Induced pluripotent stem cells for modeling and cell therapy of Parkinson's disease.

Abstract

Neurodegenerative disorders include a variety of hereditary or sporadic diseases involving the chronic, progressive loss on neural tissue. Parkinson's disease (PD) is the second most common neurodegenerative disease, affecting more than 6 million people worldwide (Wan et al., 2015). Degeneration of nigrostriatal dopamine (DA) neurons is the main pathology in PD, although other dopaminergic and non-dopaminergic systems are also affected. Characteristic symptoms are rigidity, hypokinesia, tremor, and postural instability. The loss of DA neurons is accompanied by lewy bodies and lewy neuritis, which are mainly formed by insoluble aggregates of alpha-synuclein and Tau protein and might restrain the survival and development of newborn neurons. Etiology of PD remains unclear, however interactions between environmental and genetic factors are believed to cause the loss of nigral DA neurons and ensuing locomotor system. Research indicated that increasing level of iron, oxidative stress, mitochondrial and ubiquitin-proteasome system dysfunction, inflammation, and apoptosis may lead to the progression of PD (Pu et al., 2012; Zhu et al., 2016).