A review of pulmonary neutrophilia and insights into the key role of neutrophils in particle-induced pathogenesis in the lung from animal studies of lunar dusts and other poorly soluble dust particles.

The mechanisms of particle-induced pathogenesis in the lung remain poorly understood. Neutrophilic inflammation and oxidative stress in the lung are hallmarks of toxicity. Some investigators have postulated that oxidative stress from particle surface reactive oxygen species (psROS) on the dust produces the toxicopathology in the lungs of dust-exposed animals. This postulate was tested concurrently with the studies to elucidate the toxicity of lunar dust (LD), which is believed to contain psROS due to high-speed micrometeoroid bombardment that fractured and pulverized lunar surface regolith. Results from studies of rats intratracheally instilled (ITI) with three LDs (prepared from an Apollo-14 lunar regolith), which differed 14-fold in levels of psROS, and two toxicity reference dusts (TiO2 and quartz) indicated that psROS had no significant contribution to the dusts' toxicity in the lung. Reported here are results of further investigations by the LD toxicity study team on the toxicological role of oxidants in alveolar neutrophils that were harvested from rats in the 5-dust ITI study and from rats that were exposed to airborne LD for 4 weeks. The oxidants per neutrophils and all neutrophils increased with dose, exposure time and dust's cytotoxicity. The results suggest that alveolar neutrophils play a critical role in particle-induced injury and toxicity in the lung of dust-exposed animals. Based on these results, we propose an adverse outcome pathway (AOP) for particle-associated lung disease that centers on the crucial role of alveolar neutrophil-derived oxidant species. A critical review of the toxicology literature on particle exposure and lung disease further supports a neutrophil-centric mechanism in the pathogenesis of lung disease and may explain previously reported animal species differences in responses to poorly soluble particles. Key findings from the toxicology literature indicate that (1) after exposures to the same dust at the same amount, rats have more alveolar neutrophils than hamsters; hamsters clear more particles from their lungs, consequently contributing to fewer neutrophils and less severe lung lesions; (2) rats exposed to nano-sized TiO2 have more neutrophils and more severe lesions in their lungs than rats exposed to the same mass-concentration of micron-sized TiO2; nano-sized dust has a greater number of particles and a larger total particle-cell contact surface area than the same mass of micron-sized dust, which triggers more alveolar epithelial cells (AECs) to synthesize and release more cytokines that recruit a greater number of neutrophils leading to more severe lesions. Thus, we postulate that, during chronic dust exposure, particle-inflicted AECs persistently release cytokines, which recruit neutrophils and activate them to produce oxidants resulting in a prolonged continuous source of endogenous oxidative stress that leads to lung toxicity. This neutrophil-driven lung pathogenesis explains why dust exposure induces more severe lesions in rats than hamsters; why, on a mass-dose basis, nano-sized dusts are more toxic than the micron-sized dusts; why lung lesions progress with time; and why dose-response curves of particle toxicity exhibit a hockey stick like shape with a threshold. The neutrophil centric AOP for particle-induced lung disease has implications for risk assessment of human exposures to dust particles and environmental particulate matter.

Protective Effect of Curcumin and Nanocurcumin on Sperm Parameters and Oxidant-antioxidants System of Rat Testis in Aluminium Phosphide Subacute Poisoning.

