NCBI Summary:
This gene encodes a member of the peroxiredoxin family of antioxidant enzymes, which reduce hydrogen peroxide and alkyl hydroperoxides. The encoded protein plays an antioxidant protective role in cells, and it may contribute to the antiviral activity of CD8(+) T-cells. The crystal structure of this protein has been resolved to 2.7 angstroms. This protein prevents hemolytic anemia from oxidative stress by stabilizing hemoglobin, thus making this gene a therapeutic target for patients with hemolytic anemia. This protein may have a proliferative effect and play a role in cancer development or progression. Related pseudogenes have been identified on chromosomes 5, 6, 10 and 13. [provided by RefSeq, Mar 2013]
Proteomic biomarkers of type 2 diabetes mellitus risk in women with polycystic ovary syndrome. Galazis N et al. (2013) Women with polycystic ovary syndrome (PCOS) are at increased risk of developing insulin resistance and type 2 diabetes mellitus (T2DM). In this study, we attempted to list the proteomic biomarkers of PCOS and T2DM that have been published in the literature so far. We identified eight common biomarkers that were differentially expressed in both women with PCOS and T2DM when compared with healthy controls. These include pyruvate kinase M1/M2, apolipoprotein A-I, albumin, peroxiredoxin 2, annexin A2, α-1-B-glycoprotein, flotillin-1 and haptoglobin. These biomarkers could help improve our understanding of the links between PCOS and T2DM and could be potentially used to identify subgroups of women with PCOS at increased risk of T2DM. More studies are required to further evaluate the role these biomarkers play in women with PCOS and T2DM.//////////////////
Ovarian function
Cumulus expansion, Follicle atresia, Oogenesis, Oocyte maturation, Early embryo development
Comment
Involvement of peroxiredoxin 2 in cumulus expansion and oocyte maturation in mice. Jang YJ et al. (2020) Peroxiredoxin 2 (Prdx2), an antioxidant enzyme, is expressed in the ovary during the ovulatory process. The aim of the present study was to examine the physiological role of Prdx2 during ovulation using Prdx2-knockout mice and mouse cumulus-oocyte complex (COC) from WT mice. Two days of treatment of immature mice (21-23 days old) with equine chorionic gonadotrophin and followed by treatment with human chorionic gonadotrophin greatly impaired cumulus expansion and oocyte maturation in Prdx2-knockout but not wild-type mice. Treatment of COCs in culture with conoidin A (50µM), a 2-cys Prdx inhibitor, abolished epiregulin (EPI)-induced cumulus expansion. Conoidin A treatment also inhibited EPI-stimulated signal molecules, including signal transducer and activator of transcription-3, AKT and mitogen-activated protein kinase 1/2. Conoidin A treatment also reduced the gene expression of EPI-stimulated expansion-inducing factors (hyaluronan synthase 2 (Has2), pentraxin 3 (Ptx3), TNF-α induced protein 6 (Tnfaip6) and prostaglandin-endoperoxide synthase 2 (Ptgs2)) and oocyte-derived factors (growth differentiation factor 9 (Gdf9) and bone morphogenetic protein 15 (Bmp15)). Furthermore, conoidin A inhibited EPI-induced oocyte maturation and the activity of connexins 43 and 37. Together, these results demonstrate that Prdx2 plays a role in regulating cumulus expansion and oocyte maturation during the ovulatory process in mice, probably by modulating epidermal growth factor receptor signalling.//////////////////
Peroxiredoxin as a functional endogenous antioxidant enzyme in pronuclei of mouse zygotes. Morita K et al. (2018) Antioxidant mechanisms to adequately moderate levels of endogenous reactive oxygen species (ROS) are important for oocytes and embryos to obtain and maintain developmental competence, respectively. Immediately after fertilization, ROS levels in zygotes are elevated but the antioxidant mechanisms during the maternal-to-zygotic transition (MZT) are not well understood. First, we identified peroxiredoxin 1 (PRDX1) and PRDX2 by proteomics analysis as two of the most abundant endogenous antioxidant enzymes eliminating hydrogen peroxide (H2O2). We here report the cellular localization of hyperoxidized PRDX and its involvement in the antioxidant mechanisms of freshly fertilized oocytes. Treatment of zygotes at the pronuclear stage with H2O2enhanced pronuclear localization of hyperoxidized PRDX in zygotes and concurrently impaired the generation of 5-hydroxymethylcytosine (5hmC) on the male genome, which is an epigenetic reprogramming event that occurs at the pronuclear stage. Thus, our results suggest that endogenous PRDX is involved in antioxidant mechanisms and epigenetic reprogramming during the MZT.//////////////////
