Expression Of Antioxidant Enzymes Research Articles

Stress response regulation of mRNA translation: Implications for antioxidant enzyme expression in cancer

From tumorigenesis to advanced metastatic stages, tumor cells encounter stress, ranging from limited nutrient and oxygen supply within the tumor microenvironment to extrinsic and intrinsic oxidative stress. Thus, tumor cells seize regulatory pathways to rapidly adapt to distinct physiologic conditions to promote cellular survival, including manipulation of mRNA translation. While it is now well established that metastatic tumor cells must up-regulate their antioxidant capacity to effectively spread and that regulation of antioxidant enzymes is imperative to disease progression, relatively few studies have assessed how translation and the hijacking of RNA systems contribute to antioxidant responses of tumors. Here, we review the major stress signaling pathways involved in translational regulation and discuss how these are affected by oxidative stress to promote prosurvival changes that manipulate antioxidant enzyme expression. We describe how tumors elicit these adaptive responses and detail how stress-induced translation can be regulated by kinases, RNA-binding proteins, RNA species, and RNA modification systems. We also highlight opportunities for further studies focused on the role of mRNA translation and RNA systems in the regulation of antioxidant enzyme expression, which may be of particular importance in the context of metastatic progression and therapeutic resistance.

Dietary pot marigold (Calendula officinalis) extract improved the growth performance, expression of digestive enzymes, antioxidant enzymes and immune-related genes in rainbow trout (Oncorhynchus mykiss)

Dietary pot marigold (Calendula officinalis) extract improved the growth performance, expression of digestive enzymes, antioxidant enzymes and immune-related genes in rainbow trout (Oncorhynchus mykiss)

TRNA modification enzyme-dependent redox homeostasis regulates synapse formation and memory

Post-transcriptional modification of RNA regulates gene expression at multiple levels. ALKBH8 is a tRNA-modifying enzyme that methylates wobble uridines in a subset of tRNAs to modulate translation. Through methylation of tRNA-selenocysteine, ALKBH8 promotes selenoprotein synthesis and regulates redox homeostasis. Pathogenic variants in ALKBH8 have been linked to intellectual disability disorders in the human population, but the role of ALKBH8 in the nervous system is unknown. Through in vivo studies in Drosophila, we show that ALKBH8 controls oxidative stress in the brain to restrain synaptic growth and support learning and memory. ALKBH8 null animals lack wobble uridine methylation and exhibit reduced protein synthesis in the nervous system, including a specific decrease in selenoprotein levels. Either loss of ALKBH8 or independent disruption of selenoprotein synthesis results in ectopic synapse formation. Genetic expression of antioxidant enzymes fully suppresses synaptic overgrowth in ALKBH8 null animals, confirming oxidative stress as the underlying cause of dysregulation. ALKBH8 null animals also exhibit associative memory impairments that are reversed by pharmacological antioxidant treatment. Together, these findings demonstrate the critical role of tRNA wobble uridine modification in redox homeostasis in the developing nervous system and reveal antioxidants as a potential therapy for ALKBH8-associated intellectual disability.

Systematical characterization of Rab7 gene family in Gossypium and potential functions of GhRab7B3-A gene in drought tolerance

BackgroundCotton serves as a primary source of natural fibers crucial for the textile industry. However, environmental elements such as drought have posed challenges to cotton cultivation, resulting in adverse impacts on both production and fiber quality. Improving cotton’s resilience to drought could mitigate yield losses and foster the expansion of cotton farming. Rab7 protein, widely present in organisms, controls the degradation and recycling of cargo, and has a potential role in biotic and abiotic tolerance. However, comprehensive exploration of the Rab7 gene family in Gossypium remains scarce.ResultsHerein, we identified a total of 10, 10, 20, and 20 Rab7 genes through genome-wide analysis in Gossypium arboreum, Gossypium raimondii, Gossypium hirsutum, and Gossypium barbadense, respectively. Collinearity analysis unveiled the pivotal role of whole genome or segmental duplication events in the expansion of GhRab7s. Study of gene architecture, conserved protein motifs, and domains suggested the conservation of structure and function throughout evolution. Exploration of cis-regulatory elements revealed the responsiveness of GhRab7 genes to abiotic stress, corroborated by transcriptome analysis under diverse environmental stresses. Notably, the greatly induced expression of GhRab7B3-A under drought treatment prompted us to investigate its function through virus-induced gene silencing (VIGS) assays. Silencing GhRab7B3-A led to exacerbated dehydration and wilting compared with the control. Additionally, inhibition of stomatal closure, antioxidant enzyme activities and expression patterns of genes responsive to abiotic stress were observed in GhRab7B3-A silenced plants.ConclusionsThis study sheds light on Rab7 members in cotton, identifies a gene linked to drought stress, and paves the way for additional investigation of Rab7 genes associated with drought stress tolerance.

