Fisiologia

STEM CELLS AND DEVELOPMENT Volume 18, Number 8, 2009 © Mary Ann Liebert, Inc. DOI: 10.1089/scd.2008.0411

ORIGINAL RESEARCH REPORT

Protective Effects of Neurotrophic Factors-Secreting Cells in a 6-OHDA Rat Model of Parkinson Disease
Ofer Sadan,1 Merav Bahat-Stromza,2 Yael Barhum,1 Yossef S. Levy,2 Anat Pisnevsky,2 Hagit Peretz,2 Avihay Bar Ilan,2 Shlomo Bulvik,3 Noam Shemesh,4 Dana Krepel,4Yoram Cohen,4 Eldad Melamed,1 and Daniel Offen1,2

Stem cell-based therapy is a promising treatment for neurodegenerative diseases. In our laboratory, a novel protocol has been developed to induce bone marrow-derived mesenchymal stem cells (MSC) into neurotrophic factorssecreting cells (NTF-SC), thus combining stem cell-based therapy with the NTF-based neuroprotection. These cells produce andsecrete factors such as brain-derived neurotrophic factor (BDNF) and glial cell-derived neurotrophic factor. Conditioned medium of the NTF-SC that was applied to a neuroblastoma cell line (SH-SY5Y) 1 h before exposure to the neurotoxin 6-hydroxydopamine (6-OHDA) demonstrated marked protection. An efficacy study was conducted on the 6-OHDA-induced lesion, a rat model of Parkinson’s disease. Thecells, either MSC or NTF-SC, were transplanted on the day of 6-OHDA administration and amphetamine-induced rotations were measured as a primary behavior index. We demonstrated that when transplanted posterior to the 6-OHDA lesion, the NTF-SC ameliorated amphetamine-induced rotations by 45%. HPLC analysis demonstrated that 6-OHDA induced dopamine depletion to a level of 21% compared to the untreatedstriatum. NTF-SC inhibited dopamine depletion to a level of 72% of the contralateral striatum. Moreover, an MRI study conducted with iron-labeled cells, followed by histological verification, revealed that the engrafted cells migrated toward the lesion. In a histological assessment, we found that the cells induced regeneration in the damaged striatal dopaminergic nerve terminal network. We thereforeconclude that the induced MSC have a therapeutic potential for neurodegenerative processes and diseases, both by the NTFs secretion and by the migratory trait toward the diseased tissue.

Introduction

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tem cell-based therapy offers promise for future treatment of neurodegenerative disease. There are 2 main potential approaches to stem cell-based therapy. One strategy is aimed at simplyreplacing the lost cells by transplanting stem cells. The second approach is to utilize the cells as vectors that contain and secrete neuroprotective agents in order to preserve the surviving neurons or to induce renewal of axonal sprouting. Parkinson’s disease (PD) is a debilitating neurodegenerative disorder that mainly results from a specific loss of nigral dopaminergic neurons. This particularcellular loss has made it a common target for stem cells-based replacement therapy

[1–3]. Several potential cells sources have been investigated to replace the degenerated dopaminergic neurons, including embryonic stem (ES) cells [4,5] and adult stem cells. The later are of various origins, whether induced pluripotent stem cells (iPS) [6], multipotent mesenchymal stromal cells (MSC) [7–14], orneural stem cells [15,16]. Additionally, clinical trials for cell replacement using human fetal mesencephalic tissue have been reported [17,18]. Not only that clinical benefit was not observed, several issues were raised, such as graft-induced dyskinesias, appearance of Lewy bodies in the grafted cells [19,20], and some immune response against the graft. Apart from these difficulties, probably themain obstacle of fetal midbrain grafts is the low availability

1 Laboratory of Neurosciences, Felsenstein Medical Research Center, Department of Neurology, Rabin Medical Center, Sackler Faculty of Medicine, and 4School of Chemistry, The Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, Israel. 2 Brainstorm Cell Therapeutics Ltd., Petah-Tikva, Israel. 3...