Revistas
Revista:
GLIA
ISSN:
0894-1491
Año:
2023
Vol.:
71
N°:
3
Págs.:
571 - 587
Inflammation is a common feature in neurodegenerative diseases that contributes to neuronal loss. Previously, we demonstrated that the basal inflammatory tone differed between brain regions and, consequently, the reaction generated to a pro-inflammatory stimulus was different. In this study, we assessed the innate immune reaction in the midbrain and in the striatum using an experimental model of Parkinson's disease. An adeno-associated virus serotype 9 expressing the alpha-synuclein and mCherry genes or the mCherry gene was administered into the substantia nigra. Myeloid cells (CD11b(+)) and astrocytes (ACSA2(+)) were purified from the midbrain and striatum for bulk RNA sequencing. In the parkinsonian midbrain, CD11b(+) cells presented a unique anti-inflammatory transcriptomic profile that differed from degenerative microglia signatures described in experimental models for other neurodegenerative conditions. By contrast, striatal CD11b(+) cells showed a pro-inflammatory state and were similar to disease-associated microglia. In the midbrain, a prominent increase of infiltrated monocytes/macrophages was observed and, together with microglia, participated actively in the phagocytosis of dopaminergic neuronal bodies. Although striatal microglia presented a phagocytic transcriptomic profile, morphology and cell density was preserved and no active phagocytosis was detected. Interestingly, astrocytes presented a pro-inflammatory fingerprint in the midbrain and a low number of differentially displayed transcripts in the striatum. During alpha-synuclein-dependent degeneration, microglia and astrocytes experience context-dependent activation states with a different contribution to the inflammatory reaction. Our results point towards the relevance of selecting appropriate cell targets to design neuroprotective strategies aimed to modulate the innate immune system during the active phase of dopaminergic degeneration.
Revista:
NEUROBIOLOGY OF DISEASE
ISSN:
0969-9961
Año:
2023
Vol.:
183
Págs.:
106166
Synucleinopathies are a group of neurodegenerative diseases without effective treatment characterized by the abnormal aggregation of alpha-synuclein (aSyn) protein. Changes in levels or in the amino acid sequence of aSyn (by duplication/triplication of the aSyn gene or point mutations in the encoding region) cause familial cases of synucleinopathies. However, the specific molecular mechanisms of aSyn-dependent toxicity remain unclear. Increased aSyn protein levels or pathological mutations may favor abnormal protein-protein interactions (PPIs) that could either promote neuronal death or belong to a coping response program against neurotoxicity. Therefore, the identification and modulation of aSyn-dependent PPIs can provide new therapeutic targets for these diseases. To identify aSyn-dependent PPIs we performed a proximity biotinylation assay based on the promiscuous biotinylase BioID2. When expressed as a fusion protein, BioID2 biotinylates by proximity stable and transient interacting partners, allowing their identification by streptavidin affinity purification and mass spectrometry. The aSyn interactome was analyzed using BioID2-tagged wild-type (WT) and pathological mutant E46K aSyn versions in HEK293 cells. We found the 14-3-3 epsilon isoform as a common protein interactor for WT and E46K aSyn. 14-3-3 epsilon correlates with aSyn protein levels in brain regions of a transgenic mouse model overexpressing WT human aSyn. Using a neuronal model in which aSyn cell-autonomous toxicity is quantitatively scored by longitudinal survival analysis, we found that stabilization of 14-3-3 protein-proteins interactions with Fusicoccin-A (FC-A) decreases aSyn-dependent toxicity. Furthermore, FC-A treatment protects dopaminergic neuronal somas in the substantia nigra of a Parkinson's disease mouse model. Based on these results, we propose that the stabilization of 14-3-3 epsilon interaction with aSyn might reduce aSyn toxicity, and highlight FC-A as a potential therapeutic compound for synucleinopathies.
Revista:
ANTIOXIDANTS
ISSN:
2076-3921
Año:
2021
Vol.:
10
N°:
8
Págs.:
1311
Blood-Brain barrier (BBB) disruption is a hallmark of central nervous system (CNS) dysfunction, and oxidative stress is one of the molecular mechanisms that may underlie this process. NADPH oxidases (NOX) are involved in oxidative stress-mediated vascular dysfunction and participate in the pathophysiology of its target organs. The NADPH oxidase 5 (NOX5) isoform is absent in rodents, and although little is known about the role it may play in disrupting the BBB, it has recently been implicated in experimental stroke. Our aim was to investigate the role of NADPH oxidase 5 (NOX5) in promoting vascular alterations and to identify its impact on the cognitive status of aged mice. No differences were detected in the arterial blood pressure or body weight between knock-in mice expressing endothelial NOX5 and the control mice. The Morris water maze test showed memory impairments in the aged knock-in mice expressing NOX5 compared with their control littermates. For assessing the BBB integrity, we studied the protein expression of two tight junction (TJ) proteins: Zonula occludens-1 (ZO-1) and occludin. Compared to the control animals, Aged NOX5 mice exhibited reduced levels of both proteins, demonstrating an alteration of the BBB integrity. Our data indicate that vascular NOX5 may favor behavioral changes with aging through oxidative stress-mediated BBB breakdown.
