Transplantation of differentiated and genetically modified human embryonic stem cells in Parkinsonian rats via a hydrogel-biomatrix enriched in GDNF, VEGF, reelin and tenascin-C
Final Report Abstract
This project aimed at establishing a new stem cell-based therapeutic approach for the treatment of Parkinson`s disease (PD), which - as a neurologic movement disorder - is associated with a progressive degeneration of dopaminergic neurons in the substantia nigra. Current treatment options are initially effective but loose their efficacy with disease progression in a considerable number of patients. Therefore, patients might benefit from transplantation of dopaminergic neurons to replace degenerated neurons in the substantia nigra. During the last few years, a new technology was established to generate induced pluripotent stem (iPS) cells from somatic cells, which have characteristics of embryonic stem (ES) cells including pluripotency and potentially unlimited self-renewal. In a collaborative study with the Massachusetts Institute of Technology, several iPS cell lines were generated from patients with Parkinson`s disease, which could be differentiated into dopaminergic neurons in vitro. The differentiation ability of these PDiPS cells was compared with the differentiation potential of human ES cells (line H9) and of iPS cells that had been derived from a non-PD human subject. All cell lines differentiated into dopaminergic neurons to a similar extent showing that the PD origin did not affect cellular differentiation of PDiPS cells. Several differentiated PDiPS cell lines were transplanted into the striatum of adult rats in order to analyze if patient-derived dopaminergic neurons survive the transplantation into the adult brain. PDiPS cell-derived dopaminergic neurons survived the transplantation at high numbers and without signs of neurodegeneration for at least 16 weeks after transplantation. We compared the survival rates of implanted dopaminergic neurons derived from either PDiPS cells, nonPDiPS cells or human ES cells (line H9) and found comparable number between all groups. The PDiPS cell-derived dopaminergic neurons co-expressed marker molecules, which are typically expressed in midbrain dopaminergic neurons, and importantly, the PD patient-derived dopaminergic neurons were functional in an animal model of PD as determined by reduction of amphetamine- and apomorphine-induced rotational asymmetry. In addition, differentiated PDiPS cells were purified prior to transplantation applying fluorescence-activated cell sorting for the neural cell adhesion molecule NCAM. PD-patientderived dopaminergic neurons survived the purification procedure and showed functional effects after transplantation in a rodent animal model of PD. Such cell purification methods are important in regard to potential clinical application of iPS cells in patients since tumorforming pluripotent stem cells can remain in an unsorted cell population for transplantation despite extended pre-differentiation in vitro. This DFG-funded project described beneficial properties of PD-patient-derived iPS cells in an animal model of PD but it also highlighted, which parameters have to be further improved before considering PD patient-derived iPS cells for any clinical application in patients.
Publications
- (2009) Parkinson’s Disease Patient- Derived Induced Pluripotent Stem Cells Free of Viral Reprogramming Factors. (2009) Cell 136, 964–977
Soldner F, Hockemeyer D, Beard C, Gao Q, Bell GW, Cook EG, Hargus G, Blak A, Cooper O, Mitalipova M, Isacson O, and Jaenisch R
