Expression of gilt acts as a positive regulator of mouse hematopoietic progenitor cells.

Gamma interferon inducible lysosomal thiol reductase (GILT), is known to be involved in immunity, but its role in hematopoiesis has not been previously reported. Herein, we demonstrate using gilt knockout (-/-) mice that loss of gilt associates with decreased numbers and cycling status of femoral hematopoietic progenitor cells (CFU-GM, BFU-E, and CFU-GEMM) with more modest effects on splenic progenitor cells. Thus, GILT is associated with positive regulation of hematopoietic progenitor cells in mice, mainly in bone marrow.

Evaluation of HIV-1 derived lentiviral vectors as transductors of Mucopolysaccharidosis type IV a fibroblasts.

Mucopolysaccharidosis type IVA (MPS IVA) is a lysosomal storage disease produced by the deficiency of the N-acetylgalactosamine-6-sulfate sulfatase (GALNS) enzyme, leading to glycosaminoglycans (GAGs) accumulation. Since currently available treatments remain limited and unspecific, novel therapeutic approaches are essential for the disease treatment. In an attempt to reduce treatment limitations, gene therapy rises as a more effective and specific alternative. We present in this study the delivery assessment of GALNS and sulfatase-modifying factor 1 (SUMF1) genes via HIV-1 derived lentiviral vectors into fibroblasts from MPS IVA patients. After transduction, we determined GALNS enzymatic activity, lysosomal mass change, and autophagy pathway impairment. Additionally, we computationally assessed the effect of mutations over the enzyme-substrate interaction and phenotypic effects. The results showed that the co-transduction of MPS IVA fibroblasts with GALNS and SUMF1 cDNAs led to a significant increase in GALNS enzyme activity and a reduction of lysosomal mass. We show that patient-specific differences in cellular response are directly associated with the set of mutations on each patient. Lastly, we present new evidence supporting autophagy impairment in MPS IVA due to the presence and changes in autophagy proteins in treated MPS IVA fibroblasts. Our results offer new evidence that demonstrate the potential of lentiviral vectors as a strategy to correct GALNS deficiency.

Sulfiredoxin-1 protects spinal cord neurons against oxidative stress in the oxygen-glucose deprivation/reoxygenation model through the bax/cytochrome c/caspase 3 apoptosis pathway.

BACKGROUND: Spinal cord ischemia/reperfusion injury is a common clinical, pathophysiological phenomenon with complex molecular mechanisms. Currently, there are no therapeutics available to alleviate the same. This study investigates the protective effects of sulfiredoxin-1 (Srxn 1) on spinal cord neurons following exposure to oxygen-glucose deprivation/reoxygenation (OGD/R) treatment. MATERIALS AND METHODS: Primary spinal cord neurons were cultured, detected by anti-tubulin ßⅢ, and transfected with adeno-associated virus (AAV)-Srxn 1 to overexpress Srxn 1. They were identified by their morphology and CCK-8 assay. The superoxide dismutase level was measured by superoxide dismutase assay. Malondialdehyde level was measured by malondialdehyde assay. The apoptosis ratio was calculated by Hoechst 33342 and Annexin V-PE/7-AAD staining. Mitochondrial transmembrane potential (Δψm) was detected by tetramethylrhodamine-methyl ester-perchlorate (TMRM) staining. The mRNA expression levels of Srxn 1 and caspase 3 were detected by quantitative reverse transcription-polymerase chain reaction, and the protein expression levels of Srxn 1, bax, bcl-2, cytosolic cytochrome c, and caspase 3 were detected by western blotting. RESULTS: AAV-Srxn 1 up-regulated mRNA and protein levels of Srxn 1 in spinal cord neurons. Following exposure to OGD/R, overexpression of Srxn 1 improved the neuronal viability, alleviated the neuron apoptosis, enhanced the mitochondrial transmembrane potential, increased the SOD level, decreased the MDA level, inhibited the expression of cytosolic cytochrome c, bax, and caspase 3, and promoted the expression of bcl-2. CONCLUSION: Srxn 1 plays a significant role in anti-apoptosis of spinal cord neurons, and Srxn 1 may be a potential therapeutic target for spinal cord I/R injury.

Genome-wide expression analysis reveals six contravened targets of EZH2 associated with breast cancer patient survival.

