Magazine article Science News

Brain Cell Death Remains Unsolved Mystery

Magazine article Science News

Brain Cell Death Remains Unsolved Mystery

Article excerpt

If detectives found several corpses with bullet holes through the heart, they'd be surprised if autopsies showed that the deaths were actually from poisoning.

Similarly, when scientists last year found that people with neurodegenerative disorders such as Huntington's disease have brain cells stuffed with unusual clumps of mutant proteins, many simply assumed that the abnormal buildup inside the cells' nuclei caused the cell death characteristic of the illnesses (SN: 8/16/97, p. 102). That clue may have been misleading: Two studies in the Oct. 2 Cell suggest that the clumping is a largely irrelevant, perhaps even protective, cellular phenomenon.

In the first study, scientists genetically engineered mice to have the mutant gene responsible for spinocerebellar ataxia type 1 (SCA1), one of the diseases in which mutant proteins clump inside cells' nuclei. In some cases, the researchers had modified the gene so that the protein it encodes no longer sticks so readily to other copies of itself. Indeed, the mutant proteins didn't form discernible clumps inside nuclei. Nevertheless, the mice came down with typical symptoms of SCA1.

The proteins must still get into the nucleus to wreak havoc, the investigators found. They disabled the part of the mutant SCA1 gene that encodes the signal for its protein to move into the nucleus. Mice with this altered gene developed no disease symptoms. "If you block the protein from getting into nucleus, you have a cure," says Harry T. Orr of the University of Minnesota in Minneapolis who headed the team that created the mice. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed

Oops!

An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.