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1.
Brain Struct Funct ; 228(3-4): 907-920, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36995433

RESUMO

The development and survival of dopaminergic neurons are influenced by the fibroblast growth factor (FGF) pathway. Anosmin-1 (A1) is an extracellular matrix protein that acts as a major regulator of this signaling pathway, controlling FGF diffusion, and receptor interaction and shuttling. In particular, previous work showed that A1 overexpression results in more dopaminergic neurons in the olfactory bulb. Prompted by those intriguing results, in this study, we investigated the effects of A1 overexpression on different populations of catecholaminergic neurons in the central (CNS) and the peripheral nervous systems (PNS). We found that A1 overexpression increases the number of dopaminergic substantia nigra pars compacta (SNpc) neurons and alters the striosome/matrix organization of the striatum. Interestingly, these numerical and morphological changes in the nigrostriatal pathway of A1-mice did not confer an altered susceptibility to experimental MPTP-parkinsonism with respect to wild-type controls. Moreover, the study of the effects of A1 overexpression was extended to different dopaminergic tissues associated with the PNS, detecting a significant reduction in the number of dopaminergic chemosensitive carotid body glomus cells in A1-mice. Overall, our work shows that A1 regulates the development and survival of dopaminergic neurons in different nuclei of the mammalian nervous system.


Assuntos
Doença de Parkinson , Camundongos , Animais , Doença de Parkinson/patologia , Substância Negra/metabolismo , Proteínas da Matriz Extracelular/metabolismo , Dopamina/metabolismo , Neurônios Dopaminérgicos/metabolismo , Sistema Nervoso Periférico/metabolismo , Sistema Nervoso Periférico/patologia , Camundongos Endogâmicos C57BL , Mamíferos
2.
Nat Neurosci ; 26(2): 226-238, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36624276

RESUMO

Vaccines against SARS-CoV-2 have been shown to be safe and effective but their protective efficacy against infection in the brain is yet unclear. Here, in the susceptible transgenic K18-hACE2 mouse model of severe coronavirus disease 2019 (COVID-19), we report a spatiotemporal description of SARS-CoV-2 infection and replication through the brain. SARS-CoV-2 brain replication occurs primarily in neurons, leading to neuronal loss, signs of glial activation and vascular damage in mice infected with SARS-CoV-2. One or two doses of a modified vaccinia virus Ankara (MVA) vector expressing the SARS-CoV-2 spike (S) protein (MVA-CoV2-S) conferred full protection against SARS-CoV-2 cerebral infection, preventing virus replication in all areas of the brain and its associated damage. This protection was maintained even after SARS-CoV-2 reinfection. These findings further support the use of MVA-CoV2-S as a promising vaccine candidate against SARS-CoV-2/COVID-19.


Assuntos
COVID-19 , SARS-CoV-2 , Camundongos , Animais , Humanos , Camundongos Transgênicos , Vacinas contra COVID-19 , Encéfalo
3.
Int J Mol Sci ; 22(18)2021 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-34575909

RESUMO

Aquaporin-4 (AQP4) is the principal water channel in the brain being expressed in astrocytes and ependymal cells. AQP4 plays an important role in cerebrospinal fluid (CSF) homeostasis, and alterations in its expression have been associated with hydrocephalus. AQP4 contributes to the development of hydrocephalus by hypoxia in aged mice, reproducing such principal characteristics of the disease. Here, we explore whether these alterations associated with the hydrocephalic state are permanent or can be reverted by reexposure to normoxia. Alterations such as ventriculomegaly, elevated intracranial pressure, and cognitive deficits were reversed, whereas deficits in CSF outflow and ventricular distensibility were not recovered, remaining impaired even one month after reestablishment of normoxia. Interestingly, in AQP4-/- mice, the impairment in CSF drainage and ventricular distensibility was completely reverted by re-normoxia, indicating that AQP4 has a structural role in the chronification of those alterations. Finally, we show that aged mice subjected to two hypoxic episodes experience permanent ventriculomegaly. These data reveal that repetitive hypoxic events in aged cerebral tissue promote the permanent alterations involved in hydrocephalic pathophysiology, which are dependent on AQP4 expression.


Assuntos
Aquaporina 4/genética , Suscetibilidade a Doenças , Hidrocefalia/etiologia , Hidrocefalia/metabolismo , Hipóxia/genética , Hipóxia/metabolismo , Fatores Etários , Animais , Aquaporina 4/líquido cefalorraquidiano , Aquaporina 4/metabolismo , Biomarcadores , Encéfalo/metabolismo , Encéfalo/patologia , Encéfalo/fisiopatologia , Modelos Animais de Doenças , Hidrocefalia/diagnóstico , Hidrocefalia/patologia , Imuno-Histoquímica , Imageamento por Ressonância Magnética , Camundongos , Fenótipo
4.
Cytotherapy ; 22(1): 1-5, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31866320