Revista:
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
ISSN:
1422-0067
Año:
2021
Vol.:
22
N°:
6
Págs.:
3107
Sirtuin 2 (SIRT2) has been associated to aging and age-related pathologies. Specifically, an age-dependent accumulation of isoform 3 of SIRT2 in the CNS has been demonstrated; however, no study has addressed the behavioral or molecular consequences that this could have on aging. In the present study, we have designed an adeno-associated virus vector (AAV-CAG-Sirt2.3-eGFP) for the overexpression of SIRT2.3 in the hippocampus of 2 month-old SAMR1 and SAMP8 mice. Our results show that the specific overexpression of this isoform does not induce significant behavioral or molecular effects at short or long term in the control strain. Only a tendency towards a worsening in the performance in acquisition phase of the Morris Water Maze was found in SAMP8 mice, together with a significant increase in the pro-inflammatory cytokine Il-1 beta. These results suggest that the age-related increase of SIRT2.3 found in the brain is not responsible for induction or prevention of senescence. Nevertheless, in combination with other risk factors, it could contribute to the progression of age-related processes. Understanding the specific role of SIRT2 on aging and the underlying molecular mechanisms is essential to design new and more successful therapies for the treatment of age-related diseases.
Revista:
BIOMOLECULES
ISSN:
2218-273X
Año:
2020
Vol.:
10
N°:
8
Págs.:
1198
Monoacylglycerol lipase inhibition (MAGL) has emerged as an interesting therapeutic target for neurodegenerative disease treatment due to its ability to modulate the endocannabinoid system and to prevent the production of proinflammatory mediators. To obtain a beneficial response, it is necessary to understand how this inhibition affects the neuron-glia crosstalk and neuron viability. In this study, the effect of MAGL inhibition by KML29 was evaluated in two types of rat cortical primary cultures; mixed cultures, including neuron and glial cells, and neuron-enriched cultures. The risk of neuronal death was estimated by longitudinal survival analysis. The spontaneous neuronal risk of death in culture was higher in the absence of glial cells, a process that was enhanced by KML29 addition. In contrast, neuronal survival was not compromised by MAGL inhibition in the presence of glial cells. Blockade of cannabinoid type 2 (CB2) receptors expressed mainly by microglial cells did not affect the spontaneous neuronal death risk but decreased neuronal survival when KML29 was added. Modulation of cannabinoid type 1 (CB1) receptors did not affect neuronal survival. Our results show that neuron-glia interactions are essential for neuronal survival. CB2 receptors play a key role in these protective interactions when neurons are exposed to toxic conditions.
Autores:
Elgueta, D. ; Contreras, F. ; Prado, C.; et al.
Revista:
FRONTIERS IN IMMUNOLOGY
ISSN:
1664-3224
Año:
2019
Vol.:
10
Págs.:
981
Neuroinflammation constitutes a fundamental process involved in Parkinson's disease (PD). Microglial cells play a central role in the outcome of neuroinflammation and consequent neurodegeneration of dopaminergic neurons in the substantia nigra. Current evidence indicates that CD4(+) T-cells infiltrate the brain in PD, where they play a critical role determining the functional phenotype of microglia, thus regulating the progression of the disease. We previously demonstrated that mice bearing dopamine receptor D3 (DRD3)-deficient CD4(+) T-cells are completely refractory to neuroinflammation and consequent neurodegeneration induced by the administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). In this study we aimed to determine whether DRD3-signalling is altered in peripheral blood CD4(+) T-cells obtained from PD patients in comparison to healthy controls (HC). Furthermore, we evaluated the therapeutic potential of targeting DRD3 confined to CD4(+) T-cells by inducing the pharmacologic antagonism or the transcriptional inhibition of DRD3-signalling in a mouse model of PD induced by the chronic administration of MPTP and probenecid (MPTPp). In vitro analyses performed in human cells showed that the frequency of peripheral blood Th1 and Th17 cells, two phenotypes favoured by DRD3-signalling, were significantly increased in PD patients. Moreover, native CD4(+) T-cells obtained from PD patients displayed a significant higher Th1 -biased differentiation in comparison with those naive CD4(+) T-cells obtained from HC. Nevertheless, DRD3 expression was selectively reduced in CD4(+) T-cells obtained from PD patients. The results obtained from in vivo experiments performed in mice show that the transference of CD4(+) T-cells treated ex vivo with the DRD3-selective antagonist PG01037 into MPTPp-mice resulted in a significant reduction of motor impairment, although without significant effect in neurodegeneration. Conversely, the transference CD4(+) T-cells transduced ex vivo with retroviral pArtículos codifying for an shRNA for DRD3 into MPTPp-mice had no effects neither in motor impairment nor in neurodegeneration. Notably, the systemic antagonism of DRD3 significantly reduced both motor impairment and neurodegeneration in MPTPp mice. Our findings show a selective alteration of DRD3-signalling in CD4(+) T-cells from PD patients and indicate that the selective DRD3-antagonism in this subset of lymphocytes exerts a therapeutic effect in parkinsonian animals dampening motor impairment.
