Peroxiredoxin 5 protects HepG2 cells from ethyl ß-carboline-3-carboxylate-induced cell death via ROS-dependent MAPK signalling pathways.

Peroxiredoxin 5 (PRDX5) is the member of Prxs family, widely reported to be involved in various types of cell death. We previously found that PRDX5 knockdown increases the susceptibility of cell death upon oxidative stress treatment. Ethyl ß-carboline-3-carboxylate (ß-CCE), an alkaloid extracted from Picrasma quassioides, has been reported to play a role in neuronal disease, but its anti-cancer potential on liver cancers remains unknown. Here, we studied the effect of PRDX5 on ethyl ß-carboline-3-carboxylate (ß-CCE)-induced apoptosis of hepatomas. High expression level of PRDX5 was deeply related with the postoperative survival of patients with liver cancer, indicating that PRDX5 may be a biomarker of live cancer processing. Moreover, PRDX5 over-expression in HepG2 cells significantly inhibited ß-CCE-induced cell apoptosis and cellular ROS levels as well as mitochondrial dysfunction. Signalling pathway analysis showed that ß-CCE could significantly up-regulate the ROS-dependent MAPK signalling, which were in turn boosts the mitochondria-dependent cell apoptosis. Moreover, PRDX5 over-expression could reverse the anti-cancer effects induced by ß-CCE in HepG2 cells. Our findings suggest that PRDX5 has a protective role on ß-CCE-induced liver cancer cell death and provides new insights for using its anti-cancer properties for liver cancer treatment.

Ethyl ß-Carboline-3-Carboxylate Increases Cervical Cancer Cell Apoptosis Through ROS-p38 MAPK Signaling Pathway.

BACKGROUND/AIM: Ethyl ß-carboline-3-carboxylate (ß-CCE) is one of the effective ingredients of Picrasma quassioides (P. quassioides). As a ß-carboline alkaloid, it can antagonize the pharmacological effects of benzodiazepines by regulating neurotransmitter secretion through receptors, thus affecting anxiety and physiology. However, its efficacy in cancer treatment is still unclear. MATERIALS AND METHODS: We explored the effect of b-CCE on SiHa cells using MTT assay, western blot, flow cytometry, LDH release, T-AOC, SOD, and MDA assays. RESULTS: We investigated the cytotoxicity of ß-CCE in SiHa cells and verified that ß-CCE could induce cell apoptosis in a time- and concentration-dependent manner. In this process, treatment with ß-CCE significantly increased the levels of cytoplasmic and mitochondrial reactive oxygen species (ROS), which disturb the oxidation homeostasis by regulating the total antioxidant capacity (T-AOC), superoxide dismutase (SOD) activity, and malondialdehyde (MDA) production. Notably, the addition of N-acetylcysteine (NAC) (ROS scavenger) effectively alleviated ß-CCE-induced apoptosis in SiHa cells. In addition, ß-CCE might activate the p38/MAPK signaling pathway, as the pre-treatment with SB203580 (p38 inhibitor) significantly reduced ß-CCE-induced apoptosis in SiHa cells. CONCLUSION: ß-CCE has an anti-tumor activity. It activates the p38/MAPK signaling pathway by increasing intracellular ROS levels, which subsequently induce SiHa cell apoptosis. Our results provide a novel therapeutic target for treatment of cervical cancer.

Peroxiredoxin I deficiency increases pancreatic ß­cell apoptosis after streptozotocin stimulation via the AKT/GSK3ß signaling pathway.

