Comprehensively characterizing cellular changes and the expression of THSD7A and PLA2R1 under multiple in vitro models of podocyte injury

The unique morphology and gene expression of podocytes are critical for kidney function, and their abnormalities lead to nephropathies such as diabetic nephropathy and membranous nephropathy. Podocytes cultured in vitro are valuable tools to dissect the molecular mechanism of podocyte injury relative to nephropathy, however, these models have never been comprehensively compared. Here, we comprehensively compared the morphology, cytoskeleton, cell adhesion, cell spreading, cell migration, and lipid metabolism under five commonly used in vitro models including lipopolysaccharide (LPS), puromycin aminonucleoside (PAN), doxorubicin (Dox), high glucose, and glucose deprivation. Our results indicate that all stimulations significantly downregulate the expression of synaptopodin both in human and mouse podocytes. All stimulations affect podocyte morphology but show different intensity and phenotypes. In general, the five stimulations reduce cell adhesion, cell spreading, and cell migration, but the effect in human and mouse podocytes is slightly different. Human podocytes show high expression of genes enriched in the pentose phosphate pathway. Dox and PAN treatment show a strong effect on gene expression in lipid metabolism, while the other three stimulations show minimal effect. The expression of phospholipase A2 receptor (PLA2R1) and type-1 domain-containing protein 7 A (THSD7A) show opposite trends in given cells. Stimulations can dramatically affect the expression of PLA2R1 and THSD7A. Inhibition of super-enhancers reduces PLA2R1 and THSD7A expression, but ERK inhibition enhances their expression. Our results demonstrate distinctive responses in five commonly used in vitro podocyte injury models and the dynamic expression of PLA2R1 and THSD7A, which supply novel information to select suitable podocyte injury models.