The impact of PPARα activation on whole genome gene expression in human precision cut liver slices.
The impact of PPARα activation on whole genome gene expression in human precision cut liver slices.
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DOI：
10.1186/s12864-015-1969-3
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发表时间：
2015-10-08
期刊：
影响因子：
4.4
通讯作者：
Kersten S
中科院分区：
文献类型：
--
作者：
Janssen AW;Betzel B;Stoopen G;Berends FJ;Janssen IM;Peijnenburg AA;Kersten S
对小鼠的研究表明，PPARα是肝脏脂代谢的重要调节因子，也是参与禁食适应性反应的关键转录因子。然而，人们对PPARα在人类肝脏中的作用知之甚少。在这里，我们开始通过分析PPARα激动剂Wy14643处理的人肝切片全基因组基因调控来研究PPARα在人肝脏中的功能。定量聚合酶链式反应表明，PPARα在人肝和人肝切片中均有较好的表达，经典的PPARα靶标PLIN2、VLDLR、ANGPTL4、CPT1a和PDK4均被PPARα激活所诱导。转录组学分析表明，PPARα的激活上调了617个基因，下调了665个基因(Q值 <； 0.05)。PPARα激活诱导的许多基因参与脂类代谢(ACSL5、AGPAT9、FADS1、SLC27A4)、异源代谢(POR、ABCC2、CYP3A5)或未折叠的蛋白质反应，而下调的基因大多参与免疫相关途径。在抑制PPARα活性最强的基因中，有几种趋化因子(如CXCL9-11、CCL8、CX3CL1、CXCL6)、干扰素γ诱导基因(如IFITM1、IFIT1、IFIT2、IFIT3)和许多其他免疫相关基因(如TLR3、NOS2和LCN2)。Wy14643对人肝切片和原代人肝细胞基因调控的比较分析表明，与原代肝细胞相比，PPARα对基因表达的下调更能被肝切片捕捉到。特别是，PPARα的激活显著抑制了人肝切片中的免疫/炎症相关基因，但在原代肝细胞中则没有。最后，在TSKU、RHOF、CA12和VSIG10L两个人肝模型系统中发现了几个可能的PPARα新的靶基因，它们是由PPARα激活共同诱导的。我们论证了人肝切片比原代肝细胞更适合于研究PPARα在人肝中的功能作用。我们的数据强调了PPARα在调节肝脏脂质和异物代谢中的主要作用，并揭示了PPARα在人肝切片中显著的免疫抑制/抗炎作用，这可能与非酒精性脂肪性肝病的治疗相关。本文的在线版本(doi：10.1186/s12864-015-1969-3)包含补充材料，授权用户可以使用。
Studies in mice have shown that PPARα is an important regulator of lipid metabolism in liver and key transcription factor involved in the adaptive response to fasting. However, much less is known about the role of PPARα in human liver. Here we set out to study the function of PPARα in human liver via analysis of whole genome gene regulation in human liver slices treated with the PPARα agonist Wy14643. Quantitative PCR indicated that PPARα is well expressed in human liver and human liver slices and that the classical PPARα targets PLIN2, VLDLR, ANGPTL4, CPT1A and PDK4 are robustly induced by PPARα activation. Transcriptomics analysis indicated that 617 genes were upregulated and 665 genes were downregulated by PPARα activation (q value < 0.05). Many genes induced by PPARα activation were involved in lipid metabolism (ACSL5, AGPAT9, FADS1, SLC27A4), xenobiotic metabolism (POR, ABCC2, CYP3A5) or the unfolded protein response, whereas most of the downregulated genes were involved in immune-related pathways. Among the most highly repressed genes upon PPARα activation were several chemokines (e.g. CXCL9-11, CCL8, CX3CL1, CXCL6), interferon γ-induced genes (e.g. IFITM1, IFIT1, IFIT2, IFIT3) and numerous other immune-related genes (e.g. TLR3, NOS2, and LCN2). Comparative analysis of gene regulation by Wy14643 between human liver slices and primary human hepatocytes showed that down-regulation of gene expression by PPARα is much better captured by liver slices as compared to primary hepatocytes. In particular, PPARα activation markedly suppressed immunity/inflammation-related genes in human liver slices but not in primary hepatocytes. Finally, several putative new target genes of PPARα were identified that were commonly induced by PPARα activation in the two human liver model systems, including TSKU, RHOF, CA12 and VSIG10L. Our paper demonstrates the suitability and superiority of human liver slices over primary hepatocytes for studying the functional role of PPARα in human liver. Our data underscore the major role of PPARα in regulation of hepatic lipid and xenobiotic metabolism in human liver and reveal a marked immuno-suppressive/anti-inflammatory effect of PPARα in human liver slices that may be therapeutically relevant for non-alcoholic fatty liver disease. The online version of this article (doi:10.1186/s12864-015-1969-3) contains supplementary material, which is available to authorized users.