Peroxiredoxins are required for spindle assembly, chromosome organization, and polarization in mouse oocytes. Jeon HJ et al. (2017) Peroxiredoxins (Prxs) are highly conserved antioxidant enzymes and are implicated in multiple biological processes; however, their function in oocyte meiosis has not been studied. Here we show that inhibition of Prx I and II results in spindle defects, chromosome disorganization, and impaired polarization in mouse oocytes. Prx I was specifically localized at the spindle, whereas Prx II was enriched at the oocyte cortex and chromosomes. Inhibition of Prx activity with conoidin A disturbed assembly of the microtubule organizing center (MTOC) through Aurora A regulation, leading to defects in spindle formation. Moreover, conoidin A impaired actin filament and cortical granule (CG) distribution, disrupting actin cap and CG formation, respectively. Conoidin A also increased DNA damage without significantly increasing reactive oxygen species (ROS) levels, suggesting that the effects of conoidin A on meiotic maturation are not likely associated with ROS scavenging pathways. Therefore, our data suggest that Prxs are required for spindle assembly, chromosome organization, and polarization during meiotic maturation.//////////////////
Peroxiredoxin 2 Inhibits Granulosa Cell Apoptosis During Follicle Atresia Through the NFKB Pathway in Mice. Yang S et al. Peroxiredoxin 2 (PRDX2) has been known to act as an antioxidant enzyme whose main function is H(2)O(2) reduction in cells. We aim to study the expression patterns of PRDX2 in mouse ovaries and explore the function of this protein in apoptosis of granulosa cells (GCs). We found that the expression of PRDX2 protein in atretic follicle GCs was markedly higher than in healthy follicle GCs. In vitro, the transfection of siRNA targeted towards Prdx2 inhibited the proliferation and induced the apoptosis of the primary cultured GCs. Furthermore, suppression of PRDX2 resulted in the augmentation of endogenous H(2)O(2), and the ability to eliminate the exogenous H(2)O(2) was attenuated. The expression of PRDX2 and nuclear NFKB whose activity was inhibited by binding to IKB increased in GCs treated with various concentrations of H(2)O(2) for 30 min. However, no significant change in cytoplasmic IKB expression was observed. Two hours after treatment with H(2)O(2), nuclear NFKB expression level was reduced, cytoplasmic IKB expression was increased, and PRDX2 was unchanged. Silencing of the Prdx2 gene caused early changes in NFKB and IKB expression in the primary cultured GCs compared to control cells. Taken together, these data suggest that PRDX2 plays an important role in inhibiting apoptosis in GCs and PRDX2 actions may be related to the expression of NFKB and IKB.
Expression regulated by
FSH, LH
Comment
Periovulatory Expression of Hydrogen Peroxide-Induced Sulfiredoxin and Peroxiredoxin 2 in the Rat Ovary: Gonadotropin Regulation and Potential Modification. Park JI et al. Reactive oxygen species are involved in ovulation. The aim of this study was to examine gonadotropin regulation of antioxidant enzyme sulfiredoxin (Srx) and peroxiredoxin 2 (PRDX2) expressions and modification during the ovulatory process in rats. Administration of antioxidants in vivo reduced ovulation rate and cumulus expansion. LH treatment increased H(2)O(2) levels within 15 min, which, in turn, induced Srx gene expression in cultured preovulatory follicles. Treatment of preovulatory follicles with catalase suppressed the stimulatory effect of LH on Akt phosphorylation. LH- or H(2)O(2)-stimulated Srx mRNA levels were suppressed by inhibitors of antioxidant agents and MAPK kinase. An in vivo injection of equine chorionic gonadotropin-human chorionic gonadotropin (hCG) stimulated Srx mRNA within 1 h in granulosa but not thecal cells of preovulatory follicles. Srx protein levels were stimulated from 3 h post-hCG injection. Immunofluorescence analysis revealed that oocytes expressed the Srx protein. Furthermore, hCG treatment increased Srx expression in mural granulosa, theca and cumulus cells, but the Srx protein was not detected in corpora lutea. Gene expression of PRDX2, identified as an Srx-dependent modified enzyme, was stimulated by gonadotropins. In situ hybridization analysis demonstrated that PRDX2 mRNA was detected in oocytes and theca cells as well as granulosa cells of some antral and preovulatory follicles. High levels of PRDX2 mRNA were detected in corpora lutea. Total levels of PRDX2 protein were not changed by gonadotropins. However, levels of hyperoxidized PRDX2 increased within 2-3 h after the hCG injection. Taken together, gonadotropin stimulation of Srx expression and PRDX2 modification in the ovary suggest the existence of an antioxidant system to maintain H(2)O(2) production and elimination during the periovulatory period.
