科學家發現JUK-JUN通路在多能幹細胞分化中的作用
作者:
小柯機器人發布時間:2019/7/7 11:05:37
斯隆-凱特林癌症中心的Danwei Huangfu課題組與約翰霍普金斯大學的Michael A. Beer課題組合作揭示JNK-JUN信號通路在多能幹細胞分化過程中扮演的角色。 相關論文發表在2019年6月出版的《Nature Genetics》雜誌上。
首先,研究人員進行了全基因組CRISPR篩選參與胚胎幹細胞往定型內胚層(definitive endoderm,DE)分化過程中的調控因子,並意外地發現了五個JNK-JUN家族的基因涉及抑制DE分化。JNK-JUN通路並不直接通過抑制負責DE分化的增強子來發揮功能。相反,JUN與OCT4、NANOG、SMAD2和SMAD3這些轉錄因子共同定位於胚胎幹細胞的增強子處,進而通過阻礙胚胎幹細胞增強子的失活以及抑制SMAD2和SMAD3從胚胎幹細胞增強子處轉移到DE增強子處來實現對多潛能幹細胞分化的抑制。因此,JUK-JUN通路可維持多潛能性以免過早的DE分化。使用JNK的小分子抑制劑能夠提升胚胎幹細胞向DE分化以及形成DE來源的胰腺和肺前體細胞的效率。這項研究表明利用發育生物學的知識進行再生醫學研究擁有巨大潛力。
據悉,人類胚胎幹細胞和誘導性多能幹細胞為細胞治療與藥物發現帶來新的曙光。但如何讓這些幹細胞均質分化是實現其應用道路上的一個重大挑戰,因此解析這背後的發育機制有助於解決這一問題。
附:英文原文
Title: Genome-scale screens identify JNK–JUN signaling as a barrier for pluripotency exit and endoderm differentiation
Author: Qing V. Li, Gary Dixon, Nipun Verma, Bess P. Rosen, Miriam Gordillo, Renhe Luo, Chunlong Xu, Qiong Wang, Chew-Li Soh, Dapeng Yang, Miguel Crespo, Abhijit Shukla, Qing Xiang, Friederike Dndar, Paul Zumbo, Matthew Witkin, Richard Koche, Doron Betel, Shuibing Chen, Joan Massagu, Ralph Garippa, Todd Evans, Michael A. Beer, Danwei Huangfu
Issue&Volume:Volume 51 Issue 6, June 2019
Abstract: Human embryonic stem cells (ESCs) and human induced pluripotent stem cells hold great promise for cell-based therapies and drug discovery. However, homogeneous differentiation remains a major challenge, highlighting the need for understanding developmental mechanisms. We performed genome-scale CRISPR screens to uncover regulators of definitive endoderm (DE) differentiation, which unexpectedly uncovered five Jun N-terminal kinase (JNK)JUN family genes as key barriers of DE differentiation. The JNKJUN pathway does not act through directly inhibiting the DE enhancers. Instead, JUN co-occupies ESC enhancers with OCT4, NANOG, SMAD2 and SMAD3, and specifically inhibits the exit from the pluripotent state by impeding the decommissioning of ESC enhancers and inhibiting the reconfiguration of SMAD2 and SMAD3 chromatin binding from ESC to DE enhancers. Therefore, the JNKJUN pathway safeguards pluripotency from precocious DE differentiation. Direct pharmacological inhibition of JNK significantly improves the efficiencies of generating DE and DE-derived pancreatic and lung progenitor cells, highlighting the potential of harnessing the knowledge from developmental studies for regenerative medicine.
DOI: 10.1038/s41588-019-0408-9
Source:https://www.nature.com/articles/s41588-019-0408-9