Search Results (23)

Peroxiredoxins (Prdxs) are a family of thiol-specific peroxidases that play a central role in maintaining intracellular redox homeostasis. In addition to their classical antioxidant activities, Prdxs function as peroxide sensors, modulators of redox signaling, and molecular chaperones. In this review, we summarize the peroxide-reducing activity, their redox-switch mechanism driven by reversible hyperoxidation, and the chaperone function that arises through oligomerization and accompanying structural changes. We also highlight that the Prdx1–Prdx6 isoforms exhibit distinct subcellular localizations and perform isoform-specific functions, thereby contributing to a wide range of physiological and pathological processes. Furthermore, we compile recent findings showing that diverse post-translational modifications (PTMs), including phosphorylation, acetylation, ubiquitination, glutathionylation, sumoylation, and S-nitrosylation, not only regulate Prdx activity but also contribute to cellular signaling processes. Overall, this review emphasizes that Prdxs are more than simple antioxidant enzymes: they serve as guardians of cellular redox balance and dynamic regulators of signaling networks, underscoring their potential as disease biomarkers and therapeutic targets. Full article

Hepatocellular carcinoma (HCC) remains one of the leading causes of cancer-related mortality worldwide, with limited therapeutic options and poor clinical outcomes. Mounting evidence suggests that targeting cancer-specific metabolic and redox adaptations represents a promising therapeutic strategy. Peroxiredoxin 1 (PRDX1), a key antioxidant enzyme that is frequently overexpressed in HCC, enables tumor cells to neutralize excessive reactive oxygen species (ROS), thereby sustaining survival and conferring therapeutic resistance. In this study, using human hepatocellular carcinoma HepG2 cells as an in vitro model, we identify ginsenoside Rg5 (Rg5) as a previously unrecognized small-molecule inhibitor of PRDX1. Structural and functional analyses demonstrate that Rg5 directly binds to the Asn145 residue of PRDX1, effectively suppressing its peroxidase activity. Mechanistically, this inhibition disrupts ROS detoxification in HepG2 cells, leading to mitochondrial ROS accumulation, activation of the intrinsic apoptotic pathway, and consequent HepG2 cell death. Additionally, Rg5 not only suppresses HepG2 cell survival but also acts synergistically with doxorubicin, a first-line chemotherapeutic agent, to markedly enhance antitumor efficacy and potentially mitigate chemoresistance. Collectively, these findings suggest that PRDX1 inhibition may represent a broadly exploitable vulnerability in liver cancer and establish Rg5 as a promising candidate for developing targeted and combinatorial therapies against HCC. Full article

Peroxiredoxin 6 (Prdx6) is a bifunctional antioxidant enzyme with glutathione peroxidase and phospholipase A₂ activities that plays an essential role in cellular redox regulation. However, the modulation of Prdx6 activity by endogenous small metabolites remains poorly understood. In this study, we investigated the effect of β alanine on Prdx6 structure and function using biochemical, biophysical, computational, and cellular approaches. Enzymatic assays revealed that β alanine enhances the peroxidase activity of Prdx6 in a dose-dependent manner. Spectroscopic analyses demonstrated β alanine-induced conformational stabilization of Prdx6, which was further supported by increased thermal stability. Molecular docking and molecular dynamics simulations identified a stable interaction of β alanine at a distinct allosteric site on Prdx6, accompanied by reduced local flexibility. In a proof-of-concept cellular system, β alanine treatment resulted in a significant reduction in intracellular reactive oxygen species, consistent with enhanced Prdx6-associated antioxidant activity. Collectively, these findings identify β alanine as a biochemical modulator of Prdx6 activity. The study is limited to mechanistic and cellular redox regulation and does not address tissue- or disease-specific physiology. Full article

