Inhibition Of Reactive Oxygen Species Research Articles

Breast cancer 1 (BRCA1) protection in altered gene expression and neurodevelopmental disorders due to physiological and ethanol-enhanced reactive oxygen species formation

The breast cancer 1 (Brca1) susceptibility gene regulates the repair of reactive oxygen species (ROS)-mediated DNA damage, which is implicated in neurodevelopmental disorders. Alcohol (ethanol, EtOH) exposure during pregnancy causes fetal alcohol spectrum disorders (FASD), including abnormal brain function, associated with enhanced ROS-initiated DNA damage. Herein, oxidative DNA damage in fetal brains and neurodevelopmental disorders were enhanced in saline-exposed +/- vs. +/+ Brca1 littermates. A single EtOH exposure during gestation further enhanced oxidative DNA damage, altered the expression of developmental/DNA damage response genes in fetal brains, and resulted in neurodevelopmental disorders, all of which were BRCA1-dependent. Pretreatment with the ROS inhibitor phenylbutylnitrone (PBN) blocked DNA damage and some neurodevelopmental disorders in both saline- and EtOH-exposed progeny, corroborating a ROS-dependent mechanism. Fetal BRCA1 protects against altered gene expression and neurodevelopmental disorders caused by both physiological and EtOH-enhanced levels of ROS formation. BRCA1 deficiencies may enhance the risk for FASD.

Tripterine Serves a Dual Role in Palmitate-Induced Pancreatic Beta-Cell Lipotoxicity.

Tripterine (TP, also called celastrol), a pentacyclic triterpene extracted from Tripterygium wilfordii, has beneficial effects on multiple diseases, including obesity and diabetes. However, the effects of TP on β‑cell lipotoxicity have not been fully explored. Here, we found that TP modulated β-cell lipotoxicity in a concentration-dependent and bidirectional manner. At low concentrations, TP potentially protected MIN6 β-cells from palmitate (PA)-induced lipotoxicity. At high concentrations, TP significantly promoted β-cell lipotoxicity, further reinforcing PA-induced cell apoptosis. Furthermore, low-concentration TP inhibited the PA-induced increase in reactive oxygen species (ROS) levels, and its protective effects were abolished by the ROS inducer tert-butyl hydroperoxide. Conversely, high-concentration TP significantly exacerbated the PA-triggered ROS generation, and its enhanced cytotoxicity was partially reversed by the ROS inhibitor N-acetyl-L-cysteine. Thus, TP plays a dual role in β-cell lipotoxicity, suggesting that care should be taken when it is used for obesity and diabetes treatment.

15-deoxy-Δ12,14-prostaglandin J2 relieved acute liver injury by inhibiting macrophage migration inhibitory factor expression via PPARγ in hepatocyte.

15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) exhibited potential to alleviate liver inflammation in chronic injury but was less studied in acute injury. Acute liver injury was associated with elevated macrophage migration inhibitory factor (MIF) levels in damaged hepatocytes. This study aimed to investigate the regulatory mechanism of hepatocyte-derived MIF by 15d-PGJ2 and its subsequent impact on acute liver injury. In vivo, mouse models were established by carbon tetrachloride (CCl4) intraperitoneal injection, with or without 15d-PGJ2 administration. 15d-PGJ2 treatment reduced the necrotic areas induced by CCl4. In the same mouse model constructed using enhanced green fluorescent protein (EGFP)-labeled bone marrow (BM) chimeric mice, 15d-PGJ2 reduced CCl4 induced BM-derived macrophage (BMM, EGFP+F4/80+) infiltration and inflammatory cytokine expression. Additionally, 15d-PGJ2 down-regulated liver and serum MIF levels; liver MIF expression was positively correlated with BMM percentage and inflammatory cytokine expression. In vitro, 15d-PGJ2 inhibited Mif expression in hepatocytes. In primary hepatocytes, reactive oxygen species inhibitor (NAC) showed no effect on MIF inhibition by 15d-PGJ2; PPARγ inhibitor (GW9662) abolished 15d-PGJ2 suppressed MIF expression and antagonists (troglitazone, ciglitazone) mimicked its function. In Pparg silenced AML12 cells, the suppression of MIF by 15d-PGJ2 was weakened; 15d-PGJ2 promoted PPARγ activation in AML 12 cells and primary hepatocytes. Furthermore, the conditioned medium of recombinant MIF- and lipopolysaccharide-treated AML12 respectively promoted BMM migration and inflammatory cytokine expression. Conditioned medium of 15d-PGJ2- or siMif-treated injured AML12 suppressed these effects. Collectively, 15d-PGJ2 activated PPARγ to suppress MIF expression in injured hepatocytes, reducing BMM infiltration and pro-inflammatory activation, ultimately alleviating acute liver injury.

