Contribution of IL-33/ILC2-mediated Th2 cytokines during the progression of minimal change disease

Minimal change disease (MCD) is a common type of nephrotic syndrome with high recurrence rate. This study aims to explore the impacts of interleukin (IL)–33 in MCD and to discuss its potential mechanism. In adriamycin (ADM) and puromycin aminonucleoside (PAN)-induced MCD rat model, IL-33 was used for treatment. H&E staining was applied for detecting histological changes. Critical proteins were examined by western blot. Corresponding commercial kits tested oxidative stress- and inflammation-related factors. Cell apoptosis was measured by TUNEL assay. ADM-induced podocyte injury model was establish to mimic MCD in vitro. Cell proliferation and apoptosis were detected by CCK-8 and TUNEL assays. Finally, podocyte was stimulated by innate lymphoid type-2 cells-secreted Th2 cytokines (ILC2s: IL-13 and IL-5 respectively), with or without incubation with M1 macrophage medium to further explore the immune-regulation of ILC2s behind the inflammatory environment of MCD. It was found that PAN-induced kidney jury, inflammation, oxidative stress and apoptosis were severer than ADM, and IL-33 treatment significantly alleviated the above injuries in PAN and ADM-induced MCD rat model. Moreover, IL-33 reversed the reduced viability and increased oxidative stress and apoptosis in ADM-induced podocyte injury model. Further, the capacities of IL-13 alone in inducing M1/M2 macrophage polarization, apoptosis, inflammation, kidney injury and reducing cell viability are stronger than IL-5. However, IL-13 reversed reduced cell viability and stimulated apoptosis, inflammation, kidney injury mediated by co-incubation with M1-conditioned medium. Collectively, IL-33 might protect against immunologic injury in MCD via mediating ILC2s-secreted IL-13.