Identification and Signature Sequences of Bacterial Δ4,5Hexuronate-2-O-Sulfatases

Glycosaminoglycan (GAG) sulfatases, which catalyze the hydrolysis of sulfate esters from GAGs, belong to a large and conserved sulfatase family. Bacterial GAG sulfatases are essential in the process of sulfur cycling and are useful for the structural analysis of GAGs. Only a few GAG-specific sulfatases have been studied in detail and reported to date. Herein, the GAG-degrading Photobacterium sp. FC615 was isolated from marine sediment, and a novel Δ4,5hexuronate-2-O-sulfatase (PB2SF) was identified from this bacterium. PB2SF specifically removed 2-O-sulfate from the unsaturated hexuronate residue located at the non-reducing end of GAG oligosaccharides produced by GAG lyases. A structural model of PB2SF was constructed through a homology-modeling method. Six conserved amino acids around the active site were chosen for further analysis using site-directed mutagenesis. N113A, K141A, K141H, H143A, H143K, H205A, and H205K mutants exhibited only feeble activity, while the H310A, H310K, and D52A mutants were totally inactive, indicating that these conserved residues, particularly Asp52 and His310, were essential in the catalytic mechanism. Furthermore, bioinformatic analysis revealed that GAG sulfatases with specific degradative properties clustered together in the neighbor-joining phylogenetic tree. Based on this finding, 60 Δ4,5hexuronate-2-O-sulfatases were predicted in the NCBI protein database, and one with relatively low identity to PB2SF was characterized to confirm our prediction. Moreover, the signature sequences of bacterial Δ4,5hexuronate-2-O-sulfatases were identified. With the reported signature motifs, the sulfatase sequence of the Δ4,5hexuronate-2-O-sulfatase family could be simply identified before cloning. Taken together, the results of this study should aid in the identification and further application of novel GAG sulfatases

Modulating gut microbiota and metabolites with dietary fiber oat β-glucan interventions to improve growth performance and intestinal function in weaned rabbits

The effect of oat β-glucan on intestinal function and growth performance of weaned rabbits were explored by multi-omics integrative analyses in the present study. New Zealand White rabbits fed oat β-glucan [200 mg/kg body weight (BW)] for 4 weeks, and serum markers, colon histological alterations, colonic microbiome, colonic metabolome, and serum metabolome were measured. The results revealed that oat β-glucan increased BW, average daily gain (ADG), average daily food intake (ADFI), and decreased serum tumor necrosis factor-α (TNF-α) interleukin-1β (IL-1β), and lipopolysaccharide (LPS) contents, but did not affect colonic microstructure. Microbiota community analysis showed oat β-glucan modulated gut microbial composition and structure, increased the abundances of beneficial bacteria Lactobacillus, Prevotellaceae_UCG-001, Pediococcus, Bacillus, etc. Oat β-glucan also increased intestinal propionic acid, valeric acid, and butyric acid concentrations, decreased lysine and aromatic amino acid (AAA) derivative contents. Serum metabolite analysis revealed that oat β-glucan altered host carbohydrate, lipid, and amino acid metabolism. These results suggested that oat β-glucan could inhibit systemic inflammation and protect intestinal function by regulating gut microbiota and related metabolites, which further helps to improve growth performance in weaned rabbits

Equilibrium Model of Housing Choice for Heterogeneous Households under Public Rental Housing Policy

The rapid development of urban rail transit system leads to the rising land rent and housing rent along the rail transit line. In order to respond to housing demand for low-income households, the public rental housing policy came into being. Public rental housing, with the advantage of lower rent than commercial housing, has become the primary choice for low-income households. However, the preset location of public rental housing is usually in the suburbs, separating the workplace and residence, which increases in travel cost. Consequently, it is particularly necessary to study the effect of public rental housing on the utilities of heterogeneous households from the perspective of transportation, and an equilibrium model of housing choice for heterogeneous households under public rental housing policy has been suggested in this paper. The result shows that the change in average operating speed of the rail may lead to the difference in urban residential formation and the increased speed of the rail may not be able to eliminate the location disadvantage of public rental housing. Furthermore, we find that ultra-limit public rental housing with the remote location is detrimental for low-income households. The model explicitly considers the interaction among the government, property developers, and heterogeneous households in the housing market, and can be utilized as an instruction for the future sustainable development of public rental housing

A novel Ag/AgO/carboxymethyl chitosan bacteriostatic hydrogel for drug delivery

pH-sensitive Ag/AgO/carboxymethyl chitosan (CMCS) bacteriostatic hydrogels and Ag/AgO/CMCS/Aspirin (ASP) carrier hydrogels were prepared by Ag/AgO in situ precipitation method, and the effects of swelling, degradation, drug release and antibacterial properties of hydrogels were studied. The network of Ag/AgO/CMCS/ASP drug-loaded gels produced was mainly cross-linking by hydrogen bonding and intermolecular forces, and the cross-linking silver was mainly present in the elemental Ag and Ag ^2+ states. Under the condition of buffer solution pH = 7.4, the cumulative release amount of Ag/AgO/CMCS/ASP drug-loaded gel was 75.20% within 12 h, and the inhibition rate of Gram-negative Escherichia coli ( E. coli ) reached the maximum of 92.32%, which had broad application prospects in the medical field

Disentangling the age-related manner in the associations between gut microbiome and women’s health: a multi-cohort microbiome study

ABSTRACTWomen’s health encompasses life-course healthcare, and mounting evidence emphasizes the pivotal contribution of gut microbiota. Therefore, understanding the temporal dynamics of gut microbiota and how age influences disease-gut microbiota associations is essential for improving women’s health. By analyzing metagenomic data from 3625 healthy women, we revealed significant effects of age on gut microbiota and age-dependent patterns in microbial features, such as relative abundance, Shannon index, and microbial network properties. Additionally, declining trends in the predictive accuracy of gut microbiota for age groups were shown using iterative sub-sampling based random forest (ISSRF) model. Age-specific species markers were also identified, many of which were shared across age groups. To investigate the influence of age on disease-gut microbiota associations, metagenomic data from 681 women with various disease conditions and 491 matched healthy controls were collected. A substantial proportion of species markers for inflammatory bowel disease (IBD), type 2 diabetes (T2D), atherosclerotic cardiovascular disease (ACVD), and impaired glucose tolerance (IGT) differed in relative abundance across age groups, and were also age-specific species markers. Besides, the microbiota-based probabilities of IBD and ACVD were positively correlated with age. Furthermore, the age specificity of disease-gut microbiota associations was explored using the ISSRF model. Associations between IBD and gut microbiota were age-specific, with reduced stability of disease species markers in childhood and adolescence, possibly due to decrease in the effect size between patients and controls. Our findings provided valuable insights into promoting healthy aging and developing personalized healthcare strategies for women