Recombinant Human Peroxiredoxin-5 Improves Anti-tumor Immunity by Inducing Macrophage Polarization / 中国生物化学与分子生物学报

Tumor cells can use different strategies to suppress the immune system and disable them for killing tumor cells. Previous studies have shown that recombinant human peroxiredoxin-5 (hPRDX5) can activate the normal anti-tumor immune, so as to control and eliminate the tumor cells, but its exact mechanism of action needs to be studied in depth. The study aimed to investigate whether hPRDX5 exerts its anti-tumor activity by activating or reversing the polarization state of mouse macrophages RAW264. 7 cells. The results of CCK8 showed that different doses of hPRDX5 could significantly enhance the viability of macrophage compared with the control group (P < 0. 001); The results of Nitric oxide (NO) test showed that hPRDX5 significantly enhanced NO secretion levels in RAW264. 7 cells (P < 0. 001); ELISA experiments revealed that hPRDX5 promotes TNF-α (P<0. 01) and IL-6 (P<0. 001) secretion in RAW264. 7 cells; Flow cytometry revealed that hPRDX5 increased the expression of antigen differentiation cluster (CD) 80 (P < 0. 01) and inducible nitric oxide oxide synthase (iNOS) (P < 0. 001) in RAW264. 7 cells, and reduced the expression of CD206 (P < 0. 001) in RAW264. 7 cells induced by tumor conditional culture solution (TCS); Lactate dehydrogenase (LDH) experiments revealed that hPRDX5 can increase the killing activity of mouse macrophages on mouse pancreatic cancer Panc02 cells. hPRDX5 is able to activate mouse macrophage RAW264. 7 cells, promotes its M1-type polarization, reverses M2-type polarization, and exerts antitumor activity through the immune-enhancing effect.

Biochemical relationship between leiomyosarcoma and peroxiredoxin-6 expression level: Clinical implications

Uterine leiomyosarcomas are tumors with a heterogeneous genetic profiles that respond very poorly to cytotoxic chemotherapy with aggressive progression. We aimed to show the status of peroxiredoxin 6 as a biomarker in leiomyosarcoma progression.Study included 12 patients diagnosed with "leiomyosarcoma" and 13 patients diagnosed with "myoma" (as control) after histopathological examinations of clinical samples. Peroxiredoxin-6 gene expression and protein levels were evaluated on the tumor preparations (blocks) utilizing ELISA and PCR methods.Peroxiredoxin-6 protein was mainly localized in the cytoplasm of leiomyosarcoma cells, and the expression of peroxiredoxin-6 was significantly increased in cancerous tissues compared to normal myoma tissues (3.33±1.7 vs. 2.03±1.07fold change; P= 0.031). Peroxiredoxin-6 tissue protein levels were also significantly higher in leiomyosarcoma cases (100.54±66.86 vs. 183.72±64.54 pg/µg protein; P= 0.005). Our findings demonstrate that peroxiredoxin-6 plays a vital role in the emergence and development of leiomyosarcoma and that peroxiredoxin-6 level assessments can be used as a biomarker in guiding better prognosis andtreatment plans while managing leiomyosarcoma.

18beta-glycyrrhetinic acid induces ROS-mediated apoptosis to ameliorate hepatic fibrosis by targeting PRDX1/2 in activated HSCs / 药物分析学报

Hepatic stellate cells(HSCs)are essential drivers of fibrogenesis.Inducing activated-HSC apoptosis is a promising strategy for treating hepatic fibrosis.18beta-glycyrrhetinic acid(18β-GA)is a natural com-pound that exists widely in herbal medicines,such as Glycyrrhiza uralensis Fisch,which is used for treating multiple liver diseases,especially in Asia.In the present study,we demonstrated that 18β-GA decreased hepatic fibrosis by inducing the apoptosis in activated HSCs.18β-GA inhibited the expression of α-smooth muscle actin and collagen type Ⅰ alpha-1.Using a chemoproteomic approach derived from activity-based protein profiling,together with cellular thermal shift assay and surface plasmon reso-nance,we found that 18β-GA covalently targeted peroxiredoxin 1(PRDX1)and peroxiredoxin 2(PRDX2)proteins via binding to active cysteine residues and thereby inhibited their enzymatic activities.18β-GA induced the elevation of reactive oxygen species(ROS),resulting in the apoptosis of activated HSCs.PRDX1 knockdown also led to ROS-mediated apoptosis in activated HSCs.Collectively,our findings revealed the target proteins and molecular mechanisms of 18β-GA in ameliorating hepatic fibrosis,highlighting the future development of 18β-GA as a novel therapeutic drug for hepatic fibrosis.

