Trimethylamine N-oxide Research Articles

Effect of low-salinity seawater transient on antioxidant capacity, muscle quality and intestinal microorganism of crucian carp (Carassius auratus gibelio)

Freshwater fish are frequently disliked by consumers due to their fishy odor and loose texture. Therefore, salinity treatment before market release is crucial for improving the muscle quality of freshwater fish. In this study, Carassius auratus gibelio was temporarily reared in low-salinity seawater (6 ppt) for 15 days, and changes of antioxidant levels, muscle texture, and intestinal microbial were determined. After temporary rearing in seawater, the hardness, gumminess, and chewiness of the muscle texture improved, and the relative contents of fishy and fatty odors decreased. This indicated that low-salinity treatment can enhance muscle quality and flavor while reducing fishy odor. According to microbiome research, low-salinity saltwater temporarily reduced the relative abundance of some opportunistic pathogens, such as Vibrio (from 47.61% to 0.1%) and Shewanella (from 15.20% to 5.86%) in the intestinal tract of crucian carp, and increased the relative abundance of beneficial bacteria, such as Sphingomonas (from 2.52% to 28.38%). This study can provide a reference for using low-salinity seawater for temporary rearing to enhance the quality of fish prior to marketing.

Trimethylamine N-Oxide Aggravates Neuro-Inflammation via lncRNA Fendrr/miR-145-5p/PXN Axis in Vascular Dementia Rats.

Vascular dementia (VaD) is the second most common dementia in the world. An increasing number of studies have demonstrated the important role of long non-coding RNAs (lncRNAs) in VaD. Our previous investigation demonstrated that Trimethylamine-N-oxide (TMAO) exacerbates cognitive impairment and neuropathological alterations in VaD rats. Thus, we hypothesized that TMAO could play an injury role in VaD by regulating lncRNAs. The rats using the bilateral common carotid artery (2VO) model were administered TMAO (120 mg/kg) for 8 consecutive weeks, 4weeks preoperatively and 4weeks postoperatively. High-throughput sequencing was conducted to investigate the effects of TMAO treatment on lncRNA expression in rat hippocampus and bioinformatics analysis was performed to identify potential downstream targets. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to detect the levels of lncRNA fetal-lethal noncoding developmental regulatory RNA (Fendrr), miR-145-5p, and paxillin (PXN). Learning and spatial memory capacities were measured, as well as inflammatory factors. Nissl staining was used to observe neuronal injury in the CA1 area of the hippocampus. Furthermore, we used the Fendrr loss-of-function assay, miR-145-5p gain-of-function assays and PXN loss-of-function assay to explore the mechanisms by which TMAO acts on VaD. TMAO administration upregulated lncRNA Fendrr expression in the rat hippocampus, while the damaging effects of TMAO were counteracted after knockdown of Fendrr. Fendrr exhibits highly expressed in 2VO rats and sponged miR-145-5p, which targets PXN. Silencing of Fendrr or PXN, or promotion of miR-145-5p improved neurological function injury, reduced neuronal damage, as well as repressed inflammation response. Inhibition of miR-145-5p abrogated up Fendrr knockdown mediated influence on 2VO rats. The results of this study indicated that TMAO inhibits the miR-145-5p/PXN axis by increasing the Fendrr expression, thus exacerbating the development of VaD.

Effect of rosemary extract on volatile flavor profile and flavor source of skipjack tuna

A fishy odor can significantly hinder the development of products made from nutritious skipjack tuna. To address this issue, rosemary extract (RE) was used as a deodorizing agent for skipjack tuna. Multi-omics techniques, including e-nose, e-tongue, gas chromatography-ion mobility mass spectrometry (GC-IMS), and gas chromatography-mass spectrometry (GC-MS), were employed to analyze the volatile flavor compounds in the skipjack tuna meat before and after deodorization. The main fishy odors found in the skipjack tuna were identified as nonanal, heptanal, hexanal, and 1-octen-3-ol, primarily resulting from lipid oxidation. Treatment with RE solutions at concentrations of 0.8% and 1.0% completely removed nonanal, hexanal, and heptanal from the skipjack tuna meat, while the level of 1-octen-3-ol was significantly reduced by 67.21% (p < 0.05). The GC-MS analysis of the impregnated solution indicated a 31% increase in 1-octen-3-ol content at a concentration of 0.2% (p < 0.05). Additionally, skipjack tuna meat treated with 0.8% and 1.0% RE showed lower peroxide values and thiobarbituric acid reactive substances values (p < 0.05). The reduction of fishy odor by RE was directly linked to decreased lipid oxidation. Quantitative analysis of phenolics revealed that the relative content of phenolics in RE was 52.54%, with the main phenolics being chlorogenic acid, caffeic acid, and luteolin. Thus, RE shows promise in eliminating fishy odors and minimizing lipid oxidation in skipjack tuna.

