTIVE OXYGEN SPECIES IN PLATELETS

Abstract: Review. Reactive oxygen species are formed as a result of redox reactions and are involved in signaling associated with cell growth, differentiation, and death. Platelets are both a source and a target of reactive oxygen species. The review regards the molecular mechanisms of the reactive oxygen species formation under platelet activation conditions and effects of altered redox balance on platelet function. The main platelet sources of reactive oxygen species are isoforms of NADPH oxidases, cyclooxygenase, xanthine oxidase, and mitochondrial electron transport chain. Reactive oxygen species produced during platelet activation by agonists act as secondary messengers and can interfere with signaling pathways that enhance agonist-induced platelet activation. The signaling pathway mediated by glycoprotein VI, the main platelet receptor for collagen, leading mainly to the generation of intracellular reactive oxygen species, as well as the signaling pathway activated by thrombin, leading to the production of extracellular reactive oxygen species are considered. Extracellular reactive oxygen species enhance initial signaling and support platelet recruitment and activation. Activated platelets are involved in the coupling of thrombosis, inflammation, and innate immune responses. The platelet antioxidant systems play an important role in preventing the cytotoxic effects of reactive oxygen species, as well as in the regulation of platelet signaling pathways. The authors of the review and other researchers have shown that the redox status of platelets can serve as a biomarker in the studies on prevention and treatment of diseases involving oxidative stress and can be used for objective assessments of the patients' condition severity (including depression and schizophrenia, in which the authors found a decrease in the activity of platelet glutathione -dependent antioxidant enzymes).

Comparative Efficiency of Lutein and Astaxanthin in the Protection of Human Corneal Epithelial Cells In Vitro from Blue-Violet Light Photo-Oxidative Damage

The aim of this study was to compare in vitro the protective and antioxidant properties of lutein and astaxanthin on human primary corneal epithelial cells (HCE-F). To this purpose, HCE-F cells were irradiated with a blue-violet light lamp (415–420 nm) at different energies (20 to 80 J/cm2). Lutein and astaxanthin (50 to 250 μM) were added to HCE-F right before blue-violet light irradiation at 50 J/cm2. Viability was evaluated by the CKK-8 assay while the production of reactive oxygen species (ROS) by the H2DCF-DA assay. Results have shown that the viability of HCE-F cells decreased at light energies from 20 J/cm2 to 80 J/cm2, while ROS production increased at 50 and 80 J/cm2. The presence of lutein or astaxanthin protected the cells from phototoxicity, with lutein slightly more efficient than astaxanthin also on the blunting of ROS, prevention of apoptotic cell death and modulation of the Nrf-2 pathway. The association of lutein and astaxanthin did not give a significant advantage over the use of lutein alone. Taken together, these results suggest that the association of lutein and astaxanthin might be useful to protect cells of the ocular surface from short (lutein) and longer (astaxanthin) wavelengths, as these are the most damaging radiations hitting the eye from many different LED screens and solar light.

Isoalantolactone Enhances the Antitumor Activity of Doxorubicin by Inducing Reactive Oxygen Species and DNA Damage.

Colon cancer is one of the most common cancer in the world. Doxorubicin (DOX) is a classical anti-tumor drug which widely used in treatment of cancers, however, high toxicity limited its further clinical application. Thus, it is urgent to find new drugs with low toxicity and high efficiency to treat colon cancer. Isoalantolactone (IATL), an isomeric sesquiterpene lactone isolated from the plant of inula helenium, has been reported to have anti-cancer activity against a variety of cancer cells. However, the function of IATL in colon cancer remains unclear. Here, we demonstrated that IATL inhibited colon cancer cell growth by increasing cellular reactive oxygen species (ROS) production. Further study showed that ROS accumulation contributed to DNA damage and JNK signaling pathway activation. In addition, we found that IATL markedly enhanced DOX-induced cell cytotoxicity in colon cancer cells. IATL in combination with DOX significantly increased the ROS production, induced DNA damage and activated JNK signaling pathway. Taken together, our data suggested that combined treatment with IATL and DOX may serve as a potential therapeutics for colon cancer.

Ferric Ammonium Citrate Upregulates PD-L1 Expression through Generation of Reactive Oxygen Species.

