The influence of calcitriol and methylprednisolone on podocytes function in minimal change disease in vitro model

Minimal change disease (MCD), considered one of the major causes of nephrotic syndrome, is a complex pathological condition with disturbances in podocytes' foot processes. Numerous studies suggested the essential role of vitamin D3 in maintaining proper glomerulus function. However, the data on direct potential of that compound in reference to podocytes are scarce. Thus, here we assessed the influence of calcitriol (active vitamin D3) on podocyte function, apart from commonly used steroids (methylprednisolone). CIHP-1 podocyte cell line was used to implement the LPS-PAN-induced MCD in vitro model. Viability, podocyte-related slit diaphragm proteins, morphology, function as a barrier was evaluated using flow cytometry, RT-PCR, confocal microscopy, and TEER analysis. Calcitriol or methylprednisolone did not affect cell viability. Podocyte-related proteins demonstrated different responses to in vitro treatment compared to previously reported changes in total glomeruli. Podocyte morphology was partially restored in the presence of the tested compounds. In addition, TEER analysis revealed improvement of LPS-PAN-induced cells' function as a barrier when vitamin D3 or steroid was used. In conclusion, a significant potential for modulation of MCD in vitro model podocytes with calcitriol or selected steroids was reported. Further studies on vitamin D3 in context of podocyte-related phenomenon accompanying MCD are of great importance.