Environmental enrichment in combination with Bifidobacterium breve HNXY26M4 intervention amplifies neuroprotective benefits in a mouse model of Alzheimer's disease by modulating glutamine metabolism of the gut microbiome

The gut microbiota-brain axis has emerged as a novel target for Alzheimer's disease(AD),a neurodegenerative disease characterised by behavioural and cognitive impairment.However,most previous microbiome-based intervention studies have focused on single factors and yielded only modest cognitive improvements.Here,we proposed a multidomain intervention strategy that combined Bifidobacterium breve treatment with environmental enrichment(EE)training.In this study,we found that compared with EE or B.breve treatment alone,B.breve intervention combined with EE amplified its neuroprotective effects on AD mice,as reflected by improved cognition,inhibited neuroinflammation and enhanced synaptic function.Moreover,using microbiome and metabolome profiling,we found that the combination of B.breve and EE treatment restored AD-related gut microbiota dysbiosis and reversed microbial metabolite changes.Finally,by integrating behavioural and neurological data with metabolomic profiles,we revealed that the underlying mechanism may involve the modulation of microbiota-derived glutamine metabolism via gut-brain interactions.Collectively,combined B.breve intervention with EE treatment can alleviate AD-related cognitive impairment and improve brain function by regulating glutamine metabolism of the gut microbiome.Our findings provide a promising multidomain intervention strategy,with a combination of dietary microbiome-based and lifestyle-targeted interventions,to promote brain function and delay the progression of AD.

Characterization of prognosis and immune infiltration by a novel glutamine metabolism-related model in cutaneous melanoma

Glutamine metabolism(GM)plays an important role in tumor growth and proliferation.Skin cutaneous melanoma(SKCM)is a glutamine-dependent cancer.However,the molecular characteristics and action mechanism of GM on SKCM remain unclear.Therefore,we aimed to explore the effects of GM-related genes on survival,clinicopathological characteristics,and the tumor microenvironment in SKCM.In this study,682 SKCM samples were obtained from the Cancer Genome Atlas(TCGA)and Gene Expression Omnibus(GEO)databases.Consensus clustering was used to classify SKCM samples into distinct subtypes based on 41 GM-related genes.Differences in survival,immune infiltration,clinical characteristics,and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathways as well as differentially expressed genes(DEGs)between subgroups were evaluated.A prognostic model was constructed according to prognostic DEGs.Differential analyses in survival,immune infiltration,tumor microenvironment(TME),tumor mutation burden(TMB),stemness,and drug sensitivity between risk groups were conducted.We identified two distinct GM-related subtypes on SKCM and found that GM-related gene alterations were associated with survival probability,clinical features,biological function,and immune infiltration.Then a risk model based on six DEGs(IL18,SEMA6A,PAEP,TNFRSF17,AIM2,and CXCL10)was constructed and validated for predicting overall survival in SKCM patients.The results showed that the risk score was negatively correlated with CD8+T cells,activated CD4+memory T cells,M1 macrophages,andγδT cells.The group with a low-risk score was accompanied by a better survival rate with higher TME scores and lower stemness index.Moreover,the group with high-and low-risk score had a significant difference with the sensitivity of 75 drugs(p<0.001).Overall,distinct subtypes in SKCM patients based on GM-related genes were identified and the risk model was constructed,which might contribute to prognosis prediction,guide clinical therapy,and develop novel therapeutic strategies.

Prognostic model and treatment plan analysis of hepatocellular carcinoma based on genes related to glutamine metabolism

Objective:To identify the prognosis of hepatocellular carcinoma(HCC)and the effect of anti-cancer drug therapy by screening glutamine metabolism-related signature genes because glutamine metabolism plays an important role in tumor development.Methods:We obtained gene expression samples of normal liver tissue and hepatocellular carcinoma from the TCGA database and GEO database,screened for differentially expressed glutamine metabolismrelated genes(GMRGs),constructed a prognostic model by lasso regression and step cox analysis,and assessed the differences in drug sensitivity between high-and low-risk groups.Results:We screened 23 differentially expressed GMRGs by differential analysis,and correlation loop plots and PPI protein interaction networks indicated that these differential genes were strongly correlated.The four most characterized genes(CAD,PPAT,PYCR3,and SLC7A11)were obtained by lasso regression and step cox,and a risk model was constructed and confirmed to have reliable predictive power in the TCGA dataset and GEO dataset.Finally,immunotherapy is better in the high-risk group than in the low-risk group,and chemotherapy and targeted drug therapy are better in the low-risk group than in the high-risk group.Conclusion:In conclusion,we have developed a reliable prognostic risk model characterized by glutamine metabolism-related genes,which may provide a viable basis for the prognosis and Treatment options of HCC patients.

