Glucocorticoid signaling in myeloid cells worsens acute CNS injury and inflammation.

Glucocorticoid stress hormones (GCs) are well known for being anti-inflammatory, but some reports suggest that GCs can also augment aspects of inflammation during acute brain injury. Because the GC receptor (GR) is ubiquitously expressed throughout the brain, it is difficult to know which cell types might mediate these unusual "proinflammatory" GC actions. We examined this with cell type-specific deletion or overexpression of GR in mice experiencing seizure or ischemia.

Prior exposure to glucocorticoids sensitizes the neuroinflammatory and peripheral inflammatory responses to E. coli lipopolysaccharide.

Acute and chronic stress has been found to sensitize or prime the neuroinflammatory response to both peripheral and central immunologic challenges. Several studies suggest that stress-induced sensitization of neuroinflammatory processes may be mediated by the glucocorticoid (GC) response to stress. GCs, under some conditions, exhibit pro-inflammatory properties, however whether GCs are sufficient to prime neuroinflammatory responses has not been systematically investigated.