How cells integrate nutrient availability to coordinate metabolism and growth remains poorly understood. Here, we identify branched-chain amino acid (BCAA) synthesis as a metabolic sensing system linking mitochondrial activity to translational and transcriptional control. Yeast limits Leu and Val import and instead relies on their synthesis, allowing BCAA production to reflect mitochondrial anabolic capacity. Reduced Val synthesis activates Gcn2, whereas reduced Leu synthesis inhibits TORC1, together decreasing translation efficiency and restricting growth. This response lowers levels of the transcriptional repressor Mig1, suppressing the Warburg/Crabtree effect and promoting alternative carbon source utilization. Remarkably, pharmacological inhibition of Leu/Val synthesis induces this metabolic reprogramming even in nutrient-rich medium, indicating that mitochondrial BCAA synthesis can partially override other nutrient-sensing pathways. Thus, BCAA synthesis couples mitochondrial anabolic capacity to Gcn2 and TORC1 activity and, through translational control of transcription factor abundance, shapes cellular metabolism.

Branched-chain amino acids (BCAA) have been implicated in diabetes and heart failure, leading to ongoing clinical trials with inhibitors of BCKDK, a key regulator of BCAA catabolism. We have previously shown that these inhibitors promote vasodilation and lower blood pressure, well-known cardioprotective effects, but how this occurs remained unclear. We show here, using explanted vessels, in vivo hemodynamics and telemetry, and genetically modified mice, that the vasodilatory effect of BCKDK inhibitors is direct, rapid, independent of nitric oxide, independent of BCAA catabolism, and most strikingly, independent of BCKDK itself. Instead, we demonstrate, using structural and biochemical studies, that BCKDK inhibitors directly antagonize the angiotensin II type I receptor (AT1R) and consequent angiotensin-mediated vasoconstriction. These data demonstrate a strong off-target effect of BCKDK inhibitors, independent of BCAA or BCKDK, which may explain their cardioprotective effects but also questions if this protection would be additive to existing AT1R blockers.

Fruit sweetness is a primary determinant of consumer preference and market value in tomato (Solanum lycopersicum), yet increasing sugar content without negatively affecting plant performance remains a major challenge in breeding programs. In this study, we targeted Acetolactate synthase 1 (SlALS1), a key enzyme in branched-chain amino acids (BCAAs) biosynthesis, to investigate whether modulation of primary metabolism could enhance fruit sugar accumulation. Tomato contains two ALS homologs, SlALS1 and SlALS2. Using CRISPR/Cas9-mediated genome editing, we generated SlALS1 knock-out lines in the Micro-Tom background. Loss of SlALS1 function led to a significant reduction in the levels of valine, leucine, and isoleucine in fruit tissues, confirming disruption of the BCAA biosynthetic pathway. Notably, soluble sugar content was markedly increased in the mutant lines, with glucose and fructose levels elevated by approximately 1.3-fold compared with wild-type fruits, resulting in a significantly higher Brix index. Metabolic profiling indicates that reduced BCAA biosynthesis may influence carbon allocation toward soluble sugar accumulation in fruit tissues, revealing an association between amino acid metabolism and carbohydrate accumulation during fruit development. Our findings demonstrate that precise editing of a central metabolic enzyme can enhance tomato fruit sweetness and suggest that SlALS1 may represent a promising target for genome editing aimed at improving fruit quality traits. However, further evaluation of agronomic traits, including plant growth and fruit yield, will be necessary to assess its potential for practical breeding applications.

Yeast protein-derived high Fischer ratio peptides (HFYP) show great potential for alleviating exercise-induced fatigue, yet existing studies have focused only on skeletal muscle regulation, overlooking the muscle-liver axis in systemic lactate metabolism. We optimized HFYP preparation via response surface methodology, yielding peptides with a Fischer ratio of 40.01 and 23.95% BCAA content. Low-dose HFYP (0.128 g/kg) prolonged exhaustive swimming time from 9.53 to 29.88 min (3.1-fold), outperforming taurine (16.89 min) and BCAA-matched amino acid mixtures (22.25 and 18.78 min). Mechanistically, HFYP activated AMPK/PGC-1α and AKT/FOXO1 pathways in muscle to promote mitochondrial biogenesis and glucose utilization, while upregulating hepatic PCK1 to enhance Cori cycle activity. HFYP alleviates exercise-induced fatigue through the synergistic regulation of skeletal muscle lactate metabolism and hepatic lactate-to-glucose recycling via the muscle-liver axis, which provides a solid theoretical basis for the high-value utilization of yeast protein and the development of HFYP-based antifatigue functional foods.

