Early cardiac gene transcript levels in peripheral blood mononuclear cells in patients with untreated essential hypertension.

Objectives: To assess the expression of early cardiac genes, implicated in the hypertrophic growth response of the adult heart, in peripheral blood mononuclear cells in patients with essential hypertension and its relationship to ambulatory blood pressure monitoring (ABPM) parameters and to echocardiographic left ventricular mass.

Methods: Twenty-four-hour ABPM, echocardiography and blood sampling were performed in 62 untreated participants with essential hypertension. Blood samples from 38 healthy individuals were included for comparison. Peripheral blood mononuclear cells (PBMCs) were isolated and gene transcript levels were determined by quantitative real-time reverse transcription PCR.

Results: Myocardin (3.92±0.68 versus 2.09±0.67, P<0.001), GATA4 (3.48±0.68 versus 0.32±0.08, P<0.001) and Nkx2.5 (208.91±35.01 versus 129.75±49.70, P<0.001) were upregulated in hypertensive patients compared with controls. In hypertensive patients, transcript levels of myocardin (r=0.698, P<0.001) and GATA4 (r=0.374, P=0.003) showed significant positive correlations with 24-h systolic blood pressure (BP) as well as with mean BP, (r=0.626, P<0.001) and (r=0.340, P=0.007), respectively. A significant positive correlation between myocardin and 24-h pulse pressure (r=0.467, P<0.001) was also observed. Myocardin (r=-0.606, P<0.001) and GATA4 (r=-0.453, P<0.001) transcript levels also showed significant negative correlations with the mean 24-h dipping status. Additionally, myocardin (r=0.341, P=0.007), GATA4 (r=0.337, P=0.007) and Nkx2.5 (r=0.325, P=0.010) transcript levels showed significant positive correlations with left ventricular mass index.

Conclusion: Myocardin and GATA4 transcript levels correlate significantly with 24-h ABPM parameters, rendering them potential candidate biomarkers in hypertension. Early cardiac gene transcript levels in PBMCs of hypertensive patients are associated with left ventricular mass and may reflect activation of the hypertrophic response gene network in these patients.