Apoptosis of pancreatic ß­cells is involved in the pathogenesis of type I and II diabetes. Peroxiredoxin I (Prx I) serves an important role in regulating cellular apoptosis; however, the role of Prx I in pancreatic ß­cell apoptosis is not completely understood. In the present study, the role of peroxiredoxin 1 (Prx I) during streptozotocin (STZ)­induced apoptosis of pancreatic ß­cells was investigated. The expression level of Prx I was decreased by STZ treatment in a time­dependent manner, and apoptosis of Prx I knockdown MIN6 cells was increased by STZ stimulation, compared with untransduced MIN6 cells. Furthermore, an intraperitoneal injection of STZ increased pancreatic islet damage in Prx I knockout mice, compared with wild­type and Prx II knockout mice. AKT and glycogen synthase kinase (GSK)­3ß phosphorylation significantly decreased following Prx I knockdown in MIN6 cells. However, phosphorylated ß­catenin and p65 levels significantly increased after STZ stimulation, compared with untransduced cells. The results of the present study indicate that deletion of Prx I mediated STZ­induced pancreatic ß­cell death in vivo and in vitro by regulating the AKT/GSK­3ß/ß­catenin signaling pathway, as well as NF­κB signaling. These findings provide a theoretical basis for treatment of pancreatic damage.

Picrasma quassioides Extract Elevates the Cervical Cancer Cell Apoptosis Through ROS-Mitochondrial Axis Activated p38 MAPK Signaling Pathway.

BACKGROUND/AIM: Picrasma quassioides (P. quassioides) is used in traditional Asian medicine widely for the treatment of anemopyretic cold, eczema, nausea, loss of appetite, diabetes mellitus, hypertension etc. In this study we aimed to understand the effect of P. quassioides ethanol extract on SiHa cervical cancer cell apoptosis. MATERIALS AND METHODS: The P. quassioides extract-induced apoptosis was analyzed using the MTT assay, fluorescence microscopy, flow cytometry and western blotting. RESULTS: P. quassioides extract induced cellular apoptosis by increasing the accumulation of cellular and mitochondrial reactive oxygen species (ROS) levels and inhibiting ATP synthesis. Pretreatment with N-Acetylcysteine (NAC), a classic antioxidant, decreased the intracellular ROS production and inhibited apoptosis. In addition, the P38 MAPK signaling pathway is a key in the apoptosis of SiHa cells induced by the P. quassioides extract. CONCLUSION: The P. quassioides extract exerts its anti-cancer properties on SiHa cells through ROS-mitochondria axis and P38 MAPK signaling. Our data provide a new insight for P. quassioides as a therapeutic strategy for cervical cancer treatment.

Anti-tumor Properties of Picrasma quassioides Extracts in H-RasG12V Liver Cancer Are Mediated Through ROS-dependent Mitochondrial Dysfunction.

BACKGROUND: Picrasma quassioides (PQ) is a traditional Asian herbal medicine with anti-tumor properties that can inhibit the viability of HepG2 liver cancer cells. H-Ras is often mutated in liver cancer, however, the effect of PQ treatment on H-Ras mutated liver cancer is unclear. This study aimed to investigate the role of PQ on ROS accumulation and mitochondrial dysfunction in H-ras mutated HepG2 (HepG2G12V) cells. MATERIALS AND METHODS: PQ ethanol extract-induced HepG2G12V apoptosis was analyzed by the MTT assay, fluorescence microscopy, flow cytometry and western blotting. RESULTS: PQ treatment affected cell migration and colony formation in HepG2G12V cells. Cleaved-caspase-3, cleaved-caspase-9 and BCL2 associated agonist of cell death (BAD) expression levels were increased, while the levels of B-cell lymphoma-extra large (Bcl-xL) were decreased with PQ treatment. PQ treatment led to a reduction of H-Ras expression levels in liver cancer cells, thus reducing their abnormal proliferation. Furthermore, it led to increased expression levels of Peroxiredoxin VI, which regulates the redox signal in cells. CONCLUSION: Taken together these results provide a new functional significance for the role of PQ in treating HepG2G12V liver cancer.

Deletion of Peroxiredoxin II Inhibits the Growth of Mouse Primary Mesenchymal Stem Cells Through Induction of the G0/G1 Cell-cycle Arrest and Activation of AKT/GSK3ß/ß-Catenin Signaling.