Revista:
JOURNAL OF NEUROINFLAMMATION
ISSN:
1742-2094
Año:
2019
Vol.:
16
N°:
1
Págs.:
233
Background Inflammation is a critical process for the progression of neuronal death in neurodegenerative disorders. Microglia play a central role in neuroinflammation and may affect neuron vulnerability. Next generation sequencing has shown the molecular heterogeneity of microglial cells; however, the variability in their response to pathological inputs remains unknown. Methods To determine the effect of an inflammatory stimulus on microglial cells, lipopolysaccharide (LPS) was administered peripherally to mice and the inflammatory status of the cortex, hippocampus, midbrain, and striatum was assessed. Microglial activation and interaction with the immune system were analyzed in single cell suspensions obtained from the different brain regions by fluorescence-activated cell sorting, next generation RNA sequencing, real-time PCR, and immunohistochemical techniques. Antigen-presenting properties of microglia were evaluated by the ability of isolated cells to induce a clonal expansion of CD4(+) T cells purified from OT-II transgenic mice. Results Under steady-state conditions, the midbrain presented a high immune-alert state characterized by the presence of two unique microglial subpopulations, one expressing the major histocompatibility complex class II (MHC-II) and acting as antigen-presenting cells and another expressing the toll-like receptor 4 (TLR4), and by the presence of a higher proportion of infiltrating CD4(+) T cells. This state was not detected in the cortex, hippocampus, or striatum. Systemic LPS administration induced a general increase in classic pro-inflammatory cytokines, in co-inhibitory programmed death ligand 1 (PD-L1), and in cytotoxic T lymphocyte antigen 4 (CTLA-4) receptors, as well as a decrease in infiltrating effector T cells in all brain regions. Interestingly, a specific immune-suppressive response was observed in the midbrain which was characterized by the downregulation of MHC-II microglial expression, the upregulation of the anti-inflammatory cytokines IL10 and TGF beta, and the increase in infiltrating regulatory T cells. Conclusions These data show that the midbrain presents a high immune-alert state under steady-state conditions that elicits a specific immune-suppressive response when exposed to an inflammatory stimulus. This specific inflammatory tone and response may have an impact in neuronal viability.
Revista:
NEUROTHERAPEUTICS
ISSN:
1933-7213
Año:
2018
Vol.:
15
N°:
3
Págs.:
742 - 750
Drug efficacy in the central nervous system (CNS) requires an additional step after crossing the blood-brain barrier. Therapeutic agents must reach their targets in the brain to modulate them; thus, the free drug concentration hypothesis is a key parameter for in vivo pharmacology. Here, we report the impact of neurodegeneration (Alzheimer's disease (AD) and Parkinson's disease (PD) compared with healthy controls) on the binding of 10 known drugs to postmortem brain tissues from animal models and humans. Unbound drug fractions, for some drugs, are significantly different between healthy and injured brain tissues (AD or PD). In addition, drugs binding to brain tissues from AD and PD animal models do not always recapitulate their binding to the corresponding human injured brain tissues. These results reveal potentially relevant implications for CNS drug discovery.
