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Celiac disease (CD) is an autoimmune enteropathy. Peroxiredoxins (PRDXs) are powerful antioxidant enzymes having an important role in significant cellular pathways including cell survival, apoptosis, and inflammation. This study aimed at investigating the expression levels of all PRDX isoforms (1–6) and their possible relationships with a transcription factor, HIF-1α, in the small intestinal tissue samples of pediatric CD patients. The study groups consisted of first-diagnosed CD patients (n = 7) and non-CD patients with functional gastrointestinal tract disorders as the controls (n = 7). The PRDXs and HIF-1α expression levels were determined by using real-time PCR and Western blotting in duodenal biopsy samples. It was observed that the mRNA and protein expression levels of PRDX 5 were significantly higher in the CD patients, whereas the PRDX 1, -2, and -4 expressions were decreased in each case compared to the control group. No significant differences were detected in the PRDX 3 and PRDX 6 expressions. The expression of HIF-1α was also significantly elevated in CD patients. These findings indicate, for the first time, that PRDXs, particularly PRDX 5, may play a significant role in the pathogenesis of CD. Furthermore, our results suggest that HIF-1α may upregulate PRDX-5 transcription in the duodenal tissue of CD.

Fasciolosis caused by the liver flukes Fasciola hepatica and Fasciola gigantica is one of the most important neglected parasitic diseases of humans and animals. The ability of the parasites to infect and multiply in their intermediate snail hosts, and their adaptation to a wide variety of mammalian definitive hosts contribute to their high transmissibility and distribution. Within the mammalian host, the trauma caused by the immature flukes burrowing through the liver parenchyma is associated with most of the pathogenesis. Similarly, the feeding activity and the physical presence of large flukes in the bile ducts can lead to anaemia, inflammation, obstruction and cholangitis. The high frequency of non-synonymous polymorphisms found in Fasciola spp. genes allows for adaptation and invasion of a broad range of hosts. This is also facilitated by parasite's excretory-secretory (ES) molecules that mediate physiological changes that allows their establishment within the host. ES contains cathepsin peptidases that aid parasite invasion by degrading collagen and fibronectin. In the bile ducts, cathepsin-L is critical to haemoglobin digestion during feeding activities. Other molecules (peroxiredoxin, cathepsin-L and Kunitz-type inhibitor) stimulate a strong immune response polarised towards a Treg/Th2 phenotype that favours fluke's survival. Helminth defence molecule, fatty acid binding proteins, Fasciola-specific glycans and miRNAs modulate host pro-inflammatory responses, while antioxidant scavenger enzymes work in an orchestrated way to deter host oxidant-mediated damage. Combining these strategies Fasciola spp. survive for decades within their mammalian host, where they reproduce and spread to become one of the most widespread zoonotic worm parasites in the world.

The review of the literature presents current data on the role of NOX proteins in the physiology of the lungs and in the development of respiratory diseases. The value of the transcription factor NRF2, superoxide dismutase, catalase, glutathione system, glutaredoxin, thioredoxin, peroxiredoxin in the development of respiratory diseases was shown. Hereditary di­seases associated with generators of activated oxygen-contai-ning metabolites and components of the antioxidant system are presented. The main markers of oxidative stress and the process of inflammation in the respiratory tract are described.

Peroxiredoxins (Prdxs) are known to play a critical role in regulating male fertility as antioxidant enzymes. Although several studies have suggested a close association between Prdxs and male fertility, few studies have explored the efficacy of Prdxs to predict male fertility. Therefore, the current study was designed to discover the most efficient biomarkers among the Prdxs with six isoforms. Our study showed a significant positive correlation between the litter size and the levels of PRDX 4 among all isoforms in spermatozoa. Subsequently, a regression analysis using a combination of markers was conducted to increase efficacy for fertility prediction. Nevertheless, PRDX4 had the highest efficacy compared to other combination models to predict litter size. The prediction accuracy of male fertility was further evaluated through receiver operating characteristic curve analysis, which showed that PRDX 4 could predict the litter size with high overall accuracy of 95%. Moreover, litter size was increased by 1.55 piglets after predicting high litter size using PRDX 4. This is the first study to comprehensively elucidate the role of all isoforms of PRDXs on male fertility to the best of our knowledge. PRDX 4 was tested and evaluated up to a practical level. Data here reported suggesting PRDX 4 marker allowed the highest accuracy for male fertility prediction and diagnosis, leading to a measurable improvement in the male fertility outcome.

The temporal and spatial patterns of reactive oxygen species (ROS) in cells and tissues decisively determine the plant acclimation response to diverse abiotic and biotic stresses. Recent progress in developing dynamic cell imaging probes provides kinetic information on changes in parameters like H2O2, glutathione (GSH/GSSG) and NAD(P)H/NAD(P)+, that play a crucial role in tuning the cellular redox state. Central to redox-based regulation is the thiol-redox regulatory network of the cell that integrates reductive information from metabolism and oxidative ROS signals. Sensitive proteomics allow for monitoring changes in redox-related posttranslational modifications. Thiol peroxidases act as sensitive peroxide and redox sensors and play a central role in this signal transduction process. Peroxiredoxins (PRX) and glutathione peroxidases (GPX) are the two main thiol peroxi-dases and their function in ROS sensing and redox signaling in plants is emerging at present and summarized in this review. Depending on their redox state, PRXs and GPXs act as redox-dependent binding partners, direct oxidants of target proteins and oxidants of thiol redox transmitters that in turn oxidize target proteins. With their versatile functions, the multiple isoforms of plant thiol peroxidases play a central role in plant stress acclimation, e.g. to high light or osmotic stress, but also in ROS-mediated immunity and development.

Endoplasmic reticulum (ER) stress activates the unfolded protein response (UPR) signaling via the accumulation of unfolded and misfolded proteins. ER stress leads to the production of reactive oxygen species (ROS), which are necessary to maintain redox homeostasis in the ER. Although peroxiredoxin 1 (Prx1) is an antioxidant enzyme that regulates intracellular ROS levels, the link between Prx1 and ER stress remains unclear. In this study, we investigated the role of Prx1 in X-box binding protein 1 (XBP-1) activation, the C/EBP homologous protein (CHOP) pathway, and apoptosis in response to ER stress. We observed that Prx1 overexpression inhibited the nuclear localization of XBP-1 and the expression of XBP-1 target genes and CHOP after thapsigargin (Tg) treatment to induce ER stress. In addition, Prx1 inhibited apoptosis and ROS production during ER stress. The ROS scavenger inhibited ER stress-induced apoptosis but did not affect XBP-1 activation and CHOP expression. Therefore, the biological role of Prx1 in ER stress may have important implications for ER stress-related diseases.

Yajun Shen,1 Haoyue Xu,2 Lingyu Li,1 Yunping Lu,1 Min Zhang,1 Xin Huang,2 Xiaofei Tang1 1Beijing Institute of Dental Research, Beijing Key Laboratory, Beijing Stomatological Hospital & School of Stomatology, Capital Medical University, Beijing, 100050, People’s Republic of China; 2Department of Oral and Maxillofacial Surgery, Beijing Stomatological Hospital & School of Stomatology, Capital Medical University, Beijing, 100050, People’s Republic of ChinaCorrespondence: Xiaofei TangDivision of Oral Pathology, Beijing Institute of Dental Research, Beijing Stomatological Hospital & School of Stomatology, Capital Medical University, No. 4 Tiantanxili, Dongcheng District, Beijing, 100050, People’s Republic of ChinaTel +86 01057099311Fax +86 01057099310Email xftang10@ccmu.edu.cnXin HuangDepartment of Oral and Maxillofacial Surgery, Beijing Stomatological Hospital & School of Stomatology, Capital Medical University, No. 4 Tiantan Xili, Dongcheng District, Beijing, 100050, People’s Republic of ChinaEmail huangxin@ccmu.edu.cnPurpose: The role of the peroxiredoxin (PRDX) family in oral squamous cell carcinoma (OSCC) remains unclear. This study aimed to investigate the expression of PRDXs and their effects on the prognosis in OSCC.Methods: The expression of PRDXs and their effects on prognosis were analysed in 216 OSCC samples from The Cancer Genome Atlas (TCGA) database. OSCC tissues and adjacent noncancerous tissues (ANTs) were obtained from 68 clinical patients. Quantitative real-time (qRT)-PCR, Western blot, and immunohistochemical (IHC) staining were used to verify the relationship between the expression level of PRDX1 and different clinical features. Gene set enrichment analysis (GSEA) was used to examine the molecular mechanism of PRDX1 in OSCC.Results: PRDX1 was found to be the only gene in PRDX family that highly expressed in OSCC samples and affected the prognosis of patients with OSCC. PRDX1 expression was significantly related to tumor stage, lymphatic metastasis, and pathological grade. A nomogram consisting of tumor stage, N stage, and PRDX1 level was constructed. GSEA showed that high expression of PRDX1 involved many cancer-related molecular functions and signaling pathways.Conclusion: PRDX1 may play an important role in the occurrence and development of OSCC, and may be a potential new target for OSCC treatment.Keywords: peroxiredoxin 1, oral squamous cell carcinoma, lymph node metastasis, prognosis, nomogram

