Showing papers on "Oxidative stress published in 2021"
TL;DR: In this article, a review of the relationship between oxidative stress, redox signalling and disease, the mechanisms through which oxidative stress can contribute to pathology, how antioxidant defences work, what limits their effectiveness, and how antioxidant defenses can be increased through physiological signalling, dietary components and potential pharmaceutical intervention.
Abstract: Oxidative stress is a component of many diseases, including atherosclerosis, chronic obstructive pulmonary disease, Alzheimer disease and cancer. Although numerous small molecules evaluated as antioxidants have exhibited therapeutic potential in preclinical studies, clinical trial results have been disappointing. A greater understanding of the mechanisms through which antioxidants act and where and when they are effective may provide a rational approach that leads to greater pharmacological success. Here, we review the relationships between oxidative stress, redox signalling and disease, the mechanisms through which oxidative stress can contribute to pathology, how antioxidant defences work, what limits their effectiveness and how antioxidant defences can be increased through physiological signalling, dietary components and potential pharmaceutical intervention.
548 citations
TL;DR: In this article, a review of the literature on the generation and effects of reactive oxygen species (ROS) in biological processes, both in terms of alteration and their role in cellular signaling and regulatory pathways is presented.
Abstract: Living species are continuously subjected to all extrinsic forms of reactive oxidants and others that are produced endogenously. There is extensive literature on the generation and effects of reactive oxygen species (ROS) in biological processes, both in terms of alteration and their role in cellular signaling and regulatory pathways. Cells produce ROS as a controlled physiological process, but increasing ROS becomes pathological and leads to oxidative stress and disease. The induction of oxidative stress is an imbalance between the production of radical species and the antioxidant defense systems, which can cause damage to cellular biomolecules, including lipids, proteins and DNA. Cellular and biochemical experiments have been complemented in various ways to explain the biological chemistry of ROS oxidants. However, it is often unclear how this translates into chemical reactions involving redox changes. This review addresses this question and includes a robust mechanistic explanation of the chemical reactions of ROS and oxidative stress.
363 citations
TL;DR: In this article, the status of known sites of production, signaling mechanisms/pathways, effects, and management of reactive oxygen species (ROS) within plant cells under stress.
Abstract: Climate change is an invisible, silent killer with calamitous effects on living organisms As the sessile organism, plants experience a diverse array of abiotic stresses during ontogenesis The relentless climatic changes amplify the intensity and duration of stresses, making plants dwindle to survive Plants convert 1-2% of consumed oxygen into reactive oxygen species (ROS), in particular, singlet oxygen (1O2), superoxide radical (O2•-), hydrogen peroxide (H2O2), hydroxyl radical (•OH), etc as a byproduct of aerobic metabolism in different cell organelles such as chloroplast, mitochondria, etc The regulatory network comprising enzymatic and non-enzymatic antioxidant systems tends to keep the magnitude of ROS within plant cells to a non-damaging level However, under stress conditions, the production rate of ROS increases exponentially, exceeding the potential of antioxidant scavengers instigating oxidative burst, which affects biomolecules and disturbs cellular redox homeostasis ROS are similar to a double-edged sword; and, when present below the threshold level, mediate redox signaling pathways that actuate plant growth, development, and acclimatization against stresses The production of ROS in plant cells displays both detrimental and beneficial effects However, exact pathways of ROS mediated stress alleviation are yet to be fully elucidated Therefore, the review deposits information about the status of known sites of production, signaling mechanisms/pathways, effects, and management of ROS within plant cells under stress In addition, the role played by advancement in modern techniques such as molecular priming, systems biology, phenomics, and crop modeling in preventing oxidative stress, as well as diverting ROS into signaling pathways has been canvassed
278 citations
TL;DR: The present review paper focuses on the chemistry of oxidative stress mitigation by antioxidants, and the specific mechanism of a series of endogenous and exogenous antioxidants in particular aspects of oxidative Stress, is detailed.