Phospholipid remodeling and Parkinson's disease / 药学学报

The remodeling of phospholipid includes two processes: deacylation and reacylation. It realizes the conversion of nascent phospholipids to mature phospholipids by changing the length and types of fatty acids at specific sites of phospholipids, which is a key step in phospholipid metabolism. Phospholipids are not only the basic components of biological membranes, but also participate in the transduction of many molecular signals in cells. Therefore, phospholipid remodeling disorders can affect the structure and function of cell membranes, as well as the activity of membrane proteins, causing a series of intricate signaling cascades, and finally lead to many pathological changes including neurodegeneration. This paper reviews the basic process of phospholipid remodeling and the involvement of its key enzymes, calcium independent group VIA phospholipase A2 (iPLA2β), peroxiredoxin 6 (PRDX6), calcium independent group VIB phospholipase A2 (iPLA2γ) as well as acyl-CoA lysocardiolipin acyltransferase 1 (ALCAT1) in the pathology of Parkinson's disease. The mutations in the gene encoding iPLA2β, PLA2G6, have been widely reported to be directly related to hereditary Parkinson disease-14 (PARK14). Here we focus on the molecular mechanism of iPLA2β in the development of Parkinson's disease, mainly involving phospholipid fatty acid metabolism disorders, mitochondrial physiology abnormalities and α-synuclein aggregate formation and other aspects, which will help to understand the role of phospholipid remodeling in Parkinson's disease, and provide new clues for the development of new Parkinson's disease diagnosis and treatment strategies.

The antitumor activity of hPRDX5 against pancreatic cancer and the possible mechanisms

Recombinant human peroxiredoxin-5 (hPRDX5), isolated from anti-cancer bioactive peptide (ACBPs), shows a homology of 89% with goat peroxiredoxin-5 (gPRDX5) and is reported to display anti-tumor activity in vivo. Herein, we explored the effect of hPRDX5 and the responsible mechanism in treating pancreatic cancer. Tumor-bearing mice were randomly divided into normal PBS group and treatment group (n=5; 10 mg/kg hPRDX5). Flow cytometry was employed to examine lymphocytes, myeloid-derived suppressor cell subsets, and the function proteins of natural killer (NK) cells in peripheral blood, spleen, and tumor tissues of mice. Western blot was used to measure the protein expressions of the key nodes in TLR4-MAPK-NF-κB signaling pathway. The rate of tumor suppression was 57.6% at a 10 mg/kg dose in orthotopic transplanted tumor mice. Moreover, the population of CD3+CD4+T cells, NK cells, and CD3+CD8+T cells was significantly increased in the tumor tissue of the hPRDX5 group, while the proportion of granulocytic-myeloid-derived suppressor cells decreased slightly. In addition, after treatment with hPRDX5, the percentage of NK cells in blood increased more than 4-fold. Our findings indicated that hPRDX5 effectively suppressed pancreatic cancer possibly via the TLR4-MAPK-NF-κB signaling cascade; hence hPRDX5 could be a prospective immunotherapy candidate for treating pancreatic cancer.

