Trimethylamine N-oxide promotes atherosclerosis via regulating the enriched abundant transcript 1/miR-370-3p/signal transducer and activator of transcription 3/flavin-containing monooxygenase-3 axis

Noncoding RNAs in atherosclerosis: regulation and therapeutic potential

Atherosclerosis, a chronic disease of arteries, results in high mortality worldwide as the leading cause of cardiovascular disease. The development of clinically relevant atherosclerosis involves the dysfunction of endothelial cells and vascular smooth muscle cells. A large amount of evidence indicates that noncoding RNAs, such as microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs), are involved in various physiological and pathological processes. Recently, noncoding RNAs were identified as key regulators in the development of atherosclerosis, including the dysfunction of endothelial cells, and vascular smooth muscle cells and it is pertinent to understand the potential function of noncoding RNAs in atherosclerosis development. In this review, the latest available research relates to the regulatory role of noncoding RNAs in the progression of atherosclerosis and the therapeutic potential for atherosclerosis is summarized. This review aims to provide a comprehensive overview of the regulatory and interventional roles of ncRNAs in atherosclerosis and to inspire new insights for the prevention and treatment of this disease.

The roles of long noncoding RNA NEAT1 in cardiovascular diseases

The morbidity of cardiovascular diseases (CVDs) gradually increases worldwide. Long noncoding RNAs (lncRNAs) are a large class of non-(protein)-coding RNAs with lengths beyond 200 nucleotides. Increasing evidence suggests that lncRNA NEAT1 plays important roles in the pathogenesis of CVDs, such as myocardial infarction, heart failure, myocardial ischemia-reperfusion (I/R) injury, atherosclerosis, hypertension, cardiomyopathy, and others. We summarized the current studies of NEAT1 in CVDs, which shed light on the understanding of the molecular mechanisms of CVDs and understanding the therapeutic potential of NEAT1.

Time-dependent specific molecular signatures of inflammation and remodelling are associated with trimethylamine-N-oxide (TMAO)-induced endothelial cell dysfunction

Endothelial dysfunction is a critical initiating factor contributing to cardiovascular diseases, involving the gut microbiome-derived metabolite trimethylamine N-oxide (TMAO). This study aims to clarify the time-dependent molecular pathways by which TMAO mediates endothelial dysfunction through transcriptomics and metabolomics analyses in human microvascular endothelial cells (HMEC-1). Cell viability and reactive oxygen species (ROS) generation were also evaluated. TMAO treatment for either 24H or 48H induces reduced cell viability and enhanced oxidative stress. Interestingly, the molecular signatures were distinct between the two time-points. Specifically, few Gene Ontology biological processes (BPs) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were modulated after a short (24H) compared to a long (48H) treatment. However, the KEGG signalling pathways namely "tumour necrosis factor (TNF)" and "cytokine-cytokine receptor interaction" were downregulated at 24H but activated at 48H. In addition, at 48H, BPs linked to inflammatory phenotypes were activated (confirming KEGG results), while BPs linked to extracellular matrix (ECM) structural organisation, endothelial cell proliferation, and collagen metabolism were repressed. Lastly, metabolic profiling showed that arachidonic acid, prostaglandins, and palmitic acid were enriched at 48H. This study demonstrates that TMAO induces distinct time-dependent molecular signatures involving inflammation and remodelling pathways, while pathways such as oxidative stress are also modulated, but in a non-time-dependent manner.

Optimization of enzyme-linked immunosorbent assay kit protocol to detect trimethylamine N-oxide levels in humans

The serum level of trimethylamine N-oxide (TMAO), a gut microbiota metabolite associated with diabetes, cancer, inflammatory and neurological diseases, can be determined by the micro-enzyme-linked immunosorbent assay (ELISA) method. However, we had problems obtaining accurate standard curves with the original kit protocol from Bioassay Technology Laboratory. We aimed to acquire proper standard curves by modifying the kit protocol in this study. First, we evaluated the human TMAO ELISA kit protocols and other human ELISA kits. We maintained the incubation times longer and increased the wash cycle. Moreover, we incubated the standards containing biotinylated antibody in the wells alone. Then we washed the wells and added streptavidin-HRP for the second incubation step. The data of original and modified ELISA kit protocol were analyzed with Student's t-test. We measured higher absorbance with lower standard solution concentration in experiments that followed the original kit protocol. After investigating other human TMAO ELISA kits, we noticed that the SunRed Biotechnology Company and MyBioSource companies suggested similar protocols to the Bioassay Technology Laboratory company. The ELK Biotechnology ELISA protocol was different from others. However, since there is no biotinylated antibody in the standard solution in the ELK biotechnology kit, we changed some steps by examining other human ELISA protocols from different companies. After performing the modified protocol, we found that the absorbances of the standard solutions were consistent with their concentrations, and we obtained an accurate standard curve. Higher R2 values and lower absolute difference of standard concentrations were found in the modified kit protocol. The human TMAO ELISA protocol, which we modified in this study, will enable researchers to obtain more reliable results and prevent them from failing time and resources.

