Protein-protein interaction disruptors as therapeutic targets(an example of a drug discovery

project)

Yvonne Lai, Ph.D.Department of Psychological and Brain Sciences

Indiana University, BloomingtonNavigator, Indiana CTSI (Bloomington campus)

Image from Cayman Chemical

NMDAR Signaling Cascade

Small molecule inhibitors:IC87201/ZL006

NMDAR -----------PSD95----------nNOS-------------NOS1AP--------MAPK------PTSD Depression Stroke

Pain behavior

(CAPON)

Protein-protein interaction disruptors ofNMDAR-dependent signaling

Peptide inhibitorTat-NR2B9c (NA-1)

Target Discovery

Lead Discover

y

Lead Optimizatio

n

Preclinical Evaluation

Full Developmen

tClinical Trials

Assay development

High-throughput screen

Candidate selection

Drug Development

Current collaborative Team

Chemistry:Ganesh Thakur (Northeastern University)-Pushkar Kukarni

Pain efficacy:Andrea Hohmann (IUB)-Wan-hung LeeNeurotoxicity:

Andy Hudmon (IUSM)-Aarti Chawla

PTSD efficacy:Anantha Shekhar (IUSM)-Stephanie Fitz

nNOS-NOS1AP disruptionMichael Courtney (University of Southern Finland)-Lilli Li

Small molecule nNOS-PSD95 protein-protein interaction inhibitors

IC87201:•Inhibited NMDA-induced nNOS-dependent NO formation•Efficacious in chronic pain model (Florio, BJP 2009; Lai, Hohmann unpublished)•Decrease symptoms of PTSD in a rat preclinical model (Shekhar, unpublished) •Efficacious in one depression model (Doucet 2013)

ZL006 (analog of IC87201):•Blocked focal cerebral ischemic damage in mice and rats (Zhou, Nat Med 2010)•Efficacious in one depression model (Doucet 2013)

Additional profile of IC87201/ZL006•Efficacious systemic or i.t., found in CSF and brain tissues•No significant inhibition of 35 target (Receptorgram, MDS Pharma)•No effect on basal pain sensation•No motor ataxia•No effect on novel object recognition•No effect on Morris water maze •No effect on other PDZ P-P interactions (e.g. Erb4-PSD95)

Target Discovery

Lead Discover

y

Assay development

High-throughput screen

HTS (NIH clinical library)

Alpha Screen using NIH clinical library (~800 cpds); nNOS-PSD95 vs nNOS-NOS1AP (Fan, Courtney, Hohmann, Lai, unpublished)

Target Discover

y

Lead Discove

ry

Virtual screen?

Model of PSD95 PDZ2 and the nNOS PDZ complex (PDZ2 is superimposed on the α-syntrophin structure. From Tochio 2000)

Virtual Screen

Seeking collaborators! CTSI CTR deadline May 9!

Preclinical Evaluation

Side effect profile

Drug Development

Additional:•Memory models?•Toxicity profile?•Oral bioavailability?

What are the critical No Go side effects for treatment of pain and PTSD?

Drug DevelopmentCTSI Core Facilities

Target Discover

y

Lead Discove

ry

HTS: Chemical GenomicsIUB-Light Microscopy Imaging Center (high content screen)

Lead Optimization

Need for library:For unusual targets (e.g. P-P interactions)For cell based or more complicated assays

Chemical design and synthesis

Computational modelingVirtual screening

Preclinical Evaluation

Full Development

FundingCTSI Core facility grant (collaboration with Purdue’s BAL)IURCG collaborative grant (Hohmann, IUB and Hudmon, IUSM)

NIH likes our innovative approaches:•Funded:

o R21/NIDA (pain efficacy)-Hohmann PI; Lai, Co-PI•Expected to be funded:

o R21/NIMH (PTSD)-Shekhar, PI; Lai, Co-PIo SBIR phase I (two years)-Lai, PI

What other funding resources? VC, Angel funds?Collaboration with industry?

Collaboration between start ups with academic universities:What is the model? How to optimize expertise and minimize duplications?