The Regulatory Effect of Remifentanil on JNK Signaling during Remission of Flap Ischemia-Reperfusion Injury.

Background: The impact of remifentanil on hypogastric flap function following ischemia-reperfusion (I/R) injury remains largely unknown, limiting its potential clinical application in flap surgery. This study investigated the therapeutic effects of remifentanil on hypogastric flap I/R injury.

Methods: Aortic endothelial cells were extracted from the hypogastric flap I/R injury models established in-house using Sprague-Dawley rats, and were treated under hypoxic conditions. The cells were treated with 0.1, 1, 10 and 100 ng/mL remifentanil and 10 ng/mL anisomycin (the activator of c-Jun N-terminal kinase [JNK]). Histopathological changes and tumor necrosis factor alpha (TNF-α) content of the flaps were observed after hematoxylin-eosin staining and immunohistochemistry. Immunofluorescence, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining and flow cytometry were employed for apoptosis evaluation. Western blotting, quantitative real-time polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA) were utilized to assess the protein and gene expression levels of TNF receptor 1 (TNFR1), JNK1, phosphorylated (p)-JNK1, malondialdehyde (MDA), superoxide dismutase (SOD), nitric oxide (NO) and TNF-α in the flaps and cells.

Results: The endothelial necrosis and cell apoptosis of rat flaps induced by I/R injury were ameliorated by remifentanil, and declining aortic endothelial cell viability and augmented apoptosis induced by hypoxia were reversed by remifentanil (10, 100 ng/mL) (p < 0.05). Remifentanil reversed the increased expressions of TNFR1, JNK1, p-JNK1, MDA and TNF-α induced by I/R injury or hypoxia in the flaps and cells (p < 0.05), and counteracted the decreased levels of NO and SOD induced by I/R injury in the flaps (p < 0.05). Anisomycin reversed the effects of remifentanil on suppressing TNFR1, JNK1 and p-JNK1 levels and apoptosis in the cells (p < 0.05).

Conclusion: Remifentanil ameliorates cell apoptosis and vascular endothelial necrosis induced by I/R injury in the hypogastric flap, likely by downregulating the TNF-α/TNFR1 pathway and JNK1 signaling. These findings suggest that remifentanil may be a promising therapeutic agent for improving hypogastric flap survival in clinical settings.