Optical imaging detects apoptosis in the brain and peripheral organs of prion-infected mice

Abstract

Activation of the caspase family of cysteine proteases is proposed tobe an important cell death mechanism in transmissible spongiform encephalopathies or prion diseases. We determined the extent of caspase activation in the brain and peripheral organs of mice that showed clinical signs after intracerebral inoculation with mouse-adapted prionsby in vivo administration of a red fluorescent pan-caspase inhibitor, sulforhodamine B-Val-Ala-Asp(OMe)- fluoromethylketone. Fluorescence reflectance imaging identified a significant increase in active caspases in brains of prion-infected, but not uninfected, mice that correlated with increases in procaspase-3 and cleaved caspase-3, a central effector ca..