| 11. |
- Anisimov, Sergey, et al.
(författare)
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Identification of molecules derived from human fibroblast feeder cells that support the proliferation of human embryonic stem cells.
- 2011
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Ingår i: Cellular & Molecular Biology Letters. - : Walter de Gruyter GmbH. - 1689-1392. ; 16:1, s. 79-88
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Tidskriftsartikel (refereegranskat)abstract
- The majority of human embryonic stem cell lines depend on a feeder cell layer for continuous growth in vitro, so that they can remain in an undifferentiated state. Limited knowledge is available concerning the molecular mechanisms that underlie the capacity of feeder cells to support both the proliferation and pluripotency of these cells. Importantly, feeder cells generally lose their capacity to support human embryonic stem cell proliferation in vitro following long-term culture. In this study, we performed large-scale gene expression profiles of human foreskin fibroblasts during early, intermediate and late passages using a custom DNA microarray platform (NeuroStem 2.0 Chip). The microarray data was validated using RT-PCR and virtual SAGE analysis. Our comparative gene expression study identified a limited number of molecular targets potentially involved in the ability of human neonatal foreskin fibroblasts to serve as feeder cells for human embryonic stem cell cultures. Among these, the C-KIT, leptin and pigment epithelium-derived factor (PEDF) genes were the most interesting candidates.
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| 12. |
- Anisimov, Sergey, et al.
(författare)
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"NeuroStem Chip": a novel highly specialized tool to study neural differentiation pathways in human stem cells.
- 2007
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Ingår i: BMC Genomics. - : Springer Science and Business Media LLC. - 1471-2164. ; 8:Feb 8, s. 46-46
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Human stem cells are viewed as a possible source of neurons for a cell-based therapy of neurodegenerative disorders, such as Parkinson's disease. Several protocols that generate different types of neurons from human stem cells (hSCs) have been developed. Nevertheless, the cellular mechanisms that underlie the development of neurons in vitro as they are subjected to the specific differentiation protocols are often poorly understood. RESULTS: We have designed a focused DNA (oligonucleotide-based) large-scale microarray platform (named "NeuroStem Chip") and used it to study gene expression patterns in hSCs as they differentiate into neurons. We have selected genes that are relevant to cells (i) being stem cells, (ii) becoming neurons, and (iii) being neurons. The NeuroStem Chip has over 1,300 pre-selected gene targets and multiple controls spotted in quadruplicates (approximately 46,000 spots total). In this study, we present the NeuroStem Chip in detail and describe the special advantages it offers to the fields of experimental neurology and stem cell biology. To illustrate the utility of NeuroStem Chip platform, we have characterized an undifferentiated population of pluripotent human embryonic stem cells (hESCs, cell line SA02). In addition, we have performed a comparative gene expression analysis of those cells versus a heterogeneous population of hESC-derived cells committed towards neuronal/dopaminergic differentiation pathway by co-culturing with PA6 stromal cells for 16 days and containing a few tyrosine hydroxylase-positive dopaminergic neurons. CONCLUSION: We characterized the gene expression profiles of undifferentiated and dopaminergic lineage-committed hESC-derived cells using a highly focused custom microarray platform (NeuroStem Chip) that can become an important research tool in human stem cell biology. We propose that the areas of application for NeuroStem microarray platform could be the following: (i) characterization of the expression of established, pre-selected gene targets in hSC lines, including newly derived ones, (ii) longitudinal quality control for maintained hSC populations, (iii) following gene expression changes during differentiation under defined cell culture conditions, and (iv) confirming the success of differentiation into specific neuronal subtypes.
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| 13. |
- Araujo, IM, et al.
(författare)
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Calpain activation is involved in early caspase-independent neurodegeneration in the hippocampus following status epilepticus
- 2008
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Ingår i: Journal of Neurochemistry. - : Wiley. - 1471-4159 .- 0022-3042. ; 105:3, s. 666-676
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Tidskriftsartikel (refereegranskat)abstract
- Evidence for increased calpain activity has been described in the hippocampus of rodent models of temporal lobe epilepsy. However, it is not known whether calpains are involved in the cell death that accompanies seizures. In this work, we characterized calpain activation by examining the proteolysis of calpain substrates and in parallel we followed cell death in the hippocampus of epileptic rats. Male Wistar rats were injected with kainic acid (KA; 10 mg/kg) intraperitoneally and sacrificed 24h later, after development of grade 5 seizures. We observed a strong Fluoro-Jade labelling in the CA1 and CA3 areas of the hippocampus in the rats that received KA, as compared to saline-treated rats. Immunohistochemistry and Western blot analysis for the calpain-derived breakdown products of spectrin (SBDP) showed evidence of increased calpain activity in the same regions of the hippocampus where cell death is observed. No evidence was found for caspase activation, in the same conditions. Treatment with the calpain inhibitor MDL 28170 significantly prevented the neurodegeneration observed in CA1. Taken together, our data suggest that early calpain activation, but not caspase activation, is involved in neurotoxicity in the hippocampus after status epilepticus.
