Adrenomedullin in the eye

Adrenomedullin (AM) is a multifunctional regulatory peptide that is produced and secreted by various types of cells. We showed the presence of high concentrations of adrenomedullin-immunoreactivity in the vitreous fluid, and the levels were elevated in patients with proliferative vitreoretinopathy. Furthermore, adrenomedullin mRNA expression levels were elevated in the tissues of intraocular tumors and orbital tumors. Adrenomedullin is produced and secreted by cultured human retinal pigment epithelial (RPE) cells. Inflammatory cytokines and hypoxia are strong stimulators for the adrenomedullin expression in retinal pigment epithelial cells. Adrenomedullin stimulated the proliferation of retinal pigment epithelial cells both under normoxia and hypoxia. Dexamethasone (DEX) increased the adrenomedullin expression in two cultured cell lines of human retinal pigment epithelial cells; ARPE-19 cells and D407 cells, while it had no noticeable effects on the cytokine-induced adrenomedullin expression. These findings suggest that adrenomedullin is involved in the pathophysiology of inflammatory and neoplastic eye diseases as an autocrine or paracrine growth stimulator. The findings on glucocorticoid-induced AM expression raise the possibility that it may be related to the pathogenesis of some eye diseases, such as central serous chorioretinopathy and multifocal posterior pigment epitheliopathy, which are frequently seen in patients treated with high doses of glucocorticoids.     

New estimation method for fatty acid composition in oil using near infrared spectroscopy

The absorption bands of cis-unsaturation and the carbon chain length of the fatty acid moieties in oil appear in the near infrared (NIR) wavelength region, especially around 1600-1800 nm. Using this region, a new estimation method for fatty acid composition analysis is proposed. Because the differences of the original NIR spectra are miniscule even in this region, the second derivative NIR spectra were examined in order to estimate the fatty acid composition in oil exclusively from the spectral patterns obtained. The parameters for calculating the second derivative NIR spectra were examined to make the spectral difference clearer. In any parameter, the absorption band was shifted to the shorter wavelength region when the unsaturation in fatty acid moieties increased, and it was shifted to the longer wavelength region when the carbon chain length increased. When the parameters were correct, this NIR method can estimate the fatty acid composition roughly, but simply, easily, and sometimes nondestructively.     

Oxidation of 3-C-(2-amino-2-deoxy-D-glucopyranosyl)-1-propene compounds and the structure of 3-C-(2-amino-2-deoxy-D-glucopyranosyl)-1,2-propanediol derivatives for a synthesis of 2,3-didehydro-2,7-dideoxy-N-acetylneuraminic acid

Oxidation of 5-acetamido-4,8-anhydro-1,2,3,5-tetradeoxy-D-glycero-D-ido-non-1-enitol [3-C-(2-amino-2-deoxy-beta-D-glucopyranosyl)-1-propene] was studied to search for preparative routes to aminodeoxy didehydro nonulosonic acid derivatives. Since only moderate chiral induction was observed with osmium tetroxide dihydroxylation as well as with peracid epoxidation, the catalytic asymmetric dihydroxylation conditions were applied to give the stereocontrolled formation of 1,2-propanediol derivatives. The structures of these diastereoisomeric 1,2-propanediol derivatives were determined by X-ray crystallographic analyses. The formation of diastereoisomeric 1,2-propanediols also varied with the nature of 2-substituent on the aminodoexy glycosyl moiety. Thus 5-acetamido-4,8-anhydro-3,5-dideoxy-D-erythro-L-ido-nonitol [(2S)-3-C-(2-acetamido-2-deoxy-beta-D-glucopyranosyl)-1,2-propanediol] was obtained predominantly up to 70% from 3-C-(2-acetamido-2-deoxyglycosyl)-1-propene by the use of ADmixbeta reagent. The (2S)-propanediol derivative was transformed in a five-step reaction sequence to 2,3-didehydro-2,7-dideoxy-N-acetylneuraminic acid.     

Surface ��-1,3-Glucan Facilitates Fungal Stealth Infection by Interfering with Innate Immunity in Plants

Plants evoke innate immunity against microbial challenges upon recognition of pathogen-associated molecular patterns (PAMPs), such as fungal cell wall chitin. Nevertheless, pathogens may circumvent the host PAMP-triggered immunity. We previously reported that the ascomycete Magnaporthe oryzae, a famine-causing rice pathogen, masks cell wall surfaces with α-1,3-glucan during invasion. Here, we show that the surface α-1,3-glucan is indispensable for the successful infection of the fungus by interfering with the plant''s defense mechanisms. The α-1,3-glucan synthase gene MgAGS1 was not essential for infectious structure development but was required for infection in M. oryzae. Lack or degradation of surface α-1,3-glucan increased fungal susceptibility towards chitinase, suggesting the protective role of α-1,3-glucan against plants'' antifungal enzymes during infection. Furthermore, rice plants secreting bacterial α-1,3-glucanase (AGL-rice) showed strong resistance not only to M. oryzae but also to the phylogenetically distant ascomycete Cochlioborus miyabeanus and the polyphagous basidiomycete Rhizoctonia solani; the histocytochemical analysis of the latter two revealed that α-1,3-glucan also concealed cell wall chitin in an infection-specific manner. Treatment with α-1,3-glucanase in vitro caused fragmentation of infectious hyphae in R. solani but not in M. oryzae or C. miyabeanus, indicating that α-1,3-glucan is also involved in maintaining infectious structures in some fungi. Importantly, rapid defense responses were evoked (a few hours after inoculation) in the AGL-rice inoculated with M. oryzae, C. miyabeanus and R. solani as well as in non-transgenic rice inoculated with the ags1 mutant. Taken together, our results suggest that α-1,3-glucan protected the fungal cell wall from degradative enzymes secreted by plants even from the pre-penetration stage and interfered with the release of PAMPs to delay innate immune defense responses. Because α-1,3-glucan is nondegradable in plants, it is reasonable that many fungal plant pathogens utilize α-1,3-glucan in the innate immune evasion mechanism and some in maintaining the structures.     

