| 1. |
- Rosenblad, Carl, et al.
(författare)
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Vector-mediated l-3,4-dihydroxyphenylalanine delivery reverses motor impairments in a primate model of Parkinson's disease
- 2019
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Ingår i: Brain : a journal of neurology. - : Oxford University Press (OUP). - 1460-2156. ; , s. 2402-2416
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Tidskriftsartikel (refereegranskat)abstract
- Ever since its introduction 40 years ago l-3,4-dihydroxyphenylalanine (l-DOPA) therapy has retained its role as the leading standard medication for patients with Parkinson's disease. With time, however, the shortcomings of oral l-DOPA treatment have become apparent, particularly the motor fluctuations and troublesome dyskinetic side effects. These side effects, which are caused by the excessive swings in striatal dopamine caused by intermittent oral delivery, can be avoided by delivering l-DOPA in a more continuous manner. Local gene delivery of the l-DOPA synthesizing enzymes, tyrosine hydroxylase and guanosine-tri-phosphate-cyclohydrolase-1, offers a new approach to a more refined dopaminergic therapy where l-DOPA is delivered continuously at the site where it is needed i.e. the striatum. In this study we have explored the therapeutic efficacy of adeno-associated viral vector-mediated l-DOPA delivery to the putamen in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-treated rhesus monkeys, the standard non-human primate model of Parkinson's disease. Viral vector delivery of the two enzymes, tyrosine hydroxylase and guanosine-5'-tri-phosphate-cyclohydrolase-1, bilaterally into the dopamine-depleted putamen, induced a significant, dose-dependent improvement of motor behaviour up to a level identical to that obtained with the optimal dose of peripheral l-DOPA. Importantly, this improvement in motor function was obtained without any adverse dyskinetic effects. These results provide proof-of-principle for continuous vector-mediated l-DOPA synthesis as a novel therapeutic strategy for Parkinson's disease. The constant, local supply of l-DOPA obtained with this approach holds promise as an efficient one-time treatment that can provide long-lasting clinical improvement and at the same time prevent the appearance of motor fluctuations and dyskinetic side effects associated with standard oral dopaminergic medication.
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| 2. |
- Adler, Andrew F., et al.
(författare)
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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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Ingår i: Cell Reports. - : Elsevier BV. - 2211-1247. ; 28:13, s. 5-3473
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Tidskriftsartikel (refereegranskat)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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| 3. |
- Aldén, Lina, 1979-, et al.
(författare)
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Early health and school outcomes for children with lesbian parents : evidence from Sweden
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Sweden was early to legalize same-sex partnership (1995), to allow same-sex couples to adopt children (2003), and to offer same-sex couples fertility treatment through the national health system (2005). Using population data, we identify children of lesbian parents as those whose biological mother was a registered same-sex partner no later than six months after the child's birth. The number of such children increased markedly from 1995 to 2010 with a total of 750 children for the whole period. We find that boys and girls with lesbian parents had 2.4 percent lower birth weight than other children, a difference that is statistically significant from zero at the 5 percent level. Girls, but not boys, also have a higher probability of having a low birth weight. We follow these children until age ten and observe diseases of the respiratory system. Boys with lesbian parents have a significantly lower probability of such diseases (-3.4 percentage points), and girls with lesbian parents an insignificantly higher probability (+2.4 percentage points). Our analysis of school outcomes at age ten uses a small sample so precision is low. The point estimates show that boys with lesbian parents outperform other children by around 10 percentiles higher test scores in Math and Swedish. These differences are barely significant, while estimates for girls are lower and not significant. For all outcomes, we find that children with lesbian parents benefit from their mother's socio-economic status, whereas they suffer in terms of birth weight from having been exposed to fertility treatment.
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| 4. |
- Alvarsson, A, et al.
(författare)
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Emotional memory impairments induced by AAV-mediated overexpression of human α-synuclein in dopaminergic neurons of the ventral tegmental area.
- 2016
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Ingår i: Behavioural Brain Research. - : Elsevier BV. - 0166-4328 .- 1872-7549. ; 296, s. 129-133
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Tidskriftsartikel (refereegranskat)abstract
- Parkinson's disease (PD) is associated with extensive degeneration of dopaminergic neurons originating in the substantia nigra pars compacta, but neuronal loss is also found in the ventral tegmental area (VTA). The VTA projects to areas involved in cognitive and emotional processes, including hippocampus, amygdala, nucleus accumbens and prefrontal cortex, and has thus been proposed to play a role in emotional memory impairments in PD. Since the formation of α-synuclein inclusions throughout the central nervous system is a pathological hallmark of PD, we studied the progressive effects of α-synuclein overexpression in the VTA on motor functions, emotional behaviour and emotional memory. Adeno-associated viral (AAV) vectors encoding either human α-synuclein or green fluorescent protein (GFP) were injected stereotactically into the VTA, and behaviour was monitored 3 and 8 weeks following AAV injection. At week 8, there was a 22% reduction of TH+ neurons in the VTA. We demonstrate that α-synuclein overexpression in dopaminergic neurons of the VTA induced mild motor deficits that appeared 3 weeks following AAV-α-synuclein injection and were aggravated at week 8. No depressive- or anxiety-like behaviours were found. To address emotional memory, we used the passive avoidance test, a one-trial associative learning paradigm based on contextual conditioning which requires minimal training. Interestingly, emotional memory impairments were found in α-synuclein overexpressing animals at week 8. These findings indicate that α-synuclein overexpression induces progressive memory impairments likely caused by a loss of function of mesolimbic dopaminergic projections.