TXNDC5-Prx2 axis regulates drug resistance of prostate cancer cells / 国际肿瘤学杂志

Objective:To study the effect of thioredoxin domain containing protein 5 (TXNDC5)-peroxiredoxin 2 (Prx2) on the drug resistance of prostate cancer cells.Methods:Prostate cancer PC3 cells were cultured in vitro, treated with the chemotherapy drug cyclophosphamide (5, 10, 15 μmol/L) for 24 hours, and PC3 cells without any treatment was served as the control group. The expression levels of TXNDC5 in PC3 cells were detected by real-time fluorescent quantitative PCR (RT-qPCR) and Western blotting. PC3 cells with TXNDC5 knocking down were exposed by cyclophosphamide and CCK-8 was used to detect the cell viability of siTXNDC5 group and siNC group. The content of reactive oxygen free radicals was determined by reactive oxygen detection kit. PC3 cells and its parental cyclophosphamide-resistant ones with TXNDC5 knocking down were treated by 10 μmol/L cyclophosphamide and subjected for CCK8 assay. The expression of Prx2 in PC3 cells was detected by Western blotting after TXNDC5 was silenced. Prx2 expression was silenced in PC3 cells overexpressing TXNDC5, and cell viability and reactive oxygen free radical content were detected in Vec-Ctrl group, pcTXNDC5 group, siNC group, siPrx2 group and pcTXNDC5+ siPrx2 group. Results:Compared with the control group, cyclophosphamide treatment significantly increased the expression of TXNDC5 at mRNA and protein levels in PC3 cells. After PC3 cells were treated with cyclophosphamide (10, 15 μmol/L) for 12 h, compared with the siNC group, the cell viability in the siTXNDC5 group was significantly suppressed (0.44±0.08 vs. 0.74±0.10, t=3.647, P=0.031; 0.30±0.04 vs. 0.53±0.06, t=6.115, P=0.006). When PC3 cells were treated with 10 μmol/L cyclophosphamide for 6 and 12 h, compared with the siNC group, the production of reactive oxygen free radicals in the siTXNDC5 group was significantly increased (2.68±0.19 vs. 1.58±0.26, t=-6.027, P=0.005; 4.56±0.37 vs. 2.73±0.26, t=-6.995, P=0.003). When PC3 cells and its cyclophosphamide-resistant ones were treated with 10 μmol/L cyclophosphamide for 12 h, compared with the siNC group, the cell viability was significantly inhibited in the siTXNDC5 group. Western blotting analysis showed that the expression of Prx2 was significantly reduced when TXNDC5 was silenced. Silencing Prx2 could significantly attenuate the increase of cell viability and the decrease of reactive oxygen content resulting from TXNDC5 overexpression. PC3 cells were treated with 10 μmol/L cyclophosphamide for 12 h, and the cell viabilities of the Vec-Ctrl group, pcTXNDC5 group, siNC group, siPrx2 group and pcTXNDC5+ siPrx2 group were 0.52±0.07, 0.69±0.03, 0.56±0.05, 0.43±0.05, 0.58±0.07, respectively, and there was a statistically significant difference ( F=8.868, P=0.003). Furthermore, the cell viability in the pcTXNDC5+ siPrx2 group decreased significantly when compared to that of the pcTXNDC5 group ( P=0.045). The contents of reactive oxygen free radicals in the above 5 groups were 3.26±0.46, 2.09±0.49, 3.16±0.38, 4.62±0.26, 2.87±0.36, respectively, and there was a statistically significant difference ( F=16.037, P<0.001). The content of reactive oxygen radicals in the pcTXNDC5+ siPrx2 group was higher than that of the pcTXNDC5 group ( P=0.036). Conclusion:TXNDC5 can reduce the level of reactive oxygen free radicals in prostate cancer cells by regulating the expression of Prx2, so as to promote the drug resistance of prostate cancer cells.

Nicotine promotes the development of oral leukoplakia via regulating peroxiredoxin 1 and its binding proteins

Tobacco can induce reactive oxygen species (ROS) production extensively in cells, which is a major risk factor for oral leukoplakia (OLK) development. Peroxiredoxin 1 (Prx1) is a key antioxidant protein, upregulated in a variety of malignant tumors. We previously found that nicotine, the main ingredient of tobacco, promotes oral carcinogenesis via regulating Prx1. The aim of the present study was to screen and identify the Prx1 interacting proteins and investigate the mechanisms of nicotine on the development of OLK. Through liquid chromatography-tandem mass spectrometry combined with bioinformatics analysis, the candidate Prx1 interacting proteins of cofilin-1 (CFL1), tropomyosin alpha-3 chain (TPM3), and serine/threonine-protein phosphatase 2A 65 kDa regulatory subunit A alpha isoform (PPP2R1A) were screened in human dysplastic oral keratinocyte cells treated with nicotine. CFL1, TPM3, and PPP2R1A were highly expressed in human OLK tissues. The expression of CFL1 increased and the expression of PPP2R1A decreased in OLK of smokers compared to that in OLK of non-smokers. Nicotine upregulated CFL1 and downregulated PPP2R1A in 4-nitro-quinoline-1-oxide (4NQO)-induced OLK tissues in mice in part dependent on Prx1. Furthermore, the in-situ interaction of CFL1, TPM3, and PPP2R1A with Prx1 were validated in human OLK tissues. Our results suggested that tobacco might promote the development of OLK via regulating Prx1 and its interacting proteins CFL1 and PPP2R1A.

