1-carbon Metabolism Research Articles

Lactobacillus Eats Amyloid Plaque and Post-Biotically Attenuates Senescence Due to Repeat Expansion Disorder and Alzheimer's Disease.

Patients with Alzheimer's disease and related dementia (ADRD) are faced with a formidable challenge of focal amyloid deposits and cerebral amyloid angiopathy (CAA). The treatment of amyloid deposits in ADRD by targeting only oxidative stress, inflammation and hyperlipidemia has not yielded significant positive clinical outcomes. The chronic high-fat diet (HFD), or gut dysbiosis, is one of the major contributors of ADRD in part by disrupted transport, epigenetic DNMT1 and the folate 1-carbon metabolism (FOCM) cycle, i.e., rhythmic methylation/de-methylation on DNA, an active part of epigenetic memory during genes turning off and on by the gene writer (DNMT1) and eraser (TET2/FTO) and the transsulfuration pathway by mitochondrial 3-mercaptopyruvate sulfur transferase (3MST)-producing H2S. The repeat CAG expansion and m6A disorder causes senescence and AD. We aim to target the paradigm-shift pathway of the gut-brain microbiome axis that selectively inhibits amyloid deposits and increases mitochondrial transsulfuration and H2S. We have observed an increase in DNMT1 and decreased FTO levels in the cortex of the brain of AD mice. Interestingly, we also observed that probiotic lactobacillus-producing post-biotic folate and lactone/ketone effectively prevented FOCM-associated gut dysbiosis and amyloid deposits. The s-adenosine-methionine (SAM) transporter (SLC25A) was increased by hyperhomocysteinemia (HHcy). Thus, we hypothesize that chronic gut dysbiosis induces SLC25A, the gene writer, and HHcy, and decreases the gene eraser, leading to a decrease in SLC7A and mitochondrial transsulfuration H2S production and bioenergetics. Lactobacillus engulfs lipids/cholesterol and a tri-directional post-biotic, folic acid (an antioxidant and inhibitor of beta amyloid deposits; reduces Hcy levels), and the lactate ketone body (fuel for mitochondria) producer increases SLC7A and H2S (an antioxidant, potent vasodilator and neurotransmitter gas) production and inhibits amyloid deposits. Therefore, it is important to discuss whether lactobacillus downregulates SLC25A and DNMT1 and upregulates TET2/FTO, inhibiting β-amyloid deposits by lowering homocysteine. It is also important to discuss whether lactobacillus upregulates SLC7A and inhibits β-amyloid deposits by increasing the mitochondrial transsulfuration of H2S production.

Multicohort Epigenome-Wide Association Study of All-Cause Cardiovascular Disease and Cancer Incidence: A Cardio-Oncology Approach

BackgroundEmerging evidence reveals a complex relationship between cardiovascular disease (CVD) and cancer, which share common risk factors and biological pathways. ObjectivesThe aim of this study was to evaluate common epigenetic signatures for CVD and cancer incidence in 3 ethnically diverse cohorts: Native Americans from the SHS (Strong Heart Study), European Americans from the FHS (Framingham Heart Study), and European Americans and African Americans from the ARIC (Atherosclerosis Risk In Communities) study. MethodsA 2-stage strategy was used that included first conducting untargeted epigenome-wide association studies for each cohort and then running targeted models in the union set of identified differentially methylated positions (DMPs). We also explored potential molecular pathways by conducting a bioinformatics analysis. ResultsCommon DMPs were identified across all populations. In a subsequent meta-analysis, 3 and 1 of those DMPs were statistically significant for CVD only and both cancer and CVD, respectively. No meta-analyzed DMPs were statistically significant for cancer only. The enrichment analysis pointed to interconnected biological pathways involved in cancer and CVD. In the DrugBank database, elements related to 1-carbon metabolism and cancer and CVD medications were identified as potential drugs for target gene products. In an additional analysis restricted to the 950 SHS participants who developed incident CVD, the C index for incident cancer increased from 0.618 (95% CI: 0.570-0.672) to 0.971 (95% CI: 0.963-0.978) when adjusting the models for the combined cancer and CVD DMPs identified in the other cohorts. ConclusionsThese results point to molecular pathways and potential treatments for precision prevention of CVD and cancer. Screening based on common epigenetic signatures of incident CVD and cancer may help identify patients with newly diagnosed CVD at increased cancer risk.

