Effect of salinity on the bioremediation of petroleum hydrocarbons in a saline-alkaline soil

AIMS

 The aim of this paper is to check the effect of salinity on the bioremediation process of petroleum hydrocarbons in the saline-alkaline soil.

METHODS AND RESULTS

 In this study, soil salinity was adjusted to different levels by water leaching method and the bioremediation process was conducted for 28 days. Soil pH increased after leaching and decreased during bioremediation process. At initial time, moderate salinity enhanced the biodegradation and addition of microbial consortium was not effective in enhancing degradation rate of petroleum hydrocarbons. At day of 28 days, higher degradation rate was found in treatments with more leaching times with a maximum value of 42·36%. Dehydrogenase activity increased with the progress of bioremediation and positive correlation was found between dehydrogenase activity and degradation rate of petroleum hydrocarbons. Denaturing gradient gel electrophoresis analysis result showed decreased microbial community diversity with increased salt content.

CONCLUSIONS

 The result suggested that salinity had great impact on bioremediation, and leaching and addition of inoculated consortium were effective in enhancing biodegradation of petroleum hydrocarbons in the saline-alkaline soil.

SIGNIFICANCE AND IMPACT OF THE STUDY

 The result of this study is important for understanding the bioremediation process of petroleum in contaminated soil. New remediation method of petroleum contaminated soil can be developed based on this study.

Efficacy of folic acid supplementation in stroke prevention: new insight from a meta-analysis

AIMS

  There are growing data and a continuing controversy over the efficacy of folic acid supplementation in stroke prevention. We conducted a meta-analysis based on relevant, up-to-date published randomised trials to further examine this issue.

METHODS

  Relative risk (RR) was used to measure the effect of folic acid supplementation on risk of stroke with a fixed-effects model.

RESULTS

  Overall, folic acid supplementation reduced the risk of stroke by 8% (n = 55,764; RR: 0.92; 95% CI: 0.86-1.00, p = 0.038). In the 10 trials with no or partial folic acid fortification (n = 43,426), the risk of stroke was reduced by 11% (0.89; 0.82-0.97, p = 0.010). Within these trials, a greater beneficial effect was observed among trials with a lower percent use of statins [≤ 80% (median); 0.77; 0.64-0.92, p = 0.005], and a meta-regression analysis also suggested a positive dose-response relationship between percent use of statins and log-RR for stroke associated with folic acid supplementation (p = 0.013). A daily dose of 0.4-0.8mg folic acid appeared to be adequate for stroke prevention in comparison with larger doses. In the remaining five trials conducted in populations with folic acid fortification (n = 12,338), folic acid supplementation had no effect on stroke risk (1.03; 0.88-1.21, 0.69).

CONCLUSIONS

  Our analysis indicated that folic acid supplementation is effective in stroke prevention in populations with no or partial folic acid fortification. In addition, a greater beneficial effect was observed among trials with a lower percent use of statins. Our findings underscore the importance of identifying target populations that can particularly benefit from folic acid therapy.

Reliable high-throughput approach for screening of engineered constitutive promoters in the yeast Pichia pastoris

AIMS

To develop a reliable and sensitive high-throughput approach for the screening of engineered constitutive promoters in the yeast Pichia pastoris.

METHODS AND RESULTS

The yeast-enhanced green fluorescent protein (yEGFP) was used as the reporter to monitor the promoter strength. After eliminating the interfering components (yeast extract and tryptone) with fluorescence signal from the medium, a high-throughput screening approach was established and optimized to obtain a low standard deviation of cell density (6.9%) and fluorescence (7.4%) in 48-deep-well microplates. Then, 300 clones containing GAP promoter (P(GAP)) variants were screened, exhibiting a wide range in fluorescent intensity from about 8% to 218% of that obtained with P(GAP). Six representative clones with unique promoter sequence were picked for further characterization. A good correlation between yEGFP fluorescence in microplates and shake flasks was observed. Furthermore, the high correlation between fluorescence and transcript levels confirmed that expression was transcriptionally controlled.

CONCLUSIONS

We developed a reliable high-throughput screening approach that can be used to select engineered constitutive promoters of varying strengths.

SIGNIFICANCE AND IMPACT OF THE STUDY

This approach is expected to accelerate the selection of constitutive promoters in P. pastoris and can also be applied for the screening of other constitutive expression clones.

Erythromycin inhibited glycinergic inputs to gastric vagal motoneurons in brainstem slices of newborn rats

BACKGROUND

Motilin has been known to stimulate the motility of digestive organs peripherally via activation of motilin receptors located at gastrointestinal (GI) cholinergic nerve endings and/or smooth muscle cells. Recent studies have indicated that motilin may also promote GI motility via actions in the central nervous system; however the sites of action and the mechanisms are not clear yet. The present study aimed to test the hypothesis that motilin receptor agonist erythromycin alters the synaptic inputs of preganglionic gastric vagal motoneurons (GVMs) located in the dorsal motor nucleus of the vagus (DMV).