Owing to its lipophilic nature, cypermethrin makes entry into the brain through the blood-brain barrier and causes severe damage to the nigrostriatal dopaminergic neurons after prolonged exposure. Following substantial accrual in the brain, cypermethrin induces the abnormal expression and accumulation of α-synuclein. Besides, cytochrome P450 2E1 (CYP2E1) causes free radical generation leading to lipid peroxidation in toxicant-induced parkinsonism. Conversely, 4-hydroxynonenal (4-HNE), a byproduct of lipid peroxidation, is known to contribute to neuronal damage. The current investigation aimed to explicate the participation of endogenous redox-sensitive proteins in cypermethrin-induced cellular and animal models of parkinsonism. The qualitative and quantitative expressions of selected redox-sensitive proteins were evaluated employing the standard procedures. Cypermethrin reduced the expression of peroxiredoxin 3 (Prx3), thioredoxin 2 (Trx2), and protein deglycase-1 (DJ-1). Knocking down of Prx3, Trx2, or DJ-1 further reduced the level of expression in the cypermethrin-treated group. Reduction in the expression of Prx3, Trx2, or DJ-1 was found to be associated with overexpression of α-synuclein and 4-HNE modification of proteins. Besides, cypermethrin increased the expression of CYP2E1, which was not altered after Prx3 or Trx2 knockdown. However, knocking down the DJ-1 augmented the level of CYP2E1 both in the cypermethrin-treated group and its respective control. The outcomes of the study demonstrate that cypermethrin reduces the level of Prx3, Trx2, and DJ-1 proteins. While the reduction in the expression of selected redox-sensitive proteins leads to α-synuclein overexpression and 4-HNE modification of proteins, DJ-1 attenuation is also linked with increased CYP2E1 expression, which in turn could lead to oxidative stress-mediated neuronal damage.

To explore gene expression and serum profile of selected antioxidant markers during periparturient period in dromedary camels, blood samples were collected from sixty apparently healthy pregnant female at − 14, 0, and + 14 days of expected date of delivery. Superoxide dismutase1 (SOD1), superoxide dismutase 3 (SOD3), catalase (CAT), peroxiredoxin 2 (PRDX2), peroxiredoxin 3 (PRDX3), peroxiredoxin 4 (PRDX4), peroxiredoxin 6 (PRDX6), glutathione peroxidase (GPX), and alkyl hydroperoxide reductase/thiol-specific antioxidant (AhpC/TSA) markers showed upregulations at (− 14) and (+ 14) compared to their values at calving. A significant upregulation of oxidative stress-responsive kinase 1 (OXSR1), stress-associated endoplasmic reticulum proteins (SERP2), and stress-induced phosphoprotein (STIP1) was also reported at (− 14) compared to their corresponding values at calving and (+ 14). At (− 14), serum GSH levels were low, and increased gradually until early lactation. Total antioxidant capacity (TAC) concentrations were low at (− 14) and at parturition, and the peak values were observed at (+ 14), whereas an opposite trend was noted for Malondialdehyde (MDA) levels. SOD activity was lower at (0) and (+ 14) compared to at (− 14). Glutathione peroxidase (GSH-Px) was also low at (0) and (+ 14) days postpartum compared to that at (− 14). Linear discriminant analysis (LDA) showed that gene expression and serum profile of antioxidant markers could discriminate peri-parturient period. The overall correctly classified percent was 62.0% and 48.1% for results of gene expression and serum parameters respectively. Profound alteration in antioxidant parameters could be a biomarker to that helps follow-up health during the peri-parturient period in order to minimize the incidence and severity of diseases and, consequently, to build up a good management protocol.

Transmission of reductive and oxidative cues from the photosynthetic electron transport chain to redox regulatory protein networks plays a crucial role in coordinating photosynthetic activities. The tight balance between these two signals dictates the cellular response to changing light conditions. While the role of reductive signals in activating chloroplast metabolism is well established, the role of their counterbalanced oxidative signals is still unclear, mainly due to monitoring difficulties. Here, we introduced chl-roGFP2-PrxΔCR, a 2-Cys peroxiredoxin-based biosensor, into Arabidopsis thaliana chloroplasts to monitor the dynamic changes in photosynthetically derived oxidative signaling. We showed that chl-roGFP2-PrxΔCR oxidation states reflected oxidation patterns similar to those of endogenous 2-Cys peroxiredoxin under varying light conditions. By employing a set of genetically encoded biosensors, we showed the induction of 2-Cys peroxiredoxin-dependent oxidative signals, throughout the day, under varying light intensities and their inverse relationship with NADPH levels, unraveling the combined activity of reducing and oxidizing signals. Furthermore, we demonstrated the induction of 2-Cys peroxiredoxin-derived oxidative signals during a dark–to–low-light transition and uncovered a faster increase in carbon assimilation rates during the photosynthesis induction phase in plants deficient in 2-Cys peroxiredoxins compared with wild type, suggesting the involvement of oxidative signals in attenuating photosynthesis. The presented data highlight the role of oxidative signals under nonstress conditions and suggest that oxidative signals measured by peroxiredoxin-based biosensors reflect the limitation to photosynthesis imposed by the redox regulatory system.

In chloroplasts, thiol-dependent redox regulation is linked to light since the disulfide reductase activity of thioredoxins (Trxs) relies on photo-reduced ferredoxin (Fdx). Furthermore, chloroplasts harbor an NADPH-dependent Trx reductase (NTR) with a joint Trx domain, termed NTRC. The activity of these two redox systems is integrated by the redox balance of 2-Cys peroxiredoxin (Prx), which is controlled by NTRC. However, NTRC was proposed to participate in redox regulation of additional targets, prompting inquiry into whether the function of NTRC depends on its capacity to maintain the redox balance of 2-Cys Prxs or by direct redox interaction with chloroplast enzymes. To answer this, we studied the functional relationship of NTRC and 2-Cys Prxs by a comparative analysis of the triple Arabidopsis (Arabidopsis thaliana) mutant, ntrc-2cpab, which lacks NTRC and 2-Cys Prxs, and the double mutant 2cpab, which lacks 2-Cys Prxs. These mutants exhibit almost indistinguishable phenotypes: in growth rate, photosynthesis performance, and redox regulation of chloroplast enzymes in response to light and darkness. These results suggest that the most relevant function of NTRC is in controlling the redox balance of 2-Cys Prxs. A comparative transcriptomics analysis confirmed the phenotypic similarity of the two mutants and suggested that the NTRC-2-Cys Prxs system participates in cytosolic protein quality control. We propose that NTRC and 2-Cys Prxs constitute a redox relay, exclusive to photosynthetic organisms that fine-tunes the redox state of chloroplast enzymes in response to light and affects transduction pathways towards the cytosol

Pasteurella multocida is an important zoonotic pathogen that causes multiple diseases in both animals and humans. Test of good immunogenic proteins is beneficial for vaccine development and disease control. In the present study, we determined four novel immunogenic proteins of P. multocida by using 2-DE MALDI-TOF MS with immune serum. These four proteins included a trimethylamine-N-oxide reductase TorA, a translation elongation factor Ts, a phosphoglyceromutase PGAM, and a peroxiredoxin PrX. Among these proteins, TorA, Prx, and PGAM were successfully expressed by using E. coli. Western-blotting assays showed that recombinant TorA, Prx, and/or PGAM displayed good reactions with infectious sera of P. multocida serogroups A, B, D and F. Immunization of either rTorA, rPrx, and/or rPGAM induced significantly high levels of antibodies as well as IFN-γ, IL-4 and IL-10 in mice (P 0.01). Protective efficacy tests revealed that vaccination of either rTorA, rPrx, and/or rPGAM protected 60% ~ 80% of the tested mice against the challenge with P. multocida field isolate. Our results obtained from the present study suggest that these three proteins could be tested as good vaccine candidates against P. multocida infections.

