Pyridostigmine Protects Against Diabetic Cardiomyopathy by Regulating Vagal Activity, Gut Microbiota, and Branched-Chain Amino Acid Catabolism in Diabetic Mice

Abstract

The disruption of gut microbes is associated with diabetic cardiomyopathy, but the mechanism by which gut microbes affect cardiac damage remains unclear. We explored gut microbes and branched-chain amino acid (BCAA) metabolite catabolism in diabetic cardiomyopathy mice and investigated the cardioprotective effect of pyridostigmine. The experiments were conducted using a model of diabetic cardiomyopathy induced by a high-fat diet + streptozotocin in C57BL/6 mice. The results of high-throughput sequencing showed that diabetic cardiomyopathy mice exhibited decreased gut microbial diversity, altered abundance of the diabetes-related microbes, and increased abundance of the BCAA-producing microbes Clostridiales and Lachnospiraceae. In addition, diabetes downregulated tight junction proteins (ZO-1, occludin, and claudin-1) and increased intestinal permeability to impair the intestinal barrier. These impairments were accompanied by reduction in vagal activity that manifested as increased acetylcholinesterase levels, decreased acetylcholine levels, and heart rate variability, which eventually led to cardiac damage. Pyridostigmine enhanced vagal activity, restored gut microbiota homeostasis, decreased BCAA-producing microbe abundance, and improved the intestinal barrier to reduce circulating BCAA levels. Pyridostigmine also upregulated BCAT2 and PP2Cm and downregulated p-BCKDHA/BCKDHA and BCKDK to improve cardiac BCAA catabolism. Moreover, pyridostigmine alleviated abnormal mitochondrial structure; increased ATP production; decreased reactive oxygen species and mitochondria-related apoptosis; and attenuated cardiac dysfunction, hypertrophy, and fibrosis in diabetic cardiomyopathy mice. In conclusion, the gut microbiota, BCAA catabolism, and vagal activity were impaired in diabetic cardiomyopathy mice but were improved by pyridostigmine. These results provide novel insights for the development of a therapeutic strategy for diabetes-induced cardiac damage that targets gut microbes and BCAA catabolism.

The Role of Branched-Chain Amino Acids and Branched-Chain α-Keto Acid Dehydrogenase Kinase in Metabolic Disorders

“…Also, pyridostigmine was found to promote BCAAs catabolism by enhancing vagal activity and attenuating intestinal barrier injury and gut bacteria dysbiosis in diabetic cardiomyopathy mice. Pyridostigmine was also found to enhance cardiac BCAAs catabolism by upregulating BCAT2 and PP2Cm and downregulating p-BCKDHA/BCKDHA and BCKDK ( 78 ).…”

Comprehensive analyses of the microRNA–messenger RNA–transcription factor regulatory network in mouse and human renal fibrosis

“…Bckdha has been reported to play a protective role in liver fibrosis ( Wang et al, 2012 ). Conversely, Yang et al suggested that pyridostigmine downregulated p- Bckdha / Bckdha to improve cardiac branched-chain amino acid catabolism and alleviated cardiac hypertrophy and fibrosis in diabetic cardiomyopathy mice ( Yang et al, 2021 ). The expression of Lpl contributed to hepatic fibrosis in nonalcoholic steatohepatitis ( Teratani et al, 2019 ).…”

Effects of salvianolic acid A on intestinal microbiota and lipid metabolism disorders in Zucker diabetic fatty rats

“…Afterward, our results showed that SalA could increase ZO-1, Occludin, and Claudin-1 expressions and decrease LPS, IL-6, and TNF-α levels. Accordingly, the preceding report has noted that DM diminishes tight junction proteins, including ZO-1, occludin, and claudin-1, and increases intestinal permeability to damage the intestinal barrier [ 60 ]. Additionally, the decline in intestinal permeability is positively-associated with LPS levels and DM patients exhibit elevated plasma LPS [ 17 , 46 ].…”