Steroidal glycosides from the bulbs of Lilium dauricum.

The bulbs of Lilium dauricum yielded 11 compounds, including six new steroidal glycosides. The structures have been determined by spectral analysis and hydrolysis to be (25R,26R)-26-methoxyspirost-5-en-3 beta-ol 3-O-alpha-L-rhamnopyranosyl-(1----2)-O-[alpha-L-arabinopyranosyl-( 1----3)]- beta-D-glucopyranoside, (25R,26R)-26-methoxyspirost-5-en-3 beta-ol 3-O-alpha-L-rhamnopyranosyl-(1----2)-O-[beta-D-glucopyranosyl-(1----4)]- beta-D-glucopyranoside, (25R)-spirost-5-en-3 beta-ol (diosgenin) 3-O-alpha-L-rhamnopyranosyl-(1----2)-O-[alpha-L-arabinopyranosyl- (1----3)]-beta-D-glucopyranoside, (25R)-3 beta,17 alpha-dihydroxy-5 alpha-spirostan-6-one 3-O-alpha-L-rhamnopyranosyl-(1----2)-beta-D-glucopyranoside, (25R)-3 beta, 17 alpha-dihydroxy-5 alpha-spirostan-6-one 3-O-alpha-L-rhamnopyranosyl-(1----2)-O-[alpha-L- arabinopyranosyl-(1----3)]-beta-D-glucopyranoside and (20R,22R)-3 beta,20,22-trihydroxy-5 alpha-cholestan-6-one (tenuifoliol) 3-O-alpha-L-rhamnopyranosyl-(1----2)-beta-D-glucopyranoside. The absolute configurations of C-20 and C-22 of tenuifoliol were further confirmed by detailed analysis of the NOE difference spectrum of the corresponding isopropylidene derivative. Several known compounds were also isolated and identified.     

Perception of Graphical Virtual Environments by Blind Users via Sensory Substitution

Graphical virtual environments are currently far from accessible to blind users as their content is mostly visual. This is especially unfortunate as these environments hold great potential for this population for purposes such as safe orientation, education, and entertainment. Previous tools have increased accessibility but there is still a long way to go. Visual-to-audio Sensory-Substitution-Devices (SSDs) can increase accessibility generically by sonifying on-screen content regardless of the specific environment and offer increased accessibility without the use of expensive dedicated peripherals like electrode/vibrator arrays. Using SSDs virtually utilizes similar skills as when using them in the real world, enabling both training on the device and training on environments virtually before real-world visits. This could enable more complex, standardized and autonomous SSD training and new insights into multisensory interaction and the visually-deprived brain. However, whether congenitally blind users, who have never experienced virtual environments, will be able to use this information for successful perception and interaction within them is currently unclear.We tested this using the EyeMusic SSD, which conveys whole-scene visual information, to perform virtual tasks otherwise impossible without vision. Congenitally blind users had to navigate virtual environments and find doors, differentiate between them based on their features (Experiment1:task1) and surroundings (Experiment1:task2) and walk through them; these tasks were accomplished with a 95% and 97% success rate, respectively. We further explored the reactions of congenitally blind users during their first interaction with a more complex virtual environment than in the previous tasks–walking down a virtual street, recognizing different features of houses and trees, navigating to cross-walks, etc. Users reacted enthusiastically and reported feeling immersed within the environment. They highlighted the potential usefulness of such environments for understanding what visual scenes are supposed to look like and their potential for complex training and suggested many future environments they wished to experience.     

CCAAT/enhancer-binding protein beta (C/EBPβ) knockdown reduces inflammation,ER stress,and apoptosis,and promotes autophagy in oxLDL-treated RAW264.7 macrophage cells

Molecular and Cellular Biochemistry - Atherosclerosis is associated with deregulated cholesterol metabolism and formation of macrophage foam cells. CCAAT/enhancer-binding protein beta (C/EBPβ)...     

Understanding How Noncatalytic Carbohydrate Binding Modules Can Display Specificity for Xyloglucan

Plant biomass is central to the carbon cycle and to environmentally sustainable industries exemplified by the biofuel sector. Plant cell wall degrading enzymes generally contain noncatalytic carbohydrate binding modules (CBMs) that fulfil a targeting function, which enhances catalysis. CBMs that bind β-glucan chains often display broad specificity recognizing β1,4-glucans (cellulose), β1,3-β1,4-mixed linked glucans and xyloglucan, a β1,4-glucan decorated with α1,6-xylose residues, by targeting structures common to the three polysaccharides. Thus, CBMs that recognize xyloglucan target the β1,4-glucan backbone and only accommodate the xylose decorations. Here we show that two closely related CBMs, CBM65A and CBM65B, derived from EcCel5A, a Eubacterium cellulosolvens endoglucanase, bind to a range of β-glucans but, uniquely, display significant preference for xyloglucan. The structures of the two CBMs reveal a β-sandwich fold. The ligand binding site comprises the β-sheet that forms the concave surface of the proteins. Binding to the backbone chains of β-glucans is mediated primarily by five aromatic residues that also make hydrophobic interactions with the xylose side chains of xyloglucan, conferring the distinctive specificity of the CBMs for the decorated polysaccharide. Significantly, and in contrast to other CBMs that recognize β-glucans, CBM65A utilizes different polar residues to bind cellulose and mixed linked glucans. Thus, Gln¹⁰⁶ is central to cellulose recognition, but is not required for binding to mixed linked glucans. This report reveals the mechanism by which β-glucan-specific CBMs can distinguish between linear and mixed linked glucans, and show how these CBMs can exploit an extensive hydrophobic platform to target the side chains of decorated β-glucans.     

