Transcranial pulsed current stimulation alleviates neuronal pyroptosis and neurological dysfunction following traumatic brain injury via the orexin-A/NLRP3 pathway

Abstract

Traumatic brain injury (TBI) is a life-threatening condition with high incidence and mortality rates. The current pharmacological interventions for TBI exhibit limited efficacy, underscoring the necessity to explore novel and effective therapeutic approaches to ameliorate its impact. Previous studies have indicated that transcranial pulsed current stimulation (tPCS) can improve neurofunctional deficits in patients by modulating brain neuroplasticity. However, the exact mechanism underlying this neuroprotective effect remains elusive. In this study, mice with TBI induced by controlled cortical impact were subjected to 30 min of daily tPCS for 5 consecutive days and intraperitoneally administered an orexin receptor type 1 (OX₁R) antagonist (SB334867). The neuroprotective effects of tPCS and its potential mechanisms were assessed through behavioral tests, histopathological examination, immunohistochemistry and Western blotting. In vitro experiments involved stimulating HT22 cells with LPS + ATP to assess the anti-neuroinflammatory effects of Orexin-A (OX-A) using CCK-8, Western blotting, and Flow cytometry. The results demonstrated that tPCS reduced the mNSS in TBI mice, ameliorated tissue damage, improved motor and cognitive deficits, and upregulated OX-A expression. Notably, SB334867 reversed the protective effects of tPCS. In vitro studies revealed that OX-A inhibited the formation and activation of NLRP3 inflammasomes, resulting in reduced levels of ROS and restoration of MMP. However, this effect could be reversed by the NLRP3 agonist BMS-986299. Our findings suggest that tPCS promotes the release of OX-A and modulates the OX₁R/NLRP3 pathway to mitigate the inflammatory response following TBI, thereby exerting neuroprotective effects.