Synthesis and SAR development of novel mGluR1 antagonists for the treatment of chronic pain

High throughput screening identified the pyridothienopyrimidinone 1 as a ligand for the metabotropic glutamate receptor 1 (mGluR1 = 10 nM). Compound 1 has an excellent in vivo profile; however, it displays unfavorable pharmacokinetic issues and metabolic stability. Therefore, using 1 as a template, novel analogues (10i) were prepared. These analogues displayed improved oral exposure and activity in the Spinal Nerve Ligation (SNL) pain model.     

Human heat shock protein (Hsp) 90 interferes with Neisseria meningitidis adhesin A (NadA)-mediated adhesion and invasion

NadA (N eisseria meningitidisadhesin A), a meningococcal surface protein, mediates adhesion to and invasion of human cells, an activity in which host membrane proteins have been implicated. While investigating these host factors in human epithelial cells by affinity chromatography, we discovered an unanticipated interaction of NadA with heat shock protein (Hsp) 90, a molecular chaperone. The specific in vitro interaction of recombinant soluble NadA and Hsp90 was confirmed by co-immunoprecipitations, dot and far-Western blot. Intriguingly, ADP, but not ATP, was required for this association, and the Hsp90 inhibitor 17-AAG promoted complex formation. Hsp90 binding to an Escherichia coli strain used as carrier to express surface exposed NadA confirmed these results in live bacteria. We also examined RNA interference, plasmid-driven overexpression, addition of exogenous rHsp90 and 17-AAG inhibition in human epithelial cells to further elucidate the involvement of Hsp90 in NadA-mediated adhesion and invasion. Together, these data suggest an inverse correlation between the amount of host Hsp90 and the NadA adhesive/invasive phenotype. Confocal microscopy also demonstrated that meningococci interact with cellular Hsp90, a completely novel finding. Altogether our results show that variation of host Hsp90 expression or activity interferes with adhesive and invasive events driven by NadA.     

Expression of Ca(2+)-independent and Ca(2+)-dependent phospholipases A(2) and cyclooxygenases in human melanocytes and malignant melanoma cell lines

We provide novel evidence that human melanoma cell lines (M10, M14, SK-MEL28, SK-MEL93, 243MEL, 1074MEL, OCM-1, and COLO38) expressed, at mRNA and protein levels, either Ca(2+)-independent phospholipase A(2) (iPLA(2)) or cytosolic phospholipase A(2) (cPLA(2)) and its phosphorylated form. Normal human melanocytes contained the lowest levels of both PLA(2)s. Cyclooxygenase-1 and -2 (COX-1 and COX-2) were also expressed in cultured tumor cells as measured by Western blots. The most pronounced overexpression of iPLA(2) and COX-1 was found in two melanoma-derived cells, M14 and COLO38. Normal human melanocytes and the M10 melanoma cell line displayed no COX-2 expression. Using subcellular fractionation, Western blot and confocal microcopy analyses, in paradigmatic SK-MEL28 and SK-MEL93 cells we showed that iPLA(2), COX-1 and even cPLA(2) were equally located in the cytosol, membrane structures and perinuclear region while COX-2 was preferentially associated with the cytosol. Specific inhibitors of these three enzymes significantly reduced the basal proliferation rate either in melanocytes or in melanoma cell lines. These results, coupled with the inhibition of the cell proliferation by electroporation of melanoma cells with cPLA(2) or COX-2 antibodies, demonstrate that a possible correlation between PLA(2)-COX expression and tumor cell proliferation in the melanocytic system does exist. In addition, the high expression level of both PLA(2)s and COXs suggests that eicosanoids modulate cell proliferation and tumor invasiveness.     

Ng-MIP, a surface-exposed lipoprotein of Neisseria gonorrhoeae, has a peptidyl-prolyl cis/trans isomerase (PPIase) activity and is involved in persistence in macrophages

Macrophage infectivity potentiators (MIPs) are a family of surface-exposed virulence factors of intracellular microorganisms such as Legionella, Chlamydia and Trypanosoma. These proteins display peptidyl-prolyl cis/trans isomerase (PPIase) activity that is inhibited by immunosuppressants FK506 and rapamycin. Here we describe the identification and characterization in Neisseria gonorrhoeae of Ng-MIP, a surface-exposed lipoprotein with high homology to MIPs. The protein is an homodimer with rapamycin-inhibited PPIase activity confirming that it is a functional member of the MIP family. A knock-out strain, generated by deletion of the mip gene in N. gonorrhoeae F62 strain, was evaluated for its role in infection of mouse and human macrophages. We show that Ng-MIP promotes the intracellular survival of N. gonorrhoeae in macrophages, highlighting a possible role of this protein in promoting the persistence of gonococcal infection.     

Expression in Escherichia coli and in vitro refolding of the human protein pLG72

Recently, genes coding for pLG72 and d-amino acid oxidase have been related to schizophrenia, a widespread psychiatric disorder that affects about 1% of population. pLG72 is a puzzling, novel protein present only in primates and proposed to be an activator of d-amino acid oxidase. Here we report on the overexpression of wild-type and His-tagged pLG72 in Escherichia coli. Both variants form inclusion bodies and have been refolded and purified to homogeneity: the acquisition of secondary and tertiary structure was demonstrated by CD spectroscopy. A figure of approximately 70 mg of pure protein per liter of fermentation broth was achieved.     

