RESUMEN
Glutaric acidaemia type I (GA I) is an inborn error of metabolism caused by a deficiency of glutaryl-CoA dehydrogenase (GCDH) and is characterized clinically by striatal degeneration that almost always occurs in early childhood. A murine knockout model of GA I has the organic aciduria seen in the human disorder, but this model does not develop striatal degeneration spontaneously. 3-Nitropropionic acid (3NP), a succinic dehydrogenase inhibitor with specificity for the striatum, was investigated as a potential initiator of striatal degeneration in GCDH-deficient mice. This study shows that GCDH-deficient mouse pups are more susceptible to 3NP than their wild-type littermates, and that all mouse pups are more sensitive to 3NP as infants than as adolescents and adults. Increased sensitivity to 3NP early in life may model the developmental window for the striatal damage observed in human GA I.
Asunto(s)
Encefalopatías Metabólicas Innatas/metabolismo , Glutaratos/metabolismo , Nitrocompuestos/toxicidad , Propionatos/toxicidad , Animales , Animales Recién Nacidos , Encéfalo/patología , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Glutaratos/orina , Humanos , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Enfermedades Neurodegenerativas/patología , Nitrocompuestos/farmacología , Propionatos/farmacologíaRESUMEN
OBJECTIVES: To determine if bilateral transplantation of embryonic mesencephalic dopamine cells into the putamen of patients with PD significantly affected their cognitive functioning when compared with patients receiving sham surgery and to examine the effect of age on cognitive performance after implantation. METHODS: Forty patients (19 women, 21 men; age 34 to 75 years) with idiopathic PD of at least 7 years' duration (mean 14 years) who had disabling motor signs despite optimal drug management were randomly assigned to tissue implants or sham craniotomies in a double-blind design. Neuropsychological tests assessing orientation, attention, language, verbal and visual memory, abstract reasoning, executive function, and visuospatial and construction abilities were administered before and 1 year after surgery. Treatment groups did not differ at baseline in demographic, neuropsychological, motor, depression, or levodopa equivalent measures. RESULTS: Postsurgical change in cognitive performance was not significantly different for real or sham surgery groups. Performance in both groups remained unchanged at follow-up for most measures. CONCLUSIONS: Embryonic dopamine producing neurons can be implanted safely into the putamen bilaterally without impairing cognition in patients with PD, but within the first year, improved cognition should not be expected.
Asunto(s)
Dopamina/metabolismo , Trasplante de Tejido Fetal , Neuronas/trasplante , Enfermedad de Parkinson/cirugía , Adulto , Anciano , Antiparkinsonianos/uso terapéutico , Terapia Combinada , Craneotomía , Progresión de la Enfermedad , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neuronas/metabolismo , Pruebas Neuropsicológicas , Enfermedad de Parkinson/diagnóstico por imagen , Enfermedad de Parkinson/tratamiento farmacológico , Enfermedad de Parkinson/psicología , Putamen , Tomografía Computarizada de Emisión , Insuficiencia del TratamientoAsunto(s)
Encéfalo/citología , Línea Celular , Embrión de Mamíferos/citología , Antígenos de Diferenciación , Genes Virales , Humanos , Neuroglía/citología , Neuronas/citología , Poliomavirus , ARN Mensajero/aislamiento & purificación , Virus 40 de los Simios , Transfección , Tirosina 3-Monooxigenasa/genéticaRESUMEN
Many central nervous system regions at all stages of life contain neural stem cells (NSCs). We explored how these disparate NSC pools might emerge. A traceable clone of human NSCs was implanted intraventricularly to allow its integration into cerebral germinal zones of Old World monkey fetuses. The NSCs distributed into two subpopulations: One contributed to corticogenesis by migrating along radial glia to temporally appropriate layers of the cortical plate and differentiating into lamina-appropriate neurons or glia; the other remained undifferentiated and contributed to a secondary germinal zone (the subventricular zone) with occasional members interspersed throughout brain parenchyma. An early neurogenetic program allocates the progeny of NSCs either immediately for organogenesis or to undifferentiated pools for later use in the "postdevelopmental" brain.
