The endocannabinoid system in experimental models of Alzheimer's disease

415 p.Durante la progresión de la enfermedad de Alzheimer (EA) se produce una degeneración del sistema de neurotransmisión colinérgico del prosencéfalo basal, que conduce a una pérdida progresiva e irreversible de funciones cognitivas, así como alteraciones del sistema endocannabinoide (eCB) y cambios en la composición lipídica cerebral. Cada vez más estudios apuntan al posible papel neuroprotector del sistema eCB en procesos neurodegenerativos y ya han sido demostrados los efectos beneficiosos de agonistas cannabinoides para el tratamiento de alteraciones conductuales asociadas a la EA. El sistema eCB modula entre otros al sistema colinérgico a través del receptor CB1 y, la síntesis de sus ligandos está ligada a la señalización muscarínica colinérgica en áreas que controlan procesos cognitivos. En este trabajo se ha estudiado el papel del sistema eCB en diferentes modelos de degeneración colinérgica y de EA. La inmunotoxina 192IgG-saporina elimina específicamente neuronas colinérgicas del prosencéfalo basal y se ha utilizado en cultivos organotípicos y ratas adultas como modelos ex vivo e in vivo de EA. Además se han administrado cannabinoides en el modelo 3xTg-AD para la EA y evaluado aprendizaje y memoria. El tratamiento con cannabinoides muestra protección sobre la muerte celular asociada a la lesión colinérgica en el modelo ex vivo. Los estudios in vivo, tras la administración de la inmunotoxina, muestran un deterioro cognitivo, una gran pérdida de inervación colinérgica cortical, un proceso adaptativo del sistema eCB a través del receptor CB1 y una profunda alteración del perfil fosfolipídico, todo ello asociado a la lesión colinérgica. El modelo 3xTg-AD presenta alteraciones conductuales asociadas a una desregulación del sistema eCB, que son parcialmente revertidas tras la activación subcrónica del receptor CB1. Proponemos al sistema eCB como modulador de la neurotransmisión colinérgica en neurodegeneración y potencial diana de intervención terapéutica en la EA

The endocannabinoid system in experimental models of Alzheimer's disease

415 p.Durante la progresión de la enfermedad de Alzheimer (EA) se produce una degeneración del sistema de neurotransmisión colinérgico del prosencéfalo basal, que conduce a una pérdida progresiva e irreversible de funciones cognitivas, así como alteraciones del sistema endocannabinoide (eCB) y cambios en la composición lipídica cerebral. Cada vez más estudios apuntan al posible papel neuroprotector del sistema eCB en procesos neurodegenerativos y ya han sido demostrados los efectos beneficiosos de agonistas cannabinoides para el tratamiento de alteraciones conductuales asociadas a la EA. El sistema eCB modula entre otros al sistema colinérgico a través del receptor CB1 y, la síntesis de sus ligandos está ligada a la señalización muscarínica colinérgica en áreas que controlan procesos cognitivos. En este trabajo se ha estudiado el papel del sistema eCB en diferentes modelos de degeneración colinérgica y de EA. La inmunotoxina 192IgG-saporina elimina específicamente neuronas colinérgicas del prosencéfalo basal y se ha utilizado en cultivos organotípicos y ratas adultas como modelos ex vivo e in vivo de EA. Además se han administrado cannabinoides en el modelo 3xTg-AD para la EA y evaluado aprendizaje y memoria. El tratamiento con cannabinoides muestra protección sobre la muerte celular asociada a la lesión colinérgica en el modelo ex vivo. Los estudios in vivo, tras la administración de la inmunotoxina, muestran un deterioro cognitivo, una gran pérdida de inervación colinérgica cortical, un proceso adaptativo del sistema eCB a través del receptor CB1 y una profunda alteración del perfil fosfolipídico, todo ello asociado a la lesión colinérgica. El modelo 3xTg-AD presenta alteraciones conductuales asociadas a una desregulación del sistema eCB, que son parcialmente revertidas tras la activación subcrónica del receptor CB1. Proponemos al sistema eCB como modulador de la neurotransmisión colinérgica en neurodegeneración y potencial diana de intervención terapéutica en la EA

Handling and novel object recognition modulate fear response and endocannabinoid signaling in nucleus basalis magnocellularis

