Implantation of c-mycER^TAMImmortalized Human Mesencephalic-Derived Clonal Cell Lines Ameliorates Behavior Dysfunction in a Rat Model of Parkinson’s Disease

Abstract

Human neural stem cells offer the hope that a cell therapy treatment for Parkinson's disease (PD) could be made widely available. In this study, we describe two clonal human neural cell lines, derived from two different 10-week-old fetal mesencephalic tissues and immortalized with the c-mycER(TAM) transgene. Under the growth control of 4-hydroxytamoxifen, both cell lines display stable long-term growth in culture with a normal karyotype. In vitro, these nestin-positive cells are able to differentiate into tyrosine hydroxylase (TH)-positive neurons and are multipotential. Implantation of the undifferentiated cells into the 6-OHDA substantia nigral lesioned rat model displayed sustained improvements in a number of behavioral tests compared with noncell-implanted, vehicle-injected controls over the course of 6 months. Histological analysis of the brains showed survival of the implanted cells but no evidence of differentiation into TH-positive neurons. An average increase of approximately 26% in host TH immunoreactivity in the lesioned dorsal striatum was observed in the cell-treated groups compared to controls, with no difference in loss of TH cell bodies in the lesioned substantia nigra. Further analysis of the cell lines identified a number of expressed trophic factors, providing a plausible explanation for the effects observed in vivo. The exact mechanisms by which the implanted human neural cell lines provide behavioral improvements in the PD model are not completely understood; however, these findings provide evidence that cell therapy can be a potent treatment for PD acting through a mechanism independent of dopaminergic neuronal cell replacement.

Human midbrain precursors activate the expected developmental genetic program and differentiate long-term to functional A9 dopamine neurons in vitro. Enhancement by Bcl-XL

“…In parallel to the work with primary cultures, several groups have developed immortalized hNSC lines derived from the fetal human VM (MESC2.10, NGC-407, ReNcell VM, vm c-mycER™ and hVMl, Refs. [30][31][32][33][34]). However, their properties and capacity to activate correct developmental programs, has remained largely unexplored or uncertain.…”

“…In addition, there is a large controversy on the actual capacity of various cultures derived from the fetal human VM to generate A9-DAn, in a stable manner [8, [25][26][27][28][29]. In parallel to the work with non-immortal precursor cells, several groups, including ours, have recently developed immortalized cell lines of human neural stem/precursor cells (hNSCs), some of them derived from the fetal human VM (MESC2.10, NGC-407, ReNcell VM, vm c-mycER™ and hVMl) [30][31][32][33][34]. In these model cell lines, the non-transforming, immortalizing gene, v-myc overcomes the problem of limited expansion.…”

Soliciting Strategies for Developing Cell-Based Reference Materials to Advance Mesenchymal Stromal Cell Research and Clinical Translation

“…MSC lines generated using a combination of siRNA against p53 and overexpression of human telomerase reverse transcriptase retain similar proliferation, colony formation, differentiation, and gene expression profiles as do primary MSCs [15]. Other approaches for immortalization, including the use of conditionally induced oncogenes, may also be considered [16]. It could also be argued, however, that disruption of key regulatory control pathways by immortalization and genetic manipulation may cause reluctance to accept such reference cell bank(s) as a standard, although it is important to emphasize that such cell bank(s) would serve as reference standards, not gold standards.…”

Effects of Biologic Scaffolds on Human Stem Cells and Implications for CNS Tissue Engineering

“…Transplantation of NSCs in animal models of CNS pathology (e.g., stroke, Parkinson's disease, and congenital dysmyelination) have shown positive results, [4][5][6][7][8] but there are concerns regarding the safety of a clinical NSC-based approach. 9,10 In vivo maintenance and regulation of stem cell behavior in the CNS are partially attributable to the NSC niche, a complex microenvironment of extracellular cues.…”