Jefferson Researchers Define Ideal Time for Stem Cell Collection for Parkinson’s Disease Therapy
Researchers
have identified a stage during dopamine neuron differentiation that may
be an ideal time to collect human embryonic stem cells for
transplantation to treat Parkinson’s disease, according to data
presented at Neuroscience 2008, the 38th annual meeting of the Society for Neuroscience (Program # 720.15).
Lorraine
Iacovitti, Ph.D., professor and interim director of the Farber
Institute for Neurosciences of Thomas Jefferson University, and her
research team found that neural progenitor cells that express the gene Lmx1a
are committed to the midbrain dopamine neuron lineage, but still retain
proliferative capacity. Because of these characteristics, the stage at
which Lmx1a is expressed may be ideal for transplantation.
“Identifying
the subset of developing dopamine neurons and selecting those cells at
the stage appropriate for their transplantation has been challenging,”
said Dr. Iacovitti. “Our research demonstrates that we are now able to
grow neurons and select the ones that may work as a therapy, without
the use of synthetic genes. This advance represents an important leap
forward in the quest to devise a viable cell replacement therapy for
Parkinson’s disease.”
The Lmx1a-positive cells cannot be identified solely by this transcription factor. However, Dr. Iacovitti and her team also found that
a large percentage of the Lmx1a-positive
cells express a cell surface protein called TrkB. This protein was not
expressed on any of the other cell types identified in the cell
culture. With TrkB as a cell surface marker, dopamine neuron progenitor
cells derived from human embryonic stem cells can be selected from a
heterogenous population using magnetic-activated cell sorting (MACS) or
fluorescence-activated cell sorting (FACS). Neither process alters the
stem cell’s genome. Dr. Iacovitti and her team are now testing the
ability of these cells to counteract Parkinson’s disease in animal
models. They will also be adapting these procedures developed in human
embryonic stem cells to adult-derived human induced-pluripotent stem
cells.
According
to the National Parkinson Foundation, Parkinson’s disease affects one
in 100 people over the age of 60. The disease is caused by the loss of
dopamine neurons, which help control movement, cognition and other
critical brain functions. Although there are treatments for the
symptoms of Parkinson’s disease, none of the treatments appear to slow
or stop the progression of the disease. Human embryonic stem cell
transplantation represents a promising method for replacement of the
lost dopamine neurons, since mature dopamine cells do not survive
harvest and transplantation.
Media Only Contact:
Emily Shafer
Thomas Jefferson University Hospital
Phone: (215) 955-6300
Published: 11/20/2008