260 citations
TL;DR: An effort has been made to decipher the interplay among heavy metals/metalloids exposures, oxidative stress, and signal transduction, which are essential to mount the cellular and organismal response.
213 citations
03 Apr 2021
TL;DR: The antioxidant defense activity in fish is discussed, influencing factors with special focus on dietary approaches and microbial feed additives are discussed, and the proposed mechanism of action of microbialFeed additives on the antioxidant system has been discussed.
Abstract: In fish, like other organisms, the lack of balance between the production of reactive oxygen species (ROS) and antioxidant defense system (so-called oxidative stress) can cause DNA hydroxylation, p...
157 citations
TL;DR: In this paper, the role of free radicals and antioxidants in diabetic wound healing is discussed and several therapeutic strategies especially dietary bioactive compounds by targeting oxidative stress to improve wounds healing are discussed.
Abstract: Foot ulcers are one of the most common and severe complication of diabetes mellitus with significant resultant morbidity and mortality. Multiple factors impair wound healing include skin injury, diabetic neuropathy, ischemia, infection, inadequate glycemic control, poor nutritional status, and severe morbidity. It is currently believed that oxidative stress plays a vital role in diabetic wound healing. An imbalance of free radicals and antioxidants in the body results in overproduction of reactive oxygen species which lead to cell, tissue damage, and delayed wound healing. Therefore, decreasing ROS levels through antioxidative systems may reduce oxidative stress-induced damage to improve healing. In this context, we provide an update on the role of oxidative stress and antioxidants in diabetic wound healing through following four perspectives. We then discuss several therapeutic strategies especially dietary bioactive compounds by targeting oxidative stress to improve wounds healing.
148 citations
TL;DR: Despite continued progress in research on various aspects of natural agents exerting protective effects against EC injury by activating Nrf2/HO-1 signaling, the development of new drugs for the treatment of atherosclerosis and other CVDs based on these agents will require more detailed preclinical and clinical studies.
145 citations
TL;DR: The role of NADPH oxidase 4 (NOX4), a major source of ROS, has been identified in brain damage, but the mechanism by which NOX4 regulates ferroptosis of astrocytes in AD remains unclear.
Abstract: Oxidative stress has been implicated in the pathogenesis of Alzheimer's disease (AD). Mitochondrial dysfunction is linked to oxidative stress and reactive oxygen species (ROS) in neurotoxicity during AD. Impaired mitochondrial metabolism has been associated with mitochondrial dysfunction in brain damage of AD. While the role of NADPH oxidase 4 (NOX4), a major source of ROS, has been identified in brain damage, the mechanism by which NOX4 regulates ferroptosis of astrocytes in AD remains unclear. Here, we show that the protein levels of NOX4 were significantly elevated in impaired astrocytes of cerebral cortex from patients with AD and APP/PS1 double-transgenic mouse model of AD. The levels of 4-hydroxynonenal (4-HNE) and malondialdehyde (MDA), a marker of oxidative stress-induced lipid peroxidation, were significantly also elevated in impaired astrocytes of patients with AD and mouse AD. We demonstrate that the over-expression of NOX4 significantly increases the impairment of mitochondrial metabolism by inhibition of mitochondrial respiration and ATP production via the reduction of five protein complexes in the mitochondrial ETC in human astrocytes. Moreover, the elevation of NOX4 induces oxidative stress by mitochondrial ROS (mtROS) production, mitochondrial fragmentation, and inhibition of cellular antioxidant process in human astrocytes. Furthermore, the elevation of NOX4 increased ferroptosis-dependent cytotoxicity by the activation of oxidative stress-induced lipid peroxidation in human astrocytes. These results suggest that NOX4 promotes ferroptosis of astrocytes by oxidative stress-induced lipid peroxidation via the impairment of mitochondrial metabolism in AD.
