Potential oxidative stress related targets of mitochondria-focused therapy of PTSD

Activation of GPER1 by G1 prevents PTSD-like behaviors in mice: Illustrating the mechanisms from BDNF/TrkB to mitochondria and synaptic connection

BACKGROUND

G1 is a specific agonist of G protein-coupled estrogen receptor 1 (GPER1), which binds and activates GPER1 to exert various neurological functions. However, the preventive effect of G1 on post-traumatic stress disorder (PTSD) and its mechanisms are unclear.

OBJECTIVE

To evaluate the protective effect of G1 against synaptic and mitochondrial impairments and to investigate the mechanism of G1 to improve PTSD from brain-derived neurotrophic factor (BDNF)/tyrosine kinase receptor B (TrkB) signaling.

METHODS

This study initially detected GPER1 expression in the hippocampus of single prolonged stress (SPS) mice, utilizing both Western blot and immunofluorescence staining. Subsequently, the effects of G1 on PTSD-like behaviors, synaptic, and mitochondrial functions in SPS mice were investigated. Additionally, the involvement of BDNF/TrkB signaling involved in the protection was further confirmed using GPER1 antagonist and TrkB inhibitor, respectively.

RESULTS

The expression of GPER1 was reduced in the hippocampus of SPS mice, and G1 treatment given for 14 consecutive days significantly improved PTSD-like behaviors in SPS mice compared with model group. Electrophysiological local field potential (LFP) results showed that G1 administration for 14 consecutive days could reverse the abnormal changes in the gamma oscillation in the CA1 region of SPS mice. Meanwhile, G1 administration for 14 consecutive days could significantly improve the abnormal expression of synaptic proteins, increase the expression of mitochondria-related proteins, increase the number of synapses in the hippocampus, and ameliorate the damage of hippocampal mitochondrial structure in SPS mice. In addition, G15 (GPER1 inhibitor) and ANA-12 (TrkB inhibitor) blocked the ameliorative effects of G1 on PTSD-like behaviors and aberrant expression of hippocampal synaptic and mitochondrial proteins in SPS mice and inhibited the reparative effects of G1 on structural damage to hippocampal mitochondria, respectively.

CONCLUSION

G1 improved PTSD-like behaviors in SPS mice, possibly by increasing hippocampal GPER1 expression and promoting BDNF/TrkB signaling to repair synaptic and mitochondrial functional impairments. This study would provide critical mechanism for the prevention and treatment of PTSD.

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

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.