Iron plays an important role in macrophage polarization by altering metabolic and redox status. However, the impact of iron on the immune status of macrophages is still controversial. In this study, we report that ferric ammonium citrate (FAC) upregulates PD-L1 expression in macrophages. FAC not only altered the phenotype of macrophages but also led to enriching immune-modulatory T cell subsets. Since iron is known to be a constituent of coenzymes facilitating metabolic processes in mitochondria, we examined the metabolic status of FAC-overloaded macrophages by measuring the oxygen consumption rate (OCR) and the represented coenzyme, aconitase. In addition to enhancement of metabolic processes, FAC accelerated the Fenton reaction in macrophages, which also contributed to the facilitation of oxygen consumption. We reasoned that the enhancement of the OCR leads to the production of reactive oxygen species (ROS), which are directly linked to PD-L1 induction. Using ferrostatin, rotenone, and N-acetyl-L-cysteine, we confirmed that metabolic and redox regulation is responsible for FAC-mediated PD-L1 expression. Furthermore, we suggested that FAC-induced ROS production may explain FAC-mediated pro- and anti-inflammatory responses in macrophages. These findings may extend our understanding of regulating iron concentration during immune checkpoint therapy in cancer patients.

Study on a Ru(III) complex containing picolinate with potent inhibition effect against melanoma cell line

A ruthenium(III) complex formulated as [Ru(pyc)3]·H2O (where pyc is pyridine-2-carboxylate) was prepared through a one-pot reaction of pyridine-2,6-dicarboxylic acid and anhydrous ruthenium(III) chloride. Here, hydrothermal conditions led to decarboxylation from pyridine-2,6-dicarboxylic acid into pyridine-2-carboxylate. The compound was identified by spectroscopic methods and its crystal structure was determined by single-crystal X-ray diffraction. The cytotoxicity of the compounds was evaluated by MTT(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide) assay against three cancer cell lines containing a human melanoma (A375), a human non-small cell lung carcinoma (H1299), a human colon adenocarcinoma (HT29), and also one normal cell human foreskin fibroblast (HFF). A strong and selective inhibitory effect of the complex (IC50 = 6.50 μM, viability inhibition = 67.12%) was exhibited toward A375 cells. The apoptosis through a mitochondrial pathway was suggested via reactive oxygen species (ROS) production and mitochondria membrane potential (MMP) collapse. The cytostatic effect of the complex in the A375 3 D spheroid model was depicted.

Investigation of Reactive Oxygen Species production in Human Hepatocytes

1. Aim/Background: Reactive oxygen species (ROS) have been identified as compounds responsible for producing cellular damage. The purpose of this research is to examine if there is production of reactive oxygen species through free radical intermediates within human hepatocytes treated with morphine, bilirubin, or furosemide. The investigation examines the early stages of biotransformation by measuring the levels of reactive oxygen species produced inside of the treated hepatocytes within the first and second hours of treatment. The experiment was designed upon a case of a jaundiced (elevated bilirubin) infant who received morphine and furosemide and later died through unknown mechanisms. The experiment looks to examine if these drug compounds could contribute to cellular damage. This can help to further understand the potential interactions and complications of free radical intermediates produced during the phases of biotransformation. 2. Method: Previously cultured human hepatocytes were washed by centrifugation and re-suspended in 1x supplemental buffer to a concentration of 1x106 cells/mL and seeded in a dark clear bottom 96-well microplate at 100,000 stained cells/well. The cells were treated with either furosemide, morphine, bilirubin, a Tert-Butyl hydro peroxide (TBHP) positive control, or left as a background. Reactive oxygen generated in the presence of these agents were quantified by fluorescence excitation/emission measurement at 495nm/529nm. Fluorescence was measured at one and two hours. ROS generated convert 2',7'-dichlorodihydrofluorescein diacetate to 2',7'-dichlorodihydrofluorescein within the cells, which fluoresces. The fluorescence intensity detected is equivalent to the level of ROS generated. Wells that were untreated were used as blanks and subtracted from background and TBPH. 3. Results: Furosemide and Morphine did not produce statistically significant levels of ROS (p >0.05) above the background in both hours 1 and 2 of biotransformation and ROS measurement (Figure 1). Although Bilirubin did not produce statistically significant (p >0.05) levels of ROS above the background (Figure 2) during the first hour, it did produce statistically significant levels in the second hour of biotransformation. Each compound’s level of ROS was reduced during the second hour, signaling the removal of intermediate ROS metabolites (Figure 2). The production of ROS in each compound signifies that there is biotransformation to an intermediate that produces ROS. 4. Conclusion: The production of ROS above the background by each of the compounds shows there is an intermediate free radical compound that is produced during the biotransformation of each compound [21]. In this study, although furosemide and morphine did not produce statistically significant levels of ROS in both hours of biotransformation, bilirubin did produce significant levels of ROS in the second hour of biotransformation. This finding is in line with previous studies that shows morphine to offer protective effects against ROS production [16, 17]; and bilirubin demonstrating deleterious production of ROS at high doses [18]. Further work must be done to examine the correlation between the levels of ROS and extent of hepatocellular damage.

