Gene expression modulation in human aortic smooth muscle cells under induced physiological mechanical stretch

In this study, we investigated gene expression in vitro of human primary Aortic smooth muscle cells (AoSMCs) in response to 9% physiological dynamic stretch over a 4 to 72-h timeframe using RT-qPCR. AoSMC were derived from primary culture and were exposed to continuous cycles of stretch and relaxation at 1 Hz by a computer-controlled Flex Jr.™ Tension System. Unstretched control AoSMCs were simultaneously cultured in the same dishes. Our results revealed a rapid and significant upregulation of specific genes (COL1A1, FBN1, LAMA5, TGFBR1 and TGFBR2) within the initial 4 h for AoSMCs subjected to dynamic stretching, whilst control cells did not respond within the same 4 h. The upregulated genes were the ones associated with extracellular matrix (ECM) fibrillogenesis and regulation of traction forces. Interestingly, stretched cells maintained stable gene expression between 4 and 72 h, whilst control cells exhibited variations over time in the absence of mechanical cues. These findings shed light on the essential role played by pulsatile stretches in the regulation of gene expressions by AoSMCs and the intricate processes governing their mechanobiological function, paving the way for further investigations in cardiovascular health.