Neuromedin U has a novel anorexigenic effect independent of the leptin signaling pathway

Neuromedin U (NMU) is a hypothalamic neuropeptide that regulates body weight and composition. Here we show that mice lacking the gene encoding NMU (Nmu(-/-) mice) develop obesity. Nmu(-/-) mice showed increased body weight and adiposity, hyperphagia, and decreased locomotor activity and energy expenditure. Obese Nmu(-/-) mice developed hyperleptinemia, hyperinsulinemia, late-onset hyperglycemia and hyperlipidemia. Notably, however, treatment with exogenous leptin was effective in reducing body weight in obese Nmu(-/-) mice. In addition, central leptin administration did not affect NMU gene expression in the hypothalamus of rats. These results indicate that NMU plays an important role in the regulation of feeding behavior and energy metabolism independent of the leptin signaling pathway. These characteristic functions of NMU may provide new insight for understanding the pathophysiological basis of obesity.     

Vitamin D receptor gene polymorphism is associated with chronic periodontitis

Chronic periodontitis (CP) is caused by enhanced resorption of the alveolar bone supporting the teeth and is associated with intraoral inflammation after infection with certain bacteria. The VDR gene polymorphism was reported recently to be deeply related to the occurrence of tuberculosis and infection of chronic hepatitis B virus. This may be interpreted to indicate a close relationship between VDR gene polymorphism and the immunological action, because vitamin D activates monocytes, stimulates cell-mediated immunity, and suppresses lymphocyte proliferation. The purpose of the present study was to clarify whether polymorphisms in VDR gene exons are associated with the incidence of CP. A case-controlled study was performed on a group of 168 unrelated Japanese subjects whose ages ranged from 35 to 65 years. The Taq I polymorphism in the VDR gene was found to be associated significantly with CP (X2=4.48, P=0.034). We performed multiple logistic regression analyses on the TT genotype, which was found to be associated with CP, and on well-recognized risk factors, smoking and diabetes. The odds ratio (OR) for the genotype (TT/Tt) was 2.73 (95% CI 1.11-6.68, P=0.028), being larger than the unadjusted value. This indicates that the VDR gene polymorphism (TT genotype) is a risk factor for CP, independently of smoking and diabetes.     

The Bh (black at hatch) gene that causes abnormal feather pigmentation maps to chromosome 1 of the Japanese quail

Japanese quail embryos normally have longitudinal black and brown stripes formed by colored feather buds on their back whereas an autosomal dominant mutation, black at hatch (Bh), disrupts this pigmentation pattern by causing overall black and brown coating in heterozygotes and homozygotes, respectively. These phenotypes of the Bh mutant embryos suggest that the Bh locus plays an important role in the pigment pattern formation of plumage, but its genetic origin, including cloning of the responsible gene, has been insufficiently studied. In this study, we adapted genetically directed representational difference analysis with elimination of excessive clones (GDRDA-WEEC) to Bh quails and isolated two genetic markers linked to the Bh locus as DNA fragments. Cytogenetic study by fluorescence in situ hybridization (FISH) of the DNA fragments used as probes demonstrated that the marker loci were located in the same region on the long arm of chromosome 1. Close genetic linkage between the Bh and the marker loci, and the chromosomal location of the latter suggested that the Bh locus is located on the long-arm of chromosome 1 of the Japanese quail.     

Extracellular acidic polysaccharide production by a two-membered bacterial coculture

A two-membered coculture of strains KYM-7 and KYM-8, identified as Cellulomonas cellulans and Agrobacterium tumefaciens, respectively, produced a large amount of an extracellular polysaccharide, designated APK-78, from starch. Each strain in pure culture produced only very little amount of polysaccharide from starch; the coexistence of the two strains from the early stage of cultivation was indispensable for a large amount of polysaccharide to be produced. The polysaccharide APK-78 was acidic and composed of glucose, galactose, succinic acid, and pyruvic acid with a molar ratio of 8.1:1.0:1.7:1.0, indicating that it is a succinoglycan type of polysaccharide.     

Purification and characterization of laminaran hydrolases from Trichoderma viride

At least three extracellular laminaran hydrolases which hydrolyzed laminaran (beta-1,3:1,6-glucan) from Eisenia bicyclis were secreted in wheat bran solid medium by Trichoderma viride U-1. These three enzymes, lam AI, AII, and B, were purified to electrophoretic homogeneity. Their molecular masses were estimated to be 70.1, 70.4, and 45.0 kDa for lam AI, AII, and B, respectively, by SDS-PAGE. Whereas both lam AI and AII could hydrolyze laminarin from Laminaria digitata, lam AII showed higher activity against Laminaria laminarin rather than Eisenia laminaran. On the other hand, lam B preferentially hydrolyzed pustulan, a beta-1,6-glucan. Laminarioligosaccharide was hydrolyzed by lam AI and AII but not B, whereas gentiooligosaccharide was hydrolyzed by only lam B. It showed that lam AI and AII were specific for beta-1,3-linkages, but lam B was specific for beta-1,6-linkages. These results indicated that T. viride U-1 has a multiple glucanolytic enzyme system.     

Characterization of the <Emphasis Type="Italic">Selaginella remotifolia</Emphasis> MADS-box gene

Recent progress in plant molecular genetics has revealed that floral organ development is regulated by several homeotic selector genes, most of which belong to the MADS-box gene family. Here we report on SrMADS1, a MIKC^c-type MADS-box gene from Selaginella, a spikemoss belonging to the lycophytes. SrMADS1 phylogenetically forms a monophyletic clade with genes of the LAMB2 group, which are MIKC^c genes of the clubmoss Lycopodium, and is expressed in whole sporophytic tissues except roots and rhizophores. Our results and the previous report on Lycopodium MIKC^c genes suggest that the ancestral MIKC^c gene of primitive dichotomous plants in the early Devonian was involved in the development of basic sporophytic tissues such as shoot, stem, and sporangium. Electronic Publication     

Novel cadherin-related membrane proteins,Alcadeins, enhance the X11-like protein-mediated stabilization of amyloid beta-protein precursor metabolism

Previously we found that X11-like protein (X11L) associates with amyloid beta-protein precursor (APP). X11L stabilizes APP metabolism and suppresses the secretion of the amyloid beta-protein (Abeta) that are the pathogenic agents of Alzheimer's disease (AD). Here we found that Alcadein (Alc), a novel membrane protein family that contains cadherin motifs and originally reported as calsyntenins, also interacted with X11L. Alc was abundant in the brain and occurred in the same areas of the brain as X11L. X11L could simultaneously associate with APP and Alc, resulting in the formation of a tripartite complex in brain. The tripartite complex stabilized intracellular APP metabolism and enhanced the X11L-mediated suppression of Abeta secretion that is due to the retardation of intracellular APP maturation. X11L and Alc also formed another complex with C99, a carboxyl-terminal fragment of APP cleaved at the beta-site (CTFbeta). The formation of the Alc.X11L.C99 complex inhibited the interaction of C99 with presenilin, which strongly suppressed the gamma-cleavage of C99. In AD patient brains, Alc and APP were particularly colocalized in dystrophic neurites in senile plaques. Deficiencies in the X11L-mediated interaction between Alc and APP and/or CTFbeta enhanced the production of Abeta, which may be related to the development or progression of AD.