RESUMO

In the current article we summarize the 15-year experience of the Spanish Cell Therapy Network (TerCel), a successful collaborative public initiative funded by the Spanish government for the support of nationwide translational research in this important area. Thirty-two research groups organized in three programs devoted to cardiovascular, neurodegenerative and immune-inflammatory diseases, respectively, currently form the network. Each program has three working packages focused on basic science, pre-clinical studies and clinical application. TerCel has contributed during this period to boost the translational research in cell therapy in Spain, setting up a network of Good Manufacturing Practice-certified cell manufacturing facilities- and increasing the number of translational research projects, publications, patents and clinical trials of the participating groups, especially those in collaboration. TerCel pays particular attention to the public-private collaboration, which, for instance, has led to the development of the first allogeneic cell therapy product approved by the European Medicines Agency, Darvadstrocel. The current collaborative work is focused on the development of multicenter phase 2 and 3 trials that could translate these therapies to clinical practice for the benefit of patients.


Assuntos
Terapia Baseada em Transplante de Células e Tecidos/métodos , Medicina Regenerativa/métodos , Pesquisa Translacional Biomédica/métodos , Pesquisa Biomédica , Doenças Cardiovasculares/terapia , Humanos , Doenças do Sistema Imunitário/terapia , Colaboração Intersetorial , Doenças Neurodegenerativas/terapia , Espanha
5.
Cells ; 8(2)2019 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-30813473

RESUMO

Aquaporin 1 (AQP1), expressed in epithelial cells of the choroid plexus, and aquaporin 4 (AQP4) present in ependymal cells and glia limitants have been proposed to play a significant role in cerebrospinal fluid (CSF) production and homeostasis. However, the specific contribution of each water channel to these functions remains unknown, being a subject of debate during the last years. Here, we analyzed in detail how AQP1 and AQP4 participate in different aspects of the CSF homeostasis such as the load and drainage of ventricles, and further explored if these proteins play a role in the ventricular compliance. To do that, we carried out records of intraventricular pressure and CSF outflow, and evaluated ventricular volume by magnetic resonance imaging in AQP1-/-, AQP4-/-, double AQP1-/--AQP4-/- knock out and wild type mice controls. The analysis performed clearly showed that both AQPs have a significant participation in the CSF production, and additionally revealed that the double AQP1-AQP4 mutation alters the CSF drainage and the ventricular compliance. The data reported here indicate a significant extra-choroidal CSF formation mediated by AQP4, supporting the idea of an important and constant CSF production/absorption process, sustained by efflux/influx of water between brain capillaries and interstitial fluid. Moreover, our results suggest the participation of AQPs in structural functions also related with CSF homeostasis such as the distensibility capacity of the ventricular system.


Assuntos
Aquaporina 1/líquido cefalorraquidiano , Aquaporina 4/líquido cefalorraquidiano , Homeostase , Animais , Imageamento por Ressonância Magnética , Masculino , Camundongos Knockout , Pressão Ventricular
6.
Biochim Biophys Acta Mol Basis Dis ; 1864(10): 3515-3526, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30293570

RESUMO

Aquaporin-4, present in ependymal cells, in glia limiting and abundantly in pericapillary astrocyte foot processes, and aquaporin-1, expressed in choroid plexus epithelial cells, play an important role in cerebrospinal fluid production and may be involved in the pathophysiology of age-dependent hydrocephalus. The finding that brain aquaporins expression is regulated by low oxygen tension led us to investigate how hypoxia and elevated levels of cerebral aquaporins may result in an increase in cerebrospinal fluid production that could be associated with a hydrocephalic condition. Here we have explored, in young and aged mice exposed to hypoxia, whether aquaporin-4 and aquaporin-1 participate in the development of age-related hydrocephalus. Choroid plexus, striatum, cortex and ependymal tissue were analyzed separately both for mRNA and protein levels of aquaporins. Furthermore, parameters such as total ventricular volume, intraventricular pressure, cerebrospinal fluid outflow rate, ventricular compliance and cognitive function were studied in wild type, aquaporin-1 and aquaporin-4 knock-out animals subjected to hypoxia or normoxia. Our data demonstrate that hypoxia is involved in the development of age-related hydrocephalus by a process that depends on aquaporin-4 channels as a main route for cerebrospinal fluid movement. Significant increases in aquaporin-4 expression that occur over the course of animal aging, together with a reduced cerebrospinal fluid outflow rate and ventricular compliance, contribute to produce more severe hydrocephalus related to hypoxic events in aged mice, with a notable impairment in cognitive function. These results indicate that physiological events and/or pathological conditions presenting with cerebral hypoxia/ischemia contribute to the development of chronic adult hydrocephalus.