Asunto(s)
Movimiento Celular , Neocórtex/citología , Neocórtex/embriología , Neuronas/citología , Prosencéfalo/citología , Prosencéfalo/embriología , Células Madre/citología , Animales , Trasplante de Tejido Encefálico , Diferenciación Celular , Linaje de la Célula , Trasplante de Células , Células Clonales/citología , Células Clonales/trasplante , Humanos , Macaca radiata/embriología , Neuronas/trasplante , Trasplante de Células Madre , Trasplante HeterólogoRESUMEN
BACKGROUND: Transplantation of human embryonic dopamine neurons into the brains of patients with Parkinson's disease has proved beneficial in open clinical trials. However, whether this intervention would be more effective than sham surgery in a controlled trial is not known. METHODS: We randomly assigned 40 patients who were 34 to 75 years of age and had severe Parkinson's disease (mean duration, 14 years) to receive a transplant of nerve cells or sham surgery; all were to be followed in a double-blind manner for one year. In the transplant recipients, cultured mesencephalic tissue from four embryos was implanted into the putamen bilaterally. In the patients who received sham surgery, holes were drilled in the skull but the dura was not penetrated. The primary outcome was a subjective global rating of the change in the severity of disease, scored on a scale of -3.0 to 3.0 at one year, with negative scores indicating a worsening of symptoms and positive scores an improvement. RESULTS: The mean (+/-SD) scores on the global rating scale for improvement or deterioration at one year were 0.0+/-2.1 in the transplantation group and -0.4+/-1.7 in the sham-surgery group. Among younger patients (60 years old or younger), standardized tests of Parkinson's disease revealed significant improvement in the transplantation group as compared with the sham-surgery group when patients were tested in the morning before receiving medication (P=0.01 for scores on the Unified Parkinson's Disease Rating Scale; P=0.006 for the Schwab and England score). There was no significant improvement in older patients in the transplantation group. Fiber outgrowth from the transplanted neurons was detected in 17 of the 20 patients in the transplantation group, as indicated by an increase in 18F-fluorodopa uptake on positron-emission tomography or postmortem examination. After improvement in the first year, dystonia and dyskinesias recurred in 15 percent of the patients who received transplants, even after reduction or discontinuation of the dose of levodopa. CONCLUSIONS: Human embryonic dopamine-neuron transplants survive in patients with severe Parkinson's disease and result in some clinical benefit in younger but not in older patients.
Asunto(s)
Trasplante de Tejido Encefálico , Grupos Control , Trasplante de Tejido Fetal , Mesencéfalo/trasplante , Neuronas/trasplante , Enfermedad de Parkinson/cirugía , Adulto , Factores de Edad , Anciano , Encéfalo/metabolismo , Encéfalo/patología , Técnicas de Cultivo , Dihidroxifenilalanina/análogos & derivados , Dihidroxifenilalanina/farmacocinética , Dopamina/metabolismo , Método Doble Ciego , Femenino , Radioisótopos de Flúor/farmacocinética , Humanos , Masculino , Mesencéfalo/embriología , Persona de Mediana Edad , Neuronas/metabolismo , Enfermedad de Parkinson/clasificación , Enfermedad de Parkinson/patología , Índice de Severidad de la Enfermedad , Tomografía Computarizada de EmisiónRESUMEN
Fetal cell transplantation therapies are being developed for the treatment of a number of neurodegenerative disorders including Parkinson's disease [10-12,21,22,24,36,43]. Massive apoptotic cell death is a major limiting factor for the success of neurotransplantation. We have explored a novel protein kinase pathway for its role in apoptosis of dopamine neurons. We have discovered that inhibitors of p38 MAP kinase (the pyridinyl imidazole compounds: PD169316, SB203580, and SB202190) improve survival of rat dopamine neurons in vitro and after transplantation into hemiparkinsonian rats. In embryonic rat ventral mesencephalic cultures, serum withdrawal led to 80% loss of dopamine neurons due to increased apoptosis. Incubation of the cultures with p38 MAP kinase inhibitors at the time of serum withdrawal prevented dopaminergic cell death by inhibiting apoptosis. In the hemiparkinsonian rat, preincubation of ventral mesencephalic tissue with PD169316 prior to transplantation accelerated behavioral recovery and doubled the survival of transplanted dopamine neurons. We conclude that inhibitors of stress-activated protein kinases improve the outcome of cell transplantation by preventing apoptosis of neurons after grafting.
