Faculty Profile — Keith Choe, Biology

He is on a quest to live long and prosper.

By Gigi Marino

scientist uses syringe with DNA testing kit
Keith Choe uses genetic analysis of C. elegans to understanding aging. Lyon Duong/UF Photography

The humble nematode C. elegans is at first glance a simple animal. A millimeter long and barely visible to the human eye, C. elegans is hermaphroditic and has a lifespan of two to three weeks. However, this simple creature has approximately the same number of genes as a human and shares a third of them with us, making it an expeditious and inexpensive research model. Keith Choe, associate professor of biology, studies mutations in C. elegans with the goal of understanding how cells respond to environmental stress and how this information could one day stave off aging and disease.

“In the same way that you need to be able to detect when something is wrong with your home or your car, you need to diagnose what’s wrong and then how to go about calling the right repair person to deal with the job. In the case of the cell, there are quite a number of networks of genes and proteins that are responsible for this,” says Choe. “These pathways are very complex. There are at least 20,000 genes in most animals. In order to gain fundamental insights, we use the simplest organism we can as a model.”

Aging determines general cell health, organ health, and systems health. “One of the biggest risk factors for most diseases in modernized civilization — cancer, cardiovascular disease, degeneration — is just your age,” he says. “If you can understand how to unlock and prevent this decline in environmental response, you should be able to slow aging and reduce or delay the incidence of many different diseases.”

Choe and his lab specifically look at the antioxidation response in C. elegans as oxidation causes damage. They mutate the proteins that normally slow down this pathway and have discovered that doing so increases the levels of antioxidants and detoxification, thereby extending lifespan by 15 to 20 percent.

Certain supplements such as vitamin C are touted for their antioxidant properties. Choe warns against relying on such supplements in an unregulated fashion. “You can cause more harm than good because you can shut off your own cells’ natural ability to deal with oxidants because they no longer have a signal to respond to,” he says. “By flooding your system with antioxidants from the outside, you’re basically shutting off your own protection system.” He points out that oxidant levels are not necessarily deleterious to the body and that researchers now understand that oxidant levels are a way for cells to communicate. “Your internal protection systems are much better at fine-tuning responses in each cell than you can achieve by taking a bunch of pills.”

The Choe Lab is staffed by four undergraduates, three graduate students, and one postdoc. Eighteen UF students have been trained in the Choe Lab with six earning authorship on scientific publications. For the past five years, Choe has partnered with UF’s Center for Precollegiate Education and Training to introduce 90 middle and high school teachers and 101 high school students to C. elegans genetics and biology and to host a high school student each summer. “They have all been top-notch students interested in going into science,” he says, “and it’s been a wonderful opportunity for our graduate students to teach and mentor them. They accomplish a lot while they’re here.”