Peroxiredoxin Research Articles

In vitro cytotoxicity of resin cement and its influence on the expression of antioxidant genes

Aim: This study evaluated cytotoxicity and antioxidant gene expression of resin cements on human gingival fibroblasts (hGF). Materials and Method: RelyX UltimateTM(RXU), VariolinkTMII(VLII), and RelyXU200TM(RXU200) resin cements were incubated with culture medium for 24 h to obtain eluates. Then, the eluates were applied over hGF to assess cell viability at 24 h, 48 h, and 72 h and antioxidant gene expression at 24 h. hGF cultures non-exposed to the eluates were used as Control. Data were submitted to ANOVA and Bonferroni tests (α≤0.05). Results: RXU and RXU200 reduced the number of viable cells in 24 h. Longer exposure to cement extracts caused cell death. Gene expression showed peroxiredoxin 1 (PRDX1) induction by all resin cement types, and superoxide dismutase 1 (SOD1) induction by RXU200 and VLII. Moreover, RXU200 induced not only PRDX1 and SOD1, but also glutathione peroxidase 1 (GPX1), catalase (CAT), and glutathione synthetase (GSS). Conclusions: All resin cements showed toxicity, and induced antioxidant genes in hGF. Antioxidant gene induction is at least partly associated with cytotoxicity of tested cements to oxidative stress experience.

Changes in antioxidant status and DNA repair capacity are corroborated with molecular alterations in malignant thyroid tissue of patients with papillary thyroid cancer.

Introduction: Papillary thyroid cancer (PTC) accounts for approximately 80% of all thyroid cancer cases. The mechanism of PTC tumourigenesis is not fully understood, but oxidative imbalance is thought to play a role. To gain further insight, this study evaluated antioxidant status, DNA repair capacity and genetic alterations in individuals diagnosed with benign thyroid lesion in one lobe (BTG) and PTC lesion in another. Methods: Individuals with coexisting BTG and PTC lesions in their thyroid lobes were included in this study. Reactive oxygen species (ROS) level, ABTS radical scavenging activity, ferric reducing antioxidant capacity, glutathione peroxidase and superoxide dismutase activities were measured in the thyroid tissue lysate. The expression of selected genes and proteins associated with oxidative stress defence and DNA repair were analysed through quantitative real-time PCR and Western blotting. Molecular alterations in genomic DNA were analysed through whole-exome sequencing and the potentially pathogenic driver genes filtered through Cancer-Related Analysis of Variants Toolkit (CRAVAT) analysis were subjected to pathway enrichment analysis using Metascape. Results: Significantly higher ROS level was detected in the PTC compared to the BTG lesions. The PTC lesions had significantly higher expression of GPX1, SOD2 and OGG1 but significantly lower expression of CAT and PRDX1 genes than the BTG lesions. Pathway enrichment analysis identified "regulation of MAPK cascade," "positive regulation of ERK1 and ERK2 cascade" and "negative regulation of reactive oxygen species metabolic process" to be significantly enriched in the PTC lesions only. Four pathogenic genetic variants were identified in the PTC lesions; BRAF V600E, MAP2K7-rs2145142862, BCR-rs372013175 and CD24 NM_001291737.1:p.Gln23fs while MAP3K9 and G6PD were among 11 genes that were mutated in both BTG and PTC lesions. Conclusion: Our findings provided further insight into the connection between oxidative stress, DNA damage, and genetic changes associated with BTG-to-PTC transformation. The increased oxidative DNA damage due to the heightened ROS levels could have heralded the BTG-to-PTC transformation, potentially through mutations in the genes involved in the MAPK signalling pathway and stress-activated MAPK/JNK cascade. Further in-vitro functional analyses and studies involving a larger sample size would need to be carried out to validate the findings from this pilot study.

