Genetic Models to Probe the Role of Complex-1 Dysfunction in Neurologic Disease

Brigham And Women'S Hospital, Boston MA

Investigators

Linked publications & trials

Abstract

DESCRIPTION (provided by applicant): Perhaps the greatest obstacle in the development of disease-modifying therapeutics to combat or cure Parkinson's disease (PD) is the lack of predictive animal models. While familial forms of PD have guided the current generation of mouse models, they have thus far failed to recapitulate essential features of the human condition. Most notably lacking from these models is the spontaneous degeneration of the substantia nigra, and the accumulation of a-synuclein in non-synuclein based mice. Given the undeniable need for vertebrate models for target identification and validation in the translational arena, new models must be considered. We have focused our attention toward aspects of idiopathic PD in our rational design of a novel mouse model of this disease. Deficiencies in mitochondrial Complex-1 are routinely reported in idiopathic PD. In addition, chemical inhibitors of Complex-1 reproduce the characteristic selective lesion of the substantia nigra, deposition of the a-synuclein protein, and subsequent parkinsonism in rodents and non-human primates. There is even a small population of humans who ingested a Complex-1 toxin and subsequently presented clinically with an L-DOPA responsive parkinsonism. Numerous genetic studies have likewise implicated familial PD genes in mitochondrial biology, further heightening our interest in the role that mitochondrial dysfunction plays as a primary event in PD. We propose to characterize a novel model of PD by genetically targeting Complex-1 function. Complex-1 is a large integral membrane complex comprised of over 45 subunits whose assembly is aided by several proprietary chaperones. A critical question is which of these ~50 genes would be the most suitable target for a model of PD. We have focused on a Complex-1 gene that, when deficient in humans, results in severe degeneration of the substantia nigra, the same brain region affected in all PD cases. These data strongly suggest this gene to be an ideal target for the generation of an idiopathic PD animal model. The goal of this exploratory research proposal is to examine the downstream molecular consequences of Compex-1 dysfunction in vitro and characterize the basic neuropathological properties of Complex-1 deficiency in a novel genetic mouse model of PD. This work will determine the suitability of our model for further basic and translational efforts to understand and treat the PD disease process. PUBLIC HEALTH RELEVANCE: A major obstacle in the generation of new therapeutics for the treatment or prevention of Parkinson's disease is the lack of suitable animal models of spontaneous, premature nigral degeneration accompanied by other classic features of idiopathic Parkinson's disease. Here we will examine the suitability of a novel genetic model of Parkinson's disease in neuronal cell culture and in mice in an effort to satisfy perhaps the greatest unmet need in the field.