Peroxiredoxins (Prx's) are a superfamily of peroxidases that are ubiquitous in all super-kingdoms. Previous biochemical and structural studies have suggested that Prx's could be divided into five subfamilies (1-Cys, Typical 2-Cys, Atypical 2-Cys C-, L- and R- types). In this work, we have developed a set of regular expression patterns describing subfamily-specific spatial constraints of the key catalytic residues. Using these patterns, 1,016 Prx's available in public databases were classified into the five subfamilies. Our method performed well for most of the types except for Atypical 2 Cys R type.
Classification* ; Peroxidases ; Peroxiredoxins*

PURPOSE: Peroxiredoxins(PRDXs) are antioxidant enzymes that play an important role on cell differentiation, proliferation and apoptosis. In this study, we investigated if the expression levels of PRDX I were related to bladder cancer. MATERIALS AND METHODS: The mRNA level of PRDX I was examined via real time polymerase chain reaction(PCR) in 186 cancer specimens from patients with primary bladder cancer, 73 corresponding samples of normal looking bladder mucosae surrounding the cancer and 21 samples of normal bladder mucosae. We investigated the correlation between the expression levels of PRDX I and the clinico-pathological parameters of the 154 patients who could be followed up more than three years. RESULTS: The expression levels of PRDX I in bladder cancer(0.73pg/ml) were significantly higher that that in the normal bladder mucosae (0.04 pg/ml)(p<0.01) or that in the corresponding normal bladder mucosae surrounding the cancer(0.38pg/ml)(p<0.01). The expression level of PRDX I was not significantly enhanced in the non-recurred(0.87pg/ml) superficial bladder tumor patients compared with the recurred superficial bladder tumor patients(0.63pg/ml), but it was significantly enhanced in the non-progressed(0.82pg/ml) patients compared with the progressed (0.50pg/ml) patients(p<0.05 for each). CONCLUSIONS: An enhanced expression of PRDX I is strongly associated with the development of bladder cancer. Moreover, enhanced expressions of PRDX I are also positively associated with a low rate of progression of bladder cancer, and this might be useful as a marker for assessing progression in human bladder cancers.
Apoptosis ; Cell Differentiation ; Humans ; Mucous Membrane ; Peroxiredoxins ; RNA, Messenger ; Urinary Bladder ; Urinary Bladder Neoplasms

OBJECTIVE: To assess the expression pattern of all six Prxs in normal ovarian tissue and epithelial ovarian tumor cell using immunohistochemical staining. METHODS: Patients were retrieved from those who had undertaken operation in Obstetrics and Gynecology of our hospital from January 1995 to June 2005. According to the pathologic result, five patients were allocated randomly in each group of malignant serous, malignant mucinous, benign serous and benign mucinous ovarian tumor. And another five with normal ovarian epithelial cell were included for the comparison. Immunohistochemical staining was performed with Prx I to VI antibodies. Using microscopy, we evaluated the immunoreactivities of nucleus and cytoplasm semiquantitatively by dividing into four categories : -; no immunoactivity present, +; weak, ++; moderate, +++; strong staining. RESULTS: The immunopositivity of Prx III in cytoplasm shows weak to moderate and Prx VI moderate to strong in normal ovarian tissue. In mucinous epithelial ovarian tumor cell, cytoplasmic Prx IV shows stronger activity than in normal epithelial cell or serous tumor cell. In malignant epithelial cell, Prx V shows stronger activity in cytoplasm than normal epithelial cell. It shows characteristically granular pattern. Prx VI shows stronger activity in the nucleus of malignant epithelial cell compared to normal epithelial cell or benign tumor epithelial cell. CONCLUSION: Normal ovarian tissue showed higher affinity for Prx III and VI. In epithelial ovarian tumor, cytosolic Prx IV in mucinous tumor, cytosolic Prx V and nuclear Prx VI in malignant tumor were overexpressed.
Antibodies ; Cytoplasm ; Cytosol ; Epithelial Cells ; Female ; Gynecology ; Humans ; Microscopy ; Mucins ; Obstetrics ; Ovary* ; Peroxiredoxins* ; Protein Isoforms*

Oxidative stress plays a critical role in the pathogenesis of asthma. To effectively control oxidative stress in asthmatics, it is important to investigate the precise intracellular mechanism by which the development of immunity, rather than immune tolerance and progression of airway inflammation, is induced. In this article, we suggest that protein tyrosine phosphatases, as intracellular negative regulators, and intracellular antioxidant enzymes such as peroxiredoxins can be regulated by oxidative stress during intracellular signaling.
Antioxidants ; Asthma ; Hypersensitivity ; Immune Tolerance ; Inflammation ; Oxidative Stress ; Peroxiredoxins ; Protein Tyrosine Phosphatases

