Hypoglycemic mechanism of Tegillarca granosa polysaccharides on type 2 diabetic mice by altering gut microbiota and regulating the PI3K-akt signaling pathwaye

Type 2 diabetes mellitus(T2DM)is a complex metabolic disease threatening human health.We investigated the effects of Tegillarca granosa polysaccharide(TGP)and determined its potential mechanisms in a mouse model of T2DM established through a high-fat diet and streptozotocin.TGP(5.1×10^(3) Da)was composed of mannose,glucosamine,rhamnose,glucuronic acid,galactosamine,glucose,galactose,xylose,and fucose.It could significantly alleviate weight loss,reduce fasting blood glucose levels,reverse dyslipidemia,reduce liver damage from oxidative stress,and improve insulin sensitivity.RT-PCR and Western blotting indicated that TGP could activate the phosphatidylinositol-3-kinase/protein kinase B signaling pathway to regulate disorders in glucolipid metabolism and improve insulin resistance.TGP increased the abundance of Allobaculum,Akkermansia,and Bifidobacterium,restored the microbiota abundance in the intestinal tracts of mice with T2DM,and promoted short-chain fatty acid production.This study provides new insights into the antidiabetic effects of TGP and highlights its potential as a natural hypoglycemic nutraceutical.

Metagenomic analysis revealing the metabolic role of microbial communities in the free amino acid biosynthesis of Monascus rice vinegar during fermentation

Free amino acid(FAA)is the important component of vinegar that infl uences quality perception and consumer acceptance.FAA is one of the major metabolites produced by microorganisms;however,the microbial metabolic network on FAA biosynthesis remains unclear.Through metagenomic analysis,this work aimed to elucidate the roles of microbes in FAA biosynthesis during Monascus rice vinegar fermentation.Taxonomic profiles from functional analyses showed 14 dominant genera with high contributions to the metabolism pathways.The metabolic network for FAA biosynthesis was then constructed,and the microbial distribution in different metabolic pathways was illuminated.The results revealed that 5 functional genera were closely involved in FAA biosynthesis.This study illuminated the metabolic roles of microorganisms in FAA biosynthesis and provided crucial insights into the functional attributes of microbiota in vinegar fermentation.

不同产地“宁杞1号”枸杞果实的多糖合成代谢差异

基于同位素标记相对和绝对定量(isobaric tags for relative and absolute quantity,iTRAQ)技术,以采自宁夏中宁的“宁杞1号”枸杞果实为样品,以采自新疆精河、内蒙古乌拉特前旗、甘肃瓜州和青海德令哈的“宁杞1号”枸杞果实为对照,进行差异蛋白组学的生物信息学分析。结果表明,新疆/宁夏组、内蒙古/宁夏组、甘肃/宁夏组和青海/宁夏组分别有446,166,966个和1015个差异表达蛋白(DEPs),与枸杞多糖合成代谢相关的DEPs共160个。进一步筛选得到23个与枸杞多糖相关DEPs,包括蔗糖磷酸合成酶、β-葡萄糖苷酶和α-半乳糖苷酶等。推测采自不同产地的枸杞果实的多糖合成代谢差异通路主要包括蔗糖、纤维素、半乳聚糖、半纤维素和果胶合成代谢过程,且这些过程均可通过UDP-葡萄糖链接在一起。通过蛋白组学分析枸杞多糖合成途径上的相关蛋白,为深入研究不同产地同种枸杞多糖调控机制提供理论参考。

De novo nucleotide biosynthetic pathway and cancer

De novo nucleotide biosynthetic pathway is a highly conserved and essential biochemical pathway in almost all organisms.Both purine nucleotides and pyrimidine nucleotides are necessary for cell metabolism and proliferation.Thus,the dysregulation of the de novo nucleotide biosynthetic pathway contributes to the development of many human diseases,such as cancer.It has been shown that many enzymes in this pathway are overactivated in different cancers.In this review,we summarize and update the current knowledge on the de novo nucleotide biosynthetic pathway,regulatory mechanisms,its role in tumorigenesis,and potential targeting opportunities.

花脸香蘑荧光定量PCR内参基因筛选及多糖合成代谢相关基因表达量测定

对适用于花脸香蘑(Lepista sordida)荧光定量PCR内参基因进行筛选,并检测花脸香蘑高产胞外多糖诱变菌株LS01_10_9及其出发菌株LS01_10多糖合成途径关键基因和多糖代谢途径基因表达量。结果表明:核糖体蛋白L4(ribosomal protein L4,rpl4)基因和3-磷酸甘油脱氢酶(glyceraldehyde-3-phosphate dehydrogenase,gapdh)基因表达丰度高、扩增效率较好且稳定,是花脸香蘑荧光定量PCR理想的内参基因。与出发菌株LS01_10比较,高产胞外多糖诱变菌株LS01_10_9中5个参与多糖合成途径的关键基因GK、GMD-3、UGE、UGDG、PFK表达量显著增加,4个参与多糖代谢途径的基因GT-1、GT-2、NOX-3、NOX-4表达量显著增加。

Cell-free protein synthesis enabled rapid prototyping for metabolic engineering and synthetic biology

Advances in metabolic engineering and synthetic biology have facilitated the manufacturing of many valuable-added compounds and commodity chemicals using microbial cell factories in the past decade.However,due to complexity of cellular metabolism,the optimization of metabolic pathways for maximal production represents a grand challenge and an unavoidable barrier for metabolic engineering.Recently,cell-free protein synthesis system(CFPS)has been emerging as an enabling alternative to address challenges in biomanufacturing.This review summarizes the recent progresses of CFPS in rapid prototyping of biosynthetic pathways and genetic circuits(biosensors)to speed up design-build-test(DBT)cycles of metabolic engineering and synthetic biology.