Asunto(s)
Trasplante de Tejido Encefálico , Supervivencia Celular/efectos de los fármacos , Dopamina/metabolismo , Supervivencia de Injerto/efectos de los fármacos , Proteínas Quinasas Activadas por Mitógenos/antagonistas & inhibidores , Neuronas/trasplante , Animales , Supervivencia Celular/fisiología , Células Cultivadas/citología , Células Cultivadas/efectos de los fármacos , Células Cultivadas/metabolismo , Inhibidores Enzimáticos/farmacología , Feto , Supervivencia de Injerto/fisiología , Imidazoles/farmacología , Masculino , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Trastornos Parkinsonianos/inducido químicamente , Trastornos Parkinsonianos/terapia , Piridinas/farmacología , Ratas , Ratas Sprague-Dawley , Recuperación de la Función/efectos de los fármacos , Recuperación de la Función/fisiología , Proteínas Quinasas p38 Activadas por MitógenosRESUMEN
To promote dopamine cell survival in human fetal tissue strands transplanted into immunosuppressed 6-OHDA-lesioned rats, we have preincubated tissue in insulin-like growth factor-I (IGF-I, 150 ng/ml) and basic fibroblast growth factor (bFGF, 15 ng/ml) in vitro for 2 weeks. Growth factor treatment did not affect the rate of homovanillic acid production in vitro but increased overall dopamine neuron survival in animals after transplant from 1240 +/- 250 to 2380 +/- 440 neurons (P < 0.05). Animals in the growth factor-treated group had a significantly greater reduction in methamphetamine-induced rotation (66%) compared to control transplants (30%, P < 0.05). We conclude that in vitro preincubation of human fetal tissue strands with IGF-I and bFGF improves dopamine cell survival and the behavioral outcome of transplants.
Asunto(s)
Trasplante de Tejido Encefálico/fisiología , Encéfalo/metabolismo , Trasplante de Tejido Fetal/fisiología , Factor 2 de Crecimiento de Fibroblastos/farmacología , Factor I del Crecimiento Similar a la Insulina/farmacología , Neuronas/citología , Trastornos Parkinsonianos/terapia , Aborto Inducido , Animales , Apomorfina/farmacología , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Modelos Animales de Enfermedad , Dopamina/metabolismo , Femenino , Ácido Homovanílico/metabolismo , Humanos , Masculino , Metanfetamina/farmacología , Actividad Motora/efectos de los fármacos , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Oxidopamina , Embarazo , Ratas , Ratas Sprague-Dawley , Rotación , Trasplante Heterólogo/fisiología , Tirosina 3-Monooxigenasa/metabolismoRESUMEN
Glutaric acid (GA) and 3-hydroxyglutaric acid (3GA) are thought to contribute to the degeneration of the caudate and putamen that is seen in some children with glutaric acidaemia type I, a metabolic disorder caused by a glutaryl-CoA dehydrogenase deficiency. This study assessed the neurotoxicity of GA and 3GA (0-50 mmol/L) compared to quinolinic acid (QUIN) in striatal and cortical cultures. All three acids were neurotoxic in a dose-dependent manner; however, GA and 3GA were both more toxic than QUIN. The neurotoxic effects of low concentrations of GA or 3GA were additive to QUIN toxicity. A series of hormones and growth factors were tested for protection against GA and 3GA toxicity. Insulin (5-500 microU /ml), basic fibroblast growth factor (bFGF; 10 ng/ml), insulin-like growth factor (IGF-1; 50 ng/ml), brain-derived neurotrophic factor (BDNF; 10 ng/ml), glial-derived neurotrophic factor (GDNF; 10 ng/ml), and two glutamate antagonists were evaluated in brain cultures to which 7 mmol/L GA or 3GA were added. GA and 3GA neurotoxicities were prevented by bFGF. Attenuation of 3GA-induced neurotoxicity was seen with insulin (5 microU/ml) and IGF-1. BDNF and GDNF had no effects on neuronal survival. Glutamate antagonists MK801 (10 micromol/L) and NBQX (10 micromol/L) failed to prevent GA or 3GA neurotoxicity. We conclude that GA and 3GA are neurotoxic in cultures of embryonic rat striatum and cortex. Striatal neurons were rescued from death by bFGF and IGF-1 but not by glutamate antagonist, suggesting that toxicity in this embryonic system is not necessarily mediated by glutamate receptors.
