Homo sapiens
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PROVIDER: PRJNA184810 | ENA |
REPOSITORIES: ENA
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Project description:Rationale: Low B12 has been shown to play an important role in the prediction of metabolic risk, but its significance and mechanism in the development of adiposity and adipose tissue dysfunction is largely unknown. Objective: To investigate the role of B12 and folic acid in the development of adipocyte dysfunction. Methods and Results: Microarray analysis of human adipocytes (CHUB-S7 cell line) cultured and differentiated in customised media with varying concentrations of B12 and folic acid led to the identification of two important pathways: cholesterol synthesis and unfolded protein response (UPR). Adipocytes cultured in media with low B12 (150 pmol/L) or no B12 had increased intracellular total cholesterol, higher secreted homocysteine levels, induced UPR and reduced glucose uptake capacity compared to adipocytes cultured in normal media with higher B12. The folate concentrations had either no or little effect on the measured functions. Further analysis of these adipocytes for overall DNA methylation showed that the promoter regions of sterol regulatory element-binding transcription factor 1 (SREBF1) and low density lipoprotein receptor (LDLR) were hypomethylated in the low and no B12 conditions. The SREB proteins (SREBP1 and 2) and mRNA expressions (SREBF1 and LDLR) were also increased in the same conditions. Conclusion: The data suggest that low B12 can lead to adipocyte dysfunction by inducing excess cholesterol biosynthesis, homocysteine production and induction of UPR and overall adipocyte dysfunction. Both of these pathways and adipocyte dysfunction play a significant role in the development of cardiovascular diseases. Independent replicate samples of the human adipocyte cell line CHUB-S7 were treated with four different concentrations of B12 and folate.
2012-12-30 | E-GEOD-43166 | biostudies-arrayexpress
Project description:Rationale: Low B12 has been shown to play an important role in the prediction of metabolic risk, but its significance and mechanism in the development of adiposity and adipose tissue dysfunction is largely unknown. Objective: To investigate the role of B12 and folic acid in the development of adipocyte dysfunction. Methods and Results: Microarray analysis of human adipocytes (CHUB-S7 cell line) cultured and differentiated in customised media with varying concentrations of B12 and folic acid led to the identification of two important pathways: cholesterol synthesis and unfolded protein response (UPR). Adipocytes cultured in media with low B12 (150 pmol/L) or no B12 had increased intracellular total cholesterol, higher secreted homocysteine levels, induced UPR and reduced glucose uptake capacity compared to adipocytes cultured in normal media with higher B12. The folate concentrations had either no or little effect on the measured functions. Further analysis of these adipocytes for overall DNA methylation showed that the promoter regions of sterol regulatory element-binding transcription factor 1 (SREBF1) and low density lipoprotein receptor (LDLR) were hypomethylated in the low and no B12 conditions. The SREB proteins (SREBP1 and 2) and mRNA expressions (SREBF1 and LDLR) were also increased in the same conditions. Conclusion: The data suggest that low B12 can lead to adipocyte dysfunction by inducing excess cholesterol biosynthesis, homocysteine production and induction of UPR and overall adipocyte dysfunction. Both of these pathways and adipocyte dysfunction play a significant role in the development of cardiovascular diseases.
