PAI-1 promotes thromboangiitis obliterans progression through NF-κB-NLRP3 pathway activation via HIF-1α-dependent signaling

Background Thromboangiitis obliterans (TAO, Buerger's disease) is a chronic inflammatory disorder that affects small and medium-sized vessels in the limbs. Although the pathogenesis of TAO remains incompletely understood, elevated levels of plasminogen activator inhibitor-1 (PAI-1) have been associated with cardiovascular diseases. This study investigates the mechanism by which PAI-1 activates the NF-κB/NLRP3 inflammatory pathway in vascular endothelial cells through hypoxia-inducible factor-1α (HIF-1α), contributing to the progression of TAO. Methods Proteomic analysis was performed on plasma samples from 5 TAO patients and 5 healthy controls to identify differentially expressed proteins (DEPs). In vitro, human umbilical vein endothelial cells (HUVECs) were subjected to 1 % hypoxia to mimic TAO conditions. Interventions included PAI-1 knockdown using lentiviral vectors and treatment with the HIF-1α agonist dimethyloxalylglycine (DMOG). Cell viability was assessed using the CCK-8 assay, apoptosis was measured by flow cytometry, and inflammatory factor levels were detected by enzyme-linked immunosorbent assay (ELISA). Protein expression was analyzed by Western blotting. In vivo, a TAO rat model was established by sodium laurate injection. The severity of limb ischemia was evaluated using gross lesion grading and infrared thermography, while pathological changes were assessed by hematoxylin and eosin (H&E) staining and Masson's trichrome staining. Results Elevated levels of PAI-1, HIF-1α, and key molecules in the NLRP3/NF-κB pathway were observed in both TAO rats and hypoxic HUVECs. PAI-1 knockdown significantly improved limb ischemia and suppressed the NLRP3/NF-κB pathway in TAO rats. Compared with the DMOG intervention group, combined treatment with PAI-1 knockdown and DMOG effectively alleviated ischemic symptoms, increased body weight, and reduced the expression of HIF-1α and inflammatory pathway molecules in TAO rats. Conclusion PAI-1 promotes the progression of TAO by activating the NF-κB pathway via HIF-1α. Targeted inhibition of PAI-1 represents a potential therapeutic strategy for TAO.