METHODS

Gastric vagal motoneurons were retrogradely labeled by fluorescent tracer from the stomach wall of newborn rats. Fluorescently labeled GVMs in DMV were recorded using whole-cell patch-clamp in brainstem slices and the effects of motilin receptor agonist erythromycin on the synaptic inputs were examined.

KEY RESULTS

Erythromycin (100 nmol L(-1), 1 μmol L(-1), 10 μmol L(-1)) significantly inhibited the frequency of glycinergic spontaneous inhibitory postsynaptic currents (sIPSCs) of GVMs and significantly inhibited the amplitude at the concentration of 10 μmol L(-1). These responses were prevented by GM-109, a selective motilin receptor antagonist. In the pre-existence of tetradotoxin (TTX, 1 μmol L(-1)), erythromycin (10 μmol L(-1)) caused significant decreases of the glycinergic miniature inhibitory postsynaptic currents (mIPSCs), in both the frequency and the amplitude. However, erythromycin (10 μmol L(-1)) didn't cause significant changes of the GABAergic sIPSCs.

CONCLUSIONS & INFERENCES

Erythromycin selectively inhibits the glycinergic inputs of GVMs.

Cisplatin induces programmed death-1-ligand 1(PD-L1) over-expression in hepatoma H22 cells via Erk /MAPK signaling pathway

Cisplatin has been widely used in cancer treatment. However, the prognosis of the cancer patients following chemotherapy has not been substantially improved and several different mechanisms could be involved. Clinically alternative strategies such as immunotherapy and their combinations with chemotherapy have being used. Cancer immunoresistance and immune escape are major obstacles in chemotherapy. However, the effects of cisplatin on the immune responses of cancer cells are not clear. In the present studies, we investigate the expression of immunoresistance moleculor PD-L1 (the negative regulator programmed death-1-ligand 1) on cisplatin-induced hepatoma H22 cells, which can interact with PD-1 on T cells to mediate cancer immunoresistance. Hepatoma H22 cells were treated with cisplatin in vivo or in vitro to analysis the expression of PD-L1 by flow cytometry (FACS). Erk1/Erk2 phosphorylation expressions were examined by western blotting. We demonstrated that cisplatin was able to induce H22 cell apoptosis and when the concentration less than IC50 cisplatin could up-regulate PD-L1 expression in hepatoma H22 cells. The optimal concentration of cisplatin for the highest expression of PD-L1 was 0.5 μg/ml in vitro. Meanwhile, cisplatin could induce the phosphorylation of Erk1/2.The lack of effect during treatment with a specific MAPK pathway inhibitor PD98059, demonstrated that cisplatin-induced PD-L1 expression is dependent of Erk1/2 phosphorylation. Our studies reveal a potential link between chemotherapy and cancer immunoresistance. PD-L1 and its signaling pathway appear to be a potential therapeutic target for the cisplatin treatment of hepatoma.

RKTG inhibits angiogenesis by suppressing MAPK-mediated autocrine VEGF signaling and is downregulated in clear-cell renal cell carcinoma

Vascular endothelial growth factors (VEGFs) are crucial regulators of angiogenesis and vasculogenesis. The autocrine VEGF signaling is required for maintaining the homeostasis of vasculature. Dysregulation of angiogenesis is implicated in the development of many human cancers, especially in clear-cell renal cell carcinoma (ccRCC), a highly vascularized tumor. Meanwhile, antiangiogenesis has become a mainstay in the treatment of human cancers. In this study, we analyzed the functional roles of RKTG (Raf Kinase Trapping to Golgi), a negative regulator of mitogen-activated protein kinase (Raf/MEK/ERK) signaling, by sequestration of Raf kinase to the Golgi apparatus, in angiogenesis and ccRCC. Through a series of in vitro and in vivo experiments, we found that RKTG has a negative effect on cell proliferation, migration, sprouting and angiogenesis of endothelial cells. RKTG, by suppressing mitogen-activated protein kinase signaling, negatively regulates the transactivation activity of hypoxia-inducible factor 1α (HIF-1α) by inhibiting formation of HIF-1α/p300 complex and suppressing VEGF transcription, thereby reducing hypoxia-induced VEGF production. The expression level of RKTG is significantly downregulated in clinical ccRCC tumor samples, with an inverse correlation with VEGF expression level. These results highlight the functional roles of RKTG and its regulated Raf/ERK/MEK signaling cascade in angiogenesis and autocrine VEGF signaling. In addition, this study indicates that RKTG is likely implicated in the development of ccRCC through its regulation on angiogenesis.

Detection of PCR products using self-reporting duplex mutation primers

A novel oligonucleotide probe, with duplex mutation primers, which comprised a normal reverse primer labelled with a fluorophore at its 5'-end and a single-base mismatched complementary oligonucleotide labelled with a quencher at its 3'-end, was designed. Its application in the detection of hepatitis B virus (HBV) DNA of serum was investigated; results were compared with those obtained using a commercial TaqMan kit. There was a good linear correlation in the range of 10(2) approximately 10(7) copies/ml (r(2) = 0.999) with the method. Intra-experimental coefficients of variation (CVs) were 0.70% approximately 7.80%, and inter-experimental CVs were 0.78% approximately 9.02%, respectively. There was no significant difference of HBV genome number tested by the two methods (p<0.05) in 132 hepatitis B patients; HBV DNA was not detected in any serum samples of 20 healthy volunteers by the two methods.

