Patient-derived induced stem cells retain dise...( MADISON When neurons started dyin...)

MADISON When neurons started dying in Clive Svendsen's lab dishes, he couldn't have been more pleased.

The dying cells the same type lost in patients with the devastating neurological disease spinal muscular atrophy confirmed that the University of Wisconsin-Madison stem cell biologist had recreated the hallmarks of a genetic disorder in the lab, using stem cells derived from a patient. By allowing scientists the unparalleled opportunity to watch the course of a disease unfold in a lab dish, the work marks an enormous step forward in being able to study and develop new therapies for genetic diseases.

As reported this week in the journal Nature, Svendsen and colleagues at UW-Madison and the University of Missouri-Columbia created disease-specific stem cells by genetically reprogramming skin cells from a patient with spinal muscular atrophy, or SMA. In this inherited disease, the most common genetic cause of infant mortality, a mutation leads to the death of the nerves that control skeletal muscles, causing muscle weakness, paralysis, and ultimately death, usually by age two.

Genetic reprogramming of skin cells, first reported in late 2007 by UW-Madison stem cell biologists James Thomson and Junying Yu and a Japanese group led by Shinya Yamanaka, turns back the cells' developmental clock and returns them to an embryonic-like state from which they can become any of the body's 220 different cell types. The resulting induced pluripotent stem cells, known as iPS cells, harness the blank-slate developmental potential of embryonic stem cells without the embryo and have been heralded as a powerful potential way to study development and disease.

Just one year later, the new work is fulfilling that promise.

"When scientists study diseases in humans, they can normally only look at the tissues affected after death and then try to work out how did that disease happen? It's a little like the police arriving
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