The role of glutamine metabolism in castration-resistant prostate cancer

Reprogramming of metabolism is a hallmark of tumors,which has been explored for therapeutic purposes.Prostate cancer(PCa),particularly advanced and therapy-resistant PCa,displays unique metabolic properties.Targeting metabolic vulnerabilities in PCa may benefit patients who have exhausted currently available treatment options and improve clinical outcomes.Among the many nutrients,glutamine has been shown to play a central role in the metabolic reprogramming of advanced PCa.In addition to amino acid metabolism,glutamine is also widely involved in the synthesis of other macromolecules and biomasses.Targeting glutamine metabolic network by maximally inhibiting glutamine utilization in tumor cells may significantly add to treatment options for many patients.This review summarizes the metabolic landscape of PCa,with a particular focus on recent studies of how glutamine metabolism alterations affect therapeutic resistance and disease progression of PCa,and suggests novel therapeutic strategies.

Glutamine addiction and therapeutic strategies in pancreatic cancer

Pancreatic cancer remains one of the most lethal diseases worldwide owing to its late diagnosis,early metastasis,and poor prognosis.Because current therapeutic options are limited,there is an urgent need to investigate novel targeted treatment strategies.Pancreatic cancer faces significant metabolic challenges,principally hypoxia and nutrient deprivation,due to specific microenvironmental constraints,including an extensive desmoplastic stromal reaction.Pancreatic cancer cells have been shown to rewire their metabolism and energy production networks to support rapid survival and proliferation.Increased glucose uptake and glycolytic pathway activity during this process have been extensively described.However,growing evidence suggests that pancreatic cancer cells are glutamine addicted.As a nitrogen source,glutamine directly(or indirectly via glutamate conversion)contributes to many anabolic processes in pancreatic cancer,including amino acids,nucleobases,and hexosamine biosynthesis.It also plays an important role in redox homeostasis,and when converted toα-ketoglutarate,glutamine serves as an energy and anaplerotic carbon source,replenishing the tricarboxylic acid cycle intermediates.The present study aims to provide a comprehensive overview of glutamine metabolic reprogramming in pancreatic cancer,focusing on potential therapeutic approaches targeting glutamine metabolism in pancreatic cancer.

Review:Do Horses Receive Optimum Amounts of Glutamine in Their Diets?

In some species of growing mammals glutamine is an essential amino acid that,if inadequate in the diet,is needed for normal growth and development.It is thus sometimes considered to be a conditionally essential amino acid in some species.A review of studies that have measured L-glutamine concentrations([glutamine])in horses demonstrates that plasma[glutamine]has routinely been reported to be much lower(~330μmol/L)than in other mammals(>600μmol/L).Plasma[glutamine]represents the balance between intestinal transport into the blood after hepatic first pass,tissue synthesis and cellular extraction.The hypothesis is proposed that sustained low plasma[glutamine]represents a chronic state of sub-optimal glutamine intake and glutamine synthesis that does not meet the requirements for optimum health.While this may be without serious consequence in feral and sedentary horses,there is evidence that provision of supplemental dietary glutamine ameliorates a number of health consequences,particularly in horses with elevated metabolic demands.The present review provides evidence that glutamine is very important(and perhaps essential)for intestinal epithelial cells in mammals including horses,that horses with low plasma[glutamine]represents a sub-optimal state of well-being,and that horses supplemented with glutamine exhibit physiological and health benefits.

Anticancer Properties of Lobetyolin,an Essential Component of Radix Codonopsis(Dangshen)

Lobetyolin(LBT)is a polyacetylene glycoside found in diverse medicinal plants but mainly isolated from the roots of Codo-nopsis pilosula,known as Radix Codonopsis or Dangshen.Twelve traditional Chinese medicinal preparations containing Radix Codonopsis were identified;they are generally used to tonify spleen and lung Qi and occasionally to treat cancer.Here we have reviewed the anticancer properties of Codonopsis extracts,LBT and structural analogs.Lobetyolin and lobetyolinin are the mono-and bis-glucosylated forms of the polyacetylenic compound lobetyol.Lobetyol and LBT have shown activi-ties against several types of cancer(notably gastric cancer)and we examined the molecular basis of their activity.A down-regulation of glutamine metabolism by LBT has been evidenced,contributing to drug-induced apoptosis and tumor growth inhibition.LBT markedly reduces both mRNA and protein expression of the amino acid transporter Alanine-Serine-Cysteine Transporter 2(ASCT2).Other potential targets are proposed here,based on the structural analogy with other anticancer compounds.LBT and related polyacetylene glycosides should be further considered as potential anticancer agents,but more work is needed to evaluate their efficacy,toxicity,and risk-benefit ratio.

