Reactive Oxygen Species Exposure Research Articles

Assessing the discrepant role of anions in the transformation of reactive oxygen species in H2O2 and PDS system: A comparative kinetic analysis

Clarifying reactive oxygen species (ROS) variation in the presence of co-existing anions is significant for understanding the catalytic effect of magnetite (Fe3O4)-induced advanced oxidation processes (AOPs) in natural environment, yet this remains controversial. Herein, we compare the specific impacts of NO3-, SO42-, and Cl- on ROS (•OH, SO4•-, O2•-, and 1O2) exposure concentration in H2O2 and peroxydisulfate (PDS) systems, as well as how these variations affect the catalytic efficiency by developing kinetic model. In both two systems, NO3- demonstrates no discernible effect on ROS, whereas SO42- inhibits the exposure of all ROS and thus micropollutants degradation. Through theoretical calculation, it is proposed that SO42- primarily exerts its influence through affecting the electronic structure over catalyst surface. Regarding Cl-, it affects ROS exposure mainly by reacting with ROS. It shows inhibitory effect on 1O2 in both systems, but its suppressive impact on •OH is markedly more pronounced in H2O2 system compared to PDS system, which may be related to its rapid reactivity with SO4•-. Besides, the chlorine radicals (mainly ClO•) generated through the reaction of Cl- may exert a selective influence on micropollutants degradation. This study can help to re-understand the influence behavior of co-existing anions during AOPs.

Ball milling of pyrolytic residue from oil sands with MnO2 and reuse as PMS activator: Measurement of ROS exposure and mechanism insights

Pyrolysis is an important process to recover petroleum from oil sands, while the pyrolytic residue of oil sands (PROS) is commonly treated as solid waste. In this study, PROS was treated by ball milling with manganese dioxide and converted into Mn-loaded carbon sand (MnBMCS), which was reused as a peroxymonosulfate (PMS) activator to degrade aniline (AN) in wastewater. The AN (100 mg/L) was almost completely removed by 2 g/L MnBMCS and 1 g/L PMS. Electron paramagnetic resonance tests confirmed the existence of three reactive oxygen species (ROS) including sulfate radical (SO4∙−), hydroxyl radical (∙OH) and singlet oxygen (O21) in MnBMCS/PMS system. A probe-based kinetics model was constructed to measure the ROS exposure. The O21 exposure was 6.73 and 22.95 times of SO4∙− and ∙OH exposure, respectively. But the contribution of SO4∙− to AN degradation was much greater than that of O21 due to its higher oxidation capacity. Characterization analysis showed that Mn(Ⅳ)/Mn(Ⅲ) redox electrons could activate PMS to produce SO4∙− and ∙OH, CO activated PMS to produce O21, and π-π* was also beneficial to generate SO4∙− and ∙OH. This study proposes an innovative integrated process to promote the governance mode of PROS from harmless disposal to high-value resource utilization.

A shift in chromatin binding of phosphorylated p38 precedes transcriptional changes upon oxidative stress.

P38 mitogen-activated protein kinases are key in the regulation of the cellular response to stressors. P38 is known to regulate transcription, mRNA processing, stability, and translation. The transcriptional changes mediated by phosphorylated p38 (P-p38) in response to extracellular stimuli have been thoroughly analyzed in many tissues and organisms. However, the genomic localization of chromatin-associated P-p38 remains poorly understood. Here, we analyze the chromatin binding of activated P-p38 and its role in the response to reactive oxygen species (ROS) in Drosophila S2 cells. We found that P-p38 is already bound to chromatin in basal conditions. After ROS exposure, chromatin-associated P-p38 relocates towards genes involved in the recovery process. Our findings highlight the role of P-p38 dynamic chromatin binding in orchestrating gene expression responses to oxidative stress.

Dual targeting of KDM1A and antioxidants is an effective anticancer strategy.

