Insights into gene expression profiles induced by Socs3 depletion in Keratinocytes

Specific deletion of suppressor of cytokine signaling 3 (Socs3) in keratinocytes can cause severe skin inflammation with infiltration of immune cells, however the molecular mechanisms and key regulatory pathways involved remains poorly understood. To investigate the role of Socs3 in keratinocytes, we generated and analyzed global RNA-Seq profiles in Socs3 conditional knockout (cKO) mice at two different stages (2- and 10- weeks). Over 400 shared genes were found to be significantly regulated at both time points. Two week samples were marked by initial skin barrier dysfunction established by the downregulation of keratin associated genes and upregulation of genes regulating lipid metabolism. Subsequent increase in expression level of multiple chemokines and cytokines at 10 week were observed representing response to skin inflammation caused by the disruption of skin barrier function. A group of activator protein-1 related genes were to found to be highly elevated in Socs3 cKO mice at both time points. This observation was duly validated using qRT-PCR in Socs3 depleted human keratinocyte–derived HaCaT cells. Overall this study reveals an important regulatory dynamics of Socs3 in skin barrier dysfunction. Socs3 cKO mice mRNA profiles of 2 and 10 week wild type (WT) C57BL/6 mice were generated by sequencing using HiSeq 1000 system (Illumina) machine which could read a 50 bp sequence.在角质形成细胞（keratinocytes）中特异性敲除细胞因子信号转导抑制因子3（suppressor of cytokine signaling 3，Socs3）可引发严重的皮肤炎症并伴随免疫细胞浸润，但目前对其涉及的分子机制与关键调控通路仍知之甚少。为探究Socs3在角质形成细胞中的作用，我们对两个不同发育阶段（2周龄与10周龄）的Socs3条件性敲除（conditional knockout，cKO）小鼠进行了全转录组RNA测序（RNA-Seq）分析并构建其基因表达谱。研究发现，共计超过400个共有基因在两个时间点均发生显著表达调控。2周龄样本以早期皮肤屏障功能障碍为特征，该障碍由角蛋白相关基因表达下调与脂质代谢调控基因表达上调共同介导。而在10周龄时，多种趋化因子与细胞因子的表达水平显著升高，这代表了皮肤屏障功能破坏所引发的皮肤炎症应答。另有一组激活蛋白1（activator protein-1，AP-1）相关基因在两个时间点的Socs3 cKO小鼠中均呈高表达水平。该研究结果通过在Socs3敲低的人角质形成细胞来源的HaCaT细胞中开展实时定量聚合酶链反应（quantitative real-time polymerase chain reaction，qRT-PCR）验证得以确认。本研究整体揭示了Socs3在皮肤屏障功能障碍过程中的重要调控动态。本研究采用Illumina公司的HiSeq 1000测序系统（该系统可读取50 bp序列），对2周龄与10周龄的野生型（wild type，WT）C57BL/6小鼠及Socs3条件性敲除小鼠的mRNA进行测序，从而构建其mRNA表达谱。