title: Enhanced expression of the LDH-A gene after gravity-changing stress in human RSa cells.
abstract: A major issue in radiation and space biology is whether gene expression levels are altered in cells exposed to gravity-changing stress. In the present study, genes up- or down-regulated in radiation-sensitive human RSa cells cultured under gravity-changing conditions, were identified using a PCR-based mRNA differential display method. Exposure of cells to gravity-changing stress was performed by free-fall with a drop-shaft facility or by an airplane-conducted parabolic flight. Among the candidates for gravity-changing stress-responsive genes obtained by the differential display analysis, the lactate dehydrogenase A gene (LDH-A) was confirmed by Northern blotting analysis to exhibit increased expression levels. The gravity-changing stress consisted of a combination of microgravity and hypergravity. However, exposure of the cells to hypergravity produced by centrifuge only slightly affected the LDH-A mRNA expression. Thus, LDH-A was found to be a candidate for the genes which play a role in the cellular response to gravity-changing stress, and mainly to microgravity.
authors.affiliation: Department of Environmental Biochemistry, Graduate School of Medicine, Chiba University, Chiba City, Chiba, Japan.
authors.forename: Tetsuhiro
authors.initials: T
authors.lastname: Moriya
authors.forename: Kazuko
authors.initials: K
authors.lastname: Kita
authors.forename: Shigeru
authors.initials: S
authors.lastname: Sugaya
authors.forename: Chieko
authors.initials: C
authors.lastname: Wano
authors.forename: Nobuo
authors.initials: N
authors.lastname: Suzuki
mesh_terms: D002460:Cell Line; D002478:Cells, Cultured; D002498:Centrifugation; D005786:Gene Expression Regulation / Q000502:physiology*; D006112:Gravitation; D006801:Humans; D018471:Hypergravity; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism*; D007770:L-Lactate Dehydrogenase / Q000235:genetics / Q000378:metabolism*; D000080864:Lactate Dehydrogenase 5; D012333:RNA, Messenger; D013026:Space Flight; D014893:Weightlessness
chemical_list: D007527:Isoenzymes; D012333:RNA, Messenger; D007770:L-Lactate Dehydrogenase; D000080864:Lactate Dehydrogenase 5