Insulin stimulates gene expression of ferritin light chain in osteoblast cells

We explored to identify differentially expressed gene(s) by insulin in osteoblast-like UMR-106 cells by employing annealing control primer (ACP)-based GeneFishing PCR. UMR-106 cells were treated with insulin and total RNA was isolated. The GeneFishing differential display (DD) PCR was carried out and the profiles of expressed genes were compared between control and insulin treated group, and followed by cloning, sequencing and screened by a BLAST search. It has been found that expression of a PCR product was significantly increased by insulin: It was identified as ferritin light chain. It was further confirmed by reverse transcriptase-PCR (RT-PCR) analysis that insulin significantly stimulates the mRNA expression of ferritin light chain. In a Western blot analysis, insulin also increased the protein expression of ferritin light chain. When ERK inhibitor or Casein Kinase II inhibitor (DRB) was pretreated, the stimulation of ferritin light chain expression by insulin was significantly inhibited, suggesting that ERK I/II or Casein Kinase II may play a role in the insulin stimulated increase of ferritin light chain. These results suggest that insulin may play an important role in Fe metabolism in osteoblast cells.