Identifying Therapeutic Agents for Amelioration of Mitochondrial Clearance Disorder in Neurons of Familial Parkinson Disease

Abstract

Parkinson disease (PD) is a neurodegenerative disorder caused by the progressive loss of midbrain dopaminergic neurons, and mitochondrial dysfunction is involved in its pathogenesis. This study aimed to establish an imaging-based, semi-automatic, high-throughput system for the quantitative detection of disease-specific phenotypes in dopaminergic neurons from induced pluripotent stem cells (iPSCs) derived from patients with familial PD having Parkin or PINK1 mutations, which exhibit abnormal mitochondrial homeostasis. The proposed system recapitulates the deficiency of mitochondrial clearance, ROS accumulation, and increasing apoptosis in these familial PD-derived neurons. We screened 320 compounds for their ability to ameliorate multiple phenotypes and identified four candidate drugs. Some of these drugs improved the locomotion defects and reduced ATP production caused by PINK1 inactivation in Drosophila and were effective for idiopathic PD-derived neurons with impaired mitochondrial clearance. Our findings suggest that the proposed high-throughput system has potential for identifying effective drugs for familial and idiopathic PD.

Keywords: PARK2; PARK6; Parkinson disease; drug screening; iPS cells; mitochondria; mitophagy.