NRF2-mediated Oxidative Stress Research Articles

The protective roles of eugenol on type 1 diabetes mellitus through NRF2-mediated oxidative stress pathway.

Type 1 diabetes mellitus (T1DM), known as insulin-dependent diabetes mellitus, is characterized by persistent hyperglycemia resulting from damage to the pancreatic β cells and an absolute deficiency of insulin, leading to multi-organ involvement and a poor prognosis. The progression of T1DM is significantly influenced by oxidative stress and apoptosis. The natural compound eugenol (EUG) possesses anti-inflammatory, anti-oxidant, and anti-apoptotic properties. However, the potential effects of EUG on T1DM had not been investigated. In this study, we established the streptozotocin (STZ)-induced T1DM mouse model in vivo and STZ-induced pancreatic β cell MIN6 cell model in vitro to investigate the protective effects of EUG on T1DM, and tried to elucidate its potential mechanism. Our findings demonstrated that the intervention of EUG could effectively induce the activation of nuclear factor E2-related factor 2 (NRF2), leading to an up-regulation in the expressions of downstream proteins NQO1 and HMOX1, which are regulated by NRF2. Moreover, this intervention exhibited a significant amelioration in pancreatic β cell damage associated with T1DM, accompanied by an elevation in insulin secretion and a reduction in the expression levels of apoptosis and oxidative stress-related markers. Furthermore, ML385, an NRF2 inhibitor, reversed these effects of EUG. The present study suggested that EUG exerted protective effects on pancreatic β cells in T1DM by attenuating apoptosis and oxidative stress through the activation of the NRF2 signaling pathway. Consequently, EUG holds great promise as a potential therapeutic candidate for T1DM.

CRISPRi-based screens in iAssembloids to elucidate neuron-glia interactions.

The complexity of the human brain makes it challenging to understand the molecular mechanisms underlying brain function. Genome-wide association studies have uncovered variants associated with neurological phenotypes. Single-cell transcriptomics have provided descriptions of changes brain cells undergo during disease. However, these approaches do not establish molecular mechanism. To facilitate the scalable interrogation of causal molecular mechanisms in brain cell types, we developed a 3D co-culture system of induced pluripotent stem cell (iPSC)-derived neurons and glia, termed iAssembloids. Using iAssembloids, we ask how glial and neuronal cells interact to control neuronal death and survival. Our CRISPRi-based screens identified that GSK3β inhibits the protective NRF2-mediated oxidative stress response elicited by high neuronal activity. We then investigate the role of APOE-ε4, a risk variant for Alzheimer's disease, on neuronal survival. We find that APOE-ε4-expressing astrocytes may promote neuronal hyperactivity as compared with APOE-ε3-expressing astrocytes. This platform allows for the unbiased identification of mechanisms of neuron-glia cell interactions.

Lead (Pb) Induces Osteotoxicity Through the Activation of Mutually Reinforced ER Stress and ROS in MC3T3-E1 Cells.

Lead (Pb) is the most common contaminant of heavy metals and is widely present in the environment. Destruction of bone structure, malformation of bone development, and loss of bone mass are important pathological features of lead-exposed individuals. However, the exact molecular mechanisms associated with lead exposure and osteogenic injury are still not fully understood. MC3T3-E1 mouse embryonic osteoblast is a cell line widely used in osteoblast cytology. It can differentiate into mature osteoblasts and express bone-specific genes in cell culture. The doses of 1, 2, and 4 mM Pb were adopted to study the toxicity of Pb on MC3T3-E1 proliferation and differentiation. In this study, the results show that Pb increases the expression of apoptosis-related proteins, including PARP1, cleaved caspase-3, Bax, and cleaved caspase-9. More importantly, Pb activated endoplasmic reticulum stress and oxidative stress, as evident by elevated PERK/ATF4/CHOP and ROS/NRF2 signaling pathway. Pb induced ROS production in MC3T3-E1 cells through endoplasmic reticulum stress and produced a lethal effect. NAC mitigated these effects. Endoplasmic reticulum stress inhibitor 4-PBA can block the ER stress pathway, reduce ROS production, and enhance cell viability. In addition, studies have shown that ERO1 activation in the ER stress pathway is responsible for inducing ROS production. ROS produced by the mitochondrial pathway also aggravates ER stress. This study suggests that Pb induces MC3T3-E1 cell apoptosis by inducing PERK-mediated ER stress and NRF2-mediated oxidative stress via mutual enhancement, which may be an important mechanism leading to skeletal toxicity.