OBJECTIVE: Aluminum phosphide (AlP) as an effective pesticide may contribute to oxidative stress and adversely influence sperm parameters. This study aimed to investigate the protective role of curcumin and nanocurcumin on oxidative damage in the testis of rats with AlP toxicity. METHODS: A total of 42 adult male Wistar rats were equally randomized into the following study groups (n = 7): Control, Control+Curcumin, Control+Nanocurcumin, AlP, AlP+Curcumin, and AlP+Nanocurcumin. The testis tissue was used to investigate the levels of testicular malondialdehyde (MDA), total oxidant status (TOS), total antioxidant capacity (TAC), and reduced glutathione (GSH) as well as the Catalase (CAT) and superoxide dismutase (SOD) enzyme activity. Epididymal sperm was used to perform sperm analysis. RESULTS: AlP administration led to a significant increase in MDA, and TOS levels and also markedly decreased the SOD activity and the levels of TAC and GSH in testis tissue (p <0.001). Moreover, the motility and viability of sperms were significantly reduced (p <0.001). Curcumin and Nanocurcumin co-administration with AlP remarkably decreased the MDA and TOS level (p <0.001) and significantly increased the GSH and TAC levels as well as the activity of SOD in AlP intoxicated groups (p<0.001). Our findings demonstrated that Nanocurcumin administration has significantly enhanced the sperm quality in AlP intoxicated rats as compared to the control group (p <0.001). CONCLUSION: According to the results of this study, Curcumin as a potential antioxidant could be an effective attenuative agent against AlP-induced oxidative damage in testis, especially when it is used in encapsulated form, nanocurcumin.

Evaluation of algaecide effectiveness of five different oxidants applied on harmful phytoplankton.

Harmful algal blooms (HABs) in coastal areas similarly impact both ecosystems and human health. The translocation of phytoplankton species via maritime transport can potentially promote the growth of HABs in coastal systems. Accordingly, ballast water must be disinfected. The main goal of this study is to assess the effectiveness of different emerging biocides, including H2O2, peracetic acid (PAA), peroxymonosulfate (PMS), and peroxydisulfate (PDS). The effectiveness of these biocides is compared with that of conventional chlorination methods. Their effects on two ichthyotoxic microalgae with worldwide distribution, i.e., Prymnesium parvum and Heterosigma akashiwo, are examined. To ensure the prolonged effectiveness of the different reagents, their concentration-response curves for 14 days are constructed and examined. The results suggest a strong but shorter effect by PMS (EC50 = 0.40-1.99 mg·L-1) and PAA (EC50 = 0.32-2.70 mg·L-1), a maintained effect by H2O2 (EC50 = 6.67-7.08 mg·L-1), and a negligible effect by PDS. H. akashiwo indicates higher resistance than P. parvum, except when H2O2 is used. Based on the growth inhibition performance and consumption of the reagents as well as a review of important aspects regarding their application, using H2O2, PAA, or PMS can be a feasible alternative to chlorine-based reagents for inhibiting the growth of harmful phytoplankton.

PBX1 attenuates H2O2-induced oxidant stress in human trabecular meshwork cells via promoting NANOG-mediated PI3K/AKT signaling pathway.

Oxidative stress-induced excessive extracellular matrix (ECM) deposition in trabecular meshwork (TM) tissue is considered the major pathological procedure of glaucoma. This study aimed to explore the role and regulatory mechanism of pre-B-cell leukemia transcription factor 1 (PBX1) in H2O2-induced human trabecular meshwork cells (HTMCs). Expressions of PBX1, NANOG, ECM, and pathway-related factors were detected by qRT-PCR and western blot. Cell viability and apoptosis of HTMCs were measured using CCK-8 and flow cytometry assays. Reactive oxygen species (ROS), superoxide dismutase (SOD), and L-glutathione (GSH) levels were detected to evaluate oxidative stress. Through luciferase reporter assay, the association between PBX1 and NANOG was verified. Results presented that PBX1 was significantly upregulated in H2O2-induced HTMCs. Functionally, PBX1 and NANOG promoted cell viability, inhibited cell apoptosis and ECM deposition, suppressed ROS accumulation, and enhanced the productions of SOD and GSH in H2O2-stimulated HTMCs, while PBX1 inhibition showed the opposite effects. In addition, PBX1 promoted the transcription of NANOG by upregulating the promoter activity of NANOG which activated the PI3K-AKT signaling pathway. What's more, the inhibitions of PI3K-AKT signaling pathway or NANOG reversed the protective effect of PBX1 on H2O2-stimulated HTMCs. In summary, our study firstly revealed that PBX1 attenuated the oxidative damage in HTMCs via regulating NANOG-mediated PI3K/AKT signaling, suggesting that PBX1 might be a potential treatment target for glaucoma patients.

