High Content Screening and Proteomic Analysis Identify a Kinase Inhibitor that rescues pathological phenotypes in a Patient-Derived Model of Parkinson’s Disease

Abstract

Combining high throughput screening approaches with induced pluripotent stem cell (iPSC)based disease models represents a promising unbiased strategy to identify therapies for neurodegenerative disorders. Here we applied high content imaging on iPSC-derived neurons from patients with familial Parkinson's disease bearing the G209A (p.A53T) α-synuclein (αSyn) mutation and launched a screening campaign on a small kinase inhibitor library. We thus identified the multi-kinase inhibitor BX795 that at a single dose effectively restores diseaseassociated neurodegenerative phenotypes. Proteomics profiling mapped the molecular pathways underlying the neuroprotective effects of BX795 that comprised a cohort of 118 protein-mediators of the core biological processes of RNA metabolism, protein synthesis, modification and clearance, and stress response, all linked to the mTORC1 signaling hub. In agreement, expression of human p.A53T-αSyn in neuron-like cells affected key components of the mTORC1 pathway resulting in aberrant protein synthesis that was restored in the presence of BX795 with concurrent facilitation of autophagy. Taken together, we have developed an adaptable platform based on p.A53T iPSC-derived neurons for drug screening and identified a promising small molecule with potent neuroprotective actions as candidate therapeutic for PD and other protein conformational disorders.3 Key words α-synuclein, p.A53T α-synuclein mutation, induced pluripotent stem cell derived neurons, drug screening, mTOR signaling, mRNA metabolism, proteostasis AcknowledgementsWe thank Drs. Tamotsu Yoshimori and Terje Johansen for providing GFP-LC3 and mChery-GFP-p62 plasmids, respectively.

Emerging hiPSC Models for Drug Discovery in Neurodegenerative Diseases

“…Similar to the above phenotypic screenings, a third study performed the screening of 273 small molecule kinase inhibitors on A53T-αSyn hiPSC-DA neurons. They identified BX795, a multikinase inhibitor, as a drug candidate that rescued PD pathology by robustly increasing TH expression [ 165 ].…”

Patient-Derived Induced Pluripotent Stem Cell-Based Models in Parkinson’s Disease for Drug Identification

“…The selective vulnerability of dopaminergic neurons was further attributed in this study to the dysregulation of intracellular calcium homeostasis via T-type calcium channels, revealing a previously unidentified pathway in PD and offering a potential treatment opportunity. More recently, using A53T-αSyn patient-derived neurons, we performed a small-scale phenotypic screen to identify neuroprotective compounds and identified the multikinase inhibitor BX795 as a candidate therapeutic that rescued the pathological features of PD neurons [ 94 ].…”