Therapeutic potential of hesperidin in diabetes mellitus-induced erectile dysfunction through Nrf2-mediated ferroptosis and oxidative stress.

Among erectile dysfunction (ED) caused by metabolic abnormalities, diabetes mellitus-induced ED (DMED) progresses rapidly, manifests with severe symptoms, and shows reduced responsiveness to conventional medications. Hyperglycemia in the corpus cavernosum has been linked to the induction of both ferroptosis and oxidative stress, which are mediated by nuclear factor E2 related factor 2 (Nrf2). Hesperidin (Hes), a flavonoid compound, has been revealed to activate Nrf2 in certain diabetic complications, yet the efficacy of Hes on DMED and the specific mechanism remain unclear. To elucidate the potential mechanism and efficacy of Hes in regulating Nrf2-mediated ferroptosis and oxidative stress in DMED. DMED rats were constructed through the intraperitoneal injection of streptozotocin (STZ), partially supplemented with Hes. In parallel, in vitro research utilized human umbilical vein endothelial cells (HUVECs), with glucose addition to simulating a high glucose (HG) environment, and induced with Hes or ML385 (an Nrf2 inhibitor). Penile tissues and HUVECs were harvested for subsequent analyses. The results of this study indicate that Hes partially reversed the impaired erectile function. The expression of Nrf2, glutathione peroxidase 4 (GPX4), and heme oxygenase-1 (HO-1) in the corpus cavernosum elevated after supplementing with Hes, resulted in an inhibition in ferroptosis and oxidative stress. Moreover, the quantity and function of erectile effector cells were restored, and cavernous fibrosis was ameliorated. In HG-induced HUVECs, Hes ameliorated Nrf2-mediated ferroptosis and oxidative stress, effects which ML385 partially reversed. Hes exerts a therapeutic effect on DMED rats and a regulatory mechanism on the Nrf2-HO-1/GPX4 axis, concurrently revitalizing endothelial and smooth muscle cells, and diminishing fibrosis. Our study provides robust preclinical evidence for employing Hes in treating DMED.

CRISPRi-based screens in iAssembloids to elucidate neuron-glia interactions.

The sheer complexity of the brain has complicated our ability to understand the cellular and molecular mechanisms underlying its function in health and disease. Genome-wide association studies have uncovered genetic variants associated with specific neurological phenotypes and diseases. In addition, single-cell transcriptomics have provided molecular descriptions of specific brain cell types and the changes they undergo during disease. Although these approaches provide a giant leap forward towards understanding how genetic variation can lead to functional changes in the brain, they do not establish molecular mechanisms. To address this need, we developed a 3D co-culture system termed iAssembloids (induced multi-lineage assembloids) that enables the rapid generation of homogenous neuron-glia spheroids. We characterize these iAssembloids with immunohistochemistry and single-cell transcriptomics and combine them with large-scale CRISPRi-based screens. In our first application, we ask how glial and neuronal cells interact to control neuronal death and survival. Our CRISPRi-based screens identified that GSK3β inhibits the protective NRF2-mediated oxidative stress response in the presence of reactive oxygen species elicited by high neuronal activity, which was not previously found in 2D monoculture neuron screens. We also apply the platform to investigate the role of APOE- ε4, a risk variant for Alzheimer's Disease, in its effect on neuronal survival. We find that APOE- ε4-expressing astrocytes may promote more neuronal activity as compared to APOE- ε3-expressing astrocytes. This platform expands the toolbox for the unbiased identification of mechanisms of cell-cell interactions in brain health and disease.

Protective effect of 6'-Sialyllactose on LPS-induced macrophage inflammation via regulating Nrf2-mediated oxidative stress and inflammatory signaling pathways.

