Molecular Basis Of Mitochondrial Complex I Deficiency, The Most Common Energy Generation Disorder
Funder
National Health and Medical Research Council
Funding Amount
$515,750.00
Summary
Oxygen is needed by every cell in the body to burn fuels (ie sugar, fat and protein) in small power plants inside each cell called mitochondria. In Australia, about 50 children born each year have inherited disorders of mitochondrial energy generation. The most severe disorders cause infant death, while others cause a range of degenerative diseases later in life, particularly affecting brain, muscle and heart. In most cases we do not have any effective treatments. A major problem in understandin ....Oxygen is needed by every cell in the body to burn fuels (ie sugar, fat and protein) in small power plants inside each cell called mitochondria. In Australia, about 50 children born each year have inherited disorders of mitochondrial energy generation. The most severe disorders cause infant death, while others cause a range of degenerative diseases later in life, particularly affecting brain, muscle and heart. In most cases we do not have any effective treatments. A major problem in understanding mitochondrial energy generation disorders is that the genetic causes are incredibly diverse. So far more than 20 genes have been shown to cause mitochondrial disorders, and it is likely that over one hundred more genes remain to be discovered. In addition to the regular genes that cause these and other genetic disorders, mitochondria are unique in carrying 37 extra genes located in a different part of the cell away from the rest of the human genome, and inherited only from the mother. This grant focuses on the most common energy generation disorder, known as Complex I deficiency. Complex I requires 43 separate components to be assembled together in order to work properly, but mutations in the 43 genes encoding these components are not present in most patients. We believe that the most common problems will be in genes involved in assembling the 43 components rather than in the components themselves. We will use a number of methods to pinpoint where in the genome the causative genes are located and then home in on the exact changes in the genes that cause disease. Identifying these genes will allow us to improve future diagnosis and prevention of mitochondrial disease. Understanding the basic biology may also allow us to develop new methods of treatment. Recent studies suggest that milder mitochondrial problems also contribute to a range of more common diseases such as diabetes and Parkinson disease, so any new treatments could potentially have wide application.Read moreRead less
First Generation Mouse Models Of MtDNA Disease: Testing Genotype/phenotype Predictions
Funder
National Health and Medical Research Council
Funding Amount
$256,527.00
Summary
Mitochondrial diseases comprise a diverse group of inherited diseases affecting infants, children and adults. These disorders result from defective energy production by the mitochondria, tiny structures in all cells which have their own unique DNA. This mitochondrial DNA is inherited only from our mothers. To make energy for cells to function normally, special enzymes are produced in the mitochondria from mitochondrial and nuclear genes. In their most severe form mitochondrial disease results in ....Mitochondrial diseases comprise a diverse group of inherited diseases affecting infants, children and adults. These disorders result from defective energy production by the mitochondria, tiny structures in all cells which have their own unique DNA. This mitochondrial DNA is inherited only from our mothers. To make energy for cells to function normally, special enzymes are produced in the mitochondria from mitochondrial and nuclear genes. In their most severe form mitochondrial disease results in infants with muti-system failure. Adult forms are less severe, with symptoms including epilepsy, cardiomyopathy, late-onset blindness or deafness, and commonly diabetes. We do not understand why different mitochondrial mutations result in such diverse symptoms, and no therapies have been consistently successful. Unusual features of mitochondrial DNA has meant that it has remained beyond the reach of techniques which are commonly used now to produce mice with altered genes. These so-called 'mouse models' are powerful tools to better understand human diseases and importantly, to enable experimental therapies to be tested and improved. This grant proposes a novel method of producing such mouse models, for the first time allowing mice with different levels of defective mitochondrial function to be produced to model the human diseases. In the proposed work, mitochondria from different mouse species will be introduced into laboratory mice. This unusual approach is based on previous work by the investigators who have shown that this produces defective mitochondria in cultured mouse cells. These mice will be allowed to age and the function of mitochondria from different organs tested as the animals age. Secondly, a range of mitochondrial DNA mutations will be produced in cultured cells and mutants selected to make other mice which should accurately model the diverse human diseases.Read moreRead less