Abstract
BACKGROUND: Renal fibrosis-characterized by microcirculatory disturbances and endothelial-mesenchymal transition (EndMT)-is a major pathological feature of chronic kidney disease (CKD) and remains a significant therapeutic challenge. The mechanosensitive ion channel Piezo1 plays a pivotal role in endothelial mechanotransduction and has been implicated in fibrogenesis, yet specific pharmacological interventions targeting Piezo1 are lacking. METHODS: We evaluated the renoprotective effects of paeoniflorin (PF), a bioactive monoterpene glycoside, in 5/6 nephrectomy-induced chronic renal failure (CRF) rats and diabetic kidney disease (DKD) db/db mice. PF-Piezo1 interactions were characterized using molecular docking, surface plasmon resonance (SPR), and functional assays. In vitro studies employing models of matrix stiffness, endothelial-fibroblast crosstalk, and HIF-1α inhibition were performed to elucidate the underlying mechanisms. RESULTS: PF treatment preserved renal function, reduced glomerulosclerosis, and ameliorated microvascular rarefaction in both CRF and DKD. Molecular docking and SPR analyses revealed that PF binds Piezo1 with high affinity, thereby inhibiting Yoda1-induced Ca2(+) influx and attenuating stiffness-induced EndMT. PF restored the expression of endothelial markers including VE-cadherin and eNOS, and suppressed HIF-1α-mediated upregulation of Vimentin and TGF-β1. Moreover, co-culture experiments demonstrated that PF disrupted endothelial-derived TGF-β1 paracrine signaling, reducing fibroblast activation and extracellular matrix deposition. Notably, Piezo1 knockdown or HIF-1α inhibition recapitulated the dual effects of PF on endothelial restoration and fibrosis suppression. CONCLUSIONS: Our findings indicate that PF exerts renoprotective effects by targeting the Piezo1/Ca(2+)/HIF-1α axis, thereby mitigating renal fibrosis. By interrupting pathological endothelial-fibroblast communication and restoring microvascular integrity, PF represents a promising mechanotherapeutic strategy for CKD.