The delivery of tyrosine hydroxylase accelerates the neurorestoration of Macaca Rhesus model of Parkinson's disease provided by Neurturin

Mesenchymal stem cell therapy in Parkinson's disease animal models

Parkinson's disease is a neurodegenerative disorder characterized by the loss of dopaminergic neurons in the substantia nigra, and as a consequence, by decreased dopamine levels in the striatum. Currently available therapies are not able to stop or reverse the progression of the disease. A novel therapeutic approach is based on cell therapy with stem cells, in order to replace degenerated neurons. Among stem cells, mesenchymal stem cells seemed the most promising thanks to their capacities to differentiate toward dopaminergic neurons and to release neurotrophic factors. Indeed, mesenchymal stem cells are able to produce different molecules with immunomodulatory, neuroprotective, angiogenic, chemotactic effects and that stimulate differentiation of resident stem cells. Mesenchymal stem cells were isolated for the first time from bone marrow, but can be collected also from adipose tissue, umbilical cord and other tissues. In this review, we focused our attention on mesenchymal stem cells derived from different sources and their application in Parkinson's disease animal models.

Molecular Mechanism of Regulation of MTA1 Expression by Granulocyte Colony-stimulating Factor

Parkinson disease (PD) is a neurodegenerative disorder with loss of dopaminergic neurons of the brain, which results in insufficient synthesis and action of dopamine. Metastasis-associated protein 1 (MTA1) is an upstream modulator of tyrosine hydroxylase (TH), the rate-limiting enzyme in dopamine synthesis, and hence MTA1 plays a significant role in PD pathogenesis. To impart functional and clinical significance to MTA1, we analyzed MTA1 and TH levels in the substantia nigra region of a large cohort of human brain tissue samples by Western blotting, quantitative PCR, and immunohistochemistry. Our results showed that MTA1 and TH levels were significantly down-regulated in PD samples as compared with normal brain tissue. Correspondingly, immunohistochemistry analysis for MTA1 in substantia nigra sections revealed that 74.1% of the samples had a staining intensity of <6 in the PD samples as compared with controls, 25.9%, with an odds ratio of 8.54. Because of the clinical importance of MTA1 established in PD, we looked at agents to modulate MTA1 expression in neuronal cells, and granulocyte colony-stimulating factor (G-CSF) was chosen, due to its clinically proven neurogenic effects. Treatment of the human neuronal cell line KELLY and acute 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine mouse model with G-CSF showed significant induction of MTA1 and TH with rescue of phenotype in the mouse model. Interestingly, the observed induction of TH was compromised on silencing of MTA1. The underlying molecular mechanism of MTA1 induction by G-CSF was proved to be through induction of c-Fos and its recruitment to the MTA1 promoter.

Conversion of human umbilical cord mesenchymal stem cells in Wharton's jelly to dopamine neurons mediated by the Lmx1a and neurturin in vitro: potential therapeutic application for Parkinson's disease in a rhesus monkey model

hUC-MSCs hold great promise in vitro neuronal differentiation and therapy for neurodegenerative disorders including Parkinson's disease. Recent studies provided that Lmx1α play an important role in the midbrain dopamine cells differentiation. Neurturin is desired candidate gene for providing a neuroprotective to DA neurons. In this study, we investigated a novel neuronal differentiation strategy in vitro with Lmx1α and NTN. We transferred these two genes to hUC-MSCs by recombinant adenovirus combined with Lmx1α regulatory factor and other inductor to improve the efficiency of inducing. Then those induced cells were implanted into the striatum and substantia nigra of MPTP lesioned hemi-parkinsonian rhesus monkeys. Monkeys were monitored by using behavioral test for six months after implantation. The result showed that cells isolated from the umbilical cord were negative for CD45, CD34 and HLA-DR, but were positive for CD44, CD49d, CD29. After those cells were infected with recombinant adenovirus, RT-PCR result shows that both Lmx1α and NTN genes were transcribed in hUC-MSCs. We also observed that the exogenous were highly expressed in hUC-MSCs from immunofluorescence and western blot. Experiments in vitro have proved that secretion NTN could maintain the survival of rat fetal midbrain dopaminergic neurons. After hUC-MSCs were induced with endogenous and exogenous factors, the mature neurons specific gene TH, Pitx3 was transcripted and the neurons specific protein TH, β-tubulinIII, NSE, Nestin, MAP-2 was expressed in those differentiated cells. In addition, the PD monkeys, transplanted with the induced cells demonstrated the animals' symptoms amelioration by the behavioral measures. Further more, pathological and immunohistochemistry data showed that there were neuronal-like cells survived in the right brain of those PD monkeys, which may play a role as dopaminergic neurons. The findings from this study may help us to better understand the inside mechanisms of PD pathogenesis and may also help developing effective therapy for Parkinson's disease.

Recovery of behavioral symptoms in hemi-parkinsonian rhesus monkeys through combined gene and stem cell therapy

BACKGROUND AIMS

The use of adipose mesenchymal stromal cells (ASCs) in cellular and genic therapy has attracted considerable attention as a possible treatment for neurodegenerative disorders, including Parkinson disease. However, the effects of gene therapy combined with intracerebral cell transplantation have not been well defined. Recent studies have demonstrated the respective roles of LIM homeobox transcription factor 1, alpha (LMX1A) and Neurturin (NTN) in the commitment of embryonic stem cells (ESCs) to a midbrain dopaminergic neuronal fate and the commitment of mesenchymal stromal cells to cells supporting the nutrition and protection of neurons.

METHODS

We investigated a novel in vitro neuronal differentiation strategy with the use of LMX1A and Neurturin. We were able to elicit a neural phenotype regarding cell morphology, specific gene/protein expression and physiological function. Neuronal-primed ASCs derived from rhesus monkey (rASCs) combined with adenovirus containing NTN and tyrosine hydroxylase (TH) (Ad-NTN-TH) were implanted into the striatum and substantia nigra of methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP)-lesioned hemi-parkinsonian rhesus monkeys. Monkeys were monitored with the use of behavioral tests and health measures until the fourth month after implantation.

RESULTS

The differentiated cells transcribed and expressed a variety of dopaminergic neuron-specific genes involved in the SHH/LMX1A pathway. Single-photon emission computed tomography analysis and postmortem analysis revealed that the grafting of rASCs combined with Ad-NTN-TH had neuroprotective effects compared with Ad-NTN-TH or rASCs alone. Behavioral measures demonstrated autograft survival and symptom amelioration.

CONCLUSIONS

These findings may lead to cellular sources for autologous transplantation of Parkinson disease. Combined transplantation of Ad-NTN-TH and induced rASCs expressing LMX1A and NTN may be a better therapy candidate for the treatment of Parkinson disease.