Clinical significance of peroxiredoxin 2 in esophageal squamous cell carcinoma and its role in cell proliferation and apoptosis <i>in vitro,/i>

Purpose: To evaluate the expression of peroxiredoxin 2 (PRDX2) and its clinical significance in esophageal squamous cell carcinoma (ESCC) and its effect on the proliferation and apoptosis of ESCC cells.Methods: The expression of PRDX2 in clinical tissues (120 samples of tumor tissues compared to 20 samples of non-tumor tissues) was determined. The tissues were divided into high-expression group (n = 56) or low-expression group (n = 64) based on the level of PRDX2. Association between PRDX2 expression and clinicopathological features of patients was further analyzed. In vitro, si-NC and si- PRDX2 were transfected into ECA-109 cells, respectively, to determine the influences of PRDX2 on the function of ESCC cells. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to determine the different expressions of PRDX2 in the clinical tissues.Results: The results from qRT-PCR indicated that PRDX2 was upregulated in ESCC tissues compared to normal control. Correlation between the expression of PRDX2 and clinical pathological data revealed that the expression of PRDX2 showed correlation with tumor differentiation, size, and clinical tumor node metastasis (TNM) stage. Modulation of PRDX2 expression by transfecting si-PRDX2 in ESCC cell lines demonstrated effective regulation of cell proliferation and apoptosis. Specifically, it was observed that cell proliferation decreased, while cell apoptosis was increased.Conclusion: Peroxiredoxin 2 is a novel factor that plays a significant role in ESCC progression, and constitutes a potential biomarker and therapeutic target for ESCC.

Proteomic analysis of high and low-motility frozen-thawed spermatozoa in yak provides important insights into the molecular mechanisms underlying sperm cryodamage

Sperm cryodamage caused by cryopreservation limits the use of frozen yak spermatozoa in artificial insemination (AI). However, the proteomic changes involved in the cryodamage of yak spermatozoa have not been investigated to date. Therefore, this study aimed to identify proteins related to freezing tolerance. Tandem mass tag (TMT) were used in combination with liquid chromatography–tandem mass spectrometry (LC-MS/MS) for identifying differentially expressed proteins (DEPs) between high-motility (HM) and low-motility (LM) frozen-thawed yak spermatozoa. A total of 116 DEPs were identified (>1.5-fold, P < 0.05); of which, 104 proteins were upregulated in HM spermatozoa and 12 proteins were upregulated in LM spermatozoa. The results of functional annotation analysis revealed that the DEPs were mainly involved in metabolic processes. A total of 20 DEPs that were abundantly expressed in HM spermatozoa were strongly associated with carbohydrate metabolism. The results of KEGG analysis revealed that the DEPs were enriched in glycolysis/gluconeogenesis, PPAR signaling pathway, and Ras signaling pathway. In addition, many antioxidant enzymes such as superoxide dismutase (SOD1), peroxiredoxin-6 (PRDX6), and Parkinson disease protein 7 (PARK7) were upregulated in HM spermatozoa, suggesting that these enzymes affect the motility of spermatozoa by regulating the levels of reactive oxygen species (ROS) in frozen-thawed spermatozoa. Altogether, the findings of this study elucidate the mechanisms through which cryopreservation affects the movement of yak spermatozoa and offer a novel basis for refining freezing techniques and modifying cryopreservation extender components.

An Increase in Peroxiredoxin 6 Expression Induces Neurotoxic A1 Astrocytes in the Lumbar Spinal Cord of Amyotrophic Lateral Sclerosis Mice Model.

Amyotrophic lateral sclerosis (ALS) is a severe neurodegenerative disease with selective degeneration of motor neurons. It has been reported that an increase in the levels of inflammatory cytokines and glial cells such as reactive astrocytes is closely involved in the pathological progression of ALS. Recently, the levels of neuropathic cytotoxic (A1) astrocytes among reactive astrocytes have reportedly increased in the central nervous system of ALS mice, which induce motor neuron degeneration through the production of inflammatory cytokines and secretion of neuropathic factors. Hence, elucidating the induction mechanism of A1 astrocytes in ALS is important to understand the mechanism of disease progression in ALS. In this study, we observed that the expression of peroxiredoxin 6 (PRDX6), a member of the peroxiredoxin family, was markedly upregulated in astrocytes of the lumbar spinal cord of SOD1G93A mice model for ALS. Additionally, when PRDX6 was transiently transfected into the mouse astrocyte cell line C8-D1A and human astrocytoma cell line U-251 MG, the mRNA expression of complement C3 (a marker for A1 astrocyte phenotype) and inflammatory cytokines was increased. Furthermore, the mRNA expression of C3 and inflammatory cytokine was increased in C8-D1A and U-251 MG cells stably expressing PRDX6, and the increased mRNA expression was significantly suppressed by MJ33 (lithium[1-hexadecoxy-3-(2,2,2-trifluoroethoxy) propan-2-yl] methyl phosphate), an inhibitor of the phospholipase A2 activity of PRDX6. Our results suggest that the expression of PRDX6 in astrocytes plays an important role in the induction of A1 astrocytes and expression of inflammatory cytokines in the ALS mice model.