Several pioneering work have established that apart from genetic alterations, epigenetic modifications contribute significantly in tumor progression. Remarkable role of EZH2 in cancer highlights the importance of identifying its targets. Although much emphasis has been placed in recent years in designing drugs and inhibitors targeting EZH2, less effort has been given in exploring its existing targets that will help in understanding the oncogenic role of EZH2 in turn which may provide a more stringent method of targeting EZH2. In the present study, we validated six direct targets of EZH2 that are GPNMB, PMEPA1, CoL5A1, VGLL4, POMT2 and SUMF1 associated with cancer related pathways. Upon EZH2 knockdown, more than two fold increase in the target gene expression was evident. CHIP-qPCR performed in both MCF-7 and MDA-MDA-231 confirmed the in-vivo binding of EZH2 on its identified target. Thirty invasive breast carcinoma cases with their adjacent normal tissues were included in the study. Immunohistochemistry in primary breast tumor tissue array showed tumor dependent expression of EZH2. Array of MERAV expression database revealed the strength of association of EZH2 with its target genes. Real time PCR performed with RNA extracted from breast tumor tissues further authenticated the existing negative correlation between EZH2 and its target genes. Pearson correlation coefficient & statistical significance computed using the matrix provided in the database strengthened the negative correlation between identified target genes and EZH2. KM plotter analysis showed improved relapse-free survival with increased expression of PMEPA1, POMT2, VGLL4 and SUMF1 in breast cancer patients indicating their therapeutic potential. While investigating the relevance of these target genes, different mutations of them were found in breast cancer patients. Seeking the clinical relevance of our study, following our recent publication that reports the role of EZH2 in nicotine-mediated breast cancer development and progression, we observed significant reduced expression of SUMF1 in breast cancer patient samples with smoking history in comparison to never-smoked patient samples.

Genomic structure, expression pattern and polymorphisms of GILT in golden pompano Trachinotus ovatus (Linnaeus 1758).

The interferon-g-inducible lysosomal thiol reductase (GILT) plays a significant character in the processing and presentation of MHC class II restricted antigen (Ag) by catalyzing disulfide bond reduction in mammals. To explore the function of GILT in the immune system of fish, we cloned a GILT gene homologue from Trachinotus ovatus, the full-length cDNA of GILT, which consisted of 2, 747 bp with a 771 bp open reading frame, encoding a protein of 256 amino acids. Moreover, similar to other species GILT gene, 7 exons and 6 introns were identified in T. ovatus, the deduced protein also possessed a representative characteristic of known GILT proteins. The result of real-time quantitative PCR showed that GILT mRNA was dramatically expressed in immune-associated tissues, such as spleen (p < 0.01) and kidney (p < 0.05). Bacterial challenge revealed that GILT mRNA level remarkably up-regulation in liver, spleen, kidney and intestine after induction with Photobacterium damsela. Furthermore, based on cloned sequences and genome BLAST, only one SNP site (ToGILT-S1-g.148C>G) was identified, and the allele C was significantly associated with high-susceptibility (HS) group, nevertheless, the allele G was dramatically associated with high-resistance (HR) group, indicating potential application for disease resistant breeding selection in T. ovatus.

Sulfiredoxin may promote metastasis and invasion of cervical squamous cell carcinoma by epithelial-mesenchymal transition.

Sulfiredoxin (Srx), a novel oxidative stress-induced antioxidant protein, has been reported to be expressed in several human tumour tissues. However, the expression and functions of Srx in cervical squamous cell carcinoma remain unknown. Here, we proved that expression of Srx was upregulated in cervical tissues as revealed by immunohistochemistry, and revealed a close correlation between the protein's expression and the expression level of one core epithelial-mesenchymal transition marker, E-cadherin. We demonstrated that Srx was overexpressed in cervical squamous cell carcinoma and its expression level was closely correlated with lymph node metastasis and invasion of cervical squamous cell carcinoma. Meanwhile, Srx expression was negatively correlated with E-cadherin expression. The remission time (tumour-free status after surgery) of the Srx strong staining group was significantly shorter than that of the Srx weak staining group. We silenced Srx by short hairpin RNA in HeLa and SiHa cells. Diminished Srx expression upregulated E-cadherin expression. The cell invasion and migration activity in the ShSrx group were obviously decreased in HeLa and SiHa cells. Moreover, Srx regulated the expression of the other marker of epithelial-mesenchymal transition, vimentin. In conclusion, the study suggested that Srx was highly expressed in cervical squamous cell carcinoma and may promote invasion and metastasis of cervical squamous cell carcinoma via regulating epithelial-mesenchymal transition.

