Abstract 20166: Obesity-Related Changes in Circulating Microrna Profile After Standardized Meal
Background: MicroRNAs (miRNAs) are small non-coding RNAs that post-transcriptionally silence gene expression. While primarily intracellular, miRNAs are detectable in the human blood where they potentially serve as intercellular communicators. Recent evidence suggests that circulating miRNA levels may be affected by dietary factors. However, little is known about the acute effects of a meal challenge on plasma miRNA profiles and its relationship with inflammatory biomarkers in young adults with normal and elevated BMI.
Methods: We enrolled 10 obese (BMI: 38.9±6.5 kg/m2;average age: 18.6±3.0 years) and 10 control (BMI: 21.7±1.9 kg/m2; average age: 18.3±3.3 years) males in our case-control study where participants consumed a standardized low-fat mixed meal after 12 hours fast. Venous blood was collected at baseline and at 2, 4 and 6 hours and the expression of the following miRNAs was determined using qRT-PCR and normalized to total RNA: miR-126, -21, -155, -222, -223, -122, -145, -346, -191 and 520-5p. In addition, levels of TNF-α, E-selectin and hs-CRP were measured at 0 and 4 hours.
Results: We found significantly elevated circulating miR-155 expression in obese individuals at baseline (p<0.05) while difference for other miRNA was not significant. TNF-α, E-selectin and hs-CRP were significantly elevated in this group suggestive of underlying chronic low grade inflammation. MiR-145, -222 and -223 levels increased in controls as early as 2 hours and remained elevated at 6 hours while no such change was noted in obese subjects. MiR-21 expression spiked transiently at 4 hours only in the control group returning to baseline at 6 hours. There was no significant change in post-prandial inflammatory biomarker levels during our study period.
Conclusions: Our study demonstrates the effect of diet on circulating miRNA profiles and emphasizes the importance of standardized, fasting blood collection for circulating miRNA profiling. Our data also demonstrate that circulating miRNAs are very early markers of the inflammatory post-prandial response, and this response is dysregulated in young, obese individuals. These findings have implications for the increased long-term cardiovascular risk in this population.
Author Disclosures: T. Alexy: None. K. Rooney: None. N. Le: None. A.H. Slyper: None. C.D. Searles: None.
- © 2014 by American Heart Association, Inc.