The Mitotic Protein Kinase Haspin and Its Inhibitors

Haspin is an atypical serine/threonine protein kinase essential to mitosis. Unlike other protein kinases, its kinase domain does not require phosphorylation in order to be activated and bears very high substrate specificity and selectivity. Few substrates have been identified so far. Haspin phosphorylation on threonine 3 of Histone H3 from prophase to anaphase participates to centromeric Aurora B localization and ensures proper kinetochore-microtubule attachment. Haspin is also involved in the maintenance of centromeric cohesion and the mitotic spindle. Inhibitors have been developed and provided tools to dissect Haspin function. The kinase is now considered as a potential therapeutic target against cancer. We discuss here the latest findings on this essential mitotic protein

Advances in tetrahydropyrido[1,2-a]isoindolone (valmerins) series: Potent glycogen synthase kinase 3 and cyclin dependent kinase 5 inhibitors.

International audienceAn efficient synthetic strategy was developed to modulate the structure of the tetrahydropyridine isoindolone (Valmerin) skeleton. A library of more than 30 novel final structures was generated. Biological activities on CDK5 and GSK3 as well as cellular effects on cancer cell lines were measured for each novel compound. Additionally docking studies were performed to support medicinal chemistry efforts. A strong GSK3/CDK5 dual inhibitor (38, IC50 GSK3/CDK5 32/84 nM) was obtained. A set of highly selective GSK3 inhibitors was synthesized by fine-tuning structural modifications (29 IC50 GSK3/CDK5 32/320 nM). Antiproliferative effects on cells were correlated with the in vitro kinase activities and the best effects were obtained with lung and colon cell lines

Prodromal neuroinflammatory, cholinergic and metabolite dysfunction detected by PET and MRS in the TgF344-AD transgenic rat model of AD: a collaborative multi-modal study

Mouse models of Alzheimer's disease (AD) are valuable but do not fully recapitulate human AD pathology, such as spontaneous Tau fibril accumulation and neuronal loss, necessitating the development of new AD models. The transgenic (TG) TgF344-AD rat has been reported to develop age-dependent AD features including neuronal loss and neurofibrillary tangles, despite only expressing APP and PSEN1 mutations, suggesting an improved modelling of AD hallmarks. Alterations in neuronal networks as well as learning performance and cognition tasks have been reported in this model, but none have combined a longitudinal, multimodal approach across multiple centres, which mimics the approaches commonly taken in clinical studies. We therefore aimed to further characterise the progression of AD-like pathology and cognition in the TgF344-AD rat from young-adults (6 months (m)) to mid- (12 m) and advanced-stage (18 m, 25 m) of the disease.Methods: TgF344-AD rats and wild-type (WT) littermates were imaged at 6 m, 12 m and 18 m with [18F]DPA-714 (TSPO, neuroinflammation), [18F]Florbetaben (A beta) and [18F]ASEM (α7-nicotinic acetylcholine receptor) and with magnetic resonance spectroscopy (MRS) and with (S)-[18F]THK5117 (Tau) at 15 and 25 m. Behaviour tests were also performed at 6 m, 12 m and 18 m. Immunohistochemistry (CD11b, GFAP, Aβ, NeuN, NeuroChrom) and Tau (S)-[18F]THK5117 autoradiography, immunohistochemistry and Western blot were also performed.Results: [18F]DPA-714 positron emission tomography (PET) showed an increase in neuroinflammation in TG vs wildtype animals from 12 m in the hippocampus (+11%), and at the advanced-stage AD in the hippocampus (+12%), the thalamus (+11%) and frontal cortex (+14%). This finding coincided with strong increases in brain microgliosis (CD11b) and astrogliosis (GFAP) at these time-points as assessed by immunohistochemistry. In vivo [18F]ASEM PET revealed an age-dependent increase uptake in the striatum and pallidum/nucleus basalis of Meynert in WT only, similar to that observed with this tracer in humans, resulting in TG being significantly lower than WT by 18 m. In vivo [18F]Florbetaben PET scanning detected Aβ accumulation at 18 m, and (S)-[18F]THK5117 PET revealed subsequent Tau accumulation at 25m in hippocampal and cortical regions. Aβ plaques were low but detectable by immunohistochemistry from 6 m, increasing further at 12 and 18 m with Tau-positive neurons adjacent to Aβ plaques at 18 m. NeuroChrom (a pan neuronal marker) immunohistochemistry revealed a loss of neuronal staining at the Aβ plaques locations, while NeuN labelling revealed an age-dependent decrease in hippocampal neuron number in both genotypes. Behavioural assessment using the novel object recognition task revealed that both WT & TgF344-AD animals discriminated the novel from familiar object at 3 m and 6 m of age. However, low levels of exploration observed in both genotypes at later time-points resulted in neither genotype successfully completing the task. Deficits in social interaction were only observed at 3 m in the TgF344-AD animals. By in vivo MRS, we showed a decrease in neuronal marker N-acetyl-aspartate in the hippocampus at 18 m (-18% vs age-matched WT, and -31% vs 6 m TG) and increased Taurine in the cortex of TG (+35% vs age-matched WT, and +55% vs 6 m TG).Conclusions: This multi-centre multi-modal study demonstrates, for the first time, alterations in brain metabolites, cholinergic receptors and neuroinflammation in vivo in this model, validated by robust ex vivo approaches. Our data confirm that, unlike mouse models, the TgF344-AD express Tau pathology that can be detected via PET, albeit later than by ex vivo techniques, and is a useful model to assess and longitudinally monitor early neurotransmission dysfunction and neuroinflammation in AD.</p