Slow H2S-Releasing Donors and 3D Printable Arrays Cellular Models in Osteo-Differentiation of Mesenchymal Stem Cells for Personalized Therapies

The effects of the hydrogen sulfide (H2S) slow-releasing donor, named GSGa, a glutathione-conjugate water-soluble garlic extract, on human mesenchymal stem cells (hMSCs) in both bidimensional (2D) and three-dimensional (3D) cultures were investigated, demonstrating increased expression of the antioxidant enzyme HO-1 and decreased expression of the pro-inflammatory cytokine interleukin-6 (IL-6). The administration of the H2S donor can therefore increase the expression of antioxidant enzymes, which may have potential therapeutic applications in osteoarthritis (OA). Moreover, GSGa was able to promote the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs), but not of cardiac mesenchymal stem cells (cMSCs) in a 2D culture system. This result highlights the varying sensitivity of hMSCs to the H2S donor GSGa, suggesting that the induction of osteogenic differentiation in stem cells by chemical factors is dependent on the tissue of origin. Additionally, a 3D-printable mesenchymal stem cells–bone matrix array (MSCBM), designed to closely mimic the stiffness of bone tissue, was developed to serve as a versatile tool for evaluating the effects of drugs and stem cells on bone repair in chronic diseases, such as OA. We demonstrated that the osteogenic differentiation process in cMSCs can be induced just by simulating bone stiffness in a 3D system. The expression of osteocalcin, RUNX2, and antioxidant enzymes was also assessed after treating MSCs with GSGa and/or increasing the stiffness of the culture environment. The printability of the array may enable better customization of the cavities, enabling an accurate replication of real bone defects. This could optimize the BM array to mimic bone defects not only in terms of stiffness, but also in terms of shape. This culture system may enable a rapid screening of antioxidant and anti-inflammatory compounds, facilitating a more personalized approach to regenerative therapy.

Versatile MXenzymes Scavenging ROS for Promotion of Seed Germination under Salt Stress.

Salinization is recognized as a global problem, restricting agricultural production and sustainability. Targeting the salinity-induced oxidative stress, antioxidant treatment represents a protective strategy to improve plant salt tolerance. Herein, we report a V4C3 MXene nanozyme (MXenzyme), which exhibits good biocompatibility and excellent reactive oxygen species scavenging activity to ameliorate the salt stress-induced inhibition of seed germination. V4C3 MXenzyme treatment can significantly relieve salinity-induced oxidative stress and restore the antioxidant system in pea seeds, thus improving the phenotypic traits during germination. The molecular mechanism by which antioxidant V4C3 MXenzymes augment salt tolerances is revealed through transcriptomics and metabolomics. V4C3 MXenzymes significantly regulate the gene expression of antioxidant enzymes and molecule biosynthesis that correlate closely with hormone signal transduction genes and energy metabolism genes. With correlation and the combined analysis, redox homeostasis targeted by antioxidant V4C3 MXenzymes plays a critical role in promoting plant growth under salt stress.

Metabolic dysfunction-associated steatotic liver disease-induced changes in the antioxidant system: a review.