Introduction. The fundamental mechanisms of the body's pathological reaction to coal and dust exposure are hypoxia, excessive activation of free radical processes, structural and metabolic disorders in various organs. Organ-specific molecular defense mechanisms begin to function in the form of changes in the level of proteins with antihypoxic (HIF-3a), chaperone (HSP72), and antioxidant functions (HOx-1 — heme-oxygenase, Prx-1 — peroxiredoxin) under damaging effects. Its high level contributes to the restoration of cells' functional state or indicates significant damage in tissues. Hypoxia and free radical processes are known to lead to severe brain damage and behavioral disorders. To date, little is known about the expression of protective proteins and morphological changes in the brain under prolonged exposure to coal-rock dust on the body. The study aimed to learn the level of intracellular protective proteins HIF-3a, HSP72, HOx-1, Prx-1, and morphological changes in the brain in the dynamics of long-term dust exposure. Materials and methods. Sixty white male Wistar rats weighing 200-250 g of the same age took part in the experiment. Dust exposure was modeled by way of dynamic inhalation priming of rats with coal-rock dust (coal of a gas-fat brand) in an intermittent mode for 12 weeks. We perform morphological studies of the brain after 1, 3, 6, 9, and 12 weeks of dust exposure. The cytosolic fraction of brain tissue researchers determined the expression level of HIF-3a, HSP72, HOx-1, and Prx-1 by Western blot analysis. We selected the activity of free radical processes in the brain tissue. Results. Long-term exposure to coal-rock dust on the body at the morphological level in the brain revealed changes that indicate the development of hypoxia and activation of free radical processes: microvascular disorders, pericellular edema, severe dystrophic damage to neurons, focal loss of neurons, activation of glial cells. Activation of the protective proteins HIF-3a, HSP72, HOx-1, and Prx-1 in the early stages (1–3 weeks) of coal-dust exposure provided compensation for free radical processes in brain neurons. An increase in the duration of dust exposure of more than six weeks influences a low level of HSP72, but high HIF-3a and Prx-1, indicating an increase in hypoxic and free radical damage brain. Conclusions. The results obtained to expand the understanding of the morphological and molecular mechanisms that occur in the brain tissue during prolonged dust exposure to the body are essential for developing methods for organ-specific pharmacological correction. Ethics. We keep, fed and remove the animals from the experiment by the requirements of the guidelines of the Ministry of Health and Social Development of the Russian Federation "On Approval of the Rules of Laboratory Practice" (No. 199n of 01.04.2016), as well as the Guide for the Care and Use of Laboratory Animals (Guide for the Care and Use of Laboratory Animals, 1996). The study was approved by the Bioethical Committee of the Research Institute of Complex Problems of Hygiene and Occupational Diseases (Protocol No. 2 of October 25, 2018).

Melatonin (MT) has been reported to regulate certain plant physiological processes and promote tolerance to different environmental stresses such as salinity. Green bean (Phaseolus vulgaris L. cv. Royal Nel) seedlings were exposed to 200 mM NaCl with or without pre-treatment with 150 μM MT. Salt stress led to a lower chlorophyll content, a reduced photosynthetic activity, increased reactive oxygen species (ROS) contents, and decreased photosystem II (PSII) activity. The application of exogenous MT to green bean seedlings under salt stress improved photosynthetic activity and alleviated the oxidative damages by enhancing the activity of antioxidant enzymes. The expression of catalase (CAT1), glutathione reductase (GR), superoxide dismutase (CuZnSOD1), ascorbate peroxidase (APX), Peroxiredoxin Q (PrxQ), and 2-cysteine peroxiredoxin (2-Cys-Prx) encoding genes was significantly increased under salt stress in green bean seedling compared with the untreated control. However, plants treated with exogenous MT and NaCl had 28.8, 21.1, 26.1, 20, 26.2, and 22.4% higher CuZnSOD, CAT1, APX, GR, PrxQ, and 2-Cys-Prx transcript levels, respectively, compared to NaCl stress alone. Our study revealed the protective mechanisms mediated by exogenous MT application in NaCl stress alleviation and our findings could be used in the management of green bean cultivation in salinity-prone soils.

International audience; Stomatal movements via the control of gas exchanges determine plant growth in relation to environmental stimuli through a complex signalling network involving reactive oxygen species that lead to post‐translational modifications of Cys and Met residues, and alter protein activity and/or conformation. Thiol‐reductases (TRs), which include thioredoxins, glutaredoxins (GRXs) and peroxiredoxins (PRXs), participate in signalling pathways through the control of Cys redox status in client proteins. Their involvement in stomatal functioning remains poorly characterized. By performing a mass spectrometry‐based proteomic analysis, we show that numerous thiol reductases, like PRXs, are highly abundant in guard cells. When investigating various Arabidopsis mutants impaired in the expression of TR genes, no change in stomatal density and index was noticed. In optimal growth conditions, a line deficient in cytosolic NADPH‐thioredoxin reductases displayed higher stomatal conductance and lower leaf temperature evaluated by thermal infrared imaging. In contrast, lines deficient in plastidial 2‐CysPRXs or type‐II GRXs exhibited compared to WT reduced conductance and warmer leaves in optimal conditions, and enhanced stomatal closure in epidermal peels treated with abscisic acid or hydrogen peroxide. Altogether, these data strongly support the contribution of thiol redox switches within the signalling network regulating guard cell movements and stomatal functioning.

Peroxiredoxin IV (Prx4), a typical two-cysteine-containing member of the peroxidase family, functions as an antioxidant to maintain cellular redox homeostasis through the reduction of reactive oxygen species (ROS) via cycles of oxidation–reduction reactions. Under oxidative stress, all Prxs including Prx4 are inactivated as their catalytic cysteines undergo hyperoxidation, and hyperoxidized two-cysteine Prxs can be exclusively repaired and revitalized through the reduction cycle catalyzed by sulfiredoxin (Srx). Previously, we showed that Prx4 is a preferred substrate of Srx, and knockout of Srx in mice leads to resistance to azoxymethane/dextran sulfate sodium (AOM/DSS)-induced colon carcinogenesis. To further understand the significance of the Srx/Prx4 axis in colorectal cancer development, Prx4−/− mice were established and subjected to standard AOM/DSS protocol. Compared with wildtype littermates, mice with Prx4−/− genotype had significantly fewer and smaller tumors. Histopathological analysis revealed that loss of Prx4 leads to increased cell death through lipid peroxidation and lower infiltration of inflammatory cells in the knockout tumors compared to wildtype. Treatment with DSS alone also showed decreased infiltration of macrophages and lymphocytes in the colon of knockout mice, suggesting a role for Prx4 in inflammatory response. In addition, loss of Prx4 caused alterations in plasma cytokines and chemokines after DSS and AOM/DSS treatments. These findings suggest that loss of Prx4 protects mice from AOM/DSS-induced colon tumorigenesis. Thus, targeting Prx4 may provide novel strategies for colon cancer prevention and treatment.

The molecular mechanism of high-temperature stress (HTS) response, in plants, has so far been investigated using transcriptomics, while the dynamics of HTS-responsive proteome remain unexplored. We examined the adaptive responses of the resilient wheat cultivar 'Unnat Halna' and dissected the HTS-responsive proteome landscape. This led to the identification of 55 HTS-responsive proteins (HRPs), which are predominantly involved in metabolism and defense pathways. Interestingly, HRPs included a 2-cysteine peroxiredoxin (2CP), designated Ta2CP, presumably involved in stress perception and adaptation. Complementation of Ta2CP in yeast and heterologous expression in Arabidopsis demonstrated its role in thermotolerance. Both Ta2CP silencing and overexpression inferred the involvement of Ta2CP in plant growth and chlorophyll biosynthesis. We demonstrated that Ta2CP interacts with protochlorophyllide reductase b, TaPORB. Reduced TaPORB expression was found in Ta2cp-silenced plants, while upregulation was observed in Ta2CP-overexpressed plants. Furthermore, the downregulation of Ta2CP in Taporb-silenced plants and reduction of protochlorophyllide in Ta2cp-silenced plants suggested the key role of Ta2CP in chlorophyll metabolism. Additionally, the transcript levels of AGPase1 and starch were increased in Ta2cp-silenced plants. More significantly, HTS-treated Ta2cp-silenced plants showed adaptive responses despite increased reactive oxygen species and peroxide concentrations, which might help in rapid induction of high-temperature acclimation.

