Today, Shinya Yamanaka receives the 2012 Nobel Prize in Physiology or Medicine for his work on induced pluripotent stem cells (iPS cells, as opposed to controversial embryonic stem cells).
As part of his Nobel Lecture at Karolinska Institutet in Stockholm, Professor Yamanaka used Motor Neurone Disease as an example for a pharmaceutical in-vitro application of iPS cells.
"[MND patients] become unable to move – and in the end, they become unable to breathe. So it's a very, very sad situation for patients and the family members. Despite numerous efforts by numerous scientists we still don't have effective drugs for these patients suffering from Motor Neurone Disease, primarily because we don't have a good disease model to perform drug screening.
"For many diseases, we have animal models by which we can perform drug screening, and by which we have identified many drugs which are effective on both animal models and human patients. We do have mouse models for Motor Neurone Diseases like ALS. Many drugs have been developed using the animal models, many drugs have found to be effective on mice, but very sadly all of these drugs turned out not to be effective on human patients.
"So for Motor Neurone Disease – for people – we do have to use human cells to perform drug screening. However, it is impossible to provide sufficient amounts of motor neurons from patients by biopsy to perform drug screening. So that has been the limitation. But now, with this iPS cell technology, many researchers all over the world have been generating iPS cells from patients suffering from Motor Neurone Diseases and other intractable diseases. They have succeeded in making a large amount of motor neurons having the same genetic information as the patient.
"Now we have an opportunity to generate disease models using patients' own motor neurons, and perform drug screening using patients' own cells. One of my colleagues in Kyoto, Dr Haruhisa Inoue, has generated iPS cells from both patients with ALS and other Motor Neurone Diseases as well as healthy control individuals.
"As you know, motor neurons and other neurons have these kinds of projections that are necessary for signal transaction from brain to muscles. Dr Inoue has shown that motor neurons from patients had significantly shorter projections than control motor neurons."
Shinya Yamanaka's work on iPS cells is explained in one chapter of the documentary Stem Cell Revolutions, made by our friends Amy Hardie and Clare Blackburn. We highly recommend this film if you want to learn more about how stem cells work. Here is a trailer for the chapter with Yamanaka: