1. |
- Aldrin-Kirk, Patrick, et al.
(author)
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A novel two-factor monosynaptic TRIO tracing method for assessment of circuit integration of hESC-derived dopamine transplants
- 2022
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In: Stem Cell Reports. - : Elsevier BV. - 2213-6711. ; 17:1, s. 159-172
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Journal article (peer-reviewed)abstract
- Transplantation in Parkinson's disease using human embryonic stem cell (hESC)-derived dopaminergic (DA) neurons is a promising future treatment option. However, many of the mechanisms that govern their differentiation, maturation, and integration into the host circuitry remain elusive. Here, we engrafted hESCs differentiated toward a ventral midbrain DA phenotype into the midbrain of a preclinical rodent model of Parkinson's disease. We then injected a novel DA-neurotropic retrograde MNM008 adeno-associated virus vector capsid, into specific DA target regions to generate starter cells based on their axonal projections. Using monosynaptic rabies-based tracing, we demonstrated for the first time that grafted hESC-derived DA neurons receive distinctly different afferent inputs depending on their projections. The similarities to the host DA system suggest a previously unknown directed circuit integration. By evaluating the differential host-to-graft connectivity based on projection patterns, this novel approach offers a tool to answer outstanding questions regarding the integration of grafted hESC-derived DA neurons.
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2. |
- Drouin-Ouellet, Janelle, et al.
(author)
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Age-related pathological impairments in directly reprogrammed dopaminergic neurons derived from patients with idiopathic Parkinson's disease
- 2022
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In: Stem Cell Reports. - : Elsevier BV. - 2213-6711. ; 17:10, s. 2203-2219
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Journal article (peer-reviewed)abstract
- We have developed an efficient approach to generate functional induced dopaminergic (DA) neurons from adult human dermal fibroblasts. When performing DA neuronal conversion of patient fibroblasts with idiopathic Parkinson's disease (PD), we could specifically detect disease-relevant pathology in these cells. We show that the patient-derived neurons maintain age-related properties of the donor and exhibit lower basal chaperone-mediated autophagy compared with healthy donors. Furthermore, stress-induced autophagy resulted in an age-dependent accumulation of macroautophagic structures. Finally, we show that these impairments in patient-derived DA neurons leads to an accumulation of phosphorylated alpha-synuclein, the classical hallmark of PD pathology. This pathological phenotype is absent in neurons generated from induced pluripotent stem cells from the same patients. Taken together, our results show that direct neural reprogramming can be used for obtaining patient-derived DA neurons, which uniquely function as a cellular model to study age-related pathology relevant to idiopathic PD.
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3. |
- Johansson, Pia A, et al.
(author)
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A cis-acting structural variation at the ZNF558 locus controls a gene regulatory network in human brain development
- 2022
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In: Cell Stem Cell. - : Elsevier BV. - 1934-5909 .- 1875-9777. ; 29:1, s. 8-69
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Journal article (peer-reviewed)abstract
- The human forebrain has expanded in size and complexity compared to chimpanzees despite limited changes in protein-coding genes, suggesting that gene expression regulation is an important driver of brain evolution. Here, we identify a KRAB-ZFP transcription factor, ZNF558, that is expressed in human but not chimpanzee forebrain neural progenitor cells. ZNF558 evolved as a suppressor of LINE-1 transposons but has been co-opted to regulate a single target, the mitophagy gene SPATA18. ZNF558 plays a role in mitochondrial homeostasis, and loss-of-function experiments in cerebral organoids suggests that ZNF558 influences developmental timing during early human brain development. Expression of ZNF558 is controlled by the size of a variable number tandem repeat that is longer in chimpanzees compared to humans, and variable in the human population. Thus, this work provides mechanistic insight into how a cis-acting structural variation establishes a regulatory network that affects human brain evolution.
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4. |
- Jönsson, Marie, et al.
(author)
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Comprehensive analysis of microRNA expression in regionalized human neural progenitor cells reveals microRNA-10 as a caudalizing factor.
- 2015
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In: Development: For advances in developmental biology and stem cells. - : The Company of Biologists. - 1477-9129. ; 142:18, s. 3166-3177
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Journal article (peer-reviewed)abstract
- MicroRNAs (miRNAs) have been implicated in regulating multiple processes during brain development in various species. However, the function of miRNAs in human brain development remains largely unexplored. Here, we provide a comprehensive analysis of miRNA expression of regionalized neural progenitor cells derived from human embryonic stem cells and human foetal brain. We found miR-92b-3p and miR-130b-5p to be specifically associated with neural progenitors and several miRNAs that display both age-specific and region-specific expression patterns. Among these miRNAs, we identified miR-10 to be specifically expressed in the human hindbrain and spinal cord, while being absent from rostral regions. We found that miR-10 regulates a large number of genes enriched for functions including transcription, actin cytoskeleton and ephrin receptor signalling. When overexpressed, miR-10 influences caudalization of human neural progenitor cells. Together, these data confirm a role for miRNAs in establishing different human neural progenitor populations. This dataset also provides a comprehensive resource for future studies investigating the functional role of different miRNAs in human brain development.