Copper induced intestinal inflammation response through oxidative stress induced endoplasmic reticulum stress in Takifugu fasciatus

Copper (Cu) pollution in aquaculture water has seriously threatened the healthy and sustainable development of the aquaculture industry. Recently, many researchers have studied the toxic effects of Cu exposure on fish. However, the relationship between endoplasmic reticulum stress (ERS) and the inflammatory response, as well as its possible mechanisms, remain unclear. Particularly, information related to fish intestines must be expanded. Our study initially investigated the mechanisms underlying intestinal toxicity and inflammation resulting from Cu-induced ERS in vivo and in vitro in Takifugu fasciatus. In vivo study, T. fasciatus were treated with different concentrations (control, 20, and 100 µg/L) of Cu exposure for 28 days, causing intestinal oxidative stress, ERS, inflammatory responses, and histopathological and ultrastructural damage. Transcriptomic data further showed that Cu exposure caused ERS, as well as inflammatory responses, in the intestinal tracts of T. fasciatus. In vitro experiments on the intestinal cells of T. fasciatus showed that Cu exposure treatment (7.5 µg/mL) for 24 h induced ERS and increased mitochondrial numbers and inflammatory responses. In contrast, the addition of 4-phenylbutyric acid (4-PBA) alleviated ERS and inflammatory response in the Cu-exposed group. Furthermore, the reactive oxygen species (ROS) inhibitor, N-Acetyl-l-cysteine (NAC), effectively alleviated Cu-induced ERS. In conclusion, our in vivo and in vitro studies have confirmed that oxidative stress triggers the ERS pathway, which is involved in the intestinal inflammatory response. Our study provides new insights into the relationship among Cu-induced oxidative stress, ERS, and inflammatory responses in fish, as well as for the healthy culture of fish in aqueous environments.

VDR alleviates endothelial cell injury in arteriovenous fistula through inhibition of P66Shc-mediated mitochondrial ROS

To investigate the effects and mechanism of Vitamin D receptor (VDR) signaling on arteriovenous fistula (AVF) endothelial cell injury. Venous tissues of AVF stenosis patients were collected and analyzed, vascular morphology, reactive oxygen species (ROS), and the expression of VDR, P66Shc, fibronectin (FN), collagen-1 (Col-1) were detected. In addition, human umbilical vein endothelial cells (HUVECs) was used in in vitro studies. HUVECs was incubated with transforming growth factor-beta (TGF-β, 50 ng/ml). Aditionally, paricalcitol, VDR overexpression plasmid and Pin1 inhibitor Juglone were used to investigate the regulatory mechanism of VDR in mitochondrial ROS. The parameters of ROS (e.g. MitoSox) and the expression of FN, Col-1 were tested. Moreover, the mitochondrial translocation of P66Shc was analyzed. The expression of VDR was obviously decreased in the venous tissues of AVF stenosis patients. On the contrary, the expression of P66Shc, P-P66Shc, FN, Col-1 and 8-OHdG were increased significantly in the venous tissues of AVF stenosis patients (P < 0.05). In line with this, the level of mitochondrial ROS and the expression of P66Shc, P-P66Shc, FN, Col-1 increased obviously in HUVECs cells under TGF-β condition. Both VDR over-expression plasmid and Pin1 inhibitor Juglone could alleviate TGF-β induced endothelial injury. Mechanistically, VDR overexpression plasmid and Juglone could inhibit the expression of Pin1, and then restrain P66Shc mitochondrial translocation, eventually reduce the level of mitochondrial ROS. Our research indicated that activation of VDR could alleviate venous endothelial cell dysfunction through inhibiting Pin1-mediated mitochondrial translocation of P66Shc and consequently reducing mitochondrial ROS. It suggested that VDR signaling might be an effective target for AVF stenosis treatment.

Inhibitors of NLRP3 Inflammasome in Ischemic Heart Disease: Focus on Functional and Redox Aspects.