Peroxiredoxins (Prxs) are antioxidant enzymes that protect cells from oxidative stress by reducing intracellular accumulation of reactive oxygen species (ROS). In mammalian cells, the six Prx isoforms are ubiquitously expressed in diverse intracellular locations. They are involved in the regulation of various physiological processes including cell growth, differentiation, apoptosis, immune response and metabolism as well as intracellular ROS homeostasis. Although there are increasing evidences that Prxs are involved in carcinogenesis of many cancers, their role in cancer is controversial. The ROS levels in cancer cells are increased compared to normal cells, thus promoting cancer development. Nevertheless, for various cancer types, an overexpression of Prxs has been found to be associated with poor patient prognosis, and an increasing number of studies have reported that tumorigenesis is either facilitated or inhibited by regulation of cancer-associated signaling pathways. This review summarizes Prx isoforms and their basic functions, the relationship between the expression level and the physiological role of Prxs in cancer cells, and their roles in regulating cancer-associated signaling pathways.
Apoptosis ; Carcinogenesis ; Homeostasis ; Humans ; Metabolism ; Oxidative Stress ; Peroxiredoxins ; Physiological Processes ; Prognosis ; Protein Isoforms ; Reactive Oxygen Species

BACKGROUND: The characterization of progenitor/keratinocyte stem cells (KSC) remains an unachieved goal. A previous study showed that rapid adhering cells to collagen IV had the characteristics of putative progenitor/KSCs. OBJECTIVE: The purpose of this study was to investigate the genetic expression of rapid adhering cells compared to non adhering cells to determine the characteristic of KSCs. METHODS: We isolated rapid adhering cells representative of KSCs from non adhering cells representative of transient amplifying cells. In addition, we differentiated cells from human tonsilar keratinocytes utilizing the adhering capability of the KSCs to collagen IV. Annealing control primer based differentially displayed polymerase chain reaction (PCR) was performed as well as Western blot analysis. RESULTS: The levels of mitochondria-related gene expression were low in the rapid adhering cells compared to the non adhering cells. Mitochondrial complex I, COX IV, peroxiredoxins (I, II and IV) and mitochondrial membrane potential were all low in the rapid adhering cells compared to the non adhering cells. CONCLUSION: Using an adhesion method on human collagen IV-coated plates, our results suggest that reduced mitochondrial function may be an important characteristic of KSCs.
Blotting, Western ; Collagen ; Gene Expression ; Humans ; Keratinocytes ; Membrane Potential, Mitochondrial ; Mitochondria ; Peroxiredoxins ; Polymerase Chain Reaction ; Stem Cells

BACKGROUND: Peroxidases (Prx) of the peroxiredoxin family reduce hydrogen peroxide and alkyl hydroperoxides to water and alcohol respectively. Hydrogen peroxide is implicated as an intracellular messenger in various cellular responses such as proliferation and differentiation. And Prx I activity is regulated by Cdc-2 mediated phosphorylation. This work was undertaken to investigate the proliferation role of peroxiredoxin III as a member of Prx family in Prx III overexpressed HeLa cell line. METHODS: To provide further evidence of proliferation, we selected Prx III stably expressed HeLa Tet-off cell lines. Cell proliferation was examined by using proliferation reagent WST-1 in the presence or absence of doxycycline. Prx III, 2-cys Prx enzymes exist as homodimer. The activation of Prx III heterodimer with induced and endogenous Prx III was examined by immunoprecipitation. RESULTS: Immunoprecipitation analysis of the induced and endogenous Prx III with anti-myc showed that the induced wild type (WT) and dominant negative (DN) Prx III from HeLa Prx III Tet-off stable cell heterodimerized with endogenous Prx III each other. And the expression level of induced Prx III was examined after addition of doxycycline. By 72 hr, the expression level of induced Prx III was diminished gradually and the half-life of the induced wild type Prx III was approximately 17 hr. The proliferation experiment demonstrated that the relative proliferation value of induced and endogenous WT Prx III stable cell has no changes but the DN Prx III induced HeLa Tet-off stable cells were lower than endogenous Prx III. CONCLUSION: In conclusion, the HeLa dominant negative Prx III Tet-off stable cells were decreased the proliferation.
Cell Line ; Cell Proliferation ; Doxycycline ; Half-Life ; HeLa Cells* ; Humans* ; Hydrogen Peroxide ; Immunoprecipitation ; Peroxidases ; Peroxiredoxin III* ; Peroxiredoxins* ; Phosphorylation

