RESUMEN

SUMMARY: Despite comprehensive studies and reports about the properties of dental pulp stem cells (DPSCs) in vitro, we still need to confirm whether these in vitro characteristics coincide with the nature of DPSCs in situ. The anatomical location of DPSCs populations in the dental pulp has yet to be investigated. Moreover, the mesenchymal DPSCs have been much more studied than the neural crest-derived DPSCs. In this study, well-recognized neural/neural crest stem cell markers NCAM1, Nestin, SNAIL/SLUG, SOX9, and S100 are being investigated by immunohistochemistry to localize the precise location of these populations of DPSCs within the human adult dental pulp.All previously mentioned markers were expressed in the dental pulp, and their intensity and location of expression were reported.

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A pesar de estudios e informes exhaustivos sobre las propiedades de las células madre de la pulpa dental (DPSC) in vitro, todavía necesitamos confirmar si estas características in vitro coinciden con la naturaleza de las DPSC in situ. La ubicación anatómica de las poblaciones de DPSC en la pulpa dental aún no se ha investigado. Además, las DPSC mesenquimales han sido mucho más estudiadas que las DPSC derivadas de la cresta neural. En este estudio, se están investigando mediante inmunohisto química marcadores de células madre de la cresta neural/ neural NCAM1, Nestin, SNAIL/SLUG, SOX9 y S100 para localizar la ubicación precisa de estas poblaciones de DPSC dentro de la pulpa dental humana adulta. Todos los marcadores mencionados anteriormente se expresaron en la pulpa dental y se informó su intensidad y ubicación de expresión.

Asunto(s)

Humanos , Adolescente , Adulto Joven , Células Madre/metabolismo , Pulpa Dental/citología , Cresta Neural/citología , Inmunohistoquímica , Proteínas S100 , Antígeno CD56 , Factor de Transcripción SOX9 , Nestina

RESUMEN

Mucopolysaccharidosis type II (MPS II) is a disorder caused by a deficient activity of iduronate-2-sulfatase, a lysosomal enzyme responsible for degrading glycosaminoglycans (GAGs). The abnormal storage of GAGs within lysosomes disrupts cellular homeostasis and leads to a severe symptomatology. Patients present neuropsychiatric impairment characterized by mental retardation and impaired cognition. The aim of this study was to quantify four neurodegeneration biomarkers in plasma: brain-derived neurotrophic factor (BDNF), platelet-derived growth factor (PDGF-AA), neural cell adhesion molecule (NCAM) and cathepsin-D, as well as to identify possible correlations with urinary GAGs in seven patients undergoing treatment with ERT (Elaprase® 0.5 mg/kg of body weight). Patients with both severe and attenuated forms of MPS II showed signs of neurodegeneration in neuroimaging exams. Patients have a decrease in BDNF and PDGF-AA concentrations, and an increase in NCAM level compared to controls. No alterations in cathepsin-D concentration were seen. GAGs levels were higher in patients than in controls, but no significant correlations between GAGs and biomarkers were observed. These results evidence that patients have neurodegeneration and that monitoring these biomarkers might be useful for assessing this process. To this date, this is the first work to analyze these plasmatic markers of neurodegeneration in patients.

Asunto(s)

Mucopolisacaridosis II , Humanos , Mucopolisacaridosis II/complicaciones , Mucopolisacaridosis II/tratamiento farmacológico , Mucopolisacaridosis II/diagnóstico , Factor Neurotrófico Derivado del Encéfalo/uso terapéutico , Terapia de Reemplazo Enzimático , Glicosaminoglicanos/metabolismo , Glicosaminoglicanos/uso terapéutico , Biomarcadores , Moléculas de Adhesión de Célula Nerviosa/uso terapéutico

RESUMEN

BACKGROUND: Autism spectrum disorders (ASD) are synaptopathies characterized by area-specific synaptic alterations and neuroinflammation. Structural and adhesive features of hippocampal synapses have been described in the valproic acid (VPA) model. However, neuronal and microglial contribution to hippocampal synaptic pattern and its time-course of appearance is still unknown. METHODS: Male pups born from pregnant rats injected at embryonic day 10.5 with VPA (450 mg/kg, i.p.) or saline (control) were used. Maturation, exploratory activity and social interaction were assessed as autistic-like traits. Synaptic, cell adhesion and microglial markers were evaluated in the CA3 hippocampal region at postnatal day (PND) 3 and 35. Primary cultures of hippocampal neurons from control and VPA animals were used to study synaptic features and glutamate-induced structural remodeling. Basal and stimuli-mediated reactivity was assessed on microglia primary cultures isolated from control and VPA animals. RESULTS: At PND3, before VPA behavioral deficits were evident, synaptophysin immunoreactivity and the balance between the neuronal cell adhesion molecule (NCAM) and its polysialylated form (PSA-NCAM) were preserved in the hippocampus of VPA animals along with the absence of microgliosis. At PND35, concomitantly with the establishment of behavioral deficits, the hippocampus of VPA rats showed fewer excitatory synapses and increased NCAM/PSA-NCAM balance without microgliosis. Hippocampal neurons from VPA animals in culture exhibited a preserved synaptic puncta number at the beginning of the synaptogenic period in vitro but showed fewer excitatory synapses as well as increased NCAM/PSA-NCAM balance and resistance to glutamate-induced structural synaptic remodeling after active synaptogenesis. Microglial cells isolated from VPA animals and cultured in the absence of neurons showed similar basal and stimuli-induced reactivity to the control group. Results indicate that in the absence of glia, hippocampal neurons from VPA animals mirrored the in vivo synaptic pattern and suggest that while neurons are primed during the prenatal period, hippocampal microglia are not intrinsically altered. CONCLUSIONS: Our study suggests microglial role is not determinant for developing neuronal alterations or counteracting neuronal outcome in the hippocampus and highlights the crucial role of hippocampal neurons and structural plasticity in the establishment of the synaptic alterations in the VPA rat model.

