| The differentiation of myosin into the respective heavy chain isoforms has shown a correlation with high mechanical stress. Aortic valve myosin expression has been reported; however, the characterization of the pressure response has yet to be fully developed. Thus, a cyclic pressure bioreactor was developed to elucidate the alpha/beta-myosin heavy chain (MHC) expression in aortic valve leaflets subject to physiological and pathological transvalvular pressure loads. The pressure bioreactor achieved the desired pressure modulation via LabVIEW controlled solenoid valves. Results showed alpha/beta-MHC expression on the fibrosal endothelium and minimal dispersal in the subendothelium, indicating the presence of smooth muscle cells. Endothelial layer denudation was evident with time progression while protein expression was limited to sites of excision or injury, indicating a causal relationship with high shear stress. In conclusion, alpha/beta-MHC expression is limited by endothelium detachment and lack of smooth muscle cells, possibly on account of insufficient mechanical stimuli. |