Waist circumference, body mass index and waist to hip ratio for prediction of the metabolic syndrome in Chinese

BACKGROUND AND AIMS

To explore the ability of waist circumference (WC), body mass index (BMI) and waist to hip ratio (WHR) to predict two or more non-adipose components of the metabolic syndrome (MetS) among individuals aged 18-85 in North China.

METHODS AND RESULTS

This study is a cluster sample survey of 101,510 individuals, complete data are 75,788 subjects, 59,874 males and 15,914 females. Their ages were 51.9+/-12.7 years (males) and 48.7+/-11.5 years (females). Receiver operating characteristic (ROC) analysis was used to examine discrimination and find optimal cut off values of WC, BMI and WHR to predict two or more non-adipose components of MetS. The area under the ROC curve (AURC) for WC (0.694) and BMI (0.692) in females showed no difference. In males BMI (0.657) had a better discrimination than WC (0.634). WHR was weaker in both sexes. The optimal cut off value of WC in males (86.5 cm) was higher than in females (82.1cm); and that of BMI was about 24 kg/m(2) in both genders. The optimal cut off values of WC, BMI, and WHR, increased with age in both sexes.

CONCLUSIONS

BMI and WC are more useful than WHR for predicting two or more non-adipose components of MetS. Cut off values for WC in males, and those of BMI and WHR in both sexes are lower than that in present MetS criteria; WC in females is slightly higher. Cut off values of WC, BMI and WHR were increased with age in the Chinese.

Therapeutic vaccination against advanced pancreatic cancer by autologous dendritic cells pulsed with a MUC1 peptide: Preclinical results of a clinical phase I trial

e15652

Background: Pancreatic ductal adenocarcinoma has a particularly poor prognosis. Therefore, novel therapeutic strategies such as immunotherapy are required. The aim of the present phase I study was to evaluate the safety, immune responses and clinical activity of a vaccine based on autologous dendritic cells (DC) pulsed with a specific MUC1 peptide in advanced pancreatic cancer patients. Methods: Five patients who had pancreatic cancer ductal adenocarcinoma expressing MUC1 in stage of III/IV were enrolled to the clinical trial. Patients underwent leukapheresis to generate dendritic cells by culture in vitro with granulocyte macrophage colony-stimulating factor and interleukin-4 for 5 days. Dendritic cells were then pulsed overnight with MUC1 peptide (GVTSAPDTRPAPGSTAPPAH) and harvested for vaccination. Dendritic cells (3×106-6×106) were injected intradermally every 2 weeks for 3–4 times. Results: All patients remained with progressive disease. Four patients developed strong T-cell IFN-γ and Granzyme B Elispot responses to the vaccine. Most interestingly, the patient who was treated with the highest number of DC(6×106) had more number of CTL than other patients and showed delayed-type hypersensitivity responses at injection sites and this patient stopped application of the analgetics. Another patient with relapsed pancreatic cancer who had finished the 4 times of vaccination and then followed 6 times of chemotherapy with Gemcitabine had a surprisingly long term of survival of 12 month. No evidence of significant treatment related toxicity or auto-immunity was observed. Conclusions: This study showed the safety and clinical response of MUC1 peptide-pulsed dendritic cell therapy for patients with advanced pancreatic cancer. It confirms the capability of this DC vaccine to stimulate an immune response in patients with pancreatic cancer even in the presence of a large tumor burden. Dendritic cell therapy is recommended for further clinical studies in pancreatic cancer patients.

No significant financial relationships to disclose.

A novel recombinant tandem repeat DNA vaccine targeting at MUC1

3066

Background: Tandem repeat (TR) is the key epitope of mucin 1 (MUC1) for inducing cytotoxic T lymphocytes (CTL) to kill the tumor cells specifically. A novel recombinant TR DNA vaccine was constructed to study its induced immune responses. Methods: A recombinant human TR (rhTR) gene encoding a single TR polypeptide of MUC1 was synthesized and cloned into the multiple cloning sites of plasmid pcDNA3.1/Myc-his (+) A to construct the recombinant plasmid pcDNA3.1-TR/Myc-his (+) A (pTR plasmid). Expression of pTR plasmid was confirmed by transfection assay and Western blot analysis. C57BL/6 (H-2b) mice were immunized with pTR plasmid (n=15) by tibial muscle injection. Mice inoculated with the empty vector (EV group, n=15) and 0.9% NaCl solution (NS group, n=15) were used as vector and blank control respectively. Four weeks later, all mice were immunized again. Specific antibody detection and cytotoxic assay were used to evaluate the vaccine-induced TR specific immune responses. Results: DNA sequencing confirmed that the pTR plasmid was exactly constructed. Transfection assay and Western blot analysis found that the transfected COS7 cells expressed TR polypeptide of MUC1 48 hours after transfection. Cytotoxic assay showed that immunization with pTR plasmid into C57BL/6 mice resulted in more efficient induction of CTL specific cytolysis against TR polypeptide than that of EV group and NS group (p<0.01). Vaccine immunized mice had a higher equivalent concentration of anti-TR specific antibodies (2324μg/ml±238μg/ml) than that of EV group (1896μg/ml±533μg/ml, p<0.01) and NS group (1736μg/ml±142μg/ml, p<0.01). Conclusions: The novel recombinant TR DNA vaccine targeting at MUC1 was exactly constructed, immunization with which could induce TR specific CTL response and antibodies response in mice.

