DNA dioxygenases TET2 deficiency promotes cigarette smoke induced chronic obstructive pulmonary disease by inducing ferroptosis of lung epithelial cell.

Chronic obstructive pulmonary disease (COPD) is a significant global cause of morbidity and mortality currently. Long-term exposure of cigarette smoke (CS) inducing persistent inflammation, small airway remodeling and emphysematous lung are the distinguishing features of COPD. Ferroptosis, occurred in lung epithelial cells has recently been reported to be associated with COPD pathogenesis. DNA dioxygenase ten-eleven translocation 2 (TET2) is an important demethylase and its genetic mutation is associated with low forced expiratory volume in 1 s (FEV1) of lung function. However, its role in COPD remains elusive. Here, we found that TET2 regulates CS induced lipid peroxidation through demethylating glutathione peroxidase 4 (GPx4), thus alleviating airway epithelial cell ferroptosis in COPD. TET2 protein levels were mainly reduced in the airway epithelia of COPD patients, mouse models, and CS extract-treated bronchial epithelial cells. The deletion of TET2 triggered ferroptosis and further exaggerated CS-induced airway remodeling, inflammation, and emphysema in vivo. Moreover, we demonstrated that TET2 silencing intensified ferroptosis, while TET2 overexpression inhibited ferroptosis in airway epithelial cell treated with CSE. Mechanically, TET2 protected airway epithelial cells from CS-induced lipid peroxidation and ferroptosis through demethylating the promoter of glutathione peroxidase 4 (GPx4). Finally, co-administration of methylation inhibitor 5'-aza-2'-deoxycytidine (5-AZA) and the antioxidant N-acetyl-cysteine (NAC) have more protective effects on CS-induced COPD than either administration alone. Overall, our study reveals that TET2 is an essential modulator in the lipid peroxidation and ferroptosis of airway epithelial cell, and could act as a potential therapeutic target for CS-induced COPD.

The effects of Ellagic acid supplementation on neurotrophic, inflammation, and oxidative stress factors, and indoleamine 2, 3-dioxygenase gene expression in multiple sclerosis patients with mild to moderate depressive symptoms: A randomized, triple-blind, placebo-controlled trial.

BACKGROUND: Depression is one of the most common psychological disorders among multiple sclerosis (MS) patients that characterized as the first symptoms. Ellagic acid is a natural polyphenol that may have neuroprotective properties through antioxidant, anti-inflammatory, and immunomodulatory effects. PURPOSE: The aim of the present study was to investigate the effects of Ellagic acid on circulating levels of brain derived neurotrophic factor (BDNF), interferon-γ (IFN-Æ´), nitric oxide (NO), nuclear factor erythroid-2-related factor 2 (Nrf2), cortisol, serotonergic system, and indoleamine 2, 3-dioxygenase (IDO) gene expression in MS patients with mild to moderate depressive symptoms. STUDY DESIGN: A randomized triple-blind clinical trial. METHODS: The eligible patients according to the inclusion criteria were randomly divided into two groups: either 180 mg Ellagic acid (Axenic company) (n = 25) or 180 mg maltodextrin (n = 25) group for 12 weeks. The Ellagic acid supplement were identical to placebo in shape, color and odor. Serum BDNF, NO, Nrf2, cortisol, serotonin, and IFN-Æ´ were measured by ELISA kit in the baseline and end of the study. Also, demographic characteristics, anthropometric measurements, physical activity, food intake, Beck Depression Inventory-II (BDI-II) and expanding disability status scale (EDSS) questionnaires, as well as IDO gene expression were assessed. SPSS software version 24 was used for statistical analysis. RESULTS: Fifty patients were evaluated, and a significant decrease in BDI-II (p = 0.001), IFN-Æ´ (p = 0.001), NO (p = 0.004), cortisol (p = 0.015), IDO gene expression (p = 0.001) and as well as increased the level of BDNF (p = 0.006) and serotonin (p = 0.019) was observed among those who received 90 mg Ellagic acid twice a day for 12 weeks versus control group. However, there were no significant differences between groups for Nrf2 levels (p>0.05) at the end of study. CONCLUSION: The current study indicates that Ellagic acid intervention has a favorable effect on depression in MS patients. This is achieved by reducing BDI-II scores, as well as levels of NO, cortisol, IFN-Æ´, and IDO gene expression. Furthermore, we found a significant elevation in circulating levels of BDNF and serotonin.