Peroxiredoxin I (Prx I) is a member of the peroxiredoxins (Prxs) family, which are antioxidant enzymes that regulate various cellular process via intracellular oxidative signal pathways. In order to investigate the correlation between Prx I and the gamma-secretase complex, which causes Alzheimer's disease (AD), the expression level of Prx I was firstly evaluated in an animal model for AD. NSE/hPen-2 transgenic (Tg) mice, which were used as animal model in this study, showed a high level of Pen-2 expression and accumulation of Abeta-42 peptides in the hippocampus of brain. The expression level of Prx I was significantly higher on the mRNA and protein level in the brain of this model, while not change in Prx VI expression was observed. Furthermore, to verify the effect of Prx I on the gamma-secretase components in vitro, the expression level of these components was analyzed in the Prx I transfectants. Of the components of the gamma-secretase complex, the expression of PS-2 and Pen-2 was lower in the transfectants overexpressing Prx I compared to the vector transfectants. However, the expression of APP, NCT and APH-1 did not change in Prx I transfectants. Therefore, these results suggested that the expression of Prx I may be induced by the accumulation of Abeta-42 peptides and the overexpression of Prx I in neuroblastoma cells may regulate the expression of gamma-secretase components.
Alzheimer Disease ; Amyloid Precursor Protein Secretases ; Animals ; Brain ; Hippocampus ; Humans ; Mice ; Models, Animal ; Neuroblastoma ; Peptides ; Peroxiredoxins ; RNA, Messenger ; Signal Transduction

Atherosclerotic vascular dysfunction is a chronic inflammatory process that spreads from the fatty streak and foam cells through lesion progression. Therefore, its early diagnosis and prevention is unfeasible. Reactive oxygen species (ROS) play important roles in the pathogenesis of atherosclerotic vascular disease. Intracellular redox status is tightly regulated by oxidant and antioxidant systems. Imbalance in these systems causes oxidative or reductive stress which triggers cellular damage or aberrant signaling, and leads to dysregulation. Paradoxically, large clinical trials have shown that non-specific ROS scavenging by antioxidant vitamins is ineffective or sometimes harmful. ROS production can be locally regulated by cellular antioxidant enzymes, such as superoxide dismutases, catalase, glutathione peroxidases and peroxiredoxins. Therapeutic approach targeting these antioxidant enzymes might prove beneficial for prevention of ROS-related atherosclerotic vascular disease. Conversely, the development of specific antioxidant enzyme-mimetics could contribute to the clinical effectiveness.
Atherosclerosis ; Catalase ; Early Diagnosis ; Foam Cells ; Glutathione ; Oxidation-Reduction ; Peroxidases ; Peroxiredoxins ; Reactive Oxygen Species ; Superoxides ; Vascular Diseases* ; Vitamins

PURPOSE: We evaluated the hypothesis that the telomerase expression is associated with c-Myc and peroxiredoxin I (Prx I) in patients with prostate cancer. The study determined the link between Prx I, c-Myc and human telomerase reverse transcriptase (hTERT) in prostate cancer cells. MATERIALS AND METHODS: The cDNA of the Prx I gene was obtained by reverse-transcriptase polymerase chain reaction (RT-PCR) amplification. Cotransfections were performed by using a hTERT luciferase reporter plasmid and each expression vector as indicated (c-Myc or Prx I). Empty vectors were used as controls for determining the basal promoter activity. RT-PCR was performed to evaluate the effect of the DEM-induced Prx I mRNA expression. Luciferase assay was performed to evaluate the inhibitory effect of transfected Prx I and the DEM induced Prx I on the transcriptional activity of hTERT in the human prostatic cancer cell lines PC-3 and DU-145. RESULTS: In this study, we found that Prx I could inhibit hTERT expression through direct interaction with c-Myc protein in the prostate cancer cell lines. In addition, it was obvious that Prx I could interact with c-Myc protein. We also found that DEM could induce upregulation of the Prx I mRNA expression and that the increased expression of Prx I could downregulate the expression of hTERT. CONCLUSIONS: Our results demonstrated a direct link between Prx I, c-Myc and hTERT, and we suggest that Prx I regulates cellular immortalization through c-Myc and hTERT, which is activation step in carcinogenesis.
Carcinogenesis ; Cell Line ; DNA, Complementary ; Humans* ; Luciferases ; Peroxiredoxins* ; Plasmids ; Polymerase Chain Reaction ; Prostatic Neoplasms* ; RNA, Messenger ; Telomerase* ; Up-Regulation