Liquid–liquid phase separation (LLPS) compartmentalizes and concentrates biomacromolecules into distinct condensates. Liquid-like condensates can transition into gel and solid states, which are essential for fulfilling their different functions. LLPS plays important roles in multiple steps of autophagy, mediating the assembly of autophagosome formation sites, acting as an unconventional modulator of TORC1-mediated autophagy regulation, and triaging protein cargos for degradation. Gel-like, but not solid, protein condensates can trigger formation of surrounding autophagosomal membranes. Stress and pathological conditions cause aberrant phase separation and transition of condensates, which can evade surveillance by the autophagy machinery. Understanding the mechanisms underlying phase separation and transition will provide potential therapeutic targets for protein aggregation diseases.

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ObjectiveRecent studies have demonstrated that gut microbiota was closely related to metabolic disorders such as type 2 diabetes. Oral antidiabetic medications including metformin, acarbose and sitagliptin lowered blood glucose levels via acting on the gastrointestinal tract. The aim of the study was to observe the comparisons among those medications on gut microbiota composition.Research design and methodsZucker diabetic fatty rats (n=32) were randomly divided into four groups, and had respectively gastric administration of normal saline (control), metformin (215.15 mg/kg/day), acarbose (32.27 mg/kg/day), or sitagliptin (10.76 mg/kg/day) for 4 weeks. Blood glucose levels were measured during an intragastric starch tolerance test after the treatments. 16S rRNA gene sequencing was used to access the microbiota in the fecal samples.ResultsMetformin, acarbose, and sitagliptin monotherapy effectively decreased fasting and postprandial blood glucose levels (p<0.001). Acarbose group displayed specific cluster and enterotype mainly composed byRuminococcus 2whileLactobacilluswas the dominant bacterium in the enterotype of the other three groups. The relative abundance of generaRuminococcus 2andBifidobacteriumwas dramatically higher in acarbose group. Metformin and sitagliptin increased the relative abundance of genus Lactobacillus. Metagenomic prediction showed that the functional profiles of carbohydrate metabolism were enriched in acarbose group.ConclusionsMetformin, acarbose and sitagliptin exerted different effects on the composition of gut microbiota and selectively increased the beneficial bacteria. Supplementation with specific probiotics may further improve the hypoglycemic effects of the antidiabetic drugs.