143 citations
TL;DR: In this paper, a two-dimensional vanadium carbide (V2C) MXene nanoenzyme (MXenzyme) was constructed to mimic up to six naturally-occurring enzymes, including superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), glutathione peroxido-oxide (GPx), thiol peroxide (TPx), and haloperoxidases (HPO), which not only possesses high biocompatibility but also exhibits robust in vitro cytoprotection
Abstract: Reactive oxygen species (ROS) are generated and consumed in living organism for normal metabolism. Paradoxically, the overproduction and/or mismanagement of ROS have been involved in pathogenesis and progression of various human diseases. Here, we reported a two-dimensional (2D) vanadium carbide (V2C) MXene nanoenzyme (MXenzyme) that can mimic up to six naturally-occurring enzymes, including superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), glutathione peroxidase (GPx), thiol peroxidase (TPx) and haloperoxidase (HPO). Based on these enzyme-mimicking properties, the constructed 2D V2C MXenzyme not only possesses high biocompatibility but also exhibits robust in vitro cytoprotection against oxidative stress. Importantly, 2D V2C MXenzyme rebuilds the redox homeostasis without perturbing the endogenous antioxidant status and relieves ROS-induced damage with benign in vivo therapeutic effects, as demonstrated in both inflammation and neurodegeneration animal models. These findings open an avenue to enable the use of MXenzyme as a remedial nanoplatform to treat ROS-mediated inflammatory and neurodegenerative diseases.
142 citations
TL;DR: In this paper, the authors provide an overview of the generation and sources of reactive oxygen species within tumor cells, ROS-associated signaling pathways, their regulation by antioxidant defense systems, as well as the effect of elevated ROS production in tumor progression.
Abstract: Reactive oxygen species (ROS) are important in regulating normal cellular processes whereas deregulated ROS leads to the development of a diseased state in humans including cancers. Several studies have been found to be marked with increased ROS production which activates pro-tumorigenic signaling, enhances cell survival and proliferation and drives DNA damage and genetic instability. However, higher ROS levels have been found to promote anti-tumorigenic signaling by initiating oxidative stress-induced tumor cell death. Tumor cells develop a mechanism where they adjust to the high ROS by expressing elevated levels of antioxidant proteins to detoxify them while maintaining pro-tumorigenic signaling and resistance to apoptosis. Therefore, ROS manipulation can be a potential target for cancer therapies as cancer cells present an altered redox balance in comparison to their normal counterparts. In this review, we aim to provide an overview of the generation and sources of ROS within tumor cells, ROS-associated signaling pathways, their regulation by antioxidant defense systems, as well as the effect of elevated ROS production in tumor progression. It will provide an insight into how pro- and anti-tumorigenic ROS signaling pathways could be manipulated during the treatment of cancer.
Stanford University1, Johns Hopkins University School of Medicine2, East China University of Science and Technology3, Chinese Academy of Sciences4, University of Illinois at Urbana–Champaign5, École Polytechnique Fédérale de Lausanne6, Salk Institute for Biological Studies7, China Pharmaceutical University8
TL;DR: A safe, mitochondria-targeted, copper-depleting nanoparticle (CDN) is developed and tested against triple-negative breast cancer and shown to be less toxic than existing copper chelators, demonstrating low toxicity of CDNs in healthy mice.
Abstract: Depletion of mitochondrial copper, which shifts metabolism from respiration to glycolysis and reduces energy production, is known to be effective against cancer types that depend on oxidative phosphorylation. However, existing copper chelators are too toxic or ineffective for cancer treatment. Here we develop a safe, mitochondria-targeted, copper-depleting nanoparticle (CDN) and test it against triple-negative breast cancer (TNBC). We show that CDNs decrease oxygen consumption and oxidative phosphorylation, cause a metabolic switch to glycolysis and reduce ATP production in TNBC cells. This energy deficiency, together with compromised mitochondrial membrane potential and elevated oxidative stress, results in apoptosis. CDNs should be less toxic than existing copper chelators because they favorably deprive copper in the mitochondria in cancer cells instead of systemic depletion. Indeed, we demonstrate low toxicity of CDNs in healthy mice. In three mouse models of TNBC, CDN administration inhibits tumor growth and substantially improves survival. The efficacy and safety of CDNs suggest the potential clinical relevance of this approach.
