Long non-coding RNA profiling in 6 cell types

To identify endothelial cell (EC)-enriched long noncoding RNAs (lncRNAs), gene expression analysis was conducted on two EC cell types and 4 non-EC cell types. Specifically, the EC cell types were human umbilical vein endothelial cells (HUVEC) and human dermal microvascular endothelial cells (HMVEC). The 4 non-EC cell types were human aortic smooth muscle cells (HASMC), Fibroblasts, Hepatocytes, and keratinocytes. Of the 23 155 putative lncRNAs represented in the custom lncRNA microarrays, 18 524 lncRNAs were found to be expressed above the 20% percentile in at least one cell type. Importantly, 28 EC-enriched lncRNAs were identified in common between HUVEC and HMVEC with 28 and 59 enriched uniquely in either HUVEC or HMVEC, respectively. Of interest, STEEL, an EC-enriched lncRNA was identified and its role in EC biology was further characterized. RNA samples of HUVEC, HMVEC, HASMC, fibroblasts, hepatocytes and keratinocytes were extracted and subjected to gene expression analysis using a custom nimblegen microarray that recognizes 23 155 putative lncRNAs and 19 484 protein-coding genes.