| 1. |
- Kokaia, Merab, et al.
(författare)
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Suppressed kindling epileptogenesis in mice with ectopic overexpression of galanin
- 2001
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 98:24, s. 14006-14011
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Tidskriftsartikel (refereegranskat)abstract
- The neuropeptide galanin has been shown to suppress epileptic seizures. In cortical and hippocampal areas, galanin is normally mainly expressed in noradrenergic afferents. We have generated a mouse overexpressing galanin in neurons under the platelet-derived growth factor B promoter. RIA and HPLC analysis revealed up to 8-fold higher levels of galanin in transgenic as compared with wild-type mice. Ectopic galanin overexpression was detected especially in dentate granule cells and hippocampal and cortical pyramidal neurons. Galanin-overexpressing mice showed retardation of seizure generalization during hippocampal kindling, a model for human complex partial epilepsy. The high levels of galanin in mossy fibers found in the transgenic mice were further increased after seizures. Frequency facilitation of field excitatory postsynaptic potentials, a form of short-term synaptic plasticity assessed in hippocampal slices, was reduced in mossy fiber-CA3 cell synapses of galanin-overexpressing mice, indicating suppressed glutamate release. This effect was reversed by application of the putative galanin receptor antagonist M35. These data provide evidence that ectopically overexpressed galanin can be released and dampen the development of epilepsy by means of receptor-mediated action, at least partly by reducing glutamate release from mossy fibers.
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| 2. |
- Magnusson, Jens P, et al.
(författare)
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A latent neurogenic program in astrocytes regulated by Notch signaling in the mouse.
- 2014
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 1095-9203 .- 0036-8075. ; 346:6206, s. 237-241
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Tidskriftsartikel (refereegranskat)abstract
- Neurogenesis is restricted in the adult mammalian brain; most neurons are neither exchanged during normal life nor replaced in pathological situations. We report that stroke elicits a latent neurogenic program in striatal astrocytes in mice. Notch1 signaling is reduced in astrocytes after stroke, and attenuated Notch1 signaling is necessary for neurogenesis by striatal astrocytes. Blocking Notch signaling triggers astrocytes in the striatum and the medial cortex to enter a neurogenic program, even in the absence of stroke, resulting in 850 ± 210 (mean ± SEM) new neurons in a mouse striatum. Thus, under Notch signaling regulation, astrocytes in the adult mouse brain parenchyma carry a latent neurogenic program that may potentially be useful for neuronal replacement strategies.
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| 3. |
- Lindvall, Olle, et al.
(författare)
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Stem cells for the treatment of neurological disorders.
- 2006
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 441:7097, s. 1094-1096
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Tidskriftsartikel (refereegranskat)abstract
- Many common neurological disorders, such as Parkinson's disease, stroke and multiple sclerosis, are caused by a loss of neurons and glial cells. In recent years, neurons and glia have been generated successfully from stem cells in culture, fuelling efforts to develop stem-cell-based transplantation therapies for human patients. More recently, efforts have been extended to stimulating the formation and preventing the death of neurons and glial cells produced by endogenous stem cells within the adult central nervous system. The next step is to translate these exciting advances from the laboratory into clinically useful therapies.
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| 4. |
- Delavaran, Hossein, et al.
(författare)
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Spontaneous Recovery of Upper Extremity Motor Impairment After Ischemic Stroke : Implications for Stem Cell-Based Therapeutic Approaches
- 2017
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Ingår i: Translational Stroke Research. - : Springer Science and Business Media LLC. - 1868-4483 .- 1868-601X. ; 8:4, s. 351-361
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Tidskriftsartikel (refereegranskat)abstract
- Preclinical studies suggest that stem cell therapy (SCT) may improve sensorimotor recovery after stroke. Upper extremity motor impairment (UEMI) is common after stroke, often entailing substantial disability. To evaluate the feasibility of post-stroke UEMI as a target for SCT, we examined a selected sample of stroke patients potentially suitable for SCT, aiming to assess the frequency and recovery of UEMI, as well as its relation to activity limitations and participation restrictions. Patients aged 20–75 years with first-ever ischemic stroke, and National Institutes of Health Stroke Scale (NIHSS) scores 1–18, underwent brain diffusion-weighted MRI within 4 days of stroke onset (n = 108). Survivors were followed up after 3–5 years, including assessment with NIHSS, Fugl-Meyer assessment of upper extremity (FMA-UE), modified Rankin Scale (mRS), and Stroke Impact Scale (SIS). UEMI was defined as NIHSS arm/hand score ≥1. UEMI recovery was evaluated with change in NIHSS arm/hand scores between baseline and follow-up. Of 97 survivors, 84 were available to follow-up. Among 76 subjects (of 84) without recurrent stroke, 41 had UEMI at baseline of which 10 had residual UEMI at follow-up. The FMA-UE showed moderate-severe impairment in seven of 10 survivors with residual UEMI. UEMI was correlated to mRS (rs = 0.49, p < 0.001) and the SIS social participation domain (rs = −0.38, p = 0.001). Nearly 25% of the subjects with UEMI at baseline had residual impairment after 3–5 years, whereas about 75% showed complete recovery. Most of the subjects with residual UEMI had moderate-severe impairment, which correlated strongly to dependency in daily activities and social participation restrictions. Our findings suggest that SCT targeting post-stroke UEMI may be clinically valuable with significant meaningful benefits for patients but also emphasize the need of early prognostication to detect patients that will have residual impairment in order to optimize patient selection for SCT.