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is a prevalent pelvic pain disorder in men, yet effective pharmacotherapies remain limited. Emerging evidence suggests that oxidative stress and dysregulated iron metabolism contribute to the pathogenesis of CP/CPPS, with ferroptosis increasingly implicated in CP/CPPS-related pathology. Qianlie Zhitong Formula (QLZTF) has shown therapeutic potential in treating CP/CPPS; however, its underlying mechanisms remain incompletely understood. This study integrated proteomics, metabolomics, and in vivo experiments to investigate the therapeutic mechanisms of QLZTF. A carrageenan-induced rat model was established, and rats were randomly assigned to five groups: control, model, Qianliekang, low-dose QLZTF, and high-dose QLZTF. QLZTF significantly reduced inflammatory cytokines (TNF-α, IL-6, and IL-1β), alleviated pain responses, and ameliorated prostate tissue injury. Proteomic analysis identified BCAT2, ALDH1B1, and ALDH2 as significantly upregulated proteins closely associated with ferroptosis. KEGG enrichment analysis of both proteomic and metabolomic data revealed that pantothenate and CoA biosynthesis and branched-chain amino acid (BCAA) degradation pathways were significantly enriched. Integrated analysis indicated that QLZTF synergistically regulates these pathways, activates the BCAT2/ALDH axis, and inhibits ferroptosis, thereby alleviating inflammation, pain, and fibrosis in CP/CPPS. This study provides the first multiomics evidence for the anti-ferroptotic mechanism of QLZTF.

Type 2 diabetes mellitus (T2DM) is a highly prevalent chronic metabolic disease worldwide, and the clinical prevention and control situation is severe. Although the various antidiabetic drugs currently in clinical use can lower blood glucose levels through different mechanisms, there are significant differences in efficacy among individuals. Existing evidence suggests that differences in gut microbiota (GM) composition and metabolic function may be one of the key factors contributing to the heterogeneity in drug efficacy. Based on this, this review describes the physiological and pathological mechanisms of the GM-metabolism axis and systematically reviews the modulatory effects of different classes of antidiabetic drugs on this axis and their underlying mechanisms. Available studies suggest that metformin, α-glucosidase inhibitors, dipeptidyl peptidase-4 inhibitors (DPP-4i), sodium-glucose cotransporter-2 inhibitors (SGLT2i), thiazolidinediones (TZDs), and oral glucagon-like peptide-1 receptor agonists (GLP-1RAs) may differentially affect GM composition and/or microbial metabolites, including short-chain fatty acids (SCFAs), branched-chain amino acids (BCAAs), and bile acids. These alterations may be associated with glucose homeostasis and insulin resistance through pathways involving GPR41/43, HDACs, AMPK, mTORC1/S6K1, FXR-FGF15/19, and TGR5-GLP-1 signaling. By integrating clinical and mechanistic evidence, this review highlights the potential contribution of the GM-metabolism axis to the glucose-lowering effects of antidiabetic drugs. However, the quantity and confidence of evidence vary substantially across drug classes, and causal and clinical relevance requires further validation. These findings provide a basis for future research on personalized interventions for T2DM characterized by SCFA-producing bacterial deficiency, BCAA overload, or dysregulated bile acid metabolism.

The combination immunotherapies, including those with atezolizumab and bevacizumab (Atez/Bev), have become standard therapy for hepatocellular carcinoma (HCC). However, its efficacy remains limited and reliable biomarkers are lacking. In this study, we analyzed paired tumor and background liver tissues from Atez/Bev-treated HCC patients and found that high programmed cell death-1 (PD-1) expression in CD8[+] tumor-infiltrating lymphocytes (TILs) correlated with therapeutic response independent of etiology. RNA sequencing on the tumor samples revealed that the branched-chain amino acid (BCAA)-related metabolic pathway was enriched in the group with high PD-1 expression in CD8[+] TILs. Along with in vitro experiments, we identified the importance of BCAAs for activation and differentiation of CD8[+] T cells. In addition, BCAA metabolism was related to response to PD-1 blockade in not subcutaneous but intrahepatic mouse model-specific manner. Actually, public dataset analyses revealed that high expression of BCAT1, a key enzyme in BCAA metabolism, was associated with poor prognosis in HCC, but not in other cancer types. These findings suggest the importance of liver-specific BCAA metabolism in antitumor immunity and highlight the need to assess the tumor microenvironment within its organ-specific metabolic context.

