Melbourne Researchers Uncover Underlying Cause of Mitochondrial=20 Diseases

Findings to Be Presented at BIO 2007, Published in Molecular Biology = of the=20 Cell

MELBOURNE, AUSTRALIA and BOSTON, MA -- (MARKET WIRE) -- May 7, 2007 = --=20 Mitochondrial diseases, a class of rare and incurable conditions, are = believed=20 to result from the failure of mitochondria in the cells to produce a = universal=20 energy carrying molecule called ATP (adenosine triphosphate). Now = research=20 conducted at Melbourne's LaTrobe University suggests that a signaling = problem in=20 the cells is at fault, turning the commonly held theory on its head. The = findings have implications for development of drug therapies to treat = the many=20 forms of mitochondrial disease as well as for most major = neurodegenerative=20 disorders, where mitochondrial dysfunction has been demonstrated to play = a=20 central role. These include Amyotrophic Lateral Sclerosis (Lou Gehrig's=20 Disease), Parkinson's, Huntington's and Alzheimer's disease. The = research will=20 be presented at the BIO2007 conference in a poster to be located in the=20 Innovation Corridor, and a publication is planned in the journal = Molecular=20 Biology of the Cell.=20

"This research gives us a completely novel understanding of the = causal=20 mechanisms of mitochondrial disease, demonstrating that such conditions = may=20 result from a signaling disorder in the cells, rather than a fundamental = energy=20 insufficiency as was previously thought," said Paul Fisher, Ph.D., lead=20 investigator and Chair in Microbiology at LaTrobe University.=20

"We are hopeful that this finding will lead to effective new = approaches to=20 treating both rare and prevalent diseases involving mitochondrial = dysfunction,"=20 said John Brumby, Minister of Innovation, Victoria, Australia.=20

"Like a smoke alarm that activates at the first sign of trouble, AMPK = is an=20 energy-sensing alarm protein that averts an impending energy crisis in = the cell=20 by activating before the situation becomes critical," said Dr. Fisher. = "When=20 triggered, AMPK temporarily shuts down a variety of activities and = initiates=20 energy production within the cell. In a healthy cell this returns ATP = supplies=20 to normal and allows the cell to return to regular functioning.=20

"What we found is that in a mitochondrially diseased cell, the AMPK = alarm is=20 permanently activated," Dr. Fisher said. "Many of the cellular outcomes = of=20 mitochondrial dysfunction are known also to be associated with AMPK = signaling,=20 but this is the first time the 'alarm protein' has itself been = implicated in=20 mitochondrial disease causation."=20

About the Research=20

Using the slime mould Dictyostelium discoideum as a model for = mitochondrial=20 disease, researchers genetically manipulated the signaling pathways that = control=20 cellular functions thought to be involved in mitochondrial disease.=20 Overproduction of an active form of AMPK was shown to create the same = symptoms=20 as mitochondrial disease, while decreasing the supply of AMPK completely = suppressed those symptoms in "Dicty."=20

About Mitochondrial Disease=20

About one in 4,000 children in the United States will develop = mitochondrial=20 disease by the age of ten. Any organ or tissue can be affected by = mitochondrial=20 disease, but it is generally the central nervous system, muscles, hearts = and=20 less often the kidneys or insulin-producing cells of the pancreas that = are=20 affected. Overtly mitochondrial diseases are rare but incurable and = range in=20 severity from mild to fatal. Friedreich's Ataxia, MERRF (Myoclonic = Epilepsy and=20 Ragged Red Fibres and MELAS (Myoclonic Epilepsy, Lactic Acidosis and = Stroke-like=20 Episodes) are examples of mitochondrial diseases.=20

The World Health Organization (WHO) calculates that neurodegenerative = diseases, also associated with mitochondrial dysfunction, will become = the=20 world's second leading cause of death by the year 2040.

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Michelle Linn
Linnden=20 Communications
Office: 508-419-1555
Mobile: 774-696-3803
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