42 research outputs found

    Thyrotropin-releasing-hormone (TRH) and its physiological metabolite TRH-OH inhibit Na+ channel activity in mammalian septal neurons

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    The interaction of thyrotropin-releasing hormone (TRH) and its physiological metabolite TRH-OH with Na+ channels was studied in enzymatically dissociated guinea pig septal neurons by using the whole-cell variant of the patch-clamp technique. In about 60% of the cells tested, the neuropeptides at concentrations between 0.01 and 2.5 ,uM produced a dose-dependent reversible attenuation of Na+ currents. With 2 ,uM TRH-OH, peak Na+ current amplitude was reduced by 20-50% (27 ± 8%, mean ± SD; n = 16), whereas at the same concentration TRH was approximately half as effective as TRH-OH. In the presence of the tripeptides, the voltage-dependent parameters of the Na+ current were unaltered. TRH-induced reduction of Na+ current amplitude was transient and recovered almost completely during maintained exposure to the peptides. In addition, the response to either TRH-OH or TRH decreased with repeated treatment. Our results demonstrate that neuronal Na+ channels can be modulated by naturally occurring neuropeptides

    Direct confocal acquisition of fluorescence from X-gal staining on thick tissue sections

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    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

    Trophic restoration of the nigrostriatal dopaminergic pathway in long-term carotid body-grafted parkinsonian rats

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    We studied the mechanisms underlying long-term functional recovery of hemiparkinsonian rats grafted intrastriatally with carotid body (CB) cell aggregates. Amelioration of their motor syndrome is a result of the trophic actions of these grafts on the remaining ipsilateral substantia nigra neurons rather than of the release of dopamine from the CB grafts. The grafts maintain a stable morphological appearance and differentiated cell phenotype for the duration of the life of the host. Adult CB expresses high levels of glial cell line-derived neurotrophic factor (GDNF) and the multicomponent GDNF receptor complex. These properties may contribute to the trophic actions of the CB transplants on nigrostriatal neurons and to their extraordinary longevity. We show that CB glomus cells, although highly dopaminergic, are protected from dopamine-mediated oxidative damage because of the absence of the high-affinity dopamine transporter. Thus, intrastriatal CB grafts are uniquely suited for long-term delivery of trophic factors capable of promoting restoration of the nigrostriatal pathway

    Carotid Body Transplants as a Therapy for Parkinson’s Disease

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    Affecting over 1.5 million people across the world, Parkinson's disease is a progressive neurological condition characterized, in part, by the loss of dopaminergic neurons in the substantia nigra pars compacta. It affects 1.5% of the global population over 65 years of age. As life expectancy is increasing, over the next few years the number of patients with Parkinson´s disease will grow exponentially. To date, there are no available treatments that are capable of curing Parkinson´s disease, and the current goal of therapy, dopamine replacement strategies, is to reduce symptoms. After several years of disease progression, treatment is complicated by the onset of motor fluctuations and dyskinesias. This information reveals the great importance and social need of finding an effective therapeutic intervention for Parkinson´s disease. This exemplary new book reviews some of the most outstanding examples of new drugs currently in pharmaceutical development or new targets currently undergoing the validation process to try to reach the Parkinson´s drug market in the next few years as potential disease modifying drugs. Providing up to date and comprehensive coverage, this book will be essential reading for researchers working in academia and industry in any aspect of medicinal chemistry or drug discovery

    Selective Glial Cell Line-Derived Neurotrophic Factor Production in Adult Dopaminergic Carotid Body Cells In Situ and after Intrastriatal Transplantation

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    Glial cell line-derived neurotrophic factor (GDNF) exerts a notable protective effect on dopaminergic neurons in rodent and primate models of Parkinson’s disease (PD). The clinical applicability of this therapy is, however, hampered by the need of a durable and stable GDNF source allowing the safe and continuous delivery of the trophic factor into the brain parenchyma. Intrastriatal carotid body (CB) autografting is a neuroprotective therapy potentially useful in PD. It induces long-term recovery of parkinsonian animals through a trophic effect on nigrostriatal neurons and causes amelioration of symptoms insomePDpatients. Moreover, the adult rodentCBhas been shown to express GDNF. Here we show, using heterozygous GDNF/lacZ knock-out mice, that unexpectedly CB dopaminergic glomus, or type I, cells are the source of CB GDNF. Among the neural or paraneural cells tested, glomus cells are those that synthesize and release the highest amount ofGDNFin the adult rodent (as measured by standard and in situ ELISA). Furthermore,GDNFexpression by glomus cells is maintained after intrastriatal grafting and in CB of aged and parkinsonian 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-treated animals. Thus, glomus cells appear to be prototypical abundant sources of GDNF, ideally suited to be used as biological pumps for the endogenous delivery of trophic factors in PD and other neurodegenerative diseases

    Effects of Rho kinase inhibitors on grafts of dopaminergic cell precursors in a rat model of Parkinson's Disease

