Two isoforms of chicken melanopsins show blue light sensitivity

Melanopsin is a vertebrate non-visual opsin and functions as a circadian photoreceptor in mammalian retinas. Here we found the expression of two kinds of melanopsin genes in the chicken pineal gland and identified the presence of five isoforms derived from these two genes. Reconstitution of the recombinant proteins with 11-cis-retinal revealed that at least two of these melanopsin protein isoforms can function as blue-sensitive photopigments with absorption maxima at 476-484nm. These values are consistent with maximal sensitivities of action spectra determined from the physiological and behavioral studies on mammalian melanopsins. The melanopsin isoforms found in this study may function as pineal circadian photoreceptors.     

Sensitive determination of aspirin and its metabolites in plasma by LC-UV using on-line solid-phase extraction with methylcellulose-immobilized anion-exchange restricted access media

We describe a sensitive determination of aspirin (ASA) and its three metabolites (salicylic acid [SA], 2,3-dihydroxybenzoic acid [2,3-DHBA], and 2,5-dihydroxybenzoic acid [gentisic acid (GA)]) in rat plasma. Analysis was carried out by on-line solid-phase extraction (SPE) using a methylcellulose-immobilized-strong anion-exchanger (MC-SAX), followed by liquid chromatography (LC) coupled with UV detection. The lower limits of quantitation for ASA and SA were 60 ng/mL in 100 microL of plasma, respectively. This method was validated with respect to intra- and inter-day precision, accuracy, and linearity up to concentrations of 20,000 ng/mL for ASA, SA, 2,3-DHBA and gentisic acid, respectively. The method was successfully applied to an analysis of the pharmacokinetics of ASA and SA in rats.     

Activation of human T lymphocytes by ganglioside-containing liposomes

We investigated the in vitro stimulatory effect of ganglioside (G_M3, G_D1a, G_D1b, G_T1b, or G_Q1b)-containing liposomes on human immune cells. The effect of ganglioside-containing liposomes on the concentration of cytoplasmic free calcium ions ([Ca²⁺]₁) in human immunocytes was examined using the confocal laser fluorescence microscopic method. The G_D1a- and G_T1b-containing liposomes significantly increased [Ca²⁺]₁ of human T lymphocytes compared with the G_M3-, G_D1b- and G_Q1b-containing ones. The response of CD8⁺ and CD4⁺ cells was significantly higher than that of CD20⁺ cells. Our results show that the increase in [Ca²⁺]_i may be caused by not the number of sialic acids contained in the gangliosides but the conformation of the sialic acid moiety to protrude exteriorly from the liposomal membrane surface, and that a sort of receptor recognizing the sialic acid moiety exists on human T lymphocytes (both CD8⁺ and CD4⁺ cells), which may be involved in the activation of the cells. The present results are almost the same as those obtained for the rat T lymphocyte system previously reported. This clearly confirms that a sort of ganglioside surely stimulates T lymphocytes directly, which is not species-specific but conserved in humans and rats among animal species.     

Chemo-enzymatic synthesis and structure-activity study of artificially N-glycosylated eel calcitonin derivatives with a complex type oligosaccharide

Starting from N-glycosylated eel calcitonin derivatives that contain an N-acetyl-D-glucosamine residue specifically at the 3rd, 14th, 20th or 26th amino acid residue, corresponding glycopeptides with a complex-type oligosaccharide attached to the respective amino acid residue were synthesized by means of a transglycosylation reaction catalyzed by an endo-beta-N-acetylglucosaminidase from Mucor hiemalis . The use of a recombinant enzyme and an excess of a glycosyl donor led to a yield in excess of 60%. Calcitonin derivatives containing truncated oligosaccharides were also prepared via digestion of the complex-type N-glycan with exoglycosidases. Using these N-glycosylated calcitonin derivatives, the effect of carbohydrate structure and glycosylation site on the three-dimensional structure and the biological activity of the peptide were studied. The conformation of the peptide backbone did not change irrespective of the carbohydrate structure or the glycosylation site. However, hypocalcemic activity, calcitonin-receptor binding activity and the biodistribution of the derivatives were affected by the glycosylation and were dependent on both the carbohydrate structure and the glycosylation site. Although the larger oligosaccharides tended to hinder receptor binding, the biodistribution altered by N-glycosylation appeared to enhance the hypocalcemic activity in some cases, and the magnitude of the effect was dependent on the site of glycosylation.     

