A Study Into the Underlying Biochemical Pathways Involved in Parkinson's Disease, Such as Mitochondrial (Cellular "Powerhouse") Dysfunction

Parkinson's disease (PD) is a progressive neurological disorder that is increasingly prevalent with age, with the incidence rising from approximately 4 people per 10,000 in their forties to 2 in 100 over the age of eighty. Besides motor symptoms, such as tremor, rigidity, bradykinesia, and postural instability, PD patients often experience a variety of non-motor symptoms, such as fatigue, depression, sleep disturbance, and dementia.

Although symptomatic treatments exist to partially compensate for motor dysfunction, no neuroprotective treatment has yet been established to slow PD progression, which inevitably renders patients incapable of living independently. Compared to age- and sex-matched controls, PD patients are about 5 times more likely to require nursing home care and this care costs about 5 times more than average nursing home care. This, combined with the European demographic shift toward an increasingly larger fraction of aged individuals, creates a social and economic challenge to develop new medications to slow the progression of PD.

Our understanding of the aetiopathogenesis of PD has rapidly developed in the past two decades, but this has not yet translated into any clinically established neuroprotective treatment that slows disease progression. There is a growing consensus that the failure of previous efforts is mainly due to the aetiopathogenic diversity of PD and the estrangement of existing preclinical models from clinical PD. For example, it is known that mutations in mitochondrial genes can cause monogenic PD and biochemical evidence indicates that in a proportion of cases, idiopathic PD is associated with detectable mitochondrial dysfunction.

Therefore, the investigators focus is on monogenic forms of PD that involve mitochondrial abnormalities as a primary (e.g., Parkin, PINK1), or secondary (e.g., LRRK2, GBA1) phenomenon, in order to extrapolate to idiopathic PD (IPD) patients with and without mitochondrial dysfunction (Mito-IPD and Amito-IPD, respectively). Biochemical pathways focusing on, but not restricted to mitochondrial function, will be assessed using a variety of techniques including biochemical assays on blood, urine, CSF and tissue samples. The investigators will explore both the relevance and measurement of specific biochemical pathways in Parkinson's and related disorders

The main overall objective is to stratify PD patients based on dysfunction in biochemical pathways related to PD. This will aid in developing new candidate neuroprotection compounds to slow the progression of neurodegeneration.