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| 14. |
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| 15. |
- Aziz, N. A., et al.
(författare)
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Weight loss in Huntington disease increases with higher CAG repeat number
- 2008
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Ingår i: Neurology. - : Ovid Technologies (Wolters Kluwer Health). - 1526-632X .- 0028-3878. ; 71:19, s. 1506-1513
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Huntington disease (HD) is a hereditary neurodegenerative disorder caused by an expanded number of CAG repeats in the huntingtin gene. A hallmark of HD is unintended weight loss, the cause of which is unknown. In order to elucidate the underlying mechanisms of weight loss in HD, we studied its relation to other disease characteristics including motor, cognitive, and behavioral disturbances and CAG repeat number. Methods: In 517 patients with early stage HD, we applied mixed-effects model analyses to correlate weight changes over 3 years to CAG repeat number and various components of the Unified Huntington's Disease Rating Scale (UHDRS). We also assessed the relation between CAG repeat number and body weight and caloric intake in the R6/2 mouse model of HD. Results: In patients with HD, mean body mass index decreased with -0.15 units per year (p < 0.001). However, no single UHDRS component, including motor, cognitive, and behavioral scores, was independently associated with the rate of weight loss. Patients with HD with a higher CAG repeat number had a faster rate of weight loss. Similarly, R6/2 mice with a larger CAG repeat length had a lower body weight, whereas caloric intake increased with larger CAG repeat length. Conclusions: Weight loss in Huntington disease (HD) is directly linked to CAG repeat length and is likely to result from a hypermetabolic state. Other signs and symptoms of HD are unlikely to contribute to weight loss in early disease stages. Elucidation of the responsible mechanisms could lead to effective energy-based therapeutics. Neurology (R) 2008;71:1506-1513
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| 16. |
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| 17. |
- Bacos, Karl, et al.
(författare)
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Islet beta-cell area and hormone expression are unaltered in Huntington's disease.
- 2008
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Ingår i: Histochemistry and Cell Biology. - : Springer Science and Business Media LLC. - 1432-119X .- 0948-6143. ; 129, s. 623-629
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Tidskriftsartikel (refereegranskat)abstract
- Neurodegenerative disorders are often associated with metabolic alterations. This has received little attention, but might be clinically important because it can contribute to symptoms and influence the course of the disease. Patients with Huntington's disease (HD) exhibit increased incidence of diabetes mellitus (DM). This is replicated in mouse models of HD, e.g., the R6/2 mouse, in which DM is primarily caused by a deficiency of beta-cells with impaired insulin secretion. Pancreatic tissue from HD patients has previously not been studied and, thus, the pathogenesis of DM in HD is unclear. To address this issue, we examined pancreatic tissue sections from HD patients at different disease stages. We found that the pattern of insulin immunostaining, levels of insulin transcripts and islet beta-cell area were similar in HD patients and controls. Further, there was no sign of amyloid deposition in islets from HD patients. Thus, our data show that pancreatic islets in HD patients appear histologically normal. Functional studies of HD patients with respect to insulin secretion and islet function are required to elucidate the pathogenesis of DM in HD. This may lead to a better understanding of HD and provide novel therapeutic targets for symptomatic treatment in HD.
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| 18. |
- Barker, Roger A., et al.
(författare)
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A new approach to disease-modifying drug trials in Parkinson's disease
- 2013
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Ingår i: Journal of Clinical Investigation. - 0021-9738. ; 123:6, s. 2364-2365
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Translating new findings in the laboratory into therapies for patients is a slow and expensive process. The development of therapies for neurodegenerative diseases is further complicated by the difficulty in determining whether the drug truly retards the slow degenerative process or provides only symptomatic benefit. In this issue, Aviles-Olmos et al. describe a first in Parkinson's disease (PD) patient study using a drug previously approved for diabetes treatment. In addition to suggesting that the drug may indeed be disease modifying in PD, their innovative approach suggests there may be more rapid and inexpensive avenues for testing novel therapies in PD.
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| 19. |
- 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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| 20. |
- 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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