Background: The senescence of testicular Leydig cells (LCs) is a key cause of age-related testosterone deficiency, in which oxidative stress (OS) and mitochondrial dysfunction are critical driving mechanisms. We explore whether the bioactive peptide C248 of PRDX4, an intracellular antioxidant, exerts mitochondrial protection to ameliorate LCs’ function. Methods: Based on the antioxidant domains of the PRDX4 protein, small molecular peptides were designed, and bioactive peptide C248 stood out from the crowd. An OS-induced senescence model of LCs was constructed by treating the MLTC-1 cell line with hydrogen peroxide (H₂O₂). C248 peptide or nicotinamide mononucleotide (NMN), as the positive control, was administered in the culture medium. The cellular function-related indicators, including DPPH free radical scavenging rate, cell viability, testosterone level, hydrogen peroxide (H₂O₂) content, senescence-associated β-galactosidase (SA-β-gal) activity, 8-hydroxy-2′-deoxyguanosine (8-OHDG) level, and 4-hydroxynonenal (4-HNE) level, were evaluated. The mitochondrial function and structural indicators, such as mitochondrial membrane potential, ATP production, mitochondrial morphology, and mitochondrial DNA (mtDNA) copy number, were subsequently tested. Results: In vitro experiments confirmed that C248 could scavenge DPPH free radicals in a dose-dependent manner, reduce the levels of reactive oxygen species, and increase antioxidant enzyme activity in LCs (p < 0.01). Both C248 and NMN increased testosterone secretion and improved cell viability (p < 0.01). Both C248 and NMN increased mitochondrial morphology and quantity, mitochondrial membrane potential (p < 0.01), ATP production (p < 0.01), and mitochondrial DNA (mtDNA) copy number (p < 0.01). Conclusion: This study reveals that the small molecular C248, a bioactive peptide of PRDX4, is a new candidate molecule for intervening in LC senescence and confirms that mitochondrial protection is a key strategy for improving age-related testicular dysfunction. Full article

The core objective of racehorse breeding is to enhance the speed and endurance of the horses. The Grassland-Thoroughbred is an emerging horse breed developed in northern China in recent years, characterized by excellent speed performance, enduring stamina, and strong environmental adaptability. However, research on the genetic characteristics within this breed and the genes associated with athletic performance remains relatively limited. We conducted whole-genome resequencing of Grassland-Thoroughbred F1, F2, F3, and the crossbred population (CY) and obtained a total of 4056.23 Gb of high-quality data after quality control. The single nucleotide polymorphisms (SNPs) were primarily distributed in intergenic regions, followed by intronic regions. Principal component analysis (PCA) and STRUCTURE revealed clear distinctions among the generations, with a notable overlap between CY and F3. Using the SNP dataset, we analyzed the number and length distribution patterns of runs of homozygosity (ROHs) in the genomes of different generational groups of Grassland-Thoroughbreds. Short ROHs ranging from 0.5 to 2 Mb were the most abundant, with the following distribution: F1 (85.15%) > F2 (82.92%) > CY (78.75%) > F3 (77.51%). Medium-length ROHs (2–8 Mb) and long ROHs (>8 Mb) together exhibited a similar but opposite trend. The average length of ROHs was 1.57 Mb. The inbreeding coefficients (F_ROH) among different generational groups of Grassland-Thoroughbreds were as follows: F1 (0.0942) < F2 (0.1197) < CY (0.1435) < F3 (0.1497). Through ROH island analysis, 10 high-frequency ROH regions were identified and annotated with 120 genes. Genomic regions and candidate genes associated with athletic traits—ACAD8, OPCML, PRDX2, NTM, NDUFB7, SCL25A15, FOXO1, and SLC4A10—were identified. These genes may play important roles in regulating muscle performance, mitochondrial energy supply, and learning and memory processes in horses and are closely associated with the athletic ability of the Grassland-Thoroughbred population. This study is the first to systematically characterize the genomic diversity and inbreeding dynamics of the Grassland-Thoroughbred during the breeding process. It identifies candidate genes that may influence athletic performance, thereby providing an important molecular foundation and theoretical basis for the genetic improvement and performance-based selection of this emerging breed. Full article

