Renoprotective effects of DAPT against zymosan-induced acute kidney injury and senescence: Unraveling the role of toll like receptor 2 and Notch1 signaling pathways through an integrated in vivo and in silico analysis.

Renal tubular cell senescence driven by interaction of Notch with Toll like receptor (TLR) signaling is a principal mediator of acute kidney injury (AKI). The present study explored the crosstalk between TLR2 and Notch signaling in modulating senescence-associated secretory phenotype (SASP) and apoptosis during Zymosan (Zym)-induced AKI in mice. DAPT, a potent γ-secretase inhibitor, antagonizes the Notch signaling axis. Balb/c mice were used to evaluate the effects of Zym and DAPT over two timepoints (6 and 24 h); control groups: I and IV, AKI groups: II and V received Zym, and DAPT treated groups: III and VI received DAPT 1 h before Zym. Groups I, II, and III were euthanized after 6 h, while groups IV, V, and VI after 24 h. Almost all variations in renal tissues were evident 6 h after Zym injection and became more prominent at 24 h. DAPT reduced plasma creatinine, urea, and kidney injury molecule-1 as well as renal expression of TLR2, Notch1/Notch intracellular domain, and hairy and enhancer of split 1. DAPT lowered p21Waf1/Cip1 and p16INK4a along with nuclear factor-κB, tumor necrosis factor-α, CCL2, and CXCL10 levels. DAPT modulated apoptotic signals, augmented Ki67 expression and exhibited improved renal histopathology. Molecular docking confirmed the interaction of DAPT with p21Waf1/Cip1 and TLR2. ShinyGO-0.81 database was scrutinized for functional enrichment analysis and KEGG pathway mapping. Conclusively, the current study is the first to declare that DAPT could attenuate TLR2 activation-induced renal cellular senescence via inhibition of Notch signaling and its impact on TLR2 and p21Waf1/Cip1.