Reactive oxygen species (ROS) play a dual role in mammalian spermatozoa. At high levels, they are detrimental to sperm function since they can promote oxidative stress that produces oxidation of protein, lipids, and sperm DNA. This oxidative damage is associated with male infertility. On the other hand, when ROS are produced at low levels, they participate in the redox signaling necessary for sperm capacitation. Capacitation-associated ROS are produced by the sperm oxidase, whose identity is still elusive, located in the plasma membrane of the spermatozoon. ROS, such as superoxide anion, hydrogen peroxide, nitric oxide, and peroxynitrite, activate protein kinases and inactivate protein phosphatases with the net increase of specific phosphorylation events. Peroxiredoxins (PRDXs), antioxidant enzymes that fight against oxidative stress, regulate redox signaling during capacitation. Among them, PRDX6, which possesses peroxidase and calcium-independent phospholipase A 2 (iPLA 2 ) activities, is the primary regulator of redox signaling and the antioxidant response in human spermatozoa. The lysophosphatidic acid signaling is essential to maintain sperm viability by activating the phosphatidylinositol 3-kinase/protein kinase (PI3K/AKT) pathway, and it is regulated by PRDX6 iPLA 2 , protein kinase C (PKC), and receptor-type protein tyrosine kinase. The understanding of redox signaling is crucial to pave the way for novel diagnostic tools and treatments of male infertility.
Humans ; Male ; Spermatozoa/physiology* ; Signal Transduction/physiology* ; Oxidation-Reduction ; Peroxiredoxins/physiology* ; Reactive Oxygen Species/metabolism* ; Oxidative Stress/physiology* ; Sperm Capacitation/physiology* ; Infertility, Male/metabolism*

This study explored the generation site and regulation mechanism of reactive oxygen species(ROS) in the apoptosis of colorectal cancer cells induced by furanodienone(Fur). RKO cells were treated with 200 μmol·L~(-1) of Fur, and the changes in intracellular nicotinamide adenine dinucleotide phosphate oxidase(NOX) activity were detected by the NOX activity detection method. The control group, Fur group, diphenyleneiodonium(DPI) inhibitor group for general NOX, mitochondrial-targeted antioxidant(MitoTEMPO) group, Fur+DPI group, Fur+MitoTEMPO group, and H_2O_2 positive control group were set up. Intracellular ROS levels were detected by the ROS fluorescent staining method, and NOX1-NOX5 protein expressions were detected by Western blot. The NOX1-specific inhibitor ML171 and NOX4-specific inhibitor(GLX351322) were further introduced, and the cell activity was determined by cell counting kit-8(CCK-8) assay. The effects of ROS level change on the protein expressions of NOX4 and peroxiredoxin 1(PRDX1) were measured by Western blot. BAY11-7082, which is an inhibitor of the inhibitor of nuclear factor κB protein α(IκBα), was used to explore the effect of the expression of phosphorylated nuclear factor κB(p-NF-κB) in the nucleus after the Fur treatment on the NOX4 protein level. The lentiviral plasmid and empty plasmid for PRDX1 gene silencing were constructed to transfect RKO cells, and stably transfected strains were screened. The impact of PRDX1 gene knockout on Fur-induced apoptosis was further analyzed using the flow cytometry assay. The findings demonstrate a considerable increase in mitochondrial ROS level in response to Fur treatment, with an increase in intracellular NOX activity. However, the mitochondrial ROS level is significantly reduced in the Fur+DPI group. The results from Western blot and CCK-8 analysis suggest that intracellular NOX1 and NOX4 protein expressions are elevated by Fur treatment, and GLX351322 effectively reverses the pro-apoptotic effect of Fur, while ML171 has a minimal impact on apoptosis rate. Meanwhile, Fur significantly boosts the level of p-NF-κB in the nucleus, whereas the protein levels of p-NF-κB and NOX4 are reduced after the BAY treatment. The regulation of Fur on NOX4 and PRDX1 protein expressions is negatively correlated. In the stably transfected cell strain with PRDX1 gene knockout, the apoptosis rate is considerably higher than that of the negative control group after Fur treatment. The above results indicate that Fur can induce the apoptosis of colorectal cancer cells by promoting the signal transduction of NF-κB in the nucleus and increasing the generation of mitochondrial ROS derived from NOX4 to inhibit the PRDX1 protein expression.
Humans ; Peroxiredoxins/metabolism* ; Apoptosis/drug effects* ; Reactive Oxygen Species/metabolism* ; NADPH Oxidase 4/metabolism* ; Mitochondria/genetics* ; Cell Line, Tumor ; Colorectal Neoplasms/drug therapy* ; NADPH Oxidases/metabolism* ; Furans/pharmacology*

