One-Carbon Metabolism in Health and Disease

Relationship between MTHFR, MTRR gene polymorphisms and H-type hypertension: a systematic review and meta-analysis

CONTEXT

The relationship between methylenetetrahydrofolate reductase (MTHFR) and methionine synthase reductase (MTRR) gene polymorphisms and H-type hypertension susceptibility has been deeply analysed, but the conclusions are not consistent. Therefore, we carried out a meta-analysis aimed at assessing the relationship exactly.

METHODS

Six English databases (PubMed, Embase, EBSCO, ScienceDirect, Cochrane Library, and Web of Science) and four Chinese databases (China Biological Medicine, WanFang, China Science and Technology Journal, and China National Knowledge Infrastructure) were used for searching studies from inception to August 2023. MTHFR C677T/A1298C and MTRR A66G genetic polymorphisms were evaluated.

RESULTS

A total of 24 papers were included in our research, including 3649 H-type hyperpietics, 2772 non-H-type hyperpietics, and 2149 healthy controls. Our analysis shows that MTHFR C677T polymorphism showed significant association with H-type hypertension in both healthy individuals and non-H-type hyperpietics (TT vs. CC: OR = 3.43, 95% CI = 2.48-4.75). Further subgroup analysis based on geography revealed that homocysteine levels in the southern Chinese population were more susceptible to MTHFR C677T polymorphism (p < 0.05). However, there was no significant association in all genetic models for the polymorphisms of MTHFR A1298C and MTRR A66G.

CONCLUSION

MTHFR C677T polymorphisms are associated with H-type hypertension in non-H-type hyperpietics and healthy individuals.

Timing of dietary effects on the epigenome and their potential protective effects against toxins

Exposure to toxins causes lasting damaging effects on the body. Numerous studies in humans and animals suggest that diet has the potential to modify the epigenome and these modifications can be inherited transgenerationally, but few studies investigate how diet can protect against negative effects of toxins. Potential evidence in the primary literature supports that caloric restriction, high-fat diets, high protein-to-carbohydrate ratios, and dietary supplementation protect against environmental toxins and strengthen these effects on their offspring's epigenome. Most notably, the timing when dietary interventions are given - during a parent's early development, pregnancy, and/or lifetime - result in similar transgenerational epigenetic durations. This implies the existence of multiple opportunities to strategically fortify the epigenome. This narrative review explores how to best utilize dietary modifications to modify the epigenome to protect future generations against negative health effects of persistent environmental toxins. Furthermore, by suggesting an ideal diet with specific micronutrients, macronutrients, and food groups, epigenetics can play a key role in the field of preventive medicine. Based on these findings, longitudinal research should be conducted to determine if a high protein, high-fat, and low-carbohydrate diet during a mother's puberty or pregnancy can epigenetically protect against alcohol, tobacco smoke, and air pollution across multiple generations.

Proteomic analysis reveals immune-related proteins of coelomic fluid in Urechis unicinctus

Urechis unicinctus is a marine benthic invertebrate that relies primarily on humoral immunity within the nonspecific immune system for body defense. In order to elucidate the protein components of the coelomic fluid and investigate its immune response mechanism, proteomic analysis and antimicrobial characterization of the coelomic fluid of U. unicinctus were carried out. A total of 2194 proteins were identified, with 427 showing differential expression in coelomocytes compared to those in the coelomic fluid supernatant. Of these proteins, 346 were upregulated and 81 were downregulated. Next, these identified proteins were analyzed for biological information, including GO, COG, and KEGG pathway analysis. The results from the GO analysis revealed that cytoplasm and ATP-binding were the two prominent categories of proteins found in the coelomocytes as well as the coelomic fluid supernatant of U. unicinctus. From the COG analysis, it was evident that the categories of proteins identified in the coelomocytes were essentially the same as those identified in the coelomic fluid supernatant, with only the number of proteins differing. The KEGG pathway analysis indicated that 45 pathways from the coelomic fluid supernatant and 42 from the coelomocytes were profiled, with carbon metabolism and ribosome being the two most prominent pathways. The Pfam database displayed that the immune-related proteins in U. unicinctus were neurofascin, cell adhesion molecule 4, receptor-type tyrosine-protein phosphatase F, limbic system-associated membrane protein, four and a half LIM domains protein 2, neuroglian, fasciclin-2, and neural cell adhesion molecule. Furthermore, the active substances from the coelomic fluid underwent isolation, purification, and antimicrobial characterization. The process yielded two purified components (b1 and b2), that were found to significantly inhibit the growth of Vibrio anguillarum, Aeromonas veronii, Micrococcus lysodeik, and Staphylococcus aureus. Based on the nano LC-MS/MS and homology analysis, it was concluded the two purified proteins from b1 and b2 might have been histones with a molecular weight of 11,367 Da. Our study is the first to provide proteomic information on U. unicinctus, which can extend our understanding on the roles of functional proteins in the defense mechanism of U. unicinctus and contribute to the advancement of related drug development in U. unicinctus farming.

Quantification of the inputs and outputs of serine and glycine metabolism in cancer cells

BACKGROUND

The significance of serine and glycine metabolism in cancer cells is increasingly acknowledged, yet the quantification of their metabolic flux remains incomplete, impeding a comprehensive understanding. This study aimed to quantify the metabolic flux of serine and glycine in cancer cells, focusing on their inputs and outputs, by means of Combinations of C-13 Isotopes Tracing and mathematical delineation, alongside Isotopically Nonstationary Metabolic Flux Analysis.

RESULTS

In HeLa cells, serine uptake, the serine synthesis pathway (SSP), and other sources (e.g., protein degradation) contribute 71.2 %, 24.0 %, and 5.7 %, respectively, to serine inputs. Conversely, glycine inputs stem from uptake (45.6 %), conversion from serine (45.1 %), and other sources (9.4 %). Serine input flux surpasses glycine by 7.3-fold. Serine predominantly directs a major fraction (94.7 %) to phospholipid, sphingolipid, and protein synthesis, with only a minor fraction (5.3 %) directing towards one-carbon unit and glycine production. Glycine mainly supports protein and nucleotide synthesis (100 %), without conversion back to serine. Serine output rate exceeds glycine output rate by 7.3-fold. Serine deprivation mainly impairs output to synthesis of phospholipid and sphingolipid, crucial for cell growth, while other outputs unaffected. AGS cells exhibit comparable serine and glycine flux to HeLa cells, albeit lacking SSP activity. Serine deprivation in AGS cells halts output flux to phospholipid, sphingolipid, protein synthesis, completely inhibiting cell growth.

CONCLUSIONS

By providing quantitative insights into serine and glycine metabolism, this study delineates the association of serine flux to different metabolic pathway with cancer cell growth and offers potential targets for therapeutic intervention, highlighting the importance of serine flux to pathway for the synthesis of phospholipids and sphingolipids in cancer cells growth.

Mitochondria: An overview of their origin, genome, architecture, and dynamics

Mitochondria are traditionally viewed as the powerhouses of eukaryotic cells, i.e., the main providers of the metabolic energy required to maintain their viability and function. However, the role of these ubiquitous intracellular organelles far extends energy generation, encompassing a large suite of functions, which they can adjust to changing physiological conditions. These functions rely on a sophisticated membrane system and complex molecular machineries, most of which imported from the cytosol through intricate transport systems. In turn, mitochondrial plasticity is rooted on mitochondrial biogenesis, mitophagy, fusion, fission, and movement. Dealing with all these aspects and terminology can be daunting for newcomers to the field of mitochondria, even for those with a background in biological sciences. The aim of the present educational article, which is part of a special issue entitled "Mitochondria in aging, cancer and cell death", is to present these organelles in a simple and concise way. Complex molecular mechanisms are deliberately omitted, as their inclusion would defeat the stated purpose of the article. Also, considering the wide scope of the article, coverage of each topic is necessarily limited, with the reader directed to excellent reviews, in which the different topics are discussed in greater depth than is possible here. In addition, the multiple cell type-specific genotypic and phenotypic differences between mitochondria are largely ignored, focusing instead on the characteristics shared by most of them, with an emphasis on mitochondria from higher eukaryotes. Also ignored are highly degenerate mitochondrion-related organelles, found in various anaerobic microbial eukaryotes lacking canonical mitochondria.

