Accumulation of protease-resistant prion protein (PrP) and apoptosis of cerebellar granule cells in transgenic mice expressing a PrP insertional mutation

Accumulation of protease-resistant prion protein (PrP) and apoptosis of cerebellar granule cells in transgenic mice expressing a PrP insertional mutation

^*Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63110; ^†Department of Neuroscience, Laboratory of Neuropathology, University of Turin, 10126 Turin, Italy; and ^‡Division of Neuropathology, Indiana University School of Medicine, Indianapolis, IN 46202

Communicated by Gerald D. Fischbach, National Institutes of Health, Bethesda, MD (received for review November 9, 1999)

Abstract

We have generated lines of transgenic mice that express a mutant prion protein (PrP) containing 14 octapeptide repeats whose human homologue is associated with an inherited prion dementia. These mice develop a neurological illness with prominent ataxia at 65 or 240 days of age, depending on whether the transgene array is, respectively, homozygous or hemizygous. Starting from birth, mutant PrP is converted into a protease-resistant and detergent-insoluble form that resembles the scrapie isoform of PrP, and this form accumulates dramatically in many brain regions throughout the lifetime of the mice. As PrP accumulates, there is massive apoptosis of granule cells in the cerebellum. Our analysis provides important insights into the molecular pathogenesis of inherited prion disorders in humans.

Footnotes

↵ § To whom reprint requests should be addressed. E-mail: dharris{at}cellbio.wustl.edu.
Abbreviations:

PrP,

prion protein;

PrPSc,

scrapie isoform of PrP;

PrPC,

cellular isoform of PrP;

Tg,

transgenic;

ISEL,

in situ end labeling;

WT,

wild type