[Exogenous Spermidine Regulates Ryegrass Root System Response to Cd Stress and Its Transcriptome Analysis].

The application of exogenous growth-regulating substances is an effective technique to enhance plant stress tolerance. Here, a hydroponic experiment was conducted to investigate the effects of exogenous basal application of 0.1 mmol·L-1 spermidine (Spd) on both the physiology and molecular biology of ryegrass root systems under varying degrees (0, 5, and 10 mg·L-1) of cadmium (Cd) stress using ryegrass as the test plants. The results of physiological studies revealed that Cd stress significantly reduced the physiological functions of the ryegrass root system, whereas the addition of Spd effectively alleviated the negative effects caused by Cd. The most significant effect was on the root soluble protein content, which increased by 90.91% and 158.35% compared with 5 mg·L-1and 10 mg·L-1 Cd alone. Spd also inhibited the accumulation of oxidative stress products malondialdehyde (MDA) and hydrogen peroxide (H2O2) by increasing the ascorbic acid (ASA) and glutathione (GSH) content and peroxidase (POD) activity, whereas the effects on root activity and superoxide dismutase (SOD) activity were not significant. The results of molecular biology studies demonstrated that 10 mg·L-1 Cd stress caused differential expression of a large number of genes in ryegrass roots, and the number of differentially expressed genes, differential significance, and differential multiplicity were significantly reduced after the application of exogenous Spd. The most significant part of the GO enrichment analysis shifted from responding to organic cyclic compounds and aldehyde/ketone group transferase activity to responding to trivalent iron ions and 2'-deoxymugineic-acid 2'-dioxygenase activity. Single gene expression heat map analysis revealed that exogenous Spd upregulated the expression of genes encoding zinc-iron transporter protein and 2'-deoxymugineic-acid 2'-dioxygenase, which improved the uptake and utilization of iron by the root system. In conclusion, the application of certain concentrations of Spd could effectively regulate the response of ryegrass roots to Cd stress, enhance its tolerance physiology, and mitigate the toxic effects of Cd.

Liver tryptophan 2,3-dioxygenase: a determinant of anxiety-like behaviour - studies with chronic nicotine administration in rats.

Deletion of the tryptophan 2,3-dioxygenase ( TDO2 ) gene induces an anxiolytic-like behaviour in mice and TDO inhibition by allopurinol elicits an antidepressant-like effect in rats exposed to restraint stress. Chronic nicotine administration inhibits TDO activity, enhances brain serotonin synthesis and exerts anxiolytic- and antidepressant-like effects in rodent models. There is a strong association between anxiety, depression and tobacco use, which is stronger in women than in men. The present study aimed to examine the relationship between behavioural measures of anxiety and depression with liver TDO activity, brain tryptophan concentration and serotonin synthesis in rats treated chronically with nicotine. Behavioural measures included the elevated plus maze (EPM), open field (OFT) and forced swim (FST) tests. Biochemical measures included TDO activity, serum corticosterone and brain Trp, 5-HT and 5-HIAA concentrations. Anxiolytic-like and antidepressant-like effects of chronic nicotine were confirmed in association with TDO inhibition and elevation of brain Trp and 5-HT. Sex differences in behaviour were independent of the biochemical changes. At baseline, female rats performed better than males in OFT and FST. Nicotine was less anxiolytic in females in the open arm test. Nicotine treatment did not elicit different responses between sexes in the FST. Our findings support the notion that liver TDO activity exhibits a strong association with behavioural measures of anxiety and depression in experimental models, but provide little evidence for sex differences in behavioural response to nicotine. The TDO-anxiety link may be underpinned by kynurenine metabolites as well as serotonin.

Punicalagin protects against impaired skeletal muscle function in high-fat-diet-induced obese mice by regulating TET2.