Assuntos
Envelhecimento/líquido cefalorraquidiano , Envelhecimento/genética , Aquaporina 4/genética , Hidrocefalia/líquido cefalorraquidiano , Hidrocefalia/genética , Envelhecimento/metabolismo , Animais , Aquaporina 1/genética , Aquaporina 1/metabolismo , Aquaporina 4/metabolismo , Encéfalo/metabolismo , Pressão do Líquido Cefalorraquidiano , Modelos Animais de Doenças , Humanos , Hidrocefalia/metabolismo , Camundongos , Regulação para Cima , Pressão Ventricular
7.
J Neurosci ; 38(4): 814-825, 2018 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-29217686

RESUMO

Synaptic protein α-synuclein (α-SYN) modulates neurotransmission in a complex and poorly understood manner and aggregates in the cytoplasm of degenerating neurons in Parkinson's disease. Here, we report that α-SYN present in dopaminergic nigral afferents is essential for the normal cycling and maintenance of neural stem cells (NSCs) in the brain subependymal zone of adult male and female mice. We also show that premature senescence of adult NSCs into non-neurogenic astrocytes in mice lacking α-SYN resembles the effects of dopaminergic fiber degeneration resulting from chronic exposure to 1-methyl-4-phenyl-1,2,3,6-tetra-hydropyridine or intranigral inoculation of aggregated toxic α-SYN. Interestingly, NSC loss in α-SYN-deficient mice can be prevented by viral delivery of human α-SYN into their sustantia nigra or by treatment with l-DOPA, suggesting that α-SYN regulates dopamine availability to NSCs. Our data indicate that α-SYN, present in dopaminergic nerve terminals supplying the subependymal zone, acts as a niche component to sustain the neurogenic potential of adult NSCs and identify α-SYN and DA as potential targets to ameliorate neurogenic defects in the aging and diseased brain.SIGNIFICANCE STATEMENT We report an essential role for the protein α-synuclein present in dopaminergic nigral afferents in the regulation of adult neural stem cell maintenance, identifying the first synaptic regulator with an implication in stem cell niche biology. Although the exact role of α-synuclein in neural transmission is not completely clear, our results indicate that it is required for stemness and the preservation of neurogenic potential in concert with dopamine.


Assuntos
Encéfalo/metabolismo , Neurônios Dopaminérgicos/metabolismo , Células-Tronco Neurais/metabolismo , Nicho de Células-Tronco/fisiologia , alfa-Sinucleína/metabolismo , Animais , Encéfalo/citologia , Senescência Celular/fisiologia , Dopamina/metabolismo , Neurônios Dopaminérgicos/citologia , Feminino , Humanos , Masculino , Camundongos , Camundongos Mutantes , Células-Tronco Neurais/citologia , Neurogênese/fisiologia , Neurônios Aferentes/citologia , Neurônios Aferentes/metabolismo
8.
Int J Mol Sci ; 17(8)2016 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-27455255

RESUMO

Detection of IgG anti-Aquaporin-4 (AQP4) in serum of patients with Neuromyelitis optica syndrome disorders (NMOSD) has improved diagnosis of these processes and differentiation from Multiple sclerosis (MS). Recent findings also claim that a subgroup of patients with NMOSD, serum negative for IgG-anti-AQP4, present antibodies anti-AQP1 instead. Explore the presence of IgG-anti-AQP1 using a previously developed cell-based assay (CBA) highly sensitive to IgG-anti-AQP4. Serum of 205 patients diagnosed as NMOSD (8), multiple sclerosis (94), optic neuritis (39), idiopathic myelitis (29), other idiopathic demyelinating disorders of the central nervous system (9), other neurological diseases (18) and healthy controls (8), were used in a CBA over fixed HEK cells transfected with hAQP1-EGFP or hM23-AQP4-EGFP, treated with Triton X-100 and untreated. ELISA was also performed. Analysis of serum with our CBA indicated absence of anti-AQP1 antibodies, whereas in cells pretreated with detergent, noisy signal made reliable detection impossible. ELISA showed positive results in few serums. The low number of NMOSD serums included in our study reduces its power to conclude the specificity of AQP1 antibodies as new biomarkers of NMOSD. Our study does not sustain detection of anti-AQP1 in serum of NMOSD patients but further experiments are expected.


Assuntos
Anticorpos Anti-Idiotípicos/imunologia , Aquaporina 1/imunologia , Autoanticorpos/imunologia , Biomarcadores/sangue , Imunoglobulina G/imunologia , Neuromielite Óptica/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Anti-Idiotípicos/sangue , Autoanticorpos/sangue , Estudos de Casos e Controles , Ensaio de Imunoadsorção Enzimática , Feminino , Imunofluorescência , Seguimentos , Humanos , Imunoglobulina G/sangue , Masculino , Pessoa de Meia-Idade , Neuromielite Óptica/sangue , Prognóstico , Adulto Jovem
9.
J Cell Physiol ; 231(1): 243-56, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26081645

