| 1. |
- Barker, Roger A, et al.
(författare)
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Animal Models of Parkinson's Disease : Are They Useful or Not?
- 2020
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Ingår i: Journal of Parkinson's Disease. - 1877-718X. ; 10:4, s. 1335-1342
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Forskningsöversikt (refereegranskat)abstract
- The use of animal models in Parkinson's disease research has been controversial in terms of how well they relate to the clinical condition and thus their utility for translating therapies from the lab to the clinic. In this article, two researchers debate this issue with Roger Barker taking the view that such models are not useful and may even be misleading, while Anders Björklund defends their use and highlights their value in better understanding and treating this condition.
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| 2. |
- Barker, Roger A., et al.
(författare)
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GDNF and Parkinson's Disease : Where Next? A Summary from a Recent Workshop
- 2020
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Ingår i: Journal of Parkinson's Disease. - 1877-7171. ; 10:3, s. 875-891
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Tidskriftsartikel (refereegranskat)abstract
- The concept of repairing the brain with growth factors has been pursued for many years in a variety of neurodegenerative diseases including primarily Parkinson's disease (PD) using glial cell line-derived neurotrophic factor (GDNF). This neurotrophic factor was discovered in 1993 and shown to have selective effects on promoting survival and regeneration of certain populations of neurons including the dopaminergic nigrostriatal pathway. These observations led to a series of clinical trials in PD patients including using infusions or gene delivery of GDNF or the related growth factor, neurturin (NRTN). Initial studies, some of which were open label, suggested that this approach could be of value in PD when the agent was injected into the putamen rather than the cerebral ventricles. In subsequent double-blind, placebo-controlled trials, the most recent reporting in 2019, treatment with GDNF did not achieve its primary end point. As a result, there has been uncertainty as to whether GDNF (and by extrapolation, related GDNF family neurotrophic factors) has merit in the future treatment of PD. To critically appraise the existing work and its future, a special workshop was held to discuss and debate this issue. This paper is a summary of that meeting with recommendations on whether there is a future for this therapeutic approach and also what any future PD trial involving GDNF and other GDNF family neurotrophic factors should consider in its design.
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| 3. |
- Barker, Roger A., et al.
(författare)
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Restorative cell and gene therapies for Parkinson's disease
- 2023
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Ingår i: Precision Medicine in Neurodegenerative Disorders, Part II. - 0072-9752 .- 2212-4152. - 9780323855556 ; 193, s. 211-226
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Bokkapitel (refereegranskat)abstract
- One of the core pathological features of Parkinson's disease (PD) is the loss of the dopaminergic nigrostriatal pathway which lies at the heart of many of the motor features of this condition as well as some of the cognitive problems. The importance of this pathological event is evident through the clinical benefits that are seen when patients with PD are treated with dopaminergic agents, at least in early-stage disease. However, these agents create problems of their own through stimulation of more intact dopaminergic networks within the central nervous system causing major neuropsychiatric problems including dopamine dysregulation. In addition, over time the nonphysiological stimulation of striatal dopamine receptors by L-dopa containing drugs leads to the genesis of L-dopa-induced dyskinesias that can become very disabling in many cases. As such, there has been much interest in trying to better reconstitute the dopaminergic nigrostriatal pathway using either factors to regrow it, cells to replace it, or gene therapies to restore dopamine transmission in the striatum. In this chapter, we lay out the rationale, history and current status of these different therapies as well as highlighting where the field is heading and what new interventions might come to clinic in the coming years.
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| 4. |
- Barker, Roger A, et al.
(författare)
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Stem Derived Dopamine Neurons : Will They Replace DBS as the Leading Neurosurgical Treatment for Parkinson's Disease?
- 2021
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Ingår i: Journal of Parkinson's Disease. - 1877-718X. ; 11:3, s. 909-917
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Tidskriftsartikel (refereegranskat)abstract
- The use of stem cell derived dopamine neurons for treating patients with Parkinson's disease has now evolved to the first in human clinical trials. In this debate, we argue that assuming these trials give positive outcomes that this therapy will supercede DBS as the neurosurgical treatment of choice for PD patients in the future given it is a one-off therapy that repairs a critical pathway in the parkinsonian brain.
