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Updated: Aug 11, 2026
Isolation and Characterization of Primary Rat Valve Interstitial Cells: A New Model to Study Aortic Valve Calcification
Published on: November 20, 2017
Differential immediate-early gene responses to elevated pressure in porcine aortic valve interstitial cells
James N Warnock1, Shane C Burgess, Allen Shack
1Agricultural and Biological Engineering, Mississippi State University, Box 9632, Mississippi State, MS 39762-9632, USA. jwarnock@abe.msstate.edu
Background And Aim Of The Study:
Cardiovascular risk factors are believed to play a role in the pathogenesis of aortic valve disease. In the present study the hypothesis was proposed that elevated pressure would cause a change in the expression of prototypical pro-inflammatory genes. Hence, the expression of MCP-1, osteopontin (OPN), VCAM-1, GM-CSF and PAI-1 was examined using semi-quantitative real-time RT-PCR.
Methods:
Porcine aortic valve interstitial cells at passage 1 were exposed to constant pressures of 100, 140, or 170 mmHg or cyclic pressures of 80-120, 120-160, or 150-190 mmHg for 2 h. Static cultures at atmospheric pressure served as controls. Total RNA from pooled experiments was isolated for analysis of gene expression. Single tube primer-mediated RT-PCR was performed directly on the RNA.
Results:
Cells responded differently to constant and cyclic pressure. The most notable response was the expression of OPN, which was significantly up-regulated under steady conditions but down-regulated under cyclic conditions. The opposite was true in VCAM-1 expression, which was significantly down-regulated at 170 mmHg static pressure, but up-regulated at 140 and 170 mmHg mean cyclic pressure. There was no clear proportional correlation between pressure magnitude and expression of MCP-1, GM-CSF, or PAI-1. However, elevated cyclic pressure caused a proportional increase in VCAM-1 expression and a proportional decrease in OPN expression.
Conclusion:
Elevated cyclic pressure is a potent stimulus for the up-regulation of VCAM-1 expression and the down-regulation of OPN expression. This demonstrates an association between hypertension and aortic valve stenosis and calcification. The regulation of the chemotactic genes MCP-1 and GM-CSF is not correlated to a change in compressive forces.