Excess Folic Acid Exposure Increases Uracil Misincorporation into DNA in a Tissue-Specific Manner in a Mouse Model of Reduced Methionine Synthase Expression

BackgroundFolate and vitamin B12 (B12) are cofactors in folate-mediated 1-carbon metabolism (FOCM), a metabolic network that supports synthesis of nucleotides (including thymidylate [dTMP]) and methionine. FOCM impairments such as a deficiency or imbalance of cofactors can perturb dTMP synthesis, causing uracil misincorporation into DNA. ObjectiveThe purpose of this study was to determine how reduced expression of the B12-dependent enzyme methionine synthase (MTR) and excess dietary folic acid interact to affect folate distribution and markers of genome stability in mouse tissues. MethodsHeterozygous Mtr knockout mice (Mtr+/–) model the FOCM-specific effects of B12 deficiency. Folate accumulation and vitamer distribution, genomic uracil concentrations, and phosphorylated histone H2AX (γH2AX) immunostaining were measured in male Mtr+/+ and Mtr+/− mice weaned to either a folate-sufficient control (C) diet (2 mg/kg folic acid) or a high folic acid (HFA) diet (20 mg/kg folic acid) for 7 wk. ResultsExposure to the HFA diet led to tissue-specific patterns of folate accumulation, with plasma, colon, kidney, and skeletal muscle exhibiting increased folate concentrations compared with control. Liver total folate did not differ. Although unmetabolized folic acid (UMFA) increased 10-fold in mouse plasma with HFA diet, UMFA accounted for <0.2% of total folate in liver and colon tissue. Exposure to HFA diet resulted in a shift in folate distribution in colon tissue with higher 5-methyl-THF and lower formyl-THF than in control mice. Mtr heterozygosity did not impact folate accumulation or distribution in any tissue. Mice on HFA diet exhibited higher uracil in genomic DNA and γH2AX foci in colon. Similar differences were not seen in liver. ConclusionsThis study demonstrates that folic acid, even when consumed at high doses, does not meaningfully accumulate in mouse tissues, although high-dose folic acid shifts folate distribution and increases uracil accumulation in genomic DNA in colon tissue.

Associations among dietary 1-carbon metabolism nutrients, genetic risk, and Alzheimer disease: a prospective cohort study

BackgroundThe associations between 1-carbon metabolism (OCM) nutrients (methionine, folate, vitamin B-6, and vitamin B-12) and Alzheimer disease (AD) remains inconclusive. ObjectivesThis study aimed to investigate the association of dietary OCM nutrients with subsequent risk of AD and further assess whether participants with high genetic risk for AD might benefit from dietary OCM nutrients. MethodsWe analyzed data from 192,214 participants who completed at least one 24-h dietary questionnaire and had no previous history of AD based on the UK Biobank. Nutrients intake was calculated using McCance and Widdowson’s The Composition of Food and USDA’s Food and Nutrient Database for Dietary Studies. Cox proportional models with restricted cubic splines were applied to explore the associations. ResultsOver a median follow-up of 13.35 y, 959 cases of AD (41 early-onset cases and 918 late-onset cases) were identified. Compared with those in the low-intake OCM group (quartile 1), participants in the high-intake OCM group (quartile 4) had reduced risk of developing AD. The corresponding hazard ratios (HRs) and 95% confidence intervals (CIs) for methionine, folate, vitamin B-6, and vitamin B-12 intake were 0.66 (0.54, 0.80), 0.71 (0.58, 0.87), 0.71 (0.59, 0.87), and 0.77 (0.64, 0.93), respectively. Similar associations were observed in late-onset AD. In early-onset AD, high methionine and vitamin B-12 intake were associated with 70% (HR: 0.30; 95% CI: 0.10, 0.86) and 71% (HR: 0.29; 95% CI: 0.09, 0.96) reduction in risk, respectively. Participants with low genetic risk and high OCM nutrients intake had >75% reduced AD risk compared with high-risk, low-intake participants. ConclusionsIn this prospective cohort study, we found that higher intake of OCM nutrients is associated with reduced risk of AD. Participants with high genetic risk of AD are more likely to benefit from dietary OCM nutrients intake.

Abstract B027: The MAT2A inhibitor IDE397: a novel combination backbone for urothelial cancer subjects with MTAP deficiency

