Project description:We detected numerous copy number aberrations in SNP arrays from follicular lymphoma patients. Additionally, we found an outstanding homozygous state involving folic acid-related genes. To study a hypothetical association between both traits, we cultured folate-depleted cell lines. After restoring normal medium to the cultures, we performed CGH arrays to examine the induced copy number aberrations.
Project description:We detected numerous copy number aberrations in SNP arrays from follicular lymphoma patients. Additionally, we found an outstanding homozygous state involving folic acid-related genes. To study a hypothetical association between both traits, we cultured folate-depleted cell lines. After restoring normal medium to the cultures, we performed CGH arrays to examine the induced copy number aberrations.
Project description:Folate, an essential vitamin, is a one-carbon acceptor and donor in key metabolic reactions. Erythroid cells harbor a unique sensitivity to folate deprivation, as revealed by the primary pathological manifestation of nutritional folate deprivation: megaloblastic anemia. To study this metabolic sensitivity, we applied mild folate depletion to human and mouse erythroid cell lines, and primary murine erythroid progenitors. We show that folate depletion induces early blockade of purine synthesis and accumulation of the purine synthesis intermediate and signaling molecule, AICAR, followed by enhanced heme metabolism, hemoglobin synthesis, and erythroid differentiation. This is phenocopied by inhibition of folate metabolism using the SHMT1/2 inhibitor - SHIN1, and by AICAR supplementation. Mechanistically, the metabolically-driven differentiation is independent of nucleotide sensing through mTORC1 and AMPK, and is instead mediated by protein kinase C (PKC). Our findings suggest that folate deprivation-induced premature differentiation of erythroid progenitor cells is a molecular etiology to folate-deficiency induced anemia.
Project description:Renal ischemia-reperfusion injury (IRI) is a leading cause of acute kidney injury (AKI) and presents significant challenges during kidney transplantation. Due to the detrimental effects of IRI on kidney function and the lack of effective intervention strategies, we conduct a multi-omics study on surgically induced mouse IRI, revealing a modulatory role for the metabolite S-adenosylmethionine (SAM) in AKI development. Our metabolic analysis of clinical samples establishes a link between various AKI conditions and marked elevations in serum SAM, underlying its potential as a biomarker for diagnosis. Furthermore, we find that short-term dietary methionine deprivation, which reduces circulating methionine and kidney SAM levels, effectively enhances renal resilience against IRI. In vivo isotopic tracing demonstrates that this diet preconditions kidney metabolic programs, enhancing glucose and fatty acid oxidation in preparation for IRI. Particularly, the activation of pyruvate dehydrogenase, which produces acetyl-CoA to fuel the tricarboxylic acid (TCA) cycle, highlights an energy-efficient strategy of glucose metabolism that is essential for the protective effects of dietary methionine deprivation.
Project description:Dietary methionine deprivation enhances renal resilience against ischemia-reperfusion injury through modulation of glucose oxidation
Project description:What is known is that methionine-dependency is a feature of some cancers. So far, it was attributed to mutations in genes involved in the methionine de novo or salvage pathways. What is new is that in this work we propose that methionine dependency stems from an altered cellular metabolism. We provide evidence that in U251 glioblastoma cell line, only cancer stem cells -isolated as tumor spheres in non adherent conditions- are methionine dependent and not monolayer cells grown in adherent conditions. Transcriptome wide-sequencing reveals that several genes involved in cytosolic folate cycle are downregulated whereas some transcripts of genes involved in mitochondrial folate cycle are upregulated. Genome wide DNA methylation does not account for these changes in gene expression. Mass spectrometry measurements confirm that tumor spheres display low cytosolic folate cycle unable to produce enough 5-methyltetrahydrofolate to remethylate homocystein to methionine. This decreased 5-methyltetrahydrofolate bioavailability is presumably due to a reprogrammed mitochondrial folate cycle which instead of synthesizing formate, intended to fuel the cytosolic folate cycle, oxidizes the formyl group to CO2 with the attendant reduction of NADP+ to NADPH and release of tetrahydrofolate. The originality of this work resides in that it replaces methionine deprivation as a useful nutritional strategy in cancer growth control since cancer stem cells are much more tumoregenic than their non stem-like counterparts. Second, it reveals that the primary default responsible of the reprogrammation of folate metabolism originates in the mitochondria. Thus, mitochondrial enzymes could be novel and more promising anticancer targets than dihydrofolate reductase (DHFR), the current target of drug therapy linked with folate metabolism.
Project description:Folate is a vitamin essential for cell growth and has been used to prevent congenital abnormalities. However, little is known about how folate affects health in older adults. We examined healthspan as a function of dietary folate intake. To begin to measure such effects, we performed a small (2x2; sex-by-diet) pilot study in the long-lived inbred mouse strain C57BL/6.