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a heterogeneous condition characterized by liver steatosis, inflammation, consequent fibrosis, and cirrhosis. Chronic impairment of lipid metabolism is closely related to oxidative stress, leading to cellular lipotoxicity, mitochondrial dysfunction, and endoplasmic reticulum stress. The detrimental effect of oxidative stress is usually accompanied by changes in antioxidant defense mechanisms, with the alterations in antioxidant enzymes expression/activities during MASLD development and progression reported in many clinical and experimental studies. This review will provide a comprehensive overview of the present research on MASLD-induced changes in the catalytic activity and expression of the main antioxidant enzymes (superoxide dismutases, catalase, glutathione peroxidases, glutathione S-transferases, glutathione reductase, NAD(P)H:quinone oxidoreductase) and in the level of non-enzymatic antioxidant glutathione. Furthermore, an overview of the therapeutic effects of vitamin E on antioxidant enzymes during the progression of MASLD will be presented. Generally, at the beginning of MASLD development, the expression/activity of antioxidant enzymes usually increases to protect organisms against the increased production of reactive oxygen species. However, in advanced stage of MASLD, the expression/activity of several antioxidants generally decreases due to damage to hepatic and extrahepatic cells, which further exacerbates the damage. Although the results obtained in patients, in various experimental animal or cell models have been inconsistent, taken together the importance of antioxidant enzymes in MASLD development and progression has been clearly shown.

Gochujang suppresses cell survival and changes reactive oxygen species metabolism in colorectal cancer cells

There is a significant global increase in colorectal cancer (CRC) among young adults. Gochujang, one of the signature Korean traditional fermented foods, contains various bioactive compounds and has multiple health-beneficial effects, including anticancer effects; however, the detailed cellular and molecular mechanisms of its anticancer outcomes are not fully understood. The objective of the present study was to investigate the detailed underlying anticancer mechanisms of Gochujang in CRC cells. Gochujang was extracted with 80% ethanol, and total polyphenol contents (9.9 ± 1.63 mgGAE/g) and total flavonoid contents (0.14 ± 0.07 mgQE/g) of Gochujang extract (GE) were evaluated. GE significantly suppressed cell viability, migration, and colony formation in CRC cells. Also, GE increased the cell cycle arrest-related protein p21 level, whereas it decreased cell cycle progression-associated proteins, such as p-Rb. Moreover, GE markedly elevated the levels of proapoptotic proteins (e.g. Bim and c-PARP), while it downregulated antiapoptotic protein expressions (e.g. Bcl-2 and Bcl-xL). GE also altered the expression of the autophagy-involved proteins. Furthermore, GE strongly reduced the expression of major antioxidant enzymes and increased the reactive oxygen species (ROS) generation in CRC cells, causing an imbalance of ROS metabolism. In conclusion, this study demonstrated that Gochujang exerts anticancer effects in CRC cells by inhibiting cell proliferation, increasing cell death, and interrupting ROS metabolism.

Genetic Signature of a Healthy Lifestyle: New Horizons for Preventing Noncommunicable Chronic Diseases by Modulating MicroRNA-155.

The development and progression of several noncommunicable diseases (NCDs) are associated with microRNA (miR) 155 (miR-155) activation, which promotes inflammation and oxidative stress. In particular, miR-155 regulates nuclear transcription factor-kappa B (NF-κB) by silencing gene expression of proteins involved in NF-κB suppression, such as suppressor of cytokine signaling 1 (SOCS1) and SH-2 containing inositol 5' polyphosphate 1 (SHIP1), increases the production of reactive oxygen species, and suppresses gene expression of antioxidant enzymes through nuclear factor erythroid 2-related factor 2 (Nrf2) inhibition. In this context, a healthy lifestyle based on a diet rich in nutrients and bioactive compounds as well as regular physical activity may modulate the activity of several miRs. Following this concept, studies involving nutrients, bioactive compounds, and physical activity have been developed to modulate miR-155 activation. This narrative review aims to discuss how a healthy lifestyle based on a diet rich in nutrients, bioactive compounds, and physical activity may modulate the miR-155 pathway and consequently prevent the development and progression of NCDs. Nutrients and bioactive compounds from food may act by inhibiting pathways that promote miR-155 activation such as NF-κB and promote activation of pathways that are associated with the downregulation of miR-155, such as Nrf2, and SOCS1 pathways. Regular physical activity also seems to influence miR-155 levels through an improvement in the immune system during muscle recovery. There is relevant evidence that shows a positive effect of nutrients, bioactive compounds, and physical activity with the modulation of miR-155, which can potentially provide benefits in the clinical setting in cases of NCDs.