Cyclophosphamide and epirubicin induce high apoptosis in microglia cells while epirubicin provokes DNA damage and microglial activation at sub-lethal concentrations.

Chemotherapy Related Cognitive Impairment (CRCI), also called chemobrain, diminishes cancer patient's life quality. Breast cancer (BC) patients have been described to be importantly affected, however, the mechanism leading to CRCI has not been fully elucidated. Recent research proposes microglia as the main architect of CRCI, thus dysregulations in these cells could trigger CRCI. The aim of this research was to evaluate the effects of two drugs commonly used against breast cancer, cyclophosphamide (CTX) and epirubicin (EPI), on the microglia cell line SIM-A9, using the BC cell line, 4T1, as a control. Our results show that CTX and EPI decrease microglia-cell viability and increase cell death on a concentration-dependent manner, being 5 and 2 times more cytotoxic to microglia cell line than to breast cancer 4T1cells, respectively. Both chemotherapies induce cell cycle arrest and a significant increase in p53, p16 and γ-H2AX in breast cancer and microglia cells. Furthermore, mitochondrial membrane potential (ΔΨm) diminishes as cell death increases, and both chemotherapies induce reactive oxygen species (ROS) production on SIM-A9 and 4T1. Moreover, caspase activation increases with treatments and its pharmacological blockade inhibits CTX and EPI induced-cell death. Finally, low concentrations of CTX and EPI induce γ-H2AX, and EPI induces cytokine release, NO production and Iba-1 overexpression. These findings indicate that microglia cells are more sensitive to CTX and EPI than BC cells and undergo DNA damage and cell cycle arrest at very low concentrations, moreover EPI induces microglia activation and a pro-inflammatory profile.

Involvement of FoxO1, Sp1, and Nrf2 in Upregulation of Negative Regulator of ROS by 15d-PGJ2 Attenuates H2O2-Induced IL-6 Expression in Rat Brain Astrocytes

Excessive production of reactive oxygen species (ROS) by NADPH oxidase (Nox) resulted in inflammation. The negative regulator of ROS (NRROS) dampens ROS generation during inflammatory responses. 15-Deoxy-∆12,14-prostaglandin J2 (15d-PGJ2) exhibits neuroprotective effects on central nervous system (CNS). However, whether 15d-PGJ2-induced NRROS expression was unknown in rat brain astrocytes (RBA-1). NRROS expression was determined by Western blot, RT/real-time PCR, and promoter activity assays. The signaling components were investigated using pharmacological inhibitors or specific siRNAs. The interaction between transcription factors and the NRROS promoter was investigated by chromatin immunoprecipitation assay. Upregulation of NRROS on the hydrogen peroxide (H2O2)-mediated ROS generation and interleukin 6 (IL-6) secretion was measured. 15d-PGJ2-induced NRROS expression was mediated through PI3K/Akt-dependent activation of Sp1 and FoxO1 and established the essential promoter regions. We demonstrated that 15d-PGJ2 activated PI3K/Akt and following by cooperation between phosphorylated nuclear FoxO1 and Sp1 to initiate the NRROS transcription. In addition, Nrf2 played a key role in NRROS expression induced by 15d-PGJ2 which was mediated through its phosphorylation. Finally, the NRROS stable clones attenuated the H2O2-induced ROS generation and expression of IL-6 through suppressing the Nox-2 activity. These results suggested that 15d-PGJ2-induced NRROS expression is mediated through a PI3K/Akt-dependent FoxO1 and Sp1 phosphorylation, and Nrf2 cascade, which suppresses ROS generation through attenuating the p47phox phosphorylation and gp91phox formation and IL-6 expression in RBA-1 cells. These results confirmed the mechanisms underlying 15d-PGJ2-induced NRROS expression which might be a potential strategy for prevention and management of brain inflammatory and neurodegenerative diseases.