TL;DR: A link between oxidative stress and hypertension has been established in multiple animal models of hypertension but remains elusive in humans while initial studies focused on inactivation of nitric oxide by superoxide, our understanding of relevant reactive oxygen species (superoxide, hydrogen peroxide, and peroxynitrite) and how they modify complex signaling pathways to promote hypertension has expanded significantly.
Abstract: A link between oxidative stress and hypertension has been firmly established in multiple animal models of hypertension but remains elusive in humans While initial studies focused on inactivation of nitric oxide by superoxide, our understanding of relevant reactive oxygen species (superoxide, hydrogen peroxide, and peroxynitrite) and how they modify complex signaling pathways to promote hypertension has expanded significantly In this review, we summarize recent advances in delineating the primary and secondary sources of reactive oxygen species (nicotinamide adenine dinucleotide phosphate oxidases, uncoupled endothelial nitric oxide synthase, endoplasmic reticulum, and mitochondria), the posttranslational oxidative modifications they induce on protein targets important for redox signaling, their interplay with endogenous antioxidant systems, and the role of inflammasome activation and endoplasmic reticular stress in the development of hypertension We highlight how oxidative stress in different organ systems contributes to hypertension, describe new animal models that have clarified the importance of specific proteins, and discuss clinical studies that shed light on how these processes and pathways are altered in human hypertension Finally, we focus on the promise of redox proteomics and systems biology to help us fully understand the relationship between ROS and hypertension and their potential for designing and evaluating novel antihypertensive therapies
TL;DR: This review focuses on 8-hidroxy-2-deoxyguanosine (8-OHdG) and antioxidative enzymes as biomarkers for measurement of oxidative stress in different types of cancer and their potential in defining the stage of tumor progression.
Abstract: Reactive oxygen species (ROS) can damage lipids, nucleic acids, and proteins, thereby altering their functions. When a balance between production of ROS and antioxidative defense is disturbed, state of oxidative stress occurs. Oxidative stress leads to many diseases. There are few biomarkers that are used for better understanding how oxidative stress is involved in cancer pathophysiology. This review focuses on 8-hidroxy-2-deoxyguanosine (8-OHdG) and antioxidative enzymes as biomarkers for measurement of oxidative stress in different types of cancer. This review also deals with the product of lipid peroxidation, malondialdehyde (MDA), and across a variety of cancers. To address this aim, analysis of studies of breast, prostate, lung, colon, cervical, ovarian, brain, bladder, renal, thyroid cancer, and chronic lymphocytic leukemia has been conducted. In general, levels of antioxidative enzymes are mostly lower in cancer patients, while 8-OHdG and MDA are higher. Further research is needed, with focus on correlation levels of these biomarkers and advancement of the disease. Moreover, all studies explored the idea of those biomarkers as a useful tool in determining the levels of oxidative stress. Some of the studies proposed their potential in defining the stage of tumor progression.
TL;DR: In this paper, a review highlights the link between disturbed lipid metabolism and oxidative stress in the context of NAFLD and discusses potential therapies based on antioxidant effects and their likely molecular targets.
Abstract: Oxidative stress (OxS) is considered a major factor in the pathophysiology of inflammatory chronic liver diseases, including non-alcoholic liver disease (NAFLD). Chronic impairment of lipid metabolism is closely related to alterations of the oxidant/antioxidant balance, which affect metabolism-related organelles, leading to cellular lipotoxicity, lipid peroxidation, chronic endoplasmic reticulum (ER) stress, and mitochondrial dysfunction. Increased OxS also triggers hepatocytes stress pathways, leading to inflammation and fibrogenesis, contributing to the progression of non-alcoholic steatohepatitis (NASH). The antioxidant response, regulated by the Nrf2/ARE pathway, is a key component in this process and counteracts oxidative stress-induced damage, contributing to the restoration of normal lipid metabolism. Therefore, modulation of the antioxidant response emerges as an interesting target to prevent NAFLD development and progression. This review highlights the link between disturbed lipid metabolism and oxidative stress in the context of NAFLD. In addition, emerging potential therapies based on antioxidant effects and their likely molecular targets are discussed.
