Arylphthalazines as potent,and orally bioavailable inhibitors of VEGFR-2

A series of arylphthalazine derivatives were synthesized and evaluated as antagonists of VEGF receptor II (VEGFR-2). IM-094482 57, which was prepared in two steps from commercially available starting materials, was found to be a potent inhibitor of VEGFR-2 in enzymatic, cellular and mitogenic assays (comparable activity to ZD-6474). Additionally, 57 inhibited the related receptor, VEGF receptor I (VEGFR-1), and showed excellent exposure when dosed orally to female CD-1 mice.     

Structure-toxicity relationship of aminoglycosides: correlation of 2'-amine basicity with acute toxicity in pseudo-disaccharide scaffolds

A new pseudo-disaccharide NB23 with a 3',4'-methylidene protection was designed and its properties were evaluated in comparison to other two structurally related pseudo-disaccharides. The basicity of the 2'-amine was found to be well correlated to acute toxicity data in mice: the increase in the basicity is associated with the toxicity increase. Based on these data, a new pseudo-trisaccharide NB45 was constructed. NB45 exhibited significant antibacterial activity while at the same time retained low acute toxicity.     

Beta-glycosphingolipids improve glucose intolerance and hepatic steatosis of the Cohen diabetic rat

A link between altered levels of various gangliosides and the development of insulin resistance was described in transgenic mice. Naturally occurring glycosphingolipids were shown to exert immunomodulatory effects in a natural killer T (NKT) cell-dependent manner. This study examined whether glycosphingolipid-induced modulation of the immune system may reduce pancreatic and liver steatosis and stimulate insulin secretion in the Cohen diabetes-sensitive (CDS) rat, a lean model of non-insulin-resistant, nutritionally induced diabetes. Four groups of CDS rats fed a diabetogenic diet were treated with daily intraperitoneal injections of glycosphingolipids beta-glucosylceramide, beta-lactosylceramide, a combination of both (IGL), or vehicle (PBS) for up to 45 days. Immune modulation was assessed by fluorescence-activated cell sorting analysis of intrahepatic and intrasplenic lymphocytes. Steatosis was assessed by MRI imaging and histological examination of liver and pancreas, Blood glucose and plasma insulin concentrations were assessed during an oral glucose tolerance test. Administration of glycosphingolipids, particularly IGL, increased intrahepatic trapping of CD8 T and NKT lymphocytes. Pancreatic and liver histology were markedly improved and steatosis was reduced in all treated groups compared with vehicle-treated rats. Insulin secretion was restored after glycosphingolipid treatment, resulting in improved glucose tolerance. The immunomodulatory effect of beta-glycosphingolipids improved the beta-cell function of the hyperglycemic CDS rat. Thus our results suggest a role for the immune system in the pathogenesis of diabetes in this model.     

The effects of leflunomide on clinical parameters and serum levels of IL-6, IL-10, MMP-1 and MMP-3 in patients with resistant rheumatoid arthritis

OBJECTIVE: The purpose of this open pilot study was to assess possible mechanisms of the effects of leflunomide by studying the influence of the drug on the serum levels of MMP-1, MMP-3, IL-10, IL-6 and their possible correlation with clinical disease parameters. PATIENTS AND METHODS: Thirty patients with long standing active rheumatoid arthritis were enrolled in this study. All patients failed at least 5 DMARDs in the past and were on stable treatment for at least 3 months before starting the protocol. The patients received a loading dose of 100 mg for 3 days followed by 20 mg/day thereafter and followed up monthly for 6 months. Disease activity was assessed at baseline, 2 weeks, and every month of therapy thereafter using the following variables: tender joint count, swollen joint count, morning stiffness duration, pain, tiredness, physician's and patient's global assessment, using VAS, ESR and CRP. Clinical effects of the treatment regimen were calculated using the American College of Rheumatology (ACR) criteria for clinical response. Adverse events were recorded. Serum levels of MMP-1, MMP-3, IL-10 and IL-6 were measured before and 3 months after starting the protocol. RESULTS: Except for tiredness, a statistically significant improvement in all clinical and laboratory parameters of disease activity was reached after 3 months. At this time point the ACR-20 response rate was 46.2%. The levels of MMP-1, MMP-3, IL-6 and IL-10 decreased significantly after 3 months. A statistically significant correlation between serum levels of MMP-1, IL-10 and IL-6 and clinical and laboratory parameters was also shown. After 6 months, 16 out of 30 patients withdrew from the study [adverse events (35.4%), lack of efficacy (9.7%), and low compliance (6.4%)]. CONCLUSIONS: Leflunomide was clinically efficacious in this group of long standing resistant RA in an open study "real life" design. These results comply with those reported in previous clinical trials. Serum MMP-1, MMP-3, IL-10 and IL-6 levels decreased significantly. Despite high withdrawal rate, no serious adverse effects were recorded.     

