The cortex of the right kidneys of rats was dissected and at −80°C for RNA protein extraction. The remaining kidney tissues were fixed in 4% paraformaldehyde, embedded in paraffin, and cut into 4-μm sections. Then, the sections were stained with a Periodic Acid-Schiff (PAS) staining kit (Sbjbio Life Sciences, Nanjing, Jiangsu, China) and observed under an optical microscope (magnification × 400). The proportion of PAS staining area to total area of the glomerulus was examined using the Image J software (NIH). In each group of kidney tissues, 20 glomeruli were collected. In addition, hematoxylin and eosin (HE) staining was conducted to examine the pathological changes in rat kidney tissues. The staining in 20 random glomerular areas was scored by three pathologists who had no idea of the grouping details, and the scoring was performed according to tubular cell necrosis, cytoplasmic vacuole formation, hemorrhage, and tubular dilatation.15 (link) Moreover, immunohistochemical staining was performed to examine the protein level of a fibrosis-marker collagen I (Col. I) in the rat kidney tissues using anti-collagen I (1:200, ab254113, Abcam). To each tissue section, 20 continuous fields of views were observed and the integrated optical density (IOD) value was examined using the Image J to examine the expression of Col. I.