The oncoprotein SET promotes serine-derived one-carbon metabolism by regulating SHMT2 enzymatic activity

Cancer cells frequently reprogram one-carbon metabolic pathways to fulfill their vigorous demands of biosynthesis and antioxidant defense for survival and proliferation. Dysfunction of oncogenes or tumor suppressor genes is critically involved in this process, but the precise mechanisms by which cancer cells actively trigger one-carbon metabolic alterations remain incompletely elucidated. Here, by using untargeted metabolomic analysis, we identify the oncoprotein SE translocation (SET) as a key regulator of one-carbon metabolism in cancer cells. SET physically interacts with mitochondrial SHMT2 and facilitates SHMT2 enzymatic activity. Loss of SET profoundly suppresses serine-derived one-carbon metabolic flux, whereas reexpression of ectopic SET leads to the opposite effect. Notably, although the presence of SHMT2 is critical for SET-mediated one-carbon metabolic alterations, the depletion of SHMT2 alone is insufficient to antagonize SET-induced tumor growth, probably due to functional compensation by its cytosolic isozyme SHMT1 upon SHMT2 knockdown. Instead, pharmacological targeting of cellular SHMT (including both SHMT1 and SHMT2) activity results in dramatic suppression of SET-induced tumor growth. Moreover, by using a Kras/Lkb1 mutation-driven lung tumor mouse model, we demonstrate that the loss of SET compromises both tumor formation and intratumoral SHMT2 enzymatic activity. Clinically, the overexpression of SET and SHMT2 is observed in lung tumors, both of which correlate with poor prognosis. Our study reveals a SET-SHMT2 axis in regulating serine-derived one-carbon metabolism and uncovers one-carbon metabolic reprogramming as a mechanism for SET-driven tumorigenesis.

MTHFD2: A significant mitochondrial metabolic enzyme and a novel target for anticancer therapy

Methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) is a crucial mitochondrial enzyme that operates within the folate one-carbon metabolic pathway. In recent years, it has been discovered that its expression is upregulated in numerous tumors and is correlated with the onset and progression of tumors, as well as poor prognosis. In contrast to its isoenzymes, it is overexpressed in tumors and is either expressed at low levels or not expressed at all in normal tissues. Consequently, it has received extensive attention and has been proposed as a novel anticancer target. In this paper, we review the functions of MTHFD2 in tumors, its regulatory mechanisms, and research progress on MTHFD2 inhibitors. Additionally, we provide insights into future research directions and the design and development of inhibitors for MTHFD2.

Vitamins and dietary supplements in cancer treatment: is there a need for increased usage?

INTRODUCTION

Vitamins are essential for homeostasis and proper functioning of organisms. These micronutrients prevent tumor onset by functioning as antioxidants and enzymatic cofactors involved in anti-stress and immune responses, modulating epigenetic regulators, and shaping the microbiota composition. Unbalanced diets and sedentary lifestyles contribute to obesity, associated with increasing cancer risk. Cancer patients often exhibit vitamin deficiencies due to chronic inflammation, anticancer therapies, and tumor-induced metabolic changes, leading to malnutrition and cachexia.

AREAS COVERED

This review critically analyzes preclinical and clinical studies, sourced from PubMed and ClinicalTrials.gov databases, that investigate the potential benefits of vitamin supplementation and dietary interventions, such as intermittent fasting and ketogenic diets, in mouse tumor models and cancer patients. This analysis elucidates the limitations of such interventions and suggests optimal dietary strategies to prevent cancer and enhance patients' quality of life and prognosis.

EXPERT OPINION

To date, clinical studies have found no substantial benefit of over-the-counter vitamin supplements and dietary interventions on cancer patients' health and prognosis. To prevent the spread of useless and potentially harmful products by the nutraceutical industry, establishing a regulatory authority is necessary to monitor and ensure product quality and validity before commercialization.

Mechanism and Therapeutic Progress of One-Carbon Metabolic Key Enzyme: Serine Hydroxymethyltransferase 2 in Cancer

Serine hydroxymethyltransferase 2 (SHMT2) is a crucial mitochondrial enzyme in 1-carbon (1C) metabolism. It catalyzes the conversion of serine to glycine, generating 1C units essential for purine and pyrimidine synthesis, thereby supporting DNA replication and repair. Abnormally high expression is associated with malignant progression and treatment tolerance in various cancers. This review systematically summarizes the functions of SHMT2 in different types of cancer, underscoring on its roles in metabolism, immune microenvironment, and key signaling pathways (PI3K/AKT/mTOR, JAK-STAT, etc.) and outlines its epigenetic regulation and posttranslational modification mechanisms. Compared with the existing research, we focused on the latest regulatory mechanisms of SHMT2 and its potential in cancer treatment, such as the development and application of small-molecule inhibitors (SHIN2 and AGF347).

One-carbon metabolism, insulin resistance, and fecundability in a Singapore prospective preconception cohort study

BACKGROUND

One-carbon metabolism, which consists of the folate cycle, methionine cycle, and transsulphuration pathway, is associated with nucleotide synthesis. However, the association between one-carbon metabolites, metabolic status, and reproductive health remains poorly understood.

OBJECTIVE

We examined the association between the one-carbon cycle plasma metabolites and fecundability, and determined whether it is modified by metabolic health status, as assessed by insulin resistance (IR).

METHODS

This prospective cohort study utilized data from the Singapore PREconception Study of Long-Term Maternal and Child Outcomes. Fasting blood samples were collected and one-carbon cycle metabolites were measured. Fecundability was measured by time to pregnancy in menstrual cycles within a year of enrollment. We identified patterns in plasma one-carbon cycle metabolites using principal component analysis. We estimated fecundability ratios (FRs) and confidence intervals (CIs), with confounder adjustment using discrete-time proportional hazards models. IR was determined using the Homeostatic Model Assessment 2 Insulin Resistance score, classified into lower IR (<0.65) and higher IR (≥0.65). The role of IR was examined through interaction tests and stratification.

RESULTS

We identified three one-carbon cycle principal components (PCs). PC1, characterized by higher folate and lower homocysteine levels; PC2, characterized by higher levels of dimethylglycine, choline, methionine and betaine; PC3, characterized by higher levels of vitamins B2, B12 and B6. Each z-score increase in PC1 was associated with a 17% increase in fecundability (FR 1.17; 95% CI 1.03, 1.33). The association between PC1 and fecundability was more evident in women with lower IR (1.30; 1.08, 1.57), but was attenuated in those with higher IR (1.09; 0.92, 1.30), with a p-for-interaction of 0.127. PC2 and PC3 were not associated with fecundability.

CONCLUSIONS

Our findings suggest that higher folate and lower homocysteine levels, which reflected the interlinked folate and methionine cycles, was associated with higher fecundability in preconception women with lower IR, but less so in those with higher IR. Clinical Trial Registry number and website where it was obtained NCT03531658, https://www.

CLINICALTRIALS

gov/study/NCT03531658.

DmdA-independent lag phase shortening in Phaeobacter inhibens bacteria under stress conditions

Bacteria can shorten their lag phase by using methyl groups from compounds like dimethylsulfoniopropionate (DMSP), which are incorporated into cellular components via the methionine cycle. However, the role of specific methionine synthases in this process is not fully understood. Using transcriptomics, genetics, and biochemical assays, we investigated methionine synthases involved in lag phase shortening in Phaeobacter inhibens. We focused on a cobalamin-dependent methionine synthase (MetH)-like complex encoded by three genes: a betaine-homocysteine S-methyltransferase (bmt), a cobalamin-binding protein (cbp), and an intermediate methyl carrier (PGA1_c16040). Expression profiling revealed transcriptional decoupling among these genes. Deleting bmt disrupted lag phase shortening in response to DMSP. Functional assays showed that Bmt can directly produce methionine from DMSP and betaine, independent of tetrahydrofolate (THF) or cobalamin. Interestingly, under stress conditions, lag phase shortening occurred even in the absence of dimethylsulfoniopropionate demethylase DmdA, the primary DMSP demethylase. Under osmotic and oxidative stress, bmt expression increased significantly in response to both DMSP and betaine, suggesting an alternative methylation route. This highlights the role of Bmt as both demethylase and a methionine synthase under stress, offering a cost-effective strategy for methyl group assimilation. Our findings reveal a novel stress-responsive pathway for methionine synthesis and demonstrate the role of Bmt in promoting bacterial adaptation by accelerating the lag phase.

Longitudinal pathway analysis using structural information with case studies in early type 1 diabetes

Pathway analysis is a frequent step in studies involving gene or protein expression data, but most of the available pathway methods are designed for simple case versus control studies of two sample groups without further complexity. The few available methods allowing the pathway analysis of more complex study designs cannot use pathway structures or handle the situation where the variable of interest is not defined for all samples. Such scenarios are common in longitudinal studies with so long follow up time that healthy controls are required to identify the effect of normal aging apart from the effect of disease development, which is not defined for controls. To address the need, we introduce a new method for Pathway Analysis of Longitudinal data (PAL), which is suitable for complex study designs, such as longitudinal data. The main advantages of PAL are the use of pathway structures and the suitability of the approach for study settings beyond currently available tools. We demonstrate the performance of PAL with simulated data and three longitudinal datasets related to the early development of type 1 diabetes, which involve different study designs and only subtle biological signals, and include both transcriptomic and proteomic data. An R package implementing PAL is publicly available at https://github.com/elolab/PAL .

