Abstract 216: Single-cell And Spatially Resolved Transcriptome Analysis Reveals Cellular Heterogeneities And Novel Regulators Of Atherosclerotic Plaque Destabilization

Background: Cardiovascular diseases, including atherosclerosis, are the major cause of death in western societies, still molecular mechanisms of plaque destabilization remain unclear. Long non-coding RNAs (lncRNAs) are one example of novel molecular modulators, as their expression is highly cell-type specific. Methods: We utilized combined total (bulk) RNA and single cell (sc) RNA to study the transcriptome of advanced carotid artery lesions from patients undergoing carotid endarterectomy in our vascular surgery clinic. Additionally, we performed hybridization-based RNA in situ sequencing (HybRISS) to indicate where cluster-defining genes are located within the plaques. Results: In this current study, four sequencing datasets were investigated (total RNA from early vs. late lesions from the same individual patient and unstable vs. stable lesions from individual patients; two separate scRNA-seq datasets).16 lncRNAs were cross-referenced between all four datasets. All of these lncRNAs presented a cell-type specific expression pattern, with 11 lncRNAs being significantly enriched in different smooth muscle cell (SMC) clusters. We found all newly identified lncRNAs conserved in our scRNA-seq datasets of genetically mutated ( LDLR-/- ) Yucatan mini-pigs and the inducible carotid artery plaque rupture mice ( ApoE-/- ). The cluster-defining genes from the human scRNA-seq data were then located in human carotid artery tissue sections using the HybRISS method to unravel their distinct location within these plaques. Discussion: Taken together, our datasets, methods and different animal-models demonstrate that combining bulk with scRNA-seq data and spatially resolved sequencing methods are powerful tools to identify and characterize novel lncRNAs being expressed by a certain cell-type in the disease progression.