As a moonlighting protein with multiple enzymatic activities, peroxiredoxin 6 (PRDX6) maintains redox homeostasis, regulates phospholipid metabolism, and mediates intra- and inter-cellular signaling transduction. Its expression and activity can be regulated by diverse stressors. However, the roles and relevant mechanisms of these regulators in various conditions have yet to be comprehensively reviewed. In this study, these stressors were systematically reviewed both in vivo and in vitro and classified into chemical, physical, and biological categories. We found that the regulatory effects of these stressors on PRDX6 expression were primarily mediated via key transcriptional factors (e.g., NRF2, HIF-1α, SP1, and NF-κB), micro-RNAs, and receptor- or kinase-dependent signaling pathways. Additionally, certain stressors, including reactive oxygen species, pH fluctuations, and post-translational modifications, induced the structure-based functional switches in the PRDX6 enzyme. We further reviewed the altered expression of PRDX6 under various disease conditions, with a particular focus on neuropsychiatric disorders and cancers, and proposed the concept of PRDX6-related disorders (PRD), which refers to a spectrum of diseases mediated by or associated with dysregulated PRDX6 expression. Finally, we found that an exogenous supplementation of PRDX6 protein provided preventive and therapeutic potentials for oxidative stress-related injuries in both in vivo and in vitro models. Taken together, this review underscores the critical role of PRDX6 as a cellular orchestrator in response to various stressors, highlighting its clinical potential for disease monitoring and the development of therapeutic strategies. Full article

Objective: The objective of this study was to explore the possibility of treating heart failure in rats by delivering mRNA of 24-dehydrocholesterol reductase (DHCR24) into the body through lipid nanoparticles (LNPs). Methods: We established a heart failure rat model using doxorubicin. The experiment was divided into blank, model, mRNA stock solution cardiac injection, mRNA stock solution intravenous injection, LNP-mRNA stock solution cardiac injection, and LNP-mRNA stock solution intravenous injection groups. We directly injected DHCR24-mRNA or LNP-DHCR24-mRNA into the myocardium in three regions through an insulin needle passing through the intercostal space under the guidance of B-ultrasound. We recorded the mortality rate, body weight, 6-min walk test return times, and organ weight of rats after administration and detected the cardiac structure and function using B-ultrasound and transmission electron microscopy (TEM). Additionally, we tested for HE staining; PRDX2, Sirt3, and TRX1 protein expression; and IL-1 β, IL-10, VEGF, NT proBNP, and BNP cytokine concentrations. Results: Compared with the model group, the administration of DHCR24-mRNA significantly reduced mortality; decreased weight loss, the ratio of heart to tibia length, and spleen weight; and improved rat motility. The administration of DHCR24-mRNA can postpone the pathological morphological alterations of myocardial cells and reduce inflammatory infiltration. In terms of biochemistry, the administration of DHCR24-mRNA can increase the expression of the PRDX2, Sirt3, and TRX1 proteins; increase the concentrations of IL-10 and VEGF; and reduce the concentrations of IL-1β, NT proBNP, and BNP. The administration of DHCR24-mRNA can also delay the process of heart failure. The delivery and therapeutic effect of DHCR24-mRNA encapsulated in LNPs were better when compared to the other groups. Conclusions: DHCR24-mRNA encapsulated in LNPs can be effectively administered to rats with heart failure and exhibits some curative effects. Full article

Colorectal cancer ranks as the third most prevalent form of cancer on a global scale. The abnormal expression of Peroxiredoxin 1, or PRDX1, plays an important role in cancer progression and tumor cell survival. This makes inhibiting this protein a promising target for colorectal cancer treatment. In order to develop effective PRDX1 inhibitors, a drug design investigation based on computational methods was carried out using a collection of recently synthesized compounds derived from two main chemical base structures: C-5 sulfenylated amino uracils and 1,2,3-triazole benzothiazole derivatives. To obtain the PRDX1 protein PDB ID: 7WET, molecular docking was performed on the studied compounds in combination with PRDX1. The 1,2,3-triazole benzothiazole derivatives showed interesting docking results. For instance, nine promising candidates were distinguished by their formation of better stable complexes with PRDX1 in terms of E (binding) from −7.0 to −7.3 kcal/mol, namely, 7WET-L18, 7WET-L17, 7WET-L25, 7WET-L19, 7WET-L20, 7WET-L26, 7WET-L22, 7WET-L23, and 7WET-L24, as well as an E of −6.8 kcal/mol for Celastrol, a known PRDX1 inhibitor. Moreover, an extensive evaluation of ADME-TOX was performed to predict the pharmacokinetic, pharmacodynamic, and toxicological properties of the compounds studied. The findings offer significant support for the prospective application of these analogs in the fight against colorectal cancer. Full article