Pure cerebellar ataxia due to bi-allelic PRDX3 variants including recurring p.Asp202Asn.

Bi-allelic variants in peroxiredoxin 3 (PRDX3) have only recently been associated with autosomal recessive spinocerebellar ataxia characterized by early onset slowly progressive cerebellar ataxia, variably associated with hyperkinetic and hypokinetic features, accompanied by cerebellar atrophy and occasional olivary and brainstem involvement. Herein, we describe a further simplex case carrying a reported PRDX3 variant as well as two additional cases with novel variants. We report the first Brazilian patient with SCAR32, replicating the pathogenic status of a known variant. All presented cases from the Brazilian and Indian populations expand the phenotypic spectrum of the disease by displaying prominent neuroradiological findings. SCAR32, although rare, should be included in the differential diagnosis of sporadic or recessive childhood and adolescent-onset pure and complex cerebellar ataxia.

Changes of the Protein CoAlation Pattern in Response to Oxidative Stress and Capacitation in Human Spermatozoa.

The spermatozoa have limited antioxidant defences, a high polyunsaturated fatty acids content and the impossibility of synthesizing proteins, thus being susceptible to oxidative stress. High levels of reactive oxygen species (ROS) harm human spermatozoa, promoting oxidative damage to sperm lipids, proteins and DNA, leading to infertility. Coenzyme A (CoA) is a key metabolic integrator in all living cells. Recently, CoA was shown to function as a major cellular antioxidant mediated by a covalent modification of surface-exposed cysteines by CoA (protein CoAlation) under oxidative or metabolic stresses. Here, the profile of protein CoAlation was examined in sperm capacitation and in human spermatozoa treated with different oxidizing agents (hydrogen peroxide, (H2O2), diamide and tert-butyl hydroperoxide (t-BHP). Sperm viability and motility were also investigated. We found that H2O2 and diamide produced the highest levels of protein CoAlation and the greatest reduction of sperm motility without impairing viability. Protein CoAlation levels are regulated by 2-Cys peroxiredoxins (PRDXs). Capacitated spermatozoa showed lower levels of protein CoAlation than non-capacitation cells. This study is the first to demonstrate that PRDXs regulate protein CoAlation, which is part of the antioxidant response of human spermatozoa and participates in the redox regulation associated with sperm capacitation.

Abstract P3177: Complex I-induced Protein Turnover, A Novel Mitochondrial Protein Quality Regulation Clipt Goes Beyond The Mitochondrial Calcium Uniporter

In the setting of mitochondrial disease, patients with cardiac involvement have a nearly threefold increased mortality. Yet, patients often survive months to years suggesting that in cardiomyocytes, there is a compensatory mechanism that maintains energy synthesis despite defective mitochondria. We have recently shown that enhanced activity of the mitochondrial Calcium (Ca 2+ ) uniporter channel preserves energetic homeostasis in mitochondrial cardiomyopathies. Here, we describe a novel mechanism responsible for this enhancement. During normal physiology, interaction between the uniporter and Complex I of the electron transport chain promotes its degradation. However, upon Complex I dysfunction, loss of this interaction results in increased functional channels. We termed this form of mitochondrial protein regulation, Complex I-Induced protein turnover (CLIPT). We hypothesize that CLIPT is not unique to the uniporter. To identify other candidates subject to CLIPT, we performed a pulse-chase screen using TurboID, a biotin-ligase proximity labeling tool. HEK cells expressing a mitochondrial TurboID were grown with or without Complex I inhibitors. Following a pulse-chase with biotin, proteins were purified with streptavidin and identified through mass spectrometry. Of these proteins, whose lifetimes increased after Complex I inhibition, Peroxiredoxin-3 (PRDX-3) is a mitochondrial antioxidant shown to provide protection against cell death and in myocardial infarction. Using heterologous expression in c2c12 cells, inhibition of Complex I prolongs PRDX-3 lifetime. Thus, our data suggests that CLIPT can affect mitochondrial proteins beyond the uniporter.

