Function of Metallothionein-3 in Neuronal Cells: Do Metal Ions Alter Expression Levels of MT3?

A study of factors proposed to affect metallothionein-3 (MT3) function was carried out to elucidate the opaque role MT3 plays in human metalloneurochemistry. Gene expression of and was examined in tissues extracted from the dentate gyrus of mouse brains and in human neuronal cell cultures. The whole-genome gene expression analysis identified significant variations in the mRNA levels of genes associated with zinc homeostasis, including and . was found to be the most differentially expressed gene in the identified groups, pointing to the existence of a factor, not yet identified, that differentially controls expression. To examine the expression of the human metallothioneins in neurons, mRNA levels of and were compared in BE(2)C and SH-SY5Y cell cultures treated with lead, zinc, cobalt, and lithium. was highly upregulated by Zn in both cell cultures, while was not affected, and no other metal had an effect on either or .