Proceedings of the National Academy of Sciences of the United States, Sept 3, 2013, Vol.110(36), p.14735(6)
Disruption of the blood--brain barrier (BBB) is a hallmark of acute inflammatory lesions in multiple sclerosis (MS) and its animal model experimental autoimmune encephalomyelitis. This disruption may precede and facilitate the infiltration of encephalitogenic T cells. The signaling events that lead to this BBB disruption are incompletely understood but appear to involve dysregulation of tight-junction proteins such as claudins. Pharmacological interventions aiming at stabilizing the BBB in MS might have therapeutic potential. Here, we show that the orally available small molecule LY-317615, a synthetic bisindolylmaleimide and inhibitor of protein kinase C[beta], which is clinically under investigation for the treatment of cancer, suppresses the transmigration of activated T cells through an inflamed endothelial cell barrier, where it leads to the induction of the tight-junction molecules zona occludens-1, claudin 3, and claudin 5 and other pathways critically involved in transendothelial leukocyte migration. Treatment of mice with ongoing experimental autoimmune encephalomyelitis with LY-317615 ameliorates inflammation, demyelination, axonal damage, and clinical symptoms. Although LY-317615 dose-dependently suppresses T-cell proliferation and cytokine production independent of antigen specificity, its therapeutic effect is abrogated in a mouse model requiring pertussis toxin. This abrogation indicates that the anti-inflammatory and clinical efficacy is mainly mediated by stabilization of the BBB, thus suppressing the transmigration of encephalitogenic T cells. Collectively, our data suggest the involvement of endothelial protein kinase C[beta] in stabilizing the BBB in autoimmune neuroinflammation and imply a therapeutic potential of BBB-targeting agents such as LY-317615 as therapeutic approaches for MS. EAE | enzastaurin | CNS www.pnas.org/cgi/doi/10.1073/pnas.1302569110
Protein Kinases -- Physiological Aspects ; Protein Kinases -- Health Aspects ; Blood-brain Barrier -- Physiological Aspects ; Blood-brain Barrier -- Health Aspects ; Encephalomyelitis -- Physiological Aspects
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