BACKGROUND/AIM: Dermal mesenchymal stem cells (DMSCs) are pluripotent stem cells found in the skin which maintain the thickness of the dermal layer and participate in skin wound healing. MATERIALS AND METHODS: The MTT assay was performed to detect cell proliferation and cell-cycle progression and cell-surface markers were assessed by flow cytometry. The levels of proteins in related signaling pathways were detected by western blotting assay and the translocation of ß-catenin into the nucleus were detected by immunofluorescence. Red oil O staining was performed to examine the differentiational ability of DMSCs. RESULTS: Knockout of PRDX2 inhibited DMSC cell growth, and cell-cycle arrest at G0/G1 phase; p16, p21 and cyclin D1 expression levels in Prdx2 knockout DMSCs were significantly increased. Furthermore, AKT phosphorylation were significantly increased in Prdx2 knockout DMSCs, GSK3ß activity were inhibited, result in ß-Catenin accumulated in the nucleus. CONCLUSION: In conclusion, these results demonstrated that PRDX2 plays a pivotal role in regulating the proliferation of DMSCs, and this is closely related to the AKT/glycogen synthase kinase 3 beta/ß-catenin signaling pathway.

Peroxiredoxin II Maintains the Mitochondrial Membrane Potential against Alcohol-Induced Apoptosis in HT22 Cells.

Excessive alcohol intake can significantly reduce cognitive function and cause irreversible learning and memory disorders. The brain is particularly vulnerable to alcohol-induced ROS damage; the hippocampus is one of the most sensitive areas of the brain for alcohol neurotoxicity. In the present study, we observed significant increasing of intracellular ROS accumulations in Peroxiredoxin II (Prx II) knockdown HT22 cells, which were induced by alcohol treatments. We also found that the level of ROS in mitochondrial was also increased, resulting in a decrease in the mitochondrial membrane potential. The phosphorylation of GSK3ß (Ser9) and anti-apoptotic protein Bcl2 expression levels were significantly downregulated in Prx II knockdown HT22 cells, which suggests that Prx II knockdown HT22 cells were more susceptible to alcohol-induced apoptosis. Scavenging the alcohol-induced ROS with NAC significantly decreased the intracellular ROS levels, as well as the phosphorylation level of GSK3ß in Prx II knockdown HT22 cells. Moreover, NAC treatment also dramatically restored the mitochondrial membrane potential and the cellular apoptosis in Prx II knockdown HT22 cells. Our findings suggest that Prx II plays a crucial role in alcohol-induced neuronal cell apoptosis by regulating the cellular ROS levels, especially through regulating the ROS-dependent mitochondrial membrane potential. Consequently, Prx II may be a therapeutic target molecule for alcohol-induced neuronal cell death, which is closely related to ROS-dependent mitochondria dysfunction.

Peroxiredoxin V Reduces ß-Lapachone-induced Apoptosis of Colon Cancer Cells.

BACKGROUND/AIM: Peroxiredoxin (Prx) V has been known as an antioxidant enzyme which scavenges intracellular reactive oxygen species (ROS). Also, Prx V has been shown to mediate cell apoptosis in various cancers. However, the mechanism of Prx V-induced apoptosis in colon cancer cells remains unknown. Thus, in this study we analyzed the effects of Prx V in ß-lapachone-induced apoptosis in SW480 human colon cancer cells. MATERIALS AND METHODS: ß-lapachone-induced apoptosis was analyzed by the MTT assay, western blotting, fluorescence microscopy, Annexin V staining and flow cytometry. RESULTS: Overexpression of Prx V, significantly decreased ß-lapachone-induced cellular apoptosis and Prx V silencing increased ß-lapachone-induced cellular apoptosis via modulating ROS scavenging activity compared to mock SW480 cells. In addition, to further explore the mechanism of Prx V regulated ß-lapachone-induced SW480 cells apoptosis, the Wnt/ß-catenin signaling was studied. The Wnt/ ß-catenin signaling pathway was found to be induced by ß-lapachone. CONCLUSION: Prx V regulates SW480 cell apoptosis via scavenging ROS cellular levels and mediating the Wnt/ß-catenin signaling pathway, which was induced by ß-lapachone.

Protective Role of Peroxiredoxin I in Heat-Killed Staphylococcus Aureus-infected Mice.

