| 1. |
- Barker, Roger, et al.
(författare)
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Cell-based therapies for Parkinson disease-past insights and future potential.
- 2015
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Ingår i: Nature Reviews Neurology. - : Springer Science and Business Media LLC. - 1759-4766 .- 1759-4758. ; 11:9, s. 492-503
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Forskningsöversikt (refereegranskat)abstract
- Parkinson disease (PD) is characterized by loss of the A9 nigral neurons that provide dopaminergic innervation to the striatum. This discovery led to the successful instigation of dopaminergic drug treatments in the 1960s, although these drugs were soon recognized to lose some of their efficacy and generate their own adverse effects over time. Despite the fact that PD is now known to have extensive non-nigral pathology with a wide range of clinical features, dopaminergic drug therapies are still the mainstay of therapy, and work well for many years. Given the success of pharmacological dopamine replacement, pursuit of cell-based dopamine replacement strategies seemed to be the next logical step, and studies were initiated over 30 years ago to explore the possibility of dopaminergic cell transplantation. In this Review, we outline the history of this therapeutic approach to PD and highlight the lessons that we have learned en route. We discuss how the best clinical outcomes have been obtained with fetal ventral mesencephalic allografts, while acknowledging inconsistencies in the results owing to problems in trial design, patient selection, tissue preparation, and immunotherapy used post-grafting. We conclude by discussing the challenges of bringing the new generation of stem cell-derived dopamine cells to the clinic.
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| 2. |
- Birtele, Marcella, et al.
(författare)
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Dual modulation of neuron-specific microRNAs and the REST complex promotes functional maturation of human adult induced neurons
- 2019
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Ingår i: FEBS Letters. - : Wiley. - 0014-5793 .- 1873-3468. ; 593:23, s. 3370-3380
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Tidskriftsartikel (refereegranskat)abstract
- Direct neuronal reprogramming can be achieved using different approaches: by expressing neuronal transcription factors or microRNAs; and by knocking down neuronal repressive elements. However, there still exists a high variability in terms of the quality and maturity of the induced neurons obtained, depending on the reprogramming strategy employed. Here, we evaluate different long-term culture conditions and study the effect of expressing the neuronal-specific microRNAs, miR124 and miR9/9*, while reprogramming with forced expression of the transcription factors Ascl1, Brn2, and knockdown of the neuronal repressor REST. We show that the addition of microRNAs supports neuronal maturation in terms of gene and protein expression, as well as in terms of electrophysiological properties.
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| 3. |
- Brambach, Max, et al.
(författare)
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Neural tube patterning : from a minimal model for rostrocaudal patterning toward an integrated 3D model
- 2021
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Ingår i: iScience. - : Elsevier BV. - 2589-0042. ; 24:6
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Tidskriftsartikel (refereegranskat)abstract
- Rostrocaudal patterning of the neural tube is a defining event in vertebrate brain development. This process is driven by morphogen gradients which specify the fate of neural progenitor cells, leading to the partitioning of the tube. Although this is extensively studied experimentally, an integrated view of the genetic circuitry is lacking. Here, we present a minimal gene regulatory model for rostrocaudal patterning, whose tristable topology was determined in a data-driven way. Using this model, we identified the repression of hindbrain fate as promising strategy for the improvement of current protocols for the generation of dopaminergic neurons. Furthermore, we combined our model with an established minimal model for dorsoventral patterning on a realistic 3D neural tube and found that key features of neural tube patterning could be recapitulated. Doing so, we demonstrate how data and models from different sources can be combined to simulate complex in vivo processes.
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| 4. |
- Bruzelius, Andreas, et al.