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| 5. |
- Kokaia, Zaal, et al.
(författare)
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Human Neural Stem Cells for Ischemic Stroke Treatment
- 2018
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Ingår i: Results and Problems in Cell Differentiation. - Cham : Springer International Publishing. - 1861-0412 .- 0080-1844. ; 66, s. 249-263
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Bokkapitel (refereegranskat)abstract
- Ischemic stroke is the second most common cause of death worldwide and a major cause of disability. It takes place when the brain does not receive sufficient blood supply due to the blood clot in the vessels or narrowing of vessels’ inner space due to accumulation of fat products. Apart from thrombolysis (dissolving of blood clot) and thrombectomy (surgical removal of blood clot or widening of vessel inner area) during the first hours after an ischemic stroke, no effective treatment to improve functional recovery exists in the post-ischemic phase. Due to their narrow therapeutic time window, thrombolysis and thrombectomy are unavailable to more than 80% of stroke patients. Many experimental studies carried out in animal models of stroke have demonstrated that stem cell transplantation may become a new therapeutic strategy in stroke. Transplantation of stem cells of different origin and stage of development has been shown to lead to improvement in experimental models of stroke through several mechanisms including neuronal replacement, modulation of cellular and synaptic plasticity and inflammation, neuroprotection and stimulation of angiogenesis. Several clinical studies and trials based on stem cell delivery in stroke patients are in progress with goal of improvements of functional recovery through mechanisms other than neuronal replacement. These approaches may provide therapeutic benefit, but generation of specific neurons for reconstruction of stroke-injured neural circuitry remains ultimate challenge. For this purpose, neural stem cells could be developed from multiple sources and fated to adopt required neuronal phenotype.
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| 6. |
- Tornero, Daniel, et al.
(författare)
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Synaptic inputs from stroke-injured brain to grafted human stem cell-derived neurons activated by sensory stimuli
- 2017
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Ingår i: Brain. - : Oxford University Press (OUP). - 0006-8950 .- 1460-2156. ; 140:3, s. 692-706
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Tidskriftsartikel (refereegranskat)abstract
- Transplanted neurons derived from stem cells have been proposed to improve function in animal models of human disease by various mechanisms such as neuronal replacement. However, whether the grafted neurons receive functional synaptic inputs from the recipient's brain and integrate into host neural circuitry is unknown. Here we studied the synaptic inputs from the host brain to grafted cortical neurons derived from human induced pluripotent stem cells after transplantation into stroke-injured rat cerebral cortex. Using the rabies virus-based trans-synaptic tracing method and immunoelectron microscopy, we demonstrate that the grafted neurons receive direct synaptic inputs from neurons in different host brain areas located in a pattern similar to that of neurons projecting to the corresponding endogenous cortical neurons in the intact brain. Electrophysiological in vivo recordings from the cortical implants show that physiological sensory stimuli, i.e. cutaneous stimulation of nose and paw, can activate or inhibit spontaneous activity in grafted neurons, indicating that at least some of the afferent inputs are functional. In agreement, we find using patch-clamp recordings that a portion of grafted neurons respond to photostimulation of virally transfected, channel-rhodopsin-2-expressing thalamo-cortical axons in acute brain slices. The present study demonstrates, for the first time, that the host brain regulates the activity of grafted neurons, providing strong evidence that transplanted human induced pluripotent stem cell-derived cortical neurons can become incorporated into injured cortical circuitry. Our findings support the idea that these neurons could contribute to functional recovery in stroke and other conditions causing neuronal loss in cerebral cortex.
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| 7. |
- Ahlenius, Henrik, et al.
(författare)
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Isolation and generation of neurosphere cultures from embryonic and adult mouse brain.
- 2010
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Ingår i: Methods in Molecular Biology. - Totowa, NJ : Humana Press. - 1940-6029. ; 633, s. 241-252
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Tidskriftsartikel (refereegranskat)abstract
- Neural stem cells are defined as cells that either gives rise to or derives from the cells of the central nervous system and have the unique properties of stem cells, i.e. self-renewal and multipotentiality. One of the widely used methods of expanding neural stem cells under culture conditions is based on the capacity of these cells to divide continuously when cultured in serum-free medium supplemented with various growth factors. One common method used is to grow neural stem cells as free-floating aggregates of cells called neurospheres. Neurospheres can be generated from several structures of the embryonic and adult mammalian brain. Although viable lines can be generated from crude extracts of brain, a precise dissection is crucial to get a pure population of cells. Here we describe methods for dissection, isolation and generation of neurospheres from embryonic ganglionic eminences and adult subventricular zone of mice and rats.
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| 8. |
- Aked, Joseph, et al.
