Characterization of Inflammasomes and Their Regulation in the Red Fox.

BACKGROUND: Inflammasomes recognize endogenous and exogenous danger signals, and subsequently induce the secretion of IL-1ß. Studying inflammasomes in the red fox (Vulpes vulpes) is crucial for wildlife veterinary medicine, as it can help control inflammatory diseases in foxes. METHODS: We investigated the activation and intracellular mechanisms of three inflammasomes (NLRP3, AIM2, and NLRC4) in fox peripheral blood mononuclear cells (PBMCs), using established triggers and inhibitors derived from humans and mice. RESULTS: Fox PBMCs exhibited normal activation and induction of IL-1ß secretion in response to representative inflammasome triggers (ATP and nigericin for NLRP3, dsDNA for AIM2, flagellin for NLRC4). Additionally, PBMCs showed normal IL-1ß secretion when inoculated with inflammasome-activating bacteria. In inhibitors of the inflammasome signaling pathway, fox inflammasome activation was compared with mouse inflammasomes. MCC950, a selective NLRP3 inhibitor, suppressed the secretion of dsDNA- and flagellin-mediated IL-1ß in foxes, unlike mice. CONCLUSIONS: These findings suggest that NLRP3 may have a common role in dsDNA- and flagellin-mediated inflammasome activation in the red fox. It implies that this fox inflammasome biology can be applied to the treatment of inflammasome-mediated diseases in the red fox.

Focused Ion Beam-Induced Displacive Phase Transformation From Austenite to Martensite during Fabrication of Quenched and Partitioned Steel Micro-Pillar.

We report evidence of a displacive phase transformation from retained austenite to martensite during preparation of quenched and partitioned steel micro-pillars by using a focused ion beam (FIB) technique. The BCC phase produced by the FIB damage was identified as martensite. The invariant-plane strain surface relief associated with the martensitic transformation was observed in the retained austenite phase immediately after a FIB scan of the surface with the Ga+ ion beam. Use of a low acceleration voltage appears to lower the probability of the phase transformation, while a decrease of the acceleration voltage will result in an increase of the total milling time required to prepare a micro-pillar. This report addresses challenges related to the preparation of austenite micro-pillars by a conventional FIB technique.

Design for Fe-high Mn alloy with an improved combination of strength and ductility.

Recently, Fe-Mn twinning-induced plasticity steels with an austenite phase have been the course of great interest due to their excellent combination of tensile strength and ductility, which carbon steels have never been able to attain. Nevertheless, twinning-induced plasticity steels also exhibit a trade-off between strength and ductility, a longstanding dilemma for physical metallurgists, when fabricated based on the two alloy design parameters of stacking fault energy and grain size. Therefore, we investigated the tensile properties of three Fe-Mn austenitic steels with similar stacking fault energy and grain size, but different carbon concentrations. Surprisingly, when carbon concentration increased, both strength and ductility significantly improved. This indicates that the addition of carbon resulted in a proportionality between strength and ductility, instead of a trade-off between those characteristics. This new design parameter, C concentration, should be considered as a design parameter to endow Fe-Mn twinning-induced plasticity steel with a better combination of strength and ductility.

Column chromatography-free solution-phase synthesis of a natural piper-amide-like compound library.

We have achieved an efficient solution-phase parallel synthesis of a library of natural piper-amide-like compounds from the bifunctional ß-phosphono-N-hydroxy-succinimidyl ester intermediate. The primary important feature in our study is the construction of natural-product-like molecules through the adaptation of sophisticated organic reactions that create water-soluble byproducts for a chromatography-free purification. This simple and efficient method rapidly provides a combinatorial library of high yield and purity. The library was evaluated against GPCR targets to demonstrate its potential use as a tool for drug discovery and in chemical biology.

Pachastrissamine from Pachastrissa sp. inhibits melanoma cell growth by dual inhibition of Cdk2 and ERK-mediated FOXO3 downregulation.