(författare)
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Reprogramming human adult fibroblasts into GABAergic interneurons
- 2021
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Ingår i: Cells. - : MDPI AG. - 2073-4409. ; 10:12
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Tidskriftsartikel (refereegranskat)abstract
- Direct reprogramming is an appealing strategy to generate neurons from a somatic cell by forced expression of transcription factors. The generated neurons can be used for both cell replacement strategies and disease modelling. Using this technique, previous studies have shown that γ-aminobutyric acid (GABA) expressing interneurons can be generated from different cell sources, such as glia cells or fetal fibroblasts. Nevertheless, the generation of neurons from adult human fibroblasts, an easily accessible cell source to obtain patient-derived neurons, has proved to be challenging due to the intrinsic blockade of neuronal commitment. In this paper, we used an optimized protocol for adult skin fibroblast reprogramming based on RE1 Silencing Transcription Factor (REST) inhibitn together with a combination of GABAergic fate determinants to convert human adult skin fibroblasts into GABAergic neurons. Our results show a successful conversion in 25 days with upregulation of neuronal gene and protein expression levels. Moreover, we identified specific gene combinations that converted fibroblasts into neurons of a GABAergic intraneuronal fate. Despite the well-known difficulty in converting adult fibroblasts into functional neurons in vitro, we could detect functional maturation in the induced neurons. GABAergic interneurons have relevance for cognitive impairments and brain disorders, such as Alzheimer’s and Parkinson’s diseases, epilepsy, schizophrenia and autism spectrum disorders.
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| 5. |
- Cisbani, G, et al.
(författare)
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Cystamine/cysteamine rescues the dopaminergic system and shows neurorestorative properties in an animal model of Parkinson's disease.
- 2015
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Ingår i: Neurobiology of Disease. - : Elsevier BV. - 0969-9961. ; 82, s. 430-444
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Tidskriftsartikel (refereegranskat)abstract
- The neuroprotective properties of cystamine identified in pre-clinical studies have fast-tracked this compound to clinical trials in Huntington's disease, showing tolerability and benefits on motor symptoms. We tested whether cystamine could have such properties in a Parkinson's disease murine model and now provide evidence that it can not only prevent the neurodegenerative process but also can reverse motor impairments created by a 6-hydroxydopamine lesion 3weeks post-surgery. Importantly, we report that cystamine has neurorestorative properties 5weeks post-lesion as seen on the number of nigral dopaminergic neurons which is comparable with treatments of cysteamine, the reduced form of cystamine used in the clinic, as well as rasagiline, increasingly prescribed in early parkinsonism. All three compounds induced neurite arborization of the remaining dopaminergic cells which was further confirmed in ex vivo dopaminergic explants derived from Pitx3-GFP mice. The disease-modifying effects displayed by cystamine/cysteamine would encourage clinical testing.
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| 6. |
- Collins, Lucy M., et al.
(författare)
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Dermal fibroblasts from patients with Parkinson's disease have normal GCase activity and autophagy compared to patients with PD and GBA mutations
- 2018
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Ingår i: F1000Research. - : F1000 Research Ltd. - 2046-1402. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Background: Recently, the development of Parkinson's disease (PD) has been linked to a number of genetic risk factors, of which the most common is glucocerebrosidase (GBA) mutations. Methods: We investigated PD and Gaucher Disease (GD) patient derived skin fibroblasts using biochemistry assays. Results: PD patient derived skin fibroblasts have normal glucocerebrosidase (GCase) activity, whilst patients with PD and GBA mutations have a selective deficit in GCase enzyme activity and impaired autophagic flux. Conclusions: This data suggests that only PD patients with a GBA mutation have altered GCase activity and autophagy, which may explain their more rapid clinical progression.
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| 7. |
- Drouin-Ouellet, Janelle, et al.
(författare)
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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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Ingår i: Stem Cell Reports. - : Elsevier BV. - 2213-6711. ; 17:10, s. 2203-2219
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Tidskriftsartikel (refereegranskat)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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| 8. |
- Drouin-Ouellet, Janelle, et al.
(författare)
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Direct neuronal reprogramming for disease modeling studies using patient-derived neurons : What have we learned?
