Houttuynia cordata polysaccharide attenuates LPS-induced lung injury by inhibiting the HMGB3/JNK pathway through upregulation of miR-200b-3p

Abstract

The aim was to investigate the therapeutic effects and molecular mechanisms of Houttuynia cordata polysaccharide (HCP) on LPS-induced lung injury. Effects were analyzed by HE, TUNEL, ELISA, MTT, and flow cytometry. Roles and mechanisms of HCP, miR-200b-3p, HMGB3, and JNK were studied by RT-qPCR, Western Blot, transfection, and dual luciferase reporter gene. HCP treatment effectively ameliorated LPS-induced lung injury in mice and TC-1 cells and was able to inhibit inflammatory factors as well as apoptosis with an effect close to that of dexamethasone-positive control. miR-200b-3p expression was down-regulated in LPS-induced lung injury and up-regulated by HCP treatment, and miR-200b-3p inhibitors reduced the therapeutic effects of HCP. miR-200b-3p targeted and negatively regulated HMGB3. HMGB3 was able to activate the JNK pathway to suppress the therapeutic effects of HCP on lung cell injury.HCP attenuates LPS-induced lung injury by upregulating miR-200b-3p to inhibit the HMGB3/JNK pathway.