Phosphorylation of Drosophila Jun by the MAP kinase rolled regulates photoreceptor differentiation.

Drosophila Jun (D-Jun) is a nuclear component of the receptor tyrosine kinase/Ras signal transduction pathway which triggers photoreceptor differentiation during eye development. Here we show that D-Jun is a substrate for the ERK-related Drosophila MAP kinase Rolled, which has previously been shown to be a part of this pathway. A D-Jun mutant that carries alanines in place of the Rolled phosphorylation sites acts as a dominant suppressor of photoreceptor cell fate if expressed in the eye imaginal disc. In contrast, a mutant in which the phosphorylation sites are replaced by phosphate-mimetic Asp residues, as well as a VP16-D-Jun fusion protein, can promote photoreceptor differentiation. These data implicate Jun phosphorylation in the choice between neuronal and non-neuronal fate during Drosophila eye development.     

Could glucose be a proaging factor?

There is an ever-increasing scientific interest for the interplay between cell's environment and the aging process. Although it is known that calorie restriction affects longevity, the exact molecular mechanisms through which nutrients influence various cell signalling/modulators of lifespan remain a largely unresolved issue. Among nutrients, glucose constitutes an evolutionarily stable, precious metabolic fuel, which is catabolized through glycolytic pathway providing energy in the form of ATP and consuming NAD. Accumulating evidence shows that among the important regulators of aging process are autophagy, sirtuin activity and oxidative stress. In light of recent work indicating that glucose availability decreases lifespan whilst impaired glucose metabolism extends life expectancy, the present article deals with the potential role of glucose in the aging process by regulating - directly through its metabolism or indirectly through insulin secretion - autophagy, sirtuins as well as other modulators of aging like oxidative stress and advanced glycation end-products (AGEs).     

Mycological flora of cigarettes

Hundred strains of fungi were isolated from 48 packets of Greek cigarettes. They were:Aspergillus (28 strains),Penicillium (22),Mucor (18),Alternaria (14),Cladosporium (1),Streptomyces (4),Candida (11) andGeotrichum (2). From 55 packets of cigarettes manufactured outside of Greece other 100 strains of fungi were isolated and identified asAspergillus (35),Penicillium (23),Mucor (10),Alternaria (13),Cladosporium (5),Streptomyces (4),Candida (3),Geotrichum (1),Cephalosporium (2) andScopulariopsis (4).Results of the present study are discussed in relation to the mycological flora of the air in Athens and to the coli-aerogenes bacteria of cigarettes.

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Résumé Les auteurs ont isolé 100 souches de champignons à partir de 48 paquets de cigarettes préparées en Grèce. Ces souches étaient identifiées commeAspergillus (28 souches),Penicillium (22),Mucor (18),Alternaria (14),Cladosporium (1),Streptomyces (4),Candida (11) etGeotrichum (2). D'autre part on a isolé 100 souches de champignons à partir de 55 paquets de cigarettes préparées à l'étranger (surtout aux Etats-Unis et en Angleterre). Ces souches étaientAspergillus (35),Penicillium (23),Mucor (10),Alternaria (13),Cladosporium (5),Streptomyces (4),Candida (3),Geotrichum (1),Cephalosporium (2) etScopulariopsis (4).Les résultats sont discutés en relation avec la flore mycosique de l'air à Athènes et les bactéries coliformes rétrouvées dans les cigarettes préparées en Grèce.

     

Association of NADPH oxidase p22phox gene C242T, A640G and −930A/G polymorphisms with primary knee osteoarthritis in the Greek population

Osteoarthritis (OA) is the most common form of arthritis with still unknown pathogenic etiology and considerable contribution of genetic factors. Recently, a new emerging role of oxidative stress in the pathology of OA has been reported, lacking however elucidation of the underlying mechanism. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase being a complex enzyme produced by chondrocytes, presents the major source of reactive oxygen species and main contributor of increased oxidative stress. The present study aims to evaluate the association of NADPH oxidase p22phox gene C242T, A640G and ?A930G polymorphisms with primary knee OA in the Greek population. One hundred fifty five patients with primary symptomatic knee OA participated in the study along with 139 matched controls. Genotypes were determined using polymerase chain reaction and restriction fragment length polymorphism technique. Allelic and genotypic frequencies were compared between both study groups. NADPH p22phox ?A930G polymorphism was significantly associated with knee OA in the crude analysis (P = 0.018). No significant difference was detected for C242T and A640G polymorphisms (P > 0.05). The association between ?A930G polymorphism and knee OA disappeared when the results were adjusted for obesity (P = 0.078, odds ratio 0.54, 95 % CI 0.272–1.071). The interaction between all three polymorphisms was not significant. The present study shows that NADPH oxidase p22phox gene C242T, A640G and ?A930G polymorphisms are not risk factors for knee OA susceptibility in the Greek population. Further studies are needed to give a global view of the importance of this polymorphism in the pathogenesis of OA.