Myocardial ischemia-reperfusion injury (MIRI) is caused by several mechanisms, including the production of reactive oxygen species (ROS), altered cellular osmolarity, and inflammatory response. Calcium overload, altered oxygen levels, and mitochondrial ROS are also involved in these MIRI processes, resulting in the irreversible opening of the mitochondrial permeability transition pore (mPTP). These mechanisms and processes are associated with NLRP3 inflammasome priming and activation, which can also induce cell death by pyroptosis through the up-regulation of the caspase-1 pathway and IL-18 release. In addition, endothelial dysfunction, both in the presence and absence of MIRI, is also accompanied by altered oxygen levels, decreased nitric oxide production, and ROS overproduction, resulting in the expression of adhesion molecules and leukocyte infiltration in which the NLRP3 inflammasome plays a central role, thus contributing, through endothelial dysfunction, to the alteration of coronary flow, typical of ischemic heart disease. Given the intricate interrelationship between ROS and NLRP3, ROS inhibitors can reduce NLRP3 inflammasome activation, while NLRP3 inhibitors can reduce oxidative stress and inflammation. NLRP3 inhibitors have been intensively studied as anti-inflammatory agents in basic cardiovascular sciences. In this review, we analyze the interrelation between ROS and NLRP3 in ischemic heart disease and the effects of some NLRP3 inhibitors as possible therapeutic agents in this disease condition. All compounds considered in this review need larger studies to confirm their appropriate use in clinical scenarios as anti-ischemic drugs.

Peptide G-Protein-Coupled Receptors and ErbB Receptor Tyrosine Kinases in Cancer.

The ErbB RTKs (EGFR, HER2, HER3, and HER4) have been well-studied in cancer. EGFR, HER2, and HER3 stimulate cancer proliferation, principally by activating the phosphatidylinositol-3-kinase and extracellular signal-regulated kinase (ERK) pathways, resulting in increased cancer cell survival and proliferation. Cancer cells have high densities of the EGFR, HER2, and HER3 causing phosphorylation of tyrosine amino acids on protein substrates and tyrosine amino acids near the C-terminal of the RTKs. After transforming growth factor (TGF) α binds to the EGFR, homodimers or EGFR heterodimers form. HER2 forms heterodimers with the EGFR, HER3, and HER4. The EGFR, HER2, and HER3 are overexpressed in lung cancer patient tumors, and monoclonal antibodies (mAbs), such as Herceptin against HER2, are used to treat breast cancer patients. Patients with EGFR mutations are treated with tyrosine kinase inhibitors, such as gefitinib or osimertinib. Peptide GPCRs, such as NTSR1, are present in many cancers, and neurotensin (NTS) stimulates the growth of cancer cells. Lung cancer proliferation is impaired by SR48692, an NTSR1 antagonist. SR48692 is synergistic with gefitinib at inhibiting lung cancer growth. Adding NTS to lung cancer cells increases the shedding of TGFα, which activates the EGFR, or neuregulin-1, which activates HER3. The transactivation process is impaired by SRC, matrix metalloprotease, and reactive oxygen species inhibitors. While the transactivation process is complicated, it is fast and occurs within minutes after adding NTS to cancer cells. This review emphasizes the use of tyrosine kinase inhibitors and SR48692 to impair transactivation and cancer growth.

ROS-responsive exogenous functional mitochondria can rescue neural cells post-ischemic stroke.

Background: The transfer of mitochondria from healthy mesenchymal stem cells (MSCs) to injured MSCs has been shown to have potential therapeutic benefits for neural cell post-ischemic stroke. Specifically, functional mitochondria can perform their normal functions after being internalized by stressed cells, leading to host cell survival. However, while this approach shows promise, there is still a lack of understanding regarding which neural cells can internalize functional mitochondria and the regulatory mechanisms involved. To address this gap, we investigated the ability of different neural cells to internalize exogenous functional mitochondria extracted from MSCs. Methods: Functional mitochondria (F-Mito) isolated from umbilical cord derived-MSCs (UCMSCs) were labeled with lentivirus of HBLV-mito-dsred-Null-PURO vector. The ability of stressed cells to internalize F-Mito was analyzed using a mouse (C57BL/6J) middle cerebral artery occlusion (MCAO) model and an oxygen-glucose deprivation/reoxygenation (OGD/R) cell model. The cell viability was measured by CCK-8 kit. Time-course of intracellular ROS levels in stressed cells were analyzed by DCFH-DA staining after OGD/R and F-Mito treatment. MitoSOX, Mitotracker and WGA labeling were used to assess the relationship between ROS levels and the uptake of F-Mito at the single-cell level. Pharmacological modulation of ROS was performed using acetylcysteine (ROS inhibitor). Results: Our findings demonstrate that neurons and endothelial cells are more effective at internalizing mitochondria than astrocytes, both in vitro and in vivo, using an ischemia-reperfusion model. Additionally, internalized F-Mito decreases host cell reactive oxygen species (ROS) levels and rescues survival. Importantly, we found that the ROS response in stressed cells after ischemia is a crucial determinant in positively mediating the internalization of F-Mito by host cells, and inhibiting the generation of ROS chemicals in host cells may decrease the internalization of F-Mito. These results offer insight into how exogenous mitochondria rescue neural cells via ROS response in an ischemic stroke model. Overall, our study provides solid evidence for the translational application of MSC-derived mitochondria as a promising treatment for ischemic stroke.