RESUMO

Aquaporin-1 (AQP1) has been associated with tumor development. Here, we investigated how AQP1 may affect cell proliferation. The proliferative rate of adult carotid body (CB) cells, known to proliferate under chronic hypoxia, was analyzed in wild-type (AQP1(+/+) ) and knock out (AQP1(-/-) ) mice, maintained in normoxia or exposed to hypoxia while BrdU was administered. Fewer numbers of total BrdU(+) and TH-BrdU(+) cells were observed in AQP1(-/-) mice, indicating a role for AQP1 in CB proliferation. Then, by flow cytometry, cell cycle state and proliferation of cells overexpressing AQP1 were compared to those of wild-type cells. In the AQP1-overexpressing cells, we observed higher cell proliferation and percentages of cells in phases S and G2/M and fewer apoptotic cells after nocodazole treatment were detected by annexin V staining. Also in these cells, proteomic assays showed higher expression of cyclin D1 and E1 and microarray analysis revealed changes in many cell proliferation-related molecules, including, Zeb 2, Jun, NF-kß, Cxcl9, Cxcl10, TNF, and the TNF receptor. Overall, our results indicate that the presence of AQP1 modifies the expression of key cell cycle proteins apparently related to increases in cell proliferation. This contributes to explaining the presence of AQP1 in many different tumors.


Assuntos
Aquaporina 1/metabolismo , Ciclo Celular/fisiologia , Proliferação de Células/fisiologia , Animais , Corpo Carotídeo/metabolismo , Hipóxia Celular/fisiologia , Proliferação de Células/genética , Camundongos Endogâmicos C57BL , RNA Mensageiro/metabolismo
10.
Adv Exp Med Biol ; 860: 139-52, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26303476

RESUMO

The carotid body (CB) is a polymodal chemoreceptor that triggers the hyperventilatory response to hypoxia necessary for the maintenance of O(2) homeostasis essential for the survival of organs such as the brain or heart. Glomus cells, the sensory elements in the CB, are also sensitive to hypercapnia, acidosis and, although less generally accepted, hypoglycemia. Current knowledge on CB function is mainly based on studies performed on lower mammals, but the information on the human CB is scant. Here we describe the structure, neurotrophic properties, and cellular responses to hypoxia and hypoglycemia of CBs dissected from human cadavers. The adult CB parenchyma contains clusters of chemosensitive glomus (type I) and sustentacular (type II) cells as well as nestin-positive progenitor cells. This organ also expresses high levels of the dopaminotrophic glial cell line-derived neurotrophic factor (GDNF). GDNF production and the number of progenitor and glomus cells were preserved in the CBs of human subjects of advanced age. As reported for other mammalian species, glomus cells responded to hypoxia by external Ca(2+)-dependent increase of cytosolic [Ca(2+)] and quantal catecholamine release. Human glomus cells are also responsive to hypoglycemia and together the two stimuli, hypoxia and hypoglycemia, can potentiate each other's effects. The chemo-sensory responses of glomus cells are also preserved at an advanced age. Interestingly, a neurogenic niche similar to that recently described in rodents is also preserved in the adult human CB. These new data on the cellular and molecular physiology of the CB pave the way for future pathophysiological studies involving this organ in humans.


Assuntos
Corpo Carotídeo/fisiologia , Cálcio/metabolismo , Corpo Carotídeo/química , Corpo Carotídeo/citologia , Fator Neurotrófico Derivado de Linhagem de Célula Glial/análise , Humanos , Hipoglicemia/fisiopatologia , Hipóxia/fisiopatologia
11.
BMC Neurol ; 14: 139, 2014 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-24980919

RESUMO

BACKGROUND: Cell-based assays for neuromyelitis optica (NMO) diagnosis are the most sensitive and specific methods to detect anti-aquaporin 4 (AQP4) antibodies in serum, but some improvements in their quantitative and specificity capacities would be desirable. Thus the aim of the present work was to develop a sensitive quantitative method for detection of anti-AQP4 antibodies that allows clear diagnosis of NMO and distinction of false labeling produced by natalizumab treatment. METHODS: Sera from 167 individuals, patients diagnosed with NMO (16), multiple sclerosis (85), optic neuritis (24), idiopathic myelitis (21), or other neurological disorders (13) and healthy controls (8), were used as the primary antibody in an immunofluorescence assay on HEK cells transfected with the M23 isoform of human AQP4 fused with enhanced green fluorescent protein. Cells used were freshly transfected or stored frozen and then thawed just before adding the serum. RESULTS: Microscopic observation and fluorescence quantification produced similar results in fresh and frozen samples. Serum samples from patients diagnosed with NMO were 100% positive for anti-AQP4 antibodies, while all the other sera were negative. Using serum from patients treated with natalizumab, a small and unspecific fluorescent signal was produced from all HEK cells, regardless of AQP4 expression. CONCLUSIONS: Our cell-based double-label fluorescence immunoassay protocol significantly increases the signal specificity and reduces false diagnosis of NMO patients, especially in those receiving natalizumab treatment. Frozen pretreated cells allow faster detection of anti-AQP4 antibodies.


