Atorvastatin reduces the expression of aldo-keto reductases in HUVEC and PTEC. A new approach to influence the polyol pathway

PURPOSE: Increased flux of glucose via the polyol pathway, oxidative stress and ischaemia lead to the upregulation of the aldose reductase (AR), the key enzyme of the polyol pathway. This adversely affects the organism and can in part be reduced by inhibition of the enzyme. METHODS: In this study, we examined the effect of the HMG-CoA-reductase inhibitor atorvastatin on the expression of aldose reductase (AR, AKR1B1), aldehyde reductase (AldR, AKR1A1) and small intestine reductase (SIR, AKR1B10) in human umbilical vein endothelial cells (HUVEC) and human proximal tubular epithelial cells (PTEC) by RT-PCR. RESULTS: In HUVEC, atorvastatin reduces the expression of aldehyde reductase and aldose reductase compared with control medium (-20% and -12% respectively, P < 0.05), while small intestine reductase is not expressed. In PTEC no regulation of aldehyde reductase and aldose reductase by atorvastatin could be measured, while the expression of small intestine reductase was reduced by 37% compared with control medium (P < 0.05). The reduction observed was not abolished by the addition of mevalonic acid. CONCLUSION: The reduction of members of the aldo-keto-reductase family by atorvastatin is a novel way to influence the polyol pathway and a new pleiotropic effect of atorvastatin.