Penehyclidine hydrochloride suppresses inflammation response and reduces podocyte injury in diabetic nephropathy by targeting fibrinogen-like protein 2

Diabetic nephropathy (DN) is one of the main complications of diabetes. Penehyclidine hydrochloride (PHC) has anti-inflammatory, anti-apoptotic and anti-oxidative stress effects. Nevertheless, whether PHC can be used to prevent podocyte injury has not been reported.This present study aimed to identify the functional role of PHC in DN as well as its underlying mechanism.The high-glucose (HG)-induced podocyte damage in vitro model was established. The proliferation, apoptotic rate, inflammatory factors, and gene/protein expressions of HG-induced MPC5 cells were determined using CCK-8 assay, flow cytometry, ELISA, real-time PCR, and Western blot upon PHC treatment. Co-immunoprecipitation experiments and pull-down assay were performed to verify the interactions between fibrinogen-like protein 2 (Fgl2) and toll-like receptor 4 (TLR4) as well as TLR4 and NLRP3. A rat in vivo model was used to confirm the effect of PHC treatment.PHC treatment reduced Fgl2 expression and inhibited HG-induced podocyte injury and DN-induced kidney damage. Flg2 was associated with TLR4 and NLRP3. It was further proved that PHC treatment suppressed the TLR4-NF-кB and NLRP3-Caspase-1 pathways through Fgl2, which eventually inhibited inflammatory cytokines and prevented HG-induced podocyte injury both in vitro and in vivo.PHC treatment possibly ameliorates DN by preventing podocyte injury via inactivating the TLR4-NF-кB and NLRP3-Caspase-1 signaling pathways by Flg2.