Patterns of Chemical Diversity in the Mediterranean Sponge Spongia lamella

The intra-specific diversity in secondary metabolites can provide crucial information for understanding species ecology and evolution but has received limited attention in marine chemical ecology. The complex nature of diversity is partially responsible for the lack of studies, which often target a narrow number of major compounds. Here, we investigated the intra-specific chemical diversity of the Mediterranean sponge Spongia lamella. The chemical profiles of seven populations spreading over 1200 km in the Western Mediterranean were obtained by a straightforward SPE-HPLC-DAD-ELSD process whereas the identity of compounds was assessed by comparison between HPLC-MS spectra and literature data. Chemical diversity calculated by richness and Shannon indexes differed significantly between sponge populations but not at a larger regional scale. We used factor analysis, analysis of variance, and regression analysis to examine the chemical variability of this sponge at local and regional scales, to establish general patterns of variation in chemical diversity. The abundance of some metabolites varied significantly between sponge populations. Despite these significant differences between populations, we found a clear pattern of increasing chemical dissimilarity with increasing geographic distance. Additional large spatial scale studies on the chemical diversity of marine organisms will validate the universality or exclusivity of this pattern

Synaptic versus extrasynaptic NMDA receptor signalling: implications for neurodegenerative disorders

There is a long-standing paradox that N-methyl-D-aspartate receptors (NMDARs) can both promote neuronal health and kill neurons. Recent studies show that NMDAR-induced responses depend on the receptor location: stimulation of synaptic NMDARs, acting primarily through nuclear Ca(2+) signaling, leads to the build-up of a neuroprotective ‘shield’, whereas stimulation of extrasynaptic NMDARs promotes cell death. These differences result from the activation of distinct genomic programmes and opposing actions on intracellular signalling pathways. Perturbations in the balance between synaptic and extrasynaptic NMDAR activity contribute to neuronal dysfunction in acute ischaemia and Huntington’s disease and could be a common theme in the aetiology of neurodegenerative diseases. Neuroprotective therapies should aim to both enhance the effect of synaptic activity and disrupt extrasynaptic NMDAR-dependent death signalling

CYCLOPHILIN D MODULATES MITOCHONDRIAL FOF1 ATP SYNTHASE BY INTERACTING WITH THE LATERAL STALK OF THE COMPLEX

Blue native gel electrophoresis purification and immunoprecipitation of F(0)F(1)-ATP synthase from bovine heart mitochondria revealed that cyclophilin (CyP) D associates to the complex. Treatment of intact mitochondria with the membrane-permeable bifunctional reagent dimethyl 3,3-dithiobis-propionimidate (DTBP) cross-linked CyPD with the lateral stalk of ATP synthase, whereas no interactions with F(1) sector subunits, the ATP synthase natural inhibitor protein IF1, and the ATP/ADP carrier were observed. The ATP synthase-CyPD interactions have functional consequences on enzyme catalysis and are modulated by phosphate (increased CyPD binding and decreased enzyme activity) and cyclosporin (Cs) A (decreased CyPD binding and increased enzyme activity). Treatment of MgATP submitochondrial particles or intact mitochondria with CsA displaced CyPD from membranes and activated both hydrolysis and synthesis of ATP sustained by the enzyme. No effect of CsA was detected in CyPD-null mitochondria, which displayed a higher specific activity of the ATP synthase than wild-type mitochondria. Modulation by CyPD binding appears to be independent of IF1, whose association to ATP synthase was not affected by CsA treatment. These findings demonstrate that CyPD association to the lateral stalk of ATP synthase modulates the activity of the complex

Conjoint PERSONA – SOPRANO Workshop 1

Abstract. Being both EU-IST integrated projects in the field of AAL, PERSONA and SOPRANO organized a conjoint workshop on the occasion of the AmI-07 conference in order for the researchers of the projects to exchange insights of the approaches to the key field challenges, the achievements so far in each of the projects, and possible synergies in the future. Here, we summarize the exchanged info and the workshop results. The paper gives a good overview of the two projects and their status by the end of October 2007. Keywords: EU-IST integrated project, ambient intelligence, assisted living, use cases and scenarios, architectural design, technological approach