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5. |
- Adler, Andrew F., et al.
(author)
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hESC-Derived Dopaminergic Transplants Integrate into Basal Ganglia Circuitry in a Preclinical Model of Parkinson's Disease
- 2019
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In: Cell Reports. - : Elsevier BV. - 2211-1247. ; 28:13, s. 5-3473
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Journal article (peer-reviewed)abstract
- Cell replacement is currently being explored as a therapeutic approach for neurodegenerative disease. Using stem cells as a source, transplantable progenitors can now be generated under conditions compliant with clinical application in patients. In this study, we elucidate factors controlling target-appropriate innervation and circuitry integration of human embryonic stem cell (hESC)-derived grafts after transplantation to the adult brain. We show that cell-intrinsic factors determine graft-derived axonal innervation, whereas synaptic inputs from host neurons primarily reflect the graft location. Furthermore, we provide evidence that hESC-derived dopaminergic grafts transplanted in a long-term preclinical rat model of Parkinson's disease (PD) receive synaptic input from subtypes of host cortical, striatal, and pallidal neurons that are known to regulate the function of endogenous nigral dopamine neurons. This refined understanding of how graft neurons integrate with host circuitry will be important for the design of clinical stem-cell-based replacement therapies for PD, as well as for other neurodegenerative diseases. Adler et al. graft hESC-derived dopaminergic progenitors into a rat model of Parkinson's disease. They find grafts correctly innervate host targets and receive appropriate synaptic input after intranigral and intrastriatal placement. Furthermore, the same host neurons projecting toward endogenous dopamine neurons are found to also connect to the grafts.
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6. |
- Adler, Andrew, et al.
(author)
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Transsynaptic tracing and its emerging use to assess graftreconstructed neural circuits
- 2020
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In: Stem Cells. - : Oxford University Press (OUP). - 1549-4918 .- 1066-5099. ; 38:6, s. 716-726
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Journal article (peer-reviewed)abstract
- Fetal neural progenitor grafts have been evaluated in preclinical animal models of spinal cord injury and Parkinson’s disease for decades, but the initial reliance on primary tissue as a cell source limited the scale of their clinical translatability. With the development of robust methods to differentiate human pluripotent stem cells to specific neural subtypes, cell replacement therapy holds renewed promise to treat a variety of neurodegenerative diseases and injuries at scale. As these cell sources are evaluated in preclinical models, new transsynaptic tracing methods are making it possible to study the connectivity between host and graft neurons with greater speed and detail than was previously possible. To date, these studies have revealed that widespread, long-lasting, and anatomically-appropriate synaptic contacts are established between host and graft neurons, as well as new aspects of host-graft connectivity which may be relevant to clinical cell replacement therapy. It is not yet clear, however, whether the synaptic connectivity between graft and host neurons is as celltype specific as it is in the endogenous nervous system, or whether that connectivity is responsible for the functional efficacy of cell replacement therapy. Here, we review evidence suggesting that the new contacts established between host and graft neuronsmay indeed be cell-type specific, and how transsynaptic tracing can be used inthe future to further elucidate the mechanisms of graft-mediated functional recovery in spinal cord injury and Parkinson’s disease.
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7. |
- Aldrin-Kirk, Patrick, et al.
(author)
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DREADD Modulation of Transplanted DA Neurons Reveals a Novel Parkinsonian Dyskinesia Mechanism Mediated by the Serotonin 5-HT6 Receptor
- 2016
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In: Neuron. - : Elsevier BV. - 0896-6273. ; 90:5, s. 955-968
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Journal article (peer-reviewed)abstract
- Transplantation of DA neurons is actively pursued as a restorative therapy in Parkinson's disease (PD). Pioneering clinical trials using transplants of fetal DA neuroblasts have given promising results, although a number of patients have developed graft-induced dyskinesias (GIDs), and the mechanism underlying this troublesome side effect is still unknown. Here we have used a new model where the activity of the transplanted DA neurons can be selectively modulated using a bimodal chemogenetic (DREADD) approach, allowing either enhancement or reduction of the therapeutic effect. We show that exclusive activation of a cAMP-linked (Gs-coupled) DREADD or serotonin 5-HT6 receptor, located on the grafted DA neurons, is sufficient to induce GIDs. These findings establish a mechanistic link between the 5-HT6 receptor, intracellular cAMP, and GIDs in transplanted PD patients. This effect is thought to be mediated through counteraction of the D2 autoreceptor feedback inhibition, resulting in a dysplastic DA release from the transplant.