Protective Effects of Peroxiredoxin 6 in Pro-Inflammatory Response Model Using Raw 264.7 Macrophages.

The aim of the work was to study effects of peroxiredoxin 6 (PRDX6), a recombinant antioxidant protein, on the level of pro-inflammatory responses of RAW 264.7 macrophages to endotoxin exposure. Addition of LPS to the RAW 264.7 cell culture medium expectedly increased production of TNF-α, and addition of PRDX6 led to a significant (15-20%) decrease in its production. The level of production of another pro-inflammatory cytokine, IL-1β, which was significantly activated by endotoxin, was completely normalized under the PRDX6 action. Moreover, addition of PRDX6 reduced production of reactive oxygen species (ROS) induced by endotoxin and also prevented overexpression of the iNos gene in the RAW 264.7 cells. The results showed that PRDX6 had a suppressive effect on the expression of Nrf-2 gene and production of the transcription factor NRF-2 during the first 6 h of cell cultivation. Addition of endotoxin caused activation of the NF-κB and SAPK/JNK signaling cascades, while in the presence of PRDX6, activity of these signaling cascades decreases. It is known that the pro-inflammatory response of cells caused by exposure to bacterial LPS leads to activation of apoptosis and elimination of the damaged cells. Our studies confirm this, since exposure to LPS led to activation of the expression of P53 gene, a marker of apoptosis. Peroxiredoxin 6 added within the first hours of the development of acute pro-inflammatory response suppressed the P53 gene expression, indicating protective effect of PRDX6 that reduced apoptosis in the RAW 264.7 macrophages.

Conoidin A, a Covalent Inhibitor of Peroxiredoxin 2, Reduces Growth of Glioblastoma Cells by Triggering ROS Production.

Compounds that cause oxidative stress have recently gained considerable interest as potential anticancer treatment modalities. Nevertheless, their efficiency may be diminished by the antioxidant systems often upregulated in cancer cells. Peroxiredoxins (PRDXs) are antioxidant enzymes that scavenge peroxides and contribute to redox homeostasis. They play a role in carcinogenesis and are upregulated in several cancer types. Here, we assessed the expression pattern of PRDX1 and PRDX2 in glioblastoma (GBM) and examined the efficacy of their inhibitors in GBM cell lines and patient-derived GBM cells. Both PRDX1 and PRDX2 were upregulated in GBM compared to non-tumor brain tissues and their considerable amounts were observed in GBM cells. Adenanthin, a compound inhibiting PRDX1 activity, slightly decreased GBM cell viability, while conoidin A (CONA), a covalent PRDX2 inhibitor, displayed high toxicity in GBM cells. CONA elevated the intracellular reactive oxygen species (ROS) level. Pre-treatment with an ROS scavenger protected cells from CONA-induced death, indicating that ROS accumulation plays a crucial role in this phenomenon. Menadione or celecoxib, both of which are ROS-inducing agents, potentiated the anticancer activity of CONA. Collectively, our results unveil PRDX1 and PRDX2 as potential targets for GBM therapy, and substantiate the further exploration of their inhibitors.

Hydrogen peroxide-induced oxidative damage and protective role of peroxiredoxin 6 protein via EGFR/ERK signaling pathway in RPE cells.

Damage to retinal pigment epithelium (RPE) cells caused by oxidative stress is closely related to the pathogenesis of several blinding retinal diseases, such as age-related macular degeneration (AMD), retinitis pigmentosa, and other inherited retinal degenerative conditions. However, the mechanisms of this process are poorly understood. Hence, the goal of this study was to investigate hydrogen peroxide (H2O2)-induced oxidative damage and protective role of peroxiredoxin 6 (PRDX6) protein via EGFR/ERK signaling pathway in RPE cells. Cells from a human RPE cell line (ARPE-19 cells) were treated with H2O2, and then cell viability was assessed using the methyl thiazolyl tetrazolium assay. Cell death and reactive oxygen species (ROS) were detected by flow cytometry. The levels of PRDX6, epidermal growth factor receptor (EGFR), P38 mitogen-activated protein kinase (P38MAPK), c-Jun N-terminal kinase (JNK), and extracellular signal-regulated kinase (ERK) were detected by Western blot assay. PRDX6 and EGFR were also detected via immunofluorescence staining. Our results show that H2O2 inhibited cell viability, induced cell death, and increased ROS levels in ARPE-19 cells. It was also found that H2O2 decreased the levels of PRDX6, EGFR, and phosphorylated ERK but increased the levels of phosphorylated P38MAPK and JNK. PRDX6 overexpression was found to attenuate H2O2-induced inhibition of cell viability and increased cell death and ROS production in ARPE-19 cells. PRDX6 overexpression also increased the expression of EGFR and alleviated the H2O2-induced decrease in EGFR and phosphorylated ERK. Moreover, inhibition of epidermal growth factor-induced EGFR and ERK signaling in oxidative stress was partially blocked by PRDX6 overexpression. Our findings indicate that PRDX6 overexpression protects RPE cells from oxidative stress damage caused by decreasing ROS production and partially blocking the inhibition of the EGFR/ERK signaling pathway induced by oxidative stress. Therefore, PRDX6 shows promise as a therapeutic target for the prevention of RPE cell damage caused by oxidative stress associated with retinal diseases.

