ABSTRACT
Aim: This study aimed to measure and evaluate serum trimethylamine N-oxide (TMAO) levels in patients with COVID-19. Material(s) and Method(s): The patients were divided into three groups according to their polymerase chain reaction (PCR) results and the clinical picture of the disease: Group 1 (negative PCR result, n = 44), Group 2 (positive PCR result and non-severe disease, n = 38) and Group 3 (positive PCR result and severe disease, n = 45). Result(s): TMAO levels were significantly different among the three patient groups. Post Hoc Dunn's analysis revealed a significant difference between Group 1 and Group 2 (p = 0.006), Group 1 and Group 3 (p < 0.001) and Group 2 and Group 3 (p = 0.031). ROC analysis revealed that a cut-off value of 2.92 had a sensitivity of 74.70%, a specificity of 68.18%, a positive predictive value of 81.6% and a negative predictive value of 58.8%. Discussion(s): The results of this study demonstrated that TMAO levels increased in the patients with COVID-19, and further TMAO levels increased as the severity of the disease progressed.Copyright © 2023, Derman Medical Publishing. All rights reserved.
ABSTRACT
Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) is a novel coronavirus that infects many types of cells and causes cytokine storms, excessive inflammation, acute respiratory distress to induce failure of respiratory system and other critical organs. In this study, our results showed that trimethylamine-N-oxide (TMAO), a metabolite generated by gut microbiota, acts as a regulatory mediator to enhance the inerleukin-6 (IL-6) cytokine production and the infection of human endothelial progenitor cells (hEPCs) by SARS-CoV-2. Treatment of N-3 polyunsaturated fatty acids (PUFAs) such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) could effectively block the entry of SARS-CoV-2 in hEPCs. The anti-infection effects of N-3 PUFAs were associated with the inactivation of NF-κB signaling pathway, a decreased expression of the entry receptor angiotensin-converting enzyme 2 (ACE2) and downstream transmembrane serine protease 2 in hEPCs upon the stimulation of TMAO. Treatment of DHA and EPA further effectively inhibited TMAO-mediated expression of IL-6 protein, probably through an inactivation of MAPK/p38/JNK signaling cascades and a downregulation of microRNA (miR)-221 in hEPCs. In conclusion, N-3 PUFAs such as DHA and EPA could effectively act as preventive agents to block the infection of SARS-CoV-2 and IL-6 cytokine production in hEPCs upon the stimulation of TMAO.