No significant financial relationships to disclose.

Preoperative hepatic and regional arterial chemotherapy in the prevention of liver metastasis after colorectal cancer surgery

4090

Background: To investigate whether preoperative hepatic and regional arterial chemotherapy are able to prevent liver metastasis and improve overall survival in patients receiving curative colorectal cancer resection. Methods: Patients with Stage II or Stage III colorectal cancer (CRC) were randomly assigned to receive preoperative hepatic and regional arterial chemotherapy (PHRAC group, n=256) or surgery alone (control group, n=253). The primary endpoint was disease-free survival, whereas the secondary endpoints included liver metastasis-free survival and overall survival. Results: There were no significant differences in overall morbidity between PHRAC and Control groups. During the follow-up period (median, 42 months), the median liver metastasis time for patients with stage III CRC was significantly longer in the PHRAC group (16±3 months v.s. 8±1 months, P=0.01). In stage III patients, there was also significant difference between the two groups with regard to the incidence of liver metastasis (18.9% vs 27.3%, P=0.01), 5-year disease-free survival (70.2% vs 52.0%, P=0.0076), 5-year overall survival (80.3% vs 69.5%, P=0.020) and the median survival time (40.1± 4.6 months vs 36.3 ± 3.2 months, P=0.03). In the PHRAC arm, the risk ratio of recurrence was 0.63 (95% CI, 0.51–0.79, P=0.0001), of death was 0.50(95% CI, 0.32–0.67; P=0.005), and of liver metastasis was 0.70 (95% CI, 0.52–0.86; p=0.01). In contrast, PHRAC seemed to be no benefit for stage II patients. Toxicities, such as hepatic toxicity and leucocyte decreasing, were mild and could be cured with medicine. Conclusions: Preoperative hepatic and regional arterial chemotherapy, in combination with surgical resection, could be able to reduce and delay the occurrence of liver metastasis and therefore improve survival rate in patients with stage III colorectal cancer.

No significant financial relationships to disclose.

A phase I study of CNTO328, an anti-interleukin (IL)-6 monoclonal antibody combined with docetaxel in subjects with metastatic castration-resistant prostate cancer (CRPC)

5063

Background: IL-6 is a potential mediator of prostate cancer morbidity and mortality and may protect prostate cancer cells from chemotherapy-induced apoptosis. CNTO328, a chimeric anti-IL-6 antibody, has been shown to inhibit prostate tumor growth in xenograft mouse models. Methods: Chemotherapy-naïve patients with metastatic CRPC were administered CNTO328 in combination with T (75 mg/m2 q3w) in 3 dose-escalation cohorts (6 mg/kg q2w, and 9 and 12 mg/kg q3w) following an initial run-in cycle of T alone to examine the effect of CNTO328 on T pharmacokinetics (PK). Safety was evaluated prior to each dose escalation. Prostate specific antigen (PSA), radiological response, and C-reactive protein (CRP), the best-known surrogate of serum IL-6 bioactivity, were also assessed. Results: This study is fully enrolled December 2008 with 38 patients. 36 patients with KPS ≥70, median age 66 (range 43–82) received 6 (median) cycles of T (range 1–37). 32 patients received at least one dose of CNTO328 in combination with T and are evaluable. Baseline patient characteristics included: median PSA of 59 ng/mL (range 12–1430) and median CRP was 3.85 mg/L (range <1 to 91.3). One DLT was observed in each cohort (grade 4 neutropenic infection, grade 3 syncope and dehydration, grade 3 GI bleeding), though MTD for the combination was not reached. Most frequent ≥grade 3 adverse events (AE) were neutropenia (69%); leukopenia (63%); lymphopenia (31%); dyspnea (19%); fatigue (16%). One patient died due to AE (sepsis) reported as possible related to T and unlikely related to CNTO328 by investigator. Preliminary data show CNTO328 does not appear to have a major effect on T PK. Preliminary efficacy data is shown in the table . Ongoing evaluation indicates 3/12 partial responses in patients with measurable disease reported thus far. Conclusions: CNTO328 with T is well tolerated and demonstrates biological and clinical activity in CRPC that warrants further study.

[Table: see text]

[Table: see text]

Is the relationship between syndromes of depression and dementia temporal? The MRC-ALPHA and Hefei-China studies

BACKGROUND

Recent studies have shown a temporal association between depressive symptoms and cognitive decline. However, the relationship between syndromes of depression and dementia is unknown.