BACKGROUND/AIM: Staphylococcus aureus (S. aureus) is a major gram-positive pathogen, which can cause toxic and immunogenic injuries both in nosocomial and community-acquired infections. Peroxiredoxin (Prx) I plays crucial roles in cellular apoptosis, proliferation, and signal transduction as well as in immunoregulation. The present study aimed to investigate whether Prx I protects mice from death caused by the heat-killed Staphylococcus aureus. MATERIALS AND METHODS: In the present study, we challenged the wild-type and Prx I-deficient mice with heat-killed S. aureus (HKSA). The effects of Prx I were evaluated by a series of in vitro and in vivo experiments including western blot, Haematoxylin and Eosin staining, splenocyte analysis and cytokines analysis. RESULTS: Intra-peritoneal (ip) inoculation of HKSA resulted in increased mortality of Prx I-knockout (KO) mice with severe liver damage and highly populated spleens with lymphocytes. Furthermore, HKSA infections also bursted the production of both pro-inflammatory and anti-inflammatory serum cytokines in Prx I KO compared to wild-type mice. CONCLUSION: Enhanced mortality of S. aureus-infected mice with Prx I deficiency suggested that Prx I may protect against the infection-associated lethality of mice.

Peroxiredoxin I deficiency increases LPS­induced lethal shock in mice.

Peroxiredoxin I (Prx I) plays a role in regulating macrophage proinflammatory cytokine production and gene expression and participates in immune regulation. However, the possible protective role of Prx I in endotoxin­induced lethal shock is poorly understood. In the present study, western blot analysis, ELISA and haematoxylin and eosin staining were performed to examine the protein expression of cytoines and analyses the levels of cytokines in the serum and tissue to evaluate the tissue damage. The present study revealed that lipopolysaccharide (LPS)­induced lethality in Prx I­/­ mice was is accelerated via the observed decreased serum IL­10 levels. Results also demonstrated rapid immune cell infiltration and oxidative stress in the Prx I­/­mice liver after LPS injections. These phenomena increased liver apoptosis through increasing cleaved caspase­3 protein expression in Prx I­/­ mice after LPS injections, resulting in high lethality after LPS challenges. These findings provide a new insight for understanding the function of Prx I against endotoxin­induced injury.

Knockdown of peroxiredoxin V increases glutamate­induced apoptosis in HT22 hippocampal neuron cells.

High concentrations of glutamate may mediate neuronal cell apoptosis by increasing intracellular reactive oxygen species (ROS) levels. Peroxiredoxin V (Prx V), a member of the Prx family, serves crucial roles in protecting cells from oxidative stress. The present study investigated the regulatory effect of Prx V on glutamate­induced effects on viability and apoptosis in HT22 cells. Western blotting was used for protein expression analysis and Annexin V/PI staining and flow cytometry for determination of apoptosis. The results demonstrated that glutamate may ROS­dependently increase HT22 cell apoptosis and upregulate Prx V protein levels. Furthermore, knockdown of Prx V protein expression with a lentivirus significantly enhanced HT22 cell apoptosis mediated by glutamate, which was reversed by inhibition of ROS with N­acetyl­L­cysteine. Inhibiting the extracellular signal­regulated kinase (ERK) signaling pathway with PD98059, a specific inhibitor for ERK phosphorylation, markedly decreased glutamate­induced HT22 cell apoptosis in Prx V knockdown cells, indicating the potential involvement of ERK signaling in glutamate­induced HT22 cell apoptosis. In addition, an increase in nuclear apoptosis­inducing factor was observed in Prx V knockdown HT22 cells following glutamate treatment, compared with mock cells, whereas no differences in B­cell lymphoma­2 and cleaved­caspase­3 protein expression levels were observed between mock and Prx V knockdown cells. The results of the present study indicated that Prx V may have potential as a therapeutic molecular target for glutamate­induced neuronal cell death and provide novel insight into the role of Prx V in oxidative­stress induced neuronal cell death.

Novel 1,4-naphthoquinone derivatives induce apoptosis via ROS-mediated p38/MAPK, Akt and STAT3 signaling in human hepatoma Hep3B cells.

