Transient induction of metallothionein isoform 3 (MT-3), c-fos, c-jun and c-myc in human proximal tubule cells exposed to cadmium.
Cadmium (Cd(+2)) has been shown to transiently increase the expression of mRNA for the third isoform of the metallothionein (MT-3) gene family in cultured human proximal tubule (HPT) cells. The goal of the present study was to further define the expression of MT-3 in mortal (HPT) and immortal (HK-2) cultures of HPT cells when exposed to lethal and sub-lethal concentrations of Cd(+2) under both acute and chronic time periods of exposure. Expression of MT-3 mRNA and protein was determined in cultured HPT cells and HK-2 cells using reverse-transcription-polymerase chain reaction (RT-PCR) and immuno-blotting, and expression of c-fos, c-jun and c-myc mRNA by RT-PCR. The results confirmed that exposure of the HPT cells to Cd(+2) induced a transient increase in MT-3 mRNA and extended the induction to include a subsequent transient increase in the level of the MT-3 protein. The induction of MT-3 was rapid and returned to control values within 48 h of exposure despite the continued presence of lethal and sublethal concentrations of Cd(+2). It was also demonstrated that the pattern of expression of MT-3 mRNA was similar to that of the early response genes, c-fos, c-jun and c-myc. It was shown that the HK-2 cells did not express MT-3 when exposed to Cd(+2), but had similar expression of the c-fos, c-jun and c-myc genes. The results demonstrate that MT-3 expression is metal responsive in HPT cells.
Garrett
Scott H
SH
Program in Genetics and Developmental Biology, Department of Urology, Robert C. Byrd Health Sciences Center, West Virginia University, PO Box 9251, Morgantown, WV 26506-9251, USA.
Phillips
Veronica
V
Somji
Seema
S
Sens
Mary Ann
MA
Dutta
Rana
R
Park
Seongmi
S
Kim
Doyeob
D
Sens
Donald A
DA
D000368:Aged; D002104:Cadmium / Q000633:toxicity*; D004247:DNA / Q000096:biosynthesis / Q000235:genetics; D004587:Electrophoresis, Agar Gel; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D015151:Immunoblotting; D007687:Kidney Tubules, Proximal / Q000187:drug effects / Q000473:pathology*; D008297:Male; D008668:Metallothionein / Q000096:biosynthesis* / Q000235:genetics; D000090023:Metallothionein 3; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000096:biosynthesis* / Q000235:genetics; D016760:Proto-Oncogene Proteins c-fos / Q000096:biosynthesis* / Q000235:genetics; D016755:Proto-Oncogene Proteins c-jun / Q000096:biosynthesis* / Q000235:genetics; D016271:Proto-Oncogene Proteins c-myc / Q000096:biosynthesis* / Q000235:genetics; D011519:Proto-Oncogenes / Q000187:drug effects; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured
D000090023:Metallothionein 3; D009419:Nerve Tissue Proteins; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D016271:Proto-Oncogene Proteins c-myc; D012333:RNA, Messenger; D002104:Cadmium; D004247:DNA; D008668:Metallothionein