Melanoma cells are relatively resistant to apoptosis compared with other tumor cell types, and thus, chemotherapy, radiotherapy and immunotherapy are not effective in treating melanoma. Pachastrissamine (PA) exhibits cytotoxic activity and promotes apoptosis in several cancer cells. However, its specific molecular mechanisms have not been characterized fully. This study investigated the antimelanoma effect of PA, an anhydrophytosphingosine derived from marine sponge, and its underlying molecular mechanisms. The data demonstrated that treatment with PA inhibited the phosphorylation of ERK and subsequent ERK-mediated FOXO3 phosphorylation in melanoma cells. Interestingly, PA did not inhibit AKT-mediated FOXO3 phosphorylation. Therefore, it appears that PA-induced apoptosis results from the inhibition of ERK. Furthermore, intravenous administration of PA was found to suppress melanoma cell growth in a C57BL6 mouse without causing side effects. Additionally, PA inhibited the production of Cdk2, which is involved in cell cycle regulation. Taken together, inhibition of melanoma cell growth by PA is a result of the inhibition of ERK-mediated FOXO3 downregulation and decreased Cdk2 levels. The results of this study imply that dual inhibition of the ERK pathway and cell cycle progression could be an effective approach to control the growth of melanoma cells.

Design and synthesis of pyrrolidine-containing sphingomimetics.

Based on the structures of natural sphingolipids, we designed heterocyclic sphingoid base mimetics in which the conformational restriction is introduced by incorporation of a pyrrolidine moiety between the 2-amino group and the C-4 carbon atom of the sphingoid base. Our synthesis features a regioselective nucleophilic ring opening of a cyclic sulfate with cyanide and subsequent manipulation of the cyanide group. During the course of synthesis, Staudinger-type reductive cyclization of 1,3-azido carboxylic acid and 1,4-azido alcohol offers a direct route to the five-membered pyrrolidone and pyrrolidine products. The preliminary biological evaluation indicates that the designed pyrrolidine analog is biologically active and its cytotoxic effect is associated with the induction of apoptosis.

Efficient and selective synthesis of D-arabino-, D-lyxo-, and D-xylo-phytosphingosine from D-ribo-phytosphingosine.

A new high-yield approach to the regio- and stereoselective synthesis of d-arabino-, D-lyxo-, and D-xylo-phytosphingosines from inexpensive D-ribo-phytosphingosine is described. The synthetic methodologies mainly rely on the selective configurational inversion of the stereocenter through a neighboring group participation mechanism.

Design, synthesis, and preliminary biological evaluation of a novel triazole analogue of ceramide.

The amide bond of ceramide was replaced by the non-hydrolyzable 1,2,3-triazole functionality. Click chemistry was employed for synthesis of the designed analogues. Our preliminary biological evaluation indicated that the amide moiety of ceramide is amenable to bioisosteric substitution with the triazole moiety. Some of the analogues were more potent than C2-ceramide as cytotoxic agents, and the observed cytotoxicity was possibly mediated through the induction of apoptosis.

Synthesis of pachastrissamine from phytosphingosine: a comparison of cyclic sulfate vs an epoxide intermediate in cyclization.

[reaction: see text] The syntheses of the cytotoxic natural product pachastrissamine and its unnatural 4-epi-congener were accomplished starting from a natural phytosphingosine. The relatively unstrained cyclic sulfate intermediate smoothly underwent the 5-endo cyclization to yield the 2,3,4-trisubstituted tetrahydrofuran ring system of pachastrissamine. The corresponding epoxy alcohol afforded the 4-epi-congener via a tosylate-mediated double inversion process.

Efficient synthesis of D-erythro-sphingosine and D-erythro-azidosphingosine from D-ribo-phytosphingosine via a cyclic sulfate intermediate.

The synthesis of naturally occurring d-erythro-sphingosine and synthetically useful D-erythro-2-azidosphingosine from commercially available d-ribo-phytosphingosine is described. An important feature of this synthesis is the selective transformation of the 3,4-vicinal diol of phytosphingosine into the characteristic E-allylic alcohol of sphingosine via a cyclic sulfate intermediate.