hOgg1-6pcDNA3.1 was initially amplified by PCR by primers to introduce a kozak sequence at the 5' end [27] . Digestion of this product with EcoRI and SalI was performed and then hOgg1 was subcloned into digested plasmid vector pSF91.1, with T4 DNA ligase. DNA sequencing was performed to confirm integrity of the hOgg1 gene.