Abstract Methylthioadenosine phosphorylase (MTAP) loss, due to focal homozygous deletions in chromosome 9 (9p21.3), occurs in over 25% of urothelial carcinoma and is an adverse prognostic factor for overall survival. Furthermore, MTAP-deleted tumors are associated with a “cold” tumor immune microenvironment and are resistant to immune checkpoint inhibitor therapy. Loss of MTAP confers a dependency on methionine adenosyltransferase 2A (MAT2A), which catalyzes the production of the primary methyl donor for all cellular methyltransferase reactions, S-adenosyl methionine (SAM). IDE397, a potent small molecule inhibitor of MAT2A, was developed to selectively exploit this synthetic lethal vulnerability in MTAP −/− tumors. The accumulation of the metabolite MTA in MTAP −/− tumors combined with a reduction of SAM by MAT2A inhibition results in selective inhibition of PRMT5, a methyltransferase that governs spliceosome fidelity. This triggers pre-mRNA splicing defects that may induce RNA polymerase stalling and can cause R-loop accumulation. Furthermore, due to essential roles in 1-carbon metabolism, MAT2A inhibition together with MTAP loss leads to depletion of metabolites required for both de novo and salvage nucleotide biosynthesis, thus preventing effective management of DNA replication and DNA damage repair. Notably, R-loops must be resolved by topoisomerase activity (TOP1) to prevent replication conflict and mitotic catastrophe. These combinatorial mechanistic relationships underpin a hypothesis that dual inhibition of MAT2A and TOP1 will fully capitalize on the synthetic lethal vulnerabilities associated with MTAP loss in urothelial cancers (replication stress, genomic instability). Consistent with this, IDE397 in combination with TOP1 inhibitors demonstrated synergistic combination benefit in MTAP −/− bladder cancer cell lines in vitro and in cell-line derived xenograft (CDX) models in vivo. IDE397 exposure was associated with heavily disordered methionine metabolism and accumulation of DNA damage response intermediates. In the ongoing Phase 1 dose escalation/expansion study of IDE397 in MTAP −/− solid tumors (NCT04794699), measurable tumor shrinkage has been observed in urothelial cancers (including a CR per RECIST 1.1) along with molecular responses on serial ctDNA measurements. Supported by our preclinical data, and the clinical observation that MTAP −/− urothelial cancers may be more sensitive to sacituzumab govitecan (SG); a TROP-2-targeting TOP1 ADC (UNITE study; JCO.2023.41.16_suppl.4572), a combination of SG+IDE397 could represent a novel early-line therapy for these patients with high unmet need. We plan to evaluate the combination of SG+IDE397 in MTAP-/- urothelial cancers in the next stage of the ongoing IDE397 trial (NCT04794699). Citation Format: Claire L. Neilan, Marcus M. Fischer, Damien Garbett, Arjun A. Rao, Mili Mandal, Michael A. White, Jasgit C. Sachdev. The MAT2A inhibitor IDE397: a novel combination backbone for urothelial cancer subjects with MTAP deficiency [abstract]. In: Proceedings of the AACR Special Conference on Bladder Cancer: Transforming the Field; 2024 May 17-20; Charlotte, NC. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(10_Suppl):Abstract nr B027.

33 1-Carbon metabolism: Methionine and more

Abstract Methionine, via S-adenosylmethionine, has an important role in the post-translational methylation of Arg, Lys, and His in proteins, methylation of DNA and RNA, and methylation of serotonin (to melatonin), noradrenaline (to adrenaline), and guanidinoacetate (to creatine). After the methyl-group of Met is transferred to an acceptor, the resulting homocysteine can transfer its sulfur group to Ser yielding Cys. Homocysteine can also be remethylated back to Met in the so-called Met salvage pathway, which requires betaine or N5-methyl tetrahydrofolate (THF) as a 1-carbon donor. Methionine is, thus, not necessarily the dietary source of 1-carbon in methylation reactions. N5-methyl THF is one of the “1-carbon flavors” of THF and the catabolism of Ser, Gly, His, and formate (e.g., from Trp catabolism) results in the formation of 1-carbon metabolites linked to THF. These amino acids (and choline and betaine) are thus potential dietary sources of 1-carbon groups, of which only Ser and Gly can be synthesized de novo. In recent years, there has been an increased interest in the role of Ser and Gly in 1-carbon metabolism. Glycine has the unique property that it is able to accept and donate 1-carbon groups and the high concentration of Gly in plasma may be indicative for its 1-carbon buffering capacity. Glycine is also one of the few non-essential amino acids for which the retention (e.g., for collagen synthesis) largely exceeds the dietary intake. However, the de novo synthesis of Gly has been considered “a weak link in metabolism” because it is always associated with the synthesis of a 1-carbon group, and the capacity of the animal to dispose of excess 1-carbon groups may be limited. An excess supply of 1-carbon groups may therefore lead to a dietary requirement for Gly.

Study of Correlation between Serum Vitamin B12 Level and Aberrant DNA Methylation in Infertile Males.

Altered DNA methylation pattern in sperms has been associated with infertility in males demonstrating defective spermatogenesis or low semen quality. Vitamin B-12, by affecting 1-carbon metabolism pathways, might alter the DNA methylation pattern. We aimed to study the correlation of serum vitamin B12 levels with aberrant DNA methylation in infertile male patients. A cross-sectional study was conducted on 17 oligozoospermic infertile males (WHO criteria, 2010) and 10 healthy fertile males. Serum vitamin B12 levels were estimated using the chemiluminescence method. Global methylation was determined using the ELISA system (Imprint Methylated DNA Quantification Kit, Sigma-Aldrich). The levels of global DNA methylation were calculated and compared relative to the methylated (100%) control DNA provided with the kit. Mean serum vitamin B12 concentration in the control group was higher than that of the case group. This difference in serum vitamin B12 concentration in both groups was found statistically significant. Although the results of this study show that oligozoospermic men have relatively lower global DNA methylation as compared to normozoospermic control, the values could not reach a statistically significant level. A small positive correlation was found between serum vitamin B12 levels and percent methylation defect (r = 0.14) but was statistically insignificant. Our study concludes that oligozoospermic infertile males have a significant deficiency of vitamin B12 as compared to normozoospermic fertile males. This study did not find any significant difference in global DNA methylation between the two groups. The present study does not suggest any correlation between serum vitamin B12 level and percent DNA methylation.

Platelet Metabolic Profiling Reveals Glycolytic and 1-Carbon Metabolites Are Essential for GP VI-Stimulated Human Platelets-Brief Report.

