Background: Traumatic Spinal Cord Injury (SCI) is a severe condition usually accompanied
by an inflammatory process that gives rise to uncontrolled local apoptosis and a subsequent
unfavorable prognosis. One reason for this unfavorable outcome could be the activation of the NLRP3
Objective: MCC950 is a specific inhibitor of NLRP3 that further inhibits the formation of the NLRP3
inflammasome. The purpose of this study was to determine whether the NLRP3 inflammasome
was associated with the severity of local apoptosis and whether MCC950 could prevent neuronal
apoptosis following SCI.
Methods: In this study, primary cortical neurons were cultured in vitro. With or without pretreatment/
posttreatment with MCC950, neurons were subjected to Oxygen-Glucose Deprivation (OGD)
for 2 h and then reperfusion for 20 h. Immunofluorescence was used to determine the expression of
NLRP3, ASC, and cleaved caspase-1 in neurons. In vivo, SCI model mice were established with a
5 g weight-drop method. MCC950 was intraperitoneally injected at 0, 2, 4, 6, 8, 10, and 12 days after
SCI. Basso Mouse Scale (BMS) scores and footprint assays were used to assess motor function.
Paw withdrawal threshold and tail-flick latency were used to assess somatosensory function. H&E,
Nissl, and TUNEL staining were used to measure histological changes and apoptosis at 3 days after
SCI, and scar formation was observed by Masson staining and GFAP immunohistochemical analysis
at 28 days after SCI.
Results: Immunofluorescence analysis confirmed that MCC950 inhibited OGD-induced activation
of the NLRP3 inflammasome in neurons. Behavioral tests, Masson staining, and GFAP immunohistochemical
analysis showed that MCC950-treated mice had improved neuronal functional recovery
and reduced scar formation at 28 days after SCI. H&E, Nissl, and TUNEL staining confirmed that
there were more living neurons and fewer apoptotic neurons in MCC950-treated mice than control
mice at 3 days after SCI.
Conclusion: These results reveal that MCC950 exerts neuroprotective effects by reducing neuronal
apoptosis, preserving the survival of the remaining neurons, attenuating the severity of the damage,
and promoting the recovery of motor function after SCI.