Ambystoma mexicanum/immunology* ; Amputation ; Animals ; Biomarkers/metabolism* ; Blastomeres/immunology* ; Cell Lineage/immunology* ; Connective Tissue Cells/immunology* ; Epithelial Cells/immunology* ; Forelimb ; Gene Expression ; High-Throughput Nucleotide Sequencing ; Humans ; Immunity ; Peroxiredoxins/immunology* ; Regeneration/immunology* ; Regenerative Medicine/methods* ; Single-Cell Analysis/methods*

Objective: To investigate the relationship of electromagnetic radiation (EMR) from 900 MHz cellphone frequency with testicular oxidative damage and its influence on the Prdx2 protein expression in the rat testis, and to explore the mechanism of Guilingji Capsules (GC) alleviating oxidative damage to the testis tissue. METHODS: Fifty healthy SD male rats were randomly divided into five groups of equal number, sham-EMR, 4-h EMR, 8-h EMR, 4-h EMR+GC and 8-h EMR+GC and exposed to 900 MHz EMR (370 μW/cm2) for 0, 4 or 8 hours daily for 15 successive days. The rats of the latter two groups were treated intragastrically with GC suspension and those of the first three groups with pure water after exposure to EMR each day. After 15 days of exposure and treatment, all the rats were sacrificed and their testis tissue collected for observation of the histomorphological and ultrastructural changes by HE staining and transmission electron microscopy, measurement of the levels of serum glutathione (GSH), superoxide dismutase (SOD) and malondialdehyde (MDA) with thiobarbiuric acid and determination of the Prdx2 protein expression by immunohistochemistry and Western blot. RESULTS: Compared with the rats in the sham-EMR group, those in the 4-h and 8-h EMR groups showed different degrees of histomorphological and ultrastructural changes in the testis tissue, significantly decreased levels of GSH (［80.62 ± 10.99］ vs ［69.58 ± 4.18］ and ［66.17 ± 8.45］ mg/L, P < 0.05) and SOD (［172.29 ± 10.98］ vs ［158.92 ± 6.46］ and ［148.91 ± 8.60］ U/ml, P < 0.05) and increased level of MDA (［7.51 ± 1.73］ vs ［9.84 ± 1.03］ and ［11.22 ± 2.13］ umol/ml, P < 0.05), even more significantly in the 8-h than in the 4-h EMR group (P < 0.05). In comparison with the sham-EMR group, the expression of the Prdx2 protein was markedly downregulated in the 4-h and 8-h EMR groups (0.56 ± 0.03 vs 0.49 ± 0.03, 0.21 ± 0.01, P < 0.05), but again upregulated in the 4-h and 8-h EMR+GC groups (0.55±0.03 and 0.37±0.04) (P < 0.05). CONCLUSIONS Electromagnetic radiation from cellphones can cause ultrastructural damage to the testis tissue of male rats, while Guilingji Capsules can alleviate it, presumably by upregulating the Prdx2 protein expression in the testis tissue and reducing testicular oxidative damage.
Animals ; Capsules ; Cell Phone ; Drugs, Chinese Herbal/therapeutic use* ; Electromagnetic Radiation ; Glutathione/blood* ; Male ; Malondialdehyde/blood* ; Microscopy, Electron, Transmission ; Oxidative Stress ; Peroxiredoxins/metabolism* ; Radiation Injuries, Experimental/drug therapy* ; Rats ; Superoxide Dismutase/blood* ; Testis/pathology* ; Thiobarbituric Acid Reactive Substances/analysis*