Evolving evidence suggests that besides signaling pathways, platelet activation involves a complex interplay between metabolic pathways to support thrombus growth. Selective targeting of metabolic checkpoints may inhibit platelet activation and provide a novel antiplatelet strategy. We, therefore, examined global metabolic changes that occur during the transition of human platelets from resting to an activated state to identify metabolites and associated pathways that contribute to platelet activation. We performed metabolic profiling of resting and convulxin-stimulated human platelet samples. The differential levels, pathway analysis, and PCA (principal component analysis) were performed using Metaboanalyst. Metascape was used for metabolite network construction. Of the 401 metabolites identified, 202 metabolites were significantly upregulated, and 2 metabolites were downregulated in activated platelets. Of all the metabolites, lipids scored highly and constituted ≈50% of the identification. During activation, aerobic glycolysis supports energy demand and provides glycolytic intermediates required by metabolic pathways. Consistent with this, an important category of metabolites was carbohydrates, particularly the glycolysis intermediates that were significantly upregulated compared with resting platelets. We found that lysophospholipids such as 1-palmitoyl-GPA (glycero-3-phosphatidic acid), 1-stearoyl-GPS (glycero-3-phosphoserine), 1-palmitoyl-GPI (glycerophosphoinositol), 1-stearoyl-GPI, and 1-oleoyl-GPI were upregulated in activated platelets. We speculated that platelet activation could be linked to 1-carbon metabolism, a set of biochemical pathways that involve the transfer and use of 1-carbon units from amino acids, for cellular processes, including nucleotide and lysophospholipid synthesis. In alignment, based on pathway enrichment and network-based prioritization, the metabolites from amino acid metabolism, including serine, glutamate, and branched-chain amino acid pathway were upregulated in activated platelets, which might be supplemented by the high levels of glycolytic intermediates. Metabolic analysis of resting and activated platelets revealed that glycolysis and 1-carbon metabolism are necessary to support platelet activation.

Abstract 19037: Metabolomics Reveals Aerobic Glycolysis and 1-Carbon Metabolism as Major Metabolic Signature During Human Platelet Activation

Introduction: Evolving evidence suggests that besides signaling pathways, platelet activation involve a complex interplay between metabolic pathways to support thrombus growth. Selective targeting of metabolic checkpoints may inhibit platelet activation and provide a novel antiplatelet strategy. We examined global metabolic changes that occur during the transition of human platelets from resting to an activated state to identify metabolites and associated pathways that contribute to platelet activation. Methods: We performed metabolic profiling (through Metabolon Inc.) of resting and stimulated human platelet samples. The differential levels analysis, pathway analysis, and PCA were performed using Metaboanalyst. Metascape was used for metabolite network construction. Results: Of the 401 metabolites identified, 202 metabolites were significantly upregulated, and two metabolites were downregulated in activated platelets. Of all the metabolites, lipids scored highly and constituted ~50% of the identification. During activation, aerobic glycolysis supports energy demand and provides glycolytic intermediates required by metabolic pathways. Consistent with this, an important category of metabolites was carbohydrates, particularly the glycolysis intermediates that were significantly upregulated compared to resting platelets. We found that lysophospholipids such as 1-palmitoyl-GPA, 1-stearoyl-GPS, 1-palmitoyl-GPI, 1-stearoyl-GPI, 1-oleoyl-GPI were upregulated in activated platelets. We speculated that platelet activation could be linked to One-carbon (1C) metabolism, a set of biochemical pathways that involve transfer and use of 1C units from amino acids, for cellular processes, including nucleotide and lysophospholipid synthesis. In alignment, based on pathway enrichment and network-based prioritization, the metabolites from amino acid metabolism, including serine, glutamate, and branched-chain amino acids pathway were upregulated in activated platelets, which might be supplemented by the high levels of glycolytic intermediates. Conclusions: Metabolic analysis of resting and activated platelets revealed that aerobic glycolysis and 1-C carbon metabolism are vital to support platelet activation.

The role of the transsulfuration pathway in spermatogenesis of vitamin D deficient mice

Vitamin D deficiency is a global health problem and has been linked to defective spermatogenesis and male infertility. In this study, we aimed to investigate the main enzymes involved in the transsulfuration pathway of 1-carbon metabolism, and spermatogenesis function. Therefore, sixteen male C57 mice were addressed to a control (standard diet) or vitamin D deficient (VDD) diet for 14 weeks. The results show that compared to the standard diet, VDD increased final body weight and reduced sperm quality, caused damage to the testicular structure, and decreased the serum levels of testosterone. In addition, serum concentrations of homocysteine, vitamin B12, and sperm oxidative stress markers increased. In testicular tissues, the CBS and CSE protein levels were down-regulated whereas HO-1 was up-regulated at both mRNA and protein expression levels. Within a mice deprivation model, VDD deeply suppressed testosterone and impaired spermatogenesis with oxidative stress-mediated mechanisms. The effects of the deprivation appeared to be at least in part independent of genomic and receptor-mediated vitamin D actions and suggest a specific impairment of the alternative transsulfuration pathway.