Comparative pulmonary toxicities of lunar dusts and terrestrial dusts (TiO2 & SiO2) in rats and an assessment of the impact of particle-generated oxidants on the dusts' toxicities.

Humans will set foot on the Moon again soon. The lunar dust (LD) is potentially reactive and could pose an inhalation hazard to lunar explorers. We elucidated LD toxicity and investigated the toxicological impact of particle surface reactivity (SR) using three LDs, quartz, and TiO2. We first isolated the respirable-size-fraction of an Apollo-14 regolith and ground two coarser samples to produce fine LDs with increased SR. SR measurements of these five respirable-sized dusts, determined by their in-vitro ability to generate hydroxyl radicals (•OH), showed that ground LDs > unground LD ≥ TiO2 ≥ quartz. Rats were each intratracheally instilled with 0, 1, 2.5, or 7.5 mg of a test dust. Toxicity biomarkers and histopathology were assessed up to 13 weeks after the bolus instillation. All dusts caused dose-dependent-increases in pulmonary lesions and toxicity biomarkers. The three LDs, which possessed mineral compositions/properties similar to Arizona volcanic ash, were moderately toxic. Despite a 14-fold •OH difference among these three LDs, their toxicities were indistinguishable. Quartz produced the lowest •OH amount but showed the greatest toxicity. Our results showed no correlation between the toxicity of mineral dusts and their ability to generate free radicals. We also showed that the amounts of oxidants per neutrophil increased with doses, time and the cytotoxicity of the dusts in the lung, which supports our postulation that dust-elicited neutrophilia is the major persistent source of oxidative stress. These results and the discussion of the crucial roles of the short-lived, continuously replenished neutrophils in dust-induced pathogenesis are presented.

Topological Relationships Cytoskeleton-Membrane Nanosurface-Morphology as a Basic Mechanism of Total Disorders of RBC Structures.

The state of red blood cells (RBCs) and their functional possibilities depend on the structural organization of the membranes. Cell morphology and membrane nanostructure are compositionally and functionally related to the cytoskeleton network. In this work, the influence of agents (hemin, endogenous oxidation during storage of packed RBCs, ultraviolet (UV) radiation, temperature, and potential of hydrogen (pH) changes) on the relationships between cytoskeleton destruction, membrane nanostructure, and RBC morphology was observed by atomic force microscope. It was shown that the influence of factors of a physical and biochemical nature causes structural rearrangements in RBCs at all levels of organization, forming a unified mechanism of disturbances in relationships "cytoskeleton-membrane nanosurface-cell morphology". Filament ruptures and, consequently, large cytoskeleton pores appeared. The pores caused membrane topological defects in the form of separate grain domains. Increasing loading doses led to an increase in the number of large cytoskeleton pores and defects and their fusion at the membrane nanosurfaces. This caused the changes in RBC morphology. Our results can be used in molecular cell biology, membrane biophysics, and in fundamental and practical medicine.

Chlorine exposure induces Caspase-3 independent cell death in human lung epithelial cells.

Chlorine (Cl2) is a common toxic industrial gas and human inhalation exposure causes tissue damage with symptoms ranging from wheezing to more severe symptoms such as lung injury or even death. Because the mechanism behind Cl2-induced cell death is not clearly understood, the present study aimed to study the cellular effects in vitro after Cl2 exposure of human A549 lung epithelial cells. In addition, the possible treatment effects of the anti-inflammatory antioxidant N-acetyl cysteine (NAC) were evaluated. Exposure of A549 cells to Cl2 (100-1000 ppm) in the cell medium induced cell damage and toxicity within 1 h in a dose-dependent manner. The results showed that 250 ppm Cl2 increased cell death and formation of apoptotic-like bodies, while 500 ppm Cl2 exposure resulted in predominantly necrotic death. Pre-treatment with NAC was efficient to prevent cell damage at lower Cl2 concentrations in part by averting the formation of apoptotic-like bodies and increasing the expression of the anti-apoptotic proteins clusterin and phosphorylated tumour protein p53(S46). Analysis showed that Cl2 induced cell death by a possibly caspase-independent mechanism, since no cleavage of caspase-3 could be detected after exposure to 250 ppm. Currently, these results justifies further research into new treatment strategies for Cl2-induced lung injury.