Asunto(s)

Anticonvulsivantes , Trastorno del Espectro Autista/inducido químicamente , Hipocampo/efectos de los fármacos , Neuronas/efectos de los fármacos , Sinapsis/efectos de los fármacos , Ácido Valproico , Animales , Trastorno del Espectro Autista/metabolismo , Conducta Animal/efectos de los fármacos , Células Cultivadas , Modelos Animales de Enfermedad , Femenino , Hipocampo/metabolismo , Hipocampo/ultraestructura , Masculino , Microglía/efectos de los fármacos , Moléculas de Adhesión de Célula Nerviosa/metabolismo , Plasticidad Neuronal/efectos de los fármacos , Neuronas/metabolismo , Neuronas/ultraestructura , Fosfoproteínas Fosfatasas/metabolismo , Embarazo , Ratas Wistar

RESUMEN

The posterodorsal medial amygdala (MePD) has a high concentration of receptors for gonadal hormones, is a sexually dimorphic region and dynamically controls the reproductive behavior of both males and females. Neurotrophic factors can promote dendritic spine remodeling and change synaptic input strength in a region-specific manner. Here, we analyzed the gene and protein expression of brain-derived neurotrophic factor (BDNF), insulin-like growth factor-I (IGF-1), polysialylated neural cell adhesion molecule (PSA-NCAM) and Ephrin-A4 in the MePD of adult males and females in diestrus, proestrus and estrus using real-time qPCR and fluorescent immunohistochemistry. The first approach showed their amplification except for Igf1 and the latter revealed that BDNF, IGF-1, PSA-NCAM and Ephrin-A4 are expressed in the MePD of the adult rats. Protein expression of these neurotrophic factors showed no differences between groups. However, proestrus females displayed a higher number of labelled puncta than males for BDNF expression and diestrus females for IGF-1 expression. In conjunction, results indicate that IGF-1 might be released rather than synthetized in the MePD, and the expression of specific neurotrophic factors varies specifically during proestrus. The dynamic modulation of BDNF and IGF-1 during this cyclic phase is coincident with synaptic changes and spine density remodeling in the MePD, the disinhibition of gonadotrophin secretion for ovulation and the display of sexual behavior.

Asunto(s)

Complejo Nuclear Corticomedial/fisiología , Ciclo Estral , Factores de Crecimiento Nervioso/fisiología , Animales , Factor Neurotrófico Derivado del Encéfalo/fisiología , Efrina-A4/análisis , Efrina-A4/fisiología , Femenino , Expresión Génica , Masculino , Moléculas de Adhesión de Célula Nerviosa/fisiología , Plasticidad Neuronal/fisiología , Ratas Wistar , Caracteres Sexuales

RESUMEN

Maple syrup urine disease (MSUD) is an inherited disorder caused by deficient activity of the branched-chain α-keto acid dehydrogenase complex involved in the degradation pathway of branched-chain amino acids (BCAAs) and their respective α-keto-acids. Patients affected by MSUD present severe neurological symptoms and brain abnormalities, whose pathophysiology is poorly known. However, preclinical studies have suggested alterations in markers involved with neurodegeneration. Because there are no studies in the literature that report the neurodegenerative markers in MSUD patients, the present study evaluated neurodegenerative markers (brain-derived neurotrophic factor (BDNF), cathepsin D, neural cell adhesion molecule (NCAM), plasminogen activator inhibitor-1 total (PAI-1 (total)), platelet-derived growth factor AA (PDGF-AA), PDGF-AB/BB) in plasma from 10 MSUD patients during dietary treatment. Our results showed a significant decrease in BDNF and PDGF-AA levels in MSUD patients. On the other hand, NCAM and cathepsin D levels were significantly greater in MSUD patients compared to the control group, while no significant changes were observed in the levels of PAI-1 (total) and PDGF-AB/BB between the control and MSUD groups. Our data show that MSUD patients present alterations in proteins involved in the neurodegenerative process. Thus, the present findings corroborate previous studies that demonstrated that neurotrophic factors and lysosomal proteases may contribute, along with other mechanisms, to the intellectual deficit and neurodegeneration observed in MSUD.