Various proteins in plant chloroplasts are subject to thiol-based redox regulation, allowing light-responsive control of chloroplast functions. Most redox-regulated proteins are known to be reductively activated in the light in a thioredoxin (Trx)-dependent manner, but its regulatory network remains incompletely understood. Using a biochemical procedure, we here show that a specific form of phosphofructokinase (PFK) is a novel redox-regulated protein whose activity is suppressed upon reduction. PFK is a key enzyme in the glycolytic pathway. In Arabidopsis thaliana, PFK5 is targeted to chloroplasts and uniquely contains an insertion sequence harboring two Cys residues (Cys152 and Cys157) in the N-terminal region. Redox shift assays using a thiol-modifying reagent indicated that PFK5 is efficiently reduced by a specific type of Trx, namely, Trx-f. PFK5 enzyme activity was lowered with the Trx-f-dependent reduction. PFK5 redox regulation was bidirectional; PFK5 was also oxidized and activated by the recently identified Trx-like2/2-Cys peroxiredoxin pathway. Mass spectrometry-based peptide mapping analysis revealed that Cys152 and Cys157 are critical for the intramolecular disulfide bond formation in PFK5. The involvement of Cys152 and Cys157 in PFK5 redox regulation was further supported by a site-directed mutagenesis study. PFK5 catalyzes the reverse reaction of fructose 1,6-bisphosphatase (FBPase), which is reduced and activated specifically by Trx-f. Our data suggest that PFK5 redox regulation, together with that of FBPase, constitutes a checkpoint for switching light/dark metabolism in chloroplasts.

Objectives Synthetic biology has emerged from molecular biology and engineering approaches and aims to develop novel, biologically-inspired systems for industrial and basic research applications ranging from biocomputing to drug production. Surprisingly, redoxin (thioredoxin, glutaredoxin, peroxiredoxin) and other thiol-based redox systems have not been widely utilized in many of these synthetic biology applications. Methods We reviewed thiol-based redox systems and the development of synthetic biology applications that have used thiol-dependent parts. Results The development of circuits to facilitate cytoplasmic disulfide bonding, biocomputing and the treatment of intestinal bowel disease are amongst the applications that have used thiol-based parts. We propose that genetically encoded redox sensors, thiol-based biomaterials and intracellular hydrogen peroxide generators may also be valuable components for synthetic biology applications. Discussion Thiol-based systems play multiple roles in cellular redox metabolism, antioxidant defense and signaling and could therefore offer a vast and diverse portfolio of components, parts and devices for synthetic biology applications. However, factors limiting the adoption of redoxin systems for synthetic biology applications include the orthogonality of thiol-based components, limitations in the methods to characterize thiol-based systems and an incomplete understanding of the design principles of these systems.

Molecular modelling and design are valued and vital tools in the pharmaceutical research for defining, developing and analyzing active biological and chemical molecules. It is based on the evolution of computational theories and methods to study molecules behavior enabling scientists to hypothesize potent drugs for a particular disease. Quercetin is one of the flavonoid family that possesses pharmacological properties due to its interface with cellular targets including, anti-inflammatory, anti-oxidant, anti-cytotoxicity and anti-cancer activities. Molecular docking analyses were performed to predicted quercetin possible binding action along with absorption, distribution, metabolism and excretion (ADME) study. The molecular docking results revealed the bind of quercetin to the active site of Serine/threonine mammalian sterile-20 (MST3) and peroxiredoxin 5 pockets. Moreover, ADME results show its vital properties absorption and drug mimic where the ability to enter blood brain barrier (BBB) was not high, low permeable and strongly bound. Pre-metabolism analyze results show that 2D9 liver microsomal enzyme has more effect on quercetin than CYP2D6 enzymes. In conclusion, molecular docking study documented some important mechanisms of quercetin as a promising anticancer and antioxidant compound.

The dithiocarbamate fungicide maneb (MB) has attracted interest due to increasing concern of the negative health effects of pesticides, as well as its association with Parkinson’s disease (PD). Our laboratory has previously reported distinct phenotypic changes of neuroblastoma cells exposed to acute, sub-toxic levels of MB, including decreased mitochondrial respiration, altered lactate dynamics, and metabolic stress. In this study, we aimed to further define the specific molecular mechanisms of MB toxicity through the comparison of several thiol-containing compounds and their effects on cellular energy metabolism and thiol redox nodes. Extracellular flux analyses and stable isotope labeled tracer metabolomics were employed to evaluate alterations in energy metabolism of SK-N-AS human neuroblastoma cells after acute exposure of an array of compounds, including dithiocarbamates (maneb, nabam, zineb) and other thiol-containing small molecules (glutathione, N-acetylcysteine). These studies revealed MB and its methylated form (MeDTC) as unique toxicants with significant alterations to mitochondrial respiration, proliferation, and glycolysis. We observed MB to significantly impact cellular thiol redox status by oxidizing cellular glutathione and altering the thiol redox status of peroxiredoxin 3 (Prx3, mitochondrial) after acute exposure. Redox Western blotting revealed a MB-specific modification of cellular Prx3, strengthening the argument that MB can preferentially target mitochondrial enzymes containing reactive cysteine thiols. Further, stable isotope tracer metabolomics confirmed our energetics assessments, and demonstrated that MB exposure results in acute derangement of central carbon metabolism. Specifically, we observed shunting of cellular glucose into the pentose-phosphate pathway and reduction of TCA intermediates derived from glucose and glutamine. Also, we report novel lactate utilization for TCA enrichment and glutathione synthesis after MB exposure. In summary, our results further confirm that MB exerts its toxic effects via thiol modification, and significantly transforms central carbon metabolism.

Peroxiredoxins (Prxs) are cysteine-based peroxide-reducing enzymes that have been extensively studied over the past two decades. The reduction of the Prx disulfide form is dependent on electron donating enzymes to shift the Prx back into a catalytically active state. However, this reaction is poorly understood and reductant enzymes for this reaction to reduce the Prx disulfide bond have received little attention. Prxs from the bacterium Xanthomonas campestris (XcPrxQ) were used to assess how reductants affect Prx turnover by identifying potential electron transfer interactions between Prxs and reductants, Glutaredoxins (Grxs) and Thioredoxins (Trxs). To examine potential interactions between PrxQ and reducing proteins, we used PrxQ, Grx, and Trx mutants to determine the effect of specific cysteines in each of the proteins. Mutant and wildtype proteins were expressed in E. coli and purified using anion-exchange and gel filtration chromatography and purity was verified by SDS-PAGE. The results clarified the role of the two cysteines in PrxQ, C48 and C84, which are thought to participate in the reduction reaction of hydrogen peroxide. They also show Trx and Grx proteins from the same bacterium are possible reductants for Prx turnover, as reactions with PrxQ have produced complex formation at a larger molecular weight, suggesting the reductant binding to PrxQ and reducing its disulfide bond. This study is significant because it reveals potential binding interactions between reductants and Prxs that regulate Prx turnover into a catalytically active state, allowing the enzyme to break down peroxide and prevent oxidative damage, as well as highlighting Trxs in bacteria as a potential drug target due to their regulation of hydrogen peroxide levels in pathogenic strains.

Responding appropriately to exercise is essential to maintenance of skeletal muscle mass and function at all ages and particularly during aging. Here, a hypothesis is presented that a key component of the inability of skeletal muscle to respond effectively to exercise in aging is a denervation-induced failure of muscle redox signalling. This novel hypothesis proposes that an initial increase in oxidation in muscle mitochondria leads to a paradoxical increase in the reductive state of specific cysteines of signalling proteins in the muscle cytosol that suppresses their ability to respond to normal oxidising redox signals during exercise. The following are presented for consideration:Transient loss of integrity of peripheral motor neurons occurs repeatedly throughout life and is normally rapidly repaired by reinnervation, but this repair process becomes less efficient with aging. Each transient loss of neuromuscular integrity leads to a rapid, large increase in mitochondrial peroxide production in the denervated muscle fibers and in neighbouring muscle fibers. This peroxide may initially act to stimulate axonal sprouting and regeneration, but also stimulates retrograde mitonuclear communication to increase expression of a range of cytoprotective proteins in an attempt to protect the fiber and neighbouring tissues against oxidative damage. The increased peroxide within mitochondria does not lead to an increased cytosolic peroxide, but the increases in adaptive cytoprotective proteins include some located to the muscle cytosol which modify the local cytosol redox environment to induce a more reductive state in key cysteines of specific signalling proteins. Key adaptations of skeletal muscle to exercise involve transient peroxiredoxin oxidation as effectors of redox signalling in the cytosol. This requires sensitive oxidation of key cysteine residues. In aging, the chronic change to a more reductive cytosolic environment prevents the transient oxidation of peroxiredoxin 2 and hence prevents essential adaptations to exercise, thus contributing to loss of muscle mass and function. Experimental approaches suitable for testing the hypothesis are also outlined., Graphical abstract Image 1, Highlights • It is hypothesised that denervation leads to failed redox signalling and attenuated muscle exercise responses in aging. • Loss of peripheral motor neurons leads to increased mitochondrial peroxide in denervated and neighbouring muscle fibers. • This peroxide stimulates increased expression of cytoprotective proteins to protect the fiber against oxidative damage. • Increased mitochondrial peroxide does not increase cytosolic peroxide, but adaptations reduce the cytosol redox state. • Key adaptations of skeletal muscle to exercise involve transient peroxiredoxin oxidation in the cytosol. • Peroxiredoxin oxidation is suppressed during aging by a chronic change to a more reductive local cytosolic environment.