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

Glutamate leads to neuronal cell damage by generating neurotoxicity during brain development. The objective of this study is to identify proteins that differently expressed by glutamate treatment in neonatal cerebral cortex. Sprague-Dawley rat pups (post-natal day 7) were intraperitoneally injected with vehicle or glutamate (10 mg/kg). Brain tissues were isolated 4 h after drug treatment and fixed for morphological study. Moreover, cerebral cortices were collected for protein study. Two-dimensional gel electrophoresis and mass spectrometry were carried out to identify specific proteins. We observed severe histopathological changes in glutamate-exposed cerebral cortex. We identified various proteins that differentially expressed by glutamate exposure. Identified proteins were thioredoxin, peroxiredoxin 5, ubiquitin carboxy-terminal hydrolase L1, proteasome subunit alpha proteins, isocitrate dehydrogenase, and heat shock protein 60. Heat shock protein 60 was increased in glutamate exposed condition. However, other proteins were decreased in glutamate-treated animals. These proteins are related to anti-oxidant, protein degradation, metabolism, signal transduction, and anti-apoptotic function. Thus, our findings can suggest that glutamate leads to neonatal cerebral cortex damage by regulation of specific proteins that mediated with various functions.
Animals ; Brain ; Cerebral Cortex ; Chaperonin 60 ; Electrophoresis, Gel, Two-Dimensional ; Glutamic Acid ; Humans ; Infant, Newborn ; Isocitrate Dehydrogenase ; Mass Spectrometry ; Metabolism ; Neurons ; Peroxiredoxins ; Proteasome Endopeptidase Complex ; Proteolysis ; Proteomics ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; Thioredoxins ; Ubiquitin Thiolesterase

4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is a potent and prevalent nitrosamine procarcinogen found in cigarette smoke. The aim of this work is to study alterations in peroxiredoxin (Prx) expression induced by NNK during carcinogenesis. Characterization of Prx genes from hamster was performed using bioinformatics. V79 cells were induced with different concentrations of NNK (0.1-0.4 mg/mL), and the expression levels of six Prx genes (Prx1-Prx6) were measured by qRT-PCR 24 h following NNK treatment. Prx gene expression was induced by NNK stress, and the highest transcription levels were induced by over 20.42-fold relative to that of the control. NNK induced alterations in Prx expression over the course of lung cancer, which means Prxs may play important roles in ROS detoxification under NNK stress and their functions are complementary.
Animals ; Carcinogens ; administration & dosage ; toxicity ; Cell Line ; Cell Survival ; Cricetinae ; Cricetulus ; Dose-Response Relationship, Drug ; Gene Expression Regulation ; drug effects ; Nitrosamines ; administration & dosage ; toxicity ; Peroxiredoxins ; genetics ; metabolism

Silicosis is one of the most serious occupational diseases in China and dates back to centuries ago. In this study, we successfully established a rat model of silicosis by intratracheal silica injection for 28 days and determined hydroxyproline levels to evaluate collagen metabolism in lung homogenates. Oxidative stress status was evaluated by detecting catalase and glutathione peroxidase activities. Expression levels of peroxiredoxins (Prx I and Prx VI) were detected by Western blotting. Pulmonary surfactant protein A (SP-A) levels in rat serum and lung tissue were analyzed by ELISA, and SP-A and Prx expression levels in lung tissues were detected by immunohistochemistry. The results suggest that Prx proteins may be involved in pulmonary fibrosis induced by silica. Downregulation of SP-A expression caused due to silica is an important factor in the occurrence and development of silicosis.
Animals ; Disease Models, Animal ; Humans ; Lung ; enzymology ; metabolism ; Male ; Oxidative Stress ; Peroxiredoxin VI ; genetics ; metabolism ; Peroxiredoxins ; genetics ; metabolism ; Pulmonary Surfactant-Associated Protein A ; genetics ; metabolism ; Rats ; Silicon Dioxide ; toxicity ; Silicosis ; genetics ; metabolism