Correlation of Triethylamine N-oxide (TMAO), LPS, and TNF-Alpha Levels With Clinical Features of the Disease in Patients With and Without Septic Shock Infected With COVID-19 Virus

BackgroundInflammation is a response of the immune system to protect the body against various diseases or injuries. Serum trimethylamine N-oxide (TMAO) levels may vary depending on age, gender, habits, comorbidities, and microbiota. AimsIn this study, we investigated whether TMAO levels have diagnostic significance and their potential as a marker in the early diagnosis of the disease. Another aim of the research was to identify changes in TMAO levels as a reflection of the deterioration in the microflora, and IL-6, IL-10, IL-1β, TNF-alpha, and LPS levels in patient groups. Then, we recognized relationships between these parameters in patients infected with COVID-19 without septic shock and with COVID-19 who were without transmission of COVID-19 in septic shock. Study DesignA total of 160 patients were investigated, including 40 patients infected with COVID-19 without septic contact, 40 patients with COVID-19 positive septic shock, 40 patients with COVID-19 negative septic shock, and 40 healthy individuals as the control group. ResultsTNF-α and IL-1β levels were significantly lower (P < 0.001) and IL-6 and IL-10 levels were significantly higher (P < 0.001) in patient groups than in control groups. IL-1β showed a significant decrease, especially in the groups infected with COVID-19. Although IL-6, increased even more in the groups infected with COVID-19. ConclusionsLPS level was remarkably high in the sepsis group infected with COVID-19 compared to the other groups. TMAO level was significantly higher (P < 0.001) in the sepsis group. Therefore, TMAO is a potential biomarker in sepsis and septic shock.

Betaine and B12 Intake, Glutathione Concentration, and MTHFR, PEMT, and MTHFD1 Genotypes Are Associated with Diabetes-Related Parameters in Polish Adults

BackgroundThere is a growing body of evidence on associations between one-carbon metabolism (OCM) and diabetes-related parameters. For this reason, we aimed to examine the associations of plasma choline, betaine, trimethylamine N-oxide (TMAO), glutathione (GSH), serum folate, vitamin B12, dihydrofolate reductase (rs70991108) genotype, methylenetetrahydrofolate reductase (MTHFR) (rs180113) genotype, methylenetetrahydrofolate dehydrogenase (MTHFD1) (rs2236225) genotype, and phosphatidylethanolamine N-methyltransferase (rs7946 and rs12325817) genotype with fasting glucose level, insulin level, and diabetes-related indices. MethodsThe study group consisted of 421 Polish adults aged 20–40 y. Food intake was assessed using a 3-d food diary. Plasma concentrations of choline, betaine, and TMAO were determined by ultra-high-performance liquid chromatography-electrospray ionization mass spectrometry. The total plasma GSH level was measured by high-performance liquid chromatography. Insulin, folate, and vitamin B12 concentrations were estimated by enzyme-linked immunosorbent assay method. Genotyping was performed with TaqMan probes. ResultsGSH level was negatively associated with insulin (β = −0.11, P < 0.05) and gamma-glutamyl transferase (GGTP) (β = −0.12, P < 0.05), and positively associated with fasting glucose (β = 0.11, P < 0.05). Betaine intake was negatively associated with serum insulin concentration (β = −0.13, P < 0.05) and HOMA-IR (β = −0.12, P < 0.05). Choline intake was negatively associated with insulin (β = −0.17, P < 0.01). Serum folate level was negatively associated with GGTP (β = −0.11; P < 0.05). The methylenetetrahydrofolate reductase (MTHFR) CC genotype was associated with higher serum insulin levels (β = 0.15; P < 0.01) and higher HOMA-IR (β = 0.15, P < 0.01), whereas the MTHFD1 AA genotype was negatively associated with Quantitative Insulin Sensitivity Check Index (β = −0.11, P < 0.05). ConclusionsOur findings suggest that higher GSHL and higher intake of betaine, B12, and choline, as well as the TT genotype of MTHFR and the AA genotype of MTHFD1, are associated with lower diabetes-related parameters among adults.