Asunto(s)
Factor 2 de Crecimiento de Fibroblastos/farmacología , Glutaratos/antagonistas & inhibidores , Glutaratos/toxicidad , Factor I del Crecimiento Similar a la Insulina/farmacología , Neostriado/efectos de los fármacos , Animales , Muerte Celular/efectos de los fármacos , Células Cultivadas , Corteza Cerebral/citología , Corteza Cerebral/efectos de los fármacos , Antagonistas de Aminoácidos Excitadores/farmacología , Sustancias de Crecimiento/farmacología , Concentración de Iones de Hidrógeno , Inmunohistoquímica , Insulina/farmacología , Masculino , Neostriado/citología , Degeneración Nerviosa/patología , Ácido Quinolínico/toxicidad , Ratas , Ratas Sprague-Dawley , Triptófano/metabolismoRESUMEN
OBJECTIVES: In patients with glutaric acidemia type 1 (GAI), biochemical and molecular markers fail to predict the course of individual patients; therefore we sought to identify nonbiochemical variables that correlate with severity of motor deficits or overall clinical outcome. STUDY DESIGN: Archival data was collected from 42 published articles describing 115 patients with GA1. A forward, stepwise, multiple regression analysis was used to find predictors for outcome. RESULTS: Analyses show that in patients who did not have a precipitating illness before the first appearance of motor symptoms, the age at onset was significantly associated with the severity of motor impairments and overall clinical outcome. In patients who had a precipitating illness, the age at onset did not predict the outcome. In both groups of patients, basal ganglia degeneration, enlargement of spaces containing cerebrospinal fluid, and white matter abnormalities were indicative of a poorer prognosis. Treatment given after the appearance of symptoms was not associated with a better clinical outcome or fewer motor deficits. CONCLUSION: Because the age at symptom onset can significantly predict the severity of motor deficits and the overall outcome, it is important to identify patients with GA1 as early as possible. Several studies suggest that presymptomatic treatment may prevent or postpone the onset of symptoms.
Asunto(s)
Errores Innatos del Metabolismo/fisiopatología , Enfermedades Neuromusculares/fisiopatología , Oxidorreductasas actuantes sobre Donantes de Grupo CH-CH , Oxidorreductasas/deficiencia , Edad de Inicio , Atrofia , Ganglios Basales/patología , Corteza Cerebral/patología , Preescolar , Progresión de la Enfermedad , Glutaril-CoA Deshidrogenasa , Humanos , Lactante , Errores Innatos del Metabolismo/epidemiología , Pronóstico , Análisis de Regresión , Índice de Severidad de la Enfermedad , Espacio Subaracnoideo/patologíaRESUMEN
Parkinson's disease (PD) is a neurodegenerative disorder characterized by the appearance of intracytoplasmic inclusions called Lewy bodies (LB) in dopamine neurons in the substantia nigra and the progressive loss of these neurons. Recently, mutations in the alpha-synuclein gene have been identified in early-onset familial PD, and alpha-synuclein has been shown to be a major component of LB in all patients. Yet, the pathophysiological function of alpha-synuclein remains unknown. In this report, we have investigated the toxic effects of adenovirus-mediated alpha-synuclein overexpression on dopamine neurons in rat primary mesencephalic cultures and in a rat dopaminergic cell line - the large T-antigen immortalized, mesencephalon-derived 1RB3AN27 (N27). Adenovirus-transduced cultures showed high-level expression of alpha-synuclein within the cells. Overexpression of human mutant alpha-synuclein (Ala(53)Thr) selectively induced apoptotic programmed cell death of primary dopamine neurons as well as N27 cells. The mutant protein also potentiated the neurotoxicity of 6-hydroxydopamine (6-OHDA). By contrast, overexpression of wild-type human alpha-synuclein was not directly neurotoxic but did increase cell death after 6-OHDA. Overexpression of wild-type rat alpha-synuclein had no effect on dopamine cell survival or 6-OHDA neurotoxicity. These results indicate that overexpression of human mutant alpha-synuclein directly leads to dopamine neuron death, and overexpression of either human mutant or human wild-type alpha-synuclein renders dopamine neurons more vulnerable to neurotoxic insults.