Knockout of microglial Hv1 proton channel reduces neurotoxic A1 astrocytes and neuronal damage via the ROS/STAT3 pathway after spinal cord injury.

Spinal cord injury (SCI) causes severe functional deficits and neuronal damage, accompanied by intense glial activation. The voltage-gated proton channel Hv1, selectively expressed on microglia, is associated with SCI progression. However, the effect of Hv1 on the phenotypes and functions of reactive astrocytes after SCI remains unclear. Here, we combined Hv1 knockout (Hv1-/- ) mice and T10 spinal cord contusion to investigate the effects of microglial Hv1 on SCI pathophysiology and the phenotypes and functions of reactive astrocytes. After SCI, astrocytes proliferated and activated in the peri-injury area and exhibited an A1-dominant phenotype. Hv1 knockout reduced neurotoxic A1 astrocytes and shifted the dominant phenotype of reactive astrocytes from A1 to A2, enhancing synaptogenesis promotion, phagocytosis, and neurotrophy of astrocytes. Moreover, synaptic and axonal remodeling as well as motor recovery after SCI benefited from the improved astrocytic functions of Hv1 knockout. Furthermore, exogenous and endogenous reactive oxygen species (ROS) in astrocytes after SCI were reduced by Hv1 knockout. Our in vitro results showed that inhibition of ROS reduced the neurotoxic A1 phenotype in primary astrocytes via the STAT3 pathway. Similar to the effect of Hv1 knockout, the application of the ROS scavenger N-acetylcysteine reduced SCI-induced neurotoxic A1 astrocytes in vivo. Based on the in vivo and vitro results, we elucidated that microglial Hv1 knockout promotes synaptic and axonal remodeling in SCI mice by decreasing neurotoxic A1 astrocytes and increasing neuroprotective A2 astrocytes via the ROS/STAT3 pathway. Therefore, the Hv1 proton channel is a promising target for the treatment of SCI.

A C-type lectin induces NLRP3 inflammasome activation via TLR4 interaction in human peripheral blood mononuclear cells.

Lectins are a large group of proteins found in many snake venoms. BjcuL is a C-type lectin from Bothrops jararacussu snake venom that does not present cytotoxicity action on human peripheral blood mononuclear cells (PBMCs) at concentrations of 5 and 10μg/mL. BjcuL demonstrates an immunomodulatory role in PBMCs with the production of pro- and anti-inflammatory cytokines (IL-2, IL-10, IFN-γ, IL-6, TNF-α, and IL-17) in addition to stimulate T cells to produce reactive oxygen species (ROS) that could play a role in the acute inflammatory reaction observed in the victims. Inflammasomes are an essential arm in cells of innate immunity to detect and sense a range of endogenous or exogenous, sterile, or infectious stimuli to elicit cellular responses and effector mechanisms. NLRP3 inflammasome is a significant target for this study, because the lectin is responsible for leukocyte activation stimulating the release of inflammatory mediators, which results in dynamic cellular responses to remove the detrimental process to the body in snakebites. Thus, this study aimed to investigate how isolated BjcuL fromB. jararacussuvenom affects NLRP3 inflammasome activation on PBMCs. For this, the cells were isolated by density gradient and incubated with BjcuL at different periods and concentrations for the evaluation of the activation of the NLRP3 inflammasome through gene and protein expressions of ASC, CASPASE-1, and NLRP3 by RT-qPCR, Western blot, and immunofluorescence, as well as the participation of Toll-like receptor 4 (TLR4) and ROS in the IL-1β production, a product resultant of the NLRP3 inflammasome activation. Herein, BjcuL interacts with TLR4 as demonstrated by in vitro and in silico studies and induces cytokines release via NF-κB signaling. By genic and protein expression assays, BjcuL activates NLRP3 inflammasome, and the pharmacological modulation with LPS-RS, an antagonist of TLR4; LPS-SM, an agonist of TLR4; MCC950, a specific NLRP3 inhibitor, and rotenone, an inhibitor of mitochondrial ROS, confirmed the participation of TLR4 and ROS in the NLRP3 inflammasome activation and IL-1β liberation. The effects of BjcuL on the regulation and activation of the NLRP3 inflammasome complex via TLR4 activation with ROS participation may be determinant for the development of the inflammatory local effects seen in snakebite victims. In addition, in silico together with in vitro studies provide information that may be useful in the rational design of TLR agonists as well as new adjuvants for immunomodulatory therapy.