Pseudomonas aeruginosa kills Staphylococcus aureus in a polyphosphate-dependent manner.

Due to their frequent coexistence in many polymicrobial infections, including in patients with cystic fibrosis or burn/chronic wounds, many studies have investigated the mechanistic details of the interaction between the opportunistic pathogens Pseudomonas aeruginosa and Staphylococcus aureus. P. aeruginosa rapidly outcompetes S. aureus under in vitro cocultivation conditions, which is mediated by several of P. aeruginosa's virulence factors. Here, we report that polyphosphate (polyP), an efficient stress defense system and virulence factor in P. aeruginosa, plays a role in the pathogen's ability to inhibit and kill S. aureus in a contact-independent manner. We show that P. aeruginosa cells characterized by low polyP levels are less detrimental to S. aureus growth and survival while the Gram-positive pathogen is significantly more compromised by the presence of P. aeruginosa cells that produce high levels of polyP. The polyP-dependent phenotype of P. aeruginosa-mediated killing of S. aureus could at least in part be direct, as polyP was detected in the spent media and causes significant damage to the S. aureus cell envelope. However, more likely is that polyP's effects are indirect through modulating the production of one of P. aeruginosa's virulence factors, pyocyanin. We show that pyocyanin production in P. aeruginosa occurs polyP-dependently and harms S. aureus through membrane damage and potentially the generation of reactive oxygen species, resulting in the increased expression of antioxidant enzymes. In summary, our study adds a new component to the list of biomolecules that the Gram-negative pathogen P. aeruginosa generates to compete with S. aureus for resources.IMPORTANCEHow do interactions between microorganisms shape the course of polymicrobial infections? Previous studies have provided evidence that the two opportunistic pathogens Pseudomonas aeruginosa and Staphylococcus aureus generate molecules that modulate their interaction with potentially significant impact on disease outcomes. Our study identified the biopolymer polyphosphate (polyP) as a new effector molecule that impacts P. aeruginosa's interaction with S. aureus. We show that P. aeruginosa kills S. aureus in a polyP-dependent manner, which occurs primarily through the polyP-dependent production of the P. aeruginosa virulence factor pyocyanin. Our findings add a new role for polyP to an already extensive list of functions. A more in-depth understanding of how polyP influences interspecies interactions is critical, as targeting polyP synthesis in bacteria such as P. aeruginosa may have a significant impact on other microorganisms and potentially result in dynamic changes in the microbial composition.

Adherence to Mediterranean Diet and Biomarkers of Redox Balance and Inflammation in Old Patients Hospitalized in Internal Medicine.

We have previously described that low adherence to the Mediterranean diet (MD) in elderly patients admitted in internal medicine wards is linked to poorer clinical outcomes. This investigation was designed to explore whether adherence to the MD is related to circulating markers of redox balance and inflammation in this clinical scenario. A cross-sectional study was performed on 306 acute old patients hospitalized in internal medicine wards. Adherence to the MD was estimated by the Italian Mediterranean Index (IMI). The circulating markers of redox balance were assessed in serum and erythrocytes and correlated with inflammatory markers across different MD adherence groups. Compared to the patients with high adherence, those with low adherence to the MD exhibited severely impaired redox balance, as evidenced by a higher GSSG/GSH ratio and increased serum hydroxynonenal/malondialdehyde-protein adducts. No modifications were described in the expression of antioxidant enzymes in peripheral blood mononuclear cells. Patients with low adherence to the MD exhibited a higher neutrophil-to-lymphocyte ratio and markers of systemic inflammation, as well as raised levels of interleukin-6 and tumor necrosis factor, compared to those with high MD adherence. A strong association was observed between the circulating markers of redox balance and inflammation/immune response, with the highest regression coefficients found in the low adherence group. Old patients admitted to internal medicine wards with low adherence to the MD display unfavorable profiles of the circulating markers of redox balance and inflammation. It is conceivable that such effects on redox balance can be linked to the high polyphenol content of MD. This study supports the rationale for intervention trials that attest to the effectiveness of MD as a nutritional strategy for disease prevention.

