Location: Exhibit/Poster Hall A-B - Pennsylvania Convention Center
Poster Board Number: E113
Alvaro Gurovich (The University of Texas at El Paso, The University of Texas at El Paso), Shelsea Cabral (The University of Texas at El Paso), Carmen Rodriguez (The University of Texas at El Paso), Daniel Conde (The University of Texas at El Paso), Mario Garcia (The University of Texas at El Paso)
Presenting Author The University of Texas at El Paso, The University of Texas at El Paso
Background
Physical activity has been shown to reduce the risk of cardiovascular disease. Exercise-induced endothelial shear stress (ESS) produces a mechanical force on the surface of endothelial cells that triggers an intracellular signaling response regulating vascular function. SIRT-1 and eNOS are mechanosensitive genes that have been shown to improve vascular function and their expression levels may be upregulated in response to higher ESS levels. Although it has been reported that higher physiological levels of ESS may improve vascular function, the role of pulsatile exercise induced ESS varying in exercise intensities has not been studied. Therefore, the purpose of this study was to determine the effects of varying pulsatile exercise-induced ESS intensities on NOS3 and SIRT-1 mRNA expression.
Methods
Commercially available human umbilical vein endothelial cells (HUVEC; Sigma-Aldrich, St Louis, MO) were cultured until 90–100% confluence. Exercise-induced ESS in vivo was obtained from our previous reports. Cultured HUVEC cells were exposed to pulsatile resting ESS (18 dynes/cm2) for 2 hours, followed by 1 hour at low-intensity exercise-induced ESS (35 dynes/cm2), moderate exercise-induced ESS, or high-intensity exercise-induced ESS (75 dynes/cm2) on a closed circuit pump and channeled slide (Ibidi pump system (PumpControl Software 1.5.4) and slides, Ibidi Inc., Fitchburg, WI). Total RNA was extracted and reverse transcribed followed by measurement of SIRT-1 and eNOS mRNA expression via qRT-PCR. qRT-PCRs were performed in duplicates and changes in gene expression were calculated using the ΔΔ-CT method with GAPDH used as the normalizing control gene. Statistical analysis was performed using graphpad prism 8 software (Graphpad Software.). Significance was considered at plt;0.05.
Results
There were no alterations in mRNA expression of SIRT-1 in response to varying exercise intensities. Moderate intensity exercise-induced ESS produced significantly higher eNOS mRNA expression compared to low and high intensity exercise-induced ESS (plt;0.05).
Conclusions
Our data shows that moderate intensity of exercise-induced ESS may promote an anti-atherogenic phenotype due to higher expression levels of eNOS. Although SIRT-1 mRNA levels were not altered in response to varying exercise intensities, it is possible that SIRT-1 is chronically activated and one bout of exercise will not alter its expression. Further research needs to be performed on the role of exercise and molecular pathways for endothelial health.
Research reported in this publication was supported by the National Institute Of General Medical Sciences of the National Institutes of Health under Award Number SC2GM140952. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
SIRT-1 and eNOS mRNA expression after 3 intensities of exercise-induced endothelial shear stress in vitro. (*: p<0.05)
