RESUMEN
OBJECTIVES: To compare hospital admission rates for all causes and specific causes of injury in children and the elderly by a measure of economic deprivation. STUDY DESIGN: All emergency admissions for Welsh residents from 1997-99 were located to one of 865 electoral tracts, which were grouped into fifths using a measure of socioeconomic deprivation. Standardised admission rates for all ages and 0-14, 15-75, and 75+ year groups for each quintile were calculated with 95% confidence intervals. RESULTS: There were 90 935 admissions in a population of 2.84 million yielding a crude admission rate of 1601/100 000/year and a standardised rate of 1493/100 000. The ratio of admissions in deprived and affluent areas varied with category of injury and age group. In general, socioeconomic variations in injury rates were much smaller in older people than in children with the exception of pedestrian related injuries where the rates were similar. The largest variations were for injuries sustained in assaults or self inflicted. CONCLUSIONS: The relationship between socioeconomic position and injury varies by cause and age group. This should be considered when developing area based preventive interventions or monitoring the effectiveness of policies to reduce inequalities in injury occurrence.
Asunto(s)
Hospitalización/estadística & datos numéricos , Heridas y Lesiones/epidemiología , Adolescente , Adulto , Distribución por Edad , Anciano , Niño , Preescolar , Intervalos de Confianza , Humanos , Lactante , Persona de Mediana Edad , Factores Socioeconómicos , Gales/epidemiologíaRESUMEN
The lack of supply and access to human tissue has prompted the development of xenotransplantation as a potential clinical modality for neural cell transplantation. The goal of the present study was to achieve a better understanding of the immune factors involved in neural xenograft rejection in primates. Initially, we quantified complement mediated cell lysis of porcine fetal neurons by primate serum and demonstrated that anti-C5 antibody treatment inhibited cell death. We then developed an immunosuppression protocol that included in vivo anti-C5 monoclonal antibody treatment, triple drug therapy (cyclosporine, methylprednisolone, azathioprine) and donor tissue derived from CD59 or H-transferase transgenic pigs and applied it to pig-to-primate neural cell transplant models. Pre-formed alphaGal, induced alphaGal and primate anti-mouse antibody (PAMA) titers were monitored to assess the immune response. Four primates were transplanted. The three CD59 neural cell recipients showed an induced anti-alphaGal response, whereas the H-transferase neural cell recipient exhibited consistently low anti-alphaGal titers. Two of these recipients contained surviving grafts as detected by immunohistochemistry using selected neural markers. Graft survival correlated with high dose cyclosporine treatment, complete complement blockade and the absence of an induced PAMA response to the murine anti-C5 monoclonal antibodies.
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Trasplante de Tejido Encefálico , Trasplante de Tejido Fetal , Supervivencia de Injerto/inmunología , Trasplante Heterólogo/inmunología , Animales , Animales Modificados Genéticamente , Anticuerpos Monoclonales/farmacología , Antígenos CD59/genética , Antígenos CD59/inmunología , Activación de Complemento/inmunología , Complemento C5/inmunología , Fucosiltransferasas/genética , Fucosiltransferasas/inmunología , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Terapia de Inmunosupresión , Macaca fascicularis , Macaca mulatta , Trastornos Parkinsonianos/cirugía , PorcinosRESUMEN
Embryonic neurons transplanted to the adult CNS extend axons only for a developmentally defined period. There are certain intercellular factors that control the axonal extension, one of which may be the expression of the bcl-2 protein. In this study, rats with complete striatal dopamine fiber denervation received embryonic day 14 mouse ventral mesencephalon cells overexpressing human bcl-2 or control wild-type ventral mesencephalon cells. All rats were treated with cyclosporine to prevent rejection and the surviving grafts were analyzed for cell survival and outgrowth of dopaminergic fibers. The results demonstrate that bcl-2 overexpression does not enhance neuronal graft survival. However, the bcl-2 overexpressing neurons had a higher number of dopaminergic fibers that grew longer distances. These results show that overexpression of bcl-2 can result in longer distance axonal growth of transplanted fetal dopaminergic neurons and that genetic modification of embryonic donor cells may enhance their ability to reinnervate a neuronal target territory.