Decreased ability to manage increases in reactive oxygen species may underlie susceptibility to arrhythmias in mice lacking Scn1b.

Scn1b plays essential roles in the heart, where it encodes β1-subunits that serve as modifiers of gene expression, cell surface channel activity, and cardiac conductivity. Reduced β1 function is linked to electrical instability in various diseases with cardiac manifestations and increased susceptibility to arrhythmias. Recently, we demonstrated that loss of Scn1b in mice leads to compromised mitochondria energetics and reactive oxygen species (ROS) production. In this study, we examined the link between increased ROS and arrhythmia susceptibility in Scn1b-/- mice. In addition, ROS-scavenging capacity can be overwhelmed during prolonged oxidative stress, increasing arrhythmia susceptibility. Therefore, we isolated whole hearts and cardiomyocytes from Scn1b-/- and Scn1b+/+ mice and subjected them to an oxidative challenge with diamide, a glutathione oxidant. Next, we analyzed gene expression and activity of antioxidant enzymes in Scn1b-/- hearts. Cells isolated from Scn1b-/- hearts died faster and displayed higher rates of ROS accumulation preceding cell death compared with those from Scn1b+/+. Furthermore, Scn1b-/- hearts showed higher arrhythmia scores and spent less time free of arrhythmia. Lastly, we found that protein expression and enzymatic activity of glutathione peroxidase is increased in Scn1b-/- hearts compared with wild type. Our results indicate that Scn1b-/- mice have decreased capability to manage ROS during prolonged oxidative stress. ROS accumulation is elevated and appears to overwhelm ROS scavenging through the glutathione system. This imbalance creates the potential for altered cell energetics that may underlie increased susceptibility to arrhythmias or other adverse cardiac outcomes.NEW & NOTEWORTHY Using an oxidative challenge, we demonstrated that isolated cells from Scn1b-/- mice are more susceptible to cell death and surges in reactive oxygen species accumulation. At the whole organ level, they were also more susceptible to the formation of cardiac arrhythmias. This may in part be due to changes to the glutathione antioxidant system.

The combination of allantoin, bisabolol, D-panthenol and dipotassium glycyrrhizinate mitigates UVB-induced PGE2 synthesis by keratinocytes.

Erythema, characterized by the redness of the skin, is a common skin reaction triggered by various endogenous and exogenous factors. This response is often a result of the activation of underlying inflammatory mechanisms within the skin. The objective of this study is to investigate the potential benefits of applying a combination of skincare ingredients, namely allantoin, bisabolol, D-panthenol and dipotassium glycyrrhizinate (AB5D), in the modulation of inflammatory factors associated with erythema. Additionally, the study aims to elucidate the mechanisms by which these ingredients exert their combined actions to alleviate erythema-associated inflammation. Human epidermal keratinocytes were exposed to UVB and subsequently treated with AB5D. Transcriptomics profiling was performed to analyse the dose-response effect of AB5D treatment on keratinocytes. The quantitation of inflammatory mediators, including PGE2, IL-1α, IL-6, IL-8, IL-1RA and TNFα, was performed on cultured media. Additionally, the oxygen radical absorbance capacity (ORAC) assay was carried out to evaluate the total antioxidant capacity of both individual ingredients and the AB5D combination. To assess the in-vitro antioxidant effects of AB5D against UVB-induced oxidative stress in hTERT keratinocytes, real-time quantitation of mitochondrial superoxide was measured through live-cell imaging. The application of AB5D to UVB-exposed keratinocytes downregulated gene sets associated with inflammatory responses, highlighting the anti-inflammatory properties of AB5D. Specifically, AB5D effectively reduced the production of PGE2, leading to the downregulation of inflammatory cytokines. Moreover, our findings indicate that AB5D exhibits antioxidative capabilities, functioning as both an antioxidant agent and a regulator of antioxidant enzyme expression to counteract the detrimental effects of cellular oxidative stress. We demonstrated that AB5D can reduce UVB-induced PGE2, IL-1α, IL-6, IL-8, IL-1RA and TNFα as well as mitochondrial superoxide. These findings suggest that AB5D may alleviate erythema by modulating inflammation via PGE2 and through antioxidation mechanisms.