Prodromal neuroinflammatory, cholinergic and metabolite dysfunction detected by PET and MRS in the TgF344-AD transgenic rat model of AD: a collaborative multi-modal study

Mouse models of Alzheimer's disease (AD) are valuable but do not fully recapitulate human AD pathology, such as spontaneous Tau fibril accumulation and neuronal loss, necessitating the development of new AD models. The transgenic (TG) TgF344-AD rat has been reported to develop age-dependent AD features including neuronal loss and neurofibrillary tangles, despite only expressing APP and PSEN1 mutations, suggesting an improved modelling of AD hallmarks. Alterations in neuronal networks as well as learning performance and cognition tasks have been reported in this model, but none have combined a longitudinal, multimodal approach across multiple centres, which mimics the approaches commonly taken in clinical studies. We therefore aimed to further characterise the progression of AD-like pathology and cognition in the TgF344-AD rat from young-adults (6 months (m)) to mid- (12 m) and advanced-stage (18 m, 25 m) of the disease. Methods: TgF344-AD rats and wild-type (WT) littermates were imaged at 6 m, 12 m and 18 m with [18F]DPA-714 (TSPO, neuroinflammation), [18F]Florbetaben (Aβ) and [18F]ASEM (α7-nicotinic acetylcholine receptor) and with magnetic resonance spectroscopy (MRS) and with (S)-[18F]THK5117 (Tau) at 15 and 25 m. Behaviour tests were also performed at 6 m, 12 m and 18 m. Immunohistochemistry (CD11b, GFAP, Aβ, NeuN, NeuroChrom) and Tau (S)-[18F]THK5117 autoradiography, immunohistochemistry and Western blot were also performed. Results: [18F]DPA-714 positron emission tomography (PET) showed an increase in neuroinflammation in TG vs wildtype animals from 12 m in the hippocampus (+11%), and at the advanced-stage AD in the hippocampus (+12%), the thalamus (+11%) and frontal cortex (+14%). This finding coincided with strong increases in brain microgliosis (CD11b) and astrogliosis (GFAP) at these time-points as assessed by immunohistochemistry. In vivo [18F]ASEM PET revealed an age-dependent increase uptake in the striatum and pallidum/nucleus basalis of Meynert in WT only, similar to that observed with this tracer in humans, resulting in TG being significantly lower than WT by 18 m. In vivo [18F]Florbetaben PET scanning detected Aβ accumulation at 18 m, and (S)-[18F]THK5117 PET revealed subsequent Tau accumulation at 25m in hippocampal and cortical regions. Aβ plaques were low but detectable by immunohistochemistry from 6 m, increasing further at 12 and 18 m with Tau-positive neurons adjacent to Aβ plaques at 18 m. NeuroChrom (a pan neuronal marker) immunohistochemistry revealed a loss of neuronal staining at the Aβ plaques locations, while NeuN labelling revealed an age-dependent decrease in hippocampal neuron number in both genotypes. Behavioural assessment using the novel object recognition task revealed that both WT & TgF344-AD animals discriminated the novel from familiar object at 3 m and 6 m of age. However, low levels of exploration observed in both genotypes at later time-points resulted in neither genotype successfully completing the task. Deficits in social interaction were only observed at 3 m in the TgF344-AD animals. By in vivo MRS, we showed a decrease in neuronal marker N-acetyl-aspartate in the hippocampus at 18 m (-18% vs age-matched WT, and -31% vs 6 m TG) and increased Taurine in the cortex of TG (+35% vs age-matched WT, and +55% vs 6 m TG). Conclusions: This multi-centre multi-modal study demonstrates, for the first time, alterations in brain metabolites, cholinergic receptors and neuroinflammation in vivo in this model, validated by robust ex vivo approaches. Our data confirm that, unlike mouse models, the TgF344-AD express Tau pathology that can be detected via PET, albeit later than by ex vivo techniques, and is a useful model to assess and longitudinally monitor early neurotransmission dysfunction and neuroinflammation in AD