Macrophages play a central role in cardiovascular diseases, like atherosclerosis, by accumulating in vessel walls and inducing sustained local inflammation marked by the release of chemokines, cytokines, and matrix-degrading enzymes. Recent studies indicate that 6'-sialyllactose (6'-SL) may mitigate inflammation by modulating the immune system. Here, we examined the impact of 6'-SL on lipopolysaccharide (LPS)-induced acute inflammation using RAW 264.7 cells and a mouse model. In vivo, ICR mice received pretreatment with 100 mg/kg 6'-SL for 2 h, followed by intraperitoneal LPS injection (10 mg/kg) for 6 h. In vitro, RAW 264.7 cells were preincubated with 6'-SL before LPS stimulation. Mechanistic insights were gained though Western blotting, qRT-PCR, and immunofluorescence analysis, while reactive oxygen species (ROS) production was assessed via DHE assay. 6'-SL effectively attenuated LPS-induced p38 MAPK and Akt phosphorylation, as well as p65 nuclear translocation. Additionally, 6'-SL inhibited LPS-induced expression of tissue damage marker MMP9, IL-1β, and MCP-1 by modulating NF-κB activation. It also reduced ROS levels, mediated by p38 MAPK and Akt pathways. Moreover, 6'-SL restored LPS-suppressed Nrf2 and HO-1 akin to specific inhibitors SB203580 and LY294002. Consistent with in vitro results, 6'-SL decreased oxidative stress, MMP9, and MCP-1 expression in mouse endothelium following LPS-induced macrophage activation. In summary, our findings suggest that 6'-SL holds promise in mitigating atherosclerosis by dampening LPS-induced acute macrophage inflammation.

A Butyrate-Yielding Dietary Supplement Prevents Acute Alcoholic Liver Injury by Modulating Nrf2-Mediated Hepatic Oxidative Stress and Gut Microbiota.

Alcoholic liver disease (ALD) is a globally prevalent form of liver disease for which there is no effective treatment. Recent studies have found that a significant decrease in butyrate was closely associated with ALD development. Given the low compliance and delivery efficiency associated with oral-route butyrate administration, a highly effective butyrate-yielding dietary supplement, butyrylated high-amylose maize starch (HAMSB), is a good alternative approach. Here, we synthesized HAMSB, evaluated the effect of HAMSB on acute ALD in mice, compared its effect with that of oral administration of butyrate, and further studied the potential mechanism of action. The results showed HAMSB alleviated acute ALD in mice, as evidenced by the inhibition of hepatic-function impairment and the improvement in liver steatosis and lipid metabolism; in these respects, HAMSB supplementation was superior to oral sodium butyrate administration. These improvements can be attributed to the reduction of oxidative stress though the regulation of Nrf2-mediated antioxidant signaling in the liver and the improvement in the composition and function of microbiota in the intestine. In conclusion, HAMSB is a safe and effective dietary supplement for preventing acute ALD that could be useful as a disease-modifying functional food or candidate medicine.

Unraveling cysteine deficiency-associated rapid weight loss.

Forty percent of the US population and 1 in 6 individuals worldwide are obese, and the incidence of this disease is surging globally1,2. Various dietary interventions, including carbohydrate and fat restriction, and more recently amino acid restriction, have been explored to combat this epidemic3-6. We sought to investigate the impact of removing individual amino acids on the weight profiles of mice. Compared to essential amino acid restriction, induction of conditional cysteine restriction resulted in the most dramatic weight loss, amounting to 20% within 3 days and 30% within one week, which was readily reversed. This weight loss occurred despite the presence of substantial cysteine reserves stored in glutathione (GSH) across various tissues7. Further analysis demonstrated that the weight reduction primarily stemmed from an increase in the utilization of fat mass, while locomotion, circadian rhythm and histological appearance of multiple other tissues remained largely unaffected. Cysteine deficiency activated the integrated stress response (ISR) and NRF2-mediated oxidative stress response (OSR), which amplify each other, leading to the induction of GDF15 and FGF21, hormones associated with increased lipolysis, energy homeostasis and food aversion8-10. We additionally observed rapid tissue coenzyme A (CoA) depletion, resulting in energetically inefficient anaerobic glycolysis and TCA cycle, with sustained urinary excretion of pyruvate, orotate, citrate, α-ketoglutarate, nitrogen rich compounds and amino acids. In summary, our investigation highlights that cysteine restriction, by depleting GSH and CoA, exerts a maximal impact on weight loss, metabolism, and stress signaling compared to other amino acid restrictions. These findings may pave the way for innovative strategies for addressing a range of metabolic diseases and the growing obesity crisis.

