Smooth muscle cell-specific translatome profiling of mouse atherosclerosis uncovers Itih4 as a novel SMC-enriched gene
The development of atherosclerosis, a chronic disease characterized by the buildup of plaque in arterial walls, involves the contribution of vascular smooth muscle cells (SMCs) and SMC-derived cells. To better understand the specific role of SMCs in atherosclerosis, a transgenic mouse line expressing EGFP-tagged ribosomal protein L10a (EGFP-L10a) under the SMC-specific aSMA promoter (SMCTRAP mice) was developed, enabling translating ribosome affinity purification followed by sequencing (TRAP-Seq). SMCTRAP mice were crossed with an atherosclerosis model (SMCTRAP-Athero mice). Using TRAP-Seq and bulk RNA-Seq, the aortas of 15-month-old SMCTRAP and SMCTRAP-Athero mice were analyzed to identify atherosclerosis-induced changes in the profiles of SMC ribosome-associated RNA. The results showed high enrichment of known SMC-specific genes in the TRAP fraction, indicating the specificity of the construct. The intersection of SMC-specific genes identified by TRAP-Seq, and atherosclerosis-induced genes identified by bulk RNA-Seq revealed the contribution of SMCs to the expression of several known disease-induced genes, as well as the identification of previously unlinked genes in atherosclerosis that warrant further investigation. These findings provide new insights into the role of SMCs in atherosclerosis and may offer potential targets for future treatments of this chronic disease. Overall design: Vascular smooth muscle cell ribosome-associated RNA was extracted using immunoprecipitation (IP) enrichment, along with bulk total RNA (Input), from the thoracic aorta of atherosclerosis model (SMCTRAP-Athero) and control mice (SMCTRAP). The extracted RNA was used to identify changes in the SMC ribosome-associated RNA profiles (translatomes) in atherosclerosis.