Iron metabolism gene expression in human skeletal muscle

Little is known about iron metabolism in skeletal muscle while hepatic iron metabolism is well understood. The aim of this study is to compare the iron metabolism gene expression profile in skeletal muscle and the liver in humans. Muscle and hepatic biopsies from six normal individuals were acquired. Twelve genes involved in iron metabolism( import, storage, export) were selected to be studied. Reverse transcriptase polymerase chain reaction (RT-PCR) was performed in order to determine the expression profile in skeletal muscle and compare it to the one from the liver. Semi-quantification of the gene expression in the studied tissues was performed by densitometric analysis (DA). The results were expressed relative to the percentage of the β-actin gene. Fine analysis was performed by real-time PCR (q-PCR) quantification for the genes that their expression presented a difference of more than 20% in the 2 tissues in the first applied densitometric analysis. Most of the studied genes, HJV, TFR1, HFE, DMT1, DMT1nonIRE, NGAL, HEPH, IREG1, FTH1 were well expressed (>70% of β-actin) in skeletal muscle . HAMP, CP, and TFR2 were absent or minimally expressed (<10% of β-actin) in skeletal muscle while they were well expressed in liver. HJV and Heph were found to have higher expression in skeletal muscle (SM) compared to liver (L) (SM/L=2.65 ± 1.1(p<0.05) and SM/L=1.5 ± 0.06(p<0.05 respectively in q-PCR). The relative expressions of the studied genes in both tissues and their relative contribution in iron homeostasis in different pathways are discussed.