Oxidative stress has been implied in cellular injury even in the early phases of multiple sclerosis (MS). In this study, we quantified levels of biomarkers of oxidative stress and antioxidant capacity in cerebrospinal fluid (CSF) in newly diagnosed MS patients and their associations with brain atrophy and iron deposits in the brain tissue. Consecutive treatment-naive adult MS patients (n = 103) underwent brain MRI and CSF sampling. Healthy controls (HC, n = 99) had brain MRI. CSF controls (n = 45) consisted of patients with non-neuroinflammatory conditions. 3T MR included isotropic T1 weighted (MPRAGE) and gradient echo (GRE) images that were processed to quantitative susceptibility maps. The volume and magnetic susceptibility of deep gray matter (DGM) structures were calculated. The levels of 8-hydroxy-2′-deoxyguanosine (8-OHdG), 8-iso prostaglandin F2α (8-isoPG), neutrophil gelatinase-associated lipocalin (NGAL), peroxiredoxin-2 (PRDX2), and malondialdehyde and hydroxyalkenals (MDA + HAE) were measured in CSF. Compared to controls, MS patients had lower volumes of thalamus, pulvinar, and putamen, higher susceptibility in caudate nucleus and globus pallidus, and higher levels of 8-OHdG, PRDX2, and MDA + HAE. In MS patients, the level of NGAL correlated negatively with volume and susceptibility in the dentate nucleus. The level of 8-OHdG correlated negatively with susceptibility in the caudate, putamen, and the red nucleus. The level of PRDX2 correlated negatively with the volume of the thalamus and both with volume and susceptibility of the dentate nucleus. From MRI parameters with significant differences between MS and HC groups, only caudate susceptibility and thalamic volume were significantly associated with CSF parameters. Our study shows that increased oxidative stress in CSF detected in newly diagnosed MS patients suggests its role in the pathogenesis of MS.

Environmental oxidative stress threatens cellular integrity and should therefore be avoided by living organisms. Yet, relatively little is known about environmental oxidative stress perception. Here, using microfluidics, we showed that like I2 pharyngeal neurons, the tail phasmid PHA neurons function as oxidative stress sensing neurons in C. elegans, but display different responses to H2O2 and light. We uncovered that different but related receptors, GUR-3 and LITE-1, mediate H2O2 signaling in I2 and PHA neurons. Still, the peroxiredoxin PRDX-2 is essential for both, and might promote H2O2-mediated receptor activation. Our work demonstrates that C. elegans can sense a broad range of oxidative stressors using partially distinct H2O2 signaling pathways in head and tail sensillae, and paves the way for further understanding of how the integration of these inputs translates into the appropriate behavior.Graphical abstract

The involvement of peroxisomes in cellular hydrogen peroxide (H2O2) metabolism has been a central theme since their first biochemical characterization by Christian de Duve in 1965. While the role of H2O2 substantially changed from an exclusively toxic molecule to a signaling messenger, the regulatory role of peroxisomes in these signaling events is still largely underappreciated. This is mainly because the number of known protein targets of peroxisome-derived H2O2 is rather limited and testing of specific targets is predominantly based on knowledge previously gathered in related fields of research. To gain a broader and more systematic insight into the role of peroxisomes in redox signaling, new approaches are urgently needed. In this study, we have combined a previously developed Flp-In T-REx 293 cell system in which peroxisomal H2O2 production can be modulated with a yeast AP-1-like-based sulfenome mining strategy to inventory protein thiol targets of peroxisome-derived H2O2 in different subcellular compartments. By using this approach, we identified more than 400 targets of peroxisome-derived H2O2 in peroxisomes, the cytosol, and mitochondria. We also observed that the sulfenylation kinetics profiles of key targets belonging to different protein families (e.g., peroxiredoxins, annexins, and tubulins) can vary considerably. In addition, we obtained compelling but indirect evidence that peroxisome-derived H2O2 may oxidize at least some of its targets (e.g., transcription factors) through a redox relay mechanism. In conclusion, given that sulfenic acids function as key intermediates in H2O2 signaling, the findings presented in this study provide valuable insight into how peroxisomes may be integrated into the cellular H2O2 signaling network.

A new series of 4-(3-(2-amino-3,5-dibromophenyl)-1-(4-substitutedbenzoyl)-4,5-dihydro-1H-pyrazol-5-yl)benzonitrile (4a-h) compounds were synthesized and evaluated for in-vitro anti-inflammatory activities. The spectral (IR, NMR) and elemental analyses data of the product indicated the formation of new pyrazoles 4a-h. Compound 4e exhibited potent anti-inflammatory property with 85.45 % inhibitions. This value was compared with standard diclofenac sodium. This data is explained using molecular docking analysis of receptor-ligand binding. These results demonstrated that pyrazole derivatives are potential inhibitors of Human Peroxiredoxin 5 and Tyrosine kinase receptor in the treatment of inflammation related illness.

Continuous and sustained production of good quality eggs and larvae is required to have economically viable and ecologically sustainable rearing of Seriola rivoliana. Nonetheless, the complete production cycle of these species has been challenging to achieve due to high mortality during embryonic and larval stages. The objective of the project was to study the expression of the proteins involved in the embryonic process of almaco jack. Proteomic characterization of fertilized eggs was performed using two-dimensional electrophoresis and mass spectrometry. Different vitellogenin proteins A, B, C and Ab, β-actin, peroxiredoxin, superoxide dismutase 1, alpha subunit proteasome, and keratin II were identified to their functions related to embryonic development, energy metabolism, protein synthesis, cell structure, cytoskeleton, and antioxidant proteins with defense enzymatic activity.

Peroxiredoxins (Prxs) are crucial antioxidant proteins that protect against biotic and abiotic stresses in many organisms, ranging from bacteria to mammals. In the present work, a novel 2-Cys Peroxiredoxin gene (PmPrxn), which contains a 153 bp 5'-terminal untranslated region (5'-UTR), a 636 bp open reading frame encoding a protein with 211 amino acids, and an 898 bp 3'-UTR, was successfully identified and characterized in the black tiger shrimp, Penaeus monodon. Tissue-specific expression analysis revealed that the PmPrxn mRNA was ubiquitously expressed and was comparatively highly expressed in the hepatopancreas. To explore the immunity-related and anti-stress roles of PmPrxn, the gills and hepatopancreas were chosen as target tissues in P. monodon and challenged with Vibrio harveyi, Streptococcus agalactiae, and toxic environmental stressors. The results indicate that PmPrxn might play a vital role in response to biotic and abiotic stresses. Furthermore, the antimicrobial and heavy metal toxicity stress-resistance properties of PmPrxn were evaluated and investigated in vitro using a prokaryotic expression system. These results provide useful information that will help further understand the functional mechanisms of PmPrxn in the defense against bacterial pathogens and environmental acute stresses in shrimp.

Skeletal muscle generates superoxide during contractions which is rapidly converted to H2O2. This molecule has been proposed to activate signalling pathways and transcription factors that regulate key adaptive responses to exercise but the concentration of H2O2 required to oxidise and activate key signalling proteins in vitro is much higher than the intracellular concentration in muscle fibers following exercise. We hypothesised that Peroxiredoxins (Prx), which reacts with H2O2 at the low intracellular concentrations found in muscle, would be rapidly oxidised in contracting muscle and hence potentially transmit oxidising equivalents to downstream signalling proteins as a method for their oxidation and activation. The aim of this study was to characterise the effects of muscle contractile activity on the oxidation of Prx1, 2 and 3 and determine if these were affected by aging. Prx1, 2 and 3 were all rapidly and reversibly oxidised following treatment with low micromolar concentrations of H2O2 in C2C12 myotubes and also in isolated mature flexor digitalis brevis fibers from adult mice following a protocol of repeated isometric contractions. Significant oxidation of Prx2 was seen within 1 min (i.e. after 12 contractions), whereas significant oxidation was seen after 2 min for Prx1 and 3. In muscle fibers from old mice, Prx2 oxidation was significantly attenuated following contractile activity. Thus we show for the first time that Prx are rapidly and reversibly oxidised in response to contractile activity in skeletal muscle and hypothesise that these proteins act as effectors of muscle redox signalling pathways which are key to adaptations to exercise that are attenuated during aging., Graphical abstract Image 1, Highlights • Hydrogen peroxide is generated by skeletal muscle during contractions. • Peroxiredoxins (Prx) react with H2O2 at the physiological levels generated during contractions. • Prx 1–3 are all oxidised by H2O2 and contractile activity in muscle fibers. • Prx2 oxidation during contractions is attenuated in muscle fibers from old mice. • Prx may act as effectors in activation of redox-regulated adaptations to contractile activity in muscle.

