Citations

The first clinical description of Parkinson’s disease (PD) will embrace its two century anniversary in 2017. For the past 30 years, mitochondrial dysfunction has been hypothesized to play a central role in the pathobiology of this devastating neurodegenerative disease. The identifications of mutations in genes encoding PINK1 (PTEN-induced kinase 1) and Parkin (E3 ubiquitin ligase) in familial PD and their functional association with mitochondrial quality control provided further support to this hypothesis. Recent research focused mainly on their key involvement in the clearance of damaged mitochondria, a process known as mitophagy. It has become evident that there are many other aspects of this complex regulated, multifaceted pathway that provides neuroprotection. As such, numerous additional factors that impact PINK1/Parkin have already been identified including genes involved in other forms of PD. A great pathogenic overlap amongst different forms of familial, environmental and even sporadic disease is emerging that potentially converges at the level of mitochondrial quality control. Tremendous efforts now seek to further detail the roles and exploit PINK1 and Parkin, their upstream regulators and downstream signaling pathways for future translation. This review summarizes the latest findings on PINK1/Parkin-directed mitochondrial quality control, its integration and cross-talk with other disease factors and pathways as well as the implications for idiopathic PD. In addition, we highlight novel avenues for the development of biomarkers and disease-modifying therapies that are based on a detailed understanding of the PINK1/Parkin pathway.

ABSTRACT Background : The aim of this postmortem study was to compare, in Parkinson's disease subjects with and without bilateral subthalamic nucleus deep brain stimulation (STN‐DBS), the loss of pigmented neurons within the substantia nigra and pathological alpha‐synuclein density within the SN and other brain regions. Methods : PD subjects were identified from the Arizona Study of Aging and Neurodegenerative Disorders database (STN‐DBS = 11, non‐DBS = 156). Pigmented neuron loss scores within the substantia nigra as well as alpha‐synuclein density scores within the substantia nigra and 9 other brain regions were compared, the latter individually and in summary as the Lewy body brain load score. Results : DBS subjects had higher alpha‐synuclein density scores within the substantia nigra, olfactory bulb, and locus ceruleus, as well as higher total Lewy body brain load scores when compared with non‐DBS subjects. No differences in substantia nigra pigmented neuron loss scores were found. Conclusions : STN‐DBS subjects tend to have higher alpha‐synuclein density scores, but do not have a differential loss of substantia nigra pigmented neurons. © 2016 International Parkinson and Movement Disorder Society