Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Stem Cell Res ; 69: 103083, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37003180

RESUMO

Mutations in tubulin alpha 4a (TUBB4A) result in a spectrum of leukodystrophies, including Hypomyelination with atrophy of basal ganglia and cerebellum (H-ABC), resulting from a recurring mutation p.Asp249Asn (TUBB4AD249N). H-ABC presents with dystonia, motor and cognitive impairment and pathological features of hypomyelination and loss of cerebellar and striatal neurons. We have generated three induced pluripotent stem cell (iPSC) lines from fibroblast and peripheral blood mononuclear cells (PBMCs) of individuals with TUBB4AD249N mutation. The iPSCs were assessed to confirm a normal karyotype, pluripotency, and trilineage differentiation potential. The iPSCs will allow for disease modeling, understanding mechanisms and testing of therapeutic targets.


Assuntos
Células-Tronco Pluripotentes Induzidas , Humanos , Atrofia/patologia , Gânglios da Base/metabolismo , Gânglios da Base/patologia , Cerebelo/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Leucócitos Mononucleares/metabolismo , Mutação/genética , Fenótipo , Tubulina (Proteína)/genética , Tubulina (Proteína)/metabolismo
2.
Proc Natl Acad Sci U S A ; 119(13): e2107391119, 2022 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-35312356

RESUMO

Connexin 43 (Cx43) gap junctions and hemichannels mediate astrocyte intercellular communication in the central nervous system under normal conditions and contribute to astrocyte-mediated neurotoxicity in amyotrophic lateral sclerosis (ALS). Here, we show that astrocyte-specific knockout of Cx43 in a mouse model of ALS slows disease progression both spatially and temporally, provides motor neuron (MN) protection, and improves survival. In addition, Cx43 expression is up-regulated in human postmortem tissue and cerebrospinal fluid from ALS patients. Using human induced pluripotent stem cell­derived astrocytes (hiPSC-A) from both familial and sporadic ALS, we establish that Cx43 is up-regulated and that Cx43-hemichannels are enriched at the astrocyte membrane. We also demonstrate that the pharmacological blockade of Cx43-hemichannels in ALS astrocytes using GAP 19, a mimetic peptide blocker, and tonabersat, a clinically tested small molecule, provides neuroprotection of hiPSC-MN and reduces ALS astrocyte-mediated neuronal hyperexcitability. Extending the in vitro application of tonabersat with chronic administration to SOD1G93A mice results in MN protection with a reduction in reactive astrocytosis and microgliosis. Taking these data together, our studies identify Cx43 hemichannels as conduits of astrocyte-mediated disease progression and a pharmacological target for disease-modifying ALS therapies.


Assuntos
Esclerose Lateral Amiotrófica , Esclerose Lateral Amiotrófica/genética , Astrócitos , Conexina 43/genética , Humanos , Neurônios Motores
3.
Elife ; 92020 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-32463361

RESUMO

Mutations in TUBB4A result in a spectrum of leukodystrophy including Hypomyelination with Atrophy of Basal Ganglia and Cerebellum (H-ABC), a rare hypomyelinating leukodystrophy, often associated with a recurring variant p.Asp249Asn (D249N). We have developed a novel knock-in mouse model harboring heterozygous (Tubb4aD249N/+) and the homozygous (Tubb4aD249N/D249N) mutation that recapitulate the progressive motor dysfunction with tremor, dystonia and ataxia seen in H-ABC. Tubb4aD249N/D249N mice have myelination deficits along with dramatic decrease in mature oligodendrocytes and their progenitor cells. Additionally, a significant loss occurs in the cerebellar granular neurons and striatal neurons in Tubb4aD249N/D249N mice. In vitro studies show decreased survival and dysfunction in microtubule dynamics in neurons from Tubb4aD249N/D249N mice. Thus Tubb4aD249N/D249N mice demonstrate the complex cellular physiology of H-ABC, likely due to independent effects on oligodendrocytes, striatal neurons, and cerebellar granule cells in the context of altered microtubule dynamics, with profound neurodevelopmental deficits.


