Internucleosomal breakdown of the DNA of brain cortex in human spongiform encephalopathy.

The analysis of chromatin structure in cases of human spongiform encephalopathies could show the possible involvement of apoptosis in neuronal cell death. Genomic DNA was purified from peripheral blood lymphocytes and from a biopsy of the brain cortex in a case of Creutzfeldt-Jakob disease. Restriction fragment polymorphism with AspI, PvuII, Del and NspI showed the pattern of wild type PrP gene. The DNA purified from the brain consisted of partially degraded DNA in internucleosomal-sized fragments, whereas the DNA from peripheral blood lymphocytes showed the high molecular weight of unbroken DNA. These results are consistent with the possible activation in vivo of the apoptotic endonuclease and the internucleosomal fragmentation of DNA of the brain cortex in the patient affected by Creutzfeldt-Jakob disease, suggesting the involvement of apoptosis in neuronal cell death in human spongiform encephalopathy.