Lysine Specific Demethylase 1 (KDM1A / LSD1) regulates mitochondrial respiration and stabilizes HIF-1A (hypoxia-inducible factor 1A). HIF-1A modulates reactive oxygen species (ROS) levels by increasing cellular glucose uptake, glycolysis, and endogenous antioxidants. The role of KDM1A in cellular ROS response has not previously been described. We determined the role of KDM1A in regulating the ROS response and the utility of KDM1A inhibitors in combination with ROS-inducing cancer therapies. Our results show that KDM1A inhibition sensitized cells to oxidative stress and increased total cellular ROS, which was mitigated by treatment with the antioxidant N-acetyl cysteine. KDM1A inhibition decreased basal mitochondrial respiration and impaired induction of HIF-1A after ROS exposure. Overexpression of HIF-1A salvaged cells from KDM1A inhibition enhanced sensitivity to ROS. Thus we found that increased sensitivity of ROS after KDM1A inhibition was mediated by HIF-1A and depletion of endogenous glutathione. We also show that KDM1A-specific inhibitor bizine synergized with antioxidant-depleting therapies, buthionine sulfoximine, and auranofin in rhabdomyosarcoma cell lines (Rh28 and Rh30). In this study, we describe a novel role for KDM1A in regulating HIF- 1A functions under oxidative stress and found that dual targeting of KDM1A and antioxidant systems may serve as an effective combination anticancer strategy.

Roquin-2 promotes oxidative stress-induced cell death by ubiquitination-dependent degradation of TAK1

Reactive oxygen species (ROS) are highly reactive and their accumulation causes oxidative damage to cells. Cells maintain survival upon mild oxidative stress with anti-oxidative systems, such as the kelch-like ECH-associated protein 1 (Keap1)-nuclear factor erythroid 2-related factor 2 (Nrf2) system. On the other hand, upon severe oxidative stress, cells undergo regulated cell death, including apoptosis, for eliminating damaged cells. To execute efficient cell death, cells need to turn off the anti-oxidant systems, while triggering cell death. However, it remains unknown how cells orchestrate these two conflicting systems under excessive oxidative stress.Herein, we show that when cells are exposed to excessive oxidative damage, an E3 ubiquitin ligase Roquin-2 (also known as RC3H2) plays a key role in switching cell fate from survival to death by terminating activation of transforming growth factor-β-activated kinase 1 (TAK1), a positive regulator for Nrf2 activation. Roquin-2 interacted with TAK1 via four cysteine residues in TAK1 (C96, C302, C486, and C500) that are susceptible to oxidative stress and participate in oligomer formation via disulfide bonds, promoting K48-linked polyubiquitination and degradation of TAK1. Nrf2 was inactivated upon lethal oxidative stress in wild-type mouse embryonic fibroblast (MEF) cells, whereas it sustained activation and conferred resistance to Roquin-2 deficient cells, which was reversed by pharmacological or genetic inhibition of TAK1. These data demonstrate that in response to excessive ROS exposure, Roquin-2 promotes ubiquitination and degradation of TAK1 to suppress Nrf2 activation, and thereby contributes to an efficient cell death, providing insight into the pathogenesis of oxidative stress-related diseases, including cancer.

Thioketal-Based Electrochemical Sensor Reveals Biphasic Effects of l-DOPA on Neuroinflammation.

Neuroinflammation is linked closely to neurodegenerative diseases, with reactive oxygen species (ROS) exacerbating neuronal damage. Traditional electrochemical sensors show promise in targeting cellular ROS to understand their role in neuropathogenesis and assess therapies. Nevertheless, these sensors face challenges in mitigating the ROS oxidation overpotential. We herein introduce an ROS oxidation-independent nucleic acid sensor for in situ ROS analysis and therapeutic assessment. The sensor comprises ionizable and thioketal (TK)-based lipids with methylene blue-tagged nucleic acids on a glass carbon electrode. ROS exposure triggers cleavage within the sensor's thioketal moiety, detaching the nucleic acid from the electrode and yielding quantifiable results via square-wave voltammetry. Importantly, the sensor's low potential window minimizes interference, ensuring precise ROS measurements with high selectivity. Using this sensor, we unveil levodopa's dose-dependent biphasic effect on neuroinflammation: low doses alleviate oxidative stress, while high doses exacerbate it. The TK-based sensor offers a promising methodology for investigating neuroinflammation's pathogenesis and screening potential treatments, advancing neurodegenerative disease research.