Inside human and other animal cells, filaments known as microtubules help support the shape of the cell and move proteins to where they need to be. Defects in microtubules may lead to disease. For example, genetic mutations affecting a microtubule component called TUBB4A cause a rare brain disease in humans known as H-ABC. Individuals with H-ABC display many symptoms including abnormal walking, speech defects, impaired swallowing, and several cognitive defects. Abnormalities in several areas of the brain, including the cerebellum and striatum contribute to these defects. . In these structures, the neurons that carry messages around the brain and their supporting cells, known as oligodendrocytes, die, which causes these parts of the brain to gradually waste away. At this time, there are no therapies available to treat H-ABC. Furthermore, research into the disease has been hampered by the lack of a suitable "model" in mice or other laboratory animals. To address this issue, Sase, Almad et al. generated mice carrying a mutation in a gene which codes for the mouse equivalent of the human protein TUBB4A. Experiments showed that the mutant mice had similar physical symptoms to humans with H-ABC, including an abnormal walking gait, poor coordination and involuntary movements such as twitching and reduced reflexes. H-ABC mice had smaller cerebellums than normal mice, which was consistent with the wasting away of the cerebellum observed in individuals with H-ABC. The mice also lost neurons in the striatum and cerebellum, and oligodendrocytes in the brain and spinal cord. Furthermore, the mutant TUBB4A protein affected the behavior and formation of microtubules in H-ABC mice. The findings of Sase, Almad et al. provide the first mouse model that shares many features of H-ABC disease in humans. This model provides a useful tool to study the disease and develop potential new therapies.


Assuntos
Modelos Animais de Doenças , Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central , Neurônios/patologia , Oligodendroglia/patologia , Tubulina (Proteína)/genética , Animais , Gânglios da Base/citologia , Gânglios da Base/patologia , Cerebelo/citologia , Cerebelo/patologia , Técnicas de Introdução de Genes , Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central/genética , Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central/metabolismo , Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central/patologia , Camundongos , Camundongos Transgênicos , Mutação/genética , Neurônios/metabolismo , Oligodendroglia/metabolismo
4.
Exp Neurol ; 289: 96-102, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28038988

RESUMO

Neural stem cells (NSCs) are being investigated as a possible treatment for amyotrophic lateral sclerosis (ALS) through intraspinal transplantation, but no longitudinal imaging studies exist that describe the survival of engrafted cells over time. Allogeneic firefly luciferase-expressing murine NSCs (Luc+-NSCs) were transplanted bilaterally (100,000 cells/2µl) into the cervical spinal cord (C5) parenchyma of pre-symptomatic (63day-old) SOD1G93A ALS mice (n=14) and wild-type age-matched littermates (n=14). Six control SOD1G93A ALS mice were injected with saline. Mice were immunosuppressed using a combination of tacrolimus+sirolimus (1mg/kg each, i.p.) daily. Compared to saline-injected SOD1G93A ALS control mice, a transient improvement (p<0.05) in motor performance (rotarod test) was observed after NSC transplantation only at the early disease stage (weeks 2 and 3 post-transplantation). Compared to day one post-transplantation, there was a significant decline in bioluminescent imaging (BLI) signal in SOD1G93A ALS mice at the time of disease onset (71.7±17.9% at 4weeks post-transplantation, p<0.05), with a complete loss of BLI signal at endpoint (120day-old mice). In contrast, BLI signal intensity was observed in wild-type littermates throughout the entire study period, with only a 41.4±8.7% decline at the endpoint. In SOD1G93A ALS mice, poor cell survival was accompanied by accumulation of mature macrophages and the presence of astrogliosis and microgliosis. We conclude that the disease progression adversely affects the survival of engrafted murine Luc+-NSCs in SOD1G93A ALS mice as a result of the hostile ALS spinal cord microenvironment, further emphasizing the challenges that face successful cell therapy of ALS.