Effects of three nanomaterials on growth, photosynthetic characteristics and production of reactive oxygen species of diatom Nitzschia Palea

ABSTRACT Harmful effect of nanomaterials on aquatic organisms has accelerated in recent decades due to the growth emission of nanomaterials into water. In the present study, we analysed the toxic effects of TiO2, ZnO and MWCTN on diatoms Nitzschia palea in both individual and a combined way. After a short-term (96 h) exposure, the changes of cell density, chlorophyll a, MDA, SOD, CAT, total protein content and morphological structure were determined. Our results showed that: (1) The growth of N. palea was inhibited with the increase of concentration of nanomaterials; (2) The chlorophyll a content of N. palea was sensitive to these three individual nanomaterials; (3) Low concentration of nanomaterials promoted the MDA content in N. palea, but high concentration inhibited it; (4) The protein content of N. palea increased first and then decreased, indicating that nanomaterial stress inhibited diatom protein synthesis and showed dose-effect relationship; (5) After nanomaterial exposure, the SOD enzyme activity of N. palea was significantly inhibited, the CAT enzyme activity showed significantly decreased after exposure, comparing with control. The results of this study provide data for the study of algae nano-toxicology and provide a theoretical basis for the study of the toxicity of nanomaterials to freshwater microalgae.

Protective effects of Quercus acuta Thunb. fruit extract against UVB-induced photoaging through ERK/AP-1 signaling modulation in human keratinocytes

BackgroundQuercus acuta Thunb. (Fagaceae) or Japanese evergreen oak is cultivated as an ornamental plant in South Korea, China, Japan, and Taiwan and used in traditional medicine. The acorn or fruit of Quercus acuta Thunb. (QAF) is the main ingredient of acorn jelly, a traditional food in Korea. Its leaf was recently shown to have potent xanthine oxidase inhibitory and anti-hyperuricemic activities; however, there have been no studies on the biological activity of QAF extracts. Solar ultraviolet light triggers photoaging of the skin, which increases the production of reactive oxygen species (ROS) and expression of matrix metalloproteinase (MMPs), and destroys collagen fibers, consequently inducing wrinkle formation. The aim of this study was to investigate the effect of water extracts of QAF against UVB-induced skin photoaging and to elucidate the underlying molecular mechanisms in human keratinocytes (HaCaT).MethodsIn this study, we used HPLC to identify the major active components of QAF water extracts. Anti-photoaging effects of QAF extracts were evaluated by analyzing ROS procollagen type I in UVB-irradiated HaCaT keratinocytes. Antiradical activity was determined using 2,2-diphenyl-1-picrylhydrazyl and 2,20-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) assays. The expression of MMP-1 was tested by western blotting and ELISA kits. QAF effects on phosphorylation of the MAPK (p38, JNK, and ERK) pathway and transcription factor AP-1, which enhances the expression of MMPs, were analyzed by western blots.ResultsWe identified two major active components in QAF water extracts, gallotannic acid and ellagic acid. The QAF aqueous extracts recovered UVB-induced cell toxicity and reduced oxidative stress by inhibiting intracellular ROS generation in HaCaT cells. QAF rescued UVB-induced collagen degradation by suppressing MMP-1 expression. The anti-photoaging activities of QAF were associated with the inhibition of UVB-induced phosphorylation of extracellular signal-regulated kinase (ERK) and activator protein 1 (AP-1). Our findings indicated that QAF prevents UVB-induced skin damage due to collagen degradation and MMP-1 activation via inactivation of the ERK/AP-1 signaling pathway. Overall, this study strongly suggests that QAF exerts anti-skin-aging effects and is a potential natural biomaterial that inhibits UVB-induced photoaging.ConclusionThese results show that QAF water extract effectively prevents skin photoaging by enhancing collagen deposition and inhibiting MMP-1 via the ERK/AP-1 signaling pathway.

EFFECTS OF GLYPHOSATE ON GERMINATION AND PHOTOSYNTHESIS IN Prosopis alba G.: A BIOCHEMICAL APPROACH

In recent decades, the phytogeographic region of the Western Chaco has been subjected to heavy deforestation. The native forest was gradually replaced by agricultural crops using high doses of herbicides. Glyphosate is the most widely used herbicide, and its impact on the surrounding native flora is unknown. The aim of this work was to determine the effect of glyphosate on the germination of Prosopis alba seeds and the photosynthesis of seedlings. Seeds were placed between paper towels, moistened with solutions of 0, 10, 20, 20, 30 and 40 mg a.i. glyphosate l-1, in a growth chamber at 25 oC and a 12 h photoperiod. The percentage of germinated seeds and the mean germination time were calculated. The respiratory rate was measured in these seeds, and the activity of complexes I and III of the respiratory chain was quantified. The shikimate concentration and antioxidant response of the seeds were also quantified. Chlorophyll a fluorescence emission variables were measured in the cotyledons. It was concluded that glyphosate inhibits germination in P. alba seeds and decreases the speed of the process. This effect can partly be explained by inhibition of respiration, mainly at the level of complex III of the mitochondrial electron transport chain. It is also due to oxidative stress produced by the herbicide, since the antioxidant response of the seeds fails to compensate for the high production of reactive oxygen species. Glyphosate inhibits the photochemical stage of photosynthesis on P. alba cotyledons.

