Project description:Examination of the impact of vitamin B12 and various one-carbon metabolism and/or epigenetic modifieres during in vitro OSKM reprogramming
Project description:Reprogramming in vivo using OCT4, SOX2, KLF4 and MYC (OSKM) triggers cell dedifferentiation, which is considered of relevance for tissue repair and regeneration. However, little is known about the metabolic requirements of this process. We found that antibiotic depletion of the gut microbiota abolished in vivo reprogramming. Analysis of bacterial metagenomes from stool samples of wild type (WT) and OSKM mice treated with doxycycline led us to identify vitamin B12 as a key factor for in vivo reprogramming, which is partly supplied by the microbiome. We report that B12 demand increases during reprogramming due to enhanced expression of enzymes in the methionine cycle, and supplementing B12 levels both in vitro and in vivo enhances the efficiency of OSKM reprogramming.
Project description:Background: Chronic stress significantly contributes to mood- and anxiety disorders. Previous data suggest a correlative connection between vitamin B12 supplementation, depression, and stress resilience. However, the underlying mechanisms are still poorly understood. Methods: Using the chronic variable stress mouse model coupled with RNA-sequencing, we determined vitamin B12-induced transcriptional changes related to stress resilience. By viral-mediated gene transfer and in vivo epigenome editing, we reveal a functional pathway linking vitamin B12, DNA methylation, and depressive-like symptoms. Results: We identified Transthyretin (Ttr) as a sex-specific key target of vitamin B12 action in chronic stress. Accordingly, TTR expression was increased postmortem in the prefrontal cortex of male, but not female, depressed patients. Virally altered Ttr in the prefrontal cortex functionally contributed to stress- and depression-related behaviors, changes in dendritic spine morphology, and gene expression. In stressed mice, vitamin B12 reduced DNAme in the Ttr promoter region. Importantly, using in vivo epigenome editing to alter DNAme in the brains of living mice for the first time, we establish a direct causal link between DNAme on Ttr and stress-associated behaviors. Discussion: In summary, using state-of-the-art techniques, this study uncovers a mechanistic link between cobalamin supplementation, Ttr, and markers of chronic stress and depression, encouraging further studies into dietary interventions for mood disorders.
Project description:Background: Chronic stress significantly contributes to mood- and anxiety disorders. Previous data suggest a correlative connection between vitamin B12 supplementation, depression, and stress resilience. However, the underlying mechanisms are still poorly understood. Methods: Using the chronic variable stress mouse model coupled with RNA-sequencing, we determined vitamin B12-induced transcriptional changes related to stress resilience. By viral-mediated gene transfer and in vivo epigenome editing, we reveal a functional pathway linking vitamin B12, DNA methylation, and depressive-like symptoms. Results: We identified Transthyretin (Ttr) as a sex-specific key target of vitamin B12 action in chronic stress. Accordingly, TTR expression was increased postmortem in the prefrontal cortex of male, but not female, depressed patients. Virally altered Ttr in the prefrontal cortex functionally contributed to stress- and depression-related behaviors, changes in dendritic spine morphology, and gene expression. In stressed mice, vitamin B12 reduced DNAme in the Ttr promoter region. Importantly, using in vivo epigenome editing to alter DNAme in the brains of living mice for the first time, we establish a direct causal link between DNAme on Ttr and stress-associated behaviors. Discussion: In summary, using state-of-the-art techniques, this study uncovers a mechanistic link between cobalamin supplementation, Ttr, and markers of chronic stress and depression, encouraging further studies into dietary interventions for mood disorders.
Project description:Astrocytes express a vitamin B12 uptake receptor, CD320/TCblR, that is regulated by S1P1 signaling. In search of genes controlled under B12 deficiency in astrocytes, we employed RNA-seq using RNA of astrocytes cultured in normal or B12 deficient media.
Project description:Vitamin B12 (B12) is an important cofactor in mycobacterial metabolism, and some pathogenic mycobacteria need to obtain it from the host. In this study, we investigated the transport of vitamin B12 in Mycobacterium marinum. We identified a transcriptor regulator that could be potentially involved in the uptake process. RNA sequencing analysis were performed in order to elucidate the regulon of this new transcriptor.