27 research outputs found

    Predicción de la afinidad de ligandos antagonistas por receptores de adenosina A2A usando árboles de decisión

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    Neurodegenerative diseases are being treated by modulating adenosine receptors with more effective, safe and selective antagonists. The objective of the study was to develop a methodology to obtain classification models based on decision tree algorithms and descriptors from 0D to 2D of non-congenital families of organic compounds to qualitatively predict ligand-RAA2A affinity. For this purpose, a non-congeneric database of 315 antagonists was constructed and cured with its inhibition constant in nano molar, labeled as potent and weak. The Dragon and ISIDA / QSPR programs were used to calculate molecular descriptors and five groups of descriptors were obtained. In each group 50 descriptors were selected using the mRMR criterion. The database was divided into Training, Test and External series through a random selection and a generalized k-means cluster analysis. Classifiers were developed and validated using the WEKA program. The results were analyzed using the statistical tests of Friedman and Wilcoxon. The significant influence of parameter m of algorithm J48 on the predictivity was verified for the models that used the descriptors of the aug.a-b and hyb.aug.a groups of ISIDA / QSPR. The best performance model was obtained from the selected descriptors of the ISIDA-all group with a value of m = 6 and reached 90.6% prediction on the External series. The methodology developed to obtain classification models based on decision tree algorithms and descriptors from 0D to 2D of non-congenital families of organic compounds is effective in qualitatively predicting ligand-RAA2A affinity with accuracy, specificity and selectivity greater than 90 %. Keywords: classification, machine learning, modeling, QSARLas enfermedades neurodegenerativas están siendo tratadas mediante la modulación de los receptores de adenosina con antagonistas más eficaces, seguros y selectivos. El objetivo del estudio consistió en desarrollar una metodología para obtener modelos de clasificación sobre la base de algoritmos de árboles de decisión y descriptores de 0D a 2D de familias no congenéricas de compuestos orgánicos para predecir cualitativamente la afinidad ligando-RAA2A. Para ello se construyó y curó una base de datos no congenérica de 315 antagonistas con su constante de inhibición en nano molar, etiquetados como potentes y débiles. Se utilizaron los programas Dragon e ISIDA/QSPR para calcular descriptores moleculares y se obtuvieron cinco grupos de descriptores. En cada grupo se seleccionaron 50 descriptores usando el criterio mRMR. La base de datos se dividió en series de Entrenamiento, Prueba y Externa mediante una selección aleatoria y un análisis de clúster k-means generalizado. Se desarrollaron y validaron clasificadores utilizando el programa WEKA. Los resultados fueron analizados mediante las pruebas estadísticas de Friedman y Wilcoxon. Se comprobó la influencia significativa del parámetro m del algoritmo J48 en la predictividad, para los modelos que usaron los descriptores de los grupos aug.a-b e hyb.aug.a del ISIDA/QSPR. El modelo de mejor desempeño se obtuvo de los descriptores seleccionados del grupo ISIDA-todos con un valor de m=6 y alcanzó 90.6% de predicción sobre la serie Externa. La metodología desarrollada para obtener modelos de clasificación sobre la base de algoritmos de árboles de decisión y descriptores de 0D a 2D de familias no congenéricas de compuestos orgánicos es efectiva para predecir cualitativamente la afinidad ligando-RAA2A con una exactitud, especificidad y selectividad superiores al 90%. Palabras clave: aprendizaje automatizado; clasificación; modelación; QSA

    Drug-target residence time : a case for the adenosine A1 and A2A receptors

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    Ligand-receptor binding kinetics is increasingly recognized to play a pivotal role in the early phase of drug design and discovery. In this thesis ligand-receptor binding kinetics, particularly residence time, at the adenosine A1 and A2A receptors was extensively investigated. Several case studies at these two prototypical GPCRs demonstrate that binding kinetics as an emerging paradigm can provide additional information of drug-target interactions at the molecular level. This thesis will contribute to stipulating the importance of kientics-based drug design and discovery in the future.Medicinal Chemistr

    Development of novel ligands influencing neurotransmission in the central nervous system

