Histone 3 (k14) acetilation in hyperbilirubinmia

Bilirubin toxicity to the CNS has been widely studied for decades, and shown impacting potential toxic/adaptation mechanisms by a significant modulation of gene expression, suggesting that mechanisms having crucial role on the regulation of gene expression, such as epigenetic mechanisms, should have a strong impact in unconjugated bilirubin toxicity. In this work, we followed the levels of histone 3 acetylation (H3K14Ac) in the cerebellum (Cll) of the developing (2, 9, 17 days after the birth and in adult age) Gunn rat (the natural model for neonatal hyperbilirubinemia and kernicterus) by Western blot, discovering an age specific alteration of the H3K14Ac in the hyperbilirubinemic animals. Then, the H3K14Ac linked chromatin was immune-precipitated and submitted to sequencing (ChIP-Seq). The GeneOntology analysis revealed that almost the 45% of H3K14Ac ChiP-Seq TSS-promoter genes were involved in the CNS development.数十年来，中枢神经系统（Central Nervous System，CNS）的胆红素毒性已被广泛研究。研究表明，胆红素可通过显著调控基因表达，影响潜在的毒性与适应机制，这提示诸如表观遗传机制（epigenetic mechanisms）这类对基因表达调控具有关键作用的机制，会对未结合胆红素（unconjugated bilirubin）毒性产生极强影响。本研究采用蛋白质免疫印迹（Western Blot）技术，检测了发育阶段（出生后2、9、17天及成年）冈恩大鼠（Gunn rat，新生儿高胆红素血症与核黄疸（kernicterus）的天然动物模型）的小脑（cerebellum，Cll）中组蛋白3乙酰化（histone 3 acetylation，H3K14Ac）的水平，结果发现高胆红素血症动物体内H3K14Ac的改变具有年龄特异性。随后，我们对与H3K14Ac结合的染色质进行免疫沉淀，并开展染色质免疫共沉淀测序（Chromatin Immunoprecipitation Sequencing，ChIP-Seq）。基因本体（Gene Ontology，GO）分析结果显示，在H3K14Ac ChIP-Seq检测的转录起始位点（Transcription Start Site，TSS）-启动子区域相关基因中，近45%的基因参与了中枢神经系统发育过程。