title: MicroRNA-26a induced by hypoxia targets HDAC6 in myogenic differentiation of embryonic stem cells.
abstract: The importance of epigenetic regulation for maintenance of embryonic stem cell (ESC) pluripotency or for initiation of differentiation is widely accepted. However, the molecular mechanisms are poorly understood. We recently reported that a hypoxic microenvironment induces ESC differentiation. In the present study, we found that hypoxia-responsive histone deacetylase 6 (HDAC6) performs an essential signaling function for myogenic differentiation of ESCs. HDAC6 was downregulated in hypoxic ESCs or during differentiation. A knock-down of HDAC6 in ESCs resulted in induction of myogenic markers, including Pax7. Suppression of HDAC6 increased acetylation of core histones H3 and H4, leading to enhanced binding of RNA polymerase II to the Pax7 promoter. Transplantation of HDAC6 knock-down cells facilitated muscle regeneration in vivo. Importantly, the downregulation of HDAC6 by hypoxia was not mediated by HIF1α or HIF2α, master transcription regulators under hypoxia, but by induction of microRNA-26a that directly targeted the 3'-untranslated region (3'-UTR) of HDAC6. A point mutation of the microRNA-26a-binding sequence in the HDAC6 3'-UTR diminished the luciferase reporter activity. Taken together, these results suggest that environmental cues of differentiation modulate the epigenetic machinery and guide stem cells to commit to a specific lineage.
authors: Department of Internal Medicine and Innovative Research Institute for Cell Therapy, Seoul National University Hospital, Seoul, Korea Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea.
authors: Sae-Won
authors: SW
authors: Lee
authors: Department of Internal Medicine and Innovative Research Institute for Cell Therapy, Seoul National University Hospital, Seoul, Korea.
authors: Jimin
authors: J
authors: Yang
authors: Department of Internal Medicine and Innovative Research Institute for Cell Therapy, Seoul National University Hospital, Seoul, Korea.
authors: Su-Yeon
authors: SY
authors: Kim
authors: Department of Internal Medicine and Innovative Research Institute for Cell Therapy, Seoul National University Hospital, Seoul, Korea.
authors: Han-Kyul
authors: HK
authors: Jeong
authors: Department of Internal Medicine and Innovative Research Institute for Cell Therapy, Seoul National University Hospital, Seoul, Korea.
authors: Jaewon
authors: J
authors: Lee
authors: National Research Laboratory of Regenerative Sexual Medicine, Department of Urology, Inha University School of Medicine, Incheon, Korea.
authors: Woo Jean
authors: WJ
authors: Kim
authors: Department of Internal Medicine and Innovative Research Institute for Cell Therapy, Seoul National University Hospital, Seoul, Korea Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea.
authors: Eun Ju
authors: EJ
authors: Lee
authors: Department of Internal Medicine and Innovative Research Institute for Cell Therapy, Seoul National University Hospital, Seoul, Korea Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, Seoul National University, Seoul, Korea hyosoo@snu.ac.kr.
authors: Hyo-Soo
authors: HS
authors: Kim
mesh_terms: D000818:Animals; D015687:Cell Hypoxia; D019070:Cell Lineage; D002478:Cells, Cultured; D015536:Down-Regulation; D053595:Embryonic Stem Cells / Q000201:enzymology / Q000502:physiology*; D044127:Epigenesis, Genetic; D000073864:Histone Deacetylase 6; D006655:Histone Deacetylases / Q000378:metabolism*; D008297:Male; D008648:Mesoderm / Q000166:cytology; D008810:Mice, Inbred C57BL; D035683:MicroRNAs / Q000378:metabolism*; D024510:Muscle Development / Q000235:genetics*; D018482:Muscle, Skeletal / Q000502:physiology; D051763:PAX7 Transcription Factor / Q000235:genetics; D011401:Promoter Regions, Genetic; D012038:Regeneration
chemical_list: D035683:MicroRNAs; C543693:Mirn26 microRNA, mouse; D051763:PAX7 Transcription Factor; C499033:Hdac6 protein, mouse; D000073864:Histone Deacetylase 6; D006655:Histone Deacetylases