Asunto(s)
Apoptosis/fisiología , Dopamina/metabolismo , Mesencéfalo/metabolismo , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Neuronas/metabolismo , Adenoviridae/genética , Animales , Línea Celular Transformada , Embrión de Mamíferos , Técnicas de Transferencia de Gen , Humanos , Mesencéfalo/citología , Mutación/fisiología , Neuronas/citología , Neurotoxinas/farmacología , Oxidopamina/farmacología , Enfermedad de Parkinson/etiología , Enfermedad de Parkinson/fisiopatología , Ratas , Sinucleínas , alfa-SinucleínaRESUMEN
Extracts from skeletal muscle cell cultures have been shown to increase levels of the enzyme tyrosine hydroxylase (TH) and promote survival of different types of developing neurons in vitro. To determine the effect of muscle cell co-grafts on the survival of dopamine neurons in a rat model of Parkinson's disease, we transplanted an embryonic day (ED)-15 rat mesencephalic cell suspension alone or with neonatal muscle cells into 6-hydroxydopamine (6-OHDA) denervated rat striatum. In parallel experiments conducted in vitro, we cultured ED-15 rat mesencephalon or rat striatum in conditioned medium from neonatal rat muscle cultures (MC-CM). Our results showed that: (A) in vitro, MC-CM increased the number of TH-immunoreactive (TH-IR) neurons in embryonic mesencephalic cultures but did not induce expression of TH in embryonic striatal cultures; (B) in vivo, animals with co-grafts of muscle cells and ED-15 mesencephalon had more TH-IR in the grafted striatum compared to animals that received mesencephalic cells grafts alone, although the graft-induced reversal of circling behavior in response to methamphetamine was the same in both transplanted groups; and (C) grafts of muscle cells alone did not induce TH-IR in the denervated striatum and did not reduce methamphetamine-induced circling. These findings suggest that in vivo, neonatal muscle cells secrete factors that promote survival and/or outgrowth of fetal midbrain dopamine cells and improve the levels of TH-IR in grafted striatum.
Asunto(s)
Trasplante de Células , Trasplante de Tejido Fetal , Mesencéfalo/embriología , Músculo Esquelético/citología , Enfermedad de Parkinson/psicología , Enfermedad de Parkinson/cirugía , Animales , Animales Recién Nacidos , Encéfalo/metabolismo , Células Cultivadas , Cuerpo Estriado/citología , Cuerpo Estriado/embriología , Cuerpo Estriado/enzimología , Cuerpo Estriado/cirugía , Medios de Cultivo Condicionados/farmacología , Desnervación , Femenino , Histocitoquímica , Masculino , Mesencéfalo/citología , Mesencéfalo/efectos de los fármacos , Mesencéfalo/enzimología , Enfermedad de Parkinson/metabolismo , Ratas , Ratas Endogámicas F344 , Ratas Sprague-Dawley , Tirosina 3-Monooxigenasa/metabolismoRESUMEN
6-Hydroxydopamine (6-OHDA) causes selective degeneration of dopaminergic neurons in the rat brain and has been used to produce an animal model of Parkinsonism. Recently, a clonal line of immortalized dopamine (DA) neurons (1RB3AN27), which expresses varying levels of tyrosine hydroxylase, dopamine transporter, neuron specific enolase, and nestin, was established. These DA neurons reduce behavioral deficits in 6-OHDA-lesioned rats. The relative sensitivity of fetal and adult neurons to potential neurotoxins is not well defined. The availability of immortalized DA neurons provides a unique opportunity to compare the relative neurotoxicity of 6-OHDA in differentiated and undifferentiated DA neurons in vitro and identify neuroprotective agents. Our results showed that 6-OHDA treatment for 24 hr decreased the viability of undifferentiated and differentiated immortalized DA neurons in vitro, as determined by the MTT assay, and increased the rate of apoptosis in differentiated DA neurons. The differentiated DA neurons (IC50 = 33 microM) were about 2-fold more sensitive to 6-OHDA than undifferentiated DA neurons (IC50 = 75 microM) in cell culture. Similarly, the differentiated DA neurons were more sensitive to another neurotoxin, 1-methyl-4-phenylpyridinium (MPP+), which is commonly used to induce Parkinsonism in animal models, than were the undifferentiated DA neurons in culture. Among growth factors tested, only glial cell line-derived neurotrophic factor (GDNF) partially protected differentiated DA neurons against 6-OHDA-induced toxicity. These results suggest that undifferentiated and differentiated immortalized DA neurons can be a useful experimental model to study relative sensitivity to neurotoxins and neuroprotective agents that could have relevance to fetal and adult neurons.
