Patient-specific hiPSC-Podocytes as an in vitro model of genetic FSGS.

Mutations in podocyte-specific genes are associated with genetic focal segmental glomerulosclerosis (FSGS), yet the potential for targeted treatments remains uncertain. Therefore, patient-specific models are essential for understanding cellular phenotypes, identifying personalized therapies, and avoiding ineffective treatments. This study utilized patient-specific human induced pluripotent stem cell (hiPSC)-Podocytes to investigate cellular phenotypic and functional alterations associated with genetic FSGS in vitro. HiPSC-Podocytes were generated from a patient with a mutation in the inverted formin 2 (INF2) gene, who showed a partial clinical response to steroid treatment. Compared to healthy donor-derived hiPSC-Podocytes, the patient-specific hiPSC-Podocytes exhibited decreased protrusion length, reduced levels of actin-associated markers, and alterations in INF2 protein levels. Additionally, actin filaments were disrupted, characterized by increased actin depolymerization. Next to the actin-modulating agent Bis-T-23, the steroid Solu-Decortin H (SDH) improved the actin cytoskeleton in the patient-specific cells, which aligned with the patient's partial response to steroids. This underscores the importance of personalized treatment strategies based on specific cellular responses in genetic FSGS.