Effects of pinealectomy and crocin treatment on rats with isoproterenol-induced myocardial infarction.

The present study aimed to analyze the effects of pinealectomy and crocin treatment in isoproterenol-induced myocardial damage. Seventy rats were divided into seven groups: control, sham control, pinealectomy (PNX), isoproterenol (ISO; 85 mg/kg on the 29th and 30th days of the experiment, subcutaneous injection), PNX + ISO, PNX + crocin (50 mg/kg/day for 30 days, intragastric administration), and PNX + ISO + crocin. PNX procedure was performed on the first day of the study. A significant increase was observed in serum cardiac damage markers (CK-MB, Troponin I) after ISO administration. ISO administration led to a significant increase in cardiac oxidative stress parameters, such as malondialdehyde (MDA) and total oxidant status (TOS), while it led to a decrease in antioxidant defense system parameters, such as reduced glutathione (GSH), superoxide dismutase (SOD), catalase (CAT) and total antioxidant status (TAS) when compared to control groups. Elevated MDA and TOS levels were observed, while reduced SOD and CAT activities, and decreased GSH and TAS levels were observed in the group that underwent PNX and ISO administration when compared to the PNX group. Furthermore, in the PNX + ISO + Crocin group, SOD and CAT activities, and GSH and TAS levels ameliorated and MDA and TOS levels were reduced with the crocin treatment when compared to the PNX + ISO group. Also, marked increases were observed in serum cardiac markers, histopathological and immunohistochemical findings after the crocin treatment. All findings demonstrated that crocin could be employed as a cardioprotective agent due to its antioxidant, anti-inflammatory, and anti-apoptotic properties.

RNA-seq identifies long non-coding RNAs as potential therapeutic targets for human corneal endothelial dysfunction under oxidative stress.

Human corneal endothelial cells (CECs) have limited ability to regenerate in vivo. Oxidative stress has been proposed as one potential reason. Understanding the mechanism of oxidative stress-induced CEC dysfunction might provide novel targets for improving CEC regenerative capacity, and help develop non-surgical therapeutic strategies for CEC dysfunction. Long non-coding RNAs (lncRNAs) are non-coding transcripts with multiple biological functions. The roles of lncRNAs in ocular cells under oxidative stress have been widely studied, such as lens epithelial cells, trabecular meshwork cells, and retinal ganglion cells. In the current study, we established oxidative stress-induced CEC dysfunction model in vitro. By RNA sequencing technology, we identified 824 differentially expressed lncRNAs in CEC dysfunction group, including 667 upregulated lncRNAs and 157 downregulated lncRNAs. We finally demonstrated that CEC functions under oxidative stress, including cellular proliferation, apoptosis, and anti-oxidative stress ability, could be regulated by different lncRNAs, including lncRNA-Z93241.1, lncRNA-XLOC_000818, and lncRNA-AC007952.4. Targeting these lncRNAs might be useful to further elucidate the pathology of CEC dysfunction and develop novel therapeutic strategy.

Formulation of liposomes loading lentisk oil to ameliorate topical delivery, attenuate oxidative stress damage and improve cell migration in scratch assay.

