The thiol proteinase inhibitor E-64-d ameliorates amyloid-β-induced reduction of sAPPα secretion by reversing ceramide-induced protein kinase C down-regulation in SH-SY5Y neuroblastoma cells

In Alzheimer’s disease (AD), enhancing α-secretase processing of amyloid precursor protein (APP) is an important pathway to decrease neurotoxic amyloid β (Aβ) secretion. The α-secretase is reported to be regulated by protein kinase C (PKC) and various endogenous proteins or cell surface receptors. In this report, we first examined whether Aβ reduces α-secretase activity, and showed that Aβ peptide 1–40 (0.001 and 0.01 μM) reduced the secretion of soluble amyloid precursor protein α (sAPPα) in carbachol-stimulated SH-SY5Y neuroblastoma cells. E-64-d (3 μM), which is a potent calpain inhibitor that prevents PKC degradation, ameliorated the Aβ-induced reduction of sAPPα secretion. In addition, we observed that Aβ significantly enhanced ceramide production by activating neutral sphingomyelinase. The cell-permeable ceramide analog, C₂-ceramide (1 μg/mL), also reduced sAPPα secretion, and in addition, E-64-d eliminated the observed decrease of sAPPα secretion. C₂-ceramide induced down-regulation of PKC-α, -β₁, and -β₂ isozymes in SH-SY5Y cells. These findings suggest that ceramide may play an important role in sAPPα processing by modulating PKC activity.     

Effects of the methoxy group in the side chain of debromoaplysiatoxin on its tumor-promoting and anti-proliferative activities

Debromoaplysiatoxin (DAT) is a tumor promoter isolated from sea hare and exhibits anti-proliferative activity against several cancer cell lines. To clarify key residues that are responsible for its tumor-promoting activity, we focused on the chiral methoxy group in the side chain, whose role had not yet been discussed or examined before. Demethoxy-DAT (8) was derived from DAT and we evaluated its tumor-promoting activity, anti-proliferative activity, and ability to bind to protein kinase C (PKC) isozymes. Compound 8 showed somewhat weaker tumor-promoting activity than that of DAT both in vitro and in vivo, but showed higher anti-proliferative activity against several cancer cell lines. Although the affinity to novel PKC isozymes of 8 was comparable to that of DAT, the affinity to conventional PKC isozymes decreased slightly. These results suggest that the methoxy group of DAT is one of the key residues critical for tumor-promoting activity but not for anti-proliferative activity. Since the methoxy group has little influence on the molecular hydrophobicity, this is the first report showing that structural factors other than hydrophobicity in the side chain of DAT affected its biological activities.     

Identification of a novel benzimidazole derivative as a highly potent NPY Y5 receptor antagonist with an anti-obesity profile

Optimization of HTS hit 1 for NPY Y5 receptor binding affinity, CYP450 inhibition, solubility and metabolic stability led to the identification of some orally available oxygen-linker derivatives for in vivo study. Among them, derivative 4i inhibited food intake induced by the NPY Y5 selective agonist, and chronic oral administration of 4i in DIO mice caused a dose-dependent reduction of body weight gain.     

Mangrove stilt root morphology modeling for estimating hydraulic drag in tsunami inundation simulation

The submerged tree volume and the projection area of mangroves play a significant role in damping tsunami inundation flow with a distinct root formation above ground. We modeled the stilt root morphology of the Rhizophora sp., especially to incorporate into a hydraulic drag of tsunami inundation simulation. The equivalent Manning’s roughness coefficient has been used as the hydraulic drag of mangroves for the computation of inundation flow [Yanagisawa et al. (Coast Shelf Sci 81: 27–37, 2009)], but it could not elucidate the effectiveness under different tree conditions. The field data from 18 sample trees in Ranong Province, Thailand, were measured. The total number of primary roots, the root height at trunk, and the root-spread distance, the root diameter, and the vertical root angle from trunk could be estimated with the diameter of the breast height. The quadratic equation expressed the root curve of the primary stilt root, and functions to estimate root volume and projected area were derived by the integration of the equation that will be used to calculate drag force in tsunami simulation.     

Volatile Gas Components Contribute to Cigarette Smoke-induced DNA Single Strand Breaks in Cultured Human Cells

Thermostable purine nucleoside phosphorylases, PUN PI and PUNPII, have been purified from Bacillus stearothermophilus JTS 859. The characterization of PUNPI was reported previously. [Hori et al.₉ Agric. Biol. Chem. 53, 2205 (1989)] PUNPII had a molecular weight of 113,000, consisting of 4 identical subunits (M_w 28,000). The isoelectric point was 5.3. The Michaelis constants for inosine, guanosine, and adenosine were 0.22, 0.34, and 0.075 mm, respectively. The optimal temperature of the reaction was 70°C. The enzyme was stable at 70°C. Although other reported purine nucleoside phosphorylases were SH-enzymes, PUNPII was not a SH-enzyme because the enzyme reaction was not inhibited by PCMB and iodoacetic acid, the optimal pH of the enzyme reaction was from 7.0 to 11.0, and the enzyme did not contain cysteine.