- 2017
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Ingår i: Frontiers in Neuroscience. - : Frontiers Media SA. - 1662-4548 .- 1662-453X. ; 11:SEP
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Forskningsöversikt (refereegranskat)abstract
- Direct neuronal reprogramming, by which a neuron is formed via direct conversion from a somatic cell without going through a pluripotent intermediate stage, allows for the possibility of generating patient-derived neurons. A unique feature of these so-called induced neurons (iNs) is the potential to maintain aging and epigenetic signatures of the donor, which is critical given that many diseases of the CNS are age related. Here, we review the published literature on the work that has been undertaken using iNs to model human brain disorders. Furthermore, as disease-modeling studies using this direct neuronal reprogramming approach are becoming more widely adopted, it is important to assess the criteria that are used to characterize the iNs, especially in relation to the extent to which they are mature adult neurons. In particular: i) what constitutes an iN cell, ii) which stages of conversion offer the earliest/optimal time to assess features that are specific to neurons and/or a disorder and iii) whether generating subtype-specific iNs is critical to the disease-related features that iNs express. Finally, we discuss the range of potential biomedical applications that can be explored using patient-specific models of neurological disorders with iNs, and the challenges that will need to be overcome in order to realize these applications.
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| 9. |
- Drouin-Ouellet, Janelle, et al.
(författare)
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REST suppression mediates neural conversion of adult human fibroblasts via microRNA-dependent and -independent pathways
- 2017
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Ingår i: EMBO Molecular Medicine. - : EMBO. - 1757-4684 .- 1757-4676. ; 9:8, s. 1117-1131
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Tidskriftsartikel (refereegranskat)abstract
- Direct conversion of human fibroblasts into mature and functional neurons, termed induced neurons (iNs), was achieved for the first time 6 years ago. This technology offers a promising shortcut for obtaining patient- and disease-specific neurons for disease modeling, drug screening, and other biomedical applications. However, fibroblasts from adult donors do not reprogram as easily as fetal donors, and no current reprogramming approach is sufficiently efficient to allow the use of this technology using patient-derived material for large-scale applications. Here, we investigate the difference in reprogramming requirements between fetal and adult human fibroblasts and identify REST as a major reprogramming barrier in adult fibroblasts. Via functional experiments where we overexpress and knockdown the REST-controlled neuron-specific microRNAs miR-9 and miR-124, we show that the effect of REST inhibition is only partially mediated via microRNA up-regulation. Transcriptional analysis confirmed that REST knockdown activates an overlapping subset of neuronal genes as microRNA overexpression and also a distinct set of neuronal genes that are not activated via microRNA overexpression. Based on this, we developed an optimized one-step method to efficiently reprogram dermal fibroblasts from elderly individuals using a single-vector system and demonstrate that it is possible to obtain iNs of high yield and purity from aged individuals with a range of familial and sporadic neurodegenerative disorders including Parkinson's, Huntington's, as well as Alzheimer's disease.
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| 10. |
- Drouin-Ouellet, Janelle, et al.
(författare)
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The 2022 International Society for Stem Cell Research (ISSCR) Annual Meeting : Celebrating 20 Years of Achievements
- 2022
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Ingår i: Cellular Reprogramming. - : Mary Ann Liebert Inc. - 2152-4971 .- 2152-4998. ; 24:5, s. 212-222
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Tidskriftsartikel (refereegranskat)abstract
- Last June, the stem cell community came together to celebrate the 20th anniversary of the International Society for Stem Cell Research (ISSCR), one of the leading organizations in the field. The hybrid event mixed a varied program filled with plenary talks, concurrent track sessions, poster presentations, exhibit booths, and plenty of opportunities to enhance stem cell research through bonding between academia and industry. This report highlights the Plenary sessions, with the main topics discussed by each speaker. All the impressive research showcased during the meeting is genuine proof of the great advancements the field has witnessed during these last 20 years, and the more to come.
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| 11. |
- Merlevede, Adriaan, et al.