Cytosolic NADK is conditionally essential for folate-dependent nucleotide synthesis

Nicotinamide adenine dinucleotide kinase (NADK) catalyses the phosphorylation of NAD+ to produce NAD phosphate, the oxidized form of NADPH, a cofactor that serves a critical role in driving reductive metabolism. Cancer cells co-express two distinct NAD kinases that differ by localization (NADK, cytosol; NADK2, mitochondria). CRISPR screens performed across hundreds of cancer cell lines indicate that both are dispensable for growth in conventional culture media. By contrast, NADK deletion impaired cell growth in human plasma-like medium. Here we trace this conditional NADK dependence to the availability of folic acid. NADPH is the preferred cofactor of dihydrofolate reductase (DHFR), the enzyme that mediates metabolic activation of folic acid. We find that NADK is required for enabling cytosolic NADPH-driven DHFR activity sufficient to maintain folate-dependent nucleotide synthesis under low folic acid conditions. Our results reveal a basis for conditional NADK essentiality and suggest that folate availability determines whether DHFR activity can be sustained by alternative electron donors such as NADH.

Analysis of stress response in multiple bacterial pathogens using a network biology approach

Stress response in bacterial pathogens promotes adaptation, virulence and antibiotic resistance. In this study, a network approach is applied to identify the common central mediators of stress response in five emerging opportunistic pathogens; Enterococcus faecium Aus0004, Staphylococcus aureus subsp. aureus USA300, Klebsiella pneumoniae MGH 78,578, Pseudomonas aeruginosa PAO1, and Mycobacterium tuberculosis H37Rv. A Protein-protein interaction network (PPIN) was constructed for each stressor using Cytoscape3.7.1 from the differentially expressed genes obtained from Gene expression omnibus datasets. A merged PPIN was constructed for each bacterium. Hub-bottlenecks in each network were the central stress response proteins and common pathways enriched in stress response were identified using KOBAS3.0. 31 hub-bottlenecks were common to each individual stress response, merged networks in all five pathogens and an independent cross stress (CS) response dataset of Escherichia coli. The 31 central nodes are in the RpoS mediated general stress regulon and also regulated by other stress response systems. Analysis of the 20 common metabolic pathways modulating stress response in all five bacteria showed that carbon metabolism pathway had the highest crosstalk with other pathways like amino acid biosynthesis and purine metabolism pathways. The central proteins identified can serve as targets for novel wide-spectrum antibiotics to overcome multidrug resistance.

Titaminates, a Biocompatible Titanium-Organic Hybrid Film, Support the Growth and Function of Conjunctival Epithelial Cells

PURPOSE

To find an ideal biosurface to regenerate conjunctival epithelium.

DESIGN

Experimental study.

METHODS

Pieces of human cadaveric conjunctival epithelium removed of connective tissues were randomly placed on 8 different biosurfaces to grow primary conjunctival epithelial cells for 9 to 14 days until the fastest growing cultures covered 80% to 90% of the film surface. Main outcome measures were growth, proliferation capacity, startification, mucin 5AC (MUC5AC) secretion, and compositional balance in cell types.

RESULTS

All titanium-based films (titaminates) supported the growth, stratification, proliferation, and MUC5AC secretion function of human primary conjunctival epithelial cells (HCjECs), but none of the zinc-based films grew cells at all. Although HCjECs' ability to proliferate, stratify, and secrete MUC5AC per unit cell area was similar across all titaminates, titanium dioxide (TiO2) and glycine titaminates (TiG) outperformed TiD and TiGD in terms of outgrowth, recapitulation of native conjunctival epithelium, and compositional balance in cell types. When goblet cells (a subtype of HCjECs) were predominantly grown on these films by using a different culture medium, the results were similar in all aspects.

CONCLUSIONS

Given the body-friendly nature and clinically proven safety and efficacy of titanium, titaminates TiO2 and TiG have potential as an alternative bioactive substrate for conjunctival epithelium regeneration.

MTHFD2 promotes esophageal squamous cell carcinoma progression via m6A modification‑mediated upregulation and modulation of the PEBP1‑RAF1 interaction

One‑carbon metabolism plays an important role in cancer progression. Methylenetetrahydrofolate dehydrogenase 2 (MTHFD2), a mitochondrial enzyme in one‑carbon metabolism, is dysregulated in several cancer types. However, the precise role and mechanisms of MTHFD2 in esophageal squamous cell carcinoma (ESCC) remain unclear. The present study unravels the multifaceted mechanisms by which MTHFD2 contributes to ESCC pathogenesis. Bioinformatics analyses revealed significant upregulation of MTHFD2 in ESCC tumor tissues, which was associated with advanced disease stage and poor patient prognosis. Validating these findings in clinical samples, MTHFD2 overexpression was confirmed through immunohistochemistry, Reverse transcription‑quantitative PCR and western blotting. Knockdown of MTHFD2 inhibited ESCC cell viability, colony formation, invasion, and tumor growth in vivo, indicating its oncogenic potential. Mechanistically, the present study elucidated a novel regulatory axis involving N6‑methyladenosine modification and MTHFD2 mRNA stability. Specifically, methyltransferase‑like 3 (METTL3) and insulin‑like growth factor 2 mRNA binding protein 2 (IGF2BP2) were identified as key mediators of m6A‑dependent stabilization of MTHFD2 mRNA, contributing to its elevated expression in ESCC. Furthermore, MTHFD2 was found to activate PI3K/AKT and ERK signaling pathways by modulating interaction between phosphatidylethanolamine‑binding protein 1 (PEBP1) and raf‑1 proto‑oncogene (RAF1). This modulation was achieved through direct binding of MTHFD2 to PEBP1, disrupting the inhibitory effect of PEBP1 on RAF1 and promoting downstream pathway activation. The oncogenic functions of MTHFD2 were attenuated upon PEBP1 knockdown, underscoring the role of the MTHFD2‑PEBP1 axis in ESCC progression. In summary, the present study uncovers a novel regulatory mechanism involving m6A modification and the MTHFD2‑PEBP1 axis, unveiling potential therapeutic avenues for targeting MTHFD2 in ESCC.

Quantification of multi-pathway metabolites related to folate metabolism and application in natural population with MTHFR C677T polymorphism

Folate, serving as a crucial micronutrient, plays an important role in promoting human growth and supporting transformations to a variety of metabolic pathways including one-carbon, pyrimidine, purine, and homocysteine metabolism. The 5,10-methylenetetrahydrofolate reductase (MTHFR) enzyme is pivotal in the folate metabolic pathway. Polymorphism in the MTHFR gene, especially C677T, was associated with decreased enzyme activity and disturbance of folate metabolism, which is linked to various diseases including birth defects in newborns and neural tube abnormalities. However, the detailed metabolic disturbance induced by MTHFR C677T polymorphism is still elusive. In this study, a novel liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the precise quantification of 93 metabolites from six important metabolic pathways related to folate metabolism. The method characteristics demonstrated high accuracy and precision, with r2 values ranging from 0.981 to 1.000 for all metabolites. Then the impact of the MTHFR C677T polymorphism on folate metabolism was further investigated, revealing a significant reduction in the level of 5-methyltetrahydrofolate and abnormal levels of metabolites associated with DNA synthesis pathways in individuals carrying the mutation. These data highlight the pivotal role of folic acid supplementation for individuals with the MTHFR C677T polymorphism to mitigate health risks and show the value of precision measurement of folate-related metabolites.

Dysfunctional one-carbon metabolism identifies vitamins B6, B9, B12, and choline as neuroprotective in glaucoma

Glaucoma, characterized by the loss of retinal ganglion cells (RGCs), is a leading cause of blindness for which there are no neuroprotective therapies. To explore observations of elevated homocysteine in glaucoma, we elevate vitreous homocysteine, which increases RGC death by 6% following ocular hypertension. Genetic association with higher homocysteine does not affect glaucoma-associated outcomes from the UK Biobank and serum homocysteine levels have no effect on glaucomatous visual field progression. This supports a hypothesis in which elevated homocysteine is a pathogenic, rather than causative, feature of glaucoma. Further exploration of homocysteine metabolism in glaucoma animal models demonstrates early and sustained dysregulation of genes involved in one-carbon metabolism and the interaction of essential cofactors and precursors (B6, B9, B12, and choline) in whole retina and optic nerve head and RGCs. Supplementing these provides neuroprotection in an acute model and prevents neurodegeneration and protects visual function in a chronic model of glaucoma.

