Pharmacological inhibition of STING reduces neuroinflammation-mediated
damage post-traumatic brain injury
Abstract
Background and Purpose: Traumatic brain injury (TBI) remains a major
public health concern worldwide with unmet effective treatment.
Stimulator of Interferon Genes (STING) protein and its downstream type-I
Interferon (IFN) signaling are now appreciated to be involved in TBI
pathogenesis. Compelling evidence have shown that STING and type-I IFNs
are key in mediating detrimental neuroinflammatory response after TBI,
exacerbating outcome. Therefore, pharmacological inhibition of STING
presents a viable therapeutic opportunity in combating the detrimental
neuroinflammatory response after TBI. Experimental Approach: This study
investigated the neuroprotective effects of the small-molecule STING
inhibitor C-176 in the controlled-cortical impact (CCI) mouse model of
TBI in 10–12-week-old male mice. 30-minutes post-CCI surgery, a single
750nmol dose of C-176 or saline (vehicle) was administered
intravenously. Analysis was conducted 2h- and 24h-post TBI. Key Results:
Mice administered C-176 had significantly smaller cortical lesion area
when compared to vehicle-treated mice 24h post-TBI. Quantitative
temporal gait analysis conducted using DigiGait™ showed C-176
administration attenuated TBI-induced impairments in gait symmetry,
stride frequency and forelimb stance width. C-176-treated mice displayed
a significant reduction in striatal gene expression of pro-inflammatory
cytokines TNF-α, IL-1β and CXCL10 compared to their vehicle-treated
counterparts 2h post-TBI. Conclusion and Implications: This study
demonstrates the neuroprotective activity of C-176 in ameliorating acute
neuroinflammation and preventing white matter neurodegeneration
post-TBI. This study highlights the therapeutic potential of
small-molecule inhibitors targeting STING for the treatment of trauma
induced inflammation and neuroprotective potential.