TL;DR: Recent progress in research on the Keap1-Nrf2 system involving oxidative stress and aging is focused on, providing an empirical basis for the development of antiaging drugs.
Abstract: Oxidative stress, a term that describes the imbalance between oxidants and antioxidants, leads to the disruption of redox signals and causes molecular damage. Increased oxidative stress from diverse sources has been implicated in most senescence-related diseases and in aging itself. The Kelch-like ECH-associated protein 1- (Keap1-) nuclear factor-erythroid 2-related factor 2 (Nrf2) system can be used to monitor oxidative stress; Keap1-Nrf2 is closely associated with aging and controls the transcription of multiple antioxidant enzymes. Simultaneously, Keap1-Nrf2 signaling is also modulated by a more complex regulatory network, including phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt), protein kinase C, and mitogen-activated protein kinase. This review presents more information on aging-related molecular mechanisms involving Keap1-Nrf2. Furthermore, we highlight several major signals involved in Nrf2 unbinding from Keap1, including cysteine modification of Keap1 and phosphorylation of Nrf2, PI3K/Akt/glycogen synthase kinase 3β, sequestosome 1, Bach1, and c-Myc. Additionally, we discuss the direct interaction between Keap1-Nrf2 and the mammalian target of rapamycin pathway. In summary, we focus on recent progress in research on the Keap1-Nrf2 system involving oxidative stress and aging, providing an empirical basis for the development of antiaging drugs.
TL;DR: In this article, the authors explored the regulatory mechanism of the gut flora in the host defense against lipopolysaccharide (LPS)-induced acute lung injury through the TLR4/NF-kB pathway by constructing a gut microflora dysbiosis-model with antibiotic administration and reconstruction of the intestinal microecology.
TL;DR: In this article, the effects of polystyrene microplastics (PS-MPs) on the ovary in rats were investigated and the underlying molecular mechanisms were found out, which showed that MPs could enter into granulosa cells and result in the reducing of growing follicles number.
TL;DR: A growing body of evidence supports a key role for smoking-induced ROS and the resulting oxidative stress in inflammation and carcinogenesis, and potentially increased oxidative damage to macromolecular targets that may lead to cancer initiation and/or progression.
Abstract: Smoking is a major risk factor for a variety of diseases, including cancer and immune-mediated inflammatory diseases. Tobacco smoke contains a mixture of chemicals, including a host of reactive oxygen- and nitrogen species (ROS and RNS), among others, that can damage cellular and sub-cellular targets, such as lipids, proteins, and nucleic acids. A growing body of evidence supports a key role for smoking-induced ROS and the resulting oxidative stress in inflammation and carcinogenesis. This comprehensive and up-to-date review covers four interrelated topics, including 'smoking', 'oxidative stress', 'inflammation', and 'cancer'. The review discusses each of the four topics, while exploring the intersections among the topics by highlighting the macromolecular damage attributable to ROS. Specifically, oxidative damage to macromolecular targets, such as lipid peroxidation, post-translational modification of proteins, and DNA adduction, as well as enzymatic and non-enzymatic antioxidant defense mechanisms, and the multi-faceted repair pathways of oxidized lesions are described. Also discussed are the biological consequences of oxidative damage to macromolecules if they evade the defense mechanisms and/or are not repaired properly or in time. Emphasis is placed on the genetic- and epigenetic alterations that may lead to transcriptional deregulation of functionally-important genes and disruption of regulatory elements. Smoking-associated oxidative stress also activates the inflammatory response pathway, which triggers a cascade of events of which ROS production is an initial yet indispensable step. The release of ROS at the site of damage and inflammation helps combat foreign pathogens and restores the injured tissue, while simultaneously increasing the burden of oxidative stress. This creates a vicious cycle in which smoking-related oxidative stress causes inflammation, which in turn, results in further generation of ROS, and potentially increased oxidative damage to macromolecular targets that may lead to cancer initiation and/or progression.
