Inhibition of microbiota-dependent TMAO production attenuates chronic kidney disease in mice

Wenchao Zhang,Zeneng Wang,Clara Magyar,Diana M Shih,Aika Miikeda,Susanne B Nicholas,Sarada Charugundla,Stanley L Hazen,Matteo Pellegrini,Xun Jia,Jonathan Zuckerman,Fangfei Guo,Karolina Elżbieta Kaczor-Urbanowicz,Zhiqiang Zhou,Aldons J Lusis

doi:10.1038/s41598-020-80063-0

Abstract

Patients with chronic kidney disease (CKD) have elevated circulating levels of trimethylamine N-oxide (TMAO), a metabolite derived from gut microbes and associated with cardiovascular diseases. High circulating levels of TMAO and its dietary precursor, choline, predict increased risk for development of CKD in apparently healthy subjects, and studies in mice fed TMAO or choline suggest that TMAO can contribute to kidney impairment and renal fibrosis. Here we examined the interactions between TMAO, kidney disease, and cardiovascular disease in mouse models. We observed that while female hyperlipidemic apoE KO mice fed a 0.2% adenine diet for 14 weeks developed CKD with elevated plasma levels of TMAO, provision of a non-lethal inhibitor of gut microbial trimethylamine (TMA) production, iodomethylcholine (IMC), significantly reduced multiple markers of renal injury (plasma creatinine, cystatin C, FGF23, and TMAO), reduced histopathologic evidence of fibrosis, and markedly attenuated development of microalbuminuria. In addition, while the adenine-induced CKD model significantly increased heart weight, a surrogate marker for myocardial hypertrophy, this was largely prevented by IMC supplementation. Surprisingly, adenine feeding did not increase atherosclerosis and significantly decreased the expression of inflammatory genes in the aorta compared to the control groups, effects unrelated to TMAO levels. Our data demonstrate that inhibition of TMAO production attenuated CKD development and cardiac hypertrophy in mice, suggesting that TMAO reduction may be a novel strategy in treating CKD and its cardiovascular disease complications.

Highlights

Previous studies by our groups identified a novel dietary/meta-organismal pathway for cardiovascular disease (CVD) whereby bacterial metabolism of dietary choline and L-carnitine in the intestine leads to an intermediate metabolite, trimethylamine (TMA), which is absorbed from the gut and subsequently oxidized by hepatic flavincontaining monooxygenases (FMO) to generate trimethylamine N-oxide (TMAO)[1,2,3]
One-month old female apolipoprotein E (apoE) KO mice were fed standard chow or adenine (Ade) diets with or without iodomethylcholine (IMC; see Methods) for 14 weeks to examine the effects of reduced TMAO on Chronic kidney disease (CKD) and atherosclerosis
The decreased body weights observed in the Ade and Ade + IMC groups compared to the control groups were not due to decreased food consumption since there were no significant differences in food consumption among the 4 groups of mice (Supplemental Fig. S1)

Summary

Introduction

Previous studies by our groups identified a novel dietary/meta-organismal pathway for cardiovascular disease (CVD) whereby bacterial metabolism of dietary choline and L-carnitine in the intestine leads to an intermediate metabolite, trimethylamine (TMA), which is absorbed from the gut and subsequently oxidized by hepatic flavincontaining monooxygenases (FMO) to generate trimethylamine N-oxide (TMAO)[1,2,3]. TMAO has been suggested to promote CVD through several other proatherogenic mechanisms, including foam cell formation, reverse cholesterol transport, platelet responsiveness/ thrombosis, activation of the NLR family pyrin domain containing 3 (NLRP3) inflammasome, and changes in tissue cholesterol, sterol, and bile acid m etabolism[2,3,15,27,28,29]. These studies support the notion that the increased CVD risk associated with CKD may arise in part from elevated TMAO levels. Our results indicate that TMAO promotes CKD, and that in the context of CKD this contributes to cardiac hypertrophy

Objectives

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Conclusion