Mechanistic Insights into HOTAIR-Driven ADAM17/NF-Κb Activation and Endothelial Dysfunction in LPS-Challenged HUVECs

HOX transcript antisense intergenic RNA (HOTAIR) has been implicated in inflammation and vascular pathology, but its role in regulation of ADAM17 and sepsis-induced endothelial injury remains unclear. LPS-treated human umbilical vein endothelial cells (HUVECs) modeled sepsis-induced endothelial injury, which were assessed via qRT-PCR, western blot and immunofluorescence. HOTAIR-knockout mice were treated with cecal ligation and perforation to establish sepsis model. LPS-stimulation increased expression of HOTAIR and ADAM17 and decreased miR-326 levels in HUVECs. HOTAIR-knockdown by antisense oligonucleotides (ASOs) decreased ADAM17, TNF-α production and NF-κB activities; it also alleviated endothelial inflammation, VE-cadherin integrity damage, apoptosis and barrier dysfunction, while miR-326 inhibition reversed these effects. MiR-326 inhibited TNF-α/NF-κB via targeting ADAM17. Further experiments demonstrated recombinant TNF-α reversed the inhibitory effect of HOTAIR-ASOs on LPS-triggered TNF-α/NF-κB activation and downstream endothelial injury, which were further mitigated by NF-κB or p38 MAPK inhibitors. In-vivo experiments in HOTAIR-knockout mice confirmed the role of HOTAIR/miR-326/ADAM17 in regulating NF-κB and p38 MAPK inflammation, with improved lung injury and survival following sepsis. The HOTAIR/miR-326/ADAM17 axis is a key regulator of inflammation, endothelial injury and barrier dysfunction during sepsis via modulation of TNF-α/NF-κB signaling, providing new insights into the mechanisms underlying endothelial injury in sepsis.