METHOD

A total of 1736 people aged > or = 65 years in China and 5222 older people in the UK were interviewed using the Geriatric Mental State Examination (GMS) and reinterviewed at follow-up. Five levels of syndromes of depression and dementia were diagnosed using the Automated Geriatric Examination for Computer Assisted Taxonomy (AGECAT).

RESULTS

Although there were fewer depressive syndromes in Chinese than British participants, both populations showed a similarly high level of syndromes of dementia (organic disorder) (20% for women, 14% for men). There was a significant cross-sectional correlation between syndrome levels of depression and dementia (correlation coefficients: 0.141-0.248 for Chinese, 0.168-0.248 for British). This was maintained for different age, gender and people with and without cardiovascular disease (CVD). The relationship between syndromes of baseline depression and follow-up dementia was less substantial: the correlation coefficient was 0.075 [95% confidence interval (CI) 0.021-0.128] for the Chinese sample at the 1-year follow-up, and 0.093 (95% CI 0.061-0.125) for the British at the 2-year follow-up and 0.093 (95% CI 0.049-0.130) at the 4-year follow-up. This relationship disappeared in participants without baseline organic syndromes. In a multiple adjusted logistic regression analysis, an increased risk of organic syndromes seemed to be associated with baseline, mainly in the highest level of, depressive syndromes.

CONCLUSIONS

The relationship between syndromes of depression and dementia might be temporal. The lack of an obvious dose-response relationship between baseline depressive syndromes and follow-up dementia syndromes suggests that the causal relationship between depression and dementia needs further investigation.

Repression of NFAT3 transcriptional activity by estrogen receptors

Nuclear factor of activated T cells 3 (NFAT3) activities have been implicated in many biological processes, such as breast cancer, cardiac hypertrophy, learning and memory, and adipocyte differentiation. However, how protein factors regulate NFAT3 transcriptional activity is poorly understood. Here, we report that regardless of estrogen, overexpression of estrogen receptor alpha and beta (ERalpha and ERbeta) suppresses NFAT3 transcriptional activity, whereas knockdown of endogenous ERalpha and ERbeta enhances the activity. Estrogen further enhances ER inhibition of NFAT3-dependent transcription. ERalpha and ERbeta interact with NFAT3 independently of the NFAT agonists phorbol myristate acetate (PMA) and ionomycin, and ERalpha is recruited to an NFAT3 target gene promoter. Phosphorylation of ERalpha at different sites differentially affects ERalpha modulation of NFAT3 transcriptional activity. These results suggest that ER may play a critical role in regulation of NFAT3 transcriptional activity.

Peroxisome proliferator-activated receptor-delta induces insulin-induced gene-1 and suppresses hepatic lipogenesis in obese diabetic mice

Primary nonalcoholic fatty liver disease is one of the most common forms of chronic liver diseases and is associated with insulin-resistant states such as diabetes and obesity. Recent work has revealed potential implications of peroxisome proliferator-activated receptor-delta (PPARdelta) in lipid homeostasis and insulin resistance. In this study, we examined the effect of PPARdelta on sterol regulatory element-binding protein-1 (SREBP-1), a pivotal transcription factor controlling lipogenesis in hepatocytes. Treatment with GW0742, the PPARdelta agonist, or overexpression of PPARdelta markedly reduced intracellular lipid accumulation. GW0742 and PPARdelta overexpression in hepatocytes induced the expression of insulin-induced gene-1 (Insig-1), an endoplasmic reticulum protein braking SREBP activation, at both the mRNA and the protein levels. PPARdelta inhibited the proteolytic processing of SREBP-1 into the mature active form, thereby suppressing the expression of the lipogenic genes fatty acid synthase, stearyl CoA desaturase-1, and acetyl coenzyme A carboxylase. Our results revealed a direct binding of PPARdelta to a noncanonical peroxisome proliferator responsive element motif upstream of the transcription initiation site of human Insig-1. The disruption of this site diminished the induction of Insig-1, which suggested that Insig-1 is a direct PPARdelta target gene in hepatocytes. Knockdown of endogenous Insig-1 attenuated the suppressive effect of GW0742 on SREBP-1 and its target genes, indicating PPARdelta inhibited SREBP-1 activation via induction of Insig-1. Furthermore, overexpression of PPARdelta by intravenous infection with the PPARdelta adenovirus induced the expression of Insig-1, suppressed SREBP-1 activation, and, consequently, ameliorated hepatic steatosis in obese db/db mice.

CONCLUSION

Our study reveals a novel mechanism by which PPARdelta regulates lipogenesis, suggesting potential therapeutic applications of PPARdelta modulators in obesity and type 2 diabetes, as well as related steatotic liver diseases.

Suppression of pro-inflammatory adhesion molecules by PPAR-delta in human vascular endothelial cells

OBJECTIVE

Endothelial activation is implicated in atherogenesis and diabetes. The role of peroxisome proliferator-activated receptor-delta (PPAR-delta) in endothelial activation remains poorly understood. In this study, we investigated the anti-inflammatory effect of PPAR-delta and the mechanism involved.