Prevalence of Vitamin B12 and Folate Deficiencies in Indian Children and Adolescents.

Deficiencies of vitamin B12 (B12) and folate (FA) are of particular interest due to their pleiotropic role in 1-carbon metabolism. In addition to adverse birth outcomes, deficiencies of B12 and FA, or an imbalance in FA/B12 status, are linked to metabolic disorders. Indian diets that are predominantly plant food-based could be deficient in these vitamins, but there are no national estimates of the prevalence of B12 and FA deficiency in Indian children and adolescents, nor their associations with age, sex and growth indicators. The recent Comprehensive National Nutrition Survey (CNNS-2016-18) provided estimates of the prevalence of B12 and FA deficiency at the national and state levels among preschool (1-4 years: 9976 and 11,004 children, respectively), school-age children (5-9 years: 12,156 and 14,125) and adolescents (10-19 years: 11,748 and 13,621). Serum B12 and erythrocyte FA were measured by the direct chemiluminescence method and their deficiency was defined using WHO cut-offs. The prevalence of B12 and FA deficiency was high among adolescents (31.0%, CI: 28.7-33.5 and 35.6%, CI: 33.1-8.2) compared to school-age (17.3%, CI: 15.4-19.3 and 27.6%, CI: 25.5-29.9) and preschool children (13.8%, CI: 11.7-16.2 and 22.8%, CI: 20.5-25.2, respectively). The prevalence of both B12 and FA deficiency was significantly higher by 8% and 5%, respectively, in adolescent boys compared to girls. There was no association between anthropometric undernutrition and B12 and FA deficiency. There was wide regional variation in the prevalence of B12 and FA deficiency, but no rural-urban differences were observed across all age groups. The national prevalence of B12 deficiency among preschool or school-age children was <20% (the cut-off that indicates a public health problem). However, FA deficiency in these age groups and both FA and B12 deficiencies in adolescents were >20%, warranting further investigation.

Inhibition of distinct glycolytic enzymes produces differential effects on CD4 T cell function

Abstract Introduction: When T cells are activated, they upregulate glycolysis and take on a requisite Warburg phenotype. In this study, we evaluated the effect of inhibiting two distinct glycolytic enzymes, GAPDH and PGAM, on CD4 T cell differentiation. Methods/Results: Using the GAPDH inhibitor heptelidic acid, we found that GAPDH inhibition produces a potent anti-inflammatory phenotype in Th1 cells, significantly reducing IFNγ expression. We further showed that GAPDH inhibition produces the anti-inflammatory metabolite methylglyoxal, which is necessary for its anti-inflammatory effect. GAPDH inhibition also produced anti-inflammatory effects in vivo, as heptelidic acid significantly reduced disease severity and altered immune subsets in a therapeutic treatment paradigm in the MOG 35–55EAE model of multiple sclerosis. Furthermore, we showed that GAPDH inhibition enhances Treg polarization, while inhibiting PGAM, a downstream glycolytic enzyme, potently blocked Treg polarization. Additionally, we found that inhibition of PGAM increases serine biosynthesis and subsequently alters 1-carbon metabolism. We also found that PGAM gene expression is associated with Treg differentiation and response to immunotherapy in lung cancer patients. Conclusion: Overall, our in vitroand in vivoresults indicate that targeting the glycolytic enzyme GAPDH produces an anti-inflammatory phenotype via the methylglyoxal pathway, while targeting the downstream enzyme PGAM produces an opposite effect via regulation of serine synthesis. Our findings suggest that the functional consequences of glycolysis inhibition depend on the specific enzymes targeted, which represent promising novel therapeutic targets for immunological disease. This work was supported by NIH/NINDS grant K08NS104266 and Conrad N. Hilton Foundation Marilyn Hilton Bridging Award for Physician Scientists grant 17316 to MDK. WHG was supported by NIH MSTP Grant T32 GM136577 and the American Association of Immunologists’ Careers in Immunology Fellowship Program.

Abstract 1004: Higher circulating tryptophan metabolites are associated with improved survival among patients with stage I-III colorectal cancer: results from the FOCUS consortium