[EN] Storage of aversive memories is of utmost importance for survival, allowing animals to avoid upcoming similar stimuli. However, without reinforcement, the learned avoidance response gradually decreases over time. Although the molecular mechanisms controlling this extinction process are not well known, there is evidence that the endocannabinoid system plays a key role through CB1 receptor-mediated modulation of cholinergic signaling. In this study, we measured fear extinction throughout 7 months using naive rats, assessed in passive avoidance (PA) test in a non-reinforced manner. Then, we evaluated the effect of gentle handling and non-aversive novel object recognition test (NORT) on the extinction and expression of fear memories by measuring passive avoidance responses. Neurochemical correlates were analyzed by functional autoradiography for cannabinoid, cholinergic, and dopaminergic receptors. Despite results showing a gradual decrease of passive avoidance response, it did not fully disappear even after 7 months, indicating the robustness of this process. Meanwhile, in rats that received gentle handling or performed NORT after receiving the PA aversive stimulus, extinction occurred within a week. In contrast, gentle handling performed before receiving the aversive stimulus exacerbated fear expression and triggered escape response in PA. The neurochemical analysis showed increased cannabinoid and cholinergic activity in the nucleus basalis magnocellularis (NBM) in rats that had performed only PA, as opposed to rats that received gentle handling before PA. Additionally, a correlation between CB1 mediated-signaling in the NBM and freezing in PA was found, suggesting that the endocannabinoid system might be responsible for modulating fear response induced by aversive memories.Basque Government IT975-16 to the "Neurochemistry and Neurodegeneration" consolidated research group; Instituto de Salud Carlos III, Grant/Award Number: PI20/0015

Modulation of Neurolipid Signaling and Specific Lipid Species in the Triple Transgenic Mouse Model of Alzheimer’s Disease

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder and the most common cause of dementia in aging populations. Recently, the regulation of neurolipid-mediated signaling and cerebral lipid species was shown in AD patients. The triple transgenic mouse model (3xTg-AD), harboring βAPPSwe, PS1M146V, and tauP301L transgenes, mimics many critical aspects of AD neuropathology and progressively develops neuropathological markers. Thus, in the present study, 3xTg-AD mice have been used to test the involvement of the neurolipid-based signaling by endocannabinoids (eCB), lysophosphatidic acid (LPA), and sphingosine 1-phosphate (S1P) in relation to the lipid deregulation. [35S]GTPγS autoradiography was used in the presence of specific agonists WIN55,212-2, LPA and CYM5442, to measure the activity mediated by CB1, LPA1, and S1P1 Gi/0 coupled receptors, respectively. Consecutive slides were used to analyze the relative intensities of multiple lipid species by MALDI Mass spectrometry imaging (MSI) with microscopic anatomical resolution. The quantitative analysis of the astrocyte population was performed by immunohistochemistry. CB1 receptor activity was decreased in the amygdala and motor cortex of 3xTg-AD mice, but LPA1 activity was increased in the corpus callosum, motor cortex, hippocampal CA1 area, and striatum. Conversely, S1P1 activity was reduced in hippocampal areas. Moreover, the observed modifications on PC, PA, SM, and PI intensities in different brain areas depend on their fatty acid composition, including decrease of polyunsaturated fatty acid (PUFA) phospholipids and increase of species containing saturated fatty acids (SFA). The regulation of some lipid species in specific brain regions together with the modulation of the eCB, LPA, and S1P signaling in 3xTg-AD mice indicate a neuroprotective adaptation to improve neurotransmission, relieve the myelination dysfunction, and to attenuate astrocyte-mediated neuroinflammation. These results could contribute to identify new therapeutic strategies based on the regulation of the lipid signaling in familial AD patients.This research was funded by the regional Basque Government IT975-16 to the “Neurochemistry and Neurodegeneration” consolidated research group and ISCIII Spanish Ministry for Health PI20/00153

Lisofosfolipidoen eta Alzheimer gaixotasunaren arteko erlazioa: etorkizuneko itu farmakologikoaren bila

