GDNF-expressing macrophages mitigate loss of dopamine neurons and improve Parkinsonian symptoms in MitoPark mice

Cang Chen,Senlin Li,Eliezer Masliah,Guo Ge,Robert A Clark,Zhixu He,Cori Ballard,K C Biju,Jingwei Liu,Suzette D Laing,Yusheng Qian,Xiuhua Li,Jason C O’Connor

doi:10.1038/s41598-018-23795-4

Abstract

Glial cell line-derived neurotrophic factor (GDNF) is the most potent neuroprotective agent tested in cellular and animal models of Parkinson’s disease (PD). However, CNS delivery of GDNF is restricted by the blood-brain barrier (BBB). Using total body irradiation as transplant preconditioning, we previously reported that hematopoietic stem cell (HSC) transplantation (HSCT)-based macrophage-mediated gene therapy could deliver GDNF to the brain to prevent degeneration of nigrostriatal dopamine (DA) neurons in an acute murine neurotoxicity model. Here, we validate this therapeutic approach in a chronic progressive PD model – the MitoPark mouse, with head shielding to avoid inducing neuroinflammation and compromising BBB integrity. Bone marrow HSCs were transduced ex vivo with a lentiviral vector expressing macrophage promoter-driven GDNF and transplanted into MitoPark mice exhibiting well developed PD-like impairments. Transgene-expressing macrophages infiltrated the midbrains of MitoPark mice, but not normal littermates, and delivered GDNF locally. Macrophage GDNF delivery markedly improved both motor and non-motor symptoms, and dramatically mitigated the loss of both DA neurons in the substantia nigra and tyrosine hydroxylase-positive axonal terminals in the striatum. Our data support further development of this HSCT-based macrophage-mediated GDNF delivery approach in order to address the unmet need for a disease-modifying therapy for PD.

Highlights

Parkinson’s disease (PD) is a prevalent chronic neurodegenerative disease characterized clinically by resting tremor, muscle rigidity, slowness of voluntary movement, and postural instability
In order to validate in vitro the neuroprotective capacity of lentiviral vector-driven expression of Glial cell line-derived neurotrophic factor (GDNF), we measured the production of GDNF from vector-transfected murine macrophage cell line RAW 264.7 (Suppl. 2a) and used SH-SY5Y human neuroblastoma cells as a dopaminergic neuronal model to the assess GDNF-mediated cellular protection (Suppl. 2b)
Our study demonstrates significant monocyte/macrophage homing to areas of neurodegeneration in the MitoPark PD model, with the infiltrating macrophages settling in close proximity to degenerating neurons

Summary

Introduction

Parkinson’s disease (PD) is a prevalent chronic neurodegenerative disease characterized clinically by resting tremor, muscle rigidity, slowness of voluntary movement, and postural instability. GDNF to the primary sites of neurodegeneration or the inability to cover large lesion areas in human brain To overcome these limitations, we previously introduced a hematopoietic stem cell (HSC) transplantation-based macrophage-mediated GDNF delivery strategy[15]. We previously introduced a hematopoietic stem cell (HSC) transplantation-based macrophage-mediated GDNF delivery strategy[15] This unique approach utilizes the macrophage property of homing to sites of neurodegeneration[16,17,18]. It capitalizes on our highly active macrophage synthetic promoter (MSP)[19,20], as well as efficient transduction of lentiviral vectors[21,22,23] Using this model, either GDNF or neurturin (NTN) was effectively delivered to sites of neurodegeneration and dramatically ameliorated MPTP (1-methyl-4phenyl-1,2,3,6-tetrahydropyridine)-induced loss of DA neurons in the SN and their terminals in the striatum[20,24]. The results demonstrated that HSC-based macrophage delivery of GDNF effectively protected against dopaminergic neurodegeneration, resulting in significant reversal of both motor and non-motor dysfunction without adverse effects

Methods

Results

Conclusion