Defensive bacteriome symbiont with a drastically reduced genome.

Diverse insect species harbor symbiotic bacteria, which play important roles such as provisioning nutrients and providing defense against natural enemies [1-6]. Whereas nutritional symbioses are often indispensable for both partners, defensive symbioses tend to be of a facultative nature [1-12]. The Asian citrus psyllid Diaphorina citri is a notorious agricultural pest that transmits Liberibacter spp.

Dual action of sphingosine 1-phosphate in eliciting proinflammatory responses in primary cultured rat intestinal smooth muscle cells.

Sphingosine 1-phosphate (S1P) is involved in the local inflammatory response within the intestinal muscularis, which has been suggested to play a major role in the pathogenesis of postoperative ileus. The aim of the present study was to elucidate the role of S1P and the molecular mechanisms underlying regulation of inflammatory mediators in primary cultured rat intestinal smooth muscle (RISM) cells. Although our experimental data clearly show the mediatory role of sphingosine kinase (SK)-derived S1P in the TNF-alpha and the LPS induced activation of NF-kB, exogenously added S1P failed to trigger this transcription factor.

Golgi localization of glycosyltransferases involved in ganglioside biosynthesis.

Gangliosides make up a group of sialic acid-containing complex glycosphingolipids particularly abundant in the central nervous system. The finding indicating gangliosides are stored in certain hereditary diseases affecting the central nervous system opened the interest in studying their metabolism. The initial in vitro pioneering work on the glycosyltransferases involved in ganglioside biosynthesis was done by Roseman and his associates primarily in embryonic chick brains almost forty years ago.

Skeletal muscle insulin resistance induced by adipocyte-conditioned medium: underlying mechanisms and reversibility.

Insulin resistance in skeletal muscle is an early event in the development of diabetes, with obesity being one of the major contributing factors. In vitro, conditioned medium (CM) from differentiated human adipocytes impairs insulin signaling in human skeletal muscle cells, but it is not known whether insulin resistance is reversible and which mechanisms may underlie this process. CM induced insulin resistance in human myotubes at the level of insulin-stimulated Akt and GSK-3 phosphorylation.

Trichothecenes induce accumulation of glucosylceramide in neural cells by interfering with lactosylceramide synthase activity.

Trichothecenes are sesquiterpenoid metabolites produced by several fungal strains that impair human and animal health. Since sphingolipids were connected with fungal toxicity the aim of the present study was to test the influence of fungal metabolites on sphingolipid metabolism in neural cells. The crude extract of fungal strain Spicellum roseum induced accumulation of glucosylceramide (GlcCer), and simultaneous reduction of the formation of lactosylceramide (LacCer) and complex gangliosides in primary cultured neurons.