The past, present, and future of the Brain Imaging Data Structure (BIDS)

The Brain Imaging Data Structure (BIDS) is a community-driven standard for the organization of data and metadata from a growing range of neuroscience modalities. This paper is meant as a history of how the standard has developed and grown over time. We outline the principles behind the project, the mechanisms by which it has been extended, and some of the challenges being addressed as it evolves. We also discuss the lessons learned through the project, with the aim of enabling researchers in other domains to learn from the success of BIDS

Méthodologie en chimie hétérocyclique et application à la synthèse d'inhibiteurs de kinases

Le cancer constitue l une des principales causes de mortalité, et représente, de ce fait aujourd hui un problème de santé publique majeur. Depuis quelques années, les alcaloïdes marins représentent une source d inspiration importante pour les chimistes en vue d obtenir de nouveaux médicaments anticancéreux. Dans cette optique, des recherches effectuées au sein de notre laboratoire ont fait état de la synthèse d analogues de ces alcaloïdes possédant une structure tris aromatique. Nous avons développé des molécules originale analogues de ces alcaloïdes disposant d un hétérocycle central (1,2,4-triazine et imidazo[1,2-b][1,2,4,5]tétrazine) sur lequel sont greffés deux noyaux phényles diversement substitués. L obtention de ces composés a également été l occasion de développer de nouvelles méthodologies de synthèse. Ainsi une nouvelle réaction de type Buchwald-Hartwig sur des méthylsulfanyl-1,2,4-triazines a pu être mise au point ainsi qu une méthode de CH arylation palladocatalysée sur le noyau imidazo[1,2-b][1,2,4,5]tétrazine. Une partie est aussi consacrée aux réactions multicomposants de type Groebke-Blackburn. Différentes évaluations pharmacologiques ont été réalisées, notamment des tests d inhibition sur différentes kinases et de cytotoxicité sur diverses lignées cellulaires cancéreuses humaines.Cancer, one of the leading causes of death, represents today a major public health problem. Over the last few years, marine alkaloids represent a source of inspiration for chemists in order to obtain new anticancer drugs. For this purpose, as a part of our laboratory researches, analogues of marine alkaloids were synthesized possessing a tris-aromatic structure. We developed originals analogs of these alacaloïds formed by a central heterocycle core (1,2,4-triazine et imidazo[1,2-b][1,2,4,5]tetrazine) on wich is graft two arylic moiety variously substituted. Obtaining these compounds was also an opportunity to develop news synthetic methodologies. So a new Buchwald-Hartwig reaction type based on methylsulfanyl-1,2,4-triazines has been perfect, as palladocatalyzed CH arylation pathway on imidazo[1,2-b][1,2,4,5]tetrazine. A part is devoted to Groebke-Blackburn multicomponant reaction. Various pharmacological analyses were carried out in particular with inhibition of various kinases and cytotoxicity evaluation on various human cancer cell lines.ORLEANS-SCD-Bib. electronique (452349901) / SudocSudocFranceF

Synthèse de tétrahydropyrido-[isoindolones/isoquinolones/indolizinones] pour l'élaboration d'inhibiteurs de CDks