Redox adaptation is an important concept that explains the mechanisms by which cancer cells survive under persistent endogenous oxidative stress and become resistant to certain anticancer agents. To investigate this concept, we determined the expression levels of peroxiredoxins (Prxs), antioxidant enzymes in drug-resistant non-small cell lung carcinoma cells. Prx II was remarkably increased only in A549/GR (gefitinib-resistant) cells compared with A549 cells, consistent with methylation/demethylation. Prx II was highly methylated in the A549 cells but was demethylated in the A549/GR cells. The elevated expression of Prx II resulted in the downregulation of reactive oxygen species (ROS) and cell death and upregulation of cell cycle progression in the A549/GR cells. When Prx II mRNA in the A549/GR cells was knocked down, the levels of ROS and apoptosis were significantly recovered to the levels of the controls. In addition, signaling molecules involved in apoptosis were increased in the A549/GR-shPrx II cells. There was no difference in the expression of MAPK/ERK between the A549/GR cells and A549/GR-shPrx II cells, but the phosphorylation of JNK was increased in the A549/GR cells and was markedly decreased in the A549/GR-shPrx II cells. Colony number and tumor growth were significantly decreased in the A549/GR-shPrx II cells compared with the A549/GR cells. Our findings suggest that Prx II has an important role in cancer cell survival via the modulation of signaling molecules involved in apoptosis and the phosphorylation of JNK by the downregulation of ROS levels in A549/GR cells.
Animals ; Antineoplastic Agents/*therapeutic use ; Apoptosis/drug effects ; Carcinoma, Non-Small-Cell Lung/*drug therapy/genetics/metabolism/pathology ; Cell Line, Tumor ; Drug Resistance, Neoplasm ; Female ; Humans ; Lung/drug effects/metabolism/pathology ; Lung Neoplasms/*drug therapy/genetics/metabolism/pathology ; Mice, Inbred BALB C ; Mice, Nude ; Oxidative Stress/drug effects ; Peroxiredoxins/*genetics/metabolism ; Quinazolines/*therapeutic use ; Reactive Oxygen Species/metabolism

Redox adaptation is an important concept that explains the mechanisms by which cancer cells survive under persistent endogenous oxidative stress and become resistant to certain anticancer agents. To investigate this concept, we determined the expression levels of peroxiredoxins (Prxs), antioxidant enzymes in drug-resistant non-small cell lung carcinoma cells. Prx II was remarkably increased only in A549/GR (gefitinib-resistant) cells compared with A549 cells, consistent with methylation/demethylation. Prx II was highly methylated in the A549 cells but was demethylated in the A549/GR cells. The elevated expression of Prx II resulted in the downregulation of reactive oxygen species (ROS) and cell death and upregulation of cell cycle progression in the A549/GR cells. When Prx II mRNA in the A549/GR cells was knocked down, the levels of ROS and apoptosis were significantly recovered to the levels of the controls. In addition, signaling molecules involved in apoptosis were increased in the A549/GR-shPrx II cells. There was no difference in the expression of MAPK/ERK between the A549/GR cells and A549/GR-shPrx II cells, but the phosphorylation of JNK was increased in the A549/GR cells and was markedly decreased in the A549/GR-shPrx II cells. Colony number and tumor growth were significantly decreased in the A549/GR-shPrx II cells compared with the A549/GR cells. Our findings suggest that Prx II has an important role in cancer cell survival via the modulation of signaling molecules involved in apoptosis and the phosphorylation of JNK by the downregulation of ROS levels in A549/GR cells.
Animals ; Antineoplastic Agents/*therapeutic use ; Apoptosis/drug effects ; Carcinoma, Non-Small-Cell Lung/*drug therapy/genetics/metabolism/pathology ; Cell Line, Tumor ; Drug Resistance, Neoplasm ; Female ; Humans ; Lung/drug effects/metabolism/pathology ; Lung Neoplasms/*drug therapy/genetics/metabolism/pathology ; Mice, Inbred BALB C ; Mice, Nude ; Oxidative Stress/drug effects ; Peroxiredoxins/*genetics/metabolism ; Quinazolines/*therapeutic use ; Reactive Oxygen Species/metabolism