Fermentation characteristics and probiotic activity of a purified fraction of polysaccharides from Fuzhuan brick tea

Polysaccharides from Fuzhuan brick tea(FBTPS),one of most important bioactive components in tea,showed various health-promoting functions.Our previous work demonstrated that the crude FBTPS(CFBTPS)could modulate the gut microbiota.However,which purified fraction in CFBTPS contributing to the modulation of gut microbiota remains unclear.Thus,the fermentation characteristics and probiotic activity of a purified fraction(FBTPS-2-1)of CFBTPS were evaluated in this work.The results showed that gut microbiota could utilize FBTPS-2-1 to produce short-chain fatty acids including acetic,propionic,n-butyric and n-valeric acids.FBTPS-2-1 could modulate the structure and metabolic pathways of gut microbiota.FBTPS-2-1 could increase the health-promoting gut microbiota such as Prevotellaceae and Bifidobacteriaceae,and decreased the harmful bacteria such as Enterobacteriaceae and Fusobacteriaceae.The results of metagenomics showed that Prevotella copri and Megamonas funiformis were the dominant bacteria after fermentation of FBTPS-2-1.Furthermore,FBTPS-2-1 could regulate the biosynthesis and metabolism pathways of gut microbiota.Thus,the enrichment of food with FBTPS-2-1 is expected as a potential strategy for promoting human health due to modulation of gut microbiota.

Development of a radiolabeled site-specific single-domain antibody positron emission tomography probe for monitoring PD-L1 expression in cancer

Despite advances in immunotherapy for the treatment of cancers,not all patients can benefit from programmed cell death ligand 1(PD-L1)immune checkpoint blockade therapy.Anti-PD-L1 therapeutic effects reportedly correlate with the PD-L1 expression level;hence,accurate detection of PD-L1 expression can guide immunotherapy to achieve better therapeutic effects.Therefore,based on the high affinity antibody Nb109,a new site-specifically radiolabeled tracer,^(68)Ga-NODA-cysteine,aspartic acid,and valine(CDV)-Nb109,was designed and synthesized to accurately monitor PD-L1 expression.The tracer ^(68)Ga-NODA-CDV-Nb109 was obtained using a site-specific conjugation strategy with a radiochemical yield of about 95%and radiochemical purity of 97%.It showed high affinity for PD-L1 with a dissociation constant of 12.34±1.65 nM.Both the cell uptake assay and positron emission tomography(PET)imaging revealed higher tracer uptake in PD-L1-positive A375-hPD-L1 and U87 tumor cells than in PD-L1-negative A375 tumor cells.Meanwhile,dynamic PET imaging of a NCI-H1299 xenograft indicated that doxorubicin could upregulate PD-L1 expression,allowing timely interventional immunotherapy.In conclusion,this tracer could sensitively and dynamically monitor changes in PD-L1 expression levels in different cancers and help screen patients who can benefit from anti-PD-L1 immunotherapy.

Protective effects of peptide KSPLY derived from Hericium erinaceus on H_(2)O_(2)-induced oxidative damage in HepG2 cells

Reactive oxygen species(ROS)-induced oxidative damage is strongly associated with the pathogenesis of chronic diseases,and natural antioxidant peptides have good abilities of scavenging ROS.The antioxidant activity of peptide Lys-Ser-Pro-Leu-Tyr(KSPLY)derived from Hericium erinaceus remains unclear.In the present study,the antioxidant effect and mechanism of KSPLY on H_(2)O_(2)-induced oxidative damage in HepG2 cells were investigated.The results indicated that KSPLY exhibited the antioxidant capacity in H_(2)O_(2)-induced HepG2 cells by enhancing superoxide dismutase(SOD),glutathione peroxidase(GSH-Px),and catalase(CAT)activities.In comparison with the H_(2)O_(2)-treated damage group,the apoptosis rate,ROS level,and malondialdehyde(MDA)content of HepG2 cells treated with KSPLY were significantly decreased.The H.erinaceus-derived peptide KSPLY pretreatment promoted the expression of detoxification and antioxidant enzymes via the Keap1/Nrf2 signal pathway,thereby inhibiting the generation of ROS and MDA.In conclusion,the H.erinaceus-derived peptide KSPLY effectively protected HepG2 cells against H_(2)O_(2)-induced oxidative damage,and it provided a theoretical basis for the further development of new natural antioxidants.

Lipid-conjugated siRNA hitchhikes endogenous albumin for tumor immunotherapy

With the development of a small interfering RNA(siRNA)delivery strategy,increasing siRNA therapeutics for tumor treatment appeared in clinical trials and pre-clinical development.However,the test results of such therapeutics unveiled that efficient siRNA delivery to tumor tissues is still challenging.Albumin is considered an ideal carrier for delivering hydrophobic agents into tumor tissue because it is highly concentrated and long-circulating in blood and has propensity of tumor enrichment.Herein,we synthesized lipid conjugated siRNAs(LsiRNAs),which showed high affinity to albumin.Mechanistically,LsiRNAs non-covalently bind to the hydrophobic core of albumin through its octadecyl tails.The small size of albumin/LsiRNAs allows the complex to penetrate tumor tissue efficiently.Biodistribution test proved that albumin extremely prolonged circulation time and increased tumor retention of associated LsiRNAs.Notably,LsiRNA against programmed death ligand-1(Pdl1)efficiently suppressed tumor growth as well as prolonged survival time of tumor bearing mice by increasing infiltration of CD8^(+)T cells as well as promoted the maturation of dendritic cells both in tumor and lymph.Together,LsiRNAs provide a simple but effective way for siRNA tumor delivery that“hitchhikes”on albumin.

Bioactivities and molecular mechanisms of polysaccharides from Hericium erinaceus

Hericium erinaceus,an edible and medicinal mushroom,has been utilized since ancient China due to its delicious taste and health benefits.The polysaccharide from H.erinaceus(HEP)is supposed to be one of the major bioactive compounds,which garnered widespread attention in seeking innovative applications for precision nutrition.Both in vitro and in vivo studies have shown that HEP possesses antioxidant and anti-aging,gastrointestinal protecting,anti-tumor,hypolipidemic and hypoglycemic,immune-enhancing,neuroprotective,and hepatoprotective activities,verifying its functional benefits to human health.This review provides an overview of the extraction and structure of HEP,and concluded that HEP had different structures with different sources of H.erinaceus and extraction methods.Besides,the biochemical and pharmacological properties of HEP as well as the relative mechanism were highlighted and summarized on the basis of in vivo and in vitro studies,which could be helpful for the healthy application of HEP.Finally,the research prospects of HEP for specific populations or precision nutrition were proposed.

COVID-19 countermeasures of Chinese national athletes:Prevention,treatment,and return to play

Under the condition of normalized epidemic,how athletes train and compete well has been in the spotlight.This article reported the symptom,hospitalization and training situation of seven confirmed cases of coronavirusdisease-2019(COVID-19)among Chinese national teams.Moreover,the paper summarized the experience of Chinese national teams in terms of epidemic prevention and control,treatment of infection,and safe return to play.Through a scientific combination of medication and non-medical treatment,seven athletes were all discharged from the hospital.These discharged athletes underwent strict isolation and scientific training before returning to sports teams.Before returning to play,continuous monitoring of physical and mental condition was required.All seven athletes returned to play safely and performed excellently.As for hosting large-scale sporting events,the entire enclosed-loop management from immigration to competition was proposed in this paper.This study could serve as a standard of epidemic prevention and control,treatment for infection and safe return to play during competition and training around the world.