The Inquirer Health Blog
Last week, a study in the Journal of the American Medical Association added to evidence that abnormalities in mitochondria - the so-called powerhouses of the cell - are common in autistic children.
Douglas C. Wallace, a mitochondrial research pioneer who joined Children's Hospital of Philadelphia last summer, says autism is just one of many disorders in which malfunctioning mitochondria are implicated. The list includes diabetes, obesity, heart disease, cancer, Parkinson's, and Alzheimer's.
Wallace also foresees therapies for the malfunctions. Developing them is a focus of the Center for Mitochondrial and Epigenomic Medicine, the new program he has established at Children's.
"We believe this is going to revolutionize medicine," said the former University of California-Irvine researcher.
Hyperbole? Maybe not. Within every cell, 200 to 10,000 mitochondria - self-replicating structures with their own DNA - use oxygen and food to generate energy, then regulate its flow. Without energy, cells can't work and ultimately die.
Wallace was among the first scientists to recognize the vital importance of mitochondria. In the 1970s, he led a Stanford University group that showed the single-stranded DNA within each mitochondrion is separate from the cell's double-stranded nuclear DNA, and is inherited exclusively from the mother.
Degenerative diseases can arise from mitochondrial DNA damage, particularly in energy-demanding cells such as those in the brain. In mice, Wallace's team has induced Parkinson's, blindness, and other conditions by putting mutations in the DNA.
Even if the DNA is intact, energy can be impaired.
"Many pesticides and herbicides inhibit mitochondrial function," Wallace said. "If you can't burn the food you eat, you store it as fat."
Too much fat has spawned the modern epidemics of obesity and diabetes.
In animal models, Wallace's team has relieved mitochondrial dysfunction using certain chemicals derived from traditional Asian herbal medications such as ginkgo biloba.
Asian concepts of disease, he noted, are based on bodily energy flow, or "ch'i," while Western medicine focuses on individual organ systems.
"We've missed half the story," Wallace said. Mitochondria are more sensitive to upsets "than anything else in your body."