Mitochondrial ROS and base excision repair steps leading to DNA nick formation drive ultraviolet induced-NETosis.

Reactive oxygen species (ROS) is essential for neutrophil extracellular trap formation (NETosis), and generated either by NADPH oxidases (e.g., during infections) or mitochondria (e.g., sterile injury) in neutrophils. We recently showed that ultraviolet (UV) radiation, a sterile injury-inducing agent, dose-dependently induced mitochondrial ROS generation, and increasing levels of ROS shifted the neutrophil death from apoptosis to NETosis. Nevertheless, how ROS executes UV-induced NETosis is unknown. In this study, we first confirmed that UV doses used in our experiments generated mitochondrial ROS, and the inhibition of mitochondrial ROS suppressed NETosis (Mitosox, SYTOX, immunocytochemistry, imaging). Next, we showed that UV irradiation extensively oxidized DNA, by confocal imaging of 8-oxyguanine (8-oxoG) in NETs. Immunofluorescence microscopy further showed that a DNA repair protein, proliferating cell nuclear antigen, was widely distributed throughout the DNA, indicating that the DNA repair machinery was active throughout the genome during UV-induced NETosis. Inhibition of specific steps of base excision repair (BER) pathway showed that steps leading up to DNA nick formation, but not the later steps, suppressed UV-induced NETosis. In summary, this study shows that (i) high levels of mitochondrial ROS produced following UV irradiation induces extensive oxidative DNA damage, and (ii) early steps of the BER pathway leading to DNA nicking results in chromatin decondensation and NETosis. Collectively, these findings reveal how ROS induces NOX-independent NETosis, and also a novel biological mechanism for UV irradiation- and -mitochondrial ROS-mediated NETosis.

A novel mitochondrial complex I ROS inhibitor partially improves muscle regeneration in adult but not old mice

It is unclear whether mitochondrial dysfunction and redox stress contribute to impaired age-related muscle regenerative capacity. Here we characterized a novel compound, BI4500, that inhibits the release of reactive oxygen species (ROS) from the quinone site in mitochondrial complex I (site IQ). We tested the hypothesis that ROS release from site IQ contributes to impaired regenerative capacity in aging muscle. Electron transfer system site-specific ROS production was measured in adult and aged mouse isolated muscle mitochondria and permeabilized gastrocnemius fibers. BI4500 inhibited ROS production from site IQ in a concentration-dependent manner (IC50 = ∼985 nM) by inhibiting ROS release without impairing complex I-linked respiration. In vivo BI4500 treatment decreased ROS production from site IQ. Muscle injury and sham injury were induced using barium chloride or vehicle injection to the tibialis anterior (TA) muscle in adult and aged male mice. On the same day as injury, mice began a daily gavage of 30 mg/kg BI4500 (BI) or placebo (PLA). Muscle regeneration (H&E, Sirius Red, Pax7) was measured at 5 and 35 days after injury. Muscle injury increased centrally nucleated fibers (CNFs) and fibrosis with no treatment or age effect. There was a significant age by treatment interaction for CNFs at 5- and 35-days post injury with significantly more CNFs in BI adults compared to PLA adults. Muscle fiber cross-sectional area (CSA) recovered significantly more in adult BI mice (−89 ± 365 μm2) compared to old PLA (−599 ± 153 μm2) and old BI (−535 ± 222 μm2, mean ± SD). In situ TA force recovery was measured 35 days after injury and was not significantly different by age or treatment. Inhibition of site IQ ROS partially improves muscle regeneration in adult but not old muscle demonstrating a role for CI ROS in the response to muscle injury. Site IQ ROS does not contribute to impaired regenerative capacity in aging.

Atovaquone exerts its anticancer effect by inhibiting Na+/K+-ATPase ion transport in canine cancer cells.

