DeLaForest Ann, Di Furio Francesca, Jing Ran, Ludwig-Kubinski Amy, Twaroski Kirk, Urick Amanda, Pulakanti Kirthi, Rao Sridhar, Duncan Stephen A
Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA.
Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Basic Science Building BS657A, 173 Ashley Ave, MSC 508, Charleston, SC 29425, USA.
Genes (Basel). 2018 Dec 28;10(1):21. doi: 10.3390/genes10010021.
Elucidating the molecular basis of cell differentiation will advance our understanding of organ development and disease. We have previously established a protocol that efficiently produces cells with hepatocyte characteristics from human induced pluripotent stem cells. We previously used this cell differentiation model to identify the transcription factor hepatocyte nuclear factor 4 α (HNF4A) as being essential during the transition of the endoderm to a hepatic fate. Here, we sought to define the molecular mechanisms through which HNF4A controls this process. By combining HNF4A chromatin immunoprecipitation (ChIP) followed by high-throughput DNA sequencing (ChIP-seq) analyses at the onset of hepatic progenitor cell formation with transcriptome data collected during early stages of differentiation, we identified genes whose expression is directly dependent upon HNF4A. By examining the dynamic changes that occur at the promoters of these HNF4A targets we reveal that HNF4A is essential for recruitment of RNA polymerase (RNA pol) II to genes that are characteristically expressed as the hepatic progenitors differentiate from the endoderm.
阐明细胞分化的分子基础将增进我们对器官发育和疾病的理解。我们之前建立了一种方案，可有效地从人诱导多能干细胞中产生具有肝细胞特征的细胞。我们之前利用这个细胞分化模型确定转录因子肝细胞核因子4α（HNF4A）在内胚层向肝命运转变过程中至关重要。在此，我们试图确定HNF4A控制这一过程的分子机制。通过在肝祖细胞形成开始时结合HNF4A染色质免疫沉淀（ChIP）并随后进行高通量DNA测序（ChIP-seq）分析，以及在分化早期收集的转录组数据，我们鉴定出其表达直接依赖于HNF4A的基因。通过检查这些HNF4A靶基因启动子处发生的动态变化，我们发现HNF4A对于将RNA聚合酶（RNA pol）II招募到那些在肝祖细胞从内胚层分化时典型表达的基因至关重要。