Middle-aged dogs with low and high Aβ CSF concentrations show differences in energy and stress related metabolic profiles in CSF

BackgroundAmyloid beta (Aβ) accumulation in the brain is one of the earliest findings in Alzheimer's disease (AD). The dog is a natural animal model for amyloid processing and early brain amyloid pathology. The goal of this study is to examine which differences in metabolomic profiles in cerebrospinal fluid (CSF) could be detected in dogs with a difference in CSF Aβ concentrations before amyloid accumulation occurs. MethodMetabolic profiling was performed on CSF from 4 to 8 year old dogs with different CSF Aβ concentrations. ResultsMetabolomic profiling of CSF showed differences in brain energy metabolism. More specifically, increases in N-acetylation of amino acids and amino sugars, creatine and pentose metabolism, and a decrease in tricarboxylic acid (TCA) cycle were seen in dogs with a high CSF Aβ concentration. In addition, signs of elevated oxidative stress, higher methionine, lipid and nucleotide metabolism and increased levels of cysteine, myo-inositol and trimethylamine N-oxide were noted in these animals. ConclusionsDifferences in energy metabolism and stress mediated metabolic changes are seen in the brain of dogs with different CSF Aβ concentrations, before any amyloid deposition occurs. Similar metabolic changes, as in the high Aβ dogs, have been described in AD in humans and/or transgenic AD mice, some of them in very early phases. General significanceThe differences observed in metabolomic profiles could help in identifying potential biomarkers for an increased risk of developing amyloid pathology in the brain and open the door to the evaluation of preventive treatments for amyloid pathology in humans.

Trimethylamine N-oxide Can Trigger Cardiovascular Disease by Affecting Endothelial Cell-to-Cell Junctions through ZO-1 Expression Decreasing

Trimethylamine N-oxide Can Trigger Cardiovascular Disease by Affecting Endothelial Cell-to-Cell Junctions through ZO-1 Expression Decreasing

New Therapeutic Rargets for Cynodon Dactylon in Atherosclerosis: Attenuation of TMAO Generation and Down-regulation of TLR-4 in Rats

Purpose: Atherosclerosis (AS) is a chronic disease with worldwide incidence. The current study was conducted to highlight the molecular pathogenesis of AS and equal effectiveness of cynodon dactylon’s ethanolic extract (CDE) on the AS-induced injuries. Methods: Atherosclerosis was induced experimentally in healthy male rats with a hypercholesterolemic diet (HCD) for 24 weeks. The HCD-received animals were either treated with normal saline or various doses of CDE and/or atorvastatin. After 24 weeks of the treatment period, the effects of HCD on lipid profile, oxidative/nitrosative stress status, inflammatory enzymes (LDH, ALP and CKMB) activities, trimethylamine oxide (TMAO) concentration in serum along with the expression of TLR-4 (qPCR) and CD31 (Immunohistochemistry) in coronary and aorta were analyzed Results: CDE was able to reduce the HCD-enhanced cholesterol and triglycerides. The HCDelevated activities of LDH, ALP and CK-MB were declined by CDE. The antioxidant potency of CDE was comparable with atorvastatin on HCD-induced oxidative/nitrosative stress. The serum concentration of TMAO was lowered (1.7-fold) by CDE in a dose-dependent manner, while CD31 expression in the endothelial of coronary arterials and aorta in CDE and atorvastatin-received animals was remarkably increased. The up-regulated expression of TLR-4 (2.5-fold) at mRNA level was regulated significantly (p &lt; 0.05) and returned to normal level by CDE treatment. Conclusion: Results of the current study indicate that the up-regulation of TLR-4 as a main inflammatory gene and elevation of TMAO are involved in the pathophysiology of AS. Moreover, the protective effects of CDE on AS may be attributed to its anti-inflammatory and hypolipidemic properties.

Decreasing of Trimethylamine N-Oxide by Cecal Microbiota and Choline-Trimethylamine Lyase are Associated with Sishen Pill on Diarrhea with Kidney-Yang Deficiency Syndrome.

