MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XR, UK.
Centre for Mammalian Synthetic Biology, University of Edinburgh, Edinburgh EH9 3FF, UK.
Hum Mol Genet. 2018 Oct 1;27(19):3434-3448. doi: 10.1093/hmg/ddy255.
Complex diseases, such as diabetes, are influenced by comprehensive transcriptional networks. Genome-wide association studies have revealed that variants located in regulatory elements for pancreatic transcription factors are linked to diabetes, including those functionally linked to the paired box transcription factor Pax6. Pax6 deletions in adult mice cause rapid onset of classic diabetes, but the full spectrum of pancreatic Pax6 regulators is unknown. Using a regulatory element discovery approach, we identified two novel Pax6 pancreatic cis-regulatory elements in a poorly characterized regulatory desert. Both new elements, Pax6 pancreas cis-regulatory element 3 (PE3) and PE4, are located 50 and 100 kb upstream and interact with different parts of the Pax6 promoter and nearby non-coding RNAs. They drive expression in the developing pancreas and brain and code for multiple pancreas-related transcription factor-binding sites. PE3 binds CCCTC-binding factor (CTCF) and is marked by stem cell identity markers in embryonic stem cells, whilst a common variant located in the PE4 element affects binding of Pax4, a known pancreatic regulator, altering Pax6 gene expression. To determine the ability of these elements to regulate gene expression, synthetic transcriptional activators and repressors were targeted to PE3 and PE4, modulating Pax6 gene expression, as well as influencing neighbouring genes and long non-coding RNAs, implicating the Pax6 locus in pancreas function and diabetes.
复杂疾病，如糖尿病，受到全面的转录网络的影响。全基因组关联研究表明，位于胰腺转录因子调节元件中的变体与糖尿病有关，包括那些与配对盒转录因子 Pax6 功能相关的变体。成年小鼠中 Pax6 的缺失会导致经典糖尿病的快速发作，但胰腺 Pax6 调节因子的全貌尚不清楚。我们使用调节元件发现方法，在一个特征不明显的调节沙漠中鉴定了两个新的 Pax6 胰腺顺式调节元件。这两个新的元件，Pax6 胰腺顺式调节元件 3（PE3）和 PE4，分别位于上游 50kb 和 100kb 处，与 Pax6 启动子和附近的非编码 RNA 的不同部分相互作用。它们在发育中的胰腺和脑中驱动表达，并编码多个与胰腺相关的转录因子结合位点。PE3 与结合 CT 基序的因子（CTCF）结合，在胚胎干细胞中被标记为干细胞特征标记物，而位于 PE4 元件中的常见变体影响已知的胰腺调节因子 Pax4 的结合，改变 Pax6 基因的表达。为了确定这些元件调节基因表达的能力，将合成的转录激活剂和抑制剂靶向 PE3 和 PE4，调节 Pax6 基因的表达，以及影响邻近基因和长非编码 RNA，暗示 Pax6 基因座在胰腺功能和糖尿病中起作用。