Conjugation to Nedd8 instigates ubiquitylation and down-regulation of activated receptor tyrosine kinases

When appended to the epidermal growth factor receptor (EGFR), ubiquitin serves as a sorting signal for lysosomal degradation. Here we demonstrate that the ubiquitin ligase of EGFR, namely c-Cbl, also mediates receptor modification with the ubiquitin-like molecule Nedd8. EGF stimulates receptor neddylation, which enhances subsequent ubiquitylation, as well as sorting of EGFR for degradation. Multiple lysine residues, located within the tyrosine kinase domain of EGFR, serve as attachment sites for Nedd8. A set of clathrin coat-associated binders of ubiquitin also bind Nedd8, but they undergo ubiquitylation, not neddylation. We discuss the emerging versatility of the concerted action of ubiquitylation and neddylation in the process that desensitizes growth factor-activated receptor tyrosine kinases.     

Transmission of Escherichia coli O157:H7 from contaminated manure and irrigation water to lettuce plant tissue and its subsequent internalization.

The transmission of Escherichia coli O157:H7 from manure-contaminated soil and irrigation water to lettuce plants was demonstrated using laser scanning confocal microscopy, epifluorescence microscopy, and recovery of viable cells from the inner tissues of plants. E. coli O157:H7 migrated to internal locations in plant tissue and was thus protected from the action of sanitizing agents by virtue of its inaccessibility. Experiments demonstrate that E. coli O157:H7 can enter the lettuce plant through the root system and migrate throughout the edible portion of the plant.     

Microenvironment-derived IL-1 and IL-17 interact in the control of lung metastasis

Inflammatory cytokines modulate immune responses in the tumor microenvironment during progression/metastasis. In this study, we have assessed the role of IL-1 and IL-17 in the control of antitumor immunity versus progression in a model of experimental lung metastasis, using 3LL and B16 epithelial tumor cells. The absence of IL-1 signaling or its excess in the lung microenvironment (in IL-1β and IL-1R antagonist knockout [KO] mice, respectively) resulted in a poor prognosis and reduced T cell activity, compared with WT mice. In IL-1β KO mice, enhanced T regulatory cell development/function, due to a favorable in situ cytokine network and impairment in APC maturation, resulted in suppressed antitumor immunity, whereas in IL-1R antagonist KO mice, enhanced accumulation and activity of myeloid-derived suppressor cells were found. Reduced tumor progression along with improved T cell function was found in IL-17 KO mice, compared with WT mice. In the microenvironment of lung tumors, IL-1 induces IL-17 through recruitment of γ/δ T cells and their activation for IL-17 production, with no involvement of Th17 cells. These interactions were specific to the microenvironment of lung tumors, as in intrafootpad tumors in IL-1/IL-17 KO mice, different patterns of invasiveness were observed and no IL-17 could be locally detected. The results highlight the critical and unique role of IL-1, and cytokines induced by it such as IL-17, in determining the balance between inflammation and antitumor immunity in specific tumor microenvironments. Also, we suggest that intervention in IL-1/IL-17 production could be therapeutically used to tilt this balance toward enhanced antitumor immunity.