TL;DR: The involvement of lipid peroxidation in the mechanism of neuronal loss and some novel therapeutic directions to oppose it are discussed.
Abstract: The world's population aging progression renders age-related neurodegenerative diseases to be one of the biggest unsolved problems of modern society. Despite the progress in studying the development of pathology, finding ways for modifying neurodegenerative disorders remains a high priority. One common feature of neurodegenerative diseases is mitochondrial dysfunction and overproduction of reactive oxygen species, resulting in oxidative stress. Although lipid peroxidation is one of the markers for oxidative stress, it also plays an important role in cell physiology, including activation of phospholipases and stimulation of signaling cascades. Excessive lipid peroxidation is a hallmark for most neurodegenerative disorders including Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, and many other neurological conditions. The products of lipid peroxidation have been shown to be the trigger for necrotic, apoptotic, and more specifically for oxidative stress-related, that is, ferroptosis and neuronal cell death. Here we discuss the involvement of lipid peroxidation in the mechanism of neuronal loss and some novel therapeutic directions to oppose it.
TL;DR: It is shown that fructose intake causes protein nitration of intestinal TJ and AJ proteins, resulting in increased gut leakiness, endotoxemia, and steatohepatitis with liver fibrosis, at least partly, through a CYP2E1‐dependent manner.
TL;DR: In this paper, the main physiological characteristics responsible for the higher susceptibility of the nigrostriatal circuit to mitochondrial dysfunction and oxidative stress, as hinted by the acting mechanisms of the PD-causing neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), were discussed.
TL;DR: In this paper, the authors synthesize the current literature on the effect of neuronal oxidative stress on mitochondrial dysfunction, DNA damage and epigenetic changes related to cognitive aging and Alzheimer's disease, and further describe how oxidative stress therapeutics such as antioxidants, caloric restriction and physical activity can reduce oxidation and prevent cognitive decline in brain aging and AD.
TL;DR: In this paper, the authors discuss the participation of oxidative stress in obesity and the important groups of compounds found in plants with antioxidant properties, which include (a) polyphenols such as phenolic acids, stilbenes, flavonoids (flavonols, flavanols, anthocyanins, flavones, flavanonols, and isoflavones), and curcuminoids (b) carotenoids, capsaicinoids and casinoids, (c) isothiocyanates, (e) catechins,
Abstract: Oxidative stress is important in the pathophysiology of obesity, altering regulatory factors of mitochondrial activity, modifying the concentration of inflammation mediators associated with a large number and size of adipocytes, promoting lipogenesis, stimulating differentiation of preadipocytes to mature adipocytes, and regulating the energy balance in hypothalamic neurons that control appetite. This review discusses the participation of oxidative stress in obesity and the important groups of compounds found in plants with antioxidant properties, which include (a) polyphenols such as phenolic acids, stilbenes, flavonoids (flavonols, flavanols, anthocyanins, flavanones, flavones, flavanonols, and isoflavones), and curcuminoids (b) carotenoids, (c) capsaicinoids and casinoids, (d) isothiocyanates, (e) catechins, and (f) vitamins. Examples are analyzed, such as resveratrol, quercetin, curcumin, ferulic acid, phloretin, green tea, Hibiscus Sabdariffa, and garlic. The antioxidant activities of these compounds depend on their activities as reactive oxygen species (ROS) scavengers and on their capacity to prevent the activation of NF-κB (nuclear factor κ-light-chain-enhancer of activated B cells), and reduce the expression of target genes, including those participating in inflammation. We conclude that natural compounds have therapeutic potential for diseases mediated by oxidative stress, particularly obesity. Controlled and well-designed clinical trials are still necessary to better know the effects of these compounds.
TL;DR: In the open metabolic system, redox-related signaling requires continuous monitoring and fine-tuning of the steady-state redox set point, which operates within a physiological range that has been called the "Homeodynamic Space", the "Goldilocks Zone" or the "Golden Mean".