Revista:
FRONTIERS IN NEUROANATOMY
ISSN:
1662-5129
Año:
2018
Vol.:
12
Págs.:
34
The pedunculopontine tegmental nucleus (PPN) and laterodorsal tegmental nucleus (LDT) are functionally associated brainstem structures implicated in behavioral state control and sensorimotor integration. The PPN is also involved in gait and posture, while the LDT plays a role in reward. Both nuclei comprise characteristic cholinergic neurons intermingled with glutamatergic and GABAergic cells whose absolute numbers in the rat have been only partly established. Here we sought to determine the complete phenotypical profile of each nucleus to investigate potential differences between them. Counts were obtained using stereological methods after the simultaneous visualization of cholinergic and either glutamatergic or GABAergic cells. The two isoforms of glutamic acid decarboxylase (GAD), GAD65 and GAD67, were separately analyzed. Dual in situ hybridization revealed coexpression of GAD65 and GAD67 mRNAs in ~90% of GAD-positive cells in both nuclei; thus, the estimated mean numbers of (1) cholinergic, (2) glutamatergic, and (3) GABAergic cells in PPN and LDT, respectively, were (1) 3,360 and 3,650; (2) 5,910 and 5,190; and (3) 4,439 and 7,599. These data reveal significant differences between PPN and LDT in their relative phenotypical composition, which may underlie some of the functional differences observed between them. The estimation of glutamatergic cells was significantly higher in the caudal PPN, supporting the reported functional rostrocaudal segregation in this nucleus. Fi
Revista:
NEUROBIOLOGY OF DISEASE
ISSN:
0969-9961
Año:
2018
Vol.:
118
Págs.:
64 - 75
Management of levodopa-induced dyskinesias (LID) is one of the main challenges in the treatment of Parkinson's disease patients. Mechanisms involved in the appearance of these involuntary movements are not well known but modifications in the activity of different neurotransmitter pathways seem to play an important role. The objective of this study was to determine differences in the expression levels of the endocannabinoid system (ECS) elements that would support a role in LID. The basal ganglia nuclei, putamen, external segment of the globus pallidus (GPe), internal segment of the globus pallidus (GPi), subthalamic nucleus (STN) and substantia nigra (SN) were dissected out from cryostat sections obtained from two groups of parkinsonian monkeys treated with levodopa to induce dyskinesias. One group of dyskinetic animals was sacrificed under the effect of levodopa, during the active phase of LID, and the other group 24 h after the last levodopa dose (OFF levodopa). Biochemical analysis by real-time PCR for ECS elements was performed. CBI receptor expression was upregulated in the putamen, GPe and STN during the active phase of dyskinesia and downregulated in the same nuclei and in the SN when dyskinetic animals were OFF levodopa. Changes in the 2-arachidonoyl glycerol (2-AG) synthesizing/degrading enzymes affecting the pallidal-subthalamic projections in dyskinetic animals OFF levodopa would suggest that 2-AG may play a role in LID. Anandamide (AEA) synthesizing/degrading enzymes were altered specifically in the GPe of untreated parkinsonian monkeys, suggesting that increased AEA levels may be a compensatory mechanism. These results indicate that the expression of the ECS elements is influenced by alterations in dopaminergic neurotransmission. On one hand, changes in CBI, receptor expression and in the 2-AG synthesizing/degrading enzymes suggest that they could be a therapeutic target for the active phase of LID. On the other hand, AEA metabolism could provide a non-dopaminergic target for symptomatic relief. However, further research is needed to unravel the mechanism of action of the ECS and how they could be modulated for a therapeutic purpose.
Revista:
NEUROPHARMACOLOGY
ISSN:
0028-3908
Año:
2017
Vol.:
125
Págs.:
319 - 332
The GPR55 receptor is expressed abundantly in the brain, especially in the striatum, suggesting it might fulfill a role in motor function. Indeed, motor behavior is impaired in mice lacking GPR55, which also display dampened inflammatory responses. Abnormal-cannabidiol (Abn-CBD), a synthetic cannabidiol (CBD) isomer, is a GPR55 agonist that may serve as a therapeutic agent in the treatment of inflammatory diseases. In this study, we explored whether modulating GPR55 could also represent a therapeutic approach for the treatment of Parkinson's disease (PD). The distribution of GPR55 mRNA was first analyzed by in situ hybridization, localizing GPR55 transcripts to neurons in brain nuclei related to movement control, striatum, globus pallidus, subthalamic nucleus, substantia nigra and cortex. Striatal expression of GPR55 was downregulated in parkinsonian conditions. When Abn-CBD and CBD (5 mg/kg) were chronically administered to mice treated over 5 weeks with 1-methyl-4-phenyl-1,2,3,6tetrahydropyridine and probenecid (MPTPp), Abn-CBD but not CBD prevented MPTPp induced motor impairment. Although Abn-CBD protected dopaminergic cell bodies, it failed to prevent degeneration of the terminals or preserve dopamine levels in the striatum. Both compounds induced morphological changes in microglia that were compatible with an anti-inflammatory phenotype that did not correlate with a neuroprotective activity. The symptomatic relief of Abn-CBD was further studied in the haloperidol-induced
Revista:
NEUROPHARMACOLOGY
ISSN:
0028-3908
Año:
2017
Vol.:
113
Págs.:
110 - 123
Neuroinflammation involves the activation of glial cells, which is associated to the progression of neurodegeneration in Parkinson's disease. Recently, we and other researchers demonstrated that dopamine receptor D3 (D3R)-deficient mice are completely refractory to neuroinflammation and consequent neurodegeneration associated to the acute intoxication with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). In this study we examined the therapeutic potential and underlying mechanism of a D3R-selective antagonist, PG01037, in mice intoxicated with a chronic regime of administration of MPTP and probenecid (MPTPp). Biodistribution analysis indicated that intraperitoneally administered PG01037 crosses the blood-brain barrier and reaches the highest concentration in the brain 40 min after the injection. Furthermore, the drug was preferentially distributed to the brain in comparison to the plasma. Treatment of MPTPp-intoxicated mice with PG01037 (30 mg/kg, administrated twice a week for five weeks) attenuated the loss of dopaminergic neurons in the substantia nigra pars compacta, as evaluated by stereological analysis, and the loss of striatal dopaminergic terminals, as determined by densitometric analyses of tyrosine hydroxylase and dopamine transporter immunoreactivities. Accordingly, the treatment resulted in significant improvement of motor performance of injured animals. Interestingly, the therapeutic dose of PG01037 exacerbated astrdgliosis and resulted in increased ramification density of microglial cells in the striatum of MPTPp-intoxicated mice. Further analyses suggested that D3R expressed in astrocytes favours a beneficial astrogliosis with antiinflammatory consequences on microglia. Our findings indicate that D3R-antagonism exerts a therapeutic effect in parkinsonian animals by reducing the loss of dopaminergic neurons in the nigrostriatal pathway, alleviating motor impairments and modifying the pro-inflammatory phenotype of glial cells. (C) 2016 Elsevier Ltd. All rights reserved.
