title: Time course gene expression in the one-carbon metabolism network using HepG2 cell line grown in folate-deficient medium.
abstract: The integrated view of the expression of genes involved in folate-dependent one-carbon metabolism (FOCM) under folate deficiency remains unknown. Dynamics of changes in the transcriptional expression of 28 genes involved in the FOCM network were evaluated at different time points (0, 2, 4, 6, 12, 24 and 48 h) in human hepatoma HepG2 cell line. Combined experimental and computational approaches were conducted for emphasizing characteristic patterns in the gene expression changes produced by cellular folate deficiency. Bivariate analysis showed that folate deficiency (0.3 nmol/L of folate vs. 2.27 mumol/L in control medium) displayed rapid and coordinated regulation during the first 2 h with differential expression for hRfc1 (increased by 69%) and Ahcy (decreased by 437%). Density analysis through the time points gave evidence of differential expression for five genes (Ahcy, Cth, Gnmt, Mat1A, Mtrr and hRfc1). Differential expression of Ahcy, Gnmt, Mat1A and Mtrr was confirmed by time-series analysis gene expression. We also found a marked differential expression of Mtrr. Qualitative analysis of genes allowed identifying four clusters of gene that was coexpressed. Two of these clusters were consistent with specific metabolic functions as they associated genes involved in the remethylation (Mthfr and Mtrr) and in the transmethylation (Dnmt1and Dnmt3B) pathways. The study shows a strong influence of folate status on Mtrr transcription in HepG2 cells. It suggests also that folate deficiency produces transcription changes that particularly involve the clusters of genes related with the remethylation and the transmethylation pathways.
authors.affiliation: Institut Polytechnique LaSalle, EGEAL, F-60026 Beauvais Cedex, France. abalo.chango@lasalle-beauvais.fr
authors.forename: Abalo
authors.initials: A
authors.lastname: Chango
authors.forename: Afif Abdel
authors.initials: AA
authors.lastname: Nour
authors.forename: Souad
authors.initials: S
authors.lastname: Bousserouel
authors.forename: Damien
authors.initials: D
authors.lastname: Eveillard
authors.forename: Pauline M
authors.initials: PM
authors.lastname: Anton
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Guéant
mesh_terms: D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D045744:Cell Line, Tumor; D005287:Ferredoxin-NADP Reductase / Q000235:genetics / Q000378:metabolism; D058973:Folate Receptors, GPI-Anchored; D005492:Folic Acid / Q000378:metabolism*; D005494:Folic Acid Deficiency / Q000235:genetics* / Q000378:metabolism*; D015870:Gene Expression; D006801:Humans; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism; D013997:Time Factors
chemical_list: D002352:Carrier Proteins; D058973:Folate Receptors, GPI-Anchored; D026901:Membrane Transport Proteins; D011956:Receptors, Cell Surface; C120043:SLC19A2 protein, human; D005492:Folic Acid; C111241:methionine synthase reductase; D005287:Ferredoxin-NADP Reductase