Pistacia lentiscus L. is a sclerophyllous shrub capable of growing under harsh climatic conditions especially in the Mediterranean Basin. Different products can be obtained from this plant, such as essential oil, mastic gum or even fixed oil. The last is well known for its flavor which is mainly exploited in the food industry. Additionally, it has been traditionally used in the treatment of skin diseases, but, at the moment, any suitable formulation for skin delivery has been formulated and its biological effects was not deeply confirmed. Given that, in the present study, the lentisk oil has been formulated in liposomes at different concentrations (10, 20, 30 mg/ml) and their physicochemical, technological and main biological properties have been evaluated. Vesicles were prepared by using natural soy lecithin and a green and organic solvent free method, thus obtaining spherical, small (~ 118 nm), homogeneously dispersed (0.27) and highly negatively charged (~ -62 mV) vesicles. The used amount of oil loaded in liposomes (10, 20, 30 mg/ml) modulated the penetration ability of vesicles in the skin, favoring the deposition of the payload in the deeper strata. The loading in the vesicles potentiated the ability of oil to counteract the damaging effects caused by hydrogen peroxide in keratinocytes and fibroblasts and facilitate their migration in a cell monolayer lesion. Overall findings suggested that the incorporation of lentisk oil in liposomes made from soy lecithin can be an alternative and natural approach to exploit it in pharmaceutical ad cosmetical applications and manufacturing natural products suitable for the treatment of skin lesions.

Biological and Cytoprotective Effect of Piper kadsura Ohwi against Hydrogen-Peroxide-Induced Oxidative Stress in Human SW1353 Cells.

Oxidative stress plays a role in regulating a variety of physiological functions in living organisms and in the pathogenesis of articular cartilage diseases. Piper kadsura Ohwi is a traditional Chinese medicine that is used as a treatment for rheumatic pain, and the extracts have anti-inflammatory and antioxidant effects. However, there is still no study related to cell protection by P. kadsura. The P. kadsura extracts (PKE) were obtained by microwave-assisted extraction, liquid-liquid extraction, and column chromatography separation. The extracts could effectively scavenge free radicals in the antioxidant test, the EC50 of extracts is approximately the same as vitamin C. PKE decreased the apoptosis of SW1353 cells treated with H2O2 and could upregulate the gene expression of antioxidant enzymes (SOD-2, GPx, and CAT) and the Bcl-2/Bax ratio, as well as regulate PARP, thus conferring resistance to H2O2 attack. PKE protects cells against apoptosis caused by free radicals through the three pathways of JNK, MEK/ERK, and p38 by treatment with MAPK inhibitor. The identified components of PKE were bicyclo [2.2.1] heptan-2-ol-1,7,7-trimethyl-,(1S-endo)-, alpha-humulene, and hydroxychavicol by gas chromatography-mass spectrometry.

Cell survival after DNA damage in the comet assay.

The comet assay is widely used in basic research, genotoxicity testing, and human biomonitoring. However, interpretation of the comet assay data might benefit from a better understanding of the future fate of a cell with DNA damage. DNA damage is in principle repairable, or if extensive, can lead to cell death. Here, we have correlated the maximally induced DNA damage with three test substances in TK6 cells with the survival of the cells. For this, we selected hydrogen peroxide (H2O2) as an oxidizing agent, methyl methanesulfonate (MMS) as an alkylating agent and etoposide as a topoisomerase II inhibitor. We measured cell viability, cell proliferation, apoptosis, and micronucleus frequency on the following day, in the same cell culture, which had been analyzed in the comet assay. After treatment, a concentration dependent increase in DNA damage and in the percentage of non-vital and apoptotic cells was found for each substance. Values greater than 20-30% DNA in tail caused the death of more than 50% of the cells, with etoposide causing slightly more cell death than H2O2 or MMS. Despite that, cells seemed to repair of at least some DNA damage within few hours after substance removal. Overall, the reduction of DNA damage over time is due to both DNA repair and death of heavily damaged cells. We recommend that in experiments with induction of DNA damage of more than 20% DNA in tail, survival data for the cells are provided.

The Potential Antioxidant Activity and Characterization of Bioactive Compounds of Stahlianthus involucratus.

