Brain ‘organoids’ point to new drug target for fragile X syndrome
'New findings hint at why drugs that work in mouse models of fragile X syndrome have not been effective in people'
From an article on Spectrum website by NICHOLETTE ZELIADT:
Many drugs that work in mouse models of fragile X syndrome have not proven effective in people. New findings hint at why: The protein missing in the syndrome controls different cellular processes in mice than in people.
“Clinical trials solely based on animal-model studies have failed,” says Yujing Li, staff scientist in the lab of co-lead investigator Peng Jin at Emory University in Atlanta, Georgia. The findings underscore “the limitations of animal models in mimicking fragile X syndrome in humans,” Li says. He presented the work yesterday at the 2019 American Society of Human Genetics meeting in Houston, Texas.
The findings also pinpoint a potential new drug target for the condition.
The fragile X protein, called FMRP, typically keeps levels of certain proteins in check. In the absence of FMRP, these proteins pile up, impairing the function of neurons.
However, FMRP loss arises differently in mice and people: Mouse models of the syndrome lack the gene that encodes FMRP, whereas people with the syndrome carry mutations that diminish its levels.
So Li and his colleagues turned to a different model: human brain ‘organoids’ — tiny spheres of brain cells made from reprogrammed skin or blood cells. Brain organoids are known to mimic several aspects of human brain development...
