The mRNA expression in renal cortical tissues was analysed by RT-PCR using a LightCycler FastStart DNA Master SYBR Green I kit and an ABI Prism 7, 000 Sequence Detection System (Applied Biosystems, Foster City, USA) as previously described [15 (link), 35 (link)]. The oligonucleotide primer sequences for rat and human are listed in ESM Tables 1 and 2, respectively. All data from in vivo studies are expressed as the relative difference in expression compared with LETO rats after normalisation for β-actin expression. Data from in vitro studies are expressed as the relative difference in expression compared with 5 mmol/l glucose after normalisation for β-actin expression.