At UW-Madison, 500 scientists study stem cells 20 years after their discovery | State and region

Ashton's three-dimensional neuronal tubes in a cup could also be used to screen chemicals and environmental toxins to determine if they kill brain cells or modify cells to cause birth defects.

"This could be a useful model for detecting chemicals that disrupt the development process," said Ashton, assistant professor of biomedical engineering at UW-Madison.

At the university, Ashton is one of about 100 university researchers – and among about 500 scientists in total – who use stem cells for drug or chemical screening, disease modeling or development. of cell therapies for diseases, according to Dr. Tim Kamp, director of the university. Center for Regenerative Medicine and Stem Cells.

Some researchers are studying human embryonic stem cells. James Thomson, the campus scientist, announced for the first time his ability to develop in the laboratory 20 years ago this month. Others rely on induced pluripotent stem cells – skin cells or blood reprogrammed in the embryonic state – developed by Thomson and Japanese researcher Shinya Yamanaka in 2007.

Ashton was attracted to stem cells because of Thomson's pioneering role in this area. In 2001, while Ashton was studying chemical engineering, Time magazine put Thomson on the cover.

Ashton has read Time's article and has decided to dedicate his career to applying the principles of stem cell engineering. "I thought," How can we make them useful products? "

Krishanu Saha, also an assistant professor in biomedical engineering, uses stem cells to test the effectiveness of another new biological tool: CRISPR, a form of gene editing.

CRISPR, which stands for "short palindromic repeats interspersed in clusters", is a "molecular chisel" that allows accurate editing of genes, potentially as therapy. Discovered in 2012, the technique is based on a defense mechanism of bacteria.

Saha has integrated CRISPR editing machines into a nanoparticle that can be injected to patients to repair the genes of the disease. He is collaborating with Dr. David Gamm in the development of a gene modification therapy for macular degeneration, among other potential clinical uses.

Gene editing can lead to unintended changes in the genome that can lead to immune responses or even cancer. To test the accuracy of the editing process, Saha uses stem cells by exploiting their ability to grow indefinitely in a dish.

"You can systematically test genome publishers for months or years with the same cell lines," he said.

Another pathology that Saha could benefit from is the fragile X syndrome, a developmental disorder at the heart of Anita Bhattacharyya's research.

Bhattacharyya, an assistant professor of biology at the Waisman Center at UW-Madison, is studying iPS cells in patients with fragile X and CRISPR-published embryonic stem cells, with the help of Saha, to bring the gene mutation to life. origin of the disease. In affected individuals, the gene is disabled.

"We are looking for ways to reactivate the gene, which may be able to relieve some of the symptoms," said Bhattacharyya.

She also studies iPS cells of people with Down syndrome to understand why they suffer from a shortage of nerve cells and tend to develop Alzheimer's disease, apparently due to what is known as oxidative stress. their cells. The hope is not to cure, but to find a treatment that could help patients live more independently.

"We can use our neurons derived from iPS cells to ask if this helps correct oxidative stress, to improve its functioning?", She said.