LRRK2-mediated mitochondrial dysfunction in Parkinson's disease

Parkinson's disease (PD) is a neurodegenerative disorder characterized by motor symptoms including tremor, rigidity, and bradykinesia as well as degeneration of dopamine (DA) neurons in the substantia nigra pars compacta (SNc). A minority of PD cases are familial and are caused by a single genetic mutation. One of the most common PD-causing genes is leucine-rich repeat kinase 2 (LRRK2), which causes an autosomal dominant PD that presents very similarly to sporadic PD. Pathogenic mutations in LRRK2 increase its kinase activity, indicated by both LRRK2 autophosphorylation and phosphorylation of its substrates. To date, the mechanism(s) by which elevated LRRK2 kinase activity induces DA neuron degeneration and PD has not been fully elucidated. One potential mechanism may involve the role of LRRK2 on mitochondria, as mitochondrial dysfunction has been linked to PD pathogenesis, and exciting recent evidence has connected PD pathogenic mutations in LRRK2 to multiple aspects of mitochondrial dysfunction associated with the disease. In this review, we discuss the current knowledge implicating LRRK2 in mitochondrial energetics, oxidative stress, genome integrity, fission/fusion, mitophagy, and ion/protein transport in PD, as well as examine the potential role LRRK2 may play in mediating the effects of mitochondrial therapeutics being investigated for treatment of PD.