New anticancer drugs are being developed to avoid the toxicity and chemoresistance of the currently available drugs. The Food and Drug Administration-approved anti-malarial drug atovaquone is known to act as a selective oxidative phosphorylation inhibitor in the mitochondria by competing with CO Q10 (mitochondrial complex II and III). This study aimed to investigate the effect of atovaquone by examining the Na+/K+-ATPase (NKA) activity in various canine cell lines. Canine cell lines were treated with various concentrations (2.5, 5, 10, 15, and 20 μM) of atovaquone for 24, 48, and 72 h. Human cell lines were used as a control to validate the canine cancer cell lines. The activities of the drugs against the cancer cell lines were measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromideassay. The cell metabolic activity was determined by measuring the activities of the nicotinamide adenine dinucleotide phosphate-dependent cellular oxidoreductase enzymes. The NKA activity was measured using the single-cell patch clamping assay. Atovaquone-induced apoptosis by elevating the concentration of reactive oxygen species (ROS) in the tumor cells, leading to cell death. Treatment of canine cancer cells with N-acetylcysteine (ROS inhibitor) reduced the activity of the drug. Furthermore, atovaquone inhibited more than 45% of the NKA ion current. This study demonstrated effects of atovaquone against canine cancer cell lines. The data may prove beneficial in repurposing the drug as a new anticancer agent in canine clinical trials, which might aid in fighting human cancer.

Involvement of the JNK/HO‑1/FTH1 signaling pathway in nanoplastic‑induced inflammation and ferroptosis of BV2 microglia cells.

Nanoplastics (NPs) are a newly discovered type of environmental pollutant. The potential for neurotoxicity caused by NPs and their mechanisms are unclear. The present study aimed to determine the molecular mechanism underlying neurotoxicity induced by NPs. Microglia (BV2) cells were used for invitro studies, and it was found that NPs invaded cells, activated inflammasomes, induced the release of significant quantities of inflammatory factors by detection of inflammatory response‑associated proteins through Western blot and ELISA. By detection of FITC, SOD, GSH, cellular iron level, and ferroptosis‑related proteins, it was found that NPs compromised the anti‑oxidative mechanisms of cells, increased intracellular lipid peroxidation and Fe2+ concentration and triggered inflammatory reactions and ferroptosis. Pretreatment with reactive oxygen species (ROS) inhibitor N‑acetylcysteine (NAC) alleviated induction of inflammatory reactions and ferroptosis of cells. In addition, inhibiting expression of c‑Jun N‑terminal kinase (JNK) increased expression of heme oxygenase (HO‑1), resulting in decreased ferroptosis, indicating that the JNK/HO‑1 signaling pathway was involved in NP‑induced effects on ferroptosis in BV2 cells. In conclusion, NPs could induce inflammatory responses and ferroptosis in BV2 cells. JNK/HO‑1 mediated ferroptosis may serve an important role in the toxicity of microglia induced by NPs. This study provided novel evidence for the toxic effects of NPs and highlighted a theoretical mechanistic basis for safe prevention and treatment of plastic pollution‑induced neurotoxicity.

The involvement of reactive oxygen species in wounding-induced archeospores production in Neopyropia yezoensis

The archeospores released from the blades of Neopyropia yezoensis via dedifferentiated vegetative cells have drawn attention both in cultivation and research. Wounding-induced archeospores formation and release have been observed in N. yezoensis, but the mechanism behind them is unclear. In this study, the involvement of reactive oxygen species (ROS) in the process of wounding-induced archeospores formation and release was investigated. Based on ROS fluorescence observations, the blade fragments began to accumulate ROS after 12 h wounding, while no ROS signals were observed in normal blades. Next, when the blade fragments were treated with ROS inhibitor diphenyleneiodonium (DPI), it showed that the production of archeopores was significantly suppressed. Under normal culturing after wounding, 78.3% of the fragments could release archeospores, and the ROS fluorescence was enriched in the released archeospores. Under 0.05 μM DPI treatment, the percentage of fragments releasing archeospores was dropped to 16.2%, with decreased ROS fluorescence levels. Under 0.1 μM DPI treatment, no archeospores were released from the fragments, and ROS fluorescence was also undetectable in the fragments. Our findings proved that ROS are essential for wounding-induced archeospores production, which might play regulatory roles in the cell dedifferentiation of N. yezoensis.