Oral squamous cell carcinoma (OSCC) remains a major cause of cancer-associated mortality worldwide, with current treatments limited by chemoresistance and long-term toxicities. N6-methyladenosine (m[6]A) modification regulates mRNA fate to drive cancer progression. However, how m[6]A modification regulates OSCC progression remains to be elucidated. The present study integrated bioinformatics analysis of The Cancer Genome Atlas and Genotype-Tissue Expression datasets and experimental validation to explore the role of heterogeneous nuclear ribonucleoprotein C (hnRNPC), an m[6]A-associated RNA-binding protein, in OSCC. Bioinformatics analysis of 515 patients with head and neck squamous cell carcinoma (HNSCC) suggested that hnRNPC may have prognostic relevance in HNSCC. High hnRNPC expression associated with advanced pathological stages, poor overall survival and served as a potential risk factor for HNSCC. Functional experiments demonstrated that hnRNPC knockdown in OSCC cell lines inhibited cell proliferation, colony formation, tumor sphere formation and in vivo tumor growth, while downregulating stemness-associated genes (Oct4, Sox2 and Nanog). Mechanistically, hnRNPC promoted branched-chain amino acid (BCAA) metabolism in OSCC. High hnRNPC expression was associated with activated BCAA metabolic pathways and hnRNPC knockdown reduced BCAA uptake, glutamate levels, oxygen consumption rate and glutathione levels. Furthermore, hnRNPC stabilized BCCAA transaminase 1 (BCAT1) mRNA in an m[6]A-dependent manner. BCAT1 inhibition via ERG240 enhanced the tumor-suppressive effects of hnRNPC knockdown. Exogenous supplementation of α-ketoglutarate rescued energy deficiency and functional defects in hnRNPC-knockdown OSCC cells. Collectively, the present study findings revealed a novel mechanism driving OSCC progression. In this mechanism, hnRNPC regulates BCAA metabolism by stabilizing BCAT1 mRNA in an m[6]A-dependent manner. The present study supports the prognostic relevance of hnRNPC and may offer a promising therapeutic direction in improving OSCC treatment outcomes by disrupting tumor-specific metabolic and epigenetic adaptations.

Resistance to next-generation androgen receptor antagonists represents a major clinical challenge in prostate cancer (PCa), underscoring the need to define its underlying mechanisms. Here, through an integrated analysis of multiple cohorts, we identify PABPC1 as an RNA-binding protein upregulated in therapy-resistant tumors, whose expression correlates with adverse clinicopathological features. Elevated PABPC1 confers enzalutamide (Enz) resistance by suppressing tumor-cell ferroptosis and CD8[+] T-cell cytotoxicity. Mechanistically, PABPC1 promotes the cytoplasmic colocalization of EIF4A1 with ATF4 mRNA and enhances EIF4A1-associated translation of ATF4 mRNA. Subsequently, ATF4 binds the BCAT1 promoter and transcriptionally upregulates BCAT1, thereby promoting branched-chain amino acid (BCAA) metabolic remodeling and ferroptosis resistance, with leucine emerging as a major functional contributor to both ferroptosis regulation and CD8[+] T-cell effector responses. In preclinical models, ixazomib restores ferroptotic vulnerability, reinvigorates T-cell activity, and synergizes with Enz, without overt histopathological abnormalities in major organs. These results identify the PABPC1-ATF4-BCAT1 axis as a key regulatory pathway linking RNA regulation with metabolic and immune reprogramming to facilitate treatment resistance in PCa.

Sex-biased metabolic dysfunction-associated steatotic liver disease susceptibility is usually attributed to differences in adiposity, insulin resistance, and sex-hormone levels. I propose that hepatic estrogen receptor α shapes the partitioning of muscle-derived branched-chain amino acid carbon and amino nitrogen between oxidation, lipid synthesis, recycling, and disposal. This framework supports endocrine-state-aware biomarkers and sex-stratified trials integrating liver and muscle endpoints.

