The impact of methylprednisolone and rituximab on podocyte injury caused by puromycin aminonucleoside.

INTRODUCTION: To explore how MP and RTX impact TRPC6's expression and localization, and assess MP's and RTX's effects on podocyte injury and recovery. METHODS: MPC5 cells were simultaneously grown alongside a control group and under various conditions: exposure to puromycin aminonucleoside (PAN) stimulation, treatment with methylprednisolone (MP), and treatment with rituximab (RTX), and a combined treatment with both MP and RTX. RESULTS: At 8, 24, and 48 h, CCK-8 assay showed that PAN (50 μg/mL) had a decrease in cell viability and an increase in cell death, and it could be used as the optimum concentration to induce podocyte injury; MP (100 ng/mL) and RTX (100 μg/mL) maintained cell viability and had minimal impact on cell morphology, and they were the best concentrations. Following 24 and 48-h exposure to MP or RTX, there was a decrease of 30%-50% in apoptosis rates by flow cytometry in comparison to the group stimulated with PAN, accompanied by a substantial reduction in nearly 10%-60% of TRPC6 mRNA and 5%-20% of protein levels which were measured using qRT-PCR and western blot analyses, akin to the observed decrease in levels of IL-1β and IL-18. Additionally, calcium entry showed considerable reductions after 8, 24, and 48 h of MP treatment relative to the PAN-stimulation group, paralleling the effect seen with 24-h RTX treatment. DISCUSSION: Therefore, MP and RTX safeguarded podocytes, and averted proteinuria by decreasing podocyte apoptosis, diminishing TRPC6 mRNA and protein levels, and suppressing inflammatory markers and calcium entry.