2012-12-30 | GSE43166 | GEO
Project description:Elucidation of new roles for vitamin B12 in regulation of folate, ubiquinone, and methionine metabolism
2018-10-22 | PXD005723 | Pride
Project description:Folate, and its synthetic form folic acid, function as donor of one-carbon units and have been, together with other B-vitamins, implicated in programming of epigenetic processes such as DNA methylation during early development. To what extent regulation of DNA methylation can be altered via B-vitamins later in life, and how this relates to health and disease, is not exactly known. The aim of this study was to identify effects of long-term supplementation with folic acid and vitamin B12 on genome-wide DNA methylation in elderly subjects. This project was part of a randomized, placebo-controlled trial on effects of supplemental intake of folic acid and vitamin B12 on bone fracture incidence (B-PROOF study). Participants with mildly elevated homocysteine levels, aged 65-75 years, were randomly assigned to take 400 µg folic acid and 500 µg vitamin B12 per day or a placebo during an intervention period of two years. DNA was isolated from buffy coats, collected before and after intervention, and genome-wide DNA methylation was determined in 87 participants (n=44 folic acid/vitamin B12, n=43 placebo) using the Infinium HumanMethylation450 BeadChip. After intervention with folic acid and vitamin B12, 162 (versus 14 in the placebo group) of the 431,312 positions were differentially methylated as compared to baseline. Comparisons of the DNA methylation changes in the participants receiving folic acid and vitamin B12 versus placebo, revealed one single differentially methylated position (cg19380919) with a borderline statistical significance. However, based on the analyses of differentially methylated regions (DMRs) consisting of multiple positions, we identified 6 regions that differed statistically significantly between the intervention and placebo group. Pronounced changes were found for regions in the DIRAS3, ARMC8 and NODAL genes, implicated in carcinogenesis and early embryonic development. Furthermore, serum levels of folate and vitamin B12 or plasma homocysteine were related to DNA methylation of 173, 425 and 11 regions, respectively. Interestingly, for several members of the developmental HOX genes, DNA methylation was related to serum levels of folate. Long-term supplementation with folic acid and vitamin B12 in elderly subjects resulted in effects on DNA methylation of several genes, among which genes implicated in developmental processes.
2015-11-16 | GSE74548 | GEO
Project description:RNA-Seq results accompanying submission of a manuscript: "Cholesterol-dependent transcriptome remodeling reveals new insight into the contribution of cholesterol to Mycobacterium tuberculosis pathogenesis" describing the role of cholesterol and vitamin B12 in shaping the transcriptome of the Mycobacterium tuberculosis H37Rv and M. tuberculosis ∆prpR - propionate regulator (PrpR) mutant. Next generation sequencing results are provided in three independent biological replicates for each strain growing in three different media - minimal medium with glycerol or cholesterol as the sole carbon source and standard 7H9/10% OADC medium. The influence of vitamin B12 on M. tuberculosis transcriptome was analysed on 7H9/10% OADC medium supplemented with B12. The study allowed us to re-establish the list of genes potentially involved in cholesterol metabolism. We further proposed a novel regulatory function of vitamin B12 and PrpR, a propionate regulator, in coordinated cholesterol breakdown metabolite dissipation and virulent phenotype induction. Finally, we demonstrated that a key role of cholesterol in Mtb metabolism is not only providing carbon and energy but also inducing a transcriptome remodeling program that helps in developing tolerance to the unfavorable host cell environment.
2021-05-31 | GSE175812 | GEO
Project description:It is clearly established that the maternal diet during pregnancy can induce physiological and metabolic adaptations in the developing fetus which determine its susceptibility later in life to develop diabetes, obesity... The molecular and genomic mechanisms underlying the programming of the metabolic syndrome remain largely unknown but may involve resetting of epigenetic marks and fetal gene expression. We analyzed the profile of the liver transcriptome in 21-day-old rats born to mothers fed with a standard diet or a diet lacking methyl donor nutrients (Vitamin B12 and folates) during gestation and lactation. From a total of 44,000 probes for 26,456 genes, we found two gene clusters whose expression levels had statistically significant differences between control and deficient rats: 3,269 up-regulated and 2,841 down-regulated genes. Bioinformatics analysis revealed that these genes are mainly involved in glucose and lipid metabolism, nervous system, coagulation, endoplasmic reticulum (ER) stress and mitochondrial function. Modifications of gene expression in rat liver were measured in 21-day-old rats born to mothers fed with a standard diet or a diet lacking methyl donor nutrients (Vitamin B12 and folates). Eight independent experiments were performed (4 Controls versus 4 Methyl Donor Deficiency - MDD).
