Review
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World J Stem Cells. Oct 26, 2013; 5(4): 172-187
Published online Oct 26, 2013. doi: 10.4252/wjsc.v5.i4.172
MicroRNAs as novel regulators of stem cell fate
Eunhyun Choi, Eunmi Choi, Ki-Chul Hwang
Eunmi Choi, Ki-Chul Hwang, Severance Biomedical Science Institute, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, South Korea
Eunhyun Choi, Severance Integrative Research Institute for Cerebral & Cardiovascular Disease, Yonsei University Health System, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, South Korea
Author contributions: All authors contributed to the writing, the illustrations and the revision of this manuscript.
Supported by This research was supported by a South Korea Science and Engineering Foundation grant funded by the South Korea government (MEST) (2011-0019243, 2011-0019254), a grant from the South Korea Health 21 R and D Project, Ministry of Health and Welfare, South Korea (A120478), and a grant from the Korea Health 21 R and D Project, Ministry of Health and Welfare, South Korea (A085136).
Correspondence to: Ki-Chul Hwang, PhD, Severance Biomedical Science Institute, Cardiovascular Research Institute, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, South Korea. kchwang@yuhs.ac
Telephone: +82-2-22288523 Fax: +82-2-3651878
Received: June 28, 2013
Revised: July 23, 2013
Accepted: August 16, 2013
Published online: October 26, 2013
Processing time: 125 Days and 2.9 Hours
Abstract

Mounting evidence in stem cell biology has shown that microRNAs (miRNAs) play a crucial role in cell fate specification, including stem cell self-renewal, lineage-specific differentiation, and somatic cell reprogramming. These functions are tightly regulated by specific gene expression patterns that involve miRNAs and transcription factors. To maintain stem cell pluripotency, specific miRNAs suppress transcription factors that promote differentiation, whereas to initiate differentiation, lineage-specific miRNAs are upregulated via the inhibition of transcription factors that promote self-renewal. Small molecules can be used in a similar manner as natural miRNAs, and a number of natural and synthetic small molecules have been isolated and developed to regulate stem cell fate. Using miRNAs as novel regulators of stem cell fate will provide insight into stem cell biology and aid in understanding the molecular mechanisms and crosstalk between miRNAs and stem cells. Ultimately, advances in the regulation of stem cell fate will contribute to the development of effective medical therapies for tissue repair and regeneration. This review summarizes the current insights into stem cell fate determination by miRNAs with a focus on stem cell self-renewal, differentiation, and reprogramming. Small molecules that control stem cell fate are also highlighted.

Keywords: MicroRNA; Stem cell fate; Differentiation; Self-renewal; Reprogramming; Small molecule

Core tip: Stem cells are important in regenerative medicine applications due to their capacity to self-renew and differentiate into specific cell types. MicroRNAs (miRNAs) are short non-coding RNAs that negatively regulate gene expression at the post-transcriptional level. Recent studies suggest that miRNAs are key molecules in the regulation of stem cell fate decisions; this regulation is manifested as the fine tuning of cell- and tissue-specific gene expression. This review summarizes the current insights into stem cell fate determination by miRNAs and focuses on stem cell self-renewal, differentiation, and reprogramming. Small molecules that control stem cell fate are also highlighted.