The function of skeletal muscles can be markedly hampered by obesity. Ten-eleven translocation 2 (TET2) is an important therapeutic target for ameliorating skeletal muscle dysfunction. Our previous study revealed that punicalagin (PUN) regulated TET2 in obese mice; however, whether PUN can prevent obesity-induced skeletal muscle dysfunction by regulating TET2 remains unclear. In the present study, 40 male C57BL/6J mice were divided into four groups (n = 10 per group): the control (CON) group, the high-fat-diet (HFD, negative control) group, the resveratrol (positive control) group, and the PUN group. The ratio of gastrocnemius weight to body weight (0.0097 ± 0.0016 vs. 0.0080 ± 0.0011), the grip strength (120.04 g ± 11.10 vs. 98.89 g ± 2.79), and the muscle fiber count (314.56 per visual field ± 92.73 vs. 236.44 per visual field ± 50.58) in the PUN group were higher than those in the HFD group. Moreover, the levels of the TET2 protein, 5-hydroxymethylcytosine (5hmC), and 5-formylcytosine (5fC) in skeletal muscles were significantly lower in the HFD group than those in the CON group; these levels increased after PUN treatment. Compared with the HFD group, the phosphorylation level of AMP-activated protein kinase (AMPK) α in the PUN group was higher, which effectively enhanced the stability of the TET2 protein. Besides, the ratio of (succinic acid + fumaric acid)/α-ketoglutarate in the PUN group was lower than that in the HFD group (43.21 ± 12.42 vs. 99.19 ± 37.07), and a lower ratio led to a higher demethylase activity of TET2 in the PUN group than in the HFD group. This study highlights that PUN supplementation protects against obesity-induced impairment of the skeletal muscle function via regulating the protein stability of TET2 and the enzymatic activity of TET2 demethylation.

TET2 confers a mechanistic link of microRNA-210 and mtROS in hypoxia-suppressed spontaneous transient outward currents in uterine arteries of pregnant sheep.

Hypoxia during pregnancy impairs uterine vascular adaptation via microRNA-210 (miR-210)-mediated mitochondrial dysfunction and mitochondrial reactive oxygen species (mtROS) generation. TET methylcytosine dioxygenase 2 (TET2) participates in regulating inflammation and oxidative stress and its deficiency contributes to the pathogenesis of multiple cardiovascular diseases. Thus, we hypothesize a role of TET2 in hypoxia/miR-210-mediated mtROS suppressing spontaneous transient outward currents (STOCs) in uterine arteries. We found that gestational hypoxia downregulated TET2 in uterine arteries of pregnant sheep and TET2 was a target of miR-210. Knockdown of TET2 with small interfering RNAs suppressed mitochondrial respiration, increased mtROS, inhibited STOCs and elevated myogenic tone. By contrast, overexpression of TET2 negated hypoxia- and miR-210-induced mtROS. The effects of TET2 knockdown in uterine arteries on mtROS, STOCs and myogenic contractions were blocked by the mitochondria-targeted antioxidant MitoQ. In addition, the recovery effects of inhibiting endogenous miR-210 with miR-210-LNA on hypoxia-induced suppression of STOCs and augmentation of myogenic tone were reversed by TET2 knockdown in uterine arteries. Together, our study reveals a novel mechanistic link between the miR-210-TET2-mtROS pathway and inhibition of STOCs and provides new insights into the understanding of uterine vascular maladaptation in pregnancy complications associated with gestational hypoxia. KEY POINTS: Gestational hypoxia downregulates TET methylcytosine dioxygenase 2 (TET2) in uterine arteries of pregnant sheep. TET2 is a downstream target of microRNA-210 (miR-210) and miR-210 mediates hypoxia-induced TET2 downregulation. Knockdown of TET2 in uterine arteries recapitulates the effect of hypoxia and miR-210 and impairs mitochondrial bioenergetics and increases mitochondrial reactive oxygen species (mtROS) . Overexpression of TET2 negates the effect of hypoxia and miR-210 on increasing mtROS. TET2 knockdown reiterates the effect of hypoxia and miR-210 and suppresses spontaneous transient outward currents (STOCs) and elevates myogenic tone, and these effects are blocked by MitoQ. Knockdown of TET2 reverses the miR-210-LNA-induced reversal of the effects of hypoxia on STOCs and myogenic tone in uterine arteries.

Atranorin driven by nano materials SPION lead to ferroptosis of gastric cancer stem cells by weakening the mRNA 5-hydroxymethylcytidine modification of the Xc-/GPX4 axis and its expression.

Gastric cancer is a highly malignant tumor. Gastric cancer stem cells (GCSCs) are the main causes of drug resistance, metastasis, recurrence, and poor prognosis. As a secondary metabolite of lichen, Atranorin has a variety of biological effects, such as antibacterial, anti-inflammatory, analgesic, and wound healing; however, its killing effect on GCSCs has not been reported. In this study, we constructed Atranorin complexes comprising superparamagnetic iron oxide nanoparticles (SPION) (Atranorin@SPION). In vitro and in vivo experiments confirmed that Atranorin@SPION could significantly inhibit the proliferation, invasion, angiogenesis, and tumorigenicity of CD44+/ CD24+ GCSCs, and induce oxidative stress injury, Fe2+ accumulation, and ferroptosis. Quantitative real-time reverse transcription PCR and western blotting results showed that Atranorin@SPION not only reduced the expression levels of GCSC stem cell markers and cell proliferation and division markers, but also significantly inhibited the expression levels of key molecules in the cystine/glutamate transporter (Xc-)/glutathione peroxidase 4 (GPX4) and Tet methylcytosine dioxygenase (TET) family proteins. The results of high performance liquid chromatography-mass spectrometry and Dot blotting showed that Atranorin@SPION significantly inhibited the mRNA 5­hydroxymethylcytidine modification of GCSCs. Meanwhile, the results of RNA immunoprecipitation-PCR also indicated that Atranorin@SPIONs significantly reduced the 5-hydroxymethylcytidine modification level of GPX4 and SLC7A11 mRNA 3' untranslated region in GCSCs, resulting in a decrease in their stability, shortening their half-lives and reducing translation activity. Therefore, this study revealed that Atranorin@SPIONs induced ferroptosis of GCSCs by weakening the expression of the Xc-/GPX4 axis and the 5-hydroxymethylcytidine modification of mRNAs in the pathway, thereby achieving their therapeutic effect on gastric cancer.

Tetrahydroxy stilbene glucoside alters neurogenesis and neuroinflammation to ameliorate radiation-associated cognitive disability via AMPK/Tet2.

Along with the extensive application of radiation in medical, military and other fields, human beings carry a greater risk of exposure to radiation environment that causes a range of physical injure, particularly to the brain in cognition. However, the radiation-associated cognitive disability is poorly understood and there is no effective prevention or long-term treatment. Here, we demonstrate that neurogenesis and neuroinflammation disorder are primarily involved in the pathophysiological basis of irradiation-induced cognitive decline. Furthermore, we discovered that tetrahydroxy stilbene glucoside (TSG), a natural active ingredient from Heshouwu that has been well known for its unique anti-aging effect as the Chinese herb, can be a promising mitigator to improve learning-memory ability by facilitating the neurogenesis in the proliferation and differentiation of the surviving neural progenitor cells via AMPK/Tet2, and attenuating the neuroinflammation in the microglial NLRP3 inflammasomes activation via AMPK in vivo. Additionally, TSG was also revealed to activate AMPK by molecular docking and kinase enzyme system assay in vitro. Taken together, our findings identify TSG, as the AMPK activator, prevents radiation-induced cognitive dysfunction by regulating neurogenesis and neuroinflammation via AMPK/Tet2 in rodents, and represents a very promising candidate for developing drugs that can be used for radiation-associated brain injury.

Ectopic expression of a rice triketone dioxygenase gene confers mesotrione tolerance in soybean.