The effect of peroxiredoxin 2 on transforming growth factor-β1-induced fibroblast proliferation and collagen synthesis / 中华劳动卫生职业病杂志

Objective@#To investigate the effect of peroxiredoxin 2 (Prx2) overexpression on fibroblast proliferation and collagen synthesis induced by transforming growth factor-β1 (TGF-β1) .@*Methods@#Fibroblasts were randomly divided into control group (DMEM medium) , TGF-β1 group (5 μg/L TGF-β1) , negative control group (treated with 5 μg/L TGF-β1 and transfected with empty lentiviral vector) , and Prx2 group (treated with 5 μg/L TGF-β1 and transfected with Prx2 overexpression lentiviral vector) . MTT assay was used to measure cell proliferation, immunofluorescence assay was used to measure the expression of 8-OHdG, and Western blot was used to measure the expression of p-JNK, p-P38, collagen type I, collagen type III, and Prx2. SPSS 18.0 was used for statistical analysis. The continuous data were expressed as mean±standard deviation; an analysis of variance was used for comparison between groups, and the least significant difference t-test was used for further comparison between two groups.@*Results@#Lentiviral transfection was performed successfully, and the Prx2 group had a significant increase in the protein expression of Prx2 (P<0.05) . Compared with the control group, the TGF-β1 group had a significant increase in the proliferation ability (P<0.05) , and compared with the TGF-β1 group, the Prx2 group had a significant reduction in the proliferation ability (P<0.05) . Compared with the control group, the TGF-β1 group had significant increases in the expression of 8-OHdG, p-JNK, p-P38, collagen type I, and collagen type III (P<0.05) ; compared with the TGF-β1 group, the negative control group had no significant changes in the expression of 8-OHdG, p-JNK, p-P38, collagen type I, and collagen type III (P>0.05) , while the Prx2 group had significant reductions in the above parameters (P<0.05) .@*Conclusion@#Prx2 overexpression inhibits fibroblast proliferation and collagen synthesis induced by TGF-β1 through inhibiting reactive oxygen species and activating the JNK and P38 pathways.

Oxidative Stress Modulates the Expression Pattern of Peroxiredoxin-6 in Peripheral Blood Mononuclear Cells of Asthmatic Patients and Bronchial Epithelial Cells

PURPOSE: Reduction-oxidation reaction homeostasis is vital for regulating inflammatory conditions and its dysregulation may affect the pathogenesis of chronic airway inflammatory diseases such as asthma. Peroxiredoxin-6, an important intracellular anti-oxidant molecule, is reported to be highly expressed in the airways and lungs. The aim of this study was to analyze the expression pattern of peroxiredoxin-6 in the peripheral blood mononuclear cells (PBMCs) of asthmatic patients and in bronchial epithelial cells (BECs).METHODS: The expression levels and modifications of peroxiredoxin-6 were evaluated in PBMCs from 22 asthmatic patients. Phosphorylated and acetylated peroxiredoxin-6 in hydrogen peroxide-treated human BECs was detected using immunoprecipitation analysis. The expression level of peroxiredoxin-6 was also investigated in BECs treated with hydrogen peroxide. Cycloheximide and proteasome inhibitors were used to determine whether peroxiredoxin-6 is degraded by proteasomes.RESULTS: Peroxiredoxin-6 expression was significantly reduced in the PBMCs of asthmatic patients compared to control subjects. Distinct modification patterns for peroxiredoxin-6 were observed in the PBMCs of asthmatic patients using 2-dimensional-electrophoresis. The levels of phosphorylated serine and acetylated lysine in peroxiredoxin-6 were significantly increased in the BECs following hydrogen peroxide treatment. The level of peroxiredoxin-6 expression was reduced in hydrogen peroxide-stimulated BECs, presumably due to proteasomes.CONCLUSIONS: The expression of peroxiredoxin-6, which is down-regulated in the immune cells of asthmatic patients and BECs, can be modified by oxidative stress. This phenomenon may have an effect on asthmatic airway inflammation.

Mechanism of Schisandrae Chinensis Fructus Lignans in Alleviating Learning and Memory Ability in D-galactose Aging Mice / 中国实验方剂学杂志

