U researchers discovered a potential cause for human obesity8212;in fruit flies.
Carl Thummel, a professor of human genetics, released findings Tuesday from two studies detailing the similarities between fruit flies and human molecular mechanisms that help the body regulate cholesterol levels. It also is a main form in which fat cells are stored in the body, which contributes to obesity in both flies and humans.
Studying fruit flies gave scientists better insight into how genetics and biological mechanisms affect cholesterol and metabolism in humans. U researchers found that when a particular protein is active and present in large numbers, the flies became fat, and the same might apply to humans.
“The main reason to study this is we need as much information as we can get to know the cause of obesity,” Thummel said. “Obesity has been set aside by the Centers for Disease Control and also the World Health Organization as a major health problem.”
About one-fourth of people in the United States are considered obese, with a body mass index of 30 or higher, Thummel said. That is often linked to heart disease, diabetes and other diseases. Thummel believes this research is essential to helping address people with these health risks.
In the study, Thummel and his team of researchers were able to identify a protein in the flies that can sense fats. Using a process developed by Kent Golic, a U professor of biology, researchers were able to disable or increase the amount of the protein in the flies.
Thummel then placed the flies on strict high- or low-fat content diets and gave some of them drugs to help them lose weight, he said.
The flies acted just as Thummel suspected humans would. Depending on the amount of fat, the flies either had too much or not enough cholesterol. Those with an excessive amount developed a high blood cholesterol disorder, and the flies with too little died.
“When they lacked (the protein), the flies were unable to maintain cholesterol homeostasis,” Thummel said. “This is similar to what happens in humans who have high cholesterol levels.”
The flies with normal functioning proteins were able to maintain a proper level.
“We used the fly to do this study easily and quickly,” because of their short lifespan Thummel said.
From these findings, Thummel learned that the balance between fat and cholesterol levels plays an important role in developing obesity. The receptor has also shown to be necessary to break down dietary fat in the flies’ intestines. The receptors in the flies work similarly to those in humans, but researchers are unsure how they control the pathways, Thummel said.
Thummel said he would like to research the functions of the genes that control the receptor to learn more about how they regulate metabolism.
His findings were published today in Cell Metabolism.