Northwestern University – By creating pores in the walls of the stem cell nuclei and slipped in segments of DNA and gene-regulating proteins called transcription factors that are associated with the neurons -researchers were able to turn human embryonic stem cells into neurons.
Researchers transplanted the neurons they had engineered into slices of mouse brain, the cells wove themselves into the tissue of the hippocampus, a brain region involved in the formation of memories. The neurons produced axons, or connecting fibers, to the hippocampus and pumped out acetylcholine, a chemical needed by the hippocampus to retrieve memories from other parts of the brain.
The new technique is most exciting because it could lead to new kinds of therapy for Alzheimer’s, says team member John Kessler. “Now we can have human neurons in a dish in front of us and rapidly screen tens of thousands of drugs,” Kessler says. This could be useful for cell replacement therapy, in which doctors would graft lab-grown neurons into the brains of people with Alzheimer’s to replace brain cells destroyed by the disease.
In new, unpublished research, Northwestern Medicine scientists also have discovered a second novel way to make the neurons. They made human embryonic stem cells (called induced pluripotent stem cells) from human skin cells and then transformed these into the neurons.
This technique to produce the neurons allows for an almost infinite number of these cells to be grown in labs.
Scripps Research points to liver as source of Alzheimer plaques
Scripps Research Institute and ModGene, LLC research points to the liver instead of the brain as the source of the “amyloid” that deposits as brain plaques associated with this devastating condition. The findings could offer a relatively simple approach for Alzheimer’s prevention and treatment.
Scientists used a mouse model for Alzheimer’s disease to identify genes that influence the amount of amyloid that accumulates in the brain. They found three genes that protected mice from brain amyloid accumulation and deposition. For each gene, lower expression in the liver protected the mouse brain. One of the genes encodes presenilin — a cell membrane protein believed to contribute to the development of human Alzheimer’s.
An estimated 5.1 million Americans have Alzheimer’s disease, including nearly half of people age 85 and older. By 2050, the number of people age 65 and over with this disease will range from 11 million to 16 million unless science finds a way to prevent or effectively treat it. In addition to the human misery caused by the disease, there is the unfathomable cost. A new report from the Alzheimer’s Association shows that in the absence of disease-modifying treatments, the cumulative costs of care for people with Alzheimer’s from 2010 to 2050 will exceed $20 trillion.