Asunto(s)
1-Metil-4-fenilpiridinio/farmacología , Dopamina/fisiología , Sustancias de Crecimiento/farmacología , Factores de Crecimiento Nervioso , Neuronas/citología , Neuronas/fisiología , Fármacos Neuroprotectores/farmacología , Neurotoxinas/farmacología , Oxidopamina/farmacología , Animales , Apoptosis/efectos de los fármacos , Encéfalo/citología , Encéfalo/fisiología , Diferenciación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Células Clonales , Factor 2 de Crecimiento de Fibroblastos/farmacología , Factor Neurotrófico Derivado de la Línea Celular Glial , Factor I del Crecimiento Similar a la Insulina/farmacología , Proteínas del Tejido Nervioso/farmacología , Neuronas/efectos de los fármacos , Ratas , Proteínas Recombinantes/farmacologíaRESUMEN
Fetal striatal tissue transplants have been shown to restore motor deficits in rat and monkey models of Huntington's disease (HD). In the present study, using rats with unilateral striatal lesions, we compared fetal striatal tissue transplants to transplants of human NT (hNT) neurons. hNT neurons are terminally differentiated cells derived from the human NTera-2 cell line. In vitro, we have found that purified hNT neurons have a biochemical phenotype similar to that of human fetal striatal tissue. Both hNT neurons and fetal striatal tissue express mRNAs for glutamic acid decarboxylase, choline acetyltransferase, and the D1 and D2 dopamine receptors. Grafts of either hNT neurons or fetal striatal tissue into unilateral quinolinic acid-lesioned rat striatum improved methamphetamine-induced circling behavior. Sham controls showed no changes in methamphetamine-induced circling behavior. In the staircase test for skilled forelimb use, both transplant groups showed partial recovery in skilled use of the paw contralateral to the side of lesion, whereas the control animals showed continued deficits. These findings suggest that transplantation of hNT neurons may be an alternative to transplantation of fetal striatal tissue in the treatment of HD.
Asunto(s)
Cuerpo Estriado/cirugía , Trasplante de Tejido Fetal , Enfermedad de Huntington/cirugía , Neuronas/trasplante , Trasplante Heterólogo , Animales , Conducta Animal , Diferenciación Celular , Cuerpo Estriado/lesiones , Humanos , Enfermedad de Huntington/inducido químicamente , Neuronas/citología , Ratas , TeratocarcinomaRESUMEN
The autosomal dominant neurological syndrome of Huntington's disease has been modeled in transgenic mice by the expression of a portion of the human huntingtin gene together with 140 CAG repeats (the R6/2 strain). The mice develop progressive chorea with onset at approximately 9 weeks of age and with death at approximately 13 weeks. Associated symptoms include weight loss and polyuria in the absence of eating or drinking deficits. We have found that these mice have insulin-responsive diabetes. Fasting glucose was 211 + 19 mg/dl in R6/2 mice compared with 93 + 5 mg/dl in C57/B6 controls (n = 12, both groups; P < 0.01). Administration of insulin intraperitoneally led to a reduction in blood glucose. At 12.5 weeks, animals were killed and pancreas weighed and analyzed for insulin and glucagon. Pancreatic mass in R6/2 mice was the same as controls, and islets appeared normal in morphology without lymphocytic infiltration. Immunohistochemical staining showed dramatic reductions in glucagon in the alpha-cells and in insulin in the beta-cells. Direct tissue assays showed glucagon and insulin content were reduced to only 10 and 15% of controls, respectively. Diabetes has been reported as being more common in Huntington's disease and other triplet repeat disorders. The R6/2 mouse should prove useful for elucidating the mechanism of diabetes in these genetic diseases.
Asunto(s)
Diabetes Mellitus Tipo 1/genética , Enfermedad de Huntington/genética , Proteínas del Tejido Nervioso/genética , Proteínas Nucleares/genética , Repeticiones de Trinucleótidos , Envejecimiento , Animales , Glucemia/metabolismo , Cruzamientos Genéticos , Diabetes Mellitus Tipo 1/tratamiento farmacológico , Diabetes Mellitus Tipo 1/fisiopatología , Femenino , Glucagón/metabolismo , Humanos , Proteína Huntingtina , Enfermedad de Huntington/fisiopatología , Inmunohistoquímica , Insulina/metabolismo , Insulina/uso terapéutico , Islotes Pancreáticos/metabolismo , Islotes Pancreáticos/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos CBA , Ratones Transgénicos , Poliuria , Factores de TiempoRESUMEN
Since 1988, patients with Parkinson's disease have participated in clinical trials evaluating the efficacy of transplantation of human fetal dopamine cells into the caudate and putamen. Transplantation of fetal tissue leads to clinical benefits in some patients which is associated with a reduction of the amount of LDOPA administered. Major issues in transplant research need to be addressed before this technique can be widely applied. In this review, a pool of 35 patients was generated from the published cases of human fetal tissue transplantation. This group of transplant recipients was examined for motor improvement and reduction in L-DOPA dosage at one year post-transplant. Issues addressed in this review include the benefits of unilateral vs bilateral transplantation, age of the transplant recipient, solid vs suspensions of fetal mesencephalon and the number of fetal donors per recipient.