QSOX1 expression is associated with aggressive tumor features and reduced survival in breast carcinomas.

The biological role of quiescin sulfhydryl oxidase 1 (QSOX1) in tumor development is not well known, and its relation to breast cancer progression and prognosis is controversial. Here, our aim was to study the expression pattern and prognostic impact of QSOX1 in breast cancer, in relation to molecular subgroups and tumor cell proliferation. We examined a population-based series as part of the prospective Norwegian Breast Cancer Screening Program, including all women (50-69 years) diagnosed with breast cancer in one county of Norway during 1996-2003. QSOX1 expression was assessed by immunohistochemistry on tissue microarrays (n=458). Median follow-up time was 13 years. High expression of QSOX1 protein was associated with features of poor prognosis including high histologic grade, hormone receptor negativity, HER2 positivity, and increased tumor cell proliferation. High QSOX1 expression was further associated with reduced breast cancer-specific survival in both univariate and multivariate analysis, independent of molecular subtypes. High QSOX1 expression is a strong and independent factor of reduced survival in breast cancer, also reflected by elevated levels in more aggressive molecular subgroups. QSOX1 expression may represent a biomarker for aggressive disease and a potential treatment target.

Activation of the Nrf2 response by intrinsic hepatotoxic drugs correlates with suppression of NF-κB activation and sensitizes toward TNFα-induced cytotoxicity.

Drug-induced liver injury (DILI) is an important problem both in the clinic and in the development of new safer medicines. Two pivotal adaptation and survival responses to adverse drug reactions are oxidative stress and cytokine signaling based on the activation of the transcription factors Nrf2 and NF-κB, respectively. Here, we systematically investigated Nrf2 and NF-κB signaling upon DILI-related drug exposure. Transcriptomics analyses of 90 DILI compounds in primary human hepatocytes revealed that a strong Nrf2 activation is associated with a suppression of endogenous NF-κB activity. These responses were translated into quantitative high-content live-cell imaging of induction of a selective Nrf2 target, GFP-tagged Srxn1, and the altered nuclear translocation dynamics of a subunit of NF-κB, GFP-tagged p65, upon TNFR signaling induced by TNFα using HepG2 cells. Strong activation of GFP-Srxn1 expression by DILI compounds typically correlated with suppression of NF-κB nuclear translocation, yet reversely, activation of NF-κB by TNFα did not affect the Nrf2 response. DILI compounds that provided strong Nrf2 activation, including diclofenac, carbamazepine and ketoconazole, sensitized toward TNFα-mediated cytotoxicity. This was related to an adaptive primary protective response of Nrf2, since loss of Nrf2 enhanced this cytotoxic synergy with TNFα, while KEAP1 downregulation was cytoprotective. These data indicate that both Nrf2 and NF-κB signaling may be pivotal in the regulation of DILI. We propose that the NF-κB-inhibiting effects that coincide with a strong Nrf2 stress response likely sensitize liver cells to pro-apoptotic signaling cascades induced by intrinsic cytotoxic pro-inflammatory cytokines.

Transient GFER knockdown in vivo impairs liver regeneration after partial hepatectomy.

BACKGROUND AND AIMS: Augmenter of Liver Regeneration is a protein encoded by the Growth Factor Erv1-Like gene. Its biological properties are crucial for cell survival since knock-out mice for Growth Factor Erv1-Like gene do not survive. In this study, we injected hepatotropic adenoviral particles harboring oligonucleotide sequences against Growth Factor Erv1-Like gene into 70% partially hepatectomized rats and studied the effect of gene silencing on the progression liver regeneration. METHODS: Partially hepatectomized rats were divided into three groups of animals and, before surgery, received either phosphate buffer saline, or adenoviral particles alone or adenoviral particles harboring the oligonucleotide silencing sequence. In each group, rats were sacrificed at 12, 24 and 48 h after surgery. Liver tissues were collected to analyze the expression of Augmenter of Liver Regeneration, Bax, Bcl-2 and activated Caspase-9 and -3, as well as hepatocyte proliferation and apoptosis, polyamines levels and histological and ultrastructural features. RESULTS: Growth Factor Erv1-Like gene silencing reduced the compensatory hepatocellular proliferation triggered by surgery through (i) the reduction of polyamines synthesis, hepatocyte proliferation and anti-apoptotic gene expression and (ii) the increase of pro-apoptotic gene expression and caspase activation. CONCLUSIONS: For the first time, using a technique of gene silencing in vivo, our results demonstrate that Growth Factor Erv1-Like gene knock-down, i.e., the lack of Augmenter of Liver Regeneration, modifies the expression of genes involved in cell apoptosis and inhibits early phase of DNA synthesis. As a consequence, a promotion of cell death and a reduction of cell proliferation occurs.