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    The development of novel drugs targeting GPCRs is of particular interest since modulation of subfamilies of this receptor class highly influences neurotransmission in the central nervous system. This study has focused on the development of ligands for the dopamine D3 receptor. The receptor belongs to the dopamine D2-like family among the biogenic amine binding GPCRs. The dopamine D3 receptor is involved in neurological and neuropsychiatric disorders such as Parkinson’s disease, schizophrenia and drug addiction. Due to its close structural similarity to the dopamine D2 receptor subtype, it is still a challenge to identify and further optimize new leads. Therefore an in vitro screening assay, which also allows elucidating comprehensive structure-affinity relationships, is required. In this investigation the implementation and evaluation of radioligand binding assays for human dopamine D2S and dopamine D3 receptors and for the related aminergic human histamine H1 receptor stably expressed in Chinese hamster ovary (CHO) cells has been performed. Saturation binding experiments with [³H]spiperone at dopamine D2S and D3 receptors and with [³H]mepyramine at histamine H1 receptors were carried out. The determined equilibrium dissociation constant of radioligands (Kd) and the total number of specific binding sites (Bmax) of the receptor membrane preparations were in good agreement with reference data. Inhibition constants (Ki) of reference ligands obtained in radioligand competition binding experiments at dopamine hD2S, hD3 and histamine H1 receptors validated the reliability and reproducibility of the assay. In order to discriminate agonists from antagonists, a GTP shift assay has been investigated for dopamine D2S and D3 receptors. In competition binding studies at dopamine D2S receptors the high- and low affinity state in the absence of the GTP analogue Gpp(NH)p has been recognized for the agonists pramipexole and the seleno analogue 54. In the presence of Gpp(NH)p a decrease in affinity, referred to as “GTP shift”, has been revealed for agonists at dopamine D2S and D3 receptors. An effect of Gpp(NH)p on dopamine D2S receptor binding has not been observed for the antagonists ST 198 and BP 897, while a reverse “GTP shift” has been noticed at the dopamine D3 receptor. For the development of novel ligands with high affinity and selectivity for dopamine D3 receptors, investigation in refined structure-affinity relationships (SAR) of analogues of the lead BP 897 has been performed. Replacement of the naphthalen-2-carboxamide of BP 897 by aryl amide residues (1 - 4) had a clear influence on affinity binding and selectivity for dopamine D3 receptors. Introduction of the benzo[b]thiophen-2-carboxamide (1) has markedly improved binding with subnanomolar affinity and enhanced selectivity for dopamine D3 receptors. Exchanging the aryl substituted basic alkanamine residue of 1 by a 1,2,3,4-tetrahydroisoquinoline moiety (6) emphasized the benefit of the 4-(2-methoxyphenyl) piperazine residue of BP 897 regarding dopamine D2 and D3 receptor affinities. The change of particular elements of BP 897 and the rearrangement of the amide functionality resulted in inverse amide compounds with new chemical properties. Moderate affinity binding data, as obtained for the isoindol-1-carbonyl compound 11, suggest that inverse amides provide a worthwhile new lead structure with a novel structural scaffold. A hybrid approach combining privileged scaffolds of histamine H1 receptor antagonists and fragments of dopamine D3 receptor-preferring ligands, related to BP 897and analogues has been investigated. Various benzhydrylpiperazine derivatives and related structures have shown moderate to high affinities for