Inhibition Of One-Carbon Metabolism In Ewing Sarcoma Results In Profound And Prolonged Growth Suppression Associated With Purine Depletion

Ewing sarcoma (EWS) is the second most common primary bone malignancy in adolescents and young adults. Patients who present with localized disease have experienced a steadily improving survival rate over the years, whereas those who present with metastatic disease have the same dismal prognosis as 30 years ago, with long term survival rates less than 20%, despite maximal intensification of chemotherapy. Thus, novel treatment approaches are a significant unmet clinical need. Targeting metabolic differences between EWS and normal cells offers a promising approach to improve outcomes for these patients. One-carbon metabolism utilizes serine and folate to generate glycine and tetrahydrofolate (THF)-bound one-carbon units required for de novo nucleotide biosynthesis. Elevated expression of several one-carbon metabolism genes is significantly associated with reduced survival in EWS patients. We show that both genetic and pharmacological inhibition of a key enzyme of the mitochondrial arm of the one-carbon metabolic pathway, serine hydroxymethyltransferase 2 (SHMT2), leads to substantial inhibition of EWS cell proliferation and colony-forming ability, and that this effect is primarily caused by depletion of glycine and one-carbon units required for synthesis of purine nucleotides. Inhibition of one-carbon metabolism at a different node, using the clinically relevant dihydrofolate reductase inhibitor Pralatrexate, similarly yields a profound growth inhibition, with depletion of thymidylate and purine nucleotides. Genetic depletion of SHMT2 dramatically impairs tumor growth in a xenograft model of EWS. Together, these data establish the upregulation of the one-carbon metabolism as a novel and targetable vulnerability of EWS cells, which can be exploited for therapy.

Statement of Significance

Using both genetic and pharmacologic approaches, this study identifies Ewing sarcoma's dependence on the mitochondrial arm, but not the cytoplasmic arm, of one-carbon metabolism as a targetable vulnerability that can be effectively harnessed for therapy.

SYNLAC Prime probiotics alleviate Enterocytozoon hepatopenaei-induced damage in white shrimp, Penaeus vannamei by enhancing growth, immunity, and resistance to Vibrio parahaemolyticus

This study evaluates the efficacy of SYNLAC Prime probiotics, both live and heat-killed, in alleviating growth retardation and enhancing the health of white shrimp, Penaeus vannamei infected with Enterocytozoon hepatopenaei (EHP). Probiotic supplementation significantly improved growth performance of EHP-infected shrimp by increasing digestive enzyme activity in the hepatopancreas and guts. Interestingly, the final weight and weight gain percentage of EHP-infected shrimp supplemented with live probiotics surpassed that of healthy control shrimp. Probiotics modulated the gut microbiota, notably reducing Vibrio abundance. The immunomodulatory effects of probiotics were further highlighted by increased expression of immune-related genes and enhanced immune parameters. These immune responses are critical for pathogen defense and may contribute to the observed reduction in EHP load and increased resistance to Vibrio parahaemolyticus infection. To elucidate the metabolic differences between healthy and EHP-infected shrimp and to assess the effects of dietary probiotic supplementation, hepatopancreatic metabolite profiles were analyzed using LC-MS/MS. In positive ion mode, 54, 76, and 84 differential metabolites were identified in the NCON, P5D, and P5L groups, respectively, relative to the PCON group. In negative ion mode, 89, 80, and 64 metabolites were significantly altered across the same comparisons. KEGG pathway enrichment indicated that differential metabolites were primarily involved in key metabolic pathways, including terpenoid backbone biosynthesis, one-carbon metabolism, glycolysis/gluconeogenesis, pyrimidine metabolism, and amino acid biosynthesis. Notably, probiotic supplementation modulated multiple metabolic pathways associated with host immunity and energy metabolism. Heatmap analyses further revealed distinct metabolite expression patterns across all experimental groups. Overall, the findings demonstrate that probiotics, particularly live strains, offer a promising intervention for mitigating EHP-induced growth impairment and disease, enhancing both immune responses and metabolic stability in shrimp. This highlights the potential of probiotics as an effective tool in shrimp aquaculture, not only to improve growth performance but also to manage infections and improve overall health.

Association between oxidative balance score and methylation cycle biomarkers in US adults: insights from the national health and nutrition examination survey

Background

Oxidative stress(OS) is implicated in various diseases, and the methylation cycle plays a critical role in numerous biological processes including DNA methylation and antioxidant defense. We aimed to investigate the relationship between oxidative balance score (OBS) and methylation cycle.

Materials and methods

The study enrolled 28,061 adults ≥20 years old from the NHANES 2003-2014. Methylation cycle biomarkers included serum folate, RBC folate, vitamin B6, vitamin B12, homocysteine (HCY), and methylmalonic acid (MMA). OBS was scored by 20 dietary and lifestyle factors. We employed weighted linear regression and restricted cubic spline (RCS) models to analyze the correlations among OBS, and methylation cycle.

Results

In a nationally representative cohort of US adults (mean age: 47.04 ± 0.25 years; 51.76% female), OBS demonstrated significant associations with key methylation cycle biomarkers. After adjusting for potential confounders, OBS exhibited a positive association with serum folate, RBC folate, vitamin B6, and vitamin B12, a negative correlation with HCY (all P for trend < 0.001), and no correlation with MMA (P for trend = 0.07). Higher dietary OBS was correlated with increased levels of serum folate, RBC folate, vitamin B6, and vitamin B12, and decreased levels of HCY (all P for trend < 0.001). Similarly, a higher lifestyle OBS corresponded to increased serum folate, vitamin B6, and vitamin B12, as well as decreased HCY (all P for trend < 0.05). Stratified analyses demonstrated that OBS had a strong positive correlation with serum folate, RBC folate, vitamin B6, and vitamin B12, and a strong negative correlation with HCY. Additionally, the negative correlation between OBS and MMA was observed in the elderly population (≥ 60 years old) when stratified by age. RCS regression analysis revealed that with the increase in OBS, serum folate, RBC folate, vitamin B6, and vitamin B12 also increased, while HCY and MMA decreased.

Conclusion

Our findings demonstrate a significant relationship between OBS and the methylation cycle. Higher OBS is positively associated with folate and vitamins B6/B12, and negatively with HCY.

Targeting MTHFD2 alters metabolic homeostasis and synergizes with bortezomib to inhibit multiple myeloma

Multiple myeloma (MM) is an incurable hematologic malignancy. While recent therapies have significantly improved survival in MM patients, drug resistance and refractory phenomenon underscores the urgent need of new therapeutic targets. Methylenetetrahydrofolate dehydrogenase 2(MTHFD2) has been widely reported as a potential and promising anti-cancer target, but its role and underlying mechanisms remain unclear in MM. We aimed to investigate the biologic function and mechanisms of MTHFD2 in MM. First, we demonstrated that MTHFD2 is overexpressed in MM and associated with poor prognosis. We then illustrated that targeting MTHFD2 exhibits anti-MM effects in vitro and in vivo. Mechanistically, targeting MTHFD2 inhibited glycolysis and mitochondrial respiration in MM cells. For the nonmetabolic function of MTHFD2, we found that MTHFD2 knockdown affected the unfolded protein response (UPR) via decreasing expression of the splice form of X-box binding protein 1 (XBP1s). Importantly, the level of MTHFD2 in MM cells was associated with sensitivity of bortezomib, and targeting MTHFD2 synergizes with bortezomib against MM in vitro and in vivo. In summary, our innovative findings suggest that MTHFD2 is a promising target for MM, targeting it alters metabolic homeostasis of MM and synergizes with bortezomib to inhibit MM.

Targeted plasma proteomics reveals organ damage signatures of AIDS- and noncommunicable disease-related deaths in people with HIV

Antiretroviral therapy (ART) is shifting the primary driver of mortality for people with HIV (PWH) from opportunistic infections to noncommunicable diseases (NCDs). Protein biomarkers differentiating both AIDS-related and NCDs-related deaths from PWH may help early and precise risk prediction and intervention. We conduct a nested case-control study where 126 HIV deaths, 162 age-sex-matched HIV survivors and 152 HIV-negative controls are analyzed with 92 protein biomarkers of the Olink Organ Damage panel by proximity extension assays (PEA). Using LASSO regression, logistic regression, and ROC analysis, twelve proteins are significantly associated with HIV death, of which six (SIRT5, PPM1B, PSMA1, GALNT10, VEGFC, PTN) are specifically associated with NCDs-related death, two (RCOR1, SERPINA9) are specifically associated with AIDS-related death, and four (CA12, CA14, RARRES1, EDIL3) are associated with both. Three of these proteins are replicable in the external validation sample. The adjusted protein panels consisting of significantly associated proteins selected through both LASSO and logistic regression model well predicted NCDs-related death (AUC = 0.970) and AIDS-related death (AUC = 0.960) in PWH. The selected proteins also displayed a significant correlation with traditional biomarkers of NCDs among PWH (P < 0.05). The potential clinical utility of these biomarkers could shed light on pathogenesis of end-stage organ dysfunction in PWH.