Asunto(s)
Trasplante de Tejido Encefálico/métodos , Dopamina/metabolismo , Supervivencia de Injerto/genética , Conos de Crecimiento/trasplante , Neostriado/cirugía , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Sustancia Negra/trasplante , Animales , Células Cultivadas , Desnervación , Femenino , Feto , Conos de Crecimiento/metabolismo , Conos de Crecimiento/ultraestructura , Humanos , Masculino , Ratones , Ratones Transgénicos , Neostriado/patología , Neostriado/fisiopatología , Oxidopamina , Enfermedad de Parkinson/metabolismo , Enfermedad de Parkinson/fisiopatología , Enfermedad de Parkinson/cirugía , Fenotipo , Proteínas Proto-Oncogénicas c-bcl-2/genética , Ratas , Ratas Sprague-Dawley , Sustancia Negra/citología , Sustancia Negra/metabolismoRESUMEN
Neural and stem cell transplantation is emerging as a potential treatment for neurodegenerative diseases. Transplantation of specific committed neuroblasts (fetal neurons) to the adult brain provides such scientific exploration of these new potential therapies. Huntington's disease (HD) is a fatal, incurable autosomal dominant (CAG repeat expansion of huntingtin protein) neurodegenerative disorder with primary neuronal pathology within the caudate-putamen (striatum). In a clinical trial of human fetal striatal tissue transplantation, one patient died 18 months after transplantation from cardiovascular disease, and postmortem histological analysis demonstrated surviving transplanted cells with typical morphology of the developing striatum. Selective markers of both striatal projection and interneurons such as dopamine and c-AMP-related phosphoprotein, calretinin, acetylcholinesterase, choline acetyltransferase, tyrosine hydroxylase, calbindin, enkephalin, and substance P showed positive transplant regions clearly innervated by host tyrosine hydroxylase fibers. There was no histological evidence of immune rejection including microglia and macrophages. Notably, neuronal protein aggregates of mutated huntingtin, which is typical HD neuropathology, were not found within the transplanted fetal tissue. Thus, although there is a genetically predetermined process causing neuronal death within the HD striatum, implanted fetal neural cells lacking the mutant HD gene may be able to replace damaged host neurons and reconstitute damaged neuronal connections. This study demonstrates that grafts derived from human fetal striatal tissue can survive, develop, and are unaffected by the disease process, at least for 18 months, after transplantation into a patient with HD.
Asunto(s)
Cuerpo Estriado/trasplante , Trasplante de Tejido Fetal , Enfermedad de Huntington/terapia , Humanos , Enfermedad de Huntington/inmunología , Enfermedad de Huntington/patología , Inmunohistoquímica , Masculino , Persona de Mediana Edad , FenotipoRESUMEN
Our understanding of speech and language disorders may be aided by information about the constraints and predispositions contributed by neural developmental processes. As soon as we begin to look at human neuroanatomy and development from a comparative perspective, it is possible to recognize a number of ways that human brains diverge from the general pattern of other ape and monkey brains. These divergences may offer clues to language evolution. Large-scale quantitative changes in the relative proportions of brain regions (as opposed to just overall expansion) offer some of the most obvious clues. Additional information about how axons are guided in their extensions to distant developmental targets and how competitive trophic processes sculpt these connections also provides a way to understand how gross quantitative changes in cell numbers could affect circuit organization and ultimately behavior.
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Evolución Biológica , Encéfalo/fisiología , Lenguaje , Plasticidad Neuronal/fisiología , Animales , Encéfalo/anatomía & histología , Humanos , Red Nerviosa/fisiologíaRESUMEN
The anatomical specificity of axon growth from fetal pig septal xenografts was studied by transplanting septal cells from E30-35 pig fetuses into cholinergic deafferented (192-IgG-saporin-infused) rats or into aged rats (> 18 months). Cell suspensions (100,000 cells/microl) were injected bilaterally into the dorsal and ventral hippocampus of immunosuppressed rats (10 mg/kg/day cyclosporine A). To assess axonal growth and synapse formation, acetylcholinesterase histochemistry, an antibody to choline acetyltransferase (ChAT), and three pig-positive/rat-negative antibodies: bovine 70kD neurofilament (NF70), human low-affinity NGF receptor (hNGFr), and human synaptobrevin (hSB) were used. In rats with surviving grafts at 6 months, NF70 axonal labeling was more extensive than either ChAT or hNGFr labeling. All three markers demonstrated graft axons extending selectively through the hippocampal CA fields and the molecular layer of the dentate gyrus. Graft axons did not extend into adjacent entorhinal cortex or neocortex. The distribution of pig hSB-positive synapses correlated with AChE-positive fiber outgrowth in to the host. Electron microscopic analysis of hSB-immunostained hippocampal sections revealed pig presynaptic terminals in contact with normal rat postsynaptic structures in the CA fields and the dentate gyrus. These data demonstrate target-appropriate growth of pig cholinergic axons and the formation of cross-species synapses in the deafferented or aged rat hippocampus.