Abstract Introduction: Dysregulation of the tryptophan metabolic pathway has been linked to colorectal cancer (CRC) development. While circulating levels of tryptophan metabolites have been associated with a decreased risk of CRC, epidemiological studies assessing tryptophan metabolites in relation to CRC outcomes are limited. In this study, we investigated associations between biomarkers of the tryptophan metabolism and clinical outcomes in prospectively followed, non-metastatic CRC patients. Materials and Methods: A total of 2,102 patients with stage I-III CRC participated in six cohorts in the international FOCUS (folate dependent 1-carbon metabolism in colorectal cancer recurrence and survival) consortium. Preoperative circulating concentrations of tryptophan and its metabolites (kynurenine, kynurenic acid (KA), xanthurenic acid (XA), 3-hydroxy-anthralinic acid (HAA), anthranilic acid (AA), and picolinic acid (PA)) were measured by liquid chromatography-tandem mass spectrometry. Using Cox proportional hazards regression, we examined associations of tryptophan metabolites with overall survival (OS) and disease-free survival (DFS). Models were adjusted for patient age, sex, circulating creatinine levels, tumor site, tumor stage, and study site. Results: After a median follow-up of 3.2 years for OS, higher tryptophan levels were associated with a 25-44% better overall and disease-free survival (hazard ratio, HROS, 0.56; 95% confidence interval (CI), 0.41-0.76, HRDFS, 0.75; 95% CI, 0.57-0.99). Furthermore, the tryptophan metabolites XA and PA were associated with a better OS and DFS (XA: HROS, 0.74; 95% CI, 0.64-0.85, HRDFS, 0.84; 95% CI, 0.75-0.94; PA: HROS, 0.76; 95% CI, 0.64-0.92, HRDFS, 0.86; 95% CI, 0.75-0.99). No statistically significant associations were found between kynurenine, KA, HAA, and AA concentrations and OS and DFS. The kynurenine-to-tryptophan ratio was positively associated with worse CRC survival (HROS, 2.12; 95% CI, 1.57-2.88, HRDFS, 1.32; 95% CI, 1.01-1.73). Conclusion: Higher preoperative circulating tryptophan and its metabolites XA and PA are associated with improved OS and DFS. Furthermore, the kynurenine-to-tryptophan ratio may represent a promising predictor for survival among stage I-III CRC patients. Citation Format: Victoria Damerell, Stefanie Brezina, Jennifer Ose, Anne JMR Geijsen, Arve Ulvik, Eline H. van Roekel, Andreana N. Holowatyj, Dieuwertje E. Kok, Fränzel JB van Duijnhoven, Christopher I. Li, Nina Habermann, Alexis B. Ulrich, Ellen Kampman, Matty P. Weijenberg, Andrea Gsur, Per M. Ueland, Martin Schneider, Cornelia M. Ulrich, Biljana Gigic, FOCUS Consortium. Higher circulating tryptophan metabolites are associated with improved survival among patients with stage I-III colorectal cancer: results from the FOCUS consortium [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1004.

Grf10 regulates the response to copper, iron, and phosphate in Candida albicans.

The pathogenic yeast, Candida albicans, and other microbes must be able to handle drastic changes in nutrient availability within the human host. Copper, iron, and phosphate are essential micronutrients for microbes that are sequestered by the human host as nutritional immunity; yet high copper levels are employed by macrophages to induce toxic oxidative stress. Grf10 is a transcription factor important for regulating genes involved in morphogenesis (filamentation, chlamydospore formation) and metabolism (adenylate biosynthesis, 1-carbon metabolism). The grf10Δ mutant exhibited resistance to excess copper in a gene dosage-dependent manner but grew the same as the wild type in response to other metals (calcium, cobalt, iron, manganese, and zinc). Point mutations in the conserved residues D302 and E305, within a protein interaction region, conferred resistance to high copper and induced hyphal formation similar to strains with the null allele. The grf10Δ mutant misregulated genes involved with copper, iron, and phosphate uptake in YPD medium and mounted a normal transcriptional response to high copper. The mutant accumulated lower levels of magnesium and phosphorus, suggesting that copper resistance is linked to phosphate metabolism. Our results highlight new roles for Grf10 in copper and phosphate homeostasis in C. albicans and underscore the fundamental role of Grf10 in connecting these with cell survival.

X-linked genodermatoses from diagnosis to tailored therapy.

Genodermatoses are rare heterogeneous genetic skin diseases with multiorgan involvement. They severely impair an individual's well-being and can also lead to early death. During the progress of this review, we have implemented a targeted research approach, diligently choosing the most relevant and exemplary articles within the subject matter. Our method entailed a systematic exploration of the scientific literature to ensure a compre-hensive and accurate compilation of the available sources. Among genodermatoses, X-linked ones are of particular importance and should always be considered when pediatric males are affected. Regardless of other syndromic forms without prevalence of skin symptoms, X-linked genodermatoses can be classified in three main groups: keratinization defects, pigmentation defects, and inflammatory skin diseases. Typical examples are dyskeratosis congenita, keratosis follicularis spinulosa decalvans, hypohidrotic ectodermal dysplasia, chondrodysplasia punctata, hypohidrotic ectodermal dysplasia, incontinentia pigmenti, chronic granulomatous disease, CHILD syndrome and ichthyosis. In this field, genetic diagnosis of the specific disease is important, also considering that numerous clinical trials of orphan drugs and genetic therapies are being proposed for these rare genetic diseases. Thus, this chapter starts from clinical to molecular testing and ends with a review of all clinical trials on orphan drugs and gene therapy for genodermatoses.