Age-dependent heat shock hormesis to HSF-1 deficiency suggests a compensatory mechanism mediated by the unfolded protein response and innate immunity in young Caenorhabditis elegans.

The transcription factor HSF-1 (heat shock factor 1) acts as a master regulator of heat shock response in eukaryotic cells to maintain cellular proteostasis. The protein has a protective role in preventing cells from undergoing ageing, and neurodegeneration, and also mediates tumorigenesis. Thus, modulating HSF-1 activity in humans has a promising therapeutic potential for treating these pathologies. Loss of HSF-1 function is usually associated with impaired stress tolerance. Contrary to this conventional knowledge, we show here that inactivation of HSF-1 in the nematode Caenorhabditis elegans results in increased thermotolerance at young adult stages, whereas HSF-1 deficiency in animals passing early adult stages indeed leads to decreased thermotolerance, as compared to wild-type. Furthermore, a gene expression analysis supports that in young adults, distinct cellular stress response and immunity-related signaling pathways become induced upon HSF-1 deficiency. We also demonstrate that increased tolerance to proteotoxic stress in HSF-1-depleted young worms requires the activity of the unfolded protein response of the endoplasmic reticulum and the SKN-1/Nrf2-mediated oxidative stress response pathway, as well as an innate immunity-related pathway, suggesting a mutual compensatory interaction between HSF-1 and these conserved stress response systems. A similar compensatory molecular network is likely to also operate in higher animal taxa, raising the possibility of an unexpected outcome when HSF-1 activity is manipulated in humans.

Bergenin attenuates triptolide-caused premature ovarian failure in mice based on the antioxidant activity

Tripterygium wilfordii (TW) preparations have been utilized in China for treating rheumatoid arthritis and autoimmune diseases. However, their clinical use is limited due to reproductive toxicity, notably premature ovarian failure (POF). Our study aimed to investigate the effect and mechanism of bergenin in attenuating POF induced by triptolide in mice. POF was induced in female ICR mice via oral triptolide administration (50 μg/kg) for 60 days. Mice received bergenin (25, 50, 100 mg/kg, i.g.) or estradiol valerate (EV) (0.1 mg/kg, i.g.) daily, 1 h before triptolide treatment. In vitro, ovarian granulosa cells (OGCs) were exposed to triptolide (100 nM) and bergenin (1, 3, 10 μM). Antioxidant enzyme activity, protein expression, apoptosis rate, and reactive oxygen species (ROS) levels were assessed. The results showed that triptolide-treated mice exhibited evident atrophy, along with an increase in atretic follicles. Bergenin (50, 100 mg/kg) and EV (0.1 mg/kg), orally administered, exerted significant anti-POF effect. Bergenin and EV also decreased apoptosis in mouse ovaries. In vitro, bergenin (1, 3, 10 μM) attenuated triptolide-induced OGCs apoptosis by reducing levels of apoptosis-related proteins. Additionally, bergenin reduced oxidative stress through downregulation of antioxidant enzymes activity and overall ROS levels. Moreover, the combined use with Sh-Nrf2 resulted in a reduced protection of bergenin against triptolide-induced apoptosis of OGCs. Together, bergenin counteracts triptolide-caused POF in mice by inhibiting Nrf2-mediated oxidative stress and preventing OGC apoptosis. Combining bergenin with TW preparations may effectively reduce the risk of POF.

Study on the Protective Effect and Mechanism of Umbilicaria esculenta Polysaccharide in DSS-Induced Mice Colitis and Secondary Liver Injury.