Gut Molecules in Cardiometabolic Diseases: The Mechanisms behind the Story

Atherosclerotic cardiovascular disease is the most common cause of morbidity and mortality worldwide. Diabetes mellitus increases cardiovascular risk. Heart failure and atrial fibrillation are associated comorbidities that share the main cardiovascular risk factors. The use of incretin-based therapies promoted the idea that activation of alternative signaling pathways is effective in reducing the risk of atherosclerosis and heart failure. Gut-derived molecules, gut hormones, and gut microbiota metabolites showed both positive and detrimental effects in cardiometabolic disorders. Although inflammation plays a key role in cardiometabolic disorders, additional intracellular signaling pathways are involved and could explain the observed effects. Revealing the involved molecular mechanisms could provide novel therapeutic strategies and a better understanding of the relationship between the gut, metabolic syndrome, and cardiovascular diseases.

LncRNA NEAT1 Promotes Vascular Endothelial Cell Dysfunction via miR-218-5p/GAB2 and Serves as a Diagnostic Biomarker for Deep Vein Thrombosis

OBJECTIVE

Deep vein thrombosis (DVT) is a common peripheral disease. This study aimed to elucidate the diagnostic biomarker of lncRNA nuclear-enriched abundant transcript 1 (NEAT1) in the DVT, and explore possible mechanisms in Human umbilical vein endothelial cells (HUVECs).

METHODS

101 patients with lower extremity DVT and 82 healthy controls were enrolled. RT-qPCR was designed to resolve the mRNA levels of NEAT1, miR-218-5p, and GAB2. ROC was applied for the diagnosis of DVT. Systemic inflammation (IL-1β, IL-6, and TNF-α) and adhesion factor (SELP, VCAM-1, and ICAM-1) were examined by the ELISA. And cell proliferation, migration, and apoptosis were conducted by the CCK-8, Transwell, flow cytometry assay. The targeting relationship was validated by Dual luciferase reporter and RIP analysis.

RESULTS

NEAT1 and GAB2 were upregulated in patients with DVT, while miR-218-5p was decreased (P < .01). Serum NEAT1 can identify DVT patients from healthy individuals. NEAT1 was positively correalted with fibrinolysis factors, coagulation factors, and vasoconstrictors. NEAT1 inhibited the proliferation, migration, and promoted apoptosis as well as inflammation and adhesion factors secretion of HUVECs (P < .05), but all were impaired by overexpression of miR-218-5p (P < .05). NEAT1 promoted GAB2 expression in DVT by acting as a sponge for miR-218-5p.

CONCLUSION

Elevated NEAT1 is a possible DVT diagnostic biomarker, and is implicated in vascular endothelial cell dysfunction via miR-218-5p/GAB2 axis.

Therapeutic potential of traditional Chinese medicine against atherosclerosis: Targeting trimethylamine N-oxide

BACKGROUND

Recent studies have shown that plasma trimethylamine-N-oxide (TMAO) level is highly correlated with the risk of atherosclerosis (AS), and the elevated level is significantly positively correlated with the incidence of AS.

PURPOSE

The purpose of this article is to offer a useful summary of the correlation between TMAO and AS, and the effect of herbal monomers, herbal extracts, and formulas on anti-atherosclerosis mediated by TMAO.

METHOD

The data contained in this article comes from PubMed, Web of Science, and China National Knowledge Infrastructure.

RESULTS

This review discusses the main mechanism of AS induced by TMAO, including endothelial dysfunction, macrophage foaming, platelet reactivity, and cholesterol metabolism, and summarizes 6 herb monomers, 5 herb extracts, and 2 formulas that have been tested for their anti-TMAO activity.

CONCLUSION

The current understanding of possible ways to reduce TMAO generation is discussed, with the effect and potential of herb monomers, herb extracts, and formulas highlighted.