Asunto(s)

Biomarcadores/metabolismo , Enfermedad de la Orina de Jarabe de Arce/metabolismo , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Muerte Celular , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Estrés Oxidativo/fisiología , Inhibidor 1 de Activador Plasminogénico/metabolismo , Factor de Crecimiento Derivado de Plaquetas/metabolismo

RESUMEN

Background: Atypical teratoid/rhabdoid tumors (AT/RT) are aggressive embryonal tumors of the central nervous system. They are largely characterized by inactivating mutations of the SMARCB1 tumor suppressor gene. AT/RT patients have a very poor prognosis and no standard therapeutic protocol has been defined yet. Recently, multimodal therapy with multiple drug combinations has slightly improved the overall survival, however drug toxicity remains high. In this scenario, a better understanding of the pathophysiology of the disease is needed. Methods: We evaluated the gene expression profile of AT/RT samples to find new genetic factors contributing to the pathophysiology of the disease. We found target genes significantly differentially expressed between AT/RT and medulloblastoma (MB), the most common embryonal brain tumor. The mRNA expression was validated by quantitative real-time PCR and, at the protein level, expression was validated by immunohistochemistry in an independent set of tumors. Results: The Neural cell adhesion molecule 1 (NCAM1) gene was found to be consistently downregulated in AT/RT samples when compared to MB and normal brain tissue. Immunohistochemistry showed that the expression of NCAM1 in AT/RT was significantly lower than that of MB. Conclusion: NCAM1 is an important molecule involved in neuron-to-neuron and neuron-to-muscle adhesion during development. Downregulation of NCAM1 has been implicated in several human cancers suggesting that it might have a tumor repressor role. In this study we found a significantly reduced expression of NCAM1 in AT/RT when compared to MB and we suggest that this feature can be used as a diagnostic marker, along with demonstration of SMARCB1 (INI1) or SMARCA4 (BRG1) inactivation. The roles of NCAM1 in the pathophysiology of AT/RT are still to be determined (AU)

Asunto(s)

Humanos , Teratoma/diagnóstico , Inmunoglobulinas , Biomarcadores de Tumor , Tumor Rabdoide/diagnóstico , Antígeno CD56

RESUMEN

The formation of synaptic connections during nervous system development requires the precise control of dendrite growth and synapse formation. Although glial cell line-derived neurotrophic factor (GDNF) and its receptor GFRα1 are expressed in the forebrain, the role of this system in the hippocampus remains unclear. Here, we investigated the consequences of GFRα1 deficiency for the development of hippocampal connections. Analysis of conditional Gfra1 knockout mice shows a reduction in dendritic length and complexity, as well as a decrease in postsynaptic density specializations and in the synaptic localization of postsynaptic proteins in hippocampal neurons. Gain- and loss-of-function assays demonstrate that the GDNF-GFRα1 complex promotes dendritic growth and postsynaptic differentiation in cultured hippocampal neurons. Finally, in vitro assays revealed that GDNF-GFRα1-induced dendrite growth and spine formation are mediated by NCAM signaling. Taken together, our results indicate that the GDNF-GFRα1 complex is essential for proper hippocampal circuit development.

Asunto(s)

Dendritas/fisiología , Receptores del Factor Neurotrófico Derivado de la Línea Celular Glial/fisiología , Factor Neurotrófico Derivado de la Línea Celular Glial/fisiología , Hipocampo/crecimiento & desarrollo , Moléculas de Adhesión de Célula Nerviosa/fisiología , Neurogénesis/genética , Plasticidad Neuronal/genética , Animales , Diferenciación Celular/genética , Células Cultivadas , Embrión de Mamíferos , Factor Neurotrófico Derivado de la Línea Celular Glial/genética , Factor Neurotrófico Derivado de la Línea Celular Glial/metabolismo , Receptores del Factor Neurotrófico Derivado de la Línea Celular Glial/genética , Receptores del Factor Neurotrófico Derivado de la Línea Celular Glial/metabolismo , Hipocampo/citología , Hipocampo/metabolismo , Ratones , Ratones Noqueados , Complejos Multiproteicos/fisiología , Red Nerviosa/crecimiento & desarrollo , Red Nerviosa/metabolismo , Neuronas/fisiología , Unión Proteica , Ratas , Ratas Wistar

RESUMEN

Regulation of alternative splicing is coupled to transcription quality, the polymerase elongation rate being an important factor in modulating splicing choices. In a recently published work, we provide evidence that intragenic histone acetylation patterns can be affected by neural cell excitation in order to regulate alternative splicing of the neural cell adhesion molecule (NCAM) mRNA. This example illustrates how an extracellular stimulus can influence transcription-coupled alternative splicing, strengthening the link between chromatin structure, transcriptional elongation and mRNA processing.