The PRX-1/TLR4 axis promotes hypoxia-induced radiotherapy resistance in non-small cell lung cancer by targeting the NF-κB/p65 pathway

Hypoxic lung cancer cells are highly resistant to radiation. Peroxiredoxin-1 (PRX-1), a transcriptional coactivator that enhances the DNA-binding activity of serum reactive factor, has been identified as a target for radiotherapy sensitization, but the underlying molecular mechanism remains unclear. This study aimed to investigate the influence of PRX-1 on radiotherapy sensitivity in hypoxic tumors. Hypoxic lung cancer cells exhibited radiotherapy-resistant phenotypes after irradiation, including increased proliferation, DNA damage repair, cell migration, invasion and stemness. Radio-resistant hypoxic lung cancer cells showed high expression levels of PRX-1. Furthermore, we observed that PRX-1 bound to the promoter region of TRL4 (−300 to −600) and promoted its transcription and expression and that PRX-1/TRL4 activated the NF-κB/p65 signaling pathway. Increased radiotherapy resistance of hypoxic lung cancer cells increased their ability to proliferate, migrate, and maintain stemness in vivo and in vitro. These findings suggest that PRX-1/TRL4 could be used as a target for the treatment of radiotherapy-resistant lung cancer cells and further provide a theoretical basis for the clinical treatment of hypoxic lung cancer cells.

Cytotoxicity of alkaline serine protease (ASPNJ) on Jurkat cells and its correlation with changes in the expression of membrane-associated proteins.

We aim to study the inhibitory effect of alkaline serine protease (ASPNJ) on lymphocytic leukemia Jurkat cells and its related mechanism through examining the expression of membrane proteins or membrane-associated proteins. MTT assay and trypan blue staining were used to detect the inhibitory effect of ASPNJ on the proliferation and growth of Jurkat cells. Wright-Giemsa staining was used to observe the effect of ASPNJ on the morphology of Jurkat cells. The effect of ASPNJ on Jurkat cell apoptosis was detected by flow cytometry. Two-dimensional electrophoresis-mass spectrometry (2-DE-MS) was used to detect and identify the differentially expressed proteins of Jurkat cells treated with ASPNJ (4 μg/mL, 3 h), of which three were selected and verified by Western blot. ASPNJ significantly inhibited the proliferation of leukemia cells (Raji, U937, and Jurkat), caused obvious morphological changes, and induced apoptosis of Jurkat cells. ASPNJ also increased the sensitivity of Jurkat cells to vincristine (VCR). Seven differentially expressed proteins were obtained through 2DE-MS, of which Peroxiredoxin-6 (PRDX6), Calcium-binding protein (CHP1), and 40S ribosomal protein SA (RPSA) were validated. ASPNJ can cause significant toxic effects on Jurkat cells and enhance the effects of VCR. The mechanism of action of ASPNJ on Jurkat cells may be related to differentially expressed proteins such as PRDX6. This study provides a new experimental basis and direction for antileukemia research.

Ferrostatin-1 attenuates brain injury in animal model of subarachnoid hemorrhage via phospholipase A2 activity of PRDX6.

