Comparative Transcriptomic Analysis of Smooth Muscle Cells and Endothelial Cells Identifies Distinct Signaling Networks Following Inflammatory Challenges

Background: Drug-eluting devices have shown promising outcomes in patients receiving endovascular procedures, particularly in managing post-intervention restenosis that often leads to failure of the reconstructions. However, emerging evidences have revealed increased thrombogenic risk associated with the use of drug-eluting stents and balloons. It has been widely acknowledged that the major culprit responsible for the observed thrombosis events is the non-selective damage of the anti-restenotic compounds on vascular endothelial cells (ECs), which, under physiological conditions, serve as the protective barrier for maintaining vascular homeostasis. Given the clinical relevance, there is an urgent need for a therapeutic agent that could confer selective management of smooth muscle cells (SMCs) without damaging ECs. However, by far the differential mechanisms in the two cell types underlying their distinct cellular behaviors toward pathogenic stimuli are poorly understood. Thus, a systematic and comparative analysis of their cellular dynamics at the transcriptomic level is needed. Methods and Results: Human primary aortic SMCs and ECs were starved and then stimulated with 2 pro-inflammatory cytokines (TNF-α and IL-1β), which are well-established inducers of SMCs’ proliferative and migratory phenotypes while simultaneously damaging ECs. Samples were then subject to RNA sequencing. We developed a customized algorithm to evaluate the differential responses and transcriptomic network dynamics in the two cell types, and successfully identified multiple gene modules that contain functionally related genes that possibly are involved in the distinct regulations of SMCs versus ECs post inflammatory challenges. Conclusions: Our study provides the first comprehensive analysis of the differential transcriptomic dynamics between SMCs and ECs following inflammatory challenges, which are prominent contributors to the pathogenesis of both restenosis and thrombosis following vascular injury. Our data identify several module groups of genes that could serve as potential targets to achieve differential modulation of the pathophysiologies of SMCs versus ECs. Further studies are warranted to validate the contributions of these genes.