(författare)
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Attitudes to Stem Cell Therapy among Ischemic Stroke Survivors in the Lund Stroke Recovery Study
- 2017
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Ingår i: Stem Cells and Development. - : Mary Ann Liebert Inc. - 1547-3287 .- 1557-8534. ; 26:8, s. 566-572
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Tidskriftsartikel (refereegranskat)abstract
- Preclinical studies suggest that stem cell therapy (SCT) may improve poststroke recovery, and clinical trials investigating safety are ongoing. However, knowledge about patients' attitudes to SCT in stroke is limited. We evaluated the knowledge and attitudes to this therapeutic approach as well as possible factors influencing this among stroke patients potentially suitable for SCT. Consecutive first-ever acute ischemic stroke patients aged 20-75 years with NIH stroke scale scores 1-18 were included. Exclusion criteria were severe comorbidities or infratentorial stroke. Clinical follow-up after 3-5 years assessed severity of residual stroke symptoms, cognitive function, functional status, patient-reported outcome, and comorbidity, and after receiving standardized information, the participants also completed an eight-item questionnaire on knowledge and attitudes about SCT. The relationships between clinical variables and positive attitude to SCT were assessed with logistic regression analyses. Of 108 patients included at baseline, 84 participated at follow-up and completed the questionnaire. In total, 12% had prior knowledge of SCT. When informed, 63% were positive toward it and 36% reported willingness to participate in SCT trials. Only 5%-8% expressed ethical considerations regarding different stem cell sources. Positive attitudes to SCT were associated with male gender (OR: 3.74; 95% CI: 1.45-9.61; P < 0.01) and better patient-reported outcome (OR: 1.02; 95% CI: 1.00-1.04; P < 0.05). In conclusion, stroke patients had limited prior knowledge of SCT, yet attitudes were positive among the majority after receiving standardized and neutral information. Gender and degree of stroke recovery may influence attitudes to SCT, indicating a need for targeted information to improve knowledge about SCT.
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| 9. |
- Andsberg, Gunnar, et al.
(författare)
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Upregulation of p75 neurotrophin receptor after stroke in mice does not contribute to differential vulnerability of striatal neurons
- 2001
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Ingår i: Experimental Neurology. - : Elsevier BV. - 0014-4886. ; 169:2, s. 351-363
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Tidskriftsartikel (refereegranskat)abstract
- The survival of different neuron types and the expression of the p75 neurotrophin receptor (p75(NTR)) after focal cerebral ischemia were studied in the mouse striatum using immunocytochemical and histochemical techniques and stereological procedures. As assessed at 1 week after 30 min of middle cerebral artery occlusion, the order of vulnerability was projection neurons > parvalbumin-expressing interneurons > nitric oxide synthase-containing interneurons > cholinergic interneurons. Within the ischemic lesion, projection neurons were almost completely lost whereas cholinergic interneurons were spared. Calretinin-immunoreactive interneurons also seemed resistant to the insult. Expression of p75(NTR) was induced in cholinergic interneurons within the lesioned area, raising the possibility of a protective action. However, the number of cholinergic interneurons was unaffected in p75(NTR) knockout mice subjected to the same ischemic insult. These quantitative data demonstrate that striatal neurons in the mouse are differentially susceptible to ischemic damage and argue against a significant role of p75(NTR) for the high resistance of cholinergic interneurons.
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| 10. |
- Bengzon, Johan, et al.
(författare)
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Apoptosis and proliferation of dentate gyrus neurons after single and intermittent limbic seizures
- 1997
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Ingår i: Proceedings of the National Academy of Sciences. - 1091-6490. ; 94:19, s. 10432-10437
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Tidskriftsartikel (refereegranskat)abstract
- Neuronal apoptosis was observed in the rat dentate gyrus in two experimental models of human limbic epilepsy. Five hours after one hippocampal kindling stimulation, a marked increase of in situ terminal deoxynucleotidyltransferase-mediated dUTP nick-end labeling (TUNEL) of fragmented DNA was observed in nuclei located within and on the hilar border of the granule cell layer and in the polymorphic region. Forty kindling stimulations with 5-min interval produced higher numbers of labeled nuclei compared with one stimulation. The increase of TUNEL-positive nuclei was prevented by the protein synthesis inhibitor cycloheximide but not affected by the N-methyl-D-aspartate receptor antagonist MK-801. Kainic acid-induced seizures lead to a pattern of labeling in the hippocampal formation identical to that evoked by kindling. A large proportion of cells displaying TUNEL-positive nuclei was double-labeled by the neuron-specific antigen NeuN, demonstrating the neuronal identity of apoptotic cells. Either 1 or 40 kindling stimulations also gave rise to a marked increase of the number of cells double-labeled with the mitotic marker bromodeoxyuridine and NeuN in the subgranular zone and on the hilar border of the dentate granule cell layer. The present data show that single and intermittent, brief seizures induce both apoptotic death and proliferation of dentate gyrus neurons. We hypothesize that these processes, occurring early during epileptogenesis, are primary events in the development of hippocampal pathology in animals and possibly also in patients suffering from temporal lobe epilepsy.
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