PUNPII and PUNPI were different in several points. Not PUNPI but PUNPII could catalyze the phosphorolysis of adenosine. Specific activity of PUNPI and II for inosine were 405 and 50.6 μmol/min/mg protein at 60°C, respectively. PUNPI was stable at 80°C. PUNPII was stable at 70°C, but was denatured at 80°C.     

Studies on the Hypertrophic Disease of Cherry (Genus Prunus), So-called “Witch’s Broom” Caused by Taphrina wiesneri

Metabolites of Taphrina wiesneri (Rath.) Mix. were examined. Brassicasterol, stearic acid, and p-hydroxyphenylacetic acid were isolated in crystalline form. p-Hydroxybenzoic acid and vanillic acid were identified by paper chromatography and UV measurement. Palmitic acid was identified by gas-chromatography. The fungus produced usually these compounds on any one of four kinds of medium used. p-Hydroxyphenylacetic acid promoted germination of rape seeds at the concentration of 20 ppm in water and showed inhibition at 250 ppm.

Phenolic acids and their related compounds in Japanese flowering cherry leaves infected by Taphrina wiesneri were examined. In the acidic and neutral extracts of infected cherry leaves (I), eighteen compounds positive to diazotized sulfanilic acid and two fluorescent compounds were detected by paper chromatography. Of these compounds, coumarin, 3, 4-dihydrocoumarin, melilotic acid, o- and p-coumaric acids, p-hydroxybenzoic melilotic acid, ferulic acid and caffeic acid were identified. Melilotic acid and coumarin were obtained in crystalline form. The amount of melilotic acid in I was higher than that in healthy leaves independent of sample source, although increased with the growth of cherry leaves.     

Distribution Patterns of 14C in the Labelled Vitamin B6 Prepared with the Cell-suspension of Achromobacter cycloclastes

The biosynthetic pathway of vitamin B₆ (abbreviated as Be) has been studied with the cell-suspension of B₆-producing bacteria, Achromobacter cycloclastes A.M.S. 6201. The distribution of ¹⁴C in the Be molecule prepared with the cell-suspensions containing glycerol-1,3-¹⁴C, glycerol-2-¹⁴C or γ-aminobutyric acid-U-¹⁴C was investigated by using three novel degradation methods. The results showed that carbon skeletons of glycerol and γ-aminobutyric acid were used for the formation of the major part of B₆ carbon skeleton respectively. The implication of these compounds as precursors of B₆ was discussed.     

Eligibility for Bevacizumab as an Independent Prognostic Factor for Patients with Advanced Non-Squamous Non-Small Cell Lung Cancer: A Retrospective Cohort Study

Background

Bevacizumab requires some unique eligibility criteria, such as absence of hemoptysis and major blood vessel invasion by the tumor. The prognostic impact of these bevacizumab-specific criteria has not been evaluated.

Methods

Patients with stage IIIB/IV, non-squamous non-small cell lung cancer who started chemotherapy before the approval of bevacizumab were reviewed. Patients with impaired organ function, poor performance status or untreated/symptomatic brain metastasis were excluded before the evaluation of bevacizumab eligibility. We compared overall survival and time to treatment failure among patients who were eligible (Group A) or ineligible (Group B) to receive bevacizumab.

Results

Among 283 patients with stage IIIB/IV non-squamous non-small cell lung cancer, eligibility for bevacizumab was evaluated in 154 patients. Fifty-seven patients were considered ineligible (Group B) based on one or more of a history of hemoptysis (n = 20), major blood vessel invasion (n = 43) and cardiovascular disease (n = 8). The remaining 97 patients were classified into Group A. Overall survival was significantly better in Group A (median, 14.6 months) than in Group B (median, 7.1 months; p<0.0001). Time to treatment failure was also significantly longer in Group A (median, 6.9 months) than in Group B (median, 3.0 months; p<0.0001). Adjusted hazard ratios of bevacizumab eligibility for overall survival and time to treatment failure were 0.48 and 0.38 (95% confidence intervals, 0.33–0.70 and 0.25–0.58), respectively.

Conclusion

Eligibility for bevacizumab itself represents a powerful prognostic factor for patients with non-squamous non-small cell lung cancer. The proportion of patients who underwent first-line chemotherapy without disease progression or unacceptable toxicity can also be biased by bevacizumab eligibility. Selection bias can be large in clinical trials of bevacizumab, so findings from such trials should be interpreted with extreme caution.