Antiapoptotic Therapy Little Help In Prion Disease

NEW YORK (Reuters Health) - In a mouse model of prion dementia, deletion of the Bax gene rescues neurons from cell death but does not reduce neurological symptoms, researchers report in the December 20th early edition of the Proceedings of the National Academy of Sciences.

These findings, say Dr. David A. Harris, from Washington University School of Medicine in St. Louis, and colleagues, strongly suggest that the pathogenesis of prions is largely due to the effect of accumulated proteins on neuronal connections and not the death of the neurons themselves.

Bax, a proapoptotic gene of the Bcl-2 family, they note, plays an important role in regulating cell death in the nervous system.

In transgenic mice with prion disease, Bax inactivation markedly suppressed apoptotic death of cerebellar granule neurons, "implying that these cells die via a Bax-dependent process," the investigators note. "Surprisingly," however, Bax inactivation did not stop synaptic degeneration or neurological symptoms.

These findings have "important implications" for the design of therapies for prion disease and other neurodegenerative diseases, the investigators conclude. "It seems unlikely that antiapoptotic therapies alone will have a beneficial therapeutic effect unless associated with pharmacological intervention aimed at preventing synaptic damage and neuronal dysfunction."

Source: Proc Natl Acad Sci 2004. [ Google search on this article ]

MeSH Headings: Genes, bcl-2