Peroxiredoxin 6 (Prdx6), a unique 1-Cys member of the peroxiredoxin family, exhibits peroxidase activity, phospholipase activity, and lysophosphatidylcholine acyltransferase (LPCAT) activity. Prdx6 has been known to be an important enzyme for the maintenance of lipid peroxidation repair, cellular metabolism, inflammatory signaling, and antioxidant damage. Growing research has demonstrated that the altered activity of this enzyme is linked with various pathological processes including central nervous system (CNS) disorders. This review discusses the distinctive structure, enzyme activity, and function of Prdx6 in different CNS disorders, as well as emphasizing the significance of Prdx6 in neurological disorders. Full article

Sperm proteins play vital roles in improving sperm freezing resilience in domestic animals. However, it remains poorly defined which proteins regulate the freezing resilience of spermatozoa in rams (Ovis aries). Here, we compared the proteome of ram sperm with a high cryopreservation recovery ratio (HCR) with that of ram sperm with a low cryopreservation recovery ratio (LCR) using a tandem mass tag-based quantitative proteomics approach. Bioinformatic analysis was performed to evaluate differentially expressed proteins (DEPs). A total of 2464 proteins were identified, and 184 DEPs were screened. Seventy-two proteins were higher in the LCR group. One hundred and twelve proteins were more abundant in the HCR group, and they were mainly involved in the regulation of oxidative phosphorylation and thermogenesis pathways. Proteins in high abundance in the HCR group included the S100A family, such as S100A8, S100A9, S100A14, and S100A16, effectively controlling for CA²⁺ and maintaining flagella structure; HYOU1 and PRDX1, which participate in antioxidant protection and anti-apoptosis to prevent cell death; and HSP90B1, which maintains cell activity and immune response. Our results could help illuminate the molecular mechanisms underlying cryopreservation of ram semen and expand the potential direction of cryopreservation of high-quality semen. Full article

Employing a combination of liquid chromatography electrospray ionization and paper spray ionization high-resolution tandem mass spectrometry, extracts from cupuassu (Theobroma grandiflorum) pulp prepared with either water, methanol, acetonitrile or combinations thereof were subjected to metabolite fingerprinting. Among the tested extractors, 100% methanol extracted preferentially phenols and cinnamic acids derivatives, whereas acetonitrile and acetonitrile/methanol were more effective in extracting terpenoids and flavonoids, respectively. And while liquid chromatography- mass spectrometry detected twice as many metabolites as paper spray ionization tandem mass spectrometry, the latter proved its potential as a screening technique. Comprehensive structural annotation showed a high production of terpenes, mainly oleanane triterpene derivatives. of the mass spectra Further, five major metabolites with known antioxidant activity, namely catechin, citric acid, epigallocatechin-3′-glucuronide, 5,7,8-trihydroxyflavanone, and asiatic acid, were subjected to molecular docking analysis using the antioxidative enzyme peroxiredoxin 5 (PRDX5) as a model receptor. Based on its excellent docking score, a pharmacophore model of 5,7,8-trihydroxyflavanone was generated, which may help the design of new antioxidants. Full article