Bioenergetics of iron snow fueling life on Europa

The main sources of redox gradients supporting high-productivity life in the Europan and other icy ocean world oceans were proposed to be photolytically derived oxidants, such as reactive oxygen species (ROS) from the icy shell, and reductants (Fe(II), S(-II), CH4, H2) from bottom waters reacting with a (ultra)mafic seafloor. Important roadblocks to maintaining life, however, are that the degree of ocean mixing to combine redox species is unknown, and ROS damage biomolecules. Here, we envisage a unique solution using an acid mine drainage (AMD)-filled pit lakes analog system for the Europan ocean, which previous models predicted to be acidic. We hypothesize that surface-generated ROS oxidize dissolved Fe(II) resulting in Fe(III) (hydr)oxide precipitates, that settle to the seafloor as "iron snow." The iron snow provides a respiratory substrate for anaerobic microorganisms ("breathing iron"), and limits harmful ROS exposure since they are now neutralized at the ice-water interface. Based on this scenario, we calculated Gibbs energies and maximal biomass productivities of various anaerobic metabolisms for a range of pH, temperatures, and H2 fluxes. Productivity by iron reducers was greater for most environmental conditions considered, whereas sulfate reducers and methanogens were more favored at high pH. Participation of Fe in the metabolic redox processes is largely neglected in most models of Europan biogeochemistry. Our model overcomes important conceptual roadblocks to life in icy ocean worlds and broadens the potential metabolic diversity, thus increasing total primary productivity, the diversity and volume of habitable environmental niches and, ultimately, the probability of biosignature detection.

Ultrasmall MnOx Nanodots Catalyze Glucose for Reactive Oxygen Species‐Dependent Sequential Anti‐Infection and Regeneration Therapy

The management of diabetic wounds poses significant challenges due to persistent bacterial infections and chronic inflammation caused by hyperglycemia. Herein, a sequential two‐phase treatment strategy involving a reactive oxygen species (ROS) burst in the first phase for anti‐infection is proposed, followed by a benign level of ROS in the second phase for wound regeneration. To this end, ultra‐small manganese oxide nanodots (BM‐NDs) are incorporated into a gelatin methacrylamide (GelMA) hydrogel via a ROS‐responsive linker to form GelMA@BM dressing. The BM‐NDs catalyze a self‐cascade reaction that decomposes glucose into hydrogen peroxide, generates hydroxyl radicals (·OH), and simultaneously depletes glutathione. Upon application on diabetic wounds, BM‐NDs are rapidly released from the hydrogel due to endogenous ROS exposure, leading to high levels of ·OH that effectively eliminate bacteria and promote macrophage polarization to M1 phenotype, thereby facilitating phagocytosis of bacteria. With the consumption of glucose and degradation of BM‐NDs, ROS in the wound area declines to a benign level, which stimulates polarization of M2 macrophages and promotes wound healing. This two‐phase treatment strategy based on GelMA@BM dressing demonstrates potent antibacterial and pro‐healing efficacy, showcasing its potential for clinical translation.

Exposure to cooking fumes is associated with perturbations in nasal microbiota composition: A pilot study

Air pollution is one of the leading causes of overall mortality globally. Cooking emissions are a major source of fine particulate matter (PM2.5). However, studies on their potential perturbations on the nasal microbiota as well as their association with respiratory health are lacking. This pilot study aims to assess the environmental air quality among occupational cooks and its associations with nasal microbiota and respiratory symptoms. A total of 20 cooks (exposed) and 20 unexposed controls (mainly office workers), were recruited in Singapore from 2019 to 2021. Information on sociodemographic factors, cooking methods, and self-reported respiratory symptoms were collected using a questionnaire. Personal PM2.5 concentrations and reactive oxygen species (ROS) levels were measured using portable sensors and filter samplers. DNA was extracted from nasal swabs and sequenced using 16s sequencing. Alpha-diversity and beta-diversity were calculated, and between-group variation analysis of species was performed. Multivariable logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for associations between exposure groups and self-reported respiratory symptoms. Higher daily mean PM2.5 (P = 2 × 10−7) and environmental ROS exposure (P = 3.25 × 10−7) were observed in the exposed group. Alpha diversity of the nasal microbiota between the two groups was not significantly different. However, beta diversity was significantly different (unweighted UniFrac P = 1.11 × 10–5, weighted UniFrac P = 5.42 × 10−6) between the two exposure groups. In addition, certain taxa of bacteria were slightly more abundant in the exposed group compared to unexposed controls. There were no significant associations between the exposure groups and self-reported respiratory symptoms. In summary, the exposed group had higher PM2.5 and ROS exposure levels and altered nasal microbiotas as compared to unexposed controls, though further studies are required to replicate these findings in a larger population.