Sishen Pill (SSP) is a traditional Chinese medicine prescription commonly used to treat diarrhea with kidney-yang deficiency syndrome. The aim was to investigate the underlying mechanisms of SSP's therapeutic effects, providing experimental evidence for its mechanism of action. A mouse model of diarrhea with kidney-yang deficiency syndrome was induced using adenine combined with Folium sennae. After successful model replication, SSP decoction was administered. CutC activity, TMAO, IL-6, TNF-α levels, and cecal content microbiota were measured. SSP significantly improved the general behavioral characteristics of diarrhea mice, and reduced CutC activity, TMAO and IL-6 levels. Sequencing results indicated significant changes at the phylum and genus levels. Correlation analysis revealed a positive correlation between CutC activity and Faecalibaculum (p<0.05) and Chryseobacterium (p<0.05), and a significant negative correlation with Prevotellaceae UCG-001, Rikenella (p<0.05), Acinetobacter (p<0.05), Parasutterella (p<0.05), and Lacticaseibacillus (p<0.05). TNF-α levels showed a significant negative correlation with Lacticaseibacillus (p<0.05), Prevotellaceae UCG-001 (p<0.01), Parasutterella (p<0.05), and Candidatus Saccharimonas (p<0.05). IL-6 levels exhibited a significant negative correlation with Rikenella (p<0.05), Acinetobacter (p<0.05), Prevotellaceae UCG-001 (p<0.05), Lacticaseibacillus (p<0.01), and Parasutterella (p<0.05), and a significant positive correlation with Faecalibaculum (p<0.05), Chryseobacterium (p<0.01), and A2. Serum TMAO levels showed a significant positive correlation with Faecalibaculum (p<0.05) and Chryseobacterium (p<0.01), and hepatic TMAO levels exhibited a significant positive correlation with Chryseobacterium (p<0.05). SSP significantly alleviated the symptoms of diarrhea with kidney-yang deficiency syndrome by modulating the cecal microbiota, downregulating CutC activity, and reducing TMAO and inflammatory factor levels. The cecal microbiota-CutC-TMAO-inflammatory cytokine axis may be a key mechanism underlying the therapeutic effects of SSP.

Gut Microbe-Derived Metabolite Trimethylamine N-oxide and Risk of CKD Progression

Gut Microbe-Derived Metabolite Trimethylamine N-oxide and Risk of CKD Progression

Small Molecule Inhibitor of Gut Microbial Choline Trimethylamine Lyase Reduces Serum Trimethylamine N-oxide and Slows the Loss of Kidney Function in a Rat Model of CKD

Small Molecule Inhibitor of Gut Microbial Choline Trimethylamine Lyase Reduces Serum Trimethylamine N-oxide and Slows the Loss of Kidney Function in a Rat Model of CKD

A review of gut microbial metabolites and therapeutic approaches in hypertension

Abstract Background Hypertension is a prevalent and complex disease that is increasingly recognized to be influenced by the gut microbiome and its metabolites. Understanding the relationship between gut microbial metabolites and blood pressure regulation could provide new therapeutic avenues. Main body This review examines the role of key microbial metabolites—short-chain fatty acids, trimethylamine N-oxide, tryptophan derivatives, polyamines, bile acids, and phenylacetylglutamine—in blood pressure regulation. Short-chain fatty acids, produced through dietary fiber fermentation, can lower blood pressure by modulating immune responses and reducing inflammation. Elevated trimethylamine N-oxide levels are associated with increased cardiovascular risk and hypertension, influencing cholesterol metabolism and promoting atherosclerosis. Tryptophan derivatives interact with vascular and renal functions to modulate blood pressure. Polyamines affect blood pressure regulation through their impact on nitric oxide synthesis and vascular tone. Bile acids influence blood pressure via gut microbiota modulation and activation of metabolic receptors. Phenylacetylglutamine has been linked to hypertension through its effects on platelet hyperactivity and thrombosis. Therapeutic approaches targeting these metabolites, including probiotics, prebiotics, fecal microbiota transplantation, dietary interventions, and polyphenols, have shown varying degrees of success. Probiotics and prebiotics promote the growth of beneficial gut bacteria and may lower blood pressure. Dietary interventions, such as the Mediterranean diet, positively affect blood pressure and cardiovascular health by modulating the gut microbiota. Polyphenols, known for their antioxidant properties, are associated with blood pressure reductions and improved vascular function. Fecal microbiota transplantation shows promise in restoring gut microbial balance and improving metabolic health, potentially influencing blood pressure regulation. Conclusion The review highlights the significant role of gut microbial metabolites in regulating blood pressure, offering new avenues for hypertension management. Key metabolites, including short-chain fatty acids, trimethylamine N-oxide, and bile acids, play critical roles in blood pressure modulation. Therapeutic strategies targeting these metabolites, such as probiotics, prebiotics, and dietary interventions, hold promise, though further research is needed to fully understand their mechanisms and optimize their use. Advancing microbiota-based interventions through large-scale studies and exploring personalized therapies will be essential for developing effective treatments in hypertension management.