Stahlianthus involucratus (S. involucratus) has anti-inflammatory, antinociceptive, and antipyretic activities; however, there are no literature reports on its antioxidant capacity. This study presents a comparative assessment of the polyphenols contents, flavonoids contents, and antioxidant activity of the aqueous and methanol extracts of S. involucratus (ASI and MSI). Moreover, the expression of oxidative stress-related genes in H2O2-induced H9c2 cells pretreated with the MSI was measured by RT-qPCR, and furthermore, MSI were characterized by UHPLC-Q-Orbitrap-MS/MS. The results indicated that the MSI had higher antioxidant contents and antioxidant capacity, and MSI could inhibit H2O2-induced oxidative stress in H9c2 cells by activating the Nrf2/HO-1 pathway. UHPLC-Q-Orbitrap-MS/MS characterized 15 phenolic compounds from the MSI. In conclusion, S. involucratus has the potential antioxidant capacity.

The Oxidation of Equol by Tyrosinase Produces a Unique Di-ortho-Quinone: Possible Implications for Melanocyte Toxicity.

Equol (7-hydroxy-3-(4'-hydroxyphenyl)-chroman, EQ), one of the major intestinally derived metabolites of daidzein, the principal isoflavane found in soybeans and most soy foods, has recently attracted increased interest as a health-beneficial compound for estrogen-dependent diseases. However, based on its structure with two p-substituted phenols, this study aimed to examine whether EQ is a substrate for tyrosinase and whether it produces o-quinone metabolites that are highly cytotoxic to melanocyte. First, the tyrosinase-catalyzed oxidation of EQ was performed, which yielded three EQ-quinones. They were identified after being reduced to their corresponding catechols with NaBH4 or L-ascorbic acid. The binding of the EQ-quinones to N-acetyl-L-cysteine (NAC), glutathione (GSH), and bovine serum albumin via their cysteine residues was then examined. NAC and GSH afforded two mono-adducts and one di-adduct, which were identified by NMR and MS analysis. It was also found that EQ was oxidized to EQ-di-quinone in cells expressing human tyrosinase. Finally, it was confirmed that the EQ-oligomer, the EQ oxidation product, exerted potent pro-oxidant activity by oxidizing GSH to the oxidized GSSG and concomitantly producing H2O2. These results suggest that EQ-quinones could be cytotoxic to melanocytes due to their binding to cellular proteins.

The oxidation-resistant CaMKII-MM281/282VV mutation does not prevent arrhythmias in CPVT1.

Catecholaminergic polymorphic ventricular tachycardia type 1 (CPVT1) is an inherited arrhythmogenic disorder caused by missense mutations in the cardiac ryanodine receptors (RyR2), that result in increased ß-adrenoceptor stimulation-induced diastolic Ca2+ leak. We have previously shown that exercise training prevents arrhythmias in CPVT1, potentially by reducing the oxidation of Ca2+ /calmodulin-dependent protein kinase type II (CaMKII). Therefore, we tested whether an oxidation-resistant form of CaMKII protects mice carrying the CPVT1-causative mutation RyR2-R2474S (RyR2-RS) against arrhythmias. Antioxidant treatment (N-acetyl-L-cysteine) reduced the frequency of ß-adrenoceptor stimulation-induced arrhythmogenic Ca2+ waves in isolated cardiomyocytes from RyR2-RS mice. To test whether the prevention of CaMKII oxidation exerts an antiarrhythmic effect, mice expressing the oxidation-resistant CaMKII-MM281/282VV variant (MMVV) were crossed with RyR2-RS mice to create a double transgenic model (RyR2-RS/MMVV). Wild-type mice served as controls. Telemetric ECG surveillance revealed an increased incidence of ventricular tachycardia and an increased arrhythmia score in both RyR2-RS and RyR2-RS/MMVV compared to wild-type mice, both following a ß-adrenoceptor challenge (isoprenaline i.p.), and following treadmill exercise combined with a ß-adrenoceptor challenge. There were no differences in the incidence of arrhythmias between RyR2-RS and RyR2-RS/MMVV mice. Furthermore, no differences were observed in ß-adrenoceptor stimulation-induced Ca2+ waves in RyR2-RS/MMVV compared to RyR2-RS. In conclusion, antioxidant treatment reduces ß-adrenoceptor stimulation-induced Ca2+ waves in RyR2-RS cardiomyocytes. However, oxidation-resistant CaMKII-MM281/282VV does not protect RyR2-RS mice from ß-adrenoceptor stimulation-induced Ca2+ waves or arrhythmias. Hence, alternative oxidation-sensitive targets need to be considered to explain the beneficial effect of antioxidant treatment on Ca2+ waves in cardiomyocytes from RyR2-RS mice.