Assuntos
Anticorpos Monoclonais Humanizados/sangue , Aquaporina 4/sangue , Autoanticorpos/sangue , Imunoensaio/métodos , Neuromielite Óptica/diagnóstico , Adolescente , Adulto , Idoso , Anticorpos Monoclonais Humanizados/uso terapêutico , Autoantígenos/imunologia , Feminino , Imunofluorescência , Humanos , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/tratamento farmacológico , Natalizumab , Neuromielite Óptica/sangue , Neuromielite Óptica/imunologia , Adulto Jovem
12.
J Cell Physiol ; 229(11): 1787-801, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24676973

RESUMO

AQP3 has been correlated with higher transport of glycerol, increment of ATP content, and larger proliferation capacity. Recently, we described the gold(III) complex Auphen as a very selective and potent inhibitor of AQP3's glycerol permeability (Pgly ). Here we evaluated Auphen effect on the proliferation of various mammalian cell lines differing in AQP3 expression level: no expression (PC12), moderate (NIH/3T3) or high (A431) endogenous expression, cells stably expressing AQP3 (PC12-AQP3), and human HEK293T cells transiently transfected (HEK-AQP3) for AQP3 expression. Proliferation was evaluated in the absence or presence of Auphen (5 µM) by counting number of viable cells and analyzing 5-bromo-2'-deoxyuridine (BrdU) incorporation. Auphen reduced ≈50% the proliferation in A431 and PC12-AQP3, ≈15% in HEK-AQP3 and had no effect in PC12-wt and NIH/3T3. Strong arrest in the S-G2/M phases of the cell cycle, supported by analysis of cyclins (A, B1, D1, E) levels, was observed in AQP3-expressing cells treated with Auphen. Flow-cytometry of propidium iodide incorporation and measurements of mitochondrial dehydrogenases activity confirmed absence of cytotoxic effect of the drug. Functional studies evidenced ≈50% inhibition of A431 Pgly by Auphen, showing that the compound's antiproliferative effect correlates with its ability to inhibit AQP3 Pgly . Role of Cys-40 on AQP3 permeability blockage by Auphen was confirmed by analyzing the mutated protein (AQP3-Ser-40). Accordingly, cells transfected with mutated AQP3 gained resistance to the antiproliferative effect of Auphen. These results highlight an Auphen inhibitory effect on proliferation of cells expressing AQP3 and suggest a targeted therapeutic effect on carcinomas with large AQP3 expression.


Assuntos
Aquaporina 3/antagonistas & inibidores , Complexos de Coordenação/farmacologia , Ouro/farmacologia , Animais , Aquaporina 3/genética , Aquaporina 3/metabolismo , Bromodesoxiuridina/metabolismo , Contagem de Células , Ciclo Celular/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Permeabilidade da Membrana Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Complexos de Coordenação/química , Citometria de Fluxo , Regulação da Expressão Gênica/efeitos dos fármacos , Glicerol/metabolismo , Ouro/toxicidade , Células HEK293 , Humanos , Camundongos , Mutagênese Sítio-Dirigida , Células NIH 3T3 , Células PC12 , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Água/metabolismo
13.
Sci Rep ; 3: 2937, 2013 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-24121824

RESUMO

X-gal staining is a common procedure used in the histochemical monitoring of gene expression by light microscopy. However, this procedure does not permit the direct confocal acquisition of images, thus preventing the identification of labelled cells on the depth (Z) axis of tissue sections and leading sometimes to erroneous conclusions in co-localization and gene expression studies. Here we report a technique, based on X-gal fluorescence emission and mathematically-based optical correction, to obtain high quality fluorescence confocal images. This method, combined with immunofluorescence, makes it possible to unequivocally identify X-gal-labelled cells in tissue sections, emerging as a valuable tool in gene expression and cell tracing analysis.


Assuntos
Galactosídeos/metabolismo , Indóis/metabolismo , Microscopia Confocal , Microscopia de Fluorescência , beta-Galactosidase/metabolismo , Animais , Fluorometria , Expressão Gênica , Genes Reporter , Técnicas de Preparação Histocitológica , Camundongos , Microscopia Confocal/métodos , Microscopia de Fluorescência/métodos , beta-Galactosidase/genética
14.
J Physiol ; 591(24): 6157-73, 2013 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-24167224

RESUMO

The carotid body (CB) is the major peripheral arterial chemoreceptor in mammals that mediates the acute hyperventilatory response to hypoxia. The CB grows in response to sustained hypoxia and also participates in acclimatisation to chronic hypoxaemia. Knowledge of CB physiology at the cellular level has increased considerably in recent times thanks to studies performed on lower mammals, and rodents in particular. However, the functional characteristics of human CB cells remain practically unknown. Herein, we use tissue slices or enzymatically dispersed cells to determine the characteristics of human CB cells. The adult human CB parenchyma contains clusters of chemosensitive glomus (type I) and sustentacular (type II) cells as well as nestin-positive progenitor cells. This organ also expresses high levels of the dopaminotrophic glial cell line-derived neurotrophic factor (GDNF). We found that GDNF production and the number of progenitor and glomus cells were preserved in the CBs of human subjects of advanced age. Moreover, glomus cells exhibited voltage-dependent Na(+), Ca(2+) and K(+) currents that were qualitatively similar to those reported in lower mammals. These cells responded to hypoxia with an external Ca(2+)-dependent increase of cytosolic Ca(2+) and quantal catecholamine secretion, as reported for other mammalian species. Interestingly, human glomus cells are also responsive to hypoglycaemia and together these two stimuli can potentiate each other's effects. The chemosensory responses of glomus cells are also preserved at an advanced age. These new data on the cellular and molecular physiology of the CB pave the way for future pathophysiological studies involving this organ in humans.