Oxidative stress and protection against it in bacteria

Microorganisms are exposed to reactive oxygen species (ROS) that are formed in various ways, in particular, as a result of respiration or other intracellular processes, during metal-catalyzed Fenton reactions, as a result of the action of UV- and X-radiation, under the influence of some antimicrobial drugs, or during the host immune oxidative-burst response against infection agents. In this review, we take a look at the mechanisms of microbial cell damage, including damage of lipids and proteins. Lipid peroxidation (LPO) is one of the main molecular mechanisms involved in oxidative damage to cellular structures. A variety of products are formed during LPO reactions: alkoxyl radicals, peroxyl radicals, hydroperoxides, diene conjugates, carbonyl compounds, aldehyde adducts with biopolymers, alcohols, esters, etc. These products include cytotoxic and highly reactive compounds. Free radical reactions of protein damage occur via hydrogen atom abstraction from α-carbon or SH-, NH2-groups of aminoacids and electron abstraction from nucleophile centers of proteins resulting in the fragmentation of proteins, their denaturation and the formation of amino acid radicals. Bacteria show a significant adaptive potential to the influence of stress agents, including ROS. We summarized the data on bacterial antioxidant protection, ROS redox sensors, and regulators of bacterial cell response to ROS exposure, focusing on the features of anaerobic microorganisms, as their responses to the oxidative damage are the least studied, and many problems remain unsolved. This review contains information about changes in fatty acid composition of lipids of the plasma membrane to maintain the necessary fluidity, and, thus, counteract the effects of various stressing agents, including ROS. The main modifications of the fatty acid composition of lipids important for the regulation of membrane fluidity are described, in particular, via changes in the degree of lipid saturation, cis/trans isomerization, and synthesis of cyclopropane fatty acids.

Molecular evolution of Keap1 was essential for adaptation of vertebrates to terrestrial life.

Reactive oxygen species (ROS) posed a risk for the transition of vertebrates from aquatic to terrestrial life. How ancestral organisms adapted to such ROS exposure has remained a mystery. Here, we show that attenuation of the activity of the ubiquitin ligase CRL3Keap1 for the transcription factor Nrf2 during evolution was key to development of an efficient response to ROS exposure. The Keap1 gene was duplicated in fish to give rise to Keap1A and the only remaining mammalian paralog Keap1B, the latter of which shows a lower affinity for Cul3 and contributes to robust Nrf2 induction in response to ROS exposure. Mutation of mammalian Keap1 to resemble zebrafish Keap1A resulted in an attenuated Nrf2 response, and most knock-in mice expressing such a Keap1 mutant died on exposure as neonates to sunlight-level ultraviolet radiation. Our results suggest that molecular evolution of Keap1 was essential for adaptation to terrestrial life.

Intestinal ACE2 regulates glucose metabolism in diet-induced obese mice through a novel gut-islet axis mediated by tryptophan.

Angiotensin-converting enzyme 2 (ACE2) plays a vital role in regulating intestinal tryptophan (Trp) transport and maintaining Trp homeostasis. This study aimed to investigate the functional relationship between intestinal ACE2 and Trp in the regulation of glucose metabolism under metabolic stress. ACE2-knockout mice and mice with adeno-associatedvirus-mediated overexpression of ACE2 were fed with a high-fat diet for 12 weeks to establish a high-fat-induced metabolic stress model. They were subjected to a Trp gavage intervention for another 4 weeks. Here, it is reported that ACE2 regulates intestinal Trp absorption by stabilizing neutral amino acid transporter B0 AT1. Notably, in ACE2-knockout mice, it was found that B0 AT1 and serum Trp levels were significantly reduced, which was not reversed by Trp supplementation. However, mice receiving adeno-associatedvirus-ACE2 did the opposite and showed significantly improved glycolipid metabolism. It was then confirmed that Trp potentiated glucagon-like peptide 1 production from intestinal and islet α-cells. Meanwhile, Trp-treated MIN6 cells ameliorated mitochondrial function and safely guarded MIN6 cells against reactive oxygen species exposure. This study highlights an essential role of ACE2 in the maintenance of systemic metabolism to optimize the function of the islets through a novel gut-islet axis mediated by Trp. These results provide proof-of-concept evidence for treating obesity and diabetes.

