ACTA1 and chronic kidney disease: Immunohistochemical results showed very weak labeling of α-SMA and collagen I in the renal tissue of wild-type rats, whereas α-SMA levels of CKD rats showed a significant temporal increase in the cytoplasm of specific tubular epithelial cells compared with normal wild-type (CKD 4 weeks, p < 0.001; CKD 10 weeks, p < 0.001; one-way ANOVA; Figure 2A,C).