Protective effect of necrosulfonamide on rat pulmonary ischemia-reperfusion injury via inhibition of necroptosis

Necroptosis plays an important role in cell death during pulmonary ischemia-reperfusion injury (IRI). We hypothesized that therapy with necrosulfonamide (NSA), a mixed-lineage kinase domain-like protein inhibitor, would attenuate lung IRI.Rats were assigned at random into the sham operation group (n = 6), vehicle group (n = 8), or NSA group (n = 8). In the NSA and vehicle groups, the animals were heparinized and underwent left thoracotomy, and the left hilum was clamped for 90 minutes, followed by reperfusion for 120 minutes. NSA (0.5 mg/body) and a solvent were administered i.p. in the NSA group and the vehicle group, respectively. The sham group underwent 210 minutes of perfusion without ischemia. After reperfusion, arterial blood gas analysis, physiologic data, lung wet-to-dry weight ratio, histologic changes, and cytokine levels were assessed. Fluorescence double immunostaining was performed to evaluate necroptosis and apoptosis.Arterial partial pressure of oxygen/fraction of inspired oxygen (PaO2/FiO2) was better, dynamic compliance was higher, and mean airway pressure and lung edema were lower in the NSA group compared with the vehicle group. Moreover, in the NSA group, lung injury was significantly alleviated, and the mean number of necroptotic cells (55.3 ± 4.06 vs 78.2 ± 6.87; P = .024), but not of apoptotic cells (P = .084), was significantly reduced compared with the vehicle group. Interleukin (IL)-1β and IL-6 levels were significantly lower with NSA administration.In a rat model, our results suggest that NSA may have a potential protective role in lung IRI through the inhibition of necroptosis.