Antigen epitopes of animal coronaviruses:a mini-review

Coronaviruses are widespread in nature and can infect mammals and poultry,making them a public health concern.Globally,prevention and control of emerging and re-emerging animal coronaviruses is a great challenge.The mecha-nisms of virus-mediated immune responses have important implications for research on virus prevention and control.The antigenic epitope is a chemical group capable of stimulating the production of antibodies or sensitized lympho-cytes,playing an important role in antiviral immune responses.Thus,it can shed light on the development of diagnos-tic methods and novel vaccines.Here,we have reviewed advances in animal coronavirus antigenic epitope research,aiming to provide a reference for the prevention and control of animal and human coronaviruses.

Dietary bamboo leaf flavonoids improve quality and microstructure of broiler meat by changing untargeted metabolome

Background Dietary bamboo leaf flavonoids(BLFs)are rarely used in poultry production,and it is unknown whether they influence meat texture profile,perceived color,or microstructure.Results A total of 720 one-day-old Arbor Acres broilers were supplemented with a basal diet with 20 mg bacitracin/kg,50 mg BLFs/kg,or 250 mg BLFs/kg or without additions.Data showed that the dietary BLFs significantly(P<0.05)changed growth performance and the texture profile.In particular,BLFs increased birds’average daily gain and average daily feed intake,decreased the feed:gain ratio and mortality rate,improved elasticity of breast meat,enhanced the gumminess of breast and leg meat,and decreased the hardness of breast meat.Moreover,a significant(P<0.05)increase in redness(a*)and chroma(c*)of breast meat and c*and water-holding capacity of leg meat was found in BLF-supplemented broilers compared with control broilers.In addition,BLFs supplementation significantly decreased(P<0.05)theβ-sheet ratio and serum malondialdehyde and increased theβ-turn ratio of protein secondary structure,superoxide dismutase,and glutathione peroxidase of breast meat and total antioxidant capacity and catalase of serum.Based on the analysis of untargeted metabolome,BLFs treatment considerably altered 14 metabolites of the breast meat,including flavonoids,amino acids,and organic acids,as well as phenolic and aromatic compounds.Conclusions Dietary BLFs supplementation could play a beneficial role in improving meat quality and sensory color in the poultry industry by changing protein secondary structures and modulating metabolites.

Interplays of liver fibrosis-associated microRNAs:Molecular mechanisms and implications in diagnosis and therapy

microRNAs(miRNAs)are a class of non-coding functional small RNA composed of 21e23 nucleotides,having multiple associations with liver fibrosis.Fibrosis-associated miRNAs are roughly classified into pro-fibrosis or anti-fibrosis types.The former is capable of activating hepatic stellate cells(HSCs)by modulating pro-fibrotic signaling pathways,mainly including TGF-b/SMAD,WNT/b-catenin,and Hedgehog;the latter is responsible for maintenance of the quiescent phenotype of normal HSCs,phenotypic reversion of activated HSCs(aHSCs),inhibition of HSCs proliferation and suppression of the extracellular matrix-associated gene expression.Moreover,several miRNAs are involved in regulation of liver fibrosis via alternative mechanisms,such as interacting between hepatocytes and other liver cells via exosomes and increasing autophagy of aHSCs.Thus,understanding the role of these miRNAs may provide new avenues for the development of novel interventions against hepatic fibrosis.

Three Novel Avastroviruses Identified in Dead Wild Crows

Dear Editor,Astroviruses(AstVs)are non-enveloped,single-stranded RNA viruses with a diameter of approximately 35 nm(Madeley and Cosgrove 1975).The genomes of AstVs range in size from 6.8 to 7.9 kb(De Benedictis et al.2011),consisting of a 5'-untranslated region(UTR),three open reading frames(ORFs),a 3'-UTR,and a poly-adenylated(polyA)tail(Pantin-Jackwood et al.2006).In 1975,AstVs were first discovered in faeces of infants(Madeley and Cosgrove 1975).Until now,a variety of animal species,including cows,sheep,pigs,dogs,deer,rats,bats,chickens,ducks,turkeys,sea lions and seals have been reported to be infected with AstVs(Tzipori et al.1981;Cattoli et al.2007;Chu et al.2008,2010;Atkins et al.2009;Toffan et al.2009;Rivera et al.2010;Guix et al.2013;Kang et al.2012;Reuter et al.2012a,2012b;Li et al.2021).Currently,AstVs comprise two genera,Mamastrovirus(MAstV)and Avastrovirus(AAstV).Herein,we describe three novel AAstVs identified from dead crow tissues.To our knowledge,this is the first report for identification of AstVs in crows.

A GSH-depleted platinum(Ⅳ) prodrug triggers ferroptotic cell death in breast cancer

Cisplatin is the first-line drug for treatment of various solid tumors including breast cancer due to the broad anti-tumor spectrum and strong anti-tumor effect.However,serious side effects and long-term medication of reduced sensitivity by high GSH in tumor cells have severely restricted its further clinical application.Herein,a GSH-depleted Pt(Ⅳ)prodrug(Platin B)based on cisplatin and 4-carboxylphenylboronic acid pinacol ester was prepared to solve the problems.As an excellent GSH scavenger,4-carboxylphenylboronic acid pinacol ester could be activated by intracellular redox reactions to release quinone methide,thereby amplifying oxidative stress and leading to breast cancer ferroptosis therapy.Interestingly,the consumption of GSH can also reduce cisplatin inactivation,enhance the sensitivity of tumor cells to cisplatin and efficiently induce apoptosis/ferroptosis.This work highlights the use of GSH scavenger for triggering ferroptotic cell death in breast cancer.