Curcumin Synergizes with Cisplatin to Inhibit Colon Cancer through Targeting the MicroRNA-137-Glutaminase Axis

Objective:Colorectal cancer(CRC)is one of the most lethal and prevalent malignancies world-wide.Currently,surgery,radiotherapy and chemotherapy are clinically applied as common approaches for CRC patients.Cisplatin is one of the most frequently used chemotherapy drugs for diverse cancers.Although chemotherapeutic strategies have improved the prognosis and survival of cancer patients,development of cisplatin resistance has led to cancer recurrence.Curcumin,isolated from turmeric,has been used as an effective anti-cancer agent.However,the molecular mechanisms for curcumin-mediated cisplatin sensitivity of CRC have not been elucidated.

Glutamine metabolic microenvironment drives M2 macrophage polarization tomediate trastuzumab resistance in HER2-positive gastric cancer

Background:Trastuzumab is a first-line targeted therapy for human epidermal growth factor receptor-2(HER2)-positive gastric cancer.However,the inevitable occurrence of acquired trastuzumab resistance limits the drug benefit,and there is currently no effective reversal measure.Existing researches on the mechanism of trastuzumab resistance mainly focused on tumor cells themselves,while the understanding of the mechanisms of environment-mediated drug resistance is relatively lacking.This study aimed to further explore the mechanisms of trastuzumab resistance to identify strategies to promote survival in these patients.Methods:Trastuzumab-sensitive and trastuzumab-resistant HER2-positive tumor tissues and cells were collected for transcriptome sequencing.Bioinformatics were used to analyze cell subtypes,metabolic pathways,and molecular signaling pathways.Changes in microenvironmental indicators(such as macrophage,angiogenesis,and metabolism)were verified by immunofluorescence(IF)and immunohistochemical(IHC)analyses.Finally,a multi-scale agent-based model(ABM)was constructed.The effects of combination treatment were further validated in nude mice to verify these effects predicted by the ABM.Results:Based on transcriptome sequencing,molecular biology,and in vivo experiments,we found that the level of glutamine metabolism in trastuzumabresistant HER2-positive cells was increased,and glutaminase 1(GLS1)was significantly overexpressed.Meanwhile,tumor-derived GLS1 microvesicles drove M2macrophage polarization.Furthermore,angiogenesis promoted trastuzumab resistance.IHC showed high glutamine metabolism,M2 macrophage polarization,and angiogenesis in trastuzumab-resistant HER2-positive tumor tissues from patients and nudemice.Mechanistically,the cell division cycle 42(CDC42)promoted GLS1 expression in tumor cells by activating nuclear factor kappa-B(NF-κB)p65 and drove GLS1microvesicle secretion through IQmotif-containing GTPase-activating protein 1(IQGAP1).Based on the ABM and in vivo experiments,we confirmed that the combination of anti-glutamine metabolism,anti-angiogenesis,and pro-M1 polarization therapy had the best effect in reversing trastuzumab resistance in HER2-positive gastric cancer.Conclusions:This study revealed that tumor cells secrete GLS1 microvesicles via CDC42 to promote glutamine metabolism,M2 macrophage polarization,and pro-angiogenic function of macrophages,leading to acquired trastuzumab resistance in HER2-positive gastric cancer.A combination of anti-glutamine metabolism,anti-angiogenesis,and pro-M1 polarization therapy may provide a new insight into reversing trastuzumab resistance.

Targeting glutamine utilization to block metabolic adaptation of tumor cells under the stress of carboxyamidotriazole-induced nutrients unavailability

Tumor cells have unique metabolic programming that is biologically distinct from that of corresponding normal cells.Resetting tumor metabolic programming is a promising strategy to ameliorate drug resistance and improve the tumor microenvironment.Here,we show that carboxyamidotriazole(CAI),an anticancer drug,can function as a metabolic modulator that decreases glucose and lipid metabolism and increases the dependency of colon cancer cells on glutamine metabolism.CAI suppressed glucose and lipid metabolism utilization,causing inhibition of mitochondrial respiratory chain complex I,thus producing reactive oxygen species(ROS).In parallel,activation of the aryl hydrocarbon receptor(Ah R)increased glutamine uptake via the transporter SLC1A5,which could activate the ROS-scavenging enzyme glutathione peroxidase.As a result,combined use of inhibitors of GLS/GDH1,CAI could effectively restrict colorectal cancer(CRC)energy metabolism.These data illuminate a new antitumor mechanism of CAI,suggesting a new strategy for CRC metabolic reprogramming treatment.

