IL-11 ameliorates oxidative stress damage in neurons after spinal cord injury by activating the JAK/STAT signaling pathway.

ABSTRACT

OBJECTIVE: Excess reactive oxygen species (ROS) generated by oxidative stress is a crucial factor affecting neuronal dysfunction after spinal cord injury (SCI). IL-11 has been reported to have antioxidative stress capacity. In the present study, we investigated the protective effect and mechanism of IL-11 against neuronal cell damage caused by oxidative imbalance. METHODS: We established a H2O2-induced oxidative stress injury model in PC12 cells and observed the effects of IL-11 on cellular activity, morphology, oxidase and antioxidant enzymes, and ROS release. Furthermore, the effect of IL-11 on apoptosis of PC12 cells was assessed by flow cytometry, a TUNEL assay and Western blotting. Transcriptome analysis and rescue experiments revealed the mechanism by which IL-11 protects neurons from oxidative stress damage. For the in vivo investigation, an adenovirus-mediated IL-11 overexpression SCI rat model was constructed to validate the beneficial effect of IL-11 against SCI. RESULTS: IL-11 significantly improved the viability and enhanced the antioxidant activity of H2O2-treated PC12 cells while reducing ROS release. In addition, IL-11 reduced H2O2-induced PC12 cell apoptosis. Transcriptome analysis revealed that the JAK/STAT pathway may be related to the antioxidant activity of IL-11. Treatment with a JAK/STAT inhibitor (Stattic) exacerbated the oxidative damage induced by H2O2 and attenuated the protective effects of IL-11. The results of in vivo studies showed that IL-11 prevented neuronal apoptosis due to oxidative imbalance and promoted the restoration of motor function in SCI rats by activating the JAK/STAT signaling pathway. CONCLUSION: IL-11 inhibited oxidative stress-induced neuronal apoptosis at least in part by activating the JAK/STAT signaling pathway and further promoted the recovery of motor function. These findings suggest that IL-11 may be an effective target for the treatment for SCI.