Trimethylamine N-oxide dihydrate is a gut microbe-dependent metabolite of dietary choline and other trimethylamine-containing nutrients. Trimethylamine N-oxide dihydrate induces inflammation by activating the ROS/NLRP3 inflammasome. Trimethylamine N-oxide dihydrate also accelerates fibroblast-myofibroblast differentiation and induces cardiac fibrosis by activating the TGF-β/smad2 signaling pathway[2].In Vitro: The size and migration of fibroblasts are increased after Trimethylamine N-oxide (TMAO) dihydrate treatment compared with non-treated fibroblasts in vitro. Trimethylamine N-oxide dihydrate increases TGF-β receptor I expression, which promotes the phosphorylation of Smad2 and up-regulates the expression of α-SMA and collagen I. The ubiquitination of TGF-βRI is decreased in neonatal mouse fibroblasts after Trimethylamine N-oxide dihydrate treatment. Trimethylamine N-oxide dihydrate also inhibits the expression of smurf2[2].
Trimethylamine N-oxide is frequently found in the tissues of a variety of marine organisms that protects against the adverse effects of temperature, salinity, high urea and hydrostatic pressure.In Vivo: Trimethylamine N-oxide (TMAO) dihydrate contributes to cardiovascular diseases by promoting inflammatory responses. C57BL/6 mice are fed a normal diet, high-choline diet and/or 3-dimethyl-1-butanol (DMB) diet. The levels of Trimethylamine N-oxide dihydrate and choline are increased in choline-fed mice. Left ventricular hypertrophy, pulmonary congestion, and diastolic dysfunction are markedly exacerbated in heart failure with preserved ejection fraction (HFpEF) mice fed high-choline diets compared with mice fed the control diet. Myocardial fibrosis and inflammation were markedly increased in HFpEF mice fed high-choline diets compared with animals fed the control diet.