Food-derived bio-functional peptides for the management of hyperuricemia and associated mechanism

Hyperuricemia,a metabolic disorder related to uric acid metabolism dysregulation,has become a common metabolic disease worldwide,due to changes in lifestyle and dietary structure.In recent years,owing to their high activity and few adverse effects,food-derived active peptides used as functional foods against hyperuricemia have attracted increasing attention.This article aims to focus on the challenge associated with peptide-specific preparation methods development,functional components identification,action mechanism(s)clarification,and bioavailability improvement.The current review proposed recent advances in producing the food-derived peptides with high anti-hyperuricemia activity by protein source screening and matched enzymatic hydrolysis condition adjusting,increased the knowledge about strategies to search antihyperuricemia peptides with definite structure,and emphasized the necessity of combining computer-aided approaches and activity evaluations.In addition,novel action mechanism mediated by gut microbiota was discussed,providing different insights from classical mechanism.Moreover,considering that little attention was paid previously on the structure-activity relationships of anti-hyperuricemia peptides,we collected the sequences from published studies and make a preliminary summary about the structure-activity relationships,which in turn provided guides for enzymatic hydrolysis optimization and bioavailability improvement.Hopefully,this article could promote the development,application and commercialization of food-derived anti-hyperuricemia peptides in the future.

Targeted screening of an anti-inflammatory polypeptide from Rhopilema esculentum Kishinouye cnidoblasts and elucidation of its mechanism in alleviating ulcerative colitis based on an analysis of the gut microbiota and metabolites

Ulcerative colitis(UC)is a recurrent inflammatory bowel disease that imposes a severe burden on families and society.In recent years,exploiting the potential of marine bioactive peptides for the treatment of diseases has become a topic of intense research interest.This study revealed the mechanism underlying the protective effect of the dominant polypeptide PKKVV(Pro-Lys-Lys-Val-Val)of Rhopilema esculentum cnidoblasts against DSS-induced UC through a combined analysis of the metagenome and serum metabolome.Specifically,the polypeptide composition of R.esculentum cnidoblasts was determined by matrix-assisted laser desorption ionization time-of-flight mass spectrometry(MALDI-TOF/TOF-MS).Molecular docking showed that the dominant peptide PKKVV could bind better with tumor necrosis factor-α(TNF-α)than the original ligand.Subsequent animal experiments suggested that PKKVV could modulate disorganized gut microorganisms in mice with UC;affect serum metabolites through the arachidonic acid,glycerophospholipid and linoleic acid metabolism pathways;and further alleviate UC symptoms.This study provides a reference for the comprehensive development of marine bioactive substances and nonpharmaceutical treatments for UC.

Corrigendum to “Peptide backbone-copper ring structure: A molecular insight into copper-induced amyloid toxicity”

The author list originally given in Wang et al. Chin. Phys. B 31 108702 (2022) has been amended to remove four authors, Hua Li, Bin Wu, Jun Guo and Chenqi Xu, who believe their contributions are more suitable to be credited in the acknowledgments.

Chinese Torreya grandis cv.Merrillii seed oil affects obesity through accumulation of sciadonic acid and altering the composition of gut microbiota

Torreya grandis cv.Merrillii(Taxace,Torreya)is mainly distributed across the hilly areas of subtropical China and is well known for its nutritional value.In this study,the ameliorative effects of T.grandis seed oil on lipid metabolism were investigated,and the underlying mechanism was explored from the perspective of gut microbiota.Mice experiments showed that the rate of body mass gain in the group where the mice were fed a high-fat diet(HFD)and supplemented with 550 mg/(kg·day)T.grandis seed oil(HFD+TO550 group)was 42.27%,while it was 62.25%in the HFD group.Compared with the HFD group,the liver and fat indices,total cholesterol,triglycerides,and low-density lipoprotein cholesterol were reduced in the oil-supplement groups.Moreover,the oil supplement significantly changed the fatty acid composition and alleviated pathological damage to the liver caused by the high-fat diet.Additionally,the distinct clustering of bacteria in the composition of gut microbiota was observed in the oil treatment group compared with that in the HFD group.T.grandis seed oil significantly increased the abundance of the beneficial bacteria and short-chain fatty acid producers,including Lactobacillus,Bifidobacterium,Faecalibaculum and Allobaculum.Our results suggest that the supplements of T.grandis seed oil could alleviate hyperlipidemia caused by HFD.These positive effects are considered to be related with sciadonic acid(SCA)and are partially mediated by alterations in gut microbiota composition and functionality.

Peptide backbone-copper ring structure:A molecular insight into copper-induced amyloid toxicity

Copper ions can promote amyloid diseases that are associated with amyloid peptides, such as type 2 diabetes(T2D),Alzheimer's disease(AD), Parkinson's disease(PD), and amyotrophic lateral sclerosis(ALS). However, the underlying molecular mechanism remains obscure. Here we present that Cu^(2+)is able to specifically bind to the backbone of T2D related human islet amyloid polypeptide(hIAPP) by forming a ring structure, which causes the reduction of Cu^(2+)to Cu^(+) to produce reactive oxygen species(ROS) and the modulation of hIAPP aggregation. Nuclear magnetic resonance spectroscopy showed that Cu^(2+)bound to the backbone of a turn region, His18-Ser21, which is critical for hIAPP aggregation.Ab initio calculations and x-ray absorption fine structure analyses revealed that Cu^(2+)simultaneously bound with both the amide nitrogen and carbonyl oxygen on the peptide backbone, resulting in a ring structure, and causing the reduction of Cu^(2+)to Cu^(+) to form a hIAPP-Cu^(+) complex. 2′,7′-dichlorodihydrofluorescin diacetate fluorescence measurements further indicated that this complex led to enhanced ROS levels in rat insulinoma cells. Additionally, thioflavin T fluorescence and atomic force microscopy measurements denoted that the backbone-Cu ring structure largely modulated hIAPP aggregation,including the inhibition of hIAPP fibrillation and the promotion of peptide oligomerization. These findings shed new light on the molecular mechanism of Cu^(2+)-induced amyloid toxicity involving both the enhancement of ROS and the modulation of hIAPP aggregation.

Protective effects and microarray-based mechanism of sea cucumber hydrolysates against high-glucose induced nephrotoxicity in mouse glomerulus mesangial cells

Diabetic nephropathy(DN)is a common type of end-stage renal disease and glomerular mesangial cells(GMCs)are widely used as a cell model for DN.This study firstly investigated the inhibitory effects of the Apostichopus japonicus and Acaudina leucoprocta hydrolysates on cellular growth under high-glucose treatment,better inhibitory effect of A.japonicus hydrolysate was observed compared to that of A.leucoprocta hydrolysate.Subsequently,the global transcription profiles obtained via microarray analysis showed that 6070 and 7015 genes were identified in the A.japonicus and A.leucoprocta groups compared with the model group,respectively.Among them,transcriptions of the slc30a4,slc35dl,tppp3,tp53inpl,bcl-2,apafl,alox12b and adrala genes were restored from the levels of the model group to those of the control group,contributed to cell mitosis and proliferation in both treatment groups.In addition,other apoptosis-related genes,such as bcl-6,clu,foxo3 and akt,showed opposite trends between two groups,which might cause the difference in inhibitory effect.We preliminarily proposed that the regulation effects of A.japonicus and A.leucoprocta on the genes involved in cellular mitosis,proliferation and apoptosis,might contribute to their inhibitory activity on GMCs under high-glucose environment.