An Engineered Zinc Finger Protein Activator of the Endogenous Glial Cell Line-Derived Neurotrophic Factor Gene Provides Functional Neuroprotection in a Rat Model of Parkinson's Disease

Abstract

Loss of dopaminergic neurons is primarily responsible for the onset and progression of Parkinson's disease (PD); thus, neuroprotective and/or neuroregenerative strategies remain critical to the treatment of this increasingly prevalent disease. Here we explore a novel approach to neurotrophic factor-based therapy by engineering zinc finger protein transcription factors (ZFP TFs) that activate the expression of the endogenous glial cell line-derived neurotrophic factor (GDNF) gene. We show that GDNF activation can be achieved with exquisite genome-wide specificity. Furthermore, in a rat model of PD, striatal delivery of an adeno-associated viral vector serotype 2 encoding the GDNF activator resulted in improvements in forelimb akinesia, sensorimotor neglect, and amphetamine-induced rotations caused by 6-hydroxydopamine (6-OHDA) lesion. Our results suggest that an engineered ZFP TF can drive sufficient GDNF expression in the brain to provide functional neuroprotection against 6-OHDA; therefore, targeted activation of the endogenous gene may provide a method for delivering appropriate levels of GDNF to PD patients.

Pericyte-derived Glial Cell Line-derived Neurotrophic Factor Increase the Expression of Claudin-5 in the Blood–brain Barrier and the Blood-nerve Barrier

“…New studies for the development of better and safer viral vectors or engineered cell lines suitable for the CNS grafting and delivery have been launched [39][40][41]. Indeed, promising results have been obtained with cell grafts including astrocytes, which have been successfully engineered to deliver GDNF within therapeutic window [41][42][43][44]. Pericytes as well as astrocytes are also very promising candidates for new methods for carrying out GDNF delivery, and they may be easily engineered to produce and secrete the most beneficial dose of this neurotrophin in the BBB and BNB.…”

Creation of a Six-fingered Artificial Transcription Factor That Represses the Hepatitis B Virus HBx Gene Integrated into a Human Hepatocellular Carcinoma Cell Line

“…A company in the United States, named Sangamo BioSciences, Inc. (Richmond, CA) has focused on preclinical and clinical studies of zinc finger proteins (including zinc finger artificial transcription factors) for many years. 14,[28][29][30] For instance, it is developing an ATF that upregulates the gene for glial cell line-derived neurotrophic factor (GDNF), a potent neurotrophic factor that has shown promise in preclinical testing to slow or stop the progression of Parkinson disease. 30 According to Sangamo's reports, zinc finger ATFs have been tested in humans and to date have an excellent safety profile.…”

“…14,[28][29][30] For instance, it is developing an ATF that upregulates the gene for glial cell line-derived neurotrophic factor (GDNF), a potent neurotrophic factor that has shown promise in preclinical testing to slow or stop the progression of Parkinson disease. 30 According to Sangamo's reports, zinc finger ATFs have been tested in humans and to date have an excellent safety profile. 31 In this study, we constructed ATFs to downregulate the expression of the HBx integrant in the Hep3B genome.…”

Engineering Transcription Factors in Breast Cancer Stem Cells

“…Some of the genes successfully regulated by ATFs are listed on Table I. Recently regulated genes include: mammary serine protease inhibitor (maspin) [103,118], dystrophin-related gene utrophin [119], vascular endothelial growth factor A (VEGF-A) [120,121], gamma-globin [122], heme oxygenase-1 gene (HMOX1) [123], glial cell line-derived neurotrophic factor gene (GDNF) [124], derived tyrosine kinase receptors ErbB2 [90,125], and ErbB3 [100,125]. Genes that were successfully downregulated by ATFs comprise: VEGF-A [120,121], ErbB2 [90,125], ErbB3 [100], the human telomerase reverse transcriptase (hTERT) [126], the nuclear hormone receptor PPARγ gene (PPARγ) [127], and the repression of the checkpoint kinase 2 (CHK2) gene [88].…”