Apolipoprotein A-I gene expression is regulated by cellular zinc status in hep G2 cells.
The influence of Zn on the expression of the apolipoprotein A-I (apoA-I) gene in Hep G2 cells was examined. Zn depletion was achieved with a low-Zn (ZD) medium prepared from Zn-free growth medium (Opti), a ZD medium containing Chelex 100-extracted fetal bovine serum (CHE), and a medium containing chelator 1, 10-phenanthroline (OP). Compared with those for their respective controls, cellular Zn levels were reduced by 55, 48, and 46% and apoA-I mRNA abundances were reduced by 20, 29, and 28% in Opti, CHE, and OP systems, respectively, after one passage in ZD media or 24 h in OP medium. To establish the specificity of Zn treatment, groups of ZD cells were treated with their respective control media for the last 24 h (ZDA) or normal cells were cultured with OP medium supplemented with Zn (OP-Zn). ZDA treatments partially normalized cellular Zn levels in the Opti system and restored or elevated apoA-I mRNA levels in the Opti or CHE system, respectively. Similarly, the OP-Zn treatment restored the cellular Zn and apoA-I mRNA levels. Furthermore, one passage of culture with Zn-supplemented media in both the Opti and CHE systems resulted in higher cellular Zn and apoA-I mRNA levels than those for controls. Most significantly, short-term high-Zn induction to normal cells markedly elevated the cellular Zn (3-fold) and apoA-I mRNA (5-fold) levels. Data derived from this study strongly suggest that the expression of apoA-I is regulated by cellular Zn status.
Wu
J Y
JY
Department of Nutritional Sciences, University of Arizona, Tucson, Arizona 85721, USA.
Wu
Y
Y
Reaves
S K
SK
Wang
Y R
YR
Lei
P P
PP
Lei
K Y
KY
D016632:Apolipoprotein A-I / Q000235:genetics*; D005786:Gene Expression Regulation / Q000502:physiology*; D006801:Humans; D008099:Liver / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D008668:Metallothionein / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D014407:Tumor Cells, Cultured; D015032:Zinc / Q000172:deficiency / Q000378:metabolism* / Q000494:pharmacology
D016632:Apolipoprotein A-I; D012333:RNA, Messenger; D008668:Metallothionein; D015032:Zinc