Discovery of 4-[4-({(3R)-1-butyl-3-[(R)-cyclohexyl(hydroxy)methyl]-2,5-dioxo-1,4,9-triazaspiro[5.5]undec-9-yl}methyl)phenoxy]benzoic acid hydrochloride: a highly potent orally available CCR5 selective antagonist

Based on the original spirodiketopiperazine design framework, further optimization of an orally available CCR5 antagonist was undertaken. Structural hybridization of the hydroxylated analog 4 derived from one of the oxidative metabolites and the new orally available non-hydroxylated benzoic acid analog 5 resulted in another potent orally available CCR5 antagonist 6a as a clinical candidate. Full details of a structure-activity relationship (SAR) study and ADME properties are presented.     

Different Impacts of Neck Circumference and Visceral Obesity on the Severity of Obstructive Sleep Apnea Syndrome

Our aim was to investigate the significance of neck circumference (NC) on the presence and severity of obstructive sleep apnea (OSA) syndrome independent of visceral fat (VF) obesity. A total of 219 subjects with suspected OSA underwent a complete polysomnography (PSG) study, along with the measurement of NC, and total body fat (TF) and VF levels (VFLs) measured by bioelectrical impedance analysis. We proposed NC divided by height (NC/H) as the simple index for height‐corrected NC in Japanese subjects. NC/H exhibited a significantly stronger correlation than NC per se with BMI (r = 0.781 vs. 0.675, P = 0.0178), TF (r = 0.531 vs. 0.156, P < 0.0001), and VF (r = 0.819 vs. 0.731, P = 0.0203), indicating that NC/H is a better indicator of visceral obesity than NC per se. Interestingly, despite the strong correlation between NC/H and VFL, VFL was significantly associated with the apnea‐hypopnea index (AHI) ≥5, ≥15, and ≥30, but not with ≥40 or ≥50, whereas NC/H was significantly associated with higher AHI values, i.e., AHI ≥50 but not with lower AHI value. Furthermore, multiple regression analyses revealed that VFL and NC/H were independently associated with the square root of AHI (AHI^0.5) levels in obese and nonobese patients, respectively. In conclusion, NC is associated with the severity of OSA independently of visceral obesity, especially in nonobese patients.     

Suppression of PI3K/mTOR pathway rescues LLC cells from cell death induced by hypoxia

Cancer cells in solid tumors are challenged by various microenvironmental stresses, including hypoxia, and cancer cells in hypoxic regions are resistant to current cancer therapies. To investigate the mechanism of resistance to hypoxia in cancer cells, we examined mouse Lewis lung carcinoma (LLC) cells, which died due to necrosis at high density under hypoxic but not under normoxic conditions. Levels of mammalian target of rapamycin (mTOR), a central regulator of cellular energy, are reported to be suppressed in hypoxia. We found that phosphorylation of two molecules downstream to it, ribosomal p70 S6 kinase (S6K) and ribosomal protein S6, was markedly suppressed by hypoxia. Overexpression of the active form of S6K increased the sensitivity of LLC cells to hypoxia. On the other hand, inhibition of PI3K or mTOR dramatically reduced hypoxia-induced cell death under hypoxic conditions. Under hypoxic conditions, blockade of the PI3K or mTOR pathway increased levels of intracellular ATP and delayed decreases in pH and glucose level in culture medium, without affecting the cell cycle.     

Oral immunotherapy against a pollen allergy using a seed-based peptide vaccine

Peptide immunotherapy using dominant T-cell epitopes is safer and more effective than conventional immunotherapy for the treatment of immunoglobulin E (IgE)-mediated allergic diseases. When allergenic T-cell epitope peptides are expressed in the edible part of transgenic plants, successful mucosal immune tolerance to these allergens may be attainable by the consumption of these plants. In this study, we generated transgenic rice seed that accumulated high concentrations (about 60 microg per grain) of polypeptide consisting of seven dominant human T-cell epitopes derived from the Japanese cedar pollen allergens, Cry j 1 and Cry j 2, in the endosperm. Oral administration of these transgenic rice seeds to B10.S mice before or after they were immunized with Cry j 1 holoprotein reduced not only their T-cell proliferative response to Cry j 1, but also their serum IgE levels, proving the efficacy of oral immunotherapy for the treatment of pollinosis.     

Gene expression and characterization of two 2-oxoacid:ferredoxin oxidoreductases from Aeropyrum pernix K1

A hyperthermophilic and aerobic crenarchaeon, Aeropyrum pernix K1, has two sets of genes possibly encoding 2-oxoacid:ferredoxin oxidoreductases. One is encoded in open reading frames (ORFs) ape2126 and ape2128, and the other in ORFs ape1473 and ape1472. The two sets of genes were expressed. The product enzymes, Ape2126/2128 and Ape1473/1472, showed optimal temperatures of 105 and over 110 degrees C, and optimal pHs of 8.5 and 9.0, respectively, using pyruvate as a substrate. Pyruvate, 2-oxobutyrate, and glyoxylate were the best substrates for both enzymes, and additionally Ape1473/1472 was able to act on 2-oxoglutarate, suggesting the enzyme operates in the TCA cycle.     

Selective silencing of a mutant transthyretin allele by small interfering RNAs

Familial amyloidotic polyneuropathy (FAP) is a hereditary systemic amyloidosis caused by dominantly acting missense mutations in the gene encoding transthyretin (TTR). The most common mutant TTR is of the Val30Met type, which results from a point mutation. Because the major constituent of amyloid fibrils is mutant TTR, agents that selectively suppress mutant TTR expression could be powerful therapeutic tools. This study has been performed to evaluate the use of small interfering RNAs (siRNAs) for the selective silencing of mutant Val30Met TTR in cell culture systems. We have identified an siRNA that specifically inhibits mutant, but not wild-type, TTR expression even in cells expressing both alleles. Thus, this siRNA-based approach may have potential for the gene therapy of FAP.