Pathological histology
Kidneys were fixed in 4% formalin (Shanghai Reith Biotechnology, Co., Ltd., China) and embedded in paraffin. Sections with a thickness of 4 μm were prepared before staining. Then, the sections were deparaffinized using xylene and rehydrated in a graded alcohol series (100%, 90%, 80%, and 70%), stained with hematoxylin-eosin staining (H&E, Shanghai Reith Biotechnology, Co., Ltd.) and periodic acid-Schiff (PAS, Shanghai Reith Biotechnology, Co., Ltd.) for histological examination and then hydrated in a graded alcohol series (30% to 100%). The results were quantified by bright-field light microscopy.