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Trasplante de Tejido Encefálico , Trasplante de Tejido Fetal , Hipocampo/cirugía , Inmunotoxinas , N-Glicosil Hidrolasas , Tabique Pelúcido/trasplante , Trasplante Heterólogo , Vías Aferentes/efectos de los fármacos , Factores de Edad , Animales , Axones , Fibras Colinérgicas/efectos de los fármacos , Femenino , Proteínas de Plantas/farmacología , Ratas , Ratas Sprague-Dawley , Proteínas Inactivadoras de Ribosomas Tipo 1 , Saporinas , Tabique Pelúcido/citología , Porcinos , SinapsisRESUMEN
Adults rats were lesioned with 192-IgG-saporin, an immunotoxin that targets cholinergic neurons in the basal forebrain expressing the low-affinity nerve growth factor receptor (p75). One month later, rats received E30-35 porcine cholinergic neurons bilaterally into the hippocampus, and were tested in the Morris water maze and the passive avoidance task 4.5-6 months after transplantation (in two experiments, rats were retested in the water maze) followed by histological and cellular analyses. The 192-IgG-saporin-lesioned animals displayed clear cognitive deficits in the Morris water maze. In all experiments the lesioned animals had spatial probe deficits on day 5 testing. A large variance was found among the transplanted animals, with individual animals exhibiting improved performance, but little overall improvement when compared to lesion-alone animals as a group. The relationships between behavioral performance and graft cholinergic factors were established by histological analyses. Grafted animals exhibited an increase in cholinergic innervation of the dentate gyrus (DG) region of the dorsal hippocampus when compared to lesion-alone animals. There was a significant correlation between the level of cholinergic innervation in the dentate gyrus and spatial navigation performance (latency and spatial probe) in the Morris water maze task. These data provide evidence of memory and spatial deficits following cholinergic denervation, and of target-specific growth of xenogeneic cholinergic neurons into the hippocampus. The lack of a clear treatment (transplant) effect in the behavioral measures leads us to believe that functional restoration of cognitive function would require cholinergic reinnervation of both the hippocampus and the neocortex in this 192-IgG-saporin animal model.
Asunto(s)
Trasplante de Tejido Encefálico , Fibras Colinérgicas/trasplante , Trasplante de Tejido Fetal , Hipocampo/cirugía , Trastornos de la Memoria/cirugía , Tabique Pelúcido/trasplante , Acetilcolina/metabolismo , Animales , Anticuerpos Monoclonales/farmacología , Reacción de Prevención , Colinérgicos/farmacología , Giro Dentado/citología , Inmunotoxinas/farmacología , Aprendizaje por Laberinto , N-Glicosil Hidrolasas , Neuronas/trasplante , Prosencéfalo/efectos de los fármacos , Ratas , Proteínas Inactivadoras de Ribosomas Tipo 1 , Saporinas , PorcinosRESUMEN
We used brain imaging to study long-term neurodegenerative and bioadaptive neurochemical changes in a primate model of Parkinson disease. We gradually induced a selective loss of nigrostriatal dopamine neurons, similar to that of Parkinson disease, by creating oxidative stress through infusion of the mitochondrial complex 1 inhibitor MPTP for 14+/-5 months. Repeated evaluations over 3 years by positron emission tomography (PET) demonstrated progressive and persistent loss of neuronal dopamine pre-synaptic re-uptake sites; repeated magnetic resonance spectroscopy (MRS) studies indicated a 23-fold increase in lactate and macromolecules in the striatum region of the brain for up to 10 months after the last administration of MPTP. By 2 years after the MPTP infusions, these MRS striatal lactate and macromolecule values had returned to normal levels. In contrast, there were persistent increases in striatal choline and decreases in N-acetylaspartate. Thus, these combined PET/MRS studies demonstrate patterns of neurochemical changes that are both dynamic and persistent long after selective dopaminergic degeneration.
