WASHINGTON – A newly discovered “survival protein” protects the brain against the effects of stroke by interfering with a particular kind of brain cell death that is often found in cases of Parkinson’s disease and heart attack. Scientists from Johns Hopkins University in the US say they exploited the fact that when brain tissue is subjected to a stressful but not lethal effect, a defence response occurs that protects cells from subsequent effects.
The scientists dissected this preconditioning pathway to identify the most critical molecular players, one of which is the newly identified protein protector called Iduna, reports the journal Nature Medicine. Named for a mythological Norwegian goddess who guards a tree full of golden apples used in restoring health to sick and injured gods, the Iduna protein increased three-to four-fold in preconditioned mouse brain tissue, according to the scientists. “Apparently, what doesn’t kill you makes you stronger,” says Valina Dawson, professor of neurology and neuroscience at the Johns Hopkins Institute of Cell Engineering.
“This protective response was broad in its defence of neurons and glia and blood vessels – the entire brain. It’s not just a delay of death, but real protection that lasts for about 72 hours,” adds Dawson, according to a Johns Hopkins statement. The team noted that Iduna works by interrupting a cascade of molecular events that result in a common and widespread type of rain cell death called parthanatos often found in cases of stroke, Parkinson’s disease, diabetes and heart attack. By binding with a molecule known as PAR polymer, Iduna prevents the movement of cell-death-inducing factor (AIF) into a cell’s nucleus.
In some of the experiments, Dawson and her team exposed mouse brain cells to short bursts of a toxic chemical, and then screened these “preconditioned” cells for genes that turned on as a result. Focusing on Iduna, the researchers turned up the gene’s activity in the cells during exposure to the toxic chemical that induced preconditioning. Cells deficient in Iduna did not survive, but those with more Iduna did. – Khaleejtimes
