A single‐cell transcriptomic analysis reveals precise... : Hepatology (original) (raw)
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A single‐cell transcriptomic analysis reveals precise pathways and regulatory mechanisms underlying hepatoblast differentiation
Yang, Li1,2,†; Wang, Wei‐Hua1,2,†; Qiu, Wei‐Lin1,3,†; Guo, Zhen1; Bi, Erfei4; Xu, Cheng‐Ran*,1
1Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, College of Life Sciences, Peking‐Tsinghua Center for Life SciencesPeking UniversityBeijingChina
2Academy for Advanced Interdisciplinary StudiesPeking UniversityBeijingChina
3PKU‐Tsinghua‐NIBS Graduate ProgramPeking UniversityBeijingChina
4Department of Cell and Developmental BiologyUniversity of Pennsylvania Perelman School of MedicinePhiladelphiaPA
* ADDRESS CORRESPONDENCE AND REPRINT REQUESTS TO:
Cheng‐Ran Xu, Ph.D.
Ministry of Education Key Laboratory of Cell Proliferation and Differentiation College of Life Sciences
Peking‐Tsinghua Center for Life Sciences, Peking University
Beijing 100871, China
E‐mail: [email protected]
†These authors contributed equally to this work.
Abstract
How bipotential hepatoblasts differentiate into hepatocytes and cholangiocytes remains unclear. Here, using single‐cell transcriptomic analysis of hepatoblasts, hepatocytes, and cholangiocytes sorted from embryonic day 10.5 (E10.5) to E17.5 mouse embryos, we found that hepatoblast‐to‐hepatocyte differentiation occurred gradually and followed a linear default pathway. As more cells became fully differentiated hepatocytes, the number of proliferating cells decreased. Surprisingly, proliferating and quiescent hepatoblasts exhibited homogeneous differentiation states at a given developmental stage. This unique feature enabled us to combine single‐cell and bulk‐cell analyses to define the precise timing of the hepatoblast‐to‐hepatocyte transition, which occurs between E13.5 and E15.5. In contrast to hepatocyte development at almost all levels, hepatoblast‐to‐cholangiocyte differentiation underwent a sharp detour from the default pathway. New cholangiocyte generation occurred continuously between E11.5 and E14.5, but their maturation states at a given developmental stage were heterogeneous. Even more surprising, the number of proliferating cells increased as more progenitor cells differentiated into mature cholangiocytes. Based on an observation from the single‐cell analysis, we also discovered that the protein kinase C/mitogen‐activated protein kinase signaling pathway promoted cholangiocyte maturation. Conclusion: Our studies have defined distinct pathways for hepatocyte and cholangiocyte development in vivo, which are critically important for understanding basic liver biology and developing effective strategies to induce stem cells to differentiate toward specific hepatic cell fates in vitro. (Hepatology 2017;66:1387–1401).
© 2017 by the American Association for the Study of Liver Diseases.