Lipidoak funtzio energetikoaz eta egitura-funtzioez gain deskribatu diren beste funtzioei esker garrantzitsuak bilakatzen ari dira. Funtzio neurotransmisorea edota neuromoduladorea aurkeztu duten lipidoen artean, lisofosfolipidoak aurkitu ditzakegu. Lisofosfolipidoak lipido molekula txiki bioaktiboak, karbonodun kate bakarra eta buru polar bat edukitzeagatik bereizten direnak dira. Lisofosfolipidoen artean, azido lisofosfatidikoa eta esfingosina 1-fosfatoaren egitura eta sistemen funtzioak izan dira hobeto deskribatu direnak. Lisofosfolipidoak zelulaz kanpoko bitartekari aritzen dira berentzat espezifikoak diren G proteinei loturiko hartzaileak aktibatuz. Molekula horien seinaleztapenaren bidez zenbait prozesu neurokimiko modulatzen dira, adibidez, neuromodulazioa eta neuroinflamazioa. Gainera, ikasketarekin eta oroimenarekin erlazioa erakutsi dute. Horren haritik, orain arte ondoen deskribatutako lisofosfolipidoen sistemak, azido lisofosfatidikoa eta esfingosina l-fosfatoa, hain zuzen ere, asaldatuta daude Alzheimer gaixotasunean eta gaixotasun honetako zenbait animalia-eredutan. Aldaketa horien zentzua oraindik ez dago finkatuta, baina haien eragina beste neurotransmisio-sistemen edota bestelako funtzio biologikoen modulazioaren bidez gerta daitezke. Beraz, lipido hauek etorkizun handiko itu farmakologikoak izan daitezke Alzheimer gaixotasunean agertzen diren sintoma neuropatologikoak eta neuropsikiatrikoak arintzeko. Hortaz, merkatuan dauden lipidoen seinaleztapena itutzat duten eta beste neuroendekapenezko gaixotasunak tratatzeko erabilgarriak diren farmakoak baliagarriak izan litezke Alzheimer gaixotasuna tratatzeko, aukera emanez horrela Alzheimer gaixotasuna tratatzeko dagoen hutsune farmakologikoa betetzeko.; In addition to energy and structural functions, lipids are becoming important thanks to the other functions described. Some lipids have been shown to exhibit neurotransmitter or neuromodulatory function, including lysophospholipids. Lysophospholipids are small bioactive lipid molecules that are distinguished only by having a single carbon chain and a single polar head. The lysophosphatidic acid and sphingosine l-phosphate structure and system functions are best described among those with neurotransmitter function. Lysophospholipids act as extracellular mediators that activate receptor-specific G proteins that are specific to them. The signaling of these molecules modulate certain neurochemical processes, including neuromodulation and neuroinflammation. They have also presented the relationship with learning and memory. In this respect, the best described lysophospholipid systems, lysophosphatidic acid and sphingosine 1-phosphate, are indeed disturbed in Alzheimer’s disease and in some animal models of this disease. The meaning of these changes is not yet established, but their effect may be related to the modulation of other neurotransmission systems or other biological functions. These lipids are therefore supposed to be the promising pharmacological targets to alleviate the neuropathological and neuropsychiatric symptoms that appear in Alzheimer’s disease. Therefore, marketed drugs that have lipid signaling as a pharmacological target and that are useful to treat other neurodegenerative diseases could be also helpful to treat the Alzheimer’s disease, and with this it might be possible to fill the pharmacological gap in the treatment of Alzheimer’s disease so far

Cannabinoid signaling modulation through JZL184 restores key phenotypes of a mouse model for Williams-Beuren syndrome

Williams-Beuren syndrome (WBS) is a rare genetic multisystemic disorder characterized by mild-to-moderate intellectual disability and hypersocial phenotype, while the most life-threatening features are cardiovascular abnormalities. Nowadays, there are no pharmacological treatments to directly ameliorate the main traits of WBS. The endocannabinoid system (ECS), given its relevance for both cognitive and cardiovascular function, could be a potential druggable target in this syndrome. We analyzed the components of the ECS in the complete deletion (CD) mouse model of WBS and assessed the impact of its pharmacological modulation in key phenotypes relevant for WBS. CD mice showed the characteristic hypersociable phenotype with no preference for social novelty and poor short-term object-recognition performance. Brain cannabinoid type-1 receptor (CB1R) in CD male mice showed alterations in density and coupling with no detectable change in main endocannabinoids. Endocannabinoid signaling modulation with subchronic (10 days) JZL184, a selective inhibitor of monoacylglycerol lipase, specifically normalized the social and cognitive phenotype of CD mice. Notably, JZL184 treatment improved cardiovascular function and restored gene expression patterns in cardiac tissue. These results reveal the modulation of the ECS as a promising novel therapeutic approach to improve key phenotypic alterations in WBS

Practicando Ingeniería Química: Prácticas colaborativas de bajo coste para grupos numerosos

Elaboración de un catálogo de prácticas de laboratorio de bajo coste para trabajar los fundamentos de ingeniería química con grupos numerosos, usando metodologías activas de aprendizaje para incrementar la motivación de los estudiantes.Depto. de Ingeniería Química y de MaterialesFac. de Ciencias QuímicasFALSEsubmitte

