Tiny transparent zebra fish yields big clue to black box of Alzheimer’s disease

The PR folks at the Flanders Institute for Biotechnology in Belgium produced an unusual press release to describe recent work there published in Developmental Cell. They devoted the first half to the marvels of their animal model the zebra fish.

zebrafish1For those who have only seen these nearly transparent little guys in a home aquarium the story provides a nice explanation for why they are such popular lab models. It is not unusual to walk into a lab with dozens of small fish tanks holding thousands of zebra fish. A couple key reasons: their DNA matches 90 percent of ours and the guys reproduce quickly, just three months after birth.

Nerve stem cells, key players to brain development in the embryo, become few in number in adults. More important, those few we have left seem to be less active when we need them most, when Alzheimer’s disease or other neurodegenerative disease destroys some of our existing nerves. Evgenia Salta at the Institute used the fish to try to discern why.

We have known for some time that the genes in a pathway known as Notch regulate the ability of nerve stem cells to mature into adult nerves. But we don’t know why that goes awry in disease. She focused on a genetic regulatory molecule called a microRNA that is known to be in abnormally low supply in cells from patients with Alzheimer’s.

When they manipulated the fish to lower the levels of this microRNA, the nerve stem cells in the fish failed to mature properly into nerve cells. In the press release published on ScienceDaily Salta is quoted saying:

“To our surprise, the reduced activity of miRNS-132 in the zebra fish blocks the further ripening of the stem cell into nerves cells. This new knowledge about the molecular signaling pathway that underlies this process gives us an insight into the exact blocking mechanism. Thanks to this work in zebra fish, we can now examine in detail what exactly goes wrong in the brains of patients with Alzheimer’s disease.”

You can read about CIRMM-funded projects seeking solutions to Alzheimer’s Disease on our fact sheet.

Don Gibbons

First of its kind stem cell production facility sets its sights on deadly childhood disease

We are used to hearing about immune suppression when transplanting organs or cells from one person to another. It’s a necessary step in preventing the body from attacking the transplanted material. Now Children’s Hospital of Orange County (CHOC) has just unveiled its newest tool to treat rare childhood diseases. Instead of focusing on immune suppression this focuses on immune-matching.

CHOC's new stem cell production facility

CHOC’s new stem cell production facility

CHOC has opened up a new stem cell production facility. It’s funded by CIRM and it’s a state-of-the-art mini clean room/manufacturing facility that will allow researchers to produce patient-specific cells for future immune-matching therapies.

“We are excited. We’ve been planning this for at least five years,” says Philip Schwartz, Ph.D., senior scientist at the CHOC Children’s Research Institute and managing director of the National Human Neural Stem Cell Resource.

“The major thing is that the footprint is much smaller than a traditional stem cell manufacturing facility, it’s all housed in one room so that keeps the cost down. The device we use to reproduce the cells is also much smaller so this set up doesn’t require multiple rooms and complex pass-throughs as you move from one room to another. All that meant the cost was only around $500,000 which is many times smaller than the more conventional facility.”

Dr. Schwartz is wasting little time putting the new facility to work. It’s already up and running and culturing cells for his work in developing a treatment for mucopolysaccharidosis (MPS-1), a rare neurodegenerative disease that usually kills children before the age of 10.

He is working on a kind of 1-2 punch approach to the disease. Using donated umbilical cord blood to help replace the child’s damaged immune system and then turning some of those blood stem cells into neural cells, the kind damaged by MPS-1, and transplanting those into the brain to repair and prevent further damage.

“This is a really interesting approach. Bone marrow transplants treat a neck down disease. Brain transplants treat a neck up disease. But conditions like MPS-1 are system wide and need both a neck down and neck up approach. Our approach could help combine those and because the cells are carefully matched also mean they won’t need to be on immune-suppressant therapy for life.”

Dr. Schwartz says animal studies using this two pronged approach have been very encouraging but he cautions there is still a lot of work to do before it would be ready for a clinical trial in people. However, if this approach is effective then it could be useful for more than just MPS-1:

“I have a high level of confidence that this will work and if it does work then we can use it in other conditions as well, such as Multiple Sclerosis. Some clinical studies show that MS patients with leukemia who got a bone marrow transplant also saw a decrease in their MS symptoms.”

Kevin McCormack