Cardiovascular Division, Department of Medicine, University of Virginia, 409 Lane Road, Charlottesville, VA 22908, USA.
Hum Mol Genet. 2010 Feb 1;19(3):468-79. doi: 10.1093/hmg/ddp511. Epub 2009 Nov 19.
Vascular smooth muscle cells (SMCs) display remarkable phenotypic plasticity in response to environmental cues. The nuclear factor of activated T-cells (NFAT) family of transcription factors plays a critical role in vascular pathology. However, known functional NFAT gene targets in vascular SMCs are currently limited. Publicly available whole-genome expression array data sets were analyzed to identify differentially expressed genes in human, mouse and rat SMCs. Comparison between vehicle and phenotypic modulatory stimuli identified 63 species-conserved, upregulated genes. Integration of the 63 upregulated genes with an in silico NFAT-ome (a species-conserved list of gene promoters containing at least one NFAT binding site) identified 18 putative NFAT-dependent genes. Further intersection of these 18 potential NFAT target genes with a mouse in vivo vascular injury microarray identified four putative NFAT-dependent, injury-responsive genes. In vitro validations substantiated the NFAT-dependent role of Cyclooxygenase 2 (COX2/PTGS2) in SMC phenotypic modulation and uncovered Down Syndrome Candidate Region 1 (DSCR1/RCAN1) as a novel NFAT target gene in SMCs. We show that induction of DSCR1 inhibits calcineurin/NFAT signaling through a negative feedback mechanism; DSCR1 overexpression attenuates NFAT transcriptional activity and COX2 protein expression, whereas knockdown of endogenous DSCR1 enhances NFAT transcriptional activity. Our integrative genomics approach illustrates how the combination of publicly available gene expression arrays, computational databases and empirical research methods can answer specific questions in any cell type for a transcriptional network of interest. Herein, we report DSCR1 as a novel NFAT-dependent, injury-inducible, early gene that may serve to negatively regulate SMC phenotypic switching.
血管平滑肌细胞 (SMC) 在响应环境线索时表现出显著的表型可塑性。核因子活化 T 细胞 (NFAT) 家族转录因子在血管病理学中起着关键作用。然而，目前已知血管 SMC 中的 NFAT 基因靶标是有限的。分析了公共全基因组表达谱数据集，以鉴定人、鼠和大鼠 SMC 中差异表达的基因。在车辆和表型调节刺激之间的比较中鉴定了 63 个物种保守的上调基因。将这 63 个上调基因与体内 NFAT-ome（包含至少一个 NFAT 结合位点的物种保守基因启动子列表）进行整合，确定了 18 个潜在的 NFAT 依赖性基因。将这 18 个潜在的 NFAT 靶基因与体内血管损伤微阵列进一步交叉，确定了 4 个潜在的 NFAT 依赖性、损伤反应基因。体外验证证实了环氧化酶 2 (COX2/PTGS2) 在 SMC 表型调节中的 NFAT 依赖性作用，并揭示了唐氏综合征候选区 1 (DSCR1/RCAN1) 是 SMC 中一种新的 NFAT 靶基因。我们表明，DSCR1 的诱导通过负反馈机制抑制钙调神经磷酸酶/NFAT 信号传导；DSCR1 过表达减弱 NFAT 转录活性和 COX2 蛋白表达，而内源性 DSCR1 的敲低增强 NFAT 转录活性。我们的综合基因组学方法说明了如何将公共可用的基因表达谱、计算数据库和经验研究方法相结合，以回答任何细胞类型中特定问题的转录网络。在这里，我们报告 DSCR1 是一种新的 NFAT 依赖性、损伤诱导的早期基因，可能负调节 SMC 表型转换。