Assuntos
Esclerose Lateral Amiotrófica/diagnóstico por imagem , Esclerose Lateral Amiotrófica/cirurgia , Células-Tronco Neurais/transplante , Esclerose Lateral Amiotrófica/genética , Animais , Sobrevivência Celular , Modelos Animais de Doenças , Progressão da Doença , Embrião de Mamíferos , Seguimentos , Imunossupressores/farmacologia , Luciferases/metabolismo , Masculino , Camundongos , Camundongos Transgênicos , Atividade Motora/efeitos dos fármacos , Atividade Motora/fisiologia , Proteínas do Tecido Nervoso/metabolismo , Transtornos Psicomotores/etiologia , Transtornos Psicomotores/cirurgia , Sirolimo/farmacologia , Medula Espinal/diagnóstico por imagem , Medula Espinal/cirurgia , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo , Tacrolimo/farmacologia , Transplante Homólogo
5.
Glia ; 64(7): 1154-69, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27083773

RESUMO

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by progressive loss of motor neurons in the CNS. Astrocytes play a critical role in disease progression of ALS. Astrocytes are interconnected through a family of gap junction proteins known as connexins (Cx). Cx43 is a major astrocyte connexin conducting crucial homeostatic functions in the CNS. Under pathological conditions, connexin expression and functions are altered. Here we report that an abnormal increase in Cx43 expression serves as one of the mechanisms for astrocyte-mediated toxicity in ALS. We observed a progressive increase in Cx43 expression in the SOD1(G93A) mouse model of ALS during the disease course. Notably, this increase in Cx43 was also detected in the motor cortex and spinal cord of ALS patients. Astrocytes isolated from SOD1(G93A) mice as well as human induced pluripotent stem cell (iPSC)-derived astrocytes showed an increase in Cx43 protein, which was found to be an endogenous phenomenon independent of neuronal co-culture. Increased Cx43 expression led to important functional consequences when tested in SOD1(G93A) astrocytes when compared to control astrocytes over-expressing wild-type SOD1 (SOD1(WT) ). We observed SOD1(G93A) astrocytes exhibited enhanced gap junction coupling, increased hemichannel-mediated activity, and elevated intracellular calcium levels. Finally, we tested the impact of increased expression of Cx43 on MN survival and observed that use of both a pan Cx43 blocker and Cx43 hemichannel blocker conferred neuroprotection to MNs cultured with SOD1(G93A) astrocytes. These novel findings show a previously unrecognized role of Cx43 in ALS-related motor neuron loss. GLIA 2016;64:1154-1169.


Assuntos
Esclerose Lateral Amiotrófica/patologia , Astrócitos/fisiologia , Córtex Cerebral/patologia , Conexina 43/metabolismo , Regulação da Expressão Gênica/genética , Neurônios Motores/fisiologia , Medula Espinal/patologia , Trifosfato de Adenosina/farmacologia , Idoso , Idoso de 80 Anos ou mais , Esclerose Lateral Amiotrófica/genética , Animais , Astrócitos/efeitos dos fármacos , Células Cultivadas , Conexina 43/genética , Feminino , Regulação da Expressão Gênica no Desenvolvimento/genética , Proteína Glial Fibrilar Ácida/genética , Proteína Glial Fibrilar Ácida/metabolismo , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/fisiologia , Interleucina-1beta/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Pessoa de Meia-Idade , Neurônios Motores/efeitos dos fármacos , Peptídeos/farmacologia , Fator de Necrose Tumoral alfa/farmacologia
6.
Stem Cell Res Ther ; 3(5): 37, 2012 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-23021042

RESUMO

Therapeutic strategies using stem cells for treating neurological diseases are receiving more attention as the scientific community appreciates cell-autonomous contributions to several diseases of the central nervous system. The transplantation of stem cells from various sources is now being employed for both neuronal and glial replacement. This review provides an assessment of glial contributions to some of the central nervous system diseases and the advancements in cellular replacement approaches. The rationale for glial replacement in individual diseases and the potential hurdles for cell-replacement strategies are also emphasized. The significant progress in the field of stem cell biology with the advent of tools such as induced pluripotent stem cells and imaging techniques holds promise for the clinical application of cell therapeutics.


Assuntos
Doenças do Sistema Nervoso/terapia , Neuroglia/patologia , Transplante de Células-Tronco/métodos , Diferenciação Celular/fisiologia , Humanos , Doenças do Sistema Nervoso/patologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...