Subarachnoid hemorrhage (SAH) is an acute catastrophic neurological disorder with high morbidity and mortality. Ferroptosis is one of the pathophysiological processes during secondary brain injury of SAH, which could be inhibited by ferrostatin-1 (Fer-1) effectively. Peroxiredoxin6 (PRDX6) is an antioxidant protein and is currently proven to be associated with lipid peroxidation in ferroptosis except in GSH/GPX4 and FSP1/CoQ10 antioxidant systems. However, the alteration and function of PRDX6 in SAH are still unknown. In addition, whether PRDX6 is involved in the neuroprotection of Fer-1 in SAH is yet to be investigated. Endovascular perforation was employed to induce the SAH model. Fer-1 and in vivo siRNA aiming to knockdown PRDX6 were administrated intracerebroventricularly to investigate relevant regulation and mechanism. We confirmed the inhibition of ferroptosis and neuroprotection from brain injury by Fer-1 in SAH. The induction of SAH reduced the expression of PRDX6, which could be alleviated by Fer-1. Accordingly, dysregulated lipid peroxidation indicated by GSH and MDA was improved by Fer-1, which was counteracted by si-PRDX6. Similarly, the neuroprotection of Fer-1 in SAH was diminished by the knockdown of PRDX6 and the administration of a calcium-independent phospholipase A2 (iPLA2) inhibitor. PRDX6 is involved in ferroptosis induced by SAH and is associated with Fer-1 neuroprotection from brain injury via its iPLA2 activity.

Peroxinredoxin 6 reduction accelerates cigarette smoke extract‑induced senescence by regulating autophagy in BEAS‑2B cells.

Cigarette smoke (CS)-induced accelerated senescence and insufficient autophagy has been implicated in the pathogenesis of chronic obstructive pulmonary disease (COPD). Peroxiredoxin (PRDX) 6 is a protein with prevalent antioxidant capacity. Previous studies indicate that PRDX6 could activate autophagy and alleviate senescence in other diseases. The present study investigated whether PRDX6-regulated autophagy was involved in the regulation of CS extract (CSE)-induced BEAS-2B cell senescence via the knockdown of PRDX6 expression. Furthermore, the present study evaluated the mRNA levels of PRDX6, autophagy and senescence-associated genes in the small airway epithelium from patients with COPD by analyzing the GSE20257 dataset from the Gene Expression Omnibus database. The results demonstrated that CSE reduced PRDX6 expression levels and transiently induced the activation of autophagy, followed by the accelerated senescence of BEAS-2B cells. Knockdown of PRDX6 induced autophagy degradation and accelerated senescence in CSE-treated BEAS-2B cells. Furthermore, autophagy inhibition by 3-Methyladenine increased P16 and P21 expression levels, while autophagy activation by rapamycin reduced P16 and P21 expression levels in CSE-treated BEAS-2B cells. The GSE20257 dataset revealed that patients with COPD had lower PRDX6, sirtuin (SIRT) 1 and SIRT6 mRNA levels, and higher P62 and P16 mRNA levels compared with non-smokers. P62 mRNA was significantly correlated with P16, P21 and SIRT1, which indicated that insufficient autophagic clearance of damaged proteins could be involved in accelerated cell senescence in COPD. In conclusion, the present study demonstrated a novel protective role for PRDX6 in COPD. Furthermore, a reduction in PRDX6 could accelerate senescence by inducing autophagy impairment in CSE-treated BEAS-2B cells.

Panax notoginseng alleviates oxidative stress through miRNA regulations based on systems biology approach

BackgroundHerbal medicine Sanqi (SQ), the dried root or stem of Panax notoginseng (PNS), has been reported to have anti-diabetic and anti-obesity effects and is usually administered as a decoction for Chinese medicine. Alternative to utilizing PNS pure compound for treatment, we are motivated to propose an unconventional scheme to investigate the functions of PNS mixture. However, studies providing a detailed overview of the transcriptomics-based signaling network in response to PNS are seldom available.MethodsTo explore the reasoning of PNS in treating metabolic disorders such as insulin resistance, we implemented a systems biology-based approach with RNA sequencing (RNA-seq) and miRNA sequencing data to elucidate key pathways, genes and miRNAs involved.ResultsFunctional enrichment analysis revealed PNS up-regulating oxidative stress-related pathways and down-regulating insulin and fatty acid metabolism. Superoxide dismutase 1 (SOD1), peroxiredoxin 1 (PRDX1), heme oxygenase-1 (Hmox1) and glutamate cysteine ligase (GCLc) mRNA and protein levels, as well as related miRNA levels, were measured in PNS treated rat pancreatic β cells (INS-1). PNS treatment up-regulated Hmox1, SOD1 and GCLc expression while down-regulating miR-24-3p and miR-139-5p to suppress oxidative stress. Furthermore, we verified the novel interactions between miR-139-5p and miR-24-3p with GCLc and SOD1.ConclusionThis work has demonstrated the mechanism of how PNS regulates cellular molecules in metabolic disorders. Therefore, combining omics data with a systems biology strategy could be a practical means to explore the potential function and molecular mechanisms of Chinese herbal medicine in the treatment of metabolic disorders.