Protection of C2C12 skeletal muscle cells toward oxidation by a polyphenol-rich plant extract

Graphical abstract Abstract Sarcopenia is a very disabling age-related disease which affects the mass and strength of skeletal muscles. This syndrome has no efficient treatment and is associated with important oxidative stress which could play important role in skeletal muscle degeneration. In this context, the cytoprotective activity and the antioxidant properties of a polyphenol-rich plant extract (PRPE) were evaluated in undifferentiated C2C12 murine skeletal muscle cells (myoblasts). PRPE is a potent antioxidant mixture as shown by its reactive oxygen species (ROS) scavenging properties by using the Kit Radicaux Libres method and the dihydroethidium (DHE) scavenging assay. In addition, PRPE has significant protecting properties in C2C12 cells toward oxidative stress triggered by 2, 2′-azobis (2-amidinopropane) dihydrochloride (AAPH) which is an ROS generator, as measured by different complementary approaches. PRPE counteracts several AAPH-induced cytotoxic effects. PRPE prevents morphological changes evaluated by phase contrast microscopy and decreases the number of dying cells determined by counting in the presence of trypan blue and the intracellular ROS overproduction evaluated by flow cytometry after staining with DHE. In addition, PRPE tends to normalize the expression of genes (peroxiredoxin 1 (Pdrx1), nuclear factor erythroid 2-related factor 2 (Nrf2), and peroxisome proliferator-activator receptor gamma coactivator 1-alpha (Pgc1α)) involved in the oxidant stress defense under ROS exposure. Altogether; our data show that PRPE has potent antioxidant properties and protects C2C12 skeletal muscle cells toward AAPH-induced oxidative stress. These cytoprotective properties of PRPE in skeletal muscle cells submitted to a pro-oxidant environment deserve further investigation in the context of sarcopenia.

Double-layer mucin microencapsulation enhances the stress tolerance and oral delivery of Lactobacillus plantarum B2

The delivery of beneficial bacteria to the gut microbiome holds a promise to avert and treat diseases such as ariboflavinosis. Nevertheless, adverse gastrointestinal (GI) conditions, a high concentration of reactive oxygen species (ROS), exhausted mucus layer, constant peristalsis of the gastrointestinal tract, and complex pathological microenvironment result in low oral bioavailability lead to limited intestinal colonization of probiotics and affect their related health benefits. Herein, we established a bio-based strategy of double-layer gelatin-mucin-alginate and chitosan-mucin-alginate microcapsules that endow the transplanted riboflavin (vitamin B2) over-producing strain Lactobacillus plantarum B2 with robust resistance to adverse environments and remarkable adhesiveness to the intestine. The outer gelatin (or chitosan) membrane was observed by building a gelatin-genipin (or chitosan-genipin) fluorescent complex. We demonstrated that co-encapsulating with mucin and the secondary coating of gelatin or chitosan could effectively maintain the regular surface morphology of gel beads and protect probiotics during the lyophilization process, possibly by improving the internal cross-linking and mechanical strength of the microcapsules. The encapsulated probiotic strain was endowed with strong resistance during storage, simulated gastrointestinal digestion fluid, and ROS exposure. In addition, co-embedded mucin augmented the adherence rate of L. P. B2 on the simulated intestinal mucus. Most importantly, microcapsule encapsulation not only retained the probiotic potential of L. P. B2 but also improved the B2 production during soymilk fermentation. Altogether, the encapsulation strategy can be used as an effective way to deliver explicit probiotics to the gut microbiota for the intestinal colonization of probiotics to deliver B2 in the human gut.

Pathogenic fungi neutralize plant‐derived ROS via Srpk1 deacetylation

In response to infection, plants can induce the production of reactive oxygen species (ROS) to restrict pathogen invasion. In turn, adapted pathogens have evolved a counteracting mechanism of enzymatic ROS detoxification, but how it is activated remains elusive. Here, we show that in the tomato vascular wilt pathogen Fusarium oxysporum f. sp. lycopersici (Fol) this process is initiated by deacetylation of the FolSrpk1 kinase. Upon ROS exposure, Fol decreases FolSrpk1 acetylation on the K304 residue by altering the expression of the acetylation‐controlling enzymes. Deacetylated FolSrpk1 disassociates from the cytoplasmic FolAha1 protein, thus enabling its nuclear translocation. Increased accumulation of FolSrpk1 in the nucleus allows for hyperphosphorylation of its phosphorylation target FolSr1 that subsequently enhances transcription of different types of antioxidant enzymes. Secretion of these enzymes removes plant‐produced H2O2, and enables successful Fol invasion. Deacetylation of FolSrpk1 homologs has a similar function in Botrytis cinerea and likely other fungal pathogens. These findings reveal a conserved mechanism for initiation of ROS detoxification upon plant fungal infection.