Abstract: In the open metabolic system, redox-related signaling requires continuous monitoring and fine-tuning of the steady-state redox set point. The ongoing oxidative metabolism is a persistent challenge, denoted as oxidative eustress, which operates within a physiological range that has been called the 'Homeodynamic Space', the 'Goldilocks Zone' or the 'Golden Mean'. Spatiotemporal control of redox signaling is achieved by compartmentalized generation and removal of oxidants. The cellular landscape of H2O2, the major redox signaling molecule, is characterized by orders-of-magnitude concentration differences between organelles. This concentration pattern is mirrored by the pattern of oxidatively modified proteins, exemplified by S-glutathionylated proteins. The review presents the conceptual background for short-term (non-transcriptional) and longer-term (transcriptional/translational) homeostatic mechanisms of stress and stress responses. The redox set point is a variable moving target value, modulated by circadian rhythm and by external influence, summarily denoted as exposome, which includes nutrition and lifestyle factors. Emerging fields of cell-specific and tissue-specific redox regulation in physiological settings are briefly presented, including new insight into the role of oxidative eustress in embryonal development and lifespan, skeletal muscle and exercise, sleep-wake rhythm, and the function of the nervous system with aspects leading to psychobiology.
TL;DR: In this article, the effects of polystyrene MPs (PS MPs) on the ovary and its mechanism in rats remained unclear. But, exposure to microplastics had adverse effects on ovarian and could be a potential risk factor for female infertility, which provided new insights into the toxicity of MPs on female reproduction.
TL;DR: In this article, mesenchymal stem cells derived extracellular vesicles (MSC-EVs) were shown to attenuate mtDNA damage and inflammation after acute kidney injury (AKI) and that this effect was at least partially dependent on the mtDNA pathway.
Abstract: Mitochondrial dysfunction is a key feature of injury to numerous tissues and stem cell aging. Although the tissue regenerative role of mesenchymal stem cell (MSC)-derived extracellular vesicles (MSC-EVs) is well known, their specific role in regulating mitochondrial function in target cells remains elusive. Here, we report that MSC-EVs attenuated mtDNA damage and inflammation after acute kidney injury (AKI) and that this effect was at least partially dependent on the mitochondrial transcription factor A (TFAM) pathway. In detail, TFAM and mtDNA were depleted by oxidative stress in MSCs from aged or diabetic donors. Higher levels of TFAM mRNA and mtDNA were detected in normal control (NC) MSC-EVs than in TFAM-knockdown (TFAM-KD) and aged EVs. EV-mediated TFAM mRNA transfer in recipient cells was unaffected by transcriptional inhibition. Accordingly, the application of MSC-EVs restored TFAM protein and TFAM-mtDNA complex (nucleoid) stability, thereby reversing mtDNA deletion and mitochondrial oxidative phosphorylation (OXPHOS) defects in injured renal tubular cells. Loss of TFAM also led to downregulation of multiple anti-inflammatory miRNAs and proteins in MSC-EVs. In vivo, intravenously injected EVs primarily accumulated in the liver, kidney, spleen, and lung. MSC-EVs attenuated renal lesion formation, mitochondrial damage, and inflammation in mice with AKI, whereas EVs from TFAM-KD or aged MSCs resulted in poor therapeutic outcomes. Moreover, TFAM overexpression (TFAM-OE) improved the rescue effect of MSC-EVs on mitochondrial damage and inflammation to some extent. This study suggests that MSC-EVs are promising nanotherapeutics for diseases characterized by mitochondrial damage, and TFAM signaling is essential for maintaining their regenerative capacity.
TL;DR: In this article, the authors highlight the impact of polyphenols from Mediterranean foods on molecular mechanisms that mediate obesity-related oxidative stress and inflammation, and discuss the effects of these poly-phenols on a number of signaling pathways.