Autores:
Silveira, M. M.; Arnold, J. C.; Laviolette, S. R.; et al.
Revista:
NEUROSCIENCE AND BIOBEHAVIORAL REVIEWS
ISSN:
0149-7634
Año:
2017
Vol.:
76
N°:
Part B
Págs.:
380 - 395
Public opinion surrounding the recreational use and therapeutic potential of cannabis is shifting. This review describes new work examining the behavioural and neural effects of cannabis and the endocannabinoid system, highlighting key regions within corticolimbic brain circuits. First, we consider the role of human genetic factors and cannabis strain chemotypic differences in contributing to interindividual variation in the response to cannabinoids, such as THC, and review studies demonstrating that THC-induced impairments in decision-making processes are mediated by actions at prefrontal CB1 receptors. We further describe evidence that signalling through prefrontal or ventral hippocampal CB1 receptors modulates mesolimbic dopamine activity, aberrations of which may contribute to emotional processing deficits in schizophrenia. Lastly, we review studies suggesting that endocannabinoid tone in the amygdala is a critical regulator of anxiety, and report new data showing that FAAH activity is integral to this response. Together, these findings underscore the importance of cannabinoid signalling in the regulation of cognitive and affective behaviours, and encourage further research given their social, political, and therapeutic implications
Revista:
BRAIN BEHAVIOR AND IMMUNITY
ISSN:
0889-1591
Año:
2016
Vol.:
57
Págs.:
94 - 105
Elements of the endocannabinoid system are strongly expressed in the basal ganglia where they suffer profound rearrangements after dopamine depletion. Modulation of the levels of the endocannabinoid 2-arachidonoyl-glycerol by inhibiting monoacylglycerol lipase alters glial phenotypes and provides neuroprotection in a mouse model of Parkinson's disease. In this study, we assessed whether inhibiting fatty acid amide hydrolase could also provide beneficial effects on the time course of this disease. The fatty acid amide hydrolase inhibitor, URB597, was administered chronically to mice treated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine and probenecid (MPTPp) over 5 weeks. URB597 (1 mg/kg) prevented MPTPp induced motor impairment but it did not preserve the dopamine levels in the nigrostriatal pathway or regulate glial cell activation. The symptomatic relief of URB597 was confirmed in haloperidol-induced catalepsy assays, where its anti-cataleptic effects were both blocked by antagonists of the two cannabinoid receptors (CB1 and CB2), and abolished in animals deficient in these receptors. Other fatty acid amide hydrolase inhibitors, JNJ1661010 and TCF2, also had anti-cataleptic properties. Together, these results demonstrate an effect of fatty acid amide hydrolase inhibition on the motor symptoms of Parkinson's disease in two distinct experimental models that is mediated by cannabinoid receptors.
Autores:
Aymerich, MS; Rojo-Bustamante, E.; Molina, C.; et al.
Revista:
MOLECULAR NEUROBIOLOGY
ISSN:
0893-7648
Año:
2016
Vol.:
53
N°:
4
Págs.:
2312 -2319
Growing evidence suggests that the endocannabinoid system plays a role in neuroprotection in Parkinson's disease. Recently, we have shown the neuroprotective effect of monoacylglycerol lipase (MAGL) inhibition with JZL184 in the chronic 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model. However, further investigation is needed to determine the neuroprotective mechanisms of the endocannabinoid system on the nigrostriatal pathway. The aim of this work was to investigate whether the neuroprotective effect of JZL184 in mice could be extended to an in vitro cellular model to further understand the mechanism of action of the drug. The SH-SY5Y cell line was selected based on its dopaminergic-like phenotype and its susceptibility to 1-methyl-4-phenylpyridinium iodide (MPP(+)) toxicity. Furthermore, SH-SY5Y cells express both cannabinoid receptors, CB1 and CB2. The present study describes the neuroprotective effect of MAGL inhibition with JZL184 in SH-SY5Y cells treated with MPP(+). The effect of JZL184 in cell survival was blocked by AM630, a CB2 receptor antagonist, and it was mimicked with JWH133, a CB2 receptor agonist. Rimonabant, a CB1 receptor antagonist, did not affect JZL184-induced cell survival. These results demonstrate that the neuroprotective effect of MAGL inhibition with JZL184 described in animal models of Parkinson's disease could be extended to in vitro models such as SH-SY5Y cells treated with MPP(+). This represents a useful tool to study mechanisms of neuroprotection mediated by MAGL inhibition, and we provide evidence for the possible involvement of CB2 receptors in the improvement of cell survival.
