Review: Direct conversion in Neuro-regenerative Medicine Myung Rae Park 1 , Danbi Song 1 , Jihye Park 1 , Kang Seok Lee 1 , Suk Hwan Joung 1 , Jeong Beom Kim 1* 1 Max Planck Partner Group-Molecular Biomedicine Laboratory, School of Life Sciences, Ulsan National Institute of Science and Technology, Ulsan, South Korea Abstract. Recent advances in direct conversion technology are of great significance in neuro-regenerative medicine. Conversion of somatic cells to a desired cell type is next generation reprogramming technology for clinical applications. The novel strategy of direct conversion of somatic cells into expandable multipotent neural cells (induced multipotent neural cells, iMNCs) and specific neurons (induced neurons, iNs) opens a new window of opportunities for cell therapy, disease specific modeling, and drug discovery for brain diseases. Keywords: Direct conversion, multipotent neural cells, somatic cells, neurodegenerative disorders 1 Introduction Regenerative medicine opens new windows for effective and safe therapies for incurable and debilitating disorders. Stem cells, which can be isolated from human tissues, are considered as an essential resource in regenerative medicine. There are several types of stem cells such as embryonic stem cells (ESCs), adult stem cells, and induced pluripotent stem cells (iPSCs) depending on their developmental sources [1]. The discovery of iPSCs in 2006 not only offered an opportunity for a patient-specific cell-based therapy but also provided disease-specific modeling, which can be used as a valuable platform for drug screening. Furthermore, the derivations of iPSCs from adult cells avoided the ethical debate concerning the derivation of ESCs from human embryos [2]. However, many practical obstacles still remain to bring stem cell technology from bench to bed. One of the limitations is difficulty in inducing differentiation of pluripotent stem cells into a desired cell type. It takes significant time and efforts to reprogram somatic cells to pluripotent cells and later induce them into desired cells. Another limitation is that there still is a high possibility that remaining undifferentiated cells may form a teratoma during differentiation within the human body. To date, there are many reviews on induced conversion of specialized cells into other cell types by using lineage specific transcription factors. In the past few years, many research groups have focused on direct conversion between somatic cells, within or outside their original lineages [3]. Neurodegenerative diseases such as Parkinson’s disease (PD), Alzheimer’s disease (AD), Amyotrophic Lateral Sclerosis (ALS) and Multiple Sclerosis (MS) occur as the result of neurodegenerative processes Advanced Science and Technology Letters Vol.47 (Bioscience and Medical Research 2014), pp.79-83 http://dx.doi.org/10.14257/astl.2014.47.19 ISSN: 2287-1233 ASTL Copyright © 2014 SERSC