METHODS AND RESULTS

In human umbilical vein endothelial cells (HUVECs), the synthetic PPAR-delta ligands GW0742 and GW501516 significantly inhibited tumor necrosis factor (TNF)-alpha-induced expression of vascular cell adhesion molecule-1 and E-selectin (assayed by real-time RT-PCR and Northern blotting), as well as the ensuing endothelial-leukocyte adhesion. Activation of PPAR-delta upregulated the expression of antioxidant genes superoxide dismutase 1, catalase, and thioredoxin and decreased reactive oxygen species production in ECs. Chromatin immunoprecipitation assays showed that GW0742 switched the association of BCL-6, a transcription repressor, from PPAR-delta to the vascular cell adhesion molecule (VCAM)-1 promoter. Small interfering RNA reduced endogenous PPAR-delta expression but potentiated the suppressive effect of GW0742 on EC activation, which suggests that the nonliganded PPAR-delta may have an opposite effect.

CONCLUSIONS

We have demonstrated that ligand activation of PPAR-delta in ECs has a potent antiinflammatory effect, probably via a binary mechanism involving the induction of antioxidative genes and the release of nuclear corepressors. PPAR-delta agonists may have a potential for treating inflammatory diseases such as atherosclerosis and diabetes.

Role of cGMP-dependent protein kinase in development of tolerance to nitroglycerine in porcine coronary arteries

BACKGROUND AND PURPOSE

The cGMP-dependent protein kinase (PKG) is a key enzyme for nitrovasodilator-induced vasodilation. The present study was to determine its role in nitrate tolerance.

EXPERIMENTAL APPROACH

isolated porcine coronary arteries were incubated for 24 h with nitroglycerin (NTG) and their relaxant responses were determined. PKG activity was assayed by measuring the incorporation of (32)P into BPDEtide. PKG protein was determined by Western blotting and PKG mRNA by real-time PCR.

KEY RESULTS

A 24 h incubation with NTG attenuated relaxation of coronary arteries to NTG, which was associated with decreased PKG activity. The nitrate tolerance induced with NTG at 10(-7) M was affected by a scavenger of reactive oxygen species and the tolerance induced with NTG at 10(-6) and 10(-5) M showed cross-tolerance to DETA NONOate and 8-Br-cGMP (a cell permeable cGMP analogue). PKG protein and mRNA were down-regulated by a 24 h incubation with NTG at 10(-5) M but not at 10(-7) M. Acute exposure to exogenous superoxide inhibited PKG activity stimulated by NTG at 10(-7) M but not at 10(-5) M. Superoxide had no effect on PKG activity stimulated with exogenous cGMP.

CONCLUSIONS AND IMPLICATIONS

Nitrate tolerance induced by NTG at low concentrations may result from an increased production of reactive oxygen species acting on sites upstream of PKG. The tolerance induced by NTG at higher concentrations may be in part due to suppression of PKG expression resulting from sustained activation of the enzyme. These distinct mechanisms of nitrate tolerance may be of clinical significance.

Protein kinase G regulates the basal tension and plays a major role in nitrovasodilator-induced relaxation of porcine coronary veins

BACKGROUND AND PURPOSE

Coronary venous activity is modulated by endogenous and exogenous nitrovasodilators. The present study was to determine the role of protein kinase G (PKG) in the regulation of the basal tension and nitrovasodilator-induced relaxation of coronary veins.

EXPERIMENTAL APPROACH

Effects of a PKG inhibitor on the basal tension and responses induced by nitroglycerin, DETA NONOate, and 8-Br-cGMP in isolated porcine coronary veins were determined. Cyclic cGMP was measured with radioimmunoassay. PKG activity was determined by measuring the incorporation of 32P from gamma-32P-ATP into the specific substrate BPDEtide.

KEY RESULTS

Rp-8-Br-PET-cGMPS, a specific PKG inhibitor, increased the basal tension of porcine coronary veins and decreased PKG activity. The increase in tension was 38% of that caused by nitro-L-arginine. Relaxation of the veins induced by nitroglycerin and DETA NONOate was accompanied with increases in cGMP content and PKG activity. These effects were largely eliminated by inhibiting soluble guanylyl cyclase with ODQ. The increase in PKG activity induced by the nitrovasodilators was abolished by Rp-8-Br-PET-cGMPS. The relaxation caused by these dilators and by 8-Br-cGMP at their EC50 was attenuated by the PKG inhibitor by 51-66%.

CONCLUSIONS AND IMPLICATIONS

These results suggest that PKG is critically involved in nitric oxide-mediated regulation of the basal tension in porcine coronary veins and that it plays a primary role in relaxation induced by nitrovasodilators. Since nitric oxide plays a key role in modulating coronary venous activity, augmentation of PKG may be a therapeutic target for improving coronary blood flow.