Expression level of quiescin sulfhydryl oxidase 1 (QSOX1) in neuroblastomas.

Neuroblastoma is the most common extracranial solid malignant tumor observed during childhood. Although these tumors can sometimes regress spontaneously or respond well to treatment in infants, genetic alterations that influence apoptosis can, in some cases, confer resistance to chemotherapy or result in relapses and adversely affect prognosis for these patients. The aim of this study was to correlate immunohistochemical expression of the protein QSOX1 (quiescin sulfhydryl oxidase 1) in samples obtained from untreated neuroblastomas with the patients' clinical and pathological prognostic factors and clinical course. Neuroblastoma samples (n=23) obtained from histology blocks were arrayed into tissue microarrays and analysed by immunohistochemistry. The cases were classified according to the following clinical and pathological prognostic factors: age at diagnosis greater or less than/equal to 18 months; location of the lesion at diagnosis (abdominal or extra-abdominal); presence or absence of bone-marrow infiltration; tumor differentiation (well or poorly differentiated); Shimada histopathologic classification (favourable or unfavourable); state of the tumor extracellular matrix (Schwannian-stroma rich or poor); amplification of the MYCN oncogene; and clinical course (dead or alive with or without relapses/residual lesions). Twelve of the cases were female, 9 children were over 18 months old, 9 cases presented with extra-abdominal tumors and 9 cases exhibited tumors with unfavourable histologies. Fifteen patients underwent bone-marrow biopsy, and 4 of these were positive for metastasis. Nine patients died. The higher immunohistochemical expression of QSOX1 was more common in well-differentiated samples (P=0.029), in stroma-rich samples (P=0.029) and in samples from patients with a high prevalence of relapses/residual disease. The functions of QSOX1 include extracellular matrix maturation and the induction of apoptosis. Therefore, QSOX1 may be involved in neuroblastoma differentiation and regression and may thus function as a biomarker for identifying risk groups for this neoplasm.

The emerging role of QSOX1 in cancer.

SIGNIFICANCE: Quiescin sulfhydryl oxidase 1 (QSOX1) is an enzyme that oxidizes thiols during protein folding, reducing molecular oxygen to hydrogen peroxide. Tumor cells may take advantage of oxidative environments at different stages of tumorigenesis, but QSOX1 may also serve additional functions in tumors. RECENT ADVANCES: Several groups have reported the over-expression of QSOX1 in breast, pancreas, and prostate cancers. A consensus is building that QSOX1 over-expression is important during tumor cell invasion, facilitating tumor cell migration at the tumor-stroma interface. As such, QSOX1 may be considered a prognostic indicator of metastatic potential or even indicate that cancer is present in a host. CRITICAL ISSUES: However, some controversy exists between QSOX1 as a marker of poor or favorable outcome in breast cancer. More studies are required to reveal what advantage QSOX1 provides to breast and other types of cancer. More specifically, it is critical to learn which tumor types over-express QSOX1 and use its enzymatic activity to their advantage. FUTURE DIRECTIONS: As interest increases in understanding the mechanisms of tumorigenesis within the extracellular matrix and how tumor cells influence fibroblasts and other stromal cells, QSOX1 may be revealed as an important player in cancer detection and prognosis. Defining the mechanism(s) of QSOX1 activity in tumors and in in vivo models will provide important insights into how to target QSOX1 with anti-neoplastic agents.

A comprehensive analysis of the human placenta transcriptome.