Assuntos
Potenciais de Ação , Corpo Carotídeo/citologia , Adolescente , Adulto , Células-Tronco Adultas/citologia , Células-Tronco Adultas/metabolismo , Idoso , Cálcio/metabolismo , Sinalização do Cálcio , Corpo Carotídeo/metabolismo , Corpo Carotídeo/fisiologia , Hipóxia Celular , Células Cultivadas , Criança , Feminino , Glucose/metabolismo , Humanos , Canais Iônicos/metabolismo , Masculino , Pessoa de Meia-Idade , Nestina/genética , Nestina/metabolismo , Neuroglia/citologia , Neuroglia/metabolismo , Potássio/metabolismo , Sódio/metabolismo
15.
Stem Cell Rev Rep ; 8(2): 445-58, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21717132

RESUMO

Motorneuron degenerative diseases, such as amyotrophic lateral sclerosis (ALS), are characterized by the progressive and rapid loss of motor neurons in the brain and spinal cord, leading to paralysis and death. GDNF (glial cell line derived neurotrophic factor) has been previously shown to be capable of protecting motor-neurons in ALS animal models although its delivery to the spinal cord after systemic administration is blocked by the blood brain barrier. Thus, it is necessary to develop new neurotrophic approaches to protect these motor neurons from death. Bone marrow-derived stem cells have been shown to be capable of improving a large variety of neurodegenerative disorders through neurotrophic mediated mechanisms. Here we analyzed the effect of transplanting whole bone marrow or cultured mesenchymal stem cells into the spinal cord of a motor neuron degenerative mouse model. Motor functions were analyzed using various behavior tests for several weeks after transplantation. We observed that bone marrow, and to a lesser degree mesenchymal stem cell, treated mice improved significantly in the motor tests performed, coinciding with a higher GDNF immunoreactivity in the grafted spinal cord. In several cases, the treated spinal cords were extracted, the engrafted bone marrow cells isolated and cultured, and finally re-transplanted into the spleen of immunodeficient mice. Re-grafted cells were detected in the host spleen, bloodstream and bone marrow, demonstrating a phenotypic stability. Thus, bone marrow cells do not suffer significant phenotypic modifications and is an efficient procedure to ameliorate motor-neuron degeneration, making it a possible therapeutic approach.


Assuntos
Transplante de Medula Óssea , Fator Neurotrófico Derivado de Linhagem de Célula Glial/metabolismo , Transplante de Células-Tronco Mesenquimais , Atividade Motora/fisiologia , Doença dos Neurônios Motores/fisiopatologia , Neurônios Motores/patologia , Recuperação de Função Fisiológica/fisiologia , Animais , Apoptose , Comportamento Animal , Células da Medula Óssea/citologia , Células da Medula Óssea/metabolismo , Movimento Celular , Proliferação de Células , Transdiferenciação Celular , Células Cultivadas , Modelos Animais de Doenças , Proteínas de Fluorescência Verde/metabolismo , Imuno-Histoquímica , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Camundongos , Camundongos Knockout , Camundongos Nus , Doença dos Neurônios Motores/patologia , Neurônios Motores/metabolismo , Fenótipo , Baço/metabolismo , Baço/patologia
16.
PLoS One ; 6(12): e28385, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22174795

RESUMO

Aquaporin-1 (AQP1) is a water channel that is highly expressed in tissues with rapid O(2) transport. It has been reported that this protein contributes to gas permeation (CO(2), NO and O(2)) through the plasma membrane. We show that hypoxia increases Aqp1 mRNA and protein levels in tissues, namely mouse brain and lung, and in cultured cells, the 9L glioma cell line. Stopped-flow light-scattering experiments confirmed an increase in the water permeability of 9L cells exposed to hypoxia, supporting the view that hypoxic Aqp1 up-regulation has a functional role. To investigate the molecular mechanisms underlying this regulatory process, transcriptional regulation was studied by transient transfections of mouse endothelial cells with a 1297 bp 5' proximal Aqp1 promoter-luciferase construct. Incubation in hypoxia produced a dose- and time-dependent induction of luciferase activity that was also obtained after treatments with hypoxia mimetics (DMOG and CoCl(2)) and by overexpressing stabilized mutated forms of HIF-1α. Single mutations or full deletions of the three putative HIF binding domains present in the Aqp1 promoter partially reduced its responsiveness to hypoxia, and transfection with Hif-1α siRNA decreased the in vitro hypoxia induction of Aqp1 mRNA and protein levels. Our results indicate that HIF-1α participates in the hypoxic induction of AQP1. However, we also demonstrate that the activation of Aqp1 promoter by hypoxia is complex and multifactorial and suggest that besides HIF-1α other transcription factors might contribute to this regulatory process. These data provide a conceptual framework to support future research on the involvement of AQP1 in a range of pathophysiological conditions, including edema, tumor growth, and respiratory diseases.