Examining cellular responses to reconstituted antibody protein liquids.

Protein ionic liquids (PIL) are a new class of biologic stabilizers designed to protect the functionality and extend the shelf-life of biotechnological and therapeutic agents making them more readily available, and resistant to austere environments. Protein biorecognition elements such as monoclonal antibodies are commonly utilized therapeutics that require the robust stabilization offered by PILs, but biocompatibility remains an important issue. This study has focused on characterizing the biocompatibility of an antibody based PIL by exposing multiple cells types to a cationized immunoglobulin suspended in an anionic liquid (IgG-IL). The IgG-IL caused no significant alterations in cellular health for all three cell types with treatments < 12.5 µg/mL. Concentrations ≥ 12.5 µg/mL resulted in significant necrotic cell death in A549 and HaCaT cells, and caspase associated cell death in HepG2 cells. In addition, all cells displayed evidence of oxidative stress and IL-8 induction in response to IgG-IL exposures. Therapeutic Ig can be utilized with a wide dose range that extends into concentrations we have found to exhibit cytotoxicity raising a toxicity concern and a need for more extensive understanding of the biocompatibility of IgG-ILs.

Bilirubin Oxidation End Products (BOXes) Induce Neuronal Oxidative Stress Involving the Nrf2 Pathway.

Delayed ischemic neurological deficit (DIND) is a severe complication after subarachnoid hemorrhage (SAH). Previous studies have suggested that bilirubin oxidation end products (BOXes) are probably associated with the DIND after SAH, but there is a lack of direct evidence yet even on cellular levels. In the present study, we aim to explore the potential role of BOXes and the involved mechanisms in neuronal function. We synthesized high-purity (>97%) BOX A and BOX B isomers. The pharmacokinetics showed they are permeable to the blood-brain barrier. Exposure of a moderate concentration (10 or 30 µM) of BOX A or BOX B to isolated primary cortical neurons increased the production of reactive oxygen species. In the human neuroblastoma SH-SY5Y cells, BOX A and BOX B decreased the mitochondrial membrane potential and enhanced nuclear accumulation of the protein Nrf2 implicated in oxidative injury repair. In addition, both chemicals increased the mRNA and protein expression levels of multiple antioxidant response genes including Hmox1, Gsta3, Blvrb, Gclm, and Srxn1, indicating that the antioxidant response element (ARE) transcriptional cascade driven by Nrf2 is activated. In conclusion, we demonstrated that primary cortical neurons and neuroblastoma cells undergo an adaptive response against BOX A- and BOX B-mediated oxidative stress by activation of multiple antioxidant responses, in part through the Nrf2 pathway, which provides in-depth insights into the pathophysiological mechanism of DIND after SAH or other neurological dysfunctions related to cerebral hemorrhage.

Hsa_circ_0004058 inhibits apoptosis of SRA01/04 cells by promoting autophagy via miR-186/ATG7 axis.

