Stem cell researchers inch toward treatment for Huntington’s Disease

Courtesy of Leslie Thompson/UC Irvine

This photo shows two mice with Huntington's Disease symptoms. The one on the left was not treated. The one on the right was injected with neural stem cells, which seem to protect neurons and neural pathways in the brain.

People with Huntington’s disease face an awful future - perhaps 20 years as it slowly strips away brain cells.

But there’s a chance that in the next 20 years, researchers at UC Irvine could develop treatments that could arrest Huntington’s – and other brain and nervous systems disorders – thanks in part to a girl from Fountain Valley.

Emily Krull of Fountain Valley was a normal, brown-haired little girl. Up until sixth grade, she got good grades and made the honor roll. But seventh grade hit and Emily’s grades plummeted. She became depressed and hard to motivate.

Her parents had adopted Emily when she was little; they figured whatever was going on was just a teenage phase. But then Emily started blinking a lot and losing her balance, like she was drunk.

Her mom, Carla Krull, says Emily’s school even wanted to give her a drug test at her prom.

"And when she went to Knott’s Scary Farm, they wanted to alcohol test her," Carla Krull remembers. "And imagine, you’re with your friends or your boyfriend and how the humiliation of having to be drug tested, and they’re not listening to you when you say, 'I'm not drunk.'"

Emily’s parents knew something was wrong. They just didn’t know what.

Eight neurologists later, they figured it out: Huntington’s Disease – the fatal genetic brain disorder. Brain cells stop communicating and die off.

Folk singer Woody Guthrie died of Huntington’s. So did Emily Krull, last October at the age of 21.

But Carla Krull says before she died, Emily walked into a lab at UC Irvine and donated a small chunk of skin. From Emily’s skin, researchers are developing stem cells that might someday help lead to a cure for Huntington’s.

"It was a real exciting day for her," Carla Krull said. "It was like a war wound. It’s like the movie, 'Twilight,' the vampires? It was like her vampire bite. Yeah, she was very excited about it."

The lab that Emily walked into is run by Leslie Thompson, who’s studying possible stem cell treatments for Huntington’s Disease, which is in some ways similar to Parkinson’s or Alzheimer’s disease. The brain’s pathways are blocked by clumps of protein.

"The cells don’t communicate well. They don’t turn over. They don’t clear out garbage, like the cell debris. They can’t clear it as well," Thompson said. "They can’t create the appropriate proteins, the correct signals between the neuron and the brain. They can’t make enough of them that they would normally need to make."

Similarities in Huntington’s, Parkinson’s, Alzheimer’s and Lou Gehrig’s disease mean there’s overlap in research. A breakthrough in Huntington’s could help move along research into the other brain-robbing diseases.

With Huntington’s, Thompson says it’s a little bit easier because scientists know it’s caused by a single genetic mutation.

"Which offers a huge advantage for this kind of work, because you know who has it – you know exactly what individuals have it, you know when they become symptomatic or who’s going to become symptomatic so you can start treatment early. You can create lines that all have the genetic mutation in them," said Thompson.

If one of your parents had Huntington’s – which usually strikes between the ages of 35 and 44 – then you have a 50 percent chance of getting it.

Thompson is working on creating models that use Huntington’s Disease stem cell lines so researchers can more quickly test which drugs work.

She’s also looking at how mice with Huntington’s Disease react when neural stem cells are injected into their brains.

"The stem cells produce very protective factors to the brain and so if we transplant these cells, certain types of cells, into the brain of, say an HD [Huntington's Disease] mouse, which is what we’re doing right now, they sort of nurse existing neurons that are there and keep them sort of protected," Thompson said.

That suggests a treatment someday that could stop symptoms from progressing or prevent them in the first place. But Thompson says there’s still a lot they don’t know.

"What are some of the initial triggers?" she said. "We know a lot about some of the things that happen in the neuron. But we’re still at the phase of trying to prevent some of the really early steps and you know, how to get a neuron that’s sick to not be sick, basically."

Thompson predicts tests on stem cell-based therapies for Huntington’s Disease could start in the next five to 15 years. That’s something that gives hope to Emily Krull’s parents.

"I feel that she was meant for us because we would carry this on. And we’re determined to carry this on until we get a cure."

And, says mom Carla Krull, if Emily could see the progress that’s been made in the past couple of years toward finding a treatment for Huntington’s Disease, Emily would be smiling.