Sulfonamide-based non-alkyne LpxC inhibitors as Gram-negative antibacterial agents

We attempted to optimize sulfonamide-based non-alkyne LpxC inhibitors by focusing on improvements in enzyme inhibitory and antibacterial activity. It was discovered that inhibitors possessing 2-aryl benzofuran as a hydrophobe exhibited good activity. In particular, compound 21 displayed impressive antibacterial activity (E. coli MIC = 0.063 μg/mL, K. pneumoniae MIC = 0.5 μg/mL, and P. aeruginosa MIC = 0.5 μg/mL), and is a promising lead for further exploration as an antibacterial agent.     

Effect of phytate-removal and deamidation of soybean proteins on calcium absorption in the in situ rats

Soybean proteins were deamidated by cation-exchange resins after phytate, the inhibitor for calcium absorption from the small intestine, was removed in order to provide the enhancement function of calcium absorption to soybean proteins. About 92% of the phosphorus was removed from the soybean proteins by anion-exchange-resin treatment, indicating that most of the phytate was removed. About 70% of the acid amide was deamidated by cation-exchange-resin treatment, and phytate-removed and deamidated soybean proteins (PrDS) having high calcium binding properties were obtained. PrDS were hydrolyzed by digestive enzymes and their calcium-binding properties and the enhancement function of the calcium absorption from the small intestine of rats were examined. As a result, PrDS retained their high calcium binding properties even after hydrolysis by digestive enzymes. In situ experiments showed that PrDS and their hydrolysates enhanced the calcium absorption from the intestine.     

Rhombomere formation and hind-brain crest cell migration from prorhombomeric origins in mouse embryos

Prior to rhombomere development, structures called prorhombomeres appear in the mammalian hindbrain. This study clarifies the developmental relationship between prorhombomeres and their descendent rhombomeres and hindbrain crest cells in mouse embryos by focal dye injections at various levels of prorhombomere A (proRhA), proRhB, and proRhC, as well as at their boundaries. ProRhA gives rise to two rhombomeres, rhombomeres 1 and 2 (r1 and r2), as well as to crest cells that migrate into the first pharyngeal arch, including the trigeminal ganglion. ProRhB develops into r3 and r4 and produces crest cells populating the second arch and acousticofacial ganglion. The anterior portion of proRhC gives rise to r5 and r6 and to crest cells migrating into the third pharyngeal arch and the IXth ganglion; its posterior portion develops into r7 and releases crest cells into the fourth pharyngeal arch region as well as the Xth ganglion. These results suggest that the boundaries between prorhombomeres serve as lineage restrictions for both hind-brain neuroepithelial cells and for segmental origins of crest cell populations in mouse embryos. The Hox code of the mouse head can be schematized in a much simpler way based on this prorhombomeric organization of the hind-brain, suggesting that prorhombomeres primarily underlie mammalian hind-brain segmentation.     

Molecular analysis of HLA-B39 subtypes

Serological studies have suggested the presence of a new HLA-B39 subtype (B39.2) in the Japanese population. To identify the new HLA-B39 subtype and compare it with an other HLA-B39 subtype (B39.1), the genes encoding HLA-B39.1 (B ^* 39013) and B39.2 (B ^* 3902) have been cloned from Japanese. We have sequenced these genes and completed the sequence of HLA-B39.1 (B ^*39011 ) gene from a Caucasian that was partially sequenced. Comparison of the sequence data revealed that B ^* 3902 and B ^* 39013 differ by three nucleotide substitutions which result in a two amino acids change at residues 63 and 67, while one silent substitution at codon 312 is found between B ^* 39011 and B ^* 39013. These results suggest that B ^* 3902 has evolved from B ^* 39013 rather than B ^* 39011.The nucleotide sequence data reported in this paper have been submitted to the GenBank nucleotide sequence database and have been assigned the accession numbers M94051 (HLA-B^*39013), M94052 (HLA-B^*39011), and M94053 (HLA-B^*3902).     

2-Aminooxyisobutyric acid inhibits the in vitro activities of both 1-Aminocyclopropane-1-carboxylate (ACC) synthase and ACC oxidase in ethylene biosynthetic pathway and prolongs vase life of cut carnation flowers