Abstract 11029: Bioenergetic Independent Stress Signaling in the Heart Due to Mitochondrial Protein Import Stress

Mitochondrial diseases are some of the most common genetically inherited disorders, yet the prognosis for affected patients has not drastically improved in recent years. Most therapies are supportive as the underlying biochemical derangements in these diseases are incompletely understood. Mitochondrial functions rely on the import of nuclear-encoded proteins, and it has recently been appreciated that defective import of mitochondrial proteins can result in the cytosolic accumulation of these preproteins. The accumulation of these preproteins results in cellular toxicity independently of any changes to the mitochondrial bioenergetic function, raising the possibility that mitochondrial protein import stress may be a yet uncharacterized pathway that links mitochondrial dysfunction with pathology. Here, we model this cytosolic mitochondrial precursor overaccumulation stress (mPOS) in mice through overexpression of the inner mitochondrial membrane protein Adenine Nucleotide Translocase 1 (ANT1). The goal of this study is to determine whether ANT1 can induce mPOS and tissue remodeling prior to the onset of cardiac bioenergetic defects. Using isolated cardiac mitochondria from these mice, we detected a moderate decrease in the levels of Complex I, II ,and IV. By measuring oxygen consumption in these mitochondria from 2-month-old animals, we found only a mild reduction in complex II based state 3 and 4 respirations. No change in complex I-based state 3 and 4 respirations was observed. Using RNAseq and western blot analysis, we find the robust activation of the integrated stress response (ISR). Transcriptomic data further demonstrates a strong upregulation of transcripts involved with 1-carbon metabolism, the amino acid starvation response, and proteolysis. Using echocardiographic evaluation of heart function on anesthetized mice at 6 months old, we find no significant alteration in systolic function. Together these data support the idea that mPOS may be a potent trigger of the ISR in a bioenergetics-independent manner. Whether activation of the ISR can alter cardiac function later in life is being evaluated.

One-carbon metabolism-related nutrients intake is associated with lower risk of preeclampsia in pregnant women: a matched case-control study

Many studies have suggested that folate plays a role in preeclampsia (PE) risks, but few studies have assessed folate-related 1-carbon metabolism (OCM)-related nutrients with the risk of PE. We hypothesized that OCM-related nutrients are associated with PE. A 1:1 matched case-control study was conducted to explore the association between dietary OCM-related nutrients intake and the risk of PE in pregnant Chinese women. Four hundred and forty pairs of pregnant women with PE and hospital-based, healthy pregnant women, matched according to gestational week (±1 week) and age (±3 years), were recruited. Dietary intake was assessed using a validated 78-item semiquantitative food frequency questionnaire. Multivariate conditional logistic regression was used to estimate odds ratios (ORs) and 95% CIs. Restricted cubic splines were plotted to evaluate the dose-response relationship between dietary OCM-related nutrient intake and the risk of PE. Intake of folate, vitamin B6, vitamin B12, methionine, and total choline were inversely related to the risk of PE after adjustment for covariates (all P trend < .05). Adjusted ORs (95% CIs) for quartile 4 versus quartile 1 were 0.71 (0.55-0.93) for folate, 0.66 (0.50-0.87) for vitamin B6, 0.68 (0.52-0.88) for vitamin B12, 0.77 (0.60-0.81) for methionine, and 0.67 (0.51-0.87) for total choline. This study suggests that dietary OCM-related nutrients intake is associated with lower odds of PE in pregnant Chinese women.

Maternal Folate Status and the Relation between Gestational Arsenic Exposure and Child Health Outcomes.

Gestational arsenic exposure adversely impacts child health. Folate-mediated 1-carbon metabolism facilitates urinary excretion of arsenic and may prevent arsenic-related adverse health outcomes. We investigated the potential for maternal folate status to modify associations between gestational arsenic exposure and child health. We used data from 364 mother–child pairs in the MIREC study, a prospective pan-Canadian cohort. During pregnancy, we measured first trimester urinary arsenic concentrations, plasma folate biomarkers, and folic acid supplementation intake. At age 3 years, we evaluated twelve neurodevelopmental and anthropometric features. Using latent profile analysis and multinomial regression, we developed phenotypic profiles of child health, estimated covariate-adjusted associations between arsenic and these phenotypic profiles, and evaluated whether folate status modified these associations. We identified three phenotypic profiles of neurodevelopment and three of anthropometry, ranging from less to more optimal child health. Gestational arsenic was associated with decreased odds of optimal neurodevelopment. Maternal folate status did not modify associations of arsenic with neurodevelopmental phenotypic profiles, but gestational arsenic was associated with increased odds of excess adiposity among those who exceed recommendations for folic acid (>1000 /day). However, arsenic exposure was low and folate status was high. Gestational arsenic exposure may adversely impact child neurodevelopment and anthropometry, and maternal folate status may not modify these associations; however, future work should examine these associations in more arsenic-exposed or lower folate-status populations.