Objective:To study the effect of Schisandrae Chinensis Fructus lignans (SCL) on learning and memory ability of D-galactose（D-gal）-induced aging model mice. Method:ICR mice were randomly divided into 4 groups: normal group (distilled water, subcutaneous injection with normal saline), model group (distilled water, subcutaneous injection with 200 mg·kg-1D-gal), piracetam group (oral administration with 200 mg·kg-1 piracetam, subcutaneous injection with 200 mg·kg-1D-gal), low-dose SCL group (oral administration with 50 mg·kg-1·d-1 SCL, subcutaneous injection with 200 mg·kg-1·d-1 D-gal), medium-dose SCL group (oral administration with 100 mg·kg-1·d-1 SCL, subcutaneous injection with 200 mg·kg-1·d-1D-gal), high-dose SCL group (oral administration with 200 mg·kg-1·d-1 SCL, subcutaneous injection with 200 mg·kg-1·d-1 D-gal). The drugs were administered continuously for 10 weeks. Dark test and Morris water maze test were performed to observe the effect of SCL on the learning and memory ability of D-gal-induced aging mice. The activities of superoxide dismutase (SOD) and malondialdehyde (MDA) in mouse brain tissue were detected by chemical colorimetry. The expressions of peroxiredoxin-6（Prdx6） and glutathione peroxidase 1（GSH-Px1） mRNA in mouse brain tissue were detected by polymerase chain reaction (PCR). The expressions of Prdx6 and GSH-Px1 protein in mouse tissues were detected by Western blot. Result:In behavioral experiments, compared with normal group, the number of dark avoidance errors in model group significantly increased (P<0.05), the latency was significantly reduced (P<0.01), and the number of mouse passes and the target quadrant residence time were significantly reduced (P<0.01), which can be used as an indicator of successful modeling. Compared with the model group, the number of errors in the piracetam group, and medium and high-dose SCL groups was significantly reduced (P<0.05，P<0.01), and the latency was significantly prolonged (P<0.05，P<0.01). At the same time, the number of water maze passes and the target quadrant retention time in the high-dose SCL group increased significantly (P<0.01). The results of biochemical indicators showed that compared with normal group, the SOD activity in brain tissue of model group mice was significantly reduced (P<0.01), while the MDA content was increased (P<0.05). Compared with the model group, SOD activity in the brain tissues of piracetam group, and low, medium and high-dose piracetam groups was significantly increased (P<0.05), whereas the level of MDA was reduced (P<0.05). The expressions of Prdx6 and GSH-Px1 were significantly increased (P<0.05，P<0.01), indicating that the SCL administration group was dose-dependent. Conclusion:SCL can improve the learning and memory ability of D-gal-induced aging mice, which may be related to the anti-oxidation ability of SCL and the up-regulation of Prdx6 and GSH-Px1 expressions in mouse brain tissue.

Up-regulation of peroxiredoxin 3 by high-risk human papillomavirus in cervical cancer cells / 中华实验和临床病毒学杂志

Objective@#The present study was conducted to investigate the response of peroxiredoxin 3 (PRX3) to oxidative stress induced by high-risk human papillomavirus (HPV).@*Methods@#Sixty patients with cervical cancer were included and sixty patients with hysteromyoma were assigned as controls. Serum PRX3 was detected by enzyme-linked immunosorbent assay. The expression of PRX3 and oncoprotein E6 of HPV16 or HPV18 was examined in cervical cancer tissues by immunohistochemistry and in cervical cancer cells by Western blotting respectively.@*Results@#Patients with invasive squamous cervical cancer showed higher level of serum PRX3 than control subjects with hysteromyoma. PRX3 expression was up-regulated and was positively associated with that of E6 of HPV16 or HPV18 in cervical cancer tissues. The correlation was confirmed in HPV-containing cervical cancer cell lines including CaSki, and HeLa.@*Conclusions@#Our result indicated a positive response of PRX3 to HPV-induced oxidative stress. Serum PRX3 might be a potential indicator of active amplification of high-risk HPV in cervical cancer cells.

Correlation between expression of Prdx2 protein in human mature spermatozoa and sperm DNA damage / 医学研究生学报

Objective The molecular mechanisms underlying sperm DNA damage remain uncertain. This study aimed to determine the expression difference of Prdx2 protein between normal and damaged sperm DNA,and analyze the correlation between expression of Prdx2 protein in human mature spermatozoa and sperm DNA damage．Methods Semen specimens of sixty-seven male infertility patients were collected．They were separated in three groups according to the sperm DNA damage levels: normal group， slight damage group，and severe damage group．Total protein of human of mature spermatozoa was extracted．The expression of Prdx2 protein was detected by western blotting．The Localization of Prdx2 in spermatozoa was detected by immunofluorescence.Results Comparing the expression of Prdx2 protein with group normal(9.06±1.80), group slight damage(6.32±1.89） and group severe damage（2.87±0.83） decreased by 30.2% and 68.2% respectively (P<0.01).Immunofluorescence showed that Prdx2 was mainly distributed in the mitochondria and nuclear of spermatozoa.Immunofluorescence Results showed that Prdx2 was mainly located in the mitochondria of human sperm midsection and the nucleus region of the sperm head. The expression of Prdx2 in both group slight damage and group severe damage was lower than that in the group normal.The positive Prdx2 response was significantly reduced in group severe damage.The protein expression of Prdx2 was negatively correlated with DFI(r=-0.478,P<0.01), and was positively correlated with progressive motility and total motility(r=0.135、0.128，P<0.01).Conclusion Human sperm Prdx2 protein expression may be involved in protecting sperm DNA and affecting sperm motility by maintaining intracellular redox balance.

