Necrostatin-1 protects against ischemia/reperfusion injury by inhibiting receptor-interacting protein 1 in a rat flap model.

INTRODUCTION: The failure of reconstructive surgeries remains a challenge for plastic surgeons. Ischemia reperfusion (I/R) injury is considered to be one of the major problems in flap surgery. Necroptosis is a recently discovered and caspase-3-independent programed necrosis. Necrostatin-1 (Nec-1) is a specific inhibitor of necroptosis. Reports indicate that Nec-1 provides protection in ischemic models, such as brain, kidney, and heart. The aim of this study is to investigate the influence of Nec-1 on the I/R process in rat abdominal skin flaps.

METHODS: Twenty male Sprague-Dawley rats, weighing 280-320 g, were randomly divided into three groups. The extended epigastric skin flap (6 cm × 9 cm) of rats was used. Three hours of complete ischemia was performed using a clamp, and the clamp was then removed to reperfusion the flap. Twenty-four hours after the onset of the reperfusion, the rats were assessed for flap survival and perfusion analysis. One sample (1 cm × 1 cm) was taken for H&E, TUNEL, electron microscopy, IHC staining for RIP-1, and ELISA analysis for caspase-3 activity.

RESULTS: Compared to the CTL group, the flap in the Nec-1 group showed a higher survival rate and better blood perfusion. In histological observation, skin flap in the Nec-1 group showed less inflammatory infiltration than the CTL group. The AI in the CTL group was higher than that in the Nec-1 group and showed typical morphological changes of apoptotic cells. In IHC study, RIP-1 expression was higher in the CTL group. But there was no significant difference between the two groups in caspase-3 activity detection.

CONCLUSION: Nec-1 has a protective effect against I/R injury through the inhibition of RIP-1 on the skin flap model; this makes it a promising novel strategy in clinical setting.