Ovarian localization
Oocyte, Cumulus, Granulosa, Follicular Fluid
Comment
Association of creatin kinase B and peroxiredoxin 2 expression with age and embryo quality in cumulus cells. Lee MS et al. PURPOSE: The purpose of this study was to identify age-related oocyte or embryo markers suitable for non-invasive analysis, as women over 38 years of age experience diminished pregnancy and ovulation rates. METHODS: We used real-time quantitative PCR to examine the gene expression profiles in cumulus cells acquired from older and younger age groups. We selected 11 genes involved in three functions that directly affect cellular aging: cell cycle control, apoptosis, and metabolism. RESULTS: CKB and PRDX2 were up-regulated in women older than 38 years, and the expression of these genes in cumulus cells was associated with embryo quality. In good-quality embryos, CKB expression was higher in the cumulus cells acquired from both older and younger age groups than in poor-quality embryos. CONCLUSIONS: These potential relationships among cumulus cell gene expression, oocyte quality, and age may expand our understanding of oogenesis and embryo development. CKB and PRDX2 may serve as biomarkers or therapeutic targets for the developmental potential of oocytes.
Identification of new proteins in follicular fluid of mature human follicles. Anahory T et al. Proteins present in human follicular fluid (HFF) have been poorly characterized to date. The purpose of our study was to analyse the protein content and identify new proteins originating from fluid of mature human follicles. A total of six females from infertile couples referred for in vitro fertilization (IVF) were stimulated and 44 follicular fluid samples from mature follicles yielding an oocyte were collected 34-36 h after human chorionic gonadotropin administration. HFF samples were processed for high-resolution two-dimensional polyacrylamide gel electrophoresis (2-D PAGE). Comparative analysis of the 2-D gels revealed up to 600 spots, of which four were selected because of variations in their expression level. Using direct sequencing procedures (Edman degradation) or matrix assisted laser desorption/ionization-mass spectrometry (MALDI-MS), these four spots were identified as three new proteins: thioredoxin peroxydase 1 (TDPX1), transthyretin (TTR) and retinol-binding protein (RBP). The proteins identified here may emerge as potential candidates for specific functions during folliculogenesis and may prove useful as biomedical markers for follicle and/or oocyte maturation.
Expression of peroxiredoxins in bovine oocytes and embryos produced in vitro.
Leyens G, Knoops B, Donnay I.
Veterinary Unit, Institut des Sciences de la Vie, Universite Catholique de Louvain, Place Croix du Sud 5, Louvain-la-Neuve, Belgium.