Assuntos
Aquaporina 1/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Regiões Promotoras Genéticas , Transcrição Gênica , Ativação Transcricional , Animais , Aquaporina 1/metabolismo , Sítios de Ligação , Hipóxia Celular/genética , Linhagem Celular Tumoral , Permeabilidade da Membrana Celular , Regulação para Baixo/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Camundongos , Estabilidade Proteica , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Deleção de Sequência/genética , Ativação Transcricional/genética , Regulação para Cima/genética , Água/metabolismo
17.
Histol Histopathol ; 26(4): 451-9, 2011 04.
Artigo em Inglês | MEDLINE | ID: mdl-21360438

RESUMO

Aquaporin-1 (AQP1) is the main water channel responsible for water transport through many epithelia and endothelia. The latest evidence pointed toward an important role of this protein also in gas permeation, angiogenesis, cell proliferation and migration. In the present work we studied the expression of AQP1 by immunohistochemical staining of 92 lung biopsies from patients diagnosed with a pleuro-pulmonary tumor (71 lung and 21 pleural neoplasms). AQP1 expression was analyzed comparing the results among the different histological patterns and against 9 control cases (5 parenchyma and 4 healthy pleura). Clear staining of AQP1 was detected in 39 of the 92 tumors analyzed. In parenchyma, AQP1 was more frequently detected in primary lung adenocarcinomas (55%, P<0.001); in contrast, small cell carcinomas were the least AQP1 expressive tumors studied (93% of negative staining, P<0.05). Carcinomas analyzed in pleura (mesotheliomas and metastatic adenocarcinomas) also revealed strong expression of AQP1. High expression of this protein was detected in small capillaries in areas near or surrounding the tumor, and novel intense AQP1 immunostaining was detected over thicker alveolar walls in alveoli inside or next to the tumoral tissue regardless of the tumor type. An important role of AQP1 in tumor angiogenesis is sustained by the abundant expression of this protein in the endothelia of tumor capillaries. Further studies are necessary to elucidate the potential pathophysiological role of this protein in pleuro-pulmonary neoplasms.


Assuntos
Adenocarcinoma/metabolismo , Aquaporina 1/metabolismo , Neoplasias Pulmonares/metabolismo , Mesotelioma/metabolismo , Neoplasias Pleurais/metabolismo , Adenocarcinoma/patologia , Adenocarcinoma/secundário , Adenocarcinoma/cirurgia , Idoso , Biomarcadores Tumorais/metabolismo , Carcinoma Adenoescamoso/metabolismo , Carcinoma Adenoescamoso/patologia , Carcinoma Adenoescamoso/cirurgia , Carcinoma de Células Grandes/metabolismo , Carcinoma de Células Grandes/patologia , Carcinoma de Células Grandes/cirurgia , Carcinoma de Células Pequenas/metabolismo , Carcinoma de Células Pequenas/patologia , Carcinoma de Células Pequenas/cirurgia , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/cirurgia , Feminino , Humanos , Técnicas Imunoenzimáticas , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/cirurgia , Masculino , Mesotelioma/patologia , Mesotelioma/cirurgia , Pessoa de Meia-Idade , Neoplasias Pleurais/patologia , Neoplasias Pleurais/cirurgia
18.
J Neural Transm (Vienna) ; 116(8): 975-82, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19263191

RESUMO

The carotid body (CB) is a neural crest-derived organ whose major function is to sense changes in arterial O(2) tension to elicit hyperventilation during hypoxia. The CB is composed of clusters of neuron-like glomus, or type I, cells that are highly dopaminergic and contain large amounts of the glial cell line-derived neurotrophic factor (GDNF). Glomus cells are enveloped by glia-like sustentacular, or type II, cells. In chronic hypoxia the CB grows with increase in glomus cell number. This adaptive response depends on a collection of neural progenitors that can be isolated and induced to form clonal neurospheres in vitro. CB neurospheres contain numerous newly differentiated glomus cells, which maintain their functional properties and the ability to synthesize dopamine and GDNF. Intrastriatal CB transplants have been assayed in animal models of Parkinson's disease (PD) to test whether they increase the striatal dopamine levels and/or exert a neuroprotective action on the nigrostriatal pathway. Two pilot safety studies performed on PD patients subjected to CB autotransplantation have suggested that a major limitation of this technique is the small size of the organ. This could, however, be overcome by the in vitro formation of new CB tissue derived from adult CB stem cells.


