Salk Institute women scientists share progress, results

On Wednesday, July 20 the Salk Institute celebrated a “Women & Science” event with the presentation “Nutritional Genomics: Health and Well-being” where three postdoctoral female scientists shared their latest discoveries in the field of human health and well-being.

Congressmember Scott Peters introduced the speakers by sharing on the misrepresentation of women in science and the urge to push students towards the science, technology, engineering and math (STEM) fields. “We need to encourage our young scientists to pursue careers in science. Supporting young females in science is a worthy investment,” he said, adding that he co-sponsored the STEM Act, a law passed in 2015 that strengthens education efforts in those areas and expands the definition of STEM to include computer science.

The first postdoctoral student to present was Amandine Chaix. She’s researching how time-restricted feedings could affect “metabolic fitness” at the Satchidananda Panda Lab.

Chaix uses mice as models to study human diseases like diabetes. She theorizes that weight gain or loss is not only dependent on the equation between fat intake and exercise, but it’s also determined by the time patterns of food intake.

Her experiment consists of measuring weight and the prevalence of diabetes — high levels of sugar in blood — in mice that have access to food 24 hours a day versus those whose food intake is limited to daytime hours. Her results so far show that the mice who only eat during the day are leaner and have decreased risk of diabetes compared to those who eat at all hours.

Her research also shows that modifying those behaviors, chiefly by not allowing the free-eating mice access to food after 8 p.m., the mice that are heavier and more prone to diabetes saw an improvement in body weight and health. “For the animals who had free access to food, a change to time-restricted feeding lowered body weight,” Chaix explained.

Next was Maryam Ahmadian, who studies the recent discovery of what is known as “brown fat” and how it affects human weight. “We know obesity is becoming more of a health problem (along with) all the medical complications attached to it, like heart problems and diabetes. … Some people eat really well, exercise and don’t lose any weight,” she explained.

“Brown fat adapts to changes in temperature and activates in cold temperature,” she said, implying that brown fat mobilizes when exposed to low temperatures as a mechanism to warm up the body, contrary to white fat, which makes up the vast majority of the fat in the human body and responds to other metabolic factors.

She was looking for answers to the question, “How can we target brown fat?” when she found a nuclear receptor that affects it, Estrogen Related Receptor (ERR-gamma). Ahmadian explained, “Mice without ERR-gamma couldn’t heat themselves up in cold situations. Brown fat can’t be activated without ERR-gamma. Now I’m looking at compounds that can activate ERR-gamma and how we can use them to combat obesity.”

Last was Sheila Rao, a postdoctoral student for assistant professor Janelle Ayres’s Lab looking into how infectious bacteria promotes health. “You must imagine that these microbes are interested in having us healthy in order to sustain themselves,” she said, adding that the most successful infectious bacteria are those who make us sick but don’t kill us.

Rao’s experiment involved infecting mice with two different salmonella virus, the common one and a mutation. She elaborated, “I’m interested in sickness behaviors. Disruptions in sleep, social withdrawal, reductions in grooming, anorexia … (Only) the animals infected with the mutant salmonella stopped eating and died, (therefore) we identified a salmonella bacteria gene that impacts our behavior.” The potential outcomes of her study include preventing or stopping anorexia and control appetite to stop obesity.