(författare)
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A quantitative model of cellular decision making in direct neuronal reprogramming
- 2021
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- The direct reprogramming of adult skin fibroblasts to neurons is thought to be controlled by a small set of interacting gene regulators. Here, we investigate how the interaction dynamics between these regulating factors coordinate cellular decision making in direct neuronal reprogramming. We put forward a quantitative model of the governing gene regulatory system, supported by measurements of mRNA expression. We found that nPTB needs to feed back into the direct neural conversion network most likely via PTB in order to accurately capture quantitative gene interaction dynamics and correctly predict the outcome of various overexpression and knockdown experiments. This was experimentally validated by nPTB knockdown leading to successful neural conversion. We also proposed a novel analytical technique to dissect system behaviour and reveal the influence of individual factors on resulting gene expression. Overall, we demonstrate that computational analysis is a powerful tool for understanding the mechanisms of direct (neuronal) reprogramming, paving the way for future models that can help improve cell conversion strategies.
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| 12. |
- Parmar, Malin, et al.
(författare)
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Cell-based therapy for Parkinson's disease : A journey through decades toward the light side of the Force
- 2019
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Ingår i: European Journal of Neuroscience. - : Wiley. - 0953-816X .- 1460-9568. ; 49:4, s. 463-471
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Tidskriftsartikel (refereegranskat)abstract
- This review describes the history, development, and evolution of cell-based replacement therapy for Parkinson's disease (PD), from the first pioneering trials with fetal ventral midbrain progenitors to future trials using stem cells as well as reprogrammed cells. In the spirit of Tom Isaacs, the review takes parallels to the storyline of Star Wars, including the temptations from the dark side and the continuous fight for the light side of the Force. It is subdivided into headings based on the original movies, spanning from A New Hope to the Last Jedi.
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| 13. |
- Pircs, Karolina, et al.
(författare)
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Distinct subcellular autophagy impairments in induced neurons from patients with Huntington's disease
- 2022
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Ingår i: Brain : a journal of neurology. - : Oxford University Press (OUP). - 1460-2156. ; 145:9, s. 3035-3057
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Tidskriftsartikel (refereegranskat)abstract
- Huntington's disease (HD) is a neurodegenerative disorder caused by CAG expansions in the huntingtin (HTT) gene. Modelling Huntington's disease is challenging, as rodent and cellular models poorly recapitulate the disease as seen in aging humans. To address this, we generated induced neurons (iNs) through direct reprogramming of human skin fibroblasts, which retain age-dependent epigenetic characteristics. HD-iNs displayed profound deficits in autophagy, characterised by reduced transport of late autophagic structures from the neurites to the soma. These neurite-specific alterations in autophagy resulted in shorter, thinner and fewer neurites specifically in HD-iNs. CRISPRi-mediated silencing of HTT did not rescue this phenotype but rather resulted in additional autophagy alterations in ctrl-iNs, highlighting the importance of wild type HTT in normal neuronal autophagy. In summary, our work identifies a distinct subcellular autophagy impairment in adult patient derived Huntington's disease neurons and provides a new rational for future development of autophagy activation therapies.
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| 14. |
- Shrigley, Shelby, et al.
(författare)
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Simple Generation of a High Yield Culture of Induced Neurons from Human Adult Skin Fibroblasts
- 2018
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Ingår i: Journal of Visualized Experiments. - : MyJove Corporation. - 1940-087X. ; 132
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Tidskriftsartikel (refereegranskat)abstract
- Induced neurons (iNs), the product of somatic cells directly converted to neurons, are a way to obtain patient-derived neurons from tissue thatis easily accessible. Through this route, mature neurons can be obtained in a matter of a few weeks. Here, we describe a straightforward andrapid one-step protocol to obtain iNs from dermal fibroblasts obtained through biopsy samples from adult human donors. We explain each stepof the process, including the maintenance of the dermal fibroblasts, the freezing procedure to build a stock of the cell line, seeding of the cellsfor reprogramming, as well as the culture conditions during the conversion process. In addition, we describe the preparation of glass coverslipsfor electrophysiological recordings, long-term coating conditions, and fluorescence activated cell sorting (FACS). We also illustrate examplesof the results to be expected. The protocol described here is easy to perform and can be applied to human fibroblasts derived from human skinbiopsies from patients with various different diagnoses and ages. This protocol generates a sufficient amount of iNs which can be used for a widearray of biomedical applications, including disease modeling, drug screening, and target validation.
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