As the components of proteoglycans, glycosaminoglycans (GAGs) are linear polysaccharides consisting of hexose and uronic acid units linked by β-1,3-glycosidic bond. GAGs mainly distribute in extracellular matrix and on cell surfaces. They guide many biological processes, such as proliferation of cells, transmission of signals and mediation of inflammation. Because of their large molecular weights, GAGs have limited biological functions in vitro. However, the appearance of chondroitinase ABC (ChSase ABC), which can lyse polysaccharides, solves the difficulties. Based on our work, we summarized the classification and the crystal structure of ChSase ABC, as well as other recent research progress on ChSase ABCs. The separation and purification methods of ChSase ABC and construction of engineering bacteria are illustrated. The stability and immobilization are also analyzed by taking account of the characterization of ChSase ABC. Finally, problems and future prospect of the ChSase ABC study are summarized.
Bacteria ; Chondroitin ABC Lyase ; chemistry ; Extracellular Matrix ; chemistry ; Glycosaminoglycans ; chemistry ; Proteoglycans ; chemistry

Intestinal dysbiosis and disrupted bile acid(BA)homeostasis are associated with obesity,but the precise mechanisms remain insufficiently explored.Hepatic protein phosphatase 1 regulatory subunit 3G(PPP1R3G)plays a pivotal role in regulating glycolipid metabolism;nevertheless,its obesity-combatting potency remains unclear.In this study,a substantial reduction was observed in serum PPP1R3G levels in high-body mass index(BMI)and high-fat diet(HFD)-exposed mice,establishing a positive correlation between PPP1R3G and non-12α-hydroxylated(non-12-OH)BA content.Additionally,hepatocyte-specific overexpression of Ppp1r3g(PPP1R3G HOE)mitigated HFD-induced obesity as evidenced by reduced weight,fat mass,and an improved serum lipid profile;hepatic steatosis alleviation was confirmed by normalized liver enzymes and histology.PPP1R3G HOE considerably impacted systemic BA homeostasis,which notably increased the non-12-OH BAs ratio,particularly lithocholic acid(LCA).16S ribosomal DNA(16S rDNA)sequencing assay indicated that PPP1R3G HOE reversed HFD-induced gut dysbiosis by reducing the Firmicutes/Bacteroidetes ratio and Lactobacillus population,and elevating the relative abundance of Blautia,which exhibited a positive correlation with serum LCA levels.A fecal microbiome transplantation test confirmed that the anti-obesity effect of hepatic PPP1R3G was gut microbiota-dependent.Mechanistically,PPP1R3G HOE markedly suppressed hepatic cholesterol 7α-hydroxylase(CYP7A1)and sterol-12α-hydroxylase(CYP8B1),and concurrently upregulated oxysterol 7-α hydroxylase and Takeda G protein-coupled BA receptor 5(TGR5)expression under HFD conditions.Furthermore,LCA administration significantly mitigated the HFD-induced obesity phenotype and elevated non-12-OH BA levels.These findings emphasize the significance of hepatic PPP1R3G in ameliorating diet-induced adiposity and hepatic steatosis through the gut microbiota-BA axis,which may serve as potential ther-apeutic targets for obesity-related disorders.

Objective:To evaluate the quantitative diagnostic value of controlled attenuation parameter (CAP) in health checkup groups with asymptomatic nonalcoholic fatty liver disease.Methods:A multicenter prospective study was conducted among Chinese individuals undergoing regular health checkups; a total of 173 subjects were investigated. Human body indexes such as height, weight, and blood pressure were measured, and complete blood count, liver function, blood lipid, FibroScan, and MRI-PDFF examinations were performed. Correlation between MRI-PDFF and CAP was described using Spearman′s and Pearson′s coefficients. Diagnostic efficacy of the CAP was evaluated using the subject work characteristic curve and the area under this curve, and the optimal cut-off value was determined according to the Youden index.Results:The average age and body mass index of the subjects were 45.0±10.5 years and 25.8±4.0 kg/m 2, respectively. A linear correlation was found between CAP and lg transformed magnetic resonance imaging-based proton density fat fraction results (Pearson′s coefficient 0.772, P<0.001). When optimized for ≥90% sensitivity, the CAP cutoff for staging ≥S1 steatosis was 244 dB/m. Conclusions:The CAP result was significantly correlated with the liver fat fraction measured by MRI-PDFF, and capable of differentiating steatosis grades. CAP can be used as a tool for screening fatty liver in health checkup groups.