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| 5. |
- Barker, Roger A., et al.
(författare)
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The need for a standard for informed consent for collection of human fetal material
- 2022
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Ingår i: Stem Cell Reports. - : Elsevier BV. - 2213-6711. ; 17:6, s. 1245-1247
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Tidskriftsartikel (refereegranskat)abstract
- The ISSCR has developed the Informed Consent Standards for Human Fetal Tissue Donation and Research to promote uniformity and transparency in tissue donation and collection. This standard is designed to assist those working with and overseeing the regulation of such tissue and reassure the wider community and public.
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| 6. |
- Birtele, Marcella, et al.
(författare)
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Single-cell transcriptional and functional analysis of dopaminergic neurons in organoid-like cultures derived from human fetal midbrain
- 2022
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Ingår i: Development: For advances in developmental biology and stem cells. - : The Company of Biologists. - 1477-9129. ; 149:23
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Tidskriftsartikel (refereegranskat)abstract
- Significant efforts are ongoing to develop refined differentiation protocols to generate midbrain dopamine (DA) neurons from pluripotent stem cells (PSCs) for application in disease modeling, diagnostics, drug screening, and cell-based therapies for Parkinson's Disease (PD). An increased understanding of the timing and molecular mechanisms promoting the generation of distinct subtypes of human midbrain DA during development will be essential for guiding future efforts to generate molecularly defined and subtype-specific DA neurons from PSCs. Here, we used droplet-based single-cell RNA sequencing to transcriptionally profile the developing human ventral midbrain (VM) when the DA neurons are generated (6-11 weeks post-conception) and their subsequent differentiation into functional mature DA neurons in primary fetal 3D organoid-like cultures. This approach revealed that 3D cultures are superior to monolayer conditions for their ability to generate and maintain mature DA neurons; hence they have the potential to be used for studying human VM development. These results provide a unique transcriptional profile of the developing human fetal VM and functionally mature human DA neurons, which can be used to guide stem cell-based therapies and disease modeling approaches in PD.
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| 7. |
- Braun, Emelie, et al.
(författare)
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Comprehensive cell atlas of the first-trimester developing human brain
- 2023
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 382:6667, s. 172-
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Tidskriftsartikel (refereegranskat)abstract
- The adult human brain comprises more than a thousand distinct neuronal and glial cell types, a diversity that emerges during early brain development. To reveal the precise sequence of events during early brain development, we used single-cell RNA sequencing and spatial transcriptomics and uncovered cell states and trajectories in human brains at 5 to 14 postconceptional weeks (pcw). We identified 12 major classes that are organized as ~600 distinct cell states, which map to precise spatial anatomical domains at 5 pcw. We described detailed differentiation trajectories of the human forebrain and midbrain and found a large number of region-specific glioblasts that mature into distinct pre-astrocytes and pre–oligodendrocyte precursor cells. Our findings reveal the establishment of cell types during the first trimester of human brain development.
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| 8. |
- 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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| 9. |
- 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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| 10. |
- Garza, Raquel, et al.
(författare)
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LINE-1 retrotransposons drive human neuronal transcriptome complexity and functional diversification
- 2023
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Ingår i: Science Advances. - 2375-2548. ; 9:44
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Tidskriftsartikel (refereegranskat)abstract
- The genetic mechanisms underlying the expansion in size and complexity of the human brain remain poorly understood. Long interspersed nuclear element-1 (L1) retrotransposons are a source of divergent genetic information in hominoid genomes, but their importance in physiological functions and their contribution to human brain evolution are largely unknown. Using multiomics profiling, we here demonstrate that L1 promoters are dynamically active in the developing and the adult human brain. L1s generate hundreds of developmentally regulated and cell type-specific transcripts, many that are co-opted as chimeric transcripts or regulatory RNAs. One L1-derived long noncoding RNA, LINC01876, is a human-specific transcript expressed exclusively during brain development. CRISPR interference silencing of LINC01876 results in reduced size of cerebral organoids and premature differentiation of neural progenitors, implicating L1s in human-specific developmental processes. In summary, our results demonstrate that L1-derived transcripts provide a previously undescribed layer of primate- and human-specific transcriptome complexity that contributes to the functional diversification of the human brain.
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