Breakthrough understanding of mitochondrial disease

Scientists at La Trobe University have made a breakthrough by discovering signalling problems in cells may be responsible for mitochondrial diseases, a set of rare and incurable conditions affecting thousands of people worldwide.

Professor Paul Fisher, chair of Microbiology at Victoria's La Trobe University, made the breakthrough using a type of amoeba known as "slime mould' (Dictyostelium discoideum).

His research team genetically manipulated the signalling pathways that control cellular functions thought to be involved in mitochondrial disease.

"At the moment, there is no successful treatment for mitochondrial disease. Due to this research, we now have a completely new understanding of how mitochondrial disease is caused " from a signalling disorder in the cells, rather than a fundamental energy insufficiency as was previously thought," said Minister for Innovation, John Brumby, at the BIO2007 conference in Boston.

"Until now mitochondrial diseases were believed to have been triggered by the failure of mitochondria " mini powerhouses in each cell of the body " to produce enough energy to meet the body's needs, especially in the cells of the nervous system and muscles.

Fisher and his team focused on the energy sensing alarm protein, known as AMPK, which activates at the first sign of trouble like a smoke alarm.

"AMPK usually averts an impending energy crisis in the cell by activating before the situation becomes critical, and in a healthy cell this returns energy supplies to normal and allows the cell to return to regular functioning," Fisher said.

"This research showed that in mitochondrially-diseased cell, AMPK is permanently activated " the first time ever that the "alarm protein' has been implicated in mitochondrial disease causation," he said.