Revista:
TRENDS IN BIOCHEMICAL SCIENCES
ISSN:
0968-0004
Año:
2015
Vol.:
40
N°:
10
Págs.:
548 - 551
G-Protein-coupled receptors (GPCRs) were classically described as monomers. We now appreciate that they also function as homo- and hetero-oligomers, for which structural information is lacking. Here, we use available 3D structures and biochemical considerations to present and evaluate experimentally testable structural models for GPCR oligomers and associated G proteins.
Revista:
HIPPOCAMPUS
ISSN:
1050-9631
GPR40, the free fatty acid receptor 1, is expressed strongly in the primate pancreas and brain. While the role of pancreatic GPR40 in glucose homeostasis has been extensively studied, the absence of this G-protein-coupled receptor from the brain of rodents has hampered studies into its role in the central nervous system. However, we found intense GPR40 mRNA expression by in situ hybridization in mouse hippocampal and motor cortex neurons. Furthermore, in a neuroblastoma cell GPR40 was activated by docosahexaenoic acid and selective agonists, yet not by palmitic acid. Significantly, the activation of GPR40 provoked the phosphorylation of the cAMP response element-binding protein, CREB. The receptor was also functional in primary cultures of murine neurons, in which its activation by a selective agonist produced the phosphorylation of CREB and of extracellular signal-regulated kinases, ERK1/2. These results suggest that mice represent a suitable model for elucidating the role of GPR40 in brain function.
Revista:
NEUROBIOLOGY OF AGING
ISSN:
0197-4580
Año:
2014
Vol.:
35
N°:
11
Págs.:
2603 - 2616
Changes in cannabinoid receptor expression and concentration of endocannabinoids have been described in Parkinson's disease; however, it remains unclear whether they contribute to, or result from, the disease process. To evaluate whether targeting the endocannabinoid system could provide potential benefits in the treatment of the disease, the effect of a monoacylglycerol lipase inhibitor that prevents degradation of 2-arachidonyl-glycerol was tested in mice treated chronically with probenecid and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTPp). Chronic administration of the compound, JZL184 (8 mg/kg), prevented MPTPp-induced motor impairment and preserved the nigrostriatal pathway. Furthermore, none of the hypokinetic effects associated with cannabinoid receptor agonism were observed. In the striatum and substantia nigra pars compacta, MPTPp animals treated with JZL184 exhibited astroglial and microglial phenotypic changes that were accompanied by increases in TGFß messenger RNA expression and in glial cell-derived neurotrophic factor messenger RNA and protein levels. JZL184 induced an increase in ß-catenin translocation to the nucleus, implicating the Wnt/catenin pathway. Together, these results demonstrate a potent neuroprotective effect of JZL184 on the nigrostriatal pathway of parkinsonian animals, likely involving restorative astroglia and microglia activation and the release of neuroprotective and antiinflammatory molecules.
Revista:
INTERNATIONAL JOURNAL OF PHARMACEUTICS
ISSN:
0378-5173
Año:
2013
Vol.:
440
N°:
1
Págs.:
19-26
Human glial cell line-derived neurotrophic factor (hGDNF) is a very promising protein for the treatment of Parkinson's disease and other neurodegenerative disorders. The present work describes a quick and simple method to obtain a high amount of purified hGDNF using a mammalian cell-derived system. The method is based on the high expression level provided by a Semliki Forest virus vector and its ability to induce a strong shut-off of host-cell protein synthesis in mammalian cells. As a result, hGDNF is the only protein present in the supernatant and can be efficiently purified by a single chromatographic step. Using this system it was possible to eliminate other secreted proteins from the culture medium, like insulin-like growth factor-5, which are hard to remove using other hGDNF production methods. Purified hGDNF presents a complex glycosylation pattern typical of mammalian expression systems and is biologically active. This protocol could be extended to other secreted proteins and could be easily scaled up for industrial purposes. (C) 2012 Elsevier B.V. All rights reserved.