2-Aminooxyisobutyric acid (AOIB) has a partial structure of aminooxyacetic acid (AOA) in its whole structure, and resembles 2-aminoisobutyric acid (AIB) in their tetrahedral structures. Both AOA and AIB are inhibitors of ethylene biosynthesis; AOA inhibits the action of 1-aminocyclopropane-1-carboxylate (ACC) synthase and AIB inhibits that of ACC oxidase. The present study showed that AOIB inhibited the in vitro activities of both ACC synthase and ACC oxidase, which were synthesized heterologously in E. coli cells from corresponding carnation cDNAs, and the magnitudes of inhibition were similar to those caused by AOA and AIB; AOIB and AOA at 0.1 mM inhibited ACC synthase action by 75%, and AOIB and AIB at 10 mM inhibited ACC oxidase action by 16.3 and 22.5%, respectively. AOIB at 1 mM caused 91.5% reduction of maximum ethylene production rate as compared to the control in cut ‘Excerea’ carnation flowers undergoing senescence, thereby lengthening their vase life to 7 d from 3 d of the control flowers. The inhibition by AOIB was probably caused by its action resembling AOA, but not AIB. AOIB also extended significantly the vase life of cut flowers of ‘Pax’ carnation, and tended to do so in ‘Primero Mango’ carnation. The present findings suggest the potential of AOIB as a new preservative for carnations and other ornamentals in which ethylene plays a key role in the induction of senescence.     

Excessive Cytokine Response to Rapid Proliferation of Highly Pathogenic Avian Influenza Viruses Leads to Fatal Systemic Capillary Leakage in Chickens

Highly pathogenic avian influenza viruses (HPAIVs) cause lethal infection in chickens. Severe cases of HPAIV infections have been also reported in mammals, including humans. In both mammals and birds, the relationship between host cytokine response to the infection with HPAIVs and lethal outcome has not been well understood. In the present study, the highly pathogenic avian influenza viruses A/turkey/Italy/4580/1999 (H7N1) (Ty/Italy) and A/chicken/Netherlands/2586/2003 (H7N7) (Ck/NL) and the low pathogenic avian influenza virus (LPAIV) A/chicken/Ibaraki/1/2005 (H5N2) (Ck/Ibaraki) were intranasally inoculated into chickens. Ty/Italy replicated more extensively than Ck/NL in systemic tissues of the chickens, especially in the brain, and induced excessive mRNA expression of inflammatory and antiviral cytokines (IFN-γ, IL-1β, IL-6, and IFN-α) in proportion to its proliferation. Using in situ hybridization, IL-6 mRNA was detected mainly in microglial nodules in the brain of the chickens infected with Ty/Italy. Capillary leakage assessed by Evans blue staining was observed in multiple organs, especially in the brains of the chickens infected with Ty/Italy, and was not observed in those infected with Ck/NL. In contrast, LPAIV caused only local infection in the chickens, with neither apparent cytokine expression nor capillary leakage in any tissue of the chickens. The present results indicate that an excessive cytokine response is induced by rapid and extensive proliferation of HPAIV and causes fatal multiple organ failure in chickens.     

Antidiabetic effect of Lactobacillus GG in streptozotocin-induced diabetic rats

Neonatally streptozotocin-induced diabetic (n-STZ) rats were given food containing Lactobacillus GG cells (GG) or a control diet (control), from 9 to 18 weeks of age. The GG cells significantly lowered the blood hemoglobin A(1C) (HbA(1C)) level and improved glucose tolerance in n-STZ rats (p<0.05). In the GG group, the serum insulin level at 30 min after glucose loading was significantly higher than in the control group (p<0.05).     

Mevastatin,an inhibitor of HMG-CoA reductase,induces apoptosis,differentiation and Rap1 expression in HL-60 cells

It has been reported that inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase suppress cell proliferation and induce apoptosis. One inhibitor which induces apoptosis is mevastatin. However, the molecular mechanism of apoptosis induction is not well understood so the effects of mevastatin on various functions of HL-60 cells were investigated. We confirmed that mevastatin activated caspase-3 by release of cytochrome c (Cyt. c) from mitochondria through a membrane permeability transition mechanism and also induced typical fragmentation and ladder formation of DNA in HL-60 cells. These effects were inhibited by mevalonate, a metabolic intermediate of cholesterol biosynthesis. Mevalonate and geranylgeraniol (GGOH) inhibited DNA fragmentation whereas farnesol (FOH) did not. Mevastatin also induced cell differentiation to monocytic cells via a mevalonate inhibitable mechanism. Furthermore, mevastatin decreased the amount of an isoprenylated membrane bound Rap1 small GTPase concomitant with an increase in cytosolic Rap1 which occurred before apoptosis and differentiation. On the contrary, both mevastatin and geranylgeranylacetone (GGA), which competes with geranylgeranyl pyrophosphate, induced membrane depolarization of isolated mitochondria without swelling and Cyt. c release. These results suggest that mevastatin-induced apoptosis of HL-60 cells might be caused indirectly by activation of the caspase cascade through the modulation of mitochondrial functions and that some relationship between a certain small GTPase molecule, such as Rap1, and mevastatin-induced apoptosis may exist.