Anaemia in children and adolescents is multifactorial, and evidence on dietary amino-acid intake in relation to anaemia remains limited. This study examined the association between dietary branched-chain amino acid (BCAA) intake and haemoglobin (Hb)-defined anaemia among Chinese children and adolescents using data from the 2016-2019 China Children and Lactating Women Nutrition and Health Survey. Among 11,134 eligible participants aged 6-17 years, quantile g-computation and the Boruta algorithm were first used to screen 20 dietary amino acids. A 1:4 propensity score-matched sample was then constructed, including 455 participants with anaemia and 1,819 with normal Hb levels. Dietary BCAA intake and its components, isoleucine (Ile), leucine (Leu) and valine (Val), were energy-adjusted using the residual method. Machine learning methods were used exploratorily for feature ranking, and conditional logistic regression was used to estimate odds ratios (ORs). After matching, total dietary protein intake was comparable between groups, whereas intakes of total BCAA, Ile, Leu, and Val were significantly lower in the anaemia group. In fully adjusted models, higher intakes of total BCAA, Ile, Leu, and Val were associated with lower odds of Hb-defined anaemia, with ORs of 0.95 (95% CI: 0.92-0.99), 0.82 (95% CI: 0.70-0.95), 0.91 (95% CI: 0.85-0.98) and 0.86 (95% CI: 0.78-0.95), respectively. Supplementary biomarker analyses showed lower ferritin and higher soluble transferrin receptor concentrations in the anaemia group, whereas high-sensitivity C-reactive protein did not differ between groups. These findings suggest that BCAA-related dietary characteristics may provide useful nutritional clues for anaemia-related assessment, although the association should not be interpreted as evidence of a BCAA-specific protective effect.

Triple-negative breast cancer (TNBC) is an aggressive subtype with high metastatic potential and poor prognosis, yet the molecular mechanisms driving metastasis remain incompletely understood. Here, we performed integrated transcriptomic, metabolomic, and imaging mass cytometry (IMC) analyses on tumor tissues from 52 TNBC patients stratified into NonMeta (long-term survival without metastasis, n = 39) and MetaPoor (metastasis-related death within 36 months after metastatic diagnosis, n = 13) groups. Transcriptomic analysis revealed significant enrichment of epithelial-mesenchymal transition (EMT), WNT signaling pathway, and angiogenesis pathways in MetaPoor tumors, with EMT identified as the top enriched hallmark by GSEA. Metabolomic profiling showed decreased branched-chain amino acids (BCAAs) and arginine derivatives, alongside elevated glycerophosphorylcholine (GPC), indicating enhanced metabolic demand and membrane remodeling. IMC-based spatial proteomics identified distinct tumor cell subpopulations, with MetaPoor tumors harboring higher proportions of stem-like and EMT-like cells characterized by upregulated HADHA (BCAA oxidation) and P38, and downregulated ATP5A (oxidative phosphorylation). Multi-omics integration revealed strong correlations between GPC and EMT markers, and between BCAA depletion and HADHA expression. Collectively, our multi-omics study demonstrates that metastatic TNBC is characterized by EMT activation, metabolic reprogramming toward altered BCAA metabolism and oxidative phosphorylation-related protein expression, and remodeling of the tumor immune microenvironment, suggesting candidate molecules that warrant independent validation and further mechanistic investigation.

Metabolic dysfunction-associated fatty liver disease (MAFLD) has become a highly prevalent chronic metabolic disease worldwide. Current clinical drugs are limited by poor long-term efficacy, potential safety risks and high costs. As a popular daily beverage, Gynostemma pentaphyllum exerts prominent hepatoprotective, lipid-regulating and hypoglycemic activities, making it a promising natural agent for MAFLD intervention. In this study, we prepared high-activity secondary gypenosides via snailase-mediated biotransformation, and explored their anti-MAFLD mechanisms through integrated multi-omics analysis and pharmacological validation. The results revealed that snailase efficiently converted primary gypenosides into rare secondary derivatives. Compared with the crude gypenosides from Gynostemma pentaphyllum extract (GYP), the transformed product SGYP exhibited stronger dose-dependent lipid-regulating and anti-inflammatory effects, and effectively alleviated MAFLD-related pathological lesions in mice. Mechanistic investigations demonstrated that SGYP ameliorated high-fat-diet-induced excessive accumulation of branched-chain amino acid (BCAA) in the liver and activated the hepatic AMPK and AKT signaling pathways. Further exogenous BCAA supplementation experiments confirmed that restoring hepatic BCAA homeostasis served as the core mechanism underlying the anti-MAFLD action of SGYP. This study provides an innovative processing technology for the preparation of high-value Gynostemma pentaphyllum products featuring strengthened lipid-lowering, anti-inflammatory activities and prominent hepatoprotective effects.