Over-expression of the testis-specific gene TSGA10 in cancers and its immunogenicity

The TSGA10 gene was originally isolated in normal testis by differential mRNA display. TSGA10 is located on chromosome 2q11.2 and consists of 19 exons extending over 3 kb. TSGA10 mRNA expression was investigated in normal and malignant tissues using quantitative real-time RT-PCR. It was predominantly expressed in the testis in adult normal tissues. In malignant tissues, TSGA10 was over-expressed in 4 of 20 hepatocellular carcinomas (HCC), 1 of 20 colon cancers, 7 of 20 ovarian cancers, 3 of 20 prostate cancers, 1 of 21 malignant melanomas, and 8 of 21 bladder cancers. Serological analysis revealed that 3 out of 346 patients with various types of cancer possessed antibody against recombinant TSGA10 protein. They included 2 patients with hepatocellular carcinoma and a patient with malignant melanoma.     

Aluminum targets elongating cells by reducing cell wall extensibility in wheat roots

Phytotoxicity of aluminum is characterized by a rapid inhibition of root elongation at micromolar concentrations, however, the mechanisms primarily responsible for this response are not well understood. We investigated the effect of Al on the viscosity and elasticity parameters of root cell wall by a creep-extension analysis in two cultivars of wheat (Triticum aestivum L.) differing in Al resistance. The root elongation and both viscous and elastic extensibility of cell wall of the root apices were hardly affected by the exposure to 10 microM Al in an Al-resistant cultivar, Atlas 66. However, similar exposure rapidly inhibited root elongation in an Al-sensitive cultivar, Scout 66 and this was associated with a time-dependent accumulation of Al in the root tissues with more than 77% residing in the cell wall. Al caused a significant decrease in both the viscous and elastic extensibility of cell wall of the root apices of Scout 66. The "break load" of the root apex of Scout 66 was also decreased by Al. However, neither the viscosity nor elasticity of the cell wall was affected by in vitro Al treatment. Furthermore, pre-treatment of seedlings with Al in conditions where root elongation was slow (i.e. low temperature) did not affect the subsequent elongation of roots in a 0 Al treatment at room temperature. These results suggest that the Al-dependent changes in the cell wall viscosity and elasticity are involved in the inhibition of root growth. Furthermore, for Al to reduce cell wall extensibility it must interact with the cell walls of actively elongating cells.     

Improvement in spermatogenic function after subcutaneous implantation of a capsule containing an aromatase inhibitor in four oligozoospermic dogs and one azoospermic dog with high plasma estradiol-17beta concentrations

A capsule containing an aromatase inhibitor (4-androsten-4-ol-3,17-dione) was subcutaneously implanted in four oligozoospermic beagle dogs and one azoospermic beagle dog with high plasma estradiol-17beta (E2) concentrations (15-19 pg/ml) and low plasma testosterone (T) concentrations (0.6-0.8 ng/ml) for 8 weeks and the effect of the aromatase inhibitor on spermatogenic dysfunction was assessed. Plasma E2 and T concentrations and semen quality were examined at 1 week intervals from 3 weeks before to 12 weeks after the start of treatment. Testicular biopsies were done twice (capsule implantation and removal). Plasma E2 concentrations of all dogs decreased (9-14 pg/ml) and plasma T concentrations increased (2.0-2.6 ng/ml) from 3 weeks after capsule implantation to capsule removal. The mean number of spermatozoa ejaculated by all four oligozoospermic dogs between 4 and 9 weeks after implantation was higher (127 x 10(6) to 205 x 10(6)) than before implantation (20 x 10(6) to 38 x 10(6)) (P < 0.05 and 0.01). Very low numbers (2 x 10(4) to 4 x 10(4)) of immotile spermatozoa were observed between 7 and 8 weeks after implantation in the semen collected from the dog with azoospermia. Before implantation, a few spermatozoa were seen in only one-fifth of the seminiferous tubules in this dog; 8 weeks after implantation, the mean diameter and mean number of round spermatids in the seminiferous tubules in all five dogs were higher than before implantation (P < 0.05). Implantation of the capsule containing the aromatase inhibitor in infertile dogs with abnormally high plasma E2 concentrations improved their spermatogenic function, concurrent with decreased plasma E2 and increased plasma T.     

