Positron Emission Tomography and Amyotrophic Lateral Sclerosis: Study of Cannabinoid subtype 2 receptor expression in ALS experimental model

Transcription

1 E ositron Emission omography and myotrophic ateral clerosis: tudy of Cannabinoid subtype 2 receptor expression in experimental model collaborative research project of CNR Institute of Clinical hysiology - isa University of isa - Department of harmaceutical ciences CNR Institute of Biomolecular Chemistry - ozzuoli resented by iero. VDORI

2 Outline: cientific background of the project & aims Why a proposal based on ositron Emission omography Mining unexploited resources, merging hightech technologies & skills Workplan roject update

3 cientific background of the project & aims Background Evidence exists that involves neuroinflammatory events. Cannabinoid type 2 Receptors (CB2R) are expressed in immune cells and tissues but are weakly present in healthy CN. However, in neuroinflammatory conditions CB2R (but not CB1R) are upregulated in the activated microglia (MG). ctivation of MG seems to precede symptoms onset in experimental models of and MG has been postulated to be involved in early motor neuron degeneration. E allows the quantitation of the regional distribution of radiolabelled tracers in vivo, dynamically and under real tracer conditions. im Development of E tracers that selectively bind to the CB2R receptor and highlight their upregulation in neuroinflammatory conditions. In vivo assessment of candidates by using an experimental model of (mod1- G93 transgenic mice) Understanding whether E in association with CB2-ligands might be considered for translational study to qualify as imaging biomarker for in humans

4 Why a proposal based on ositron Emission omography E monitoring of response to therapy E/FDG as biomarker Courtesy of eter MacCallum Cancer Institute hankar K, et al., J.Nucl.Med. 2006; 47:

5 Why a proposal based on ositron Emission omography U C MRI MR E E BIOIMGE U C MRI MR E E anatomia funzione + +/ biochimica - - +/- + +/- ++ biochemistry Damage progression anatomy function Molecular imaging Highlight an interaction occurring at the molecular level while retaining its regional information E/C

6 Why a proposal based on ositron Emission omography activity E DYNMIC IMGING Injection of labelled drug time In vivo pharmacokinetic with E/C et of images (2D) from Volume of Interest (3D) Frame 1 (t=t 0 ) Frame 2 (t=t 2 ). Frame n (t=t n ) t t t

7 Why a proposal based on ositron Emission omography Drug Development & Research flowchart Drug discovery Volunteers atients Clinical trials atients roduct launch arget ID ead Molecule Discovery reclinical Research hase I hase hase I roduct icencing Industrial roduction Marketing nimal research investments Commercialisation and Return on investments

8 sono necessari per visualizzare quest'immagine. E Mining unexploited resources, merging hightech resources & skills CNR Institute of Clinical hysiology - isa Dr... alvadori Radiopharmaceutical Chemistry & Imaging Biomarker development dvanced biomedical technologies In vivo/ex vivo imaging & pharmacology University of isa Department of harmaceutical ciences rof. C. Manera Computational Chemistry New scaffolds & nalogue modification Customised synthesis Quickime e un decompressore CNR Institute of Biomolecular Chemistry - ozzuoli Dr. V Di Marzo tructure-activity relationships & molecular pharmacology Characterisation & development of bioactive molecules Biomasses & biologically active substrates

9 Quickime e un decompressore sono necessari per visualizzare quest'immagine. Quickime e un decompressore sono necessari per visualizzare quest'immagine. E Workplan Unsatisfactory Biochemistry ead molecules, reference standard & chemical precursors Biochemical characterisation of lead compounds recursor design optimisation, test labelling, purification & formulation Unsatisfactory Radiochemistry or Biology In vivo microe & microc, dynamic imaging & biodistribution Candidate selection by in vivo imaging & proof-of-principle demonstration esting in disease model issue hystology & receptor analysis

10 roject update 18 F X N R 1 R 2 O suitable "cold" precursor should be designed so that the expected active compound can be prepared within the constraints of labelling reaction (short time and high specific-activity) General structure based on aromatic fused rings Introduction of fluorine-18 label in different positions R1, R2 and other structure modifiers to modulate R compound Ki (CB1) Ki (CB2) CB1/CB2 CB 83 > > 27 CB CB CB V F Warning: arent "cold" precursor should also be tested for biological activity as it may compete with the tracer for the binding site High specific activity: the mass associated to the radioactivity of tracer is negligible (<< µmol) from the point of view of toxicity and macroscopic effect,

11 roject update Radionuclide production Radiochemistry Radiochemical Radiopharmaceutical Development of labelling chemistry elect precursor est labelling (yield, time scale, bulk volume, impurities & toxicity) ynthesis & purification (radiation protection, radiochemical purity, specific activity) Image acquisition Microfluidic radiolabelling platform olvents, temperature, time of reaction vary with substrates and labelling chemistry Different routes for 18 F "activation: counter ions, criptands, phase-transfer agents,.. so n Os < 18 F> CH 3 CN 18 F n Os R 1 R 2 R 1 R 2 n = 2,3 R 3 R 3 Cl N N < 18 F> DMO 18 F N N R R R= morpholin (CB26), phenyl (C41) R= morpholin (CB83), phenyl (C102)

12 roject update Examples of C on µc identified organs Quickime and a NG decompressor are needed to see this picture. Quickime and a YUV420 codec decompressor are needed to see this picture. HIGH-REOUION µc and µe CD56 healthy mouse (wild type) microe/microc image fusion

13 Quickime e un decompressore sono necessari per visualizzare quest'immagine. E roject update ead molecules, reference standard & chemical precursors roject clock R RI 2011 CUY ON-GOING Biochemical characterisation of lead compounds recursor design optimisation, test labelling, purification & formulation MID ERM In vivo microe & microc, dynamic imaging & biodistribution END RI 2012 Candidate selection by in vivo imaging & proof-of-principle demonstration Control group (CD1 mice) esting in disease model dd old (young healthy) dd old (old healthy) Disease developing group (mod1 mice) issue hystology & receptor analysis dd old (young asymptomatic) dd old (symptoms onset) dd old (serious symptoms)

14 E We are grateful to ri for supporting our research hank you for your kind attention