This study aimed to explore the ameliorative effects and potential mechanisms of Huangshan Umbilicaria esculenta polysaccharide (UEP) in dextran sulfate sodium-induced acute ulcerative colitis (UC) and UC secondary liver injury (SLI). Results showed that UEP could ameliorate both colon and liver pathologic injuries, upregulate mouse intestinal tight junction proteins (TJs) and MUC2 expression, and reduce LPS exposure, thereby attenuating the effects of the gut-liver axis. Importantly, UEP significantly downregulated the secretion levels of TNF-α, IL-1β, and IL-6 through inhibition of the NF-κB pathway and activated the Nrf2 signaling pathway to increase the expression levels of SOD and GSH-Px. In vitro, UEP inhibited the LPS-induced phosphorylation of NF-κB P65 and promoted nuclear translocation of Nrf2 in RAW264.7 cells. These results revealed that UEP ameliorated UC and SLI through NF-κB and Nrf2-mediated inflammation and oxidative stress. The study first investigated the anticolitis effect of UEP, suggesting its potential for the treatment of colitis and colitis-associated liver disease.

NSUN2 relies on ALYREF to regulate Nrf2-mediated oxidative stress and alleviate Dox-induced liver injury

BackgroundDoxorubicin (Dox) is associated with various liver injuries, limiting its clinical utility. This study investigates whether NSUN2 participates in Dox-induced liver injury and the associated molecular mechanism.MethodsIn vivo and in vitro liver cell injury models were constructed based on Dox therapy. The protein levels of NSUN2 and oxidative stress indicators Nrf2, HO-1, and NQO1 were evaluated by Western blot. The RNA binding potential was detected by RNA methylation immunoprecipitation (RIP). Additionally, the effect of NSUN2 on Nrf2 mRNA synthesis and localization was evaluated using an RNA fluorescence probe.ResultsNSUN2 was downregulated, and liver tissue suffered significant pathological damage in the Dox group. The levels of ALT and AST significantly increased. NSUN2 interference exacerbated Dox-induced liver cell damage, which was reversed by NSUN2 overexpression. RIP demonstrated that NSUN2 recognized and bound to Nrf2 mRNA. Western blot analysis showed the protein level of Nrf2 in the NSUN2-WT group was significantly higher than that of the control group, whereas there was no significant change in Nrf2 level in the mutant NSUN2 group. Luciferase analysis demonstrated that NSUN2 could recognize and activate the Nrf2 5′UTR region of LO2 cells. In addition, RIP analysis revealed that ALYREF could recognize and bind to Nrf2 mRNA and that ALYREF controls the regulatory effect of NSUN2 on Nrf2.ConclusionNSUN2 regulates Dox-induced liver cell damage by increasing Nrf2 mRNA m5C methylation to inhibit inhibiting antioxidant stress. The regulatory effect of NSUN2 on Nrf2 depends on ALYREF.

Characterizing the toxicological responses to inorganic arsenicals and their metabolites in immortalized human bladder epithelial cells.

Arsenic is highly toxic to the human bladder. In the present study, we established a human bladder epithelial cell line that closely mimics normal human bladder epithelial cells by immortalizing primary uroplakin 1B-positive human bladder epithelial cells with human telomerase reverse transcriptase (HBladEC-T). The uroplakin 1B-positive human bladder epithelial cell line was then used to evaluate the toxicity of seven arsenicals (iAsV, iAsIII, MMAV, MMAIII, DMAV, DMAIII, and DMMTAV). The cellular uptake and metabolism of each arsenical was different. Trivalent arsenicals and DMMTAV exhibited higher cellular uptake than pentavalent arsenicals. Except for MMAV, arsenicals were transported into cells by aquaglyceroporin 9 (AQP9). In addition to AQP9, DMAIII and DMMTAV were also taken up by glucose transporter 5. Microarray analysis demonstrated that arsenical treatment commonly activated the NRF2-mediated oxidative stress response pathway. ROS production increased with all arsenicals, except for MMAV. The activating transcription factor 3 (ATF3) was commonly upregulated in response to oxidative stress in HBladEC-T cells: ATF3 is an important regulator of necroptosis, which is crucial in arsenical-induced bladder carcinogenesis. Inorganic arsenics induced apoptosis while MMAV and DMAIII induced necroptosis. MMAIII, DMAV, and DMMTAV induced both cell death pathways. In summary, MMAIII exhibited the strongest cytotoxicity, followed by DMMTAV, iAsIII, DMAIII, iAsV, DMAV, and MMAV. The cytotoxicity of the tested arsenicals on HBladEC-T cells correlated with their cellular uptake and ROS generation. The ROS/NRF2/ATF3/CHOP signaling pathway emerged as a common mechanism mediating the cytotoxicity and carcinogenicity of arsenicals in HBladEC-T cells.

