From the Labs: Biotechnology

Stem Cells from Amniotic Fluid
Cells collected during pregnancy could aid research and therapy

Source: “Isolation of Amniotic Stem Cell Lines with Potential for Therapy”
Paolo De Coppi et al.
Nature Biotechnology 25(1): 100-106

Results: Scientists have isolated stem cells from amniotic fluid and found that they appear to have properties similar to those of embryonic stem cells. The cells grew efficiently in the lab, doubling in number every 36 hours, and were able to develop into precursors of multiple tissue types, including brain tissue.

Why it matters: Unlike embryonic stem cells, cells routinely discarded during amniocentesis could be harvested without destroying human embryos, avoiding the ethical concerns that have slowed stem cell research. And unlike most adult stem cells, those derived from amniotic fluid appear to grow efficiently and can differentiate into multiple cell types, making them suitable for therapeutic and research uses.

Methods: The researchers, led by Anthony Atala at Wake Forest, collected samples of amniotic fluid and isolated cells that expressed a molecule unique to stem cells. They then grew the cells under different environmental and chemical conditions to trigger their differentiation into different cell types.

Next steps: The researchers plan to try to develop the cells for use in treating diseases. They’ll try to make nerves for Parkinson’s patients, for instance, or insulin-secreting cells for people with diabetes.

Source: “A Genotype of Exceptional Longevity Is Associated with Preservation of Cognitive Function”
Nir Barzilai et al.
Neurology 67(12): 2170-2175

Results: A specific version of a gene involved in cholesterol transport may also help keep the mind sharp in old age. In a group of 158 Ashkenazi Jews aged 95 and older, those with the gene variant, which has previously been linked to longevity, were twice as likely to pass tests of mental ­agility as those with a different version of the gene. Among 124 people, aged 75 to 85, from an unrelated Ashkenazi population, those individuals with the gene variant were five times as likely to be free of dementia and perform well in memory tests.

Why it matters: Scientists would like to create drugs that can mimic the effects of age-defying genes. But first, they must identify the genetic variations that allow some people to stay physically and mentally healthier in old age. In a previous study of Ashkenazi Jews, Nir Barzilai and colleagues found that this gene variant is seen three times as often in centenari­ans as in others. People with the variant also seem to have larger cholesterol particles in their blood, providing a hint at the gene’s mechanism. Now the researchers have linked the gene to preservation of mental function. Taken together, the findings point to a potential target for drugs that could protect against dementia and otherwise delay the aging process.

Methods: Barzilai and his colleague Gil Atzmonran tested people of Ashkenazi Jewish descent who were 95 or older and confirmed the results in a group of 75- to 85-year-olds of the same descent. Medical geneticists often study groups, such as the Ashkenazi, descended from a relatively small number of ancestors because they’re more genetically homogenous, making it easier to identify genetic associations.

Next steps: Scientists are now examining the frequency of the gene variant in people with Alzheimer’s. They also plan to study how expression of the protein produced by the gene affects the brain in animals.