Senile cataract is a common age-related disease in ophthalmology. Hsa_circ_0004058 has been reported to be down-regulated in the lens epithelial cells of senile cataract patients, suggesting that hsa_circ_0004058 is associated with senile cataract. However, the underlying mechanism is still unknown. This study attempted to determine the functional role of hsa_circ_0004058 in senile cataract. We treated human lens epithelial cells (SRA01/04) with H2O2 as senile cataract model, and found that cell viability and autophagy of SRA01/04 cells were severely decreased by H2O2 treatment. Hsa_circ_0004058 was notably down-regulated in H2O2-treated SRA01/04 cells. Moreover, hsa_circ_0004058 overexpression reduced apoptotic cells and the expression of Cleaved-caspase-3 and Bax, and enhanced Bcl-2 expression in H2O2-treated SRA01/04 cells. However, hsa_circ_0004058 silencing caused the opposite results. Hsa_circ_0004058 up-regulation accelerated the expression of autophagy-related proteins LC3-II/LC3-I and Beclin-1 in H2O2-treated SRA01/04 cells, which was partly abolished by 3-Methyladenine (autophagy inhibitor). Additionally, hsa_circ_0004058 functioned as a competing endogenous RNA to competitive binding miR-186, and thus accelerated the expression of its down-stream target, ATG7. Hsa_circ_0004058 promoted autophagy of SRA01/04 cells by regulating miR-186/ATG7 axis. In conclusion, these data demonstrates that hsa_circ_0004058 inhibits apoptosis of SRA01/04 cells by promoting autophagy, which attributes to regulate miR-186/ATG7 axis. Thus, hsa_circ_0004058 may be a potential target for senile cataract treatment.

Genotoxicity and oxidative stress induction by polystyrene nanoparticles in the colorectal cancer cell line HCT116.

The potential risks of environmental nanoparticles (NPs), in particular Polystyrene Nanoparticles (PNPs), is an emerging problem; specifically, the interaction of PNPs with intestinal cells has not been characterized so far. The mechanism by which polystyrene particles are transferred to humans has not yet been clarified, whether directly through ingestion from contaminated food. We evaluated the interaction between PNPs and colorectal adenocarcinoma cells (HCT116). Cells were exposed to different concentrations of PNPs, metabolic activity and the consequent cytotoxic potential were assessed through viability test; we evaluated the PNP genotoxic potential through the Cytokinesis-Block Micronucleus cytome (CBMN cyt) assay. Finally, we detected Reactive Oxygen Species (ROS) production after NPs exposure and performed Western Blot analysis to analyze the enzymes (SOD1, SOD2, Catalase, Glutathione Peroxidase) involved in the cell detoxification process that comes into play during the cell-PNPs interaction. This work analyzes the cyto and genotoxicity of PNPs in the colorectal HCT116 cell line, in particular the potential damage from oxidative stress produced by PNPs inside the cells related to the consequent nuclear damage. Our results show moderate toxicity of PNPs both in terms of ROS production and DNA damage. Further studies will be needed on different cell lines to have a more complete picture of the impact of environmental pollution on human health in terms of PNPs cytotoxicity and genotoxicity.

p66Shc-mediated hydrogen peroxide production impairs nephrogenesis causing reduction of number of glomeruli.

AIMS: Adaptor protein p66Shc, encoded by Shc1 gene, contributes to the pathogenesis of oxidative stress-related diseases. p66Shc ability to promote oxidative stress-related diseases requires phosphorylation of serine 36 residue (Ser36) and depends on translocation of p66Shc to the mitochondria. We tested the hypothesis that abnormal p66Shc-mediated reactive oxygen species (ROS) production could be critically involved in nephrons development during nephrogenesis. MAIN METHODS: We have generated unique mutant rats (termed p66Shc-Del), which express endogenous p66Shc with a 9-amino acid deletion, and lack regulatory Ser36. H2O2 renal production was measured by enzymatic microelectrode biosensors. Nephron numbers in 3-5 weeks old p66Shc-Del rats were quantified using the acid maceration method. KEY FINDINGS: p66Shc-Del rats, as wild type salt sensitive rats, display increased mean arterial blood pressure following chronic exposure to a high salt diet. In contrast to wild type rats, p66Shc-Del rats display increased H2O2 renal production and are characterized by a reduction in renal function. The number of glomeruli is significantly reduced in adult p66Shc-Del rats. SIGNIFICANCE: Since low nephron number is an established risk factor for kidney disease and hypertension in humans and rodents, our data suggest that H2O2 renal production, caused by irregular signaling of p66Shc, could be critical in regulating nephrogenesis and that abnormal p66Shc signaling negatively impacts kidney development and renal function by increasing susceptibility to diabetic nephropathy and hypertension-induced nephropathy.