Asunto(s)
Encéfalo/fisiopatología , Enfermedad de Parkinson Secundaria/fisiopatología , 1-Metil-4-fenil-1,2,3,6-Tetrahidropiridina , Animales , Encéfalo/diagnóstico por imagen , Encéfalo/patología , Radioisótopos de Carbono , Cuerpo Estriado/diagnóstico por imagen , Cuerpo Estriado/metabolismo , Cuerpo Estriado/patología , Modelos Animales de Enfermedad , Dopamina/metabolismo , Lactatos/metabolismo , Macaca fascicularis , Espectroscopía de Resonancia Magnética , Degeneración Nerviosa/patología , Neuronas/patología , Neuronas/fisiología , Enfermedad de Parkinson Secundaria/diagnóstico por imagen , Enfermedad de Parkinson Secundaria/patología , Tomografía Computarizada de EmisiónRESUMEN
Protection or regeneration of the dopaminergic (DA) system would be of significant therapeutic value for Parkinson's disease. Immunophilin ligands, such as FK506, can produce neurotrophic effects in vitro and in vivo, but their immunosuppressive effects make them unsuitable for neurological application. This study demonstrates that a novel, nonimmunosuppressive immunophilin ligand (V-10,367) increased the number of neurites extended by tyrosine hydroxylase positive (TH+) DA neurons in embryonic day 14 primary DA neuronal cultures. In contrast, the immunosuppressive immunophilin ligand FK506 increased the length of TH+ neurites. After oral administration in MPTP-treated mice, V-10,367 completely protected against MPTP-induced loss of striatal TH+ axonal density, while FK506 did not. These experiments demonstrate that nonimmunosuppressive immunophilin ligands specifically increase neurite branching in primary DA neuronal culture and possess neurotrophic actions in vivo with potential application to neurodegenerative disease.
Asunto(s)
Dopamina/fisiología , Inmunofilinas/metabolismo , Neuronas/fisiología , Enfermedad de Parkinson/tratamiento farmacológico , Piridinas/metabolismo , Piridinas/farmacología , Administración Oral , Animales , Células Cultivadas , Cuerpo Estriado/efectos de los fármacos , Cuerpo Estriado/enzimología , Modelos Animales de Enfermedad , Inmunosupresores/farmacología , Ligandos , Intoxicación por MPTP , Masculino , Ratones , Ratones Endogámicos C57BL , Fibras Nerviosas/efectos de los fármacos , Fibras Nerviosas/enzimología , Neuritas/efectos de los fármacos , Neuritas/fisiología , Neuronas/efectos de los fármacos , Enfermedad de Parkinson/patología , Piridinas/administración & dosificación , Ratas , Ratas Sprague-Dawley , Tirosina 3-Monooxigenasa/metabolismoRESUMEN
Alzheimer's disease (AD) is the most common neurodegenerative disorder that causes cognitive deficits in the elderly. Its neuropathology is characterized by amyloid deposition and specific cholinergic degeneration. To address the link between amyloid formation and cholinergic loss, we examined histologically the amyloid precursor protein (APP) changes following selective immunolesion of the basal forebrain cholinergic system with 192 IgG-saporin in rats at 6 months post-lesion. In such rats with cognitive deficits observed in Morris water maze tests, we found increased levels of APP by optical density measurements in regions of cholinergic denervation. APP elevation and performance in the water maze task correlate with reduction of acetyl-cholinesterase (AChE) activity in the frontal cortex and CA3 subfield of hippocampus. The data indicate that loss of cholinergic innervation can affect APP expression.
Asunto(s)
Acetilcolinesterasa/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Trastornos del Conocimiento/metabolismo , Prosencéfalo/metabolismo , Análisis de Varianza , Animales , Enfermedad Crónica , Femenino , Aprendizaje por Laberinto/fisiología , Ratas , Ratas Sprague-DawleyRESUMEN
In order to assess the potential of embryonic stem cells to undergo neuronal differentiation in vivo, totipotent stem cells from mouse blastocysts (D3 and E14TG2a; previously expanded in the presence of leukemia inhibitory factor) were transplanted, with or without retinoic acid pretreatment, into adult mouse brain, adult lesioned rat brain, and into the mouse kidney capsule. Intracerebral grafts survived in 61% of cyclosporine immunosuppressed rats and 100% of mouse hosts, exhibited variable size and morphology, and both intracerebral and kidney capsule grafts developed large numbers of cells exhibiting neuronal morphology and immunoreactivity for neurofilament, neuron-specific enolase, tyrosine hydroxylase (TH), 5-hydroxytryptamine (5-HT), and cells immunoreactive for glial fibrillary acidic protein. Though graft size and histology were variable, typical grafts of 5-10 mm3 contained 10-20,000 TH+ neurons, whereas dopamine-beta-hydroxylase+ cells were rare. Most grafts also included nonneuronal regions. In intracerebral grafts, large numbers of astrocytes immunoreactive for glial fibrillary acidic protein were present. Both TH+ and 5-HT+ axons from intracerebral grafts grew into regions of the dopamine-lesioned host striatum. TH+ axons grew preferentially into striatal gray matter, while 5-HT+ axons showed no white/gray matter preference. These findings demonstrate that transplantation to the brain or kidney capsule can induce a significant fraction of totipotent embryonic stem cells to become putative dopaminergic or serotonergic neurons and that when transplanted to the brain these neurons are capable of innervating the adult host striatum.