HELP LDL Apheresis Reduces Plasma Pentraxin 3 in Familial Hypercholesterolemia

Background

Pentraxin 3 (PTX3), a key component of the humoral arm of innate immunity, is secreted by vascular cells in response to injury, possibly aiming at tuning arterial activation associated with vascular damage. Severe hypercholesterolemia as in familial hypercholesterolemia (FH) promotes vascular inflammation and atherosclerosis; low-density lipoprotein (LDL) apheresis is currently the treatment of choice to reduce plasma lipids in FH. HELP LDL apheresis affects pro- and antiinflammatory biomarkers, however its effects on PTX3 levels are unknown. We assessed the impact of FH and of LDL removal by HELP apheresis on PTX3.

Methods

Plasma lipids, PTX3, and CRP were measured in 19 patients with FH undergoing chronic HELP LDL apheresis before and after treatment and in 20 control subjects. In the patients assessment of inflammation and oxidative stress markers included also plasma TNFα, fibrinogen and TBARS.

Results

At baseline, FH patients had higher (p = 0.0002) plasma PTX3 than matched control subjects. In FH PTX3 correlated positively (p≤0.05) with age, gender and CRP and negatively (p = 0.01) with HELP LDL apheresis vintage. The latter association was confirmed after correction for age, gender and CRP. HELP LDL apheresis acutely reduced (p≤0.04) plasma PTX3, CRP, fibrinogen, TBARS and lipids, but not TNFα. No association was observed between mean decrease in PTX3 and in LDL cholesterol. PTX3 paralleled lipids, oxidative stress and inflammation markers in time-course study.

Conclusion

FH is associated with increased plasma PTX3, which is acutely reduced by HELP LDL apheresis independently of LDL cholesterol, as reflected by the lack of association between change in PTX3 and in LDL levels. These results, together with the finding of a negative relationship between PTX3 and duration of treatment suggest that HELP LDL apheresis may influence both acutely and chronically cardiovascular outcomes in FH by modulating PTX3.     

γ-Herpesvirus Load as Surrogate Marker of Early Death in HIV-1 Lymphoma Patients Submitted to High Dose Chemotherapy and Autologous Peripheral Blood Stem Cell Transplantation

Autologous stem cell transplantation (ASCT) is a feasible procedure for human immunodeficiency virus-1 (HIV-1) lymphoma patients, whose underlying disease and intrinsic HIV-1- and ASCT-associated immunodeficiency might increase the risk for γ-herpesvirus load persistence and/or reactivation. We evaluated this hypothesis by investigating the levels of Epstein-Barr virus (EBV)- and Kaposi sarcoma-associated herpesvirus (KSHV)-DNA levels in the peripheral blood of 22 HIV-1-associated lymphoma patients during ASCT, highlighting their relationship with γ-herpesvirus lymphoma status, immunological parameters, and clinical events. EBV-DNA was detected in the pre-treatment plasma and peripheral blood mononuclear cells (PBMCs) of 12 (median 12135 copies/mL) and 18 patients (median 417 copies/10⁶ PBMCs), respectively; the values in the two compartments were correlated (r = 0.77, p = 0.0001). Only EBV-positive lymphomas showed detectable levels of plasma EBV-DNA. After debulking chemotherapy, plasma EBV-DNA was associated with lymphoma chemosensitivity (p = 0.03) and a significant higher mortality risk by multivariate Cox analysis adjusted for EBV-lymphoma status (HR, 10.46, 95% CI, 1.11–98.32, p = 0.04). After infusion, EBV-DNA was detectable in five EBV-positive lymphoma patients who died within six months. KSHV-DNA load was positive in only one patient, who died from primary effusion lymphoma. Fluctuations in levels of KSHV-DNA reflected the patient’s therapy and evolution of his underlying lymphoma. Other γ-herpesvirus-associated malignancies, such as multicentric Castleman disease and Kaposi sarcoma, or end-organ complications after salvage treatment were not found. Overall, these findings suggest a prognostic and predictive value of EBV-DNA and KSHV-DNA, the monitoring of which could be a simple, complementary tool for the management of γ-herpesvirus-positive lymphomas in HIV-1 patients submitted to ASCT.     

An incidental case of dihydropyrimidine dehydrogenase deficiency: One case,multiple challenges

Dihydropyrimidine dehydrogenase (DPD) deficiency is an autosomal recessive disorder that shows large phenotypical variability, ranging from no symptoms to intellectual disability, motor retardation, and convulsions. In addition, homozygous and heterozygous mutation carriers can develop severe 5-fluorouracil (5-FU) toxicity. The lack of genotype-phenotype correlation and the possibility of other factors playing a role in the manifestation of the neurological abnormalities, make the management and education of asymptomatic DPD individuals more challenging. We describe a 3-month-old baby who was incidentally found by urine organic acid testing (done as part of positive newborn screen) to have very high level of thymine and uracil, consistent with DPD deficiency. Since the prevalence of asymptomatic DPD deficiency in the general population is fairly significant (1 in 10,000), we emphasize in this case study the importance of developing a guideline in genetic counseling and patient education for this condition as well as other incidental laboratory findings.