Serum Peroxiredoxin 3 in Early Pregnant Women / 医学研究杂志

Objective To investigate the role of peroxiredoxin 3 (PRX3) in early pregnancy.Methods We collected serum and villus tissues from ninety patients at first trimester.Enzyme-linked immunosorbent assay,real-time PCR,and Western Blotting were applied to examine the PRX3 level in above samples.Results The serum PRX3 in pregnant women was significantly higher than in non -pregnant controls.The expression of PRX3 in villus tissues was increased with gestational progression.Conclusion The oxidative stress was increased in pregnant women.PRX2 plays an active role in antioxidant defense of villus tissues.

Neuroprotective effect and mechanism of liraglutide on hippocampal neurons in diabetic rats / 中华内分泌代谢杂志

Objective To investigate the neuroprotective effect and mechanism of liraglutide on diabetic rats. Methods 24 healthy male SPF Goto-Kakizaki (GK) rats with random blood glucose greater than 11.1 mmol/L were selected as the experimental group, and randomly divided into diabetes mellitus group ( n＝12) and liraglutide group (n＝12). Ten healthy male SPF Wistar rats with the same age and weight as GK rats were selected as normal control group. After adaptively feeded for 2 weeks, the liraglutide group was given liraglutide (400 μg·kg－1·d－1, subcutaneous injection), while the control group and diabetes mellitus group were given the same volume of saline, and continued to be administered for 8 weeks. After 10 weeks, data and biochemical indicators were recorded. Effects of liraglutide on learning and memory in diabetes mellitus rats were detected by Morris water maze test. HE staining observed the hippocampal neurons morphology. Western blotting method detected the expression of p- IκB kinase (IKK) β, p-NF-κB, NF-κB, Klotho, and PRX2 in hippocampus. Results Morris water maze test showed that liraglutide can improve the spatial learning and memory ability of diabetes mellitus rats. HE staining showed that liraglutide significantly reduced the pathological damage of hippocampal neurons of diabetes mellitus rats. Western blotting showed that liraglutide inhibited NF-κB signaling pathway in hippocampus of diabetes mellitus rats. The expression of Klotho protein in hippocampus of diabetes mellitus group was significantly lower than that of control group, while the expression of PRX2 protein was higher than control group (t＝8.298,－7.398,all P<0.01). The expression of Klotho and PRX2 protein in hippocampus of liraglutide group were higher than diabetes mellitus group (t＝－13.059, 14.113, all P<0.01). The expression of Klotho protein of liraglutide group was similar to that of control group ( t ＝ －1. 137, P>0. 05 ). The expression of PRX2 protein was significantly higher than control group (t＝－28.055, P<0.01). Conclusions Liraglutide may enhance the expression of antioxidant stress protein including Klotho and PRX2, by inhibiting NF-κB signaling pathway in hippocampus of diabetes mellitus rats, reduced oxidative stress and improved the injury of hippocampal neuronal in diabetes mellitus rats, which seems to play a neuroprotective effect, to prevent and delay the occurrence of diabetic encephalopathy.

Multiple genes contribute to anhydrobiosis (tolerance to extreme desiccation) in the nematode Panagrolaimus superbus

Abstract The molecular basis of anhydrobiosis, the state of suspended animation entered by some species during extreme desiccation, is still poorly understood despite a number of transcriptome and proteome studies. We therefore conducted functional screening by RNA interference (RNAi) for genes involved in anhydrobiosis in the holo-anhydrobiotic nematode Panagrolaimus superbus. A new method of survival analysis, based on staining, and proof-of-principle RNAi experiments confirmed a role for genes involved in oxidative stress tolerance, while a novel medium-scale RNAi workflow identified a further 40 anhydrobiosis-associated genes, including several involved in proteostasis, DNA repair and signal transduction pathways. This suggests that multiple genes contribute to anhydrobiosis in P. superbus.