Bilateral varicocele leads to ferroptosis, pyroptosis and necroptosis of human spermatozoa and affects semen quality in infertile men.

Purpose: This study explored the effects of bilateral varicocele on male semen quality in infertile men and the molecular mechanisms involving ferroptosis, pyroptosis and necroptosis signaling pathways. Methods: Totally, 20 healthy males and 26 patients with bilateral varicocele receiving infertility treatment were enrolled. Semen samples were collected. Basic semen parameters, acrosome integrity and membrane integrity, mitochondrial membrane potential (MMP) and apoptosis rate were compared. Levels of reactive oxygen species (ROS), iron, glutathione (GSH), total superoxide dismutase (T-SOD), and, Catalase (CAT), were detected in human seminal plasma. Relative mRNA expression of Ca 2+-independent phospholipases A2 beta (iPLA 2β), P53, Zinc finger E-box binding homeobox 1 (ZEB1) and GSH-dependent peroxidase 4 (GPX4) were evaluated. Relative protein expression was determined for GPX4, receptor interacting serine/threonine kinase 1 (RIPK1) and receptor interacting serine/threonine kinase 3 (RIPK3), as well as pyroptosis markers of Gasdermin E (GSDME) and heat shock protein 90 (HSP 90). Results: The results revealed that the bilateral varicocele group had significantly higher abnormalities (sperm progressive rate and sperm motility) compared to the control group. Meanwhile, compared to control group, GSH, T-SOD, and CAT levels were reduced in the bilateral varicocele group (p < 0.05). However, the level of ROS and iron were significantly increased (p < 0.05). Relative mRNA expression of P53, iPLA 2β, ZEB1, and GPX4 were reduced. In addition, ROS exposure activated ferroptosis-related signal pathways. RIPK1, RIPK3, GSDME and HSP 90 were increased in bilateral varicocele group. ROS exposure affected signaling pathways related to ferroptosis, necrosis and pyroptosis in human spermatozoa. Conclusion: Bilateral varicocele leads to ferroptosis, pyroptosis and necroptosis of human spermatozoa and affects semen quality in infertile men.

A putative xanthine dehydrogenase is critical for Borrelia burgdorferi survival in ticks and mice.

Borrelia burgdorferi is a pathogenic bacterium and the causative agent of Lyme disease. It is exposed to reactive oxygen species (ROS) in both the vertebrate and tick hosts. While some mechanisms by which B. burgdorferi ameliorates the effects of ROS exposure have been studied, there are likely other unknown mechanisms of ROS neutralization that contribute to virulence. Here, we follow up on a three gene cluster of unknown function, bb_0554, bb_0555, and bb_0556, that our prior unbiased transposon insertional sequencing studies implicated in both ROS survival and survival in Ixodes scapularis. We confirmed these findings through genetic knockout and provide evidence that these genes are co-transcribed as an operon to produce a xanthine dehydrogenase. In agreement with these results, we found that B. burgdorferi exposure to either uric acid (a product of xanthine dehydrogenase) or allopurinol (an inhibitor of xanthine dehydrogenase) could modulate sensitivity to ROS in a bb_0554-bb_0556 dependent manner. Together, this study identifies a previously uncharacterized three gene operon in B. burgdorferi as encoding a putative xanthine dehydrogenase critical for virulence. We propose renaming this locus xdhACB.