dopamine D3 receptors with the impressive enhancement of the cinnamide substituted bamipine-related hybrid 39, exhibiting the highest affinity and selectivity for dopamine D3 receptors. Improved affinity profiles of structural modified histamine H1 receptor antagonists for dopamine D2 and D3 receptors and a refined SAR has been achieved. A SAR of derivatives of the dopamine agonist pramipexole and the related etrabamine has been studied. The propargyl substituted etrabamine derivative 61 demonstrated highest affinity and selectivity. The ligand attracts attention since neuroprotective properties have been reported for the propargyl functionality. Further development resulted in the most promising compound 64, a cinnamide derivative with 4-fluoro substitution on the phenyl ring. Subnanomolar affinity and remarkable selectivity for dopamine D3 receptors has aroused particular interest in this ligand due to its development potential as a radioligand for PET studies. Radioligand binding studies in combination with virtual screening and different classification techniques of chemoinformatic methods resulted in further elucidation of SAR. New leads with novel chemical scaffolds have been found in the bicycle[2.2.1]heptane derivative 95 and the benzhydrylidene substituted pyrrolidindione 112 and can be further optimized by chemical modifications. The outcome of the studies provides the development of various novel high affine and dopamine D3 receptor selective ligands. Modifications of lead structures or application of chemoinformatic tools in combination with radioligand competition binding assays have resulted in new leads with different chemical scaffolds. Furthermore, a comprehensive insight into structure-affinity relationships of ligands at dopamine D3 receptors has been revealed. This refined SAR is valuable to develop more affine and selective drug candidates with a designed pharmacological receptor profile.Das Ziel der Arbeit war die Entwicklung von neuen Liganden zur Beeinflussung der Neurotransmission im zentralen Nervensystem. Der Fokus lag auf dem Dopamin-D3-Rezeptor, der eine wichtige Rolle bei Morbus Parkinson, Schizophrenie und Drogenmissbrauch spielt. Aufgrund seiner Strukturähnlichkeit zum Dopamin-D2-Rezeptor ist es eine Herausforderung, neue, selektive Leitstrukturen für den Dopamin-D3-Rezeptor zu identifizieren bzw. zu optimieren. Ein in vitro Testsystem ist hierfür erforderlich und ermöglicht das Aufstellen von Struktur-Wirkungsbeziehungen (SAR) und ein rationales Wirkstoffdesign. Die Arbeit umfasste die Etablierung von Radioliganden Bindungsassays an Dopamin-D2S- und -D3-Rezeptoren, sowie am verwandten aminergen Histamin-H1-Rezeptor, die stabil in Zelllinien von Ovarien des Chinesischen Hamsters exprimiert wurden. Sättigungsstudien wurden mit [³H]Spiperon am Dopamin-D2S- und D3-Rezeptor und mit [³H]Mepyramin am Histamin-H1-Rezeptor durchgeführt. Die ermittelten Dissoziationskonstanten (Kd) und maximale Zahl der Bindungsstellen (Bmax) stimmten mit den Literaturwerten überein. Die in Verdrängungsstudien bestimmten Inhibitionskonstanten (Ki) von Referenzsubstanzen am Dopamin-D2S- und -D3-Rezeptor sowie am Histamin-H1-Rezeptor bestätigten die Zuverlässigkeit und Reproduzierbarkeit der Bindungsassays. Zur Unterscheidung der Agonisten von Antagonisten wurden „GTP-Shift“ Assays am Dopamin-D2S- und -D3-Rezeptor angewandt. Für Pramipexol und das Selenanaloga 54 wurden zwei Bindungszustände mit unterschiedlichen Affinitäten (ein so genannter „high- und low affinity state“) am Dopamin-D2S-Rezeptor in Abwesenheit von Gpp(NH)p beobachtet. Eine Affinitätsabnahme („GTP-Shift“) in Anwesenheit von Gpp(NH)p zeigte sich für die Agonisten am Dopamin-D2S- und -D3-Rezeptor. Dieser Einfluss des Gpp(NH)p konnte nicht für den Antagonisten