MTHFD2 marks pemetrexed resistance in pulmonary adenocarcinoma with EGFR wild type

PURPOSE

Lung cancer is the leading cause of cancer-related deaths worldwide. Patients with an amplification of the MTHFD2 gene have a particularly poor prognosis. MTHFD2 signaling has been associated with migration, metastasis, and proliferation of lung cancer cells mediated through ERK signaling. Although the enzymatic activity of the MTHFD2 protein is well understood, little is known about its larger role in chemoresistance.

METHODS

Seventy-nine of non-small cell lung cancer (NSCLC) samples with clinical follow-up were subjected to immunohistochemical staining for MTHFD2 and sequenced using next generation sequencing (NGS) to determine EGFR status. MTHFD2 gene was knocked down in two NSCLC cell lines with wild type EGFR gene (HCC44 and H1993) where MTHFD2 signaling and chemotherapy resistance against pemetrexed were evaluated.

RESULTS

MTHFD2 expression data revealed a strong prognosis relevance in adenocarcinoma (LUAD). Immunoblotting of cell lines showed a MTHFD2 dependent and cell type specific ERK signaling in EGFR wild type cells. MTHFD2 expression induced proliferation of NSCLC cells and their resistance against pemetrexed. Knocking down the MTHFD2 gene induced cycle arrest, however, it did not activate apoptosis signaling within HCC44 cell line.

CONCLUSIONS

MTHFD2 expression is strongly associated with prognosis in LUAD patients, as well as with increased cellular proliferation and resistance to pemetrexed in LUAD patients with wild-type EGFR. These findings suggest that MTHFD2 could serve as a valuable biomarker for predicting treatment outcomes in LUAD. Further studies are needed to fully explore the clinical implications and potential combination therapies targeting MTHFD2 in LUAD.

G-quadruplex in cancer energy metabolism: A potential therapeutic target

In recent years, energy metabolism in cancer has received increasing attention as an important component of tumor biology, and the functions of transcription factors, mitochondria, reactive oxygen species (ROS) and the autophagy-lysosome system in which have been elucidated. G-quadruplex (G4) is a molecular switch that regulates gene transcription or translation. As an anticancer target, the effect of G4 on cancer cell proliferation, apoptosis, cycle and autophagy has been recognized. The energy metabolism system is a unified whole composed of transcription factors, metabolic regulators, metabolites and signaling pathways that run through the entire cancer process. However, the role of G4 in this complex metabolic network has not been systematically elucidated. In this review, we analyze the close correlation between G4 and transcription factors, mitochondria, ROS and the autophagy-lysosome system and suggest that G4 can exert a marked effect on cancer energy metabolism by regulating the above mentioned key regulatory elements. The anticancer effects of some G4 ligands through regulation of energy metabolism have also been summarized, confirming the clear involvement of G4 in energy metabolism. Although much more research is needed, we propose that G4 may play a critical role in the complex energy metabolism system of cancer, which is a promising target for anticancer strategies focusing on energy metabolism.

Identifying Aberrant 1CM-Related Pathways by Multi-Omics Analysis and Validating Tumor Inhibitory Effect of One-Carbon Donor Betaine in Gastric Cancer

Metabolic reprogramming, a well-established hallmark of gastric carcinogenesis, has been implicated in driving tumor progression. Nevertheless, the precise mechanisms through which these metabolic alterations orchestrate gastric cancer (GC) pathogenesis remain incompletely elucidated. We conducted metabolomic analyses of plasma samples obtained from 334 patients with GC and healthy individuals to identify differential metabolites and metabolic pathways. Transcriptome sequencing was conducted on six pairs of tissues, and a joint analysis of the transcriptome and metabolome was performed. Single-cell sequencing data were acquired and co-analyzed with metabolomics to investigate metabolic abnormalities at the single-cell level. Finally, four representative metabolites selected using Random Forest analysis were subjected to cellular experiments to elucidate the mechanisms through which these metabolites exert their effects. Metabolomic analyses revealed that serine and glycine metabolism, glycolysis, and glutamate metabolism were significantly altered in GC, suggesting that one-carbon metabolism (1CM)-related pathways are aberrantly activated. A combined analysis of the transcriptome, single-cell transcriptome, and metabolomics indicated that pathways related to oxidative phosphorylation, nucleotide metabolism, and amino acid metabolism in epithelial cells were altered in GC. Cellular experiments demonstrated that the one-carbon donor metabolite betaine could inhibit the activity, invasion, and migration of GC cells while activating the phosphorylation of AMPKα. In conclusion, the 1CM-related pathway and the metabolite betaine play significant roles in GC, and the mechanisms through which the one-carbon donor betaine influences GC warrant further investigation.

Folate from probiotic bacteria and its therapeutic applications

Folate, an essential water soluble vitamin B9 that cannot be synthesized naturally by the bodily function. Dietary sources or probiotic-folates are the two biological modes for acquiring the target vitamin which aids DNA synthesis and repair. Probiotics are known for their divergent health benefits and have garnered significant interest. Particularly in microbial strains that produce folate offers a promising way to enhance the level of folate. Notably, folate-producing probiotic strain includes Lactiplantibacillus, Lactococcus, Bifidobacterium, and Streptococcus. As an emerging source of health benefits, folate producing probiotics helps in improving the gut microbiota for overall well-being of human body. On the other side, chemically synthesized folic acid were not highly advantageous as they lacks absorption, conversion and excretion. Hence, usage of microbial-folate are safer as it can easily undergo absorption and reduces severe side effects. The present review mainly focus on folate one-carbon metabolism, its significance in human health, folate deficiency and malabsorption, adverse effects and folate synthesis from probiotic bacterial strains, and also toxicological impacts. In particular, the beneficiary role of these probiotic strains were found to be associated with therapeutic applications in several diseases such as autoimmune disorder, metabolic disorders, and cardiovascular diseases (CVDs), wound healing, drug delivery and cancer.

MTHFD2: A metabolic checkpoint altering trophoblast invasion and migration by remodeling folate-nucleotide metabolism in recurrent spontaneous abortion

Recurrent spontaneous abortion (RSA) affects female reproduction worldwide, yet its pathological mechanisms are still unclear. It has been reported that cellular metabolism reprogramming is a critical step for trophoblasts during embryo implantation. Herein, MTHFD2 was recognized as a key metabolic checkpoint attributed to RSA occurrence. This work figured out that the expression level of MTHFD2 was significantly inhibited in villus tissues from RSA patients, suggesting the potential role of MTHFD2 in RSA occurrence. Moreover, MTHFD2 knockdown impaired cellular folate-nucleotide metabolism, induced the accumulation of AICAR, and thereby impairing the EMT process to inhibit the invasion and migration of trophoblasts Besides, the AICAR accumulation further activated the downstream AMPK which deactivated the JAK/STAT/Slug pathway and ultimately deactivated the EMT process. Using a mouse model, MTHFD2 inhibition was observed to induce embryo implantation failure in vivo. Our results highlighted MTHFD2 as a metabolic checkpoint that remodeled folate-nucleotide metabolism to regulate the EMT process and ultimately altered the migration and invasion of trophoblasts in RSA occurrence. Our findings suggested that MTHFD2 was a promising therapeutic target in recurrent spontaneous abortion treatment.

Periodic dietary restriction of animal products induces metabolic reprogramming in humans with effects on cardiometabolic health

Dietary interventions constitute powerful approaches for disease prevention and treatment. However, the molecular mechanisms through which diet affects health remain underexplored in humans. Here, we compare plasma metabolomic and proteomic profiles between dietary states for a unique group of individuals who alternate between omnivory and restriction of animal products for religious reasons. We find that short-term restriction drives reductions in levels of lipid classes and of branched-chain amino acids, not detected in a control group of individuals, and results in metabolic profiles associated with decreased risk for all-cause mortality. We show that 23% of proteins whose levels are affected by dietary restriction are druggable targets and reveal that pro-longevity hormone FGF21 and seven additional proteins (FOLR2, SUMF2, HAVCR1, PLA2G1B, OXT, SPP1, HPGDS) display the greatest magnitude of change. Through Mendelian randomization we demonstrate potentially causal effects of FGF21 and HAVCR1 on risk for type 2 diabetes, of HPGDS on BMI, and of OXT on risk for lacunar stroke. Collectively, we find that restriction-associated reprogramming improves metabolic health and emphasise high-value targets for pharmacological intervention.