Revista:
JOURNAL OF NEUROPATHOLOGY AND EXPERIMENTAL NEUROLOGY
ISSN:
0022-3069
Año:
2012
Vol.:
71
N°:
11
Págs.:
973-982
The external segment of the globus pallidus (GPe) in humans and the equivalent structure in rodents, the globus pallidus (GP), influence signal processing in the basal ganglia under normal and pathological conditions. Parvalbumin (PV) immunoreactivity defines 2 main neuronal subpopulations in the GP/GPe: PV-immunopositive cells that project mainly to the subthalamic nucleus and the internal segment of the GP and PV-negative cells that mainly project to the striatum. We evaluated the number of neurons in the GP/GPe in animal models of Parkinson disease. In rats, dopaminergic denervation with 6-hydroxydopamine (6-OHDA) provoked a significant decrease in the number of GP neurons (12% +/- 4%, p < 0.05), which specifically affected the PV+ subpopulation. A similar trend was observed in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated monkeys. Markers of GABAergic activity (GAD65 and GAD67 mRNA) were not different from those of controls in 6-OHDA-lesioned rats. Taken together, these findings provide evidence for nondopaminergic neuronal cell loss in the basal ganglia of 6-OHDA-lesioned rats and suggest that a similar loss may occur in the MPTP monkey. These data suggest that in patients with Parkinson disease, the loss of GABAergic neurons projecting to the subthalamic nucleus may contribute to the hyperactivity of this nucleus despite the absence of gross alterations in GAD mRNA expression.
Revista:
MOVEMENT DISORDERS
ISSN:
0885-3185
Año:
2011
Vol.:
26
N°:
10
Págs.:
1943 - 1947
Background: Glial cell-derived neurotrophic factor is a survival factor for dopaminergic neurons and a promising candidate for the treatment of Parkinson's disease. However, the delivery issue of the protein to the brain still remains unsolved. Our aim was to investigate the effect of long-term delivery of encapsulated glial cell-derived neurotrophic factor within microspheres.
Methods: A single dose of microspheres containing 2.5 mu g of glial cell-derived neurotrophic factor was implanted intrastriatally in animals 2 weeks after a 6-hydroxydopamine lesion.
Results: The amphetamine test showed a complete behavioral recovery after 16 weeks of treatment, which was maintained until the end of the study (week 30). This effect was accompanied by an increase in dopaminergic striatal terminals and neuroprotection of dopaminergic neurons.
Conclusions: The main achievement was the long-term neurorestoration in parkinsonian animals induced by encapsulated glial cell-derived neurotrophic factor, suggesting that microspheres may be considered as a means to deliver glial cell-derived neurotrophic factor for Parkinson's disease treatment.
Revista:
THESCIENTIFICWORLDJOURNAL
ISSN:
1537-744X
Año:
2011
Vol.:
11
Págs.:
1995 - 2010
Understanding the trafficking of G-protein-coupled receptors (GPCRs) and their regulation by agonists and antagonists is fundamental to develop more effective drugs. Optical methods using fluorescent-tagged receptors and spinning disk confocal microscopy are useful tools to investigate membrane receptor dynamics in living cells. The aim of this study was to develop a method to characterize receptor dynamics using this system which offers the advantage of very fast image acquisition with minimal cell perturbation. However, in short-term assays photobleaching was still a problem. Thus, we developed a procedure to perform a photobleaching-corrected image analysis. A study of short-term dynamics of the long isoform of the dopamine type 2 receptor revealed an agonist-induced increase in the mobile fraction of receptors with a rate of movement of 0.08¿¿m/s For long-term assays, the ratio between the relative fluorescence intensity at the cell surface versus that in the intracellular compartment indicated that receptor internalization only occurred in cells co-expressing G protein-coupled receptor kinase 2. These results indicate that the lateral movement of receptors and receptor internalization are not directly coupled. Thus, we believe that live imaging of GPCRs using spinning disk confocal image analysis constitutes a powerful tool to study of receptor dynamics.
Revista:
Current Opinion in Pharmacology
ISSN:
1471-4892
Año:
2010
Vol.:
10
N°:
1
Págs.:
67 - 72
Revista:
Synapse
ISSN:
0887-4476
Año:
2010
Vol.:
64
N°:
7
Págs.:
566 - 569
Revista:
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
ISSN:
0027-8424
Año:
2010
Vol.:
107
N°:
43
Págs.:
18676 - 18681
It is well known that cocaine blocks the dopamine transporter. This mechanism should lead to a general increase in dopaminergic neurotransmission, and yet dopamine D-1 receptors (D(1)Rs) play a more significant role in the behavioral effects of cocaine than the other dopamine receptor subtypes. Cocaine also binds to sigma-1 receptors, the physiological role of which is largely unknown. In the present study, D1R and sigma R-1 were found to heteromerize in transfected cells, where cocaine robustly potentiated D1R-mediated adenylyl cyclase activation, induced MAPK activation per se and counteracted MAPK activation induced by D1R stimulation in a dopamine transporter-independent and sigma R-1-dependent manner. Some of these effects were also demonstrated in murine striatal slices and were absent in sigma R-1 KO mice, providing evidence for the existence of sigma R-1-D1R heteromers in the brain. Therefore, these results provide a molecular explanation for which D1R plays a more significant role in the behavioral effects of cocaine, through sigma R-1-D1R heteromerization, and provide a unique perspective toward understanding the molecular basis of cocaine addiction.