ST 198 und den partiellen Agonisten BP 897 gezeigt werden. Für diese Verbindung wurde ein inverser „GTP-Shift“, also eine Affinitätsverbesserung am Dopamin-D3-Rezeptor beobachtet. Um neue Liganden mit hoher Affinität und Selektivität für den Dopamin-D3-Rezeptor zu entwickeln, wurden ausführliche SAR verschiedener Derivate der Leitstruktur BP 897 und ST 198 erstellt. Der Austausch des Naphthalen-2-carboxamid-Rests von BP 897 durch verschiedene Arylamid-Strukturen (1 – 4) zeigte deren deutlichen Einfluss auf die Dopamin-D3-Rezeptorbindungsaffinität und -selektivität. Die Einführung eines Benzo[b]thiophen-2-carboxamid-Rests führte in Verbindung 1 zu herausragender subnanomolarer Affinität am Dopamin-D3-Rezeptor sowie zu deutlich erhöhter Selektivität im Vergleich zu BP 897. Die Variation des lipophilen basischen Amin-Restes von 1 ergab das 1,2,3,4-Tetrahydroisochinolin-Derivat 6. Verdrängungsstudien konnten den Vorteil des 4-(2-Methoxyphenyl)piperazine-Substituenten von BP 897 bezüglich der Affinitäten am Dopamin-D2S- und -D3-Rezeptor deutlich zeigen. Modifikationen einzelner Elemente von BP 897 und ST 198 und die veränderte Integration der Amid-Funktion in dem lipophilen Aryl-Rest führten zur Substanzklasse der inversen Amide mit neuen chemischen Eigenschaften. Moderate Bindungsaffinitäten, wie für das Isoindol-1-carbonyl-Derivat 11 gezeigt, legen nahe, dass inverse Amide eine lohnenswerte neue Leitstruktur mit andersartigem strukturellem Gerüst darstellen. In einer Hybrid-Strategie wurden Strukturelemente von Histamin-H1-Rezeptorantagonisten mit Substrukturen von Liganden mit ausgeprägter Dopamin-D3-Rezeptorpräferenz kombiniert. Daraus resultierten Benzhydrylpiperazin-Derivative und verwandte Substanzen mit moderater bis hoher Affinität am Dopamin-D3-Rezeptor. Besonders hervorzuheben ist das Zimtsäureamid substituierte und zum Bamipin verwandte Hybrid 39, welches die besten Ergebnisse in dieser Serie hinsichtlich Affinität und Selektivität am Dopamin-D3-Rezeptor erbrachte. Verbesserte pharmakologische Profile der strukturell modifizierten Histamine-H1-Rezeptorantagonisten am Dopamin-D2S- und -D3-Rezeptor und eine differenzierte SAR wurden erreicht. Für Derivate des Dopaminrezeptoragonisten Pramipexol und des strukturähnlichen Etrabamin wurden SAR ausgearbeitet. Das Propargyl substituierte Etrabamin-Derivat 61 zeigte herausragende Dopamin-D3-Rezeptoraffinität und -selektivität. Der Ligand ist von Interesse, da für den Propargyl-Rest neuroprotektive Eigenschaften berichtet wurden. Die Weiterentwicklung führte zur Verbindung 64, einem Zimtsäureamid-Derivat mit 4-Fluor-Substitution am Phenylring. Subnanomolare Affinität und hohe Selektivität am Dopamin-D3-Rezeptor prädestinieren 64 zur Anwendung als potentiellen PET-Radioliganden. Radioliganden Bindungsstudien wurden auf die Ergebnisse von virtuellen Screeningstudien angewandt. Sie führten zur Identifizierung neuer Leitstrukturen und zum weiteren Verständnis der SAR. Als neue Leitstrukturen mit verschiedenartigen chemischen Gerüsten wurden unter anderem das Bicyclo[2.2.1]heptan-Derivat 95 und der Benzhydryliden substituierte Pyrrolidindion Ligand 112 gefunden. Diese können nun zur weiteren Optimierung chemisch modifiziert werden. Die in dieser Arbeit durchgeführten Radioliganden Bindungsstudien führten zur Identifizierung, Entwicklung und Optimierung von hoch affinen und selektiven Dopamin-D3-Rezeptor Liganden. Des Weiteren ermöglichten die Ergebnisse eine ausführliche Vertiefung der SAR. Die kombinierte Strategie von chemoinformatischen Methoden und Radioliganden Bindungsstudien hat das Finden neuer Leitstrukturen als potentielle Arzneistoffe erlaubt. Die Resultate ermöglichen in der Zukunft ein gezieltes Liganden-Design mit einem gerichteten pharmakologischen Rezeptorprofil

