Inhibition of astroglial nuclear factor κB reduces inflammation and improves functional recovery after spinal cord injury

TLDR

In the CNS, NF‑κB drives inflammation and secondary injury, and its activation after trauma can have both protective and detrimental effects on recovery. Selective inactivation of astroglial NF‑κB in GFAP‑dn mice markedly improves functional recovery eight weeks after spinal cord injury, reduces lesion volume, preserves white matter, and lowers pro‑inflammatory chemokines, cytokines, and glial‑scar components, supporting NF‑κB inhibition as a therapeutic target.

Abstract

In the central nervous system (CNS), the transcription factor nuclear factor (NF)-kappaB is a key regulator of inflammation and secondary injury processes. After trauma or disease, the expression of NF-kappaB-dependent genes is highly activated, leading to both protective and detrimental effects on CNS recovery. We demonstrate that selective inactivation of astroglial NF-kappaB in transgenic mice expressing a dominant negative (dn) form of the inhibitor of kappaB alpha under the control of an astrocyte-specific promoter (glial fibrillary acidic protein [GFAP]-dn mice) leads to a dramatic improvement in functional recovery 8 wk after contusive spinal cord injury (SCI). Histologically, GFAP mice exhibit reduced lesion volume and substantially increased white matter preservation. In parallel, they show reduced expression of proinflammatory chemokines and cytokines, such as CXCL10, CCL2, and transforming growth factor-beta2, and of chondroitin sulfate proteoglycans participating in the formation of the glial scar. We conclude that selective inhibition of NF-kappaB signaling in astrocytes results in protective effects after SCI and propose the NF-kappaB pathway as a possible new target for the development of therapeutic strategies for the treatment of SCI.