Asunto(s)
Blastocisto/citología , Dopamina/metabolismo , Neuronas/metabolismo , Serotonina/metabolismo , Trasplante de Células Madre , Células Madre/citología , Animales , Axones/metabolismo , Axones/fisiología , Monoaminas Biogénicas/metabolismo , Encéfalo/citología , Encéfalo/cirugía , Diferenciación Celular/fisiología , Riñón/cirugía , Ratones/embriología , Neuroglía/citología , Neuroglía/metabolismo , Neuronas/citología , Periodo Posoperatorio , Ratas , Ratas Sprague-Dawley , Trasplante HeterotópicoRESUMEN
Basic research using cell transplantation indicates that structural developmental mechanisms seen in immature brains can also function in the adult brain. As the brain matures, cellular migration and axonal growth is impeded. However, fetal neural transplantation studies have shown that directional cues are available for fetal axons to find specific host neurons in the adult brain. By reaching specific and distant CNS target zones, donor tissue with extended axonal growth periods demonstrate both an abundance and specificity of CNS neurotropic signals. The presence of specific guidance cues, despite strong inhibition of regenerative long-distance axonal growth, suggests that these cues play other physiological roles in the adult CNS, and could be utilized therapeutically for reconnection of neuronal pathways.
Asunto(s)
Trasplante de Tejido Encefálico/fisiología , Encéfalo/fisiología , Regeneración Nerviosa/fisiología , Adulto , Animales , Trasplante de Células/fisiología , Trasplante de Tejido Fetal/fisiología , HumanosRESUMEN
The movement disorder in Parkinson's disease results from the selective degeneration of a small group of dopaminergic neurons in the substantia nigra pars compacta region of the brain. A number of exploratory studies using human fetal tissue allografts have suggested that transplantation of dopaminergic neurons may become an effective treatment for patients with Parkinson's disease and the difficulty in obtaining human fetal tissue has generated interest in finding corresponding non-human donor cells. Here we report a post-mortem histological analysis of fetal pig neural cells that were placed unilaterally into the caudate-putamen brain region of a patient suffering from Parkinson's disease. Long-term (over seven months) graft survival was found and the presence of pig dopaminergic neurons and other pig neural and glial cells is documented. Pig neurons extended axons from the graft sites into the host brain. Furthermore, other graft derived cells were observed several millimeters from the implantation sites. Markers for human microglia and T-cells showed only low reactivity in direct proximity to the grafts. This is the first documentation of neural xenograft survival in the human brain and of appropriate growth of non-human dopaminergic neurons for a potential therapeutic response in Parkinson's disease.
Asunto(s)
Trasplante de Tejido Fetal , Neuronas/trasplante , Enfermedad de Parkinson/terapia , Anciano , Animales , Supervivencia de Injerto , Humanos , Masculino , Porcinos , Trasplante HeterólogoRESUMEN
The presence and specificity of axon guidance cues in the mature brain were examined by transplanting several types of xenogeneic neural cells from fetal pig brains into adult rat brains with selective neuronal loss. Committed neuronal phenotypes from cortical, mesencephalic and striatal fetal regions were implanted in homotopic or ectopic central nervous system locations. Using specific neurofilament and neural markers, axonal target selection by transplanted fetal neurons was determined throughout the central nervous system. Different types of donor neurons grew axons specifically to appropriate adjacent and distant host brain regions from ectopic or homotopic brain implantation sites and independent of the pattern of prior selective neuronal loss. Since the fetal donor neurons could orient axonal growth towards their normal synaptic termination zones, it shows that the adult brain also elaborates highly specific signals for axon guidance. These results obtained by xenotransplantation also demonstrate that the adult brain exhibits a latent potential for long-distance axon guidance that is evolutionarily conserved. These and related studies indicate that the necessary processes for connection of specific neurocircuitry also exist in the adult central nervous system, if axonal growth inhibition is overcome.