Assuntos
Corpo Carotídeo/fisiologia , Corpo Carotídeo/transplante , Neurogênese , Neurônios/fisiologia , Transtornos Parkinsonianos/cirurgia , Nicho de Células-Tronco/fisiologia , Transplante de Células-Tronco , Células-Tronco/fisiologia , Animais , Corpo Carotídeo/citologia , Fator Neurotrófico Derivado de Linhagem de Célula Glial/metabolismo , Humanos , Plasticidade Neuronal , Neurônios/citologia , Nicho de Células-Tronco/citologia , Células-Tronco/citologia
19.
Artigo em Inglês | MEDLINE | ID: mdl-16418008

RESUMO

Aquaporins (AQPS) are transmembrane water channels poorly investigated in birds. Using degenerated primers and RT-PCR, we identified in kidney and gastrointestinal tract of Hubbard chickens (Gallus gallus) three fragments, corresponding to ck-AQP2, ck-AQP4, and ck-AQP5 mRNAs. Comparison of nucleotide ck-AQPs sequences to their rat and human orthologues revealed an overall identity of 75-90%. Expression in the renal and gastrointestinal systems of the three ck-AQPs mRNA was analysed by Northern assays. Transcript of ck-AQP2 was only identified in kidney. ck-AQP4 mRNA was highly expressed in brain, and to a lesser extent in kidney and stomach. ck-AQP5 mRNA was found in jejunum and ileum, and to a lesser extent in colon and lung. In situ hybridisation showed ck-AQP5 mRNA in the crypt cells of jejunum, ileum and colon, whereas it was absent from the cells lining the villi. Levels of ck-AQP5 mRNA (analyzed by Northern and in situ hybridisation assays) and protein (analysed by immunohistochemistry) decreased from the jejunum to the colon. This work confirmed the presence of AQPs in chicken, and showed that chicken and mammalian AQPs share a high degree of similarity in nucleotide sequence and tissue distribution.


Assuntos
Aquaporina 5/fisiologia , Aquaporinas/metabolismo , Intestino Grosso/metabolismo , Intestino Delgado/metabolismo , Sequência de Aminoácidos , Animais , Aquaporina 5/metabolismo , Sequência de Bases , Northern Blotting , Galinhas , Clonagem Molecular , Colo/metabolismo , DNA Complementar/metabolismo , Mucosa Gástrica/metabolismo , Trato Gastrointestinal/metabolismo , Humanos , Imuno-Histoquímica , Hibridização In Situ , Jejuno/metabolismo , Rim/metabolismo , Dados de Sequência Molecular , RNA/metabolismo , RNA Mensageiro/metabolismo , Ratos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homologia de Sequência de Aminoácidos
20.
Neurosurgery ; 53(2): 321-8; discussion 328-30, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12925247

RESUMO

OBJECTIVE: In this study, we assessed the feasibility of autotransplantation of carotid body (CB) cell aggregates into the striatum for the treatment of patients with Parkinson's disease (PD). METHODS: Six patients with advanced PD underwent bilateral autotransplantation of CB cell aggregates into the striatum. They were evaluated clinically preoperatively and for 18 months after surgery according to the recommendations of the Core Assessment Program for Intracerebral Transplantation. RESULTS: No major complications or adverse events resulted from the cell implantation or surgical procedures. During the course of the study, there was no significant aggravation of dyskinesia or decline in cognitive function in any of the patients. Five of the six patients who underwent transplantation manifested a measurable degree of clinical improvement evidenced by standardized clinical rating scales for PD. A decrease in the blinded Unified Parkinson's Disease Rating Scale Part III in the "off" state, the main measure of transplant efficacy in our study, was found to be maximal (between 26 and 74%) at 6 months after surgery. At 1 year, clear reductions in the blinded Unified Parkinson's Disease Rating Scale Part III were maintained in three patients (24, 38, and 52%, respectively). Modest improvement was seen in two patients (13 and 17%), and the sole patient who showed no improvement had the most fibrosis in the CB. The age of the patient and the state of the CB tissue were adversely correlated with clinical improvement after CB autotransplantation. CONCLUSION: This pilot study indicates that CB autograft transplantation is a relatively simple, safe, and viable therapeutical approach for the treatment of patients with advanced PD. More studies are needed to optimize the procedure and to assess its general applicability for the treatment of patients with PD.


Assuntos
Corpo Carotídeo/fisiopatologia , Corpo Carotídeo/transplante , Agregação Celular/fisiologia , Doença de Parkinson/fisiopatologia , Doença de Parkinson/cirurgia , Gânglios da Base/fisiopatologia , Gânglios da Base/cirurgia , Estudos de Viabilidade , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde , Projetos Piloto , Recuperação de Função Fisiológica/fisiologia , Fatores de Tempo , Transplante Autólogo
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