BACKGROUND: Herbicide-resistant weeds pose a challenge to agriculture and food production. New herbicide tolerance traits in crops will provide farmers with more options to effectively manage weeds. Mesotrione, a selective pre- and post-emergent triketone herbicide used in corn production, controls broadleaf and some annual grass weeds via hydroxyphenylpyruvate dioxygenase (HPPD) inhibition. Recently, the rice HIS1 gene, responsible for native tolerance to the selective triketone herbicide benzobicyclon, was identified. Expression of HIS1 also confers a modest level of mesotrione resistance in rice. Here we report the use of the HIS1 gene to develop a mesotrione tolerance trait in soybean. RESULTS: Conventional soybean is highly sensitive to mesotrione. Ectopic expression of a codon-optimized version of the rice HIS1 gene (TDO) in soybean confers a commercial level of mesotrione tolerance. In TDO transgenic soybean plants, mesotrione is rapidly and locally oxidized into noninhibitory metabolites in leaf tissues directly exposed to the herbicide. These metabolites are further converted into compounds similar to known classes of plant secondary metabolites. This rapid metabolism prevents movement of mesotrione from treated leaves into vulnerable emerging leaves. Minimizing the accumulation of the herbicide in vulnerable emerging leaves protects the function of HPPD and carotenoid biosynthesis more generally while providing tolerance to mesotrione. CONCLUSIONS: Mesotrione has a favorable environmental and toxicological profile. The TDO-mediated soybean mesotrione tolerance trait described here provides farmers with a new option to effectively manage difficult-to-control weeds using familiar herbicide chemistry. This trait can also be adapted to other mesotrione-sensitive crops (e.g. cotton) for effective weed management. © 2022 Bayer Crop Science. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Dichlorophene activates aryl hydrocarbon receptor (AhR) and indoleamine 2, 3-dioxygenase 1 (IDO1) to mediate splenotoxicity in rat.

Dichlorophene (DCP) is a halogenated phenolic compound, widely used as fungicide, bactericide and antiprotozoan and also exhibit therapeutic application in several pathological conditions. Taking account of broad use of DCP, its possible effect on spleen (an important immune organ) was investigated in this study. Male albino rats were treated with graded doses of DCP (10%, 20% and 30% of LD50) and spleen and blood were obtained at 24, 48 and 72 hours post treatment. Oxidative stress parameters, proinflammatory cytokines and protein expression of aryl hydrocarbon receptor (AhR), indoleamine-2, 3-Dioxygenase 1 (IDO1) and nuclear factor erythroid 2-related factor 2 (Nrf2) were measured along with histopathological evaluation of spleen. In the present study, DCP perturbs redox status of splenocytes of rats as evidenced by excess ROS generation, lipid peroxidation and nitric oxide production simultaneously with reduction of antioxidant level [glutathione (GSH)] and inhibition of antioxidative enzymes [superoxide dismutase (SOD) and catalase (CAT)]. Two important proinflammatory cytokines, IL-6 and TNF-α were found to be elevated upon DCP treatment. Moreover, DCP also caused activation of AhR and IDO1 with simultaneous down regulation of Nrf2. All these effects of DCP were found to be dose and duration dependent. DCP also affects the spleen micro-architecture in the present study and these alterations were more prominent in high dose group at 72 hours post treatment. Taken together, all these results suggested that DCP induces oxidative stress and also increases proinflammatory cytokine levels to mount its toxic effect on spleen.

Interference with Pseudomonas aeruginosa Quorum Sensing and Virulence by the Mycobacterial Pseudomonas Quinolone Signal Dioxygenase AqdC in Combination with the N-Acylhomoserine Lactone Lactonase QsdA.