Neoporphyra haitanensis is an economically important red seaweed that inhabits upper intertidal zones. The thallus tolerates extreme fluctuating environmental stresses (e.g., surviving more than 80% water loss during low tides). To elucidate the global molecular responses relevant to this outstanding desiccation tolerance, a quantitative proteomics analysis of N. haitanensis under different desiccation treatments as well as rehydration was performed. According to the clustering of expression patterns and the functional interpretation of the 483 significantly differentially expressed proteins, a three-stage cellular response to desiccation stress and subsequent rehydration was proposed. Stage I: at the beginning of water loss, multiple signal transduction pathways were triggered including lipid signaling, protein phosphorylation cascades, and histone acetylation controlling acetate biosynthesis to further modulate downstream hormone signaling. Protein protection by peptidyl-prolyl isomerase and ROS scavenging systems were also immediately switched on. Stage II: with the aggravation of stress, increases in antioxidant systems, the accumulation of LEA proteins, and the temporary biosynthesis of branched starch were observed. Multiple enzymes involved in redox homeostasis, including peroxiredoxin, thioredoxin, ascorbate peroxidase, superoxide dismutase, glutathione peroxidase, and glutathione reductase, were hypothesized to function in specific cellular compartments. Stage III: when the desiccated thalli had rehydrated for 30 mins, photosynthesis and carbon fixation were recovered, and antioxidant activities and protein structure protection were maintained at a high level. This work increases the understanding of the molecular responses to environmental stresses via a proteomic approach in red seaweeds and paves the way for further functional studies and genetic engineering.

Background Endometriosis (EMT) is a common occurrence in women of reproductive age. Since oxidative stress has been associated with the development and/or progression of the disease, the present study was conducted to detect the expression of peroxiredoxin (PRX) isoforms, including PRX1, PRX2, and PRX3. Methods Fifty-two patients with ovarian endometriosis cysts and 47 controls were included in the study. Serum levels of PRXs were detected by enzyme-linked immunosorbent assay, and the expression of PRX in the endometrium was examined by immunohistochemistry. Results Serum PRX1, PRX2, and PRX3 were significantly lower in EMT patients than in controls. The expression of the three isoforms was significantly decreased in ectopic endometrium compared to that in eutopic or control endometrium. There was no difference in PRX expression between eutopic endometrium of EMT patients and control endometrium, and no association was found between serum PRX levels and immunostaining scores. Conclusion Our results are the first report that PRXs are downregulated in EMT patients, which suggests that PRXs are involved in the oxidative state of the disease.

[Aims] To reveal the molecular mechanism of endophytic bacteria in Verticillium wilt-resistant cottons and deeply understand the interaction between soil and plants. [Methods] Active tracking screening was used for the isolation of antagonistic strain. Morphological and molecular analyses were conducted to determine its phenotypic and genotypic characteristics. MALDI-TOF/TOF MS was employed to identify the antifungal substance. Functional verification was performed by gene cloning, expression, knockout and complementation. [Results] Enterobacter sp. V1 was isolated from Verticillium-wilt-resistant cotton Xinhai 15, which showed significantly antagonistic abilities against cotton verticillium wilt. A peroxiredoxin named ProV1 with virulent against V. dahliae was obtained. The gene for the peroxiredoxin ProV1 was cloned, and the nucleotide sequence showed 85.5% similarity with peroxiredoxin C (WP 096152328) reported from E. hormaeche. The purified heterologously expressed ProV1 indicated strong inhibitory activities. Moreover, the suppression of V. dahliae also decreased in proV1 mutant strain compared with wild type strain. The inhibitory activities could be partially restored by a complementation of proV1 gene in the mutant strain. [Conclusion] The results of this study reveal that a novel peroxiredoxin from an endophytic bacterial strain Enterobacter sp. V1 can serve as a virulent factor against fungi V. dahliae, which helps understanding the interaction between endyphytic bacteria and plant pathogenic fungi, and improving the biological control of cotton Verticillium wilt.

AhpC is a bacterial representative of 2-Cys peroxiredoxins (Prxs) with broad substrate specificity and functional plasticity. However, details underpinning these two important attributes of AhpC remain unclear. Here, we studied the functions and mechanisms of regulation of AhpC in the facultative Gram-negative anaerobic bacterium Shewanella oneidensis, in which AhpC's physiological roles can be conveniently assessed through its suppression of a plating defect due to the genetic loss of a major catalase. We show that successful suppression can be achieved only when AhpC is produced in a dose- and time-dependent manner through a complex mechanism involving activation of the transcriptional regulator OxyR, transcription attenuation, and translation reduction. By analyzing AhpC truncation variants, we demonstrate that reactivity with organic peroxides (OPs) rather than H2O2 is resilient to mutagenesis, implying that OP reduction is the core catalytic function of AhpC. Intact AhpC could be recycled only by its cognate reductase AhpF, and AhpC variants lacking the Prx domain or the extreme C-terminal five residues became promiscuous electron acceptors from the thioredoxin reductase TrxR and the GSH reductase Gor in addition to AhpF, implicating an additional dimension to functional plasticity of AhpC. Finally, we show that the activity of S. oneidensis AhpC is less affected by mutations than that of its Escherichia coli counterpart. These findings suggest that the physiological roles of bacterial AhpCs are adapted to different oxidative challenges, depending on the organism, and that its functional plasticity is even more extensive than previously reported.

Ebselen is an organoselenium compound exhibiting hydroperoxide- and peroxynitrite-reducing activity, acting as a glutathione peroxidase and peroxiredoxin enzyme mimetic. Ebselen reacts with a multitude of protein thiols, forming a selenosulfide bond, which results in pleiotropic effects of antiviral, antibacterial and anti-inflammatory nature. The main protease (Mpro) of the corona virus SARS-CoV-2 is a potential drug target, and a screen with over 10,000 compounds identified ebselen as a particularly promising inhibitor of Mpro (Jin, Z. et al. (2020) Nature 582, 289–293). We discuss here the reaction of ebselen with cysteine proteases, the role of ebselen in infections with viruses and with other microorganisms. We also discuss effects of ebselen in lung inflammation. In further research on the inhibition of Mpro in SARS-CoV-2, ebselen can serve as a promising lead compound, if the inhibitory effect is confirmed in intact cells in vivo. Independently of this action, potential beneficial effects of ebselen in COVID-19 are ascribed to a number of targets critical to pathogenesis, such as attenuation of inflammatory oxidants and cytokines., Graphical abstract Image 1, Highlights • Ebselen, an organoselenium compound, exhibits anti-inflammatory and antiviral activity. • Ebselen is a glutathione peroxidase and peroxiredoxin mimetic. • Ebselen reacts with a multitude of protein thiols, resulting in pleiotropic effects. • Ebselen is an effective inhibitor of Mpro, the main protease of SARS-CoV-2. • Ebselen may serve as lead compound for drugs targeting COVID-19.

The pine wood nematode (PWN), Bursaphelenchus xylophilus (Steiner & Buhrer) Nickle, is the pathogen of pine wilt disease (PWD) which can devastate forests. PWN can be of high or low severity and the mechanisms underlying the differences in virulence are unclear. Therefore, it is necessary to study the relationship between differentiation of PWN severity and its resistance to the main defensive substances of pine species (i.e., α-pinene and H2O2). The feeding rate and fecundity of PWN was examined at different levels of virulence under conditions of α-pinene and H2O2 stress. Moreover, the expression patterns of the main resistance genes of PWN with different virulence were determined under conditions of α-pinene and H2O2 stress. The feeding rate and fecundity of the high virulence strain AMA3 were higher than those of the low virulence strain YW4. The expression levels of the autophagy gene BxATG5, cytochrome P450 gene BxCYP33D3, and glutathione S-transferase genes BxGST1 and BxGST3 in AMA3 increased significantly upon exposure to α-pinene for 2 h, while these genes showed smaller degrees of upregulation in YW4. Under conditions of H2O2 stress, the expression levels of BxATG5, catalase genes Bxy-ctl-1and Bxy-ctl-2, and the 2-cysteine peroxiredoxin gene BxPrx in AMA3 were higher than those in YW4. These findings suggest that high virulence PWN has greater resistance to pine defensive substances α-pinene and H2O2 than low virulence PWN, and resistance genes mediate the differential resistance of PWN strains. This study will contribute to the clarification of the mechanism underlying virulence differentiation of PWN and will advance understanding of the pathogenic mechanism of PWD.

