Differential gene-expression of metallothionein 1M and 1G in response to zinc in sertoli TM4 cells.
BACKGROUND
Zinc (Zn) as an important trace element is essential for testicular development and spermatogenesis. Molecular mechanism of Zn action in the reproductive system may be related to metal binding low-molecular weight proteins, metallothioneins (MT). Our objective was to determine the effect of Zn on two important isoforms of MT, MT1M and MT1G genes expression on testicular sertoli cells.


METHODS
Cultured sertoli TM4 cells were exposed to different concentrations of Zn at different time points. Cellular uptake of Zn was tested using flame atomic absorption spectrometry. The cellular viability and gene expression were assessed by MTT and real-time PCR methods, respectively.


RESULTS
The treated cells resulted in higher Zn concentration and cellular viability. The expression of MT1M and MT1G genes in the treated cells were greater than those of the untreated cells (P less than 0.05). In the high dosage treated group (100 and 500 muM), Zn concentration and expression of MT1M and MT1G genes increased three h after treatment; MT1G gene expression increased more at sixth h. At 18th h of treatment, the expression of both genes especially MT1G, increased dramatically while Zn concentration decreased.


CONCLUSIONS
Since the increase of MT1G mRNA was coincident with cellular Zn level, it seems that MT1G has a more prominent role than MT1M in the homeostasis of Zn. In addition, Zn at dosage of 50 muM (pharmacologic concentration) may protect cells by increasing the expression of MT genes at longer periods.
Kheradmand
Fatemeh
F
Dept. of Biochemistry, Iran University of Medical Sciences, Tehran, Iran.
Nourmohammadi
Issa
I
Modarressi
Mohammad Hossein
MH
Firoozrai
Mohsen
M
Ahmadi-Faghih
Mohammad Amin
MA
D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D007527:Isoenzymes / Q000235:genetics*; D008297:Male; D053511:Matrix Metalloproteinase 14 / Q000235:genetics*; D051379:Mice; D012333:RNA, Messenger / Q000378:metabolism; D012708:Sertoli Cells / Q000187:drug effects* / Q000502:physiology*; D014131:Trace Elements / Q000493:pharmacokinetics / Q000633:toxicity; D015032:Zinc / Q000493:pharmacokinetics* / Q000633:toxicity
D007527:Isoenzymes; D012333:RNA, Messenger; D014131:Trace Elements; D053511:Matrix Metalloproteinase 14; D015032:Zinc