Asunto(s)
Trasplante de Tejido Encefálico , Trasplante de Tejido Fetal , Mesencéfalo/trasplante , Enfermedad de Parkinson/cirugía , Animales , Humanos , Mesencéfalo/embriologíaRESUMEN
Dopamine (DA) deficiency is one of the primary lesions in the pathogenesis of Parkinson disease (PD). Because of long-term toxicity of L-DOPA therapy, the grafting of fetal mesencephalic tissue containing dopamine neurons or homogeneous populations of DA neurons into striatum appears to be rational. Fetal tissue transplants have many problems which include legal (in some countries), ethical, paucity of tissue availability, heterogenicity of cell populations, and the presence of antigen-presenting cells that are responsible for rejection of allogeneic grafts. In order to resolve the above problems, we have established immortalized DA neurons from fetal rat mesencephalon by inserting the large T-antigen (LTa) gene of the SV40 virus into the cells. A clone of DA neurons (1RB3AN27) was isolated, characterized, and tested in 6-hydroxydopamine (6-OHDA)-lesioned rats (a model of PD). These cells divided with a doubling time of about 26 h, expressed the LTa gene, and contained the tyrosine hydroxylase and dopamine transporter proteins and their respective mRNAs, which became elevated upon differentiation. These cells were nontumorigenic and nonimmunogenic and improved the symptoms of neurological deficits (methamphetamine-induced rotation) in 6-OHDA-lesioned rats. The differentiated DA neurons were more effective than undifferentiated ones. These studies suggest that immortalized DA neurons generated in vitro by LTa gene insertion may be used in transplant therapy without fear of tumor formation or rejection.
Asunto(s)
Dopamina/biosíntesis , Trasplante de Tejido Fetal , Neuronas/trasplante , Enfermedad de Parkinson/terapia , Animales , Línea Celular Transformada , Modelos Animales de Enfermedad , Neuronas/metabolismo , Enfermedad de Parkinson/fisiopatología , RatasRESUMEN
The success of embryonic neural transplants as a treatment for patients with Parkinson's disease has been limited by poor survival of transplanted dopamine neurons. To see if a new partially intact tissue preparation method improves survival, we have developed a technique for extruding embryonic tissue into strands. We expected this method to reduce cell damage and improve transplant survival as well as provide improved tissue delivery. We have compared transplants of tissue strands with mechanically dispersed suspensions of embryonic day 15 rat ventral mesencephalon. Tissue from ventral mesencephalon was transplanted into a single site in dopamine denervated striatum of unilateral 6-hydroxydopamine (6-OHDA) lesioned rats. To evaluate the effects of striatal cografts and growth factors on dopamine cell survival, dispersed mesencephalic cells were cotransplanted with dispersed striatal cells. Another group had dispersed mesencephalic cells cotransplanted with striatal cells incubated in the cold for 2 h with glial cell line-derived neurotrophic factor (GDNF, 100 ng/ml), insulin-like growth factor-I (IGF-I, 1500 ng/ml), and basic fibroblast growth factor (bFGF, 150 ng/ml). Behavioral improvement was assessed monthly by changes in methamphetamine-induced rotational behavior. Animals were sacrificed after 3 months, and dopamine neurons were identified by tyrosine hydroxylase (TH) immunohistochemistry. Transplants of tissue strands produced better dopamine neuron survival and led to more robust behavioral restoration than did cell suspensions even when suspensions were supported with cografts of striatal cells or pretreatment with growth factors.