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Axones/fisiología , Trasplante de Tejido Encefálico/fisiología , Fibroblastos/trasplante , Regeneración Nerviosa/fisiología , Animales , Trasplante de Células , Ratas , Ratas Sprague-DawleyRESUMEN
Neurotransplantation of human fetal dopamine (DA) neurons is currently being investigated as a therapeutic modality for Parkinson's disease (PD). However, the practical limitations of human fetal transplantation indicate a need for alternative methodologies. Using the 6-hydroxydopamine rat model of PD, we transplanted dopaminergic neurons derived from Embryonic Day 27 porcine fetuses into the denervated striatum of cyclosporine-A (CyA)-treated or non-CyA-treated rats. Functional recovery was assessed by amphetamine-induced rotation, and graft survival and morphology were analyzed using neuronal and glial immunostaining as well as in situ hybridization with a porcine repeat element DNA probe. A significant, sustained reduction in amphetamine-induced rotational asymmetry was present in the CyA-treated rats whereas the non-CyA-treated rats showed a transient behavioral recovery. The degree of rotational recovery was highly correlated to the number of surviving transplanted porcine dopaminergic neurons. TH+ neuronal survival and graft volume were significantly greater in the CyA-treated group as compared to the non-CyA group. By donor-specific neuronal and glial immunostaining as well as donor-specific DNA labeling, we demonstrate that porcine fetal neuroblasts are able to survive in the adult brain of immunosuppressed rats, mediate functional recovery, and extensively reinnervate the host striatum. These findings suggest that porcine DA neurons may be a suitable alternative to the use of human fetal tissue in neurotransplantation for PD.
Asunto(s)
Trasplante de Tejido Encefálico , Mesencéfalo/trasplante , Trasplante Heterólogo , Animales , Ciclosporina/farmacología , Modelos Animales de Enfermedad , Femenino , Enfermedad de Parkinson/terapia , Ratas , Ratas Sprague-Dawley , Porcinos , Factores de TiempoAsunto(s)
Trasplante de Tejido Encefálico/inmunología , Supervivencia de Injerto , Antígenos de Histocompatibilidad Clase I/inmunología , Fragmentos Fab de Inmunoglobulinas/uso terapéutico , Neuronas/trasplante , Trasplante Heterólogo/inmunología , Animales , Ciclofosfamida/uso terapéutico , Femenino , Trasplante de Tejido Fetal/inmunología , Edad Gestacional , Terapia de Inmunosupresión/métodos , Masculino , Embarazo , Ratas , Ratas Sprague-Dawley , PorcinosRESUMEN
The controlled differentiation of mouse embryonic stem (ES) cells into near homogeneous populations of both neurons and skeletal muscle cells that can survive and function in vivo after transplantation is reported. We show that treatment of pluripotent ES cells with retinoic acid (RA) and dimethylsulfoxide (DMSO) induce differentiation of these cells into highly enriched populations of gamma-aminobutyric acid (GABA) expressing neurons and skeletal myoblasts, respectively. For neuronal differentiation, RA alone is sufficient to induce ES cells to differentiate into neuronal cells that show properties of postmitotic neurons both in vitro and in vivo. In vivo function of RA-induced neuronal cells was demonstrated by transplantation into the quinolinic acid lesioned striatum of rats (a rat model for Huntington's disease), where cells integrated and survived for up to 6 wk. The response of embryonic stem cells to DMSO to form muscle was less dramatic than that observed for RA. DMSO-induced ES cells formed mixed populations of muscle cells composed of cardiac, smooth, and skeletal muscle instead of homogeneous populations of a single muscle cell type. To determine whether the response of ES cells to DMSO induction could be further controlled, ES cells were stably transfected with a gene coding for the muscle-specific regulatory factor, MyoD. When induced with DMSO, ES cells constitutively expressing high levels of MyoD differentiated exclusively into skeletal myoblasts (no cardiac or smooth muscle cells) that fused to form myotubes capable of spontaneous contraction. Thus, the specific muscle cell type formed was controlled by the expression of MyoD. These results provided evidence that the specific cell type formed (whether it be muscle, neuronal, or other cell types) can be controlled in vitro. Further, these results demonstrated that ES cells can provide a source of multiple differentiated cell types that can be used for transplantation.