As the conduit for nutrients and growth signals, the placenta is critical to establishing an environment sufficient for fetal growth and development. To better understand the mechanisms regulating placental development and gene expression, we characterized the transcriptome of term placenta from 20 healthy women with uncomplicated pregnancies using RNA-seq. To identify genes that were highly expressed and unique to the placenta we compared placental RNA-seq data to data from 7 other tissues (adipose, breast, hear, kidney, liver, lung, and smooth muscle) and identified several genes novel to placental biology (QSOX1, DLG5, and SEMA7A). Semi-quantitative RT-PCR confirmed the RNA-seq results and immunohistochemistry indicated these proteins were highly expressed in the placental syncytium. Additionally, we mined our RNA-seq data to map the relative expression of key developmental gene families (Fox, Sox, Gata, Tead, and Wnt) within the placenta. We identified FOXO4, GATA3, and WNT7A to be amongst the highest expressed members of these families. Overall, these findings provide a new reference for understanding of placental transcriptome and can aid in the identification of novel pathways regulating placenta physiology that may be dysregulated in placental disease.

Illuminating luminal B: QSOX1 as a subtype-specific biomarker.

Breast cancer is a complex and heterogeneous disease that affects about one out of every eight women. In the last decade, several advancements have been made that have increased our understanding of breast cancer and have allowed us to more accurately diagnose and treat this disease in a more targeted manner. For example, gene expression profiling enabled the classification of breast cancers into four main subtypes - basal-like, HER2+ (human epidermal growth factor receptor 2-positive), luminal A and luminal B - and this classification is used to direct the use of targeted therapies such as tamoxifen or trastuzumab. The luminal subtypes are generally characterized as being estrogen receptor-positive and targetable with anti-hormone therapies. However, whereas luminal A cancers have a good prognosis, luminal B cancers are associated with early relapse following endocrine therapy and a prognosis that is similar to that of the aggressive basal subtype. It is thus imperative that luminal B cancers be better characterized so that therapeutic targets and biomarkers for this disease type can be realized. In the previous issue of Breast Cancer Research, Katchman and colleagues address this need by demonstrating that quiescin sulfydryl oxidase 1 (QSOX1), a secreted enzyme involved in post-translational modifications, is associated with poor prognosis in patients with luminal B breast cancer. The authors further determined that this protein promotes breast cancer proliferation and invasion. Collectively, these studies suggest that QSOX1 is a predictive biomarker for luminal cancers and that it may be a useful target for elusive luminal B disease.

Genetic polymorphisms and protein expression of NRF2 and Sulfiredoxin predict survival outcomes in breast cancer.

NRF2 activates several protective genes, such as sulfiredoxin (SRXN1), as a response to oxidative and xenobiotic stress. Defects in NRF2 pathway may increase cancer susceptibility. In tumor cells, activation of NRF2 may lead to chemo- and radioresistance and thus affect patient outcome. Nine single-nucleotide polymorphisms on NRF2 gene and eight on SRXN1 were genotyped in 452 patients with breast cancer and 370 controls. Protein expression of NRF2 and SRXN1 was studied in 373 breast carcinomas by immunohistochemistry. Statistical significance of the associations between genotypes, protein expression, clinicopathologic variables, and survival was assessed. A high level (>25%) of cytoplasmic NRF2 positivity was observed in 237 of 361 (66%) and SRXN1 positivity was observed in 82 of 363 (23%) cases. The NRF2 rs6721961 genotype TT was associated with increased risk of breast cancer [P = 0.008; OR, 4.656; confidence interval (CI), 1.350-16.063] and the T allele was associated with a low extent of NRF2 protein expression (P = 0.0003; OR, 2.420; CI, 1.491-3.926) and negative SRXN1 expression (P = 0.047; OR, 1.867; CI = 1.002-3.478). The NRF2 rs2886162 allele A was associated with low NRF2 expression (P = 0.011; OR, 1.988; CI, 1.162-3.400) and the AA genotype was associated with a worse survival (P = 0.032; HR, 1.687; CI, 1.047-2.748). The NRF2 rs1962142 T allele was associated with a low level of cytoplasmic NRF2 expression (P = 0.036) and negative sulfiredoxin expression (P = 0.042). The NRF2 rs2706110 AA genotype was associated with an increased risk of breast cancer, and the SRXN1 rs6053666 C allele was associated with a decrease in breast cancer risk (P = 0.011 and 0.017). NRF2 and SRXN1 genetic polymorphisms are associated with breast cancer risk and survival, implicating that mechanisms associated with reactive oxygen species and NRF2 pathway are involved in breast cancer initiation and progression.

c-Jun-dependent sulfiredoxin induction mediates BDNF protection against mitochondrial inhibition in rat cortical neurons.

