Polydatin attenuates LPS-induced acute lung injury in rats via targeting HSP90AB1.

Abstract

ETHNOPHARMACOLOGICAL RELEVANCE: The root of Polygonum cuspidatum Sieb. et Zucc, referred to as Huzhang in traditional Chinese medicine, is widely employed in therapeutic formulations against inflammatory diseases. As its core bioactive constituent, polydatin (PD), exhibits anti-inflammatory, antioxidant, and immunomodulatory effects. Despite these pharmacological properties, the molecular targets underpinning PD's anti-inflammatory actions in pulmonary disorders remain unclear. PURPOSE: This study aims to identify therapeutic targets and elucidate the molecular mechanisms of PD against acute lung injury (ALI). MATERIALS AND METHODS: In a rat model of ALI induced by LPS, PD was administered at doses of 10, 20, and 40 mg/kg for 7 consecutive days to evaluate therapeutic efficacy. Integrated approaches, including cellular thermal shift assay (CETSA), thermal proteome profiling (TPP), mass spectrometry, site-directed mutagenesis, molecular docking, molecular dynamics simulations, fluorescence-based thermal shift assay (FTS) and microscale thermophoresis (MST), were used to identify potential target and binding sites. Subsequently, RAW264.7 cell lines overexpressing the target protein were established to investigate its regulatory effects on inflammatory pathways. Cellular/tissue co-localization, western blotting, and immunohistochemistry (IHC) further revealed that PD targets HSP90AB1 and modulates the IL-17/MAPK/NF-κB pathway. RESULTS: It was demonstrated that PD significantly attenuates LPS-induced inflammatory responses both in vivo and in vitro. Subsequently, PD was confirmed to specifically target HSP90AB1 by binding to its Asp88 residue. Critically, mechanistic studies revealed that PD binding disrupts HSP90AB1-mediated stabilization of the client protein ACT1, thereby suppressing the IL-17/MAPK/NF-κB pathway. CONCLUSION: Polydatin confers protection against ALI in rat models by targeting HSP90AB1 and suppressing the IL-17/MAPK/NF-κB pathway.