Reversal of Dopaminergic Degeneration in a Parkinsonian Rat following Micrografting of Human Bone Marrow-Derived Neural Progenitors

Abstract

Parkinson's disease (PD) is a common neurodegenerative disease characterized by the selective loss of dopaminergic (DA) neurons in the midbrain. Various types of stem cells that have potential to differentiate into DA neurons are being investigated as cellular therapies for PD. Stem cells also secrete growth factors and therefore also may have therapeutic effects in promoting the health of diseased DA neurons in the PD brain. To address this possibility in an experimental model of PD, bone marrow-derived neuroprogenitor-like cells were generated from bone marrow procured from healthy human adult volunteers and their potential to elicit recovery of damaged DA axons was studied in a partial lesion rat model of PD. Following collection of bone marrow, mesenchymal stem cells (MSC) were isolated and then genetically modified to create SB623 cells by transient transfection with the intracellular domain of the Notch1 gene (NICD), a modification that upregulates expression of certain neuroprogenitor markers. Ten deposits of 0.5 µl of SB623 cell suspension adjusted from 6,000 to 21,000 cells/µl in PBS or PBS alone were stereotaxically placed in the striatum 1 week after the nigrostriatal projection had been partially lesioned in adult F344 rats by injection of 6-hydroxydopamine (6-OHDA) into the striatum. At 3 weeks, a small number of grafted SB623 cells survived in the lesioned striatum as visualized by expression of the human specific nuclear matrix protein (hNuMA). In rats that received SB623 cells, but not in control rats, dense tyrosine hydroxylase immunoreactive (TH-ir) fibers were observed around the grafts. These fibers appeared to be rejuvenated host DA axons because no TH-ir in soma of surviving SB623 cells or coexpression of TH and hNuMA-ir were observed. In addition, dense serotonin immunoreactive (5-HT-ir) fibers were observed around grafted SB623 cells and these fibers also appeared to be of the host origin. Also, in some SB623 grafted rats that were sacrificed within 2 h of dl-amphetamine injection, hot spots of c-Fos-positive nuclei that coincided with rejuvenated dense TH fibers around the grafted SB623 cells were observed, suggesting increased availability of DA in these locations. Our observations suggest that NICD-transfected MSC hold potential as a readily available autologous or allogenic cellular therapy for ameliorating the degeneration of DA and 5-HT neurons in PD patients.

Development of stem cell-based therapies for Parkinson's disease

“…When neuralized BMSCs were transplanted in a 6-OHDA mouse model of PD, most of the transplanted cells survived in striatum, expressed TH and behavioral recovery was observed [57]. In addition, micrografted bone marrow derived neuroprogenitor-like cells were shown to induce rejuvenation of host DA neurons in 6-OHDA partially lesioned rat brain [58]. MSCs isolated from other sources, such as adipose tissue and umbilical cord, have also shown beneficial effects in PD models as well.…”

Induced pluripotent stem cells and regenerative medicine

“…Recent evidence has shown that dopaminergic neurons derived from ES cells and bone marrow-derived neural progenitors are functional when grafted into parkinsonian rats. 48,49 Several methods are able to improve the effectiveness of midbrain dopaminergic neuron generation from stem cells, including manipulating transcription factor (e.g., Nurr1, Pitx3, or Lmx1a), coculture with astrocytes, and using fluorescence-activated cell sorting. 47 The ability of deriving large quantities of correctly differentiated dopamine neurons makes stem cells a good cell sources for transplantation in PD.…”

Comparison of the neuropoietic activity of gene-modified versus parental mesenchymal stromal cells and the identification of soluble and extracellular matrix-related neuropoietic mediators

“…They are derived from MSCs by using transient transfection with a vector encoding the human Notch1 intracellular domain (NICD1), followed by a 1-week selection and subsequent propagation. They demonstrate positive effects in ischemic stroke and Parkinson animal models [8,9]. This manufacturing process creates a cell population that appears superior to the parental MSC in benefits it provides to the degenerating neural tissue.…”