Cole Disease Results from Mutations in ENPP1

The coexistence of abnormal keratinization and aberrant pigmentation in a number of cornification disorders has long suggested a mechanistic link between these two processes. Here, we deciphered the genetic basis of Cole disease, a rare autosomal-dominant genodermatosis featuring punctate keratoderma, patchy hypopigmentation, and uncommonly, cutaneous calcifications. Using a combination of exome and direct sequencing, we showed complete cosegregation of the disease phenotype with three heterozygous ENPP1 mutations in three unrelated families. All mutations were found to affect cysteine residues in the somatomedin-B-like 2 (SMB2) domain in the encoded protein, which has been implicated in insulin signaling. ENPP1 encodes ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1), which is responsible for the generation of inorganic pyrophosphate, a natural inhibitor of mineralization. Previously, biallelic mutations in ENPP1 were shown to underlie a number of recessive conditions characterized by ectopic calcification, thus providing evidence of profound phenotypic heterogeneity in ENPP1-associated genetic diseases.     

The sulfamide moiety affords higher inhibitory activity and oral bioavailability to a series of coumarin dual selective RAF/MEK inhibitors

Introducing a sulfamide moiety to our coumarin derivatives afforded enhanced Raf/MEK inhibitory activity concomitantly with an acceptable PK profile. Novel sulfamide 17 showed potent HCT116 cell growth inhibition (IC₅₀ = 8 nM) and good PK profile (bioavailability of 51% in mouse), resulting in high in vivo antitumor efficacy in the HCT116 xenograft (ED₅₀ = 4.8 mg/kg). We confirmed the sulfamide moiety showed no negative impact on tests run on the compound to evaluate DMPK (PK profiles in three animal species, CYP inhibition and CYP induction) and the safety profile (hERG and AMES tests). Sulfamide 17 had favorable properties that warranted further preclinical assessment     

Neutralization of pro‐inflammatory monocytes by targeting TLR2 dimerization ameliorates colitis

Monocytes have emerged as critical driving force of acute inflammation. Here, we show that inhibition of Toll‐like receptor 2(TLR2) dimerization by a TLR2 transmembrane peptide (TLR2‐p) ameliorated DSS‐induced colitis by interfering specifically with the activation of Ly6C⁺ monocytes without affecting their recruitment to the colon. We report that TLR2‐p directly interacts with TLR2 within the membrane, leading to inhibition of TLR2–TLR6/1 assembly induced by natural ligands. This was associated with decreased levels of extracellular signal‐regulated kinases (ERK) signaling and reduced secretion of pro‐inflammatory cytokines, such as interleukin (IL)‐6, IL‐23, IL‐12, and IL‐1β. Altogether, our study provides insights into the essential role of TLR2 dimerization in the activation of pathogenic pro‐inflammatory Ly6C^hi monocytes and suggests that inhibition of this aggregation by TLR2‐p might have therapeutic potential in the treatment of acute gut inflammation.     

Protozoa populations are ecosystem engineers that shape prokaryotic community structure and function of the rumen microbial ecosystem

Unicellular eukaryotes are an integral part of many microbial ecosystems where they interact with their surrounding prokaryotic community—either as predators or as mutualists. Within the rumen, one of the most complex host-associated microbial habitats, ciliate protozoa represent the main micro-eukaryotes, accounting for up to 50% of the microbial biomass. Nonetheless, the extent of the ecological effect of protozoa on the microbial community and on the rumen metabolic output remains largely understudied. To assess the role of protozoa on the rumen ecosystem, we established an in-vitro system in which distinct protozoa sub-communities were introduced to the native rumen prokaryotic community. We show that the different protozoa communities exert a strong and differential impact on the composition of the prokaryotic community, as well as its function including methane production. Furthermore, the presence of protozoa increases prokaryotic diversity with a differential effect on specific bacterial populations such as Gammaproteobacteria, Prevotella and Treponema. Our results suggest that protozoa contribute to the maintenance of prokaryotic diversity in the rumen possibly by mitigating the effect of competitive exclusion between bacterial taxa. Our findings put forward the rumen protozoa populations as potentially important ecosystem engineers for future microbiome modulation strategies.Subject terms: Microbial ecology, Food webs