185-P: IDENTIFICATION BY RNA-Seq OF NOVEL ANCESTRAL MEDIATOR TRANSCRIPTS IN ENDOTHELIAL PROGENITORS

Abstract

Aim Mediator (MED) complex functions as a pivotal adaptor between transcription factors bounded at gene regulatory elements, RNA polymerase II and general transcription factors. Different ancestral humanMED complexes including at least 30 distinct MED subunits (MEDs) have been isolated. Because of the importance of ancestral MED role in the transcription of the eukaryotic genes, disruption of MED function may have relevant pathophysiological consequence also in the cardiovascular system and transplantation. Here, we have analyzed the expression data relative to MEDs in human endothelial progenitor cells (EPCs) obtained by RNA-Seq on a next generation sequencing platform. The introduction of next generation sequencing (NGS) technologies has revealed the complexity of mammalian transcriptomes, enabling to effectively explore, with an unprecedented throughput capacity, simple and complex genomes and even their differences in health and disease conditions. Methods RNA was isolated from early human EPCs and after ribodepletion it was used for the RNA-Seq through SOLID System. Results By analysis of RNA-Seq data and RT-PCR validation we have identified novel transcripts in several MED genes (including MED1, MED 15, MED 17 and MED23). Some of these transcripts are different in their 5’ and 3’ UTRs. Other transcripts are differently spliced thus excluding or including known/new exons. Conclusions This findings contribute to the characterization of novel MED transcripts in EPCs that could participate to the regulation of genes involved in different cell states. Our findings could have relevant implications in the regenerative action of EPCs in the cardiovascular system immune response after cardiac transplantation.