Advances in the application of induced pluripotent stem cells in Alzheimer's diseases and Parkinson's diseases.

Induced pluripotent stem cells (iPSCs) are a type of pluripotent stem cells induced by somatic cells. It was found that differentiated cells could be reprogrammed to a pluripotent state by the expression of the four transcription factors such as Oct3/4, Sox2, c-Myc, and Klf4. This technology can be applied to reprogramme the patient cells into iPSCs which further be induced into research-required cells or tissues. Nowadays, a great number of reprogramming methods and various types of somatic cells can be used to produce iPSCs. The advance of this technology provides a promising pathway to disease models building, drug development and the corresponding cell-based therapy. Alzheimer's diseases (AD) and Parkinson's diseases (PD) are complex diseases affected by many factors including genetic and environmental factors. Until now, there are no effective treatments to reverse these diseases because the pathogenesis of these complex diseases is still not well understood. One important reason is that the existing disease model cannot fully recapitulate the pathologies of these multifactorial associated diseases. And iPSCs have the potential to resolve this difficulty. In this review, we discuss the application progress of iPSCs in AD and PD including the disease modeling, drug development and cell-based therapies.