Asunto(s)
Trasplante de Células , Dopamina/metabolismo , Trasplante de Tejido Fetal/métodos , Mesencéfalo/embriología , Mesencéfalo/metabolismo , Enfermedad de Parkinson/cirugía , Animales , Conducta Animal/efectos de los fármacos , Conducta Animal/fisiología , Tamaño de la Célula/fisiología , Supervivencia Celular/fisiología , Supervivencia de Injerto/fisiología , Masculino , Mesencéfalo/citología , Metanfetamina/farmacología , Neuronas/citología , Neuronas/fisiología , Enfermedad de Parkinson/psicología , Ratas , Ratas Sprague-Dawley , Conducta Estereotipada/fisiologíaRESUMEN
Embryonic dopamine neurons survive poorly after transplant into models of Parkinson's disease, possibly due to programmed cell death (apoptosis). Apoptosis in cultured dopamine neurons can be reduced by growth factors such as glial cell line-derived neurotrophic factor (GDNF) or a combination of insulin-like growth factor-I (IGF-I) and basic fibroblast growth factor (bFGF). To improve the survival of dopamine neurons in grafts, strands of E15 rat ventral mesencephalon were pretreated with a combination of GDNF, IGF-I, and bFGF and then transplanted into 6-hydroxydopamine-lesioned rats. In control animals, only 32% of dopamine neuron profiles survived the first 24 h after transplant. Growth factor pretreatment increased survival to 49% on day 1. Growth factors reduced the apoptotic rate of transplanted cells, just as they had in the previous in vitro experiments. Apoptotic nuclear morphology was observed in the transplanted dopamine neurons. We conclude that the majority of transplanted dopamine neurons die in grafts within the first 24 h after transplant, most likely by an apoptotic mechanism. Prevention of apoptosis with anti-apoptotic agents may improve the viability of dopamine neurons grafted for Parkinson's disease.
Asunto(s)
Dopamina/fisiología , Trasplante de Tejido Fetal , Sustancias de Crecimiento/farmacología , Factores de Crecimiento Nervioso , Neuronas/efectos de los fármacos , Neuronas/fisiología , Animales , Apoptosis/efectos de los fármacos , Apoptosis/fisiología , Factor Neurotrófico Derivado del Encéfalo/farmacología , Supervivencia Celular/efectos de los fármacos , Factor Neurotrófico Derivado de la Línea Celular Glial , Factor I del Crecimiento Similar a la Insulina/farmacología , Masculino , Mesencéfalo/citología , Mesencéfalo/embriología , Mesencéfalo/trasplante , Proteínas del Tejido Nervioso/farmacología , Ratas/embriología , Ratas Sprague-Dawley , Factores de Tiempo , Tirosina 3-Monooxigenasa/metabolismoRESUMEN
Allogeneic transplantation for the therapy of human Parkinson's disease is being considered as a viable approach at several clinical centers worldwide. As an attempt to understand the basic biology of central nervous system (CNS) transplantation, our laboratory has developed an experimental nonhuman primate model for human Parkinson's disease and carried out preliminary studies directed at evaluating the potential pathology at the graft site. In addition, studies have been conducted to examine whether such transplantation procedures lead to specific and/or nonspecific immunologic sensitization of the host or results in generalized immunosuppression. Groups of rhesus macaques (Macaca mulatta) were either controls operated (n = 6), autografted with adrenal medullary and peripheral nerve tissue (n = 3), or allografted with fetal mesencephalic tissue (n = 6). Immunohistological studies demonstrated the presence of mononuclear cell infiltrates as early as 1 wk and up to 1 yr postoperatively, although the frequency of the infiltrating cells declined with time. The infiltrates consisted of variable numbers of cells which express CD2+, CD3+, CD4+, CD8+, CD19+, CD22+, CD25+, and CD68+. There appeared to be no difference in the frequency, kinetics, or phenotype of the infiltrating cells in operative controls compared with recipients of auto- or allografts. Tissue sections obtained postoperatively showed low levels of major histocompatibility complex (MHC) Class I antigens and no detectable level of MHC-Class II antigens in neural tissue. A small aliquot of tissue from the operative site was placed in vitro with media containing interleukin-2 (IL-2), which led to the exudation and growth of mononuclear cells that were predominantly CD4+ cells. Phenotypic studies of peripheral blood mononuclear cells (PBMC) from operative controls, auto- and allograft recipient monkeys performed at varying time periods postoperatively failed to show differences in the frequencies of subsets of T-cells, B-cells, NK-cells, or monocytes. Studies on aliquots of the same PBMC failed to show major functional differences in NK-cells, LAK cells, or response to polyclonal mitogens. Finally, recipients of allogeneic mesencephalic grafts failed to show evidence of donor-specific humoral or cellular sensitization. These data indicate that transplantation of autograft adrenal or allograft fetal mesencephalic tissues in the CNS of nonhuman primate did not induce detectable donor-specific sensitization nor nonspecific immunosuppression.