The molecular mechanisms of skeletal muscle adaptation to spaceflight are as yet not fully investigated and well understood. The MUSCLE BIOPSY study analyzed pre and postflight deep calf muscle biopsies (m. soleus) obtained from five male International Space Station (ISS) astronauts. Moderate rates of myofiber atrophy were found in long-duration mission (LDM) astronauts (~180 days in space) performing routine inflight exercise as countermeasure (CM) compared to a short-duration mission (SDM) astronaut (11 days in space, little or no inflight CM) for reference control. Conventional H&E scout histology showed enlarged intramuscular connective tissue gaps between myofiber groups in LDM post vs. preflight. Immunoexpression signals of extracellular matrix (ECM) molecules, collagen 4 and 6, COL4 and 6, and perlecan were reduced while matrix-metalloproteinase, MMP2, biomarker remained unchanged in LDM post vs. preflight suggesting connective tissue remodeling. Large scale proteomics (space omics) identified two canonical protein pathways associated to muscle weakness (necroptosis, GP6 signaling/COL6) in SDM and four key pathways (Fatty acid β-oxidation, integrin-linked kinase ILK, Rho A GTPase RHO, dilated cardiomyopathy signaling) explicitly in LDM. The levels of structural ECM organization proteins COL6A1/A3, fibrillin 1, FBN1, and lumican, LUM, increased in postflight SDM vs. LDM. Proteins from tricarboxylic acid, TCA cycle, mitochondrial respiratory chain, and lipid metabolism mostly recovered in LDM vs. SDM. High levels of calcium signaling proteins, ryanodine receptor 1, RyR1, calsequestrin 1/2, CASQ1/2, annexin A2, ANXA2, and sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA1) pump, ATP2A, were signatures of SDM, and decreased levels of oxidative stress peroxiredoxin 1, PRDX1, thioredoxin-dependent peroxide reductase, PRDX3, or superoxide dismutase [Mn] 2, SOD2, signatures of LDM postflight. Results help to better understand the spatiotemporal molecular adaptation of skeletal muscle and provide a large scale database of skeletal muscle from human spaceflight for the better design of effective CM protocols in future human deep space exploration. Full article

Our clinical series comprises 124 patients with movement disorders (MDs) and/or ataxia with cerebellar atrophy (CA), many of them showing signs of neurodegeneration with brain iron accumulation (NBIA). Ten NBIA genes are accepted, although isolated cases compatible with abnormal brain iron deposits are known. The patients were evaluated using standardised clinical assessments of ataxia and MDs. First, NBIA genes were analysed by Sanger sequencing and 59 patients achieved a diagnosis, including the detection of the founder mutation PANK2 p.T528M in Romani people. Then, we used a custom panel MovDisord and/or exome sequencing; 29 cases were solved with a great genetic heterogeneity (34 different mutations in 23 genes). Three patients presented brain iron deposits with Fe-sensitive MRI sequences and mutations in FBXO7, GLB1, and KIF1A, suggesting an NBIA-like phenotype. Eleven patients showed very early-onset ataxia and CA with cortical hyperintensities caused by mutations in ITPR1, KIF1A, SPTBN2, PLA2G6, PMPCA, and PRDX3. The novel variants were investigated by structural modelling, luciferase analysis, transcript/minigenes studies, or immunofluorescence assays. Our findings expand the phenotypes and the genetics of MDs and ataxias with early-onset CA and cortical hyperintensities and highlight that the abnormal brain iron accumulation or early cerebellar gliosis may resembling an NBIA phenotype. Full article

The Tibetan sheep is an indigenous animal of the Tibetan plateau, and after a long period of adaptation have adapted to high-altitude hypoxia. Many physiological changes occur in Tibetan sheep as they adapt to high-altitude hypoxia, especially in the lungs. To reveal the physiological changes and their molecular mechanisms in the lungs of Tibetan sheep during adaptation to high altitudes, we selected Tibetan sheep from three altitudes (2500 m, 3500 m, and 4500 m) and measured blood-gas indicators, observed lung structures, and compared lung proteome changes. The results showed that the Tibetan sheep increased their O₂-carrying capacity by increasing the hemoglobin (Hb) concentration and Hematocrit (Hct) at an altitude of 3500 m. While at altitude of 4500 m, Tibetan sheep decreased their Hb concentration and Hct to avoid pulmonary hypertension and increased the efficiency of air-blood exchange and O₂ transfer by increasing the surface area of gas exchange and half-saturation oxygen partial pressure. Besides these, some important proteins and pathways related to gas transport, oxidative stress, and angiogenesis identified by proteome sequencing further support these physiology findings, including HBB, PRDX2, GPX1, GSTA1, COL14A1, and LTBP4, etc. In conclusion, the lungs of Tibetan sheep are adapted to different altitudes by different strategies; these findings are valuable for understanding the basis of hypoxic adaptation in Tibetan sheep. Full article

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. Full article