Peroxiredoxin (Prx) refers to a family of thiol-dependent peroxidases that decompose hydrogen peroxide, lipid hydroperoxides, as well as peroxynitrite, and protect against oxidative and inflammatory stress. There are six mammalian Prx isozymes (Prx1-6), classified as typical 2-Cys, atypical 2-Cys, or 1-Cys Prxs based on the mechanism and the number of cysteine residues involved during catalysis. In addition to their well-established peroxide-scavenging activity, some Prxs also participate in the regulation of various cell signaling pathways. Extensive animal studies employing primarily gene knockout models provide substantial evidence supporting a critical protective role of Prxs in various disease processes involving oxidative and inflammatory stress. This review surveys recent research findings, published primarily in influential journals, on the involvement of various Prx isozymes in protecting against cardiovascular injury and related disorders, including diabetes, metabolic syndromes, and sepsis, whose pathophysiology all intimately involves oxidative stress and inflammation.

Vitex peduncularis, belongs to the Verbenaceae family, locally known as ‘Boruna’, ‘Horina’, ‘Ashmul gaas’, is commonly used for treating various chronic diseases in the folk medicine such as malarial fevers, jaundice, diabetes, chest pain, joint ache, abnormality in eyes & face, and urethritis, etc. In the present study, we investigated the anxiolytic, sedative, and antioxidant activities of ethanol extract of V. peduncularis leaves (EEVP) in both in vivo and in vitro models. Then, a molecular docking analysis was carried out to determine the possible lead compounds of EEVP for the biological properties described above. The anxiolytic and sedative activity of EEVP was determined using hole board and hole cross tests, respectively. Antioxidant activity was measured using DPPH and FRPA assays, whereas docking was done by using the Schrodinger suite (Maestro v10.1). Our result demonstrated that EEVP has significant and dose-dependent anxiolytic and sedative activity at the doses of 200 and 400 mg/kg (b.w.) in both models. This study also exhibited that EEVP has significant antioxidant activity compared to reference standard ascorbic acid. The molecular docking study revealed that 3,4-dihydroxybenzoic acid, 4-hydroxybenzoic acid, and vitexilactone have the best binding affinities against the target receptors (potassium channel receptor, human gamma-aminobutyric acid receptor, and human peroxiredoxin 5) for anxiolytic, sedative, and antioxidant activities. The present study confirmed that EEVP has anxiolytic, sedative, and antioxidant properties, which could be because of the occurrence of various phytochemicals and three bioactive phytocompounds which found potential during molecular docking analysis.

Microorganism’s cycle exposure to reactive oxidants from internal metabolism and abiotic stress conditions, e.g. oxidative stress, salinity, drought, low temperature, high temperature, and high light. Synechocystis PCC6803 genomes typically encode different types of antioxidant scavenging enzymes including Peroxiredoxins (Prxs). There are five genes similar to Prxs were found inthe Synechocystis PCC 6803 genome. Based on sequence homology analysis of Synechocystis PCC 6803sll1621 gene, it is categorized into type II Prx (PrxII). The presumed amino acid sequence of Synechocystis PCC6803 PrxII protein exhibited identity about 44%-99% to other PrxII proteins from human, plants, algae, and other different cyanobacterial cells. In the last decade, the genetically controllable model organism E. coli has been introduced as a viable biotechnological model for genetically modified microorganisms. The Synechocystis PCC6803 sll1621 gene was overexpressed in pTYB21 expression vector and the resulting was named as pTYB21/sll1621. The pTYB21/sll1621 was overexpressed in Escherichia coli BL21 (DE3) host cell. The overexpressed protein of PrxII gave the recombinant E. coli cells the ability to survive under high concentrations of salinity stress, whereas the viability of wild type cells was completely inhibited at the same high concentrations of salinity stress. In conclusion, the present research documented the expressing of the sll1621 gene into E. coli cells. This result approved the absence of species barrier in relations to the function of Synechocystis PCC 6803 PrxII protein in different microorganism.

To fight oxidative damage due to reactive oxygen species (ROS), cells are equipped of different enzymes, among which Peroxiredoxins (Prxs) (EC 1.11.1.15) play a key role. Prxs are thiol-based enzymes containing one (1-Cys Prx) or two (2-Cys Prx) catalytic cysteine residues. In 2-Cys Prxs the cysteine residues form a disulfide bridge following reduction of peroxide which is in turn reduced by Thioredoxin reductase (Tr) /Thioredoxin (Trx) disulfide reducing system to regenerate the enzyme. In this paper we investigated on Prxs of Thermus thermophilus whose genome contains an ORF TT_C0933 encoding a putative Prx, belonging to the subfamily of Bacterioferritin comigratory protein (Bcp): the synthetic gene was produced and expressed in E. coli and the recombinant protein, TtBcp, was biochemically characterized. TtBcp was active on both organic and inorganic peroxides and showed stability at high temperatures. To get insight into disulfide reducing system involved in the recycling of the enzyme we showed that TtBcp catalically eliminates hydrogen peroxide using an unusual partner, the Protein Disulfide Oxidoreductase (TtPDO) that could replace regeneration of the enzyme. Altogether these results highlight not only a new anti-oxidative pathway but also a promising molecule for possible future biotechnological applications.

Clostridium difficile is a spore-forming bacterium and a leading cause of hospital-acquired antibiotic-associated diarrhoea. Symptoms of disease result from secreted toxins, while disease transmission is mediated via resistant endospores. CotE is a bifunctional spore-coat protein with peroxiredoxin and chitinase domains that are implicated in colonization. Here, the structure of the chitinase domain of CotE has been determined, revealing a GH18 family fold and, unexpectedly, a peptide bound in the active site., CotE is a coat protein that is present in the spores of Clostridium difficile, an obligate anaerobic bacterium and a pathogen that is a leading cause of antibiotic-associated diarrhoea in hospital patients. Spores serve as the agents of disease transmission, and CotE has been implicated in their attachment to the gut epithelium and subsequent colonization of the host. CotE consists of an N-terminal peroxiredoxin domain and a C-terminal chitinase domain. Here, a C-terminal fragment of CotE comprising residues 349–712 has been crystallized and its structure has been determined to reveal a core eight-stranded β-barrel fold with a neighbouring subdomain containing a five-stranded β-sheet. A prominent groove running across the top of the barrel is lined by residues that are conserved in family 18 glycosyl hydrolases and which participate in catalysis. Electron density identified in the groove defines the pentapeptide Gly-Pro-Ala-Met-Lys derived from the N-terminus of the protein following proteolytic cleavage to remove an affinity-purification tag. These observations suggest the possibility of designing peptidomimetics to block C. difficile transmission.

To characterize the high‐value protein content and to discover new bioactive peptides, present in edible organisms, as silkworm pupae, semiquantitative analytical approach has been applied. The combination of appropriate protein extraction methods, semiquantitative high‐resolution mass spectrometry analyses of peptides, in silico bioactivity and gene ontology analyses, allowed protein profiling of silkworm pupae (778 gene products) and the characterization of bioactive peptides. The semiquantitative analysis, based on the measurement of the emPAI, revealed the presence of high‐abundance class of proteins, such as larval storage protein (LSP) class. This class of proteins, beside its nutrient reservoir activity, is of great pharmaceutical interest for their efficacy in cardiovascular diseases. Potential allergens were also characterized and quantified, such as arginine kinase, thiol peroxiredoxin, and Bom m 9. This powerful bioanalytical approach proved the potential industrial applications of Bombyx mori pupae, as source of high‐value proteins in a green and “circular” economy perspective., Protein content by the semiquantitative analyses of Bombyx mori pupae. Identification of high‐value bioactive peptides by mass spectrometry. Potential industrial applications of B. mori pupae, as nutrient reservoir.

