Space mission of the ‘mighty mice’

Read this in your best announcer voice: A group of genetically modified, mutant super mice will soon be sent into space. Their mission? Heal the sick.

It sounds like a comic book, but yes, in fact, a pair of University of Connecticut researchers are preparing to do just that: send a group of genetically modified super mice into space in the hopes of solving significant health problems for humans back on Earth.

The mice themselves look like they’ve spent too much time at muscle beach.

“They are strong and larger and that’s because skeletal muscle constitutes about a third of total body weight,” Dr. SeJin Lee said of the mice.

Years ago, Lee genetically engineered a group of mice so they lack a protein called myostatin.

“The engineering of the mice was part of us trying to understand what the function of myostatin is,” he said.

The result was what he calls “mighty mice.” Myostatin, as it turns out, inhibits the growth of muscle, and the mice, without it, grew to have “twice the muscle mass of normal mice.”

That was 20 years ago and, since then, generations of mice have been bred, stronger and larger than their normal, cheeseeating cousins. Now, Lee and his research partner and wife, Dr. Emily GermainLee, are preparing to send the descendants of those original mighty mice into space.

The goal is not just to breed super space mice, but to use an environment with microgravity to study how an injected myostatin inhibitor might counteract the effects of muscle wasting.

“Microgravity is a good way to study systemic muscle loss,” Lee said.

Without Earth’s gravity to give the muscles a regular workout, astronauts find their muscles atrophied when they return home, “A big problem for astronauts during extended space travel,” Lee said.

That musclewasting effect of space life mimics other conditions — muscular dystrophy, for example, and cachexia, a condition that often comes with a cancer diagnosis.

Even otherwise healthy elderly people find their muscles less effective than in their youth.

“It’s the only way to totally mimic what’s going on not only to the astronauts but someone who is totally bedridden,” GermainLee said.

But it’s not just muscle loss. The focus of GermainLee’s career has been bone disease, and the myostatin blocker developed by her husband also targets a molecule that affects bone density.

Bone density and muscle mass are interrelated, she said. A loss of muscle often leads to a loss of bone density, and vice versa. GermainLee called it “a vicious cycle.”

“Eventually, this drug that SeJin developed could improve both muscle mass and bone mass,” she said.

So, on Dec. 4, of all goes according to plan — the researchers have been warned that there are often delays — a group of genetically modified mice and a control group of normal mice will be sent off to the International Space Station while the husband and wife research team look on.

It’s a realization of a goal Lee visualized decades ago, when he first bred some super mice.

“I’ve been trying to do this project for about 20 years. Probably about 10 or 15 years ago, I wrote a letter to the head of NASA at the time,” he said. “I specifically said I want to call to call this project ‘sending mighty mice to space.’”

The project is a collaboration between The Jackson Laboratory, UConn Health and Connecticut Children’s — the bulk of the funding, about $10 million, comes from the Center for the Advancement of Science in Space — but Lee and GermainLee will be involving Connecticut high school students as well.

“Emily and I are going to two Hartford public schools to teach biology,” Lee said. “If we get just one or two kids in those rooms saying wow I want to go into science or I want to go into medicine, it will be all worth it.”

Lee and GermainLee met in college, as students at Harvard. Lee is purely a researcher, but GermainLee spends half her time working with patients suffering from bonerelated disease.

“We really had very separate tracks,” she said. “The only thing that was coexistent was that we understood what the other was doing.”

And when Lee told his wife that he would finally have the chance to send his mighty mice into space, she jumped at the chance to be involved: “I got really interested in how this could help my patients. With this space project it was the ideal situation.”

“Ultimately, although this sounds incredibly corny, the reason we both are doing what we’re doing is, we wanted to someday think that what we’re doing is making a difference,” she said.

Contributed photo Dr. SeJin Lee’s “mighty mice,” genetically engineered to have more muscle mass than normal mice. The procedure, in which myostatin is inhibited allowing more muscle to develop, has also been performed on cattle.