APPLICATIONS  |  NEURONAL IMAGING


 

IMAGING AND BIOSIMULATION PLATFORM FOR NEW CENTRAL NERVOUS SYSTEM DRUGS

The Imaging and biosimulation platform for new Central Nervous System drugs (BICNSD) is a 3 year project aimed at the development and validation of two synergistic platforms for a unique service based on imaging and biosimulation, to enhance drug discovery and development through better understanding of Central Nervous System (CNS) diseases and tracking drug candidates’ actions at subcellular and molecular levels.

The project is an international France-Québec collaboration funded by the Québec Consortium for Drug Discovery (CQDM), Alsace-Biovalley and OSÉO. This project is aimed at the development of new technologies and processes that will have the power to facilitate the discovery or the development of new drugs.

The biosimulation of drug delivery in the central nervous system part of the project will be carried by Rhenovia Pharma, while the multiplex cellular fluorescence imaging platform will be developed by Photon etc with the collaboration of Professor Paul de Koninck of the Neurophotonics Centre of Université Laval in Québec.

 

PROJECT

Background : Fundamental mechanisms underlying diseases of the Central Nervous System (CNS) remain ill-defined, in part due to a lack of proper methods for investigating complex molecular processes down to a small scale (i.e. the synapse). This limitation explains in part the relative poor efficacy of existing treatments and our failure to discover innovative treatments for CNS diseases in the past decade. There is a need, therefore, for new tools to assess the dynamics of proteins along the neuronal membrane, following different stimulations or drug treatments.

Objectives : The project concerns the development of a drug discovery & development platform for CNS disease based on: (1) a cellular and subcellular imaging system capable of imaging simultaneously several labels; (2) the design of probes for multi-labeling of receptors in neurons; (3) the imaging analysis software tools to visualize the labels; and (4) a biosimulation platform implementing and integrating specific protein-protein interactions, signaling cascades, and receptor movement along the postsynaptic membrane.

Preliminary results :


1. Biosimulation platform (Rhenovia) :

Synapses are structures in the nervous system that permit neurons to pass electrical or chemical signals to one another and are composed of three elements:

  • the presynaptic terminal, which releases neurotransmitter following an action potential in the input neuron;
  • the synaptic cleft in which the neurotransmitter is released;
  • the postsynaptic element belonging to the target neuron.  The neurotransmitter activates receptors which transform the chemical signal into electrical and biochemical signals through the activation of ion channels and intracellular secondary messenger pathways.


Individual properties of neurotransmitter receptors such as affinity for their ligand and kinetic characteristics (activation, deactivation, desensitization) strongly influence their activation profile. In addition to these intrinsic specificities, the location within the synapse, i.e. close (synaptic) or far (extra synaptic) from the release site will also influence the response.

The preliminary step was to study protein-protein dynamics and interactions of glutamate receptors AMPA, NMDA and metaboprobic glutamate receptor (mGluR) and their subtype of receptors (NR1/NR2A and NR1/NR2B NMDAR, GluA1 and GluA2 AMPAR, mGluR5) as well as intracellular proteins of interest regarding signaling pathway (Stargazin, CaMKII).

A literature review as conducted to determine if these receptors migrated under particular pathological conditions or as effect of drug treatment. NR1/NR2B Models of receptors were developed, compared to literature, validated and implemented in the glutamatergic synapse following specific characteristics.

Future goals include definition of the remaining glutamate receptors of interest. Computational environment will be determined by characteristics observed by the cameras built by Photon etc and the focus will be extended on dendritic branches on which 10-15 excitatory synapses will be plugged into.

2. Multi-labeling of receptors in neurons (Paul De Koninck lab)

Specific labeling of two types of synaptic receptors, AMPA and NMDA, with different antibody-quantum dot combinations and labeling of post-synaptic sites on living neurons was achieved (see figure 2)

3. Multiplex cellular imaging platform

For years, cellular imaging and tissue imaging were limited by the number of label, or stains, that one could use to image and study many tissue type or molecular species simultaneously. Photon etc.'s technology can remove these limits in two ways. First, by using novel narrow band labels like quantum dots, SERS nanospheres, or other Raman labels, the spectral imager allow multiplexing tens of labels, thus imaging and monitoring tens of signal simultaneously. This can lead to much more comprehensive in vitro studies when studying the effect of new drug candidates on cellular signalisation cascades.

The design of the prototype with fluorescence cellular imaging capabilities is now completed and is now being fabricated. The system consists of Photon etc.’s hyperspectral imager coupled to an IX-73 Olympus microscope and the HNü 512 EMCCD camera from Nüvü Cameras. The filter is designed for fast acquisition of hyperspectral data in the wavelength range 500 to 900 nm with a 2 nm bandwidth. Illumination is provided by a 300 W xenon lamp (Sutter Instruments) in combination with optical filters (Semrock). The microscope is equipped with motorized focus and mirror turret to permit automatic selection of illumination wavelength and z-stack acquisitions.

The system is expected to permit acquisition of spectrally resolved fluorescence images within a few seconds.

Our Funding Partners


CQDM

The Québec Consortium for Drug Discovery (CQDM) is a meeting ground for all stakeholders in biopharmaceutical research and whose principal mission is to fund research projects carried out in partnership between the academic and hospital milieus in the public sector and the pharmaceutical and biotechnology industries in the private sector.

Alsace-BioValley

The Alsace BioValley cluster* unites all of Alsace's Health and Life Sciences players from the private and public sectors. Alsace BioValley accompanies businesses and laboratories in the health/life sciences sector looking to create, grow or locate in the Alsace region.

OSÉO

OSEO, is a public-sector institution dedicated to economic development — and a key source of financing and other support for SMEs. Its mission is to back innovation and growth of SMEs at decisive phases in their development: start-up, innovation, growth and business transfer via buyouts or other structures. By sharing risks, we make it easier for SMEs to access bank and private-equity financing. OSEO offers institutions and banks involved in SME financing both consultancy services and technical support, drawing on its long and varied experience in the field.

Our Strategic Partners


Rhenovia Pharma (Mulhouse, France)

Role in the project: Development of the biosimulation platform to model the impact on neuronal functions, under normal and pathological conditions, of protein dynamics and protein-protein interactions. The use of biosimulation will reduce both the number of lab experiments and the cost of the R&D process leading to the development of new Central Nervous System drugs. 

Professor Paul De Koninck (Quebec, Quebec)

Affiliations: Centre de recherche de l’Institut universitaire en santé mentale de Québec, Neurophotonics Centre, Université Laval.

Role in the project: Develop various approaches to specifically label multiple species of proteins on the cultured neurons and use Photon etc.’s hyperspectral imaging system to validate the biosimulation results obtained by Rhenovia.

RELATED PRODUCTS

IMA™ FLUORESCENCE

Dedicated to life sciences, IMA™ Fluorescence is an all-in-one hyperspectral fluorescence microscope perfect for studying the properties of organic and inorganic substances.

RIMA™ BIOMED

The tool of choice for non-invasive monitoring and analysis of biological tissue, RIMA BIOMED is a cutting edge hyperspectral Raman imager for biomedical sciences, available at an excitation wavelength of 785 nm.