Expression of calmodulin-related genes in lead-exposed mice

The toxic metal lead is a widespread environmental polutant that can adversely affect human health. However, the underlying mechanisms of lead-induced toxicity are still largely unknown. The mechanism of lead toxicity was presumed to involve cross reaction between Pb²⁺ and Ca²⁺ with calmodulin dependent systems. The aim of the present study was thus to identify differential expression of calmodulin-related genes in the spleen of lead-exposed mice. We performed microarray analysis to identify differentially expressed genes. RNAs from spleen tissue of lead exposed animals (n=6) and controls (n=6) were converted to labeled cRNA and hybridized to Illumina mouse WG-6_v2_Bead Chip. Expression profiles were analyzed using Illumina BeadStudio Application. Real-time RT-PCR was conducted to validate the microarray data. By microarray analysis 5 calmodulin-related genes (MAP2K6, CAMKK2, CXCR4, PHKA2, MYLK) were found to be differently expressed in lead exposed compared with control mice (p<0.05). The results of Real-time RT-PCR showed that MAP2K6 and CAMKK2 were up-regulated and CXCR4 was down-regulated in lead exposure, but there were no significant differences in PHKA2 and MYLK expression between the lead exposed and control group. These results show that lead exposure produced significant changes in expression of a variety of genes in the spleen and can affect calmodulin-related gene expression.