Propineb induced notochord deformity, craniofacial malformation, and osteoporosis in zebrafish through dysregulated reactive oxygen species generation

Dithiocarbamate (DTC) fungicides are contaminants that are ubiquitous in the environment. Exposure to DTC fungicides has been associated with a variety of teratogenic developmental effects. Propineb, a member of DTCs, was evaluated for the toxicological effects on notochord and craniofacial development, osteogenesis in zebrafish model. Embryos at 6 hours post-fertilization (hpf) were exposed to propineb at dosages of 1 and 4 μM. Morphological parameters were evaluated at exposure times of 24, 48, 72, and 120 hpf after propineb exposure. The survival and hatching rates as well as body length decreased at 1 and 4 μmol/L groups. Besides, transgenic zebrafish exposed to propineb showed abnormal vacuole biogenesis in notochord cells at the early stage of development. The expression of collagen type 2 alpha 1a (col2a1a), sonic hedgehog (shh), and heat shock protein family B member 11 (hspb11) measured by quantitative PCR and in situ hybridization experiment of col8a1a gene have consolidated the proposal process. Besides, Alcian blue, calcein, and alizarin red staining profiles displayed craniofacial malformations and osteoporosis were induced following propineb exposure. PPB exposure induced the changes in oxidative stress and reactive oxygen species inhibitor alleviated the deformities of PPB. Collectively, our data suggested that propineb exposure triggered bone abnormalities in different phenotypes of zebrafish. Therefore, propineb is a potential toxicant of high priority concern for aquatic organisms.

Non-specific LIPID TRANSFER PROTEIN 1 enhances immunity against tobacco mosaic virus in Nicotiana benthamiana.

Plant non-specific lipid transfer proteins (nsLTPs) are small, cysteine-rich proteins that play significant roles in biotic and abiotic stress responses; however, the molecular mechanism of their functions against viral infections remains unclear. In this study, we employed virus-induced gene-silencing and transgenic overexpression to functionally analyse a type-I nsLTP in Nicotiana benthamiana, NbLTP1, in the immunity response against tobacco mosaic virus (TMV). NbLTP1 was inducible by TMV infection, and its silencing increased TMV-induced oxidative damage and the production of reactive oxygen species (ROS), compromised local and systemic resistance to TMV, and inactivated the biosynthesis of salicylic acid (SA) and its downstream signaling pathway. The effects of NbLTP1-silencing were partially restored by application of exogenous SA. Overexpressing NbLTP1 activated genes related to ROS scavenging to increase cell membrane stability and maintain redox homeostasis, confirming that an early ROS burst followed by ROS suppression at the later phases of pathogenesis is essential for resistance to TMV infection. The cell-wall localization of NbLTP1 was beneficial to viral resistance. Overall, our results showed that NbLTP1 positively regulates plant immunity against viral infection through up-regulating SA biosynthesis and its downstream signaling component, NONEXPRESSOR OF PATHOGENESIS-RELATED 1 (NPR1), which in turn activates pathogenesis-related genes, and by suppressing ROS accumulation at the later phases of viral pathogenesis.

LINC00938 alleviates hypoxia ischemia encephalopathy induced neonatal brain injury by regulating oxidative stress and inhibiting JNK/p38 MAPK signaling pathway

Hypoxic-ischemic encephalopathy (HIE) is an important factor leading to permanent damage of central nervous system (CNS) and even neonatal death. Long non-coding RNAs (lncRNAs) has been shown to get involved in the pathogenesis of nervous system diseases. LINC00938 is an intergenic lncRNA which is reported to be involved in neurodegenerative disease. However, the potential role of LINC00938 in nerve injury of neonatal HIE is undetermined. Here, we found that the expression of LINC00938 in the whole blood of neonates with HIE was downregulated compared with the non-HIE group. Functional study revealed that the expression of LINC00938 was significantly decreased in oxygen-glucose deprivation (OGD)-induced SH-SY5Y. Knockdown of LINC00938 induced the neural cell apoptosis by increased the protein level of Bax, Cleaved-Caspase3 and decreased the expression of Bcl-2. In addition, overexpression of LINC00938 prevented the apoptosis of SH-SY5Y from OGD injury. RNA-seq analysis showed that MAPK signaling was involved in the anti-apoptosis function of LINC00938. LINC00938 knockdown induced the activation of c-Jun-N-terminal kinase (JNK), p38 mitogen-activated protein kinase, and inhibited the activation of ERK signaling. However, LINC00938 play neuroprotective role in OGD-induced SH-SY5Y by suppression the phosphorylation of JNK and p38 MAPK rather than regulation of ERK signaling pathway. Further analyses illustrated that the cell apoptosis of neuronal cell was dependent on the elevation of reactive oxygen species (ROS) and result in mitochondria dysfunction in LINC00938 knockdown SH-SY5Y. Pretreated with ROS inhibitor N-acetylcysteine amide (NACA) dramatically suppressed LINC00938 knockdown induced oxidative stress and mitochondria dysfunction which induced cell apoptosis. In addition, NACA treatment significantly reduced the expression of p-JNK and p-p38 in OGD-induced SH-SY5Y. Furthermore, overexpression of LINC00938 displayed a notably neuroprotective effect by suppress central nervous system cell apoptosis via alleviating oxidative stress in CoCl2-induced hypoxic HIE model of zebrafish. Taken together, these results suggested that LINC00938 can act as a neuroprotective factor to inhibit oxidative stress and apoptosis of CNS under HIE conditions.