A metabolic intervention strategy to break evolutionary adaptability of tumor for reinforced immunotherapy

The typical hallmark of tumor evolution is metabolic dysregulation.In addition to secreting immunoregulatory metabolites,tumor cells and various immune cells display different metabolic pathways and plasticity.Harnessing the metabolic differences to reduce the tumor and immunosuppressive cells while enhancing the activity of positive immunoregulatory cells is a promising strategy.We develop a nanoplatform(CLCeMOF)based on cerium metal-organic framework(CeMOF)by lactate oxidase(LOX)modification and glutaminase inhibitor(CB839)loading.The cascade catalytic reactions induced by CLCeMOF generate reactive oxygen species“storm”to elicit immune responses.Meanwhile,LOX-mediated metabolite lactate exhaustion relieves the immunosuppressive tumor microenvironment,preparing the ground for intracellular regulation.Most noticeably,the immunometabolic checkpoint blockade therapy,as a result of glutamine antagonism,is exploited for overall cell mobilization.It is found that CLCeMOF inhibited glutamine metabolism-dependent cells(tumor cells,immunosuppressive cells,etc.),increased infiltration of dendritic cells,and especially reprogrammed CD8^(+)T lymphocytes with considerable metabolic flexibility toward a highly activated,long-lived,and memory-like phenotype.Such an idea intervenes both metabolite(lactate)and cellular metabolic pathway,which essentially alters overall cell fates toward the desired situation.Collectively,the metabolic intervention strategy is bound to break the evolutionary adaptability of tumors for reinforced immunotherapy.

Metabolic dysregulation and emerging therapeutical targets for hepatocellular carcinoma

Hepatocellular carcinoma(HCC)is an aggressive human cancer with increasing incidence worldwide.Multiple efforts have been made to explore pharmaceutical therapies to treat HCC,such as targeted tyrosine kinase inhibitors,immune based therapies and combination of chemotherapy.However,limitations exist in current strategies including chemoresistance for instance.Tumor initiation and progression is driven by reprogramming of metabolism,in particular during HCC development.Recently,metabolic associated fatty liver disease(MAFLD),a reappraisal of new nomenclature for nonalcoholic fatty liver disease(NAFLD),indicates growing appreciation of metabolism in the pathogenesis of liver disease,including HCC,thereby suggesting new strategies by targeting abnormal metabolism for HCC treatment.In this review,we introduce directions by highlighting the metabolic targets in glucose,fatty acid,amino acid and glutamine metabolism,which are suitable for HCC pharmaceutical intervention.We also summarize and discuss current pharmaceutical agents and studies targeting deregulated metabolism during HCC treatment.Furthermore,opportunities and challenges in the discovery and development of HCC therapy targeting metabolism are discussed.

Biomimetic copper single-atom nanozyme system for self-enhanced nanocatalytic tumor therapy

Single-atom nanozymes(SAZs)with peroxidase(POD)-like activity have good nanocatalytic tumor therapy(NCT)capabilities.However,insufficient hydrogen peroxide(H2O2)and hydrogen ions in the cells limit their therapeutic effects.Herein,to overcome these limitations,a biomimetic single-atom nanozyme system was developed for self-enhanced NCT.We used a previously described approach to produce platelet membrane vesicles.Using a high-temperature carbonization approach,copper SAZs with excellent POD-like activity were successfully synthesized.Finally,through physical extrusion,a proton pump inhibitor(PPI;pantoprazole sodium)and the SAZs were combined with platelet membrane vesicles to create PPS.Both in vivo and in vitro,PPS displayed good tumor-targeting and accumulation abilities.PPIs were able to simultaneously regulate the hydrogen ion,glutathione(GSH),and H2O2 content in tumor cells,significantly improve the catalytic ability of SAZs,and achieve self-enhanced NCT.Our in vivo studies showed that PPS had a tumor suppression rate of>90%.PPS also limited the synthesis of GSH in cells at the source;thus,glutamine metabolism therapy and NCT were integrated into an innovative method,which provides a novel strategy for multimodal tumor therapy.

Filamentation of Metabolic Enzymes in Saccharomyces cerevisiae

Compartmentation via filamentation has recently emerged as a novel mechanism for metabolic regulation. In order to identify filamentforming metabolic enzymes systematically, we performed a genome-wide screening of all strains available from an open reading frameGFP collection in Saccharomyces cerevisiae. We discovered nine novel filament-forming proteins and also confirmed those identified previously. From the 4159 strains, we found 23 proteins, mostly metabolic enzymes, which are capable of forming filaments in vivo. In silico protein-protein interaction analysis suggests that these filament-forming proteins can be clustered into several groups, including translational initiation machinery and glucose and nitrogen metabolic pathways. Using glutamine-utilising enzymes as examples, we found that the culture conditions affect the occurrence and length of the metabolic filaments. Furthermore, we found that two CTP synthases（Ura7p and Ura8p） and two asparagine synthetases（Asn1p and Asn2p） form filaments both in the cytoplasm and in the nucleus.Live imaging analyses suggest that metabolic filaments undergo sub-diffusion. Taken together, our genome-wide screening identifies additional filament-forming proteins in S. cerevisiae and suggests that filamentation of metabolic enzymes is more general than currently appreciated.