Similar Datasets
Project description:Purpose: High γ-aminobutyric acid (GABA)-producing Levilactobacillus brevis strain NPS-QW 145 along with Streptococcus thermophilus (one of the two starter bacteria used to make yogurt for its proteolytic activity) to enhance GABA production in milk. But a mechanistic understanding on how Levilactobacillus brevis cooperated with S. thermophilus to stimulate GABA production has been lacking. Method: Metatranscriptomic analyses combined with peptidomics were carried out to unravel the casein and lactose utilization patterns during milk fermentation with the co-culture. Results: We found particular peptides hydrolyzed by S. thermophilus 1275 were transported and biodegraded with peptidase in Lb. brevis 145 to meet the growth needs of the latter. In addition, amino acid synthesis and metabolism in Lb. brevis 145 were also activated to further support its growth. Glucose, as a result of lactose hydrolysis by S. thermophilus 1275, but not available lactose in milk, was outcompeted by Lb. brevis 145 as a main carbon source for glycolysis to produce ATP.In the stationary phase, under the acidic condition due to accumulation of lactic acid produced by S. thermophilus 1275, genes expression involved in pyridoxal phosphate (coenzyme of glutamic acid decarboxylase) metabolism and glutamic acid decarboxylase (Gad) in Lb. brevis 145 were induced for GABA production.
2020-09-16 | GSE157976 | GEO
Project description:Tertiary lymphoid structures (TLS) correlate with favorable responses to immune checkpoint inhibitors (ICI) in various cancers, yet many patients with TLS-positive tumors are resistant to treatment. Multi-omic profiling of clear cell renal cell carcinoma (ccRCC) and soft tissue sarcoma tumors (STS) reveals an upregulation of gamma-aminobutyric acid (GABA)-related signatures in non-responders to ICI. In ccRCC, TLS from non-responders located near GABA-producing tumor cells, exhibit impaired B cell maturation, reduced IgG production, higher GABA receptor expression and tricarboxylic acid cycle activation. In vitro, exposure of human B cells to GABA reduces HLA-DR expression, proliferation and immunoglobulin secretion by receptor independent and dependent mechanisms. Pharmacological inhibition of GABA-synthesis increases ICI response and immune infiltration, particularly by B cells, in a TLS-positive STS mouse model. Our findings unravel GABA as an immunoregulatory metabolite and provide a rationale for its therapeutic targeting to overcome ICI resistance in patients with TLS-positive tumors.
2026-07-08 | GSE273952 | GEO
Project description:Tertiary lymphoid structures (TLS) correlate with favorable responses to immune checkpoint inhibitors (ICI) in various cancers, yet many patients with TLS-positive tumors are resistant to treatment. Multi-omic profiling of clear cell renal cell carcinoma (ccRCC) and soft tissue sarcoma tumors (STS) reveals an upregulation of gamma-aminobutyric acid (GABA)-related signatures in non-responders to ICI. In ccRCC, TLS from non-responders located near GABA-producing tumor cells, exhibit impaired B cell maturation, reduced IgG production, higher GABA receptor expression and tricarboxylic acid cycle activation. In vitro, exposure of human B cells to GABA reduces HLA-DR expression, proliferation and immunoglobulin secretion by receptor independent and dependent mechanisms. Pharmacological inhibition of GABA-synthesis increases ICI response and immune infiltration, particularly by B cells, in a TLS-positive STS mouse model. Our findings unravel GABA as an immunoregulatory metabolite and provide a rationale for its therapeutic targeting to overcome ICI resistance in patients with TLS-positive tumors.
2026-07-08 | GSE273829 | GEO
Project description:Microbiota-released extracellular vesicles (MEVs) have emerged as a key player in intercellular signaling. However, their involvement in the gut-brain axis has been poorly investigated. In this study, we aimed to investigate the cargo capacity of MEVs for bioactive metabolites and their interactions with the host. Metabolomics analysis identified various neuro-related compounds encapsulated within the 28 MEVs, such as arachidonyl-dopamine, gabapentin, glutamate, and N-acylethanolamines. 29 Metaproteomics unveiled an enrichment of enzymes involved in neuronal metabolism, primarily in the glutamine/glutamate/GABA pathway. The detected neuro-related proteins and metabolites were correlated with Bacteroides spp. A GABA-producing Bacteroides isolate, B. finegoldii, released EVs with a high GABA content (4 µM) as opposed to a low GABA-producing isolate, Phocaeicola massiliensis. MEVs exhibited a dose-dependent paracellular transport and were endocytosed by Caco-2 and hCMEC/D3 cells. RNA-Seq analyses showed that MEVs stimulate several immune pathways while suppressing cell apoptosis process. The in vivo biodistribution confirmed the presence of MEVs in the brain, liver, stomach, and spleen. Overall, our results highlight the ability of MEVs to cross the intestinal and blood-brain barriers to deliver their cargoes to distant organs, including the brain, where it may modulate the organ functionalities. MEVs could be an integral part of microbiome-host communications, with potential implication for the gut-brain axis.
2024-11-05 | PXD045162 | Pride