Asunto(s)
Interleucina-6 , Trasplante de Células Madre , Animales , Northern Blotting , Diferenciación Celular/efectos de los fármacos , Diferenciación Celular/fisiología , Línea Celular , Dimetilsulfóxido/farmacología , Trasplante de Tejido Fetal , Feto/citología , Técnica del Anticuerpo Fluorescente , Regulación del Desarrollo de la Expresión Génica/efectos de los fármacos , Inhibidores de Crecimiento/farmacología , Factor Inhibidor de Leucemia , Linfocinas/farmacología , Ratones , Músculo Esquelético/citología , Músculo Esquelético/embriología , Proteína MioD/genética , Neuronas/citología , Neuronas/trasplante , Regiones Promotoras Genéticas/efectos de los fármacos , Regiones Promotoras Genéticas/fisiología , Ratas , Ratas Sprague-Dawley , Células Madre/química , Células Madre/citología , Transfección , Tretinoina/farmacología , Ácido gamma-Aminobutírico/análisis , Ácido gamma-Aminobutírico/fisiologíaRESUMEN
Clinical trials are under way using fetal cells to repair damaged neuronal circuitry. However, little is known about how transplanted immature neurons can grow anatomically correct connections in the adult central nervous system (CNS). We transplanted embryonic porcine neural cells in vivo into adult rat brains with neuronal and axonal loss typical of Parkinson's or Huntington's disease. Using complementary species-specific cellular markers, we found donor axons and CD44+ astroglial fibres in host white matter tracts up to 8 mm from CNS transplant sites, although only donor axons were capable of reaching correct gray matter target regions. This work demonstrates that adult host brain can orient growth of transplanted neurons and that there are differences in transplant donor glial and axonal growth patterns in cellular repair of the mature CNS.
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Axones/ultraestructura , Enfermedades de los Ganglios Basales/cirugía , Encéfalo/citología , Neuroglía/citología , Neuronas/trasplante , Trasplante Heterólogo , Animales , Biomarcadores/análisis , Encéfalo/patología , Encéfalo/cirugía , Células Cultivadas , Modelos Animales de Enfermedad , Enfermedad de Huntington/cirugía , Inmunohistoquímica , Masculino , Enfermedad de Parkinson/cirugía , Ratas , Ratas Sprague-Dawley , PorcinosRESUMEN
Axonal growth from cortically placed fetal neural transplants to subcortical targets in adult hosts has been difficult to demonstrate and is assumed to be minimal; however, experiments using xenogeneic neural grafts of either human or porcine fetal tissues into the adult rat striatum, mesencephalon, and spinal cord have demonstrated the capability for long-distance axonal growth. This study reports similar results for porcine cortical xenografts placed in the adult rat cerebral cortex and compares these findings with results from cortical allografts. Adult rats that previously received unilateral cortical lesions by an oblique intracortical stereotaxic injection of quinolinic acid, were implanted with suspensions of either E14 rat or E38 xenogeneic porcine fetal cortical cells. Xenografted rats were immunosuppressed by cyclosporin A. The corpus callosum was intact in all cases and grafts were confined to the overlying cortex. After a 31-34 wk posttransplant survival period, acetylcholinesterase (AChE) staining and tyrosine hydroxylase (TH) immunocytochemistry revealed that both allo- and xenografts received host afferents. Retrograde tracer injections into the ipsilateral striatum and cerebral peduncle in allografted animals failed to show any axonal growth to either subcortical target. Using a porcine-specific axonal marker in xenografted animals, we found graft axons in white matter tracts (corpus callosum, internal capsule, cingulum bundle, and medial forebrain bundle) and within the caudate-putamen and both the ipsilateral and contralateral cerebral cortex. Graft axons were not found in the thalamus, midbrain, or spinal cord. In addition, using an antibody to porcine glial fibers, we observed more extensive graft glial fiber growth into the same host fiber tracts, as far caudally as the cerebral peduncle, but not into gray matter targets outside the cortex. These results demonstrate that porcine cortical xenograft axons and glia can extend from lesioned cerebral cortex to cortical and subcortical targets in the adult rat brain. These findings are relevant for prospects of repairing cortical damage and obtaining functional recovery.