Improvement of bone strength and dermal thickness due to dietary edible bird's nest extract in ovariectomized rats

Oral administration of edible bird's nest extract (EBNE) improved bone strength and calcium concentration in the femur of ovariectomized rats. Dermal thickness was also increased by EBNE supplementation, whereas EBNE administration did not affect the serum estradiol concentration. These results suggest that EBNE is effective for the improvement of bone loss and skin aging in postmenopause all women.     

The expression of sialylated high-antennary N-glycans in edible bird's nest

Edible bird’s nest (EBN) is the nest made from the saliva of Collocalia swift. Recently, we have found that EBN extract could strongly inhibit infection of influenza viruses in a host-range-independent manner [Guo, C. T.; Takahashi, T.; Bukawa, W.; Takahashi, N.; Yagi, H.; Kato, K.; Hidari, K. I.; Miyamoto, D.; Suzuki, T.; Suzuki, Y. Antiviral Res. 2006, 70, 140–146]. Although this antiviral activity might be attributed to O- or N-glycoconjugates, no N-glycan structures have so far been described for EBN. Here, we report the N-glycosylation profile of EBN, in which a tri-antennary N-glycan bearing the 2,3-N-acetylneuraminic acid residues is displayed as a major component. We suggest that the sialylated high-antennary N-glycans of EBN contribute to the inhibition of influenza viral infection.     

Antibody Responses Raised against a Conformational V3 Loop Peptide of HIV-1

The amino acid sequence of the principal neutralizing determinant (PND) of 224 cases of human immunodeficiency virus type 1 (HIV-1) was determined and the most frequently occurring sequence was used as a peptide antigen for studying virus-specific antibody responses. In our present study, a linear peptide of the most frequent PND was first synthesized and then oxidized to create a disulfide-bridged loop conformation. Then, in order to construct a macromolecular structure for the purpose of increasing anti-genicity, the synthetic peptide was conjugated to a core peptide. We compared the immunogenicity of the disulfide-bridged loop PND peptide antigen (AG4) and the linear PND peptide antigen (AG5). After immunizing rabbits 5 and 6 times with both peptides, the results obtained using ELISA revealed that AG4 (conformational-loop type) was more capable of inducing a high titer of antigen-specific antibodies than was AG5 (linear type). Despite an amino acid sequence homology of 72%, a 1:8 dilution of serum raised against AG4 inhibited 81.9% of HIV-1_IIIB-mediated cell fusion, suggesting that conformational V3 loop peptide is able to elicit an antibody response which is strongly HIV-1-specific.     

Overexpression of CDCA2 in Human Squamous Cell Carcinoma: Correlation with Prevention of G1 Phase Arrest and Apoptosis

Cell division cycle associated 2 (CDCA2) recruits protein phosphatase 1 to chromatin to antagonize activation of ataxia telangiectasia mutated (ATM)-dependent signal transduction. ATM kinase plays a critical role in the DNA damage response and its phosphorylation cascade to inhibit the p53-MDM2 interaction, which releases p53 to induce p21 and G1 cell-cycle arrest. However, the relevance of CDCA2 to human malignancy including oral squamous cell carcinoma (OSCC) is unknown. In the current study, we found that CDCA2 expression was up-regulated in OSCC cell lines. Functional studies with shRNA system showed that knockdown of CDCA2 significantly (P<0.05) inhibited cellular proliferation compared with the control cells by arresting cell-cycle progression at the G1 phase and up-regulating the cyclin-dependent kinase inhibitors (p21^Cip1, p27^Kip1, p15^INK4B, and p16^INK4A). CDCA2 knockdown also promoted apoptosis after treatment with the DNA damage reagent, cisplatin. In clinical samples, the CDCA2 protein expression level in primary OSCCs was significantly (P<0.05) greater than in matched normal oral tissues (67/85, 79%). Furthermore, CDCA2-positive cases were correlated significantly (P<0.05) with high cancer progression. Our results showed for the first time that CDCA2 frequently is overexpressed in OSCCs and might be associated closely with OSCC progression by preventing cell-cycle arrest and apoptosis.     

Preliminary investigation of the effect of oral supplementation of Lactobacillus plantarum strain SNK12 on mRNA levels of neurotrophic factors and GABA receptors in the hippocampus of mice under stress-free and sub-chronic mild social defeat-stressing conditions

ABSTRACT

The effect of Lactobacillus plantarum SNK12 (CPLP) supplementation on mRNA levels of hippocampal neurotrophic factors and gamma aminobutyric acid receptors (GABA_R) was tested. In Experiment 1, stress-free, unsupplemented and CPLP (4 × 10⁸ cells/head)-supplemented male C57BL/6J (B6) mice were the experimental animals. In Experiment 2, intruder (male, B6) mice [negative control; unsupplemented, sub-chronic mild social defeat stress (sCSDS)-induced; and CPLP-supplemented, sCSDS-induced] were exposed to aggressor mice (adult male Slc:ICR). mRNA levels of neurotrophic factors and GABA_R in hippocampal samples of these mice were analyzed. In CPLP-supplemented mice of both experiments, mRNA levels of bdnf, nt-3, and GABA_R were upregulated. Moreover, a tendency toward the improvement of habituation ability (Experiment 1) and behavior (Experiment 2) was observed in mice, which may be associated with upregulated neurotrophic factors and GABA_R. We demonstrated that oral supplementation of CPLP to stress-free and stress-induced mice upregulated mRNA levels of hippocampal neurotrophic factors and GABA_R.     

Oral administration of a heat-killed cell preparation of Enterococcus faecalis strain EC-12 stimulates the gene expression of Na(+)-K(+)-2Cl- co-transporter 1 in rat ileal epithelial cells

The effect of a heat-killed cell preparation of Enterococcus faecalis strain EC-12 (EC-12) on the gene expression of Na(+)-K(+)-2Cl(-) co-transporter 1 (NKCC1) in intestinal epithelial cells was evaluated by using rats. The NKCC1 gene in ileal epithelial cells was significantly up-regulated by the oral administration of EC-12. The results of this study suggest in vivo that EC-12 had the potential to stimulate intestinal NKCC1 expression.     

Genetic Control of Immune Responses to HIV-1 env DNA Vaccine

We investigated the genetic control of immunoglobulin production and the delayed-type hypersensitivity (DTH) response produced by an HIV-specific DNA vaccine using several strains of mice. Murine antigen-specific immunoglobulin production was determined by ELISA. The DTH response was assessed in terms of the footpad swelling reaction. All strains of mice, except for B10.RIII and B10.T(6R), exhibited strong immunoglobulin production and footpad swelling in response to the DNA vaccine. In vitro treatment of lymphoid cells with monoclonal antibodies showed that the footpad swelling response was mediated by CD4⁺8^? and Ia— T cells. However, CD8⁺ T cells did not suppress footpad swelling. There was no difference in the induction of HIV-specific immunoglobulin production or DTH response induced by the DNA vaccine among the strains, suggesting that HIV-specific DNA vaccine is useful for immunizing various populations against HIV-1.