Abstract: Nutrition transition can be defined as shifts in food habits, and it is characterized by high-fat (chiefly saturated animal fat), hypercaloric and salty food consumption at the expense of dietary fibers, minerals and vitamins. Western dietary patterns serve as a model for studying the impact of nutrition transition on civilization diseases, such as obesity, which is commonly associated with oxidative stress and inflammation. In fact, reactive oxygen species (ROS) overproduction can be associated with nuclear factor-κB (NF-κB)-mediated inflammation in obesity. NF-κB regulates gene expression of several oxidant-responsive adipokines including tumor necrosis factor-α (TNF-α). Moreover, AMP-activated protein kinase (AMPK), which plays a pivotal role in energy homeostasis and in modulation of metabolic inflammation, can be downregulated by IκB kinase (IKK)-dependent TNF-α activation. On the other hand, adherence to a Mediterranean-style diet is highly encouraged because of its healthy dietary pattern, which includes antioxidant nutraceuticals such as polyphenols. Indeed, hydroxycinnamic derivatives, quercetin, resveratrol, oleuropein and hydroxytyrosol, which are well known for their antioxidant and anti-inflammatory activities, exert anti-obesity proprieties. In this review, we highlight the impact of the most common polyphenols from Mediterranean foods on molecular mechanisms that mediate obesity-related oxidative stress and inflammation. Hence, we discuss the effects of these polyphenols on a number of signaling pathways. We note that Mediterranean diet (MedDiet) dietary polyphenols can de-regulate nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) and NF-κB-mediated oxidative stress, and metabolic inflammation. MedDiet polyphenols are also effective in upregulating downstream effectors of several proteins, chiefly AMPK.
TL;DR: It could be concluded that cadmium could increase intracellular ROS, result in cellular oxidative stress, activate JNK, ERK and p38 MAPK pathways and ultimately lead to apoptosis of BEAS-2B cells by activating mitochondria-mediated intrinsic apoptosis pathway.
TL;DR: It is demonstrated that hesperetin ameliorates hepatic oxidative stress through the PI3 K/AKT-Nrf2 pathway and that this antioxidative effect further suppresses NF-κB-mediated inflammation during NAFLD progression.
Abstract: Non-alcoholic fatty liver disease (NAFLD) is considered the most common liver disease. Dietary supplementation has become a promising strategy for managing NAFLD. Hesperetin, a citrus flavonoid, is mainly found in citrus fruits (oranges, grapefruit, and lemons) and possesses multiple pharmacological properties, including anti-cancer, anti-Alzheimer and anti-diabetic effects. However, the anti-NAFLD effect and mechanisms of hesperetin remain unclear. In this study, we investigated the therapeutic effect of hesperetin against NAFLD and the underlying mechanism in vitro and in vivo. In oleic acid (OA)-induced HepG2 cells, hesperetin upregulated antioxidant levels (SOD/GPx/GR/GCLC/HO-1) by triggering the PI3 K/AKT-Nrf2 pathway, alleviating OA-induced reactive oxygen species (ROS) overproduction and hepatotoxicity. Furthermore, hesperetin suppressed NF-κB activation and reduced inflammatory cytokine secretion (TNF-α and IL-6). More importantly, we revealed that this anti-inflammatory effect is attributed to reduced ROS overproduction by the Nrf2 pathway, as pre-treatment with Nrf2 siRNA or an inhibitor of superoxide dismutase (SOD) or/and glutathione peroxidase (GPx) abolished hesperetin-induced NF-κB inactivation and reductions in inflammatory cytokine secretion. In a rat model of high-fat diet (HFD)-induced NAFLD, we confirmed that hesperetin relieved hepatic steatosis, oxidative stress, inflammatory cell infiltration and fibrosis. Moreover, hesperetin activated the PI3 K/AKT-Nrf2 pathway in the liver, increasing antioxidant expression and inhibiting NF-κB activation and inflammatory cytokine secretion. In summary, our results demonstrate that hesperetin ameliorates hepatic oxidative stress through the PI3 K/AKT-Nrf2 pathway and that this antioxidative effect further suppresses NF-κB-mediated inflammation during NAFLD progression. Thus, our study suggests that hesperetin may be an effective dietary supplement for improving NAFLD by suppressing hepatic oxidative stress and inflammation.