Minnelide combined with anti-ANGPTL3-FLD monoclonal antibody completely protects mice with adriamycin nephropathy by promoting autophagy and inhibiting apoptosis.

Minimal change disease (MCD) is a common type of nephrotic syndrome (NS) in children. Currently, there is an urgent need to explore the new treatments because of the significant side effects of long-term use of glucocorticoids and immunosuppressive drugs and the failure to reduce proteinuria in some patients. Angiopoietin-like protein 3 (Angptl3) is an essential target of NS, and anti-ANGPTL3-FLD monoclonal antibody (mAb) significantly reduces proteinuria in mice with AN. However, some proteinuria is persistent. Minnelide, a water-soluble prodrug of triptolide, has been used in China for the treatment of glomerular disease for > 40 years. Therefore, the present study aimed to investigate whether minnelide combined with mAb could further protect mice with AN and the underlying mechanisms. 8-week-old C57BL/6 female mice were injected with 25 mg/kg of Adriamycin (ADR) by tail vein to establish the AN model. A dose of 200 mg/kg of minnelide or 20 mg/kg of mAb was administered intraperitoneally for the treatment. In vitro, the podocytes were treated with 0.4 mg/mL of ADR for 24 h to induce podocyte injury, and pretreatment with 10 ng/mL of triptolide for 30 min or 100 ng/mL of mAb for 1 h before ADR exposure was used to treat. The results showed that minnelide combined with mAb almost completely ameliorates proteinuria and restores the ultrastructure of the podocytes in mice with AN. In addition, minnelide combined with mAb restores the distribution of Nephrin, Podocin, and CD2AP and reduces the level of inflammatory factors [tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and IL-1β] in mice with AN. Mechanistically, minnelide combined with mAb alleviates apoptosis and promotes autophagy in mice with AN by inhibiting the mTOR signaling pathway. In vitro, triptolide combined with mAb increases the expression of Nephrin, Podocin, and CD2AP, alleviates apoptosis, and promotes autophagy by inhibiting the mTOR signaling pathway in ADR-induced podocyte injury. Overall, minnelide combined with mAb completely protects the mice with AN by promoting autophagy and inhibiting apoptosis.