Reactive oxygen species enhance rAAV transduction by promoting its escape from late endosomes

BackgroundRecent seminal studies have revealed that endosomal reactive oxygen species (ROS) promote rather than inhibit viral infection. Some ROS generators, including shikonin and H2O2, have the potential to enhance recombinant adeno-associated virus (rAAV) transduction. However, the impact of ROS on rAAV intracellular trafficking remains unclear.MethodsTo understand the effects of ROS on the transduction of rAAV vectors, especially the rAAV subcellular distribution profiles, this study systematically explored the effect of ROS on each step of rAAV intracellular trafficking pathway using fluorescently-labeled rAAV and qPCR quantification determination.ResultsThe results showed promoted in-vivo and in-vitro rAAV transduction by ROS exposure, regardless of vector serotype or cell type. ROS treatment directed rAAV intracellular trafficking towards a more productive pathway by upregulating the expression of cathepsins B and L, accelerating the rAAV transit in late endosomes, and increasing the rAAV nucleus entry.ConclusionsThese data support that ROS generative drugs, such as shikonin, have the potential to promote rAAV vector transduction by promoting rAAV’s escape from late endosomes, and enhancing its productive trafficking to the nucleus.

L-carnosine Attenuates Bleomycin-Induced Oxidative Stress via NFκB Pathway in the Pathogenesis of Pulmonary Fibrosis.

Idiopathic Pulmonary fibrosis (IPF), a chronic interstitial lung disease, has pulmonary manifestations clinically characterized by collagen deposition, epithelial cell injury, and a decline in lung function. L-carnosine, a dipeptide consisting of β-alanine and L-histidine, has demonstrated a therapeutic effect on various diseases because of its pivotal function. Despite the effect of L-carnosine in experimental IPF mice, its anti-oxidative effect and associated intercellular pathway, particularly alveolar epithelial cells, remain unknown. Therefore, we demonstrated the anti-fibrotic and anti-inflammatory effects of L-carnosine via Reactive oxygen species (ROS) regulation in bleomycin (BLM)-induced IPF mice. The mice were intratracheally injected with BLM (3 mg/kg) and L-carnosine (150 mg/kg) was orally administrated for 2 weeks. BLM exposure increased the protein level of Nox2, Nox4, p53, and Caspase-3, whereas L-carnosine treatment suppressed the protein level of Nox2, Nox4, p53, and Caspase-3 cleavage in mice. In addition, the total SOD activity and mRNA level of Sod2, catalase, and Nqo1 increased in mice treated with L-carnosine. At the cellular level, a human fibroblast (MRC-5) and mouse alveolar epithelial cell (MLE-12) were exposed to TGFβ1 following L-carnosine treatment to induce fibrogenesis. Moreover, MLE-12 cells were exposed to cigarette smoke extract (CSE). Consequently, L-carnosine treatment ameliorated fibrogenesis in fibroblasts and alveolar epithelial cells, and inflammation induced by ROS and CSE exposure was ameliorated. These results were associated with the inhibition of the NFκB pathway. Collectively, our data indicate that L-carnosine induces anti-inflammatory and anti-fibrotic effects on alveolar epithelial cells against the pathogenesis of IPF.

Green tea (Camellia sinensis) leaf extract maintained spermatozoa plasma membrane integrity, viability, and motility of mice (Mus musculus) exposed to cigarette smoke

Cigarette smoke chemicals caused oxidative stress by increasing Reactive Oxygen Species (ROS). ROS exposure could be neutralized by antioxidants, such as green tea (Camellia sinensis) leaf extract. This study aimed to determine the effect of green tea extract (GTE) on spermatozoa plasma membrane integrity, spermatozoa viability, and spermatozoa motility of mice (Mus musculus) exposed to cigarette smoke. Twenty-five mice were randomly divided into five groups. Group C- mice were given a placebo (1% Sodium carboxymethyl cellulose, Na-CMC). Group C+, T1, T2, and T3 mice were exposed to cigarette smoke and given 0, 20, 40, and 60 mg/kg BW GTE respectively. Cigarette smoke exposure used a clove cigarette per day. GTE in 1% Na-CMC solution was administered at 0.5 mL orally using a gastric probe. The treatment was conducted daily for 36 days, and on day 37, all mice were euthanized for spermatozoa evaluation. The results showed that all parameters evaluated in the C+ group were lower (p &lt;0.05) than in C- group. Administration of GTE in the T2 group increased (p &lt;0.05) all parameters compared to mice in the C+ group. However, administration of GTE to mice in the T3 group caused a decrease (p &lt;0.05) in all parameters than those of the T2 group and was not significantly different (p &gt;0.05) compared to those of the C+ group. It could be concluded that the administration of GTE at 40 mg/kg BW has maintained the spermatozoa plasma membrane integrity, spermatozoa viability, and spermatozoa motility of mice exposed to cigarette smoke.