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8. |
- Alekseenko, Zhanna, et al.
(author)
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Robust derivation of transplantable dopamine neurons from human pluripotent stem cells by timed retinoic acid delivery
- 2022
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In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 13
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Journal article (peer-reviewed)abstract
- Stem cell therapies for Parkinson’s disease (PD) have entered first-in-human clinical trials using a set of technically related methods to produce mesencephalic dopamine (mDA) neurons from human pluripotent stem cells (hPSCs). Here, we outline an approach for high-yield derivation of mDA neurons that principally differs from alternative technologies by utilizing retinoic acid (RA) signaling, instead of WNT and FGF8 signaling, to specify mesencephalic fate. Unlike most morphogen signals, where precise concentration determines cell fate, it is the duration of RA exposure that is the key-parameter for mesencephalic specification. This concentration-insensitive patterning approach provides robustness and reduces the need for protocol-adjustments between hPSC-lines. RA-specified progenitors promptly differentiate into functional mDA neurons in vitro, and successfully engraft and relieve motor deficits after transplantation in a rat PD model. Our study provides a potential alternative route for cell therapy and disease modelling that due to its robustness could be particularly expedient when use of autologous- or immunologically matched cells is considered.
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9. |
- Andersson, Elin, et al.
(author)
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Development of the mesencephalic dopaminergic neuron system is compromised in the absence of neurogenin 2.
- 2006
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In: Development: For advances in developmental biology and stem cells. - : The Company of Biologists. - 1477-9129. ; 133:3, s. 507-516
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Journal article (peer-reviewed)abstract
- Neurogenin 2 (Ngn2) is a proneural gene involved in neuronal differentiation and subtype specification in various regions of the nervous system. In the ventral midbrain, Ngn2 is expressed in a spatiotemporal pattern that correlates with the generation of mesencephalic dopaminergic (mesDA) neurons. We show here that lack of Ngn2 impairs the development of mesDA neurons, such that less than half of the normal mesDA neuron number remain in Ngn2 mutant mice at postnatal stages. Analysis of Ngn2 mutant mice during mesDA neurogenesis show that medially located precursors are formed but are arrested in their differentiation at a stage when they have not yet acquired the characteristics of mesDA neuron precursors. Loss of Ngn2 function appears to specifically affect the generation of DA neurons, as the development of other types of neurons within the ventral midbrain is unaltered. Ngn2 is the first example of a gene expressed in progenitors in the ventricular zone of the mesDA neuron domain that is essential for proper mesDA neuron differentiation, and whose loss of function causes impaired mesDA neurogenesis without other major abnormalities in the ventral midbrain.
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10. |
- Andersson, Elin, et al.
(author)
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Ngn2 and Nurr1 act in synergy to induce midbrain dopaminergic neurons from expanded neural stem and progenitor cells.
- 2007
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In: Experimental Cell Research. - : Elsevier BV. - 1090-2422 .- 0014-4827. ; 313:6, s. 1172-1180
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Journal article (peer-reviewed)abstract
- Parkinson's Disease (PD) is a debilitating motor function disorder due primarily to a loss of midbrain dopaminergic neurons and a subsequent reduction in dopaminergic innervation of the striatum. Several attempts have been made to generate dopaminergic neurons from progenitor cell populations in vitro for potential use in cell replacement therapy for PD. However, expanding cells from fetal brain with retained potential for dopaminergic differentiation has proven to be difficult. In this study, we sought to generate mesencephalic dopaminergic (mesDA) neurons from an expanded population of fetal mouse ventral midbrain (VM) progenitors through the use of retroviral gene delivery. We over-expressed Ngn2 and Nurr1, two genes present in the ventral midbrain and important for normal development of mesDA neurons, in multipassaged neurosphere-expanded midbrain progenitors. We show that over-expression of Ngn2 in these progenitors results in increased neuronal differentiation but does not promote mesDA formation. We also show that over-expression of Nurr1 alone is sufficient to generate tyrosine hydroxylase (TH) expressing cells with an immature morphology, however the cells do not express any additional markers of mesDA neurons. Overexpression of Nurr1 and Ngn2 in combination generates morphologically mature TH-expressing neurons that also express additional mesencephalic markers. (c) 2006 Elsevier Inc. All rights reserved.
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