Peroxiredoxins (PRDXs) form a family of peroxidases involved in antioxidant protection and cell signaling. Due to their peroxide reductase activity, these enzymes might be involved in fine-tuning peroxide levels in embryos during in vitro production. In this study, RT-PCR was used to examine the expression of the six PRDX isoforms (PRDX1 to PRDX6) in bovine oocytes and embryos. PRDXs were detected in oocytes both before and after in vitro maturation. Besides, PRDX6 was up-regulated after maturation. Single embryos were analyzed from the two-cell to the blastocyst stages. PRDX1 and PRDX5 transcripts were detected throughout development. PRDX2, PRDX3, and PRDX6 were not expressed around the 9- to 16-cell stage. PRDX4 transcripts were weakly detected in pools of embryos from the 9- to 16-cell stage onwards. In situ immunodetection of PRDX5, which was previously reported to exhibit the widest subcellular distribution among PRDXs in adult mammalian cells, showed a mitochondrial distribution pattern in the bovine embryo. Finally, the potential modulation by oxidative stress of PRDX expression around the major embryonic genome activation was evaluated by culturing embryos under 20% O(2) instead of 5%. No significant difference in the pattern of PRDX expression was observed under 20% O(2). In conclusion, our data show for the first time that PRDXs are expressed in mammalian oocytes and early embryos. Moreover, the bovine transcripts exhibit various patterns of expression that might be related to the potential role of PRDXs in oocyte maturation and embryo development. Mol. Reprod. Dev. 69: 243-251, 2004. .
Follicle stages
Primary, Secondary, Antral
Comment
Localization and Expression of Peroxiredoxin II in the Mouse Ovary, Oviduct, Uterus, and Preimplantation Embryo. Wang S et al. Peroxiredoxin (Prx) II belongs to a recently discovered family of peroxidases that play important roles in antioxidation and signal transduction. In this study, we aimed to study the localization and expression of Prx II in the mouse ovary, oviduct, and uterus, and preimplantation embryos. Immunohistochemical staining analysis showed that, in the ovary, Prx II was expressed in the oocyte cytoplasm of the primary follicle, the secondary follicle, and the premature follicle; Prx II was expressed in germinal vesicle-intact oocytes (GV oocytes) and metaphase II eggs (MII eggs), as well as at various stages in early embryos. Reverse transcription polymerase chain reaction (RT-PCR) results indicated that the Prx II mRNA was expressed at a high level in GV eggs, slightly lower levels in MII eggs, and had no detectable expression in four-cell embryos and early blastocysts. In the oviduct, Prx II was expressed in the epithelia, while in the uterus Prx II was mainly distributed in the endometrial stroma. Taken together, our results suggest that Prx II plays a key antioxidation role in the maturation of oocytes and development of early embryos, thus providing crucial experimental evidence for further exploring the function of Prx II in the development of oocytes and preimplantation embryos. Anat Rec, 2009. (c) 2009 Wiley-Liss, Inc.
Phenotypes
PCO (polycystic ovarian syndrome)
Mutations
1 mutations
Species: mouse
Mutation name: type: null mutation fertility: subfertile Comment: Involvement of peroxiredoxin 2 in cumulus expansion and oocyte maturation in mice. Jang YJ et al. (2020) Peroxiredoxin 2 (Prdx2), an antioxidant enzyme, is expressed in the ovary during the ovulatory process. The aim of the present study was to examine the physiological role of Prdx2 during ovulation using Prdx2-knockout mice and mouse cumulus-oocyte complex (COC) from WT mice. Two days of treatment of immature mice (21-23 days old) with equine chorionic gonadotrophin and followed by treatment with human chorionic gonadotrophin greatly impaired cumulus expansion and oocyte maturation in Prdx2-knockout but not wild-type mice. Treatment of COCs in culture with conoidin A (50µM), a 2-cys Prdx inhibitor, abolished epiregulin (EPI)-induced cumulus expansion. Conoidin A treatment also inhibited EPI-stimulated signal molecules, including signal transducer and activator of transcription-3, AKT and mitogen-activated protein kinase 1/2. Conoidin A treatment also reduced the gene expression of EPI-stimulated expansion-inducing factors (hyaluronan synthase 2 (Has2), pentraxin 3 (Ptx3), TNF-α induced protein 6 (Tnfaip6) and prostaglandin-endoperoxide synthase 2 (Ptgs2)) and oocyte-derived factors (growth differentiation factor 9 (Gdf9) and bone morphogenetic protein 15 (Bmp15)). Furthermore, conoidin A inhibited EPI-induced oocyte maturation and the activity of connexins 43 and 37. Together, these results demonstrate that Prdx2 plays a role in regulating cumulus expansion and oocyte maturation during the ovulatory process in mice, probably by modulating epidermal growth factor receptor signalling.//////////////////