Identification and characterization of the UL56 gene product of herpes simplex virus type 2

The UL56 gene product of herpes simplex virus (HSV) has been shown to play an important role in viral pathogenicity. However, the properties and functions of the UL56 protein are little understood. We raised rabbit polyclonal antisera specific for the UL56 protein of HSV type 2 (HSV-2) and examined its expression and properties. The gene product was identified as three polypeptides with apparent molecular masses ranging from 32 to 35 kDa in HSV-2-infected cells, and at least one species was phosphorylated. Studies of their origins showed that the UL56 protein of HSV-2 is also translated from the upstream in-frame methionine codon that is not present in the HSV-1 genome. Synthesis was first detected at 6 h postinfection and was not abolished by the viral DNA synthesis inhibitor phosphonoacetic acid. Indirect immunofluorescence studies revealed that the UL56 protein localized to both the Golgi apparatus and cytoplasmic vesicles in HSV-2-infected and single UL56-expressing cells. Deletion mutant analysis showed that the C-terminal hydrophobic region of the protein was required for association with the cytoplasmic membrane and that the N-terminal proline-rich region was important for its translocation to the Golgi apparatus and cytoplasmic vesicles. Moreover, the results of protease digestion assays and sucrose gradient fractionation strongly suggested that UL56 is a tail-anchored type II membrane protein associated with lipid rafts. We thus hypothesized that the UL56 protein, as a tail-anchored type II membrane protein, may be involved in vesicular trafficking in HSV-2-infected cells.     

Hypotonic stress-induced NO production in endothelium depends on endogenous ATP

The mechanism by which mechanical stress induces nitric oxide (NO) synthesis in endothelium is still controversial. Hypotonic stress (HTS, -20%) induced ATP release, which evoked Ca(2+) transients in bovine aortic endothelial cells (BAEC). HTS also induced NO synthesis, assessed by DAF-2 fluorescence, which was suppressed by inhibiting endogenous ATP-induced Ca(2+) transients with suramin or neomycin. Exogenously applied ATP mimicked these responses. Pretreatment with wortmannin did not affect DAF-2 fluorescence, suggesting that Akt phosphorylation was not involved in HTS-induced NO synthesis. These results indicate that endogenous ATP plays a central role in HTS-induced NO synthesis in BAEC.     

Chemo-enzymatic synthesis of 3-(2-naphthyl)- L-alanine by an aminotransferase from the extreme thermophile, Thermococcus profundus

Hyper-thermostable aminotransferase from Thermococcus profundus (MsAT) was used to synthesize 3-(2-naphthyl)-l-alanine (Nal) by transamination between its corresponding -keto acid, 3-(2-naphthyl)pyruvate (NPA) and l-glutamate (Glu) at 70 °C. Equilibrium of this reaction was shifted toward Nal production due to its low solubility, giving rise to Nal precipitate. Optically pure Nal (>99% ee) was synthesized with 93% (mol mol^–1) yield from 180 mM NPA and 360 mM Glu.     

Stonogobiops yasha, a new shrimp-associated goby from Japan

A new shrimp-associated goby, Stonogobiops yasha sp. nov., is described on the basis of nine specimens collected from the Ryukyu Islands, Japan. This species is easily distinguished from other congeneric species in having reddish-orange stripes on a white body and only two median cephalic sensory pores on the head. Received: July 21, 1999 / Revised: July 10, 2001 / Accepted: July 26, 2001     

Effects of recombinant human macrophage colony-stimulating factor on atherosclerotic lesions established in the aorta of high cholesterol-fed rabbits

Anti-atherosclerotic effects of human macrophage colony-stimulating factor were investigated using rabbits fed a high cholesterol diet. Rabbits fed a diet containing 2% cholesterol for 59 days developed hyperlipidemia and atheromatous aortic plaques. They were then administered 80 microg/kg/day of either macrophage colony-stimulating factor or human serum albumin, as a control, for the next 12 weeks. Compared with the control group, rabbits treated with macrophage colony-stimulating factor had significantly fewer plaques on the inner surface of the thoracic and abdominal aortae, and half the sectional area of thickened intima in the aortic arch, as well as in the thoracic and abdominal aortae. Macrophage colony-stimulating factor also decreased the cholesterol content of the atherosclerotic lesions. Serobiochemical analyses revealed that macrophage colony-stimulating factor increased the levels of high density lipoprotein-cholesterol significantly, without influencing other lipid parameters such as the level of low density lipoproteins. The effects of macrophage colony-stimulating factor were evident until the fourth week of drug injection, at which time anti-human macrophage colony-stimulating factor antibodies were clearly induced in the serum. These results indicate that exogenously administered macrophage colony-stimulating factor suppresses atherosclerotic lesions induced by a high cholesterol diet by activating lipid metabolism in vivo.