Hyperglycemia decreases preoxiredoxin-2 expression in a middle cerebral artery occlusion model / 한국실험동물학회지

Diabetes is a major risk factor for stroke and is also associated with worsened outcomes following a stroke. Peroxiredoxin-2 exerts potent neuroprotective effects against oxidative stress. In the present study, we identified altered peroxiredoxin-2 expression in an ischemic stroke model under hyperglycemic conditions. Adult male rats were administrated streptozotocin (40 mg/kg) via intraperitoneal injection to induce diabetes. Middle cerebral artery occlusion (MCAO) was induced surgically 4 weeks after streptozotocin treatment and cerebral cortex tissues were isolated 24 hours after MCAO. Peroxiredoxin-2 expression was evaluated in the cerebral cortex of MCAO-operated animals using a proteomics approach, and was found to be decreased. In addition, the reduction in peroxiredoxin-2 levels was more severe in cerebral ischemia with diabetes compared to animals without diabetes. Reverse-transcriptase PCR and Western blot analyses confirmed the significantly reduced peroxiredoxin-2 expression in MCAO-operated animals under hyperglycemic conditions. It is an accepted fact that peroxiredoxin-2 has antioxidative activity against ischemic injury. Thus, the findings of this study suggest that a more severe reduction in peroxiredoxin-2 under hyperglycemic conditions leads to worsened brain damage during cerebral ischemia with diabetes.

Effects of Prd×4 protein expression changes on the proliferation, apoptosis and migration of human lung adenocarcinoma A549 cells / 肿瘤

Objective: To investigate the effects of up-regulating or silencing peroxiredoxin 4 (Prd×4) protein expression on the proliferation, apoptosis and migration of human lung adenocarcinoma A549 cells. Methods: The recombinant plasmid pcDNA3.0-HA-Prd×4 and specific siRNA targeting human Prdx 4 gene (Prd×4-siRNA) were transfected into A549 cells by liposome, respectively; while the empty vector pcDNA3.0-HA and the negative control-siRNA were used as the controls. The expression levels of Prd×4 mRNA and protein were detected by real-time fluorescent quantitative-PCR and Western blotting, respectively. The proliferation and apoptosis of A549 cells were detected by CCK-8 assay and immunofluorescence assay, respectively. The migration ability of A549 cells was detected by wound-healing test and Transwell chamber assay. Results: The expression levels of Prd×4 mRNA and protein were up-regulated in A549 cells transfected with the recombinant plasmid pcDNA3.0-HA-Prd×4 (both P < 0.05), while they were down-regulated in A549 cells transfected with Prd×4-siRNA (both P < 0.01). The proliferation ability (D 450 nm) of A549 cells with Prd×4 over-expression was higher than that in the control group at 24, 48 and 72 h (all P < 0.05), and the difference at 96 h was most obvious (P < 0.01). The D 450 nm values of A549 cells with Prdx 4 gene-silencing were decreased (all P < 0.01) as compared with the control group at 24, 48, 72 and 96 h. After treatment with cisplatin for 24 and 48 h, the number of apoptotic cells in Prd×4 over-expression group was significantly decreased as compared with the control group (P < 0.05 and P < 0.01), while it was significantly increased in Prdx 4 gene-silencing group as compared with the control group (P < 0.05 and P < 0.01). The wound healing rate in Prd×4 over-expression group was higher than that in the control group (P < 0.01), while it was lower in Prdx 4 gene-silencing group than that in the control group (P < 0.01). The number of A549 cells passing through the membrane of Transwell chamber in Prd×4 over-expression group was significantly more than that in the control group (P < 0.01), while it was less in Prdx 4 genesilencing group than that in the control group (P < 0.01). Conclusion: Prd×4 can promote the proliferation and migration, while it can inhibit the apoptosis of A549 cells. Prd×4 may be a potential target for the clinical treatment of lung adenocarcinoma.

Down-regulation of PRDX4 protein expression was correlated with increaed malignancy of clear cell renal cell carcinoma / 肿瘤

