Endothelial Transcriptome Remodeling in a Mouse Model of Chronic Hypertension

Aims: Hypertension poses a significant challenge to vasculature homeostasis and stands as the most common cardiovascular disease in the world. Its effects are especially profound on vasculature-lining endothelial cells that are directly exposed to the effects of excess pressure. Here, we characterize the in vivo transcriptomic response of cardiac endothelial cells to hypertension using the spontaneous hypertension mouse model BPH/2J. Methods and results: Verification of defective endothelial function in the BPH/2J hypertensive mouse strain was followed by acute isolation of cardiac endothelial cells and transcriptional profiling using RNA sequencing. Gene profiles from normotensive BPN/3J mice were compared to hypertensive animals. We observed over 3000 transcriptional differences between groups including pathways consistent with the cardiac fibrosis found in hypertensive animals. Importantly, many of the fibrosis-linked genes also differ between juvenile pre-hypertensive and adult hypertensive BPH/2J mice, suggesting that these transcriptional differences are hypertension-related. We also show that blood pressure normalization with amlodipine resulted in a subset of genes reversing their expression pattern, supporting the hypertension-dependency of altered gene expression. Yet, other transcripts were recalcitrant to therapeutic intervention illuminating the possibility that hypertension may irreversibly alter some endothelial transcriptional patterns. Conclusions: Hypertension has a profound effect on both function and transcription of endothelial cells, the latter of which was only partially restored with normalization of blood pressure. This study represents one of the first to quantify how endothelial cells are reprogrammed at the molecular level in cardiovascular pathology and advances our understanding of the transcriptional events associated with endothelial dysfunction. Endothelium from hypertensive mice were acutely extracted at two different ages (4 weeks and 22 weeks) and compared to endothelium from 22 week old normotensive mice.