Evidence for loss of contractile phenotype of the mouse aortic vascular smooth muscle (MOVAS) cell line with increasing number of passages in vitro.

Abstract

Vascular smooth muscle cells (VSMCs) are characterized by a considerable plasticity. Their phenotypic switch (from contractile to synthetic) plays a crucial role in the atherosclerotic process, explaining that numerous studies focus on this phenotypic transition. Thus, it is essential to use VSMCs that have been finely phenotyped for experimental purposes. The use of MOVAS cell line is suitable because, unlike primary cells, it is believed that these cells retain their phenotype and avoid cell senescence in culture. This study aimed to assess the phenotype of MOVAS cells over culture passages to ensure that they retained a contractile phenotype, before using them for further investigations. The phenotype of MOVAS cells at different culture passages (P3, P5 and P8) was analysed morphologically and by studying the expression of genes that indicate a contractile (Acta2, Myocd and Cnn1) and synthetic (Klf4 and Lgals3) VSMC phenotype by RT-qPCR. Cell stiffness was analysed by atomic force microscopy and cell adhesion and migration. Our results showed that MOVAS cells rapidly changed morphologically and that the gene expression of contractile markers was significantly reduced in favor of markers specific to the synthetic phenotype. These changes were associated with a reduction in cell stiffness and a significant increase in adhesion and migration properties. MOVAS cells undergo a transition from contractile to synthetic phenotype with increasing number of passages in vitro, which means that these cells should be used with caution, at a low number of passages, while being regularly characterized.