Each day, we are confronted by millions of bacteria, all attempting to invade our bodies and cause infection. It’s the job of the body’s immune system to defend against these little invaders. In order to fight off bacteria (as well as viruses and cancerous cells), the immune system has an arsenal of weapons at its disposal. One of these weapons is the complement system. Complement is so important for fighting infections that people who have mutations in certain complement proteins or their regulators often suffer from frequent bacterial infections.
How to make holes in bacteria: Complement protein C6 (in foreground) is part of the innate immune system. When activated, it triggers assembly of the Membrane Attack Complex (MAC), which forms pores in bacterial membranes (three membrane-inserted MACs are shown in background).
Michiko Fukuda, Ph.D. (Photo by Nadia Borowski Scott)
Carbohydrates are not only found in many of the foods that we love to eat (think bread and pasta), they also coat the surfaces of all cells in the body. What’s more, when a healthy cell becomes a cancer cell, the surface carbohydrates (also known as glycoproteins) are sometimes altered in a way that can contribute to tumor growth and metastasis.
Glycobiology, the study of glycoproteins and their role in human health, is a relatively underappreciated scientific field. But identifying cancer cell glycoproteins and understanding their part in cancer is a focus of Michiko Fukuda, Ph.D.’s laboratory. As she puts it, “Many people don’t want to think a lot about carbohydrates.”
heart muscle in a fruit fly (image courtesy of the Bodmer lab)
Heart disease is the leading cause of death in the United States, accounting for more than 25 percent of all deaths each year. While many factors work together to contribute to heart disease—including environment, lifestyle, and genetics—we only have control over the first two. To address the third factor (genetics), researchers at Sanford-Burnham recently turned to fruit flies.
Fly and human genes are so closely related that the sequences of newly discovered human genes, including many that contribute to disease, can often be matched up with fly counterparts. Since fruit flies are relatively easy to work with (they’re small, breed quickly, and don’t require a lot of maintenance), they often give scientists clues to the functions of human genes and helps them develop drugs that target them.
As Dr. Rolf Bodmer, director of Sanford-Burnham’s Development and Aging Program, explains in the Journal of Cell Biology, “We use fruit flies to learn about the fundamental genetic mechanisms that are important for the development and function of the heart.”
Dr. Bodmer himself discovered early in his career that flies lacking Tinman, a protein that regulates the expression of other genes, fail to develop heart tissue during embryonic development. If Tinman is removed later during fly development, the flies’ hearts don’t function properly.
Now researchers in Dr. Bodmer’s lab, led by postdoctoral researcher Dr. Li Qian, uncovered a genetic network that controls heart development and function in fruit flies and mice, with additional clues that it might also play a role in human heart health.