Alterations of the Gut Microbiome and TMAO Levels in Patients with Ulcerative Colitis.

Background: Ulcerative colitis (UC) is an idiopathic and heterogeneous large intestine disease, characterized by chronic mucosa and submucosa inflammation. Alteration of the intestinal microbiome in UC may be responsible for modifications in metabolite production. Aim: To investigate the microbiota status and trimethylamine-N-oxide (TMAO) metabolite levels in patients with UC according to clinical and endoscopic activity. Methods: As part of a grant project AP14871959 from September 2022 to October 2023, 31 patients with UC and 15 healthy volunteers over 18 years at the Clinic of NCJSC "KMU" were assessed for blood TMAO level and metagenomic sequencing of fecal microbiome. Results: A significant depletion of the main representatives of Bacteroides, Parabacteroides, Prevotella; and an increase in the relative abundance of the genera Actinomyces, Klebsiella, Limosilactobacillus, Streptococcus, Escherichia-Shigella were detected in patients with UC. The number of p_Actinobacteria (g_Collinsella) and p_Eubacterium (g_Xylanophilum) representatives with genes encoding TMA-trimethylamine conversion is significantly reduced in UC patients. TMAO levels were significantly lower in UC patients than in healthy individuals (0.233 µmol/L, p = 0.004). TMAO decreased with disease severity and significantly differed between patients with different activities (p = 0.034). Conclusions: The composition of the intestinal microbiome changes and the level of TMAO decreases in patients with UC at different activities.

Impact of Four Different Chlorella vulgaris Strains on the Properties of Durum Wheat Semolina Pasta

Microalgae are a promising protein source due to their high protein content; high reproductivity; and low carbon, water, and arable land footprints. In this study, the impact of adding 3 and 5% of four Chlorella vulgaris strains, namely Smooth (SCV), Honey (HCV), White (WCV), and New Honey C. vulgaris (NHCV), on the processing, cooking behavior, color, firmness, structure, and sensory properties of durum wheat semolina pasta was investigated. It was hypothesized that (1) changes in physical properties depend on strain and concentration, (2) acceptability varies by strain due to different colors, odors, and flavors, and (3) the absence of fishy odors and flavors is crucial for acceptance rather than color. The results show that high-quality pasta could be produced with all C. vulgaris strains and concentrations. Cooking time and water absorption of all samples decreased but only significantly for the samples with NHCV added. Also, the bite resistance (determined instrumentally and sensorially) increased for almost all samples due to increasing protein and fiber content. A clear concentration dependency could not be found. In terms of sensory acceptance, NHCV performed the best, and an unaltered typical odor was identified to be crucial rather than color or the absence of fishy odor.

Trimethylamine N-oxide promotes PERK-mediated endothelial-mesenchymal transition and apoptosis thereby aggravates atherosclerosis