Targeting prooxidant MnSOD effect inhibits triple-negative breast cancer (TNBC) progression and M2 macrophage functions under the oncogenic stress

Triple-negative breast cancer (TNBC) has been shown with high mitochondrial oxidative phosphorylation and production of reactive oxygen species (ROS). MnSOD (SOD2) is a mitochondrial antioxidant defense that has been implicated in inhibition of human malignancies. However, the impact of MnSOD on immunosuppressive macrophage functions and TNBC aggressiveness has never been explored. We found here that SOD2high is primarily observed in the aggressive subtypes of HER2(+) breast cancers and TNBCs patients. Further analyses demonstrated that the oncoprotein multiple copies in T-cell malignancy-1 (MCT-1 or MCTS1) induces mitochondrial superoxide dismutase (MnSOD) in TNBC cells by stabilizing the transcription factor Nrf2. SOD2high/MCTS1high expression correlates with a poor prognosis in breast cancer patients. MnSOD in TNBC cells functions as a prooxidant peroxidase that increases mitochondrial ROS (mROS) and adaptation to oxidative stress under the oncogenic effect. Interleukin-6 (IL-6) in the MCT-1 pathway elevates Nrf2/MnSOD and mROS levels. Knockdown of MnSOD inhibits TNBC cell invasion, breast cancer stem cells (BCSCs), mROS, and IL-6 excretion promoted by MCT-1. TNBC cells deficient in MnSOD prevent the polarization and chemotaxis of M2 macrophages but improve the ability of M1 macrophages to engulf cancer cells. Quenching mROS with MitoQ, a mitochondria-targeted non-metal-based antioxidant MnSOD mimics, effectively suppresses BCSCs and M2 macrophage invasion exacerbated by MnSOD and MCT-1. Consistently, silencing MnSOD impedes TNBC progression and intratumoral M2 macrophage infiltration. We revealed a novel stratagem for TNBC management involving targeting the MCT-1 oncogene-induced mitochondrial prooxidant MnSOD pathway, which prevents the development of an immunosuppressive tumor microenvironment.

Evaluation of Levels of Advanced Oxidative Protein Products in Patients with Polycystic Ovary Syndrome with and without Chronic Periodontitis: A Cross-Sectional Study.

Polycystic ovary syndrome (PCOS) is a common condition with a multifactorial aetiology. Chronic periodontitis (CP) is an immunoinflammatory disease that is linked to PCOS via the excessive production of reactive oxygen species (ROS), which leads to an imbalance in the antioxidant system. However, limited studies have evaluated the relationship between these diseases. The current study aims to evaluate the levels of advanced oxidation protein products (AOPP) in patients with periodontitis and PCOS. Four groups, each consisting of 12 patients, with both PCOS and CP (PCOSCP), systemically healthy women with CP, periodontally healthy women with PCOS (PCOSPH), and periodontally and systemically healthy women (PH) were included in the study. Clinical parameters such as clinical attachment loss, bleeding on probing (BOP), and periodontal inflamed surface area (PISA) index were noted. AOPP were evaluated in the saliva and serum samples by spectrophotometric detection. Salivary and serum AOPP levels were highest in the PCOSCP group (75.16 ± 7.50 μmol/l, 97.92 ± 6.50 μmol/l, respectively). Statistical significance (P<0.05) was noted between the salivary AOPP levels of the PCOSCP group and PCOS group. PISA was greatest in the PCOSCP group (1338.40 ± 285.96 mm2 ) followed by the PCOS group (680.33 ± 79.49 mm2 ), which showed the impact of PCOS on gingival inflammation. According to the results of this study, increased levels of advanced oxidative protein products appeared to show the effect of CP on worsening PCOS.

Analysis of Immunity-Related Oxidative Bursts by a Luminol-Based Assay.

The rapid production of reactive oxygen species (ROS) in response to biotic and abiotic cues is a conserved hallmark of plant responses. The detection and quantification of ROS generation during immune responses is an excellent readout to analyze signaling triggered by the perception of pathogens. The assay described here is easy to employ and versatile, allowing its use in a multitude of variations. For example, ROS production can be analyzed using different tissues including whole seedlings, roots, leaves, protoplasts, and cultured cells, which can originate from different ecotypes or mutants. Samples can be tested in combination with any ROS-inducing elicitors, such as the FLS2-activating peptide flg22, but also lipids or even abiotic stresses. Furthermore, early (PAMP-triggered) and late (effector-triggered) ROS production induced by virulent and avirulent bacteria, respectively, can also be assayed.