From the University of Washington
The transplant anti-rejection drug rapamycin
showed unexpected benefits in a mouse model of a fatal defect in the energy powerhouses of cells, the mitochondria. Children with the condition, Leigh syndrome, show progressive brain damage, muscle weakness, lack of coordination or muscle control, and weight loss, and usually succumb to respiratory failure.
Leigh syndrome is often diagnosed within the first year of life. Affected children rarely survive beyond 6 or 7 years. At present, the disorder, which can result from several different underlying causes, has no effective treatment.
Reporting this week in Science Express, UW researchers said that they found that treatment with rapamycin “robustly enhances survival and attenuates disease progression in a mouse model of Leigh’s syndrome.” Given as a daily injection, the drug delayed the onset of neurological symptoms, reduced brain inflammation, and prevented brain lesions.
For most of their lives, the treated mice breathed normally, and did not clasp their legs against their bodies, a posture characteristic of this and related brain disorders in mice. Unlike the untreated mice, they could balance and run on a rotarod, a miniature log rolling exercise toy. Both the median and maximum lifespans within the group of treated mice were strikingly extended, the authors noted.
The median lifespan for this mouse condition is 50 days. In comparison, treated males lived a median of 114 days, and females 111 days. The longest survival in the treated group was 269 days, more than triple that of the untreated animals.
“We were excited at the findings because of the potential impact on treatment for kids with this or related mitochondrial diseases,” said the senior author of the study, Dr. Matt Kaeberlein, UW associate professor of pathology. “Similar intervention strategies might also prove useful for a broad range of mitochondrial diseases or for other conditions resulting from mitochondrial dysfunction."