Five-year survival analysis of liver metastasis of colorectal cancer after hepatic resection

14571

Background: To evaluate the relation between hepatic resecion and survival rate of liver metastasis of colorectal cancer ( LMCC). Methods: Use retrograde case analysis method, 133 cases of LMCC received hepatic resection from 1/1/2000 to 31/12/2005 were included,with attention to the relation between hepatic resection and survival rate. Results: There were 133 cases underwent curative hepatic resection in all 470 LMCC cases, of which 30 cases (30/196,15.3%) in synchronous liver metastasis (SLM) group and 103 cases (103/274,37.6%) in metachronous liver metastasis (MLM) group, P<0.01. Mortality rate related to operation was 3.3%(1/30) in SLM and 1.9%(2/103) in MLM(P<0.05). Until 31/6/2006, all 133 cases were followed-up, 1,3,5 years survival rate and median survival time of SLM (81.0%, 40.3%, 16.5%, 22 months) is similar to that of MLM (88.2%, 49.1%, 31.7%, 25 months, P > 0.05), but the recurrence rate is higher(36.7% vs 20.4%,P=0.03). Compared to 49 cases whose liver metastases focus can be resected but chosen non- operative therapy, 1, 3, 5 years survival rate of 133 resected cases is higher (55.6%, 11.0%, 0 vs 86.2%, 39.2%, 29.4%, P=0.0034). In SLM, 22 cases received I stage resection of the primary colorectal tumor and liver metastasis and 8 cases received liver metastasis resection after the primary surgery (II stage operation). 1, 2, 3 years survival are 90.0% vs 87.5%(P > 0.05),61.4% vs 55.3%(P > 0.05)and 35.4% vs 30.0%(P > 0.05) and the median survival time is 28 months vs 26months(P > 0.05).COX multivariate analysis was used to analyze the prognositic factors. Incision margin =1cm(β=-0.8351,P=0.0363)and reoperation after recurrence(β=- 0.9428,P=0.0411)were protective survival factors, and postoperation recurrence (β=0.6471,P=0.0226) was survival risk factor. Conclusions: Curative hepatic resection is the first choice of liver metastasis of colorectal cancer and can improve survival.

No significant financial relationships to disclose.

High-yield expression, purification and characterization of tumor-targeted IFN-alpha2a

BACKGROUND

IFN-alpha has been shown to be effective against hematologic malignancies. However, it is ineffective against most solid tumors and has not been satisfactory because of its toxicity.

METHODS

The NGR (Asn-Gly-Arg) peptide is a tumor-homing peptide. In order to increase the anti-tumor activity of IFN-alpha2a and lower the dose, we coupled a cyclic NGR peptide with the C terminus of IFN-alpha2a (named IFN-alpha2a-NGR).

RESULTS

The fusion protein was expressed in E. coli and purified by ion-exchange chromatography. The purity of IFN-alpha2a-NGR was >98% and the final purification yield of IFN-alpha2a-NGR was approximately 18 mg/L. The anti-tumor efficacy and the binding ability of IFN-alpha2a-NGR with tumor vasculature were investigated in vitro and in vivo.

DISCUSSION

Our study has demonstrated that the anti-tumor efficacy of IFN-alpha2a-NGR is significantly increased in comparison with IFN-alpha2a, and IFN-alpha2a-NGR could selectively target tumor vessels. These data indicate that the tumor-homing peptide (NGR) can enhance the therapeutic efficacy of IFN-alpha2a against tumors.

Laminar shear stress up-regulates the expression of stearoyl-CoA desaturase-1 in vascular endothelial cells

OBJECTIVE

Laminar shear stress plays critical roles in vascular homeostasis and exerts various metabolic effects on endothelial cells (ECs). Stearoyl-CoA desaturase-1 (SCD1), which catalyzes the biosynthesis of monounsaturated fatty acids, affects the lipid composition and fluidity of the cell membrane. Thus, we examined the effect of laminar flow on SCD1 expression in ECs.

METHODS

A flow chamber was used to impose a laminar shear stress on a confluent monolayer of human vascular ECs. The expression of SCD1 was examined using real-time RT-PCR and Northern and Western blotting. Immunohistochemical staining was used to assess the expression of SCD1 in Sprague-Dawley rat arteries, including the sites of arterial bifurcation.

RESULTS

Laminar shear stress (12 dyn/cm2, 12 h) markedly increased the gene expression of SCD1 in ECs. The flow-induced SCD1 expression was attenuated by peroxisome proliferator-activated receptor (PPAR)-gamma antagonists both in vitro and in vivo. Troglitazone and rosiglitazone significantly increased the gene expression of SCD1. Furthermore, overexpression of a constitutively active PPARgamma induced the expression of SCD1 in ECs. Immunohistochemical study of cross-sections from rat celiac arteries revealed that endothelial expression of SCD1 was substantially higher on the medial division apex, where the shear stress is high and more laminar, than the lateral aspect, where the shear stress is low and unsteady.

CONCLUSION

These in vitro and in vivo results demonstrate that laminar flow increased the expression of SCD1 in endothelium through a PPARgamma-specific mechanism, which may contribute to the shear stress-mediated protective roles in ECs.