The 1-cyseine peroxiredoxin (Prx6) is an importantly antioxidant enzyme that protects cells from oxidative damage caused by excessive production of reactive oxygen species (ROS). In this study, we described the molecular characteristics of the noble scallop Chlamys nobilis peroxiredoxin 6 (designed as CnPrx6), immune responses and DNA protection activity of the recombinant protein. The complete ORF (696 bp) of CnPrx6 encoded a polypeptide (25.5 kDa) of 231 amino acids, harboring a conserved peroxidase catalytic center (41PVCTTE46) and the catalytic triads putatively involved in peroxidase and phospholipase A2 activities. The deduced amino acid sequence of CnPrx6 shared a relatively high amino acid sequence similarity (more than 50%). The qRT-PCR revealed that the CnPrx6 mRNA was constitutively expressed in all examined tissues, with the highest expression observed in adductor. Upon immunological challenge with Vibrio parahaemolyticus, lipopolysaccharides (LPS) and polyinosinic-polycytidylic acid (Poly I:C), the expression level of CnPrx6 mRNA was significantly up-regulated (P

Both reactive nitrogen and oxygen species (RNS and ROS), such as nitric oxide, peroxynitrite, and hydrogen peroxide, have been implicated as mediators of pancreatic β-cell damage during the pathogenesis of autoimmune diabetes. While β-cells are thought to be vulnerable to oxidative damage due to reportedly low levels of antioxidant enzymes, such as catalase and glutathione peroxidase, we have shown that they use thioredoxin reductase to detoxify hydrogen peroxide. Thioredoxin reductase is an enzyme that participates in the peroxiredoxin antioxidant cycle. Peroxiredoxins are expressed in β-cells and, when overexpressed, protect against oxidative stress, but the endogenous roles of peroxiredoxins in the protection of β-cells from oxidative damage are unclear. Here, using either glucose oxidase or menadione to continuously deliver hydrogen peroxide, or the combination of dipropylenetriamine NONOate and menadione to continuously deliver peroxynitrite, we tested the hypothesis that β-cells use peroxiredoxins to detoxify both of these reactive species. Either pharmacological peroxiredoxin inhibition with conoidin A or specific depletion of cytoplasmic peroxiredoxin 1 ( Prdx1) using siRNAs sensitizes INS 832/13 cells and rat islets to DNA damage and death induced by hydrogen peroxide or peroxynitrite. Interestingly, depletion of peroxiredoxin 2 ( Prdx2) had no effect. Together, these results suggest that β-cells use cytoplasmic Prdx1 as a primary defense mechanism against both ROS and RNS.

The Chinese wild Vitis amurensis Rupr. is a crucial resource for cold-resistant germplasm, but the molecular mechanism of cold resistance in V. amurensis has not been clarified. We conducted a physiological and transcriptome analysis of potted plants of V. amurensis accession “Shuangyou” (cold-resistant) and Vitis vinifera cultivar “Red Globe” (cold-sensitive) subjected to 0 °C for 3, 12, 48, and 72 h. The “Shuangyou” exhibited lower electrolyte leakage (EL) and malondialdehyde (MDA) compared with “Red Globe.” The proline contents in “Shuangyou” was higher than “Red Globe” at 0 and 48 h while lower than “Red Globe” at other time points. On the whole, catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD) activity in “Shuangyou” was higher than “Red Globe,” and ascorbate peroxidase (APX) activity in “Shuangyou” was lower than “Red Globe.” Transcriptome analysis showed that 240, 310, 1072, and 1107 differentially expressed genes (DEGs) were detected in “Red Globe” at 3, 12, 48, and 72 h, respectively, and 32, 1161, 1894, and 3290 DEGs were found in “Shuangyou” at the same time points, respectively. Functional categories of DEGs included metabolic processes and signal transduction involved with cold resistance in grapevine. The high expression level of encoding peroxiredoxin genes in V. amurensis revealed a strong ability to scavenge reactive oxygen species (ROS). The expression levels of 5 DEGs in “Shuangyou” were more than 20 times higher than those of “Red Globe” at all time points, indicating that some cold-related special pathways maybe involved in V. amurensis. These related genes, as candidate transcripts, may contribute to excellent cold-hardiness breeding in grape.

Redox signaling and homeostasis are essential for cell survival and the immune response. Peroxiredoxin (Prx) modulates the level of H2O2 as a redox signal through H2O2 decomposition. The redox activity of thioredoxin (Trx) is required as a reducing equivalent to regenerate Prx. Edwardsiella piscicida is an opportunistic Gram-negative enteric pathogen that secretes a novel Trx-like effector protein, ETAE_2186 (Trxlp). Trxlp has unique structural properties compared with other Trx proteins. In enzymatic and binding assays, we confirmed Trxlp to be redox-inactive due to the low reactivity and flexibility of the resolving cysteine residue, C35, at the active site motif “31WCXXC35”. We identified key residues near the active site that are critical for reactivity and flexibility of C35 by site-directed mutagenesis analysis. NMR titration experiment demonstrated prolong inhibitory interaction of Trxlp with Prx1 resulting in the repression of Prx1–mediated H2O2 decomposition leading to increased ROS accumulation in infected host cells. Increased ROS in turn prevented nuclear translocation of NF-κB and inhibition of NF-κB target genes, leading to bacterial survival and enhanced replication inside host cells. Targeting Trxlp-mediated virulence promises to attenuate E. piscicida infection.

Peroxisome proliferator-activated receptor-γ coactivator (PGC)-1α is a transcriptional coactivator described as a master regulator of mitochondrial biogenesis and function, including oxidative phosphorylation and reactive oxygen species detoxification. PGC-1α is highly expressed in tissues with high energy demands, and it is clearly associated with the pathogenesis of metabolic syndrome and its principal complications including obesity, type 2 diabetes mellitus, cardiovascular disease, and hepatic steatosis. We herein review the molecular pathways regulated by PGC-1α, which connect oxidative stress and mitochondrial metabolism with inflammatory response and metabolic syndrome. PGC-1α regulates the expression of mitochondrial antioxidant genes, including manganese superoxide dismutase, catalase, peroxiredoxin 3 and 5, uncoupling protein 2, thioredoxin 2, and thioredoxin reductase and thus prevents oxidative injury and mitochondrial dysfunction. Dysregulation of PGC-1α alters redox homeostasis in cells and exacerbates inflammatory response, which is commonly accompanied by metabolic disturbances. During inflammation, low levels of PGC-1α downregulate mitochondrial antioxidant gene expression, induce oxidative stress, and promote nuclear factor kappa B activation. In metabolic syndrome, which is characterized by a chronic low grade of inflammation, PGC-1α dysregulation modifies the metabolic properties of tissues by altering mitochondrial function and promoting reactive oxygen species accumulation. In conclusion, PGC-1α acts as an essential node connecting metabolic regulation, redox control, and inflammatory pathways, and it is an interesting therapeutic target that may have significant benefits for a number of metabolic diseases.

This study aimed to investigate the involvement of long non-coding RNA (lncRNA) lung adenocarcinoma transcript 1 (LUADT1) LUADT1 in diabetic retinopathy (DR). We found LUADT1 may interact with miR-383 by RNA interaction prediction. QPCR analysis showed that lncRNA LUADT1 was downregulated, and miR-383 was upregulated in DR. However, correlation analysis revealed no significant correlation between them. In retinal pigment epithelial cells (RPEpiC, h1RPE7 from Sigma-Aldrich), overexpression of LUADT1 and miR-383 failed to affect the expression of each other. However, LUADT1 overexpression led to increased and miR-383 overexpression led to decreased expression level of peroxiredoxin 3 (PRX3). Cell apoptosis analysis showed that LUADT1 and PRX3 overexpression resulted in the decreased cell apoptosis. MiR-383 played an opposite role and reduced the effects of LUADT1 and PRX3 overexpression. Therefore, LUADT1 regulates PRX3 by serving as the endogenous sponge of miR-383 in DR to regulate cell apoptosis.

The quaternary structure of peroxiredoxin from Aeropyrum pernix K1 (ApPrx) is a decamer, in which five homodimers are assembled in a pentagonal ring through hydrophobic interactions. In this study, we determined the amino acid (AA) residues of ApPrx crucial for forming the decamer using AA mutations. The ApPrx0Cys mutant, wherein all cysteine residues were mutated to serine, was prepared as a model protein to remove the influence of the redox states of the cysteines on its assembling behavior. The boundary between each homodimer of ApPrx0Cys contains characteristic aromatic AA residues forming hydrophobic interactions: F46, F80, W88, W210, and W211. We found that a single mutation of F46, F80, or W210 to alanine completely disassembled the ApPrx0Cys decamer to homodimers, which was clarified by gel-filtration chromatography and dynamic light scattering measurements. F46A, F80A, and W210A mutants lacked only one aromatic ring compared with ApPrx0Cys, indicating that the assembly is very sensitive to the surface structure of the protein. X-ray structures revealed two mechanisms of disassembly of the ApPrx decamer: loss of hydrophobicity between homodimers and flip of the arm domain. The AA residues targeted in this study are well conserved in ring-type Prx proteins, suggesting the importance of these residues in the assembly. This study demonstrates the sensitivity and modifiability of peroxiredoxin assembly by a simple AA mutation.