Ethanol extract of Nymphaea lotus Linn. inhibited hepatic fibrogenesis in carbon tetrachloride-intoxicated Wistar rats

BackgroundNymphaea lotus is a plant used as food and to manage various ailments including liver diseases. Liver fibrosis is a pathological state which progresses to more chronic and fatal liver diseases but without any approved drug yet. This study thus aimed to investigate the anti-liver fibrosis mechanism of N. lotus.MethodologyLiver fibrosis was induced by carbon tetrachloride (CCl4:Olive oil, 1:1 ip). Fibrotic animals were treated with 50, 100 and 200 mg/kg b.wt. N. lotus extract. The activities of alanine aminotransaminase (ALT), aspartate aminotransferase (AST), in the serum, and levels of Malondialdehyde (MDA), superoxide dismutase (SOD), catalase, and reduced glutathione (GSH) in the liver, and histopathology of the liver were determined. The expression of fibrosis-related proteins namely alpha-smooth muscle actin (α-SMA), Collagen-4 (COL4A), Transforming growth factor-β1 (TGFβ1), Mothers against decapentaplegic homolog 2 (SMAD2), SMAD3 and matrix metalloproteinase 2 (MMP2) in the liver was also evaluated. Molecular docking and simulation analysis of N. lotus-derived phytochemicals to TGFβ1 and SMAD3 was also performed.ResultsThe extract significantly reduced the levels of ALT, AST, and MDA, increased the expression of antioxidant enzymes namely; SOD and GSH, and downregulated the expression of fibrosis-related proteins namely α-SMA, COL4A, TGFβ1, SMAD3 and MMP2. It also ameliorated CCl4-induced hepatic lesions. N. lotus-derived phytochemicals also showed a good binding affinity and interaction with the active sites of TGFβ1 and SMAD3.ConclusionN. lotus inhibited liver fibrosis by inhibiting oxidative stress and the TGFβ/SMAD signalling pathway. This demonstrates its beneficial and protective effect against CCl4-induced hepatoxicity and thus supports its use for the traditional management of liver diseases.

Discovery and Optimization of a Series of Vinyl Sulfoximine-Based Analogues as Potent Nrf2 Activators for the Treatment of Multiple Sclerosis.

Multiple sclerosis (MS) is an immune-mediated neurodegenerative disease of the central nervous system (CNS), which leads to demyelination, axonal loss, and neurodegeneration. Increased oxidative stress and neurodegeneration have been implicated in all stages of MS, making neuroprotective therapeutics a promising strategy for its treatment. We previously have reported vinyl sulfones with antioxidative and anti-inflammatory properties that activate nuclear factor erythroid 2-related factor 2 (Nrf2), a transcription factor that induces the expression of cytoprotective genes against oxidative stress. In this study, we synthesized vinyl sulfoximine derivatives by modifying the core structure and determined therapeutic potential as Nrf2 activators. Among them, 10v effectively activated Nrf2 (EC50 = 83.5 nM) and exhibited favorable drug-like properties. 10v successfully induced expression of Nrf2-dependent antioxidant enzymes and suppressed lipopolysaccharide (LPS)-induced inflammatory responses in BV-2 microglial cells. We also confirmed that 10v effectively reversed disease progression and attenuated demyelination in an experimental autoimmune encephalitis (EAE) mouse model of MS.

A Descriptive Review of the Antioxidant Effects and Mechanisms of Action of Berberine and Silymarin.