Genome sequences of the honey bee pathogens Paenibacillus larvae and Ascosphaera apis

Genome sequences offer a broad view of host-pathogen interactions at the systems biology level. With the completion of the sequence of the honey bee, interest in the relevant pathogens is heightened. Here we report the genome sequences of two of the major pathogens of honey bees, the bacterium Paenibacillus larvae (causative agent for American foulbrood disease) and the fungus Ascosphaera apis. (causative agent for chalkbrood disease). Ongoing efforts to characterize the genomes of these species can be used to understand and mitigate the effects of two important pathogens, and will provide a contrast with pathogenic, benign and freeliving relatives.

Subchronic 90-day oral (Gavage) toxicity study of a Luo Han Guo mogroside extract in dogs

A combined 28-day and 90-day oral (Gavage) study was conducted in male and female dogs to investigate the safety of PureLo, a non-caloric sweetener derived from the Chinese fruit Luo Han Guo, which achieves its sweetness from the presence of triterpene glycosides known as mogrosides. Three dogs of each sex were administered 10 mL/kg bw/day of either an aqueous solution providing 3000 mg/kg bw/day of PureLo or distilled water for either 28 days or 90 days. Measurements included clinical observations, body weight, food consumption, hematology, blood chemistry, urinalysis, gross necropsy, organ weight, and histopathology. There were no significant adverse effects on any of these measures. Based on the lack of toxicological effects in the study, the NOAEL for PureLo is 3000 mg/kg bw/day when administered to dogs by Gavage for 90 consecutive days.

Studies on the growth metabolism of Bacillus thuringiensis and its vegetative insecticidal protein engineered strains by microcalorimetry

The metabolic power-times curves of Bacillus thuringiensis and its vegetative insecticidal protein engineered strains were determined at 30 degrees C by using a thermal activity monitor air Isothermal Microcalorimeter, ampoule method. From the power-times curves, the maximum power (Pmax) in the log phase, the growth rate constant (k), the generation times (tG), the time of the maximum power (tmax), the heat effects (Qlog) for log phase, and the total heat effect in 45 h (Qtotal) of B. thuringiensis strains can be obtained. The results indicate that their power-times curves are different. The relationship between their metabolic power-times curves and character of bacteria metabolism, and thermokinetics and gene expression were analyzed and discussed. The character of the bacteria power-times curves reflected the physiologic character of gene expression. The microcalorimetric method proved to be a reliable and sensitive tool for the assessment of the growth metabolism, the heat output in bacteria and its engineered strains. The determination of the thermokinetic character is beneficial to the control of fermentation.

Analysis of the promoters and 5'-UTR of mouse Cd59 genes, and of their functional activity in erythrocytes

The complement regulatory protein CD59 inhibits formation of the membrane attack complex (MAC), the terminal effector of the complement system. There are two mouse Cd59 genes in mice but only one in humans. In the work reported here we (a) mapped the promoter regions of both mCd59a and mCd59b genes, (b) identified two different promoters for each mCd59 gene, (c) defined a previously unrecognized additional exon 1 in each mCd59 gene, (d) identified that each mCd59 gene expresses two different tissue-specific transcripts that differ in their 5'-UTR, and (e) confirmed the presence of mCd59b mRNA in multiple tissues. At the functional level, comparison of the sensitivity of mCd59ab(-/-) and mCd59a(-/-) red blood cells to MAC-mediated lysis revealed that mCd59b protects RBC from MAC-mediated lysis, at least in the setting of mCd59a deficiency. Together these findings indicate that the mCd59 genes may have complex and perhaps different regulatory mechanisms in different tissues.

CCL2 and CXCL1 trigger calcitonin gene-related peptide release by exciting primary nociceptive neurons

Chemokines are important mediators in immune responses and inflammatory processes. Calcitonin gene-related peptide (CGRP) is produced in dorsal root ganglion (DRG) neurons. In this study, CGRP radioimmunoassay was used to investigate whether the chemokines CCL2 and CXCL1 could trigger CGRP release from cultured DRG neurons of neonatal rats and, if so, which cellular signaling pathway was involved. The results showed that CCL2 and CXCL1 ( approximately 5-100 ng/ml) evoked CGRP release and intracellular calcium elevation in a pertussis toxin (PTX)-sensitive manner. The CGRP release by CCL2 and CXCL1 was significantly inhibited by EGTA, omega-conotoxin GVIA (an N-type calcium channel blocker), thapsigargin, and ryanodine. Pretreatment of DRG neurons for 30 min with the inhibitors of phospholipase C (PLC) and protein kinase C (PKC) but not mitogen-activated protein kinases (MAPKs) significantly reduced CCL2- or CXCL1-induced CGRP release and intracellular calcium elevation. Intraplantar injection of CCL2 or CXCL1 produced hyperalgesia to thermal and mechanical stimulation in rats. These data suggest that CCL2 and CXCL1 can stimulate CGRP release and intracellular calcium elevation in DRG neurons. PLC-, PKC-, and calcium-induced calcium release from ryanodine-sensitive calcium stores signaling pathways are involved in CCL2- and CXCL1-induced CGRP release from primary nociceptive neurons, in which chemokines produce painful effects via direct actions on chemokine receptors expressed by nociceptive neurons.