Ultraviolet B radiation induces oxidative stress and apoptosis in human lens epithelium cells by activating NF-κB signaling to down-regulate sodium vitamin C transporter 2 (SVCT2) expression

ABSTRACT Ultraviolet B (UVB) exposure is reported to cause cataract formation by inducing excessive reactive oxygen species (ROS) and apoptosis in human lens epithelial cells (HLECs). Sodium-dependent Vitamin C transports-2 (SVCT2) is a ascorbic acid (AsA) transporter for that can protect cells and tissues from oxidative stress. Here, we focus on the functional characterization and mechanism analysis of SVCT2 in UVB-treated HLECs. The results showed a significant reduction of SVCT2 expression in HLECs treated with UVB. SVCT2 abated apoptosis and Bax expression and increased Bcl-2 expression. Moreover, SVCT2 decreased ROS accumulation and MDA level, but increased the activities of antioxidant enzymes (SOD and GSH-PX). NF-κB inhibitor (PDTC) alleviated ROS production and apoptosis, and promoted SVCT2 expression in UVB-treated HLECs. Additionally, ROS inhibitor (NAC) suppressed oxidative stress, apoptosis, and induced SVCT2 expression in UVB-treated HLECs, while these effects were significantly abated due to the activation of NF-κB signaling. Furthermore, SVCT2 facilitated 14C-AsA absorption in UVB-treated HLECs. Together, our findings demonstrated that UVB exposure-induced ROS generation, which further activated NF-κB signaling to down-regulate SVCT2 expression in HLECs. Then, downregulated SVCT2 promoted ROS accumulation and induced apoptosis by decreasing AsA uptake. Our data reveal a novel NF-κB/SVCT2/AsA regulatory pathway and suggest the therapeutic potential of SVCT2 in UVB-induced cataract.

Anti-Warburg effect via generation of ROS and inhibition of PKM2/β-catenin mediates apoptosis of lambertianic acid in prostate cancer cells.

To elucidate the underlying antitumor mechanism of lambertianic acid (LA) derived from Pinus koraiensis, the role of cancer metabolism related molecules was investigated in the apoptotic effect of LA in DU145 and PC3 prostate cancer cells. MTT assay for cytotoxicity, RNA interference, cell cycle analysis for sub G1 population, nuclear and cytoplasmic extraction, lactate, Glucose and ATP assay by ELISA, Measurement of reactive oxygen species (ROS) generation, Western blotting, and immunoprecipitation assay were conducted in DU145 and PC3 prostate cancer cells. Herein LA exerted cytotoxicity, increased sub G1 population and attenuated the expression of pro-Caspase3 and pro-poly (ADP-ribose) polymerase (pro-PARP) in DU145 and PC3 cells. Also, LA reduced the expression of lactate dehydrogenase A (LDHA), glycolytic enzymes such as hexokinase 2 and pyruvate kinase M2 (PKM2) with reduced production of lactate in DU145 and PC3 cells. Notably, LA decreased phosphorylation of PKM2 on Tyr105 and inhibited the expression of p-STAT3, cyclin D1, C-Myc, β-catenin, and p-GSK3β with the decrease of nuclear translocation of p-PKM2. Furthermore, LA disturbed the binding of p-PKM2 and β-catenin in DU145 cells, which was supported by Spearman coefficient (0.0463) of cBioportal database. Furthermore, LA generated ROS in DU145 and PC3 cells, while ROS scavenger NAC (N-acetyl L-cysteine) blocked the ability of LA to reduce p-PKM2, PKM2, β-catenin, LDHA, and pro-caspase3 in DU145 cells. Taken together, these findings provide evidence that LA induces apoptosis via ROS generation and inhibition of PKM2/β-catenin signaling in prostate cancer cells.