The pheromone production of female Plodia interpunctella is inhibited by tyraminergic antagonists

Several compounds were found to suppress the calling behavior and in vitro pheromone biosynthesis of the Indian meal moth, Plodia interpunctella. The compounds were screened by means of a calling-behavior bioassay with female P. interpunctella. Five derivatives with activities in the nanomolar range were identified, in order of decreasing pheromonostatic activity: 4-hydroxybenzaldehyde semicarbazone (42) > 5-(4-methoxyphenyl)-1,3-oxazole (38) > 5-[4-(tert-butyl)phenyl]-1,3-oxazole (40) > 5-(3-methoxyphenyl)-1,3-oxazole (35) > 5-(4-cyanophenyl)-1,3-oxazole (36). These compounds also showed in vitro inhibitory activity in intracellular de novo pheromone biosynthesis, as determined with isolated pheromone-gland preparations that incorporated [1-(14)C]sodium acetate in the presence of the so-called pheromone-biosynthesis-activating neuropeptide (PBAN). The non-additive effect of the inhibitor with antagonist (yohimbine) for the tyramine (TA) receptor suggests that it could be a tyraminergic antagonist. Three-dimensional (3D) computer models were built from a set of compounds. Among the common-featured models generated by the program Catalyst/HipHop, aromatic-ring (AR) and H-bond-acceptor-lipophilic (HBAl) features were considered to be essential for inhibitory activity in the calling behavior and in vitro pheromone biosynthesis. Active compounds, including yohimbine, mapped well onto all the AR and HBAl features of the hypothesis. Less-active compounds were shown to be unable to achieve an energetically favorable conformation, consistent with our 3D common-feature pharmacophore models. The present hypothesis demonstrates that calling behavior and PBAN-stimulated incorporation of radioactivity are inhibited by tyraminergic antagonists.     

Gicerin,a cell adhesion molecule,promotes the metastasis of lymphoma cells of the chicken

Gicerin is an immunoglobulin superfamily cell adhesion molecule purified from chicken gizzards. This molecule displays an adhesive interaction with a laminin-like protein as well as with gicerin itself. Gicerin appears in embryonic tissues and plays a role in chick development through its cell adhesive properties. An increase in gicerin expression is found in some sporadic tumors of the chicken. To elucidate the possible role of gicerin in tumor progression in chickens, we introduced gicerin cDNA into an endogenous gicerin negative lymphoma MDCC-MSB1 cell line, and subsequently analyzed them for changes in their metastatic potentials. After intravenous implantation of the gicerin transfectants into chickens, the metastatic potential to the lung, liver and kidney was enhanced compared with parental MDCC-MSB1 cells. Self-aggregation activity was increased in gicerin transfectants. In addition, adhesive and migratory activities of the gicerin transfectants to the gicerin ligands were enhanced in vitro. These findings indicate that gicerin can contribute to the malignancy and metastatic properties of lymphoma.This work was supported in part by a Grant-in-Aid for Scientific Research (No. 13760210), and a grant for Scientific Research on Priority Areas "Cancer" (No. 12215133), from the Ministry of Education, Science, Sports and Culture, Japan, grants from the Uehara Memorial Foundation and Senri Life Science and a Grant-in-Aid for Advanced Scientific Research from Osaka Prefecture University