Quantitative Proteomics Reveal That CB2R Agonist JWH-133 Downregulates NF-κB Activation, Oxidative Stress, and Lysosomal Exocytosis from HIV-Infected Macrophages.

HIV-associated neurocognitive disorders (HAND) affect 15-55% of HIV-positive patients and effective therapies are unavailable. HIV-infected monocyte-derived macrophages (MDM) invade the brain of these individuals, promoting neurotoxicity. We demonstrated an increased expression of cathepsin B (CATB), a lysosomal protease, in monocytes and post-mortem brain tissues of women with HAND. Increased CATB release from HIV-infected MDM leads to neurotoxicity, and their secretion is associated with NF-κB activation, oxidative stress, and lysosomal exocytosis. Cannabinoid receptor 2 (CB2R) agonist, JWH-133, decreases HIV-1 replication, CATB secretion, and neurotoxicity from HIV-infected MDM, but the mechanisms are not entirely understood. We hypothesized that HIV-1 infection upregulates the expression of proteins associated with oxidative stress and that a CB2R agonist could reverse these effects. MDM were isolated from healthy women donors (n = 3), infected with HIV-1ADA, and treated with JWH-133. After 13 days post-infection, cell lysates were labeled by Tandem Mass Tag (TMT) and analyzed by LC/MS/MS quantitative proteomics bioinformatics. While HIV-1 infection upregulated CATB, NF-κB signaling, Nrf2-mediated oxidative stress response, and lysosomal exocytosis, JWH-133 treatment downregulated the expression of the proteins involved in these pathways. Our results suggest that JWH-133 is a potential alternative therapy against HIV-induced neurotoxicity and warrant in vivo studies to test its potential against HAND.

Rapid Discovery of Aβ42 Fibril Disintegrators from Ganoderma lucidum via Ligand Fishing and Their Neuroprotective Effects on Alzheimer's Disease.

An amyloid-β (Aβ) fibril is a vital pathogenic factor of Alzheimer's disease (AD). Aβ fibril disintegrators possess great potential to be developed into novel anti-AD agents. Here, a ligand fishing method was employed to rapidly discover Aβ42 fibril disintegrators from Ganoderma lucidum using Aβ42 fibril-immobilized magnetic beads, which led to the isolation of six Aβ42 fibril disintegrators including ganodermanontriol, ganoderic acid DM, ganoderiol F, ganoderol B, ganodermenonol, and ergosterol. Neuroprotective evaluation in vitro exhibited that these Aβ42 fibril disintegrators could significantly mitigate Aβ42-induced neurotoxicity. Among these six disintegrators, ergosterol and ganoderic acid DM with stronger protecting activity were further selected to evaluate their neuroprotective effect on AD in vivo. Results showed that ergosterol and ganoderic acid DM could significantly alleviate Aβ42-induced cognitive dysfunction and hippocampus neuron loss in vivo. Moreover, ergosterol and ganoderic acid DM could significantly inhibit Aβ42-induced neuron apoptosis and Nrf2-mediated neuron oxidative stress in vitro and in vivo.

Effects of multi-walled carbon nanotubes on message and Micro-RNA in human lung BEAS-2B cells.