1,4-Naphthoquinone and its derivatives have shown some efficacy as therapeutic compounds for cancer and inflammation, though their clinical application is limited by their side-effects. To reduce the toxicity of these compounds and optimize their effects, we synthesized two 1,4-naphthoquinone derivatives-2-butylsulfinyl- 1,4-naphthoquinone (BSNQ) and 2-octylsulfinyl-1,4-naphthoquinone (OSNQ)-and investigated their effects and underlying mechanisms in hepatocellular carcinoma cells. BSNQ and OSNQ decreased cell viability and significantly induced apoptosis, accompanied by the accumulation of reactive oxygen species (ROS). However, pretreatment with N-acetyl-l-cysteine, a specific ROS scavenger, blocked apoptosis. Western blot results indicated that BSNQ and OSNQ up-regulated the phosphorylation of p38 and JNK, and down-regulated the phosphorylation of ERK, Akt and STAT3, and that these effects were blocked by N-acetyl-l-cysteine. Furthermore, BSNQ and OSNQ suppressed tumor growth and modulated MAPK and STAT3 signaling in mouse xenografts without detectable effects on body weight or hematological parameters. These results indicate that BSNQ and OSNQ induce apoptosis in human hepatoma Hep3B cells via ROS-mediated p38/MAPK, Akt and STAT3 signaling pathways, suggesting that these 1,4-naphthoquinone derivatives may provide promising new anticancer agents to treat HCC.

Quinalizarin exerts an anti-tumour effect on lung cancer A549 cells by modulating the Akt, MAPK, STAT3 and p53 signalling pathways.

Quinalizarin may be a potential chemical agent for cancer therapy, as it exerts anti­tumour effects against a variety of different types of cancer. However, the underlying regulatory mechanism and signalling pathways of quinalizarin in lung cancer cells remains unknown. The present study sought to investigate the effects of quinalizarin on proliferation, apoptosis and reactive oxygen species (ROS) generation in lung cancer. MTT assays were used to evaluate the effects of quinalizarin on the viability of lung cancer A549, NCI­H460 and NCI­H23 cells. Flow cytometry was employed to evaluate the effects of quinalizarin on the cell cycle, apoptosis and ROS generation in A549 cells. Western blotting was performed to detect cell cycle and apoptosis­associated protein expression levels in A549 cells. Quinalizarin inhibited A549, NCI­H460 and NCI­H23 cell proliferation and induced A549 cell cycle arrest at the G0/G1 phase. Quinalizarin induced apoptosis by upregulating the expression of B­cell lymphoma 2 (Bcl­2)­associated agonist of cell death, cleaved­caspase­3 and cleaved­poly (adenosine diphosphate­ribose) polymerase, and downregulating the expression of Bcl­2. Furthermore, quinalizarin activated mitogen­activated protein kinase (MAPK) and p53, and inhibited the protein kinase B and signal transducer and activator of transcription­3 (STAT3) signalling pathways. In addition, quinalizarin increased ROS generation. The ROS scavenger N­acetyl­L­cysteine restored quinalizarin­induced cell apoptosis, and inactivated the MAPK and STAT3 signalling pathways. The results of the present study demonstrated that quinalizarin induces G0/G1 phase cell cycle arrest and apoptosis via ROS mediated­MAPK and STAT3 signalling pathways.

Cryptotanshinone induces ROS-mediated apoptosis in human gastric cancer cells.

Cryptotanshinone (CT), isolated from the plant Salvia miltiorrhiza Bunge, has been reported to have potential anticancer effects on human prostate and breast cancer cells. However, the mechanisms of action of CT on gastric cancer (GC) cells are not well understood. Here we investigated the antitumor effects of CT on GC cells and its possible molecular mechanism. We found CT suppressed viability of twelve GC cell lines in a dose-dependent manner. CT induced cell cycle arrest at the G2/M phase and mitochondrial apoptosis accompanying the accumulation of reactive oxygen species (ROS). Pretreatment with ROS inhibitor N-acetyl-L-cysteine (NAC) blocked CT-induced apoptosis. CT increased p-JNK and p-p38, and decreased p-ERK and p-STAT3 protein expression, these effects were prevented by NAC. Furthermore, a xenograft assay showed that CT significantly inhibited MKN-45 cell-induced tumor growth in vivo by increasing expression of pro-apoptotic proteins (p-JNK, p-38 and cleaved-caspase-3) and reducing expression of anti-apoptotic proteins (p-ERK and p-STAT3) without adverse effects on nude mice weight. In conclusion, CT induced apoptosis and cell cycle arrest in GC cells via ROS-mediated MAPK and AKT signaling pathways, and this CT may be a useful compound for the developing anticancer agents for GC.