Cette thèse est divisée en cinq parties. La première partie traite de la chimie des ions iminiums. Après une brève introduction sur leur découverte, sont présentées leurs préparations et leurs applications dans divers champs de la chimie, en particulier dans la synthèse de produits naturels. En suite nous traiterons des ions N-acyl iminiums, en évoquant les mécanismes de leur formation, les diverses applications et leurs particularités. La première partie se termine par la présentation des différentes voies d'accès à des structures du type isoindoquinolinonique obtenues notamment par formation d ions d'acyl iminiums. La seconde partie de la thèse concerne une étude méthodologique de la réaction de cyclisation présentée par le groupe du Prof. Y. Troin. Cette réaction, basée sur un intermédiaire N-acyl iminium, permet la synthèse d'un système de type isoquinolone. La réaction est une cycloaddition intermoléculaire d une cétone protégée, et le carboxy benzaldéhyde. entre une amine primaire en Nous avons repris ces premiers travaux et avons étendu la méthode à toute une série de noyaux comme des systèmes benzéniques différemment substitués (avec des groupes -OMe en différentes positions du cycle), des systèmes polyaromatiques (naphtalène) et des hétérocycles (pyridine, quinoléine etc...). La différence de réactivité des différents systèmes est discutée, et une méthode alternative de hydroxy lactames est proposée. synthèse passant par des Dans la troisième partie l application de nos recherches à la problématique de la chimiothérapie anticancéreuse est abordée. Après avoir rappelé les principales causes, les mécanismes et quelques notions sur le cycle cellulaire et sur quelques médicaments utilisables à ce jour, nous évoquerons le rationnel permettant l utilisation de la 10-amino-1,3,4,10b-tétrahydro-2H-pyrido[2,1-a]isoindol-6-one pour arriver à une série de diarylurées, inhibiteurs potentiels de kinases dépendantes des cyclines.La quatrième partie traite donc du chemin synthétique utilisé pour atteindre ces objectifs, et se termine par les résultats des tests biologiques et l étude des premières relations entre structure et activité. Enfin, des perspectives de travail sont évoquées et une conclusion générale est proposée.ORLEANS-BU Sciences (452342104) / SudocSudocFranceF

Synthèse et évaluation de nouveaux dérivés d'urées à base de tétrahydropyrido-isoindolones comme inhibiteurs de protéines kinases

La chimiothérapie antitumorale fait appel à des molécules visant des cibles thérapeutiques précises, en particulier, les protéines kinases. Afin de générer de nouveaux inhibiteurs de kinases, nous avons choisi de synthétiser des isoindolones possédant un motif urée. Ces composés constituent de nouveaux candidats susceptibles de lutter contre le cancer. Ce travail a nécessité dans un premier temps, la préparation de différentes amines portées par un noyau original de type tétrahydropyridoisoindolone. Afin d apporter une diversité fonctionnelle sur l hétérocycle précédemment nommé, différentes séquences réactionnelles ont été mises au point. Par la suite les amines ont été reliées à une large variété d hétéroaryles via une fonction urée et ce, en développant, une fois encore de nouvelles méthodologies de synthèse. Enfin, nos investigations nous ont conduit à inclure l urée dans un motif cyclique. Pour ce faire, nous avons inséré celle-ci dans une pyridopyrimidinedione. Une bibliothèque de plus de 80 molécules finales a ainsi été synthétisée et évaluée in vitro sur CDK1, CDK5 et GSK3, ainsi que sur 6 lignées de cellules cancéreuses. Une analyse structure-activité a montré que nos composés constituent une nouvelle classe d inhibiteurs dotée d une activité biologique significative. Les tests in vivo, réalisés sur trois de nos molécules, ont permis de mettre en évidence un effet antitumoral remarquable.The anti-tumor Chemotherapy uses molecules for specific therapeutic targets, particularly, protein kinases. To generate new kinases inhibitors, we tried to synthesize isoindolones containing the urea pattern. These compounds seem susceptible to fight cancer. This involved firstly, the preparation of various amines carried by an original kernel, type tétrahydropyridoisoindolone. To provide a functional diversity on the heterocycle previously named, different reactional sequences have been developed. Subsequently, the amines have been linked to a wide variety of heteroaryl via an urea function by developing, once again, new synthetic methodologies. Finally, our investigations have led us to include urea in a cyclical pattern. To this end, we inserted it in a pyridopyrimidinedione. A library of over 80 final molecules has been synthesized and evaluated in vitro on CDK1, CDK5 and GSK3, as well as on 6 different tumor cell lines. A structure-activity analysis showed that these compounds represent a new class of inhibitors of kinases with a significant biological activity. In vivo tests were done on three of our molecules and helped to highlight a significant antitumor effect.ORLEANS-SCD-Bib. electronique (452349901) / SudocSudocFranceF

Synthesis of naphthopyrrolo[3,4-c]carbazoles

International audienc