Cadmium specifically induces MKP-1 expression via the glutathione depletion-mediated p38 MAPK activation in C6 glioma cells.
Cadmium is a toxic heavy metal and an environmental pollutant. Mitogen-activated protein kinase (MAPK) phosphatase-1 (MKP-1) is a negative regulator of the family of MAPK. In this study, we investigated the effect of heavy metals on MKP-1 expression in C6 rat glioma cells. Cadmium treatment induced MKP-1 at both protein and mRNA levels while cobalt or manganese treatment did not, suggesting the specificity. Cadmium treatment also depleted intracellular GSH and activated p38 MAPK, JNKs, and AKT. Profoundly, pretreatment with thiol-containing compounds NAC or GSH, but not vitamin E, blocked GSH depletion, 38 MAPK activation and MKP-1 expression by cadmium. Moreover, pharmacological inhibition of p38 MAPK by SB203580 suppressed the cadmium-induced MKP-1. Collectively, these results demonstrate that cadmium specifically induces MKP-1 by transcriptional up-regulation in C6 cells in a mechanism associated with the glutathione depletion-dependent p38 MAPK activation.
Chronic Disease Research Center, Keimyung University School of Medicine, 194 Dongsan-dong, Jung-gu, Daegu, Republic of Korea.
Sang-Mi
SM
Kim
Jong-Gu
JG
Park
Won-Ki
WK
Baek
Min-Ho
MH
Suh
Hyung
H
Lee
Sun Kyun
SK
Yoo
Kyung-Hwan
KH
Jung
Seong-Il
SI
Suh
Byeong-Churl
BC
Jang
D000818:Animals; D002104:Cadmium / Q000494:pharmacology*; D045744:Cell Line, Tumor; D004305:Dose-Response Relationship, Drug; D054638:Dual Specificity Phosphatase 1 / Q000378:metabolism*; D004789:Enzyme Activation / Q000187:drug effects; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D005910:Glioma / Q000378:metabolism; D005978:Glutathione / Q000172:deficiency*; D051381:Rats; D013997:Time Factors; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism*
D002104:Cadmium; D048051:p38 Mitogen-Activated Protein Kinases; D054638:Dual Specificity Phosphatase 1; C517021:Dusp1 protein, rat; D005978:Glutathione