Trimethylamine n-Oxide (TMAO) modulates the expression of cardiovascular disease-related microRNAs and their targets

Authors: DIEZ-RICOTE, LAURA - Imdea Institute; RUIZ-VALDERREY, PALOMA - Imdea Institute; MICO, VICTOR - Imdea Institute; BLANCO-ROJO, RUTH - Imdea Institute; TOME-CARNEIRO, JOAO - Imdea Institute; DAVALOS, ALBERTO - Imdea Institute; ORDOVAS, JOSE - Jean Mayer Human Nutrition Research Center On Aging At Tufts University; DAIMIEL, LIDIA - Imdea Institute

Submitted to: International Journal of Molecular Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/11/2021
Publication Date: 10/15/2021
Citation: Diez-Ricote, L., Ruiz-Valderrey, P., Mico, V., Blanco-Rojo, R., Tome-Carneiro, J., Davalos, A., Ordovas, J.M., Daimiel, L. 2021. Trimethylamine n-Oxide (TMAO) modulates the expression of cardiovascular disease-related microRNAs and their targets. International Journal of Molecular Sciences. 22(20):11145. https://doi.org/10.3390/ijms222011145.
DOI: https://doi.org/10.3390/ijms222011145

Interpretive Summary: Diet is a well-known risk factor for cardiovascular diseases (CVDs). Dietary components act at many different levels in the regulation of genes. One of them is through microRNAs (miRNAs), which are tiny RNA molecules containing about 22 units, that regulate the expression of most genes in the human genome. The aim of this work conducted by investigators in Spain and at the HNRCA in Boston was to investigate, using an in vitro model, the regulation of CVD-related miRNAs by compounds found in foods of animal origin. This research found that compounds found in foods may be transformed into a chemical known as trimethylamine n-oxide (TMAO), which, in turn, instructs the expression of miRNAs related to CVD in a way that increases its risk.

Technical Abstract: Diet is a well-known risk factor of cardiovascular diseases (CVDs). Some microRNAs (miRNAs) have been described to regulate molecular pathways related to CVDs. Diet can modulate miRNAs and their target genes. Choline, betaine, and l-carnitine, nutrients found in animal products, are metabolized into trimethylamine n-oxide (TMAO), which has been associated with CVD risk. The aim of this study was to investigate TMAO regulation of CVD-related miRNAs and their target genes in cellular models of liver and macrophages. We treated HEPG-2, THP-1, mouse liver organoids, and primary human macrophages with 6 micro-M TMAO at different timepoints (4, 8, and 24 h for HEPG-2 and mouse liver organoids, 12 and 24 h for THP-1, and 12 h for primary human macrophages) and analyzed the expression of a selected panel of CVD-related miRNAs and their target genes and proteins by real-time PCR and Western blot, respectively. HEPG-2 cells were transfected with anti-miR-30c and syn-miR-30c. TMAO increased the expression of miR-21-5p and miR-30c-5p. PER2, a target gene of both, decreased its expression with TMAO in HEPG-2 and mice liver organoids but increased its mRNA expression with syn-miR-30c. We concluded that TMAO modulates the expression of miRNAs related to CVDs, and that such modulation affects their target genes.