    Integrative Systems Approaches Towards Brain Pharmacology and Polypharmacology

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    Polypharmacology is considered as the future of drug discovery and emerges as the next paradigm of drug discovery. The traditional drug design is primarily based on a “one target-one drug” paradigm. In polypharmacology, drug molecules always interact with multiple targets, and therefore it imposes new challenges in developing and designing new and effective drugs that are less toxic by eliminating the unexpected drug-target interactions. Although still in its infancy, the use of polypharmacology ideas appears to already have a remarkable impact on modern drug development. The current thesis is a detailed study on various pharmacology approaches at systems level to understand polypharmacology in complex brain and neurodegnerative disorders. The research work in this thesis focuses on the design and construction of a dedicated knowledge base for human brain pharmacology. This pharmacology knowledge base, referred to as the Human Brain Pharmacome (HBP) is a unique and comprehensive resource that aggregates data and knowledge around current drug treatments that are available for major brain and neurodegenerative disorders. The HBP knowledge base provides data at a single place for building models and supporting hypotheses. The HBP also incorporates new data obtained from similarity computations over drugs and proteins structures, which was analyzed from various aspects including network pharmacology and application of in-silico computational methods for the discovery of novel multi-target drug candidates. Computational tools and machine learning models were developed to characterize protein targets for their polypharmacological profiles and to distinguish indications specific or target specific drugs from other drugs. Systems pharmacology approaches towards drug property predictions provided a highly enriched compound library that was virtually screened against an array of network pharmacology based derived protein targets by combined docking and molecular dynamics simulation workflows. The developed approaches in this work resulted in the identification of novel multi-target drug candidates that are backed up by existing experimental knowledge, and propose repositioning of existing drugs, that are undergoing further experimental validations

    NOVEL ALGORITHMS AND TOOLS FOR LIGAND-BASED DRUG DESIGN

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    Computer-aided drug design (CADD) has become an indispensible component in modern drug discovery projects. The prediction of physicochemical properties and pharmacological properties of candidate compounds effectively increases the probability for drug candidates to pass latter phases of clinic trials. Ligand-based virtual screening exhibits advantages over structure-based drug design, in terms of its wide applicability and high computational efficiency. The established chemical repositories and reported bioassays form a gigantic knowledgebase to derive quantitative structure-activity relationship (QSAR) and structure-property relationship (QSPR). In addition, the rapid advance of machine learning techniques suggests new solutions for data-mining huge compound databases. In this thesis, a novel ligand classification algorithm, Ligand Classifier of Adaptively Boosting Ensemble Decision Stumps (LiCABEDS), was reported for the prediction of diverse categorical pharmacological properties. LiCABEDS was successfully applied to model 5-HT1A ligand functionality, ligand selectivity of cannabinoid receptor subtypes, and blood-brain-barrier (BBB) passage. LiCABEDS was implemented and integrated with graphical user interface, data import/export, automated model training/ prediction, and project management. Besides, a non-linear ligand classifier was proposed, using a novel Topomer kernel function in support vector machine. With the emphasis on green high-performance computing, graphics processing units are alternative platforms for computationally expensive tasks. A novel GPU algorithm was designed and implemented in order to accelerate the calculation of chemical similarities with dense-format molecular fingerprints. Finally, a compound acquisition algorithm was reported to construct structurally diverse screening library in order to enhance hit rates in high-throughput screening

    Development of novel anticancer agents targeting G protein coupled receptor: GPR120

