HIV-tat-mediated BCl-XL delivery protects retinal ganglion cells during experimental autoimmune optic neuritis

In multiple sclerosis (MS), post-mortem studies of human brain tissue as well as data from animal models have shown that apoptosis of neurons occurs to a significant extent during this disease. As neurodegeneration in MS correlates with permanent neurological deficits in patients, understanding the mechanisms would be an important precondition for designing appropriate neuroprotective therapies. Myelin oligodendrocyte glycoprotein-induced experimental autoimmune encephalomyelitis often affects the optic nerve and leads to consecutive apoptosis of retinal ganglion cells (RGCs), the neurons that form its axons. In this study, we fused Bcl-X-L to the protein transduction domain of the HIV-transactivator of transcription. Thereby, this antiapoptotic member of the Bcl-2 family was delivered into RGCs of rats with electrophysiologically diagnosed optic neuritis. Transduction of Bel-XI, in our study led to significant rescue of RGCs indicating the relevance of this pathway for neuronal survival under autoimmune inflammatory conditions. (c) 2005 Elsevier Inc. All rights reserved.