The nosocomial pathogen Pseudomonas aeruginosa regulates its virulence via a complex quorum sensing network, which, besides N-acylhomoserine lactones, includes the alkylquinolone signal molecules 2-heptyl-3-hydroxy-4(1H)-quinolone (Pseudomonas quinolone signal [PQS]) and 2-heptyl-4(1H)-quinolone (HHQ). Mycobacteroides abscessus subsp. abscessus, an emerging pathogen, is capable of degrading the PQS and also HHQ. Here, we show that although M. abscessus subsp. abscessus reduced PQS levels in coculture with P. aeruginosa PAO1, this did not suffice for quenching the production of the virulence factors pyocyanin, pyoverdine, and rhamnolipids. However, the levels of these virulence factors were reduced in cocultures of P. aeruginosa PAO1 with recombinant M. abscessus subsp. massiliense overexpressing the PQS dioxygenase gene aqdC of M. abscessus subsp. abscessus, corroborating the potential of AqdC as a quorum quenching enzyme. When added extracellularly to P. aeruginosa cultures, AqdC quenched alkylquinolone and pyocyanin production but induced an increase in elastase levels. When supplementing P. aeruginosa cultures with QsdA, an enzyme from Rhodococcus erythropolis which inactivates N-acylhomoserine lactone signals, rhamnolipid and elastase levels were quenched, but HHQ and pyocyanin synthesis was promoted. Thus, single quorum quenching enzymes, targeting individual circuits within a complex quorum sensing network, may also elicit undesirable regulatory effects. Supernatants of P. aeruginosa cultures grown in the presence of AqdC, QsdA, or both enzymes were less cytotoxic to human epithelial lung cells than supernatants of untreated cultures. Furthermore, the combination of both aqdC and qsdA in P. aeruginosa resulted in a decline of Caenorhabditis elegans mortality under P. aeruginosa exposure.

A C⋠As lyase for degradation of environmental organoarsenical herbicides and animal husbandry growth promoters.

Arsenic is the most widespread environmental toxin. Substantial amounts of pentavalent organoarsenicals have been used as herbicides, such as monosodium methylarsonic acid (MSMA), and as growth enhancers for animal husbandry, such as roxarsone (4-hydroxy-3-nitrophenylarsonic acid) [Rox(V)]. These undergo environmental degradation to more toxic inorganic arsenite [As(III)]. We previously demonstrated a two-step pathway of degradation of MSMA to As(III) by microbial communities involving sequential reduction to methylarsonous acid [MAs(III)] by one bacterial species and demethylation from MAs(III) to As(III) by another. In this study, the gene responsible for MAs(III) demethylation was identified from an environmental MAs(III)-demethylating isolate, Bacillus sp. MD1. This gene, termed arsenic inducible gene (arsI), is in an arsenic resistance (ars) operon and encodes a nonheme iron-dependent dioxygenase with C ⋅ As lyase activity. Heterologous expression of ArsI conferred MAs(III)-demethylating activity and MAs(III) resistance to an arsenic-hypersensitive strain of Escherichia coli, demonstrating that MAs(III) demethylation is a detoxification process. Purified ArsI catalyzes Fe(2+)-dependent MAs(III) demethylation. In addition, ArsI cleaves the C ⋅ As bond in trivalent roxarsone and other aromatic arsenicals. ArsI homologs are widely distributed in prokaryotes, and we propose that ArsI-catalyzed organoarsenical degradation has a significant impact on the arsenic biogeocycle. To our knowledge, this is the first report of a molecular mechanism for organoarsenic degradation by a C ⋅ As lyase.

Lack of congruence between cysteine dioxygenase activity and S-carboxymethyl-L-cysteine S-oxidation activity in rat cytosol.

The identity of the enzyme(s) responsible for the S-oxidation of the mucoactive drug S-carboxymethyl-L-cysteine (SCMC) is unknown but the protein(s) are a susceptibility factor for a number of chronic degenerative diseases. The structural similarities between the amino acid L-cysteine and SCMC have raised the possibility that cysteine dioxygenase (CDO) may be responsible for this biotransformation reaction. Both CDO and SCMC S-oxygenase were found to require Fe2+ for enzymatic activity, and both enzyme activities were inhibited by Fe2+ and Fe3+ chelators. However, sulphydryl group modification of the enzymes resulted in the activation of the S-oxidation of SCMC but inhibition of the S-oxidation of L-cysteine. When the two enzyme activities were quantified in 20 female hepatic cytosolic fractions no linear correlation in the production of their respective metabolites was seen. The results of this investigation indicate that CDO is not responsible for the S-oxidation of SCMC in the rat.