2-cyclohexylamino-5,8-dimethoxy-1,4-naphthoquinone inhibits LPS-induced BV2 microglial activation through MAPK/NF-kB signaling pathways.

AIMS: To verify the effects of several 5,8-dimethoxy-1,4-naphthoquinone (DMNQ) derivatives on LPS-induced NO production, cellular ROS levels and cytokine expression in BV-2 microglial cells. MAIN METHODS: An MTT assay and FACS flow cytometry were performed to assess the cellular viability and apoptosis and cellular ROS levels, respectively. To examine the expression of pro-inflammatory cytokines and cellular signaling pathways, semi-quantitative RT-PCR and Western blotting were also used in this study. KEY FINDINGS: Among the six newly synthesized DMNQ derivatives, 2-cyclohexylamino-5,8-dimethoxy-1,4-naphthoquinone (R6) significantly inhibited the NO production, cellular ROS levels and the cytokines expression in BV-2 microglial cells, which stimulated by LPS. Signaling study showed that compound R6 treatment also significantly down-regulated the LPS-induced phosphorylation of MAPKs (ERK, JNK and p38) and decreased the degradation of IκB-α in BV2 microglial cells. SIGNIFICANCE: Our findings demonstrate that our newly synthesized compound derived from DMNQ, 2-cyclohexylamino-5,8-dimethoxy-1,4-naphthoquinone (R6), might be a therapeutic agent for the treatment of glia-mediated neuroinflammatory diseases.

Establishment of a nanoparticle-assisted RT-PCR assay to distinguish field strains and attenuated strains of porcine epidemic diarrhea virus.

Porcine epidemic diarrhea virus (PEDV) can cause serious disease and even death in neonatal piglets, resulting in serious damage to the swine industry worldwide. Open reading frame 3 (ORF3) is the only accessory gene in the PEDV genome. Previous studies have indicated that PEDV vaccine strains have a partial deletion in ORF3. In this study, a nanoparticle-assisted polymerase chain reaction (nanoparticle-assisted RT-PCR) assay targeting the ORF3 of PEDV was developed to distinguish PEDV field strains from attenuated strains by using a specific pair of primers. The PCR products of field strains and attenuated strains were 264 bp and 215 bp in length, respectively. The sensitivity and specificity of this assay were also assessed. The nanoparticle-assisted RT-PCR assay was 10-100 times more sensitive than the conventional RT-PCR assay, with no cross-reactions when amplifying porcine pseudorabies virus (PRV), porcine circovirus type 2 (PCV2), classical swine fever virus (CSFV), porcine parvovirus (PPV), porcine reproductive and respiratory syndrome virus (PRRSV), porcine rotavirus (RV), and porcine transmissible gastroenteritis virus (TGEV). The nanoparticle-assisted RT-PCR assay we describe here can be used to distinguish field strains from vaccine strains of PEDV, and it shows promise for reducing economic loss due to PEDV infection.

16α, 17α-epoxypregnenolone-20-oxime inhibits NO and IL-6 production in LPS-treated RAW264.7 cells.

