Co-culture with embryonic renal stromal progenitor cell enhances podocyte differentiation and modulates doxorubicin-induced injury responses

Podocytes are specialized epithelial cells that play a central role in maintaining the selective permeability of the glomerular filtration barrier of the kidney. However, conventional podocyte mono-culture systems often lack the cellular microenvironment required to fully support podocyte differentiation. Renal stromal progenitor cells (rSPCs) contribute to glomerular development and give rise to stromal derivatives, including mesangial cells, suggesting that they may provide developmental cues that support podocyte differentiation. Therefore, this study investigates the effect of co-culturing heat-sensitive mouse podocytes (HSMPs) with mouse embryonic rSPCs on podocyte differentiation and function in a membrane-based system. Podocytes were cultured alone or in combination with sorted embryonic rSPCs on porous membranes of different pore sizes (0.4 μm and 8 μm). The results showed that co-culture with rSPCs on 8 μm membranes significantly enhanced podocyte marker expression and promoted podocyte-like morphology, likely due to improved cellular interactions. The co-culture model maintained size-selective permeability and exhibited a distinct dose-dependent response to doxorubicin-induced injury, suggesting that rSPCs modulate podocyte sensitivity to toxic stress. These findings suggest that embryonic rSPCs provide a supportive microenvironment that enhances podocyte differentiation and stability, offering a more physiologically relevant in vitro model for studying glomerular development and injury.