The endothelial-mesenchymal transition (EndMT) is involved in the development of atherosclerosis (AS) and is a key process in vascular endothelial injury. Oxidative stress, inflammation, and apoptosis are common causes of EndMT, and EndMT progression can further accelerate the development of AS. The metabolite trimethylamine N-oxide (TMAO) is produced by the gut microbiome and is implicated in the development of several diseases, including diabetes and chronic kidney disease. However, the impact of TMAO on transforming growth factor β1(TGF-β1)-induced EndMT remains unclear. We hypothesize that TMAO exacerbates plaque formation and cardiac function impairment by promoting EndMT. Herein, we showed that high serum TMAO levels caused plaque formation, cardiac function damage and haemodynamic changes in ApoE−/− mice. In vitro, TMAO upregulated mesenchymal markers and downregulated endothelial markers in HAECs. Furthermore, TMAO increased the migratory capacity of EndMT cells. Mechanistically, we found that PERK downregulation could alleviate TMAO-induced oxidative stress, EndMT, plaque formation and cardiac function damage. Further study showed that activated transcription factor 3 (ATF3), the downstream molecule of protein kinase RNA-like endoplasmic reticulum kinase (PERK), could bind with TGF-β1/2 and affect EndMT. Overall, TMAO promotes EndMT, possibly through the PERK-eIF2α-ATF4-CHOP or the PERk-eIF2α-ATF3-TGF-β signalling pathways.

Low-Molecular-Weight Compounds Produced by the Intestinal Microbiota and Cardiovascular Disease.

Cardiovascular disease is the main cause of mortality in industrialized countries, with over 500 million people affected worldwide. In this work, the roles of low-molecular-weight metabolites originating from the gut microbiome, such as short-chain fatty acids, hydrogen sulfide, trimethylamine, phenylacetic acid, secondary bile acids, indoles, different gases, neurotransmitters, vitamins, and complex lipids, are discussed in relation to their CVD-promoting or preventing activities. Molecules of mixed microbial and human hepatic origin, such as trimethylamine N-oxide and phenylacetylglutamine, are also presented. Finally, dietary agents with cardioprotective effects, such as probiotics, prebiotics, mono- and poly-unsaturated fatty acids, carotenoids, and polyphenols, are also discussed. A special emphasis is given to their gut microbiota-modulating properties.

Exhaustive Search of Dietary Intake Biomarkers as Objective Tools for Personalized Nutrimetabolomics and Precision Nutrition Implementation.

To conduct an exhaustive scoping search of existing literature, incorporating diverse bibliographic sources to elucidate the relationships between metabolite biomarkers in human fluids and dietary intake. The search for biomarkers linked to specific dietary food intake holds immense significance for precision health and nutrition research. Using objective methods to track food consumption through metabolites offers a more accurate way to provide dietary advice and prescriptions on healthy dietary patterns by healthcare professionals. An extensive investigation was conducted on biomarkers associated with the consumption of several food groups and consumption patterns. Evidence is integrated from observational studies, systematic reviews, and meta-analyses to achieve precision nutrition and metabolism personalization. Tailored search strategies were applied across databases and gray literature, yielding 158 primary research articles that met strict inclusion criteria. The collected data underwent rigorous analysis using STATA and Python tools. Biomarker-food associations were categorized into 5 groups: cereals and grains, dairy products, protein-rich foods, plant-based foods, and a miscellaneous group. Specific cutoff points (≥3 or ≥4 bibliographic appearances) were established to identify reliable biomarkers indicative of dietary consumption. Key metabolites in plasma, serum, and urine revealed intake from different food groups. For cereals and grains, 3-(3,5-dihydroxyphenyl) propanoic acid glucuronide and 3,5-dihydroxybenzoic acid were significant. Omega-3 fatty acids and specific amino acids showcased dairy and protein foods consumption. Nuts and seafood were linked to hypaphorine and trimethylamine N-oxide. The miscellaneous group featured compounds like theobromine, 7-methylxanthine, caffeine, quinic acid, paraxanthine, and theophylline associated with coffee intake. Data collected from this research demonstrate potential for incorporating precision nutrition into clinical settings and nutritional advice based on accurate estimation of food intake. By customizing dietary recommendations based on individualized metabolic profiles, this approach could significantly improve personalized food consumption health prescriptions and support integrating multiple nutritional data.This article is part of a Nutrition Reviews special collection on Precision Nutrition.