It has previously been reported that 16α, 17α-epoxypregnenolone-20-oxime (EPREGO) exerts an inhibitory effect on nitric oxide (NO) production and inducible NO synthase (iNOS) expression in microglia. The present study aimed to investigate the effects of EPREGO on the lipopolysaccharide (LPS)­induced inflammatory response in RAW264.7 macrophage cells, and to determine the underlying molecular mechanisms using western blot analysis, enzyme­linked immunosorbent assays and fluorescence­activated cell sorting. The present study demonstrated that LPS­induced production of NO and interleukin (IL)-6, and the protein expression levels of iNOS, were reduced by EPREGO in a dose­ and time­dependent manner, whereas, EPREGO did not affect tumor necrosis factor­α production. In addition, EPREGO suppressed LPS­induced cellular reactive oxygen species production and phagocytosis. Furthermore, EPREGO significantly inhibited the LPS­induced activation of mitogen­activated protein kinases and inhibitor of κB α degradation in LPS­stimulated RAW264.7 cells, thus resulting in modulation of the production of NO and IL­6. Taken together, these results suggest that EPREGO exhibits anti-inflammatory activity in macrophages, thus validating the hypothesis that EPREGO may be useful as a therapeutic agent for the treatment of macrophage-mediated inflammation.

16α,17α-Epoxypregnenolone-20-oxime prevent LPS-induced NO production and iNOS expression in BV-2 microglial cells by inhibiting JNK phosphorylation.

The free radical nitric oxide (NO), a main member of neuroinflammatory cytokine and a gaseous molecule produced by activated microglia, has many physiological functions, including neuroinflammation. In the present study, we evaluated the effects of serial 16-dehydropregnenolone-3-acetate derivatives on lipopolysaccharide (LPS)-induced NO production and inducible nitric oxide synthase (iNOS) expression in BV-2 microglial cells. Among the six derivatives tested, the increases in NO production and iNOS expression observed in BV-2 microglial cells after LPS stimulation were significantly inhibited by treatment with 16α, 17α-epoxypregnenolone-20-oxime. Moreover, the inhibitory effect of 16α,17α-epoxypregnenolone-20-oxime on NO production was similar to that of S-methylisothiourea sulfate (SMT), an iNOS inhibitor. Further studies showed that 16α,17α-epoxypregnenolone-20-oxime inhibited c-Jun N-terminal kinase (JNK) phosphorylation but not inhibitor kappa B (IκB)-α degradation. Our data in LPS-stimulated microglia cells suggest that 16α,17α-epoxypregnenolone-20-oxime might be a candidate therapeutic for treatment of NO induced neuroinflammation and could be a novel iNOS inhibitor.

Analysis of synonymous codon usage in enterovirus 71.

Enterovirus 71 (EV71) is the major cause of hand-foot-and-mouth disease in children. In our study, using the complete genome sequences of 42 EV71 representing all three genotypes, we analyzed synonymous codon usage and the relative dinucleotide abundance in EV71 genome. The general correlation between base composition and codon usage bias suggests that mutational pressure rather than natural selection is the main factor that determines the codon usage bias in EV71 genome. Furthermore, we observed that the relative abundance of dinucleotides in EV71 is independent of the overall base composition but is still the result of differential mutational pressure, which also shapes codon usage. In addition, other factors, such as hydrophobicity and aromaticity, also influence the codon usage variation among the genomes of EV71. This study represents the most comprehensive analysis of EV71 codon usage patterns and provides a basic understanding of the mechanisms for codon usage bias.

[Molecular mechanism of ORFV intervention strategies based on the UPS of host cell: a review].

In order to compete the antiviral effects of the host cell in the process of infection, ORFV(known as Orf virus) relies on a series of functional genes developed through long-term population evolution, such as interferon resistance genes, Bcl-2 protein genes and cell cycle inhibitor gene and so on, with these weapons this virus is able to effectively counteract immune clearance and immune regulation from a host cell. Concurrently, ORFV also focuses on exploiting signal transduction pathways of the ubiquitin-proteasome system(UPS), circumvents the intracellular signal transduction and CD8+ T activation, for shielding virus particles towards maturation and releasing outside. This review introduced inner link between the UPS of host cell and intervention mechanism by virus, and analyzed the key roles of certains components in UPS, these all together showed the evolution tendency of ORFV that was involved in the designing of inhibition to immune response and for intracellular immune escape upon the selection pressure in host cell infected.