The endocannabinoid system in experimental models of Alzheimer's disease

415 p.Durante la progresión de la enfermedad de Alzheimer (EA) se produce una degeneración del sistema de neurotransmisión colinérgico del prosencéfalo basal, que conduce a una pérdida progresiva e irreversible de funciones cognitivas, así como alteraciones del sistema endocannabinoide (eCB) y cambios en la composición lipídica cerebral. Cada vez más estudios apuntan al posible papel neuroprotector del sistema eCB en procesos neurodegenerativos y ya han sido demostrados los efectos beneficiosos de agonistas cannabinoides para el tratamiento de alteraciones conductuales asociadas a la EA. El sistema eCB modula entre otros al sistema colinérgico a través del receptor CB1 y, la síntesis de sus ligandos está ligada a la señalización muscarínica colinérgica en áreas que controlan procesos cognitivos. En este trabajo se ha estudiado el papel del sistema eCB en diferentes modelos de degeneración colinérgica y de EA. La inmunotoxina 192IgG-saporina elimina específicamente neuronas colinérgicas del prosencéfalo basal y se ha utilizado en cultivos organotípicos y ratas adultas como modelos ex vivo e in vivo de EA. Además se han administrado cannabinoides en el modelo 3xTg-AD para la EA y evaluado aprendizaje y memoria. El tratamiento con cannabinoides muestra protección sobre la muerte celular asociada a la lesión colinérgica en el modelo ex vivo. Los estudios in vivo, tras la administración de la inmunotoxina, muestran un deterioro cognitivo, una gran pérdida de inervación colinérgica cortical, un proceso adaptativo del sistema eCB a través del receptor CB1 y una profunda alteración del perfil fosfolipídico, todo ello asociado a la lesión colinérgica. El modelo 3xTg-AD presenta alteraciones conductuales asociadas a una desregulación del sistema eCB, que son parcialmente revertidas tras la activación subcrónica del receptor CB1. Proponemos al sistema eCB como modulador de la neurotransmisión colinérgica en neurodegeneración y potencial diana de intervención terapéutica en la EA

Endocannabinoid and Muscarinic Signaling Crosstalk in the 3xTg-AD Mouse Model of Alzheimer's Disease

The endocannabinoid system, which modulates emotional learning and memory through CB 1 receptors, has been found to be deregulated in Alzheimer's disease (AD). AD is characterized by a progressive decline in memory associated with selective impairment of cholinergic neurotransmission. The functional interplay of endocannabinoid and muscarinic signaling was analyzed in seven-month-old 3xTg-AD mice following the evaluation of learning and memory of an aversive stimulus. Neurochemical correlates were simultaneously studied with both receptor and functional autoradiography for CB 1 and muscarinic receptors, and regulations at the cellular level were depicted by immunofluorescence. 3xTg-AD mice exhibited increased acquisition latencies and impaired memory retention compared to age-matched non-transgenic mice. Neurochemical analyses showed changes in CB 1 receptor density and functional coupling of CB 1 and muscarinic receptors to G i/o proteins in several brain areas, highlighting that observed in the basolateral amygdala. The subchronic (seven days) stimulation of the endocannabinoid system following repeated WIN55,212-2 (1 mg/kg) or JZL184 (8 mg/kg) administration induced a CB 1 receptor downregulation and CB 1 -mediated signaling desensitization, normalizing acquisition latencies to control levels. However, the observed modulation of cholinergic neurotransmission in limbic areas did not modify learning and memory outcomes. A CB 1 receptor-mediated decrease of GABAergic tone in the basolateral amygdala may be controlling the limbic component of learning and memory in 3xTg-AD mice. CB 1 receptor desensitization may be a plausible strategy to improve behavior alterations associated with genetic risk factors for developing AD.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Specific Phospholipid Modulation by Muscarinic Signaling in a Rat Lesion Model of Alzheimers Disease

[Image: see text] Alzheimer’s disease (AD) represents the most common cause of dementia worldwide and has been consistently associated with the loss of basal forebrain cholinergic neurons (BFCNs) leading to impaired cholinergic neurotransmission, aberrant synaptic function, and altered structural lipid metabolism. In this sense, membrane phospholipids (PLs) can be used for de novo synthesis of choline (Ch) for the further obtaining of acetylcholine (ACh) when its availability is compromised. Specific lipid species involved in the metabolism of Ch have been identified as possible biomarkers of phenoconversion to AD. Using a rat model of BFCN lesion, we have evaluated the lipid composition and muscarinic signaling in brain areas related to cognitive processes. The loss of BFCN resulted in alterations of varied lipid species related to Ch metabolism at nucleus basalis magnocellularis (NMB) and cortical projection areas. The activity of muscarinic receptors (mAChR) was decreased in the NMB and increased in the hippocampus according to the subcellular distribution of M(1)/M(2) mAChR which could explain the learning and memory impairment reported in this AD rat model. These results suggest that the modulation of specific lipid metabolic routes could represent an alternative therapeutic strategy to potentiate cholinergic neurotransmission and preserve cell membrane integrity in AD