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    The G-protein coupled receptor, GPR120, has ubiquitous expression and multifaceted roles in modulating metabolic and anti-inflammatory processes. GPR120 - also known as Free Fatty Acid Receptor 4 (FFAR4) is classified as a free fatty acid receptor of the Class A GPCR family. GPR120 has recently been implicated as a novel target for cancer management. GPR120 gene knockdown in breast cancer studies revealed a role of GPR120-induced chemoresistance in epirubicin and cisplatin-induced DNA damage in tumour cells. Higher expression and activation levels of GPR120 is also reported to promote tumour angiogenesis and cell migration in colorectal cancer. A number of agonists targeting GPR120 have been reported, such as TUG891 and Compound39, but to date development of small-molecule inhibitors of GPR120 is limited. This research applied a rational drug discovery approach to discover and design novel anticancer agents targeting the GPR120 receptor. A homology model of GPR120 (short isoform) was generated to identify potential anticancer compounds using a combined in silico docking-based virtual screening (DBVS), molecular dynamics (MD) assisted pharmacophore screenings, structure–activity relationships (SAR) and in vitro screening approach. A pharmacophore hypothesis was derived from analysis of 300 ns all-atomic MD simulations on apo, TUG891-bound and Compound39-bound GPR120 (short isoform) receptor models and was used to screen for ligands interacting with Trp277 and Asn313 of GPR120. Comparative analysis of 100 ns all-atomic MD simulations of 9 selected compounds predicted the effects of ligand binding on the stability of the “ionic lock” – a characteristic of Class A GPCRs activation and inactivation. The “ionic lock” between TM3(Arg136) and TM6(Asp) is known to prevent G-protein recruitment while GPCR agonist binding is coupled to outward movement of TM6 breaking the “ionic lock” which facilitates G-protein recruitment. The MD-assisted pharmacophore hypothesis predicted Cpd 9, (2-hydroxy-N-{4-[(6-hydroxy-2-methylpyrimidin-4-yl) amino] phenyl} benzamide) to act as a GPR120S antagonist which can be evaluated and characterised in future studies. Additionally, DBVS of a small molecule database (~350,000 synthetic chemical compounds) against the developed GPR120 (short isoform) model led to selection of the 13 hit molecules which were then tested in vitro to evaluate their cytotoxic, colony forming and cell migration activities against SW480 – human CRC cell line expressing GPR120. Two of the DBVS hit molecules showed significant (\u3e 90%) inhibitory effects on cell growth with micromolar affinities (at 100 μM) - AK-968/12713190 (dihydrospiro(benzo[h]quinazoline-5,1′-cyclopentane)-4(3H)-one) and AG-690/40104520 (fluoren-9-one). SAR analysis of these two test compounds led to the identification of more active compounds in cell-based cytotoxicity assays – AL-281/36997031 (IC50 = 5.89–6.715 μM), AL-281/36997034 (IC50 = 6.789 to 7.502 μM) and AP-845/40876799 (IC50 = 14.16-18.02 μM). In addition, AL-281/36997031 and AP-845/40876799 were found to be significantly target-specific during comparative cytotoxicity profiling in GPR120-silenced and GPR120-expressing SW480 cells. In wound healing assays, AL-281/36997031 was found to be the most active at 3 μM (IC25) and prevented cell migration. As well as in the assessment of the proliferation ability of a single cell to survive and form colonies through clonogenic assays, AL-281/36997031 was found to be the most potent of all three test compounds with the survival rate of ~ 30% at 3 μM. The inter-disciplinary approach applied in this work identified potential chemical scaffolds –spiral benzo-quinazoline and fluorenone, targeting GPR120 which can be further explored for designing anti-cancer drug development studies

    A Themed Issue in Honor of Professor Raphael Mechoulam: The Father of Cannabinoid and Endocannabinoid Research

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    During the last 60 years the relevance of cannabis (Cannabis sativa or Cannabis indica) ingredients, like the psychoactive Δ9-tetrahydrocannabinol (THC), cannabidiol, 120+ additional cannabinoids and 440+ non-cannabinoid compounds, for human health and disease has become apparent. Approximately 30 years after the elucidation of THC structure the molecular reasons for the biological activity of these plant extracts were made clearer by the discovery of endocannabinoids, that are endogenous lipids able to bind to the same receptors activated by THC. Besides endocannabinoids, that include several N-acylethanolamines and acylesters, a complex array of receptors, metabolic enzymes, transporters (transmembrane, intracellular and extracellular carriers) were also discovered, and altogether they form a so-called “endocannabinoid system” that has been shown to finely tune the manifold biological activities of these lipid signals. Both plant-derived cannabinoids and endocannabinoids were first discovered by the group led by Prof. Dr. Raphael Mechoulam, who has just celebrated his 90th birthday and clearly stood out as a giant of modern science. The many implications of his seminal work for chemistry, biochemistry, biology, pharmacology and medicine are described in this special issue by the scientists who reached during the last 20 years the highest recognition in the field of (endo)cannabinoid research, receiving the Mechoulam Award for their major contributions. I thank them for having accepted my invitation to be part of this honorary issue of Molecules, and Raphi for continuing to illuminate our field with his always inspiring investigations and new ideas

    Approche expérimentale de la physiopathologie des dyskinésies L-Dopa induites dans la maladie de Parkinson : comparaison de la cible classique, le striatum avec l’ensemble du cerveau

