BACKGROUND/AIMS: Spinal cord injury (SCI) is a common and devastating disease, which results in systemic inflammatory response syndrome and secondary lung injury. Mitochondrial dysfunction and inflammation are closely related to lung injury in diverse disease models. No studies have demonstrated the effects of mitochondrial targeted peptide SS-31 in a mouse model of SCI-induced lung injury.
METHODS: Immediately after injury, mice in the treatment groups received a daily, single-dose intraperitoneal injection of SS-31 and for the next 2 days. The sham and SCI groups also received a daily single dose of vehicle (DMSO and 0.9% NaCl, 1: 3). The lung tissue of mice was examined after SCI, and tissue damage, apoptosis, inflammation, and mitochondrial dysfunction were recorded.
RESULTS: SS-31 treatment attenuated lung edema and tissue damage. Furthermore, SS-31 treatment reduced apoptosis of alveolar type II cells, the number of total macrophages and M1 macrophages, and neutrophil infiltration. Moreover, SS-31 treatment attenuated reactive oxygen species levels, reversed mitochondrial dysfunction and inhibited NLRP3 inflammasome activation.
CONCLUSIONS: Collectively, our results demonstrate that SS-31 attenuates mitochondrial dysfunction, controls inflammatory responses, and alleviates the severity of lung damage in a mouse model of SCI-induced lung injury.