Rumen-protected methionine during heat stress alters mTOR, insulin signaling, and 1-carbon metabolism protein abundance in liver, and whole-blood transsulfuration pathway genes in Holstein cows

We investigated effects of rumen-protected Met (RPM) during a heat stress (HS) challenge on (1) hepatic abundance of mTOR, insulin, and antioxidant signaling proteins, (2) enzymes in 1-carbon metabolism, and (3) innate immunity. Holstein cows (n = 32; mean ± standard deviation, 184 ± 59 d in milk) were randomly assigned to 1 of 2 environmental groups, and 1 of 2 diets [total mixed ration (TMR) with RPM (Smartamine M; 0.105% dry matter as top-dress) or TMR without (CON); n = 16/diet] in a split-plot crossover design. There were 2 periods with 2 phases. During phase 1 (9 d), all cows were in thermoneutral conditions (TN; temperature-humidity index = 60 ± 3) and fed ad libitum. During phase 2 (9 d), half the cows (n = 8/diet) were exposed to HS using electric heat blankets. The other half (n = 8/diet) remained in TN, but was pair-fed to HS counterparts. After a 14-d washout and 7-d adaptation period, the study was repeated (period 2) and environmental treatments were inverted relative to phase 2, but dietary treatments were the same. Blood was collected on d 6 of each phase 2 to measure immune function and isolate whole-blood RNA. Liver biopsies were performed at the end of each period for cystathione β-synthase (CBS) and methionine adenosyltransferase activity, glutathione concentration, and protein abundance. Data were analyzed using PROC MIXED in SAS. Abundance of CUL3, inhibitor of antioxidant responses, tended to be downregulated by HS suggesting increased oxidative stress. Heat-shock protein 70 abundance was upregulated by HS. Phosphorylated mTOR abundance was greater overall with RPM, suggesting an increase in pathway activity. An environment × diet (E × D) effect was observed for protein kinase B (AKT), whereas there was a tendency for an interaction for phosphorylated AKT. Abundance of AKT was upregulated in CON cows during HS versus TN, this was not observed in RPM cows. For phosphorylated AKT, tissue from HS cows fed CON had greater abundance compared with all other treatments. The same effect was observed for EIF2A (translation initiation) and SLC2A4 (insulin-induced glucose uptake). An E × D effect was observed for INSR due to upregulation in CON cows during HS versus TN cows fed CON or RPM. There was an E × D effect for CBS, with lower activity in RPM versus CON cows during HS. The CON cows tended to have greater CBS during HS versus TN. An E × D effect was observed for methionine adenosyltransferase, with lower activity in RPM versus CON during HS. Although activity increased in CON during HS versus TN, RPM cows tended to have greater activity during TN. Neutrophil and monocyte oxidative burst and monocyte phagocytosis decreased with HS. An (E × D) effect was observed for whole-blood mRNA abundance of CBS, SOD1 and CSAD; RPM led to upregulation during TN versus HS. Regardless of diet, CDO1, CTH, and SOD1 decreased with HS. Although HS increased hepatic HSP70 and seemed to alter antioxidant signaling, feeding RPM may help cows maintain homeostasis in mTOR, insulin signaling, and 1-carbon metabolism. Feeding RPM also may help maintain whole-blood antioxidant response during HS, which is an important aspect of innate immune function.

Higher vitamin B6 status is associated with improved survival among patients with stage I–III colorectal cancer

Folate-mediated 1-carbon metabolism requires several nutrients, including vitamin B6. Circulating biomarker concentrations indicating high vitamin B6 status are associated with a reduced risk of colorectal cancer (CRC). However, little is known about the effect of B6 status in relation to clinical outcomes in CRC patients. We investigated survival outcomes in relation to vitamin B6 status in prospectively followed CRC patients. A total of 2031 patients with stage I-III CRC participated in 6 prospective patient cohorts in the international FOCUS (folate-dependent 1-carbon metabolism in colorectal cancer recurrence and survival) Consortium. Preoperative blood samples were used to measure vitamin B6 status by the direct marker pyridoxal 5'-phosphate (PLP), as well as the functional marker HK-ratio (HKr)[3'-hydroxykynurenine: (kynurenic acid+xanthurenic acid+3'-hydroxy anthranilic acid+anthranilic acid)]. Using Cox proportional hazards regression, we examined associations of vitamin B6 status with overall survival (OS), disease-free survival (DFS), and risk of recurrence, adjusted for patient age, sex, circulating creatinine concentrations, tumor site, stage, and cohort. After a median follow-up of 3.2 y for OS, higher preoperative vitamin B6 status as assessed by PLP and the functional marker HKr was associated with 16-32% higher all-cause and disease-free survival, although there was no significant association with disease recurrence (doubling in PLP concentration: HROS, 0.68; 95% CI: 0.59, 0.79; HRDFS, 0.84; 95% CI: 0.75, 0.94; HRRecurrence, 0.96; 95% CI: 0.84, 1.09; HKr: HROS, 2.04; 95% CI: 1.67, 2.49; HRDFS, 1.56; 95% CI: 1.31, 1.85; HRRecurrence, 1.21; 95% CI: 0.96,1. 52). The association of PLP with improved OS was consistent across colorectal tumor site (right-sided colon: HROS, 0.75; 95% CI: 0.59, 0.96; left-sided colon: HROS, 0.71; 95% CI: 0.55, 0.92; rectosigmoid junction and rectum: HROS, 0.61; 95% CI: 0.47, 0.78). Higher preoperative vitamin B6 status is associated with improved OS among stage I-III CRC patients.