Effect of PRDX6 gene polymorphism on susceptibility to chronic obstructive pulmonary disease in the Chinese Han population.

To explore the relationship of peroxiredoxin6 (PRDX6) tag-single nucleotide polymorphisms (SNPs) with susceptibility to chronic obstructive pulmonary disease (COPD) in the Chinese Han population. A total of 502 patients with COPD and 481 healthy controls from nine hospitals in China were enrolled in this study. The PRDX6 tag-SNPs were identified by linkage disequilibrium (LD) analysis in 30 healthy controls. The associations between identified tag-SNPs and COPD risk were further evaluated. Four PRDX6 tag-SNPs, including rs7314, rs34619706, rs33951697, and rs4382766, were identified in 30 healthy controls. Moreover, in the allele model, there was no statistical difference in locus in PRDX6 between patients with COPD and healthy controls (P > 0.05). However, in the recessive model, rs33951697 locus in PRDX6 gene carrier with T/T had an increased risk of COPD (odds ratio [OR] = 2.59, 95% CI = 1.06-6.33, P = 0.028). Furthermore, in the relevance analysis between genetic polymorphisms and smoking behavior and lung function indexes, we found that the number of smoked cigarettes per day and FEV1/FVC differed among different genotypes of PRDX6, rs4382766, and rs7314 (P < 0.05). PRDX6 gene polymorphism with smoking status may contribute to the etiology of COPD in the Chinese Han population.

Polygenic Variants Linked to Oxidative Stress and the Antioxidant System Are Associated with Type 2 Diabetes Risk and Interact with Lifestyle Factors.

Oxidative stress is associated with insulin resistance and secretion, and antioxidant systems are essential for preventing and managing type 2 diabetes (T2DM). This study aimed to explore the polygenic variants linked to oxidative stress and the antioxidant system among those associated with T2DM and the interaction of their polygenic risk scores (PRSs) with lifestyle factors in a large hospital-based cohort (n = 58,701). Genotyping, anthropometric, biochemical, and dietary assessments were conducted for all participants with an average body mass index of 23.9 kg/m2. Genetic variants associated with T2DM were searched through genome-wide association studies in participants with T2DM (n = 5383) and without T2DM (n = 53,318). The Gene Ontology database was searched for the antioxidant systems and oxidative stress-related genes among the genetic variants associated with T2DM risk, and the PRS was generated by summing the risk alleles of selected ones. Gene expression according to the genetic variant alleles was determined on the FUMA website. Food components with low binding energy to the GSTA5 protein generated from the wildtype and mutated GSTA5_rs7739421 (missense mutation) genes were selected using in silico analysis. Glutathione metabolism-related genes, including glutathione peroxidase (GPX)1 and GPX3, glutathione disulfide reductase (GSR), peroxiredoxin-6 (PRDX6), glutamate-cysteine ligase catalytic subunit (GCLC), glutathione S-transferase alpha-5 (GSTA5), and gamma-glutamyltransferase-1 (GGT1), were predominantly selected with a relevance score of >7. The PRS related to the antioxidant system was positively associated with T2DM (ORs = 1.423, 95% CI = 1.22-1.66). The active site of the GASTA proteins having valine or leucine at 55 due to the missense mutation (rs7739421) had a low binding energy (<-10 kcal/mol) similarly or differently to some flavonoids and anthocyanins. The PRS interacted with the intake of bioactive components (specifically dietary antioxidants, vitamin C, vitamin D, and coffee) and smoking status (p < 0.05). In conclusion, individuals with a higher PRS related to the antioxidant system may have an increased risk of T2DM, and there is a potential indication that exogenous antioxidant intake may alleviate this risk, providing insights for personalized strategies in T2DM prevention.

