Study: stem cell therapy in rats improves Parkinson’s

A novel and untested stem cell therapy has significantly improved the symptoms of Parkinson’s disease in rats, according to a study released on Monday

A novel and untested stem cell therapy has significantly improved the symptoms of Parkinson’s disease in rats, according to a study released on Monday.

Researchers at the Whitehead Institute for Biomedical Research in Cambridge, Massachusetts, used a relatively new technique to re-engineer stem cells from skin cells and then treat rats with the debilitating neurological disease.

When the rats were tested weeks after the cell transplant, their Parkinson’s symptoms were significantly reduced, confirming that these substitutes for embryonic stem cells, so-called reprogrammed stem cells, can replace lost or damaged neurons.

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“This is the first demonstration that reprogrammed cells can integrate into the neural system or positively affect neurodegenerative disease,” said lead author Marius Wernig of the study in the Proceedings of the National Academy of Sciences.

Stem cell therapy has been touted as a promising intervention for neurodegenerative diseases such as Parkinson’s or Alzheimer’s, because these so-called master cells have the ability to change into many of the hundreds of different cell types in the body, replacing ones lost or damaged by disease.

But the use of embryonic stem cells has been mired in controversy amid ethical objections to harvesting them from discarded foetuses. In late 2007, US and Japanese researchers announced they had devised methods to reprogramme human skin cells to give them stem cell properties, potentially side-stepping the controversy that has hamstrung the field.

The experiments by the Whitehead Institute researchers provide the first evidence in animals that these reprogrammed cells act as they are supposed to. Wernig and his colleagues took skin cells from adult mice and induced pluripotent stem cells (IPS cells) by using retroviruses to activate genes that turned them into stem cells.

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Parkinson’s is a motor system disorder caused by damage to or the death of dopamine neurons and characterised by tremors, impaired balance and co-ordination and stiffness of the limbs and trunk.

Four weeks after surgery, the rats were tested for dopamine-related behaviour in a test which typically causes them to walk in circles towards the side. Eight of the nine rats that received the dopamine neuron transplants showed markedly less or even no circling.

Eight weeks after surgery, the researchers could see that the dopamine neurons had extended into the surrounding brain.