SAM transmethylation pathway and adenosine recycling to ATP are essential for systemic regulation and immune response

During parasitoid wasp infection, activated immune cells of Drosophila melanogaster larvae release adenosine to conserve nutrients for immune response. S-adenosylmethionine (SAM) is a methyl group donor for most methylations in the cell and is synthesized from methionine and ATP. After methylation, SAM is converted to S-adenosylhomocysteine, which is further metabolized to adenosine and homocysteine. Here, we show that the SAM transmethylation pathway is up-regulated during immune cell activation and that the adenosine produced by this pathway in immune cells acts as a systemic signal to delay Drosophila larval development and ensure sufficient nutrient supply to the immune system. We further show that the up-regulation of the SAM transmethylation pathway and the efficiency of the immune response also depend on the recycling of adenosine back to ATP by adenosine kinase and adenylate kinase. We therefore hypothesize that adenosine may act as a sensitive sensor of the balance between cell activity, represented by the sum of methylation events in the cell, and nutrient supply. If the supply of nutrients is insufficient for a given activity, adenosine may not be effectively recycled back into ATP and may be pushed out of the cell to serve as a signal to demand more nutrients.

How Increased Dietary Folic Acid Intake Impacts Health Outcomes Through Changes in Inflammation, Angiogenesis, and Neurotoxicity

Dietary folic acid supplementation is well known for playing a crucial role in the closure of the neural tube. Individuals have continued to increase dietary intake of folic acid in counties with mandatory fortication laws in place. Some studies have demonstrated adverse health effects in individuals with high dietary intake of folic acid. Nutrition is a modifiable risk factor for ischemic stroke. Specifically, elevated levels of homocysteine, they can be reduced by increasing intake of vitamins, such as folic acid, a B-vitamin. Hypoxia, when levels of oxygen are reduced, is a major component of cardiovascular diseases. The aim of this review paper was to summarize how increased dietary intake of folic acid interaction with hypoxia to impact health outcomes. Our survey of the literature found that increased dietary intake of folic acid promotes inflammation, angiogenesis, and neurotoxicity. We also report negative actions of increased dietary intake of folic acid with vitamin B12 and genetic deficiencies in one-carbon metabolism. Increased dietary intake of folic acid also results in elevated levels of unmetabolized folic acid in the population, of which the impact on health risks has not yet been determined. Our review of the literature emphasizes that a more comprehensive understanding of the action between increased dietary intake of folic acid on disease outcomes could pave the way for improved public health guidelines. Furthermore, adequate knowledge of an individual's one-carbon metabolism status can inform proactive management for patients at higher risk of experiencing negative health outcomes.

Potential role of genetic polymorphisms in neoadjuvant chemotherapy response in breast cancer

Chemoresistance leads to treatment failure, which can arise through different mechanisms including patients' characteristics. Searching for genetic profiles as a predictor for drug response and toxicity has been extensively studied in pharmacogenomics, thus contributing to personalized medicine and providing alternative treatments. Numerous studies have demonstrated significant evidence of association between genetic polymorphisms and response to neoadjuvant chemotherapy (NAC) in breast cancer. In this review, we explored the potential impact of genetic polymorphisms in NAC primary resistance through selecting a specific clinical profile. The genetic variability within pharmacokinetics, pharmacodynamics, DNA synthesis and repair, and oncogenic signaling pathways genes could be predictive or prognostic markers for NAC resistance. The clinical implication of these results can help provide individualized treatment plans in the early stages of breast cancer treatment. Further studies are needed to determine the genetic hosts of primary chemoresistance mechanisms in order to further emphasize the implementation of genotypic approaches in personalized medicine.

Pan‑cancer analysis of oncogene SFXN1 to identify its prognostic and immunological roles in lung adenocarcinoma

As cancer incidence and mortality rates continue to rise, the urgency for research in this field has increased globally. Sideroflexin 1 (SFXN1), a pivotal member of the SFXN protein family, serves a crucial role in transporting serine to mitochondria and participates in one‑carbon metabolism, thereby influencing cell proliferation and differentiation. While SFXN1 is linked to lung cancer and glioma, its role in other malignancies remains largely unexplored. Utilizing The Cancer Genome Atlas, Human Protein Atlas, Gene Expression Profiling Interactive Analysis and University of Alabama at Birmingham Cancer Data Analysis Portal databases, the present study investigated the expression patterns, prognostic implications and association with immune cell infiltration of SFXN1. The present findings revealed that SFXN1 was differentially expressed across various tumor types, and exhibited significant associations with clinicopathological features and patient prognosis. Through immune infiltration analysis, a significant correlation between SFXN1 and T cells, B cells and immune checkpoint genes was established in numerous tumor types. Notably, loss‑of‑function experiments demonstrated that silencing of SFXN1 decreased cell proliferation, migration and invasion, while simultaneously increasing apoptosis in lung adenocarcinoma cells. Collectively, these findings suggested that SFXN1 expression could potentially serve as a biomarker for tumor diagnosis and prognosis, also emerging as a novel therapeutic target in cancer immunotherapy. The present study highlights the critical role of SFXN1 in cancer biology and paves the way for future translational efforts aimed at leveraging its potential in clinical oncology.

The direct targets of metformin in diabetes and beyond

Metformin, an oral antihyperglycemic drug that has been in use for over 60 years, remains a first-line therapy for type 2 diabetes (T2D). Numerous studies have suggested that metformin promotes health benefits beyond T2D management, including weight loss, cancer prevention and treatment, and anti-aging, through several proposed mechanistic targets. Here we discuss the established effects of metformin and the progress made in identifying its direct targets. Additionally, we emphasize the importance of elucidating the structural bases of the drug and its direct targets. Ultimately, this review aims to highlight the current state of knowledge regarding metformin and its related emerging discoveries, while also outlining critical future research directions.

Folic Acid-Targeted Liposome-Based Nanoparticle Loaded with Sorafenib for Liver Cancer Therapy

Introduction

Sorafenib (SF) is a small molecule involved in tumor proliferation and angiogenesis. SF is inhibitor of several kinases, including RAF, VEGFR, and PDGFR. However the weak targeting ability of SF for liver tumor tissues is the major problem in clinical therapy. Therefore, a SF-loaded folic acid-targeted liposome drug delivery system was devised for targeting liver tumor therapy in this study.

Methods

Folic acid (FA), HSPC, DSPE-PEG2k, CHO, and SF were composed to prepare a folic acid-targeted SF-loaded liposome (LSF) drug delivery system. LSF and drug loading content was established through thin-film-hydration technique and HPLC, respectively. The particle size and stability of LSF were examined by dynamic light scattering (DLS). The inhibition effect of LSF was elucidated in vitro on liver cancer cells through cell cytotoxicity and apoptosis experiments. The tumor-inhibiting efficacy was measured on liver xenograft model.

Results

The drug loading content (DLC) of LSF was 3.6%. The diameter of LSF was 197.1±16.6 nm, and LSF was stable during 24 h. Liver cancer cells could be effectively inhibited by LSF in vitro. LSF could substantially induce apoptosis. Also, LSF could inhibit tumor growth effectively in vivo. LSF could reduce side effects of SF demonstrated by bio-safety tests.

Conclusion

LSF is a FA-targeted drug delivery system that could effectively inhibit the progression of liver cancer.

Epigenetic and metabolic regulation of developmental timing in neocortex evolution

The human brain is characterized by impressive cognitive abilities. The neocortex is the seat of higher cognition, and neocortex expansion is a hallmark of human evolution. While developmental programs are similar in different species, the timing of developmental transitions and the capacity of neural progenitor cells (NPCs) to proliferate differ, contributing to the increased production of neurons during human cortical development. Here, we review the epigenetic regulation of developmental transitions during corticogenesis, focusing mostly on humans while building on knowledge from studies in mice. We discuss metabolic-epigenetic interplay as a potential mechanism to integrate extracellular signals into neural chromatin. Moreover, we synthesize current understanding of how epigenetic and metabolic deregulation can cause neurodevelopmental disorders. Finally, we outline how developmental timing can be investigated using brain organoid models.

CRISPR screening identifies protein methylation and ubiquitination modifications that modulate aflatoxin B1 cytotoxicity

Aflatoxin B1 (AFB1) is one of the most potent mycotoxins affecting human health and animal production. To deeply understand the host-toxin interaction, we performed CRISPR screening and identified cystathionine β-synthase (CBS) as a critical host gene affecting AFB1 cytotoxicity. Mechanistic studies revealed that CBS affects AFB1-induced cell death by regulating the abundance of protein post-translational modifications (PTMs) in host cells. First, AFB1 disrupted the transfer of S-adenosylmethionine (SAM) from the cytoplasm to the mitochondria, thereby reducing the intra-mitochondrial protein methylation level. Deficient intra-mitochondrial protein methylation impaired mitochondrial function and caused cell death. CBS knockout (KO) can enhance SAM generation and mobilization to restore intra-mitochondrial SAM levels by rescuing the perturbed methionine cycle after AFB1 exposure, thereby alleviating AFB1-induced cell death. Second, AFB1 decreased global protein ubiquitination levels by affecting gene expression of ubiquitin-modified enzymes. CBS-KO and pharmaceutical treatment correcting gene expression of ubiquitin-modified enzymes can rescue AFB1-induced cell death. We also investigated two PTM-regulating small molecules, SAM and PR-619, which can increase cell viability in AFB1-exposed cells.

Higher serum vitamin B6 is associated with lower all-cause mortality among cancer survivors in the National Health and Nutrition Examination Survey

Variations in serum concentrations of vitamin B6, vitamin B12, and folate may influence cancer development and progression. However, the association between these 3 serum B vitamins and all-cause mortality among cancer survivors remains unclear. We evaluated the potential associations between serum vitamins B6, B12, and folate and all-cause mortality among cancer survivors. Our hypothesis proposed that higher serum concentrations of vitamin B6, vitamin B12, and folate might be inversely associated with a lower risk of all-cause mortality in this population. Data from the National Health and Nutrition Examination Survey (NHANES) 1999-2018 were used. All-cause mortality was determined by linking participant data to National Death Index records till 31 December 2019. Serum vitamins B6, B12, and folate status were measured. Multivariable Cox regression analyses were applied to investigate the relationship between serum vitamins B6, B12, and folate concentrations and all-cause mortality among cancer survivors. Serum vitamin B6 was inversely associated with all-cause mortality, with a fully-adjusted HR of 0.54 (95%CI: 0.38, 0.78, Ptrend< .001). However, no statistically significant association was observed between serum vitamin B12 as well as serum folate concentration and all-cause mortality among cancer survivors (B12: fully-adjust HR = 0.90, 95%CI: 0.63, 1.27, Ptrend = .771; folate: fully-adjust HR = 0.82, 95%CI: 0.63, 1.08, Ptrend = .269). No statistically significant interaction for age, sex, and BMI was found in stratified analyses. No non-linear relationship was found except for serum folate. These results suggest that higher serum vitamin B6 may be associated with improved survival in cancer survivors.

Betaine regulates the gut-liver axis: a therapeutic approach for chronic liver diseases

Chronic liver disease is defined by persistent harm to the liver that might result in decreased liver function. The two prevalent chronic liver diseases are alcohol-associated liver disease (ALD) and metabolic dysfunction-associated steatotic liver disease (MASLD). There is ample evidence that the pathogenesis of these two chronic liver diseases is closely linked to gastrointestinal dysfunctions that alters the gut-liver crosstalk. These alterations are mediated through the imbalances in the gut microbiota composition/function that combined with disruption in the gut barrier integrity allows for harmful gut microbes and their toxins to enter the portal circulation and reach the liver to elicit an inflammatory response. This leads to further recruitment of systemic inflammatory cells, such as neutrophils, T-cells, and monocytes into the liver, which perpetuate additional inflammation and the development of progressive liver damage. Many therapeutic modalities, currently used to prevent, attenuate, or treat chronic liver diseases are aimed at modulating gut dysbiosis and improving intestinal barrier function. Betaine is a choline-derived metabolite and a methyl group donor with antioxidant, anti-inflammatory and osmoprotectant properties. Studies have shown that low betaine levels are associated with higher levels of organ damage. There have been several publications demonstrating the role of betaine supplementation in preventing the development of ALD and MASLD. This review explores the protective effects of betaine through its role as a methyl donor and its capacity to regulate the protective gut microbiota and maintain intestinal barrier integrity to prevent the development of these chronic liver diseases. Further studies are needed to enhance our understanding of its therapeutic potential that could pave the way for targeted interventions in the management of not only chronic liver diseases, but other inflammatory bowel diseases or systemic inflammatory conditions.

Emodin and Aloe-Emodin Reduce Cell Growth and Disrupt Metabolic Plasticity in Human Melanoma Cells

Background/Objectives: Melanoma is an aggressive skin cancer with intratumor metabolic heterogeneity, which drives its progression and therapy resistance. Natural anthraquinones, such as emodin and aloe-emodin, exhibit anti-cancer properties, but their effects on metabolic plasticity remain unclear. This study evaluated their impact on proliferation and metabolic pathways in heterogenous melanoma human cell lines. Methods: COLO 800, COLO 794, and A375 melanoma cell lines representing distinct metabolic phenotypes were analyzed. Targeted and untargeted metabolomics analyses integrated with Seahorse assays were performed to assess the effects of emodin and aloe-emodin on cell proliferation, mitochondrial function, and redox homeostasis. Glucose tracing using [U-13C6] glucose and metabolic flux analysis (MFA) were carried out to evaluate the glycolysis and TCA cycle dynamics. Results: Emodin and aloe-emodin inhibited proliferation by disrupting glycolysis, oxidative phosphorylation, and energy production across all cell lines. Both compounds impaired glucose metabolism, reduced TCA cycle intermediates, and induced mitochondrial ROS accumulation, causing oxidative stress and redox imbalance. Despite intrinsic metabolic differences, COLO 800 and COLO 794 upregulated antioxidant defenses; A375 enhanced one-carbon metabolism and amino acid pathways to maintain redox balance and nucleotide biosynthesis. Conclusions: Emodin and aloe-emodin can disrupt the metabolic plasticity of melanoma cells by impairing glycolysis, mitochondrial function, and redox homeostasis. Their ability to target metabolic vulnerabilities across diverse phenotypes highlights their therapeutic potential for overcoming resistance mechanisms and advancing melanoma treatment strategies.

Size-Dependent Cytotoxicity and Multi-Omic Changes Induced by Amorphous Silicon Nanoparticles in HepG2 Cells

(1) Background: Silica nanoparticles (SiO2 NPs) have a high potential for human exposure and tend to accumulate in the liver. This study aimed to explore the size-dependent cytotoxicity induced by SiO2 NPs and identify key molecular pathways at the in vitro level through proteomics, metabolomics, and a combination of multiple omics methods. (2) Methods: The human hepatoma cells (HepG2) cells were exposed to SiO2 NPs of three different sizes (60, 250, and 400 nm) at doses of 0, 12.5, 25, 50, 100, and 200 μg/mL for 24 h. (3) Results: Exposure to 60 nm SiO2 NPs induced more reduction in cell viability than the other two larger-scale particles. Changes in the metabolomic and proteomic profiles of HepG2 cells induced by SiO2 NPs were also size-dependent. The main pathways that were significantly affected in the 60 nm SiO2 NPs treatment group represented cholesterol metabolism in proteomics and central carbon metabolism in metabolomics. Moreover, common enrichment pathways between differential proteins and metabolites included protein digestion and absorption and vitamin digestion and absorption. (4) Conclusions: Exposure to SiO2 NPs could induce size-dependent cytotoxicity and changes in proteomics and metabolomics, probably mainly by interfering with energy metabolism pathways.

The Role of AHCY Expression in Bladder Urothelial Carcinoma: A Bioinformatics and Experimental Analysis

Background

Although adenosylhomocysteinase (AHCY) is crucial to the oncogenesis and growth of some cancers, it is unknown how this affects bladder urothelial carcinoma (BLCA). Investigating the variations in AHCY expression in BLCA and examining the relationship between AHCY expression and BLCA patient prognosis were the goals of this investigation.

Methods

By leveraging The Cancer Genome Atlas (TCGA) database, we undertook a meticulous examination of AHCY expression levels, juxtaposing them between BLCA and normal tissues. Subsequently, Kaplan-Meier analysis and COX regression and nomogram was used to assess the effect of AHCY on the survival of BLCA patients. We further elaborated on the possible enriched pathways of AHCY and its immune relevance. In addition, we employed si-RNA technology to downregulate the AHCY gene expression and subsequently utilized quantitative real-time PCR (qRT-PCR), CCK-8, cell scratch assays, and Transwell migration assays to validate the pivotal role of AHCY in BLCA.

Results

The expression of AHCY was associated with various types of malignancies (including BCLA). In BLCA cancer tissues, there was an observed upregulation of AHCY expression in comparison to paracancerous tissues. Increased expression of AHCY was linked to decreased overall survival (OS), clinical stage, N stage, and T stage in individuals with BLCA. The functional enrichment of AHCY related genes mainly involves biological processes such as rRNA metabolic processes, proteasome activity, and cell cycle regulation, etc. Furthermore, AHCY showed significant associations with m6A related genes and infiltration of immune cells (Especially for Th2 cells and T-gd lymphocytes). In vitro functional experiments substantiated that the inhibition of AHCY effectively suppresses the growth, migration, and invasion of bladder cancer cells.

