Comparison between vascular smooth muscle cells isolated from descending thoracic and abdominal aortas of mice in cell function, phenotype features, and gene expression.

BACKGROUND: Vascular smooth muscle cells (VSMCs) are the primary component of the medial layer of the vessel wall, where they maintain structural integrity and regulate vascular tone. Their dysfunction contributes to vascular diseases such as aortic aneurysms and atherosclerosis. Although VSMCs isolated from thoracic and abdominal aortic regions are widely used in experimental studies, their functional differences have not been systematically compared. METHODS: In this study, we examined functional and phenotypic differences between VSMCs isolated from the descending thoracic (Th-SMCs) and abdominal aortas of male C57BL/6J mice under controlled in vitro conditions. RESULTS: Both cell types maintained high α-smooth muscle actin expression across passages, supporting smooth muscle lineage identity. Functionally, Th-SMCs demonstrated significantly greater migratory and proliferative capacities compared with abdominal SMCs. Under sublethal oxidative stress, Th-SMCs exhibited higher relative viability, accompanied by higher basal expression of antioxidant-related transcripts, including Nrf2, Catalase, and Sod1. CONCLUSIONS: These findings highlight intrinsic differences between region-specific VSMCs and underscore the importance of considering anatomical origin for in vitro models. Incorporating region-specific VSMCs may enhance experimental relevance and contribute to a better understanding of the mechanisms underlying regional vascular diseases. CLINICAL RELEVANCE: Vascular smooth muscle cells (VSMCs) play a key role in the development of vascular diseases. This study demonstrates that VSMCs isolated from the descending thoracic and abdominal aortic regions exhibit distinct functional behaviors under in vitro conditions. These region-specific differences highlight the importance of carefully selecting and reporting the anatomical origin of VSMCs in experimental studies, which may improve the physiological relevance and interpretability of vascular research models.