title: Changes in gene expression in rat thymocytes identified by cDNA array support the occurrence of oxidative stress in early magnesium deficiency.
abstract: Magnesium deficiency in experimental animals leads to inflammation, exacerbated immune stress response and a decrease of specific immune response. It also results in a significant increase in free radical species and subsequent tissue injury. An accelerated thymus involution was observed in Mg-deficient rats in relation to enhanced apoptosis and enhanced susceptibility to oxidative stress. To examine the stress-inducing effects of low Mg status on thymocytes, cDNA arrays were used to evaluate changes in gene expression in weaning rats submitted to Mg deficiency of short duration (2 days). Several genes exhibited changes in their expression caused by Mg deficiency before any perceptible modification in cell integrity and functions. The up-regulated genes included cytochrome c oxidase, glutathione transferase, CuZn superoxide dismutase, genes associated with the stress response (HSP70 and HSP84) and a gene involved in DNA synthesis and repair (GADD45). The down-regulated genes included Na/P cotransporter 1. These findings are consistent with altered cell growth, modifications of ion fluxes and oxidative stress described during Mg deficiency. The observation of induction of genes involved in protection and repair in cells from Mg-deficient animals provides additional evidence of the role of oxidative stress in the pathobiology of this deficiency.
authors.affiliation: CRNH d'Auvergne, Unité Maladies Métaboliques et Micronutriments, INRA, Theix, St Genès Champanelle, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Petrault
authors.forename: Wioletta
authors.initials: W
authors.lastname: Zimowska
authors.forename: Jacques
authors.initials: J
authors.lastname: Mathieu
authors.forename: Dominique
authors.initials: D
authors.lastname: Bayle
authors.forename: Edmond
authors.initials: E
authors.lastname: Rock
authors.forename: Alain
authors.initials: A
authors.lastname: Favier
authors.forename: Yves
authors.initials: Y
authors.lastname: Rayssiguier
authors.forename: Andrzej
authors.initials: A
authors.lastname: Mazur
mesh_terms: D000818:Animals; D001835:Body Weight; D002478:Cells, Cultured; D003576:Electron Transport Complex IV / Q000032:analysis / Q000235:genetics; D005786:Gene Expression Regulation; D050536:Glycerol-3-Phosphate Dehydrogenase (NAD+); D005993:Glycerolphosphate Dehydrogenase / Q000032:analysis / Q000235:genetics; D047908:Intracellular Signaling Peptides and Proteins; D008274:Magnesium / Q000097:blood; D008275:Magnesium Deficiency / Q000097:blood / Q000235:genetics / Q000378:metabolism*; D008297:Male; D020411:Oligonucleotide Array Sequence Analysis; D009929:Organ Size; D018384:Oxidative Stress; D011506:Proteins / Q000032:analysis / Q000235:genetics; D051381:Rats; D017208:Rats, Wistar; D013482:Superoxide Dismutase / Q000032:analysis / Q000235:genetics; D013950:Thymus Gland / Q000201:enzymology / Q000378:metabolism*; D000097642:GADD45 Proteins
chemical_list: D003576:Electron Transport Complex IV; D050536:Glycerol-3-Phosphate Dehydrogenase (NAD+); D005993:Glycerolphosphate Dehydrogenase; D047908:Intracellular Signaling Peptides and Proteins; D008274:Magnesium; D011506:Proteins; D013482:Superoxide Dismutase; D000097642:GADD45 Proteins