Researchers say it is possible to make dopamine cells from human embryonic stem cells, paving the way for a new treatment for Parkinson's.
Parkinson's disease is caused by the gradual loss of dopamine-producing cells in the brain. Dopamine is a brain chemical that, among other things, helps regulate movement and emotional responses.
There are no cures for Parkinson's disease; there are drugs that ease symptoms, but none that slow it down. Deep brain stimulation can alleviate symptoms of Parkinson's in certain patients.
Human embryonic stem cells - precursor cells that have the potential to become any cell of the body - are a promising source of new dopamine cells, but they have proved difficult to harness for this purpose.
Now, a breakthrough study from Lund University in Sweden shows it is possible to get human embryonic stem cells to produce a new generation of dopamine cells that behave like native dopamine cells when transplanted into the brains of rats.
Study leader Malin Parmar, associate professor in Lund's Department of Medicine, and colleagues report their findings in the journal Cell Stem Cell.
"The study shows that the cells that we generate from stem cells, they function equally as well as the cells that we find in the brain," says Prof. Parmar.
The team says the new cells show all the properties and functions of the dopamine neurons that are lost in Parkinson's disease, and the potentially unlimited supply sourced from stem cell lines opens the door to clinical application.
For their study, the researchers carried out experiments in rat models of Parkinson's disease. To produce a rat model of Parkinson's, researchers destroy the dopamine cells in one part of the rat's brain.
The experiments showed that dopamine cells made from human embryonic stem cells, when transplanted into the rats' brains, behaved like native dopamine cells. The authors note that the transplanted cells:
- Survived in the long term and restored production of dopamine in the brain
- Functioned in a similar way to dopamine cells of the "human fetal midbrain"
- Are capable of producing long distance links to the correct parts of the brain
- The axons that they grow "meet the requirements for use in humans."
The researchers explain their findings further in the video below:
Next step is to prepare for human clinical trials
Commenting on the breakthrough, Prof. Parmar says:
"These cells have the same ability as the brain's normal dopamine cells to not only reach, but also to connect to their target area over longer distances. This has been our goal for some time, and the next step is to produce the same cells under the necessary regulations for human use."
The team hopes the new cells will be ready for testing in human trials in about 3 years.
The authors note that their study shows "strong preclinical support" for using dopamine cells made from human embryonic stem cells, using approaches similar to those established with fetal cells for the treatment of Parkinson's disease.
There has been some success with using fetal cells, but these are harder to source and there are ethical concerns about taking tissue from aborted fetuses.
The study was conducted at Lund University and MIRCen in Paris, France, as part of the European Union networks NeuroStemCell and NeuroStemcellRepair.
Meanwhile, Medical News Today recently learned that Harvard scientists found stem cells that release cancer-killing toxins may offer a new way to treat brain tumors.