Adhesion to target cells is disrupted by the killer cell inhibitory receptor

Killer cell immunoglobulin-like receptors (KIR) inhibit the cytotoxic activity of natural killer (NK) cells by recruitment of the tyrosine phosphatase SHP-1 to immunoreceptor tyrosine-based inhibition motif (ITIM) sequences in the KIR cytoplasmic tail [1]. The precise steps in the NK activation pathway that are inhibited by KIR are yet to be defined. Here, we have studied whether the initial step of adhesion molecule LFA-1-dependent adhesion to target cells was altered by the inhibitory signal. Using stable expression of an HLA-C-specific KIR in the NK cell line YTS [2] and a two-color flow cytometry assay for conjugate formation, we show that adhesion to a target cell expressing cognate HLA-C was disrupted by KIR engagement. Conjugate formation was abruptly interrupted by KIR within less than 5 minutes. Inhibition of adhesion to target cells was mediated by a chimeric KIR molecule carrying catalytically active SHP-1 in place of its cytoplasmic tail. These results suggest that other ITIM-bearing receptors, many of which have no known function, may regulate adhesion in a wide variety of cell types.     

Discovery of 4,5-diphenyl-1,2,4-triazole derivatives as a novel class of selective antagonists for the human V(1A) receptor

In the search for a novel class of selective antagonists for the human V(1A) receptor, high-throughput screening (HTS) of the Yamanouchi chemical library using CHO cells expressing the cloned human V(1A) (hV(1A)) receptor led to the discovery of 5-(4-biphenyl)-4-(2-methoxyphenyl)-3-methyl-1,2,4-triazole (3) which possessed the novel 4,5-diphenyl-1,2,4-triazole structure. Subsequent structure-activity relationships studies on a series of the 4,5-diphenyl-1,2,4-triazole derivatives related to 3 revealed that the 4,5-diphenyl-1,2,4-triazole structure played an essential role in exerting high affinity for the hV(1A) receptor and that introduction of a basic amine moiety to the methoxy part of the 4-phenyl ring was effective in the improvement of both affinity for the hV(1A) receptor and selectivity versus the hV(2) receptor. Compound 3 and the 2-(morphorino)ethoxy derivative (11b) were shown to be antagonists for the hV(1A) receptor, from their effects on AVP-induced [Ca(2+)](i) response in CHO cells expressing the hV(1A) receptor.     

Chromosome studies in 500 induced abortions.

A survey of the chromosome constitution in 500 induced abortions (5-12 menstrual weeks) was undertaken over a period of 1 1/2 years. There were 34 cases (6.8%) of gross chromosome anomalies: 2 cases of trisomy A; 5 of trisomy C (including XXX and XXY); 1 of mosaic trisomy C; 4 of trisomy D; 2 of trisomy E; 2 of trisomy G; 1 of double trisomy E and G; 1 of XYY; 4 of monosmy C (including XO); 2 of mosaic monosomy C; 1 of mosaicism of ring D chromosome; 1 of extra small metacentric chromosome; 3 of triploidy (including triploidy with double trisomy C and G); and 5 of tetraploidy and its mosaicism. An increased risk for the occurrence of trisomic anomalies was found with advancing age of the mothers. In contrast, the production of monosomies was not age-related. Trisomies were the most common type of anomalies and were found almost at random, regardless of the characteristics of chromosomes. Neither satellited nor small chromosomes were predominantly involved in the formation of chromosome anomalies.     

Immunomodulatory properties of Enterococcus faecium JWS 833 isolated from duck intestinal tract and suppression of Listeria monocytogenes infection

The aim of this study was to evaluate the immunomodulatory properties of Enterococcus faecium JWS 833 (JWS 833) isolated from duck intestine and compare them to those of Lactobacillus rhamnosus GG (LGG), a proven immunity-enhancing probiotic. To investigate the immune-enhancing properties of JWS 833, production of nitric oxide (NO) and cytokines was measured in mouse peritoneal macrophages. In addition, a Listeria monocytogenes challenge model was used in the assessment. It was found that heat-killed JWS 833 stimulates mouse peritoneal macrophages to produce NO, interleukin-1 β (IL-1β) and tumor necrosis factor-α (TNF-α) and that oral administration of viable JWS833 enhances NO, IL-1β and TNF-α synthesis upon L. monocytogenes challenge. Moreover, mice fed with JWS 833 were partially protected against lethal challenge with L. monocytogenes. JWS 833 strain has significantly greater immunostimulatory properties than LGG. Moreover, JWS 833 strain partially protects mice against lethal challenge with L. monocytogenes. JWS 833, a novel strain of E. faecium isolated from duck intestine, is potentially a useful feed supplement for controlling pathogens and enhancing host immune responses.     

Ascochlorin inhibits growth factor-induced HIF-1α activation and tumor-angiogenesis through the suppression of EGFR/ERK/p70S6K signaling pathway in human cervical carcinoma cells

Ascochlorin, a non-toxic prenylphenol compound derived from the fungus Ascochyta viciae, has been shown recently to have anti-cancer effects on various human cancer cells. However, the precise molecular mechanism of this anti-cancer activity remains to be elucidated. Here, we investigated the effects of ascochlorin on hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) expression in human epidermoid cervical carcinoma CaSki cells. Ascochlorin inhibited epidermal growth factor (EGF)-induced HIF-1α and VEGF expression through multiple potential mechanisms. First, ascochlorin selectively inhibited HIF-1α expression in response to EGF stimulation, but not in response to hypoxia (1% O(2)) or treatment with a transition metal (CoCl(2)). Second, ascochlorin inhibited EGF-induced ERK-1/2 activation but not AKT activation, both of which play essential roles in EGF-induced HIF-1α protein synthesis. Targeted inhibition of epidermal growth factor receptor (EGFR) expression using an EGFR-specific small interfering RNA (siRNA) diminished HIF-1α expression, which suggested that ascochlorin inhibits HIF-1α expression through suppression of EGFR activation. Finally, we showed that ascochlorin functionally abrogates in vivo tumor angiogenesis induced by EGF in a Matrigel plug assay. Our data suggest that ascochlorin inhibits EGF-mediated induction of HIF-1α expression in CaSki cells, providing a potentially new avenue of development of anti-cancer drugs that target tumor angiogenesis.     

Large-scale genome-wide association study of Asian population reveals genetic factors in FRMD4A and other loci influencing smoking initiation and nicotine dependence

Diseases related to smoking are the second leading cause of death in the world. Cigarette smoking is a risk factor for several diseases such as cancer and cardiovascular and respiratory disorders. Despite increasing evidence of genetic determination, the susceptibility genes and loci underlying various aspects of smoking behavior are largely unknown. Moreover, almost all reported genome-wide association studies (GWASs) have been performed on samples of European origin, limiting the applicability of the results to other ethnic populations. In this first GWAS on smoking behavior in an Asian population, after analyzing 8,842 DNA samples from the Korea Association Resource project with 352,228 single nucleotide polymorphisms (SNPs) genotyped for each sample, we identified 8 SNPs significantly associated with smoking initiation (SI) and 4 with nicotine dependence (ND). Because of the current unavailability of an independent Asian smoking sample, we replicated the discoveries in independent samples of European-American and African-American origin. Of the 12 SNPs examined in the replicated samples, we identified two SNPs, in the regulator of G-protein signaling 17 gene (rs7747583, p value(meta)?=?6.40?×?10(-6); rs2349433, p value(meta)?=?5.57?×?10(-6)), associated with SI. Also, we found two SNPs significantly associated with ND; one in the FERM domain containing 4A (rs4424567, p value(meta)?=?2.30?×?10(-6)) and the other at 7q31.1 (rs848353, p value(meta)?=?9.16?×?10(-8)). These SNPs represent novel targets for examination of smoking behavior and warrant further investigation using independent samples.     

Isolation and Characterization of a Lytic Myoviridae Bacteriophage PAS-1 with Broad Infectivity in Aeromonas salmonicida

To search for candidate control agents against Aeromonas salmonicida subsp. salmonicida infections in aquaculture, one bacteriophage (phage), designated as PAS-1, was isolated from the sediment samples of the rainbow trout (Oncorhynchus mykiss) culture farm in Korea. The PAS-1 was morphologically classified as Myoviridae and possessed approximately 48 kb of double-strand genomic DNA. The phage showed broad host ranges to other subspecies of A. salmonicida as well as A. salmonicida subsp. salmonicida including antibiotic-resistant strains. Its latent period and burst size were estimated to be approximately 40 min and 116.7 PFU/cell, respectively. Furthermore, genomic and structural proteomic analysis of PAS-1 revealed that the phage was closely related to other Myoviridae phages infecting enterobacteria or Aeromonas species. The bacteriolytic activity of phage PAS-1 was evaluated using three subspecies of A. salmonicida strain at different doses of multiplicity of infection, and the results proved to be efficient for the reduction of bacterial growth. Based on these results, PAS-1 could be considered as a novel Aeromonas phage and might have potentiality to reduce the impacts of A. salmonicida infections in aquaculture.     

Hypothyroid States Mitigate the Diabetes-Induced Reduction of Calbindin D-28k, Calretinin, and Parvalbumin Immunoreactivity in Type 2 Diabetic Rats

In this study, we investigated the differences in calbindin D-28k (CB), calretinin, (CR) and parvalbumin (PV) immunoreactivity in the hippocampus of Zucker diabetic fatty (ZDF) rats and Zucker lean control (ZLC) rats. In addition, we observed the effects of hypothyroidism on the levels of immunoreactivity of these proteins in ZDF rats. For this study, 7-week-old ZDF rats were used, and methimazole treatment was continued for 5 weeks to induce hypothyroidism. The animals were sacrificed at 12 weeks of age. ZDF rats showed increased blood glucose levels compared to those in ZLC rats. Methimazole intervention significantly reduced total and free T3 levels, and it ameliorated the increase of blood glucose levels in ZDF rats. In ZLC rats, CB, CR, and PV immunoreactivity was detected in regions of the hippocampus proper. In vehicle-treated ZDF rats, CB, CR, and PV immunoreactivity was significantly decreased in the hippocampus. However, in the methimazole-treated rats, CB, CR, and PV immunoreactivity was significantly increased compared to that in the vehicle-treated rats. These results suggest that hypothyroidism ameliorated the diabetes-induced reduction of CB, CR, and PV immunoreactivity in the hippocampus.