Oxidative stress is a key factor in the development of chronic diseases such as type 2 diabetes, cardiovascular diseases, and liver disorders. Antioxidant therapies that target oxidative damage show significant promise in preventing and treating these conditions. Berberine, an alkaloid derived from various plants in the Berberidaceae family, enhances cellular defenses against oxidative stress through several mechanisms. It activates the AMP-activated protein kinase (AMPK) pathway, which reduces mitochondrial reactive oxygen species (ROS) production and improves energy metabolism. Furthermore, it boosts the activity of key antioxidant enzymes like superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), thus protecting cells from oxidative damage. These actions make berberine effective in managing diseases like type 2 diabetes, cardiovascular conditions, and neurodegenerative disorders. Silymarin, a flavonolignan complex derived from Silybum marianum, is particularly effective for liver protection. It activates the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway, enhancing antioxidant enzyme expression and stabilizing mitochondrial membranes. Additionally, silymarin reduces the formation of ROS by chelating metal ions, and it also diminishes inflammation. This makes it beneficial for conditions like non-alcoholic fatty liver disease (NAFLD) and alcohol-related liver disorders. This review aims to highlight the distinct mechanisms by which berberine and silymarin exert their antioxidant effects.

Changes in redox status in raspberry (Rubus idaeus L.) fruit during ripening

The knowledge of the mechanisms affecting the process of berry fruit ripening is important, not only to correctly determine the appropriate date of harvest, at which the fruit is most palatable and characterized by adequate shelf-life stability, but also, to develop new strategies of regulating the ripening process before harvesting. It is recognized that berry fruit quality and its post-harvest shelf-life depend on the cellular redox homeostasis. We, therefore, decided to conduct a comprehensive analysis of the level of oxidative stress status in the raspberry fruit proper at different stages of fruit ripening, from green to overripe fruit. We assessed both the level of typical oxidative stress markers, i.e. ROS production, expression of antioxidant enzymes, degree of cell damage, as well as the expression of selected proteins involved in the energy, glutathione, and polyphenols metabolism. We found two stage-related peaks of ROS production. The first - in green fruit, which corresponded to the maximum expression of antioxidant enzymes (MnSOD, CAT), PARP-1, as well as proteins related to glutathione biosynthesis (GS, γ-GC), autophagy (ATG-8) and ubiquitination (UBQ-11). The second one, in the overripe fruit, was responsible for the intensification of oxidative modifications of cell components, i.e. lipids, proteins, and DNA, as well as the loss of low molecular-weight antioxidants. The fruit ripening process, in turn, was manifested by a strong increase in the expression of proteins involved in the biosynthesis of polyphenols (PAL, CHS), cellular respiration (ACO-1, Cyt-C-ox, ATPase), ethylene biosynthesis and signaling (SAMs, EIN-2) and increasing amounts of ABA.

Increased susceptibility of human limbal aniridia fibroblasts to oxidative stress

Aniridia-associated keratopathy originates from a haploinsufficiency of the transcription factor PAX6 (PAX6+/−). In the corneal epithelium of PAX6+/− mice, a significant increase in oxidized proteins was observed, accompanied by impaired compensation for elevated oxidative stress (OS). The extent to which limbal fibroblast cells (LFCs) are affected by an increased susceptibility to OS in cases of congenital aniridia (AN) has not been determined, yet. Our aim was to examine the impact of OS on antioxidant enzyme expression in normal and AN-LFCs. Following isolation and culture of primary LFCs (n = 8) and AN-LFCs (n = 8), cells were treated with cobalt chloride for 48 h to chemically induce hypoxic conditions and OS. Subsequently, HIF-1α/-2α, PHD1/2, Nrf2, CAT, SOD1, PRDX6, and GPX1 gene expression was examined by qPCR. SOD1, PRDX6, and GPX1 protein levels were assessed from the cell lysate by Western blot. The induction of hypoxia led to reduced HIF-1α gene expression in both fibroblast groups (p≤0.008), while the decrease in PHD1 was limited to AN-LFCs (p = 0.0007). On the other hand, under hypoxic conditions, PHD2 showed higher mRNA expression in AN-LFCs compared to normal LFCs (p = 0.013). As a result of OS, the mRNA levels of Nrf2 (p<0.0001) and the antioxidant enzymes CAT (p = 0.005), SOD1 (p = 0.005), GPX1 (p = 0.002) decreased in AN-LFCs. This was accompanied by an increased protein expression of SOD1 (p = 0.019) and PRDX6 (p=0.0009). In the normal LFC group, the induced extent of OS had no impact on the gene (p≥0.151) and protein expression (p ≥ 0.629) of antioxidant enzymes, except for the GPX1 mRNA level (p = 0.027). AN-LFCs exhibit higher susceptibility to OS than normal LFCs. Therefore, in AN-LFCs, there are sustained alterations in gene and protein expression of antioxidative enzymes even after 48 h of CoCl2 treatment.