Revista:
INTERNATIONAL JOURNAL OF PHARMACEUTICS
ISSN:
0378-5173
Año:
2010
Vol.:
385
N°:
1-2
Págs.:
6 - 11
The administration of glial cell line-derived neurotrophic factor (GDNF) has emerged as a promising strategy for the treatment of several diseases of the nervous system as Parkinson's disease, amyotrophic lateral sclerosis, spinal cord injury and nerve regeneration as well as ocular diseases and drug addictions. A procedure for the purification of human recombinant glycosylated GDNF using a mammalian expression system as the source of the protein is discussed in the present paper. The neurotrophic factor was purified using cation exchange chromatography and gel filtration. A human cell line was chosen as the source of therapeutic protein, since a recombinant protein with a structure and glycosylation pattern equivalent to the native form is desirable for its prospective therapeutic utilization. The activity of the highly pure protein obtained was confirmed with a cell-based bioassay. The purified protein is suitable for its in vivo evaluation in animals and for possible subsequent clinical application.
Revista:
Journal of Histochemistry and Cytochemistry
ISSN:
0022-1554
Año:
2010
Vol.:
58
N°:
4
Págs.:
359 - 368
Acrolein is a potent fixative that provides both excellent preservation of ultrastructural morphology and retention of antigenicity, thus it is frequently used for immunocytochemical detection of antigens at the electron microscopic level. However, acrolein is not commonly used for fluorescence microscopy because of concerns about possible autofluorescence and destruction of the luminosity of fluorescent dyes. Here we describe a simple protocol that allows fine visualization of two fluorescent markers in 40-mu m sections from acrolein-perfused rat brain. Autofluorescence was removed by pretreatment with 1% sodium borohydride for 30 min, and subsequent incubation in a 50% ethanol solution containing 0.3% hydrogen peroxide enhanced fluorescence labeling. Thus, fluorescence labeling can be used for high-quality detection of markers in tissue perfused with acrolein. Furthermore, adjacent acrolein-fixed sections from a single experiment can be processed to produce high-quality results for electron microscopy or fluorescence labeling.
Nacionales y Regionales
Título:
SinPARK. Identificación de patrones de neuroinflamación específicos en la muerte neuronal dependiente de alfa-sinucleína en modelos de enfermedad de Parkinson
Código de expediente:
0011-1383-2019-000005 PC60
Investigador principal:
María Soledad Aymerich Soler
Financiador:
GOBIERNO DE NAVARRA
Convocatoria:
2019 GN Centros
Fecha de inicio:
01/12/2018
Fecha fin:
30/11/2019
Importe concedido:
70.700,00€
Otros fondos:
-
Título:
Identificación de dianas terapéuticas para la enfermedad de Parkinson basadas en la interacción de la neuroinflamación y la expresión de sinucleína. SinPARK-II
Código de expediente:
0011-1383-2020-000010 PC192 UNAV SinPARK-II
Investigador principal:
María Soledad Aymerich Soler
Financiador:
GOBIERNO DE NAVARRA
Convocatoria:
2020 GN Proyectos Colaborativos
Fecha de inicio:
01/06/2020
Fecha fin:
30/11/2022
Importe concedido:
196.835,25€
Otros fondos:
-
Título:
Modulación de las interacciones glia/systema immune mediante cannabinoides para identificar nuevas dianas terapeúticas en la enfermedad de Parkinson.
Código de expediente:
PI20/01063
Investigador principal:
María Soledad Aymerich Soler
Financiador:
INSTITUTO DE SALUD CARLOS III
Convocatoria:
2020 AES Proyectos de investigación
Fecha de inicio:
01/01/2021
Fecha fin:
31/12/2023
Importe concedido:
183.920,00€
Otros fondos:
Fondos FEDER
Título:
Modulación de la interacción neurona-glía a través del sistema endocannabinoide como estrategia de neuroprotección para la enfermedad de Parkinson
Código de expediente:
PI17/01931
Investigador principal:
María Soledad Aymerich Soler
Financiador:
INSTITUTO DE SALUD CARLOS III
Convocatoria:
AES2017 PROYECTOS DE INVESTIGACIÓN
Fecha de inicio:
01/01/2018
Fecha fin:
31/12/2020
Importe concedido:
99.220,00€
Otros fondos:
Fondos FEDER
