Entwicklung einer Kommunikationsstrategie für nachhaltige Aquakulturprodukte

Ziel dieses Verbundprojekts zwischen der Universität Kassel und dem Thünen-Institut (Gesamtleitung: Prof. Dr. Hamm, Universität Kassel) war es, Verbraucherpräferenzen für nachhaltig erzeugte Aquakulturprodukte deutscher Herkunft zu evaluieren und Schlussfolgerungen für das Marktpotential abzuleiten. Verschiedene qualitative und quantitative Methoden der Verbraucherforschung wurden kombiniert. Der Status-Quo der Kommunikation von nachhaltiger Aquakultur wurde über die Analyse der Verpackungen und der Internetauftritte der Hersteller und Zertifizierungsorganisationen erarbeitet. Daran schlossen zwei qualitative Erhebungsschritte, Gruppendiskussionen und Denke-Laut-Protokolle, an. Den Abschluss bildeten Kaufexperimente, in denen Testpersonen verschiedene Fischprodukte zum Kauf angeboten wurden. Verbraucher verfügten mehrheitlich nur über geringe Kenntnisse zu den Produktionsmethoden der Aquakultur und ihren Kennzeichnungen. Entsprechend unsicher waren die Probanden auch bei Fragen zur Nachhaltigkeit der Erzeugung, obwohl sie nachhaltige Produktionsmethoden insgesamt schätzten. Als wichtige Aspekte der Nachhaltigkeit wurden Kriterien wie geringer Medikamenteneinsatz, Tierwohl (Besatzdichten), Natürlichkeit bzw. Naturnähe und geografische Herkunft genannt. Naturnahe Produktionssysteme wie Erdteiche wurden gegenüber stärker technisierten Systemen wie Kreislaufanlagen bevorzugt. Die deutsche Herkunft hatte den größten Einfluss auf die Kaufentscheidung, gefolgt vom Naturland-Label und einem nicht existenten, optisch aber ansprechenden „Fake“-Label. Letzteres Ergebnis verdeutlichte auf drastische Weise, dass das Verbraucherwissen zu Nachhaltigkeitslabeln bei Fisch noch unzureichend ist. Für die zukünftige Kommunikation bedeuten die Ergebnisse, dass kurze, eindeutige und unmissverständliche Botschaften auf den Verpackungen verwendet werden sollten. Zusätzliche Informationsmöglichkeiten des Internets sollten deutlich zielgerichteter als bisher genutzt werden. Unter diesen Voraussetzungen ergibt sich ein erhebliches Differenzierungspotential für Produkte aus deutscher nachhaltiger Aquakultur

Visualizing the activation of encephalitogenic T cells in the ileal lamina propria by in vivo two- photon imaging

Autoreactive encephalitogenic T cells exist in the healthy immune repertoire but need a trigger to induce CNS inflammation. The underlying mechanisms remain elusive, whereby microbiota were shown to be involved in the manifestation of CNS autoim-munity. Here, we used intravital imaging to explore how microbiota affect the T cells as trigger of CNS inflammation. Encephalitogenic CD4(+) T cells transduced with the calcium-sensing protein Twitch -2B showed calcium signaling with higher frequency than polyclonal T cells in the small intestinal lamina propria (LP) but not in Peyer's patches. Interestingly, nonencephalitogenic T cells specific for OVA and LCMV also showed calcium signaling in the LP, indicating a general stimulating effect of microbiota. The observed calcium signaling was microbiota and MHC class II dependent as it was significantly reduced in germfree animals and after administration of anti- MHC class II antibody, respectively. As a consequence of T cell stimulation in the small intestine, the encephalitogenic T cells start expressing Th17- axis genes. Finally, we show the migration of CD4(+) T cells from the small intestine into the CNS. In summary, our direct in vivo visualization revealed that microbiota induced T cell activation in the LP, which directed T cells to adopt a Th17- like phenotype as a trigger of CNS inflammation

A multi-center study of their physicochemical characteristics, cell culture and in vivo experiments

PVP-capped silver nanoparticles with a diameter of the metallic core of 70 nm, a hydrodynamic diameter of 120 nm and a zeta potential of −20 mV were prepared and investigated with regard to their biological activity. This review summarizes the physicochemical properties (dissolution, protein adsorption, dispersability) of these nanoparticles and the cellular consequences of the exposure of a broad range of biological test systems to this defined type of silver nanoparticles. Silver nanoparticles dissolve in water in the presence of oxygen. In addition, in biological media (i.e., in the presence of proteins) the surface of silver nanoparticles is rapidly coated by a protein corona that influences their physicochemical and biological properties including cellular uptake. Silver nanoparticles are taken up by cell-type specific endocytosis pathways as demonstrated for hMSC, primary T-cells, primary monocytes, and astrocytes. A visualization of particles inside cells is possible by X-ray microscopy, fluorescence microscopy, and combined FIB/SEM analysis. By staining organelles, their localization inside the cell can be additionally determined. While primary brain astrocytes are shown to be fairly tolerant toward silver nanoparticles, silver nanoparticles induce the formation of DNA double-strand-breaks (DSB) and lead to chromosomal aberrations and sister-chromatid exchanges in Chinese hamster fibroblast cell lines (CHO9, K1, V79B). An exposure of rats to silver nanoparticles in vivo induced a moderate pulmonary toxicity, however, only at rather high concentrations. The same was found in precision-cut lung slices of rats in which silver nanoparticles remained mainly at the tissue surface. In a human 3D triple-cell culture model consisting of three cell types (alveolar epithelial cells, macrophages, and dendritic cells), adverse effects were also only found at high silver concentrations. The silver ions that are released from silver nanoparticles may be harmful to skin with disrupted barrier (e.g., wounds) and induce oxidative stress in skin cells (HaCaT). In conclusion, the data obtained on the effects of this well-defined type of silver nanoparticles on various biological systems clearly demonstrate that cell-type specific properties as well as experimental conditions determine the biocompatibility of and the cellular responses to an exposure with silver nanoparticles

Identification of dihydromyricetin as a natural DNA methylation inhibitor with rejuvenating activity in human skin

Changes in DNA methylation patterning have been reported to be a key hallmark of aged human skin. The altered DNA methylation patterns are correlated with deregulated gene expression and impaired tissue functionality, leading to the well-known skin aging phenotype. Searching for small molecules, which correct the aged methylation pattern therefore represents a novel and attractive strategy for the identification of anti-aging compounds. DNMT1 maintains epigenetic information by copying methylation patterns from the parental (methylated) strand to the newly synthesized strand after DNA replication. We hypothesized that a modest inhibition of this process promotes the restoration of the ground-state epigenetic pattern, thereby inducing rejuvenating effects. In this study, we screened a library of 1800 natural substances and 640 FDA-approved drugs and identified the well-known antioxidant and anti-inflammatory molecule dihydromyricetin (DHM) as an inhibitor of the DNA methyltransferase DNMT1. DHM is the active ingredient of several plants with medicinal use and showed robust inhibition of DNMT1 in biochemical assays. We also analyzed the effect of DHM in cultivated keratinocytes by array-based methylation profiling and observed a moderate, but significant global hypomethylation effect upon treatment. To further characterize DHM-induced methylation changes, we used published DNA methylation clocks and newly established age predictors to demonstrate that the DHM-induced methylation change is associated with a reduction in the biological age of the cells. Further studies also revealed re-activation of age-dependently hypermethylated and silenced genes in vivo and a reduction in age-dependent epidermal thinning in a 3-dimensional skin model. Our findings thus establish DHM as an epigenetic inhibitor with rejuvenating effects for aged human skin