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    The gold standard treatment for Parkinson’s disease (PD) remains the dopamine precursor L- 3,4-dihydroxyphenylalanine (L-Dopa). Long-term L-Dopa treatment systematically leads to abnormal involuntary movements (AIMs) called L-Dopa-induced dyskinesia (LID). These manifestations first led to investigate the neuronal dysfunctions in the motor regions of thebasal ganglia and unravelled an overexpression of ΔFosB, ARC, Zif268 and FRA2 immediate-early genes (IEG) in the dopamine-depleted striatum of dyskinetic rats. However, other several dopaminoceptive structures, likely affected by the exogenously produced dopamine, have been neglected although they might play a key role in mediating LID. Hence, we assessed the expression of ΔFosB, ARC, FRA2 and Zif268 IEGs in the whole brain of dyskinetic rats compared to non-dyskinetic ones. Such approach shed light notably upon 9 structures located outside of the basal ganglia displaying an IEG overexpression. Among them, the dorsolateral bed nucleus of the stria terminalis (dlBST) and the lateralhabenula (LHb) displayed a significant correlation between ΔFosB expression and LID severity. We therefore postulated that these structures might play a role in LID manifestation. Therefore, to assess dlBST and LHb causal roles upon LID severity, we inhibited the electrical activity of FosB/ΔFosB-expressing neurons using the selective Daun02/β- galactosidase inactivation method that we previously validated in a well known structure involve in LID: the striatum. Interestingly, the inactivation of dlBST and LHb ΔfosBexpressing neurons alleviated LID severity and increased the beneficial effect of L-Dopa in dyskinetic rats. Remarkably, BST involvement in LID was confirmed in the gold standard model of LID, the dyskinetic MPTP-lesioned macaque. Altogether, our results highlight for the first time the functional involvement of 2 structures.Le traitement de référence de la maladie de Parkinson (MP) reste l’utilisation du précurseurdirect de la dopamine: la L-3,4-dihydroxyphenylalanine (L-Dopa). Le traitement chroniquedes patients parkinsoniens à la L-Dopa induit, en revanche, systématiquement desmouvements involontaires anormaux que l’on qualifie de dyskinésies induites par la L-Dopa(DIL). L’étude de l’expression des dyskinésies s’est essentiellement focalisée sur lesdysfonctions neuronales engendrées dans les régions motrices des ganglions de la base et apermis de révéler une surexpression significative de gènes de réponse précoce (GRP) tels que: ΔFosB, ARC, Zif268 et FRA2 dans le striatum de rats dyskinétiques traités chroniquement à la L–Dopa. En revanche, plusieurs autres régions dopaminoceptives, probablement affectées par la dopamine exogène nouvellement synthétisée, ont été négligées alors qu’elles pourraient jouer un rôle clé dans l’expression des dyskinésies. Par conséquent, nous avons quantifié l’expression de ΔFosB, ARC, FRA2 et Zif268 dans l’ensemble du cerveau de rats dyskinétiques que nous avons comparée à des rats non-dyskinétiques. Cette approche nous a permis d’identifier 9 structures, localisées en dehors des ganglions de la base, présentant une surexpression d’au moins 3 des GRPs cités ci-dessus. Parmi ces structures, le domaine dorsolatéral du « bed nucleus of the stria terminalis » (dlBST) et l’habenula latérale (LHb) montrent une corrélation significative entre l’expression de ΔFosB et la sévérité des dyskinésies. Nous avons donc fait l’hypothèse que ces 2 structures pouvaient être impliquées dans l’expression des dyskinésies. Par conséquent, pour évaluer le rôle potentiel du dlBST et de la LHb dans les dyskinésies, nous avons inhibé l’activité électrique des neurones exprimant FosB/ΔFosB en utilisant la méthode d’inactivation sélective du Daun02/ß-galactosidase que nous avons précédemment validée dans une structure bien connue pour être impliquée dans les dyskinésies: le striatum. Nous avons démontré que l’inhibition de ces neurones, à la fois dans le dlBST et la LHb, diminuait la sévérité des dyskinésies sans affecter l’effet bénéfique de la L-Dopa chez les rats dyskinétiques. Nous avons ensuite pu confirmer l’implication du dlBST grâce au model de référence des dyskinésies: le macaque dyskinétique lésé au MPTP. L’ensemble de ces résultats nous a ainsi permis de montrer, pour la première fois, l’implication fonctionnelle de 2 structures externes aux ganglions de la base dans l’expression des dyskinésies, offrant de nouvelles perspectives thérapeutiques
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