Multi-walled Carbon nanotubes (MWCNTs) lack sufficient quality cytotoxicity, toxicity, genotoxicity and genomic data on which to make environmental and regulatory decisions. Therefore, we did a multidisciplinary in vitro study of 3 MWCNTs in human lung cells (BEAS-2B) with the following endpoints: cytotoxicity, DNA damage, reactive oxygen and nitrogen species, lipid peroxidation and mRNA and microRNA expression analyses. The MWCNTs were either unfunctionalized or functionalized with either -OH or -COOH. Doses studied ranged from 0.3 to 100 ug/ml and were exposed to a human lung cell line in vitro for 72 h., with genomic studies being done from 30 ug/ml downward. Some of the genomic pathways that were altered by MWCNT exposure were NRF2 mediated oxidative stress response, DNA damage repair, nuclear excision repair, base excision repair, mitochondrial dysfunction, oxidative phosphorylation, HIF1α signaling, unfolded protein response, protein ubiquitination, ferroptosis and sirtuin signaling pathways. The data suggested that OH functionalized MWCNT caused more and larger gene/microRNA changes, followed by COOH functionalized MWCNT and unfunctionalized MWCNT being the least biologically active. From microRNA target filter analysis, there were altered signaling hubs. MYC is the only hub that altered by all 3 MWCNTs. Signaling hubs that are common to OH and COOH functionalized MWCNTs are GRB2, AR, TP63 and AGO2. The signaling hubs that were only present in OH functionalized MWCNTs are TP53, STAT3 and BRCA1. These signaling pathways and hubs we found in vitro correlated well with the published in vivo pathological effects like oxidative stress DNA damage, inflammation and cancer in MWCNTs treated mice.

HgCl2 exposure mediates pyroptosis of HD11 cells and promotes M1 polarization and the release of inflammatory factors through ROS/Nrf2/NLRP3

Mercury (Hg) is a serious metal environmental pollutant. HgCl2 exposure causes pyroptosis. When macrophages are severely stimulated, they often undergo M1 polarization and release inflammatory factors. However, the mechanisms by which mercuric chloride exposure induces macrophage apoptosis, M1 polarization, and inflammatory factors remain unclear. HD11 cells were exposed to different concentrations of Hg chloride (180, 210 and 240 nM HgCl2). The results showed that mercury chloride exposure up-regulated ROS, C-Nrf2 and its downstream factors (NQO1 and HO-1), and down-regulated N-Nrf2. In addition, the expressions of focal death-related indicators (Caspase-1, NLRP3, GSDMD, etc.), M1 polarization marker CD86 and inflammatory factors (TNF-α, IL-1β) increased, and the above changes were related to mercury. Oxidative stress inhibitor (NAC) can block ROS/ NrF2-mediated oxidative stress, inhibit mercury-induced pyroptosis and M1 polarization, and effectively reduce the release of inflammatory factors. The addition of Vx-765 to inhibit pyroptosis can effectively alleviate M1 polarization of HD11 cells and reduce the expression of inflammatory factors. HgCl2 mediates pyroptosis of HD11 cells by regulating ROS/Nrf2/NLRP3, promoting M1 polarization and the release of inflammatory factors.

The Effect of SkQ1 on the Oxidative Stress and Inflammatory Responses in Corneal Endothelial Cells During Ex Vivo Expansion

Purpose: The purpose of this study was to characterize the oxidative stress and inflammatory responses in ex vivo corneal endothelial cells (evCEnC) during expansion and assess the impact of SkQ1, an antioxidant and anti-inflammatory compound, on measures of oxidative stress and inflammation. Methods: A CEnC line (HCEnC-21T) was cultured in media supplemented with varying SkQ1 concentrations to determine the optimal SkQ1 dose range of toxicity and protective effect on CEnC exposed to acute oxidative stress. The impact of SkQ1 treatment on intracellular free radical (IFR) levels, NRF2-mediated oxidative stress response, and NFkB-mediated inflammatory response was determined at each passage of evCEnC isolated from donor corneas and cultured in SkQ1-supplemented and untreated media. Results: HCEnC-21T cultured in media supplemented with ≤250 nM SkQ1 retained over 95% cell viability compared with untreated cells. SkQ1 provided oxidative stress protection to HCEnC-21T in a dose-dependent manner up to 500 nM. In evCEnC, 50 nM and 250 nM SkQ1 supplementation significantly reduced IFR levels across passages 0 to 3 (P-values of 0.015 and 0.023, respectively) and 50 nM SkQ1 supplementation led to decreased levels of active NRF2 in evCEnC at passage 2. However, media supplementation with SkQ1 (50 nM and 250 nM) did not alter NFkB activation at any passage. Conclusions: SkQ1 media supplementation provides oxidative stress protection to HCEnC-21T in a dose-dependent manner and decreases IFR levels and NRF2 activation in evCEnC during expansion at concentrations that do not negatively affect CEnC viability. These findings indicate that SkQ1 supplementation may increase the expansion potential of evCEnC.