2015-06-22 | E-GEOD-59039 | biostudies-arrayexpress
Project description:<p>The folate and methionine cycles (Met-C) are regulated by vitamin B12 (B12), obtained exclusively from diet and microbiota. Met-C supports amino acid, nucleotide, and lipid biosynthesis and provides one-carbon moieties for methylation reactions. While B12 deficiency and polymorphisms in Met-C genes are clinically attributed to neurological and metabolic disorders, less is known about their cell-non-autonomous regulation of systemic physiological processes. Using a B12-sensitive<em> Caenorhabditis elegans</em> mutant, we show that the neuronal Met-C responds to differential B12 content in diet to regulate p38-MAPK activation in the intestine, thereby modulating cytoprotective gene expression, osmotic stress tolerance, behaviour and longevity. Mechanistically, our data suggest that B12-driven changes in the metabolic flux through the Met-C in the mutant’s serotonergic neurons increase serotonin biosynthesis. Serotonin activates its receptor, MOD-1, in the post-synaptic interneurons, which then secretes the neuropeptide FLR-2. FLR-2 binding to its intestinal receptor, FSHR-1, induces the phase transition of the SARM domain protein TIR-1, thereby activating the p38-MAPK pathway. Together, we reveal a dynamic neuron-gut signalling axis that helps an organism modulate life history traits based on the status of neuronal Met-C, determined by B12 availability in its diet. </p>
2025-07-05 | MTBLS12457 | MetaboLights
Project description:Wistar Kyoto, inbred male rats (M & B, Ry, Denmark) were randomized and fed a semisynthetic pellet diet deficient in folate (TD350, Harland, Madison, Wisconsin, USA) or an identical diet with a normal amount of folate (TD351, Harland). Special analyses were performed to establish the content of Methionine, Vitamin B12, Folate and Vitamin B6 in the two diets. The folate content was <0.06 mg/kg and 1.63 mg/Kg, respectively. Detailed specification of the diets has been published previously. Animals were housed in stainless steel cages with a bed of sawdust, two to a cage, and were allowed free access to food and drinking water. The room temperature was 23a C and the humidity was 45-55 %. Light cycles consisted of 12 h light/12 h darkness. The animals were weighed at randomization and subsequently every seven days. The animal experiments were carried out in accordance with the guidelines of the International Scientific Committee for Thrombosis and Hemostasis, and the Danish Ethical Committee for Animal Experimentation had approved the study protocol. This study consisted of twelve rats fed the folate deficient diet and twelve rats fed the normal diet for 28 days.
2005-08-01 | E-MEXP-154 | biostudies-arrayexpress
Project description:Human cells can synthesize methionine from homocysteine and folate-coupled methyl groups via the B12-dependent enzyme methionine synthase (MTR). Yet, it has been known for decades that cancer cells fail to grow when methionine is replaced by homocysteine, a phenomenon known as methionine dependence. Here, we report single-cell RNA-sequencing data from MDA-MB-231 breast cancer cells adapted to grow without methionine in the presence of high levels of vitamin B12 for 21 days. Compared to parental cells (D0), the adapted “revertant” cells (D21) display gene expression signatures consistent with reduced invasion and metastasis.
2025-04-08 | GSE291735 | GEO
Project description:Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children, but outcomes for high-risk patients remain dismal, underscoring the critical need for novel therapeutic strategies. Our study demonstrates that RMS exhibits elevated de novo cholesterol biosynthesis. Silencing key cholesterol biosynthesis genes, such as DHCR7, disrupts cell cycle progression by inducing G2/M phase arrest. Additionally, inhibiting this pathway triggers endoplasmic reticulum (ER) stress, activates the unfolded protein response (UPR), and leads to apoptosis. These findings emphasize the essential role of de novo cholesterol synthesis in RMS and highlight a novel therapeutic strategy that targets this metabolic pathway to suppress tumor growth and promote apoptosis.
2025-10-10 | GSE279213 | GEO