#5219 PEROXIREDOXINS ARE RELATED TO EGFR DECLINE IN IGA NEPHROPATHY, MEMBRANOUS NEPHROPATHY AND LUPUS NEPHRITIS: A 5-YEAR FOLLOW-UP

Abstract Background and Aims Oxidative stress (OS) is known as a disturbance between pro- and antioxidant factors, that may lead to DNA or protein oxidation, resulting in cellular damage. Peroxiredoxins (PRDXs) are enzymes with an antioxidant properties. They play dominant role in regulation of cellular peroxide levels, which is crucial in maintaining organisms’ oxidative balance. PRDXs types 1-5 are involved in the pathophysiology of various diseases (e.g. cancer, inflammatory, or renal). We aim to study their role as a prognostic marker of eGFR changes in IgA nephropathy (IgAN), lupus nephritis (LN) and membranous nephropathy (MN) patients. Method This is a retrospective 5-year-follow-up study of 108 IgAN, MN and LN patients, in whom PRDX 1-5 serum levels were assessed with ELISA in 2017. In 2022, we were able to collect the data out of 80 patients: IgAN (n=36); MN (n=22) and LN (n=22). The remaining 28 were considered as lost-to-follow-up, namely: lack of any medical results within last 2 years (n=23); on dialysis (n=2); after renal transplantation (n=2); deceased (n=1). We classified patients depending on the changes of eGFR (decline/stable/increase; Fig. 1) between baseline and after 5 year follow-up and the PRDX levels (high/medium/low; Table 1). The Mann Whitney-U, Kruskal-Wallis and Chi-Square Test were used for statistical analysis, the p-values &amp;lt;0.05 were considered significant. Results Baseline PRDX measurements indicated, that the mean concentrations of serum PRDX 1-5 differ between the glomerulonephropathies (GN). In 2022, we observed significantly different (P = .012) change of eGFR depending on the GN type. 16/80 individuals had eGFR decline and 75% of them were diagnosed with IgAN. The MN and LN groups had increase of eGFR in the last 5 years in most cases, probably as a result of the treatment. We verified if follow-up eGFR was associated with baseline PRDX levels. The 2022 eGFR differed significantly between the GNs depending on the level of serum PRDX 2, 4 and 5 at baseline (P = .002; P = .009; P = .006, respectively, Table 1). Conclusion Our results showed the link between serum PRDXs concentration and IgAN, MN and LN follow-up. Importantly, selected PRDXs’ might be used to predict eGFR decline, particularly in IgAN and LN.

Knockdown of circSOD2 ameliorates osteoarthritis progression via the miR-224-5p/PRDX3 axis

BackgroundAlthough the implications of circular RNAs (circRNAs) with the progression of diverse pathological conditions have been reported, the circRNA players in osteoarthritis (OA) are barely studied.MethodsIn this study, twenty-five OA patients who received arthroplasty were recruited for cartilage tissue collection. Public circRNA microarray data from Gene Expression Omnibus was retrieved for circRNA identification. An in vitro cell model of OA-related damages was constructed by treating human chondrocytes (CHON-001 cell line) with IL-1β, and circSOD2 siRNA was used to silence circSOD2 expression to study its functional role in apoptosis, inflammatory responses, and extracellular matrix (ECM) degradation. Besides, we investigated the functional interactions among circSOD2, miR-224-5p, and peroxiredoxin 3 (PRDX3) by luciferase reporter assay, RNA-immunoprecipitation assay, and quantitative reverse transcription polymerase chain reaction.ResultsOur findings revealed the overexpression of circSOD2 in the OA cartilage and cell samples, and circSOD2 knockdown alleviated ECM degradation, inflammation, and apoptosis in CHON-001 cell model. In addition, our findings suggested the regulatory function of circSOD2 knockdown on miR-224-5p expression, while miR-224-5p was capable of downregulating PRDX3 expression. The co-transfection of miR-224-5p inhibitor or pcDNA-PRDX3 could prevent the effect of circSOD2 knockdown.ConclusionHence, our results demonstrated that knockdown of circSOD2 may serve as an intervention strategy to alleviate OA progression through modulating miR-224-5p/PRDX3 signaling axis.