Interleukin-1α Activity in Necrotic Endothelial Cells Is Controlled by Caspase-1 Cleavage of Interleukin-1 Receptor-2: IMPLICATIONS FOR ALLOGRAFT REJECTION*

Inflammation is a key instigator of the immune responses that drive atherosclerosis and allograft rejection. IL-1α, a powerful cytokine that activates both innate and adaptive immunity, induces vessel inflammation after release from necrotic vascular smooth muscle cells (VSMCs). Similarly, IL-1α released from endothelial cells (ECs) damaged during transplant drives allograft rejection. However, IL-1α requires cleavage for full cytokine activity, and what controls cleavage in necrotic ECs is currently unknown. We find that ECs have very low levels of IL-1α activity upon necrosis. However, TNFα or IL-1 induces significant levels of active IL-1α in EC necrotic lysates without alteration in protein levels. Increased activity requires cleavage of IL-1α by calpain to the more active mature form. Immunofluorescence and proximity ligation assays show that IL-1α associates with interleukin-1 receptor-2, and this association is decreased by TNFα or IL-1 and requires caspase activity. Thus, TNFα or IL-1 treatment of ECs leads to caspase proteolytic activity that cleaves interleukin-1 receptor-2, allowing IL-1α dissociation and subsequent processing by calpain. Importantly, ECs could be primed by IL-1α from adjacent damaged VSMCs, and necrotic ECs could activate neighboring normal ECs and VSMCs, causing them to release inflammatory cytokines and up-regulate adhesion molecules, thus amplifying inflammation. These data unravel the molecular mechanisms and interplay between damaged ECs and VSMCs that lead to activation of IL-1α and, thus, initiation of adaptive responses that cause graft rejection.     

CCDC61/VFL3 Is a Paralog of SAS6 and Promotes Ciliary Functions

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The binding,transport and fate of aluminium in biological cells

Aluminium is the most abundant metal in the Earth's crust and yet, paradoxically, it has no known biological function. Aluminium is biochemically reactive, it is simply that it is not required for any essential process in extant biota. There is evidence neither of element-specific nor evolutionarily conserved aluminium biochemistry. This means that there are no ligands or chaperones which are specific to its transport, there are no transporters or channels to selectively facilitate its passage across membranes, there are no intracellular storage proteins to aid its cellular homeostasis and there are no pathways which evolved to enable the metabolism and excretion of aluminium. Of course, aluminium is found in every compartment of every cell of every organism, from virus through to Man. Herein we have investigated each of the ‘silent’ pathways and metabolic events which together constitute a form of aluminium homeostasis in biota, identifying and evaluating as far as is possible what is known and, equally importantly, what is unknown about its uptake, transport, storage and excretion.     

Diel fragrance pattern correlates with olfactory preferences of diurnal and nocturnal flower visitors in Salix caprea (Salicaceae)

Floral scent, often a complex mixture of several volatile organic compounds (VOCs), has generally been interpreted as an adaptation to attract pollinators. However, not many studies have analysed which VOCs are functionally relevant for the reproductive success of a plant. Here, we show that, in Salix caprea (Salicaceae), temporal changes in floral scent emission during the day and night attract two different types of flower visitor: bees during the day and moths during the evening and night. We analysed the contribution of the two flower visitor groups to the reproductive success of the plant. The differences in scent emitted during the peak activity times of flower visitors (day versus night) were quantified and the response of 13 diurnal/nocturnal pollinator taxa to the floral scents was tested using gas chromatographic and electroantennographic techniques. Many of the c. 40 identified scent compounds were physiologically active, and bees and moths responded to nearly identical sets of compounds, although the response strengths differed. In bioassays, bees preferred the most abundant 1,4‐dimethoxybenzene over lilac aldehyde, a compound with increased emission at night, whereas moths preferred lilac aldehyde over 1,4‐dimethoxybenzene. Pollination by wind plus nocturnal pollinators (mainly moths) or by wind alone contributed less to seed set than pollination by wind plus diurnal pollinators (mainly bees). This suggests that the emission of scent during the night and attracting moths have no significant effect on reproductive success. It is possible that the emission of lilac aldehydes and other compounds at night is s result of phylogenetic constraints. Future studies should investigate whether moths may produce a marginal fitness gain in some years and/or some populations. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 175 , 624–640.     

Regeneration of a Gentiana pneumonanthe population in an oligotrophic wet meadow

Abstract. The aim of this study was to evaluate the critical phases of the life cycle of Gentiana pneumonanthe, the marsh gentian, a threatened species of the Bohemian flora. The effect of various conditions on germination and seedling establishment and the possible effect of competition on the performance of the species were tested. Seeds were sown in plots which were subjected to four treatments in a randomized complete blocks experiment: unmanaged meadow, mown meadow, burned meadow, and meadow with cut sod. The significantly highest recruitment was found in plots with cut sod, the lowest in the unmanaged control plots. Seedling survival also differed among the treatments. In the following year surviving individuals were only found in plots with cut sod. The influence of neighbouring vegetation on target gentian individuals was evaluated by removing the surrounding vegetation and comparing the performance of these individuals with controls. The initial height of each individual was measured and used as a covariable. No significant effect of neighbouring vegetation on performance was detected. Thus, the establishment phase appears to be critical for population persistence and is also more influenced by the management regime than other stages of the life cycle.     

Structure of a fully assembled tumor-specific T cell receptor ligated by pMHC

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Cardboard nesting cavities may promote the development of Osmia cornuta and reduce infestation of kleptoparasitic mites

Mason bees (Osmia spp.) are receiving increasing attention as they are very effective pollinators of multiple crops. However, different bee-associated kleptoparasites are known which can be detrimental to the development of the bees’ offspring. To date, clear evidence-based guidelines to control these kleptoparasites are lacking for growers. This study investigates whether different types of artificial nesting materials—cardboard tubes and wooden grooved boards—influence the development of the European orchard bee (Osmia cornuta) as well as the infestation rate of kleptoparasitic mites in the bees’ nest. This preliminary study provides insight that cardboard tubes reduce the infestation rate of mites by 81.8% and as such promote successful development of the European orchard bee by 15.5%. Using cardboard tubes over wooden grooved boards should be advised to growers as an effective management strategy to avoid infestation of kleptoparasitic mites and to enhance successful bee development.