Cibles pharmacologiques et biomarqueurs

Responsables : Séverine MORISSET-LOPEZ et Patrick BARIL

We have developed expertise in a large variety of screening methods (BRET, TR-FRET, Alpha screen, RILES) to identify potent pharmacological tools and novel biological targets involved in cancer and neurological disorders. We are currently extending our efforts in these fields of investigation and focus our attention on dysregulated cell membrane receptors and microRNA expression that are hallmarks of these pathologies.

Pharmacology of neuroreceptors

Our main topic concerns the serotonin 5-HT7 receptors that belong to the G protein-coupled receptors (GPCRs) superfamily, which is involved in neuronal development, synaptic plasticity, regulation of learning and memorization and nociception. This receptor is considered as a promising target for the treatment of inflammatory and neuropathic pain, mood disorders and cognitive deficits. Although several isoforms of the receptor have been described, their pathophysiological roles remain unexplored. In order to propose new strategies for modulating their activities in vivo, our aim is to 1) identify and characterize ligands and/or allosteric modulators of 5-HT7R 2) use these tools to study the dialogue between the drug and the receptor at molecular, cellular and tissue levels to better understand the pathophysiological role of the receptor. Our final objective is to explore the therapeutic potential of these new 5-HT7 ligands in pharmacologic or genetic mice models-associated with cognitive disabilities in a translational approach.

Immunolabelling of 5-HT7R in primary neuron cultures

In order to decipher our knowledges on the role of neuroreceptors in neurologic disorders, we have also developed expertise on LINGO-1. It is a transmembrane receptor highly expressed in neurons and oligodendrocytes, which is involved in neurological disorders associated with myelin injury and memory impairment. We have recently demonstrated that LINGO-1 forms constitutive cis-dimers and identify protein protein interaction modulators (PPIM) able to regulate its downstream signalling pathways (Cobret et al., 2015). We propose that targeting the LINGO-1 dimerization interface could open a new way to modulate its function. Our objective is now to identify PPI modulators and evaluate their interest in the treatment of neurological disorders.

Collaborations:
Pr A. Bojarski, Institut of pharmacology, Krakow, Poland
Dr MP Junier, Neurosciences Paris Seine, CNRS UMR8246/Inserm U1130/UMPC UMCR18, Paris
Pr E Kellenberger, Dr F Bihel, Laboratoire d’innovation thérapeutique, CNRS UMR 7200,  Strasbourg
Pr S Mortaud, A Menuet, INEM, CNRS UMR 7355, Orléans
Dr C. Raoul, Institut des Neurosciences,INSERM U1051, Montpellier
Dr E Reiter, Physiologie de la Reproduction et des Comportements, INRA UMR7247, Tours
Pr F Suzenet, Institut de Chimie Organique et Analytique, CNRS UMR7311, Orléans
Dr F Fayon, V. Sarou Kanain, Conditions Extrêmes et Matériaux : Haute Température et Irradition CNRS UPR3079, Orléans
Dr E.Traiffort, Laboratoire de neuroprotection et neurogéneration, INSERM UMR1195, Kremlin Bicêtre

miRNA biology and therapeutics

Increasing number of studies indicate that the underestimation of the dynamic and spatiotemporal resolution of miRNA expression result in loss of important information connecting miRNA expression and function. Recently we have developed an engineered genetic switch expression system, called RILES for RNAi-inducible Expression System, to track expression of miRNA during development of pathologies in small animal models. As the RILES is a non-invasive luciferase reporting system, it offers a temporal dimension analysis of miRNA expression that conventional monitoring methods could not do. As a result, better clues about miRNA expression and function can be collected and then exploited for miRNA based therapeutics. We are currently exploiting the RILES system to (1) study impact of the dynamic regulation of miRNA in cancer development including neurofibromatosis, (2) identify novel biomarkers and (3) screen for small synthetic and natural libraries to identify compounds unable to modulate expression of key miRNA involved in both tumour and cutaneous cells. Our objective is better understanding the molecular basis of miRNA expression and to exploit their mode of regulation to realize the principle of image-guided miRNA therapy.

Collaborations:
Dr. Emmanuel Garcion, Centre de Recherche en Cancérologie et Immunologie, INSRM U1232, Angers
Dr. Marcel Hollenstein, Institut Pasteur, Paris
Dr. Pierre Cordelier, Centre de Recherches en Cancérologie, INSERM U1052, Toulouse
Dr. Stéphanie Lerondel, Centre d’Imagerie du Petit Animal, CNRS UPS 44, Orléans,
Pr. Benoit Maunit, Emilie Destandau, Institut de Chimie Organique et Analytique, CNRS UMR7311, Orléans
Dr. Christophe Hano, Laboratoire de Biologie des Ligneux et des Grandes Cultures, Université d'Orléans EA1207,  Orléans
Pr. Nathalie Guivarch’, Laboratoire de Biotechnologie Végétale, Université de Tours EA2106  Tours
Pr. Jérôme Lamartine, Laboratoire de biologie tissulaire et Ingénierie thérapeutique, CNRS UMR5305, Lyon

Skills

-Biophysical resonance energy transfer (RET)-based approaches: BRET, nanoBRET, TR-FRET, and RILES
- Molecular biology, Biochemistry, Cell culture (cell lines and primary culture)
- Isotopic and optical molecular imaging
- Immunodetection methods (IHC, IF, confocal analysis of co-localised fluorescent events) on frozen cerebral and spinal cord tissue sections
- Animal studies : behaviour analysis of pain, learning and memory in mice ((OF, NOR, YMaze, VonFrey, Tail flick), tumour models (syngenic, orthotopic)
- Genetics of Drosophila melanogaster

Keywords:

Cognition, GPCR, LINGO, neuropharmacology, serotonin 5-HT7 receptor, BRET, microARNs, inducible genetic switch expression system, spatiotemporal analysis, cancer