Abstract Background and Aims Idiopathic focal segmental glomerular sclerosis (FSGS) is characterized by progressive damage to the renal parenchyma leading to end-stage renal disease, frequent recurrence after kidney transplantation and no specific therapeutic intervention. Since the podocytes (PODO) are the principal target of FSGS injury, their protection could be an efficient, targeted therapy. In this context, we investigated a potential therapeutic approach based on a new peptide, UPARANT, capable of modulating the Urokinase-type plasminogen activator receptor (uPAR) on PODO. Method PODO were activated with 4% sera of 5 patients with recurrent FSGS for 48 h and then treated with 100 nM of UPARANT for 48 h. Proteins were then extracted for TMT proteomics. The Gene Ontology system database, valid for large-scale analysis, was used to identify the significantly enriched biological pathways and molecular functions. An in vitro model of a glomerular filtration barrier composed of PODO-endothelial co-culture was used to assess the change in filtration capacity by albumin (BSA) permeability test. The difference from baseline BSA percentage was measured after damage induced with sera from three FSGS patients and after 48 h of treatment with UPARANT. Results First, we found that UPARANT could counteract the BSA permeability induced by FSGS sera in the PODO-endothelial co-culture (P = .04, P = .03, and P = .02, respectively). The proteomic analysis of PODO indicated that UPARANT induced the positive regulation of plasma membrane repair mechanisms (Annexin 2 P = .007 and AHNAK P = .03); this process was strongly linked to the activation of molecular functions related to both S100 and calcium-dependent proteins. Moreover, UPARANT induced the overexpression of Endophilin-B1 (P = .02) and Vimentin (P = .02), both involved in the assembly and organization of the actin filament. Conclusion We demonstrated that UPARANT efficiently counteracts in vitro the effects of FSGS sera on PODO, leading to the recovery of the spatial organization of PODO, acting on the structural integrity of the plasma membrane and restoring cytoskeletal plasticity and dynamism. This might result in vivo in the protection of the integrity of the filtration barrier.