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    In models of Parkinson’s disease (PD), Rho kinase (ROCK) inhibitors have antiapoptotic and axonstabilizing effects on damaged neurons, decrease the neuroinflammatory response, and protect against dopaminergic neuron death and axonal retraction. ROCK inhibitors have also shown protective effects against apoptosis induced by handling and dissociation of several types of stem cells. However, the effect of ROCK inhibitors on dopaminergic cell grafts has not been investigated. In the present study, treatment of dopaminergic cell suspension with ROCK inhibitors yielded significant decreases in the number of surviving dopaminergic neurons, in the density of graft-derived dopaminergic fibers, and in graft vascularization. Dopaminergic neuron death also markedly increased in primary mesencephalic cultures when the cell suspension was treated with ROCK inhibitors before plating, which suggests that decreased angiogenesis is not the only factor leading to cell death in grafts. Interestingly, treatment of the host 6-hydroxydopamine-lesioned rats with ROCK inhibitors induced a slight, nonsignificant increase in the number of surviving neurons, as well as marked increases in the density of graft-derived dopaminergic fibers and the size of the striatal reinnervated area. The study findings discourage treatment of cell suspensions before grafting. However, treatment of the host induces a marked increase in graft-derived striatal reinnervation. Because ROCK inhibitors have also exerted neuroprotective effects in several models of PD, treatment of the host with ROCK inhibitors, currently used against vascular diseases in clinical practice, before and after grafting may be a useful adjuvant to cell therapy in PDThis work was supported by Spanish Ministry of Health (PI12/00798 and RD12/0019/0020) and Spanish Ministry of Economy and Competitiveness (BFU2012-3708)S

    Comparative analysis for the presence of IgG anti-aquaporin-1 in patients with NMO-Spectrum disorders

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    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

    Chaperoned amyloid proteins for immune manipulation: A-synuclein/hsp70 shifts immunity toward a modulatory phenotype

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    a-Synuclein (aSyn) is a 140-residue amyloid-forming protein whose aggregation is linked to Parkinson’s disease (PD). It has also been found to play a critical role in the immune imbalance that accompanies disease progression, a characteristic that has prompted the search for an effective aSyn-based immunotherapy. In this study, we have simultaneously exploited two important features of certain heat-shock proteins (HSPs): their classical ‘‘chaperone’’ activities and their recently discovered and diverse ‘‘immunoactive’’ properties. In particular, we have explored the immune response elicited by immunization of C57BL/6 mice with an aSyn/Hsp70 protein combination in the absence of added adjuvant. Our results show differential effects for mice immunized with the aSyn/Hsp70 complex, including a restrained aSyn-specific (IgM and IgG) humoral response as well as minimized alterations in the Treg (CD4 CD25 Foxp3 ) and Teff (CD4 Foxp3 ) cell populations, as opposed to significant changes in mice immunized with aSyn and Hsp70 alone. Furthermore, in vitro-stimulated splenocytes from immunized mice showed the lowest relative response against aSyn challenge for the ‘‘aSyn/Hsp70’’ experimental group as measured by IFN-g and IL-17 secretion, and higher IL-10 levels when stimulated with LPS. Finally, serum levels of Th1-cytokine IFN-g and immunomodulatory IL-10 indicated a unique shift toward an immunomodulato-ry/immunoprotective phenotype in mice immunized with the aSyn/Hsp70 complex. Overall, we propose the use of functional ‘‘HSP-chaperoned amyloid/ aggregating proteins’’ generated with appropriate HSP-substrate protein combinations, such as the aSyn/Hsp70 complex, as a novel strategy for immune-based intervention against synucleinopathies and other amyloid or ‘‘misfolding’’ neurodegenerative disorders.Financial support was provided by the Carlos III Institute of Health of Spain (Spanish Ministry of Economy and Competitiveness) according to the Strategic Action in Health (CP10/00527 to CR; PI14-01600 to DP) with co-funding by FEDER funds, the Spanish Ministry of Economy and Competitiveness (SAF-2012/39720 to CR), the Andalusian Ministry of Economy, Science and Innovation (P10-CTS-6928 and P11-CTS-8161 to DP) and the PAIDI Program from the Andalusian Government (CTS- 677 to DP). ALG holds a FPU Predoctoral Fellowship from the Spanish Ministry of Education (AP-2009/3816). The works of EJDG and CMD are supported by the Wellcome Trust, and the UK Medical, and Biotechnological and Biological Sciences Research Councils

    Dual cholinergic signals regulate daily migration of hematopoietic stem cells and leukocytes.

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    Hematopoietic stem and progenitor cells (HSPCs) and leukocytes circulate between the bone marrow (BM) and peripheral blood following circadian oscillations. Autonomic sympathetic noradrenergic signals have been shown to regulate HSPC and leukocyte trafficking, but the role of the cholinergic branch has remained unexplored. We have investigated the role of the cholinergic nervous system in the regulation of day/night traffic of HSPCs and leukocytes in mice. We show here that the autonomic cholinergic nervous system (including parasympathetic and sympathetic) dually regulates daily migration of HSPCs and leukocytes. At night, central parasympathetic cholinergic signals dampen sympathetic noradrenergic tone and decrease BM egress of HSPCs and leukocytes. However, during the daytime, derepressed sympathetic noradrenergic activity causes predominant BM egress of HSPCs and leukocytes via β3-adrenergic receptor. This egress is locally supported by light-triggered sympathetic cholinergic activity, which inhibits BM vascular cell adhesion and homing. In summary, central (parasympathetic) and local (sympathetic) cholinergic signals regulate day/night oscillations of circulating HSPCs and leukocytes. This study shows how both branches of the autonomic nervous system cooperate to orchestrate daily traffic of HSPCs and leukocytes
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