In current study, we tested the hypothesis that c-Jun-dependent sulfiredoxin expression mediates protective effects of brain-derived neurotrophic factor (BDNF) against neurotoxicity induced by 3-nitropropionic acid (3-NP), a mitochondrial complex II inhibitor, in primary rat cortical cultures. We found that BDNF-dependent c-Jun expression and nuclear translocation required prior phosphorylation of extracellular signal-regulated kinase (ERK)1/2, but not Akt. BDNF also transiently activated the expression of sulfiredoxin, an ATP-dependent antioxidant enzyme, at both mRNA and protein levels. Furthermore, both c-Jun siRNA and ERK1/2 inhibitor PD98059 suppressed BDNF-induced sulfiredoxin expression. Finally, PD98059, c-Jun siRNA, and sulfiredoxin siRNA all abrogated BDNF-mediated 3-NP resistance. Together, these results established a signaling cascade of "BDNF → ERK1/2-Pi → c-Jun → sulfiredoxin → 3-NP resistance". We therefore conclude that c-Jun-induced sulfiredoxin mediates the BDNF-dependent neuroprotective effects against 3-NP toxicity in primary rat cortical neurons, at least in part.

Maesopsin 4-O-beta-D-glucoside, a natural compound isolated from the leaves of Artocarpus tonkinensis, inhibits proliferation and up-regulates HMOX1, SRXN1 and BCAS3 in acute myeloid leukemia.

The leaves of Artocarpus tonkinensis are used in Vietnamese traditional medicine for treatment of arthritis, and the compound maesopsin 4-O-ß-D-glucoside (TAT-2), isolated from them, inhibits the proliferation of activated T cells. Our goal was to test the anti-proliferative activity of TAT-2 on the T-cell leukemia, Jurkat, and on the acute myeloid leukemia, OCI-AML. TAT-2 inhibited the growth of OCI-AML (and additional acute myeloid leukemia cells) but not Jurkat cells. Growth inhibition was shown to be due to inhibition of proliferation rather than increase in cell death. Analysis of cytokine release showed that TAT-2 stimulated the release of TGF-ß, yet TGF-ß neutralization did not reverse the maesopsin-dependent effect. Gene expression profiling determined that maesopsin modulated 19 identifiable genes. Transcription factor CP2 was the gene most significantly modulated. Real-time PCR validated that up-regulation of sulphiredoxin 1 homolog (SRXN1), hemeoxygenase 1 (HMOX1), and breast carcinoma amplified sequence 3 (BCAS3) were consistently modulated.

Redox regulation of lipopolysaccharide-mediated sulfiredoxin induction, which depends on both AP-1 and Nrf2.

Sulfiredoxin (Srx) is an enzyme that catalyzes the reduction of cysteine sulfinic acid of hyperoxidized peroxiredoxins and exerts a protective antioxidant role. Here we investigated the regulatory mechanism of Srx induction by lipopolysaccharide (LPS) in mouse macrophages. LPS up-regulated Srx expression on the transcriptional level. The promoter region of the Srx gene contained putative NF-κB and AP-1 (activator protein-1) sites, and the proximal site of three AP-1 sites was embedded within the antioxidant response element (ARE), a cis-acting element for Nrf2 (nuclear factor erythroid 2-related factor). Mutational analysis of the Srx promoter revealed that Srx induction is dependent on AP-1 sites and ARE but not on NF-κB sites. Consistently, both transcription factors, AP-1 and Nrf2, were required for LPS-mediated Srx induction, as revealed by chromatin immunoprecipitation using antibodies specific for c-Jun and c-Fos and little Srx induction in Nrf2-null bone marrow-derived macrophages. Among mitogen-activated protein kinases that mediate the signal transduction by LPS, JNK played a major role in Srx induction. Moreover, chemical antioxidants, such as N-acetylcysteine and butylated hydroxyanisole, and the NADPH oxidase inhibitor diphenyleneiodonium inhibited Srx induction as well as generation of reactive oxygen species, both of which were also suppressed in Nox2 (NADPH oxidase 2)-deficient bone marrow-derived macrophages. These results suggest that LPS-mediated Srx induction is dependent on both AP-1 and Nrf2, which is regulated by Nox2-derived reactive oxygen species.