Conclusion

This study provides novel insights into the role of AHCY in BLCA, which holds significant potential to contribute towards advancing the diagnosis and treatment of BLCA in the future.

Methionine intervention induces PD-L1 expression to enhance the immune checkpoint therapy response in MTAP-deleted osteosarcoma

Osteosarcoma (OS), a malignant bone tumor with limited treatment options, exhibits low sensitivity to immune checkpoint therapy (ICT). Through genomics and transcriptomics analyses, we identify a subgroup of OS with methylthioadenosine phosphorylase (MTAP) deletion, which contributes to ICT resistance, leading to a "cold" tumor microenvironment. MTAP-deleted OS relies on methionine metabolism and is sensitive to methionine intervention, achieved through either dietary restriction or inhibition of methionine adenosyltransferase 2a (MAT2A), a key enzyme in methionine metabolism. We further demonstrate that methionine intervention triggers programmed death-ligand 1 (PD-L1) transcription factor IKAROS family zinc finger 1 (IKZF1) and enhances PD-L1 expression in MTAP-deleted OS cells. Methionine intervention also activates the immune-related signaling pathways in MTAP-deleted OS cells and attracts CD8+ T cells, thereby enhancing the efficacy of ICT. Combining methionine intervention with ICT provides a significant survival benefit in MTAP-deleted OS murine models, suggesting a rationale for combination regimens in OS ICT.

GSK3 coordinately regulates mitochondrial activity and nucleotide metabolism in quiescent oocytes

As cells transition between periods of growth and quiescence, their metabolic demands change. During this transition, cells must coordinate changes in mitochondrial function with the induction of biosynthetic processes. Mitochondrial metabolism and nucleotide biosynthesis are key rate-limiting factors in regulating early growth. However, it remains unclear what coordinates these mechanisms in developmental systems. Here, we show that during quiescence, as mitochondrial activity drops, nucleotide breakdown increases. However, at fertilization, mitochondrial oxidative metabolism and nucleotide biosynthesis are coordinately activated to support early embryogenesis. We have found that the serine/threonine kinase GSK3 is a key factor in coordinating mitochondrial metabolism with nucleotide biosynthesis during transitions between quiescence and growth. Silencing GSK3 in quiescent oocytes causes increased levels of mitochondrial activity and a shift in the levels of several redox metabolites. Interestingly, silencing GSK3 in quiescent oocytes also leads to a precocious induction of nucleotide biosynthesis in quiescent oocytes. Taken together, these data indicate that GSK3 functions to suppress mitochondrial oxidative metabolism and prevent the premature onset of nucleotide biosynthesis in quiescent eggs. These data reveal a key mechanism that coordinates mitochondrial function and nucleotide synthesis with fertilization.

HSA Adductomics in the Shanghai Women's Health Study Links Lung Cancer in Never-Smokers with Air Pollution, Redox Biology, and One-Carbon Metabolism

Nearly one fourth of lung cancers occur among never-smokers and are predominately lung adenocarcinomas (LUADs) that are distinct from smoking-related cancers. Causal links between LUADs in never-smokers have been attributed to reactive oxygen species (ROS) arising from airborne fine particulate matter (PM2.5) and polycyclic aromatic hydrocarbons (PAHs). These effects are pronounced among East Asian women who experience massive exposures to PM2.5 and PAHs and have the highest incidence of LUADs in the world. We employed untargeted adductomics to establish ROS adduct signatures in human serum albumin (HSA) from lung cancer cases and controls from never-smokers in the Shanghai Women's Health Study. Forty-seven HSA adducts were quantified by mass spectrometry, nine of which were selected for association with lung cancer, including Cys34 sulfoxidation products and disulfides of cysteine and homocysteine and two modifications to Lys525. Associated adducts include constituents of redox biology and one-carbon metabolism (OCM), which are pathways associated with lung cancer. Differences in adduct abundance between cases and controls and correlations of adducts with urinary PAHs and dietary factors provide additional evidence linking air pollutants, OCM, and redox biology with lung cancer in never-smokers.

Biological, dietetic and pharmacological properties of vitamin B9

Humans must obtain vitamin B9 (folate) from plant-based diet. The sources as well as the effect of food processing are discussed in detail. Industrial production, fortification and biofortification, kinetics, and physiological role in humans are described. As folate deficiency leads to several pathological states, current opinions toward prevention through fortification are discussed. Claimed risks of increased folate intake are mentioned as well as analytical ways for measurement of folate.

Breastfeeding and Future Cardiovascular, Kidney, and Metabolic Health-A Narrative Review

The benefits of breastfeeding for both mother and infant are generally recognized; however, the connections between breast milk, lactation, and long-term offspring health and disease remain incompletely understood. Cardiovascular-kidney-metabolic syndrome (CKMS) has become a major global public health challenge. Insufficient breast milk supply, combined with various early-life environmental factors, markedly increases the future risk of CKMS, as highlighted by the developmental origins of health and disease (DOHaD) concept. Given its richness in nutrients and bioactive components essential for infant health, this review focuses on reprogramming strategies involving breast milk to improve offspring's cardiovascular, kidney, and metabolic health. It also highlights recent experimental advances in understanding the mechanisms driving CKMS programming. Cumulatively, the evidence suggests that lactational impairment heightens the risk of CKMS development. In contrast, early interventions during the lactation period focused on animal models that leverage breast milk components in response to early-life cues show potential in improving cardiovascular, kidney, and metabolic outcomes-an area warranting further investigation and clinical translation.

Associations of Environmental Pollutant Mixtures and Red Blood Cell Folate Concentrations: A Mixture Analysis of the U.S. Adult Population Based on NHANES Data, 2007-2016

BACKGROUND

Folate is critical for many physiological processes, and low folate levels have been associated with a wide range of health outcomes, including chronic diseases and developmental outcomes. Many environmental chemicals are suspected to contribute to the etiology of health outcomes related to folate deficiency. However, little is known about how these pollutants influence folate levels as potential mechanistic pathways.

OBJECTIVE

To investigate the individual and joint associations between a mixture of 39 pollutants and red blood cell (RBC) folate concentrations in the U.S.

POPULATION

METHODS

We used available data on 27,938 participants, aged 18-80 from the U.S. National Health and Nutrition Examination survey (2007-2016), with available RBC folate concentrations and 39 environmental pollutants' concentrations. We estimated covariate-adjusted independent and joint associations between environmental pollutants and RBC folate, and compared evidence from two complimentary mixture approaches: exposome-wide association study (ExWAS) and quantile-based g computation (Q-gcomp).

RESULTS

In the ExWAS analysis, 12 environmental chemicals, including metals (cadmium, arsenic, lead, and mercury), perfluoroalkyl substances, phthalates, phenols and parabens, and polycyclic aromatic hydrocarbons, were inversely associated with RBC folate, whereas four environmental pollutants, including metals (manganese and selenium) and two phthalate metabolites, were positively associated with RBC folate. Q-gcomp showed convergent results with the ExWAS analysis; a quartile increase in the metal and PFAS mixtures was significantly associated with a decrease of -38.4 ng/mL (95%CI: -52.3, -24.4) and -48.9 ng/mL (95%CI: -57.6, -39.6) in RBC folate concentrations, respectively.

CONCLUSION

The present study shows that higher exposure to PFASs, metals, and PAHs are associated with lower RBC folate concentrations. However, given the cross-sectional design, we cannot make inferences about the directionality of the observed associations.

Genetic vitamin B6 deficiency and alcohol interaction in behavior and metabolism

Alcohol abuse is a leading cause of preventable deaths, affecting brain function and metabolism, including GABA transmission and vitamin B6 (VB6) levels. However, the interaction between genetic VB6 deficiency and alcohol consumption remains unexplored. Here, we utilized Drosophila models with mutations in pyridox(am)ine-5'-phosphate oxidase (PNPO), a key enzyme in VB6 metabolism, to examine this interaction at behavioral and biochemical levels. Our findings demonstrate that PNPO deficiency reduces alcohol aversion, increases consumption, and alters locomotor behavior. Biochemically, PNPO deficiency and alcohol exposure converge on amino acid metabolism, elevating inhibitory neurotransmitters GABA and glycine. Moreover, both PNPO deficiency and alcohol exposure lead to lethality with significant interaction, which can be rescued by VB6 supplementation. These results highlight a functional interaction between genetic VB6 deficiency and alcohol, suggesting potential therapeutic strategies for alcohol-related behaviors.