title: Dynamic Trk and G Protein Signalings Regulate Dopaminergic Neurodifferentiation in Human Trophoblast Stem Cells.
abstract: Understanding the mechanisms in the generation of neural stem cells from pluripotent stem cells is a fundamental step towards successful management of neurodegenerative diseases in translational medicine. Albeit all-trans retinoic acid (RA) has been associated with axon outgrowth and nerve regeneration, the maintenance of differentiated neurons, the association with degenerative disease like Parkinson's disease, and its regulatory molecular mechanism from pluripotent stem cells to neural stem cells remain fragmented. We have previously reported that RA is capable of differentiation of human trophoblast stem cells to dopamine (DA) committed progenitor cells. Intracranial implantation of such neural progenitor cells into the 6-OHDA-lesioned substantia nigra pars compacta successfully regenerates dopaminergic neurons and integrity of the nigrostriatal pathway, ameliorating the behavioral deficits in the Parkinson's disease rat model. Here, we demonstrated a dynamic molecular network in systematic analysis by addressing spatiotemporal molecular expression, intracellular protein-protein interaction and inhibition, imaging study, and genetic expression to explore the regulatory mechanisms of RA induction in the differentiation of human trophoblast stem cells to DA committed progenitor cells. We focused on the tyrosine receptor kinase (Trk), G proteins, canonical Wnt2B/β-catenin, genomic and non-genomic RA signaling transductions with Tyrosine hydroxylase (TH) gene expression as the differentiation endpoint. We found that at the early stage, integration of TrkA and G protein signalings aims for axonogenesis and morphogenesis, involving the novel RXRα/Gαq/11 and RARβ/Gβ signaling pathways. While at the later stage, five distinct signaling pathways together with epigenetic histone modifications emerged to regulate expression of TH, a precursor of dopamine. RA induction generated DA committed progenitor cells in one day. Our results provided substantial mechanistic evidence that human trophoblast stem cell-derived neural stem cells can potentially be used for neurobiological study, drug discovery, and as an alternative source of cell-based therapy in neurodegenerative diseases like Parkinson's disease.
authors.affiliation: Department of Obstetrics and Gynecology, Kaohsiung Medical University Hospital and Center of Excellence for Environmental Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan.
authors.forename: Eing-Mei
authors.initials: EM
authors.lastname: Tsai
authors.affiliation: Department of Obstetrics and Gynecology, Kaohsiung Medical University Hospital and Center of Excellence for Environmental Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan.
authors.forename: Yu-Chih
authors.initials: YC
authors.lastname: Wang
authors.affiliation: Accelerated Biosciences Corp., Manhattan Beach, California 90266, United States of America.
authors.forename: Tony Tung-Yin
authors.initials: TT
authors.lastname: Lee
authors.affiliation: Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan.
authors.forename: Cheng-Fang
authors.initials: CF
authors.lastname: Tsai
authors.affiliation: Department of Obstetrics and Gynecology, Kaohsiung Medical University Hospital and Center of Excellence for Environmental Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan.|Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan.
authors.forename: Hung-Sheng
authors.initials: HS
authors.lastname: Chen
authors.affiliation: Department of Dermatology, Chi-Mei Medical Center, Tainan 710, Taiwan.
authors.forename: Feng-Jie
authors.initials: FJ
authors.lastname: Lai
authors.affiliation: Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan.
authors.forename: Kazunari K
authors.initials: KK
authors.lastname: Yokoyama
authors.affiliation: Department of Physical Therapy and Graduate Institute of Rehabilitation Science, College of Medicine, Chang Gung University, Taoyuan City 33302, Taiwan.
authors.forename: Tsung-Hsun
authors.initials: TH
authors.lastname: Hsieh
authors.affiliation: Department of Neurology, National Taiwan University Hospital, Taipei 10048, Taiwan.
authors.forename: Ruey-Meei
authors.initials: RM
authors.lastname: Wu
authors.affiliation: Department of Obstetrics and Gynecology, Kaohsiung Medical University Hospital and Center of Excellence for Environmental Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan.
authors.forename: Jau-Nan
authors.initials: JN
authors.lastname: Lee
mesh_terms: D000818:Animals; D001369:Axons / Q000378:metabolism; D020013:Calcium Signaling; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2 / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects / Q000235:genetics; D002460:Cell Line; D017362:Cyclic AMP Response Element-Binding Protein / Q000235:genetics / Q000378:metabolism; D004195:Disease Models, Animal; D059290:Dopaminergic Neurons / Q000166:cytology*; D019204:GTP-Binding Proteins / Q000378:metabolism*; D005786:Gene Expression Regulation; D038362:Glycogen Synthase Kinase 3 / Q000378:metabolism; D018398:Homeodomain Proteins / Q000378:metabolism; D006801:Humans; D008954:Models, Biological; D009024:Morphogenesis; D046912:Multiprotein Complexes / Q000378:metabolism; D028861:Nuclear Pore Complex Proteins / Q000378:metabolism; D010300:Parkinson Disease / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D021381:Protein Transport; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D051381:Rats; D020917:Receptor, trkA / Q000378:metabolism*; D018168:Receptors, Retinoic Acid / Q000378:metabolism; D047490:Retinoid X Receptor alpha / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D013234:Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D014327:Trophoblasts / Q000166:cytology*; D014446:Tyrosine 3-Monooxygenase / Q000235:genetics / Q000378:metabolism; D051176:beta Catenin / Q000378:metabolism; D016875:tau Proteins / Q000378:metabolism
chemical_list: C115163:CREB1 protein, human; D017362:Cyclic AMP Response Element-Binding Protein; D018398:Homeodomain Proteins; C054369:MAPT protein, human; D046912:Multiprotein Complexes; C085914:NUP214 protein, human; D028861:Nuclear Pore Complex Proteins; D018168:Receptors, Retinoic Acid; D047490:Retinoid X Receptor alpha; D014157:Transcription Factors; D051176:beta Catenin; C433629:homeobox protein PITX3; C082925:retinoic acid receptor beta; D016875:tau Proteins; D014446:Tyrosine 3-Monooxygenase; D020917:Receptor, trkA; D051057:Proto-Oncogene Proteins c-akt; D058570:TOR Serine-Threonine Kinases; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D038362:Glycogen Synthase Kinase 3; D019204:GTP-Binding Proteins