Isolation of Rhodococcus sp. strain ECU0066, a new sulfide monooxygenase-producing strain for asymmetric sulfoxidation.

A new and efficient sulfide monooxygenase-producing strain, ECU0066, was isolated and identified as a Rhodococcus sp. that could transform phenylmethyl sulfide (PMS) to (S)-sulfoxide with 99% enantiomeric excess via two steps of enantioselective oxidations. Its enzyme activity could be effectively induced by adding PMS or phenylmethyl sulfoxide (PMSO) directly to a rich medium at the early log phase (6 h) of fermentation, resulting in over 10-times-higher production of the enzyme. This bacterial strain also displayed fairly good activity and enantioselectivity toward seven other sulfides, indicating a good potential for practical application in asymmetric synthesis of chiral sulfoxides.

Response of adiponectin and its receptors to changes in metabolic state after gastric bypass surgery: dissociation between adipose tissue expression and circulating levels.

BACKGROUND: Adiponectin is an adipokine with anti-atherogenic and insulin-sensitizing properties. Specific adiponectin receptors, adiponectin receptors 1 (AdipoR1) and 2 (AdipoR2), are present in adipose tissue, indicating adiponectin might have autocrine/paracrine effects on its production or action. In addition, endoplasmic reticulum oxidoreductase 1-Lalpha might mediate regulation of its secretion. The study aim was to determine the subcutaneous adipose tissue (SAT) adiponectin gene and protein expression and their correlation to metabolic parameters during metabolically distinct times after gastric bypass surgery. METHODS: A total of 12 morbidly obese male patients underwent SAT biopsy during gastric bypass surgery, active weight loss (negative energy state), and at weight stabilization (steady state energy). The SAT mRNA and protein content of adiponectin, AdipoR1 and AdipoR2, and endoplasmic reticulum oxidoreductase 1-Lalpha protein levels and the serum levels of adiponectin were assessed. RESULTS: SAT adiponectin, AdipoR1, and AdipoR2 gene expression increased significantly at the negative energy state, with no further change at steady state energy (P<.05, P<.05, and P=.04, respectively), without significant increases in protein at any stage. Changes in SAT adiponectin protein correlated with changes in AdipoR1 and AdipoR2 during steady state energy (P=.003 and P=.002, respectively). Changes in SAT adiponectin expression did not correlate with those in circulating levels. Changes in endoplasmic reticulum oxidoreductase 1-Lalpha did not correlate with either SAT or circulating levels of adiponectin. CONCLUSION: Our data indicate distinct functions of adiponectin receptors, AdipoR1 and AdipoR2, mediate the autocrine/paracrine actions of adiponectin. The lack of correlation between changes in SAT adiponectin gene and protein expression and its circulating levels suggests that adipose tissue synthesis and release of adiponectin are highly regulated pathways.

Induction of sulfiredoxin via an Nrf2-dependent pathway and hyperoxidation of peroxiredoxin III in the lungs of mice exposed to hyperoxia.

The cysteine residue at the active site of peroxiredoxin (Prx) I, Prx II, or Prx III is reversibly hyperoxidized to cysteine sulfinic acid, with concomitant loss of peroxidase activity, during normal catalysis. Sulfiredoxin (Srx) is the enzyme responsible for reversing this hyperoxidation. We now show that the expression of Srx at both the mRNA and protein levels is increased markedly in the lungs of mice exposed to hyperoxia. This hyperoxia-induced expression of Srx was not evident in mice deficient in the transcription factor Nrf2, indicating an essential role for an Nrf2 signaling pathway in this effect. Hyperoxia also elicited the accumulation of the sulfinic form of the mitochondrial enzyme Prx III, but not that of the cytosolic enzymes Prx I or Prx II, in lung tissue. This selective hyperoxidation of Prx III is likely due either to mitochondria being the major site of the hyperoxia-induced production of reactive oxygen species or to the translocation of Srx from the cytosol into mitochondria being rate limiting for the reduction of sulfinic Prx III. Hyperoxia induced the degradation of Prx III in Nrf2-deficient mice but not in wild-type animals, suggesting that, in the absence of a sufficient amount of Srx, sulfinic Prx III is converted to a form that is susceptible to proteolysis.