Changes by tacrolimus of the rat aortic proteome: involvement of endothelin-1

The aim was to analyze the effect of tacrolimus on the aortic expression of proteins associated with the energetic metabolism and cytoskeleton and if it could be reverted by ET-1-receptor antagonist bosentan. Wistar Kyoto rats were divided into: control (n=10), tacrolimus (n=10, 0.5mg/kg bw/day tacrolimus for 30 days) and tacrolimus+bosentan (n=10, 0.5mg/kg bw/day tacrolimus and 100mg/kg bw/day bosentan for 30 days). Rat aortic segments were homogenized and submitted to 2-dimensional electrophoresis and mass spectrometry. Tacrolimus treatment did not modify neither systolic nor diastolic arterial pressure but increased ET-1 content, ET(A)- and ET(B)-type receptor expression in aorta. Proteomic study revealed that tacrolimus treatment modified the expression of aortic proteins associated with the cytoskeleton as some isotypes of lamin A and β-tropomyosin; and energetic metabolism such as ATP synthase gamma chain, NADH dehydrogenase ubiquinone, acyl CoA dehydrogenase long chain mitochondrial and phosphatidylinositol 3-kinase regulatory subunit gamma. Aortic expression of gp91-phox and MnSOD was also increased by tacrolimus. Bosentan co-administration with tacrolimus prevented also changes in ET-1 content and the expression of proteins associated with energetic metabolism. Bosentan did not affect the increased expression of gp91-phox related to tacrolimus although significantly enhanced aortic MnSOD expression. As conclusion, tacrolimus treatment increased ET-1 content in aortic wall and modified the expression of proteins associated with the cytoskeleton and energetic metabolism independently of changes on blood pressure. Bosentan reverted some effects induced by tacrolimus in the aorta and increased the antioxidant defense system.