Figure 3.

RAS blockade downregulates profibrotic genes and inhibits endothelial-to-mesenchymal transition. (A) Expression profile by PCR array of genes involved in angiogenesis in Wistar and MWF rats treated or not treated with lisinopril. Gene expression changes were detected comparing the normalized expression of individual genes between Wistar and MWF rats as well as between MWF60 rats and MWF rats treated from 50 to 60 weeks of age with lisinopril or losartan. The lines on the scatter plots indicate the 2-fold boundary used for selecting genes with differential expression. (B) TGF-β2 and ET-1 mRNA expressions normalized to GAPDH in MWF rats with respect to Wistar rats, which were used as physiologic reference. (C) Immunostaining for Reca1 (green) and αSMA (red) showing the effect of both lisinopril and losartan on EndMT. (D) Quantitative assessment expressed as the percentage of Reca1/αSMA-positive area on total Reca1–positive area per ×40 field at glomerular (left panel) and interstitial (right panel) levels. (E) Evaluation of interstitial fibrotic vessels, which were identified as large vessels with abnormal αSMA accumulation on total Reca1+ large vessels, in untreated and lisinopril– and losartan–treated MWF rats. Values are means±SDs (n=3). Scale bar, 50 μm. **P<0.01 versus MWF60; °P<0.05 versus MWF50; °°P<0.01 versus MWF50. Ct, cycle threshold; EndMT, endothelial-to-mesenchymal transition; GAPDH, glyceraldehyde-3-phosphate dehydrogenase; LIS, lisinopril; LOS, losartan; Reca1, rat endothelial cell antigen 1.