Falk and colleagues studied a biological pathway that occurs within mitochondria, called the respiratory chain. They specifically focused on the largest component of that chain, complex I, which contains 45 subunits and is the most common culprit in human mitochondrial disease.
Her team studied the nuclear genes for 28 different complex I subunits that are very similar between humans and C. elegans, as well as two genes that help assemble the subunits into a functioning complex. By using a technique called RNA interference to knock out the function of each gene, they were able to determine how gene defects may contribute to mitochondrial diseases.
The study team found that one subset of genes impairs the ability of mitochondria to consume oxygen, called respiratory capacity, in C. elegans. Another group affects how the worms react to anesthesia. "Some children with mitochondrial complex I disease are hypersensitive to anesthesia, so this new understanding may be important in guiding their clinical management," said Falk.
Because mitochondrial diseases in humans comprise a large number of different disorders showing a wide range of severity, understanding the differences in contributions from different genes within the respiratory chain may help researchers better understand why mitochondrial dysfunction causes specific problems in people. Even better, says Falk, such research points to genes that might be targeted in potential treatments.
Dr. Falk's team continues to work to explore the many different consequences of mitochondrial respiratory chain dysfunction in animal models, and ways in which these consequences might themselves be treated. This work helps to suggest specific genes that may be the cause of mitochondrial disease in individual pat
|Contact: John Ascenzi|
Children's Hospital of Philadelphia