Specific isolation and quantification of PD-L1 positive tumor derived exosomes for accurate breast cancer discrimination via aptamer-functionalized magnetic composites and SERS immunoassay

PD-L1 positive tumor derived exosomes (TEXsPD−L1) play a significant role in disease progression, tumor metastasis and cancer immunotherapy. However, the overlap of PD-L1 between TEXs and non-tumor derived exosomes (non-TEXs) restricts the specific isolation and quantification of TEXPD−L1 from clinical samples. Herein, a new aptamer-functionalized and hydrophilic immunomagnetic substrate was designed by decorating generation 5 polyamidoamine dendrimers (G5 PAMAM), zwitterionic trimethylamine N-oxide (TMAO) and EpCAM (Epithelial cell adhesion molecule) aptamers on magnetic cores sequentially (Fe3O4@PAMAM@TMAO@Aptamer, named as FPTA) for rapid target and efficient capture of TEXs. The FPTA substrate gathered excellent characters of strong magnetic responsiveness of Fe3O4, abundant affinity sites of PAMAM, strong hydrophilicity of TMAO and enhanced affinity properties of EpCAM aptamers. Because of these advantages, FPTA can isolate TEXs quickly within 30min with high capture efficiency of 90.5 % ± 3.0 % and low nonspecific absorption of 8.2 % ± 2.0 % for non-TEXs. Furthermore, PD-L1 (Programmed cell death-ligand 1) positive TEXs (TEXsPD−L1) from the captured TEXs were recognized and quantitatively analyzed by utilizing SERS (surface-enhanced Raman spectroscopy) reporter molecules 4-NTP (4-Nitrothiophenol) on PD-L1 aptamers-functionalized gold immunoaffinity probe. The signal of TEXsPD−L1 was converted to SERS signal of 4-NTP at 1344 cm−1 which exhibited a linear correlation to concentration of TEXsPD−L1(R2 = 0.9905). With these merits, this strategy was further applied to clinical plasma samples from breast cancer (BC) patients and healthy controls (HC), exhibited an excellent diagnosis accuracy with area under curve (AUC) of receiver operating characteristic (ROC) curve reaching 0.988. All these results demonstrate that the FPTA immunomagnetic substrate combined with SERS immunoaffinity probe may become a generic tool for specific isolation and quantitative analysis of PD-L1 positive tumor-derived exosomes in clinics.

Aged garlic oligosaccharides modulate host metabolism and gut microbiota to alleviate high-fat and high-cholesterol diet-induced atherosclerosis in ApoE−/− mice

Atherosclerosis (AS) is a cardiovascular disease caused by excessive accumulation of lipids in arterial walls. In this study, we developed an AS model in ApoE−/− mice using a high-fat, high-cholesterol diet and investigated the anti-AS mechanism of aged garlic oligosaccharides (AGOs) by focusing on the gut microbiota. Results revealed that AGOs exhibited significant anti-AS effects, reduced trimethylamine N-oxide levels from 349.9 to 189.2 ng/mL, and reduced aortic lipid deposition from 31.7 % to 9.5 %. AGOs significantly increased the levels of short-chain fatty acids in feces, in which acetic, propionic, and butyric acids were increased from 1.580, 0.364, and 0.469 mg/g to 2.233, 0.774, and 0.881 mg/g, respectively. An analysis of the gut microbiota indicated that AGOs restored alpha and beta diversity, decreased the Firmicutes/Bacteroidetes ratio, and promoted the dominance of the genus Akkermansia. A metagenomic analysis revealed that AGOs alleviated AS through the ABC transporter pathway and the lipopolysaccharide biosynthesis pathway.

Gut microbiota metabolite trimethylamine N-oxide promoted NAFLD progression by exacerbating intestinal barrier disruption and intrahepatic cellular imbalance

Non-alcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease worldwide, with the gut microbiota and its metabolites are important regulators of its progression. Trimethylamine N-oxide (TMAO), a metabolite of the gut microbiota, has been closely associated with various metabolic diseases, but its relationship with NAFLD remains to be elucidated. In this study, we found that fecal TMAO levels correlated with NAFLD severity. Moreover, TMAO promoted lipid deposition in HepG2 fatty liver cells and exacerbated hepatic steatosis in NAFLD rats. In the colon, TMAO undermined the structure and function of the intestinal barrier at various levels, further activated the TLR4/MyD88/NF-κB pathway, and inhibited the WNT/β-catenin pathway. In the liver, TMAO induced endothelial dysfunction with capillarization of liver sinusoidal endothelial cells, while modulating macrophage polarization. In conclusion, our study suggests that gut microbiota metabolite TMAO promotes NAFLD progression by impairing the gut and liver and that targeting TMAO could be an alternative therapeutic strategy for NAFLD.