Objective: To screen the differentially expressed proteins in clear cell renal cell carcinoma (ccRCC), and to investigate its clinical significance. Methods: The differentially expressed proteins in 15 cases of ccRCC and their adjacent renal tissues were screened by two-dimensional fluorescence difference in gel electrophoresis combined with mass spectrometry (2-D DIGE-MS). The expression levels of differentially expressed proteins screened by 2-D DIGE-MS in 45 cases of ccRCC and their adjacent tissues were examined by Western blotting. The expression levels of this differentially expressed proteins in 152 specimens of ccRCC and 40 specimens of adjacent tissues were detected by immunohistochemistry. The correlations of this protein expression with the clinicopathologic features and prognosis of ccRCC patients were analyzed. Results: Proteomics screening results showed that the expression level of peroxiredoxin 4 (PRDX4) was significantly different in ccRCC and its adjacent tissues; compared with the adjacent tissues, PRDX4 expression was significantly down-regulated in ccRCC tissues (P 0.05). The patients with lower expression of PRDX4 had high grade of ccRCC (? = -0.211, P = 0.009) and distant metastasis (? = -0.161, P = 0.048). The 5-year survival rates of patients with positive and negative expression of PRDX4 were 75.3% and 62.7% (P = 0.862), respectively. Conclusion: PRDX4, as a differentially expressed protein in ccRCC, may be involved in the formation and development of renal cancer, and its down-regulation is correlated with the increased malignancy of ccRCC.

Effects of PRDX1 gene silencing on invasion and migration of human colorectal cancer SW480 cells / 中国免疫学杂志

Objective:To investigate the effects of RNA interference(RNAi)-mediated silencing of Peroxiredoxin 1(PRDX1)gene on the invasion and migration of human colorectal cancer SW480 cells.Methods: Lentiviruses negative control vector and PRDX1 RNAi were transfected respectively into colorectal cancer SW480 cells.The transfected cells were divided into PRDX1 silencing group(si-PRDX1)and negative control group(Vector).The expressions of PRDX1 mRNA and protein in SW480 cells were exa mined by quantitative real-time PCR(qRT-PCR)and immunoblotting(Western blot),respectively.The cell migration and invasion capabilities were evaluated with transwell chamber assay and transwell chamber,respectively.The protein expressions of TIMP-2,MMP-2 and MMP-9 were detected by Western blot.Results: Compared with control group,the expressions of PRDX1 mRNA and protein were significantly decreased in PRDX1 silencing group(P<0.01),PRDX1 gene silencing cell line was successfully constructed.The levels of invasion and migration capacities of SW480 cells transfected with si-PRDX1 were lower than those in the cells transfected with control-siRNA(vector)(P<0.01).The expression of TIMP-2 was significantly increased,while the expressions of MMP-2 and MMP-9 were significantly decreased(P<0.05).Conclusion: Silencing of PRDX1 inhibits the invasion,migration and metastasis of human colorectal cancer SW480 cells by regulating the expressions of TIMP-2,MMP-2 and MMP-9.

Expression and clinicopathologic significance of peroxiredoxin Ⅱ in gastric cancer / 中国癌症杂志

Background and purpose: Peroxiredoxin Ⅱ (PrxⅡ) has the activity of peroxidase. The relevant studies found it played an important role in gastric cancer. This study aimed to investigate the expression of PrxⅡ in human gastric cancer tissues and cells, analyze its relationship with clinicopathological characteristics, and explore the relationship between PrxⅡ and the prognosis and the development of gastric cancer. Methods: The expression of PrxⅡmRNA and protein in gastric cancer tissues and the paired adjacent normal tissues from 45 patients was detected by real-time fluorescent quantitative polymerase chain reaction (RTFQ-PCR) and Western blot. The same methods were used to detect the expression of PrxⅡ mRNA and protein in GES-1, MGC-803, MKN-45 and MKN-28. Tissue mi-croarray and immunohistochemistry were used to detect the expression of PrxⅡ protein in gastric cancer tissues and the paired adjacent normal tissues from 116 patients. The relationship between the results and clinicopathological char-acteristics was analyzed. The prognosis was analyzed. Results: According to results of RTFQ-PCR and Western blot, we found that PrxⅡ mRNA and protein in gastric cancer tissues were significantly higher than that in adjacent normal tissues (P<0.05). PrxⅡ mRNA and protein in gastric cancer cells were higher than that in normal gastric cells (P<0.01).Immunohistochemistry revealed that the expression of PrxⅡ protein in gastric cancer tissues (76.7％) was also significantly higher (P<0.01) than that in adjacent normal tissues (30.1％). The expression of PrxⅡ protein is significantly related to tumor size, histological differentiation, depth of invasion, TNM stage and lymph node metastasis (P<0.05), but had no significant relationship with the gender, age, tumor location and distant metastasis. Survival in patients with higher PrxⅡ expression significantly shorter than in those with lower expression (P<0.01). PrxⅡ is an independent prognostic factor of gastric cancer (P<0.05). Conclusion: PrxⅡ promotes the development of gastric cancer. It is one of the adverse prognostic factors of gastric cancer and may serve as a new therapeutic target for gastric cancer.