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| 5. |
- Barker, Roger A, et al.
(författare)
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Are Stem Cell-Based Therapies for Parkinson's Disease Ready for the Clinic in 2016?
- 2016
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Ingår i: Journal of Parkinson's Disease. - 1877-718X. ; 6:1, s. 57-63
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Tidskriftsartikel (refereegranskat)abstract
- Recent news of an impending clinical cell transplantation trial in Parkinson's disease using parthenogenetic stem cells as a source of donor tissue have raised hopes in the patient community and sparked discussion in the research community. Based on discussions held by a global collaborative initiative on translation of stem cell therapy in Parkinson's disease, we have identified a set of key questions that we believe should be addressed ahead of every clinical stem cell-based transplantation trial in this disorder. In this article, we first provide a short history of cell therapy in Parkinson's disease and briefly describe the current state-of-art regarding human stem cell-derived dopamine neurons for use in any patient trial. With this background information as a foundation, we then discuss each of the key questions in relation to the upcoming therapeutic trial and critically assess if the time is ripe for clinical translation of parthenogenetic stem cell technology in Parkinson's disease.
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| 6. |
- Barker, Roger A., et al.
(författare)
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Designing stem-cell-based dopamine cell replacement trials for Parkinson’s disease
- 2019
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Ingår i: Nature Medicine. - : Springer Science and Business Media LLC. - 1078-8956 .- 1546-170X. ; 25, s. 1045-1053
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Tidskriftsartikel (refereegranskat)abstract
- Clinical studies of Parkinson’s disease (PD) using a dopamine cell replacment strategy have been tried for more than 30 years. The outcomes following transplantation of human fetal ventral mesencephalic tissue (hfVM) have been variable, with some patients coming off their anti-PD treatment for many years and others not responding and/or developing significant side effects, including graft-induced dyskinesia. This led to a re-appraisal of the best way to do such trials, which resulted in a new European-Union-funded allograft trial with fetal dopamine cells across several centers in Europe. This new trial, TRANSEURO (NCT01898390), is an open-label study in which some individuals in a large observational cohort of patients with mild PD who were undergoing identical assessments were randomly selected to receive transplants of hfVM. The TRANSEURO trial is currently ongoing as researchers have completed both recruitment into a large multicenter observational study of younger onset early-stage PD and transplantation of hfVM in 11 patients. While completion of TRANSEURO is not expected until 2021, we feel that sharing the rationale for the design of TRANSEURO, along with the lessons we have learned along the way, can help inform researchers and facilitate planning of transplants of dopamine-producing cells derived from human pluripotent stem cells for future clinical trials.
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| 7. |
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| 8. |
- Björklund, Anders, et al.
(författare)
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Intergenerational mobility, intergenerational effects, sibling correlations, and equality of opportunity : a comparison of four approaches
- 2019
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This paper presents and discusses four different approaches to the study of how individuals’ income and education during adulthood are related to their family background. The most well-known approach, intergenerational mobility, describes how parents’ and offspring’s income or education are related to each other. The intergenerational-effect literature addresses the question how an intervention that changes parental income or education causally affects their children’s outcome. The sibling-correlation approach estimates the share of total inequality that is attributed to factors shared by siblings. This share is generally substantially higher than what is revealed by intergenerational mobility estimates. Finally, the equality-of-opportunity approach is looking for a set of factors, in the family background and otherwise, that are important for children’s outcomes and that children cannot be held accountable for. We argue that all four approaches are most informative and that recent research has provided insightful results. However, by comparing results from the different approaches, it is possible to paint a more nuanced picture of the role of family background. Thus, we recommend that scholars working in the four subfields pay more attention to each other’s research.
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| 9. |
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| 10. |
- Björklund, Anders, et al.
(författare)
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Replacing Dopamine Neurons in Parkinson's Disease : How did it happen?
- 2017
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Ingår i: Journal of Parkinson's Disease. - 1877-7171. ; 7:s1, s. 23-33
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Forskningsöversikt (refereegranskat)abstract
- The efforts to develop a dopamine cell replacement therapy for Parkinson's disease have spanned over more than three decades. Based on almost 10 years of transplantation studies in animal models, the first patients receiving grafts of fetal-derived dopamine neuroblasts were operated in Lund in 1987. Over the following two decades, a total of 18 patients were transplanted and followed closely by our team with mixed but also very encouraging results. In this article we tell the story of how the preclinical and clinical transplantation program in Lund evolved. We recall the excitement when we obtained the first evidence for survival and function of transplanted neurons in the diseased human brain. We also remember the setbacks that we have experienced during these 30 years and discuss the very interesting developments that are now taking place in this exciting field.
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