title: Docosahexaenoic acid promotes dopaminergic differentiation in induced pluripotent stem cells and inhibits teratoma formation in rats with Parkinson-like pathology.
abstract: Parkinson's disease (PD) is a neurodegenerative disorder characterized by the degeneration of dopaminergic (DA) neurons in the midbrain. Induced pluripotent stem (iPS) cells have shown potential for differentiation and may become a resource of functional neurons for the treatment of  PD. However, teratoma formation is a major concern for transplantation-based therapies. This study examined whether functional neurons could be efficiently generated from iPS cells using a five-step induction procedure combined with docosahexaenoic acid (DHA) treatment. We demonstrated that  DHA, a ligand for the RXR/Nurr1 heterodimer, significantly activated expression of the Nurr1 gene and the Nurr1-related pathway in iPS cells. DHA treatment facilitated iPS differentiation into tyrosine hydroxylase (TH)-positive neurons in vitro and in vivo and functionally increased dopamine  release in transplanted grafts in PD-like animals. Furthermore, DHA dramatically upregulated the endogenous expression levels of neuroprotective genes (Bcl-2, Bcl-xl, brain-derived neurotrophic factor, and glial cell-derived neurotrophic factor) and protected against  1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced apoptosis in iPS-derived neuronal precursor cells. DHA-treated iPS cells significantly improved the behavior of 6-hydroxydopamine (6-OHDA)-treated PD-like rats compared to control or eicosapentaenoic acid-treated group. Importantly,  the in vivo experiment suggests that DHA induces the differentiation of functional dopaminergic precursors and improves the abnormal behavior of 6-OHDA-treated PD-like rats by 4 months after transplantation. Furthermore, we found that DHA treatment in iPS cell-grafted rats significantly downregulated  the mRNA expression of embryonic stem cell-specific genes (Oct-4 and c-Myc) in the graft and effectively blocked teratoma formation. Importantly, 3 Tesla-magnetic resonance imaging and ex vivo green fluorescence protein imaging revealed that no teratomas were present in transplanted grafts  of DHA-treated iPS-derived DA neurons 4 months after implantation. Therefore, our data suggest that DHA plays a crucial role in iPS differentiation into functional DA neurons and that this approach could provide a novel therapeutic approach for PD treatment.
authors.affiliation: Institute of Pharmacology, Faculty of Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Yuh-Lih
authors.initials: YL
authors.lastname: Chang
authors.forename: Shih-Jen
authors.initials: SJ
authors.lastname: Chen
authors.forename: Chung-Lan
authors.initials: CL
authors.lastname: Kao
authors.forename: Shih-Chieh
authors.initials: SC
authors.lastname: Hung
authors.forename: Dah-Ching
authors.initials: DC
authors.lastname: Ding
authors.forename: Cheng-Chia
authors.initials: CC
authors.lastname: Yu
authors.forename: Yi-Jen
authors.initials: YJ
authors.lastname: Chen
authors.forename: Hung-Hai
authors.initials: HH
authors.lastname: Ku
authors.forename: Chin-Po
authors.initials: CP
authors.lastname: Lin
authors.forename: Kun-Hsiung
authors.initials: KH
authors.lastname: Lee
authors.forename: Yu-Chih
authors.initials: YC
authors.lastname: Chen
authors.forename: Jhi-Joung
authors.initials: JJ
authors.lastname: Wang
authors.forename: Chuan-Chih
authors.initials: CC
authors.lastname: Hsu
authors.forename: Liang-Kung
authors.initials: LK
authors.lastname: Chen
authors.forename: Hsin-Yang
authors.initials: HY
authors.lastname: Li
authors.forename: Shih-Hwa
authors.initials: SH
authors.lastname: Chiou
mesh_terms: D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine / Q000494:pharmacology; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002478:Cells, Cultured; D004281:Docosahexaenoic Acids / Q000494:pharmacology*; D004298:Dopamine / Q000378:metabolism; D059290:Dopaminergic Neurons / Q000166:cytology* / Q000378:metabolism; D005786:Gene Expression Regulation; D057026:Induced Pluripotent Stem Cells / Q000166:cytology* / Q000378:metabolism / Q000637:transplantation*; D051379:Mice; D008810:Mice, Inbred C57BL; D055495:Neurogenesis; D057126:Nuclear Receptor Subfamily 4, Group A, Member 2 / Q000096:biosynthesis; D016627:Oxidopamine / Q000494:pharmacology; D020734:Parkinsonian Disorders / Q000473:pathology / Q000628:therapy*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D033581:Stem Cell Transplantation / Q000379:methods*; D013724:Teratoma / Q000517:prevention & control*; D014446:Tyrosine 3-Monooxygenase / Q000096:biosynthesis
chemical_list: C539884:Nr4a2 protein, rat; D057126:Nuclear Receptor Subfamily 4, Group A, Member 2; D012333:RNA, Messenger; D004281:Docosahexaenoic Acids; D016627:Oxidopamine; D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; D014446:Tyrosine 3-Monooxygenase; D004298:Dopamine