Differential transcriptomic alterations in nasal versus lung tissue of acrolein-exposed rats

Introduction: Acrolein is a significant component of anthropogenic and wildfire emissions, as well as cigarette smoke. Although acrolein primarily deposits in the upper respiratory tract upon inhalation, patterns of site-specific injury in nasal versus pulmonary tissues are not well characterized. This assessment is critical in the design of in vitro and in vivo studies performed for assessing health risk of irritant air pollutants.Methods: In this study, male and female Wistar-Kyoto rats were exposed nose-only to air or acrolein. Rats in the acrolein exposure group were exposed to incremental concentrations of acrolein (0, 0.1, 0.316, 1 ppm) for the first 30 min, followed by a 3.5 h exposure at 3.16 ppm. In the first cohort of male and female rats, nasal and bronchoalveolar lavage fluids were analyzed for markers of inflammation, and in a second cohort of males, nasal airway and left lung tissues were used for mRNA sequencing.Results: Protein leakage in nasal airways of acrolein-exposed rats was similar in both sexes; however, inflammatory cells and cytokine increases were more pronounced in males when compared to females. No consistent changes were noted in bronchoalveolar lavage fluid of males or females except for increases in total cells and IL-6. Acrolein-exposed male rats had 452 differentially expressed genes (DEGs) in nasal tissue versus only 95 in the lung. Pathway analysis of DEGs in the nose indicated acute phase response signaling, Nrf2-mediated oxidative stress, unfolded protein response, and other inflammatory pathways, whereas in the lung, xenobiotic metabolism pathways were changed. Genes associated with glucocorticoid and GPCR signaling were also changed in the nose but not in the lung.Discussion: These data provide insights into inhaled acrolein-mediated sex-specific injury/inflammation in the nasal and pulmonary airways. The transcriptional response in the nose reflects acrolein-induced acute oxidative and cytokine signaling changes, which might have implications for upper airway inflammatory disease susceptibility.

The Functional Significance of McMafF_G_K in Molluscs: Implications for Nrf2-Mediated Oxidative Stress Response

The nuclear factor erythroid 2-related factor 2 (Nrf2) is a pivotal regulator of antioxidant gene expression in mammals, forming heterodimer complexes with small Maf proteins through its BZip domain. However, the underlying mechanism of Nrf2 action in molluscs remains poorly understood. The thick shell mussel, Mytilus coruscus, represents a model organism for the marine environment and molluscs interaction research. In this study, we used in silico cloning to obtain a small Maf homologue called McMafF_G_K from M. coruscus. McMafF_G_K possesses a typical BZip domain, suggesting its affiliation with the traditional small Maf family and its potential involvement in the Nrf2 signaling pathway. Transcriptional analysis revealed that McMafF_G_K exhibited a robust response to benzo[a]pyrene (Bap) in the digestive glands. However, this response was down-regulated upon interference with McMafF_G_K-siRNA. Interestingly, the expression levels of Nrf2, NAD(P)H: quinone oxidoreductase (NQO-1), and Glutathione Peroxidase (GPx), which are key players in oxidative stress response, showed a positive correlation with McMafF_G_K in digested adenocytes of M. coruscus. Furthermore, in vitro analysis of antioxidant capacity in digestive gland cells demonstrated that Bap exposure led to an increase in reactive oxygen species (ROS) levels, accompanied by an elevation in total antioxidant capacity (T-AOC), potentially counterbalancing the excessive ROS. Strikingly, transfection of McMafF_G_K siRNA resulted in a significant rise in ROS level and a down-regulation of T-AOC level. To validate the functional relevance of McMafF_G_K, a glutathione S-transferase (GST) pull-down assay confirmed its interaction with McNrf2, providing compelling evidence of their protein interaction. This study significantly contributes to our understanding of the functional role of McMafF_G_K in the Nrf2 signaling pathway and sheds light on its potential as a target for further research in oxidative stress response.