Natural Compounds That Activate the KEAP1/Nrf2 Signaling Pathway as Potential New Drugs in the Treatment of Idiopathic Parkinson's Disease.

Recently, a single-neuron degeneration model has been proposed to understand the development of idiopathic Parkinson's disease based on (i) the extremely slow development of the degenerative process before the onset of motor symptoms and during the progression of the disease and (ii) the fact that it is triggered by an endogenous neurotoxin that does not have an expansive character, limiting its neurotoxic effect to single neuromelanin-containing dopaminergic neurons. It has been proposed that aminochrome is the endogenous neurotoxin that triggers the neurodegenerative process in idiopathic Parkinson's disease by triggering mitochondrial dysfunction, oxidative stress, neuroinflammation, dysfunction of both lysosomal and proteasomal protein degradation, endoplasmic reticulum stress and formation of neurotoxic alpha-synuclein oligomers. Aminochrome is an endogenous neurotoxin that is rapidly reduced by flavoenzymes and/or forms adducts with proteins, which implies that it is impossible for it to have a propagative neurotoxic effect on neighboring neurons. Interestingly, the enzymes DT-diaphorase and glutathione transferase M2-2 prevent the neurotoxic effects of aminochrome. Natural compounds present in fruits, vegetables and other plant products have been shown to activate the KEAP1/Nrf2 signaling pathway by increasing the expression of antioxidant enzymes including DT-diaphorase and glutathione transferase. This review analyzes the possibility of searching for natural compounds that increase the expression of DT-diaphorase and glutathione transferase through activation of the KEAP1/Nrf2 signaling pathway.

Angiotensin 1–7 restrains vascular injury of extracorporeal membrane oxygenation by inhibiting ferroptosis

BackgroundAngiotensin 1–7 (Ang1-7) is the classical end product of angiotensin II, which has the effects of dilating blood vessels, protecting endothelial cells, anti-hypertension, improving cardiac function, and inhibiting atherosclerosis. We hypothesize that Ang1-7 inhibits human umbilical vein endothelial cells (HUVEC) ferroptosis through NF-κB/P53 signal pathway, and reduces extracorporeal membrane oxygenation (ECMO) vascular injury. MethodsCultured HUVEC were seeded into 15 wells and randomly divided into five groups: the control group and four experimental groups (erastin, erastin + Ang1-7, erastin + Ang1-7 + Betulinic acid, erastin + Betulinic acid). After stimulation, cell viability, lactate dehydrogenase (LDH), malondialdehyde (MDA), and superoxide dismutase (SOD) activity were measured. The effects of Ang1-7 on HUVEC microstructure, antioxidant enzymes (ferritin heavy chain 1 (FTH1), cystine/glutamic acid reverse transport solute carrier family 7 members 11 (SLC7A11 or XCT), superoxide dismutase-2 (SOD-2) and glutathione peroxidase 4 (GPX4)), NF-κB, P-NF-κB, P53, and P-P53). ResultsErastin stimulation promoted HUVEC lipid peroxidation, decreased antioxidant enzyme expression, increased P-NF-κB, P53, and P-P53 expressions, and damaged HUVEC mitochondrial structure. Ang1-7 alleviated the effect of erastin on HUVEC, which was destroyed by Betulinic acid. ConclusionAngiotensin1-7 pretreatment inhibited vascular endothelial cells’ ferroptosis and alleviated ECMO vessel injury through NF-κB /P53 signal pathway.