Effectiveness of a Novel PLA2R1 Knock-In Rat Model in Repairing Renal Function Damage

Phospholipase A2 receptor 1 (PLA2R1) exists in many animals and plays an important role in membranous nephropathy. In this study, we aimed to evaluate a PLA2R1 knock-in rat model with repaired kidney function to study the molecular mechanisms of membranous nephropathy. We constructed the PLA2R1 knockout [PLA2R1(-)] model and PLA2R1 knock in [PLA2R1(+)] model in rats. Consistent complement C3 and IgA expression was confirmed through colocalization studies. Urinary biochemical indicators were performed using Automatic Biochemistry Analyzer. The complement C3, IgG, and Nephrin were detected by immunofluorescence assay. The expression levels of complement C3, IgA, and PLA2R1 were detected by western blot. The differential expression proteins (DEPs) between control and PLA2R1(+) models were detected by liquid chromatography with tandem mass spectrometry. The PLA2R1(-) model showed proteinuria, complement C3 aggregation, and IgA and IgG deposition in the glomerulus. Comparing with the PLA2R1(-) model, the PLA2R1(+) model, the deposition of complement C3 and IgA in the glomerulus did not completely disappear, and IgG expression weakened. Moreover, the absolute value of urinary protein was much lower in the PLA2R1(+) model than in the PLA2R1(-) model, and some of the humanized PLA2R1 gene fragments repaired some of the kidney functions. Humanized PLA2R1-insertion in rats can repair part of the renal function and reduce proteinuria, which will help in studying the molecular mechanisms of membranous nephropathy, as well as the entire membranous nephropathy-related system and complement activation signaling pathway.